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PLEISTOCENE MARINE SUBMERGENCE 13
5 Evidence from the Connecticut Valley and Long Island
Plate 3
The Connecticut valley, like the Hudson, is filled with clay and
sand plains, deltas, terraces and occasionally beaches due to deep
standing water. The valley held an estuary contemporaneous with
the Hudson-Champlain estuary. The facts for the Connecticut
valley have been concisely given in a former publication (69).
The isobases in plate 9 were originally drawn to connect points
of equal altitude on the marine shores of the Connecticut and the
Hudson valleys; and they are found to be in accord with all knowl-
edge to date.
An examination of Long Island shows that it was also sub-
merged to the extent indicated by the isobases; and the facts are
on record in a recent paper (55). The proofs of Long Island sub-
mergence, especially at the eastern end of the island, are so abundant
and evident that it seems strange they should have been so long
overlooked.
It will be found that these isobasal lines of plate 9, with some
greater curvature, will mark the amount of the Postglacial submer-
gence and subsequent uplift of New England and the Maritime
provinces.
6 Postglacial Submergence of New England and Canada
It is well known that New England and eastern Canada have
been elevated since glacial time. The occurrence of abundant
marine fossils in extensive areas and far above present sea level is
indisputable proof of submergence. But the extent of the sub-
mergence has probably not been appreciated, and certainly has not
been accurately determined.
The Canadian geologists have recorded many evidences of stand-
ing waters and many localities of marine fossils at high altitudes in
the St Lawrence and Ottawa valleys, and eastward, to which the
geologists of the United States have not given sufficient attention.
The occurrence of marine fossils far over present sea level and
other evidences of deep glacial and postglacial submergence caused
the Canadian geologists to place some overemphasis on the work of
floating ice and icebergs in explanation of the glacial phenomena.
But it must be admitted that in the fact of deep marine waters over
eastern Canada the Canadian students had very good basis for their
ice-flotation theory.
The recognition of the work of the Labradorian ice sheet over
14 NEW YORK STATE MUSEUM
most of the glaciated territory as that of land ice has resulted in
the neglect, especially by the geologists of the United States, of the
evidences of deep marine submergence in Canada and New Eng-
land. With the emphasis on land glaciation we have discounted or
ignored the former observations of the “ diluvialists” and “ice-
bergists,” and have minimized the amount of land depression during
the removal of the ice sheet, and have neglected its study.
The writings of Robert Bell, J. W. Dawson, R. W, Ells, Robert
Chalmers and A. P. Low contain much reliable data concerning the
occurrence of marine organisms at high altitudes and of broad sand
plains and extensive deep clays, all pointing to widespread and
deep oceanic waters. A few of the writings of the authors named
above, and of A. P. Coleman for the Ontario district, are listed im
the bibliography. A good resumé of the studies up to 1897 is given
by Ells (143). The Canadians found evidence of submergence to
1000 feet or over as far west as Montreal and the Ottawa valley.
Sir William Dawson’s claim of shore features at a height of 750
feet on Mount Royal is probably true, for it now appears that the
marine waters passed over the summit. The marine plane is 800
feet at the south end of Lake Memphramagog.
7 Testimony of Former Students
All the earlier geologists in referring to the features of the Hud-
son valley assumed their estuarine character. As early as 1843
Mather listed the larger deltas north of Newburgh and Fishkill,
and in his summary said: “It is considered evident that a vast
inland sea once occupied what may be called the basin of the St
Lawrence and Hudson valleys since the period of the drift deposits.”
(28, page 157). |
In 1891 F. J. H. Merrill published two papers in description of
the Hudson deposits and recognized their estuarine character, and
the delta origin of the Albany-Schenectady plain. His figure for
the submergence at New York City was 80 feet, which is correct
for the north end of Manhattan island. In this paper he noted the
terraces on Staten island, and correlated them with the broad sand
plains of the south side of Long Island and with the plains in the
Hudson valley. He seems to have been the first geologist to appre-
ciate the relationship of these detached features. And he showed
his insight and appreciation of the problem by giving the first
explanation, and a true one, for the absence of beaches. This
‘point will be considered later.
PLEISTOCENE MARINE SUBMERGENCE 15
In 1891 and 1892 Heinrich Ries published descriptions of the
massive clays of the Hudson valley (33, 34), from Croton Point to
Albany, and in later publications (35, 36) gave detailed description
which proved their estuarine origin.
N. H. Darton, in 1894, published descriptions of the Pleistocene
deposits of the counties of Albany (38) and Ulster (39). He also
regarded the deposits as the “products of a submergence at the
close of the Glacial epoch,’ and drew a map of the “Champlain
submergence” of the Albany district (38, page 359).
An admirable description of the delta of the Catskill in the Hud-
son estuary was published by W. M. Davis in 1892 (37). He
clearly recognized that the Champlain submergence involved the
Hudson valley. His value for the summit of the Catskill delta,
about 275 feet, is precisely correct, as shown by the profile, plate 10.
In his Glacial Geology of New Jersey, R. D. Salisbury describes
the features due to Postglacial submergence, and says that the
water plane has about 100 feet altitude at the north border of the
state. This is in accordance with the plotted profile.
Some later writers on Long Island stratigraphy and glacial beds
have assumed or asserted an uplifted attitude of the lower Hudson
district, but have passed over the earlier writings and entirely
ignored the clear and positive evidence of submergence.
For the Connecticut valley the detailed studies of B. K. Emerson
show conclusively that the high sand plains and the extensive clay
fields were the products of standing water, which he called “ Con-
necticut lakes,’ and could not be the results of a swollen river
(66, 67). His altitudes for the water plane on the north and south
lines of Massachusetts are values used in the map of isobases,
plate 9.
Students of the Champlain section of the great valley have made
too much distinction between the lower deposits which carry salt-
water fossils and the upper plains and terraces without fossils.
There is probably also a psychologic factor involved. The invoking
of “glacial waters’ may have been due in part to a tendency to
utilize the new thought in Pleistocene geology, the existence and
effect of ice-dammed waters. The recognition of glacial lakes
came during the seventies of the past century,t and has been a
most useful conception. But it was always incumbent on an author
» who postulated glacial waters to find the control, or locate the out-
let and correlate the levels and beaches with their outlets. There
* Proc. Amer. Assn. Adv. Sci., 47: 285-287; Amer. Geol., 22: 183-86. 18098.
16 NEW YORK STATE MUSEUM
has been too much reference of static water features of unknown
relationship to “glacial” without proving the fact. The writer
can not be charged with any prejudice against glacial lakes; but he
has named no lake without knowing its control.
ABSENCE OF MARINE LIFE IN THE HUDSON VArrEy
No well-attested marine fossils have been found in the Hudson
valley, or in the higher water-laid deposits of the Champlain valley.
Partly for this reason the appeal has been made to glacial waters.
The tides are felt in the Hudson “ river” to Albany, but brackish
water reaches only to about Poughkeepsie, and salt water organisms
pass up the Hudson only to the Highlands. The problem relating
to the Pleistocene waters becomes simply the exclusion of salt
water.
When the receding ice front was slowly giving place to the deep
estuarine water in the Hudson valley these were loaded with silt,
for the land drainage was gathering in the freshly laid mantle of
drift and the melting glacier was contributing its load of rock flour.
The thick clay beds resting on the till or glaciated rock are suffi-
cient evidence. The waters were cold and muddy, and unfavorable
to nearly all forms of marine life.
Another deterrent factor was the volume of fresh water. The
ablation of the glacier probably supplied, even in the lower Hud-
son, sufficient fresh water to exclude the salt-water fauna. And
when the ice front receded to Albany the flood from the Ontario
basin swept into the Hudson, and for long ages subsequent all the
drainage now represented by the St Lawrence, plus the water from
the melting of the ice sheet for a thousand miles on the west, were
forced south through the narrow passes at Whitehall, West Point
and the Palisades. And during this stage the wave uplift of the
glaciated territory had probably lifted the lower Hudson valley to
nearly its present height. Such uplifted condition is indicated in
the maps, plates I and 2.
When the ice front reached Covey hill the outdrainage of the
Laurentian basin was merely shifted from the Mohawk pass to the
Covey pass, and the cold, fresh waters still passed south. When
the ice front recession let Lake Irqquois fall and blend into the
sea-level waters, so that the latter occupied the Ontario basin (see
plates 2, 3, 5), the ultimate outlet was the same. And this south-
ward flow through the Hudson of all the glacial waters, and the
land drainage, from Duluth to Maine, persisted until the waning of
PLEISTOCENE MARINE SUBMERGENCE Wf
the ice margin on Maine and New Brunswick opened a strait to
the St Lawrence gulf. Then, but not before, salt waters entered
the lower St Lawrence valley, and slowly worked up into the Cham-
plain valley.
However, by the time salt water reached the Champlain valley a
decided change in the physiography had occurred. During the
many thousands of years in the history_sketched above land uplift
had been in progress in the areas relieved of the burden of the ice
cap, and the earlier shore lines of the Hudson-Champlain had
undoubtedly been raised much above the waters. How much eleva-
tion had occurred before salt-water life entered the Champlain
waters we can not now determine. A lifting of 300 feet at Fort
Edward, of the 450 feet total rise, would have entirely broken the
connection between the Champlain and the Hudson waters. And
long before the connection was broken the long stretch of the
narrow strait with its receipt of land drainage from a large terri-
tory from both Vermont and New York would have discouraged
marine life from making the southward journey.
It would appear from the known history and the probable
physical conditions that marine fossils should not be found in the
Hudson valley or in the higher Champlain deposits.
PUBSIIINGE Ole IBA CiaveS) ION IMsUs, SIAN aING ISIE UNG)
REGION
No continuous beaches (bars, cliffs and terraces) would be
expected in the narrow stretches of the Hudson valley. But the
absence of distinct, positive beaches on the New Jersey coast, Staten
Island and Long Island has been a cause of perplexity even to those
who accept postglacial submergence. ‘The necessity for beaches
on a submerged land has been tacitly assumed by most writers. It
is believed that this assumption is wrong.
Merrill realized this difficulty, and was the first writer to sug-
gest an explanation (30, pages 105-9). In a recent paper the
writer quoted liberally from Merrill’s argument (55, pages 299,
301), but for the present purpose it may be sufficient to quote the
conclusion of his analysis of the mechanics of beach erosion:
: for the present purpose which is simply to point out the fact that a
land surface in process of subsidence or emergence may be subjected to wave
action without being incised with distirict shore lines, and also that wave
action may produce an inclined plane as well as a terrace or base level.
It is therefore evident that submergence would not leave a deeply cut shore
line as its record unless the rates of land movement were so adjusted as to
18 NEW YORK STATE MUSEUM
permit of it. In fact no very distinctly cut shore lines are to be found on
the drift about New York even at an altitude corresponding to that of the
Hudson estuary deposits. Apart from the still-water deposits the 80-foot
postglacial depression about New York can only be traced by change of
surface slope and material at this level. .Even these two varieties of evidence
are not always coexistent.
Beach phenomena have scarcely been recognized on territory of
New England which was ‘almost certainly submerged during the
removal of the ice sheet. Professor Shaler explained the lack of
beaches on Martha’s Vineyard and Nantucket by the too rapid Iift-
ing of the shores.*
To the above sound and quite sufficient argument something may
be added. On the open sea shores of Long Island and Staten
Island there was an inhibiting factor besides the rising of the land,
namely, the tidal fluctuations of level. A very little change in the
water level may effect large difference in the force and direction of
shore currents and effectively change the plane of bar construction
or of beach erosion.
However, there is an erosion cliff on the face of Staten island
and on the west end of Long Island as far as Lake Surprise, 6
miles beyond Jamaica. This has been recognrzed as a possible
beach, and Fuller has given a clear description of it as “ the great
inland cliff of western Long Island” (54, page 54). He clearly
proves the origin of the cliff as by marine erosion, but makes it
earlier than the end of the Wisconsin epoch. But the altitude and
slant of this and the Staten Island cliff agree with our map, plate 9.
The above discussion relates particularly to erosional shore fea-
tures. Constructional features, bars and embankments are more
common and under favorable conditions more readily produced by
waves. It might properly be expected that bars and beach ridges
would appear, especially on the broad sand plains of the south side
of Long Island. The lack of such phenomena has been a strong
point for these who assert nonsubmergence.
Students of ancient shore lines find gaps along beaches that are
commonly strong. It requires considerable time for wave and
shore currents, even at steady levels, to bridge unfavorable
stretches. On shores as strong as those of the glacial Lake Warren
and Lake Iroquois localities are found with only smooth, wave-
washed slopes comparable to the low surfaces of Long Island and
Staten Island. Following the removal of the sheet the land rose
* Geology of Martha’s Vineyard. Seventh Annual Rep’t, U.S. Geol. Sur-
vey, 1888, p. 321.
PLEISTOCENE MARINE SUBMERGENCE 19
rapidly (or slowly, according to mental viewpoint) and the mechani-
cal conditions produced by the constant shifting of the zone of
wave attack were unfavorable for bar construction, especially in
tidal waters, the same as for erosional work.
And there is another deterrent factor which has not been recog-
nized im this study, of perhaps even more effect than the change of
water level. Plates 3-5 show the location of beaches about the
Covey Hill salient. The summit marine shore is very strong on
the Champlain side of the highland, being represented in places by
remarkable vertical series of strong cobble bars and gravel banks
as far south as the parallel of Port Kent, the south edge of the
Dannemora quadrangle, plate 8. On the lower slope of Covey hill
at an elevation of 525 feet, 215 feet below the summit shore, is a
splendid series of heavy cobble bars, which was formerly thought
to represent the marine sumnut. The top of this inferior series of
bars lies at Covey Hill post office, and curves westward about the
hill at Stockwell, Maritana and Franklin Center, and enters New
York north of Chateaugay. When we follow this shore line south
from Covey hill we find a notable set of bars one mile south of the
international boundary, and a good display at Sciota and also west
of West Chazy. But as we pass farther south, on to the Danne-
mora quadrangle the shore features of the Franklin Center series
practically disappear. On the north edge of the sheet, 2 miles
northeast of West Plattsburg, this level of the lowering waters is
only a rolling plain of sand, like many other broad stretches in the
submerged Champlain region all devoid of beach phenomena. But
the waters stood here just as long as they did at Covey Hill post
office and Franklin Center, and the conditions of slope, exposure,
open sea, etc., were just as favorable for bar-building. What is
the explanation? Apparently the difference was due to the char-
acter of the material withm the grasp of the waves. All the bars
in the district are coarse gravel or cobble, never sand. Along the
marine summit the glacial drainage built wide tracts of very coarse
material, which the waves quickly piled into bars. When the gravel
tracts were lifted above the waters and the waves found only sand
they were unable in the time permitted to bank it at any particular
level.
All the strong beaches of the sea-level waters of the Hudson,
Champlain and St Lawrence valleys are coarse material, never
sand. Even the steadier level of Lake Iroquois produced only
cobble bars in the stretch of shorter lived waters between Water-
20 NEW YORK STATE MUSEUM
town and Covey pass. On extensive delta plains with superabund-
ance of sand all beach features are wanting. Even where there
was considerable coarse material an abundance of sand appears to
have inhibited bar construction. It appears that wave work can
much more quickly pile cobble into ridges, but that sand requires
more time. The small sand bars that have been found were in
sheltered localities with weak wave action.
The combined deterrent effect of shifting water level, tidal fluc-
tuation, and dominance of sand or silt seems to be, in the light of
facts from other districts, sufficient explanation of the absence of
high-level beaches in the sandy areas along the sea coast.
EXPLANATION OF MAPS AND DIAGRAMS
PEALE Si
Plates 1 and 2. These maps are im completion of the series of
maps showing the recession of the ice sheet over New York State,
published in New York State Museum Bulletin 160, plates 9-17.
Plate 1 shows the relation of the ice margin to the Iroquois and
marine waters during the second, and closing, stage of the glacial
Lake Iroquois, with the outflow at the pass on the international
boundary, on the south side of Covey hill. Lake Iroquois is here
at its greatest extension.
In the earlier maps the waters in the Hudson-Champlain valley
were wrongly represented as glacial. This is now known to be an
error. The low attitude of the land at the time of the ice removal
permitted the oceanic waters to enter the great valley and per-
sistently lave the receding ice front. At the time represented in
these two maps the sea-level or estuarine waters had become con-
tracted, diminished in depth and width, in consequence of the
uplift of the land, which as a progressive wave had passed north-
ward, subsequent to the ice removal. Plate 3 shows the full amount
of the land submergence and the greatest extent of the sea-level
waters.
In the Hudson valley it is probable that the land uplift never
overtook the retreating ice front; but it is possible that some little
uplift occurred in the Champlain district while the ice had the
position indicated in plate 1. The effect on the shore line will be
considered under plates 5, 10.
Plate 2 represents the ice margin as removed from Covey hill,
thus allowing equality of level between the waters of the Cham-
plain and St Lawrence valleys. Lingering points of the ice lobes
are hypothetically depicted on the north edge of the map.
PLEISTOCENE MARINE SUBMERGENCE 21
The difference in time between the stages shown in plates 1 and
2 is relatively small, and no attempt is made to show the slightly
greater constriction of the valley waters in the Hudson during the
second stage.
Plate 3. This map does not show the geography at any
moment of time, but the greatest submergence and widest extent of
the sea-level waters in all districts, as indicated by the summit shore
features. The land uplift as a progressive wave, moving north-
ward, produced constant reduction of the estuary on the south,
while near the ice front the land was at, or near, its greatest depres-
sion and the waters at their maximum extent. This is illustrated
in plates I and 2.
The amount of marine submergence and postglacial uplift is
shown approximately by the lines of equal uplift, or isobases.
Plate 4. This map is intended to show the locations of the
shore lines in the northern part of the State, east, north and west
of the Adirondack highland.
In the Champlain valley only the sea-level waters, the marine
inlet, existed, but in the St Lawrence valley the glacial Lake Iroquois
preceded the ocean-level waters. The vertical interval between the
Iroquois and the marine planes is 290 feet (see plate 11). The
marine plane passes under Lake Ontario at the south edge of the
area here shown, or approaching Oswego. The rise of the land,
over 500 feet, at the head of the St Lawrence (plate 9) has lifted
the surface of Lake Ontario to 246 feet above the sea, and buried
the southwest shore of the sea-level waters (Gilbert gulf), where
the land uplift was less.
Plate 5. We havein this map the shore phenomena plotted on
the topographic sheets. The legend and notes make the map quite
self-explanatory. Plate 6 joins the west edge of plate 5, and plate
8 joins the south edge.
In his map of the Mooers sheet Woodworth indicates many
fragments of beaches which are not here shown (81, with map).
However, the lower shore features do not involve any important
element in the history, as such are to be expected, under favoring
conditions, at all inferior levels. ‘Weak bars occur irregularly at
points where the several factors favoring their construction were
present in sufficient degree.
The lower bars in this map belong mostly to the Franklin Center-
Stockwell-Covey Hill post office shore line. This shore with its
great series of strong cobble beaches represents a level 215 feet
beneath the summit plane, and possibly records an episode of some-
to
NEW YORK STATE MUSEUM
what slower uplift of the district. But this shore series is prac-
tically limited to the area of this map. It is not found on the Danne-
mora quadrangle (plate 8), and is not recognized farther south.
The contouring of the Mooers sheet is not correct and no precise
elevations are given; and the location of bars and of the inter-
polated shore line may need some correction.
The Mooers quadrangle includes the extensive bare-rock areas,
due to the stripping of drift from the Potsdam sandstone by the
copious glacial waters (see plate 5). The remarkable development
of cobble bars indicated in the northwest and southeast parts of
the Mooers sheet was due to the abundance of coarse material
swept down by the glacial ice-border rivers to within reach of the
standing waters. The cobble tracts are the deltas of the glacial
streams. Long stretches of the summit shore have not been closely
examined. More detailed description of the features of the map
will be given in a later chapter.
Plate 6. This map, the Malone sheet, shows the westward
extension of the shore lines, the map joining plate 5.
Below the marine plane the deltas are mapped only for the
Salmon and Trout rivers, but sand and silt plains occupy most of
the northern‘ part of the area.
On the Moira quadrangle, lying west of the Malone, the shores
merely cross the southeast corner, without significant features for
the Iroquois and the marine summit, though a lower beach has
strong development between Moira and Lawrenceville and west
of the latter village. The quadrangle south of the Moira has not
been mapped, but it carries heavy deltas and bars on the St Regis
river at Dickinson Center and Nicholville. The next sheet avail-
able for our purpose is the Potsdam.
Plate 7. The Potsdam quadrangle, carrying the deltas of the
west branch of the St Regis and the Raquette rivers, has good dis-
play of the shore features.
Interesting features occur on the Canton quadrangle, lying on
the west of the Potsdam, but as Professor Chadwick plans to pub-
lish the Pleistocene geology of that area, it is not here included.
Plate 8. This map, the Dannemora quadrangle, joins the
Mooers sheet (plate 5) on the south. As on the Mooers sheet, the
highest reach of the sea-level waters is marked by the termination
of the land and ice-border rivers, with their correlating deltas.
West of Peru a few gravel bars lie above the theoretic marine
plane, but series of heavy bars are beneath the summit level, which
is the prevailing relation on all the shores of the marine inlet.
NEW YORK STATE EDUCATION DEPARTA
SCIENCE DIVISION
ARS MAP
‘+ STATE OF NEW Y¥
AND ITS
ENVIRONS
N
a pemna tN
ee ea eg
CHOMGIAN Ivy \ a al a
Casa
‘ WA [Wags
‘| agw Fo he Pe
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OF NEW YORK eal 4
The 1sobasa/ /ines, inciined 20 degrees 7 Go ™
trom the latitude. parallels, jogicare =>
the total srrount ok fond tolit? since fhe (~° 11
removal of the Labracorian 16€ Cap. ")
The live A-B /s the location of rhe
prothe 10 the cagram, plate fo. A yew
critical ports are arKed
The ine 6-0 1s the position of #hé
protiles shown in plate 11.
Stations Used ja. the pabilared
gata, plore 12, are waicuted ©
AL Fairchild 19:7,
a epye
eal | Te
MAP Ne ; ‘
= STATEOFNEWYORK “Sx
ENVIRONS \ e
WLIFT KP
yoRK ot” ok
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PLeIstoceNe upLirt or New York
PLEISTOCENE MARINE SUBMERGENCE 23
Plate 9. This map relates to the diastrophic problem, the
deformation of the continental surface. The amount of uplift out
of the sea is approximately shown by the isobases for all of the
State and the neighboring territory. The map is to be used in con-
nection with the tabulated data, plate 12.
In the Hudson-Champlain and Connecticut valleys the estuary,
sea-level waters have left a record of the submergence in the shore
features. The height of those features today is the measure of the
postglacial uplift. The lines of equal uplift, isobases, connect
points of equal rise in the two valleys; and the lines have been
extended westward across the State. Across New York the
isobases have nearly direct courses, 20 degrees north of west by
south of east. It is recognized that the extended isobases must
lie in circles or ovals about the domed area of uplift, and that both
east and west they must be given decided curvature. On the east
the curvature is determined by study of the land uplift in New
England. Westward the curvature is hypothetic.
The lines of 300 and 400 feet are located in accordance with the
determinations of Professor Emerson (66, 67). The zero isobase
should, it is probable, be laid farther south, but as it is an uncertain
and elusive element the line is drawn well within the limits of the
map.
It will be seen that the rate of tilting, or gradient, of the shore
line increases toward the north, as indicated by the spacing of the
isobases. From present knowledge it appears that the steepest
gradient lies over the Champlain district, and that the surface of
the dome of uplift has a decreasing slope in Canada. The height
of the estuary features in Lake Memphremagog district have
located the 800 feet isobase.
Plate 10. This profile has been drawn to connect points of
clear summit shore features. These stations are numbered on the
chart, 10, 22, 24, 50, 54, 58, 78, 89, 138, 144. The fact that nearly all
the topmost shore features, even in localities as far away as the
Connecticut valley and the east shore by the Green mountains,
coincide very closely with this profile is confirmation of its accu-
racy. And the vertical relation is greatly exaggerated, as the
vertical scale is 528 times the horizontal.
Since the isobases are inclined 20 degrees from the latitude
parallels and this profile is for a meridian, the proper location of
the stations is by the intersection of their isobases, and the results
are surprisingly harmonious. In only three localities are summit
bars found at heights above this profile. These are at Crown Point,
24 NEW YORK STATE MUSEUM
111; Port Henry, 114; and 131, in the Ausable river embayment
near Peru. As these are in decided embayments of the west wall
of the valley it is possible that the high features are due to glacial
waters, or lakes lateral to the ice lobation in the valley. However,
the strength of the bars and their regular spacing does not favor
the idea of ephemeral waters like the narrow pondings alongside
the ice. It appears probable that the profile does not show the total
height of the marine inlet waters in the Champlain lake district.
The profile certainly does give the uplifted plane of the sea-level
waters in the-Champlain valley at the time those waters passed
around into the St Lawrence valley. It therefore seems as if
there might have been some little rise of the land in the Champlain
region while the ice front lay about Covey hill, and that the superior
beaches indicate the amount of such lifting above the datum plane.
This has an important bearing on the relation of the land uplift
to the withdrawal of the ice cap.
It seems quite certain that through the Hudson valley, or to
about Glens Falls, number 89 of the profile, the wave uplift did
not overtake the retreating. ice front. By the time the ice cap
had waned so as to expose the Champlain valley the weight of the
ice mass had so diminished that perhaps the northward-progressing
wave of land rise did affect the border of the ice-covered territory.
This is also suggested by the Iroquois beaches in the St Lawrence
valley.
The history of the postglacial phenomena is possibly more com-
plex than here outlined, and there may be unrecognized factors in
the problem.
The lower bars along the international boundary are mapped
in plate 5.
Woodworth’s line A-B in his plate 28 (no. 82 of the list of
writings), is nearly coincident with this profile.
Plate 11. This diagram should be used in conjunction with
the maps, plates 5-7, 9.
The shore features are plotted on the profiles according to their
isobases. The vertical scale is 264 times the horizontal.
The lines for the uplifted Iroquois shore are drawn as straight
lines from, Covey outlet to beyond Adams, ignoring any slight
curvature. Southwestward from Adams the line is given slight
curvature so as to intersect the Iroquois beach at Ontario, Wayne
county. 5
The upper of the two lines of Iroquois is regarded as the closing
or extinction plane of the lake. If this be true then the lower line
TANAT VAIS FANT Laawz~ =
Plate ro
FEATURES EAST OF MERIDIAN. FEATURES WEST OF MERIDIAN FEATURES NEAR MERIDIAN FEATURES I’ VERMONT ANO MASS.
6) Hinder hook, plains aad cliffs Fas 15 N. line of N.it1,at Greenwood Lake, /o0t 10 Pork Washington, L.h, Sandplain, 60 A Portland, Cr, two heavy bars, 220-
62 Valatre, ee on plain, FOS 20 Wes+Haverstraw sardplains 120 22 Crofon Pointe head of delta, /20 8 Morine plane on Cond. River, &. Ty es 338A
63 NiverviHe sandplains F/T 23 Verplanck, (m,n, bars 1/25 IF Hudson, (ms, bar 2754 S “ ee A a Bim YS tire MB Cle EOD)
67 Schodack plains J4o 29 Vones Point ferrace 130. 72 Loudenvisfe, ch¥f and Ferrace 350+ D Selisbury, Vk cobble plain. 580 800 it Ais
69 Eustr Greenbush, bars, JZ0-320 27 Fort Moatgemery. bar /35 G2 Daeaeag Springs, bars and cliffs 70-360 E Middleburg, Vi Sm. re. cobble plain, 590-595 Ws liar
W DefreestWile, bar-chiffs, F40 28 Mighland Falls (plain, (40 89 Glens Falls, 5 m.' Sw, bars oa Hudson delta 440-45 F Brisfol, Vel delra suminit 620 ns ey Buen
V7 Schaghticoke, Moosic delta, TIS 29 West Point, plains, /60-/40 143 Cannoa Corners, bars, 730-695 iy nb) \
Ye Grand wich, Battenki// delta, #20 32 Newburg saadpleas, (60 (44 White School, bars 735-70 a) a?
87 Durkecfown, 7 m.$,, bar 425 93 Beacon, sandplains (So “4S Int Boundary, (m.s..channel, 7#o 700 is = | 700
go North Argyle, clif¥s and bars, 450 3S New Hamburg, rerrace, (ms, (75-170 Zscbake of Covey outlet, == |
foo Hague, £) George, cliff and terrace 525, 36 Marlboro, Sakdplain 170 146 Paralle/ 4500, bars 740-720; 530-360 ‘il se 3 "
/ Gpleer fice sdudplain-#$0%; bars 435-37 ° 39 Foagtkespsie sandplatas (Fo 147 Covey ti}! PO. Caa,, Clif¥ 740; bars 530-300 m io = '
“1 Crowa Point, glacial ferraces, 620 4 fig de Fark, rerrace—plara, 200-195 80 Mechanicsvi//e,3 im nw, heavy bar, 3G0 600 m = = = i
WA Fort Heury, Glacial bars, 690 42 Hosendale plain 220 (2) Uh 0G fo9 = fae malic
WG ElizebelAtowna delpa, 620 46 Hingston platas 220 Hs a i
| WE Bouguel; ferraces afd bars, 620 47 Fhinebeck delta platas, 245 S— aye Se i
W 124 Clidtonville delta 660 So Mount hiarvoa, glacial chanae/s, 240 _—t = ze, ;
wy (26 Harkness, terraces aad bars S60-FES S2 Mount Airy, glacial channel and dé/fa 250 S00 pe as = 2 = <= 00°
155° 150 ME 40 135 730 125 120 USE 410 105 100 IS
UPLIFTED WATER PLANES IN THE ONTARIO- ST. LAWRENCE VALLEY
ON THE LINE JOINING COVEY, FARR’S, ONTARIO
7o 6s 80 75
LL. Fairchild_1917.
TILTED WATER PLANES IN THE ONTARIO-ST LAWRENCE VALLEY
Plate 12
MEW YOK LOCATIONS
Fresent altitude of the upraised /roguors plane
Altitude of /rogvois af time of extinction.
Amount of uphkt since extinction of /reglo/s
Altitude of the ypratsed marine plane
Amount of land uplit? during rogers time
Total amount of land uyalitt, by /sobases
kise of /roguors fevel We ro Flooang. }
4y excess of ipiitt af Krome
liitial height of the /roguo/s plane
Fresent a/titide of *he Upra/sed /rogvals plane
38
Splitting
188
566
192
580
of beaches
due to uplifr
205
622
3/
£16
CANADA LOCAT/IOWVS
Fresent altitude of rhe uprarsed /rogio/s plane
Altitude of /roguo/s af time of extinction.
Amount of uplift since extinction of /rogvo/s
Altitude of +he wpraised marine plane
Amount of land iplitt during /raguo/s time
Teta! amount of land uplift, by 1s0bases
Kise of sroguors leve/ due fo ffoodin.
by excess of up/itf at Krome
Initial height 0f rhe sroguo's plane
Fresent altitude of the yprarsed /rogvo/s plane
OD gGLAG/IAL LAND OPAIPT JN SZ ONIATAO, BA S//V
Ht lL farrchild 19/7,
Figures show altitudes, in feet, above sea /evel
Ynderscored tgures are field measurements.
Compare with profiles, plate 1.
“
TABULATION OF DATA RELATING TO UPLIFT IN THE ONTARIO BASIN
PLEISTOCENE MARINE SUBMERGENCE 27°
localities were the first to be relieved of the burden of the ice
sheet (164, plates 9-17). Other localities between Rome and
Hamilton had proportionate movement. It will be seen that Rome
was the point of largest rise in glacial time, and the station of
lowest initial altitude. From Rome northward the glacial uplift
was small, but the postglacial was large. Toward Canada nearly
all the rise has taken place since the sea-level waters entered the
St Lawrence valley.
The low initial height of Rome is in agreement with the facts
of the early glacial drainage in central New York; for the escape
long before Iroquois time was eastward through Syracuse to the
Mohawk-Hudson; and the Syracuse channels are today, after
uplifting and some filling, less than 400 feet above tide. In apply-
ing the mathematics of the table to any particular locality it must
be understood that the figures apply to the precise point used for
Iroquois or marine altitude. Taking Rome as example, the altitude,
460 feet, is the crest of beaches southwest of the city. The lowest
part of the divide, the channel head or wasteweir of the latest
outflow of Iroquois, the Iromohawk river, is about 430 feet. Hence
the initial altitude of that point is 30 feet less than 110, or 80 feet.
If we add 20 feet for depth of water we have a fall of 100 feet
for the river flow between Rome and Schenectady, a distance of
g2 miles by the railroad.
The initial height of localities can be approximately estimated
by comparison with any near-by shore line (latest) of Iroquois,
or a summit beach of Gilbert gulf.
The profile of the closing Iroquois, plate 11, shows that from
Lacona to Chateaugay, or in the area north of the Rome isobase,
there are shore features higher than the lake level. This implies
that the land rose out of the water; in other words, the rise of the
outlet, either at Rome or Covey, did not keep pace with the land
uplift in the Watertown-Malone district. The greatest vertical
spacing or splitting of the bars is at Farr’s, 3 miles east of Water-
town, where the highest beach is 62 feet above the profile. The
table shows that Farr’s rose only 69 feet during the whole of Iro-
quois time. But Rome rose 180 feet before and 170 feet after the
extinction of Iroquois. It does not seem possible that Farr’s
could rise 62 feet over Rome in only 69 feet of total rise. The
better explanation is that the northern uplift took place rapidly
just after the outflow was shifted to Covey, as that outlet, and
hence the water level, rose only a small amount before the extinc-
tion of the lake. Certainly the land uplift in the Watertown dis-
28 NEW YORK STATE MUSEUM
trict exceeded the rise of the water level by the 62 feet of vertical
spacing. The relatively stationary attitude of the lake after the
Covey outlet became effective gave the wave of land uplift the
opportunity of rising out of water. It may be noted, as illustration
and proof of the wave movement that during glacial (Iroquois)
time Rome was lifted 111 feet more than Farr’s, but that during
Post-Iroquois (Postglacial for New York) time Farr’s rose 211
feet more than Rome. In way of summary, it may be stated that
south of Rome, which was on the fulcral line for nearly all the life
of Iroquois, all the beach phenomena appear to an effect of rising
water ; that north of the fulcral line the splitting of beaches declines
in amount both toward and beyond Watertown; that the tabulated
figures for the Canadian stations show similar relation; and that
the splitting of the bars is due to a local uplift of the ice-unloaded
territory during the relatively short period that the lake outlet was
at Covey pass.
The south shore of Lake Iroquois has the characters produced
by a rising water level. Evidently the rise of the lake surface was
produced by the excessive rise, or differential uplift, at the outlets,
especially at Rome. The huge gravel bar at Hamilton is the moat
striking feature due to the rise of the lake. This has been described
by Coleman (151, pages 351-52), who implied that the flooding by
the rise of the lake level was toward 100 feet. Our tabulation
shows that while Rome was lifted 180 feet, Hamilton was lifted only
123 feet, and the flooding at that point was 57 feet. It is an inter-
esting fact that “unworn Mammoth remains” were found in the
Hamilton bar at a depth of 83 feet (151, page 352).
By similar calculation the approximate amount of flooding is
estimated for other stations. The figures are maximum, and prob-
ably slightly excessive, being as much above the fact as the uplift
at Rome, after the outflow was shifted to Covey, exceeds the rise
at Covey. As this difference is unknown, but probably small, the
comparison of stations is made with Rome.
The beaches in Canada show relations similar to those in New
York. The figures are chiefly Professor Coleman’s. Toronto, on
nearly the same isobase as East Gaines with about the same rela-
tion to the ice body, has similar figures, the glacial uplift being
two-fifths of the total. But Quays, on the same isobase as Rome,
but much longer under the weight of the glacier, received less than
one-fourth of its rise in glacial time. The district north from
Quays shows declining glacial uplift and increasing postglacial,
similar to northern New York.
PLEISTOCENE MARINE SUBMERGENCE 29
From the data at hand it appears that New York State was not
raised as a rigid body but by a progressive wave movement. The
south side of the Iroquois basin suffered about one-half of its total
rise during Iroquois time. The northern part of the basin was
lifted very little until after extinction of Iroquois. The New York
City district did not rise at all until the ice was gone, for not until
the ice front had withdrawn considerable distance was there any
effective reduction in the weight of the ice cap. The question is,
Did the wave uplift of the land ever overtake the receding margin
of the waning glacier? In a former paper the writer expressed a
negative opinion (27, page 250), but with further study and in
the light of the accompanying charts it,seems probable that some
small rise occurred at Covey hill while the thin ice margin yet
lingered against that northern salient.
DESCRIPTION OF THE SHORE FEATURES
Long Island
The amount of Postwisconsin submergence is shown in plate 3.
The positive evidences of submergence are abundant and sufficient,
the only ones lacking being bars of wave construction and marine
fossils. The absence of bars on sand plains has been described
in an earlier chapter; and absence of fossils on a shore of abundant
drifting sand is probably to be expected.
This subject has been recently traversed in a published paper
(55), to which the reader is referred for fuller discussion. For
this present writing it will be sufficient té enumerate some of the
characters which prove the burial in the open sea.
1 The island lies entirely within the area of postglacial
depression.
2 Positive proof of the submergence of the near-by valleys of
the Hudson and Connecticut.
3 The evident shore lines about the eastern moraines.
4 The admitted wave-eroded origin of the cliff extending from
the west end of the island to 6 miles beyond Jamaica.
5 The very smooth, even surface of the lower parts of the area.
6 The materials of the plains and the occurrence of surficial
loams over large tracts of the lower plains. |
7 The subdued, wave-smoothed surfaces of the moraines beneath
the theoretic plane, and the very rough, harsh, unsubdued surface
of the same moraines above that plane.
30 NEW YORK STATE MUSEUM
8 The presence of innumerable kettles in the smooth eastern
plains, showing the subjugation by standing waters of the ice-laid
or moraine drift.
9 The admitted delta terraces or sand plains on the north side
of the island, and on the north side of the latest moraine, at the
theoretic altitude of the marine plane.
10 The occurrence of fine, evenly bedded sands containing boul-
ders, evidently rafted, in low valleys in the moraines; the valleys
opening freely southward.
Staten Island District
In the region of New York City and southward where the waters
were shallow and of diminishing depth, with fluctuating levels, it
is to be expected that the amount of submergence can not be easily
determined. But the erosional work and smoothing effect of stand-
ing water is evident.
The writer has not made any study of Staten island or in New
- Jersey except along the northern boundary. ‘Confidence has been
placed in the published descriptions of Merrill (30-32), Ries
(33-36), and Salisbury (41-43). West of the Palisades the low-
lands exhibit clear evidence of water action since the ice sheet
withdrew. Over the till, colored red by the debris of the Newark
‘beds, lie abundant water-laid, yellow sands. In the Hackensack
valley the evidence of standing water is clear up to the theoretic
plane of submergence. The silt plains are found to the head of
the Hackensack river, near the Short Clove and Long Clove. Pro-
fessor Salisbury gives many references to the presence of water
as the latest occupant of the territory.
Along the Hudson in the district of New York, and in West-
chester county, the records of standing water were conclusive to:
the earlier students. In the last four decades the great expansion
of commerce, business and building operations has obliterated many
features. “ Civilization” and “progress” have little care for such
“impractical”? matters as the geologic records. It has not been
practicable for the writer to use the time that would be necessary
to study closely this difficult area, but the testimony of the able
men named above is regarded sufficient to prove the fact of recent
submergence in the New York City district.
Hudson Valley —
Tarrytown sheet. South of Ossining close study may find some
remnants of deposits left, either by the glacial outwash or the land
‘Jooy} OZ-O9Z apnyy[e JussaIg ‘[AAa] vas }e }Inq SeM YOY
elep oy} wory ‘weasjsdn ‘yJ10U Suryooy ‘][lys}yep Jo ysaMyjnos sop Z ‘s][ey Jeary je ‘JouURYD WeI1}s [eIIL[S)
€I 93e1q .
PLEISTOCENE MARINE SUBMERGENCE 31
_ drainage, in the marine estuary, but the prevailing steep walls of
the valley, with absence of heavy tributary drainage, has prevented
the construction and preservation of conspicuous deltas. Of course,
cliff-cutting and bar construction were negligible in such narrow
waters.
But northwest of Ossining is one of the best deltas in the valley,
and the finest in the present water. Croton Point, projecting 2
mules into the Hudson river, is the remnant of the heavy delta of
Croton river. It is incontrovertible proof of high-level water in
the Hudson valley since the glacier vacated. Some small remnants
of the great delta are found in the level patches north of Ossining,
but the greater part of the original delta has been cut away by
the same stream that built it, aided by the tides and waves of
Tappan Sea. The delta promontory represents the north flank of
the original filling, and an evidence of the erosion is seen in the
gap across the middle of the promontory.
The broad sand plain at the head of the promontory is definitely
roo feet altitude, by the topographic map; but this does not give
the full height of the Hudson estuary. Ain examination. of the
eround in company with Professor Berkey finds that the summit
water level is at about 120 feet. The 100-feet plain was under.
water, though wave-swept by the lowering (relative to the land)
waters. Merrill made the usual mistake of taking the highest .
broad and conspicuous plain as marking the water surface. In
some cases this may be the fact, but commonly not so.
On the west side of Haverstraw bay, at Haverstraw, West
Haverstraw (Bensons Corners), and North Haverstraw, are thick
clays and capping sands lying in an embayment of the broad valley.
The summit altitudes of the sand plans agree closely with the
profile in plate Io. :
The northern portion of the low ground west of the Palisades,
mentioned in the preceding chapter, is shown on this sheet.
West Point sheet. North of Verplanck the clay pits of an aban-
doned brick factory testify to the deep water of the Hudson
estuary, and the capping sands are seen a mile northeast of the
village. Here leveled sands and weak bars indicate the full height
of the waters, about 125 feet.
Southwest of Peekskill for 2 miles the careful observer may see
indeterminate inscriptions of the high waters. The state camp,
over a mile northwest of Peekskill, is on a delta terrace with an
altitude of 105 feet, some 25 feet inferior to the summit level.
Across the river from Peekskill is one of the most interesting
32 NEW YORK STATE MUSEUM
sand plains, unfortunately now mostly removed. Jones point has
been for many years one of the sources of sharp sand and gravel
used in New York City construction. Seen from across the river,
or from the steamers, it yet shows the line of the gravel terrace
banked against the Dunderberg mountain. The map is faulty
and does not indicate even the remnant of the original plain. The
north end and highest part of the plain is at about 130 feet above
the sea. The southward slope of the summit shows clearly when
seen from some distance. The structure and location of the gravel
terrace, in relation to the mountain and valley, prove that it was a
glacial delta. Its position rules out any possible land drainage. It
was built by a glacial ice-border stream which flowed along the west
edge of the ice lobe and which received the contribution of the
land drainage north of the Dunderberg. The lower portion of the
deposit is very coarse, containing thousands of boulders. The top
and the southern end are finer, with the foreset and topset beds
well displayed.
The geographical relations of the Jones point gravel terrace rule
out, as explanation of the receiving water, any suggestion of glacial
ponding alongside the ice lobe. The waters were the open Hudson
inlet or estuary.
The constricted valley between Peekskill and West Point could
not hold any large shore features; but minor features can be seen
from the opposite side of the valley, or from the river steamers,
and such have been measured at Fort Montgomery and Highland
Falls.
At West Point the parade ground is the theoretic height for the
summit level of the estuary, about 150 feet. But there has been
so much grading and interference with the natural surface that
precision in this locality is not attempted.
The terraces a mile northwest of West Point and across the
river east of Cold Spring are contoured at 160 feet. As these lie
in embayments of the valley walls they probably were marginal to
the shrinking ice lobe, as described by Woodworth (82, pages
I1I-13), and were graded somewhat above the open waters to the
south. The control of the waters on the West Point side must
be the steep slope south of the point; on the Cold Spring side the
channels of outflow control will probably be found opposite the
point, a mile northeast of Garrison.
West Point, Schunnemunk and Newburg sheets. At the junction
of these three quadrangles with the Poughkeepsie quadrangle two
large and interesting deltas are found, one affording the site for
the city of Beacon and the other for part of the city of Newburgh.
PLEISTOCENE MARINE SUBMERGENCE 5 33
The southern part of Newburgh lies on the delta of Quassaic
creek. The summit plain of the delta is well shown, both on the
map and in the field, on both sides of the creek, with an elevation
of 160 feet. The broader part of the delta plain is on the south
side of the creek, underlain with scores of feet of blue clay. This
clay has been extensively excavated along the river south of New-
burgh and at New Windsor, and shows the usual succession; glaci-
ated rock and compact till at the bottom, then the thick deposit of
finely laminated blue clay becoming yellow toward the top, and a
capping of sand and gravel. This will serve as an example of the
valley deposits and the record of the succession of events since the
ice occupation. The occurrence of huge boulders in the clays is
evidence of waters laving the receding ice front.
Opposite Newburgh is the delta of the Fishkill, the larger part
showing on the West Point sheet. The summit plain is on the
Poughkeepsie quadrangle and carries the part of Beacon formerly
called Fishkill. The altitude of the main street of Beacon is about
150 feet, at the west end. The map is wrong in showing the east
end higher.
From Newburgh, or from the river steamers, the plain and
terraces of the Fishkill delta are plainly seen. South of Beacon
the delta stretches for 3 miles, and at Dutchess Junction and below
are extensive brick works. Apparently the southward drift of the
waters, aided by exposure to the northerly winds, swept the stream
detritus southward. Denning point is a little remnant of the delta,
a small imitation of Croton point.
Poughkeepsie sheet. Northward from Newburgh terraces of
gravel and excavations in clay occur at several places. Woodworth
indicates them as far as Marlboro (82, plate 5). The terraces have
been so mutilated that their original form is uncertain. The ter-
race at Roseton, like many that will not be noted, was inferior in
altitude, about 100 feet. At New Hamburg is the delta of Wap-
pinger creel; but only the lower terraces lie here, for the reason
that the summit level of the delta head forms the broad flats extend-
ing 2 to 4 miles above Wappinger Falls. A fair terrace and beach
along the highway a mile south of New Hamburg, at 175 feet by
the map, marks the summit level of the estuary. The smoothing
effect of the waves is seen on the weak shales and the silt filling of
the hollows west of Wappinger Falls, at about 170 feet.
East of Marlboro are flat-topped sand hills not properly shown
by the map, but of inferior altitude. Northwest of the village, and
north of the creek, by the railroad station, is an extensive gravel
my ‘ NEW YORK STATE MUSEUM
plain, all in fruit farms. Mr ‘Charles Young owns the point by the
station and his house stands on the edge of the plain with altitude
about 165 feet. The sand plain is 5 to 10 feet higher.
North from Marlboro are terraces and gravel and clay pits, espe-
cially on the west side of the valley. Many evidences are seen of
the leveling work of waters, many being inferior in height as should
-be expected.
The eastern part of Paweiiceeae is on a sand plain built by
Fallkill and Caspar creeks. The Vassar College campus occupies
‘the southeast portion of the plam, with an aibeuie of 175 to
180 feet.
Rhinebeck sheet. Hyde Park stands on ‘the north end of a ter-
race plain which stretches south 3 miles. The plain shows clearly
on the map, which makes the height 200 feet, about the theoretic
summit altitude. Some wave work may be seen along the highway
in low, flat bars and swells of sand. Two creeks, one at each end
of the plain, contributed material.
Rondout creek, the largest tributary of the Hudson south of the
Mohawk, enters the Hudson at Kingston. One might expect to
find here a large delta, but the deposition took place far up-stream,
above Rosendale. However, detached plains and terraces record
the summit level, about 220 feet. The broad sand plain at Rosen-
‘dale, contoured at 220 feet, seems too high for its latitude as an
estuary deposit, and may represent a distinct water body, glacial
waters, or perhaps supergradation by the Rondout creek.
The village of Rhinebeck, two and one-half miles east of the
Hudson, is located on a delta plain of the Landsmans kill. The
plain, one and one-half miles in north and south extent, has been
bisected by the creek, the village standing on the north half. The
altitude of the flat plain is 210 to 215 feet, only some 15 feet
beneath the profile. The existence of the village at this place is
evidently wholly due to the plain.
The upper left corner of the Rhinebeck sheet shows a part of
the plain of the Esopus creek, considered below.
Rosendale sheet. This quadrangle does not touch the Hudson
river but covers features mmportant in this study. We see here
the Rondout river with its large tributary, the Wallkill; and the
Esopus creek that joins the Hudson at Saugerties, on the Catskill
quadrangle.
The Rosendale plains are contoured at 220 feet, over 10 feet
above our profile. Assuming that the map is correct, excess in
ug
PLEISTOCENE MARINE SUBMERGENCE 35
height may not be more than allowance for supergradation of the
large Rondout creek. The form and relation of the rolling gravel
plain suggest that it was built by the Rondout and not by the
Wallkill.
The Esopus creek curves across the northern part of this sheet.
The mile-wide flood plain in the Kingston district lies much below
the marine plain, and is apparently a plain of erosion, graded to
the rock channel south of Saugerties (Catskill sheet). The higher
plain which carries the main portion of the city of Kingston, with
altitude up to 200 feet, represents the marine level. North of
Kingston it is apparent that the Esopus has intrenched itself in a
plain that was at least 60 feet higher than the stream, now 140 feet.
Catskill sheet. The theoretic marine summit along the Hudson
on this quadrangle is about 240 feet, rising to 275. Sufficient rec-
ords of the deepest waters are found, although no heavy deltas
occur at the full height. The village of Saugerties lies on an
inferior delta plain of Esopus creek, and Catskill is on a dissected
lower plain of the Katskill.
The east face of the Catskill highland is a series of bare rock
ledges, carved by south-flowing drainage, marginal to the waning
ice lobe. The topography is probably the result of repeated glacia-
tion with marginal stream work. The lowest channels of the latest
glacial drainage must correlate with the estuarine waters. These
significant features are found on-the east face of the Mount Marion
range of Hamilton sandstone hills, locally called the Hoogeberg.
At Dutch Settlement (Ruby P. O.) on the southeast corner of
the Kaaterskill quadrangle, the stream channels terminate at some-
thing below 240 feet, with a gravel delta at 220 feet. South of
Mount Marion P. O. the Plattekill has left a delta at 200 feet.
Along the east face of Mount Marion stream cutting is distinct
down to about 200 feet, and a delta heads at East Unionville
(Veteran) at 220 to 230 feet. It is to be expected that confined
streams along the ice margin, having torrential flow, will cut below
the surface of the receiving water. f
On the lower road to Mount Airy is a small delta at 240 feet,
with correlating channel at 260. At Great Falls, near the county
line, the Kaaterskill built a delta in the estuary with present altitude
about 250 feet. A glacial channel (see plate 13) lies behind the
hill at 260 feet, by the map. The delta of the Catskill is on the
Coxsackie quadrangle, to be described below.
A mile south of Hudson city the marine waters built a heavy
_ gravel bar, tailing from the south end of the hill on which the city
36 NEW YORK STATE MUSEUM
reservoirs are located. The house of Mr W. Tenbroeck stands on
the bar, the head of which was made 275 feet by aneroid. The
map contours the bar from 280 down to 240 feet. The profile
(plate 10) makes 275 feet the precise altitude for the estuary at
this point.
The smooth tract 6 miles east of the Hudson, stretching several
miles past Livingston, Blue Stone and Manorton, shows the leveling
and smoothing effects of standing water. Numerous kettles indi-
cate that ice blocks of the glacier margin were buried in the detritus
swept in by the land drainage from the east, perhaps aided by
glacial outwash. The smooth kettle plain southeast of Livingston
is contoured at 240 feet. The full height of the open estuary, 260
_ feet, is registered in the bare shales about the kettle area.
At Greendale, 4 miles east by south from Catskill, good bars
were seen by the writer and Professor Chadwick at over 240 feet,
by the map; and the top of the hill is planed at 260 feet.
Coxsackie sheet. ‘This sheet shows the broad clay plains west
of Hudson, traversed by the West Shore Railroad. Except for
a space west of New Baltimore these plains extend the whole length
of the quadrangle. On the north they join the great Mohawk
delta, at Ravena and Coeymans.
The marine plane is about 280 feet at Athens, and rises to 315
feet at Coeymans. ‘The clay flats are much below the summit
plane; the “Athens flat” being contoured at 120, the West Cox-
sackie plains at 120 to 140, the New Baltimore at 200, and the
Ravena at 200 feet. The deposits were laid in deep, quiet waters,
and the material was probably contributed in larger part by the
earlier strong glacial drainage through the Mohawk valley (164).
The west boundary of the estuary was here the bold face of the
rock hills. The drift had been so fully removed from the high-
land by the ice-border streams that the later land drainage found
little detritus to pile as sand or gravel, as topping for the clays, as
we find southward. The land on the west was thoroughly swept
by the glacial flow, and the glaciation and stream work, perhaps
repeated, has given the decided allineation, north and south, shown
by the map.
Only two streams were heavy enough to build deltas, and these
are not in the open Hudson valley but up stream. One is the
Catskill, extending from Leeds to South Cairo. This was years
ago the subject of an admirable paper by Davis (37), in which
he makes the altitude of the estuary waters at South Cairo about
275 feet. This proves to be the theoretic height, and the delta is
PLEISTOCENE MARINE SUBMERGENCE 3v7/
on the same isobase as the gravel bar south of Hudson, 10 miles
distant and on the opposite side of the Hudson, with the same
altitude.
The other and similar delta is that of Hannacrois creek, on the
north part of the sheet. This has not been examined, but the map
gives the height of the plains as 300 to 320 feet.
The west side of the Hudson on this sheet shows only the lower
terraces of the detrital deposits in the estuary.
Kinderhook sheet. This displays the broad sand plains related
to the Kinderhook river and its tributaries. The plain at Stuyvesant
Falls is 200 to 220 feet, or some 70 feet inferior to the summit
level. At Kinderhook the plain is 260 feet and over, or about
35 feet low. At Valatie, Niverville and Kinderhook lake the roll-
ing flats are sandy and have the summit level, 300 feet. Flat, weak
bars, characteristic of sand areas, occur northwest of Valatie at
300 to 305 feet. Weak cliffs are seen on the slopes east of Kinder-
hook and south of Valatie at the same height.
Westward toward the Hudson the detrital plains exhibit the ter-
racing produced in the soft deposits by the subsiding waters. ‘This
feature is characteristic of the detritus-filled valley from here north-
ward to Glens Falls, and very conspicuous in many sections.
Albany and Troy sheets. On the Albany map is seen the larger
part of the great delta built by the Iromohawk river. The southern
plains about Selkirk are 200 feet altitude, and the delta rises stead-
ily to 350 or 355 feet at Schenectady. The delta and its genesis
has been described by Stoller (87) and the writer (164), and fur-
ther description here seems unnecessary.
North of Albany is a bold summit shore line. Along the Lou-
donville road a strong cliff extends for two and one-half miles in
north and south direction, and the terrace facing it has provided
a level stretch for a handsome boulevard. This is a favorite subur-
ban residence district and popular drive. The south end of the
beach is along the east side of a morainal tract, and the cliff curves
sharply west about the south end of the hill between the Loudon-
ville and the Shaker roads. In altitude the beach is about 340 feet.
On the Troy sheet inferior terraced plains are conspicuous along
the Boston & Albany Railroad through Schodack town. The
higher, rolling plains with irregular surface in the district of Scho-
dack Center were probably laid in glacial waters, as noted by Wood-
worth (82, plate 8). The altitude of these plains, with kettles and
rough surface, is 20 to 30 feet over the estuary level, 330 to 340
38 NEW YORK STATE MUSEUM
feet. The difference in the surface and composition of the plains
above and below the theoretic plane is noticeable.
Shore lines are not conspicuous on the east side of the valley,
but some cliffs are found on the slopes and terraces by the streams.
A fair gravel beach occurs one-half of a mile northwest of East
Greenbush, at 320 to 325 feet; another at the south end of Grand-
view hill with similar height. Along the road from a mile south
of Defreesville to near South Troy the work of the higher waters
is quite evident; 330 to 335 feet at Defreesville and rising to about
Bybee arn SOUL Toye
Along both sides of the Hudson north and south of Albany the
terracing of the valley walls is plainly shown by the map, and is
very striking in the field. The history is clear; accumulation of
detritus in the marine estuary at all stages from the highest, level-
ing and smoothing at all levels by the subsiding waters (land
uplift), with later erosion by modern drainage.
Schenectady and Cohoes sheets. Besides the profuse estuarine
deposits these two quadrangles hold several important special fea-
tures. The Cohoes sheet displays in remarkable form the lower
terraces on both sides of the river; the extensive delta of the
Hoosick river; and a portion of the later filling by the Iromohawk
river. The Schenectady sheet exhibits the deserted channels of
the diverted Iromohawk, the north-leading one by the present
Ballston Lake, and the subsequent one leading east by the Round
lake and Anthony kill. A singular feature is the ice-block kettle
holding Round lake.
The Hoosick delta has been described and mapped by Wood-
worth (82, plates 10, 24); and the Schenectady quadrangle by
Stoller (87); while the history of the district has been recently
described by the present writer, with a large map (93). The
summit plains in the Hoosick valley are at Hoosick Junches and
North Hoosick at 400 feet.
The interesting history of the Round lake district may be briefly
epitomized as follows: The delta of the great Iromohawk river,
the predecessor of the St Lawrence, headed above Schenectady
during the time of maximum submergence, and the current flow
was to the southeast. When the land uplift began and the estuary
waters retired the river was diverted northward through the Ball-
ston Lake channel; then building the sand plains by Saratoga lake.
Further uplift with northward tilting eventually diverted the flow
eastward through the Round Lake channel. This flow seems to —
have continued until the land here had lifted 200 feet of its total
rise of 380 feet, as indicated by the stream work in the village,
PLEISTOCENE MARINE SUBMERGENCE 39
which was diverted southward by the persistent ice block. Yet
further land uplift diverted the river flow into its present channel.
If the record is correctly interpreted we have a correlation with
Lake Iroquois history. The outflow of Iroquois continued here
until the Covey outlet was opened. This implies that 200 feet
of land uplift had taken place at Round lake when the ice front
reached Covey hill, leaving 180 feet of rise in later time. It also
gives an illustration of the persistence of buried ice blocks until
exposure to the air. For further discussion the reader is referred
to paper 93.
On the irregular rocky surface of the east side of the valley the
summit shore features are weak; but they are found in the upper
terraces of the Hoosick delta at Schaghticoke and Valley Falls,
with an altitude of 380 to 385 feet. On the Schenectady sheet the
summit levels are seen on the delta plains at East Glenville, at
about 380 feet; and in the Mourning Kill delta, south of Ballston
Spay at 300 feet.
Saratoga and Schuylerville quadrangles. The Hudson river lies
on the eastern half of the Schuylerville map but the western border
of the estuary is mostly on the Saratoga sheet. On the latter sheet
we see the great sand plain north of Ballston Spa, which was built
by the glacial Kayaderosseras when it carried the glacial flow of
the upper Hudson, the latter being forced south at Corinth (76).
The full height of the plain is 400 feet by the map, which indicates
that the rolling surface was a few feet over the static waters.
Weak beaches and cliffs are found northwest and west of Sara-
toga Springs with a height of 400 feet and downward. The
Cryptozoan ledge has been laid bare by wave action of the sea-level
waters.
On the east edge of the Schuylerville sheet the summit plane of
the estuary is seen in the highest terraces of the Batten kill delta,
at Greenwich, 420 feet, and in cliffs southwest of the village. A
splendid gravel bar lies 3 miles south of Durkeetown, at an alti-
tude of 425 to 430 feet, only some 10 feet beneath the theoretic
level. The bar mapped by Woodworth, 2 miles north (plate 12
of 82), is under 300 feet. Between these two bars are several
good shore features, ranging from 4co feet down.
Many shore features are found on the hills northeast of Sara-
toga lake, which hills stood as a group of islands in the estuary
waters.
The Batten kill drains a large territory on the east and in Ver-
mont. It filled its upper valley with coarse detritus, at Cambridge,
40 NEW YORK STATE MUSEUM
Salem and East Greenwich, but the bulk of its finer burden was
swept into the estuary and forms the extensive plains stretching
for 7 miles along the east side of the Hudson.
Fish creek did not come into existence until the Saratoga dis-
trict was lifted out of the static waters. With its small volume
it made no delta of consequence.
As in the Schenectady-Cohoes section of the valley, the sand
and silt plains show elegant terracing by the subsiding waters,
at all levels from the summit down to 200 feet. The supposed
river channels at Quaker Springs and Coveville are only the effect
of wave work on the shales and delta stuff.
In the northwest corner of the Schuylerville sheet and west of
Fortsville are sand plains at 426 feet, which are the delta built
in the open estuary by the glacial outflow of the Hudson, past the
east face of Palmertown mountain.
Further details and a map for this and the Glens Falls area will
be found in paper no. 93.
Glens Falls and Fort Ann quadrangles. With this area we take
leave of the Hudson river and valley proper, and have the col or
divide between the Hudson and Champlain sections of the great
valley.
The divide is a wave-smoothed stretch a mile wide and about 4
miles northeast of Fort Edward, with altitude about 150 feet. It
never carried any river flow. The depth of the estuary over this
divide was about 300 feet. From the time when the yielding ice
front allowed the sea-level waters to pass beyond the divide into
the Champlain section, the waters became the Hudson—Champlain
estuary.
While the ice sheet lay against the Luzerne-Palmertown moun-
tain face, southwest of Glens Falls, the upper Hudson and eastern
Adirondack drainage was forced south at Corinth, through the
Kayaderosseras valley, as described above. During the later phase
of this flow the waters in the valley of Lake George were forced
over into the upper Hudson by a pass 6 miles northeast of Luzerne,
at an elevation of 760 feet (see Luzerne sheet). The delta from
the George overflow is found north of Luzerne, the broad sand
plain being 660 to 680 feet. Ten miles south, at South Corinth,
is the outlet of the Luzerne lake, fed by the upper Hudson and
the Sacandaga rivers, with altitude 630 to 640 feet (76).
When the ice front weakened on the steep face of Palmertown
mountain the Lake Luzerne found lower escape into the estuary
through the mountain pass where the Hudson now emerges from
PLEISTOCENE MARINE SUBMERGENCE AI
the highlands. Here the upper Hudson waters built their delta,
the great terraced sand plain covering all the southwestern part
of the Glens Falls sheet and some of the Schuylerville. The
summit altitude of the marine waters in the Glens Falls district is
definitely shown by a series of strong gravel bars on the terrace
east of the mountain, with a height of 440 down to 415 feet. The
farmhouse of Mrs M. Hall stands on the terrace at 440 feet. The
house of Richard Denton is on a broad bar, the third below the
summit.
As the land slowly lifted the Hudson extended itself to reach the
retiring waters, which carved the sand deposits into the cliff and
terrace so well shown southwest of Glens Falls, at 400, 380, 340,
320, 300, 280 and 260 feet.
The latest deposits of the glacier in this district are found in
the moraine and kames north of Glens Falls, at the foot of the
highlands. During this phase of the waning ice it was faced by
the waters of the George valley, occupying the passes either side
of French mountain. The detritus from the land drainage was
‘mingled with the glacial drift and outwash, together forming a
morainal tract of cobble and sand, holding kettles and lakes. Glen
lake and the neighboring “ponds” occupy the larger ice-block
kettles. These sand-cobble tracts were partially leveled by the
lowering glacial Lake George waters, down to about 460 feet, and
below that more effectively by the sea-level waters. The rolling
and knobby gravel tract north of Pattens Mills is typical of the
deposit of mixed origin. The coarser, hilly area about Glen lake
is more distinctly kame-moraine. The sand plain south of French
mountain, at 520 feet; that about Rush Pond, at 500 and lower;
and the kettle-plain at Bloody pond, west of French mountain, at
570 feet, represent the glacial George waters. The terraces in
the valley southeast of French mountain at 450 feet, and all the
lower plains and terraces are products of the estuary waters
(Woodworth's plate 14).
The estuary, sea-level waters at their higher levels occupied the
valley of Lake George, through the pass east of French mountain.
Small deltas and other shore features will occur both sides of Lake
George at and below the summit marine plane. This plane is about
450 feet at Caldwell and about 540 at Ticonderoga. The features
are.mapped in paper 93.
The Hudson-Champlain estuary. lay over the western part of
the Fort Ann quadrangle. Cliff cuttings in the shales have been
noted west of North Argyle. No close study has been made of
the rest of the area. Between Smith Basin and Fort Ann we see
42 NEW YORK STATE MUSEUM
the north portion of the narrow valley that was the long divide
between the Hudson and Champlain; now cut by Wood creek.
The only large stream is the Mettewee river. Its delta in the sea-
level waters is apparently the filling at and above Granville, on the
Vermont line.
Whitehall quadrangle. Sufficient examination has not been given
to this area to speak with confidence of the features. Good shore
phenomena must not be expected in such narrow valleys. The
small deltas of the torrential streams will be the best criteria for
the water levels. The marine altitudes are about 490 at the south
edge of the sheet and about 530 feet at Stony Point, the north
edge. The waters occupied the crooked valley of East bay and
Poultney river, and passed far east to the Green mountains in
Vermont (92).
The evidences of standing water are very clear from the trains
of the Delaware and Hudson Railroad.
Champlain Valley
Ticonderoga quadrangle. On this area the estuarine waters were’
very irregular in shape, and the shore features about the hills on
the eastern side of the lake have not been examined. The eastern
shore of the estuary lies far eastward in Vermont, beyond Bran-
don and Middlebury, against the west flank of the Green moun-
tains. The Vermont features are described in the Vermont report,
paper 92.
On the west side of Champlain the shore features are well known,
having been described by several authors, though not always with
the correct interpretation (75-77, 82, 94).
The sand and clay plains representing inferior levels of the Cham-
plain waters are conspicuous. ‘They appear along the railroad
from Baldwin to Ticonderoga, at 340 to 360 feet; north of Ticon-
deroga over a large area between the lake and the highland, at
260 to 280 feet; and especially in the embayment west and south-
west of Crown Point, ranging from 200 to 480 feet. The theoretic
marine plane lies on the west edge of the sheet at about 525 to
565 feet, or along the meridian of the lake at 530 on the south to
572 on the north.
This summit level of the sea-level waters is registered in the
Crown Point district by gravel bars. The best series occurs 3
miles northwest of Ticonderoga and a mile north of Street road,
on the east face of a kame-moraine, locally known as Sawyer hill.
This locality was cited by Baldwin in 1894 (75, page 176);
PLEISTOCENE MARINE SUBMERGENCE 43
described by Woodworth (82, pages 154-56,.plate 15) ; and recently
by Barker (94, page 12). In passing north from Street road it
is seen that the south point of the hill is strongly wave-swept. At
the forks of the road is a terrace at 350 feet; then we find a bar-
cliff at 370, a good shelf-bar at 430 to 435 feet by the cemetery
and house, a strong bar at 460 under the house of W. J. ‘Cross-
man, a heavy cobble bar-terrace at 480, the wave-smoothed edge
of the summit plain at 530 to 535, and a heavy summit cobble bar
at 540 feet. The theoretic summit of the sea-level waters here
is something over 550 feet. The rear side of the plain, next the
bare rock face of the mountain, is a few feet lower than the front
and smoothed by some stream flow past the ice margin that drained
the Crown Point embayment. Shallow kettles lie on the plain
and strong kettles at the edge. Woodworth gives a map of the
district (82, plate 15) and thought that the standing water did not
reach above 500 feet because of the unfilled kettles. But we have
multitudes of kettles in deltas and river plains, and abundant
evidence that drift-buried ice blocks may persist indefinitely as
long as the area is under water. The kettles were not produced
until the locality was lifted out of the estuary. The front of the
plain is capped with cobble beaches which have been made dis-
continuous by the slumping in production of the depressions. The
kettles have changed the surface as left by the waves, but have
not fatally obscured the record. From the edge of the plain, 540
feet, down to the lower silt plain, 340 feet, the front of the kame-
moraine is marked with bars and benches.
The deep embayment in the mountain wall, west and southwest
of Crown Point, was partially filled with drift and stream detritus,
largely of fine and clayey material. When the district was lifted
these deposits were planed by the lowering waters, producing a
conspicuous display of terraces and flat-topped areas. The evi-
dence of standing water is found much above the marine plane,
and perhaps represents glacial waters held in:the embayment. The
shifting outlet or control of the glacial waters is not determined,
but probably was along the steep east face of Buck mountain. It
is possible that there are unrecognized elements in the history of
this region. The high levels are best seen west of Crown Point
Center and at White Church, rising up to 610 to 615 feet.
Barker’s map (94, no. I) represents approximately the summit
level of the marine invasion. His maps are correlated to imaginary
outlets or flow-control which did not exist; and they attempt to
represent distinct water levels which are not recorded either there
44 NEW YORK STATE MUSEUM
or elsewhere. Evidences of wave-work can be found up and down
the valley at all levels, but water planes can not be postulated on
a few detached features. Bar-building and cliff-erosion are con-
trolled by variable factors, and except for strong and continuous
beaches or through long distances the inscriptions are not reliable
for levels. Of course it is probable that the rise of the land was not
perfectly uniform, but there were no pauses long enough to pro-
duce distinct shores for any distance in the Hudson and Cham-
plain valleys.
With reference to the assumed outlet or control of “ Lake Ver-
mont” at the divide northeast of Fort Edward, there is something
more to be said. It appears that 200 feet of uplift had taken place
at Round lake at the time Covey outlet became effective, and the
ice front lay on Covey hill (see page 39). The divide is 31 miles
farther north than Round lake, by isobases, and it should have
been later in its uplifting. But even assuming that it did rise in
company with Round lake, the 200 feet of uplift would have left
it yet 100 feet under the sea (see page 40). And it is not reason-
able to suppose that it rose the other 100 feet during the relatively
short time that Covey outlet was effective.
It is possible that the divide rose 300 feet and was out of water,
or above sea level, when the Champlain waters were permitted to
mingle with the salt water of St Lawrence gulf.
In the valley of Lake George the shore features have not been
seriously examined, but the proofs of standing water at various
levels are evident. Theoretically, the highest levels should corre-
late with the outlet toward Luzerne, 760 feet. With some allow-
ance for depth of water in the outlet it makes the water level at
Caldwell about 780 feet, or some 460 feet over the present lake.
At Ticonderoga the plane would be about 860 feet, or some 540
over the lake. The pass west of French mountain gave an outlet
185 feet lower. The marine plane is about 115 feet below the
second glacial plane. ‘The marine plane is estimated to lie at about
470 feet at Caldwell and 545 at Ticonderoga. It is for future
students to verify and correct these three planes in the George
valley.
Port Henry quadrangle. The most striking feature on the map
is the vast clay plain east of the lake, with the Dead creek, repre-
senting the later work of the receding marine waters.
Snake mountain stood as an island in all the sea-level waters,
and distinct summit shore features will doubtless reward careful
search. With this wave-beaten height we take leave of shore fea-
PLEISTOCENE MARINE SUBMERGENCE 45
tures on the east side of the Champlain valley, as they lie far
east in Vermont (92).
At Port Henry is a narrow embayment or recess in the west wall
-of the Champlain valley which holds some excellent but puzzling
records of standing waters. West and northwest of the village
good delta terraces occur, related to Mill brook. The fair ground
is on a plain at 600 feet, with wave erosion at the road corners.
The cemetery is on another plain, the higher terrace being 640 to
650 feet. These levels are seen both sides of the creek valley.
North of the fair ground on the east-facing slope are ridges and
shelves that appear wave-shaped at 640 to 660 feet.
Southwest of the village, by McKenzie brook, a good series of
bars occur on both the north and south roads. On the north road
the topmost bar is under the house of A. M. Edwards, at 620
feet by the map. Four other close-set ridges carry down to about
550 feet, with terracing on the delta to 530 feet. On the south
road the upper bar carries two houses at about 630 feet, with
moraine beyond (above) it. In the field toward the brook good
. bars occur at 605 down to 560 feet; and terraces to 500 feet.
The reason for the above detail is the fact that these features
lie much above the theoretic marine plane, which is here about
570 or 575 feet. The lower of the gravel bars falls within the
marine level, but the highest is 60 feet too high. The topography
of the valley wall and the small width of the embayment do not
favor the existence of glacial waters with wave-efficiency to pro-
duce the bars; and the vertical succession of the bars through 70
feet rules out any definite outlet or fixed control. The series of
close-set, well-developed bars is similar to those positively due to
slow rise of the land out of water; and none of several explana-
tions in appeal to nonmarine origin are satisfactory. It seems
more likely that in this region, the east flank of the Adirondack
mass, there has been an excessive uplift of 60 feet, with or with-
out Postglacial faulting. The superior height of the Crown Point
terraces, coupled with high features in the Peru region, to be noted
later, lend force to this view. In such case our theoretic or datum
plane does not represent quite the total rise in the Champlain
region. The profile, plate 10, is drawn to connect with the summit
shore at Covey hill.
About Westport are conspicuous lower plains, but the summit
features have not been sought.
The estuary waters penetrated far inland up the valley of Bou-
| quet river, which has a bend on this sheet, and the primary or full-
46 NEW YORK STATE MUSEUM
height delta appears at and south of Elizabethtown, 8 miles west
of Westport. The village is built on the delta, with altitude 600
to 640 feet, and lies just above the isobase of 600 feet. This delta
was the product of several streams uniting at this place. The
superior altitude of the delta is due to the aggradation in a narrow
valley far from the base level. The “ Pleasant valley” section
is graded to a lower level, 560 feet. This locality was made the
subject of a paper by Ries (74).
_ Willsboro quadrangle. The profile levels along the west side of
the lake rise from about 615 to 660 feet.
The lower plains of the Bouquet delta are conspicuous on the
map, north and south of Willsboro. The coarser detritus of the
river was dropped at the junction with the high-level waters far
inland, that of the south branch at Elizabethtown, as already noted,
and that of thé north branch on the Ausable quadrangle 3 miles
north of Towers Forge.
The hill 2 miles south of Willsboro carries elegant inferior bars
on the summit and east face, from 300 feet down. Northwest of
’ East Bouquet mountain clear evidence of standing water was seen
along two roads up to a height of 620 feet. The theoretic height
is about 625 feet. Examination of the area will locate many evi-
dences of summit wave action.
Plattsburg and Dannemora quadrangles. On this area the sum-
mit shore features lie inland, with handsome display. The Platts-
burg sheet shows the low ground built by the Ausable, Little
Ausable, Salmon and Saranac rivers. But the south edge of this
sheet covers the north part of the Trembleau mountain, which
carries on its northwest slope a fine series of gravel bars below
the summit of the marine flood. Woodworth maps these bars in
his plate 21.
The Trembleau gravel bars lie one and one-half miles south-
west of Port Kent, and 2 miles east of Keeseville. An east and
west road crosses the plateau which carries the higher good bars.
The highest bars, at about 590 feet, lie in weak form close to the
steep northwest face of the mountain. This is 70 feet short of
the summit plane, but the steep rock face shows its rinsing. On
the road bars appear at about 575, 560, 545 and 530 feet. The
northwest end of the hill is encircled by a series of bars to. a lower
level. The lowest feature is a cliff toward the railroad and near
the border of the silt plain. Woodworth indicates shore features
on the north and east faces of the mountain.
A mile southeast of Keeseville, on the northwest and north slope
opminty
JsoM SUDIOOT
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PLEISTOCENE MARINE SUBMERGENCE 47
of Prospect hill (Willsboro sheet) good evidences of wave work
appear at 600 feet.
About Keeseville the Ausable river has laid down extensive
gravel plains at 500 feet altitude, with terraces declining to Lake
Champlain. The summit waters extended up the river 10 miles
from Keeseville, to Ausable Forks, and broad plains between there
and Clintonville, at 660 feet by the map, represent the higher delta.
The Dannemora quadrangle carries some of the strongest, hand-
somest and most convincing shore features of the marine-level
waters of the State. As these are mapped in plate 8, detailed
description will be unnecessary. It will be seen on the map that the
bars have been plotted on the highways, but have not been traced
across country, which gives the beaches on the map a broken and
patchy appearance, untrue to fact.
Along the meridian of Harkness, Clark School, Beckwith School,
and West Plattsburg the summit plane rises from about 660 at
Harkness to over 700 feet at the north edge of the map. The
deltas, glacial channels, and summit bars agree closely with this
plane. The only discrepancy noted is the excessive height of some
bars a mile southwest of Clark School which rise to 706 feet by
the map, or nearly 40 feet above the profile (plate 10). The
Harkness embayment was competent to hold broad glacial waters,
but these bars are so closely connected with the marine shore that
they are regarded in the same category as the high Port Henry bars.
Three classes of features are depicted on the map: (1) the ice-
border drainage channels which terminate at or somewhat beneath
the static waters; (2) the cobble and gravel bars of wave con-
struction; (3) delta plains and terraces which occur at varied levels,
from somewhat above the static waters to low levels in the sub-
siding waters (plate 14).
As is usually the case along all shore lines, the heaviest bars
are somewhat below the summit plane, where the waves had suf-
ficient accumulation of coarse material. The vertical series of
heavy bars are found on stony slopes, usually so rough and stony
as to be left uncultivated. Above and below the ground may be
tilled. All the strong, close-set bars, not only on the Dannemora
quadrangle but elsewhere, are on tracts of cobble or coarse gravel,
commonly the deltas of glacial streams. Over ground immersed
in sand the waves produce only smooth or rolling surfaces. On
the areas of rising land, with open sea and free wave action, the
construction of bars required coarse materials, at least for the
basis or framework.
48 NEW YORK STATE MUSEUM
On the north edge of the sheet, 2 miles north of West Platts-
burg, is the termination of an extensive cobble delta tract, built
by glacial drainage along the high ground west of West Chazy
(plate 5). This carries a remarkably fine series of bars, as depicted
on the sheet, ranging from 684 down to 570 feet (plate 15). On
this sheet the relative vertical position of the Covey Hill P. O.
beaches is a smooth, sandy plain 2 miles northeast of West Platts-
burg, with no decided shore forms. It illustrates the fact stated
above, the absence of bars on sand plains. The Saranac sand delta
illustrates the lack of bars on sands.
The Northern Salient. Covey Hill
Plate 5
Physiography. The northern promontory of the Adirondack
highland is shown in plate 5, made up of the Mooers, Churubusco
and Chateaugay sheets, with a strip of the Canadian Chateaugay
sheet. This salient, wholly of Potsdam sandstone, terminates a
mile north of the international boundary in an oval knob, locally
known as Covey. hill. The summit of the hill is given by the map
as 1113 feet. It drops off steeply on the north, falling to 300 feet
in 2 miles. The depression south of the hill, and one-half of a
mile north of the boundary, has an altitude on the long swamp
col of 1000 feet plus, by the map. The steep gorge on the east
of the divide has been known as the “gulf.” In relation to the
glacial history this locality is perhaps the most critical in the State.
The first geologist to recognize the significance of the Covey pass
as related to the glacial waters was Dr G. K. Gilbert, who was the
pioneer in glacial work, especially in New York.
The water parting, it will be noted, is on the west side of the
promontory, which throws the larger territory into eastward drain-
age, the Chazy river. The Chateaugay river gathers the waters
of the west slope. This is partial explanation of the larger volume
of ice-border drainage on the Mooers quadrangle. Along the
boundary a strip 2 miles wide drains into Canada.
As the Labradorian ice front backed away on this salient, the
glacial outwash flowed freely away, east and west, making no
decided channels near the crest of the ridge. On the west all the
waters found their way into Lake Iroquois by the channels depicted
on the Chateaugay sheet. On the east slope the waters came to
rest in the sea-level Champlain estuary.
Mooers quadrangle. The drainage and static water features are
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PLEISTOCENE MARINE SUBMERGENCE 49
shown in a broad way in plate 5. This quadrangle was made the
subject of a special paper by Woodworth (81), and was also cov-
ered in his more comprehensive Bulletin 84 (82). At the time of
Woodworth’s study no territory adjacent to the Mooers quadrangle
had been mapped and definite correlation of features could not be
made. It becomes necessary to republish the sheet in order to
locate the summit shore line of the sea-level waters, to show the
relation of features to adjacent territory, and to reveal graphically
the sequence of events or the later Pleistocene history — the very
latest glacial events of New York State.
Much study has been given to this area, long ago by Woodworth
and later by the writer. Many visits have been made and some
localities have been visited several times. Some of the features
are so peculiar or equivocal or unusual in character that they were
uncertain, and at first were misinterpreted. Some of the heavy
tracts of cobble and boulder delta stuff had been regarded as
moraine. The key to the history has been the determination of
the summit level of the sea-level water, but much time and travel
have been required to verify phenomena at critical points. Even
now there are stretches of the summit shore line, rather inacces-
sible, far from deltas and of weak development, which are inter-
polated on the map. Future study will verify the shore line.
The position of the summit shore is determined by (1) wave-
built bars; (2) higher terraces on deltas; (3) lowest reach of the
ice-border drainage. The last is well displayed. Over large areas
the Potsdam sandstone has been stripped of its drift mantle, and
in the Altona region conspicuous channels have been cut (see
Woodworth’s illustrations). These areas of glacial drainage make
the most conspicuous features of the map.
The sandstone in this region has an eastward dip and formed
a hard floor, declining toward the receding ice front, thus favoring
the stripping. our areas of the “stripped rocks” may be dis-
criminated on the map (plate 5). First, the Altona rocks, south
and southeast of Altona (81, page 18; 82, page 161). This area
is some 5 miles long by 1 or 2 miles wide. The upper margin on
the east slope of Big Hill must lie under 1100 feet, and the lower
limit is at Pine ridge, at the marine plane. Earlier glacial stream
flow is indicated at higher levels south of Big hill. The Altona
rocks are famous for their production of huckleberries (plate 18).
The other bare rock areas are partly on the adjacent Churu-
busco quadrangle. The second is the area southwest of Cannon
Corners, called the Blackman rocks. The third is the Stafford
50 NEW YORK STATE MUSEUM
rocks, west and northwest of Cannon Corners, and traversed by
the road from White School to the Rebideau farms. Fourth, Arm-
strong’s Bush, an indefinite rocky area on the north edge of the
map, which records the latest glacial stream flow in the State.
The heavy delta tracts of coarse materials are the product of the
copious drainage noted. above, of which two are of special note.
The southern and earlier delta tract is the belt of bouldery, cobbly
stuff, complicated with moraine piling, lying west of West Beek-
mantown and West ‘Chazy, the effects of the Altona drainage. The
later large and coarse deposit is on the west edge of the Mooers
sheet at the north, and related to the bare rock areas on the west.
West Chazy district. In this district, the southern part of the
Mooers sheet, is a remarkable display of summit shore features.
The copious drainage from the Altona rocks supplied superabund-
ance of very coarse material for work of the waves, while the ice
built its frontal moraines as a foundation for bar construction.
We have here a complex of features which will be misinterpreted
and wrongly diagnosed by the geologist who has not had experience
with such deposits. Here is the work of powerful torrential waters
mingled with morainal material, and then more or less modified
or reshaped by the wave-work of the highest static waters. The
effects of the three agencies are mingled in varying proportions and
it is often difficult or even impossible to discriminate the wave
work, especially at the topmost line of the standing waters. In
some cases the approximate summit is marked by wave embank-
ments, but commonly the unmistakable bars are inferior to the
summit level.
On the junction of the Mooers and Dannemora sheets the sum-
mit beach lies against a steep slope at slightly over 700 feet. Imme-
diately west of the four corners, at the bottom edge of the Mooers
sheet, is a heavy bar ridge with precise altitude (U. S. G. S.) 684
feet; and just east of the corners is another strong, conspicuous
cobble ridge at 660 feet. The south termination of the delta tract
is seen on the Dannemora sheet, plate 8. Northward on the north-
leading road the delta gravels are shaped into indefinite ridges at
about 700 feet. The photograph is plate 16.
One-half of a mile west by south from West Beekmantown is an
isolated ridge, probably morainal, rising to 700 feet. About the
south end of the ridge are heavy bars of boulder and cobble. On
the east slope at the north end the ground is so rough that no one
would suspect it to have been subjected to centuries of heavy wave
action. It is a good example, that can be indefinitely multiplied, of
the nonvalue of negative shore-line characters.
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PERE aes ae FO ee me
PLEISTOCENE MARINE SUBMERGENCE 51
Toward and at Shelter’s Corners, northwest of West Beekman-
town, the delta stuff is shaped into a fine display of bar ridges.
Northeast of the corners the summit ridge is over 700 feet, and
between that crest and the three corners below 12 to 15 bars may
be counted in the drop to 580 feet. A mile north of Shelter’s
Corners is a long ridge carrying a road, and wave action is shown
to the summit, 700 feet. Behind this ridge, on the west, is a smooth
hollow, over 20 feet deep, which was apparently a channel for the
latest flow when the ice front was building the ridge. Such smooth
channels somewhat beneath the static water level are to be expected
near the summit level where the glacier front was piling coarse
moraine stuff in bold ridges, that the waves could not later
demolish. Where there was little moraine drift, or drift of finer
material, the frontal stream channels might be more or less
obliterated.
One and one-half miles west of West Chazy on the east-facing
slope the cobble bars are well developed. On the highway, the
Basset road, 10 to 12 bars are counted in the fall from 500 to 400
feet. This lower series of bars has about the relative vertical
position of the Franklin Center series in Canada, previously
mentioned.
Cobblestone hill. This hill, described and illustrated by Wood-
worth (81, pages 32-35), is a good example of a moraine ridge
modified in form by wave work. Lying detached, a mile north of
the Basset road, and with conspicuous, bare, cobble bars crossed by
the road, it was the subject of special notice. The top and east
slope were handsomely shaped into bars of well-rounded cobble.
The summit bar was 665 feet altitude, the lower bars ranging down
to 580 feet. The summit was at least 50 feet beneath the highest
stand of the Champlain waters. In recent years a reservoir has
been built on the west of the hill and the summit cobble bar has
been entirely destroyed for concrete material. This removal shows
that the cobbles were only a veneer for a block moraine ridge (see
plate 19). Cobblestone hill is not unique, but an example of
the moraine ridges more or less modified by wave action. The
occurrence of such a large quantity of uniform cobble on the
detached hill is, however, a puzzle, and suggests that there may be
some unknown factor in the history of the ridge.
The character of the Altona channels suggests a larger stream
flow than merely that of the local waters, the Chazy rivers and the
glacial outflow. The eastward position of the Altona highland
seems to make it quite certain that the Altona channels carried the
52 NEW YORK STATE MUSEUM
earlier Iroquois, that through the Covey pass. ‘Woodworth seems
to have recognized this. This implies that the ice front rested
against the Altona-Beekmantown highland after the ice had
deserted the notch south of Covey hill. It also requires a glacial
lake in the embayment west of Altona. There are evidences of
standing water between Altona and Alder Bend, and north of
Ellenburg Depot at 900 to 960 feet. We may refer to this water
as the Ellenburg lake.
The later outflow of Iroquois produced the features in the Can-
non Corners district.
Cannon Corners district. Here we find another remarkable dis-
play of Pleistocene features, fully matching that described in
Altona. It includes vast areas of stripped rock, numerous river
channels, enormous piling of cobble deltas over large tracts, and
splendid development of high-level bars.
The areas of stripped rock have been named above. They are
essentially a single area; that is, they represent the work of the
same drainage, the Iroquois outflow, with falling levels as it washed
the retreating ice front. The rocks are Potsdam sandstone, usually
in irregular terraces, but sometimes steeply dipping. The inclined
beds are well shown at Mitchell Rebideau’s place, 2 miles south-
east of Covey gulf. The stripped rocks may be conveniently seen
by taking either of three roads: the indefinite and branching rock
roads leading west from near the schoolhouse, three-fourths of a
mile south of Cannon Corners; the road going west from Cannon
Corners; and the road at the White School, a mile north of the
Corners, leading to the Rebideau farms. The limits of the bare
rocks are not perfectly defined on the map. The rocks are par-
tially covered with scrub, bushes and huckleberries, and the pre-
cise mapping is not worth present effort. At a rough estimate,
they extend some 6 miles north and south, and perhaps average a
mile and one-half in width, or 9 square miles in area. The surface
in general declines eastward, and the river flow which swept them
clean migrated down the slope, clinging to the ice margin as the
glacier slowly gave way. The lowest points of bare rock, and the
termination of river work, lie along the north and south road from
Cannon Corners to Shea’s Lines. One exp ure of rock is seen on
the highway one-half mile north of the VCorners, and another
three-fourths of a mile south of the international boundary.
As the rivers reached the sea-level waters near the north and
south line of the highway, it is along this road that we find the
—
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PLEISTOCENE MARINE SUBMERGENCE 53
delta tracts of coarse stuff, formerly mistaken for moraine, and
cobble bars in excellent development.
Passing south from Shea’s Lines the road lies on a boulder
moraine, at 760 feet, shown in plate 21. East and west of the low
ridge are shallow scourways, the latest and lowest definite channels
of glacial river flow in New York. The altitude of these channels
is 740 feet. The road crosses the west channel three-fourths of a
mile south of the boundary, and immediately south is seen some of
the coarse delta stuff dropped by this, or the preceding flow, when
checked by confluence with the marine-level waters. The White
School, by the corners leading to Rebideau’s, is in another river
channel (plate 20), which has an altitude on the road of 720 feet,
IO or 15 feet beneath the marine plane. The delta stuff might
be mistaken for moraine. South of the White corners the road rises
slightly on the cobble delta, follows it for one-fourth of a mile and
crosses another bare rock channel at 720 feet.
Strong cobble bars lie east of the road, the highest southeast of
the White School at 735 feet. North of Cannon Corners the road
CrOssesnasenics, Ol Six pans, the Mishest peme 720) feet and wtie
lowest, close to the corners, at 700 feet. This fine series of bars
curves about the slope and parallels the road northward. Cannon
Corners and the road leading west, up English river, are on very
coarse delta. The surface appearance is that of a bouldery
moraine, but the banks of the river cutting show its character as
torrent deposit. South of Cannon Corners one-third of a mile is
another series of cobble bars, in altitude from 720 down to 700
feet, but behind the schoolhouse and at the corners of a west-leading
road is evidence of wave work up to 730 feet. These bars swing
to southward and continue in good shape for over a mile along the
slope of the delta on the east side of the road with an altitude of
720 down to 712 feet. For one and one-half miles southward the
road lies on the delta, which suggests the amount of rock-rubbish
that the glacial drainage swept off from the Blackman rocks.
The sand plain delta of the Chazy river, north branch, heads at
720 feet but declines to 660 feet 3 miles east, as shown by rem-
nants. From this locality the marine shore turns southeastward, as
shown in the map.
The series of lower beaches, the Franklin Center shore line, is
very strongly represented on the north edge of the Mooers sheet,
in 42 bars of coarse material spaced over one and one-fourth miles.
Two miles southeast by English river the level is represented by
numerous weak bars. Southwest of Sciota the shore appears in
54. NEW YORK STATE MUSEUM
good form, and again west of West Chazy. As already stated
(page 19) this level of the lowering waters is not recognized dis-
tinctly south of the Mooers quadrangle.
The Covey channel. The form, dimensions and relations of the
Covey pass are shown on plate 5.
The postglacial drainage history of this critical locality is not
known in all its details. The locality is difficult to reach, far from
highways and farther from any hospitable place of entertainment.
It is a wild and romantic place; forest on the north wall of the
channel, the roughest kind of rocky and swampy ground on the
south side; on the west, at the head of the channel, a wide swamp
and lake; and on the east, downstream, steep or precipitous rock
cliffs and ledges, dropping down to the exceedingly rough lower
ground. Attempts to reach the pass from the south were aban-
doned on account of the difficulty and limitation in time.
The channel proper is a splendid example of an abandoned river
bed, over the hardest of sandstone; but it is unusual in the absence
of any correlating delta. Below the normal channel we expect to
find the deposited detrital burden of the current. Here is nothing
of the sort. The low ground southeast is very rough, with no
deposit of ordinary detritus. The only loose material within the
grasp of the stream was whatever filling of drift the ice sheet had
left in the pass.
It is more than possible that the recent history of the pass has
been duplicated by glaciation earlier than the Wisconsin (Labra-
dorian ice body), and this admission makes it uncertain as to how
much of the form and character of the channel are really due to
Iroquois outflow, and how much to earlier episodes of river work.
It seems probable that the earliest water across the col was
tributary to a glacial lake, which we may call the Ellenburg lake,
having its control on the Altona rocks. As the Ellenburg waters
lowered, the Covey river cascaded over the Potsdam ledges and
removed whatever detritus it had dropped in the preceding flow.
Its latest cascading must have been the most vigorous and erosive.
Another query is whether the rocks on the lower ground are partly
glacial, rinsed off by the flood, or blocks plucked from the channel
by the latest river, or by more ancient rivers.
The ravine or “ gulf” below the upper broad channel, with its
lakelets is evidence of plunging flow to low receiving waters, prob-
ably at the marine level. The ravine is not correctly contoured,
for about midway between the head of the gulf and Covey Hill
post office is an extensive filling, with piled rocks, and broad swamps.
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oYVT JO MOYINO JsojyeT Aq jdams Ajqeqoid (Arepunog [euoneussjUr) OUI] S ways Je oureIOW YOY
IZ 9}€[q
PLEISTOCENE MARINE SUBMERGENCE 55
The upper swamp was estimated as one-fourth of a mile long, with
aneroid altitude 765 feet. The lower filling was made 740 feet,
the marine level. The total length of the swamps and rock piles
was thought to be nearly a mile. This may be regarded as the
delta of the Covey river at the sea level, during its latest flow.
The rock bottom of the river channel is 1010 feet altitude on the
divide. The limit of visible water work on both the north and
south banks is about 1030 feet. The granite boundary monument
on the south side of the ravine has an altitude of 929 feet at the
base and 934 feet for the top. The altitudes given on the Churu-
busco sheet for the boundary monuments are all for “ top of monu-
ment.” On the Chateaugay sheet the altitudes refer to the base of
monuments.
North slope and shore lines of Covey hill. The steep north and
northeast slopes of Covey hill are mostly in forest, with only a few
small clearings. A traverse was made down the north slope, but
the line of strongest pressure and longest hold by the ice front
must have been on the northeast'face. The surface of the north
slope is gradual and fairly smooth, such as would be expected of
a strongly glaciated surface, down to 1010 feet, corrected aneroid.
Below that occur rock ledges, benches and irregular terraces, such
as belong to steep slopes cut by rivers held to their work by the
forceful glacier.
From over 1000 feet down to over 700 feet the slope must have
been eroded by the profuse waters of the Iroquois downdraining.
Below about 720 feet, allowing 20 or 30 feet of cutting below
static water level, the slopes were subjected to wave work of the
sea-level water. Below the marine plane the steeper slopes show
the ledges and rock piles due to wave action, while the moderate
slopes carry embankments of wave construction.
The evidence of wave work at 740 feet is clear at all points
where the plane has been examined. On the highway leading down
the east side of the hill a well-defined cliff occurs at the critical
level, and others at lower levels, especially at about 640 to 625
feet. On the north and south road, 2 miles west of the hilltop,
the level appears in terraces at the angles in the road. Three miles
farther west, by the four road angles, distinct cliffs show on the
south, and delta sands by the Outarde river at 725 to 730 feet. The
shore line can be traced along the road leading southwest; and on
the road leading northwest, 2 miles southwest from Franklin
Center, strong bars cross the road from about 725 down to about
660 feet. At Frontier the shore passes back into New York, where
56 NEW YORK STATE MUSEUM
good bars lie at 700 to 730 feet. These features are indicated on
the map, between which the shore line has been interpolated, being
mostly in forest and not examined. Future study will discover
many good features. It should be emphasized that this shore line
lies with identity of character and altitude on both flanks of the
Covey promontory, in both the Champlain and Ontario basins.
The Franklin Center-Covey Hill post office beaches. This strong
shore line, 215 feet beneath the marine summit, was formerly
regarded as the marine summit (81, 82). It carries a splendid set
of bars at all points about the Covey salient in Canada. Lying low
on the slopes it probably represents an accumulation of coarse
detritus by the rinsing down of 200 feet on the higher slopes, and
perhaps some kame-moraine at this level. Around the north side
of Covey hill the wave work had been mainly erosional from the
summit level down to the Franklin Center level. At this lower
plane the off-shore depth and other relations were such that the
work of the waves became chiefly constructional. The exceptional
development of summit bars in the Cannon Corners district was due,
as already stated, to the abundance of coarse delta stuff from the
inferior downdrainage of Iroquois.
The 215 feet interval between the two strong shore lines so
prominent on the map is rather misleading. Intermediate features
exist, and the scanty representation is due more to lack of observa-
tion than to actual absence of beach phenomena. Attention has
been chiefly directed to the two series of bars.
The unusual development of the Franklin Center bar series
might be regarded as the record of an episode of much slower land
uplift. But as the shore is not clearly recognized southward beyond
the area mapped in plate 5 or southwestward beyond Lawrence-
ville, on the Moira quadrangle, it must be explained as due to
exceptional local conditions. The possibility is recognized, how-
ever, that in the progressive wave uplift of the land this district
might have risen at first with relative rapidity, for the 215 feet,
and then more slowly.
The location and character of this shore is sufficiently shown in
the map. Below the upper bars, 525 feet, the beach phenomena
are abundant at all declining levels where conditions were favor-
able. A fair set of bars lie on the Chateaugay sheet, and a
remarkable series on the north edge of the Mooers sheet. The
shore also appears along English river, and west of West Chazy;
but southward on the Dannemora sheet its place is occupied only
by smooth or rolling tracts of sandy soils, with no bars.
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PLEISTOCENE MARINE SUBMERGENCE 57
Bar Succession
: HORIZON- GREATEST
LOCALITY NUMBER TAL Beer end men en: SINGLE
OF BARS DISTANCE, FEET ia BIE INTERVAL
IN MILES IN FEET
Bars of the marine summit.
Iiversial, Stelmerelle so aie oe. cauoe A 8 4 40 (730-690) 5 | ro (middle)
Aiemstroneseausheni een 6 i 20 (730-710) 4
North of Cannon Corners. . 7 4 20 (725-705) 3 | To (at top)
Cannon Corners School.... 6 i 25 (730-705) 5 | 10 (at bottom)
Shelters Corners.......... I5 3% | 120 (700-580) 8
Beant owitieysare caro oss TSE seal eae ae T15 (684-560) 9
HERG telcltalarecel Wieteys dee hevaueh sict s'adeyisi8ys 9 4 80 (590-510) 9
Bars of the Franklin Center series
neice Centenaanae een n. 18 38 | 112 (525-413) 6
StockwellUPNO wy seek to. 13 a | 135 (510-375) To | 12
Covey Hill P. O. north..... 16 I | 210 (530-320) 13 | 23 (at bottom)
Covey Enlil 2. O., east. 1... 18 ; I | I3I (523-392) WA |) 13) (Bie OD)
DOUbMoOLpotundanyn se se. 42 t+ | 160 (525-365) 4
IBRISSEtr OMG sadn aco coe Boos TP Oaliussattysnaeare IT00 (500-400) 8
i}
Bar succession. The above tabulation clearly proves that
the production of embankments or bars along shore lines is not
wholly a function of duration, or length of time for wave work at
a fixed level, but that it depends on a combination of physical shore
conditions. Chief of these factors is an abundance of coarse
material, as boulders and cobble, which the waves can throw beyond
their future grasp. This is proved by the large development of
bars on cobble deltas and their absence at the same level, in near
localities, on sandy tracts. Other evident conditions must be suffi-
cient breadth and depth of water for efficient waves and shore cur-
rents, and favorable shore topography for piling the detritus.
The succession of bars with close spacing through large vertical
range can not be produced in water of fixed level, in relation to the
land, nor in rising levels. They are the product of slow and steadily
falling levels. Marginal glacial lakes do not have the requisite
conditions. The series of bars shown in the accompanying maps,
for Lake Iroquois and the sea-level waters, can be constructed only
by the slow uplift of the land out of the waters.
St Lawrence Valley
Chateaugay quadrangle. The striking feature of this map (plate
5.) is the Iroquois shore line with its correlating glacial drainage
channels (plate 22). This is well marked by deltas an dweak bars,
but fading northeastward on the Churubusco and Canadian sheets
toward the second outlet at Covey pass. In this district the marine
58 NEW YORK STATE MUSEUM
shore has much stronger development of bars than the Iroquois.
The heavy representation on the map of the lower, Franklin
Center, series is somewhat misleading, as these bars are only gentle
-rolls or swells on the plains away from the stream deltas. Near
North Burke, however, is a kame-moraine which has been shaped
into bold ridges. Two views of the Chateaugay delta in Lake
Iroquois are given in plates 23 and 24.
Malone quadrangle. The shore lines and deltas are well shown
on the map, and do not require much description. The lower
marine deltas lie in position to represent the Franklin Center shore.
Below this broad sand and silt plains extend down the Trout and
Salmon rivers to Canada; but are not colored on the map.
The head of the Salmon river delta in Lake Iroquois is repre-
sented in boulder masses some 7 miles up the river ravine at
Chasm falls. Remnants of the delta are seen south of Malone in
the reservoir and other gravel hills, but the vigorous Post-Iroquois
erosion has swept away most of the Iroquois delta and redeposited
it downstream at the sea level, making the massive sand plain north
of Malone.
On this sheet no attempt has been made to map beaches below
the marine summit. The marine shore lies across the southeast
corner of the Moira quadrangle, which is not included among the
maps of this writing. The most conspicuous feature on the Moira
quadrangle is a strong shore south of Brushton and Moira and
passing through Lawrenceville, in the approximate position of the
Franklin Center shore line. So far as observed, this is the last
clear representation of that lower shore, going to the southwest.
The area south of the Moira and east of the Potsdam quad-
rangles has not been mapped, but the shores lie across the north-
west corner of this unnamed sheet in strong shape. The Iroquois
delta on the Deer river is at Dickinson Center; and on the east
branch St Regis, at Nicholville. Northwest of Dickinson Center
are good summit bars of Iroquois, and one and one-half miles
southeast of Nicholville are strong boulder bars, lying obliquely
across the road with moraine surface behind them. This will
give a good figure for the Jroquois shore when the topographic
survey is made. The marine plane is shown by bars and delta at
Fort Jackson, on the St Regis river, east branch.
Potsdam quadrangle. This quadrangle has been examined with
care, and with the assistance of Prof. George H. Chadwick. Two
large rivers cross the area, the west branch of the St Regis, and
the Raquette, and they have left heavy deltas at the Iroquois and
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PLEISTOCENE MARINE SUBMERGENCE 59
the marine levels. The map (plate 7) shows the standing water
features.
A good development of bars, with clear relation to the drift sur-
faces, gives fairly exact altitudes. One occurrence is a mile
northeast of Parishville, where three elegant bars have altitude,
928, 905 and 885 feet. At Colton and the Clafin School the strong
shore features have not been measured.
The marine shore is well shown by weak bars and points of
deltas northeast of Southville, at 600 to 615 feet, and west of
Hannawha Falls by cliff and bar.
The Franklin Center stage is only suggested; but detached
beaches are found at many levels inferior to the summit.
The delta at Allens Falls, on the St Regis, appears to have been
built during the downdraining of Lake Iroquois.
Canton quadrangle. The details on the sheet have been studied,
mainly by Professor Chadwick, and as he has projected a paper on
the Pleistocene geology, the map is not included here. Now it will
be sufficient to say that the Iroquois shore merely touches the south-
east corner of the sheet; that the marine shore crosses south of
Crarys Mills and Langdon Corners, with construction of weak
bars on the northwest face of Waterman hill, and a heavy delta on
the Grass river at Pyrites.
Russell quadrangle. On this area the Iroquois waters reached
far up the Grass River valley, among the Adirondack hills. The
plains at Burns Flat and northward, on the east side of the quad-
rangle, probably represent the delta of the Grass.
Wave erosion of Iroquois is well shown on the hills about West
Pierrepont, and on the hill at Stone School, a mile southwest. Cliffs
and bars appear on the northwest and the south faces of Kimball
hill, north of Russell. An excellent development of beaches is
found on the Hatch (Hamilton) hill, over a mile southwest of
Russell. These have been measured with sufficient precision. The
summit bar of Iroquois is here 850 feet, and bars range down to
815 feet. The vertical range of 35 feet appears to represent the
amount of land uplift at this locality during the life of Iroquois.
The Oswegatchie river crosses the southwest corner of this
quadrangle, and its delta is about South Edwards and Pond Settle-
ment. The theoretic altitude here is 780 feet for the closing level,
and the features range from 826 down to 780 feet, a vertical range
of 46 feet.
The marine shore lies on the northwest corner of the area, north
60° NEW YORK STATE MUSEUM
and south of the village of Hermon, which is built on a terrace of
the Elm creek delta. The summit shore line passes through the
east edge of the village, with altitude 520 to 525, the theoretic figure.
The extended plain lying for miles along the upper valley of Elm
creek, from Fairbanks Corners to Scotland School, appears to be
due to waters held in by rock control south of Marshville. The
marine delta of the Grass river is at Pyrites, on the Canton quad-
rangle.
Gouverneur quadrangle. The Iroquois level appears in the south-
east part of the area, in the higher sand plains about Fullerville
Ironworks, at about 780 feet. These plains are the north part of
the delta of the west branch of the Oswegatchie river, which
extends 7 miles south to Harrisville, on the Lake Bonaparte quad-
rangle. The narrow waters entangled among the hills could not
be expected to produce distinct shore features.
The lower plains north of Fullerville, 700 feet, and those at
Edwards, 660, seem to have been due to pondings of the Oswe-
gatchie while it was cutting the rock gorges at Hyatt and Emery-
ville.
The marine shore lies diagonally across the area from the north-
east to the southeast corner, with altitudes of 525 down to 480
feet. The Oswegatchie delta begins at Hailesboro, 2 miles south-
east of Gouverneur, and the lower levels are the extensive plains
at and above Gouverneur. The delta plains are fine material, as
the coarse detritus had been dropped above the rock barrier.
The Gouverneur sheet shows strikingly the singular topographic
character of that region, a complex of smoothed rock knobs and
ridges, with intervening smooth silt plains. The latter are the
product of the sea-level waters which rinsed the drift off of the
knolls and hills and spread it out evenly in the hollows. The clean-
cut horizontal line of contact between the silt plains and the steep
rock slopes is characteristic of the submarine silt plains in New
York and Vermont. The traveler on the Rome, Watertown and
Ogdensburg branch of the New York Central Railroad may see
this feature all the way from Canton south to Keenes. Southward
through Antwerp the road lies above the marine plane.
Five miles northeast of Gouverneur and 2 miles south of Rich-
ville, by the Cole School, is a good display of summit marine cobble
bars on some drift knolls. The bars are from 516 feet down.
Evidences of wave work on the slopes is common in this district.
Lake Bonaparte quadrangle. The Iroquois waters passed up the
Oswegatchie valley as a deep embayment to Harrisville, where the
PLEISTOCENE MARINE SUBMERGENCE 61
delta seems to head. The waters lay here and among the detached
hills at an altitude of 745 feet for the closing phase, but the plains
recording the earlier and uplifted levels are about 770 feet. No
study has been made of this area.
The marine waters did not reach this quadrangle.
Antwerp quadrangle. On the southern part of this area lies the
greater mass of the huge delta of the Black river built in Lake
Iroquois. The head of the delta lies south, up stream, on the
Carthage quadrangle. The theoretic altitude for closing Iroquois
in the district of the Great Bend is 700 feet, and the broader plains
are-contoured at 700. The higher plains, about Carthage are up
to 740 feet. The history of the waters in this region is told in
publications 162 and 163.
The marine waters did not reach this area; but had irregular
extension among the hills northward, on the Hammond quadrangle.
The accompanying map, plate 4, gives the approximate location
of the shore lines on the quadrangles which are not reproduced for
this writing.
Ontario Basin
Lake Iroquois. West of the St Lawrence area, above described,
the beaches of Lake Iroquois and of thé sea-level waters have
been described and mapped in former publications. The beaches
of Iroquois were the first of the ancient shore lines to be dis-
tinctly recognized as such, and are too well known in the Ontario
basin to require extended notice here. The more important papers
have been listed in the bibliography. The more recent maps are
in the following papers:
In 154 of the appended list, plate 19 is a map of the lake south
and west from Watertown; with description of the strong shore
from Watertown to Richland, pages 104-12, and tabulated details
in plates 9 and Io.
In 152, a good map by Coleman, with description of the Canadian
shore.
In 163, a part of the Black river delta is shown in plate 44, and
described in pages 136-72.
In 164, plate 17 shows the early stage when the lake had reached
its full westward extent, as a narrow stretch of water along the
south front of the Ontario glacier lobe. Plate 4 in this paper is a
detailed map of the shore line in the Watertown region, from
Carthage to Adams, with the channels of tributary glacial drainage.
Accompanying this paper, plate 1 shows Lake Iroquois at its
greatest expansion, just previous to its extinction; plate 4 shows
62 NEW YORK STATE MUSEUM
the approximate location of the shore north of Richland; and plates
5, 6 and 7 depict the northern shore in New York in detail. For
future mapping there remains only three unpublished sheets, in
part; and the short stretch from Rome to Richland.
A very brief outline of Lake Iroquois history may appropriately
close the description. The lake originated at the margin of the
waning Ontarian lobe of the latest ice sheet when the ice uncovered
the southeast part of the Ontario basin, the low ground at Rome
and Oneida lake. An early stage, when it reached westward only
to about Lyons, is mapped in plate 41, paper 160. As the ice lobe
gave way the lake extended itself westward until it was a narrow
belt of water, laving the south front of the glacier, the whole east
and west extent of the Ontario basin, as mapped in plate 42, of
160; and plate 17, of 164.
As the Ontarian ice lobe diminished the lake increased, and
inserted a tongue of its water northeastward, between the ice
margin and the foothills of the Adirondacks. The greatest extent
and area of the lake was attained while the lake had its second
outlet at Covey pass, above described and mapped in plate 1.
The lake came to its extinction when the ice barrier on the north
slope of Covey hill weakened, and melted back to a height beneath
1030 feet, or the height of the Covey river. Then the waters were
permitted to drain down to sea level, and to become part of the
Hudson-Champlain estuary, shown in plate 2.
Gilbert gulf. That the low altitude of the northern land at the
time of disappearance of the latest ice sheet must have allowed
oceanic waters to occupy the St Lawrence and Ontario valleys has
been recognized many years. As long ago as 1808 F. B. Taylor
mapped the Champlain sea as extending into the Ontario valley
(130 pasew/3))
Dr G. K. Gilbert was the first geologist to recognize the beaches
produced by this extension of sea-level waters (11, page 59), and
called them the Oswego shore line, although they do not quite
reach to Oswego.
In 1905 the writer briefly described the beaches in the southerly
stretch between Oswego and Clayton, and added sketch maps of
most of the distance (157, pages 712-18; figures 1-3); and took
the liberty of naming these marine-level waters after Doctor Gil-
bert, in admiring recognition of his leadership in the study of the
New York Pleistocene.
In 1910 the writer extended the mapping of the Gilbert gulf
Plate 25
Cobble bar on the shore of Lake Iroquois. One-fourth mile north of Farr’s
and 3 miles east of Watertown. Upper view looking northeast; lower
view looking southwest.
PLEISTOCENE MARINE SUBMERGENCE 63
shore as far northward as Alexandria Bay and Redwood, in a
partial way, as the beaches are detached and mostly weak (163,
plates 44-47; pages 136-72). The most important series of bars
is ON a moraine tract 2 miles north of Lafargeville, with summit
altitude about 440 feet. In this district of horizontal rocks, low
relief and clay plains; or farther north, with glaciated granitic
knobs and silted hollows, the waves found little material and poor
conditions for leaving their inscriptions.
SUMMARY
It seems possible that the Pleistocene history of New York
State includes more than one ice invasion, or glacial epoch; but
this writing deals with only the records of the latest ice sheet, and
specifically with the waters that occupied the low valleys as the
ice body melted.
When the Labradorian ice cap was disappearing, the land which
had been beneath the ice sheet was much lower than at present.
The amount of the depression seems to bear quite direct proportion
to the thickness and weight of the ice burden. The measure of
that depression is found in the Hudson-Champlain valley, and
about New York City and over Long Island, in the shore phenomena
left by the sea-level waters that took possession as the ice vacated.
The amount of the land uplift is shown in the maps, and for the
Hudson-Champlain valley in the diagram, plate Io.
In the St Lawrence-Ontario valley the amount of postglacial
rise of the land is found by the amount of deformation, or north-
ward up-tilting of glacial lake shore lines, which must have origi-
nally been horizontal. The shore line of Lake Iroquois has been
deformed 668 feet, and bodily lifted 72 feet more, which gives a
total rise at Covey hill of 740 feet, the same as the altitude of the
marine beaches at that point. The diagram (plate 11) shows the
tilt of the St Lawrence beaches.
The records of the sea-level waters in the Hudson-Champlain
valley cover all of the long time involved in the wamng and dis-
appearance of the ice sheet, from the moment of its greatest extent
to the time when it passed entirely off the State. But the glacial
records in the St Lawrence valley cover only the latter part of
glacial time. For this writing the history of the St Lawrence
valley is only that of Iroquois and Post-Iroquois time.
The history, in brief, is as follows. The sea-level waters con-
tinuously laved the receding front of the glacier as it retreated up
the Hudson and Champlain depression. Large glacial boulders in
64 NEW YORK STATE MUSEUM
the clays are proof of this. When the margin of the ice sheet
receded, on the high ground north of the Adirondacks, to the inter-
national boundary, it uncovered a low notch, the Covey pass, which
permitted the outflow of the glacial waters of the Ontario-St
Lawrence basin, Lake Iroquois; and from this time the St Law-
rence waters were tributary to the Champlain valley, instead of,
as formerly, to the Mohawk-Hudson. At that time the Covey out-
let was 740 feet lower than today, and only 290 feet above the sea.
With further recession of the ice barrier on the north slope of
Covey hill, Lake Iroquois was drained down to sea level. The
Hudson-Champlain estuary then passed westward around the
Covey salient and occupied the St Lawrence basin. The altitude
relations of Lake Iroquois and the sea-level waters are tabulated:
in plate 12.
The postglacial rise of the land was by a wave uplift, progress-
ive from south to north, following the removal of the ice burden.
The rise was laggard or dilatory, and it appears that no appreciable
rise occurred at any point in the Hudson valley while the ice lay
on that point. But it seems more than possible that the uplift wave
overtook the receding ice front in the Champlain valley; and that
a relatively small rise took place at Covey hill while the ice held
Lake Iroquois to the Covey outlet. This would account for some
shore features in the districts of ‘Crown Point, Port Henry and
Peru somewhat above the profile shown in plate 10. In such case
the bars at Covey hill, 740 feet, do not give the full amount of
glacial depression and postglacial uplift. The maps and profiles
do show the positive minimum of recent diastrophism.
It is recognized that there may be complications in the Pleistocene
history, and that the present altitude of the upraised water plane
is only the final or average result of any up and down land move-
ments, and any variations of the sea level; the arithmetical sum of
all the plus and minus elements. But it appears that such com-
plicating factors would probably increase the record of land depres-
sion and subsequent rise, instead of reducing it. To the degree
that the ocean level was lowered by removal of water to build the
ice caps, the ancient water plane was so much beneath present
ocean level. The present height of the summit plane above the sea
must be only the excess of land uplift over any rise of the ocean
surface.
The gravitational pull on the sea level by the ice body at the
attenuated margin of the valley lobe is thought to have been a
negligible factor in the New York district; and probably so at all
PLEISTOCENE MARINE SUBMERGENCE 65
other localities when the receding and relatively thin ice margin
was passing off.
The evidences of marine submergence of Long Island and the
Hudson-Champlain valley are briefly stated. The lack of marine
fossils in the Hudson valley, and of wave-built embankments on
the sand plains, are explained. A running description is given of
the summit shore phenomena from New York City northward; at
and around Covey hill, and through the St Lawrence valley.
The summit shore features on the Vermont side of the great
estuary has been recently published (92).
SIN @ GiRsa wee
' The Pleistocene depression of the land and the postglacial uplift
involves wide territory of northeastern America, and a full list of
writings would approximate a complete bibliography of the
Pleistocene geology. The following list is restricted to writings
which contain some reference to the static water phenomena, or
have some bearing more or less direct on Pleistocene land
deformation.
- The literature of the Ontario basin can not be entirely separated
from that of the Great Lakes area. A list of papers relating to the
glacial waters of the upper Great Lakes, up to the year 1907, is
given by Goldthwait in no. 23. In no. 82 Woodworth gives an
extended list of the older literature, to 1905, with special reference
to eastern and northern New York.
Eastern Canada is in its geography and glacial history so closely
connected with the Champlain-St Lawrence basin that some papers
describing Canadian territory are included.
Many papers relating to New England geology have direct bear-
ing on the diastrophic problem, but only a few papers concerning
the Connecticut valley are here included.
For convenient reference the titles are arranged in six groups,
with a few cross references. Within each group the order is
chronologic by authors.
A General; theoretic; land deformation
B Lower Hudson district
C Long Island |
D_ Connecticut valley
FE Upper Hudson, Champlain and eastern Canada
F Upper St Lawrence, Ottawa valley and Ontario basin
66 NEW YORK STATE MUSEUM
A General; Theoretic; Land Deformation
1 H. D. Rogers. On the Origin of the Drift, and of the Lake and River
Terraces etc. Proceedings of the American Association for the
Advancement of Science, 1849, 2:230-55
2 E. Desor. [Evidences of Marine Deposits in Eastern America.] Pre-
sented to the Boston Society of Natural History. Proceedings,
v. 3, 4, 1848-52
3 Warren Upham. A Review of the Quaternary Era with Special
‘Reference to the Deposits of Flooded Rivers. American Journal
of Science, 18901, 41:33-49
4 Glacial Lakes in Canada. Bulletin of the Geological Society
of America, 1891, 2:243-76
5 Relationship of the Glacial Lakes Warren, Algonquin, Iro-
quois, and Hudson-Champlain. Bulletin of the Geological Society
of America, 1892, 3:484-88
6 The Champlain Submergence. Bulletin of the Geological
Society of America, 1892, 3:508-11
D, Deltas of the Hudson and Mohawk Valleys. American Geolo-
gist, 1892, 9:410-11
8 Wavelike Progress of an Epeirogenic Uplift. Journal of
Geology, 1894, 2:383-95
9 Late Glacial or Champlain Subsidence and Reelevation of the
Saint Lawrence Basin. American Journal of Science, 1895, 49:1-18
ie) The Glacial Lake Agassiz. United States Geological Survey,
Monograph 25, 1895, p. 255-64
11 G. K. Gilbert. (No title.) United States Geological Survey, 18th
Annual Report, 1807, p. 58-590
Recent Earth Movements in the Great Lakes Region. United
States Geological Survey, 18th Annual Report, 1898, pt 2, p. 595-
647
13 Gerard de Geer. Isobases of the Postglacial Elevation. American
Geologist, 1892, 9:247-49
On Pleistocene Changes of Level in Eastern North America.
American Geologist, 1893, 11:22-44; Proceedings of the Boston
Society of Natural History, 1892, 25:454-77
15 Frank Taylor. The Limit of Postglacial Submergence in the High-
lands East of Georgian Bay. American Geologist, 1894, 14:273-89
12
14
16 Niagara and the Great Lakes. American Journal of Science,
1895, 49:249-70
7 The Second Lake Algonquin. American Geologist, 1895,
15 :100-20, 162-79
18 The Champlain Submergence and Uplift, etcetera. British
Association for the Advancement of Science, Report for 1897, 1808,
p. 652-53
19 Robert Bell. Proofs of the Rising of the Land Around Hudson Bay.
American Journal of Science, 1806, 1:219-28
Evidences of Northeasterly Differential Rising of the Land
Along Bell River (\Canada). Bulletin of the Geological Society of
America, 1897, 8:241-50
20
PLEISTOCENE MARINE SUBMERGENCE 67
Rising of Land Around Hudson Bay. Smithsonian Institution
Annual Report for 1898, p. 359-67
22 J. W. Goldthwait. Correlation of the Raised Beaches on the West
Side of Lake Michigan. Journal of Geology, 1906, 14:411-24
21
23 The Abandoned Shore Lines of Eastern Wisconsin. Wis-
consin Geological and Natural History Survey, Bulletin 17, 1907
24 A Reconstruction of Water Planes of the Extinct Glacial
Lakes in the Lake Michigan Basin. Journal of Geology, 1908,
16:459-76
25 Isobases of the Algonquin and Iroquois Beaches, etcetera.
Bulletin of the Geological Society of America, 1910, 21:227-48
26 H. L. Fairchild. Pleistocene Geology of New York State. Bulletin
of the Geological Society of America, 1913, 24:133-62; Science, 1913,
37 :237-49, 290-99
27 Pleistocene Uplift of New York and Adjacent Territory.
Bulletin of the Geological Society of America, 1916, 27:235-62
27a Pesiglacial Uplift of Northeastern America. Bulletin of the
Geological Society of America, 1918, 29 :187-238
See also numbers 92, 108-14, I3i1, 138-41, 144, 152-53, 166-67
B Lower Hudson District
28 W. W. Mather. Geology of New York. Survey of the First Geolog-
ical District, 1843, p. 148-58
29 J. S. Newberry. The Geological History of New York Island and
Harbor. Popular Science Monthly, 1878, 13:641-60
30 F. J. H. Merrill. Quarternary Geology of the Hudson River. toth
Annual Report of the New York State Geologist, 1890, p. 103-9
31 Some Ancient Shore Lines and Their History. ‘Transactions
of the New York Academy of Sciences, 1890, 9:78-83
32 On the Postglacial History of the Hudson River Valley.
American Journal of Science, 1891, 4:460-66
33 Heinrich Ries. Quaternary Deposits of the Hudson River Valley,
etcetera. 10th Annual Report of the New York State Geologist,
1890, p. II0-55 5
34 Notes on the Clays of New York State, etc. Transactions of
the New York Academy of Sciences, 1892, 12:44-46
35 Quaternary Clays . . . and the Estuary Clays of the Hud-
son and Champlain Valleys. Transactions of the New York Acad-
emy of Sciences, 1894, 13:165
36 Clays of New York. New York State Museum Bulletin 35,
1900, 7:576-94
37 W.M. Davis. The Catskill Delta in the Postglacial Hudson Estuary.
Proceedings of the Boston Society of Natural History, 1892,
25 :318-35
38 N. H. Darton. Pleistocene Geology of Albany County. 13th Annual
‘Report of the New York State Geologist for 1893, p. 259-61
Pleistocene Geology of Ulster County. 13th Annual Report
of the New York State Geologist for 1893, p. 368-72
40 C. C. Jones. A Geologic and Economic Survey of the Clay Deposits
of the Lower Hudson River Valley. Transactions Mining Engi-
neers, 1890, 29:40-83
39
68 NEW YORK STATE MUSEUM
41 R. D. Salisbury. - Glacial Geology of New Jersey. Geological Survey
of New Jersey, 1902, 5:196-203
42 Postglacial Submergence. United States Geoloeiee Suir veue
New York City Folio, no. 83, 1902, p. 16
43 Submergence of the Lower Part of the Newark Plain Since
the Last Glacial Stage. United States Geological Survey, Passaic
Folio, no. 157, 1908, p. 20
See also numbers 80, 82, 92
C Long Island
44 W. C. Watson. The Plains of Long Island. Transactions of the
New York State Agricultural Society, 1859, 19:485-505
45 E. Lewis. Evidence of Coast Depression Along the Shores of Long
Island. American Naturalist, 1860, 2:334-36
46 On the Water Courses upon Long Island. American Journal
of Science, 1877, 13:142-46 .
47 — Certain Features of the Valleys or Water Courses of Southern
Long Island. American Journal of Science, 1877, 13 :215-16
48 — Ups and Downs of the Long Island Coast. Popular Science
Monthly, 1877, 10:434-46
49 Warren Upham. The Terminal Moraine of ihe North American Ice
Sheet. American Journal of Science, 1879, 18:197-209 _
50 F. J. H. Merrill. Geology of Long Island. Annals, New York Acad-
emy of Sciences, 1886, 3:241-64
51 J. B. Woodworth. Pleistocene Geology of Portions of Nassau County
and Borough of Queens. New York State Museum Bulletin 48,
IQCI, p. 657-63
52 A. C. Veatch & others. Underground Water Resources of Long
Island, New York. United States Geological Survey, Professional
Paper no. 44, 1906, p. 33-50
53 W. O. Crosby. Outline of the Geology of Long Island, N. Y. Annals
of the New York Academy of Sciences, 1908, 18:425-29
54 M. L Fuller. Geology of Long Island. United States Geological
Survey, Professional Paper no. 82, 1914, p. 212-19
55 H. L. Fairchild. Postglacial Marine Submergence of Long Island.
Bulletin of the Geological Society of America, 1917, 20:279-308
D Connecticut Valley
56 James D. Dana. On the Quaternary or Post-Tertiary of the New
Haven Region. American Journal of Science, gat series, 187%, I:I-5,
125-26
57 On the Glacial ce Champlain Brae in New England. Autor
ican Journal of Science, 1873, 5:198-2I11, 217-18, 219
58 On the Submergence During the Gee! Peron. American
Journal of Science, 1875, 9:315-16
50 On Southern New England During the Melting of the Great
Glacier. American Journal of Science, 1875, 10:168-83, 280-82, 353-57,
409-38, 497-508; ee IT :151; e187, 12:125+28>
PLEISTOCENE MARINE SUBMERGENCE 69
160 The Flood of the Connecticut River Valley from the Melting
of the Quaternary Glacier. American Journal of Science, 23:87-97,
: 179-202, 360-73; 1882, 24 :98-104 :
- 61 On the Western Discharge of the Flooded Connecticut,
etcetera. American Journal of Science, 1883, 25:440-48 .
62 Phenomena of the Glacial and Champlain Periods about the
Mouth of the Connecticut Valley, etcetera. American Journal of
Science, 26:341-61; 1883, 27:113-30
63 Manual of Geology, 4th edition, 1895, p. 981-93
‘64 Warren Upham. Northern Part of the Connecticut Valley in the
Champlain and Terrace Periods. American: Journal of Science,
series 3, 1877, 14:459-70
Changes in the Relative Heights of Land and Sea During the
Glacial and Champlain Periods. Geology of New Hampshire, 1878,
Vv. 3, Pt 3, D. 329°33
66 B. K. Emerson. Geology of Old Hampshire County, Massachusetts.
U. S. Geological Survey, monograph 29, 1808
67 Holyoke Folio, U. S. Geological Survey, Folio no. 50, 1898
68 C. H. Hitchcock. The Glacial Flood in the Connecticut River Valley.
Proceedings of the American Association for the Advancement of
Science, 1883, 31:325-29
69 H. L. Fairchild. Pleistocence Marine Submergence of the Connecticut
and Hudson Valleys. Bulletin of the Geological Society of America,
IOI4, 25:219-42
E Upper Hudson, Champlain and eastern Canada
70 Ebenezer Emmons. Geology of New York. Survey of the Second
Geological District, 1842, p. 422-27
71 C. H. Hitchcock. Geology of Vermont, 1861, 1:93-I101
72 The Champlain Deposits of Northern Vermont. Report of the
State Geologist of Vermont for 1905-6, p. 236-53
73 J. W. Dawson. The Canadian Ice Age, 1893
74 Heinrich Ries. A Pleistocene Lake-bed at Elizabethtown, Essex
County, New York. Transactions of the New York Academy of
Sciences, 1893, 13:107-9
75 S. P. Baldwin. Pleistocence History of the Champlain Valley. Amer-
ican Geologist, 1894, 13:170-84
76 G. F. Wright. Glacial Phenomena Between Lake Champlain, Lake
George, and Hudson River. Science, 1895, 2:673-78
Glacial Observations in the Champlain-Saint Lawrence Valley.
American Geologist, 1898, 22:333-34
78 F. B. Taylor. Lake Adirondack. American Geologist, 1897, 19:392-96
79 R. Chalmers. Pleistocene Marine Shore Lines on the South Side of
the Saint Lawrence Valley. American Journal of Science, 1896,
1:307-8
80 C. E. Peet. Glacial and Postglacial History of the Hudson and
Champlain Valleys. Journal of Geology, 1904, 12:415-60, 617-60
81 J. B. Woodworth. Pleistocene Geology of the Mooers Quadrangle.
New York State Museum Bulletin 83, 1905
77
70 NEW YORK STATE MUSEUM
Ancient Water Levels of the Champlain and Hudson Valleys.
New York State Museum Bulletin 84, 1905
83 J. W. Goldthwait. Twenty-foot Terrace and Sea Cliff of the Lower
Saint Lawrence. Bulletin of the Geological Society of America,
LOMMpe2 ees
84 R. A. Daly. The Geology of the Northeast Coast of Labrador. Bul-
letin of the Museum of Comparative Zoology, 1902, 38:205-70
85 I. H. Ogilvie. Glacial Phenomena in the Adirondacks and Cham-
plain Valley. Journal of Geology, 1902, 10:397-412
86 H. E. Merwin. Some Late Wisconsin and Post-Wisconsin Shore
Lines of Northwestern Vermont. Report of State Geologist of
Vermont, 1907-1908, p. 113-38
87 J. H. Stoller. Glacial Geology of ‘the Schenectady Quadrangle, New
York State Museum Bulletin 154, 1011
88 G. H. Perkins. Geological History of Lake Champlain. Report of
the State Geologist of Vermont for 1911-1912, p. 38-53, I913
89 H. L. Fairchild. Report of Field-work (no title). In Report of
Director of the Science Division, New York State Museum Bul-
letin 158, 1912, p. 32-35
82 —
90 The same, Bulletin 164, 1913, p. 21-25
QI The same, Bulletin 173, 1914, p. 67-69
92 — Postglacial Marine Waters in Vermont. Report of the Ver-
mont State Geologist for 1915-16, p. I-42
93 ——— Postglacial Features of the Upper Hudson Valley. New York
State Museum Bulletin 195, 1917
o4 E. E. Barker. Ancient Water Levels of the Crown Point Embay-
ment. 12th Report of the Director of the Science Division, New
York State Museum Bulletin 187, 1916, p. 165-90
95 H. L. Alling. Glacial Lakes and Other Glacial Features of the Cen-
tral Adirondacks. Bulletin of the Geological Society of America,
19160, 27:645-72
See also number 142
F Upper St Lawrence, Ottawa Valley and Ontario Basin
96 Amos Eaton. Geological and Agricultural Survey of the District
Adjoining the Erie Canal, 1824, p. 105-6
97 Thomas Roy. In Proceedings of the Geological Society of London,
1837, 2:537-38
98 James Hall. Lake Ridge. In Report of Governor Marcy, 1838,
Pp. 310-14, 348-50 ©
99 ——— Physical: Geography of Western New York. In Report of
Governor Seward, 1840, p. 431-44
100 ——— Geology of New York. Survey of the Fourth Geological Dis-
trict, 1843, p. 348-54
101 G. E. Hayes. Remarks on the Geology and Topography of Western
New York. American Journal of Science, 1830, 35 :86—105
102 James Lyell. Travels in North America, 1845, v. 2, ch. 20, p. 71-95
103 E. Desor. On the Ridge Road front Rochester to Lewiston, etcetera.
Proceedings of the Boston Society of Natural History, 1851,
3:358-50
PLEISTOCENE MARINE SUBMERGENCE 71
104 E. J. Chapman. Notes on the Drift Deposits of Western Canada,
etcetera. Canadian Journal, 1861, 6:221-29
105 Sandford Fleming. Notes on the Davenport Gravel. Canadian Jour-
nal, 1861, 6:247-53
106 W. E. Logan. Geological Survey of Canada, Report for 1863, p. 910-15
107 G. J. Hinde. The Glacial and Interglacial Strata of Scarboro Heights
and Other Localities near Toronto, Ontario. Canadian Journal,
1878, 15:388-413
1o8 G. K. Gilbert. Old Shore Line of Lake Ontario. Science, 1885, 6:222
—(see number II)
109 The Place of Niagara alts in Geologic History. Proceedings
American Association for the Advancement of Science, 1887, 35 :222-
23; American Journal of Science, 1886, 32:322-23
IIO Old Shore Lines in Ontario Basin. Proceedings of the Cana-
dian Institute, 3rd series, 1888, 6:2-4
III Changes of Level in the Great Lakes. Forum, 1888, 5:417-28
112 History of Niagara River. 6th Annual Report, Commissioners
of State Reservation at Niagara, 1880, p. 61-84; Smithsonian Insti-
tution Annual Report, 1890
113 (Iroquois shore line discussion.) Bulletin of the Geological
Society of America, 1892, 3492-93
114 Niagara Falls and Their History. National Geographic Mono-
graph 1, no. 7, 18905, p. 203-6
115 J. W. Spencer. Terraces and Beaches about Lake Ontario. Trans-
actions of the American Association for the Advancement of
Science, 1883, 31:359-63
116 Notes on the Origin and History of the Great Lakes of North
America. Proceedings of the American Association for the
Advancement of Science, 1888, 37:197-09; American Geologist, 1888,
2:340-48
Tey, The Iroquois Beach; a Chapter in the Geological History of
‘Lake Ontario. Transactions of the Royal Society of Canada, 1880,
v. 7, sec. 4, p. 121-34; Review in American Geologist, 1890, 6:311-12
118 On the Focus of Regional Postglacial Uplift. Transactions of
the Royal Society of Canada, 1880, 7:129
ime) The Deformation of eee Beach and Birth of Lake
Ontario. American Journal of Science, 1890, 40:443-51
120 The Northeastern Extension of the Iroquois Beach in New
York. American Geologist, 1890, 6:294-95
121 High Level Shores in the Region of the Great Lakes and
Their Deformation. American Journal of Science, 1891, 41:20I-I1
122 Prof. W. M. Davis on the baguitions Beach. American Geolo-
gist, 1891, 7:68-69; 2606-67
123 Post-Pleistocene Subsidence Versus Glacial Dams. Bulletin
of the Geological Society of America, 1891, 2:465-76
124 Channels over Divides not Evidence per se of Glacial Lakes.
Bulletin of the Geological Society of America, 1892, 3:491-93, 404
125 The Iroquois Shore North of the Adirondacks. Bulletin of
the Geological Society of America, 1892, 3:488-91
126 A Review of the History of the Great Lakes. American
Geologist, 1894, 14:289-301
72 NEW. YORK STATE MUSEUM
127 The Geological Survey of the Great Lakes. Proceedings of
the American Association for the Advancement of Science, 1895,
43 :237-43 | if
128 How the Great Lakes Were Built. Popular Science Monthly,
1896, 49:157-72
129 An Account of the Researches Relating to the Great, Lakes.
American Geologist, 1898, 21:110-23
130 The Falls of Niagara, etcetera. Geological Survey of Canada,
1907
131 Postglacial Earth-movements about Lake Ontario and the
Saint Lawrence River. Bulletin of the Geological Society of
America, 1913, 24:217-28
132 W. M. Davis.. The Iroquois Beach. American Geologist, 1890, 6:400
133 Was Lake Iroquois an Arm of the Sea? American Geologist,
1891, 7:139-40
134 F. B. Taylor. Notes on the Quaternary Geology of the Mattawa and
Ottawa Vialleys. American Geologist, 1896, 18:108-20
Origin of the Gorge of the Whirlpool Rapids at Niagara.
135
Bulletin of the Geological ‘Society of America, 1808, 9:59-84
136 A Short History of the Great Lakes. Studies in Indiana
geography, 1907, p. 90-III
137 A Review of the Great Lakes History, etcetera. Science, 1908,
27 :725-26
138 Isobases of the Algonquin and Iroquois Beaches and Their
Significance. Science, 1910, 32:187
139 The Glacial and Postglacial Lakes in the Great Lakes Region.
Smithsonian Institution, Annual Report for 1912, p. 201-327
140 Later Glacial Lakes. United States Geological Survey,
Niagara Folio, no. 190, 19173, p. 18-24
141 (With Frank Leverett). The Pleistocene of Indiana and
Michigan and the History of the Great Lakes. United States
Geological Survey, Monograph 53, 1915
142 A. P. Low. Notes on the Glacial Geology of Western Labrador and
Northern Quebec. Bulletin of the Geological Society of America,
1892, 4:419-21
143 R. W. Ells. Sands and Clays of the Ottawa Basin. Bulletin of ithe
Geological Society of America, 1808, 9:211-22
144 Frank Leverett. Glacial Formations and Drainage Features of the
Erie and Ohio Basins. United States Geological Survey, Mono-
graph 41, 1902
(See number 141) :
145 Robert Chalmers. Ancient Shore Lines of the Great Lakes. Geolog-
ical Survey of Canada, Annual Report, v. 15, 1902-3, p. 274-76 A.
The Geomorphic Origin and Development of the Raised Shore
Lines of the Saint Lawrence Valley and the Great Lakes. Amer-
ican Journal of Science, 1904, 18:175-79
147 A. P. Brigham. Topography and Glacial Deposits of the Mohawk
Valley. Bulletin of the Geological Society of America, 1808,
9:183-210
148 A. P. Coleman. Lake Iroquois and Its Predecessor at Toronto. Bul-
letin of the Geological Society of America, 1890, 10:165-76
146
PLEISTOCENE MARINE SUBMERGENCE WS
149 The Iroquois Beach. Transactions of the Canadian Institute,
1899, 6:20-44 ,
150 Marine and Fresh Water Beaches of Ontario. Bulletin of the
Geological Society of America, 1901, 12:129-46
I51 Sea Beaches of Eastern Ontario. Bureau of Mines of Canada,
Report for 1901, p. 215-27
152 Iroquois Beach in Ontario. Bulletin of the Geological Society
of America, 1904, 15:347-68; Ontario Bureau of Mines, Report for
1904, pt I, p. 192-222
153 Glacial Lakes and Pleistocene ‘(Changes in the Saint Lawrence
Valley. International Geological Congress, 8th Report for 1905,
p. 480-86
154 H. L. Fairchild. Pleistocene Geology of Western New York. 20th
Annual Report of New York State Geologist for 1900, p. 105-12
155 Latest and Lowest Pre-Iroquois Channels between Syracuse
and Rome. 21st Annual Report of New York State Géologist for
IQOT, PD. 33-47
156 Glacial Waters, Oneida to Little Falls. 22nd Annual Report
of New York State Geologist for 1902, p. 17-41
157 Gilbert Gulf (marine waters in the Ontario basin). Bulletin
of the Geological Society of America, 1905, 17:712-18
158 Glacial Waters in the Lake Erie Basin. New York State
Museum Bulletin 106, 1907
159 Iroquois Extinction (abstract), Science, 1907, 26:398-099
160 Glacial Waters in Central New York. New York State
Museum Bulletin 127, 1900 :
161 Report of field work (no title). In Report of Director of the
Science Division. New York State Museum Bulletin 121, 1908,
p. 19-21
162 The same, Bulletin 149, I911, p. 17-18
163 Geology of the Thousand Islands Region (with H. P. Cushing
and others). New York State Museum Bulletin 145, 1910, p. 136-72
164 Glacial Waters of the. Black and Mohawk Valleys. New
York State Museum Bulletin 160, 1912
165 G. H. Chadwick. Fossil Lake Shores. Saint Lawrence Plaindealer
(Canton, New York), July 19, 1910; Watertown Daily Times, July
25, I9I0
166 W. A. Johnson. The Trent Valley Outlet of Lake Algonquin and the
Deformation of the Algonquin Water-plane in Lake Simcoe Dis-
trict, Ontario, Canada. Geological Survey, Bulletin 23, 1916
Late Pleistocene Oscillations of Sea-level in the Ottawa Val-
ley, Canada. Geological Survey, Bulletin 24, 1916
167
Dyer
fae
aha
i
INDEX
Albany sheet, 37
Antwerp quadrangle, 61
Beaches, absence of in Staten Island
region, 17-20
Bell, Robert, cited, 14
Bibliography, 65-73
Canada, postglacial submergence, 13
Cannon Corners district, 52-54
(Canton quadrangle, 22, 59
Catskill, clays, 10
Catskill delta, 15
Catskill sheet, 35
Chadwick, Prof. G. H., 5
Chalmers, Robert, cited, 14
Champlain section, I5
Champlain valley, shore features,
42-48
Chateaugay. quadrangle, 57
Clay deposits, 9
Cobblestone hill, 51
Cohoes sheet, 38
Coleman, A. P., cited, 14
Connecticut valley, clay deposits, 10;
evidence from, 13; deposits, 15
Covey channel, 54
Covey Hill, 6, 55; shore features,
48-57
Coxsackie sheet, 36
Dannemora quadrangle, 22, 46-48
Darton, N. H., cited, 15
Davis, W. M., cited, 15
Dawson, J. W., cited, .14
Diagrams, explanation of, 20-26
Ells, R. W., cited, 14
Emerson, B. K., cited, 15
Fort Ann quadrangle, 40
Franklin Center-Covey Hill, beaches,
56
Fuller, cited, 18
Gilbert gulf, 62
Glens Falls quadrangle, 40
Gouverneur quadrangle, 60
Hudson Valley, shore features, 30—
42
Iroquois, Lake, 61; uplift from, 12
Jones, C. C., cited, 10
Kinderhook sheet, 37
Kingston, clays, 10
Lake Bonaparte quadrangle, 60
Lake Iroquois, see Iroquois, Lake
Lakes, absence of, 7
Long Island, evidence from, 13;
shore features, 29
Low, A. P., cited, 14
Malone quadrangle, 22, 58
Maps, explanation of, 20-26
Marine life, absence of, 16
Mather, cited, 14
Merrill, F. J. H., cited, 14, 17
Mooers quadrangle, 21, 48-50
New England, postglacial submerg-
ence, 13
Newburg sheet, 32
Newburgh, clays, 10
Ontario basin, deformation and alti-
tudes, 26-29; shore features, 61-63
Plattsburg quadrangle, 46-48
Port Henry quadrangle, 44-46
Potsdam quadrangle, 22, 58
Poughkeepsie sheet, 33
Rhinebeck sheet, 34
Ries, Heinrich, cited, 10, 15
76 NEW YORK STATE MUSEUM
Rosendale sheet, 34
Russell quadrangle, 50
St-Lawrence Valley, shore features,
57-61
Salisbury, R. D., cited, 11, 15
Saratoga quadrangle, 39
Schenectady sheet, 38
Schunnemunk sheet, 32
Schuylerville quadrangle, 39
Shaler, Professor, cited, 18
Shore features, description of, 29-63
Shore line, marine, differential up-
lift of, 11
Shore lines, location, 21
Staten Island region, absence of
beaches, 17; shore features, 30
Summit shore phenomena, 10
Tarrytown sheet, 30
Ticonderoga. quadrangle, 42-44
Troy sheet, 37
West Chazy district, 50
West Point sheet, 31, 32
Whitehall quadrangle, 42
Willsboro quadrangle, 46
Woodworth, cited, 10, 21
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STAGES IN T a
WANING OF THE ICE SHEET
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NEW YORK ST,
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STAGE 14.5)
LAKE IROQUOIS AT ITS GREATEST HXTENT
With continued shrinking of the glacier, Lakelpoquois extended northeast along
the northwest slope of the Adirondack highland and finally found an outlet at the
Internationa! Boundary, south of Covey Hill ch at that time was lower than
the Rome outlet. This stage, here mapped, shows Lake Iroquois at its greatest ex-
tent; with altitude 290 feet above the sea.
A slightly further retreat of the ice margin on the north face of Covey Hill will
allow the lake waters to fall to sea-level and blend with the Hudson-Champlain
Estuary, as shown in Stage 1b.
The progressive wave uplift of the land has
estricted the sea-level waters in the
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UNIVERSITY OF THE STATE OF NEW YORK
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BULLETIN 209-10 PLATE 2
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UNIVERSITY OF THE STATE OF NEW YORK BULLETIN 209-10, PLATE 5
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Cee aaTRSGuAE YORK BULLETIN 209-10 PLATE 6
Ss . MALONE QUADRANGLE
JOHN M.OLARKE
BTATE GEOLOGIST
SHORELINES
ON THE =
H. L. FAIRCHILD
1919
LEGEND
GLACIAL STREAM
CHANNELS
Channel with both
banks preserved
Channel with south bonk
i only, the north bank
[Sass] naretng been the toe
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Channel hypethatical,
or with indefinite
borders
DELTAS
Deltax of tox-borler
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SHORELINES
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NOTE: Thix map Joins the Chateaugay Sheet,
Plate 6
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UNIVERSITY OF THE STATE OF NEW YORK BULLETIN 9
STATE MUSEUM
si
SHORELINES
ON THE
DAM QUADRANGLE
H. L. FAIRCHILD
1919
LEGEND
GLACIAL STREAM
CHANNELS
fess] Channel with both
pease
ty ks preserved
[Y =] Channel with south bank
Ds) “only, tte north bank
[zee] “nituing been the ice
Channel hypotratinal
or with indefimte
borders
DELTAS
Deltas of toe-border
[tn EN
SHORELINES
Gravel bare
Bis
The as!
Contour interval 20 ter:
Datum ix mean see taret.
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UNIVERSITY OP THE STATE OF NEW YORE
STATE MUSEUM
Mi AN
MARINE SHORE __
ON THE ae
DANNEMORA QUADRANGLE |
——+ 02 ——_
I. L. FAIRCHILD
1919
LEGEND
GLACIAL STREAM
CHANNELS
se Channel with both
. vi
Contour interval 20 feet.
Datu a rear woe level.
ved
he U University af the State of New York
New: York State Museum
JOHN ou CLARKE, Director GATE.OF
Fak Charles Dees
oLocy OF THE LAKE PLACID QUADRANGLE
By WILLIAM J. MILLER
By HAROLD. I,, ALLING
eek
c
PAGE
Pleistocene geology. nL L. Alling 74
Introduction
tee
tural geology
Gy ALBANY
THE. “UNIVERSITY OF THE STATE OF NEW YORK
ronD
e as Braue NG EENesaip M. ih ‘Ph. es io De
nee ABRAM i Es ELxus LL.B. LEDAD, CL.
5 1928 Saute: Guest Rees B a Ui D. age
“43020: JAMEs Byrne B.A, LEB. LL.D. ~~ --- ea
1929 HERBERT L. BripcMan M.A. - - - - - - Br
x 1931 THOMAS J. Mancan M.A. - - - - - -
' President of ‘the University and Commissioner of Saueion
_ Joun H. Fintey M.A. LL.D. L.H.D.
Deputy Commissioner and Counsel ;
Frank B. Gisert B.A. (eee
Assistant Commissioner and Director of Professional Education
“Avcustus S. Downie M.A. L.H.D. LL.D. Pane 9
et - Assistant Commissioner for Secondary Education
CHARLES F. WHEELOcK B. S. LL.D.
Acting Assistant Commissioner for Wiemefitaey Education
GerorcE M. Witey M.A.
Director of State Library a 2g eS
James I. Wyer, Jr, M.LS. Pd.D. Pins
Director of Science and State Mjseuia os
Joun M. Crarxke D.Sc. LL.D.
a Chiefs and Directors of Divisions
ersten Hiram C. Case a ae
_ Agricultural and Industrial Education, Lewis A. Wi1son ae
Chaaives and History, James Suttrvan M.A. Ph. D. 0m
_ Attendance, James D. SULLIVAN f cee
Educational Extension, Witt1am R. Watson B.S. et a
_. Examinations and Inspections, GEORGE M. Witey M.A. aa
- Law, Frank B. Giipert B.A., Counsel
Library School, Frank K. WaLtterR M.A.M.L.S.
School Buildings and Grounds, Frank H. Woop M.A. —
School Libraries, SHERMAN WILLIAMS Pd.D.
_ Visual Instruction, ALFRED W. Aprams Ph.B.
4
Oe
The University of the State of New York
Science Department, November 16, 1918
Dr John H. Finley
President of the University
oe the Lake Placid Ouaarangle ea has been prepared, at my
quest, by Prof. Wiliam J. Miller.
With this manuscript are alse transmitted the necessary me
and illustrations.
‘Very respectfully yours
Joun M. CLARKE
Director
ee ived for publication, November 16, 1918
President of the University i
New York State Museum Bulletin
Entered as second-class matter November 27, 1915, at the Post Office at Albany, New York,
under the act of August 24, 1912
Published monthly by The University of the State of New York
No. 211, 212 ALBANY, N. Y. July-August, 1918
The University of the State of New York
New York State Museum
JoHN M. CLARKE, Director
GEOLOGY OF THE LAKE PLACID
QUADRANGLE
By WILi1aAM J. MILLER
WITH A CHAPTER ON THE PLEISTOCENE GEOLOGY
By HAROLD L. ALLING
INTRODUCTION
The Lake Placid quadrangle: comprises a territory of approxi-
mately 214 square miles in the northeastern portion of the Adiron-
dack mountains. It is bounded by latitude lines 44° 15’ and 44°
30’, and by longitude lines 73° 45’ and 74°. More than two-thirds
of the area of the quadrangle lies in Essex county, while the
remaining (northern) portion lies in Franklin and Clinton counties.
Lake Placid, Newman, Keene, Upper Jay, and Wilmington are the
principal villages. Haselton has but a few houses, and Franklin
Falls, once a village of 30 or 40 houses, now has but two resi-
dences and an electric power plant. Only one railroad enters the
map limits, this being the Adirondack branch of the Delaware and
Hudson, which reaches I mile into the quadrangle to Newman near
Lake Placid. A new state road crosses the quadrangle from west
of Newman, through the Wilmington notch, the village of Wil-
mington, and thence eastward. Another state road passes through
Keene and Upper Jay.
Lake Placid and immediate vicinity is one of the greatest of all
_ Adirondack summer resorts. There are several large hotels and
many smaller hotels and boarding houses which accommodate
1See map in pocket of back cover of this bulletin.
6 NEW YORK STATE MUSEUM
thousands of people during the summer season. Of late years
Lake Placid has enjoyed considerable popularity as a winter resort.
Thirty-five or forty years ago there was great activity at East,
Middle and West Kilns where charcoal was made for use in iron
furnaces at Black Brook a few miles to the east.
In 1842 Prof. E. Emmons published his Survey of the Second
Geological District, including Essex county. This report, how-
ever, contains almost nothing on the geology of the Lake Placid
region. | |
To Prof. J. F. Kemp belongs the credit of first having done
extensive field work which las resulted in solving many important
problems in the geology of Essex county. He published reports,
based upon reconnaissance field work, on the geology of the county _
in 1893 and 1895. These reports contain important data pertaining
to the geology of that portion of the Lake Placid quadrangle which
lies in Essex county. Based upon this reconnaissance work, Pro-
fessor Kemp also published a report, accompanied by a geologic
map, on the vicinity of Lake Placid. At one time it was planned
that Professor Kemp and the writer should prepare-a joint report
and map based upon a detailed study of the Lake Placid quad-
rangle. Soon after entering the field in 1915, however, Professor
Kemp was obliged, on account of health, to abandon the work. He
generously allowed the use of certain data on his field map. The
writer gratefully acknowledges his indebtedness to Professor Kemp.
Prof. H. P. Cushing, in his Preliminary Report on the Geology
of Franklin County, makes a number of references to the rock
formations in the vicinity of Franklin Falls, in the northwestern
part of the quadrangle. Professor Cushing also briefly refers to
some of the formations in that part of the quadrangle which lies
in Clinton county in his Report on the Geology of Clinton County.
Mr H. L. Alling, who contributes the chapter on the Pleistocene
of the quadrangle in this bulletin, has kindly furnished data, more
especially the location of several diabase dikes and Grenville lime-
stone outcrops, and the use of some thin sections of rocks.
Mr Herbert Insley, a former student in the writer’s classes,
assisted in the survey around Keene and on the rough Sentinel
range. For this service the writer is sincerely grateful.
Prof. D. W. Johnson has kindly permitted the use of two photo-
graphs.
Fotlowing are the principal publications which bear more or less
upon the geology of the quadrangle:
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 7
1842 E. Emmons. Survey of the Second Geological District (Adiron-
dack mountains), pt 2 of The Geology of New York.
1895 J. F. Kemp. Preliminary Report on the Geology of Essex County.
13th Annual Rep’t N. P. State Geologist, p. 431-72.
1895 J. F. Kemp. Preliminary Report on the Geology of Essex County.
15th Annual Rep’t N. Y. State Geologist, p. 575+614.
1895 H. P. Cushing. Report on the Geology of Clinton County. 15th
Annual Rep’t N. P. State Geologist, p. 499-573, especially p. 543-44.
1898 J. F. Kemp. Geology of the Lake Placid Region. iN. Y. State
Mus. Bul. 21. p. 51-64.
1899 H. P. Cushing. Preliminary Report on the Geology of Franklin
County. 18th Annual Rep’t N. Y. State Geologist, p. 73-128.
1900 J. F. Kemp. Precambrian Sediments in the Adirondacks. Science,
12 :81-08.
1905 H. P. Cushing. Geology of the Northern Adirondack Region.
N. P. State Mus. Bul. 95, p. 271-453.
1914 W. J. Miller. The Geological History of New York State. N. Y.
State Mus. Bul. 168, 130 pages, especially chapter 3.
1916 W. J. Miller. Origin of Foliation in the Precambrian Rocks of
Northern New York. Jour. Geol., 24:587-610.
1917 W. J. Miller. The Adirondack Mountains. N. Y. State Mus.
Bul. 193, 97 pages. A somewhat untechnical guide to the geology and
physiography of the Adirondack mountain region. ;
1917 N. L. Bowen. The Problem of the Anorthosites. Jour. Geol.,
25 :200-43.
1918 W. J. Miller. Adirondack Anorthosite. Geol. Soc. Amer. Bul.
27 :309-462.
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 9
GENERAL GEOGRAPHY AND GEOLOGY
The Lake Placid quadrangle lies immediately north of the great
group of highest mountains in the Adirondack region. Altitudes
range from 660 feet where the East Branch Ausable river leaves
the quadrangle on the east, to 4872 feet at the summit of Mt White-
face near the center of the quadrangle. Mt Whiteface rises majes-
tically as a great mass culminating in a sharp peak from 2500 to
3800 feet above the immediately surrounding country. Around the
nearly circular base of the mountain the distance is approximately
16 miles. Eight or ten sharp, rugged spurs with deep intervening
vaileys radiate from near the summit. The great bowllike depres-
sion just east of the summit of Whiteface was formerly occupied
by a local glacier, and its remarkable shape is due to the action of
the glacier in plucking out the rock. The valley between Esther
mountain and Marble mountain was also formerly occupied by a
local glacier.
Sentinel range, some 8 miles long, has several peaks rising from
3600 to 3902 feet above the level of the sea. This, too, is a very
rugged, steep mountain mass. Just north of Sentinel peak is
another fine example of a bowllike depression cut out by a local
valley glacier. A local glacier also lay in the valley next to the
north. i
Pitch-off mountain, with altitude 3340 feet at the southern edge
of the map area, is the northern slope of the still higher mountain
within the Mount Marcy quadrangle.
St Armand mountain is an irregular mass with several points
from 3100 to 3250 feet above sea level. It lies just northeast of
Moose mountain, whose altitude is 3921 feet in the Saranac quad-
rangle.
Wilmington mountain is a relatively narrow ridge 7 miles long
with a number of points 2800 to 3450 feet above sea level. It is
a very rugged, densely wooded mountain rising 1500 feet above the
narrow valley on the west and more than 2000 feet above the broad
valley on the east.
Catamount mountain ridge, in the north-central portion of the
map area, is about 3% miles long and relatively broad with its
summit (Catamount) 3168 feet above the sea. Its western end
rises abruptly 1500 feet and, viewed from the broad valley on the
west, it is a very impressive sight (see plate 19).
On a large scale, Mt Whiteface and Wilmington mountain taken
se) NEW YORK STATE MUSEUM
together, and, on a small scale, Catamount mountain, show a north-
east-southwest trend which is common in the eastern half of the
Adirondack region. The other mountains of the quadrangle are,
however, very irregularly distributed.
There are three large, broad valleys. One of these with the vil-
lages of Wilmington, Haselton, and East Kilns in the northeastern
part of the quadrangle, is approximately 10 miles long and from 2
to 4 miles wide, with altitudes from 660 to 1400 feet. This valley
was once occupied by an extensive glacial lake (see chapter on the
Pleistocene geology). A prominent valley, 7 miles long and 3 to 5
miles wide, lies in the northeastern part of the map area. Its alti-
tudes vary from 1400 to 1700 feet, and most of it is the site of a
former glacial lake. The third large valley lies in the southeast.
It is 7 miles long and from 1% to 3% miles wide. Altitudes range
from 1640 to 1900 feet. A former glacial lake also covered this
area. Lake Placid now occupies the northern end of this valley.
Three large streams flow across the quadrangle, namely, Saranac
river for about 8 miles across the northwestern corner, East Branch
Ausable river for 9 miles across the southeastern portion, and
West Branch Ausable river for about 20 miles from southwest to
northeast almost across the middle of the map area. All the drain-
age of the quadrangle passes into these three rivers and north-
eastward into Lake Champlain. The West Branch Ausable river
drains Lake Placid and, after pursuing a winding course for some
miles through a broad valley in the vicinity of Newman, passes
through a deep, narrow pass known as Wilmington notch, the rocky
sides of which rise precipitously to a maximum height of 700 feet
above the river on the east side, and 1700 feet on the west side (see
plates 4 and 20). The explanation of this remarkable course may
be found on a subsequent page. A mile beyond the Wilmington
notch, the river descends more than 100 feet by waterfall (High
fall, see plate 5) and cascades in a small gorge (see plates 13 and
14) cut in granite. Two miles beyond the High fall gorge the
river flows through a narrow gorge known as The Flume (see
plate 8), and then enters the broad valley in which are located the
villages of Wilmington and Haselton.
There are twenty-four lakes and ponds within the quadrangle in
addition to portions of two large reservoirs along the Saranac
river... Lake Placid, over 4 miles long and from 1 to 1% miles
*These reservoirs are not shown on the accompanying geologic map,
but they occupy the swamp areas above and below Franklin Falls.
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GEOLOGY OF THE LAKE PLACID QUADRANGLE II
wide, lies 1859 feet above sea level.1. By many it is regarded as
the gem of Adirondack lakes. Mt Whiteface rises majestically
more than 3000 feet above the surface of the lake on the north-
east, and Moose mountain rises over 2000 feet above the lake on
the west. The lake contains two large, high rugged islands and
one small one. |
Morgan pond on Wilmington mountain has a remarkable situa-
tion at an altitude of 3020 feet.
The Lake Placid quadrangle contains a wonderful variety of
rock formations, including most of the familiar Adirondack types
as well as several others described in this bulletin for the first time.
Excepting the Pleistocene deposits, all the rocks are of Precam-
brian age.
Oldest of all is the Grenville series which takes rank among the
very oldest rock formations of the earth. It consists of gneisses,
quartzites, and crystalline limestones. These are sedimentary rocks
which have been thoroughly crystallized. There are no large areas,
but many small masses are scattered throughout the quadrangle.
Next in age, definitely proved, is the Marcy type of anorthosite
with its extensively developed facies known as the Whiteface
anorthosite. These rocks, which are igneous in origin, are intru-
sive into, and therefore younger than, the Grenville rocks. Anor-
thosite is the most abundant rock of the quadrangle.
The syenite-granite series, with its several variations, is intrusive
into both the Grenville and the anorthosite. It ranks next to the
anorthosite in areal extent.
Of particular interest is a peculiar rock, called the Keene gneiss,
occurring as a border zone between the anorthosite and the syenite-
granite. There is strong evidence that this rock has resulted from
the assimilation of anorthosite by the molten syenite or granite.
At several places in the northern portion of the quadrangle there
are series of parallel, gneissoid, basic, usually badly weathered
dikes cutting the granite. They are different from any rocks
hitherto observed by the writer in the Adirondacks. It is probable
that they are older than the gabbro below mientioned. |
A number of gabbro bodies of the usual Adirondack kind occur
within the quadrangle. These are seen to cut both the Grenville
and the syenite-granite series.
1The altitude number 1864 printed on the accompanying map was
determined by an older survey.
I2 NEW YORK STATE MUSEUM
Pegmatite dikes of wholly nonmetamorphosed material are
occasionally present throughout the quadrangle.
Diabase, in the form of numerous nonmetamorphosed dikes, is
the latest of the Precambrian rocks.
Paleozoic and Mesozoic rocks are entirely absent, but glacial
deposits are widespread and varied, especially in the valleys.
Faulting appears to have played a much less important part than
usual in the eastern Adirondacks, only a few fault zones having
been observed, the principal one passing through the Wilmington
notch.
THE PRECAMBRIAN ROCKS
Grenville Series
General statements. Among all the rocks of the quadrangle,
those which comprise the (Grenville? series are the most ancient.
They rank among the very oldest known rocks of the earth’s crust.
It is certain that by far most of the Grenville rocks are of sedi-
mentary origin, though all are now metamorphosed and thoroughly
crystalline. In most cases the stratification surfaces are still plainly
visible and these often separate rock layers of sharply varying com-
position. Various bedded gneisses, schists, quartzites and crystal-
line limestones almost, if not entirely, constitute the Grenville
series, the original rocks having been shales, sandstones and lime-
stones of the usual kinds. The presence of numerous flakes of
graphite (so-called “black lead”’) scattered through many of the
Grenville rocks also strongly indicates their sedimentary origin.
Grenville strata are common throughout the Adirondack moun-
tain region and also in eastern Ontario. Their thickness is known
to be very great —a few miles at the very least — with neither top
nor bottom of the series definitely known. Since the Grenville
strata throughout the Adirondacks have been all cut to pieces by
vast intrusions of igneous rocks, their present distribution is very
patchy, and the irregular scattering areas now visible are merely
remnants of what was once a continuous body of strata covering
not only all of northern New York, but also large adjacent areas,
particularly eastern Ontario.
Within the Lake Placid quadrangle the Grenville strata are less
abundant than usual throughout the Adirondacks. As shown on
the accompanying geologic map, definitely known areas of Gren-
*This name has been given from the town of Grenville in the St Law-
rence valley.
Plate 4
W. J. Miller, photo, 1916
Sunrise mountain with its precipitous eastern face rising 1700 feet
above the river at the lower end of Wilmington notch. Viewed from the
top of the gorge on the east side of the river. The rock is syenite.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 13
ville, not one of them more than a few square miles in extent, are
rather widely scattered over the quadrangle, but they make up only
a small percentage of its area. They are mere fragments of the
formerly continuous Grenville series which has been cut to pieces
by vast intrusions of plutonic igneous rocks, especially the anortho-
site and the syenite-granite series.
The actual extent of Grenville strata is somewhat greater than
indicated directly as such on the geologic map. Thus, in the
vicinity of Newman, the bedrock, probably mostly Grenville, is
largely concealed under glacial deposits. Similar conditions prob-
ably also obtain in the areas of unknown bedrock west of the river
between Keene and Upper Jay, and between Franklin Falls and
West Kilns. Again, the areas of Grenville-anorthosite mixed
gneisses, and of syenite or granite and Grenville mixed gneisses,
contain much Grenville. Finally, there are occasional small
unmappable masses of Grenville which occur as inclusions in the
great intrusives. But, after making every reasonable allowance,
it is believed that Grenville rocks do not actually occupy more than
8 or 10 per cent of the area of the quadrangle.
Compared with the Adirondacks in general, the Grenville rocks
of the Lake Placid quadrangle are mostly of quite the usual sorts,
namely, graphitic crystalline limestones, pyroxene gneisses, horn-
blende gneisses and quartzites.
Areas in the vicinity of Lake Placid. In the extreme south-
western corner of the quadrangle an area of about I square mile
shows some good outcrops of Grenville. Dark hornblende-feldspar
gneiss, hornblende-feldspar-garnet gneiss, together with some light-
gray garnetiferous feldspar gneisses and a little quartzite, make up
the main bulk of the rock.’ At one locality (near the diabase dike)
the dark gneiss contains large red garnets with hornblende rims.
The area which extends from Pulpit mountain to Connery pond
and southward several miles contains various Grenville rock types.
The eastern portion of Pulpit mountain consists mostly of dark
hornblende-feldspar-garnet gneiss with scattering red garnets up
to 4 inches in diameter enveloped in rims of black hornblende.
The hill south of Tom Peck pond contains mostly hornblende-
feldspar gneisses (often garnetiferous) interbedded with con-
siderable well-stratified pyroxene gneiss and a little biotite gneiss.
On the ridge for 2 miles south from Big Cherrypatch pond the
Grenville is mostly hornblende-feldspar gneiss, usually garnetifer-
ous and with a little interbedded pyroxene gneiss. The southern
14. NEW YORK STATE MUSEUM
part of the area shows a number of exposures of dark hornblende-
feldspar-garnet gneiss with red garnets up to one-half of an inch
in diameter. A little quartzite was noted at one place.
About one-half of a mile east of the southern end of Mirror
lake there is a large outcrop of dark, very gneissoid, but not banded,
hornblende-feldspar-garnet gneiss with garnets up to an inch or
more in diameter often inclosed in envelops of hornblende. ‘
The small Grenville masses on and near Cobble hill, and 1 mile
west of Coldspring pond, are hornblende gneisses, two of these
masses being distinct inclusions in the syenite.
On the mountainside 114 miles north of Eagle Eyrie (a few
rods above the trail) there is an interesting exposure, several hun-
dred feet long, of white, rather coarse-crystalline calcite marble
with scattering small crystals of phlogopite, pyroxene and green
apatite. On the east side it is in contact with syenite, while on the
west it seems to overlie, in part at least, gray feldspar-quartz-garnet
gneiss (presumably Grenville). /
In the bed of a small brook one-half of a mile south of Owen
pond there is a small exposure, clearly an inclusion, of Grenville
limestone — some pure white and some rich in mica, pyroxene and
pyrite — associated with Grenville gray feldspar-pyroxene gneiss.
Near Winch pond the inclusion of Grenville (see map) in the
syenite is a light-gray feldspar-quartz gneiss.
In the Wilmington notch a good exposure at the edge of the
river (see map) shows well-bedded Grenville green pyroxene-
feldspar gneiss and light-gray calcareous pyroxene-quartz gneiss,
each about 20 feet thick.
The small area in Sunrise notch consists of quartzitic and
pyroxenic gneisses.
Areas in the vicinity of Keene village. On the western side
of the gorge of Ausable river (close to the map limits) there is an
outcrop of Grenville limestone and close by it an outcrop of Gren-
ville quartz-biotite gneiss or schist.
The Grenville which constitutes the hill from one-half to 1%
miles north of Keene is quite variabie. At the south, hornblende-
feldspar gneisses and quartzites are interbedded with some light-
gray feldspar-graphite gneisses. The middle portion of the hill is
mostly hornblende-feldspar gneiss. In the northern portion of the
hill the rock is mostly green pyroxene-garnet gneiss with some
interbedded hornblende gneiss and limestone, the limestone con-
taining graphite and green pyroxene. The western of the two
limestone outcrops shown on the map is the larger. )
W. J. Miller, photo, 1916
High fall of the West branch, Ausable river
GEOLOGY OF THE LAKE PLACID QUADRANGLE 15
In the Grenville area about 1% miles a little east of north of
Keene, well-bedded quartzites and hornblende gneisses are prom-
inently developed.
The area between 2 and 3 miles north of Keene shows a number
of large exposures of typical hornblende-feldspar gneiss with one
small limestone outcrop in the southeast.
On Styles brook, just above the falls, well-stratified Grenville .
hornblende gneiss and hornblende-garnet gneiss with some inter-
bedded green pyroxene gneiss form the walls of a small gorge.
The Red Rock area shows very fine big exposures of variable
well-stratified quartzite, some sharply defined beds being rich in
green pyroxene, others in red garnets, and still others in phlogo-
pite. Most of the rock contains flakes of graphite.
The small area 114 miles northwest of Keene shows light-gray
feldspar-mica-graphite gneiss. According to Kemp’s 1898 map,
limestone occurs here, but this was not seen by the writer.
The small Grenville areas east of Keene show green pyroxene
gneiss and quartzite.
Area near Upper Jay. In this area, southwest of the village,
the main body of Grenville appears to be dark hornblende-feldspar
gneiss with quartzite or green pyroxene gneiss sometimes locally
developed. Crystalline limestone and gneiss outcrop in the eastern
corner of this area.
Wilmington mountain areas. In the area at the southern end
of Wilmington mountain there are many fine big outcrops of well-
stratified Grenville. The rocks are mostly green pyroxene-feldspar
gneisses, biotite-feldspar gneisses, and some hornblende gneisses
interbedded. In and about the graphite mines in the central-eastern
part of the area there is considerable crystalline limestone associated
with some pyroxene-garnet rocks.
_ The large West Kilns-Middle Kilns area shows a considerable
number of good outcrops. On the side of Wilmington mountain
the principal rocks are hornblende-feldspar gneisses and green
pyroxene gneisses, both of these at times carrying garnets. Quartz-
feldspar-mica gneiss and almost pure quartzite are there more
locally developed. Within one-half of a mile east of West Kilns
there are several ledges of clearly bedded quartz-feldspar-phlogo-
pite-graphite gneisses, considerably weathered and rusty looking.
Near the road three-fourths of a mile east of West Kilns, Gren-
ville limestone and quartzite are poorly exposed, and one-fourth of
a mile east of this, by the road, pyroxene-feldspar-quartz gneiss
16 NEW YORK STATE MUSEUM
outcrops. Parts of the latter rock are porous, probably due to
weathering out of calcareous material. Just west of Middle Kilns,
by the road, well-banded hornblende-feldspar gneiss shows in a
good ledge. The Grenville at the base of Catamount mountain is
mostly dark hornblende-feldspar gneiss, often garnetiferous. In
the quarry (see map) in this area there is a fine big exposure of
_ very coarse crystalline limestone with some portions containing
large irregular masses of clear quartz and one-fourth to one-half
inch crystals of dark-green pyroxene and pale bluish green apatite.
Other portions of this limestone contain considerable titanite.
Areas near Franklin Falls. The Grenville area east and north
of Franklin Falls shows very fine outcrops. By the roadside, one-
third of a mile north of the village, there is a large exposure of
distinctly bedded, impure, badly weathered limestone containing
quartz, graphite and pale-green pyroxene. It is associated with
some hornblende-feldspar gneiss and calcareous quartzite with
flakes of graphite and phlogopite and specks of pyrrhotite. On the
road just east of Franklin Falls there are good ledges of greenish
gray quartz-pyroxene gneiss, some of which contain graphite.
Steep ledges forming the north bank of the river just opposite are
of similar rock. On the road one-half of a mile east of the village
there are small exposures of rotten graphitic limestone and
quartzitic gneiss with graphite. The southern part of the area
consists of hornblende gneiss and quartzite interbedded.
The small area 14% miles east of Franklin Falls shows greenish
gray quartz-pyroxene gneiss not certainly in situ.
At Woodruff fall coarse crystalline limestone containing graphite
and green pyroxene shows in an old quarry. A few rods to the
south there are ledges of hornblende-feldspar gneiss. The other
two limestone outcrops indicated on the map are associated with
pyroxene gneiss.
In an old prospect hole, one-half of a mile south of Franklin
Falls, coarse crystalline limestone with much graphite is exposed.
The small area 1 mile east of Franklin Falls shows hornblende
gneiss and quartz-pyroxene gneiss interbedded.
Anorthosite Series
General statements. So far as now known, the anorthosite
was the first of the great intrusive bodies which broke through the
Grenville strata. This rock is almost wholly confined to an area
of about 1200 square miles mostly in Essex and Franklin counties.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 17
It is prominently: developed in the Lake Placid quadrangle. The
typical rock, known as the Marcy anorthosite, is very coarse
grained, bluish gray in color, and consists principally of basic
plagioclase feldspar. A widely developed facies, known as the
Whiteface anorthosite, is usually medium grained and character-
ized by a preponderance of milky white to light, greenish gray,
basic plagioclase feldspar with small amounts of dark minerals.
both of the types locally contain considerable quantities of dark
minerals. For most part the molten anorthosite appears to have
pushed aside or displaced the Grenville rocks, though in many cases
masses of Grenville, from small fragments to large bodies, were
enveloped by the anorthosite, and in still other cases there appears
to have been intimate injection of the Grenville by the molten
anorthosite.
Marcy type of anorthosite. Distribution. This type of the
anorthosite is named from Mt Marcy where the rock is so well
developed. When the whole great body of Adirondack anorthosite
is considered, this Marcy type is the most commonly and typically
developed. Within the Lake Placid quadrangle, however, a special
phase, known as the Whiteface anorthosite (see below) is actually
somewhat more abundant in the known areas of outcrop.
The areas colored to show the extent of the Marcy anorthosite
represent about 35 square miles wholly confined to the southern
two-thirds of the quadrangle. There are ten areas in all. By far
the largest exposed body of Marcy anorthosite in the quadrangle
extends from the northern portion of the Sentinel range north-
eastward to the village of Haselton. Next to the largest body
extends northwestward from Lake Placid for several miles. Two
small bodies occur on the large islands in Lake Placid. Other
small masses are located as follows: on Marble mountain; west of
Wilmington village; and four small ones in the vicinity of Keene
village. In addition to these definitely known areas, some Marcy
anorthosite quite certainly lies concealed under Pleistocene deposits
in the areas mapped as occupied by heavy glacial and postglacial
deposits.
Megascopic features. The most common phase of Marcy anor-
thosite is a very coarse-grained, light to dark bluish gray rock con-
sisting very largely of basic plagioclase feldspar, mainly labradorite.
The dark bluish gray labradorite crystals usually vary in length
from one-fourth of an inch to several inches, with crystals an inch
long very common. Occasionally the labradorites exhibit the
beautiful play of colors (chiefly green and blue) so characteristic
18 NEW YORK STATE MUSEUM
of this species of feldspar, but this phenomenon is neither so strik-
ing nor so common in the Marcy anorthosite as in labradorite from
certain other regions. Twinning striations are usually evident on
the shiny cleavage faces of the labradorite.
Accessory minerals visible to the naked eye are large individuals
of pyroxene and hornblende, and small individuals of biotite,
ilmenite, pyrite, garnet, and more rarely chalcopyrite and pyr-
rhotite. Due to decomposition of the dark minerals, the weathered
anorthosite is usually light brown, but such rock is not common.
Locally the amount of dark-colored minerals rises to 15 to 25 per
cent when the rock should really be called anorthosite-gabbro. In
many places such anorthosite-gabbro and typical anorthosite exhibit
perfect gradations from one into the other, often within a few rods. ©
The gabbroic facies is, however, decidedly subordinate in amount,
and it has not seemed feasible to represent it separately on the
geologic map.
An important facies of the Marcy anorthosite is one in which
dark bluish gray labradorite individuals, from a few millimeters to
an inch or more across, stand out conspicuously in a distinctly
granulated groundmass of feldspar. In the fresh rock the granu-
lated material varies from light gray to pale greenish gray. The
granules usually vary in size from microscopic to I or 2 millimeters
across. Even a glance at a hand specimen of such a rock makes
it clear that the large labradorites are roughly rounded, uncrushed
cores of what were considerably larger individuals before the rock
was subjected to the process of granulation. In this type of rock,
therefore, the labradorites stand out like phenocrysts, thus giving
the rock a distinctly porphyritic appearance, though of course
crystal boundaries are seldom if ever present. All degrees of
granulation are shown, from rocks’ in which there is little or no
evidence of crushing, to others in which relatively large, dark lab-
radorites are scattered through a granulated groundmass, to
extreme cases where the whole rock has been so thoroughly granu-
lated that few, if any, labradorite cores remain. In spite of exces-
sive granulation, the fresh rock is very firm and hard. The
extremely granulated types, especially. where somewhat weathered
to light brown, bear a close resemblance to normal weathered
syenite (see below) and may be readily mistaken for such in small
outcrops in the woods. Careful examination of a number of speci-
mens from an outcrop will, however, almost invariably yield at
least a few small uncrushed cores of labradorite to furnish the
clew to the nature of the rock. In connection with the granulation
W. J. Miller, photo
Upper figure. Photcgraph of a hand specimen of
typical Marcy anorthosite. About natural size. Large
dark patches are “augen” of labradorite whose natural
color is very dark bluish gray. Matrix is mostly granu-
lated plagioclase whose natural color is light greenish
gray. A few of the small black patches represent
chalcopyrite and pyrite whose natural colors are dark
and light brass-yellow.
Lower figure. Photograph of a hand specimen of
typical moderately gabbroid and gneissoid Whiteface
anorthosite, About natural size, and almost natural
color. White material is plagioclase, and dark ma-
terial is mostly hornblende and pyroxene.
oN ey
GEOLOGY OF THE LAKE PLACID QUADRANGLE 19
of this rock it is important to note that extreme degrees of crushing
may often be observed in single outcrops of ordinary dimensions.
A striking example of such phenomena is in the big ledge on the
shore of Lake Placid at the southwestern end of Moose island
where coarse-grained, nongneissoid anorthosite, with labradorite
crystals up to 4 inches across, has in it a zone of much finer grained
and moderately gneissoid anorthosite, the one grading into the other.
Another illustration is in the road metal quarry near the road 1%
(4
Fig. 1 Sketch of a large crystal of labradorite from the anorthosite
quarry 14% miles northeast of Upper Jay. Natural size. Note the large
amount of granulated feldspar irregularly distributed through the crystal.
Due to deformation during the process of granulation, the twinning bands
are distinctly curved in the middle right portion and sharply shifted in
position in the lower portion. Dark patches are pyroxene. Dotted rim on
left is granulated garnet.
20 NEW YORK STATE MUSEUM
miles northeast of Upper Jay where is to be found one type of
anorthosite made up of crystals of labradorite from one to several
inches across with evidence of only moderate crushing, along with
another type in which only occasional large rounded cores are leit,
and still other types in which practically all the feldspar has been
granulated into a fine to medium-grained rock. These types are
in zones which show perfect gradations from one extreme to the
other.
Most of the typical Marcy anorthosite is practically devoid of
foliation, hence the general absence of dip and strike signs from
these areas on the geologic map. In some places, where the rock
is only moderately coarse grained, there is a noticeable tendency
for the feldspars to show a crude parallelism. It is usually impos-
sible to determine satisfactorily the dip and strike of such foliation
in ordinary outcrops in the woods. The more gabbroic phases of
the rock do, however, often exhibit a fair to well-defined foliation
due to the parallel arrangement of the dark-colored minerals. An
important consideration is the frequent gradation from well-
foliated to slightly or nonfoliated anorthosites or anorthosite-
gabbros within short distances, often not more than a few rods.
The causes of the foliation and granulation of the anorthosite are
evidently closely related and this matter is considered below in
the chapter on Structural Geology.
Microscopic features. In accompanying table 1, the six thin
sections were selected to illustrate the usual mineralogical varia-
tions of the Marcy anorthosite. About a dozen mineral species in
all were noted. By far most of the feldspar is seen, under the
microscope, to be striated labradorite, to possibly bytownite in
some cases. Where more acidic plagioclase is present, it is always
in subordinate amount. In thin section, with a low power of the
microscope, the larger labradorites are usually seen to be more or .
less filled with very dark dustlike particles. With a higher power
these are seen to be practically opaque, slender prismatic, or some-
times tabular, forms with parallel arrangement often strung out
parallel to the twinning bands of the feldspar. Professors Cushing
and Kemp, who have noted such inclusions, think they are most
likely ilmenite. They no doubt give the dark color to the labra-
dorite. Monoclinic greenish gray pyroxene with good cleavage —
usually augite but sometimes diallage — appears in all the slides.
The chlorite in slide 5 was quite certainly derived from pyroxene.
The hornblende exhibits good cleavages and pleochroism from
‘DOVFOMY AA WA JO do} oy} yo oovy u1oyynos JY} SWAOF YIM o}IsOy}1ouv ddVJoHYM JO Ispo] Jeois oY,
AoMOC [fATeI Jo Asozano0p
ojoyd ‘uBvUuIpaIS “TI ‘TL
L a3zIg
GEOLOGY OF THE LAKE PLACID QUADRANGLE 21
Table 1 Thin sections of anorthosite
= a 2) £2 l
2 2 g| 25
2 l2s| 2] o& 2 oes
s=) |/e@teil| Gel || oS 3 Oeil! ‘eno ol/2
S é BAGH BE |) a |) ee a= Bel ; o 2 | #ls
2) a se | SB BP Si) Se Si) Seal se es her |e 4) SSIS
o as} a |S is =} = gs rs =| &0 =°0 =] ° iS) 5 g|2 5 5
Salo | aS SS | SS si 2 iS eee Ss 2 = | BEE
wa ll fer (Sy feet ee 1 tSy || feet] eal Gi ep tS 2a2'o) 8 | ea | Heals
e@ {| 1) 583 Fu ere Ves i
oan 2|, @ol |} Bec) Bl Blecsaiceel] Al) Sl eee cllooecllawe calle =
Peewee cht | 98...) Qo... Sh-.3f 3] 8 al) Sfidittlel 2) 7. little ue
SE) Sl) CO) bs Bia ae |e Ce a ee eee ores eae .
B || 35} 73 little} 13). fi
om eeaersasi tc) SOS) RE ane Pcie! dle woalloce a. Le Oran [ease Belle
6| 1k2 little] 5] little] little]...) 4
Gal) Wc) GE A) ey ieaae lee il eee Zee Ticitles| oreene elite | ere eee ee
2 7| Gel GOOG lin Pelee dice 22 Tittle} $/.- Uae fe Cuuna | eamenltAe
g g| 4d1 CYA} no) (0) Col lettin [eet eal fates a SIE Ge gallon little: FY e)
= 9| 5gl Cid | il | Men ee (Epa Te Lee ert | ea ae litthel! WF AN.
S{] 13] 9f38 | 98 rh eae lo aie cule taualhy eee git Iie teet
si] 14] sf | 88 4a} 7]. ADE little| little little meee Mee
PMN CSe lesions sO [Lae i Weal og 5 il | Sica a
2B || ly) Ol BG lsead) Stes oil eee nein HS | Poor ts soll opcallarwsel| ae seit
PMN ISN PeOeTS |e) 75a 25 [esce| eo Neca ee ae BE so olloascsllodoslloo sll JAMMIE sc ollo-
Feit) || 1L8)|) 95} ....|.... COW OA, callascloece eon | Rigas Beit Irae Me le
30) || Ra) OAc Dl Blocecllesdle ee Tittle | eee | ee eR lie nilteullpes
a! || @al ||...) a) Sl nO. SO) 2) TES) 8) taal] | I] Tease oe olfolle al] 8
No. 1, five-sixths of a mile east-southeast of Owen pond; no. 2, south-
western end of Moose island in Lake Placid; no. 4, same; no. 5, Under-
cliff, on Lake Placid; no. 35, three-fifths of a mile north of Undercliff;
no. 44, five-sixths of a mile north of Loch Bonnie; nos. 6 and 6a, river
gorge one-half of a mile south of Keene; no. 7, by the river two-thirds
of a mile southwest of Copperas pond; no. 8, one-half of a mile northwest
of Malcom pond; no. 9, one-half of a mile east of Owen pond; no. 13, one-
third of a mile northwest of the summit of Mt Whiteface; no. 14, summit
of Mt Whiteface; no. 15, just above bridge at The Flume; no. 17, The
Flume; no. 18, between the tongues of granite 14% miles northeast of the
summit of Little Whiteface mountain; no. 19, by the road three-fourths
of a mile east-northeast of Keene; no. 20, two-thirds of a mile northeast
of the summit of Sunrise mountain; no. 34, same locality as no. 7 above.
yellowish green to deep green. Garnet is quite certainly of second-
ary origin, having developed along the contact between feldspar
and pyroxene, or as rims around the pyroxene. The other minerals
require no special comment. Under the microscope, the granula-
tion is often a striking feature.
Whiteface type of anorthosite. Distribution. Of the defi-
nitely known areas of outcrop of anorthosite within the quadrangle,
the Whiteface type, where practically free from mixture with
other rocks, occupies about 40 square miles. It is, therefore, some-
what more extensive than the Marcy anorthosite. There must be
added some 2 or 3 square miles of Whiteface anorthosite more or
less intimately mixed with other rocks and mapped as such. An
unknown, though considerable, amount of this anorthosite also
22 NEW YORK STATE MUSEUM
extends under cover of glacial drift where such deposits effectually
conceal the underlying rocks, this being particularly true east and
southeast of Franklin Falls, west and north of Wilmington, and
north of Clifford Falls. So far as known at present, this White-
face type of anorthosite appears to be relatively more abundant in
the Lake Placid quadrangle than in any other portion of the Adi-
rondacks. Professor Kemp has described similar rocks as occur-
ring in smaller amount in the Elizabethtown quadrangle.
The Whiteface anorthosite is most irregularly distributed with
reference to the other rocks. One reason for this is that the later
syenite-granite intruded it so very irregularly. Although the
Whiteface anorthosite is quite certainly a differentiation phase of
the Marcy anorthosite, and, in a broad sense, may be regarded as
a border facies of that rock, nevertheless it does not form well-.
defined borders about the Marcy anorthosite as the gabbroic facies
do about the anorthosite of the Long Lake and Elizabethtown
quadrangles mapped by Professors Cushing and Kemp respectively.
The largest area of Marcy anorthosite is, to a considerable extent
at least, flanked on either side by Whiteface anorthosite. On the
north, however, the Whiteface rock is more extensively developed
than the Marcy rock. Also, some small mappable bodies of both
Whiteface and Marcy anorthosite are isolated from the larger
bodies. It is by no means uncommon to find within the areas of
Marcy anorthosite small local developments of rocks which greatly
resemble the Whiteface type and vice versa. In short, the differen-
tiation of the anorthosite magma was asymmetric and this, com-
bined with the very irregular intrusion of the later syenite-granite
body, accounts for the very uneven distribution of the anorthosite.
By far the largest area occupies much of Wilmington, White-
face and Esther mountains, Knapp hill and vicinity, and the
vicinity of Franklin Falls. An area several miles long mostly occu-
pies the valley of the West Branch Ausable river from The Flume
to near Connery pond. Several square miles of the Whiteface
anorthosite occur in the vicinity of Keene, and a little over 1 square
mile in the vicinity of Upper Jay. Areas of less than 1 square
mile are located as follows: the southern base of Catamount
mountain; 1 mile north of Middle Kilns; 114 miles northeast of
Wilmington; southern slope of Little Whiteface mountain; on
Hawk island, and on a portion of Moose island in Lake Placid;
along the river west of Malcom pond; 2% miles northeast of Keene;
one-half of a mile south of Keene; and 1% miles southwest of
Upper Jay.
Plate 8
W. J. Miller, photo, 1916
The Flume, through which flows the West branch, Ausable river, 2 miles
southwest of Wilmington. The rock is pinkish gray Whiteface anorthosite.
i
GEOLOGY OF THE LAKE PLACID QUADRANGLE | 23
- Megascopic features. A glance at 35 or 40 specimens of White-
face anorthosite shows the usual rock to be medium grained and
white, light gray, pale greenish gray, or, more rarely, pinkish gray,
depending upon the color of the plagioclase feldspar. In most
cases the greenish tint seems to be due to stains of chlorite or
serpentine which have resulted from the decomposition of the dark
minerals. A few specimens contain no large uncrushed cores of lab-
radorite, but the outcrops from which such specimens come show
these large labradorites to be sporadically present. Nearly all the
specimens contain from I to 10 or 12 per cent of dark minerals,
these being principally pyroxene and hornblende, with garnet and
biotite less common, and tiny grains of oxides and sulphides of
iron in most specimens.
A gneissoid structure is generally well enough developed to be
readily noticeable in the hand specimens, this being particularly
true of the rocks relatively richer in dark minerals. Many of the
rocks show more or less evidence of granulation, sometimes to an
excessive degree, but many others appear not to have been notice-
ably granulated.
The most typical Whiteface anorthosite, so well exposed at the
top of Mt Whiteface, is medium grained, and consists of white
plagioclase (all or nearly all labradorite) with 5 to 12 per cent of
dark minerals scattered through the mass parallel to a crude foli-
ated structure. Such a rock stands out in marked contrast against
the most typical Marcy anorthosite which has nearly the same com-
position, but which is very coarse grained, light to dark bluish gray,
and rarely foliated. Since both types are differentiates of the same
cooling magma, they are not sharply separated, and it is often diffi-
cult in the field to draw other than arbitrary lines between them.
This matter is more fully discussed below.
- Local variations of the more typical Whiteface anorthosite are
richer in dark minerals, which may make up from 15 to 30 per
cent of the rock. In short, they are nearly always clearly foliated
gabbroic anorthosites with white or light-gray feldspar. Such
rocks are not abundant and they do not exist as rather definite
borders about the anorthosite like the gabbroic border phase of
anorthosite in the Long Lake quadrangle, as described by Cushing.
Rather, these gabbroic phases occur very locally as zones or belts
here and there throughout the areas of Whiteface anorthosite.
So far as could be made out, they are not different from the
typical Whiteface rock except for the higher content of dark
24 NEW YORK STATE MUSEUM
minerals, including garnet. \A few examples follow. On the
southern side of Hawk island in Lake Placid, big ledges show
typical nearly white anorthosite and a gray anorthosite with 20 to
25 per cent of dark minerals, these two facies not being sharply
separated. Along the river two-thirds of a mile ‘west-northwest
of Owen pond there are big ledges of Whiteface anorthosite with
zones of very gneissoid, dark, gabbroic anorthosite. On the moun-
tain spur two-thirds of a mile southeast of Morgan pond there is
locally developed in the Whiteface anorthosite a strongly gneissoid
facies. In the little area of mixed gneisses one-half of a mile east
of Keene village the Whiteface anorthosite shows a local develop-
ment rich in black minerals and garnet. By the river three-fifths
of a mile west of Owen pond a single outcrop exhibits quite typical
Whiteface anorthosite and a very gabbroic facies (no. 34 of
table 1) in fairly sharp contact but without one cutting the other.
Local variations of the sort here described are believed to have
been produced as a result of differential flowage under moderate
pressure in the cooling and differentiating anorthosite magma, this
matter being rather fully considered beyond.
Certain exceptional types of very limited extent deserve men-
tion. One of these forms the walls of The Flume through which
flows the West Branch Ausable river. It is medium to moderately
coarse grained, consists very largely of pink labradorite together
with 2 to 15 per cent of hornblende and pyroxene scattered through
the mass, and is at times slightly gneissoid. This is no. 17 of
table 1. It contains no large blue labradorite crystals. Some small
drawnout or lenslike inclusions of (Grenville pyroxene gneiss occur,
a careful study of these in the field having led to the suggestion
that most of the much smaller (one-fourth to one-half of an inch)
lenslike masses which make up 5 to 15 per cent of considerable
portions of the rock are really very small fragments of Grenville
gneiss which were caught up in the intruding magma and roughly
arranged parallel to the magmatic lines of flowage.
The only other similar pink anorthosite found, occurs in the
small area on the mountain side 1 mile east-southeast of Owen‘
pond. This rock never shows over 2 per cent of dark minerals,
and it contains no inclusions of Grenville.
Another exceptional type is medium grained and almost pure
white, with about 1 per cent of green pyroxene and very few
scattering grains of ilmenite and titanite. In thin section it shows
fully 24 per cent of colorless monoclinic pyroxene with good
cleavages. This is no. 18 of table 1. It is finely exposed in bare
1916
photo,
J. Miller,
Mio
Lower end of The Flume, 2 miles southwest of Wilm‘ngton.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 25
ledges on top of the mountain spur 114 miles northeast of the
summit of Little Whiteface mountain.
Microscopic features. The thirteen thin sections listed in table 1
are from specimens chosen to illustrate the usual range in mineral
composition of the Whiteface anorthosite of the quadrangle.
Altogether some sixteen or seventeen mineral species were noted.
Plagioclase feldspar, chiefly labradorite, always makes up the main
bulk of the rock, being seldom less than 85 per cent. Oligoclase
and andesine commonly occur in small amounts. So far as
observed, the feldspar never shows the black dustlike inclusions
so common in the labradorite of the Marcy anorthosite. Some of
the large phenocrysts probably would show them, but none of these
appear in the thin sections examined.
Greenish gray, or less commonly a nearly colorless, monoclinic
pyroxene (in one case some diallage) appears in all the sections
except no. 6, in which slide the chlorite was evidently largely
derived from pyroxene. In no. 18 all but 1 per cent of the pyroxene
is nearly colorless and the large amount is very exceptional.
Pyroxene is the second most abundant constituent of the rock.
Next in amount comes the hornblende, never more than 5 or 6
per cent. Its pleochroism is usually greenish yellow to deep green
or brownish green, and the cleavages are good.
Biotite was noted in only one slide, but it was occasionally noted
in the field. Red garnet occurs in several slides, but it is present
as scattering grains through the Whiteface anorthosite in many
localities. Ilmenite (or magnetite) is generally present in tiny
grains. Tiny prisms or rounded grains of apatite, zircon or titanite
often occur in very slight amounts. Hematite, muscovite and quartz
(probably secondary) are rare.
So far as can be judged by a study of hand specimens and thin
sections, it seems to be quite the rule that the Whiteface anorthosite
is less granulated than the Marcy anorthosite. Only exceptionally
does the Whiteface type appear to have been severely crushed. A
possible explanation will be offered beyond under the caption
“ Foliation.”
Chemical composition of the anorthosite. Analyses of the
Marcy type of anorthosite from the summit of Mt Marcy, and of
the Whiteface type from the summit of Mt Whiteface, have been
made for, and described by, Professor Kemp. They are as follows:
1N. Y. State Mus. Bul. 138, p. 32-34 and 36-37. 1010.
26 NEW YORK STATE MUSEUM
I 2
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PN © MURA Pam E RS rs conn A Sens oA oS icnty ooo 26.45) 923025
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A Fs © ear men eG MmEnpe Neb nite Aik ora ie of a5 oa .69 2.60
CY O Rare MN Mie Men eR ea cee chil c(h ad a PRS A 10.80 11.18
INaRONIEE Fone es ee Pe re Pays Ai ohne 4.627 NEZROT,
1 AO nee re rer aren HO MMA AG cieMhig Genie. < .92 .86
1 BA © os re ee ees aA yi Asoka unon oes eectin cel 53ers
COR ei DEINE RUE, SSE eee A a ee 34
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Ii 6 O Mr ere ee MO Se ALIA RRO ing Oa 6 3 ait!
No. I represents the analysis by A. R. Leeds of the rock from
Mt Marcy, and no. 2 represents the analysis by George Steiger
of the rock from Mt Whiteface. According to Kemp, no. I, in
the Quantitative Classification of Cross Iddings, Pirsson, and Wash-
ington, belongs in class 1 (Persalane), order 5 (Canadare), rang
4 (Labradorase), subrang 3 (Labradorose); and no. 2 falls in
class 2 (Dosalane), order 5 (Germanare), rang 4 (Hessase), sub-
rang 3 (Hessose). The mineral composition of a thin section of
rock from the summit of Mt Whiteface is shown by no. 14 of
table 1 on page 21. These two analyses are doubtless very repre-
sentative of the more common Marcy and Whiteface types of
anorthosites in the Lake Placid quadrangle, as judged by the micro-
scopic examination of various thin sections. The analyses show a
close similarity in the chemical composition of these two rock
types. Order, rang and subrang are the same for both, the dif-
ference in class no doubt being due to the somewhat greater per-
centage of ferro-magnesian minerals in the Whiteface rock which
happened to be chosen for analysis. Such close similarity of chem-
ical composition strongly supports the idea that the Marcy and
Whiteface types of anorthosite represent differentiates of the
same magma.
The rather high percentage of potash in rocks of this character
calls for explanation. The lack of such dark-colored minerals as
would furnish enough potash causes Kemp?’ to think that orthoclase
*N. Y. State Mus, Bul. 138, p. 30. 1910,
Plate 10
W. J. Miller, photo, 1916
Gorge and falls (over dam) of Saranac river at Franklin Falls. The
rock is Whiteface anorthosite.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 27
must be present up to 5 per cent or more as untwinned feldspar.
Cushing, however, says: ‘‘ The potash is in the labradorite (or
other plagioclase), replacing a certain amount of soda”’ and “ that
analyses of this feldspar always show it.” If orthoclase is present
in the typical anorthosites, the writer has been unable to demon-
strate it in the thin sections examined. Usually the plagioclase is
beautifully and completely twinned, but many of them are much
less so, some of the slices showing only a little very local, very faint
twinning. Still other feldspar slices, which show no twinning but
which have apparently similar index of refraction and double
refraction, are quite certainly untwinned plagioclase. It seems
most probable, therefore, that much, if not all, of the potash is in
the plagioclase, with possibly a little in the dark minerals pyroxene
and hornblende. Certain border phases of the anorthosite (below
described) do contain orthoclase and microperthite, but these are
believed to be due to mixing with the later syenite-granite magma.
Graphite in the anorthosite. Professor Kemp has in a letter
furnished the following information regarding some interesting
occurrences of graphite in the anorthosite. “‘ Below the dam across
the Saranac river at Franklin Falls, in the ledge on which it rests,
there is a streak of graphite traceable for some yards. In several
places on Knapp hill, 2 miles to the south, I found the graphite
again in the Whiteface type. I have also found it in the Marcy type
of anorthosite where exposed near the Grenville at the Red Rocks
(near Keene). Probably the hydrocarbons which yielded the
graphite were stewed out of the neighboring or included Grenville.
This mineral is unusual in intrusive rocks.”
The anorthosite an intrusive body. Until very recently, the
Adirondack anorthosite has been regarded by the several workers
in the region as an intrusive in the ordinary sense of that term.
N. L. Bowen has, however, seriously questioned whether the anor-
thosite ever had been a truly molten mass. His reasons for think-
ing that it was never hot enough to have been really molten are
based upon certain chemical considerations. His study of the
literature led him to believe that his conception is not opposed by —
field facts. He stresses the simple mineral composition of the anor-
thosite and says in part: ‘‘ Normally rocks are made up of several
minerals, and when considering their magmas, we have to regard
the various minerals as existing therein in mutual solution. .
What, then, of the solution theory as applied to the anorthosites
which typically consist almost exciusively of the single mineral
plagioclase? Were they ever hot enough to be molten per se?
28 NEW YORK STATE MUSEUM
Chemical considerations and field facts both indicate that this latter
question is probably to be answered in the negative. The chem-
ical considerations bring out the improbability of the formation
of anorthosite in any manner other than by the accumulation of
plagioclase crystals precipitated from solution in a mixed magma.”
He therefore conceives of “the Adirondack anorthosite-syenite
complex as essentially a stratified mass with syenite above and
anorthosite below.” +
Bowen’s arguments from the theoretical standpoint, at least, are
not to be lightly brushed aside. But after months of detailed field
work in a region like the Lake Placid quadrangle where anorthosite
is so prominently developed in all its phases, the writer believes
that certain field facts are most decidedly opposed to Bowen’s
conception.2 The main facts of this sort will be here briefly men-
tioned, actual examples and detailed descriptions being given else-
where in this bulletin.
1 Sharply defined inclusions (small and large) of Grenville rocks
occur in many portions of the anorthosite. These certainly bear
every evidence of having been enveloped in an active magma.
According to Bowen’s hypothesis, how can such inclusions be
accounted for?
2 In a number of places, clearly defined inclusions of anorthosite
have been found in the syenite-granite series. Could fragments of
the anorthosite, if formed by the settling of plagioclase crystals,
have been forced upward by some process into the syenite-granite
magma? Is it not much more plausible to regard these inclusions
as indicating the envelopment of previously solidified anorthosite
in an active syenite-granite magma?
3 Tongues or dikes of syenite and granite, as off-shoots of large
masses of similar rocks, are known definitely to cut the anorthosite.
Must we assume that tonguelike masses of overlying molten syenite
or granite were forced downward into the anorthosite?
4 In a number of areas there is clear evidence that anorthosite
has not only cut to pieces, but also intimately injected, Grenville
gneiss. Could such injection gneisses have developed except by
forcible and intimate intrusion of a highly molten mass into the
Grenville?
1 These quotations are from an abstract of Bowen’s paper in Bul. Geol.
Soc. Amer. 28:154. I917.
2'The interested reader should consult Bowen’s paper “The Problem of
the Anorthosites” in Jour. Geol. 25:209-43, 1917, and the writer’s paper
“Adirondack Anorthosite” in Geol. Soc. Amer. Bul. 29:399-462, 1918.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 29
5 Certain areas of mixed gneisses are anorthosite literally cut
to pieces by syenite, often with fairly sharp contacts visible. Such
a relationship is anything but stratiform as conceived by Bowen.
6 The anorthosite is by no means an almost perfect homogeneous
mass of plagioclase. Most of the rock contains from 2 to 5 per
cent of minerals other than plagioclase; portions with 5 to 10 per
cent are not uncommon; and sometimes the rock contains 10 to 20
per cent, or even more, of dark minerals. Such gabbroic facies
exist locally throughout the anorthosite body, sometimes as narrow
zones or belts. On the basis of the origin of the anorthosite by
the settling of plagioclase crystals, how are such variations to be
accounted for? Also, since so much of the rock contains very
appreciable amounts of ferro-magnesian minerals, is the mutual
solution theory necessarily precluded?
7 Foliation, particularly of the Whiteface anorthosite, is by no
means rare, and the writer has repeatedly seen highly gneissoid
facies and facies with little or no foliation in close proximity. The
writer believes that the alternations of gabbroic and nongabbroic
facies, and gneissoid and nongneissoid facies, of the anorthosite
are not results of regional compression, but that they were devel-
oped essentially by forced differential flowage in a congealing
magma. This matter is explained at some length beyond under
the caption “ Foliation.”
Some of the phenomena above described might possibly be har-
monized with Bowen’s hypothesis that the anorthosite originated
by the “accumulation of plagioclase crystals precipitated from
solution in a mixed magma,” but, taken altogether, the writer
believes that they render such an hypothesis untenable.
Relation of Whiteface anorthosite to Marcy anorthosite. As
above stated, it is often a matter of judgment as to where the bound-
ary lines between the Whiteface and Marcy anorthosites should
be drawn. As a result of the field studies, the best evidence points
to the conclusion that the two types are merely differentiates of
the same cooling magma. On the one hand, in spite of many careful
observations in the field in passing from one type across to the
other, no evidence was obtained to show that one type cuts the
other, while, on the other hand, one type of the rock grades into
the other in many places. Transition rocks in some places form
zones only some rods in width, while in other places they may be
one-fourth of a mile across, and then any accurate delimitation
of the Whiteface and Marcy types on the geologic map is impos-
sible. Among many localities where intermediate facies are well
30 NEW YORK STATE MUSEUM
exhibited are one-fourth of a mile southeast of The Flume; on the
mountain side one-fourth of a mile northwest of High fall; a long
wide belt one-half to 1 mile west of Upper Jay; and along the
northwestern base of the Sentinel range. In some places there are
locally developed, without sharp boundaries, within the Marcy
anorthosite masses of rock which are quite certainly to be classed
with the Whiteface type and vice versa. Only two such masses are
represented on the geologic map, one on the Mt Whiteface trail
near Marble mountain, and the other on the mountainside 1%
miles east-southeast of Owen pond.
As already shown, the Marcy and Whiteface types are very
closely related in chemical composition, which strongly supports
the view that the two are differentiates of the same magma.
In the writer’s paper? already referred to evidence is presented
in support of the view that the whole body of Adirondack anortho-
site is best to be regarded as a direct derivative of a laccolithic mass
not much greater across than the area of its present outcrop; that
the anorthosite differentiated practically im situ from an intruded
gabbroid magma; that the anorthosite crystallized from the upper
or residual portion of the magma during and after the sinking of
many of the femic constituents; and that the Whiteface anorthosite
developed both as an outer and an upper, somewhat more gabbroid,
marginal facies of the anorthosite. Cushing? maintains that the
gabbroid (Whiteface) facies developed as an outer chilled border
of the anorthosite. His argument seems so conclusive that it is
unnecessary to repeat it here. But, in this connection, it should be
noted that the borders of the anorthosite body have in some dis-
tricts, like the Lake Placid and the Schroon Lake quadrangles, been
so cut out or cut to pieces by the later syenite-granite intrusions
that the full original extent of the anorthosite is not now shown.
The writer believes further that the chilled gabbroid (Whiteface)
border facies also developed as an upper limit which formerly
existed as a cover resting directly on the whole great mass of
anorthosite rather than merely as an outer limit, as Cushing suggests.
Thus, the Whiteface anorthosite of the Lake Placid quadrangle does
not exist merely as a definite fringe around the outer margin of the
Marcy anorthosite. Typical Whiteface anorthosite occurs fully
I4 or 15 miles within the present border of the anorthosite area,
and inclusions in the syenite-granite series outside the general
anorthosite area show that the Whiteface anorthosite formerly
1 Geol. Soc. Amer. Bul., 29 :399-462,
2 Jour, Geol., 1917, 25 :506.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 31
extended at least a few miles farther out than the present boundary.
One area of Marcy anorthosite, 12 miles long within the Lake
Placid quadrangle and extending an unknown distance into the
Ausable quadrangle, is flanked on either side by Whiteface anortho-
site. It is hard to resist the suggestion that the Whiteface rock
formerly covered this whole mass of Marcy anorthosite. There is
thus a distinct difficulty in the way of considering this Whiteface
anorthosite merely an outer border facies. But if we do so regard
this border facies, we are forced to conclude that it is exceedingly
thick — that is to say, fully 10 or 12 miles — the width of the area
containing Whiteface anorthosite representing practically the thick-
ness of the border phase. This is scarcely possible. If, however,
we consider the Whiteface anorthosite of the quadrangle to mark
an upper limit of the great anorthosite body, but now partially
removed by erosion and partly cut into by the syenite-granite series,
not nearly so great thickness need be assumed. On this view a
vertical thickness of fully 3000 feet is actually exposed in Mt
Whiteface, and how much more should be added to make up for
the upper portion removed by erosion is of course unknown. Prob-
ably little or none is to be added to the bottom, because Marcy
anorthosite outcrops near the base of the mountain.
The anorthosite younger than the Grenville. There is two-
fold evidence that the anorthosite is younger than the Grenville
series, namely, distinct inclusions of Grenville rocks in the anortho-
site, and the more or less intimate penetration of the Grenville
by the anorthosite, particularly by the Whiteface anorthosite.
Inclusions of Grenville in the Marcy anorthosite seem to be
uncommon, having been noted in only one locality, namely, one-
fourth to one-half of a mile north of Red rock in the vicinity
of Keene, where a number of sharply defined, small inclusions of
Grenville quartz-pyroxene gneiss and quartzite, and one 2-foot
inclusion of limestone, are plainly imbedded in the typical Marcy
anorthosite. The writer recalls having seen a 10-foot inclusion
of limestone in anorthosite on the shore of Long lake in the Blue
Mountain quadrangle (see Museum Bulletin 192).
In the Whiteface anorthosite, however, inclusions of Grenville
occur in many places. Only a few of the better, more accessible
localities will be cited. A 20-foot inclusion of nearly white Gren-
ville quartz-feldspar-garnet gneiss clearly shows in a big ledge just
east of Keene. Others, including quartzite and green pyroxene
gneiss, occur for a mile eastward on the way up the hill east of
Keene and along its summit.
32 NEW YORK STATE MUSEUM
In the quarry by the road 3 miles north of Keene, and also in
ledges by or near the road one-half to two-thirds of a mile north
of the quarry, the Whiteface anorthosite contains numerous bunches
or lenses of Grenville, usually less than a foot long, as distinct
inclusions.
Near the southeastern end of the Grenville area 2 miles due
north of Keene, and also by the road in the mixed gneiss area 1%
miles southwest of Upper Jay, the anorthosite contains numerous
sharply defined inclusions of Grenville gneiss and some of lime-
stone. Most of these are less than 2 or 3 feet across.
In The Flume southwest of Wilmington, and also in the mixed
gneiss area 21% to 314 miles west-northwest of ‘Wilmington, por-
tions of the anorthosite contain small lenses or Hee masses of
Grenville green pyroxene gneiss.
» Just west of the bridge at Franklin Falls the big ledges of White-
face anorthosite contain a number of clearly defined bands or lenses
of Grenville gneisses from a few inches wide and long, to 7 or 8
feet wide and 10 or 20 feet long (see plate 11). These inclusions
are mostly gray quartz-feldspar-biotite gneiss, white feldspar-
quartz-garnet gneiss, and quartzitic gneisses.
A big ledge of Grenville hornblende gneiss on the western shore
of the river I mile south of Upper Jay is clearly intruded by a
dike of Whiteface anorthosite 20 feet wide, this doubtless being
an off-shoot from the anorthosite body just to the north.
In the areas of Grenville-anorthosite mixed gneisses, the Gren-
ville rocks are literally cut to pieces by, and often injected with,
much anorthosite, so that a separate mapping of the two forma-
tions 1s rendered impossible. Areas of this sort are considered
below.
The above phenomena, mentioned somewhat in detail, strongly
support the view that the anorthosite is, in the strict sense of the
term, an intrusive body. Such evidence is directly opposed to the
hypothesis of origin of the anorthosite as advocated by Bowen
(see above).
The anorthosite older than the syenite-granite series. That the
anorthosite is older than the syenite-granite series (described
beyond) is conclusively proved both by tongues or dikes of syenite
and granite cutting the anorthosite, and by inclusions of anorthosite
in the syenite and granite. Several excellent examples of tongues
of syenite and granite cutting anorthosite have been discovered
by the writer within the quadrangle. These are of particular inter-
est and importance because they constitute the only known evi-
Plate 11
W. J. Miller, photo, 1916
A ledge of Wh’'teface anorthosite by the road just across the river from
Franklin Falls. The anorthosite contains a long, narrow inclusion of
Grenville, gray, gneissoid feldspar-quartz-garnet gneiss. Width of the in-
clusion, 1% to 2 feet.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 33
dence of the sort in the northern portion of the great body of
anorthosite demonstrating that the syenite-granite series is younger
than the anorthosite. In fact the only other evidence of this kind
thus far published is the important discovery by Professor Cushing
of dikes of syenite cutting the western margin of the anorthosite
in the Long Lake quadrangle.*
One mile south of Morgan pond, on a prominent spur of Wil-
mington mountain, two tongues or dikes of quartz syenite, clearly
exposed for 50 or 60 feet, cut through a big bare ledge of White-
face anorthosite (see map). The dikes are from 10 to 20 feet
wide, and they are quite certainly off-shoots from the considerable
body of quartz syenite which lies to the west. As would be expected
in such narrow dikelike masses, the syenite is somewhat finer
grained than usual, but otherwise it is quite normal. No. 39 of
table 2 gives the mineral composition of a thin section from one
of the dikes. The dike rock has weathered moderately to a light
brown. It is very slightly gneissoid. The contacts against the
anorthosite are not perfectly sharp and there may have been very
slight assimilation along the borders.
Along the brook three-fourths of a mile west of The Flume, a
tongue of quite normal quartz syenite 20 feet wide cuts typical
Marcy anorthosite. This dike is an off-shoot from the considerable
body of similar syenite extending southwestward (see map).
On the mountain spur 1% miles northeast of the summit of
Little Whiteface mountain, a number of tongues of granite cut the
Whiteface anorthosite. The relations are very clear in the big
bare ledges. Of the three tongues of granite, shown on the map
in somewhat exaggerated form, the middle one is only 20 feet wide,
while the other two are some rods in width. The dike granite
contains several per cent of hornblende, is clearly gneissoid, and
weathers to pink or brown. South of the dikes just mentioned,
several tongues of granitic syenite, none over 2 or 3 feet wide, cut
the typical Whiteface anorthosite.
Inclusions of Whiteface anorthosite in syenite and granite, fur-
nishing decisive evidence that the syenite-granite series is the
younger, were observed at a number of localities. A few of these
will be cited. Ledges of syenite by the river one-fourth of a mile
east of High fall contain inclusions of Whiteface anorthosite
arranged parallel to the foliation of the syenite. Near the base of
Little High fall three-fourths of a mile northeast of High fall,
*N. Y. State Mus. Bul. 115, p. 479-82. 1907.
2
34 NEW YORK STATE MUSEUM
an 8-foot boulder of syenite has in it several distinct inclusions of
Whiteface anorthosite, these usually not showing very sharp con-
tacts against the syenite. On top of the hill in the area of syenite-
granite and Grenville mixed gneisses, there are some small lenses
of Whiteface anorthosite in the syenite parallel to its foliation.
Near the middle of the northern boundary of the area of Keene
gneiss 1144 miles west of East Kilns, a big ledge of typical syenite
has many inclusions of Whiteface anorthosite which are bunches,
lenses or bands from 2 or 3 inches to several yards long. Their
borders are not always sharp against the syenite. This is one of
the finest exhibitions of such phenomena observed by the writer
within the quadrangle.
In the area of Whiteface anorthosite and syenite mixed gneisses ~
from one-half to 2 miles east of High fall, the anorthosite has been
much cut up by intrusions of syenite, good contacts having been
noted at several places, but neither definite dikes of syenite nor
inclusions of anorthosite were observed in this rough-wooded area.
The Syenite-granite Series
The syenite-granite series, prominently developed in the Lake
Placid quadrangle, comprises a variable lot of rocks all of which,
with one possible exception, are, apparently, facies of a single great
cooling magma. Most common is a quartz syenite which grades
into a basic (dioritic or gabbroic) facies on one side, and through
granitic syenite to medium-grained granite or coarse-grained
(usually porphyritic) granite on the other. Since such rocks, which
are very abundant in the Adirondack region, have been described
in detail in various State Museum bulletins and in other publica-
tions on Adirondack geology, no omy Oy) descriptions will be given
in this bulletin.
That the syenite-granite series is younger shen the anorthosite
series has already been shown in the discussion of the anorthosite.
Quartz syenite. This is the most common and typical facies
of the syenite-granite series. It is known to occupy approximately
35 square miles in very irregular areas mostly in the southern half
of the quadrangle. In areal extent it is, therefore, about the same
as the Marcy anorthosite but not so great as the Whiteface
anorthosite.
As usual in the Adirondacks, this typical syenite is a medium-
grained rock, dark greenish gray where fresh, and it weathers to a
light brown. In some places a pinkish gray weathering was noted.
GEOLOGY OF THE LAKE ‘PLACID QUADRANGLE 35
Outcrops seldom show a depth of weathering greater than a few
inches. Immediate surfaces are sometimes light gray due to leach-
ing out of the iron oxides by waters rich in decomposing organic
matter. 5
The granularity varies considerably, in some places being rather
fine grained, and in other places being slightly porphyritic. Granu-
lation of the rock is often a notable feature, particularly when
viewed in thin section under the microscope. The feldspars show
the greatest effects of the crushing of the mineral grains. Notable
differences in coarseness of grain or degree of granulation are
sometimes very locally exhibited.
The degree of foliation of the syenite varies extremely. Very
commonly the rock clearly displays a streaked or lenticular
gneissoid ‘structure which is accentuated by the arrangement of
the dark minerals with their long axes parallel to the foliation as,
for example, in the quarry at the extreme southern end of Lake
Placid. In other places it is excessively gneissoid as near the road
one-half of a mile north of Keene village, on the mountainside one-
half of a mile southeast of the mouth of Styles brook, and on the
mountain 1% miles south-southeast of Upper Jay. Notable varia-
tions in degree of foliation are often very local, sometimes showing
in single outcrops. The problem of the origin of the foliation
is discussed beyond under the caption “ Foliation:”
The usual range in the mineralogical composition of the normal
quartz syenite of the quadrangle is well shown in accompanying
table 2. Microperthite is the most abundant constituent, and it
occurs with orthoclase in about one-half of the slides examined.
Oligoclase and quartz in moderate amounts never fail. » Horn-
blende, pyroxene and garnet usually occur in small amounts. Some
tiny grains or crystals of magnetite, apatite, and zircon. almost
invariably occur. A few other minerals are sporadically present.
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Plate 12
Photomicrographs by W. J. Miller
Upper left figure. Part of slice of coarse granite from upper end of
gorge one-half of a mile south of Keene. All is sliced (or sheared)
and granulated quartz except a little scattering ilmenite and microperthite.
Polarized light. Magnified 23 diameters.
Upper right figure. Part of slice of syenite from roadside at southeastern
base of Ccbble hill. Diallage crystal almost surrounded with a rim of
granulated hypersthene. Embedded in microperthite and quartz. Ordinary
light. Magnified 23 diameters.
Lower left figure. Part of slice of rather gabbroid Whiteface anortho-
site from shore of river two-thirds of a mile southwest of Copperas pond.
Magnetite or ilmenite surrounded with a rim of granulated garnet. Large
somewhat rounded prisms above and below are apatite. Large white areas
are mostly plagioclase. Ordinary light. Magnified 30 diameters.
Lower right figure. Part of slice of Keene gneiss from 1 mile east-
northeast of Malcom pond. In the center, remarkable vermicular quartz
intergrown with plag’oclase. Ilmenite (black) above; orthoclase (gray) on
right; plagioclase below; and quartz and orthoclase on left. Polarized light.
Magnified 30 diameters.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 37
No. 24, from Keene gneiss area just north of Keene; no. 25, by the
road at southeastern base of Cobble hill; no. 27, quarry at southeastern
end of Lake Placid; no. 28, by the road one-half of a mile north-northeast
of Keene; no. 29, near the road one-half of a mile north of Keene; no.
30, by the road one-half of a mile west of Big Cherrypatch pond; no. 33,
by the road one-third of a mile west of Copperas pond; no. 36, White-
face brook, 1 mile from the lake; no. 38, 1% miles north-northeast of
Keene; no. 30, from tongue of syenite cutting Whiteface anorthosite 1
mile south of Morgan pond; no. 43, 1 mile west of High fall; no. 32, quarry
by the road five-sixths of a mile north of Malcom pond; no. 40, by the
river three-fourths of a mile west-southwest of Owen pond; no. 31,
granitic syenite from middle eastern shore of Buck island in Lake
Placid; no. 47, granite from the small area in Wilmington notch; no. 48,
granite from the gorge at High fall of Ausable river; no. 46, granite
porphyry from side of new road one-half of a mile southwest of Franklin ~
Falls; no. 40, granite porphyry from the gorge one-half of a mile south
of Keene.
There is no evidence that the syenite cuts the granite of the
quadrangle, or vice versa, but a gradation from one into the other
seems to be clearly shown in many places as, for example, on
Catamount mountain ridge, on Wilmington mountain, and on the
southern slope of Mt Whiteface. In a few cases the change from
syenite to granite occurs within such short distances that the inter-
mediate granitic syenite can not be mapped. Proof that the syenite
is younger than the anorthosite has already been given.
As usual in the Adirondacks, this syenite is definitely known to
be younger than the Grenville series. In certain localities the
syenite contains masses of Grenville rocks as inclusions, this being
particularly true near its borders with the Grenville. Such
inclusions are nearly always arranged with their long axes parallel
to the foliation of the syenite. Some of these inclusions are to
be measured in inches, others in yards or rods, and still others are
large enough to be separately indicated on the geologic map. Good
examples of small inclusions may be observed on Cobble hill (east
of Lake Placid village), and in Styles brook on the western border
cf the Grenville area. Some of the areas of mixed gneisses show
Grenville rocks all cut to pieces by, and intimately associated with,
svenite as, for example, 2 miles north-northeast of Keene, and 1
mile northeast of Keene.
Basic phase of the syenite. But one mass of rock of this kind
has been separately represented on the accompanying geologic map.
It lies in the valley of West Branch Ausable river east of Connery
pond. The area is 134 miles long, with a maximum width of nearly
38 NEW YORK STATE MUSEUM
one-half of a mile. The origin and relations of this rock are not
clear to the writer.
The main bulk of the rock is decidedly like the syenite in appear-
ance, being medium grained nonporphyritic, moderately to very
eneissoid, greenish gray where fresh, and weathering to brown. In
the small quarry by the road near the southern end of the area, this
type of rock is finely exposed. No. 32 of table 2 represents a thin
section of rock from the quarry. No. 40, which represents a thin
section of similar rock from the shore of the river 1% miles
farther north, is exceptional in being pinkish gray, probably due
to weathering. ‘Compared with the normal syenite, the average
amount of plagioclase in this so-called basic phase of the syenite
is seen to be higher. Thus the rock is more basic, being more like
diorite than syenite. In every other way, however, the rock shows
strong syenitic affinities.
Whether this so-called basic phase of the syenite is merely a
differentiation phase of the adjacent normal syenite, or is a product
of assimilation of some anorthosite by the syenite magma, the writer
can not say. Its situation between the Keene gneiss (below
described) and syenite strongly suggests the latter possibility. If
the rock is an assimilation product it may be regarded as a sort
of nonporphyritic outer zone of the Keene gneiss where the latter
shades off into the normal syenite. In the field the relation of the
rock to the Keene gneiss could not be positively determined because
of lack of exposures along the border. Very similar rocks, usually
regarded as basic differentiation phases of the normal syenite, are,
however, known from various parts of the Adirondacks.
Granitic syenite. This rock is clearly intermediate between
the normal quartz syenite and the granite or granite porphyry. It
is an acidic facies of the syenite in which the quartz content is
about 20 to 25 per cent. Since nothing like sharp boundaries exist,
this percentage of quartz is only approximately represented in the
twelve areas indicated on the geologic map. These areas, well
scattered over the quadrangle, do not occupy more than 5 or 6
square miles. The rock 1s in every way much like the normal quartz
syenite except for higher quartz content and frequent tendency to
weather pink or pinkish gray.
On the eastern shore of Buck island in Lake Placid, where the
pegmatite dikes cut the granitic syenite, the latter contains as much
as I per cent of graphite in small flakes (see no. 31 of table 2).
Since this granitic syenite is here closely associated with small
Photograph loaned by J. D. Washer, keeper of High fall and gorge
Looking upstream through the lower portion of the gorge of the West
branch, Ausable river below High fall. The rock is pink granite intersected
by dikes of diabase.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 39
amounts of dark Grenville gneiss, it seems probable that the gran-
itic syenite magma took up the graphite from the Grenville.
A fine big ledge, known as Pulpit rock, on the eastern shore
of Lake Placid contains some inclusions of Grenville.
The hill just east of Connery pond is mostly a great barren ledge
of quite homogeneous granitic syenite.
Granitic syenite as a transition rock between syenite and granite
is well exhibited on the southern side of Mt Whiteface, and also
on Catamount mountain ridge.
Granite. As already stated, this rock is, so far as could be
determined, an acidic differentiation phase of the normal quartz
syenite. Rather arbitrarily, when a rock of the syenite-granite
series contains more than 25 per cent of quartz it is classed as
granite. In a few instances the transition from syenite to granite
takes place within too short a distance to permit mapping of the
intermediate granitic syenite. Like the normal syenite, the granite
is more or less clearly gneissoid, medium grained, and often con-
siderably granulated. It is, however, nearly always pink or pinkish
gray instead of greenish gray like the syenite. The mineralogical
compositions of two typical granites are shown by nos. 47 and
48 of table 2.
Ten areas of this granite appear on the accompanying gealogic
map. Altogether they occupy only 8 or 9 square miles, and they
are confined to the western half of the quadrangle.
The wide belt of granite on the southern side of Mt White-
face is very typical medium to moderately coarse grained, pink
to red, and distinctly gneissoid. Transition through granitic syenite
to syenite is well shown, but on the north it appears to come sharply
against the Whiteface anorthosite. A number of tongues of the
granite sharply cut the Whiteface anorthosite at the eastern end,
as already explained (see map).
At High fall and in the gorge just below the granite is pinkish,
medium to moderately coarse grained, and very gneissoid.
The granite of the southern end of Wilmington mountain grades
through granitic syenite into syenite.
About Silver lake, and also just west of Still brook, the granite
clearly grades into the coarse granite porphyry.
Several outcrops of granite south-southwest of Woodruff fall,
and also 1 mile southwest of Malcom pond, contain small, distinct
inclusions of Grenville hornblende gneiss as lenses or irregular
masses mostly parallel to the foliation of the granite.
40 NEW YORK STATE MUSEUM
Granite porphyry. A body of coarse, usually porphyritic,
granite occupies about 25 square miles of the northern portion of
the quadrangle. Feldspar crystals nearly always range in length
from one-fourth to 1 inch, and usually these stand out conspicu-
ously as phenocrysts. Quartz individuals are often one-fourth to
three-fourths of an inch long. Dark minerals seldom make up more
than 10 or 12 per cent of the rock.
Most of the granite porphyry is more or less gneissoid, but locally
there are considerable bodies of the rock which are practically
devoid of foliation and not ‘much granulated. Such nonfoliated
rocks occur in big exposures on the hills in several square miles
of the northwestern corner of the map area, on Fremont hill, and
on the two hills respectively 2 and 3 miles east of Fremont hill.
At the other extreme there are considerable developments of highly
gneissoid coarse granite and granite porphyry. In these facies
the feldspars are generally highly granulated, with the larger ones
more or less flattened out into lenselike eyes or so-called “augen.”
The quartz crystals in these very gneissoid phases are remarkably
flattened out into thin lenses, sometimes nearly an inch long. Fine
examples of flattened quartz may be seen in the ledges from one-
half to 1 mile southwest of Franklin Falls, 114 miles north of
Woodruff fall, and three-fourths of a mile north-northwest of West
Kilns. The flattened quartz crystals are always arranged with long
axes parallel to the foliation. In some localities the degree of
foliation varies greatly within small areas. Thus, on the hillock
1% miles southeast of Fremont hill, nonfoliated, moderately foli-
ated, and highly foliated coarse granites are associated. Similar
variations in foliation occur on the hilltop 1 mile east of the south
end of Silver lake.
The coarse granite very commonly weathers to a pink or pinkish
gray, and more seldom to light brown. Fresh rock was obtained
in but few localities as, for example, from a ledge recently blasted
open by the roadside one-half of a mile southwest of Franklin
Falls. Such rock is greenish gray. Whether or not much, if any,
of the fresh granite is pink could not be determined.
The mineralogical composition of the granite porphyry is well
illustrated by no. 46 of table 2, which represents a thin section
of the typical, fresh, very gneissoid rock with large granulated
“augen”’ of feldspar and highly flattened quartz individuals. This
rock differs from the granite porphyries described by the writer
from the central and southern Adirondacks by the absence of micro-
cline, though possibly this mineral does occur in other portions of
Plate 14
W. J. Miller, photo, 1916
Looking down the gorge of the West branch, Ausable river from the foot-
bridge just below High fall. The rock is pink granite intersected by several
dikes of diabase parallel to the course of the stream.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 4I
the large area of granite porphyry. Hornblende appears to be a
constant constituent, while pyroxene often fails. No. 49 of table 2
is from the small area of mixed rock in the gorge one-half of a mile
south of Keene.
Like the other members of the syenite-granite series, inclusions
of Grenville gneiss sometimes occur in this coarse granite as, for
instance, on Catamount mountain, and on top of the hill 1 mile
east of the south end of Silver lake.
It seems very clear, as a result of both field and laboratory
studies, that the granite and granite porphyry are both only facies
of a single great cooling magma. The perfect gradations from
syenite through granitic syenite to granite and granite porphyry
strongly support the view that the members of the syenite-granite
series (except possibly the basic phase of the syenite) are differ-
entiation products of a single great cooling magma. Possibly some
of the granite may be distinctly older or younger than the syenite
but, except for the small granitic dikes below described, no such
rock could be proved to be present.
Granite, Aplite, and Pegmatite Dikes
The various acidic dikes which have been definitely located are
represented on the geologic map (each dike by a number) there
being twenty-one in all. There must be many others concealed
under glacial drift, or hidden in the woods, or not discovered where
actually outcropping. In some cases the age relations are not
altogether clear.
Granite dikes. At dike localities 1 and 2 there are several pink
granite dikes cutting anorthosite. No. 3 is a dike of pink granite
75 feet long cutting Whiteface anorthosite, but not with very
sharply defined contacts. No. 4 is a dike 4 feet wide clearly cut-
ting Grenville gneiss. Dike no. 11 is pink granite cutting Marcy
anorthosite. At locality no. 12 several dikelike masses of granite
are involved with syenite and Whiteface anorthosite.
Most of these dikes may be merely off-shoots from the great
syenite-granite intrusive body, but some may possibly be consider-
ably later in age.
Aplite dikes. Interesting dikes of aplite were observed. At
no. 9, in the bed of the river east of Copperas pond, a dike of pink
aplite, with several small tongues, clearly cuts a gabbroic, very
gneissoid facies of the Whiteface anorthosite. A thin section of
this aplite shows 20 per cent orthoclase, 20 per cent microperthite,
42 NEW YORK STATE MUSEUM
I5 per cent albite, 44 per cent quartz, I per cent magnetite, and a
little zircon. The rock is moderately gneissoid and variable in
grain from medium to coarse. Possibly it is an acidic off-shoot
from the neighboring syenite.
On the southern side of the top of Catamount mountain, a num-
ber of small nonfoliated aplite dikes lie parallel to the foliation of
the coarse granite. Whether these are younger or older than the
neighboring gabbro-diorite dikes was not definitely determined, but
the aplites are probably the older.
At number 17, t mile west of East Kilns, a fine aplite dike 3
feet wide cuts a big ledge of coarse granite. A thin section shows
the following mineral percentages: Microperthite, 58; microcline,
1; albite, 5; quartz, 35; biotite, 1; and very littl sarnetaapanic
and zircon. The rock is not gneissoid. The fact that the contact
against the granite is not very sharp strongly suggests that the
aplite was intruded while the granite was still fairly hot.
At dike locality no. 18 several small aplite dikes cut granite.
Granite-pegmatite dikes. Nos. 5, 6, 7, 8, 10, 13, 14 and 16, indi-
cated on the geologic map, are pegmatite dikes of the usual sort.
They are nonfoliated and cut the Grenville, anorthosite, and syenite-
granite series. No. 8 lies in contact with a diabase dike, and these
two. clearly cut syenite. No. 16 is a pegmatite dike 3 feet wide
very sharply cutting across the foliation of one of the gabbro-
diorite dikes below described. Within the Lake Placid quadrangle
no pegmatite was observed cutting the gabbro stocks (below
described), but in various portions of the Adirondacks dikes of
such have been found to be intrusive into the gabbro. It is quite
possible that these pegmatite dikes are not all of the same age, but
all are. doubtless younger than the syenite-granite series, most of
them probably representing a late stage in the intrusion and cooling
of the syenite-granite magma.
Syenite-pegmatite dikes. A much more unusual type of pegma-
tite dike was noted at several localities, namely, near Franklin Falls
(dike no. 19); 1% miles south of Wilmington (dike no. 20) ; and
1 mile southwest of Haselton (dike no. 21). These are very coarse-
grained rocks consisting chiefly of irregular masses of microperthite
and black hornblende (or pyroxene) up to several inches across.
No quartz occurs. Dike no. 19 is 2 feet wide, cuts Whiteface anor-
thosite, and contains masses of magnetite I or 2. inches across. The
contact against the country rock is not sharp. At no: 20 a number
of pegmatite dikes from 1 to several feet wide cut Marcy anor-
thosite usually without sharp contacts.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 43
these dikes consist almost wholly of microperthite and horn-
blende in large masses. It seems very clear that the pegmatites of
this sort were intruded very soon after the intrusion of the anortho-
site and that they are, therefore, distinctly older than the ordinary
granite-pegmatites above described.
Keene Gneiss
General statements. One of the most interesting rocks of the
quadrangle is locally developed as belts or irregular bodies along
portions of the borders between the anorthosite and syenite-granite.
Both the Marey and the Whiteface types of anorthosite show such
border rocks. There is very strong evidence, based upon field work
and a study of thin sections, that this is really a transition rock
between the anorthosite and the syenite or granite due to actual
digestion or assimilation of anorthosite along its border by the
invading syenite-granite magma. It is here proposed that this rock
be called the Keene gneiss because a fine exposure of the typical!
fresh rock occurs by the road at the northern edge of the village
of Keene. In view of the fact that many geologists maintain that
there are no definitely proved cases of magmatic assimilation on
considerable scales at least, the evidence furnished by these rocks
of the Lake Placid quadrangle has been very carefully considered
by the writer who is convinced that actual assimilation has taken
place. In other words, the Keene gneiss seems to be quite cer-
tainly a good example of a “hybrid” rock, to use the term sug-
gested by Harker, the English geologist, who has maintained that
such rocks have been produced either by the mixing of two distinct
magmas, or by the assimilation of solid rock by magmas. Fifteen
areas of Keene gneiss are represented on the geologic map which
accompanies this bulletin. Others probably exist but were not
located owing to scarcity of outcrops or roughness of country in
some places.
The typical Keene gneiss presents a different appearance from
any of the other rocks of the region, and it is usually readily recog-
nizable. The main body of the typical rock is medium grained,
gneissoid, notably granulated, and looks much like a rather basic
phase of syenite, but it contains scattering phenocrysts of bluish
gray labradorite up to an inch in length. These phenocrysts, which
are rounded and usually elongated parallel to the foliation of the
rock, doubtless represent cores of crystals which survived the
process of granulation. Locally the phenocrysts of labradorite are
44 NEW YORK STATE MUSEUM
absent or only sparingly present, ledges of such rock being very
difficult to distinguish from a) basic phase of syenite. Under the
microscope, however, the distinction may generally be made.
Where fresh the rock is greenish gray, and it weathers to brown.
The mineralogical compositions of selected samples of various
phases of the rock are shown in table 3. Labradorite and andesine
are always present, and oligoclase usually. Microperthite occurs
in most of the specimens in varying amounts up to 30 per cent,
and orthoclase in most specimens in varying amounts to over 50
per cent. A little quartz is generally present. All the thin sections
examined show greenish gray monoclinic pyroxene, sometimes
diallage. A little green hornblende nearly always occurs up to 14
per cent. Garnet varies from none to 12 per cent. Ilmenite (or
magnetite) up to a few per cent never fails. Apatite and pyrite
in small amounts always occur. N. L. Bowen, in a recent paper,
states that he has observed, in the transition rock from anorthosite
to syenite, inclusions of potash feldspar which are small patches,
uniformly oriented, and, in some cases, surrounded by areas of
plagioclase differing from the crystal as a whole. A few slight
suggestions of this sort of thing were noted by the writer, but
certainly this is not a characteristic feature of the Keene gneiss
thin sections examined.
Table 3. Thin sections of Keene gneiss
o oO o
o a | =
= x © | ,o =
G S) 1A a
2 #/ 2 ee oe eaes Bic
fe) 9° 3 o| Ss Say || 2) Sei) 2 x 2i|s
a 5 } Sl Ss | Ss sy || SHS) @ 5) q ® = ©
o ‘re “ = ia] h ¢q = = oO q p fe) he 5 5
ue! 2 S 2 8 | S88 (Se) es loa [eh ela ee eas
a ea a SloOleals | 4 i VS oO < N A | & lo
3 4£8 |ol.—-Lab. 80] ro].... Al enens 3 I 4| little Dl 1ittle| little} eyes |(eres
ro | 7£7 a |ol.—Lab. 28] 25) 20] 64 OIF ares listo 2 Wea Pe rdigacoalicocclls> = -
II 14 ¢4 |An.-Lab.66]...| 20 2 4|. heise reve ve little} little].....].. s8-[h 30 -
I2} 14b4 ol.-An. 48] 20].... 9 Bilooacl| wh Tih aioe little 3|.....| little 2
41 TO) 9) 7) | Anisvabss0|h eal 50 5 Bloc 5 3 5 Blea aeas Little | sere ees
42 |1kz10a/An.-Lab.70] 20].... I 3 2 2 I 4 a eatin: ir llonoso}(o.0 c
45 |}1k10b| ol.-Lab.40] 32] 1o}.... 2 8] 6% Tiaras Bltescves little||ie alee
No. 3, 1 mile east-northeast of Malcom pond; no. 10, 1 mile a little
south of west of High fall; no. 11, one-half of a mile south of the summit
of Catamount mountain; no. 12, one-half of a mile north of Franklin
Falls; no. 41, in the brook 134 miles due west of East Kilns; nos. 42
and 45, by the main road at northern edge of the village of Keene.
1Jour. Geol, 25:221. I917.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 45
Areas in the vicinity of Keene village. The type locality of
the Keene gneiss is a ledge by the side of the state road at the north-
ern edge of the village of Keene where an excellent opportunity is
afforded for the study of the rock and its relations to both anor-
thosite and syenite. All three of these rocks show as unweathered
material in this one ledge which has been recently blasted open.
The anorthosite, which occurs in minor amount, is the typical
Marcy facies consisting mostly of dark, bluish gray labradorite up
to an inch across embedded in some granulated feldspar, and
associated with 10 to 20 per cent of ferro-magnesian minerals.
The syenite is quite normal in every respect except that it is a
little finer grained than usual. No. 24 of table 2 gives its mineral
content. Most of the rock of the ledge, however, is clearly an
assimilation product of syenite and anorthosite. This assimila-
tion rock (Keene gneiss) exhibits at least three distinguishable
facies. One of these is highly gneissoid with elongate cores of
labradorite crystals as phenocrysts up to an inch long arranged
parallel to a distinct foliation. Its mineral content is given as no.
42 of table 3. A second facies is only faintly gneissoid, with labra-
dorite phenocrysts only roughly parallel to the foliation. Its com-
position is given as no. 45 of table 3, the presence of orthoclase
and a greater amount of microperthite making this rock much more
syenitic than the first facies. In the two facies just described, the
phenocrysts of labradorite not only finely exhibit polysynthetic
twinning, but they are also perfectly twinned according to the
albite law, thus giving the freshly broken surface a striking appear-
ance. Both of the facies are notably granulated, and the rounded
phenocrysts are the uncrushed portions of what were once still
larger crystals. A third facies, in minor quantity, is nonfoliated
‘and contains no labradorite phenocrysts, but it does contain a few
rounded red garnets up to an inch across. This third facies is
the most syenitic of the three.
All three facies just described grade into one another and they
are quite certainly only differentiates of a single cooling magma.
Also it is important to note that the Keene gneiss is not sharply
separated from the true syenite on one hand, and the true anortho-
site on the other, but rather by narrow transition zones. All three
facies of the Keene gneiss are certainly intermediate in composi-
tion between the syenite and anorthosite, the first one described
having decided anorthosite affinities, the third having decided
syenite affinities, and the second being very clearly intermediate
46 NEW YORK STATE MUSEUM
between the syenite and anorthosite. The conclusion, therefore,
based upon the field relations and composition of the rocks is that
we have here a true magmatic assimilation product, the invading
syenite magma having actually incorporated and assimilated more
or less of the anorthosite material. The close juxtaposition of sye-
nite and Keene gneiss may be reasonably explained if we consider
the syenite to have been an intrusion as an off-shoot of the great
body of syenite magma into previously formed and cooling (or
possibly solidified) Keene gneiss magma, the temperature then
having been high enough only to permit fusion along a narrow
border zone between the intruded and intrusive masses, thus
accounting for the narrow transition zone between the two in the
ledge. The foliation of the Keene gneiss is quite certainly an orig-
inal structure due to magmatic flowage under pressure, and accord-
ingly the marked differences in degree of foliation within this one
outcrop are regarded as the result of differential magmatic flowage
according to the principles explained beyond under the caption’
Soliattonhe :
Professor Kemp has informed the writer that rock similar to
that just described was formerly visible in outcrop at the present
sawmill site in Keene village, and the area of Keene gneiss is
accordingly extended that far south on the geologic map.
The little area one-half of a mile east of Keene shows a variable
lot of rocks, some being apparently Whiteface anorthosite, some
rich in black minerals and garnet, and much containing large bluish
gray labradorites in a very syenitic looking, crudely gneissoid,
brownish-weathered rock like the typical Keene gneiss above
described except for its brown weathering.
Oak ridge shows fine big exposures of a rock which, in the field,
would be taken for a rather basic phase of syenite except for the
large scattering bluish gray labradorites. It is, without doubt, a
large scale mass of the Keene gneiss.
Good outcrops of typical Keene gneiss also occur in the small
areas respectively I mile northeast; 2 miles west-northwest; and
4¥%4 miles west of the village of Keene.
Areas near Upper Jay. In the area of over one-half of a square
mile just east of Upper Jay, there are many very good exposures,
certain of them of particular interest because they throw important
light upon the origin and relations of the Keene gneiss. Near the
top of the hill at the northeastern border of the area, Whiteface
anorthosite and syenite in big exposures are separated by a zone,
a few feet wide, of basic syenitelike rock with scattering bluish
GEOLOGY OF THE LAKE PLACID QUADRANGLE ‘47
gray labradorites. This is very clearly a transition zone of typical
Keene gneiss produced by the assimilation of Whiteface anortho-
site by syenite magma. On the little hill just south of the center
of the area, several outcrops of quite typical Keene gneiss contain
bands or lenslike inclusions of Whiteface anorthosite, the Keene
gneiss magma, moving from a lower level where it was formed,
evidently having penetrated or caught up inclusions of unchanged
Whiteface anorthosite at the higher level. The Keene gneiss here
contains many tiny red garnets, and the labradorite phenocrysts
are very conspicuous on the weathered surfaces.
A little area, shown on the map 1% miles west of Upper Jay,
is thought to be Keene gneiss, but the matrix of this rock is finer
grained and more gneissoid than usual.
Sentinel range area. This long, narrow area extends east-west
across the middle of the Sentinel range. . It is about 4 miles long
and nowhere over one-fourth of a mile wide. It is all in a rough,
densely wooded country, but a good many outcrops make the
mapping fairly satisfactory. Perhaps the most instructive ledges
are on the little hill 1 mile northeast of Malcom pond. The top of
this hill is quite typical Marcy anorthosite. On the southern side
the rocks are variable, being mostly fine to medium grained,
gneissoid.and gabbroic in appearance with some closely involved
basic syenitelike rock containing a few small, scattering labradorite
phenocrysts, this latter being presumably Keene gneiss. Near the
top of the hill, on the west side, the rock is coarser grained with
few dark minerals, and this appears to be quite like typical Keene
gneiss. All the types mentioned grade into one another.
On the hillside one-half of a mile southeast of the hill just
described, there are outcrops of a moderately coarse-grained,
rather gabbroic rock with some labradorite phenocrysts. Its
mineralogical composition, given as no. 3 of table 3, shows that it
should be classed as Keene gneiss with strong anorthosite affinities.
Good exposures of Keene gneiss may be seen in other portions
of the areas mapped, particularly for a mile eastward from the
summit of Sentinel range, where the typical rock forms a wide
transition zone between the Marcy anorthosite on the north and
the quartz syenite on the south.
Sunrise notch area. This, the largest area of Keene gneiss
within the quadrangle, is about 3% miles long and from one-half
to two-thirds of a mile wide. It is a rock distinctly intermediate
between Whiteface anorthosite and syenite. Most of the outcrops
are quite typical Keene gneiss, though usually not strongly foliated.
48 NEW YORK STATE MUSEUM
It is generally medium grained with scattering labradorite pheno-
crysts, and weathered brown.
A locality of special interest is a cliff on the southern border of
the area three-fourths of a mile east of the summit of Sunrise
notch. Most of this rock is very gneissoid and only moderately
gabbroic Whiteface anorthosite, a little finer grained than usual.
Its mineral content is given as no. 20 of table 1. Within this rock
there is a wide band of fine-grained, very gneissoid, gray rock with
a reddish tinge due to numerous tiny garnets. The composition of
this local band, given as no. 10 of table 3, causes it to be classed
with the Keene gneiss, the high content of microperthite and ortho-
clase showing it to have strong syenite affinities. Its contact
against the anorthosite is not very sharp. Evidently a dike or
tongue of the Keene gneiss magma here intruded the Whiteface
anorthosite near its border, and the temperature was high enough
to cause fusion of the anorthosite walls of the dike or tongue.
The small area of Whiteface anorthosite one-third of a mile
north of the locality just described, presumably represents a body
of anorthosite which failed to become assimilated by the syenite
magma.
Area west of East Kilns. This area, ‘between 1 and 2 miles
west of East Kilns, shows certain interesting and important fea-
tures. Much of the rock, whose composition is given as no. 41 of
table 3, has strong syenite affinities because of its high orthoclase
content.
Near the middle of the northern boundary, syenite contains
Whiteface anorthosite inclusions as bunches, lenses and bands
from 2 or 3 inches to several yards long, the boundaries of the
inclusions usually not being very sharp. [Evidently very little
assimilation of the anorthosite took place here.
Along the northwestern side several ledges are very gabbroic in
appearance, in some places very gneissoid and in others not.
Locally there is intimately associated syenite and Whiteface anor-
thosite. Apparently these ledges show the effects of partial diges-
tion or assimilation of anorthosite by the syenite magma.
Along the main brook, for one-fourth of a mile after it enters
the area, there are good exposures of homogeneous, scarcely gneis-
soid Keene gneiss, with the phenocrysts of labradorite not so large
as usual. This rock, whose composition is given as no. 41 of
table 3, has strong syenite affinities because of its high ortho-
clase content. In this portion of the area, syenite magma quite
certainly completely assimilated more or less anorthosite.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 49
The little hill in the eastern portion of the area consists of rather
mixed rocks, but it is mostly Keene gneiss with large labradorites.
At one place fairly coarse granite is intimately associated with
gabbroic Whiteface anorthosite with local development of what
appears to be an assimilation product of the two containing some
quartz. Small masses of Grenville gneiss are also commonly
involved with the rocks of this hill.
Other areas. [he narrow band of Keene gneiss at the southern
base of Catamount mountain contains large labradorites but it is
scarcely gneissoid. No. 11 of table 3 gives its mineral content.
In the small area one-half of a mile north of Franklin Falls, a
medium-grained, rather gabbroic, gneissoid rock, without pheno-
crysts, has the composition of Keene gneiss as shown by no. 12 of
table 3. This rock grades into gabbroic Whiteface anorthosite, but
its relation to the nearby granite could not be determined.
The area just north of Owen pond shows big ledges of homo-
geneous, typical Keene gneiss.
The small area 1144 miles south-southeast of The Flume shows
Keene gneiss closely associated with much syenite and some White-
face anorthosite.
Significance of the distribution of the Keene gneiss. That the
Keene gneiss is actually an assimilation product of the fusion and
digestion of anorthosite by syenite or granite magma is regarded
as proved by the evidence above presented. But such rock is not
universally present,as a transition or border rock between anor-
thosite and syenite or granite. For instance, the long boundaries
between the Whiteface anorthosite and granite of Mt Whiteface,
and between the Whiteface anorthosite and syenite from the
southern side of Mt Whiteface to west of Knapp hill, were crossed
at many places without noting any rock like the Keene gneiss. As
seen on the map, other areas also show an absence of Keene gneiss
as a border rock. It is possible that some masses of Keene gneiss
may have been overlooked in the rough, densely wooded country,
or that some may exist under cover of glacial and postglacial
deposits, but, in view of the detailed survey, it is certain that any
such masses of Keene gneiss are relatively small. How is this
difference in distribution of the Keene gneiss to be accounted for?
Also why do the borders between the Grenville and syenite-granite
series, as well as in the mixed eneiss areas of Grenville and syenite-
granite, show little or no evidence of magmatic assimilation? The
writer believes that the answer to these questions may be found in
the temperature relations of the rocks at the time of the intrusion
50 NEW YORK STATE MUSEUM
of the syenite-granite series. If we consider that the great mass of
anorthosite was still at a relatively high temperature, though not
necessarily molten, at the time of the syenite-granite intrusion, it
would have been only necessary for the syenite-granite magma to
have raised the temperature of the borders of the intruded anor-
thosite comparatively little to have effected actual assimilation.
The tongues of syenite cutting Whiteface anorthosite on Wil-
mington mountain, and the tongues of granite cutting Whiteface
anorthosite on Mt Whiteface (described on page 33), furnish
important evidence in support of this view, because these tongues
or dikes, instead of being in real sharp contact with the anortho-
site, show very narrow transition zones due to slight fusion of the
anorthosite. Now, it does not seem at all probable that even smal!
amounts of relatively cold anorthosite could have been fused and
assimilated by such small masses of intrusive magma, but with the
anorthosite at a high temperature, though not really molten, its —
borders might very conceivably have been fused. Thus, if we make
the very simple and plausible assumption that the anorthosite was still
very hot (though not necessarily molten) when the syenite-granite
magma was intruded, or, in other words, that this latter magma was
forced up comparatively soon after that of the anorthosite, the
usual strong objection to magmatic assimilation, namely, that a
magma does not possess a sufficiently high temperature to raise
relatively cold country rock to the point of fusion, is distinctly
obviated.
Where no Keene gneiss occurs along the borders, it may be
plausibly conceived that either the anorthosite, or the syenite-
granite, or both, may not have been hot enough to permit assimila-
tion. Also, in harmony with this hypothesis, the failure to find any
considerable assimilation of Grenville either along its borders with,
or where involved with, the syenite-granite series may be explained
on the basis of a temperature of the Grenville too low to have per-
mitted any more than comparatively slight assimilation by the
invading syenite-granite magma. It should be borne in mind, how-
ever, as pointed out in a recent paper by the writer, that local
assimilation of Grenville was not uncommon in the Adirondack
region.+ . to
In the mixed rock areas near the center of the quadrangle, where
anorthosite has been cut to pieces by intrusions of syenite, the few
contacts observed are not very sharp. Apparently, in these areas
*Geol. Soc. Amer. Bul. 25 :254-63. 1914.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 51
either the syenite magma or the anorthosite, or both, were not hot
enough, or the syenite was not in sufficient bulk, to effect more
than slight fusion of the immediate borders of the invaded anor-
thosite.
Another important fact is that, in the field, the Keene gneiss by
no means universally forms a narrow zone or belt with syenite-
granite directly adjacent on one side and anorthosite on the other.
A fine case in point is the eastern part of the Sunrise notch area
where the Keene gneiss for 1% miles lies between granitic syenite
on one side and syenite on the other. A different case is the Oak
ridge area which is bordered on the south by Whiteface anortho-
site, and on the north by Grenville, Marcy anorthosite and syenite.
How can areas of this sort possibly be explained by Bowen's
hypothesis, which assumes that the anorthosite was never an active
magma but that it was formed by sinking of plagioclase crystals
with the development of a transition rock (called Keene gneiss in
this bulletin) occupying a position distinctly intermediate between
the syenite-granite and the anorthosite? Is it not much more in
harmony with the field relations to conceive that Keene gneiss
magma was produced by assimilation at a lower level and then
rose to invade previously formed Grenville and anorthosite, or
moved upward flanked on either side by syenite or granite? Also
are not elliptical areas like those just east of Upper Jay and 1%
miles west of East Kilns much more satisfactorily accounted for
by the latter hypothesis than by Bowen’s hypothesis? Again, do
not the inclusions of anorthosite in the Keene gneiss (see above
descriptions) strongly support the writer’s view that the Keene
gneiss, in some places at least, moved upward as a true magma?
Finally, it should be noted that the Keene gneiss accompanies
both the Marcy and the Whiteface types of anorthosite, being about
as common with one as with the other. Within the Lake Placid
quadrangle, then, the temperature relations between the syenite-
granite and Marcy anorthosite on the one hand, and the Whiteface
anorthosite on the other, do not seem to have been notably different
during the syenite-granite intrusion. The presence or absence of
the Keene gneiss appears to be irrespective of whether the syenite-
granite borders the Marcy or the Whiteface anorthosite.
Comparison with Cushing’s southwestern Franklin county
basic syenite. In Cushing’s report on the geology of the Long
Lake quadrangle, he describes a basic phase of the syenite which
grades into a rather fine-grained, even granular, gneissoid rock with
few feldspar phenocrysts, and dark minerals often equaling or
52 NEW YORK STATE MUSEUM
exceeding the feldspar in quantity. Some of the feldspar is micro-
perthite and some oligoclase-andesine. “‘ The most of the basic
syenite, and all of the more gabbroic of it, is in close association
with the anorthosite border. . . . Now the syenite is unques-
tionably younger than the anorthosite, and the observed relations
seem to point to the conclusion that the change (in the syenite) is
due to the actual digestion, by the molten syenite, of material from
the (anorthosite) gabbro.”* The Keene gneiss of the Lake Placid
region differs in being coarser grained, distinctly porphyritic, and
not so rich in dark minerals, but both Cushing’s basic syenite and
the Keene gneiss are intermediate in position and composition
between the anorthosite and the syenite-granite series in their
respective regions, and the writer believes that Cushing’s suggested
explanation is the correct one.
Another rock, earlier described by Cushing? from a railroad cut
nearly 5 miles north of Tupper Lake Junction, is regarded by him
as intermediate between the syenite and the anorthosite. Judging
by the description, this rock is, in almost all respects, similar to the
typical Keene gneiss except that the labradorite phenocrysts are
not so large. This work of Cushing, therefore, strongly supports
the idea that the Keene gneiss is a magmatic assimilation product.
Mixed Rocks
Grenville or amphibolite and Whiteface anorthosite mixed
gneisses. Under this caption there are described several areas in
which Grenville rocks and probably some ortho-amphibolite have
been cut to pieces by, and are more or less intimately associated
with, the Whiteface type of anorthosite. In some places the Gren-
ville or amphibolite predominates, and in others the anorthosite, but
the two rocks are too closely associated to be satisfactorily separated
on the geologic map. During the writer’s recent survey of the Lyon
Mountain quadrangle next to the north much gabbro-amphibolite
older than the syenite-granite and probably older than the anorthosite
was encountered. Quite likely then at least some of the amphibolite
of the Lake Placid quadrangle is to be placed in the same category.
The largest area, over 3 miles long, lies between Keene and
Upper Jay. It is traversed by the East Branch Ausable river. For
most part, the rocks of this area are Grenville hornblende gneiss
TNE YM. State) Mus Bulkeris ss par47osoo7.
“N.Y. State Mus, Rept 545 t:r43and 168. 1902:
GEOLOGY OF THE LAKE PLACID QUADRANGLE 53
and pyroxene gneiss which have been cut to pieces by intrusions of
Whiteface anorthosite, the Grenville and the anorthosite nearly
always being clearly recognizable as such. Very distinct small
inclusions of Grenville gneiss in the anorthosite’ were noted in
various ledges, particularly along the road between 1 and 2 miles
south of Upper Jay; by the road 144 miles southwest of Upper
Jay; and 2% miles due north of Keene in the western corner of the
large area.
Another type of mixed gneiss from the above-mentioned area is
of particular interest. This rock shows in good outcrops west of
the river between 2 and 3 miles north of Keene; in the quarry by
the road 314 miles north of Keene; and by, or close to, the road
between one-half and three-fourths of a mile north of the quarry
(see map). The best place to study this rock is in and around the
quarry. In the quarry the rocks are Grenville hornblende and
pyroxene gneisses, more or less intimately involved with White-
face anorthosite. Much of the rock is a true injection gneiss, the
Grenville gneiss having been so intimately penetrated by the anor-
thosite magma that the small hornblende and pyroxene crystals
were mostly separated from each other and enveloped in the molten
mass parallel to the magmatic currents, thus giving to the resulting
gray, medium-grained rock a clearly defined foliation. Some por-
tions of this rock are richer in dark minerals than others, and some
portions show lenselike masses or bunches of dark minerals as dis-
tinct inclusions I or 2 inches long which were enveloped in the
magma without being broken up. This rock contains occasional
light bluish gray labradorite crystals up to an inch in length, and
numerous tiny grains of titanite. A thin section of this injection
gneiss reveals the following mineral percentages: andesine to labra-
dorite feldspar, 58; green monoclinic pyroxene, 30; green horn-
blende, 10; titanite, 114; biotite in tiny flakes, 12; and very little
zircon. Another slide is similar, but it has several per cent of
quartz in one narrow band. Locally, where the anorthosite greatly
predominates, the rock is much coarser grained and the dark
minerals are more irregularly arranged so that the foliation is not °
so pronounced. It is very evident that Grenville gneiss has here
been more or less intimately injected by Whiteface anorthosite
magma, but there is no indication whatever of actual digestion or
assimilation of the Grenville by the magma, the crystals and frag-
ments of the Grenville always showing sharp contacts against the
enveloping anorthosite.
54 NEW YORK STATE MUSEUM
In the small area one-half of a mile east of Keene, the Grenville
gneiss occurs as bands or inclusions in the anorthosite.
The area 2 miles long on the southern end of Wilmington moun-
tain shows mostly Whiteface anorthosite, but nearly every outcrop
contains so many inclusions of Grenville, chiefly green pyroxene
gneiss, that it has seemed advisable to map this as an area of mixed
rocks. Injection gneisses like those just described above were not
noted. The small area just to the north contains similar rock.
Along the road just east of Franklin Falls there are some instruc-
tive ledges of Grenville and Whiteface anorthosite mixed gneisses.
One phase of this rock is white, medium-grained Whiteface anor-
thosite (practically all andesine to labradorite) containing approxi-
mately 20 per cent of irregular lenslike masses and bunches of dark
monoclinic pyroxene crystals, these masses ranging in size from
mere specks to an inch or two long and roughly parallel, causing
the rock to have a crude foliated structure. A thin section shows a
little ilmenite and apatite. Closely associated with this rock is a
true injection gneiss which is gray, medium grained and clearly
foliated. In thin section it reveals the following mineral percent-
ages: andesine to labradorite, 82; hornblende, 9; green and color-
less monoclinic pyroxene, 7%; biotite, 1; and ilmenite, %. Stilt
another phase of the rock from the same ledge is very similar in .
mineral composition to the last phase described, but it is finer
grained and contains several per cent of pale-red garnets in small,
scattering grains. It is very evident that this rock, with its several
facies, is a border phase of the considerable body of Grenville just
to the east (see map) where it has been penetrated more or less
intimately by the Whiteface anorthosite magma.
The small area bordering the Grenville one-half of a mile north
of Franklin Falls has a big ledge of gray, medium-grained, well-
foliated injection gneiss, similar to those above described, with
scattering light bluish gray labradorites up to nearly an inch long.
By the road 1% miles north-northeast of Franklin Falls a
single outcrop exhibits streaks and narrow bands of Grenville rusty
biotite gneiss closely involved with Whiteface anorthosite parallel
to the foliation of both.
At the edge of the quadrangle just east of Silver lake good
exposures show dark Grenville gneisses all shot through by White-
face anorthosite.
Along the border between the Whiteface anorthosite and dark
Grenville gneiss east of the gabbro at the southern base of Cata-
mount mountain, the anorthosite contains streaks and bands of the
‘aseqeip JO oYIp oy} uodn oly, S1owlUeY possor) ‘o}TULIS
Aq Jo opsoyJoue dovFoyIY\\ ApJSoU st Yor oy], ‘presses suryoo'y ‘ooo y FO YIos oI v
JO Jyey-ouo ‘JOATI apqesny oy} JO Youesrq isey oy} Jo 28103 oy} Jo pua saddn oy} Ur MoIA
916 ‘OJoyd ‘uosuyor “AM “Cd
GEOLOGY OF THE LAKE PLACID QUADRANGLE 55
Grenville due to cutting to pieces of the Grenville by the anor-
thosite magma along the border. This rock is not separately repre-
sented on the geologic map.
In the area of Whiteface anorthosite along the river west of
Malcom pond several ledges exhibit Grenville closely involved with
the anorthosite.
Grenville or amphibolite and syenite-granite mixed gneisses.
In five areas shown on the map, the Grenville or amphibolite and
syenite or granite are so closely associated that the delimitation of
these rocks was not found to be practicable.
The area bordering Lake Placid on the east shows, along the lake
shore, some ledges of pink granitic syenite with many long, narrow
inclusions of dark hornblende gneiss roughly parallel to the foliation.
Toward the interior of the area, there are some outcrops of nearly
pure granite syenite, and others which are very gneissoid, rather
basic looking, almost banded syenitic rocks which have resulted
from more or less fusion of layers of dark gneiss by the syenitic
or granitic magma. In some of these ledges there exist rather
well-defined bands or layers of dark gneiss not over a foot thick
where fusion has not been so effective.
At the map edge southwest of Keene, the area of mixed gneiss
seems to show a predominance of syenite, but there are a good
many outcrops of light and dark-gray Grenville gneisses. In some
exposures the syenite and Grenville are rather closely associated,
but, as a rule, the relationships of the rocks are not well exhibited.
One mile northeast of Keene the small area of mixed gneisses
well exhibits intimately associated Grenville light and dark gneisses
and syenite. Streaks and bands of Grenville are in some places
more or less fused in.
In the area 2 miles a little west of north of Keene, syenite pre-
dominates, but considerable quantities of Grenville are involved
with it, often having been more or less fused in. On top of the hill
there seems to be a little Whiteface anorthosite as bands or inclu-
sions parallel to foliation of the syenite.
The whole hill north of Cranberry pond is a mixture of fine to
medium-grained, gneissoid, pink granite and hornblende gneiss,
sometimes one and sometimes the other predominating. The horn-
blende gneiss (or amphibolite) occurs as bands in the granite par-
allel to the foliation. This dark gneiss is either Grenville or meta-
gabbro, probably the latter.
Whiteface anorthosite and syenite-granite mixed gneisses.
Four areas of mixed rocks of this sort are shown on the geologic
56 NEW YORK STATE MUSEUM
map. ‘They represent masses of Whiteface anorthosite which have
been more or less shot through, and cut to pieces, by syenite or
granite. Individual outcrops within these areas are usually either
good anorthosite or good syenite or granite, but they are too much
involved to be separately mapped.
The largest area, extending from 1 to 3 miles east of Wilmington
notch, is quite typical. There are many outcrops of clearly recog-
nizable Whiteface anorthosite and of syenite with contacts visible
at several places. Such contacts as, for example, on the ridge at
the northwestern border of the area, are usually not perfectly sharp
as though some fusion of the anorthosite by the syenite magma took
place along the immediate borders between the two rocks. Actual
fusion on a considerable scale did take place on the eastern side of
the area as shown by the small body of assimilation rock (Keene
gneiss) on the map. This whole area is a fine illustration of a
mass (about 1% square miles) of Whiteface anorthosite cut
through by many intrusions of syenite of considerable size, but
where apparently the temperature of one or the other, or both, of
the rocks was not high enough to permit more than slight fusion of
the anorthosite along the contacts.
The long, narrow area traversed by the river between High fall
and The Flume contains a number of interesting exposures along
the river. The Whiteface anorthosite has been badly cut through
by intrusions of syenite, such phenomena being well exhibited in
ledges by the river within one-third of a mile east of High fall.
Small inclusions of Whiteface anorthosite in the syenite and par-
allel to its foliation occur in a ledge by the river one-half of a mile
southwest of The Flume. An 8-foot boulder of syenite near the
base of Little High fall, one-third of a mile east of High fall, con-
tains several distinct inclusions of Whiteface anorthosite without
very sharp contacts against the syenite.
The little area near the eastern end of Wilmington notch con-
tains mostly good syenite with considerable Whiteface anortho-
site as bandlike inclusions through it.
In the gorge of the river one-half of a mile south of Keene, there
are excellent outcrops of Whiteface anorthosite cut by a consider-
able mass of coarse, rather porphyritic granite, with small tongues
of the granite extending into the anorthosite. The anorthosite is
the quite normal Whiteface type and clearly gneissoid. The granite
is pinkish brown, gneissoid, and medium grained with scattering
phenocrysts of feldspar. Much of the mixed rock here is badly
broken up due to crushing in a fault zone (see plate 21). These
Plate 16
waren xe
W. J. Miller, photo, 1915
The gorge of the East branch, Ausable river, one-third of a mile south of Keene.
Looking south upstream. The rock is mostly Whiteface anorthosite.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 57
crushed rocks are notably granulated, and in thin section the
crushed granite shows very interesting examples of sliced and
granulated quartz (see plate 12).
Gabbro-diorite Dikes
These very interesting dikes show considerable variation in
mineralogical composition, but all of them may be classed as ortho-
clase gabbro-diorites. No rocks of this sort have ever been
observed by the writer elsewhere in the Adirondack region. Alto-
gether ten or twelve dikes were found, eight or nine on Catamount
mountain, and two on the mountain 1%4 miles north-northeast of
East Kilns. These dikes are certainly younger than the coarse
granite of the syenite-granite series, and older than the diabase,
and some, at least, of the pegmatite, dikes. Whether they are older
or younger than the gabbro stocks could not be determined.
Five or six of these dikes at or near the summit of Catamount
very clearly cut the great bare ledges of granite for distances up to
one-fourth of a mile. They vary in width from 2 to 30 feet, those
toward the very summit all being over 20 feet wide. The strike of
the dikes is roughly parallel to the foliation of the granite but it
varies from N 10° E to N s0° E, the latter being the strike of the
large dike which lies just below the summit and reaches one-fourth
of the way down the mountain. The dikes are badly weathered
(much more so than the granite) to brownish gray, so it is impos-
sible to obtain good specimens of fresh rock. Contacts against the
granite are rather sharp, and the dikes stand in practically vertical
position. Two wide dikes just below the summit are weathered
and eroded out leaving clear-cut trenches in the granite, these
trenches being visible from the base of the mountain. All the rock
is somewhat gneissoid, but the larger dikes are usually clearly finer
grained and more gneissoid to almost schistoid at the borders. The
most common facies of the dike rock is tine to medium even grained
with mineralogical composition shown by no. 57 of table 4. Another
facies is almost medium, even grained, and looks something like a
basic phase of the syenite. Its mineral content is given as no. 56
of table 4. Least common is a fine-grained facies with scattering
flakes of biotite each several millimeters across. Its mineral con-
tent is shown by no. 59 of table 4. As already stated, it was not
positively determined whether the small aplite dikes in the immedi-
58 NEW YORK STATE MUSEUM
ate vicinity are younger or older than the gabbro-diorite dikes but,
since the aplites are more strictly parallel to the foliation of the
granite and not so sharply separated from it, it is probable that
they are the older. Since the granite is only moderately foliated
and the aplite not at all, it seems evident that the foliation of the
gabbro-diorite dikes, especially near the borders, is the result of
magmatic flowage rather than of regional pressure.
At the top of the ridge one-half of a mile northeast of the summit -
of Catamount mountain, there are three more of the gabbro-diorite
dikes. The middle one is fully 40 feet wide and distinctly gneis-
soid. All three strike about N 20° E. A diabase dike 3% feet
wide, and a pegmatite dike 3 feet wide, each cuts obliquely across
the largest of the gabbro-diorite dikes.
On the mountain 1% miles north-northwest of East Kilns, two
more gabbro-diorite dikes, presumably of the same age as those
above described, show good contacts against the coarse granite.
Each dike is about one-third of a mile long. The larger one is
fully 100 yards wide, and the other is much narrower, being
reduced to a width of only 1 foot at the western end where it
very sharply cuts the granite. Fresh rock from the larger dike is
dark greenish gray, and it weathers to a brownish gray. It is fine
to medium grained and moderately gneissoid. It looks very much
like a very basic facies of syenite, but its high content of albite
and pyroxene (see no. 58 of table 4) makes it distinctly different.
It differs from the Catamount gabbro-diorite pe its high percentage
of monoclinic pyroxene.
Table 4. Thin sections of gabbro-diorite
oO o
= 5 zs ©
a a o%
£ | 8 4 af @ [esol oe
ely Ge &| 3 S aai|a|s|e] 2 2 2 2
a rahe a 3 e S S| a 1s ise 5S Fe = E
Me} S| is q = oF raf SI pe) a) = 9
zy 3 es a 5 SO Ae Sh 8 2 E a =
a fea = || Oo ay = A | a | a ee oa) a < N
56]15¢5a] 50 OANA AR Hosnscclleasallocc. ra) 12 I 1} 3 | little
59 |15g@5b]. 18 y allo pyee el [lie ofl leoyrcra | Iioves 24 (o) 4 14 LHe Kedah eee
Sop || seis ep Aball acts} |) in} PAU sasT77 een | peepee 4 Yel lig MO lis gin a I 2 pve Pectin
SOauzukces | 10 Alb. 50 28 6 2 I 2 1} 5 a
Nos. 56, 59 and 57, from the top of Catamount mountain; no. 58, from
top of mountain 1% miles north-northwest of East Kilns.
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QyIl B JO F[VYy-auo ‘TIAIT s[qesny ‘YourIq jsey oY} JO Poq oY} UTSassToUS PoXTlU o}1UvIS PUL d}ISOYJIOUL DIVYA
916— ‘ojoyd ‘uosuyof “M ‘a
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 59
Gabbro and Metagabbro
Seven gabbro masses are represented on the accompanying geo-
logic map. These are in most respects quite like the usual gabbro
of this age throughout the Adirondacks. A rather full account of
the typical gabbro is given in the writer’s State Museum report on
“The Geology of the North Creek Quadrangle.” Most of the gab-
bro masses of the Lake Placid quadrangle appear to occur as true
stocks rather than as dikes. No tongues or branches from them
were observed to extend into the country rocks. The stocks all
have rounded or elliptical ground plans, and range in size from
one-eighth of a mile across to 1 mile across. Most of the gabbro
bodies are certainly intrusive into, and therefore, younger than, the
syenite-granite series, but, judging by experience in the Lyon Moun-
tain quadrangle some may be older than the syenite-granite. They
are clearly older than the diabase dikes. Whether they are older or
younger than the gabbro-diorite dikes above described could not be
positively determined, but they are probably younger.
The gabbro bodies nearly all consist of nongneissoid interior
facies with more or less well-developed diabasic texture, and very
gneissoid (amphibolitic) border facies without diabasic texture.
The nongneissoid diabasic textured gabbro is generally easily dis-
tinguished from the other Adirondack rocks, but the amphibolitic
border facies often greatly resemble certain of the Grenville horn-
blende gneisses.
The fresh rock is dark gray, which, on weathering changes to
deep brown. Most of the rock is medium grained. About equal
amounts of plagioclase (chiefly labradorite) and dark minerals
make up the main bulk of the rock. Portions or all of the labra-
dorite crystals are often filled with tiny dark specks of some
unknown mineral arranged parallel to the twinning bands. Most
prominent of the dark minerals are monoclinic pyroxene, hyper-
sthene and hornblende. Garnet seldom fails, and it often consti-
tutes 10 or 15 per cent of the rock. The pyroxene and garnet are
commonly much granulated, the crushed garnet generally either
forming rims around feldspar or granulated pyroxene, or borders
between feldspar and granulated pyroxene. Olivine occurs in at
least two of the masses, this mineral being rather uncommon in
Adirondack gabbros. Slide 52 of table 5 shows olivine with suc-
cessive rims of granulated hypersthene, feldspar and garnet (see
lower right figure of plate 18). Table 5 gives the mineralogical
compositions of several typical gabbro bodies.
60 NEW YORK STATE MUSEUM
Table 5 Thin sections of gabbro
Oo o
(| ~P
g 2 ° a
ok
Slept 3 ae 3 ie 86
o S| oO ABW Siw a j| aS 23 ®
Ss Re} 8 a i | el |S 2 2) aac » 2 I
Y ag} bp S| = | & | a | & 3 q 5 = Bey 9
eo a Sy EE aap is |e a | & 5 & | 8
a ca ay =} S) i) el |) Sl tae |} a Oo | t= Ay < N
26 5 cL O].—Lab. 50 Bi [ha scd ame a2 OP || eeuete)| 25a [aaa I I | little 3 | little
53 4c9 | An.—Lab. 50 HF) We oaal) LA |loncal| 2S || lore Io Gy || RE oso cblleacas
54 4c3 |An.—Lab. 50 Giilooe nll a2) Ne oooll || litle Whig a oc » 14 | little | little |.....
52 | 4ma2 | An.—Lab. 50 20 SH cues [aes I a> LA! I WE loaocn cllacdos
55 | 14¢2 Lab. 50 H@ loool i677 I 7 4 TOPs little. |e, eee tereraees
Nos. 26, 53 and 54, from Pulpit mountain gabbro mass; no. 52, from
southern side of gabbro 2%4 miles south-southeast of Upper Jay; no. 55,
from gabbro at southern base of Catamount mountain.
Most of the Pulpit mountain gabbro mass is gneissoid, only a
relatively small portion of the interior being nonfoliated and with
a diabasic texture. Nos. 26, 53 and 54 of table 5 are from this
stock.
The largest body, from 2 to 214 miles south-southeast of Upper
Jay, lies only partly within the limits of the quadrangle. Most of
the rock is medium to moderately coarse grained with good dia-
basic texture, and a gneissoid border facies is more or less well
developed. It is an olivine gabbro (see no. 52 of table 5). A
small diabase dike, with nearly north-south strike and dip 60
degrees east, sharply cuts the gabbro near the southern margin.
A small diabase dike sharply cuts the small gabbro mass 1 mile
west of East Kilns.
The other gabbro masses are quite typical in every way. The
gabbro at the southern base of Catamount mountain clearly exhibits
its relations to Whiteface anorthosite, Keene gneiss, and granite,
all three of which it sharply cuts.
Diabase Dikes
General features. Without counting two or more dikes close
together within practically single outcrops, sixty-one diabase dikes
were found within the quadrangle. These are all located and num-
bered on the accompanying geologic map. Without question still
others exist, but they are either effectually concealed or they
escaped detection in the rough wooded country. Such diabase
dikes are known to occur throughout the Adirondack region. They
are the youngest of the Precambrian rocks, and they always sharply
Plate 18
Photomicrographs by W. J. Miller
Upper left figure. Part of slice of gabbro from dike no. 5, one-half of
a mile south-southwest of Owen pond. Shows very fine diabasic texture.
Toward top, a large phenocryst of olivine with a thin rim of magnetite or
ilmenite. Dark gray angular patches, brown augite; black patches, magnetite
or ilmenite; white material, plagioclase. Ordinary light. Magnified 23
diameters.
Upper right figure. Part of slice of diabase from quarry at southern
base of Hamlin mountain. Toward top, augite phenocryst with inclusions
black patches) of pyrite. White laths are labradorite crystals embedded in
a black glassy groundmass. Ordinary light. Magnified 30 diameters.
Lower left figure. Part of slice of diabase from dike at south end of
gorge one-half of a mile south of Keene. Toward upper right, a large
idiomorphic phenocryst of olivine with a thin magnetite or ilmenite rim and
much decomposed to chlorite. On left, a large idiomorphic phenocryst of
augite with zonal structure. Dark laths, biotite; black specks, magnetite or
ilmenite; white material of matrix, plagioclase. Ordinary light. Magnified
23 diameters.
Lower right figure. Part of slice of gabbro from southern side of stock,
214 miles south-southeast of Upper Jay. Toward top, two large rounded
grains of olivine (with black streaks of secondary magnetite) surrounded by
successive rims of granulated hypersthene, plagioclase, and garnet. Dark
patches, hornblende. Part of large labradorite crystal at bottom, Ord'nary
light. Magnified 23 diameters.
”
GEOLOGY OF THE LAKE PLACID QUADRANGLE 61
cut all the other types of Adirondack rocks as narrow bands of
slight areal extent. They are wholly nonmetamorphosed.
The fresh rock is dark bluish gray and generally fine grained,
though a few of the larger dikes are medium grained toward the
middle. Many of the dikes are distinctly finer grained toward
their margins. A glassy groundmass occurs in a few cases. Many
of the rocks contain small phenocrysts of augite or olivine, or both,
and a few contain phenocrysts of plagioclase feldspar. A good
diabasic texture is often clearly discernible with the naked eye in
the relatively coarser grained rocks, and with the microscope in the
finer grained ones, though some of the dikes apparently fail alto-
gether to exhibit this texture.
In width most of the dikes range from less than an inch to 25
or 30 feet, and in length up to at least one-half of a mile. Most of
the dikes show a general northeast-southwest strike, this being
parallel to certain prominent structure (fracture) lines of the
region. Some of the dikes strike nearly east-west, but not one was
Table 6 Thin sections of. diabase
ig 3
; 2 ae 3 a
S 5 | sae 53
2 i=} uo] o o ® oS) ‘ore a o ee 2
xs ~ =] ~ iD ¢ 53 A a=
vo MS) 5 7) i ee) fe) tev) = 3) n 3
x £ 3 SS] = 2 fe S SS “’ a a,
a ea 4 < Oo fe ©) = of O. ©) <
61 723 OSt eee it Mel Wastcseer Uae hetceeneat tic DOW er sienceaelltereeretectets
62 17j6 60 20 5 3 7 ARI rcsaceete ts TO (eee ctl eeenenit cians
63 IOmtr 60 ES iil eee onremes| ass cusaet| eel arshe Sil apaevaortcveal| fess tearcnene BOW lle ievsedlors
64 5fr 58 21 I 7 A |loosc oer (OM Wicicoteensl cress 0 8
65 2k14 65 T'S in | eeoeeSenus TOM Rene See He liGtle urs seen lin eye ots little
66 1k2 30 40 4 ZOU tac snciee Ova rev oreeioral | Peareesrciesst| fopeeet caren lege ceerene
No. 61, dike no. 33, High fall of West Branch Ausable river; no. 62,
dike no. 48, 1% miles southeast of Fremont hill; no. 63, dike no. 24,
quarry at southern base of Hamlin mountain; no. 64, dike no. 5, one-half
of a mile south-southwest of Owen pond; no. 65, dike no. 14, 1 mile
north-northwest of Keene; no. 66, dike no. 9, one-half of a mile south
of Keene in the gorge.
observed to strike northwest-southeast. Many of the intrusions
quite certainly took place along zones of faulting of excessive
jointing, but tn some such cases, at least, renewed earth move-
ments occurred after the intrusion of dike material because the
dike rocks themselves, in such cases, are either brecciated or exces-
sively jointed.
As seen in table 6, the chief minerals are labradorite and augite.
62 NEW YORK STATE MUSEUM
Special descriptions. No. 65 of table 6 is very typical of a
medium-grained diabase without olivine from a dike 30 feet wide
with fine-grained margins. The diabasic texture is plainly visible
to the naked eye. Under the microscope the labradorite is seen to
be in distinct laths, the biotite pale yellow to deep brown, and the
augite pale brown with good cleavages. This rock is lighter gray
than the usual diabase of the quadrangle.
In the southern part of the gorge of the river one-half of a mile
south of Keene, a dike (no. 9) fully 5 feet wide cuts the mixture
of granite and anorthosite. It stands in a vertical position, is trace-
able for fully 100 yards, and shows a fairly good columnar struc-
ture. The rock is really an olivine basalt porphyry. It is repre-
sented by no. 66 of table 6. Two generations of crystals are evi-
dent, all of the olivine and some of the augite belonging to an
earlier period of crystallization, these two minerals clearly standing
out as phenocrysts (black and pale yellowish green respectively )
up to nearly a centimeter across. The groundmass is very fine
grained, dull black, and without a diabasic texture. Under the
microscope the olivine is colorless with crystal boundaries fairly
well defined, and it shows some alteration to serpentine and hema-
tite along the fractures. In thin section the augite is pale brown,
mostly as rather idiomorphic crystals with good cleavages, and
often with excellent zonal structures. The biotite is in the form of
slender prisms with light to dark-brown pleochroism. The biotite
evidently crystallized before the feldspar because the latter fills
spaces between the biotite crystals. Much of the labradorite is in
the form of small lath-shaped crystals.
In the gorge of West Branch Ausable river at High fall, there
are several dikes (probably branches of a single large one) sharply
cutting the granite parallel to its jointing. They are traceable for
fully 100 yards in the walls of the gorge, the largest dike being
about 5 feet wide. Just above High fall one of the dikes is brec-
ciated. No. 61 of table 6 gives its mineral content. The rock under
the microscope, is seen to be badly decomposed, which accounts for
the large amount of secondary calcite.
On top of the ridge 1 mile east of Upper Jay there are seven or
eight short dikes from 1 inch to 1 foot wide and roughly parallel,
as indicated on the map. The largest is exposed for 75 feet. The
middle ones are slightly faulted in a number of places.
A dike 4 or 5 feet wide is beautifully exposed at the lower end
of The Flume where it cuts the Whiteface anorthosite vertically.
It contains some inclusions of the anorthosite.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 63
About one-half of a mile northeast of the summit of Catamount
mountain, a diabase dike 3% feet wide sharply cuts the largest
gabbro-diorite dike obliquely and the granite parallel to its folia-
tion. A few rods farther east there are five dikes, none over a few
feet wide, and roughly parallel.
Near the summit of Catamount, a dike (no. 52) 6 feet wide may
be clearly seen cutting the granite for several hundred feet. This
may be a continuation of the large dike (no. 51) one-half of a
mile to the northeast.
On the mountain top 14 miles northeast of Catamount summit,
there are several dikes from 2 to 6 feet wide, nearly parallel, and
close together.
Dikes nos. 13 and 53, each about a foot wide, sharply cut gabbro
stocks.
Dikes nos. 3, 30 and 35 show various branches or tongues extend-
ing into the country rocks. No. 3 is in contact with a pegmatite
dike, and it is considerably brecciated due to faulting.
Dike no. 55, one-half of a mile north of Franklin Falls, is 2 feet
wide. It contains fresh labradorite crystals as phenocrysts up to
an inch long with very evident twinning bands.
Very instructive dikes may be seen at locality no. 28 where sev-
eral dikes (one 10 feet wide) sharply cut Whiteface anorthosite.
There were very plainly two injections of diabase magma here. The
earlier injected mass was the larger, and it solidified into a dark
bluish gray rock with a very fine-grained diabasic texture. The
second injected masses are only a few inches wide, in sharp con-
tact with the first; black and almost glassy with very small pheno-
crysts of labradorite whose long axes are approximately parallel
thus causing this second intrusive to have a fairly good flow-struc-
ture. A similar combination of diabase cutting diabase was
observed in a glacial boulder 1 mile southeast of Wilmington.
Dike no. 42 (see no. 63 of table 6) is only 4 inches wide, but it
exhibits a very fine diabasic texture in the middle portion, and
black glass at the margins.
At locality no. 18 several dikes from 5 inches to over 5 feet wide
are close together and sharply cut Grenville quartzite.
In the old limestone quarry at dike locality no. 16, a good diabase
dike with several small branches sharply cuts the limestone.
The Rocks of Catamount Mountain
A remarkable assemblage of rocks occurs within an area of less
than 1 square mile, including the summit and southern base of
64 NEW YORK STATE MUSEUM
Catamount. Fully fourteen kinds of rocks are represented, most of
them having been formed at different times. Oldest of all are the
Grenville hornblende gneiss and crystalline limestone well shown
in, and just west of, the quarry at the base of the mountain. In
contact with this Grenville gneiss there are good outcrops of
typical Whiteface anorthosite. On the southeastern slope of the
mountain, syenite grades into granitic syenite, and this, in turn,
into coarse granite. A narrow band of Keene gneiss, formed by
assimilation of anorthosite by the granite magma, lies between the
granite and anorthosite near the southern base of the mountain.
Numerous small aplite dikes cut the granite parallel to the foliation
toward the top of the mountain. In the vicinity of the aplite
dikes, quartz veins lie across the foliation of the granite. Dikes of
gabbro-diorite cut the granite roughly parallel to its foliation at and
near the summit, and one-half of a mile to the northeast. A small
stock of typical gabbro cuts anorthosite, Keene gneiss and granite
near the base of the mountain. A diabase dike 6 feet wide sharply
cuts the granite just. south of the summit. A diabase dike and a
small pegmatite dike cut obliquely across the larger of the gabbro-
diorite dikes one-half of a mile northeast of the summit, Glacial -
deposits are extensively developed around the foot of the mountain.
SHURE TURAL, (Gi OQLOG Ww
Tilting and Folding of the Grenville Series
It has been generally assumed that the Adirondack Grenville
strata have been severely compressed and folded as well as thor-
oughly metamorphosed and foliated by the compression. Recently,
however, the writer has presented strong evidence! that the Gren-
ville strata have neither been highly folded nor severely com-
pressed, while many broad belts of Grenville are known to be prac-
tically undisturbed or only very moderately folded, and many
masses, large and small, are merely tilted or domed at various
angles. Very locally the strata are sometimes contorted. Paral-
lelism of Grenville and syenite-granite rock belts is common with a
general tendency toward northeast-southwest strike, but there are
so many notable exceptions (some, for example, in the Lake Placid
quadrangle) that any generalization, regarding such a strike of the
rock belts as due to severe lateral compression, is of little signifi-
cance.
1 Jour. Geol., 24:588-96. 1916.
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66 NEW YORK STATE MUSEUM
preserved. Parallelism of Grenville foliation and _ stratification
appears to be universal. The Grenville has, for a long time, been
regarded as essentially a result of severe regional compression after
the great igneous intrusions had taken place. Recently, however,
the writer has seriously questioned this view.
If the Grenville and accompanying great intrusives had been sub-
jected to compression severe enough to develop the foliation, is it
not remarkable that the stratification surfaces have never been
obliterated and cleavage developed instead, and also that stratifica-
tion and foliation are always parallel? Also, unless we assume
intense isoclinal folding, so that mineral elongation could every-
where have taken place essentially at right angles to the direction
of lateral pressure, the parallelism of stratification and foliation
can not be accounted for by crystallization under severe lateral
pressure. But the Grenville strata were never highly folded. We
are thus forced to the only alternative conclusion, namely, that
the Grenville foliation was developed during the crystallization of
essentially horizontal strata under a heavy load of overlying material,
or, in other words, under conditions of static metamorphism. Those
minerals which cause the foliation were elongated during crystal-
lization under the heavy load of overlying material. According
to this view, the parallelism of foliation and stratification is pre-
cisely what would be expected. This also explains the important
fact that the Grenville rocks are notably less foliated and granu-
lated than the great intrusives, particularly the syenite-granite
series.
Foliation of the anorthosite and syenite-granite series.” By far
most of the great intrusive rocks exhibit more or less well-developed
foliation, ranging from very faintly gneissoid to very distinctly
gneissoid, the structure usually being accentuated by the roughly
parallel arrangement of the dark-colored minerals. Some masses,
particularly of the Marcy anorthosite, are practically devoid of
foliation. Granulation of minerals, especially feldspar, is common,
the more highly foliated rocks generally being most granulated.
The writer considers these intrusives to be so-called “ primary
gneisses’ whose foliation was developed as a sort of magmatic
flow-structure under moderate compression rather than by severe
lateral pressure brought to bear upon them after the cooling of
the magmas.
* Jour. Geol., 24:596-600. 1916.
_2For a rather full treatment of this subject, see the writer’s paper
in Jour. Geol., 24:600-16. 1016.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 67
A brief summary of the writer’s views may be stated as follows.
During the processes of intrusion, which were long continued,
the great magmatic masses were under only enough lateral pressure
to control the general strike of the uprising magmas with conse-
quent tendency toward parallel arrangement of intrusives and
invaded Grenville masses; the foliation is essentially a flow-struc-
ture produced by magmatic currents under moderate pressure dur-
ing the intrusions; the sharp variations of strike on large and small
scales, and rapid variations in degree of foliation, are essentially |
the result of varying magmatic currents under differentiated
pressure, principally during, a late stage of magma consolidation ;
the almost universal, but varied, granulation of these rocks was
produced mostly by movements in the partially solidified magma,
and possibly to some extent by moderate pressure after complete
consolidation; and the mineral flattening or elongation was caused
by crystallization under differential pressure in the cooling magma.
It would seem, therefore, that the general absence of foliation
from so much of the Marcy anorthosite is best explained as the
result of much more uniform intrusion of this single great body
which was probably a stiffer or less fluid magma and which is less
involved with Grenville masses, or, in other words, to much less
forced differential flowage.
Foliation of the gabbro and gabbro-diorite. As already stated,
the interior portions of most of the gabbro bodies are nonfoliated
and they possess a diabasic texture, while the outer portions are
highly foliated rocks, often true amphibolites. In many places the
degree of foliation varies considerably within single stocks. More
or less granulation is very common. This foliation and granulation
have been quite generally regarded as secondary features produced
by severe regional compression. But it is very difficult to imagine
a process of development of foliation, which boxes the compass
around the borders of the gabbro masses, by regional compression.
Such foliation often of course strikes directly across the foliation
of the older adjacent rocks. If due essentially to regional com-
pression of the solidified gabbro, should not the foliation every-
where strike at least approximately at right angles to the direction
of application of the pressure? Also how are such notable varia-
tions in foliation and granulation to be explained ?
According to the writer’s view, the foliation and granulation of
the gabbro stocks are largely, if not wholly, primary features due
to movements in the magma béfore final consolidation. Consider-
able pressures must have obtained within the stock chambers while
68. NEW YORK STATE MUSEUM
the magmas were being intruded under deep-seated conditions.
Such pressure against the country rock, combined with the usual
development of differential flowage, particularly in the magmatic
borders, would readily account for the peripheral foliated zones
which were produced, no doubt, during a late stage of magma con-
solidation. But the conditions for magmatic pressure and flowage
must often have varied considerably, and thus the local variations
in degree of foliation and granulation are accounted for.
The gabbro-diorite dikes are also more or less foliated, their
borders particularly so. As in the gabbro stocks,’so here, the folia-
tion is considered to have been due to differential magmatic flow-
age under moderate pressure during a late stage of magma con-
solidation. In these dikes, however, the foliation was developed
parallel to the strike of the dikes because cross-sections of the
magma chambers were long and narrow rather than rounded or
elliptical as in the gabbro stocks.
Faults
General features. Faults are neither so numerous nor so promi-
nently developed as is usually the case in the eastern and south-
eastern Adirondack region. Within the Lake Placid quadrangle
the faults are not sharply defined earth-fractures, but rather they
are zones of excessive jointing in which more or less crushing and
faulting of the rocks have taken place. These broken-rock zones
are relatively straight for considerable distances, in some cases for
some miles. It seems clear that such alignments of crushed-rock
zones are due primarily to faulting, probably multiple faulting.
The width of the fault zones is commonly from 25 to 100 feet or
more. Most of them strike from northeast-southwest to north-
south as usual in the eastern half of the Adirondack area. Because
the rocks are broken up into numerous small blocks, the crushed
zones form belts of weakness along which valleys (sometimes deep
and narrow) have been developed. Little or. no positive evidence
regarding the positions of. upthrow and downthrow sides could be
obtained.
Wilmington notch fault. This is the finest example of a shat-
tered-rock zone definitely known within the quadrangle. Its length,
as indicated on the geologic map, is about 5 miles. The deep, nar-
row Wilmington notch, the gorge at High fall, and the gorge at
The Flume, all owe their existence to rapid erosion along this
prominent zone of weakness. In preglacial time the river did not
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 69
flow through this deep, narrow valley, the site of the present Wil-
mington notch having then been a division of drainage or col which
has been cut through by the West Branch Ausable river, the latter
having taken this course as a result of the glaciation of the region
(see chapter on the pleistocene geology). In fact the position of
the whole valley of the river between Mt Whiteface and the Sen-
tinel range has been primarily determined by the presence of the
great zone of weakness in the rocks.
In the bed of the river three-fourths of a mile west-southwest
of Owen pond, there is a big ledge of crushed rocks, especially
pegmatite and diabase, which are distinctly brecciated. Some frag-
ments of diabase have been mingled with the pegmatite. This zone
strikes N 20° E. Along the river within the granite area in the
notch, the rock is badly broken up in a wide zone parallel to the
stream. Just northeast of this along the river, the Grenville gneiss
is faulted with slickensides visible.
At High fall the granite of the gorge is highly jointed, the joint
surfaces being from one to several feet apart, forming a zone of
weakness which has determined the stream course. The joints
strike N 40° E and dip 65° E. Slickensided joint faces are com-
mon. Just above High fall a diabase dike in the stream bed is
brecciated, and close by is a distinctly slickensided scarp 4 feet high.
At the so-called Little High fall, about one-half of a mile below
High fall, there is a very prominent crushed zone as wide as the
river bed with a strike N 30° E.
In the river bed about half way between High fall and The
Flume, there are two well-developed crushed-rock, or highly jointed,
zones with strike parallel to the river. In The Flume the rock is
considerably jointed, but just above the bridge there is an exces-
sively jointed zone parallel to the course of the stream. Evidently
the gorge development here has been greatly aided by the rock
structure.
Faults in the town of Keene. At the southern end of the gorge
one-half of a mile south of Keene, the rocks are badly broken
up and somewhat slickensided, indicating a prominent crushed-rock
zone here with strike about east-northeast by west-southwest. By
the roadside at the edge of the gorge, this fault zone is well exposed
(see plate 21). The topography strongly suggests the continua-
tion of this fault zone some distance northeastward as indicated
on the map, but this is not verified by actual outcrops.
By the roadside nearly 2 miles north of Keene, the Whiteface
anorthosite and Grenville mixed rocks are much broken up, some-
7O NEW YORK STATE MUSEUM
what slickensided, and considerably weathered. The strike of this
crushed-rock zone is about north-south, but no other crushed rocks
are exposed along this fault zone as mapped.
The Grenville gneiss in the small gorge of Styles brook is
excessively jointed, forming a zone of weakness with strike east-
west or parallel to the stream course (see map). Tracing this
zone eastward was impossible because of lack of outcrops.
A fault zone of weakness has almost certainly determined the
position of the deep, narrow valley between Pitchoff mountain and
the southern end of the Sentinel range as indicated on the geologic
map, though actual exposures of faulted or excessively jointed rocks
are lacking at the critical localities.
Other faults. Several nearly vertical faulted joints pass across
the small quarry at the southern end of Lake Placid. They strike
N 30° E and probably represent a fault zone which extends through
the long, narrow, eastern portion of Lake Placid, but, if so, it is
everywhere under water. The long, narrow, western side of the
lake basin also strongly suggests its origin along a fault zone of
weakness, but positive evidence is lacking.
The group of diabase dikes about a mile east-northeast of Upper
Jay are slightly faulted in a number of places.
Possibly a fault zone has determined the position of the promi-
nent valley which separates Catamount and Wilmington mountains,
but positive evidence is entirely lacking because of heavy drift
covering, and it is possible that simple removal of a large mass of
relatively weak Grenville rock by erosion has caused this valley.
The notch between Mt Whiteface and St Armand mountain
suggests a development along a north-south fault zone, but out-
crops in the notch do not appear to have been faulted.
W. J. Miller, phcto, 1915
Crushed-rock zone due to faulting by the road, one-half a mile south of Keene
GEOLOGY OF THE LAKE PLACID QUADRANGLE WA
PERRIS TOCHNE GEOLOGY
BY HAROLD L. ALLING
INTRODUCTION
In the detailed mapping of the quadrangles in the Adirondack
region more attention has usually been given to the crystalline
rocks than to the Pleistocene geology. The glacial phenomena,
however, are clearly discernible and promise to add materially to
the knowledge of the Pleistocene history of the State of New York
when fully worked out. Besides the usual types of glacial deposits
the Lake Placid quadrangle exhibits deltas, terraces and shore-line
features of a succession of extinct glacial lakes whose history can
be traced with a fair degree of accuracy. Unfortunately for con-
cise description, the lakes were not confined entirely to the quad-
rangle so it is necessary in many cases to examine adjacent
topographic sheets in order to appreciate the extent and history of
each during its initiation, life and extinction. Nevertheless only
those lakes which formerly covered some portion of the Lake Placid
quadrangle will be described.
Although positive evidence of multiple glaciation in the Adiron-
dacks is not, as yet, forthcoming, Prewisconsin glaciation in Penn-
sylvania, New Jersey and on Long Island’ has been established so
as to lead us to the conclusion that this area has been subjected to
continental ice bodies more than once. In some of the stream
valleys the depth of the drift is enormous and a difference in the
character of different levels can often be detected. If evidence is
to be found of Prewisconsin ice action in the Adirondacks, it is
in such deposits.
But as the surface deposits are chiefly due to the last or Lauren-
tian lobe of the Wisconsin ice, we shall confine ourselves to its
effects.
Wisconsin Glaciation
Without much doubt the entire Adirondack region was com-
pletely buried by the ice, which has been estimated to have been
gooo to 12,000 feet in altitude over the central Adirondacks.? To
this enormous load upon the land surface is attributed the well-
observed phenomenon of deformation, to which we will return
later.
* Fairchild, H. L. Bul. Geol. Soc. Amer., 24:134. ©
? Fairchi iId, H. L. Geol. Soc. Am. Bul., 24: 136. After Shackleton.
SSE
72 NEW YORK STATE MUSEUM
Movement
Seventeen occurrences of glacial striae have been noted in the
quadrangle; they are especially numerous beside the highways in
the valley of the East branch of the Ausable river. The majority
of them have been observed by Doctor Miller, who has indicated
them upon the accompanying map. The striae in the valleys were
made by the waning stages of the glacial lobes, for their direction
has been influenced very largely by the topography of the country.
The more general direction of the ice flow would be shown by striae
on the mountain summits, but their records have been destroyed by
weathering agencies. Nevertheless it can be stated that the ice that
covered the quadrangle flowed southward with a slight deviation
to the west.
; Table of Glacial Striae
STRIAE . TOWNSHIP LOCATION OBSERVER
reas 5 ooo oc 4+ mile north of Franklin Falls............. W. J. Miller
Bramiclinieerseee 2? mile northeast of Franklin Falls......... W. J. Miller
Black Brook....] 1 mile northwest of East Kilns............ H. L. Alling
Wilmington..... 2 miles east of Wilmington............... W. J. Miller
Wilmington..... 3 miles southeast of Wilmington........... J. F. Kemp
UeIeiRa rai opera oes Southeast of Upper Jay......... 5 J. F. Kemp
Wayescserecte sree 2 mile south of Upper Jay....... ae . J. Miller
Wats wate eee 2 miles southwest of Upper Jay........... W. J. Miller
KEEN a terce ene 22 mMilesmornbnor: WMeene ner arn aeeerae W. J. Miller
ISGENGS Sood hasan) et saat morn Ot IKEEIO, so c5nnneconnaoos W. J. Miller
Keenet asa cero: Tey TaMIKSS) TaVCHeEl A Chi IMINO, 555600000 ancecbo- W. J. Miller
Keene nnenn soe sia aniles morthvon INecenenere ah ener H. L. Alling
Keene sci. t t Ty miles northiot Keeneseereaceeeeeoe aeee H. L. Alling
Keene..........]| 1+ miles north northwest of Keene......... W. J. Miller
WKGGn eink reps acces ti miles northeast of Keene.............. W. J. Miller
J. Miller
KEG cists ace 1 mile southwest of Keene................ W.
Erosional Work
The residual soil resulting from weathering during interglacial
periods was completely removed by the ice, the mountains smoothed
and their contours subdued. The extent of ice action is recorded
in the comparatively fresh condition of the rocks on exposed
ledges, as is shown on the bare slopes of Pitchoff mountain, on the
southern edge of the map.
The many amphitheaters and little rocky pockets on the moun-
tainsides are due, in all probability, to the erosive action of the ice.
These cirques have been attributed to the combined work of the
continental ice bodies and to local glaciers.1 They are visible on
* Ogilvie, I. H. Glacial Phenomena in the Adirondacks, Jour. Geol.,
10:406. 1902.
Johnson, D. W. Date of Local Glaciation in the White, Adirondack,
and Catskill Mountains, Geol. Soc. Amer. Bul. 28:543-52. 1917.
GEOLOGY OF THE LAKE PLACID QUADRANGLE WS
the slopes of Whiteface, Sentinel’ and especially Esther mountain.
The origin of rocky pockets, now occupied by ponds, on the south-
western slopes of some of the mountains is not clearly understood,
but plucking action of the ice may be regarded as a contributing
cause.
In pushing through the major fault-line valleys, such as the
Pitchoff “pass,” the Wilmington Notch, and also the Middle Kilns
valley, the ice carried with it the talus material that had accumu-
lated during interglacial periods, freshened out the valley walls and
left U-shaped valleys, blocking both ends with crescent-shaped
moraines as it retreated.
The occurrence of glacial boulders is quite common, some of
which appear to have been transported from great distances while
others can be traced to parent ledges in the neighborhood. Rounded
boulders of Potsdam quartzite have been noted all over the quad-
rangle. Large irregular slabs of Potsdam sandstone and quartzite
are encountered in some of the brook valleys where the drift is
abnormally thick. To the north of the road running from Upper
Jay to Wilmington, some 2 miles directly south of the latter, irregu-
lar nonglaciated flagstones were encountered in such numbers as
strongly to suggest that a ledge of the Potsdam existed here before
the ice invasion broke it up. Similar occurrences in the Elizabeth-
town” and Mt Marcy quadrangles,* together with outliers,* point
to the conclusion that the Adirondacks were submerged in the
Potsdam sea to a much greater extent than was formerly considered
to be the case.
Moraines
There is but little true morainal material to be found in the Lake
Placid quadrangle, for most of it has been modified by water ;° the
movement of the ice during the maximum advance having evidently
been too vigorous for deposition and the material that was deposited
as the ice retreated having been sorted by the waters of the glacial
lakes.
The recessional moraines appear to be largely confined to the
fault-line valleys, being formed by the ice-tongues as they with-
drew from the narrow defiles. At the southern ends, in the broa¢
*Kemp, J. F. The Geology of the Lake Placid Region, N. Y. State
ise Bul. 27; p. 2T
* Rudemann, Rudolf, N. Y. State Mus. Bul. 138, p. 62.
* Alling, H. L., Bul. Geol. Soc. Amer. 27 :650.
*Miller, W. J., N. Y. State Mus. Bul. 182, p. 44.
*Cushing, H. P., N. Y. State Mus. Bul. 115, p. 496.
Ogilvie, I. H., Jour. Geol., 10:406.
74 NEW YORK STATE MUSEUM
valleys, the rate of retreat was slow and moraines were formed;
but in the narrow valleys the melting of an equal amount of ice
would produce a much more rapid recession, giving but little oppor-
tunity for the deposition of material. Again at the northeastern
ends of the passes the ice-tongues paused long enough to deposit
another series of moraines.
‘The damming of such valleys by recessional moraines has resulted
in the Cascade lakes, located in the Mt Marcy sheet; and in Silver
lake and Taylor pond on the northern edge of the Lake Placid
quadrangle. A very striking example of morainal damming is Lake
Placid, formed by the blockading of twa parallel (fault-line?)
valleys which have been joined by valleys, producing the islands,
thus forming a ladder-shaped body of water. In a depression in
the dam Mirror lake now lies. Just south of Mirror lake Doctor
Miller found, beside the road, an exposure 20 feet thick, which
showed glacial till with large boulders in the upper half resting
upon distinctly stratified sands.t. The writer would infer that dur-
ing slight variations in the advance and retreat of the ice lobe,
glacial debris was deposited on top of a glacial lake bottom (see
page 83. Glacial Lake Upper Newman). A similar phenomenon is
known in the Cobb’s hill kame-moraine at Rochester, N. Y.
The preglacial drainage has been modified by glacial material of
one kind or another in several localities. A good example was
found south of the town of Keene in the East branch of the Ausable
river. In this comparatively broad valley on the northern edge of
the Mt Marcy sheet we note an unnamed hill, around the two sides
of which the two highways leading to Keene Valley circle. To
the west of this hill the present river rushes between steep walls
of syenite and mixed rocks (southern edge of the Lake Placid
quadrangle), experiencing rapids and ‘falls. It is clearly a post-
glacial channel and is one of the beauty spots in the quadrangle.
On the other side of this hill the preglacial channel is plainly per-
ceptible, although now blocked by sands of a lateral delta.”
Local Moraines; Local Glaciation
The writer’s work in the central Adirondacks would lead him to
suspect that local glaciers existed on the slopes of the higher moun-
tains. This conclusion has been reached through the study of
*Miller, W. J., Personal communication, Jan. 17, I917.
? Alling, H. L., Glacial Geology of the Mt Marcy Quadrangle, in The
Geology of the Mt Marcy Quadrangle, Kemp, J. F., in preparation; N. Y.
State Mus. Bul.
‘JadF OOQE Jnoqe
JO UOeAIa UL WOIF YOU SuLyoo'T ‘UIeJUNOU ToyIsy Jo ado[s Jsvayj10u oy} UO onda oY} OJUT UMOP SsuULPOOT
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 75
lateral moraines, usually modified and dissected by streams in the
brook valleys, often of perplexing character, but suggesting local
origin; and through the presence of poorly developed cirques, on
the mountain slopes; and hanging tributary valleys. In 1916 the
writer, under the leadership of D. W. Johnson, found in the
incipient cirque on the eastern slope of Esther mountain (a portion
of the Whiteface massif) a narrow ridge of debris at an altitude
of about 3000 feet, some three-fourths of a mile in length. Its form
is that of a glacial moraine rather than that of a landslide. This
cirque valley slopes northeast, which offered a favorable opportunity
for the continental ice to force a tongue into it and to deposit a
recessional moraine; but this would have a crest declining south-
west, while the moraine found has the opposite inclination. Fur-
thermore the northeastern end points slightly toward the axis of
the valley. The moraine is very well preserved and it is incon-
ceivable that this ridge of unconsolidated material could have with-
stood the destructive forces of the ice sheet. We must, therefore,
conclude that local glaciation took place after the withdrawal of
the main ice body from the region.*
It is sometimes argued that if local glaciers occupied the cirque
valleys, small terminal moraines should, in every case, be found
at their lower extremities ; their absence being taken as evidence for
dating such action before the continental ice invasion, which caused
their destruction. The studies of de Martonne in the Alps and
the Carpathians show that in regions now undergoing Alpine glacia-
tion, where the complications of continental ice bodies are absent,
local moraines are seldom prominent features, for the glacial
streams destroy them. Thus as a rule only one or two moraines
are found in every ten cases examined.
It is reasonable to expect that local glaciation could not have
been limited to the Catskill mountains (which is a region unlikely
to support local glaciers) without the Adirondacks likewise experi-
encing it; hence, since local glaciation has been established there,’
it lends weight to the above conclusion.
*Johnson, D. W., Date of Local Glaciation in the White, Adirondack
and Catskill Mountains. 29th Annual Meeting Geol. Soc. Amer., Bul. 28:545-
52.8 I917.
* Rich, John L., Notes on the Physiography and Glacial Geology of
the Northern Catskill Mountains, Am. Jour. Sci., 39:154. Feb. 1015.
Local Glaciation in the Catskill Mountains, Jour. Geol. 14:113-21. 1906.
Local Glaciation in the Catskill Mountains, Geol. Soc. Amer. Bul. 28:133
(abstract) 1917.
76 NEW YORK STATE MUSEUM
Eskers are infrequent on this quadrangle, although a number
have been located in the Mt Marcy, Ausable, Saranac.and St Regis
sheets. The writer has seen within the present limits no glacial
deposits as undoubted eskers, but Doctor Miller considers to be
such an east-west ridge some 200 yards long and 30 to 50 feet high,
observed by him, one-half of a mile directly east of the cross roads
at Keene.
Kames are likewise uncommon. In the vicinity of the south-
western end of the Middle Kilns valley a number of irregular hills
are strongly suggestive of kame topography.
Outwash Plains
Outwash plains can generally be distinguished from deltas and
glacial lake bottoms by ice blocks, kettle holes, and the lack of shore-
line features. Frequently, however, in the field such distinctions
are difficult, if not impossible, to make unless accompanied by other
positive evidence. Some of the sand plains in the quadrangle are
rather perplexing and their origin may be complicated, although
it is believed that the majority of them were formed in connection
with the glacial lakes described here.
Extinct Glacial Lakes
Conditions Favorable for Glacial Lakes in the Region. A
number of important factors were favorable for the formation
of several series of local glacial lakes in the east central Adiron-
dacks, and some of these bodies of water existed im the area cov-
ered by this bulletin. Among the conditions we note: (1) north-~
ward-draining valleys, sloping toward and blocked by ice lobes;
(2) the complete isolation of such valleys by mountain ranges; and
(3) the presence of a huge ice ring that completely surrounded
the highlands, impounding vast quantities of water. This area
was situated close to the northeast rim of the ring. The large
amount of available material for the formation of deltas, terraces
and beaches, makes recognition possible. The cause of the great
quantities of sand is discussed later on.
A number of glacial lakes in the quadrangle have been noted
in the past by Taylor,* although he did not attempt to separate and
correlate the different levels, and by Kemp who has noted* two or
* Taylor, F. B., Lake Adirondack, Amer, Geol., 19:392-66. June 1807.
7Kemp, J. F., Geology of the Lake Placid Region, New York State
Muse Buls2ns palo:
« GEOLOGY OF THE LAKE PLACID QUADRANGLE FG),
three sets of deltas in the Keene valley. It has fallen to the writer
to attack the problems of the glacial lakes of the east central
Adirondacks, and to attempt to translate something of the wonder-
ful history. In such pioneer work mistakes and faulty interpre-
tations are apt to appear, for it is impossible to avoid errors.
In dealing with the glacial lakes the writer has, for convenience,
classified them into three sections: (1) the western section, that
is, the region around Lake Placid, to the west of the Wilmington
notch; (2) the eastern section, or the Keene valley division in the
valley of the East branch of the Ausable river; and (3) the Eliza-
bethtown valley group. The last section does not come under dis-
cussion here.
Upper series: western section. As the ice sheet began to
wane, the highest peaks of the Adirondacks were the first to be
uncovered, playing the role of islands in a sea of ice.* Slowly these
islands became larger, surrounded by a growing accumulation of
water impounded by the ice. These waters found escape over the
ice to the south and eventually passed to Susquehanna drainage.
This process of melting was continued until entire mountain ranges
were exposed.
The South Meadows lake. The highest definite level recog-
nized by the writer in the Adirondacks, as shown by sand plains,
terraces and beaches, is one ranging from 1940 to 2210 feet in
altitude. When this level was first appreciated some hesitation
was felt in describing it as glacial, for no shore-line features or
outlets had been noted. It was considered as outwash plains formed
by aggrading glacial streams that flowed from the melting ice, but
as extended field work was undertaken these lake phenomena were
discovered, or strongly suspected, and hence the true nature of the
plains was established.
The best development of the glacial deposits of this lake is in the
northwest corner of the Mt Marcy sheet in the South Meadows
country ; hence the name — South Meadows lake. As can be seen
in figure 2, the writer conceives that it covered the southwest por-
tion of the Lake Placid quadrangle and the corners of the adjacent
sheets. The ice consisted of three lobes: one covered the greater
portion of the Saranac sheet; the second lobe was fed through
the narrow passes to the east and west of the Whiteface-Esther-
Wilmington massif and covered the territory where Lake Placid
Paccwi Gein le Nie Ne state Mins, Bulyr6oi pl. 11.
78 NEW YORK STATE MUSEUM
‘now lies; the third and the most eastern lobe, here considered,
completely filled the valley of the East branch of the Ausable river
and Keene valley.
ICE SHEET
NS GLACIAL LAKE SCALE OF MILES
N SOUTH MERDOWS . ~ KEW:
; AANRC [PLACID
oo EARLY OUTLET;<-’ 4
a MT
i i U ‘
LATER OUTLET! Abul ter
'
Fig. 2 The Glacial Lake succession in the Lake Placid quadrangle. Stage
one.
The South Meadows lake, altitude 1¢40 to 2210 feet.
The South Meadows lake was of irregular shape, some 10 miles
long and wide, containing a number of islands. Its outlet has not,
as yet, been definitely established, but a very probable one is offered
as follows. It begins at the swamp just south of Alford moun-
tain in the Santanoni quadrangle, on the Essex-Franklin county
boundary line (altitude 2105% feet), and passes westward through
the narrow pass (altitude 1980 feet) directly south of Van Dorrien
mountain to Blueberry pond. Continuing westward into the Long
Lake quadrangle, on the boundary. between the two maps, it turns
to the southwest and passes three-fourths of a mile south of Palmer
brook. When within a mile of the Raquette river, the course turns
directly south over Brueyer pond. This river course is a mere sug-
gestion as actual field work has not been undertaken in the rugged
GEOLOGY OF THE LAKE PLACID QUADRANGLE 79
and inaccessible Santanoni quadrangle. Probably the waters flow-
ing through this channel did not form a single river but consisted -
of a chain of lakes and ponds. Just where the ice control was
located for each successive level is not known.
The glacial sands, gravels etc. form a filling in the South Mead-
ows country that is estimated to be at least 300 feet thick. This
matter will be referred to again in another connection.
A number of unmistakable beaches exist on the shoulders of the
Sentinel range and on Scott’s cobble, northern edge of the Mt
Marcy sheet. The altitude of a series of them ranges from 2146
to 2209 feet.1 These figures, in all probability, represent the water
levels during the early stages of the lake. Sand plains with alti-
tudes close to 1960 feet strongly suggest that the lake was under-
going constant lowering, perhaps as the small ice lobe 3 miles east
of the highest peak of Ampersand mountain retreated and allowed
escape through the channel of the East branch of Cold brook and
then south, lowering the level to 1960 feet as set by the Van Dor-
rien pass mentioned above. (See figure 2 as indicated by the
“later outlet.” )
The fault-line valley containing the Cascade lakes (Mt Marcy
quadrangle) was probably filled by morainal material and by a
glacial lobe, preventing escape to the east; thus the outlet was to
the west as suggested above.
Western portion of Upper Lake Newman. With the gradual
_ retreat of the ice and its constant shifting of position, new and
lower outlets were exposed. Succeeding the South Meadows lake,
the western portion of Upper Lake Newman, as the writer pro-
posed to call it,? was ushered in. As the remnants are rather indef-
inite in character and the range is considerable, 1800 to 1895 feet,
the writer is not unmindful that stream filling forming an outwash
plain from the glacier may be an alternative explanation; but in
‘view of the fact that sand plains are found over a considerable
area confined within definite limits of range of altitude, they are
assumed to represent a series of lake bottoms formed by a lake
whose level was experiencing periodic lowering due to the down-
cutting of the controlling spillways.. These spillways may have
been over the ice itself or a series of outlets which were over rock.
Unfortunately, however, the outlets of the lake are not positively
*Determined by a surveying aneroid barometer and checked against a
barograph, hence as accurate as this method permits.
2 Alling, H. L., “Geology of the Lake Clear Region.” N. Y. State Mus.
Bul! 207, 208, p. 133.
8o NEW YORK STATE MUSEUM
known but in all probability the drainage was to the west, similar
to that of the South Meadows lake.
This lake was even more extensive than the South Meadows lake
if the writer’s conception is correct. It covered the area nowia™
occupied by the southern end of Lake Placid, the western end of
the Wilmington notch, and sent a four-fingered bay into the South
Meadows country and flooded the southern edge of the Saranac
quadrangle. The valley of the East branch of the Ausable river
was occupied by an ice lobe, preventing any connection between
the eastern and western portions of the Lake Placid quadrangle.
oo —
VY EF
jf
FS wisconsin ICE
{EARLY STAGE OF
SUAS TIL LAKE KEENE
WA ern CRAKE NEWMAN
IM |EXISTING LAKES
Fig. 3 The Glacial Lake succession in the Lake Placid quadrangle. Stage
two. ;
The South Meadows lake was succeeded by the western section of Upper
Lake Newman, altitude 1800 to 1895 feet. The ice lobe in the valley of
the East branch of the Atssable river had retreated since stage one: to
allow the Keene lake to accumulate.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 81
The best preserved terraces of the Upper Lake Newman were
found in the extreme southwest corner of the quadrangle in the
neighborhood of John Brown’s grave and along the West branch
of the Ausable river. The name of the lake is derived from the
town of Newman, the terminus of the Delaware and Hudson Rail-
road, where well-preserved levels occur on the north, south and
more especially at the point where the Lake Placid-Keene highway
crosses the river. Here a striking view of them may be obtained.
As may be inferred from figure 3, the present theory is that a
portion of the ice body that was responsible for the existence of
Upper Lake Newman, was situated for a time near the southern
edge of what is now Lake Placid, and it is believed that the morainal
dam that later brought about Lake Placid was formed during this
period. The ice experiencing minor advances and retreats pro-
duced the exposure above mentioned, showing drift on top of the
stratined sands of Upper Lake Newman.
In the vicinity of John Brown’s grave, well-preserved benches
show a complete separation of Upper Newman from the succeeding
lake, Lower Newman; the upper series ranging from 1800 to 1820
(one well-marked level at 1806.5 feet) while the lower group vary
from 1740 to 1780 feet. The same difference in levels was found
in the Saranac quadrangle one-half of a mile north of Harrietstown,
where a corresponding group of benches occurs.+
Upper series: eastern section. The Keene lake. During
the greater portion of the life of the western portion of Upper Lake
Newman, the ice lobe in the valley of the East branch of the Ausable
river was retreating northward and allowed a growing body of
water to accumulate in the Keene valley. This body of water,
named the Keene lake, left terraces high up on the valley walls,
especially in the brook valleys where the present streams have
bisected them. The sands on East hill at 2000 feet altitude, in the
southeast corner of the Lake Placid map, were probably deposited
at this time. The greater portion of the lake, however, filled Keene
valley and thus was largely located within the confines of the
Mt Marcy sheet.
The outlet is regarded to have been to the south through the
double fault-line valley, in which the famous Ausable lakes are now
located, into standing waters in the northern half of the Schroon
lake sheet. The two passes to the east, namely, the Spruce hill
_ tAlling, H. 1 Geology of the Lake Clear Region, N. Y. State Mus.
Bul. 207, 208, p. 133.
82 NEW YORK STATE MUSEUM
|
|
: |
pass and the Chapel pond pass on the western edge of the Eliza- |
bethtown sheet, although much lower than the surface of the water, |
were effectively blocked by side ice lobes from the glacial tongue
that occupied the Elizabethtown valley, preventing eastward escape. _
It seems quite likely that as the lobe, which prevented northward
escape of the Keene lake, gradually retreated, it at last uncovered
the eastern end of the Wilmington notch which furnished connec-
tion with the western portion of the area, and then the waters in
the valley of the East branch fell to the level of Upper Lake
Niewman.
Gan
Y
TA
1]
}
Z
£4
by
© Le,
FE wisconsin Ice
ff] GLACIAL. LAKE
A LOWER NEWMAN
[P| EXISTING LAKES
[= | Towns
Fig. 4 The Glacial Lake succession in the Lake Placid quadrangle.
Stage three.
The Keene lake was succeéded by the eastern section of Upper Lake
Newman when the ice lobe in the valley of the Ausable river had retreated
to uncover the Wilmington notch, allowing discharge to the west. Both
eastern and western sections of Upper Lake Newman were succeeded by
Lower Lake Newman, altitude 1740 to 1780 feet.
SCALE QF MILES
'
4
re
x
iy
GEOLOGY OF THE LAKE PLACID QUADRANGLE 83
Eastern portion of Upper Lake Newman. The life of the east-
ern portion of Upper Lake Newman was probably relatively short
compared with that of the western area, for the terraces are very
indefinite and the separation of the benches into an upper and a
lower series does not exist, or at least can not be demonstrated.
Thus soon after the establishment of greater Upper Newman, the
outlet was changed, perhaps rapidly deepened by the additional
volume of water from the eastern section, so that the waters fell
to the level of Lower Lake Newman.
Upper series: eastern and western sections. Lower Lake
Newman. This lake was of still greater extent than any of the
above-described bodies of water. Its northern, and especially the
northwestern, extent and boundaries are still to be studied and
worked out. Our present knowledge would lead us to conclude,
however, that the valleys occupied by the West and East branches
of the Ausable river were flooded, the connecting link between the
two being the Wilmington notch. This is inferred by the fact that
deltas and terraces at similar heights were found to the east and
west of the Notch; how else could the waters of the two areas
have been confluent? These waters thus flooded the area covered
by Lake Placid and the greater portion of the Saranac quadrangle.
As the ice barrier retreated the area around Franklin Falls was
covered by the later stages of Lower Lake Newman. The outlet
is assumed to have been west, although its location is at present
unknown. It is possible, though exceedingly unlikely, that the
Chapel pond pass may have been an outlet toward the close of this
period, changing the drainage to the east.
The South Meadows, and the two Newman lakes, probably had
outlets to the west; the Keene lake drained south; but the suc-
ceeding lake (or group of lakes) had drainage to the east.
Saranac glacial waters. The series of sand plains, terraces
etc. that come under this head were recognized and described by
H. P. Cushing,* in the Saranac region, in what is generally known
as the “lake belt.’ These levels have such a wide range, 1450
to 1660 feet, that they must have been produced by a series of
glacial lakes, or have been deposited by aggrading streams which
no longer exist, or by a combination of both.
Doctor Cushing is of the opinion that “ these sands were prob-
ably deposited as deltas in a large irregular, shallow, lake formed
* Cushing, H. P., Recent Geological Work in Franklin and St Lawrence
Counties, N. Y., State Mus. Annual Rep’t. 1900, p. 29.
84 NEW YORK STATE MUSEUM
back of the ice tongue which occupied the ‘lake belt’ during its
slow retreat north, the material being furnished by the subglacial
and englacial streams flowing into the lake at the ice margin.”
As nearly two-thirds of the Saranac sheet exhibits terraces and
sand plains of the higher levels, it was proposed that the name
“Saranac glacial waters” be applied to the standing waters that
built these levels, although the waters covered portions of the Lake
Placid, Mt Marcy and Ausable quadrangles.
Extensive levels are preserved within the area in the brook val-
leys such as Clifford, Styles, Brown’s and New Bridge brooks and
to the east and west of the town of Wilmington.
The general character of the terraces is that of gently sloping
plains on the mountain slopes without any prominent shore-line
features. An exception to the last statement is a wave-cut cliff on
the south side of the Styles Brook valley. The indefinite nature
of nearly all the sand plains strongly impressed the writer and
thus he was inclined to view them as having been formed by aggrad-
ing glacial streams, the remnants now existing being merely por-
tions left undisturbed by the present streams. But field work
revealed a remarkable series of outlets in the center of the Ausable
quadrangle that furnish evidence for regarding them as glacial
lake features.
Outlets. Here again we must depart from the confines of the
Lake Placid quadrangle to understand the nature of these conspicu-
ous levels. Although a detailed description of the outlets will not
be given, a short summary of them is indispensable.*
iBeginning on the southern slopes of Ellis mountain, in the town-
ship of Jay, a long glacial channel extends south for a distance of
some 9g miles with a dozen side outlets to the east. The lake
entrance to this channel was at the northern end, south of Ellis
mountain. The controlling spillways were regulated by an ice lobe
that lay to the east. Thus it is the writer’s opinion that as the ice
retreated it permitted escape first by the most southern side outlets
which represents the outlet of the early stages of the Saranac
glacial waters; while as the ice continued to retreat, lower spill-
ways were opened farther north with a consequent lowering of the
waters.
In several of these side-outlet channels “fossil” or dried-up
falls and cataracts are found. The channels are very impressive
For a fuller account, see Alling, H. L., The Glacial Lakes and Other
Glacial Features of the ‘Central Adirondacks, Bul. Geol. Soc. Amer.,
27:658 and fig. I.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 85
and, together with the correlation of the elevations of the outiets
and minor breaks in the. sand plains, furnish positive evidence of
the nature of these levels.
i
Yi
y, Ve KLIN
QO FALLS
LAKE PLACID
WISCONSIN
LATE STAGE OF
SARANRAC WATERS [TL ON MT PANNEMORA]
KES LAKE 1
TOWNS MT >
|| ty [ee
SCRLE OF MILES
Fig. 5 The Glacial Lake succession in the Lake Placid quadrangle.
Stage four.
With the opening of the glacial channels in the Ausable sheet the Lower
Newman Lake was succeeded by the Saranac glacial waters, the late
stage of which is indicated on the map. ‘The altitude of this series of
lakes range from 1440 to 1660 feet, although the level shown is that at
1500 feet.
There is a decided “ gap” in the sand plains in the Saranac levels
at about 1550 feet, and thus it would be proper to subdivide the
lake into upper and lower phases, but as the lake had a succession
86 NEW YORK STATE MUSEUM
of outlets such a simple division is insufficient, so we shall regard
the Saranac waters as a series of lakes. The chief cause for the
indefiniteness of the levels and the lack of shore-line features must
be attributed to the fact that the ice was the barrier in many
cases. Many one-bank channels exist, showing that the spillways
were constantly being lowered by the melting ice.
The lower stages of the Saranac waters were chiefly confined to
the eastern section, as can be seen from figure 5.
Eastern section. St Huberts lake. At a lower altitude than the
Saranac water levels there are scattered over the area sloping ter-
races of indefinite character that remind the writer of the preceding
plains. They are regarded as subordinate in interest to the preceding
levels and to those which are described below. There is a small but
finely developed terrace at thé head of Keene valley at 1300 feet.
This level surface is now used as a baseball diamond. Taking this as
a starting point the other terraces seem to fit in with the general
scheme, and hence there is a possibility of a lake level in the series
that once flooded portions of the Lake Placid quadrangle. The most
prominent remnant left of this level is on the northeast slopes of
Owls Head now traversed by the Keene-Cascade highway. Its
outlet was, without much doubt, through the gulf, south of Ellis
and Black mountains in the Ausable sheet to the east, the spillways
being controlled by one-bank channels which are beautifully shown
on the southeast slopes of Black mountain.
Lower series: confined entirely to the eastern section.
In descending from the higher lake levels to the lower ones, the
character of the terraces changes from indefinite levels of consid-
erable range to neat, clear-cut deltas, wave-cut cliffs and beaches
confined within concise limits. No question can be raised as to the
origin of many of them. They represent remains of true glacial
lakes.
Wilmington lake. The history of the Wilmington lake is, per-
haps, the best understood of all these local lakes. It was chiefly
confined to the Lake Placid sheet, to the East branch of the Ausable
river, and to the territory around the town of Wilmington; and
stretches northward to Lower Jay. (See figure 6.)
The altitude is 1100 feet at the foot of Johns brook in Keene
valley where a typical delta was developed. One and one-half
miles southeast of the town of Keene, on the state road at Norton
cemetery, there is an excellent display of a bisected delta. Around
—
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 87
the town of Wilmington the development of the terraces is excep-
tionally fine and thus the name is not inappropriate.
As one investigates the terraces of the Wilmington lake from
south to north in this area and in the Ausable quadrangle, the
altitude rises at a rate of approximately 3 feet a mile and clearly
illustrates postlacustrine deformation. The subject of uplift and
tilting will be more fully treated beyond.. A number of beaches
of the lake are beautifully shown on a hill a mile directly north of
LOBE OF WISCONSIN
ICE SHEET
GLACIAL LAKE WIL-
MINGTON. ALT.1100 FT.
GLACIAL OUTLET
CHANNEL
CATARACT PLUNGE
BRSIN
SCALE OF MILES
QUADRANGLES WAL AMin ev
Fig.6 The Glacial Lake succession in the Lake Placid quadrangle.
Stage five.
St Huberts lake that succeeded the Saranac glacial waters is not shown
in this series of maps. The lake that followed, the Wilmington lake,
with an altitude of 1100 feet is given here. The outlet was to the east,
through the gulf.
*Kemp, J. F., N. Y. State Mus. Bul. 21, p. 60.
88 NEW YORK STATE MUSEUM
Keene, called by the writer “ Keene hill.” Here the altitude is 1113
feet. Farther north we find the outlet channel spillway at 1155 feet.
This level, compared with the r10o-foot delta above mentioned,
gives on calculation a deformation of 2.94 feet a mile.
Outlet. Once more we must depart from the Lake Placid quad-
rangle and consult the Ausable sheet to find the outlet. As can be
inferred from figure 6 an ice lobe lay in the valley of the East
branch of the Ausable river with its southern wall at Lower Jay.
Another body of ice blocked the narrow valley now occupied by
Trout pond. Thus northward escape was prevented. The waters
of the lake found outlet to the east through the gulf, a narrow and
deep faultline valley, south of Ellis and Black mountains. In this
interesting channel there are a number of Pleistocene cataracts, but
unfortunately the topography is incorrectly drawn and they fail to
appear on the survey map. At the eastern end of the gulf, on the
- boundary between the townships of Jay and Chesterfield, the river
turns to the southeast making a series of little ponds, which are really
plunge basin lakes at the base of former cataracts. Of the group
the remarkably beautiful Copperas pond is the most striking
example.
Beaches versus stream terraces. Below the Wilmington lake
level, on the mountain slopes, in the Ausable valley, a number either
of benches or stream terraces have been found and their altitudes
measured. The question of origin arises, naturally, in individual
cases. Many of them are probably shore-line features formed by
glacial lakes, while others are stream meander terraces formed by the
postglacial Ausable in cutting its way through the glacial sands.
A discrimination between the two is often impossible, thus leaving
the identification of succeeding lake levels extremely unsatisfactory.
Typical examples are the levels on the “ Keene hill,” a mile directly
north of Keene (see plate 25). The following are the altitudes
the writer has obtained by the use of two aneroid barometers checked
against a barograph and spirit leveling: 1146, 1113 (Wilmington
beach), 1037, 1017.7, 993.9, 985.7, 925.7 feet. The mean height of
the river at this point is 816 feet. The origin of the lower ones is a
disputed question. D. W. Johnson regards them as stream terraces,
while Fairchild and Chadwick attribute them to glacial lakes.
Another series, in the Ausable sheet, 114 miles northeast of
Lower Jay on a similar hill (the “Lower Jay hill”), has been
recorded as follows: 1046, 1043, 1024, 997, 917.5, 908 (wave-cut
cliff), 880 and 857 feet. The river is a mile distant to the west,
Plate 25
H. L. Alling, photo, 1916
Probable glacial lake beaches 1 mile north of
Keene, looking north. Altitudes: 925.7, 985.7, 993.9,
and 1017.7 feet.
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 89
while the best development of the levels is on the east side of the
hill. Here glacial lake origin seems certain. To the writer they
have exactly the same appearance as those on the hill near Keene.*
Other groups of benches in the Lake Placid quadrangle are impor-
tant. On the hill north of the junction of Clifford brook (the
“Clifford hill”) and the Ausable, a series shows the following
figures: 1074, 1070, 1020, 967 and 964. These are perhaps lacus-
trine in character, especially the 964-foot level which Johnson
admits is a wave-cut cliff.
On the east bank of the river 3% miles north of Keene (“ Quarry
point”) a series of probable stream terraces ranges as follows:
1028, 970, 921, 912.5, 903, 879 and 859. Doctor Johnson examined
them carefully with the writer and pronounced them the work of
the river; he likewise so regarded the terraces east of Upper Jay
(See plates 26 and 27).
‘Following the lead of Woodworth,” the writer has plotted upon a
north and south plane the above data of beaches, terraces and sand
plains to see how they correlate among themselves and with the
proposed spillways (see figure 8), taking into account the post-
lacustrine deformation and the 20° inclination of the isobases.
This was done on the basis of Fairchild’s recent studies which
furnish the approximate total uplift and amount of differential
tilting for the area by means of isobases. It is interesting to note
that a large number of these disputed levels fit into the general
scheme and thus strongly suggest glacial lake origin. The writer
is not, however, unmindful that pure coincidence may bring into
line a group of stream terraces that really have no relation to one
another. After lining up all available data there remained isolated
figures that are impossible to pigeon hole. It is quite possible that
with more careful examination in the field corresponding levels
will be found, but as the matter now stands there is some doubt as
to the character of some of the levels. With this uncertainty in
mind we shall, however, now discuss the next level, which probably
represents a glacial lake.
Upper phase of the Upper Jay lake. The Upper Jay lake, like
its predecessor, the Wilmington lake, has left terraces and beaches
that are very definite in character. One of the beaches on the
“ Keene hill” is 1017.7 feet in altitude, while a similar one on the
*Compare pl. 22, fig. 2, facing p. 658 in Bul. Geol. Soc. Amer., v. 27.
? Woodworth, J. B., Ancient Water Levels of the Champlain and Hud-
son Valleys, N. Y. State Mus. Bul. 84, pl. 28.
go NEW YORK STATE MUSEUM
“Lower Jay hill” presents a beach at 1046 feet. This gives upon
calculation an uptilt to the shore line of 2.80 feet a mile. The out-
let of the lake is not definitely known, but a pass one-half of a mile
directly south of Haystack mountain in the Ausable quadrangle
(not the mountain of the same name in the Marcy range) has an
altitude (1153 feet) that gives the proper figure when the tilting
is calculated. When visited, however, this pass did not show evi-
dences of stream action. The area is entirely fine sand, but farther
north a possible channel, 114 miles north of Bald mountain, is sug-
gested as a more probable control.
LOBE OF WISCONSIN
ICE SHEET
3 GLA LAKE, UPPE
CG JAY. ALTITUDE 1000 Er
GLACIAL OUTLET CHANNEL
Fig. 7 The Glacial Lake succession in the Lake Placid quadrangle.
Stage six.
Following the Wilmington lake, the Upper Jay lake formed in the valley
of the East Branch of the Ausable river. The lower levels are not shown
in this series.
Lower phase of the Upper Jay lake. A lower phase of the
Upper Jay lake is indicated by beaches on the “ Keene hill” at
993.9 feet and a beach at 999.5 feet on the slopes of Oak ridge and
a level at 1024 feet on the “ Lower Jay hill.” These figures give
the value, 2.75 feet a mile for the tilt.
Haselton lake. A possible lake with an altitude of 967 feet
around the town of Keene has left terraces, wave-cut cliffs and
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beaches. The amount of tilt based upon the wave-cut cliff on the
“ Clifford hill” at 964 and a level on the “ Lower Jay hill” with a
figure of 997 is 2.71 feet a mile. Relatively. small sand plains of
this lake are well shown about the town of Haselton village in the
Lake Placid sheet.
The controlling outlet is unknown, but the writer offers the sug-
gestion that it may have been a one-bank channel on the north side
of Haystack mountain (Ausable sheet) carrying the waters east,
for there is some evidence of water action in that region.
Lower Jay lake. This lake level is very definite and no ques-
tion seems to exist as to its nature, although the “ Lower Jay hill”
does not show a corresponding level. About Keene there are wave-
cut terraces at 930 and 930.5 feet. A well-preserved terrace bottom
is located 1%4 miles south of Upper Jay with an average height of
930 feet (see plate 30), and likewise a fine sandy plain on the
western edge of the Lake Placid quadrangle which continues on
to the Ausable sheet where we find Otis brook flowing on the east-
ern edge. Here the altitude is about 940 feet. We have not
sufficient data to calculate the amount of tilt.
Otis lake. The level called the Otis lake is one of the more
doubtful levels, as sufficient data are not at hand to determine
whether it is a lake feature or a system of stream terraces. If we
take a level that Johnson regards as a stream terrace 144 miles
north of Keene at 903 feet and a beach on the “ Lower Jay hill”
at 917.5 feet, we obtain an unsatisfactory value of 2 feet a mile for
the tilt, which of itself seems to cast some doubt upon the glacial
lake origin of the level. Errors in the measurements may, how-
ever, be a contributing cause for the discrepancy. |
Rocky Branch lake. Rocky Branch lake is recognized on the
basis of three terraces around the villages of Upper and Lower
Jay, and upon some of the disputed levels. The latter are 114
miles north of Keene, 858 feet, and on the “Lower Jay hill” at
880 feet, giving a tilt of about 3 feet a mile, which is approximately
the expected value. Although the outlet is unknown, the terraces
are definite in character and thus this level should rank as definitely
settled.
Clifford lake. This is the last and lowest of the levels definitely
recognized within the confines of the Lake Placid quadrangle. Its
origin is still in doubt, although a warp of 2.70 feet to the mile is
indicated by a beach or stream-terrace a mile south of Upper Jay
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GEOLOGY OF THE LAKE PLACID QUADRANGLE 93
at an altitude of 833.5, and another one on “‘ Lower Jay hill” at 857
feet:
Lower lake levels. At still lower altitudes several more of these
perplexing levels were found, but as they are largely outside the
Lake Placid quadrangle they will not be discussed. Suffice to say,
the most prominent level in the lower Ausable valley is the marine
plain in the vicinity of Ausable Forks. Here the measured altitudes
agreed within a foot of the value called for by Fairchild’s figures.
Cause of the large amount of material available for the
formation of terraces. One of the striking features of the glacial
geology of the Adirondacks is the small amount of true morainal
material* unmodified by water” as contrasted with the vast quanti-
ties of sand and gravel in deltas, terraces etc., when compared with
other districts, such as the Catskill mountains. The following hypo-
thesis is offered to account for this. It is generally conceded that
with the return of warmer climate the Adirondacks were completely
- surrounded by a vast ring of ice that isolated the Adirondack high-
land from the rest of the state.* It was during this stage that the
glacial lakes here described existed. The great ice sheet undoubtedly
destroyed all vegetable life in both the Adirondacks and the Catskills,
but in the latter case the ice retreated northward as an irregular edge
which allowed vegetable life to follow the ice in its withdrawal.
This condition was not possible in the Adirondacks where the ice
ring prevented much if any encroachment on the part of plants
into the ice-deforested area. In the Catskill region the glacial drift
was anchored by the roots of newly growing shrubs etc. and thus
it was not easily washed by the streams into the standing waters
in the valleys below, so a large amount of the drift still remains on
the slopes. On the contrary, the glacial debris in the A’dirondacks
was not anchored and most of it has been carried down into the
valley bottoms and there worked over into lake deposits.
Postlacustrine deformation and tilting. It has been pointed
out that at the maximum extent of the Wisconsin ice-body, the
load upon the land surface must have been tremendous and must
have compressed the land below its former level.* Since the ice was
PCushins, HH. Py IN. Y: State Mus.) Bul, 115, p.- 405.
2 Ogilvie, I. H., Jour. Geol., 10:3907—412. 1902.
witainehid da lee, Ni Y. State Mus. Bul. 160"pl. 1
#This subject of deformation has not received the attention of struc-
tural geologists in the light of isostasy.
Q4 NEW YORK STATE MUSEUM
thicker in the north than in the south, the amount of deformation
was greater in the northern part of the State. With the removal of
the load by the melting of the ice the land has “ sprung” back, thus
elevating the surface, tilting the shore-line features of the glacial
lakes. It has been shown by Fairchild’ that the character of the
postlacustrine uplift was a lifting in the form of a warped plane
with the amount of warping greater to the north. The lines of equal
uplift since the marine level are inclined west-northwest to the
east south-east (20° from the latitude parallels). The zero isobase
passes far south of New York City. The 600-foot isobase enters
the Lake Placid quadrangle at the very southeast corner of the map.
The northeast corner is cut by the 648-foot isobase. These figures
give the total uplift for the region since the marine waters occupied
the Hudson-Champlain strait. The figure for the amount of tilting
for this datum plane in this region, is 2.71 feet a mile taken along a
north and south line, or 2.83 feet perpendicular to the isobases.
Although Fairchild’s papers form a very valuable contribution
to this subject, there exists some uncertainty as to the character
of the uplift. (1) Was the upward movement gradual and uni-
form or (2) was it in the nature of a wave or a series of sudden
uplifts? The writer believes that the problem will be clarified by
the measurement of beaches, deltas etc. situated at higher levels
than the marine plain to supplement those mapped at the lower
altitudes. The shore phenomena of the lakes above described
afford an opportunity to determine the amount of tilt of the land
surface, for they furnish a series of datum planes higher than
those in the Champlain valley, which was occupied by ice during
the entire period that the lakes existed. Fairchild believes that his
figures give the total uplift since glacial time. The writer feels,
however, that this conclusion is based upon the state of affairs that
prevailed during and after the marine stage and overlooks the
shore phenomena of higher lake levels. Although accurate meas-
urement of the amount of tilt of the lake levels of the Lake Placid
quadrangle is an extremely difficult matter (for the chance of
error is great), the table given below would indicate that the uplift
was taking place while the ice was melting from the area.
1 Fairchild, H. L., Pleistocene Uplift of New York and Adjacent Ter-
ritory, Bul. Geol. Soc. Amer., 27:235-62. Post-glacial Marine Waters in
Vermont, Rep’t of Vt. State Geol. for 1915-1916, p. I-41. 1917.
fa
800
igo
ST HUBERTS
100
NFeet
WILMINGTON
Saie
UPPER JAY
[.24|967
*jFee'
HASELTON
903
ro) Feet
LOWER URY
860
feet
ROCKY BRANCH
Boge 24
| BERCHESRBENCHES
SCALE oF MILES SSSR
Fig. 9 Remains of the glacial lakes in the Lake Placid quadrangle.
Some of the doubtful “lower levels” are included under the head of the Rocky Branch lake.
GEOLOGY OF THE LAKE PLACID QUADRANGLE 95
Deformation table for the lower series oj lakes in the quadrangle
Altitude Calculated tilt,
Lake in feet feet a mile
WV MbIMITASIOM so00sc0d0ccccod 90a dgoDDODOOODODDUC 1100 2.94
Wnper phase of Wipper Jay. sc. 6 ie. cre6 soi. soe 1016 2.80
Wower phase, or lower Jaye ees «cece a 994 2.75
SAS Grae Go aro tele ols clGNB LS One ROLER TORO CRO nS Da EIAs ne 967 2.71
iLower Jaw concocsoucccmc0 po dpe0cnDOUKgGKadaC 930
COVES, os Siete BL BONA gee re eae ae eri UPR 903
ody iyeiGh, sosanccvsccadenboonaoucoccmp sae 860 sikaens
(CIRO! eB Ws eI CRO CoRR eRe a eas ere des 835 2.70
WNifaarirte melee li ters: ctccersncyois ates « ci) cia-s vie ohare wtereiereloreieae 648 2.71
The writer came to the same conclusion in 1916 although at that
time his data ‘were not so accurate as those now available, and
hence the figures are slightly different.
It will be noticed that the rate of tilt decreases as one passes
from Lake Wilmington to Lake Haselton; the tilt of the latter
appears to be the same as that of the marine plain. If any con-
fidence can be placed in the figures, it would seem that the lakes
below and including Haselton drained directly-into the marine
waters. Since warping is a function of uplift, it would appear
that the total amount of uplift for the quadrangle since glacial
times is greater than the amount, 600 feet (for the southeast cor-
ner), proposed by Fairchild.
ACKNOWLEDGMENT
The writer is indebted to Professors James F. Kemp, Herman
L. Fairchild, George H. Chadwick and D. W. Johnson for advice
and counsel in the field and in the laboratory.
96 NEW YORK STATE MUSEUM
HISTORICAL GEOLOGY?
Precambrian History
The oldest records of the Lake Placid quadrangle are written in
the rocks of the Grenville series. .A most conservative estimate by
geologists gives the age of the Grenville strata as no less than 25
or 30 million years, but it must be admitted that we have no
means of accurately measuring geologic time in years. Since the
Grenville rocks are distinctly stratified, very thick (many thousands
of feet), and of wide areal extent not only throughout the Adiron-
dacks, but also in eastern Canada, we may be sure that the earliest
known condition of the area of the quadrangle was a sea in which
the Grenville sediments were accumulated layer upon layer on the
bottom.
After the deposition of the Grenville strata came vast intrusions
of molten masses, including first the upwelling of the great body
of anorthosite in Essex and Franklin counties, and second the still
greater syenite-granite body, these two igneous series being by far
more extensively developed than any other rocks of the quad-
rangle.2 During the processes of intrusion and cooling of the
magmas, the anorthosite differentiated into the Marcy and White-
face types, and the syenite-granite split up-into various types rang-
ing from rather basic (dioritic) phases, through quartz syenite,
granitic syenite, and granite to even granite porphyry. The syenite-
granite intrusion appears to have taken place not long (geologi-
cally) after the anorthosite intrusion so that the latter was still hot,
though probably not molten, and it was locally assimilated along
the borders of the invading syenite-granite magma, thus giving
rise to the rock called the. Keene gneiss.
The whole Adirondack region was raised well above sea level
most likely at or near the time of the great intrusions. There are
strong reasons for believing that none of the rocks were ever highly
folded by orogenic movements, but that the breaking up and
tilting of the Grenville strata resulted from the upwelling of the
great bodies of magma; that the metamorphism of the Grenville
*A treatise dealing with the geography and geological history of the
Adirondack region in somewhat untechnical language was prepared by
the writer and was published as Bulletin 193 of the State Museum under
the title “The Adirondack Mountains.”
2 As already suggested, possibly some gabbro now represented by amphib-
olite, was intruded before the anorthosite.
GEOLOGY OF THE LAKE PLACID QUADRANGLE Q7
strata preceded, or possibly was in part at least concomitant with,
the great intrusions; and that the foliated character of the intrusive
rocks is essentially a flow-structure developed under moderate
pressure during late stages in the consolidation of the magmas.
The great Precambrian land mass just referred to was above
sea level, and underwent weathering and erosion for some millions
of years at least, extending through later Precambrian time and
into the early Paleozoic era, as proved by the facts that the oldest
rocks deposited upon the Precambrian floor are of late Cambrian
age, and that the rocks of this Precambrian floor immediately
below the Cambrian strata exhibit textures and structures which
could not possibly have been produced except at very considerable
depths below the earth’s surface.
Following the anorthosite and syenite-granite intrusions and, for
most part at least, during the long time of erosion above men-
tioned, came the minor intrusions of gabbro-diorite, gabbro, peg-
matite and diabase. Of these, the diabase is the youngest with the
finest grained texture showing a cooling of the rock comparatively
near the surface of the earth. In the Adirondack region, pegmatite
dikes commonly cut the gabbro and hence are younger. Whether
the gabbro bedies are younger or older than the gabbro-diorite dikes
of the Lake Placid quadrangle could not be positively determined
but they are probably younger.
Paleozoic History
By late Cambrian time the profound erosion above referred to
had worn down the whole Adirondack region to a comparatively
smooth, low-lying (peneplain) surface. This is proved by the fact
that the late Cambrian strata (particularly the Potsdam sandstone),
which are the oldest to have been deposited upon the Precambrian
rocks, everywhere rest upon a peneplain surface of the latter. In
the northeastern Adirondacks, including the Lake Placid quad-
rangle, this peneplain was moderately rough with some hills rising
probably several hundred feet above the general level, but of course
this was not at all comparable to the high, rugged relief of the
present day.
The best available evidence indicates that the ancient peneplain
became sufficiently submerged during late Cambrian time to allow
the sea to cover all but a considerable part of the central Adiron-
dack area, and that the maximum submergence occurred during
nud-Ordovician time when a still smaller part of the central Adi-
rondack region remained as a low island. Judging by the marine
4
98 NEW YORK STATE MUSEUM
character, thickness and present-day distribution of the Cambrian
and Ordovician strata, the late Cambrian sea probably covered
some of the area of the Lake Placid quadrangle, and the mid-
Ordovician sea quite certainly covered some, or possibly most, or
all, of the area of the quadrangle. However extensive the Cam-
brian and Ordovician rocks may once have been, they have since
been completely removed by erosion from the area of the
quadrangle.
At some time or times during the middle or late Paleozoic era
the whole Adirondack region, then largely mantled with Paleozoic
sediments, was raised well above sea level. Some of this upward
movement may have taken place at the time of the Taconic revolu-
tion (at the close of the Ordovician), though it is generally con-
sidered that the major uplift occurred at the time of the Appa-
lachian revolution (toward the close of the Paleozoic). In north-
ern New York this upward movement was not accompanied by
folding of the rocks, but there was a general tilting of the strata
downward toward the south or southwest.
Mesozoic History
The erosion cycle inaugurated by the Paleozoic elevation of
northern New York continued for a vast length of time, or till
late in the Mesozoic era or early in the Cenozoic era, when the
Paleozoic strata were largely removed from the Adirondack area
and another eroded surface approaching the condition of a pene-
plain was produced. This is commonly referred to as the Cre-
taceous peneplain. Apparently this peneplain was least perfectly
developed in the central and east-central Adirondack area, including
the area of the Lake Placid quadrangle, where various hard rock
masses (monadnocks) stood out more or less prominently above
the general level. This peneplain was upraised late in the Mesozoic
era or early in the Cenozoic era, and distinct remnants of it in
northern and central New York now lie at altitudes of from 2000
to 3000 feet or possibly more in some places. Within the quad-
rangle, however, no very accurate idea of this peneplain or its
remnants can be gained because it was only imperfectly developed
there.
It is quite certain that much of the faulting which has so largely
influenced the major topographic features of the eastern and
southern Adirondacks took place after the production of the
so-called Cretaceous peneplain, and probably at the time of its
uplift. Some zones of fracture, however, like the Wilmington
GEOLOGY OF THE LAKE PLACID QUADRANGLE 99
notch fault, whose displacements show little, if any, in the existing
topography, are probably much older, and they may in part at
’ least be of Precambrian age. Some of the fracturing is certainly
of later age than the diabase dikes because several of these in the
Lake Placid quadrangle have been crushed by the faulting.
Cenozoic History
The major existing relief features of the Lake Placid quadrangle
have been produced chiefly by the dissection of the upraised late
Mesozoic or early ‘Cenozoic peneplain. As a result of the uplift
the streams were greatly revived as erosive agents, and they pro-
ceeded to carve out channels and valleys principally along the com-
paratively weak belts of Grenville rocks and the fault zones of
weakness.
Late in the Cenozoic era the area of the quadrangle, in common
with most of the State, was deeply buried under the great ice
sheet of the Glacial epoch.t The continental ice body in passing
across the quadrangle, in a south-southwesterly direction, removed
the residual soil of interglacial periods and subdued the contours
of the mountains. The tongues of the waning ice were influenced
by the topography, as is shown by the striae and the ice action in
the narrow valleys. In retreating from such valleys both ends were
blocked by moraines, usually forming basins between for the
accumulation of lakes. Many other, but more open, valleys were
dammed, producing lakes such as Lake Placid. The preglacial
stream valleys were likewise blocked and in some localities, as in
the case of the Ausable river near Keene, were forced to seek new
channels.
The ice sheet left a mantle of till all over the area but much of
it has been washed into the valley bottoms where it was worked
over by the glacial lakes that were brought about by the ice
damming the normal drainage lines. Continuing after the with-
drawal of the ice body local glaciers persisted for a time on the
slopes of the higher mountains, as is indicated by the moraine in
the cirque on Esther mountain.
_ It is the belief of the writer that the Lake Placid quadrangle
was situated near the northeast rim of the ring of ice that sur-
rounded and isolated the Adirondack highland from the rest of the
State during the retreat of the great ice sheet, and thus the north-
ward-draining valleys were blocked, preventing the escape of the
1The summary of the Glacial and Postglacial history was written by Mr
H. L. Alling.
I0O NEW YORK STATE MUSEUM
vast quantities of waters which flooded the district with lakes.
These bodies of water, especially at the higher levels, did not leave
distinct shore-line features, for their outlets were controlled by ice
lobes which caused constant or periodic lowering of their surfaces.
The district covered by the glacial lakes here described can be
divided into two sections, the western and the eastern. It is con-
tended that the western section was the first to be relieved of ice,
thus giving birth to the South Meadows lake. The uncovering of
lower outlets to the west extinguished this lake which was suc-
ceeded by Upper Lake Newman. During this stage the ice lobe
that lay in the East branch of the Ausable river, eastern section,
retreated to allow the Keene lake to form, with its drainage to the
south. Further withdrawal of the lobe uncovered the Wilmington
notch and thus the waters of the Keene lake fell to the level of
Upper Newman, bringing about a union of the two sections. Suc-
ceeding Upper Newman, Lower Newman held the stage until the
lobe in the Elizabethtown valley opened the side-outlet channels
in the center of the Ausable sheet, then the Saranac glacial waters
held dominion, draining east. During the lower stages the western
section was drained and only the eastern section was flooded.
On leaving the higher levels we descend to the better defined
shore lines and levels left by lakes whose outlets were over rock.
The Wilmington lake, drained through the gulf, and the Upper
Jay lake, both upper and lower phases, likewise drained to the east.
The impossibility of distinguishing beaches and stream terraces in
certain cases leaves in doubt the exact nature of some of the lower
levels; the marine plain around Ausable Forks being the mast
important of the lower series.
The nature of the postlacustrine uptilting, which inclined the
shore lines of the lakes northward, points to the conclusion that
the land was experiencing uplift and warping while the ice was
retreating from the region. The total amount of uplift since glacial
times for the quadrangle was greater than 600 feet.
STONE QUARRIES AND MINES
The accompanying geologic map shows the locations of nineteen
stone quarries and mines or prospect holes.
Road Metal
Excellent rocks for use in the construction of macadamized
roads occur in inexhaustible quantities within the quadrangle.
GEOLOGY OF THE LAKE PLACID QUADRANGLE IOI
Most of the rocks actually used for such purposes are from the
anorthosite and the syenite-granite series. These make a good
grade of road metal. Quarries have been opened in Marcy anor-
thosite 114 miles northeast of Upper Jay, and at the southern base
of Hamlin mountain; in Whiteface anorthosite just south of The
Flume; in normal syenite at the eastern base of Cobble hill, and
near High fall; in a basic phase of syenite by the road 1 mile north
of Malcom pond; in Grenville and Whiteface anorthosite mixed
rocks by the road 3% miles north of Keene; and in weathered
Grenville limestone by the road one-half of a mile north of Frank-
lin Falls.
Building Stone
Fresh rock from most any portion of the great intrusive masses
of anorthosite or syenite-granite would yield excellent building
stone of great strength and durability, and often of unusual beauty.
Two small quarries have been opened at the southern margin of
the Pulpit mountain gabbro stock to furnish stone for the construc-
tion of a nearby reservoir. No other building stone quarries
worthy of special representation on the map were found within
the quadrangle.
Limestone for Lime
There are several quarries from which Grenville limestone was
obtained many years ago and burned to lime in nearby kilns. ‘Tlu:se
are indicated on the map 1% miles north-northwest of Keene; on
the hillside 314 miles north of Keene; near Woodruff fall; und
just west of Middle Kilns.
Iron Ore
There are two localities from which a little magnetic iron ore
was obtained many years ago. One of these is a small opening
on the hillside 1 mile west-southwest of Keene. The ore occurs
in small, irregular masses in the syenite and Grenville mixed gneiss
area apparently as segregation masses in the syenite.
The other locality is near the eastern base of Marble mountain
about 144 miles southwest of Wilmington. There are two small
openings in a rather coarse phase of Whiteface anorthosite, the
magnetite occurring as irregular masses up to an inch across in a
pegmatite dike.
Graphite
As above stated, graphite (so-called “black lead”) often occurs
in small flakes in the Grenville limestone and certain of the schists
and gneisses. So far as the writer could learn, there have been only
102 NEW YORK STATE MUSEUM
two attempts to mine this mineral within the quadrangle, this having
been in a small opening in the little area of Grenville limestone
one-half of a mile south-southeast of Franklin Falls. The lime-
stone contains numerous flakes of graphite, but apparently a vein
of fibrous graphite less than an inch wide in the limestone was
the center of interest.
Mr Alling has described a recent attempt to develop a graphite
mine 24% miles west-northwest of Wilmington on the side of
Wilmington mountain.’ This work has been done since the writer’s
survey of the region. According to Alling the last operations were
in the spring of 1917. Several prospect pits or small shafts were
sunk. The main rock is a coarsely crystalline Grenville limestone
with large flakes of graphite. Associated with this limestone are
some green pyroxene and red garnet rocks, and some basic peg-
matite.
1N. Y. State Mus. Bul. 199. 1918, p. 36-37.
Alford mountain, 78
Alling, Harold L., cited, 6, 73, 74, 79,
81, 84, 99, 102; Pleistocene geology, ©
71-95
Ampersand mountain, 79
Amphibolite, 52-55
Anorthosite, 11, 13, 45, 50, 51, 52, 53, |
56, 96; chemical composition ot, |
25; an intrusive body, 27; younger |
than Grenville, 31; foliation of, 66.
anorthosite; |
See also Marcy
Whiteface anorthosite
Anorthosite series, 16-34, 101; older |
than syenite-granite series, 32
Aplite dikes, 41
Ausable Forks, 93, 100
Ausable lakes, 81
Ausable river, 14, 37, 82, 80, 91, 99. ;
West -
See also East branch;
branch
Ausable sheet, 31, 76, 84, 86, 88, 90,
QI, 92, 100
Bald mountain, 90
Beaches, 88
Big Cherrypatch pond, 13, 37
Black Brook, 6
Black lead, 12, 101
Black Mountain, 86, 88
Blue Mountain quadrangle, 31
Blueberry pond, 78
Bowen, N. L., cited, 7, 27, 28, 32, 44,
5I
Brown’s brook, 84
Brueyer pond, 78
Buck island, 37, 38
Building stone, 101
Cascade lakes, 74, 79
Catamount mountain, 16, 22, 41, 42,
44, 49, 54, 57, 58, 60, 63, 70; rocks.
of, 63
Catamount mountain ridge, 9, 10, 37,
39°
Catskill mountains, 75
Catskill region, 93
Cenozoic history, 99
Chadwick, George H., cited, 88, 95,
Champlain valley, 94
Chapel pond pass, 82, 83
Chesterfield, 88
Clifford brook, 84, 89, 91
Clifford Falls, 22
Clifford hill, 89, 91, 92
Clifford lake, 92, 95
Cobble hill, 14, 37, 101
Cobb’s hill, 74
Cold brook, 79
Coldspring pond, 14
Connery pond, 13, 22, 37, 30
Copperas pond, 21, 37, 41, 88
Cranberry pond, 55
Crystalline limestones, 11, 12, 13
Cushing, H. P., cited, 6, 7, 20, 22, 23,
27.30; 33; 547) 733 (03: 93
Deformation, postlacustrine, 93;
table for lower series of lakes, 95
De Martonne, cited, 75
Diabase dikes, 12, 60-63
Dikes, diabase, 12, 60-63; granite,
41; aplite, 41; pegmatite, 42; gab-
bro-diorite, 57
Eagle Eyrie, 14
East Branch Ausable river, 10, 52,
TGA. 77, 78, 80; 88, 82), 83,180
88, 90, 100
East hill, 81
Elizabethtown valley, 77, 100
Ellis mountain, 84, 86, 88
Emmons, E., cited, 6, 7
Fast Kilns, 6, 10, 34, 42, 44, 51, 57,
58, 60; area west of, 48
Elizabethtown quadrangle, 22, 73, 82
Erosional work, 72
Esther mountain, 9, 22, 73, 75, 99
[103]
104
Fairchild, Herman L., cited, 71, 77,
88, 89, 93, 94, 95
Faults, 68-70
Flume, The, 10, 21, 22, 24, 30, 32, 33,
49, 50, 62, 68, 69, 101
Foliation, 65-68
Franklin county basic syenite, 51
Franklin Falls, 5, 6, 10, 13, 16, 22,
27, 32, 37, 40, 42, 44, 49, 54, 63, 83,
IOI, 102
Fremont hill, 40, 61
Gabbro-diorite dikes, 57
Gabbro masses, II, 59, 101; foliation
of, 67
Garnets, 13, 14
Geography, general, 9-12
Geology, general, 9-12; structural,
64-70; pleistocene, 71-95; histori-
cal, 96-100
Glacial lakes, extinct, 76-95
Glaciation, Wisconsin, 71; local, 74-
76
Gneisses, II, 12, 13, 52-57, I01
Granite, 13, 32, 33, 34, 39
Granite dikes, 41, 42
Granite porphyry, 40
Graphite, 12, 15, 27, 38, 101
Grenville gneiss, 24, 41, 49, 51, 52-55,
64, 60, 70, 101
Grenville hornblende gneisses, 32, 59
Grenville limestone, 6, 14, IOI, 102
Grenville mixed gneisses, 34, 55, 101
Grenville rocks, 15, 17, 28, 67, 69
Grenville series, 11, 12-16, 37, 49, 96;
older than anorthosite, 31; tilting
and folding of, 64; foliation of, 65
Hamlin mountain, 61, 101
Harker, cited, 43
Haselton, 5, 10, 17, 42, 92
Haselton lake, 90, 95
Hawk island, 22, 24
Haystack mountain, go, 92
High fall, 10, 30, 33, 34, 37, 39, 44, 56,
61, 62, 68, 69, 101
Historical geology, 96-100
Hornblende gneisses, 13
Hudson-Champlain strait, 94
NEW YORK STATE MUSEUM
Insley, Herbert, cited, 6
Iron ore, 101
Jay, 88
Johns brook, 86
Johnson, D, W., cited, O7720 75 os
89, 92, 95
Keene; 5; 6, 13, 15) 17, 2s
27, 31,32, 35, 41, 43) 44,u52n stones
61, 62, 74, 76, 86, 88, 80, 90, 91, 92,
99, IOI; areas in vicinity of, 14-
16, 45; faults in the town of, 69
Keene-Cascade highway, 86
Keene gneiss, II, 34, 37, 38, 43-52, 56,
60, 64, 96; significance of distribu-
tion of, 49; comparison with Cush-
ing’s southwestern Franklin county
basic syenite, 51
Keene hill, 88, 89, 90, 91
Keene Lake, 80, 81, 82, 83, 100
Keene valley, 77, 78, 81, 86
Keene Valley circle, 74
Kemp, James F., cited, 6, 7, 15, 20,
22, 25, 20, 27, 46, 73, 76, 87, 95
Knapp hill, 22, 27, 49
Labradorite, sketch of large crystal
of, 19
Lake Champlain, 10
Lake Placid, 10, 19, 21, 22, 24, 35, 37,
38, 30, 55, 70, 74, 77, 80, 81, 83, 99;
areas in vicinity of, 13
Lake Placid village, 5
Lakes, glacial, extinct, 76-95
Limestone for lime, Io1
Little High fall, 33, 56, 60
Little Whiteface mountain, 21, 22,
25, 33
Loch Bonnie, 21
Long Lake, 31
Long Lake quadrangle, 22, 78
‘Lower Jay, 86, 88, 91, 92
Lower Jay hill, 88, 90, 91, 92, 93
Lower Jay lake, 92, 95
Lower Lake Newman, 81, 82, 83, 85,
100
Lyon Mountain quadrangle, 52, 590
INDEX TO GEOLOGY OF THE LAKE PLACID QUADRANGLE
Malcom pond, 21, 22, 37, 39, 44,
S101
Marble mountain, 9, 17, 30, I01
Marcy anorthosite, II, 17-21, 22,
27720) 131, 33) 415 42.43, 45,147,
65, 66, 67, 96, 101
Mesozoic history, 98
Middle Kilns, 6, 16, 22, 73, 76, IOI ©
Miller, W. J., cited, 7, 72, 73, 74, 76
Mines, 100-2
Mirror lake, 14, 74
Mixed rocks, 52-57
Moose island, 19, 21, 22
Moose mountain, II
Moraines, 73-76; local, 74-76
Morgan pond, II, 24, 33, 37
Mt Marcy, 17, 26
Mt Marcy sheet, 73, 74, 76, 77, 79,
81, 84
Mt Whiteface, 9, II, 21, 22, 23, 26,
30, 37, 39, 49, 50, 69, 70, 73
25,
5I,
New Bridge brook, 84
Newman, 5, 10, 13
North Creek quadrangle, 59
Norton cemetery, 86
Oak ridge, 46, 51, 91
Ogilvie, I. H., cited, 72, 73, 93
Ontario, 12
Otis brook, 92
Otis lake, 92, 95
Outwash plains, 76
Owen pond, 14, 21, 24, 30, 37, 49, 61,
69
Owls Head, 86
Paleozoic history, 97
Palmer brook, 78
Pegmatite dikes, 12, 41, 101
Pitch-off mountain, 9, 70, 72
Pitchoff pass, 73
Pleistocene geology, 71-95
Potsdam sandstone, 07
Precambrian history, 96
Precambrian rocks, 12-64
Pulpit mountain, 13, 60, 101
Pulpit rock, 39
Pyroxene gneisses, 13, 53, 102
47,
105
Quarries, 100-2
Quarry point, 89, 91
Quartz syenite, 34-37
Quartzites, 11, 12, 13
Raquette river, 78
Red Rocks, 15, 27, 31
Rich, John L., cited 75
Road metal, 100
Rochester, 74
Recky Branch lake, 92, 95
Ruedemann, Rudolf, cited, 73
St Armand mountain, 9, 70
St Huberts lake, 86, 87
St Regis sheet, 76
Sandstones, 12, 97
Santanoni quadrangle, 78, 79
Saranac glacial waters, 83, 84, 85, 87
Saranac quadrangle, 76, 80, 81, 83
Saranac river, 10, 27
Schists, 12, 101
Schroon lake sheet, 30, 81
Scott’s cobble, 79
Sentinel range, 6, 9, 17, 30, 47, 69, 70,
73, 79
Shales, 12
Silver lake, 39, 40, 41, 54, 74
South Meadows lake, 77-79, 80, 83,
100.
Spruce hill pass, 81
Still brook, 39 —
Structural geology, 64-70
Styles brook, 15, 35, 70, 84
Sunrise mountain, 21
Sunrise notch area, 47, 48, 51
Syenite, 13, 32, 33, 45, 101; basic
phase of, 37, 101; granitic, 38
Syenite-granite mixed gneisses, 55-
SY
Syenite-granite series, II, 13, 34-41,
49, 101; foliation of, 66
Syenite-pegmatite dikes, 42
Taylor, F. B., cited, 76
Taylor pond, 74
Terraces, 88; causes of amount of
material available for, 93
Tilting, postlacustrine, 93
4
106
Tom Peck pond, 13
Trout pond, 8&8
Tupper Lake Junction, 52
Undercliff, 21
Upper Jay, 5, 13, 20, 22, 30, 32, 35;
52, 53, 60, 62, 70, 73, 89, 92, 101; |
area near, 15, 46, 51
Upper Jay lake, 80, 90, 95, 100
Upper Lake Newman, 79-81 82, 83,
100
Van Dorrien pass, 78, 79
West Branch Ausable river, Io, 22,
24, 37, O61, 62, 81; 83
West Kiln, 6, 13, 15, 40
West Kilns-Middle Kilns area, 15
27, 29, 31, 32, 33, 34, 37, 39, 41, 42,
NEW YORK STATE MUSEUM
43, 46, 47, 48, 49, 50, 51, 52-55; 55- ;.
57, 60, 62, 63, 64, 60, 75, 96, IOI
Whiteface brook, 37
Whiteface-Esther-Wilmington mas-
Sit, 77
Wilmington, 5, 10, 17, 22, 32, 42, 63,
84, 86, 87, IOI, 102
Wilmington beach, 88
Wilmington lake, 86-88, 89, 90, 95,
100 ’
Wilmington mountain, 9, II, 15,
33, 37, 39, 50, 54, 70, 102
Wilmington notch, 10, 12, 14, 37, 56,
73, 77, 80, 82, 83, 100
Wilmington notch fault, 68, 98
Winch pond, 14
2255
| Wisconsin glaciation, 71
Whiteface anorthosite, 11, 17, 21-25, |
Woodruff fall, 16, 39, 40, Io1
Woodworth, J. B., cited, 89
a
ee ee ee
JOHN M. GLARKE
STATE GEOLOGIST
UNIVERSITY OF THE STATE OF NEW YORK
STATE MUSEUM
BULLETIN 211-12
LAKE PLACID QUADRANGLE
[Me Maroy)
Geology by W. J. Miller,
1915-1916.
(Ausable
LEGEND >
a] and post-glacial
GapGatts errectualTy con:
ceuling areas of Pre-
cambric rocks.
Igneous Rocks
Ea
Diabase dikes.
|
and metagabbro
Sethare possibly older
than the syenite-granite
JE
Gabbro—diorite dikes,
more or less goeissoid,
intrusive {nto the coarse
granite but robably
Sider than the post-)
syenite gabbro.
+
Aplite, granite and peg-
matite dikes, the per~
matite, In part at least,
being younger than the
gabbro.
bs ‘e ee
Keone gneiss.
A border rock, usually
porphyritio, Detween
fAnorbhositeand syenite-
anite produce! v
Thagmatic assimilation.
ras] |
Bsuiy
Basic syentte.
A basic border phase of
Gp
Granite porphyry.
A gneissoid coarse
grained, usually por
phyritié phase of the
granite.
Granite.
A pmeissold, medium
rained. very quartzose
phase of the syenite,
=
Granitic syenite.
Intermediate becween
the syenite and granite
Sy
Quartz syentte.
Distinctly gneissotd,
moderately quartsose,
and voupker than thé
thosite. ,
anor!
Whiteface anorthosite.
A light gray or white
phase of the Marcy anor
thosite. Usually
Medium grained and
foliated.
Marcy anorthosite.
Light to dark bluish-
gray and usually very
coarse grained and non-
folintet
Mixed Rocks
Whiteface anorthosite
and syenite-granite
mixed gneisses.
Grenville or amphibo-
Nite and syenite-granice
mixed gooisses.
i
Grenville or amphibo-
Jite and Whireface anor
thosite mixed gneirsex. 7
Sedimentary Rocks
Grenville limestone out-
erops:
Grenville,
Various nelsses and
schists and orystalline
limestones, mostly dis-
tinctly stratified. Ee
Fault zones.
Ae
Dip and strike of
Tollation.
Glacial striae.
R
Stone quarries and
mies,
SURFICIAL SERIES
PLEISTOCENE
LATER INTRUSIVE SERIES
EARLIER INTRUSIVE SERIES
MIXED SERIES
GRENVILLE SERIES
PRECAMBRIAN
Pe LS
|
|
|
J
-class matter Mosertes B71. 1015, at. the Post Ofice at Albany, New York,
vunder the act of August 24, 1912 ~
2 Published monthly by The University of the State of New York
s ALBANY, N. Y. - SEPTEMBER AND OCTOBER, i918
¢
The University of the State of New York
New York State Museum- ee
Joun M. CLARKE, DIRECTOR
‘GEOLOGY OF THE SCHROON LAKE
QUADRANGLE
By
WILLIAM J. MILLER
PAGE PAGE
General geographic features..... 5 | Structural geology..... Vane aagen
ee geologic features and Pleistocene geology........ Cems Bae
-publications..... Marae ora: . 7 | Summary of geological history... 93
tniefeee. 5% .... 10 | Mines and quarries.....
eee e cee wee UG |. LLU MN ea wae eee eee eeae
\ 3 ALBANY
THE UNIVERSITY OF THE STATE OF NEW YORK
dopa)
THE UNIVERSITY OF THE STATE OF NEW YORK ,
Regents of the University
With years when terms expire
(Revised to September 1, 1919)
1926 PLINY T.Sexran LL.B. LL.D. Chancellor - = Palmyra
1927 ALBERT VANDER VEER M.D. M.A. Ph.D. LL.D.
Vice Chancellor Albany
1922 CHESTER S. Lorp M.A. LL.D.. —_- -- - - Brooklyn
1930 WiLL1AM NottincHaM M.A. Ph.D.LL.D. —- —- Syracuse
1923 ABram I. Erxus LL.B. LL.D. D.C.L. = - - New York
1924 ADELBERT Moot LL.D. - - - - - - - Buffalo
1925 CHARLES B. ALEXANDER M.A. LL.B.- LL.D.
Litt.D. - - - - —- -—- — — — — = Tuxedo
1928 WaLTER Guest Ketitocc B.A. LL.D. - - —- Ogdensburg
1920 JAMES ByRNE B.A.LL.B. LL.D. —- - —- — New York
1929 Herpert L. BripcMaNn M.A. - - - - - Brooklyn
1931 THomas J. Mancan M.A.- - - - - - -=— Binghamton
President of the University and Commissioner of Education
Joun H. Fintey M.A. LL.D. L.H.D.
Deputy Commissioner and Counsel
FRANK B. GILBERT B.A.
Assistant Commissioner and Director of Professional Education
Aucustus S. Downinc M.A. L.H.D LL.D. Pd.D.
Assistant Commissioner for Secondary Education
CHARLES F. WHEELOCK B.S. LL.D.
Acting Assistant Commissioner for Elementary Education
Greorce M Witey M.A.
Director of State Library
James I. Wykr, Jr, M.L.S. Pd.D.
Director of Science and State Museum
Joun M. CrarkeE D.Sc. LL.D:
Chiefs and Directors of Divisions
Administration, Hiram C. Case
Agricultural and Industrial Education, Lewis A. WILSON
Archives and History, JAMES SULLIVAN M.A. Ph.D.
Attendance, JAMES D. SULLIVAN
Educational Extension, WiLL1IAM R. Watson B.S.
Examinations and Inspections, GEORGE M. WILEy M.A.
Law, FRANK B. GitBert B.A., Counsel
Library School, Frank K. WALTER M.A. M.L.S.
School Buildings and Grounds, Frank H. Woop M.A.
School Libraries, SHERMAN WILLIAMS Pd.D.
Visual Instruction, ALFRED W. ABrams Ph.B.
Se
a
a The University of the State of New York —
aS Science Department, November 12, 1918 —
— Dr John H. Finley
hy President of the University
Sie | vs
[ transmit to you herewith and recommend for publication as a
Bulletin of the State Museum, a manuscript entitled Geology of —
the Schroon Lake Quadrangle which has been prepared, at my
request, by Prof. William J. Miller.
fone his ep ates is accompanied by necessary maps.
Very respectfully yours
Joun M. CLaRKE
Director
"Approved for publication this 13th day of November, 1918.
President of the University
is
iy
i
New York State Museum Bulletin
Entered as second-class matter November 27, 1915, at the Post Office at Albany, New York
under the act of August 24, 1912
Published monthly by The University of the State of New York
Nos. 213, 214 JNILIBAUNDYZ, INT, Ve. SEPTEMBER—OCTOBER, I9IS8
The University of the State of New York
New York State Museum
Joun M. CrarKke, DirEcTOR
GEOLOGY OF THE SCHROON LAKE QUADRANGLE
By WILLIAM J. MILLER
GENERAL GEOGRAPHIC. FEATURES
The Schroon Lake quadrangle? represents an area of approxi-
mately 215 square miles in the central-eastern portion of the Adi-
rondack mountain region. The territory is all in Essex county
except the southern margin, which lies in Warren county. All the
quadrangle is rugged, moderately mountainous, and mostly a
wilderness, in these respects being quite typical of the 10,000 square
miles of the Adirondack region.
’ The southern half of the quadrangle is less rugged than the
northern and contains several farms, roads and villages. Schroon
Lake, the largest village, is a well-known summer resort situated
near the northern end of the lake of the same name. The other
principal villages are Minerva, Olmstedville, South Schroon and
Adirondack.
No railroad enters the quadrangle, the nearest being the Adi-
rondack branch of the Delaware and Hudson with stations at
Riverside and North Creek in the northern portion of the quad-
rangle next to the south.
The northern half of the quadrangle is notably more mountain-
ous and less settled, there being but one traveled highway (the
Newcomb and Port Henry road) across it. All the permanent
settlements of the northern portion of the quadrangle, including
the little village of Blue Ridge, are located on this road.
*See map in pocket of back cover of this bulletin.
ee
6 NEW YORK STATE MUSEUM
Both the highest and most rugged mountains are in the north-
eastern one-fourth of the quadrangle. Hoffman mountain is the
highest with an altitude of 3715 feet, but it does not stand out as
a conspicuous peak because it is simply the loftiest of a considerable
group of mountain summits in this vicinity. In this northeastern
quarter, no other mountain rises to 3500 feet, but several lie
between 3000 and 3500 feet, like Wolf Pond mountain (3473),
Ragged mountain (3290), Sand Pond mountain (3040), Texas
ridge (3212), and several unnamed points on Blue ridge.
In the northwestern quarter of the quadrangle the country is
notably less mountainous, the highest summits being Bailey hill
(3115), the western peak of Sand Pond mountain (2970), and
Hewitt Pond hill (2480-+-).
In the southern half of the quadrangle no peak rises to 3000
feet, and only three rise to 2500 feet or more, these being Ore
Bed mountain (2856), a peak 1 mile northeast of Ore Bed moun-
tain (2584), and Hayes mountain (2822). A number of others
have altitudes between 2200 and 2500 feet, among them being
Cobble hill, Oliver hill, Beech hill, Pine hill, Green hill, Moxham
mountain, and a group of points around Barnes pond.
There is a marked tendency for the mountains and valleys to
show a north-northeast by south-southwest trend. Among the more.
or less well-defined ridges are the following: from Bailey hill,
through Hayes and Ore Bed mountains, to Moxham mountain (12
miles) ; from north of Ragged mountain, through Sand Pond moun-
tain, Washburn ridge, and Bigsby hill, to south of Oliver hill (14
miles) ; Texas ridge (3 miles); Blue ridge (7 miles); Beech hill
to south of Pat pond (6 miles); and from Dirgylot hill, through
Severance hill, Hedgehog hill, and Merrills hill, to Ledge hill
(10 miles). For the most part these ridges are separated by
narrow, nearly straight valleys. The most notable exception is
the fairly well-defined east-west valley which the road follows
across the northern part of the quadrangle.
Schroon river, by means of a network of tributaries, drains all
the area of the quadrangle except most of the northeastern por-
tion, which is drained by Boreas river. Both the Schroon and the
Boreas pass into the Hudson river.
Altogether, there are about 30 lakes and ponds, the largest being
Schroon lake with 7 miles of its length within the quadrangle.
Next largest are Cheney pond nearly 2 miles long, and Hewitt
pond about 1 mile long.
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GEOLOGY OF THE SCHROON LAKE QUADRANGLE Wn
GENERAL GEOLOGIC FEATURES AND PUBLICATIONS
Most of the more common and well-known rock formations of:
the Adirondack region, as well as certain unusual ones, are abund-
antly represented in the Schroon Lake quadrangle. In the regular
order of their geologic ages the principal rocks are as follows:
Pleistocene
Glacial and Postglacial deposits
Paleozoic (Cambrian )
Little Falls (?) dolomite
Potsdam sandstone
Precambrian
Diabase dikes
Aplite and pegmatite dikes
Gabbro stocks and dikes
Keene gneiss, and assimilation product of the anorthosite and
syenite-granite series
Syenite-granite series
Anorthosite series
Grenville series of metamorphosed strata -
~The Precambrian formations constitute the foundation rocks of
the entire quadrangle. Oldest of all are the Grenville strata, prob-
ably of Archeozoic age, which are thoroughly crystalline. Gren-
ville strata are well developed in the southern half of the quad-
rangle, but their distribution is very “‘ patchy’ because they were
invaded and cut to pieces by great masses of intrusive rocks.
Next to the oldest known is the anorthosite series which occupies
most of the northeastern half of the area. The great bulk of this
rock is very coarse grained and highly feldspathic (Marcy anor-
thosite), but it has a more or less well-defined border development
(Whiteface anorthosite). .
The syenite-granite series, so common throughout the Adiron-
dack region, is next in order of age, being clearly intrusive into
both the Grenville and the anorthosite. This series, more particu-
larly its granite facies, is wholly confined to the southwestern half
of the quadrangle where it is the most prominent rock formation.
Several considerable areas of Keene gneiss lie in general between
the anorthosite and syenite or granite areas. This rock is regarded
by the writer as an assimilation- product which resulted from the
incorporation and digestion of anorthosite by the molten syenite-
granite,
8 NEW YORK STATE MUSEUM
Gabbro stocks and dikes of the usual Adirondack sort are pronii-
nently developed in the southwestern half of the quadrangle, each
of two of the stocks occupying several square miles.
Pegmatite and diabase dikes of the usual kinds, both later than
the gabbro, are well represented. A few small dikes of aplite
were also observed cutting the gabbro.
Two small areas of Paleozoic strata are known in and near
Schroon Lake village. One of these is Potsdam sandstone and the
other is Little Falls (?) dolomite.
Fifteen faults and zones of excessive jointing have been located
and these have notably influenced the topographic development.
Pleistocene deposits are very widespread, being especially thick
in the mare prominent valleys where the underlying rocks are in -
many places effectually concealed by them.
The following list includes the principal publications which con-
tain statements regarding the Schroon Lake quadrangle itself and
the adjoining districts, as well as certain other papers which aid in
understanding the geologic features of the quadrangle:
1842 Emmons, E. Geology of the Second District. Pt 2 of The Geology
of New York
1879 Hall, C. E. Laurentian Magnetic Iron Ore Deposits of Northern
New York. N. Y. State Mus. Rep’t 32, 1870; p. 133-40
1895 Kemp, J. F. Preliminary Report on the Geology of Essex County.
15th Annual Rep’t N. Y. State Geol., p. 590-604
1897 Kemp, J. F. & Newland, D. H. Preliminary Report on the Geology
of Washington, Warren, and Parts of Essex and Hamilton Coun-
ties. 17th Annual Rep’t N. Y. State Geol., p. 547-48
18907 Kemp, J. F. Physiography of the Eastern Adirondack Region in
the Cambrian and Ordovician Periods. Geol. Soc. Amer. Bul. 8,
p. 408-12
1902 Finlay, G. I. Preliminary Report of Field Work in the Town of
Minerva, Essex County. 20th Annual Rept N. Y. State Geol,
Pp. ro6-102.
1905 Cushing, H. P. Geology of the Northern Adirondack Region.
N. Y. State Mus. Bul. 95
1905 Ogilvie, I. H. Geology of the Paradox Lake Quadrangle. N. Y.
State Mus. Bul. 96
1906 Kemp, J. F. The Physiography of the Adirondacks. The Popular
Science Monthly, March 1906
1910 Kemp, J. F. & Ruedemann, R. Geology of the Elizabethtown and
Port Henry Quadrangles. N. Y. State Mus. Bul. 138
1912 Miller, W. J. Early Paleozoic Physiography of the Southern Adi-
rondacks. .N. Y. State Mus. Bul. 164, p. 80-94
1913 Miller, W. J. The Geological History of New York State. N. Y.
State Mus. Bul. 168
1914 Miller, W. J. Magmatic Differentiation and Assimilation in the
Adirondack Region. Geol. Soc. Amer. Bul. 25, p. 243-61
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GEOLOGY OF THE SCHROON LAKE QUADRANGLE 9
1914 Miller, W J. Geology of the North Creek Quadrangle. N. Y. State
Mus. Bul. 170
1916 Miller, W. J. Origin of Foliation in the Precambrian Rocks of
Northern New York. Jour. Geol., 24:578-619
1917 Miller, W. J. The Adirondack Mountains. N. Y. State Mus. Bul.
193
1918 Miller, W. J. Adirondack Anorthosite. Geol. Soc. Amer. Bul. vol.
20, no. 4
IO NEW YORK STATE MUSEUM
PRECAMBRIAN ROCKS
Grenville Series
General character. The Grenville series of strata, including
possibly some contemporaneous igneous rocks, are considered to
belong among the oldest known, or Archeozoic, rocks of the earth.
These strata represent original shales, sandstones and limestones
which have become thoroughly crystallized into various schists and
gneisses, quartzites and crystalline limestone or marble. The
stratification is usually rather distinctly preserved though not with
its original sharpness. A more or less well-developed foliation is
always parallel to the stratification.
Grenville rocks are not very prominent in the Schroon Jake
quadrangle, the combined definitely known areas totaling not over
12 square miles. It is quite certain, however, that Grenville strata
of great thickness once spread over not only the whole area of the
quadrangle and the 10,000 square miles of the Adirondack region,
but also over much of eastern Canada. They were, no doubt,
mostly deposited under marine waters much like the typical sedi-
ments of later ages. Within the quadrangle no positive proof for
great thickness has been obtained, but in other districts a thickness
of at least several miles has been demonstrated. Regarding the
lands from which the Grenville sediments were derived, and the
floor upon which they were deposited, we know nothing at present.
That organisms lived in the waters while Grenville deposition
took place those many millions of years ago seems evident from
the dissemination of graphite (crystallized carbon) through much
of the limestone as well as through certain of the schists and
gneisses.
A glance at the accompanying geologic map will show the very
“patchy ” distribution of the Grenville rocks, this being due to the
fact that the original body of thick strata, which was the universal
country rock of the quadrangle, has been badly broken up, lifted
or tilted in masses great and small, more or less engulfed and, in
some cases, injected or even partially assimilated by the great
intrusive bodies of the region. The entire absence of Grenville
strata from the anorthosite area is doubtless due to a laccolithic
structure of the anorthosite whereby the Grenville was notably
lifted or domed over the rising magma, and completely removed
sa ro BD) |
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GEOLOGY OF THE SCHROON LAKE QUADRANGLE Wit
by subsequent erosion. The later syenite-granite magma, however,
had a much greater tendency to more or less intimately break up,
penetrate, and even engulf the Grenville strata. All except pos-
sibly the few largest areas of the quadrangle may well be regarded
as true inclusions in the syenite-granite series.
Since nearly all the various types of Grenville rocks below men-
tioned in the descriptions of the Grenville areas have been described
in the writer’s report on the Geology of the North Creek Quad-
rangle,’ it seems needless to repeat the details here.
Description of Grenville areas. The rocks of the various
- Grenville areas are described somewhat in detail, in order to have
on record the more important data which may possibly aid in work-
ing out at least the broader stratigraphic relations of the Adiron-
dack Grenville series. The structural features of the Grenville
are discussed in the chapter on Structural Geology. Dips and
strikes are shown on the accompanying geologic map.
Minerva area. ‘This is the largest area of the quadrangle (see
map) and, although there are many excellent exposures, never-
theless they are not numerous enough to make it possible to gain
anything like an accurate idea of the stratigraphy and structure
of the area. The best exposures are north, northwest and west
of Minerva. South and southeast of that village there are very
few outcrops so that the southern boundary of the area is mostly
rather uncertain. Practically all the Grenville rocks of the area
show a northwest strike (see map).
The little hill just west of Minerva consists of well-bedded
quartzitic, biotitic and hornblendic gneisses, all very typical of the
usual Grenville series. Just back of the hotel a small mass of
twisted crystalline limestone lies in contact with the granite there
mapped.
On the steep hillside one-half of a mile farther west the rock
is mostly hornblende gneiss, some with garnets, and with some
bands of biotite gneiss and quartzite interbedded.
Northwest of Minerva, in and near the garnet mine, crystalline
limestone associated with much red garnet and green pyroxene is
closely involved with granite, this being separately mapped as
mixed rocks. Just south of the mine there is a vertical ledge, nearly
100 feet high, of well-bedded granitic-looking gneiss, impure
quartzite, and some limestone.
*N, Y. State Mus. Bul. 170,
I2 NEW YORK STATE MUSEUM
On the hillside north of the road, from Calahan pond southeast
for 1 mile, there are many fine exposures of crystalline limestone
with some closely involved pyroxene and hornblende gneisses —
toward the north. Toward the south this limestone contains yellow
quartz and graphite.
That portion of the area near the map edge from Calahan pond
northward shows a number of fine exposures of crystalline lime-
stone mostly containing graphite associated with some pyroxene
and hornblende gneisses, and exhibiting local foldings or contor-
tions. Just north of the small gabbro stock at the map edge the
Grenville consists of hornblende, hornblende-garnet and pyroxene
gneisses, and some quartzite.
A very fine outcrop of Grenville was observed a few rods west
of the quadrangle boundary on the southern side of the small
gabbro stock 1 mile southwest of Sherman pond, the ledge being
clearly visible from the road. In a section fully 100 feet thick
pyroxene gneiss and biotite gneiss and quartzite are beautifully
stratified in thin beds. In the lower half of the section a dike
of granite several feet thick has been intruded, both the dike and
its foliation being perfectly parallel to the stratification of the
Grenville.
Most of the ridge 1 mile east of Calahan pond appears to be
quartzite with hornblende and pyroxene gneisses and some lme-
stone at its eastern base, and hornblende gneiss at its western base,
but the outcrops are not very good. On and near the road 1 mile
a little north of east of Minerva there are several ledges of rather
coarse graphitic limestone associated with some thin-bedded, gray,
rusty graphitic gneiss and quartzite.
Exposures showing contorted limestone with pyroxene and horn-
blende gneisses occur three-fifths of a mile west of the mouth of
Kelso brook.
The hill 1 mile west of Irishtown consists of hornblende and
biotite gneisses on the south side of the small gabbro stock, and
quartzite underlain by some limestone on the north side.
On the slope northwest of the hill just mentioned, several expos-
ures of well-bedded hornblende-garnet gneiss, and one of lime-
stone, were observed. From Falls brook northward the Grenville
nearly all appears to be typical hornblende-garnet gneiss in good
exposures. Limestone shows in a small exposure on the trail one-
half of a mile northwest of Irishtown.
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GEOLOGY OF THE SCHROON LAKE QUADRANGLE 13
Olmstedville-Irishtown area. This area of Grenville is almost
certainly connected, under the Pleistocene of Minerva stream val-
ley, with the Minerva area.
In Olmstedville, by the stream one-fifth of a mile east of the mill,
there is a big ledge of typical limestone. At the bridge just east
of Olmstedville, limestone underlying hornblende gneiss forms a
ledge 100 feet long. By and near the road one-third of a mile
east of the bridge just mentioned, there are several outcrops, includ-
ing hornblende gneiss, rusty mica quartzitic gneiss and limestone.
Two small outcrops of limestone occur by the road about a mile
east of Olmstedville.
In a field 114 miles northeast of Olmstedville, there is a large
exposure of typical graphitic limestone with some small masses
of rusty gneiss twisted into it. Nearby is an outcrop of horn-
blende gneiss.
Near the road one-half and three-fourths of a mile, respectively,
southwest of the village, there are several small exposures of
graphitic limestone with some small masses of closely involved
pyroxene gneiss. The one nearest the village is weathered to a
friable mass and is used for repairing roads.
Near the road corners one-half of a mile northwest of Olmsted-
ville there are several outcrops of limestone, some containing
graphite and green pyroxene and associated with hornblende gneiss.
From this locality northward for a mile, by and near the road,
there are other good exposures of similar rocks.
From one-half to 1 mile east-southeast of Irishtown there are
interesting exposures of Grenville. Coming against the syenite
on the south side (see map) there are several good exposures of
limestone arranged along a strike N 70° W. Just within the syenite
_there is a long, narrow inclusion of quartzite. Where the limestone
belt comes to the road, hornblende gneiss outcrops. Just north
of the tongue of syenite there are large exposures of quartzite with
a little associated limestone arranged along a N 70° W strike.
One mile north-northwest of Olmstedville, and extending from
the road eastward for 200 yards, there are good outcrops of. rusty
biotite gneiss, hornblende gneiss and quartzite.
Along the road from one-half to 1 mile north of Irishtown, there
are several exposures of hornblende gneiss (some garnetiferous)
and a little associated limestone.
The tongue of Grenville which forms part of the mountain spur
1 mile north-northeast of Irishtown consists of hornblende and
14 NEW YORK STATE MUSEUM
hornblende-garnet gneisses with a little interbedded quartzite and
biotite gneiss.
Catamount hill area. Catamount hill itself is a practically solid
mass of well-bedded biotite-graphite schist or gneiss with some belts
of quartzitic rock toward the summit. ;
At the old graphite mine by the road west of Catamount hill,
the rock which was mined is a rusty looking biotite-graphite schist
in very thin layers. Most of this rock, forming a belt 30 to 40
feet wide, contains tiny flakes of graphite, but one zone in it only
a few feet wide is very rich in large flakes of graphite. In contact
with this graphite-rich rock there is a narrow band of limestone
containing green pyroxene and graphite.
Near the road one-fifth of a mile north of the mine there occurs
a ledge of quartzitic to granitic looking gneiss with one two-foot
wide band containing lenslike garnets up to an inch long.
Adirondack village area. This small area shows only a few out-
crops. A small exposure of limestone just east of the village con-
tains some graphite and green pyroxene. By the road one-half of
a mile south of the village, there occurs a ledge of bedded horn-
blende-biotite gneiss. At the southern end of the area there are
several good exposures of variable rocks, mostly hornblende gneiss,
biotite gneiss and pyroxene-garnet gneiss. These are mostly well
bedded but shot through with some coarse granite. No outcrops
occur along, or just east of, the map boundary here, but, judging
by Doctor Ogilvie’s Paradox lake map, this Adirondack village
area of Grenville probably extends across the boundary.
Areas on the shores of Schroon Lake. At the southern end of
Isola Bella there is a mass of limestone 20 feet long, really an
inclusion in the granite. This limestone contains pyroxene, quartz
and some graphite.
At Grove Point there are two exposures by the lake shore, one
being limestone with bunches and strips of green pyroxene gneiss
kneaded into the mass, and the other pyroxenic and hornblendic
gneisses with a little associated limestone.
A few rods south of the Grove Point Grenville, syenite con-
tains a long, narrow inclusion of Grenville limestone.
On the lake shore one-half of a mile east of South Schroon,
limestone with patches of green pyroxene gneiss twisted into it
shows in a good exposure.
Areas northwest of Schroon Lake village. The small lens-
shaped area shown on the map 1 mile northwest of the village con-
GEOLOGY Of THE SCHROON LAKE QUADRANGLE 15
sists of interbedded quartzite (some garnetiferous), quartz-pyrox-
ene gneiss, and quartz-feldspar gneiss with several thin layers of
limestone containing green pyroxene.
The area just east of North pond shows a number of good
exposures of well-bedded hornblende-garnet gneiss and hornblende
gneiss with one two-foot thick layer of limestone in the horn-
blende gneiss. Near the western corner oi the area there are many
large reddish brown garnets up to 4 or 5 inches in diameter, but
without hornblende rims as is often the case with such large garnets
in the Grenville hornblende-garnet gneiss elsewhere in the
Adirondacks.
Other areas of Grenville. In the small area on the west face of
Wilson mountain, pyroxenic, hornblendic and quartzitic gneisses are
well exposed, some of these being locally contorted. Along the
eastern side of this area the Grenville rocks are more or less inti-
mately charged with granite.
At the western end of the area just southwest of Oliver pond
there is a big exposure of hornblende-garnet gneiss interstratified
with thin-bedded, fine grained, pinkish gray, quartz-biotite schist.
A few rods farther east there occurs a ledge of limestone con-
taining green pyroxene, quartz and a little graphite. Toward the
eastern end of the area the rock is hornblende-garnet gneiss.
A small lenslike inclusion of hornblende-garnet gneiss with gar-
nets up to an inch across occurs in the granite one-half of a mile
west of Oliver pond.
One mile northeast of Loch Muller, in the small area mapped,
there is a single large outcrop of hornblende gneiss, somewhat
garnetiferous.
On the southern slope of Hayes mountain, three-fourths of a
mile from its summit, a small lenslike body of typical hornblende-
garnet gneiss with garnets up to an inch across occurs as an
inclusion in granite. A similar small inclusion occurs in the syenite
2 miles north-northwest of Irishtown, and still another in granite
1% miles west-southwest of the summit of Hayes mountain.
*This is the place printed on the map accompanying this bulletin, but
since the map was printed the post office has been moved 2 miles to the
northwest to Warren’s hotel.
16 NEW YORK STATE MUSEUM
Some interesting exposures occur in the small area 1% miles —
northwest of the summit of Hayes mountain. In the old stone
quarry the rock is greenish limestone containing serpentinized green
pyroxene and some graphite. This is associated with some horn-
blendic and quartzitic gneisses. Similar rocks outcrop on the west
bank of the stream, but there the pyroxene is less serpentinized.
Undoubtedly this mass of Grenville is a fairly large inclusion in
the granite which outcrops close by on all sides.
In the Hewitt Pond brook area there are several good outcrops
of Grenville hornblende gneiss and hornblende-garnet gneiss.
A conspicuous lenslike mappable inclusion of hornblendic and
quartzitic well-bedded gneisses occurs in the granite 114 miles east-
southeast of Boreas river.
Still other masses of Grenville occur within the aval but
these are so closely associated with other rocks that they are
mapped and described as “ mixed rocks.”
Anorthosite Series
General considerations. Recently the writer has published a
rather elaborate paper’ on the whole problem of the age, relations,
and origin of the Adirondack anorthosite. The interested reader
is referred to that paper for much more material than is pre-
sented in this bulletin. Some years ago, Professor Cushing, in
his report? on the Geology of the Long Lake Quadrangle, presented
evidence to show that the anorthosite is a great intrusive body dis-
tinctly younger than the great syenite-granite series of the Adiron-
dacks. The writer heartily agrees with this view, and in his own
field studies, particularly in the Lake Placid and Schroon Lake
quadrangles, he has found much more evidence in support of Cush-
ing’s view. Recently, however, Dr N. L. Bowen® has offered quite
a different explanation of the origin and relations of the anor-
thosite. His hypothesis and the writer’s objections to it are briefly
stated below, but a fuller criticism is presented in the paper above
cited.
The anorthosite occupies a largely unbroken area of about 1200
square miles of the central-eastern Adirondack region. It is promi-
nently developed with nearly all its facies in the Schroon Lake
1Geol. Soc. Amer. Bul. 29 No. 4, 1918, p. 399-462.
7N Y. State Mus. Bul 115, p. 479-82. 10907.
*Jour. Geol., 25:209-43. 1017.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 17
quadrangle where, as a result of its careful study, important light
has been thrown upon the age, relations, structure, and origin of
the great anorthosite body. Most of the northeastern half of the
quadrangle, or an area of over 80 square miles, is occupied by
anorthosite to the exclusion of all other formations except Pleis-
tocene deposits and a few small basic dikes.
Marcy type of the anorthosite. By far the most abundant
general facies of the rock may be called Marcy anorthosite because
of its great exposures on Mount Marcy in the quadrangle next
to the north. The most typical portions of the Marcy anorthosite
are coarse grained, light to dark bluish gray, and consist largely of
basic plagioclase feldspar, mainly labradorite. The dark bluish
gray labradorite crystals usually vary in length from a fraction of
an inch to several inches, crystals about an inch long being very
common. Among other places, labradorites from 5 inches to I
foot long were observed on the western of the three Peaked hills,
and on the ridge 1 mile north-northwest of Blue Ridge village.
Only occasionally do these labradorites exhibit the play of colors
so characteristic of this species of feldspar. Twinning striations
are often evident to the naked eye on the cleavage faces.
Accessory minerals visible to the naked eye are large individuals
of pyroxene and hornblende, and small individuals of biotite,
ilmenite, pyrite, garnet, and more rarely chalcopyrite or pyrrhotite.
These accessory minerals ordinarily constitute 5 to 10 per cent of
the typical coarse anorthosite, but there are local developments of
the rock which are made up almost entirely of plagioclase, and still
others, rather abundantly developed as zones, bands and irregular
masses, which contain from 10 to 25 or more per cent dark minerals,
these last named types being really anorthosite-gabbros. Such
gabbroid facies are more fully described below.
An important facies of the anorthosite is one in which the dark
labradorites, from a few millimeters to an inch or more across,
stand out conspicuously in a distinctly granulated groundmass of
feldspar. The granulated material varies from light gray to pale
greenish gray. It is very evident that the large labradorites are
roughly rounded uncrushed cores of what were considerably larger
individuals before the rock was subjected to the process of granu-
lation. All degrees of granulation are exhibited to extreme cases
where the rock has been so thoroughly granulated that few, if
any, labradorite cores remain.
18 NEW YORK STATE MUSEUM
Much of the typical Marcy anorthosite is devoid of foliation,
though in some local zones of almost perfectly pure plagioclase
rock there is a notable tendency for the feldspars to show a crude
parallelism (plate 6). The more gabbroid facies of the rock, how-
ever, often exhibit a fair to well-defined foliation accentuated by
the crudely parallel arrangement of the dark minerals.
In thin section, with a low power of the microscope, the larger
labradorites are usually seen to be filled more or less with myriads
of very dark dustlike particles, probably ilmenite. The minerals
contained in several thin sections of the Marcy anorthosite are
shown in table 1 below.
Chilled border facies of the anorthorsite (Whiteface anortho-
site). Around the borders of the great body of Adirondack
anorthosite, and in some places a number of miles within it, there
is quite generally a notable development of white or very light-gray
labradorite and an increase in the femic minerals causing such rocks
to be anorthosite-gabbro or even gabbro. Such rocks, well devel-
oped in the Schroon Lake quadrangle, are almost invariably finer
grained and lighter colored than the typical Marcy anorthosite,
though in some localities a few large, scattering labradorite indi-
viduals occur. A foliated structure is generally evident.
Although they are more or less variable in general appearance
and composition, the writer has proposed that these border phases
of the anorthosite be classed as Whiteface anorthosite, a name
given by Professor Kemp to the type which occurs abundantly on
Mount Whiteface near Lake Placid. At the summit of Mount
Whiteface the rock is medium grained and consists of white plagio-
clase (chiefly labradorite) with 10 to 15 per cent of dark minerals
scattered through the mass parallel to a crude foliated structure.
Such rock, which is quite typical of the Schroon Lake quadrangle
Whiteface anorthosite, stands out in marked contrast against the
typical Marcy anorthosite which is not so gabbroid, very coarse
grained, light to dark bluish gray, and generally not so well foli-
ated. More exceptionally the Whiteface anorthosite is nearly pure
white, being quite free from femic minerals. Much of the rock,
however, is locally richer in dark minerals, which may constitute
15 to 30 per cent of the whole. The minerals other than the
feldspar are practically the same as in the Marcy anorthosite.
Table 1 gives a good idea of the mineral content of the Whiteface
anorthosite of the quadrangle.
ISET[IA ISPIY ING JO som ou & FO PaAryj-9u0 YOoI1d yourig IY] FO poaq oY} Ul o}ISsSoY}IOUL ADIVIN
LIGE ‘oJoyd “ASTI “£ M
a
=
GS o23°Ig
GEOLOGY OF THE SCHROON LAKE QUADRANGLE ~- 19
Table 1 Thin sections of anorthosite
fe} =
g o 2
Soleus 3g a 2
5 6 SVs g [4 = 2 eee
Bf WS See I ey | SY) eh Ae irae Ste ee eee) Gee Wrasse
o ue} b ojlm| 4 i= a|p|s bb a} ° p fe) = o| oO
Mesh al Sue Sales csr ni seen es ssi | BU | el es ae Es rl lees
ta |) He PSA Wf (EV Sy tose Wty ay esy pes | ra a < N & |HOlO
q :
Somer CT MOO eal clic cilies leds calles elie as oe| Line URAIG ona HIE So alle Ge oc
>
B Za Gls) “lens! UA al) te lleoseollecdiines eee eI HetPaearenpel att. Maes toe eonemrd 1, ee sti
P= PANT Sit Olt Owe S| cr oe UG fin) ie) K=N eee al Feet etal [ep recy Ieicren cc
S HO) | NA Le | Cte coy eel ecm ted oes [Petce, elyeal saved) Lil morons lleremeyf svenetsce teats all ois Sa eollacie ¢
= II] 5d .1| 75] Io 12 nO tert tcl leche little} little).....
6 HA” ONG) CAlecllogc 4 3 RHO oo Bolla nc oe little} little
sg i] 7) We Cs olla oe 5 TO} meh lic tle ae oil Wee. 2 oo e|fe flo after
B 14; 7e9| &5' RA aio olle Pele Enbstees tel Pee ec, little) little)..... als le
q I5| 7h1| 81 Slleao 5| 14 Bh et ce little] little}.....].. 2
: 16| 7g1| 68 10| 23 Rel aire 5 ise lie stssetail ine sstae (ieee tota| el | eel
5) 7 Sem SS) ase ge aerate 9| 14 a ee ciacs it lel een GDN 5 2l]o o{lo 6
s 18} ges] 78 4 1%] 14) 4 oo ariel se gal] Minds ols ella
S|] EO) Ob ag) ES Bolle de Ti Sif WWII) no odlloomoc little} little}. .|..]..
ae} || Quill Ges} fee Ih OV alae 6 itech Ly Gio oo coll WUE! cob elloocaslloossellsolor 5
ce || 2a) mie Apes toa aclooe TO} Mera |Wlittle| eee BS obo beaalieslloclise
37| 8 £25 67, O}] Ye alle i llevcecel [hevateats fei Rosucyeve 4| little callers
No. 20, three-fourths of a mile southeast of summit of Hoffman moun-
tain; no. 23, by the road 1 mile northeast of Boreas river; no. 24, by the
stream I mile east-southeast of summit of Ragged mountain; no. 10, 1
mile southeast of summit of Oliver hill; no. 11, 1% miles a little west
of north of Irishtown; no. 12, lake shore just north of Grove Point;
nos. 13 and 14, one-half of a mile west-northwest of Bigsby hill; no. 15,
by road at Loch Muller; no. 16, one-third of a mile west of Loch Muller;
no. 17, one-half of a mile south-southeast of summit of Severance hill;
no. 18, top of Hayes mountain; no. 19, by the brook southwest of Smith
hill; no. 21, near western summit of Sand Pond mountain; no. 22, near
cross-roads at Boreas river; no. 37, southern brow of Cobble hill.
_ No. 17 of table 1 exhibits very fine reaction rims as follows:
(1) magnetite with rims of garnet; (2) pyrite with rims of garnet;
and (3) magnetite with successive rims of hypersthene and garnet.
Both the Marcy and Whiteface types of anorthosite are quite
certainly differentiation phases of the same cooling magma, the
latter representing a chilled border or marginal portion. The one
type grades into the other, and nowhere has one been found
definitely to intrude the other.
_ Special descriptions of Whiteface anorthosite occurrences. In
the Boreas river area the Whiteface anorthosite is mostly rather
uniformly moderately gabbroid and foliated with scattering bluish
labradorites, but some local variations from this composition and
structure were observed. Near the cross-roads at Boreas river
(no. 22 of table 1) a ledge is unusually rich in pyroxene and quartz.
0S SS eee
20 NEW YORK STATE MUSEUM
In the eastern portion of the Sand Pond mountain area the rock
is nearly white and free from femic minerals, nonfoliated, and
with only a few scattering blue labradorites (no. 21 of table 1).
The rock of the western portion of the area strongly suggests
Marcy anorthosite and grades into it. It is light gray and non-
foliated with 10 to 20 per cent dark minerals and garnets and many
blue labradorites.
The Severance-Smith hill area, the pen shown on the map,
comprises mostly rather uniform, very typical, Whiteface anortho-
site (nos. 17 and 19 of table 1). At the extreme southern end it
contains an admixture of Grenville.
In the large area southwest of Bailey hill the Whiteface anor-
thosite is mostly very typical. By the old road on the west side
there are some rather gabbroid, garnetiferous, foliated zones, and
in the eastern portion there are locally developed masses with many
garnets and some scattering blue labradorites.
A large ledge of Whiteface anorthosite at Loch Muller is exceed-
ingly variable as regards both content of femic minerals and folia-
tion. It contains some bluish labradorites and scattering garnets
(no. 15, table 1). One-third of a mile farther west in the same
area the rock is distinctly gabbroid and foliated and. carries 8
or IO per cent of quartz (no. 16, table 1). In the western part of
the area the rock is very typical Whiteface anorthosite.
The long, narrow area south of Hewitt road shows Whiteface
anorthosite varying from light-colored, moderately gneissoid to
dark-colored, gabbroid, very gneissoid facies.
The rocks of the area west of Bigsby hill exhibit many local
‘variations from typical anorthosite to very gabbroid, gneissoid
anorthosite. In some ledges quartz is visible to the naked eye.
Nos. 13 and 14 of table 1 are from this area.
A big ledge of gabbroid, very gneissoid Whiteface anorthosite
(no. 11 of table 1) in the small area 114 miles a little west of
north of Irishtown is intimately associated with Grenville horn-
blende-garnet gneiss, the latter commonly occurring as distinct
strips or lenslike inclusions in the anorthosite.
The remaining small areas of Whiteface anorthosite require no
special description here.
Variable composition and structure of the anorthosite and its -
significance. General statements. Contrary to Bowen’s statement
that “anorthosites are made up almost exclusively of the single
mineral plagioclase,” the writer’s experience in the field has made
‘toddn oy}
Ul JOU yng Jared TOMO] DY) Ul JoUTSIp AIDA st ‘o}IJOpvaAqe] Jo syeysAID oSae] JO wistjoayjvsed epnsd 0} anp ‘uoreT[Osy
‘puod jeq JO JsoMYJIOU [TU B JO SYjIMOF-d914} Play ev UL o}ISOyJIOUR ADIeIY JO Japynog e JO aed FO MoIA APIN
AI6T “OJOYM “IOITYIN “Lf “AY
4
Z 9 238Id
GEOLOGY OF THE SCHROON LAKE QUADRANGLE Zu
it clear that the Adirondack anorthosite is by no means an almost
perfectly homogeneous mass of plagioclase. The main bulk of the
Marcy anorthosite contains at least 5 to 10 per cent of minerals-
other than plagioclase. Portions with about 10 per cent are com-
mon, and in many places there are 10 to 20 per cent, or even more,
of dark minerals. It is also true that some portions of the great
mass contain less than 5 per cent of femic constituents. _Con-
servatively estimated, the average Marcy anorthosite carries fully
IO per cent of minerals other than plagioclase.
In the writer’s work in both the Lake Placid and Schroon Lake
quadrangles, many observations have been made of anorthosite-
gabbro and more typical anorthosite exhibiting perfect gradations
from one into the other. Such gabbroid facies exist locally through-
out the body of Marcy anorthosite, in many places as rather dis-
tinct zones or belts a few feet or rods wide, and in other places
on much larger scales. Many other gabbroid portions are much
more irregular in shape, and not so distinctly separated from the
purer Marcy anorthosite.
The anorthosite-gabbro very commonly, and the typical Marcy
anorthosite less commonly, locally exhibit more or less well-devel-
oped foliation with exceedingly variable strikes. Marked varia-
tions in degree of foliation often occur in single ledges. It is also
important to note that granulation, so prevalent throughout the
anorthosite body, shows many extreme variations, often in single
outcrops.
Another variation of the anorthosite from a pure plagioclase
rock consists in the dustlike (schillerization) inclusions of a dark
mineral, probably ilmenite, in the labradorite. These are so numer-
ous as to cause most of the labradorites to have a dark bluish gray
color. Thus even the plagioclase crystals are not pure lime-soda
feldspar. A
Finally in this connection, attention should be called to the pres-
ence of a very appreciable amount of potash in the typical Marcy
anorthosite, as shown in an analysis made for Professor Kemp.
Whether this potash exists in regular potash-feldspar form, or is
part of the labradorite proper, it is additional proof that the anor-
thosite is not a practically pure mass of lime-soda feldspar.
Some examples of variations of Marcy anorthosite. Near the
top of the hill 1 mile a little to the west of north of Blue Ridge
village, the following variations across the strike from south are
finely exhibited: first, there is typical Marcy anorthosite; then, a
band 2 feet wide of gneissoid, moderately coarse-grained, gabbroid
is)
ie)
NEW YORK STATE MUSEUM
anorthosite with a few labradorite phenocrysts; then, a belt 40 feet
wide of less coarse-grained anorthosite with a few labradorite
phenocrysts and scarcely any femic minerals; next, a belt 35 feet
wide of very coarse-grained, gabbroid anorthosite with pyroxene
and labradorite crystals from 6 inches to 1 foot each in length.
None of these belts or zones is very sharply separated, though in
some cases the change from one into the other takes place within
a few inches.
At the rapids of Boreas river, just before the stream enters the
Brace dam reservoir, a big ledge of typical Marcy anorthosite with
very few femic minerals contains a very irregular shaped mass of
highly femic and garnetiferous anorthosite some 30 feet long with
a maximum width of 10 feet. Except for the 20 to 30 per cent
of dark minerals, this femic anorthosite is much like the inclosing
anorthosite. Boundaries against the typical anorthosite are not
sharp, but the complete transition takes place within 5 or 6 inches.
The femic rock is nonfoliated, but the typical Marcy anorthosite
on one side of it has most of its labradorites (1 to 2 inches long)
arranged parallel to the contact with the femic rock. This par-
allelism is most evident close to the contact and not at all notice-
able 6 or 8 feet out.
By the road three-fourths of a mile east of where it crosses
Boreas river, a 50-foot exposure of typical Marcy anorthosite, with
less than 5 per cent femic constituents and with many labradorites
an inch long, exhibits very distinct foliation due to parallelism of
the labradorites. This rock grades into typical nonfoliated anor-
thosite of the adjacent exposure.
By the same road above mentioned, but one-third of a mile far-
ther east, a 50-foot ledge of anorthosite with 10 or I5 per cent
femic minerals contains several distinctly foliated zones not see
SEOMICASG! TisOMN WS THESE OI mS inoyele,
In a ledge of typical Marcy anorthosite on the middle-southern
slope of Saywood hill, a distinctly foliated zone occurs in contact
with nonfoliated anorthosite on either side.
From Saywood hill to Clear Pond mountain there are large scale
variations represented chiefly by typical, nongabbroid, mostly non-
foliated, Marcy anorthosite with some labradorites up to 3 inches
long on Saywood hill; very coarse, rather gabbroid, nonfoliated
anorthosite containing labradorites up to 6 or 7 inches long and 10
to 20 per cent femic minerals on Clear Pond mountain; and many
fine exposures of more typical Marcy anorthosite with usually 10
to 15 per cent femic minerals and little foliation.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 23
In the whole area from Blue Ridge mountain eastward to the
map limit, there are many excellent exposures of remarkably uni-
form, very typical Marcy anorthosite, there being few gabbroid
or foliated variations in this large area.
Where the road crosses the Branch brook a ledge of typical
Marcy anorthosite contains an irregular gabbroid mass about 2 |
feet wide without sharp boundaries against the inclosing rock.
Variations similar to those just described were observed in many
other places, but enough have been described to illustrate the nature
of the variability of the anorthosite.
Significance of the composition and variations of the Marcy anor-
thosite. According to Bowen, “ anorthosites are made up almost
exclusively of the single mineral plagioclase” and therefore “the
conception of the mutual solution on minerals in the magma and
the lowering of temperatures consequent thereon is no longer
applicable.” But, in view of the facts above presented which show
that the anorthosite averages fully 10 per cent femic minerals
visible to the naked eye; that the labradorites carry myriads of
tiny inclusions of a dark mineral; and that the anorthosite contains
a notable percentage of potash, is the mutual solution theory neces-
sarily precluded? Have we any proof that a rock with such a
quantity and variety of constituents other than plagioclase could
not have been, largely at least, molten as such? Is it safe to argue
from experiments on small amounts of rather pure melts under
ordinary laboratory conditions that a rock like the Adirondack
anorthosite could not have existed as a true magma? Bowen says
that “a rock containing 10 per cent diopside (and 90 per cent plagio-
clase) could have had a maximum of 35 per cent liquid” in an arti-
ficial melt, and that in a natural melt “the probability is that the
amount of liquid would be relatively somewhat larger on account
of the presence of orthoclase in the liquid.” But the Adirondack
anorthosite would have formed a melt of notably more compli-
cated composition than an artificial melt with 10 per cent diopside,
and this under deep-seated geologic conditions. Is it safe to say,
therefore, that such a melt may not have been a true magma with
a*high percentage of liquid? Furthermore, allowance should be
made for various agencies well within the earth, particularly dis-
solved vapors the escape of which pressure tends to prevent, and
which tend to increase fluidity.
Since the foliation of the anorthosite is essentially a magmatic
flow-structure, it shows that, at the very least, large portions of the
24 NEW YORK STATE MUSEUM
body of anorthosite once possessed fluidity enough to permit dis-
tinct magmatic currents or movements. The significance of the
foliation is thus an important consideration. Even the typical
Marcy anorthosite, almost entirely free from femic minerals, not
rarely exhibits a magmatic flow-structure foliation (plate 6), the
labradorite crystals having been strung out into crude parallelism
in a yet molten portion of the rock. Not only was this interstitial
liquid in sufficient quantity to permit the development of distinct
magmatic flowage, but it was essentially molten plagioclase. It
could have been nothing else. Hence we here have evidence directly
opposed to Bowen’s statement that the anorthosite was never at a
temperature sufficiently high to melt plagioclase. It is not argued,
however, that the anorthosite as such necessarily was intruded
in the form of a true magma to its present position, having been
differentiated at a much lower level. Rather, it is probable that
a gabbroid magma was the original intrusive which, either during
the process of intrusion or after the magma came nearly to rest,
or both, differentiated to give rise to the anorthosite which was
then, in considerable part at least, really molten. This matter is
more fully discussed below.
Though the writer believes the anorthosite as such to have been
molten to a very considerable degree at least, it is by no means
necessary to assume that it was ever completely molten with a high
degree of fluidity, or even only a moderate degree of viscosity.
None of the field facts, however, necessarily preclude the hypothesis
that the whole mass of the anorthosite may once have been com-
pletely molten, but without a high degree of fluidity.
Before leaving this consideration of the significance of the varia-
bility of the anorthosite, emphasis should be placed upon the fact
that, in many places, its mass shows unmistakable evidence of
having differentiation phases of anorthosite-gabbro or even gabbro,
while there is no positive evidence for its differentiation into sye-
nite or granite as should be the case according to Bowen’s
hypothesis.
Relation of Whiteface and Marcy types of anorthosite. In the
Schroon Lake quadrangle as elsewhere, it is clear that the White-
face anorthosite is a gabbroid border facies of the Marcy anor-
thosite with perfect gradations from one into the other, and with
no evidence that syenite or granite was ever developed as a rock
intermediate between the border phase and the true anorthosite as
required by Bowen’s hypothesis. Though it has been notably cut
into, and partly assimilated by the syenite-granite body, a glance at
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 25
the geologic map shows beyond question that this Whiteface anor-
thosite was formerly a continuous border phase of the Marcy anor-
thosite which latter occupies the whole northeastern one-third of
the quadrangle. Three large bodies of the Whiteface anorthosite
still lie against the Marcy anorthosite in their original positions.
There is strong evidence that this border phase was formerly at
least 7 or 8 miles wide because, within that distance out from
the Marcy anorthosite, many smaller widely scattered masses of
the Whiteface rock occur as inclusions in the syenite-granite series
all the way across the quadrangle. In other words, only remnants
of the original border rock now occur. Further, since this border
rock is notably finer grained than the Marcy anorthosite, it is very
reasonable to interpret it as a chilled gabbroid border phase com-
parable in position and origin to Cushing’s Long Lake border
phase of the anorthosite, though of lighter color and usually not
so gabbroid. The Schroon Lake quadrangle Whiteface anorthosite
’ commonly carries 10 to 20 per cent dark minerals, but it is very
variable, some phases containing only 5 per cent or even less, and
some more than 20 per cent.
There is strong evidence that the chilled gabbroid border phase
developed not only as an outer limit but. also as an upper limit
which formerly existed as a cover resting directly upon the whole
great mass of anorthosite. Thus, as already pointed out in the
writer’s Lake Placid report, the Whiteface anorthosite of that area
does not exist merely as a definite fringe around the outer margin
of the Marcy anorthosite. Whiteface anorthosite there occurs
fully 14 or 15 miles within the present border of the anorthosite
area, and inclusions in the syenite-granite series outside the gen-
eral anorthosite area show that the Whiteface anorthosite formerly
extended at least a few miles farther out than the present bound-
ary. One area of Marcy anorthosite, 12 miles long within the Lake
Placid quadrangle and extending an unknown distance into the
Ausable quadrangle, is flanked on either side by Whiteface anor-
thosite. It is hard to resist the suggestion that the Whiteface rock
formerly covered this whole mass of Marcy anorthosite. There
is thus a distinct difficulty in the way of considering this White-
face anorthosite as merely an outer border facies. If we do regard
it as merely an outer facies, we are forced to conclude that it is
exceedingly thick, that is to say fully 10 or 15 miles, the width of
the area containing Whiteface anorthosite representing practically
the thickness of the border facies. This is scarcely conceivable.
The Schroon Lake quadrangle yields similar evidence since, as
26 NEW YORK STATE MUSEUM
above pointed out, the border facies (Whiteface type) there
formerly extended fully 7 or 8 miles out beyond the present margin
of the Marcy anorthosite as indicated by numerous inclusions in
the syenite-granite series. In this connection, a very interesting
inclusion of fragments of very typical Marcy anorthosite in the
granite of Wilson mountain, over 6 miles out from the present
border of that type of anorthosite, may be reasonably interpreted
as Marcy anorthosite caught up in the granite magma at a lower
level (below the Whiteface anorthosite cover) and carried upward
to the present position (see figure 1). In any case it is certain that
Marcy anorthosite existed that far out.
Within the Schroon Lake quadrangle no Whiteface anorthosite
was found within the large area of Marcy anorthosite, it apparently
all having been removed by erosion. Unless definite areas of the
basic chilled border facies are found far within the great anortho-
site area, positive proof that such a border once existed as a cover
over the whole will be wanting. But such a cover, if once unt-
versally present, would show few, if any, remains far within the
anorthosite area because of the widespread and deep erosion to
which the region has been subjected.
In short, the evidence from the outer portions of the great
Adirondack anorthosite body strongly supports the view that a
chilled gabbroid border facies should be regarded as having
formerly existed as a cover resting upon the whole mass of Marcy
anorthosite. The evidence from the interior is negative, but nothing
in the field is opposed to the conception of a former universal
cover. But this does not preclude Cushing’s conception of an
outer chilled border of the anorthosite, provided we regard the
anorthosite as a great laccolithic intrusive body (see figure 2)
over all of which a border facies developed as an upper limit,
and at the margins of which a border facies developed at the same
time as an outer limit. The writer therefore agrees with Cushing
that the area of anorthosite shown on the state geologic map shows
practically ‘‘ the original size of the mass at the depth represented
by the present erosion surface,’ and that the anorthosite can not
extend out to, or even close to, the margins of the whole Adirondack
region.
According to Bowen, the femic constituents of a great gabbroid
magma, as wide as the Adirondack region, first separated (or sank)
by gravity, while the plagioclase crystals (then in the form of
basic bytownite) remained practically suspended. At a later stage,
when the liquid became light enough, plagioclase crystals (then in
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 27
the form of labradorite) accumulated by sinking, thus giving rise
to the mass of the anorthosite, leaving the overlying liquid of such
composition as to yield syenite or granite. In his first paper, Bowen
does not consider the development of a chilled border of the Adi-
rondack anorthosite. In his second paper, by way of reply to
Cushing, he modifies his idea of the stratiform arrangement of
the igneous complex by considering the development of a “ gab-
broid chilled upper portion of a laccolithic mass extending far
beyond the limits of the present exposure.’ Directly under the
chilled border, according to Bowen, the great body of syenite-
granite developed; still lower down the typical anorthosite formed;
and at the bottom, pyroxenite and gabbro.
Since the evidence above presented shows that the great body of
Adirondack anorthosite has a chilled gabbroid border which can
not possibly extend far out beyond the present exposure of the
anorthosite, and evidence below presented is distinctly against
existence of syenite or granite formed as a differentiate between
the border facies and the typical anorthosite, it is clear that Bowen’s
hypothesis of the origin of the anorthosite by the settling of
plagioclase crystals is untenable. There simply is nothing from
which they could have settled. The writer believes, therefore, that
it is out of the question to interpret the Adirondack igneous com-
plex as even in a general way a “ sheetlike mass with syenite above
and anorthosite below” as required by Bowen’s hypothesis.
Relation of the syenite-granite to the Whiteface anorthosite.
According to Bowen, the syenite-granite and anorthosite are not
distinctly separate intrusives, but both formed as differentiates
from a single great body of intruded gabbroid magma. ‘Cushing
and the writer both believe the syenite-granite series to be dis-
‘tinctly later, and the writer has found abundant evidence in sup-
port of this view in both the Lake Placid and Schroon Lake quad-
rangles.
For the Long Lake quadrangle Cushing says*: “ The field evi-
dence seems clear that the anorthosite had solidified, with a chilled
border, and had then been attacked from the side by a mass of
molten syenite, which in places cut deeply into it.” With this
statement the writer agrees, but he would further say that both
granite and syenite of the syenite-granite series have, in certain
other districts like the Lake Placid and Schroon Lake quadrangles,
not only cut deeply into, but also they have either largely cut out
lotm Geol 25507... Tan:
28 NEW YORK STATE MUSEUM
or more or less assimilated, the border facies of the anorthosite.
Detailed field evidence in support of this view is presented below.
Cushing maintains that the chilled border is fatal to Bowen’s
conception that molten overlying syenite may have been faulted
down against solid anorthosite so that it could have laterally
attacked the anorthosite, thus accounting for the intrusive features
including the syenite dikes. Much detailed field work by the writer
shows that the chilled border (Whiteface anorthosite) grades
directly into the typical anorthosite, and that there is no reason to
think that the syenite-granite series developed between the chilled
border and the typical Marcy anorthosite. Even if we assume,
what has not been found in the field, that some such syenite or
granite exists as a rock intermediate between the chilled border
and the typical anorthosite, it is most unreasonable to suppose that
the chilled border would, in some places, grade first into the syenite
or granite and then into the Marcy anorthosite. Either one of
these might be the case, but not both.
Bowen suggests that the syenite-granite may have developed
between the chilled border and the Marcy anorthosite, and then
have been reintruded through the chilled border. But how can we
possibly imagine such a vast bulk of syenite-granite to have been
so largely reintruded that not any of it has been discovered in its
supposedly original position? Also how can we imagine the rein-
trusion of such a tremendous volume of syenite-granite through
the chilled border facies, leaving this latter as a definite fringe
about, and grading into, the Marcy anorthosite for so many miles?
Dikes of syenite and granite.in anorthosite. Some years ago,
in his report on the Geology of the Long Lake Quadrangle,’ Cush-
ing showed that several narrow well-defined dikes of syenite there
cut the typical Marcy anorthosite, one of these dikes being several
miles within the border of the great anorthosite body. He also
states that one of the small outlying masses of anorthosite is
“definitely cut by syenite which sends dikes into it.”
As a result of the surveys of both the Lake Placid and Schroon
Lake quadrangles by the writer, various excellent examples of
dikes and broad tongues of syenite and granite cutting anorthosite
have come to light. A number of fine examples of such dikes are
described in the report on the Geology of the Lake Placid Quad-
rangle.
*N. Y. State Mus, Bul. 115, p. 480-84. 1907.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 29
In the Schroon Lake quadrangle a number of clearly defined
dikes of granitic syenite and granite were observed in the anortho-
site. One of these is well shown by the road 1% miles west of
Boreas river where a dike of granite 5 feet wide cuts rather femic
Whiteface anorthosite without very sharp contacts. Another is
a dike of typical pinkish gray granite 25 feet wide 1 mile west of
the western summit of Sand Pond mountain. It sharply cuts
Whiteface anorthosite which lies near, and closely resembles
Marcy anorthosite. Both dikes just mentioned are quite certainly
off-shoots from large bodies of typical granite which, in a general
way, cut into the marginal portion of the great body of anortho-
site. A wide dike of gray granite cuts Marcy anorthosite just
north of the summit of Texas ridge (see map). The granite is
very gneissoid with highly flattened quartz and feldspar crystals.
The small mass of Whiteface anorthosite on the side of Beech hill
(see map) is cut by a number of narrow dikes of granitic syenite
and granite which are doubtless off-shoots from the large sur-
rounding body of syenite-granite. Contacts between these dikes
and the anorthosite are usually not very sharp.
Also in the Schroon Lake quadrangle many dikes or narrow
intrusive bodies of syenite and granite were observed in the areas
of anorthosite and syenite-granite mixed rocks, and to some
extent in the areas of Keene gneiss. Some of these are referred
to below. The evidence, therefore, from the dikes, that the syenite-
granite series is distinctly younger than the anorthosite series, is
very strong. .
Broad intrusive tongues of syenite and granite in anorthosite.
Broad tongues of syenite and granite extending, in a number of
places for miles, into the great body of anorthosite furnish per-
haps even more impressive evidence than the dikes that the syenite-
granite series is really younger than the anorthosite.
Cushing’s Long Lake geologic map shows an intrusive tongue
of syenite from 1 to 3 miles wide cutting into the anorthosite for
a distance of 2 miles.
The writer's Lake Placid geologic map shows a fine example of
a tongue of syenite-granite with a maximum width of 1% miles
cutting Whiteface anorthosite across a portion of Wilmington
mountain. A great body of syenite-granite from 1 to 6 miles wide
extends into the anorthosite for 13 miles across the Lake Placid
quadrangle, and thence for an unknown distance into the Mount
Marcy quadrangle on the south.
30 NEW YORK STATE MUSEUM
In the Schroon Lake quadrangle, a tongue of granite from 2 to 4
miles wide in the vicinity of Cheney pond extends into the anortho-
site for fully 4 miles, reaching all the way through the border
facies and into the Marcy anorthosite (see map). The large intru-
sive mass of later gabbro lies within this. salient and cuts out much
of the originally present granite. Tiwo of the small dikes of granite
above mentioned are off-shoots of this salient of granite in the
anorthosite. :
Inclusions of anorthosite in the syenite-granite. Inclusions
of anorthosite in the syenite-granite series furnish very strong evi-
dence that the syenite-granite body is an intrusive distinctly sepa-
rate from, and later than, the anorthosite. Such evidence is
scarcely, if at all, mentioned by Bowen, probably because few
examples of such inclusions were known to him. Many excellent
examples have come under the writer’s observation.
It seems evident from a glance at the accompanying Schroon
Lake geologic map that the anorthosite once extended out as a
continuous broad belt at least 7 or 8 miles beyond the present
margin of the Marcy anorthosite because, within that distance
from the Marcy anorthosite, there are many inclusions of anortho-
site (mostly of sufficient size to be mapped) in the syenite-granite
series all the way across the quadrangle. In other words, only
mere remnants of the former anorthosite are now visible. With
the exception of one locality, these are all inclusions of Whiteface
anorthosite. The exceptional locality is of particular interest. It
is on top of Wilson mountain, and represented on the geologic map
as a small area of mixed rocks. One patch of the granite 12 feet
across contains large dark bluish gray labradorites an inch or more
across and several small pieces of typical Marcy anorthosite as
distinct inclusions, mostly arranged roughly parallel to the folia-
tion of the granite (see figure 1). Immediately around the larger
fragments the granite exhibits fine magmatic flow-structure. A
similar exposure occurs close by. A reasonable interpretation is
that the granite magma moving upward enveloped two small masses
of Marcy anorthosite and tore them into small fragments which
became somewhat scattered and arranged parallel to distinct mag-
matic currents which moved up nearly vertically as shown by the
high angle of dip of the magmatic flow-structure foliation.
A fine example is in the bed of the brook 1 mile southeast of the
summit of Oliver hill where a mass of Whiteface anorthosite 20
feet across is inclosed in the granite (see map). This outcrop con-
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 31
sists of alternating bands of partly white and partly rather gab-
broid Whiteface anorthosite.
An interesting ledge outcrops in the small mapped area 1%4 miles
a little west of north of Irishtown. The rock is extremely gneis-
soid, moderately gabbroid, Whiteface anorthosite containing many
lens-shaped labradorities or “augen” up to 1% inches long, and
in some portions red garnets. This anorthosite also has in it many
SNe SRERETE TERRA TRY yee UN
ASUS SS “ER a
ic
eae
SP;
%
, SN
Fig. 1. Sketch of part of an exposure on top of Wilson mountain showing
small inclusions of [Marcy anorthosite in gneissoid granite. Note the
magmatic flow-structure foliation about the larger fragments.
inclusions of Grenville hornblende-garnet gneiss in the form of
lenses, strips and layers from less than 1 foot long to I or 2 rods
long, these being arranged parallel to the foliation of the ledge.
It is thus certain that this anorthosite must have been in a truly
magmatic state when it caught up the fragments of Grenville. The
immediate relation of this ledge to the nearby syenite is obscured
by drift, but no doubt it is an inclusion.
Along the western side of the Beech hill anorthosite, which is an
inclusion in the syenite-granite, there are, in the granite, some
small, irregular inclusions of Whiteface anorthosite with indefinite
boundaries, and with distinctly curving flow-structure in the granite
around them.
In the narrow belt one-fourth of a mile long, already described
as extending across the southern brow of Cobble hill, many small
inclusions of the Whiteface rock occur in the granite.
A number of inclusions of the Whiteface rock, each from 1 to
20 feet across, are finely shown in the granitic syenite on top of
the hill 1 mile east-southeast of Cobble hill.
32 NEW YORK STATE MUSEUM
All the inclusions of anorthosite above mentioned bear exactly
the same relations to the inclosing syenite-granite as do the inclu-
sions of Grenville, and it seems clear that the upward moving
syenite-granite magma enveloped masses of both these rock series
in exactly the same manner. Thus we have just as strong evidence
that the syenite-granite is distinctly younger than the anorthosite
as that it is distinctly younger than the Grenville.
Absence of Grenville and syenite-granite from the anorthosite
area. It is a striking fact that both Grenville and syenite-granite
are almost, if not quite, absent from a large part of the anorthosite
area of the Adirondacks. In the northeastern half of the anortho-
site area there are considerable developments of both Grenville
and syenite-granite. In the southwestern half of the Adirondack
anorthosite area, including the Schroon Lake quadrangle, the
absence of Grenville and syenite or granite is, however, an impres-
sive fact, though it must be remembered that many square miles of
this have not been carefully studied. The detailed Long Lake,
Schroon Lake and Paradox Lake maps, and the southern half of
the Elizabethtown map, show no Grenville or syenite-granite well
within the anorthosite there mapped. So far as known to the
writer this is also true of the southern half of the Mount Marcy
quadrangle.
Bowen, in his paper on “The Problem of the Anorthosites,”
dwells upon this absence of Grenville and syenite-granite from so
much of the anorthosite, ‘and he offers an explanation briefly stated
as follows:! “If one pictures the syenite and the anorthosite as
conventional batholiths, some difficulty is experienced in accounting
for the foregoing facts [see above paragraph]. It is necessary to
imagine an early intrusion of a huge plug of anorthosite followed
by an intrustion of syenite which took the form of a hollow cylinder
circumscribing it and invading it only peripherally. . . . On the
other hand, if one pictures the Adirondack complex as essentially a
sheetlike mass with syenite overlying anorthosite . . . one would
expect to find areas of Grenville roof covering the syenite in places
and to find it relatively little disturbed. In the interior and eastern
region of maximum uplift one would expect to find the deep-
seated anorthosite laid bare and to find it free from areas of the
roof.” Also, he says, because of the deep erosion in the region of
maximum uplift one would expect to find the layer of syenite
removed.
1 Jour. Geol., 25 :223-24. 1017.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 33
Some of the more important objections to the view just expressed
are: (1) the anorthosite represents a separate and distinctly older
intrusion than the syenite-granite, and so the sheetlike arrange-
ment advocated by Biowen is out of the question; (2) the Adi-
rondack anorthosite area is by no means practically free from
masses of syenite-granite, this being particularly true of the whole
northeastern half of the area where there are many large and
small bodies of syenite and granite in the form of real intrusives in
the anorthosite; and (3) it is not at all necessary to assume that
both syenite-granite and anorthosite were batholithic intrusions.
An explanation offered by the writer to account for the absence
of Grenville and syenite-granite from so much of the anorthosite
area may be briefly stated as follows. The anorthosite is con-
sidered to be a laccolith not much greater across than the present
area of outcrop. Its intrusion was soon followed by a very irregu-
lar intrusion of the great body of generally rather highly fluid
syenite-granite magma. That the syenite-granite magma was
mostly rather highly fluid is proved by its great power to cross-
cut, intimately penetrate, break up and tilt the Grenville strata.
Only exceptionally did local portions of this magma invade the
Grenville strata in true laccolithic fashion. Both the anorthosite
and the syenite-granite are believed to have intruded a very thick
mass of essentially undisturbed Grenville strata, largely or alto-
gether free from orthogneiss. The southwestern half of the
anorthosite body, which is so free from masses of Grenville and
syenite-granite, is believed to represent the greatest bulk of the
anorthosite where the laccolithic magma was thickest and reached
its highest level. The northeastern half of the anorthosite as now
exposed is regarded as the portion where the anorthosite magma
spread out as a relatively much thinner layer whose surface was
at a notably lower level than that of the thicker portion to the
southwest (see figure 2).- Because of the greater uplift of the
southwestern portion, the Grenville cover has there been almost, if
not completely, removed by erosion. But many areas of the Gren-
ville roof remain over the thinner northeastern part of the anortho-
site where the uplift was much less. Thus we have a simple
explanation of the absence of the Grenville from so much of the
anorthosite area. After the solidification of the great body of
anorthosite, the syenite-granite magma was batholithically intruded
in a rather highly fluid state, and it tended to avoid penetration of
the anorthosite which was much more massive, homogeneous and
34 NEW YORK STATE MUSEUM
resistant than the great mass of surrounding practically undis-
turbed Grenville strata. This satisfactorily explains not only why
‘syenite-granite masses are scarcer within the anorthosite area than
in the Adirondack region in general, but also why syenite-granite
is almost, or entirely, absent from the southwestern half of the
anorthosite area. May not there have been a wide magmatic feed-
ing channel extending northwest by southeast under the main
body of the southwestern half of the anorthosite? On this view,
the thickest portion of the laccolith developed directly over the
wide feeding channel which extended far down, with the result
that this portion of the anorthosite intrusive body was very resistant
to intrusion’ by the syenite-granite magma. The northeastern por-
tion of the anorthosite, because notably thinner, was penetrated by
considerable masses of the syenite-granite magma, as, for example,
in the Lake Placid and Ausable quadrangles. Here again we have
a simple explanation of the field facts.
Strongly supporting the above conception is the evidence from
the distribution of the stocks of later gabbro. All the recent
workers in Adirondack geology recognize this gabbro as distinctly
younger than the syenite-granite series. It usually occurs in the
form of stocks or pipelike bodies rarely more than a few miles
across. Such stocks are common and widespread throughout the.
Adirondack region, except the anorthosite area. Like the syenite-
granite, this gabbro is singularly absent from the southwestern half
of the anorthosite area. In the Schroon Lake and Elizabethtown
quadrangles a number of such gabbro stocks each from 2 to 4 miles
long lie right along the border of the anorthosite but none well
within it. In the northeastern half of the anorthosite area gabbro
stocks occur in moderate size and number. It is, then, very clear
that this later gabbro shows the same sort of distribution with
reference to the anorthosite as does the syenite-granite, and it is
believed that the same explanation (see above) applies to both.
Evidently the gabbro intrusions, too, were unable to penetrate the
thick, very resistant southwestern half of the anorthosite
laccolith.
Origin of the anorthosite by differentiation in a laccolith of
gabbroid magma. Laccolithic structure of the anorthosite. After
considering a number of the better known anorthosite bodies of the
world, Daly* concludes that all of them, including the Adirondack
mass, are to be regarded as laccoliths.
2Teneous Rocks and Their Origin, p. 328-35. 10914.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 35
The writer believes the Adirondack anorthosite (not necessarily
the anorthosite as such) was intruded essentially laccolithically,
and the syenite-granite was intruded essentially batholithically.
But it is not at all necessary to assume, as does Bowen, that both
great bodies are batholithic if they are regarded as distinctly sepa-
rate intrusions.
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No. 5, by road one-third of a mile east of South Schroon; no. 6, quarry
one-half of a mile east-northeast of South Schroon; no. 7, cross-roads
one-half of a mile northeast of Muller pond; no. 26, one-half of a mile
north-northwest of Bailey pond; no. 28, from granitic syenite area 134
miles northeast of Bailey pond; no. 49, southeastern base of Severance
hill; no. 1, top of hill 1% miles southwest iof Taylors on Schroon; no. 2,
quarry one-half of a mile a little west of north of Moxham pond; no. 3,
lake shore one-third of a mile northwest of Adirondack village; no. 4,
I mile east-northeast of Pat pond; no. 8, one-half of a mile northeast of
summit of Cobble hill; no. 9, from tongue of granite cutting anorthosite
t mile south of Sand pond; no. 25, old road crossing Minerva stream 1
mile north of mouth of Hewitt pond brook; no. 31, east of brook at north
end of granite area 2 miles northeast of Bailey pond; no. 32, little hill just
west of Hewitt pond; nos. 34 and 35, southern brow of Cobble hill.
From table 2 it is seen that microperthite always occurs as the
most prominent constituent of the syenite, while oligoclase and
quartz are always present in smaller amounts. Orthoclase is more
variable and sometimes absent. No. 7 is a fine example of a dis-
tinctly basic or dioritic facies of the syenite. Nos. 26 and 49 show
reaction rims of garnet around magnetite. No. 31 is highly granu-
lated along some zones parallel to the foliation in the thin section.
Description of granite and granite porphyry. The granite and
granite porphyry are regarded as differentiation facies of the great
Adirondack syenite-granite series. There are many places where
42 NEW YORK STATE MUSEUM
the syenite grades through gramitic syenite into granite, but not a
single locality was observed where syenite definitely cuts granite
or vice versa. The writer has been unable to demonstrate the
existence of any considerable mass of granite either distinctly older
or younger than the normal syenite, though small pegmatite and
aplite dikes are not uncommon. reat
As regards granularity, granulation and foliation the statements
above made with reference to the syenite apply almost equally well
here. Excessively gneissoid granite with highly flattened quartz
and feldspar were observed, among other places, one-fourth of a
mile northeast of the summit of ‘Cobble hill, on the southern brow
of Bigsby hill, at the summit of Oliver hill, and in the small area
of granite just east of the brook near the trail 2 miles northeast of
Bailey pond.
Most of the granite is pinkish gray, to pink, or even reddish
where fresh, but locally it is greenish gray or gray. It usually
weathers to pinkish gray or hght brown.
Like the syenite, the granite exhibits many local variations. A
hand specimen from a ledge by the lake shore one-fifth of a mile
north of the Adirondack village steamer landing is distinctly folli-
ated and granulated, with one pink band especially rich in feldspar
adjacent to a band very rich in quartz plus some garnets, these two
bands having on either side granite consisting of quartz, feldspar,
and hornblende with some biotite. These bands are not sharply
separated. In the quarry one-half of a mile north of Moxham
pond, the granite shows notable variations in coarseness of grain
often within a foot or two.
Table 2 shows the minerals contained in some thin sections of
the granite. From this table it is seen that the two most conspicu-
ous never failing constituents are microperthite and quartz. In a
few slides microcline occurs, and in only two does it equal or
exceed the microperthite. Orthoclase usually fails and it is never
prominent.
Granite with scattering garnets was observed in several places as,
for example, the whole mass of Pine hill, three-fourths of a mile
west-southwest of Taylors on Schroon, on top of Ledge hill, and
by the road three-fourths of a mile north-northeast of Pat pond.
In a number of localities numerous lenslike inclusions of horn-
blende gneiss (metagabbro or Grenville), too small to be mapped,
occur in the granite as, for example, one-half of a mile west of
Oliver pond, at the swmmit of Cobble hill, and on Ledge hill just
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 43
north of the small gabbro stock. An inclusion of particular
interest is shown in figure 8.
The granite porphyry is quite certainly a differentiation phase
of the granite, and it is only moderately developed within the quad-
rangle. One small area is represented on the map in the very
southeastern corner, and another on the southern brow of Ledge
hill, while the largest area (about 1 square mile) takes in the
vicinity of Pat pond. The granite porphyry differs from the
granite only in being coarser grained and usually more or less
porphyritic.
Grenville or Hornblende Gneiss (Metagabbro?) and Syenite-
granite Mixed Rocks
A number of small areas of mixed rocks of this sort are repre-
sented on the geologic map. The Grenville or hornblende gneiss
(metagabbro?) and granite are so intimately associated that any
attempt to separate them on the map would be unsatisfactory. The
old rocks are usually cut to pieces by, or form inclusions in, the
syenite-granite.
In the small area just south of Calahan pond, typical granite
contains small to large well-defined inclusions of Grenville. In the
two garnet mines, the larger of which is located near the edge of
the map and the other just to the west, the rocks are highly granu-
lar red garnet in considerable masses closely associated with coarse
_ pyroxenic crystalline limestone. Contacts are sharp against the
granite in the smaller mime, but not in the larger one. A few rods
to the north and by the old road, there is a small, sharply defined
inclusion of limestone in the granite parallel to the foliation of the
latter.
In the area covering about one-half of a square mile southwest
of Minerva there are many outcrops of both granite and Grenville,
the two often being closely associated in single outcrops. Evi-
dently the Grenville has here been badly cut to pieces by the
granite.
The mixed rocks of the small area 2 miles north of Minerva are
described along with the associated iron ores in the last chapter of
this bulletin.
At and near Lester dam there are extensive outcrops of pinkish,
very gneissoid granite containing much hornblende gneiss in the
form of flattened or Ienslike inclusions more or less fused into the
mass.
44 NEW YORK STATE MUSEUM
The small area three-fourths of a mile north of Loch Muller
shows good exposures of hornblende and hornblende-garnet
gneisses shot through by some dikes of granite. Some of the garnets
up to I or 2 inches in diameter have distinct rims of hornblende.
In the small area three-fourths of a mile northwest of Loch
Muller, hornblende gneiss (metagabbro?) is shot through by granite
and considerable magnetite is associated with the rocks.
Of the small areas west and southwest of Charley hill, the two
farthest out are chiefly granite with considerable intermixed
older dark gneisses, while the one nearer Charley hill is chiefly
well-bedded hornblende gneiss shot through by irregular dikes of
granitic syenite.
The small area 1 mile south-southwest of South Schroon is
mostly hornblende gneiss intricately cut into, and apparently more
or less assimilated by, granite.
The area of about one-fourth of a square mile 1 mile west of
Schroon Lake village shows many good exposures of hornblende
and hornblende-garnet gneisses, some very intimately associated with
granite in the form of small streaks and bands, and some less inti-
mately associated in bodies of considerable size.
An exposure by the road 1% miles a little north of west of
Schroon Lake village consists of very gneissoid to almost banded
intimately mixed dark gneiss and granite.
The small area 1 mile northeast of South Schroon contains very
gneissoid syenite or granitic syenite more or less intimately asso-
ciated with Grenville hornblende and pyroxene gneisses.
Hornblende gneiss and syenite are associated in the area on the
west side of Thurman pond.
Keene Gneiss
General statements. One of the most interesting rock types
of the region is locally developed as belts or irregular bodies along
or near portions of the borders between the anorthosite and the
syenite-granite series. Both the Marcy and Whiteface types of
anorthosite show such border rocks. There is very strong evi-
dence, based upon field work and a study of thin sections, that this
is really a transition rock between anorthosite and syenite or
granite formed by actual digestion or assimilation of anorthosite
by the invading syenite-granite magma along portions of its borders.
The writer has proposed that this rock be called “ Keene gneiss,”
because a fine exposure of the typical fresh rock occurs by the
GEOLOGY OF THE SCHROON LAKE QUADRANGLE nO TAS
road just north of the village of Keene in the Lake Placid quad-
rangle.
Fifteen areas of mostly Keene gneiss are represented on the
writer's Lake Placid geologic map and the rocks are described in
the accompanying report. Cushing has described rocks which
probably belong in the same category, from two localities on the
western side of the great anorthosite area. Cushing suggests that
these rocks, particularly in the Long Lake quadrangle, are mag-
matic assimilation products. Kemp has described certain peculiar
types of gabbro, called the Woolen Mill and Split Rock Falls types,
aS occurring in the Elizabethtown quadrangle. Kemp says
nothing regarding the origin of these types, but, in the writer’s
judgment, they are to be classed as Keene gneiss. These seem to
be the only rocks of the sort in the Adirondack region regarding
which even brief published statements by other workers have been
made. The whole problem of the Keene gneiss is rather fully dis-
cussed in the writer’s recent paper + on “Adirondack Anorthosite.”
~ Megascopic characters. The typical Keene gneiss presents a
different appearance from any other Adirondack rock. In the
Lake Placid and Schroon Lake quadrangles, the typical rock is
medium grained, gneissoid, notably granulated, and looks much
like some facies of the syenite-granite series except for scattering
phenocrysts of bluish gray labradorites up to an inch long. These
phenocrysts, which are rounded and usually elongated parallel to
the foliation of the rock, doubtless represent cores of crystals
which survived the process of granulation. Locally the pheno-
crysts are absent or only sparingly present, and such facies of the
Keene gneiss are often difficult to distinguish in the field from
certain phases of the syenite-granite series. Under the micro-
scope, however, the distinction may generally be made. A gneissoid
structure is nearly always present but it varies notably, in some
cases being practically absent. The fresh rock is usually greenish
gray, and it weathers brown.
Microscopic characters. The mineral contents of thin sections
of selected samples of various phases of the rock from the Schroon
Lake quadrangle are shown in table 3. It is quite clear from this
table that the Keene gneiss is’ mostly distinctly intermediate in
composition between the syenite-granite and the anorthosite.
1 Geol. Soc. Amer. Bul. v. 29, no. 4. 10918.
A007 NEW YORK STATE MUSEUM
Table 3 Thin sections of Keene gneiss
Cant
fo)
¢
abl a |e
: a sl er = S 2
SU he SMe eile fey (UE. ox AS 2 ie iii
e| a (£lelapemslelet 2 tet 3) = see
SECT ceailivcen icra weal ie iidet || Os oy) St. eigenen
a fea Selo} e ee) ate ho! @ a) < N |S! & {a
27 Of 2) ar 66 ae 7 2). pa | es 1) emer tee ees beaten pepe te ce caen di I| little
SAN Nye ool e cll Oe: Wiesel Tas ate Aleta Bel sa chieusi litthhell-4 i ceal(aealfeereere
So) NO) Ge Sy isl BSlossalh aus 5 4}. Pia dee Err Bilt 5|/o oc ccc ts o. 5
Beier ae Allee celle wal | Ofe 7\| 2 2 a bs | ited eae eed little}... 2. . P| eee
30 |Sfimgal “goll:s.| 56) To loc frétle|| 219 Teele Eee eee eee
Zhe Si IZ%a F5|....|/. 36) tall ge ree 3| 4] little Bl... scan torpepeeiemetere
Shey tee ae yp | MOM SG G8 T5 4 Bier 7) nineteol lc oodalaote allem ollb Goons
46 C5 OND ABs ase [te seed [tinsel [US| tone menel [tev eae eves 6 a Ze, Util ace 6 heehee eee 4
48 S.GiG| > Gelle geal ss El) 25 Zor. little] 6 4 Bo Trt ese eareee eters
No. 27, one-half of a mile north-northwest of Bailey pond; no. 20,
just north of the granite by the trail 2 miles northeast of Bailey pond;
no. 30, 1 mile northeast of Bailey pond: no. 33, eastern slope of Bailey
hill; nos. 36, 36a and 38, southern brow of Cobble hill; no. 46, just south
of the brook 1 mile east of Hewitt pond; no, 48, one-fourth of a mile south
of the mouth of Hewitt pond brook.
Descriptions of occurrences in the Schroon Lake quadrangle.
Most of the Keene gneiss of the quadrangle occurs in the two
largest areas separately mapped as such, but in the areas mapped
as anorthosite and syenite-granite mixed rocks, there are many
excellent local developments, and certain of these will be con-
sidered first. .
An outcrop on the southern brow of Cobble hill, 1 mile due south
of Bailey pond, is very significant because of the light it throws
upon the local origin of the Keene gneiss. The accompanying
sketch (figure 3) shows the relationships. This Keene gneiss is
distinctly granitic or syenitic in appearance except for the many
labradorite crystals, mostly an inch long, which stand out as
phenocrysts more or less parallel to the crude foliation of the
otherwise medium grained rock. Nos. 36, 36a and 38 represent
thin sections of this Keene gneiss which, though variable, is dis-
tinctly intermediate between the granite and the anorthosite in the
same ledge. Within this Keene .gneiss there are inclusions of
Whiteface anorthosite (no. 37 of table 1) which contain some
large labradorites and also scattering femic minerals up to 2 inches
long, more or less lenslike and parallel to a distinct foliation. Con-
tacts between the inclusions and the Keene gneiss are not very
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 47
sharp. Immediately above this Keene gneiss, but not in very sharp
contact with it, is a very gneissoid granite (nos. 34 and 35 of
table 2) which contains many garnets. This gneissoid granite
grades upward into typical, medium grained, only moderately
foliated granite without garnets. A similar typical granite lies
against the Keene gneiss at the bottom, but the contact there is
quite sharp. The writer’s interpretation is that the upward moving
granite magma more or less assimilated some Marcy or Whiteface
elcied
inaceueean enaeceet
ERR as BREBBS0S0P5 fa
YAAK KK RRS
XK CODA ABEEE ER EEE EE EEE CEE EEEEEELE EEE
UMN ed eit Yes Sos
eeavneuueeeunenuees scaagaagandaaaaa
A /\/\\
RP ea eo RAK RSet pooggo
Mace ORK ba Wiens
q
ad acon aM, SEs @
YX KAVAAAY YW WN ‘A :
YN \ nea sal me VAVAVAVANANANE?
LX I KKK KIX Né.
KK YX)
VA VAVANANANA INA
ANSTO KAM!
(KAA Y
LAZY)
ERin—
Fig. 3 Sketch of part of the great ledge at the southern brow of Cobble
hill showing Keene gneiss in its relation to both granite and Whiteface
anorthosite. Contacts between the Keene gneiss and both Whiteface
anorthosite and garnetiferous granite are not sharp, but the contact between
the Keene gneiss and the lower granite is rather sharp.
anorthosite at a considerable depth, and that this molten mass
(Keene gneiss magma) rose still higher and caught up and only
partly fused the borders of fragments of Whiteface anorthosite.
The origin of the garnetiferous granite is not so certain, though it
may represent a mass of granite with a small quantity of anortho-
site very thoroughly digested.
48 NEW YORK STATE MUSEUM
An interesting assemblage of rocks is well exposed on the steep
hillside one-half of a mile north-northwest of Bailey pond. Com-
monest of all is good Whiteface anorthosite, but some tongues or
dikes of granite cut through it, and still other rock is quite cer-
tainly an assimilation product of the two, that is to say, Keene
gneiss. Most of the rock taken to be Keene gneiss is of syenitic
aspect both with and without quartz, but some contains pheno-
crysts of labradorite. No. 27 of table 3 represents a thin section
of this Keene gneiss, but the labradorite does not show in the thin
section.
Still other local developments in the large area of “ anorthosite
and syenite-granite mixed rocks” are described below.
A number of small (not mappable) inclusions of Whiteface
anorthosite occur in the granite along the western side of the Beech
hill Whiteface anorthosite area. The borders of these inclusions
have been fused and assimilated by the granite which shows curved
flow-structures around the inclusions.
Interesting exposures occur in the small area of Whiteface
anorthosite and syenite mixed rocks near the southeastern base of
Severance hill. The rock is mostly quartz syenite (no. 49 of
table 2) which contains numerous inclusions of Whiteface anortho-
site. These inclusions are very irregular and usually only a few
feet long without sharp boundaries against the syenite. Evidently
syenite magma rising through Whiteface anorthosite caught up
numerous small fragments of it, the borders having been assimilated
to form Keene gneiss on small scales.
On large scales the geologic map shows two areas of Keene
gneiss, one occupying about 6 square miles, and the other nearly
3 square miles, in the central portion of the quadrangle. Before
the intrusion of the large gabbro stock, the two areas were prob-
ably connected with a total length of 7 miles, extending from
Rogers pond to and beyond Bailey hill. These bodies of Keene
gneiss lie mostly against typical Marcy anorthosite, but also, to
some extent, against Whiteface anorthosite, the border facies of
the anorthosite here having been very largely assimilated by the
syenite-granite magma. Throughout the larger area especially,
there are a good many small masses of Whiteface anorthosite, a
few of sufficient size to be mapped. There are also some outcrops
of fairly good granite and granitic syenite, thus showing that all
the original Whiteface anorthosite was not assimilated. The main
body of the rock is, however, quite typical Keene gneiss, there being
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 49
particularly fine exposures on the eastern slope of Bailey hill, and
along the middle of the crest of Washburn ridge.
Certain localities of special interest in the larger area will now
be described. One of these is along the brook 2 miles northeast
of Bailey pond. By the trail there is a large outcrop of peculiar,
variable rock. There are some small patches of Whiteface anor-
thosite embedded, but most of the rock has a granitoid texture and
contains scattering bluish gray labradorites up to an inch long (see
no. 29 of table 3). This latter rock looks much like the Cobble
hill rock above described except for fewer labradorites, and it is
considered to be Keene gneiss with a history similar to that on
Cobble hill. Just across the brook to the east there is a big ledge
of very highly foliated medium-grained granite gneiss with both
the quartz and feldspar highly flattened out parallel to the foliation.
An interesting lot of rocks occur on Washburn ridge 1 mile
north-northeast of Bailey pond. A little to the north of this local-
ity (see map) a considerable body of typical Whiteface anorthosite
is exposed. A few rods to the south of the anorthosite there are
exposures of mostly distinctly gneissoid rocks, syenitic in appear-
ance but containing tiny garnets and some large bluish labradorites,
these latter not always being arranged parallel to the foliation.
No. 30 of table 3 represents a thin section of this rock, but none
of the labradorite happened to appear in the section. This rock
is quite certainly Keene gneiss. Some portions of these same ledges
strongly suggest rather gabbroid garnetiferous facies of Whiteface
anorthosite. A few rods still farther south, typical granitic syenite
is exposed as shown on the geologic map. A careful study of these
ledges on Washburn ridge strongly supports the view that White-
face anorthosite has there been acted upon by granitic or syenitic
magma, some of the anorthosite having remained unaffected, some
having been partially assimilated, and still others completely assimi-
lated, while unaffected granitic syenite outcrops at the south. The
actual extent of the granitic syenite here is unknown because no
exposures of any kind occur for fully a mile to the south. On the
crest of the southern portion of Washburn ridge, and continuing
for one-half of a mile north from the area of Whiteface anorthosite
(see map), a somewhat variable, medium to fine-grained, basic,
syenitic-looking rock full of tiny garnets shows in good exposures.
Though large labradorites are absent, this rock is thought to have
50 NEW YORK STATE MUSEUM
resulted from pretty thorough assimilation of Whiteface anorthosite
by syenite or granite magma. Still farther north on Washburn
ridge very typical Keene gneiss is well exposed.
Many fine ledges of very typical Keene gneiss occur on the
eastern face of Bailey hill, no. 33 of table 3 representing a thin
section of this rock.
In the smaller of the two largest areas of Keene gneiss, exposures
are generally rather scarce except on the ridge north of Rogers
pond where the rock toward the south contains relatively few
large labradorites and suggests a gradation into granite, while
toward the north the large labradorites are common and the rock
appears to grade into the Marcy anorthosite.
An area about 114 miles long of mostly Keene gneiss occupies
approximately one-half of a square mile west, south and south-
east of the mouth of Hewitt pond brook (see map). A number of
good exposures show the rock to be somewhat variable, but it is
unusually rich in hornblende and never contains phenocrysts of
labradorite. In the. field the rock looks much like a gabbroid facies
of Whiteface anorthosite, but thin sections (nos. 46 and 48 of table
3) and the field relations cause it to be rather confidently classed as
Keene gneiss.
Conclusion as to the origin of the Keene gneiss. Enough
examples have been described to prove that the Keene gneiss of
the Schroon Lake quadrangle has developed on small and large
scales by assimilation of anorthosite by granite and syenite magmas.
If we adopt Bowen’s hypothesis, this Keene gneiss must be regarded
as having developed by differentiation 2m situ between an overlying
sheet of syenite-granite and underlying anorthosite. If one
admits, as the writer does not, that syenite usually may have
developed by differentiation in situ close upon the Marcy anortho-
site, how can one imagine, in places like in the Schroon Lake
quadrangle, a similar development of granite close upon the anor-
thosite? It might be argued that the granite magma formed at a
higher level and was then forced downward. But, if so, it must
have been forced downward through still lower syenitic material.
Not only is the field evidence against this view, as already pointed
out, but even if we grant it, we are still forced to conclude, by the
obvious field facts,.that the granite magma produced the transi-
tion rock (Keene gneiss) by assimilation of more or less anortho-
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 51
site, and that the Keene gneiss was not formed as a differentiate
im situ between an overlying sheet of syenite-granite magma and
underlying anorthosite.
Significance of distribution of Keene gneiss. The Keene gneiss
can not be a direct differentiate of either the syenite-granite series
or the anorthosite because it never occurs except on the border,
or close to the contact, between the syenite or granite and the
anorthosite. If we make the very simple and plausible assumption
that the anorthosite was still very hot when the syenite-granite
magma was intruded, or, in other words, if this latter magma was
forced up comparatively soon after the development of the anor-
thosite, the usual strong objection to magmatic assimilation, namely,
that a magma does not possess a sufficiently high temperature to
raise relatively cold country rock to the point of fusion, is distinctly
obviated. But the Keene gneiss is not universally present. In
many cases where no Keene gneiss occurs along the borders between
anorthosite and syenite or granite, it may be reasonably assumed
that either the anorthosite or the syenite-granite, or both, in those
places may not have been hot enough to permit assimilation.
The presence of Keene gneiss in.one place and its absence from
the same border nearby, may, in some cases, have been the result
of unequal upward intrusion of Keene gneiss magma which orig-
inated at lower levels.
The small isolated masses of Keene gneiss some distance out
from the main body of the anorthosite doubtless represent inclusions
of anorthosite which were partly or completely assimilated by the
enveloping syenite or granite magma.
The failure to find any considerable assimilation of Grenville
either along its borders with, or where involved with, the syenite-
granite series may be explained on the basis of a temperature of
the Grenville too low to have permitted any more than compara-
tively slight assimilation by the invading syenite-granite magma.
It should be borne in mind, however, as pointed out in a recent
paper’ by the writer, that local assimilation of the Grenville is
known to have taken place in certain parts of the Adirondack
region.
Anorthosite and Syenite-granite Mixed Rocks
A very irregular-shaped area of about 514 square miles, includ-
ing Hayes mountain, is represented on the map as anorthosite and
1Geol. Soc. Amer. Bul., 25:254-60. 10914.
52 NEW YORK STATE MUSEUM
syenite-granite mixed rocks. Enough outcrops were observed to
render it certain that practically all this area was originally White-
face anorthosite which was intruded, and more or less cut to pieces,
by the syenite-granite magma. Many individual outcrops are either
anorthosite or syenite or granite clearly recognizable as such, but
here and there local assimilation has taken place resulting in the
development of some Keene gneiss. In a few cases the rocks are
admittedly of doubtful origin. Some portions of the area show
few if any exposures as, for example, north and northeast of
Bailey pond, and in the valley between Hayes mountain and Cobble
hill. In view of the facts just stated, it has seemed impossible
to represent satisfactorily the various rock types on the geologic
map. A few occurrences of particular interest will be described.
Perhaps the most interesting occurrence in the area just men-
tioned is at the summit of Cobble hill and in the belt containing
Keene gneiss which extends east-west for fully one-fourth of a
mile across the southern brow of the hill (see page 46). Sur-
rounded by typical granite, there are inclusions of Whiteface anor-
thosite, most of them not more than a few feet long, arranged
roughly parallel to the foliation of the granite. Some of the inclu-
sions are rather sharply separated from the granite, many of them
had their borders assimilated, while still other anorthosite caught
up in the granite magma was completely assimilated to form Keene
gneiss.
The interesting lot of rocks on the steep hillside one-half of a
mile north-northwest of. Bailey pond has been described above under
the caption “ Keene gneiss.”
A big ledge in the brook at the old road crossing 1 mile west-
northwest of the summit of Hayes mountain shows typical White-
tace anorthosite closely involved with granite with apparently slight
development of Keene gneiss.
The margins of the small body of Whiteface anorthosite sep-
arately mapped on top of Hayes mountain appear to have been
assimilated and close to its borders the anorthosite carries quartz
. (no. 18 of table 1).
The small area of anorthosite and granite mixed rocks on top
of Wilson mountain shows numerous little inclusions of Marcy anor-
thosite in the granite, these having been described in the above dis-
cussion of the anorthosite. The relations are shown in figure 1.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE ce
In the small area near the southeastern base of Severance hill,
syenite contains numerous inclusions of Whiteface anorthosite.
These inclusions are usually only a few feet long and very irregular
with their borders more or less assimilated by the syenite.
Gabbro and Metagabbro(‘?)
Distribution. These gabbro and metagabbro (?) bodies are, in
most respects, very similar to those of the North Creek quadrangle
next to the south which have been rather fully described by the
‘writer in his report on the Geology of the North Creek Quadrangle*
and also in the Journal of Geology, volume 21, pages 160-80. On
the accompanying Schroon Lake geologic map, twenty-five gabbro
masses are represented, all but four of these lying wholly within
the quadrangle. They are well scattered over the southeastern
two-thirds of the quadrangle, but not one has been found within
the area of Marcy anorthosite. A possible explanation of their
absence from the anorthosite area is given above in the discussion
of the anorthosite. As usual in the writer's experience in the
Adirondacks, these gabbro masses appear to have rounded to
elliptical ground plans and very steep walls. The variation in
length of the areas of outcrop is from one-fifth of a mile or less
to 3 miles. In a few of the areas but one or two outcrops could
be located.
A striking feature of the distribution is the fact that the three
largest bodies of the quadrangle lie along the border of the Marcy
anorthosite. Kemp’s Elizabethtown map shows a similar distribu-
tion of the largest gabbro masses there. Also on Ogilvie's Paradox
Lake map the largest mass of gabbro occurs along the anorthosite
border. This remarkable distribution of the gabbro bodies with
reference to the anorthosite may be merely a coincidence, or it may
have a real significance. If the latter, the writer can think of no
very plausible explanation.
Age. Most or all of the gabbro is younger than the Grenville,
anorthosite and syenite-granite series (1) because of the intrusive
contacts against rocks of those series, (2) because dikes of gabbro
extend into rocks of those series, and (3) because inclusions rep-
2N. Y. State Mus. Bul. 170.
54 NEW YORK STATE MUSEUM
resenting fragments of all three series occur in the gabbro. Some
of the metagabbro(?) is quite certainly older than the syenite-
granite.?
Pegmatite dikes and certain small aplite dikes have been observed
as sharply defined intrusions in the gabbro. The diabase dikes are
later intrusions than the gabbro as proved by their distinctly finer
grain, and the fact that one actually cuts the gabbro in the northern
part of the North Creek quadrangle. It is therefore evident that
at least three very distinct minor intrusions succeeded the gabbro
intrusions of the auadrangle.
Megascopic features. The typical nonfoliated gabbro is
readily distinguished from all the other rocks of the quadrangle.
Such rock makes up the main or interior masses of nearly all the
stocks, especially the larger ones. It is medium to moderately
coarse grained, dark gray to almost black where fresh, and it
weathers to a deep brown. The plagioclase feldspar varies in color
from a light gray to a dark bluish gray. A diabasic texture is
usually more or less well developed, this being particularly striking
in the coarser grained facies. Minerals recognizable with the
naked eye or hand lens include plagioclase, pyroxene, hornblende,
ilmenite (or magnetite) and nearly always biotite and red garnet.
Variations from the typical nonfoliated gabbro just described
are common, one of the most abundant being highly foliated border
facies (usually amphibolite) which do not show a diabasic texture.
Taken by themselves, some of the amphibolitic border facies are
very difficult to distinguish from certain Grenville hornblende
gneisses, or even from certain very gneissoid gabbroid facies of
the Whiteface anorthosite. Nearly always, however, the mode of’
occurrence or the gradation into more typical gabbro renders cer-
tain the recognition of the gneissoid border facies of the gabbro
(figure 4). Even the more typical inner portions of the gabbro
stocks show many notable variations in structure, texture and
mineralogical composition as pointed out below in the special
descriptions.
Microscopic features. In the following table the mineral con-
tents of the gabbro is represented by thin sections of samples from
several of the areas.
1 Recent work by the writer in the Lyon Mountain quadrangle has shown
that most of the gabbro and metagabbro are there older than the syenite-
granite series which leads to the suspicion that some of the Schroon Lake
quadrangle gabbro may also be older but definite evidence is lacking.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 55
Table 4 Thin sections of gabbro and diabase
om a>
o = ¢ o oO
. |e elale E 2 =
° Z 4s S Onalbena a |) 4S S © a
S 3 2) | = i ati] <2 & a q ® ee iS 2 | oe
o ro a] a * rot q rt Deel 5p =) ~ ° oO i=
Z| 8 alsa ee eet cen eum || oe SAMOS Wess Ah =
a ca SP Se aS ae er: tsp i yeaa stone ty) ysl, < N @ hc
° :
= Z0l8 2e.2 8 47) 20 15 3 1} little} little} little I 5
a} 40] oht I5 45 8 5 Maas Pi Ree a) elititle |. 5 A
5 AI] 9h4 AGW 5 Sil YA 5 5 8 il Leen letters sl (een oe aes mas) a5
42| T2c4 AS 2G eyecare ce 6 4 Bes Litsble || eee es [esses 18
2 | 43) 159.3 48 30 GiRee eae GP Cc ieee aca Se ote see ro
rQ
= AAW GTO GMO) N)ssi-alloues. - Ao |Nees |i) wall alee ene Alb ee Antél el eee 8
No. 39, I mile southeast of Minerva; no. 40, 134 miles east of Bailey
_ pond and near the mapped inclusion of granite; no. 41, middle of Texas
ridge gabbro area; no. 42, 1%4 miles northeast of Lester dam; no. 43,
top of Saywood hill; no. 44, one-third of a mile north of summit of Say-
-wood hill.
In the above table, nos. 41 and 42 are more typical of the gabbro .
of the quadrangle, while nos. 39 and 4o are rather more special
or acidic facies. The more normal rock is therefore an olivine-
bearing hypersthene gabbro or norite. The garnet, which is no
doubt of secondary origin, mostly forms granulated borders about
granulated hypersthene. In slide no. 41 the biotite mostly forms
reaction rims about magnetite, and granulated garnet forms rims
around granulated hypersthene in nos. 41 and 42. Nearly colorless
diallage in no. 41 exhibits wonderful parting and schillerization
inclusions. The labradorite of nos. 41 and 42 are filled with tiny
dustlike dark inclusions.
Special descriptions. The Texas ridge mass is the finest large
scale example of a gabbro stock in the quadrangle. It covers an
area of approximately 314 square miles. An almost continuous
outcrop occurs along the whole-crest of the ridge. Near the south-
ern end of the ridge a considerable mass of well-foliated pinkish
gray granite forms an inclusion in the gabbro (see map). Imme-
diately south of this inclusion the gabbro is notably variable, being
mostly moderately foliated, but some big ledges are medium grained
and very massive. None of this rock exhibits a diabasic texture.
No. 42 of the table shows the mineral contents of a thin section
of the more common rock, and this is seen to be a distinctly acidic
or dioritic facies even carrying considerable orthoclase. The near-
56 NEW YORK STATE MUSEUM
ness of this facies to the inclusion of granite from which it is not
very sharply separated, taken in the light of various observations
made by the writer on the North Creek quadrangle gabbro, strongly
supports the view that this acidic facies of the gabbro was pro-
duced by assimilation of some granite during the intrusion of
the gabbro magma. In this same vicinity some outcrops of rather
coarse-grained, nonfoliated gabbro show 5 to Io per cent red garnets
ranging in diameter from a millimeter or two to one-third of an
inch. These variations all occur within a stone’s throw. Just
north of the granite inclusion, the gabbro is medium to fine grained,
very gneissoid, and relatively richer in feldspar. Gabbro similar
to this latter also appears on the ridge crest about three-fourths of
a mile northeast of the granite inclusion; otherwise the many
exposures along the whole ridge crest are very typical, medium
grained, nonfoliated gabbro with diabasic texture. No. 41 of table
4 shows the mineral content of a thin section of this typical gabbro.
Similar gabbro outcrops in considerable force near the extreme
southwestern end of the area, and also on the ridge along the
eastern side of the area. '
The Cheney pond stock is the second largest. It covers nearly
3 square miles. There are many good exposures. Most of this
gabbro is very typical in every way, being medium to moderately
coarse grained, nonfoliated, and possesses a diabasic texture. No. 42
of table 4 shows the minerals contained in a thin section. Good
exposures of the amphibolitic border facies occur along the south-
ern border between the pond and the old road, on the little island
in the pond, and where the river enters the pond. In a field a few
rods south of where the river enters the pond, a sharply defined
8-inch inclusion of typical Whiteface anorthosite occurs in the
gneissoid gabbro. A body of granite large enough to be mapped
occurs as an inclusion in the gabbro 114 miles northeast of the
Lester dam. Whether or not the gabbro near this inclusion is
more acidic than usual was not determined.
The large stock partly shown within the map limits northwest
of Cheney pond is mostly very typical gabbro with considerable
amphibolite developed as a border facies. In a field a few rods
north of the house (where the trail leads off) there are some very
interesting ledges showing amphibolitic gabbro and Whiteface °
anorthosite rather intimately assoctated.
A number of good exposures show the gabbro of the stock about
a mile southeast of Minerva to be mostly medium grained and
massive with only poor development of diabasic texture. Locnlly
GEOLOGY OF THE SCHROON LAKE QUADRANGLE Sih
a gneissoid structure is clearly evident. Much of this rock well
exhibits the peculiar mottled appearance so often seen in those
Adirondack gabbros which are relatively free from diabasic texture
and foliation, this mottling being due to the irregular distribution
of black minerals through the more or less granulated mass of
feldspar. No. 39 of table 4 gives the mineral content of a thin
section. This is a distinctly acidic facies and, like the local acidic
facies of the Texas ridge gabbro above described, may have resulted
from assimilation of granitic material by the gabbro.
The small gabbro stock on the hill one-half of a mile west of
Irishtown contains a 10-foot inclusion of thin-bedded Grenville
quartzite. '
Fig. 4 A small exposure showing three facies of gabbro at the eastern
margin of the Oliver hill stock. The gabbro is cut by aplite and pegmatite
dikes.
Some interesting features were observed in connection with the
Oliver hill gabbro stock. Just south of the summit of the hill the
gabbro sends three dikes into the granite. None of these dikes
is more than a few rods wide, and one is amphibolitic. At the
extreme eastern end of the stock a small outcrop shows three facies
of gabbro— one nonfoliated, another highly foliated, and a third
58 NEW YORK STATE MUSEUM
amphibolitic — cut by several white, fine-grained, aplite dikes and
a pegmatite dike. The relations are brought out in figure 4.
The stock southeast of North pond shows large developments
of very gneissoid to amphibolitic facies of gabbro, especially in its
eastern portion. Ajledge of rather typical, medium-grained gabbro
just east of the brook one-fourth of a mile north of its junction
with Rogers brook, contains many lenses and strips of nearly
white Whiteface anorthosite as inclusions with parallel arrange-
ment. A number of small faults intersect the ledge. The rela-
tions are brought out in figure 5. On the small hill in the west-
ern part of the area, typical nonfoliated gabbro is involved with
ZaSGkY (EERGEAY éARDBRRERSRRSSL IL
: HE) ARR REE? AZO oe
HAN ieee * ASREERS AOE
CCCCCACLC
Saaey Nae
ooo «am 4. oe
P| ap |
| | a geese BH AL
Fig. 5 A sketch of part of an outcrop near the brook at the southern
margin of the gabbro stock southeast of North pond. The normal gabbro
(cross-lines) contains manv narallel strips of Whiteface anorthosite (black),
and the whole is intersected by several minor faults.
well-foliated gabbro, these two facies forming zones or belts not
very sharply separated from each other. This foliation is very
clearly a flow-structure due to magmatic currents, with the wavy
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 59
flow-lines clearly preserved. Further, these well-foliated zones bear
a distinct resemblance to the gneissoid or amphibolitic border facies
of the gabbro already described, and thus we have here evidence
strongly supporting the view that the foliation of the amphibolitic
border facies of the gabbro is really essentially the result of mag-
matic flowage.
The northern part of the small stock near the southern end of
Ledge hill is typical gabbro cut by one small pegmatite dike and
several small aplite dikes.
Two small masses, one on Cobble hill and the other three-fourths
of a mile northwest of Loch Muller are hornblende gneiss (meta-
gabbro?) quite certainly older than the granite.
Aplite and Pegmatite Dikes
Aplite. Aplite dikes were observed in only a few localities
but probably others occur within the quadrangle. These are repre-
sented only in a general way on the geologic map. They probably
do not all belong to the same period of intrusion.
The best display of aplite dikes is on Wilson mountain. These
are all medium to fine grained and none are foliated, neither do
they show any notable difference in coarseness of grain between
center and sides. On the western summit of the mountain a num-
ber of small aplite dikes, none over a foot wide, cut clearly
gneissoid, coarse-grained, pinkish granite. These do not have very
sharp boundaries against the granite. This fact, together with
their uniform medium-grained texture, suggests that these aplite
dikes were intruded under fairly deep-seated conditions not long
after the intrusion of the granite, or at least before the granite
cooled very much, so that the aplite magma was able to blend with
the walls of the granite country rock.
On the eastern summit of Wilson mountain, numerous aplite
dikes very similar to those just described, and with a maximum
width of 4 feet, cut gneissoid medium-grained granite also without
very sharp contacts.
The small mass of anorthosite and granite mixed rocks on
Wilson mountain (see map) is cut by a number of medium-grained
aplite dikes, the widest being 5 inches, and all showing rather
sharp contacts against the granite.
Another locality is near the southern end of Ledge hill where
several aplite dikes very sharply cut the small gabbro stock. The
60 NEW YORK STATE MUSEUM
largest is 5 inches wide, visible for 10 or 12 feet, and has a branch
bearing off abruptly at right angles. Another is 2 inches wide and
traceable for 20 feet in the gabbro. None of these dikes could be
traced into the surrounding granite. In certain respects these aplite
dikes are quite different from those on Wilson mountain. Most
of the dike material is fine grained, particularly so at the mar-
gins, but this grades into a medium-grained, narrow, middle por-
tion which is very persistent. The dike rock is somewhat weathered
and of light-brown color, this latter probably due to stains from
iron-bearing minerals in the gabbro. Because these dikes sharply
cut the gabbro, which is distinctly later than the granite, and because
of their chilled margins, it is believed that they were intruded
considerably later than the aplite dikes on Wilson mountain above
described. A thin section shows the following mineral percentages:
microperthite, 65; oligoclase, 1; quartz, 20; diallage, 12; mag-
netite, 2; and very little zircon. The thin section shows a granitoid
texture and no granulation.
At the eastern end of the Oliver hill gabbro stock a few branch-
ing, fine-grained, white, aplite dikes a few inches wide cut the
gabbro, the relations being shown in figure 4. Although these dikes
are white and do not have distinctly coarse portions, it is probable
that they were intruded at about the same time as those on
Ledge hill.
Pegmatite. A number of pegmatite dikes were observed in
the granite on top of Ledge hill for one-half of a mile northward
from the gabbro stock. None of these is more than 2 feet wide,
and they all cut sharply across the foliation of the granite very
irregularly. Near the eastern margin of the gabbro stock a very
small pegmatite dike cuts across the foliation of the granite, and
nearby another cuts the gabbro.
On the western summit of Wilson mountain near the aplite
dikes, a number of very small pegmatite dikes sharply cut the
granite. Near the eastern margin of the Grenville area on the
western face of Wilson mountain, several small pegmatite dikes
cut a mixture of Grenville and granite.
At the eastern end of the Oliver hill gabbro stock the same ledge
which contains the aplite dikes (see figure 4) is also cut by a small
pegmatite dike which is without very sharp contacts against the
gabbro. Whether this is older or younger than the aplite was not
determined.
Pegmatite dikes are scarcer in the Schroon Lake quadrangle
than is usual in the Adirondack region. Not one was observed in
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 61
the large body of anorthosite. In certain other quadrangles, like
the Blue Mountain, the writer has found at least two sets of
pegmatite dikes notably different in age, one occurring in the form
of narrow masses essentially parallel to the foliation of, and not
very sharply separated from, the inclosing syenite or granite, and
the other, generally coarser grained, cutting across the foliation
of, and in sharp contact with, syenite or granite. The second set
is quite certainly the younger, and probably all the observed peg-
matites in the granites of the Schroon Lake quadrangle belong with
the younger set.!
Diabase Dikes-
Diabase dikes were observed in nine localities within the quad-
rangle, but doubtless others exist. They are represented on the
geologic map. Most of these are like the usual diabase dikes of
the Adirondacks, more particularly like those of the North Creek
quadrangle described by the writer. Unlike the gabbro, aplite, and
pegmatite, several of the diabase dikes cut the anorthosite. The
diabase probably represents the latest Precambrian intrusion in the
Adirondack region as shown by the fine-grained texture and usually
very distinct chilled borders, and also by the fact that a diabase
dike actually cuts one of the late pegmatite dikes in the adjoining
North Creek quadrangle. A diabasic texture is not always evident
to the naked eye, but in thin section it is generally recognizable.
None are porphyritic, but several show very distinct magmatic
flow-structure foliation. All have sharp contacts against the coun-
try rocks.
About one-fifth of a mile north of the old graphite mine at the
- western base of Catamount hill, a small typical diabase dike with
strike N 40° E cuts Grenville gneisses. .
A diabase dike 2 feet wide with strike S 20° W is well exposed
in the syenite of the quarry one-half of a mile east-northeast of
South Schroon.
In a ledge of gneissoid granite by the road 1 mile west of Schroon
Lake village, there are several small dikes varying in width from
2 to 8 inches. One is faulted 6 or 8 inches at two places.
A very typical diabase dike with a maximum width of 4o feet
and strike N 20° E is clearly traceable for fully one-half of a mile
in the Whiteface anorthosite about 11% miles north-northwest of
* Certain Adirondack pegmatites are discussed by the writer in a recent
paper (Jour. Geol., vol. 27, no, 1, 1919) where it is shown that some pegma-
tites developed as satellites of the cooling magmas of the late gabbros.
62 NEW YORK STATE MUSEUM
Schroon Lake village. At one place many small off-shoots from
the dike were observed to cut sharply the Whiteface anorthosite.
A dike 6 inches wide with strike N 20° E cuts Whiteface anor-
thosite at the summit of Severance hill.
A dike of very typical diabase with maximum width of 40 feet
cuts pinkish granite for one-quarter of a mile across the top of the
little hill 134 miles due west of Grove Point.
Three dikes of particular mterest cut typical Marcy anorthosite
at the summit of Saywood hill. They vary in width from 6 inches
to 1% feet and strike N 20° W. ‘These dikes all show rather dis-
tinct magmatic flow-structure foliation. Diabasic texture is absent,
and the fresh rock is dark gray with numerous black ferro-mag-
nesian minerals each from I to 3 millimeters long. A close inspec-
tion reveals many tiny red garnets. In thin section (no. 43 of
table 4) this rock is seen to be a hypersthene diabase.
Near the top of the hill one-third of a mile due north of the
summit of Saywood hill there are two diabase dikes, one 15 feet
wide and the other 2 feet wide, traceable for a number of yards
in sharp contact with the Marcy anorthosite. The narrower dike
is probably a branch of the wider one. These dikes have a good
diabasic texture, and they are finer grained toward their margins.
Myriads of tiny red garnets are visible under the hand lens. They
show no foliation. A thin section (no. 44 of table 4) shows these
dikes to differ from those on Saywood hill by carrying to per cent
diallage, and oligoclase to labradorite instead of labradorite alone.
On the ridge one-half of a mile north-northwest of Blue Ridge
village a dike 2 feet wide sharply cuts the Marcy anorthosite with
strike N 40° W. This dike looks almost exactly like those on
Saywood hill above described.
PALBOZOIG ROC OUTER
Two outliers of early Paleozoic strata occur within the Schroon
Lake quadrangle. One of these, in and near the village of Schroon
Lake, has long been known, but the other, 11% miles southwest of
the village, was located by the writer in 1916. During 1917 the
writer discovered another outlier in the valley of Schroon river
7 miles north of Schroon Lake village. The outliers at and near
the village are of particular geological significance, having been
formerly connected with the main body of early Paleozoic strata of
both the Champlain and Mohawk valleys, but now being isolated
masses from 13 to 16 miles from the Champlain valley strata.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 63
Potsdam Sandstone Southwest of Schroon Lake Village
This area of Potsdam sandstone lies 1% to 2 miles southwest
of Schroon Lake village, or about 1 mile west to southwest of
Grove Point. It was discovered by the writer in 1916. Just south-
west of the forks of the road three-fourths of a mile west of Grove
Point, there are four exposures, three of them in the road and
the other just across the fence to the south of the road. The
largest outcrop is several rods long. Paced at right angles across
the strike of these exposures the distance is 45 yards. Since the
dip is west 5°, a thickness of about 12 feet of the sandstone occurs
here with neither top nor bottom visible. The strata strike
N 30° E. In the brook just north of these exposures there are
many angular fragments of the sandstone, but still farther north
neither fragments nor outcrops occur, so that the northern limit
of the area must be about as indicated on the accompanying geologic
map. For fully one-half of a mile to the south-southwest, within
the area mapped, a number of small exposures of the sandstone
were observed, and also hundreds of angular fragments up to sev-
eral feet across. Hundreds of angular fragments of the sand-
stone also occur on both the north and south sides of Thurman
pond, but a careful search failed to reveal an outcrop. Probably
these are simply fragments in the glacial drift.
In all the outcrops the rock is in every way typical Potsdam
sandstone, being gray, well stratified, often cross-bedded, and not
very coarse grained. The layers are generally from a few inches
to a foot thick. No fossils were found. That these beds are very
close to the bottom of the Potsdam formation is evident from the
fact that granitic syenite, the immediately underlying rock, out-
crops close by on the east (see map). A fault passes along the
foot of the hills just west and this probably marks the western
boundary of the sandstone, though no exposures of any kind occur
close to the fault on its east side.
Little Falls (?) Dolomite in and near Schroon Lake Village
Description of occurrences. In a paper dealing with the iron
ores,of northern New York published by C. E. Hall* in 1879, men-
tion is made of this outlier.
In his Preliminary Report on the Geology of Essex County,?
_ Professor Kemp briefly describes the outlier and discusses its
significance. |
*N. Y. State Mus. Rep’t 32, p. 130-40. 1870.
*N. Y. State Geol., 15th Annual Rep’t, 1805, p. 596-08.
64 NEW YORK STATE MUSEUM
Since no detailed study of this outlier has yet been published, ~
the observations made by the writer during the summers of 1916 ©
and 1917 are here somewhat fully recorded.
The dolomitic limestone is well exposed for a distance of fully
100 feet along the shore of the lake just north of the steamer |
landing in the village. Plate 7 shows the general appearance of —
the outcrop. The strike of the beds is N 50° E and the dip N 23°. —
A detailed measured section follows:
Sreits ; Feet IJnchesmy
6) Dolomitichliniestone without@ehenien sete er 2 )
5 Dolomitic limestone with much dark chert in the
form of irregular bunches up to 6 inches or even
a MEOOb LOme a wi (ae snr aie vias, ee ea aie eee sae 8a
4 Dolomitic limestone without chert or calcite...... 2 one
3 Dolomitic limestone much like 2 below, except
that chert is less conspicuous and not in layers. 3 8
2 Dolomitic limestone with much chert mostly in thin
layers, but some in irregular bunches. Also
numerous veinlets and bunches of calcite, some
of which is dark to black with bituminous mat-
ter. On the weathered surface there are signs of
stratification surfaces separating the rock into
thin layers’). viiee ome bed oko) oine eae nceee nae 5 ae 6
I Dolomitic limestone with considerable chert (below
the -water')’ ore 2a: Gee a lal ila ele ratcinln Gen oes ane ane 2
Totals. 5,28. Baten se Ree ans Ee ec Seen 19 10
The dolomitic limestone of this section is dark gray weathering
to light gray, crystalline, fine grained and compact in texture. It ©
contains numerous rounded quartz-sand grains not visible to the
naked eye, but bits of the rock treated with hot hydrochloric acid —
leave considerable residues of the fine quartz-sand grains. Weath- —
ered surfaces of the rock are generally rough and deeply pitted
due to more rapid removal of the irregular calcite bunches.
The greatest thickness of limestone exposed in any one section
is in the bed of Rogers brook between its mouth and the main —
road. These beds strike N xo° E and dip.N 23°, and the stream —
descends about 25 feet as a cascade over the ledge. The approxi-
mate thickness of this section, based upon careful pacing (160 —
feet) across the strike, is 85 feet. There are several intervals in
the section, a thickness of 5 or 6 feet being concealed in one place. —
ISE[[IA Wye] UOOIYIS Ul SUIPUR] JoWIed}s oY} JO YOU SpOI Mog B BIOYS OAL] IY} Aq ayiwoyop (2) S][®y eV] FO espe] oy Ly
9161 ‘OJOYd “I9TTIIN “fF “AN
~— ie.
L aid
aes
Maen
OU eaev ar
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 65
Most of the beds are from 6 inches to 2 feet thick with stratification
surfaces between them very evident. Such beds are in nearly every
way like those above described as occurring just north of the
steamer landing. Chert is often present. Kemp, in the paper
above referred to, states that “thin sections of the chert merely
exhibit a brown, nearly isotropic base with numerous rhombohedra
of calcite or dolomite scattered through it.” Some relatively thin
layers are, however, very sandy. Considering the strike, dip and
location of this section and the one just north of the steamer
landing, it is quite clear that the latter underlies the former with
an intervening thickness not definitely known, but probably about Io
feet. Adding this 10 feet to the combined thickness of the two
known sections, the thickness of the dolomitic limestone underlying
this part of the village is at least 115 feet, with neither top nor
bottom visible.
Another excellent outcrop occurs in the quarry in the north-
eastern portion of the village. This exposure is about 150 feet
long (1917) parallel to the strike which is N 50° E. At the north
end the dip is W 34°, and at the south end W 30°. A thickness
of 28 feet was measured across the southern end of the quarry, and
30 feet across the northern end. ‘The rocks are very distinctly
bedded in layers a few inches to 2 feet thick, usually 1 to 2 feet.
Plate 8 gives a good idea of the appearance of the rock in the quarry.
Except for a few thin, black shale and sandy shale partings, the
rock is all dark gray, fine grained, crystalline, dolomitic limestone
very similar to that of the other localities above described. Scat-
tering veinlets and bunches of calcite, often dark with organic mat-
ter, are common, but no chert was observed. The rock weathers
to a light gray. Judging by the strike, dip and location, this quarry
section probably lies in part at the horizon of the upper beds of
the Rogers brook section, but mostly above it. On this basis, and
barring the possibility of an intervening fault, a thickness of some-
thing like 20 feet should be added to the thickness above deter-
mined for the southern part of the village. This would make the
total thickness of dolomitic limestone under the village approxi-
mately 135 feet, with neither top nor bottom exposed.
On the lake shore one-third of a mile southwest of the mouth
of Rogers brook, there are two small exposures of dolomitic lime-
stone in beds from 6 inches to 1 foot thick, with a total thickness
of 10 feet. These beds, with strike N 60° E and dip W 7°, are
about on a line with, and look much like, the beds at the steamer
66 NEW YORK STATE MUSEUM
landing. On the weathered surfaces the rock is very rough and
deeply pitted due to dissolving out of calcite bunches.
A very careful search ‘southwest, west and north of the village
failed to bring to light any other exposure of either dolomitic
limestone or Potsdam sandstone than those above described, the
glacial drift masking the underlying rocks to the foot of the hills
(see map). Neither does the drift in this area anywhere carry
angular fragments of either sandstone or dolomite which would
strongly suggest the existence of concealed ledges. In fact, even
rounded fragments are very rare. An angular fragment of typical
Trenton limestone with fossils just west of the southern end of
Thurman pond suggests such limestone in place, either now or
just before the Ice age, not farther south than the vicinity of
Schroon Lake village.
Age of the dolomite. A diligent search through the dolomitic
limestone of all the exposures failed to reveal any remains of
organisms. Kemp, in his report of 1895, likewise states that he
was unable to find fossils. This absence of fossils, combined with
the isolation of the limestone at Schroon Lake, renders it prac-
tically impossible to correlate very definitely or determine the age
of this limestone. C. E. Hall, in the paper above mentioned, makes
the following very brief statement: “At Schroon Lake village the
Chazy limestone occurs with fossils. The outcrops are not exten-
sive, being covered by a sand clay deposit.”’ With Hall, however,
consideration of the Schroon Lake outlier was an incidental matter
and more than likely, on the basis of general resemblance, the
Schroon Lake limestone was classed with the fossiliferous Chazy
limestone of the Champlain valley, the fossils having been assumed
to be present.
Kemp! notes the close resemblance of the Schroon Lake lime-
stone “to the cherty magnesian limestones that are undoubtedly
Calciferous (in age) and nonfossiliferous on Lake Champlain,”
and with some hesitation he correlates them. The writer believes
Kemp essentially correct in this view. But the old Calciferous
formation, many hundreds of feet thick in the Champlain valley,
was then considered to be wholly Ordovician in age, with cherty
beds in the lower portion.
As a result of more recent work, important changes of view
regarding the old Calciferous formation have taken place, these
changes being concisely stated by Cushing? as follows: “ The name
*r5th Annual Rep’t N. Y. State Geol., 1895, p. 507.
2IN= Ya" Staten Vins biul16Os ps 42eurOns
Plate 8
n
or
oe
Lda
ov
Puy
Onn
ey
Lo}
—
Gaia
=155)
=
= 8
5
5
E ep
x
oe
=|
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S
CB)
iy
A near view of Little Falls (?) dolomite in the quarry in the northern part of Schroon Lal
upon the rock.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 67
“Calciferous’ was originally applied to the considerable thickness
of dolomitic rocks which overlies the Potsdam sandstone in the
Champlain and Mohawk valleys. Later on Clarke and Schuchert
replaced this by the name Beekmantown, and to the rather unfossili-
ferous phase of the formation in the Mohawk valley gave the local
name of Little Falls dolomite. . . . Recent work of Ulrich, Rue-
demann and Cushing showed that the Little Falls dolomite of the
Mohawk valley was the equivalent” of the lower portion of the
Champlain Beekmantown, and that it was really separated from
the overlying Beekmantown by unconformity and graded through
transition beds (Theresa) into the underlying Potsdam sandstone.
The Schroon Lake and Little Falls dolomitic limestones are
almost exactly alike in nearly every way, both being very largely
dark-gray, fine-grained, crystalline, usually rather thick bedded,
dolomitic, sandy limestones with considerable chert as irregular
masses and irregular bunches of crystalline calcite at certain hori-
zons, and almost, or entirely, devoid of fossils. Cavities containing
very clear quartz crystals, so characteristic of certain horizons
of the Little Falls dolomite of the Mohawk valley, were not observed
at Schroon Lake, but it is quite possible either that the proper
horizons are not there exposed or that such cavities may never
have formed there. It is also of interest to note that Potsdam
sandstone, the rock with which the Little Falls dolomite is almost
invariably affiliated, outcrops to the southwest of the Schroon
Lake dolomite.
All points considered, then, it is very probable that the Schroon
Lake dolomitic limestone should be regarded as Little Falls (Upper
Cambrian) dolomite.
Newly Found Outlier in the Paradox Lake Quadrangle
During the summer of 1917 the writer discovered an outlier of
Paleozoic rock in the Schroon river valley of the Paradox Lake
quadrangle 214 miles due north of Schroon Falls, or 7 miles north
of Schroon Lake village. It lies west of the river and only one-
fourth of a mile east of the boundary of the Schroon Lake quad-
rangle. In an area of about 2 acres there are exposures of dolo-
mite in fairly thick beds resting upon sandstone, a total thickness
of not over 25 feet being visible. These strata lie in practically
horizontal position. Whether this is true Little Falls dolomite
resting upon Potsdam sandstone, or the rocks represent transition
$i
68 NEW YORK STATE MUSEUM
(Theresa) beds between the two, the writer does not know. In
any case, it is quite certain that the rocks of this outlier are to be
classed with the Potsdam-Little Falls series in general.
Significance of the Outliers
The significance of the outliers of Paleozoic rocks at and near
Schroon Lake should be considered in the light of all the outliers
of Paleozoic strata in the southeastern portion of the Adirondack
region. Altogether they afford positive evidence that early Pale-
ozoic sea waters spread over all or nearly all of that region. All
the definitely known outliers which occur well within the area
of Precambrian rocks of the southeastern Adirondacks are as
follows:
1 A small exposure of Potsdam sandstone near the southwestern
corner of the Elizabethtown quadrangle.
2, 3, 4 Three small areas of Potsdam sandstone along the. eastern
side of the Paradox Lake quadrangle.
5 Little Falls (?) dolomite at Schroon Lake village.
6 Potsdam sandstone 11% miles southwest of Schroon Lake |
village.
7 A small area of sandstone and dolomite belonging to the Pots-
dam-Little Falls series 2% miles due north of Schroon Falls in the
Paradox Lake quadrangle.
8 A small mass of Potsdam sandstone 11% miles west of North
River village in the Thirteenth Lake quadrangle.
g A small body of sandstone and dolomite belonging to the Pots-
dam-Little Falls series 1 mile west of High Street village in the .
northern part of the Luzerne quadrangle.
10 A large outlier, several miles long, in the Sacandaga river
valley at Wells in the Lake Pleasant quadrangle where are well-
exposed Potsdam sandstone, Theresa transition beds, Little Falls
dolomite, Black River (Lowville) limestone, Glens Fal's l'mesto-e
and Canajoharie (Trenton) shale.
11 A considerable outlier showing Theresa beds, Little Falls
dolomite, and Black River limestone between 1 and 3 miles north
of Hope in the Sacandaga valley of the Lake Pleasant quadrangle.
Of these, nos. 6, 7, 9 and 11 have been discovered by the writer
during the last 6 or 7 years. Besides the above, a number of out-
liers occur close to the main body of Paleozoic strata.
Wherever detailed geologic maps have been made in the south-
eastern Adirondacks, the region is shown to be literally cut to
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 69
pieces by numerous normal faults, the most prominent of which
usually strike from north-south to northeast-southwest, with known
displacements ranging from a few hundred to 2000 feet or more.
It is important to note that the outliers above listed, except pos-
sibly nos. 2, 3 and 4, lie on the downthrow sides of such faults.
Thus a prominent fault bounds the Schroon Lake valley on the
west. It appears, therefore, that the valleys containing these out-
liers have been largely produced by faulting, and that the Paleozoic
strata formerly lay at much higher levels, that is, the general level
of the surface of Precambrian rocks of the region.
Were the early Paleozoic sediments deposited in embayments or
estuaries of the sea extending well into the area of Precambrian
rocks, or were they deposited as a general mantle over the Pre-
cambrian rocks of the whole southeastern Adirondack region? As
a result of detailed studies it has been established that the southern
half or two-thirds of the Adirondack area was, by the beginning
of Potsdam time of the late Cambrian period, worn down to the
condition of a peneplain upon whose surface only a few minor
knobs or prominences existed. This being the case, notable embay-
ments or estuaries could scarcely have existed. Still further evi-
dence against the embayment idea comes out of the character of
the sediments. Thus the rocks of the outliers, including those of
Schroon Lake and Wells, are distinctly marine formations of exactly
the same character as those of the same age in the general Pale-
ozoic rock area of the Champlain and Mohawk valleys. Estuarine
deposits would show certain distinct local variations and hence the
very uniformity of the marine sediments in the outliers precludes
the possibility of their deposition in estuaries. Thus we conclude
that when the early Paleozoic, or more precisely late Cambrian,
sea encroached upon the southeastern Adirondack area a general
mantle of sediments was deposited over the whole region includ-
ing much at least of the area of the Schroon Lake quadrangle, and
that, subsequent to the emergence of the region, normal faulting
took place whereby portions of the Paleozoic strata were, in many
places, carried so far down that remnants have to this day been
protected against complete removal by erosion. Thus we explain
the existence of the outliers of early Paleozoic marine strata in
the Schroon valley.
Early and Middle Cambrian strata are unknown in northern New
York, and there is no evidence that early and middle Cambrian
seas ever spread over any portion of that area. But with the late
7O NEW YORK STATE MUSEUM
Cambrian the case is different. The first deposit to form in the
late Cambrian sea was the Potsdam sandstone which is well repre-
sented in the St Lawrence, Champlain and Mohawk valleys, these
regions all having been submerged under the Potsdam sea. In the
southeastern Adirondacks the Potsdam sea certainly extended in
as far as Wells (southern Hamilton county), North River (norti-
western Warren county), and Schroon Lake (southern Essex
county), because small outlying masses of Potsdam sandstone occur
in those localities, having been formerly connected with the larger
areas around the Adirondacks as above explained. The Potsdam
sea surrounded and more or less lapped over on the borders of the
Adirondack region, particularly the southeastern portion. There
is no evidence that the interior of the Adirondack region was sub-
merged, but rather it almost certainly formed a large island in the
Potsdam sea.
Marine conditions continued with the deposition of alternating
layers of sandstone and dolomite upon the Potsdam. This is called
the Theresa formation. After still greater submergence, the impor-
tant formation known as the Little Falls dolomite was deposited
layer upon layer to a thickness of usually several hundred feet in
the comparatively clear waters of the latest Cambrian sea. The
Little Falls sea swept all around the Adirondacks. Occurrences
of the formation in the outliers at Wells (Hamilton county) and
at Schroon Lake prove that the Little Falls sea extended well over
the eastern Adirondack area, including much at least of the Schroon
Lake quadrangle. Map figure 6 graphically shows the approximate
relations of land and water during late Cambrian time.
The Cambrian period closed with all of northern New York
above sea level, but early in the Ordovician period a submergence
set in, reaching a maximum about the middle of the period. Even
at the time of maximum submergence in the Middle Ordovician,
the best evidence points to the existence of a considerable island
comprising the interior of the Adirondack region (see map figure
6).4. Mid-Ordovician strata at Wells indicates the presence of the
sea of that age over southern Hamilton county. Though mid-
Ordovician strata are not exposed at or near Schroon Lake, such
rocks may be there concealed, or they may formerly have been
present. In any case, their strong development in the Champlain
valley only 15 or 20 miles to the east renders it highly probable
*The early Paleozoic physiography of the southern Adirondacks is dis-
cussed by the writer in a paper in N. Y. State Mus. Bul. 164, p. 80-04.
1913.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 71
that the mid-Ordovician sea spread far enough westward to cover
at least the eastern part of the Schroon Lake quadrangle.
We have no positive evidence that any part of the Schroon Lake
quadrangle has ever been submerged under sea water since mid-
Ordovician time.
rc
FRANKLIN
ST LAWRENCE
Fig. 6 Map of northern New York showing the general relations of
land and water during parts of the Cambrian and Ordovician periods. The
whole shaded portion represents land during the late Cambrian time, and
the cross-lined portion represents land during the middle of the Ordovician.
STRUCTURAL GEOLOGY
Structure of the Grenville Series
Tilting and folding. [:vidence has recently been presented by
the writer! to show that the Grenville strata of the Adirondacks
* Jour. Geol., 24:588-96. 1916
7/2 NEW YORK STATE MUSEUM
have never been highly folded or severely compressed. Many
broad belts of the strata are known to be practically horizontal or
only very moderately folded, while many masses are merely tilted
or domed at various angles. Very locally the strata exhibit con-
tortions. The many scattering bodies of Grenville strata through-
out the Adirondacks do not show any very persistent strike as
would be the case had they been subjected to notable orogenic
pressure.
The structural relations of the Adirondack Grenville strata are
reasonably explained as having been the result of the slow, irregular
upwelling of the great bodies of more or less plastic magmas,
probably under very moderate compression, whereby the strata,
previously deformed little or none at all, were either broken up,
tilted, lifted or domed, or engulfed in the magmas. According to
this view, many large blocks or belts of Grenville strata, or several
such rather locally separated by intrusive masses, with strike of
intrusive masses parallel to the strike of the Grenville, show mono-
clinical dips; many masses of Grenville were shifted around in the
irregularly rising magmas to show various strikes and dips accord-
ing to the direction of magmatic currents; some bodies of Grenville
were merely domed over bodies of laccolithically rising magma and
hence exhibit more or less quaquaversal strikes and dips; some
masses of strata were considerably bent or even folded into syn-
clines by being caught between bodies of magma upwelling at about
the same rate; some masses, especially the more plastic limestones,
were locally contorted near the igneous contacts; and many masses
of strata were caught up or enveloped by the rising magmas.
The Grenville series within the Schroon Lake quadrangle is not
extensively developed, and the exposures are mostly too scattering
to throw much light upon its structure, but most of the types of
occurrence above mentioned seem to be present, except probably
the laccolithic. Strikes and dips are platted on the accompanying
geologic map, though where several similar observations were made
within one-fourth of a mile of each other but one is usually
recorded.
In the Minerva area the Grenville strata seem to show a synclinal
structure with a west-northwest strike of the axis through the vil-
lage, but the outcrops are too scant to make this certain. If syn-
clinal, it 1s not a very sharp fold because the dips generally vary
from 30 to 50 degrees. A structure of this sort may be readily
explained as due to greater upwelling of the granite magma on
both the north and south sides of the mass of Grenville causing
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 73
the strata to be notably bent upward along those sides. It should
be noted, in accordance with this view, that the strikes of the Gren-
ville strata and the adjacent igneous rocks are essentially parallel.
In the northern portion of the Olmstedville area five good obser-
vations show the Grenville to have persistent dips of from 20 to
70 degrees northward, which is precisely the opposite of the Gren-
ville of the northern portion of the nearby Minerva area, this
latter being on the same strike. Such a sharp change would
scarcely be expected as a result of ordinary orogenic folding, and
it is more likely the result of the magmatic intrusion. The granite
magma north of Olmstedville apparently broke through and flowed
Ol!Imstedvil/le Snyder Hill
=>
8 ACS
/
/
Hill ode
x
—
~
~
hay,
Sea jeve)
Fig. 7 An early ncrth-south section through Olmstedville illustrating the
geologic structure and the probable mode of origin of the valley in the
vicinity of the village and the escarpment on the north. Several stages
of erosion are shown from the late Mesozoic or early Cenozoic penepla n
level (dotted upper line) to the present surface (heavy lower line). Length
of section, 4 miles. Vertical scale, 214 times the horizontal.
intrusively upon the Grenville strata, thus accounting for the north-
ward dip of both granite and Grenville with the latter dipping
under the former. Because of the much greater resistance of the
granite to weathering and erosion, it stands out as a local scarp
(see map), while the much weaker Grenville has been notably worn
down to form the valley around Olmstedville. Figure 7 illustrates
the principles here involved.
The very irregular dips and strikes in the small area of Gren-
ville just east of North pond are no doubt due to deformation of
this block of strata by one or more of the various intrusive masses
which rose adjacent to, or possibly engulfed it. A similar con-
dition is true of the Grenville south of Adirondack village.
The other mapped areas of Grenville are relatively small, and
they are merely inclusions in the syenite-granite series. They
74 ‘NEW YORK STATE MUSEUM
are usually lenslike or elliptical in ground plan and essentially
parallel to the foliation of the inclosing rocks.
Figure 8 shows an interesting case of a sharply bent small mass
of Grenville gneiss in granite on Ledge hill.
Foliation of the Intrusive Rocks
The anorthosite and syenite-granite series. The great instru-
sives of the quadrangle, including both the anorthosite and the
syenite-granite series, exhibit more or less foliation, though large
Fig. 8 Sketch showing ground plan of part of an exposure near the east-
ern border of the gabbro stock on Ledge hill. The gneissoid granite, with its
sharply curving foliation, wraps about a portion of a sharply bent small
inclusion of hornblende gneiss.
portions of the Marcy anorthosite commonly show practically none.
In the syenite-granite series at least a faint foliation seldom fails
to appear, and it varies from this to very highly foliated. The
degree of foliation often varies notably within very short dis-
tances. Both strike and dip of the foliation also often vary notably,
though the general trend or strike is from east-west to northwest-
southeast. Regarding the foliation in the adjoining Paradox Lake
quadrangle, Doctor Ogilvie says: “ The general direction of strike
is similar. A direction of N 40° E is the prevailing one, with low
southeast dips.” According to this, the general strike of foliation
of the Schroon Lake quadrangle is almost at right angles to that
of the Paradox Lake quadrangle. In many ledges the general strike
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 75
can be made out but not the dip, this being particularly true of
the locally gneissoid portions of the Marcy anorthosite. The
gneissoid structure is usually accentuated by the roughly parallel
arrangement of dark minerals, though locally the granite, compara-
tively free from dark minerals, is strikingly gneissoid due to
excessive flattening of feldspar and quartz.
Granulation of minerals, especially feldspar, is common in many
localities and often highly developed, the more highly foliated
rocks generally being most granulated.
On the accompanying geologic map there are recorded represen-
tative strikes and dips of foliation selected from many field
observations.
The writer considers the foliated igneous rocks to be so-called
“primary gneisses’ whose gneissoid structure was developed as
a sort of magmatic flow-structure under moderate compression
rather than by severe lateral (orogenic) pressure brought to bear
upon the region after the cooling of the magmas. Briefly stated,
the writer’s explanation follows. | During the processes of intru-
sion, which were long continued, the great magmatic masses were
under only enough lateral pressure to control the general strike of
the uprising magmas with consequent tendency toward parallel
arrangement of instrusives and invaded Grenville strata; the folia-
tion is essentially a flow-structure produced by magmatic currents
under moderate pressure during the intrusions; the sharp variaticns
of strike on large and small scales, and rapid variations in degree
of foliation, are essentially the result of varying magmatic currents
under differential pressure, principally during a late stage of magma
consolidation; the almost universal but varied granulation of these
rocks was produced mostly by movements in the partially solidified
magma, and possibly to some extent by moderate pressure after
complete solidification; and the mineral flattening or elongation
was caused by crystallization under differential pressure in the
cooling magma.
It would seem, therefore, that the general absence of foliation
from so much of the Marcy anorthosite is best explained as the
result of the much more uniform (laccolithic) intrusion of this
single great body which is much less involved with Grenville masses,
or, in other words, to much less forced differential flowage.
Figure 8 shows a case of sharp variations in strike within a few
feet in the granite of Ledge hill.
*The writer has presented a rather full discussion of this subject in
Jour. Geol., 24:600-16. 1916.
76 NEW YORK STATE MUSEUM
It is quite possible that much or all of the pressure within the
intruding magmas was simply “ shouldering pressure exerted (by
the magmas) on the adjacent rocks under bathylithic, or deep-
seated, conditions” as suggested by Cushing.
The gabbro and diabase. As already stated, the interior por-
tions of most of the gabbro stocks are nonfoliated and they pos-
sess a diabasic texture, while the outer portions are usually highly
foliated rocks, often true amphibolites. More or less granulation
is common as seen in the thin sections. In many places the degree
of foliation varies considerably within single stocks, a very fine
example already having been described as occurring on the little
hill just south of North pond (see page 58). The foliation shows
a strong tendency to box the compass around the borders of the
stocks, and, therefore, often strikes across the structures of the
older adjacent rocks. If due essentially to regional compression
after the solidification of the gabbro, should not the foliation every-
where strike at least approximately at right angles to the direction
of application of the pressure? Also, how are the notable varia-
tions in foliation and granulation to be explained on the basis of
regional pressure?
It is believed that the foliation and granulation of the gabbro
stocks are largely, if not wholly, primary features due to move-
ments in the magma before final consolidation. Considerable pres-
sures must have obtained within the stock chambers while the
magmas were being intruded under deep-seated conditions. Such
pressure against the country rock, combined with the development
of differential flowage particularly in the magmatic borders, would
readily account for the peripheral foliated zones which were, no
doubt, produced during a late stage of magma consolidation. But
the conditions of magmatic pressure and flowage must have varied
considerably, and thus the local variations in degree of foliation
and granulation are accounted for. ,
Certain of the diabase dikes which cut the Marcy anorthosite
in the vicinity of Blue Ridge village are also more or less foliated,
their borders particularly so. As in the gabbro stocks, so here, the
foliation is considered to have been due to differential magmatic
flowage under moderate pressure during a late stage of magma
consolidation. In these dikes, however, the foliation was developed
parallel to the strike of the dikes because cross-sections of these
magma chambers were long and narrow rather than rounded or
elliptical as in the gabbro stocks.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE Vi
Faults and Zones of Excessive Jointing
General features. The Schroon Lake quadrangle lies in the
midst of the faulted eastern Adirondack region. Fifteen earth
fractures are represented on the accompanying geologic map.
More than likely there are others, but only those which show at
least fairly satisfactory evidence for their existence are mapped.
In most cases these earth fractures are rather well-defined faults,
while in others they appear to be zones or belts of excessive joint-
ing in which more or less crushing and minor faulting have taken
place. These faults or broken-rock zones are relatively straight
for considerable distances, ranging from a mile or two to 10 or 12
miles within the quadrangle. Where observations were made, the
fault crush-zones are commonly from 25 to roo feet wide. In
accordance with most of the more conspicuous faults of the eastern
Adirondacks, those of the Schroon Lake quadrangle mostly strike
north-northeast. The topographic influence of the fault zones is
usually very striking as a glance at the geologic map will reveal.
It is very important to note that the fault zones of weakness,
mostly clearly marked by long, narrow valleys, nearly all trend
almost or quite at right angles to the strike of the foliation of all
the rocks and to the general trend of the belts of relatively weak
Grenville which are essentially parallel to the foliation (see map).
The faults are all of the normal type with fault surfaces vertical
or very steep. Within the area of Precambrian rocks of the eastern
Adirondacks. it is often difficult to demonstrate the existence of
faults and, when a given fault has been proved to exist, it is usually
difficult or impossible to trace it across country with any great
degree of accuracy because of scarcity of exposures due to accu-
mulation of glacial and postglacial deposits in the fault valleys.
Because of the character and structure of the rock masses (mostly
igneous) and the lack of any very clearly defined stratigraphic
relations, it is practically impossible to determine the actual amounts
of displacements, though in some instances minimum figures can
be given. Within the quadrangle such minimum figures are not
definitely known to be more than some hundreds of feet, but actual
displacements may have been many times as great.
Among the more positive criteria for the recognition of the faults
and zones of excessive jointing in the quadrangle are the following:
(1) long, narrow, almost straight valleys which trend at high
angles across the strike of the older rock structures such as the
foliation and the belts of Grenyille strata; (2) steep to vertical
78 NEW YORK STATE MUSEUM
scarps, often miles long, in hard, homogeneous rock; (3) actual
presence of crushed, sheared, slickensided or brecciated rock zones ;
and (4) Paleozoic strata lying at the base of steep hills of Pre-
cambrian rocks.
Age of the faulting. That some Adirondack faulting took place
in Precambrian time has been pretty well established, but, so far
as definitely known, such fractures are of minor importance.
There is no positive evidence for such faulting in the Schroon
Lake quadrangle. It seems quite likely as Cushing has suggested,
that considerable faulting took place during, or toward the close
of, the Paleozoic era.
Any fault scarps, ridges or valleys which may have been pro-
duced by the close of the Paleozoic must have been nearly or
quite obliterated by the long subsequent time of erosion. If so,
how do we account for the present Adirondack ridges and valleys
which follow the fault lines or zones? Accompanying the uplift
of the late Mesozoic or early Cenozoic peneplain of the Atlantic
coast region, or following it, there was either new faulting, or
renewed movement along old faults, or old fault zones, including
zones of excessive jointing with little displacement, were not
affected by new movements. How much is new faulting, and how
much renewed faulting along old lines or zones of fracture is not
known, but it is quite certain that considerable faulting in the
eastern Adirondacks must date from the uplift of the peneplain
just mentioned as shown by fault scarps in homogeneous rocks and
by the existence of tilted fault blocks which have been little modi-
fied by erosion. Some relatively long, deep, narrow, valleys of the
Schroon Lake quadrangle, like that which follows the Minerva
stream fault or the Hoffman notch fault (see below), are due
essentially to erosion along the fault or broken-rock zones of weak-
ness irrespective of when they originated, while others which are
broader, like the Schroon Lake valley and the lowland between
Green hill and Oliver hill, are due either to comparatively recent
sinking of fault blocks, or removal of weaker rocks by erosion
whereby old fault scarps are renewed, or both. Distinctly tilted
fault blocks, like some in the North Creek quadrangle just to the
south, are not certainly present in the Schroon Lake quadrangle.
Schroon valley fault. As represented on the geologic map,
this is one of the two longest and most conspicuous faults of the ©
quadrangle. Its scarp marks the western boundary of the Schroon
*N. Y. State Mus. Bul. 095, p. 405.
‘
W. J. Miller, photo, 1917
The zone of excessive jointing accompanied by some faulting in the road
metal quarry by the main road one-half mile east-northeast of South
Schroon
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 79
valley for 12 miles across the quadrangle and beyond (northward)
for fully 8 miles more. As regards both length and topographic
influence, this fracture takes rank as one of the most prominent
faults in the eastern Adirondacks. It probably does not extend
south of the quadrangle limit. The topographic evidence for the
fault is very strong (plate 3). The Potsdam sandstone east of
Grove Point and the sandstone and dolomite in the valley 7 miles
north of Schroon Lake village also both lie against the base of the
scarp and hence furnish strong evidence for faulting with down-
throw side on the east. Several ledges in the bed of Horseshoe
pond brook are badly broken parallel to the course of the stream
and these furnish still more positive evidence for the existence of
the fault. Nowhere else along the immediate base of the scarp
were outcrops of any kind observed, so that further evidence such
as slickensides and crushed or brecciated zones, is lacking. From
Thurman pond southward the trace of this fault 1s much less cer-
tain. Some idea of the minimum displacement along this fault
may be gained not only from the height of the scarp but also from
the positions of the outliers of Paleozoic strata. Thus the sand-
stone and dolomite 7 miles north of Schroon Lake village lie at an
altitude of 900 feet, while the summit of the mountain just west is
nearly 2300 feet, thus indicating a minimum downthrow of about
1300 feet on the east side of the fault. The position of the Pots-
dam sandstone west of Grove Point indicates a minimum displace-
ment of at least 400 feet, and probably 600 feet.
Schroon lake faults. The topographic evidence for a fault, or
at least a zone of excessive jointing, along the western side of
Schroon lake is strong, as shown on the map. A very conspicuous
zone of excessive jointing accompanied by moderate faulting (see
plate 9) occurs in the road metal quarry one-half of a mile east-
northeast of South Schroon. The strike of this jointed zone is
parallel to the strike of the fracture as mapped but at a high angle
to the strike of the foliation of the rocks. Probably the jointing
exhibited in the quarry lies a little to the west of a real fault,
because the topography strongly points to a downthrow of fully
200 feet on the east side.
From Adirondack village southward close to the lake shore there
is a fault which is but the northern extension of a rather prominent
fault several miles long which has been mapped and described in
the writer’s report on the North Creek quadrangle.
Along the eastern lake shore at the base of Quackenbush hill,
and extending several miles into the Paradox Lake quadrangle, a
8o NEW YORK STATE MUSEUM
long, nearly straight line, with hills rising steeply hundreds of feet
above it and at right angles to the old rock structures, makes the
existence of a line or zone of fracturing there almost certain. This
being the case, the outliers of Paleozoic strata in and near Schroon
Lake village really le in a “ graben” or fault trough.
Fuller brook fault. This zone of fracture separates Pine hill
and Ledge hill rather sharply and continues northward at least to
Horseshoe pond. The topographic evidence is quite clear and, in
the bed of the little brook about a mile south of Marsh pond, the
rock is considerably broken as a result of earth movements. The
topography suggests a moderate downthrow on the east, but instead
of being a true fault this may be simply a zone of excessive joint-
ing with little displacement.
Alder brook and Trout brook faults. That Alder brook and
Trout brook follow fault zones for several miles as shown on the
map is quite certain. Not only are these valleys narrow and
remarkably straight, but they have been cut into granite at right
angles to its structure. Such could scarcely be the case unless the
positions of the valleys were determined by zones of weakness due
to faulting. Further, the earth block between these two streams is
very distinctly depressed below the country immediately on either
side. The evidence, then, renders quite certain the existence of a
fault block from 1% to nearly 3 miles wide and several miles long
which has sunk between two faults, one along Alder brook and the
other along Trout brook. The topographic influence of this sunken
fault block is particularly striking in its southern half where the
Pine-Green hill mass on the east and the Oliver-Snyder hill mass
on the west each rise hundreds of feet very abruptly. Direct evi-
dence for the faulting from ledges along the fracture lines or zones
is wholly wanting, not a single outcrop occurring on either of the
brooks. The Alder brook fault continues for several miles south
into the North Creek quadrangle (see North Creek geologic map).
Minerva stream fault. As regards both length and topographic
influence, this fault takes rank as one of the most prominent known
lines of fracture in the eastern Adirondacks. On the accompany-
ing map it shows a length of 12% miles. It continues southward
for 614 miles across the northwestern part of the North Creek
quadrangle and thence for at least 3 miles into the Thirteenth
Lake quadrangle. Its total length is, therefore, at least 22 miles.
Its topographic influence is very striking since a deep, usually
narrow, nearly straight valley has been cut out along this zone of
weakness along its whole course of over 12 miles in the Schroon
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GEOLOGY OF THE SCHROON LAKE QUADRANGLE SI
Lake quadrangle (plate 10). Southward, also, the topographic
influence is pronounced. It seems quite clear that the downthrow
side is on the east, this being most evident in the North Creek
quadrangle where, just east of the Gore mountain mass, the dis-
placement is at least 1500 feet. Within the Schroon Lake quad-
rangle the topography does not indicate so much displacement,
though it is mostly at least some hundreds of feet except at the
north where it is much less. In the Minerva stream valley no out-
crops occur along the fault, but in the bed of the brook just west of
Washburn ridge there are several exposures of rock badly broken
by the faulting in zones parallel to the course of the stream. It is
very important to note that the strike of this fault is almost exactly
at right angles to the strike of the foliation of all the rocks, and
also at right angles to the strike of the prominent belt of Grenville
strata around Minerva and Olmstedville. It is difficult to con-
ceive how such a long, narrow valley could have developed for 12
miles across these structures except along.a fault zone of weakness
in the rocks. The lowlands in the vicinity of Minerva and Olmsted-
ville, and also in the vicinity of North Creek, are due to more rapid
erosion of the comparatively weak Grenville strata in those
localities.
Hoffman notch fault. Evidence for either a fault or zone of
crushed or excessively jointed rock in the Hoffman notch valley is
twofold. In the first place, the long, straight, deep, narrow valley,
with north-northeast strike parallel to most of the prominent faults
of the eastern Adirondacks and at right angles to the rock struc-
tures of the immediate region, almost certainly must have been
carved out along a fault zone of weakness. This valley is 5%
miles long with a maximum depth of 1200 to 1500 feet. In the
‘second place, actual crushed to even brecciated rock zones in the
bottom of the valley and parallel to it were observed at a number
of places, the principal ones being as follows: several ledges in the
brook between one-half and 114 miles north of the pond in Hoff-
man notch and several ledges in the brook between 1% and 2 miles
south of the same pond. The brook northeast of Hoffman notch
pond follows a short branch fault for about one-half of a mile
with much evidence of crushed rock. That the Hoffman notch
fault continues northward across the east-west Blue Ridge-
Boreas river road is proved by the existence of a ledge in the
Branch brook just north of the road where closely spaced jointing
with strike N 20° E is well shown.
82 NEW YORK STATE MUSEUM
Faults between Hayes mountain and Hewitt pond. West of
Hayes mountain, Minerva stream flows through a narrow north-
south valley which for 2%4 miles has been carved out along a dis-
tinct fault zone of weakness. In the bed of the stream three-fourths
of a mile north of the place marked “Camp” on the map, the
granite is considerably broken due to the faulting. Along the
stream one-third and three-fourths of a mile, respectively, south of
“Camp,” there are ledges distinctly broken or excessively jointed
parallel to the stream channel. In one case a crushed-rock zone
10 to 15 feet wide is finely exhibited. The topography suggests
moderate downthrow on the west.
A ledge in the bed of the stream one-half of a mile southeast of
the mouth of Hewitt pond shows a distinct crush-zone with almost
north-south’ strike, but with little or no topographic influence.
Hewitt pond brook also follows a fault zone of weakness with
nearly east-west strike, this being the only definite fault in the
quadrangle with such a strike. A few rods above the mouth of
the brook in a small gorge the rock is considerably broken parallel
to the channel.
Wolf pond brook fault. A narrow nearly straight valley 5%
miles long extends from Lester dam to north of Wolf pond. It
has probably been developed along a zone of excessive jointing
rather than along a distinct fault. In the bed of Wolf pond brook,
one-third of a mile from its mouth, a big ledge is considerably
broken by closely spaced joints parallel to the channel.
Boreas river fault. Boreas river, for 1% miles after it enters
the map area, quite certainly follows a channel which has been cut
out along a fault zone or a zone of excessive jointing. One ledge
along the stream shows the broken rock. This fault zone is really
only the southern end of what is evidently a very prominent earth
fracture extending far into the Mount Marcy quadrangle. The
Ausable lakes are there located in this fault zone. The topographic
influence in the Mount Marcy quadrangle is very striking.
Niagara brook fault. The long, deep, straight, narrow valley
occupied in part by Niagara brook has quite certainly been deter-
mined by a fault or joint-zone of weakness. Counting its northern
extension beyond the map area where its topographic influence is
even more pronounced, this fault or joint-zone is 6 miles long. No
broken-rock zone was observed within the Schroon Lake quad-
rangle, the bed of the brook there all being in glacial drift.
Other faults. A big ledge at the road corners southeast of
Oliver pond is all cracked into small blocks. Also, ledges by the
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 83
road one-third of a mile west of Oliver pond show many closely
spaced joints with nearly north-south strike. These zones of
broken rock are apparently minor, and since they have no topo-
graphic influence they are not mapped.
The steep southern face of Moxham mountain strongly sug-
gests a fault scarp, but it might have resulted by removal of Gren-
ville strata, such rock now forming a considerable belt not far to
the south.
In the bed of Boreas river 1 mile below Lester dam, the granite
is much broken and badly weathered in a fault zone of weakness
with nearly north-south strike, but there appears to be no topo-
graphic influence.
In still other places the topography suggests the presence of
fault zones, but in no case has the evidence seemed strong enough
to warrant mapping.
PEBISHOCENE GEOLOGY
General Statements
It is well known that, during the great Ice Age of the Quaternary
period, all of New York State except portions of the extreme
‘southern side was buried under a sheet of ice. That this great
sheet of ice was thick enough to bury even the highest mountains
of northern New York is proved by the presence of glacial pebbles
and boulders at or close to many of their summits. This is true in
the Schroon Lake quadrangle. In some cases striae and glaciated
ledges have been observed several thousand feet above sea level,
the highest which happened to be noted in the Schroon Lake quad-
rangle being at 2200 feet. Adirondack glacial lakes at altitudes of
several thousand feet above sea level also bear strong testimony to
great depth of ice. The general direction of movement of the ice
across the Adirondacks was toward the south and southwest, with
comparatively few local exceptions. Such a persistent direction of
movement also strongly argues for complete burial of the region
under ice. The ice spread southward as a part of the great Labra-
dorean ice sheet of eastern Canada. When the ice, early in its
southward movement, struck the Adirondack highland district, one
portion flowed southward through the Champlain valley and sent
a branch lobe westward into the Mohawk valley. At the same
time another portion flowed around the western side of the moun-
tains and sent a lobe eastward into the Mohawk valley. The two
lobes, one from the east and the other from the west, met in the
84 NEW YORK STATE MUSEUM
Mohawk valley leaving the main portion of the Adirondacks free
from ice. But, as the ice increased in volume, more and more of
the Adirondack region was covered till finally even the highest
points were buried. In a paper published by the writer some years
ago, the movement of the great ice sheet across northern New
York is discussed.1. During the ice retreat the higher east-central
Adirondack region was the first to be freed from the ice, and the
ice-freed portion gradually increased in size.
Direction of Ice Movement
The direction of ice movement across the Schroon Lake quad-
rangle is clearly recorded by both glacial scratches (striae) and
the distribution of glacial boulders. Distinct glacial striae were
observed in twenty localities, their bearings and locations being
plotted on the accompanying geologic map. They are as follows:
1 S 10° W. On Grenville gneiss 114 miles west-southwest of
Schroon Lake village.
2 5 10° E. On granite by the road 114 miles west-northwest of
Schroon Lake village.
3 S 10° E. Ondiabase 1% Ae due west of Grove Point.
4 N-S. On granite three-fourths of a mile northeast of Charley
hill.
5 N-S. On granitic syenite near the summit of Beech hill.
6 S 10° E. On granite by the road 1 mile west of Charley hill.
7 N-S. On granitic syenite by the road,1 mile northwest of
Taylors on Schroon.
8,9 S 10° E. Two records one-fifth of a mile apart on granite
by the road three-fourths of a mile north-northeast of Pat pond.
10 S 10° E. On Grenville gneiss three-fourths of a mile due
west of Minerva. ;
11 S 10° E. On granite by the road just south of Oliver pond.
12 N-S. On granite by the road one-third of a mile west-south-
west of Oliver pond.
13 S 30° W. On granite by the road one-half of a mile west-
southwest of Oliver pond.
14 S 10° EF. On syenite by the road one-half of a mile north-
east of Muller pond.
15 5 10° E. On Whiteface anorthosite by the road 134 miles
west-northwest of Boreas river.
1Amer, Jour. Sci., 27:289-98. 1900.
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 85
16 S 15° E. On Marcy anorthosite near the creek three-fourths
of a mile northeast of Boreas river.
17, 18, 19, 20 S 10° E. Four records on Marcy anorthosite by
_ the road between 1 and 134 miles east-northeast of Boreas river.
It will be seen from this list that the extreme range in direction
of the glacial striae is from S 15° E to S 30° W. Further, all but
two sets of the striae run from N-S to S 15° E. It is evident,
therefore, that the general direction of movement of the ice over
the quadrangle, except possibly its northeastern one-fourth where
no striae were observed, was a little to the east of south. This
harmonizes closely with the sixty sets of glacial striae observed by
the writer’ in the North Creek quadrangle next to the south, the
average direction of which is almost exactly N-S.
Regarding the Paradox Lake quadrangle which lies just east,
Doctor Ogilvie says:* “ The more southerly and easterly parts of
the quadrangle were in the region of the southwesterly moving ice
current.’ Professor Kemp* has reached a similar conclusion
regarding the southeastern portion of the Elizabethtown quad-
rangle, and further observations there by the writer reinforce this
view. In the Blue Mountain quadrangle, the second to the west of
the Schroon Lake quadrangle, the writer* has recently shown that
the general direction of ice movement was southwestward. Pro-
fessor Cushing® reached the same conclusion regarding the Long
Lake quadrangle. A's shown by the writer,® the general ice cur-
rent was southwestward across the Lake Pleasant quadrangle in
the south-central Adirondacks.
From the above facts it is evident that the southward to even
slightly southeastward movement of the ice across the Schroon
Lake and North Creek quadrangles was rather strikingly excep-
tional, having been surrounded by the great sheet of generally
southwestward moving ice. The writer has no explanation for this
puzzling fact. Local topographic control of the ice current in the
Schroon Lake area can not have been the cause of the deflection
because most of the prominent ridges and valleys have a north-
northeasterly strike and the others vary from east-west to north-
west, so that the ice moved across these sets of valleys at angles of
from 20 to 90 degrees. The location and strike of striae in valleys,
Y. State Mus. Bul. 170, p. 66. ro14.
Y. State Mus. Bul. 96, p. 470. 1905.
. Y. State Mus. Bul. 138, p. 95. ro910.
Y. State Mus. Bul. 192, p. 48. 1076.
Y. State Mus. Bul. 115, p. 495. 1907.
Y. State Mus. Bul. 182, p. 63-64. 10916.
1
2
3
4
5
6
Zee ae
8&6 NEW YORK STATE MUSEUM
like those north of Pat pond and east of Boreas river or at the
summit of Beech hill, clearly prove the failure of the topography
to determine the direction of the ice movement.
Ice Erosion
There is no evidence that the ice was a vigorous agent of erosion
within the quadrangle. It may possibly have scoured out and
somewhat deepened the basin of Schroon lake, but definite proof
is lacking. Certainly none of the more prominent valleys were
produced by ice erosion, for, as above shown, the main body oi
the ice flowed across the trend of the valleys rather than parallel
to them as would have been necessary for ice erosion to have been
very effective for their development or even notable modification.
It is quite certain, however, that the ice did remove from its
original position practically all the preglacial soils and most of the
rotten rock. Further, the vast number of glacial pebbles and
boulders of comparatively fresh rocks clearly show that much
relatively fresh rock must have been removed probably by the
process of plucking or pushing off joint blocks which during trans-
portation became more or less rounded. Altogether, however, the
total amount of material eroded by the ice made no marked dif-
ference in the preglacial topography. The dumping of glacial
material in the valleys during and after the ice retreat has probably
altered the topography more than erosion by the ice.
Glacial Deposits
Morainic deposits. Typical morainic deposits, mostly glacial
till or ground morainic material, are common throughout the quad-
rangle though usually they are more or less associated with strati-
fied or fluvio-glacial materials. Boulder clay is seldom seen.
Morainic deposits are particularly well developed over the lower
lands or valleys, while well up on the hills and mountains they are
usually absent or thin. It is evident that, during the retreat of
the great ice sheet, the burden of morainic material was largely
dumped in the valleys either by direct deposition from the ice or by
water in connection with the ice, or both.
The most extensive development of morainic and fluvio-glacial
deposits is in the area of over 6 square miles mapped as Pleisto-
cene in the central portion of the quadrangle. Within this area
the hard rocks are everywhere concealed under glacial deposits
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-
GEOLOGY OF THE SCHROON LAKE QUADRANGLE 87
except at the four places indicated on the map. A little west cf
the middle of this area, there is an area of nearly a square mile,
mostly an old clearing, where a boulder moraine is conspicuously
shown.
In the area of Pleistocene east and southeast of Olmstedville
morainic and fluvio-glacial deposits are also well exhibited, with
boulders especially prominent in the northern half. In and near
Olmstedville, in the area of Grenville, there are also fine develop-
ments of morainic and fluvio-glacial materials with boulders
common.
Very conspicuous boulder morainic deposits occur for a mile on
either side of the Trout Brook valley from 1 to 1% miles south-
east of Muller pond.
The Pleistocene of the area between South Schroon and Grove
Point is largely morainic material.
Among many smaller scale morainic deposits are those in the
valley east of Catamount hill, and three-fourths of a mile south-
west of Irishtown.
Glacial boulders (erratics). Glacial boulders or erratics are
very abundant and widespread over the quadrangle, though they
are much less common on the tops of mountains and hills than over
the lowlands. Some of the more prominent groupings of boulders
in so-called “boulder moraines” are mentioned above. In addi-
tion to those there should be noted the accumulation of hundreds
of large and small angular masses of Potsdam sandstone just south-
west of Thurman pond and all over the area of ‘Potsdam sand-
stone north of the pond.
An 8-inch angular fragment of typical Trenton limestone was
noted a few rods west of the south end of Thurman pond. This
suggests either a hidden ledge of such rock in this portion of the
Schroon valley, or a mass scraped off and broken up by the ice,
though the fragment might possibly have been carried by the ice
for many miles.
While numerous boulders represent various types of the region,
most of the largest ones are of Marcy anorthosite. The writer
was particularly impressed by many boulders, usually only moder-
ately rounded, ranging from 10 to 20 feet in diameter in the woods
on the southern portion of Texas ridge.
A very large and interesting glacial boulder of Marcy anorthosite
lies in an old field near the southeastern base of Cobble hill three-
fourths of a mile southwest of Warren’s hotel. Roughly meas-
88 NEW YORK STATE MUSEUM
ured, it is 33 feet long, 27 feet wide and 25 feet high. Since its
deposition by the ice it has been split open along a joint surface.
Plate 11 shows the appearance of this boulder. It was transported
at least several miles, since the nearest outcrops of Marcy anor-
thosite are that far to the north.
Two remarkable boulders of Marcy anorthosite are shown in
plate 12. They are close to the road two-thirds of a mile south of
Wolf pond. Both are notably rounded, suggesting transportation
for a number of miles at least. One of them, at least 14 feet in
diameter, rests in a remarkably balanced position upon the other
large one which is partially buried in the glacial drift. It scarcely
seems possible that the upper boulder can retain such a position,
and yet it remains there in spite of an attempt some years ago to
pry it off.
Kames and eskers. Kames and eskers definitely recognizable
as such are not common in the quadrangle. In the areas of heavy
glacial and fluvio-glacial deposits, some of the little hills strongly
suggest their origin as kames, but, since their structure is rarely
ever revealed, this is not certain.
But one clearly defined esker was observed, and this is a oe
fine one. It lies just northwest of Schroon Lake village with a
sinuous course and a general north-south strike for more than two-
thirds of a mile. Its northern end comes against the base of the
steep hill. The contour map only roughly suggests its position.
It consists of sand and well-rounded small to large pebbles. In
height it varies from 20 to 75 feet. Toward the north where it is
highest and covered with trees, it is a very steep-sided narrow
ridge. Plate 13 shows part of it toward the south in an open field
where it is neither so high nor so sharply defined. This esker was
probably formed by a debris-laden stream from the hillside upon
or under the ice of the great waning ice sheet which still lay in the
valley.
Lakes and Their Deposits
Extinct lakes. Glacial Lake Pottersville. This former large lake
was first recognized by the writer and described in his report on
the North Creek quadrangle.t. It is named from the village of
Pottersville which lies on the old lake bottom. Its waters spread
through the Schroon valley from near Chestertown, over the site
of Schroon lake, and to north of North Hudson. Branches of the
IN. Y. State Mus. Bul. 170, p. 70-72. 1014.
, photo, 1917
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geology.....-....-. Evidence bearing on postglacial
Description and interpretation of history of Hudson-Champlain
PHC CMEMOSIESS: v.00 sees ss Se valley..
_ The Lake Albany deposits Recent deena
rene of the upper terrace Review and summary.
pe cop tent of the lower terrace
‘ ALBANY
‘THE UNIVERSITY OF THE STATE OF NEW YORK
aa 1920 ;
THE UNIVERSITY OF THE STATE OF NEW YORK
Regents of the University
With years when terms expire
(Revised to January 1, 1920)
1926 Puiny T. Sexton LL.B. LL.D. Chancellor - - Palmyra
1927 ALBERT VANDER VEER M.D: M.A. Ph.D. LL.D. —
Vice Chancellor Albany
President of the University and Commissioner of Education
Joun H. Fintey M.A. LL.D. L.H.D.
Deputy Commissioner and Counsel
FRANK B. GILBERT B.A.
Assistant Commissioner and Director of Professional Education
Avucustus S. Downine M.A. L.H.D. LL.D. Pd.D.
Assistant Commissioner for Secondaty Education
CHARLES F. WHEELOCK B.S. LL.D.
Acting Assistant Commissioner for Elementary Education
GeorceE M. WILry M.A.
Director of State Library
James I. Wyer, Jr, M.L.S. Pd.D.
Director of Science and State Museum
Joun M. Crarke D.Sc. LL.D.
Chiefs and Directors of Divisions
1922 CHESTER S. Lorp M.A.LL.D. - - - - - Brooklyn
1930 WiLttiAM NottincHaM M.A. Ph.D, LL.D. - - Syracuse |
1924 ADELBERT Moot LL.D. - - - - - - - = Buffalo
1925 CHARLES B. ALEXANDER M.A. LL.B. LL.D. |
Litt.D. - - - - - - - - -+ = Tuxedo:
1928 WALTER GUEST KELLOGG 8. A LL. D. - - - Ogdensburg |
1920 JAMES ByrngE B.A. LL.B. LL.D. - - - - - New York
1929 HERBERT L. BRipGMAN M.A. - - - - - = Brooklyn
1931 THomas J. Mancan M.A. - - - - - - - Binghamton
:
Administration, Hiram C. Case
Agricultural and Industrial Education, Lewis A. WILSON
Archives and History, James SuLLivan M.A. Ph.D.
Attendance, JAMES D. SULLIVAN
Educational Extension, WILLIAM R. Watson B.S.
Examinations and Inspections, GEorcE M. Witey M.A.
Law, FRANK B. Giupert B.A., Counsel
Library School, James I. Wyver, Jr, M.L.S. Pd.D.
School Buildings and Grounds, Frank H..Woop M.A
School Libraries, SHERMAN: WILLIAMS Pd.D.
Visual Instruction, ALFRED W. ABRAMS Ph.B.
The University of the State of New York
& Science Department, November o, 1918
Dr John H. Finley
President of the University
SIR :
Bl beg to communicate herewith and to recommend for publica-
ion, as a Bulletin of the State Museum, a manuscript entitled
cial Geology of the Cohoes Quadrangle, which has been pre-
| red, at my request, by Prof. J. H. Stoller.
Sincerely yours 1a
Joun M. CLARKE
Director
_ Approved for publication, November 14, 1916
ae President of the University
New York State Museum Bulletin
Entered as second-class matter November 27, 1915, at the Post Office at Albany, New York’
Published monthly by The University of the State of New York
Nos. 215, 216 AMLAIBVAIND I IN|, YW November-December 1918
The University of the State of New York
New York State Museum
Joun M. Crarke, Director
GLACIAL GEOLOGY OF THE COHOES
QUADRANGLE
BYGSVMES ie Sit © MEER
INTRODUCTION
The period of geological history known as the Glacial or
Pleistocene Period and characterized by the extension of a great
ice sheet from the region of Labrador southwestward beyond the
boundary of the State of New York has its record in the materials
left by the ice and by the flooded waters following the melting of
the ice.
This bulletin deals with the Pleistocene geology of the area of
the Cohoes quadrangle. The materials for study consist in general
of the mantle of clay, sand, gravel and boulders that overlies bed-
rock. The distribution and mode of arrangement of these materials
and the surface forms which they exhibit — whether hills of definite
topographic features, terraces along the courses of stredms, or
slopes bordering ravines and valleys — reveal the agencies which
brought these materials to their present locations and gave them their
present forms. To the extent that the several kinds of earthy
materials occur in separate areas of distribution, the mapping of
the glacial deposits becomes, in a general way, a survey of soils.
In the region here reported upon the dependence of soil composition
upon geological origin is, over considerable portions of the area,
somewhat close and the accompanying map is therefore of interest
not only from the standpoint of geologic science but also that of
agriculture. Thus the soils that originated as sediments, consisting
of finely divided particles of clay and sand deposited in bodies of
6 NEW YORK STATE MUSEUM
water forming temporary lakes, at the close of the ice age, are of
quite different character from the unassorted materials left from
the melting ice. Some of the glacial deposits are also of economic
importance in other ways, especially the clays extensively used for
making bricks and the sands for building and molding purposes.
It may be noted that in other ways the industrial life of the
people is dependent upon factors. and conditions resulting from
the changes wrought upon the country during the Ice Age. The
largest city, Cohoes, owes its growth as a manufacturing center to
the source of power afforded by the falls in the postglacial gorge
of the Mohawk near its mouth. The villages of Schaghticoke and
Valley Falls are similarly related in location and industry to the
rapids of the Hoosic river where in its lower course it has carved
a channel in rock, since the close of the glacial period. A’ further
instance of the relation of human interests to conditions deter-
mined by glacial agencies is that of the restoration of an extinct
glacial lake — Lake Tomhannock, on the Cohoes quadrangle — in
order to form a storage reservoir for the water supply of the city
of Troy.
The history of the drainage of the area, especially of the streams
tributary to the Hudson, as deduced from the facts gathered in the
present work, is of exceptional interest and throws light on some
of the larger problems of the postglacial history of the Hudson-
Champlain valley. The data bearing on these questions and a dis-
cussion of them are given in the body of this report.
PHYSICAL GEOGRAPHY “AND GENERAL GEhOl@Gis
The Cohoes quadrangle is intersected by the Hudson river, which
enters the area at about the middle of the northern border (latitude
43°) and flows southwestward and southward crossing the southern
border (latitude 42° 45’) about 1 mile above the head of navigation
of the river at Troy. The elevation of the river at the northern
margin of the sheet falls between the 80 and 100 foot contour lines
and at the southern border is less than 20 feet above sea level. The
segment of the Hudson river here included belongs, therefore, to
the upper or what may be termed the river portion proper, in dis-
tinction to the lower, or estuarine portion, which is within the
influence of the ocean tidal movements.
In considering the geology of this portion of the Hudson valley
it is helpful to distinguish at the outset between the preglacial
valley which is now largely filled with sand and clay deposits of
Pleistocene age and the present valley which belongs to the recent
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 7
period, that is, has been formed since the time of the subsidence
of the body of glacial waters in which the sands and clays were
deposited. The preglacial valley is cut in rock and is somewhat
complex in form, consisting of a broad and open outer portion and
an inner portion with steeper slopes. The whole, as a physiographic
Al
Fig. 1 Diagram showing preglacial topography of the Hudson valley
ay
Ze
feature, may be described as a gorge within a valley. This ancient
rock valley represents the erosive work of the Hudson river in the
Cenozoic (Post-Cretacic) era of geologic time and its double form
is considered to be the result of an uplift of the general region fol-
lowing an earlier period of valley erosion. Its form and dimen-
sions are now evidenced by outcrops of rock that occur near the
lateral border of the clay and sand area and by the depths of the
ravines which have been cut into the filling of the ancient rock
valley and in places into the underlying bedrock. From these data
it is shown that the ancient valley has an average breadth of
between 4 and 5 miles and a depth in its middle portion of 200
feet or more. The width of the imner valley or gorge is on the
average about 2 miles: its depth, of course, is the same as that of
the broader valley.
The present valley of the Hudson, as here considered, is the
broad depression on the bottom of which the river flows in a more
or less winding course and the sides of which are the steep clay
banks which rise 100 feet or more above the valley bottom. The
present valley lies within the old rock gorge, its bottom being coin-
cident with the middle portion of the floor of the latter. The
present channel of the river, however, in the greater part of its
extent, is cut into the floor of the old gorge, forming a shallow
rock gorge representing the erosive work of the river in the recent
period. The present valley bottom, threaded by the channel, has a
width varying from three-fourths of a mile to one and one-half
miles.
Where the river enters the quadrangle and for several miles
southward this bottom is an alluvial plain, but from Stillwater to
8 NEW YORK STATE MUSEUM
the southern edge of the sheet the valley bottom stands generally
above the level of overflow of the present river and its materials
are chiefly of glacial origin or, in large areas, of bared rock or
residual soils derived from the rock in the recent period.
Legend
o ©
a S ~ g oO
6 u a, S
oO te > »
<6 be Nes _ S
= o fe e (3) 0 C
3 oie me - x = ‘J ley
i L = 5 cs) o o ©
o o > = me} rd foe, rai
vate aS 6 re 3 fe} a. iS
5 5 4 ae wl = =
- Sands or
| | | | Clayey sands
300 ft a ood
oh Pa ea
arn eS — oy 0.09 ong
SS a a
‘oo ft. —_ Se Sn ee
\ Ror Oo \\\y
Rock
Fig. 2 Section across the Hudson valley showing present surface features
and relations of Pleistocene deposits to the underlying rock surface. The
surface line is drawn to scale along an approximately east-west line taken
about 3 miles south of Mechanicville.
Rising from the flat valley bottom on either side are steep slopes
or bluffs, the materials of which are the stratified Pleistocene clays.
From the summit of these bluffs, extending outward from the valley,
are expanses of clay or sandy clay lands forming terraces. These
terraces occur on both sides of the river at approximately cor-
responding levels, showing that they are remnants of a continuous
plain that has been divided by the erosive work of the Hudson
waters.
At the outward margin of these terraces the surface again rises,
in some places rather abruptly and in other places gradually, form-
ing a slope the rise of which is, as a general average, about 60 feet.
Outward from the summit of this slope the surface again becomes
flat or moderately sloping toward the valley and extends north and
south somewhat as a bench or terrace normal to the river valley.
This area, which will be referred to in this report as the upper
terrace, consists of soils in which there is a larger proportion of
sand than in the clay soils of the lower terrace. Beyond the out-
ward limit of the upper terrace rise the uplands areas, the surface
materials of which consist chiefly of till or materials derived from
or left by the melting of the ice sheet. .
Within the limits of the quadrangle the Hudson receives its
largest tributary, the Mohawk river, from the west; and one of its
largest tributaries from the east, the Hoosic river.
‘uOISO19 afoyjod
Aq apew jatueyd MOIIeU © SuTAdNIDO IayeM MOT je UeII]S SUIMOYS
yueq yyNos Wolz MIA ‘sT[ey Sa0yod
I 93®[d
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 9
The segment of the Mohawk valley included in the southwestern
part of the sheet belongs to the portion of the river (from Aqueduct
near Schenectady, to its confluence with the Hudson) which occu-
pies a postglacial valley.t. The evidence of this is that the valley
of the river, for a distance of 5 miles east of Aqueduct, is a gorge
cut into the rocks and extending like a trench across the face of
the country. There is no buried old valley, as in the case of the
Hudson, lying outside the present valley. These features, which ~
are. well marked in the upper portion of the preglacial valley, are
considerably modified in the lower portion. The course of the
stream becomes irregular, the valley broadens and its slopes are
less steep. These differences are due in part, especially in the
segment of the valley falling within the Cohoes sheet, to structural
features of the underlying rocks which here have their strata
steeply inclined, dipping to the east, and in part to the fact that the
Mohawk here enters the region of the old eroded rock valley of
the Hudson. The river has, however, lowered its bed into the floor
of the rock valley and in the last 3 miles of its course occupies a
-rock gorge. This portion of the river is marked by the well-known
falls at Cohoes.
On the north (northeast) side of the river, stretching back from
the summit of the gorge, there is an area, several square miles in
extent, consisting of rock with a thin covering of clayey soil. This
area has evidently been swept by the currents of the Mohawk when
_ the river flowed at a level about 80 feet higher than its present bed,
above the falls. The Pleistocene clays were removed and sub-
sequently the existing clays were formed as a residuum from the
weathering of the exposed rock surface. On the south side of the
gorge only a narrow strip of the Pleistocene clays was removed by
river erosion and the surface topography of the clay formation
exhibits terraced forms, normal to the Hudson valley, as above
described. See figure 7, page 36.
About three-fourths of a mile below the falls at Cohoes the
Mohawk waters divide into several divergent streams which enter
the Hudson by as many channels, thus forming a group of rock
islands. These multiple mouths of the Mohawk are interpreted as
originally delta distributaries which became intrenched in the under-
lying weak rocks after the removal of the delta deposits from their
beds by erosion.
*Stoller. Glacial Geology of the Schenectady Quadrangle. N, Y,
State Mus, Bul. 154, p. U1,
1@) NEW YORK STATE MUSEUM
The Hoosic river, which has its sources on the western slopes of
the mountainous region of the New York-New England border,
enters the quadrangle in the northeastern quarter of the sheet and
flows in a meandering course westward and northward, discharging
into the Hudson at the head of the rock channel at Stillwater. The
river valley except for a short length west of Johnsonville, is every-
where bordered by deposits of sands and gravel. Westward from
Schaghticoke the river penetrates an immense mass of fine gravels
and coarse sands which clearly originated as a delta built by the
river into the body of waters that occupied the Hudson valley in
late glacial times. The delta formation is of the characteristic
triangular shape and at its base, fronting the Hudson valley, has a
breadth of about 7 miles. Its areal extent may be estimated at 20
square miles.
In its course through the delta the present river is flanked by a
series of terraces which rise at successively higher levels to the
general summit level of the Pleistocene clays of the Hudson valley.
A fuller description of the Hoosic delta, together with a discussion
of its development and that of the system of terraces, will be given
further on in this report.
A valley of exceptional interest from the standpoint of Pleisto-
cene history is that which enters the Hudson valley from the west
at Mechanicville. It is occupied by a small stream, Anthony kill,
which in its present size is quite out of proportion to the breadth
and depth of the valley. Anthony kill is the outlet of Round lake
(see map, p 46) which in turn receives the outlet stream of Balls-
ton lake, the latter lying at the bottom of a preglacial channel that
communicates with the valley of the Mohawk east of Schenectady.
There is quite conclusive evidence! that in late glacial times waters
from the flooded Mohawk river coursed through this system of
channels, discharging into the waters of the Hudson valley at
Mechanicville. At a later time the Mohawk became established in
its present course, and Anthony kill, draining the old channel as
far back as the divide at the head of Ballston lake, is the shrunken
remnant of the much larger stream through whose erosive work
the present relatively large valley was formed.
As in the case of the Mohawk river, Anthony kill, entering the
Hudson from the west, runs athwart the ancient rock valley of the
Hudson. From Willow Glen eastward the floor of the valley is
* Stoller. Op. cit. p. 29-31; Fairchild. Pleistocene Uplift of New York
and Adjacent Territory. Bul. Geol. Soc. of Amer., 27:251.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 1
rock with a slope to the east of 80 feet in a distance of 2 miles.
This is a part of the old valley floor, though now reduced by
erosion.
In somewhat sharp contrast to the system of valley depressions
thus far described are the uplands portions of the quadrangle. The
uplands, as here referred to, stood above the level of inundation by
the glacial waters and are clearly marked off from the area covered
by waters both in respect to topographic features and the materials
of which the soils are composed. The Pleistocene deposits filling
the valley depressions, although now trenched by the great river
courses and ravined by the minor streams, still represent, especially
where deltas have been developed, the general level of the body of
waters in which they were laid down. The uplands stand out in
marked relief above this level. This contrast is very striking in
the field when one stands at a point commanding a view of the two
topographic regions.
The surface of the uplands is in general highly irregular. This
is due primarily to the structure of the underlying rocks and to
the effects of differential erosion upon the rock surfaces in pre-
glacial times. The rocks are shales and sandstones of the Cambric
and Ordovicic series and possess the folded structure and altera-
tions due to metamorphism common to these rocks as they occur
in the Hudson valley region. The strike of the folds is in a general
north-south direction and this gives to many of the hills an elon-
gated form, with long axes trending north and south. Two of the
highest elevations, Rice mountain and Mount Rafinesque, in the
middle portion of the southern third of the quadrangle, are, how-
ever of irregular, massive form. The highest elevation of surface
is near the southeastern corner of the sheet where a ridge of
steeply inclined strata attains the height of 1265 feet.
The surface of the uplands bears evidence of considerable modifi-
cation by ice agencies. Many of the hills which show exposures of
rock have somewhat even and smoothed outlines indicating the
effects of abrasion by moving ice. In many cases the more
smoothed surfaces face north, indicating the wear of the rock on
the side from which the ice approached. In some instances low
hills of topographic form approaching that of drumlins are found
to be reduced rock hills, partly covered by glacial till. The group
of hills west of the Saratoga battlefield near the northern edge of
the sheet is of this character.
In general, the minor topographical aspects of the surface ot
the uplands are due to deposits of glacial origin, a description of
I2 NEW YORK STATE MUSEUM
which is given below. These deposits form a mantle everywhere
overlying bedrock, except where ridges and masses of rock pro-
trude through the covering. The relief is that of a region in the
mature stage of erosion but with irregularities of surface some-
what reduced by ice abrasion and by deposits of Pleistocene and
Recent Age.
The drainage of the uplands region is mainly through small .
streams that flow directly to the Hudson or to the tributary rivers,
named above. The streams that discharge into the Hudson show
interesting changes in the character of their valleys as they pass
from the uplands areas and cross the clay and sand formation. In
their upper courses the streams are adjusted to the slopes of the
surface and to underlying rock structure and they wind between the
hills in open valleys, but as they debouch upon the plain of the clay
and sand deposits their courses become more direct and their val-
leys narrower and deeper, forming ravines. It is probable that in
their upper courses the streams occupy mainly preglacial valleys
while obviously the ravines have been formed in postglacial times,
that is, since the withdrawal of the waters in which the clays and
sands were deposited.
The largest stream of the uplands region is Tomhannock creek,
which has its rise near the southeastern corner of the quadrangle
and flows northerly, emptying into the Hoosic river about 3 miles
from its mouth. In the upper and again in the middle part of its
course this stream follows broad depressions of surface which are
the beds of extinct lakes. In its lower course it penetrates the
Hoosic delta. A fuller statement of the steps of glacial history
recorded in these physiographic features is given later.
DESCRIPTION AND INTERPRETATION OF sii:
DEROSMS
Till or ground moraine. Till or rock debris derived from the
ice sheet, whether left from the bottom or deposited from the ice
at the time of melting, forms the mantle of materials overlying the
bedrock generally. In the uplands it constitutes the greater part
of the body of soils and subsoils but in the great valley depressions it
is covered by the lacustrine clays and sands, except where the latter
have been swept away by stream erosion. It includes all rock frag-
ments derived from the ice of whatever size, from boulders to grains
of sand and particles of clay.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE © 13
The boulders are nearly all of rock different from the underlying
country rock, showing that they were brought by the ice from
regions lying to the north. But the finer parts of the till include
many bits of the local rock and there is everywhere a noticeable
correspondence between the predominant mineral elements of the
till and those of the nearby exposures of the underlying rocks. As
the country rocks of the region are largely shales (slates), they
give to the soil a predominantly clayey character. It is in general
-well adapted to agricultural purposes.
The thickness of the till varies greatly in different parts of the
area. Near the summit of the main rock ridges and masses the
till sheet is generally thin and, as noted above, there are frequent
exposures of bare rock. In places these exposed rocks have under-
gone decomposition to a considerable extent, and the residual prod-
ucts, having fallen or having been washed from the slopes of the
rock surfaces, are added to the materials of the till.
In the valleys and depressions between the rock hills the till is
in general thicker than on the tops and sides of the hills. This
may be due in part to the valleys having been occupied by the ice
for a longer time than the hilltops or to a relatively greater amount
of till having been originally lodged in the valleys, but it is probably
also due to removal of till from the hills by washing. The occur-
rence of boulders resting on the exposed rock of the hills is evidence
of this, the finer materials of the till having been washed away.
In contrast with rock hills veneered by till are those hills which
are apparently made up wholly of till. Many of the low hills, and
some of larger proportions, are of this character. The most
noticeable one is that southeast of South Easton, marked by a
depression contour on its western slope. As far as could be deter-
mined by inspection, the materials of this hill are till and the depres-
sion is due to irregularity of heaping of the debris derived from
the ice. Another hill apparently composed wholly of till is that
north of Crandall Corners and crossed by the road. This is of the
type of a drumlin. An interesting drumlin is that which occurs on
the floor of the Hudson valley, east of the river and directly
opposite Bemis Heights. It stands as a conspicuous oval hill,
stréwn with cobbles and boulders, rising above the level of the
alluvial plain. It is evident that this hill was once covered with
lacustrine clays and that when the latter were swept away by
flooded stream erosion, the more resistant materials of the hill
remained,
14 NEW YORK STATE MUSEUM
Hills of Sand and Gravel. Kames. In the uplands region there
are a number of isolated groups of hills, composed mainly of sands
and gravel and presenting the characteristic features of kame topo-
graphy. Their locations are shown on the accompanying map. The
largest of these kame areas lies northward from the valley of the
eastern branch of Tomhannock creek and near the village of that
name. The surface of this area, made up of hills and hollows of
irregular shapes and without order of arrangement, is conspicuously
different from that of the surrounding country, the features of
which are largely controlled by the underlying rock surfaces. Many
of the hills have steep slopes and a degree of evenness of front that
indicates deposition of the sand and gravel materials against a
stationary mass of ice.
These groups of hills are interpreted as recessional moraines,
marking a temporary cessation of retreat of the general ice sheet at
the time of melting in the localities where the heaps of debris occur.
In the case of the moraine just described it seems probable that its
development was incident to the slower melting of the thick ice
that filled the preglacial valley now followed by the creek. There
is evidence that the moraine originally extended farther south
across the valley and that it has been reduced at its southern edge
by stream erosion, the finer materials having been carried by the
stream to glacial Lake Tomhannock, there building a delta, as
described below.
Ridges. Ina number of localities there were observed accumu-
lations of sand and gravel with admixture of clay and fragments
of slate rock having the general topographic form of ridges. In
some of them, as the one near Melrose and that north of Speigle-
town, the materials, as exposed in gravel pits, show a stratified
arrangement. The location of these ridges (see map) presents a
certain uniformity; that is, they are all located on the uplands but
within a short distance from the clay and sand deposits of the
Hudson valley. Their elevation above the latter varies from 20 to
60 feet. The direction of the ridges is in general parallel with that
of the edge of the valley deposits.
The inference drawn from these data is that these ridges repre-
sent deposits made marginal to the lobe of ice that occupied the
Hudson valley after the disappearance of the general ice sheet from
the uplands. A fuller statement of the evidence of the persistence
of an ice lobe in the Hudson valley long after the melting of the
icé from the uplands will be given later in this report. It is believed
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 15
that in places accumulations of materials from the melting of the
ice lobe at its margins gave rise to lateral morainic deposits, thus
forming these ridges.
Glacial lakes. In the middle eastern and southeastern rec-
tangular divisions of the Cohoes sheet there are two elongated
tracts conspicuous by their flatness as contrasted with the highly
irregular surface of the uplands country surrounding them. The
more northerly of these tracts, or intervales, extending from near
Raymertown northwesterly and having a length of about 5 miles
and an average breadth of about one-half of a mile, has ‘recently
been converted into a reservoir for the public water supply of the
city of Troy. This was accomplished by constructing a dam across
Tomhannock creek at the place where this stream, after following
in meandering course the length of the flattened area, entered a
gorge about I mile south of East Schaghticoke.
Lake Tomhannock. ‘There is quite conclusive evidence that this
area, now an artificial lake, was in early postglacial times a natural
lake. The stream that flows past the village of Tomhannock built
a delta in this postglacial lake which now shows quite perfectly as
a sand and gravel bench or terrace at the 400-foot level and border-
ing that arm of the artificial lake which extends northeasterly
toward Tomhannock. The materials of the terrace are well
exposed in road gradings and show horizontal stratification.
It is believed that this glacial lake (which may be named Lake
Tomhannock) originated through the gathering of waters in an
old stream valley across the course of which a dam was formed by
deposits from the ice sheet. This preglacial stream flowed north-
westerly from near Raymertown and then southwesterly toward
Melrose and the glacial dam was formed in the latter portion of
the stream course and near where at present the divide at the 400-
foot level occurs. For a time the waters of the glacial lake, held
back by the ice front, overflowed the dam and the lake had its out-
let in the stream that flows southwesterly past Melrose to the
Hudson river.
When the ice front had retreated as far north as the plain south
of East Schaghticoke, a lower outlet for Lake Tomhannock was
afforded in the line of its present course. The outflow stream thus
established degraded its bed and eventually the waters of the lake -
were drained off.
The other intervale, farther to the south, also marks an extinct
glacial lake. This tract continues southward on the Troy sheet and
16 NEW YORK STATE MUSEUM
this southern extension is drained by Quacken kill which joins
Poesten kill, the latter stream discharging into the Hudson river
at Troy. It is inferred that in preglacial times a stream heading
near Raymertown flowed southward, developing the valley which
now forms the intervale area and that at the close of the Ice Age
a barrier of glacial deposits was left across this valley at the place
where the divide now occurs, about 114 miles from the edge of the
sheet. Waters were ponded north of this barrier and this glacial
lake had its outlet in a stream that flowed past Raymertown and
emptied ‘into Lake Tomhannock. This outlet stream had a fall of
100 feet and, through downcutting, the lake was finally drained off.
The axis of drainage of the two glacial jakes thus led to the exten-
sion of Tomhannock creek southward to its present source.
A chain of small glacial lakes occupying depressions in the gen-
eral surface of the country developed in the region southwest of
Rice mountain beginning south of Haynersville. These were
eventually drained away by Deep kill, which has cut a deep gorge
on the eastern flank of the mountain. On the map two of these
areas have been designated as extinct lakes and the others as
swamps, the latter being partially covered with standing water.
Lake Hoosic. ‘There is quite good evidence that a temporary
glacial lake existed in that portion of the Hoosic valley crossed by
the eastern margin of the sheet. North of the river theresised
plain, traversed by Whiteside brook, the materials of which are
sand and fine gravel. They are distinctly stratified in arrange-
ment as shown in cuts along the Greenwich and Johnsonville Rail-
road. The general elevation of this plain is 420 feet. South of the
river in the neighborhood of Johnsonville the surface materials are
of sand and gravel character and in places rise to about the same
level as the plain opposite.
It is believed that these deposits represent a glacial lake, the
waters of which gathered behind a dam across the preglacial Hoosic
valley made by drift, or deposits from the ice sheet. About a mile
below Johnsonville till rises from the left bank of the river to the
440-foot level and on the opposite side there is a hill of till 420 feet
in elevation. The latter hill slopes toward the river, the stream
_ curving at its base. It is inferred that a mass of till of which these
hills are remnants originally extended across the valley forming a
dam behind which the waters were held in check, converting this
portion of the valley into a temporary lake.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 17
aD eA MEDAN DE POSMS
The body of glacial waters in which the stratified clays of the
upper Hudson valley were deposited was named by Woodworth
Lake Albany. He limited the extent of Lake Albany to the waters
represented by the deposits extending from near Rhinebeck on the
south to the Fort Edward district on the north* (north of the Cohoes
quadrangle). In his view, the gathering of the waters of Lake
Albany was pari passu with the melting of the ice sheet in its retreat
northward in the middle Hudson valley.
Another view is that the deposits are estuarine, having been laid
down in the sea-level waters which extended as an inlet up the
Hudson valley from the ocean at New York.?
Fairchild has stated the conclusion that the body of waters in
which the Hudson valley clays and sands were deposited was at
sea level and at its highest development formed a strait connecting
the oceanic waters which then occupied the St Lawrence valley
with the ocean at New York. “As the ice front melted back the
ocean followed it and flooded the valley. The waters were at first
the Hudson inlet; later, the Hudson-Champlain inlet; and finally,
the Hudson-Champlain strait.’*
In this report we shall refer to the waters as Lake Albany,
though without implication as to the correctness of the first men-
tioned of the above interpretations. We shall, however, below call
attention to certain facts of topography which seem to afford clear
proof that the body of waters in question subsided (that is,
dwindled to a river) while drainage from the great interior lakes
(Algonquin-Iroquois stage) was still through the Mohawk valley.
The inference is that Lake Albany disappeared prior to the opening
of the St Lawrence channel (as due to ice melting) ; that is to say,
prior to the invasion of marine waters in the St Lawrence basin.
The writer would also state that in this report the term “ sub-
sidence ” is used as pertaining to the fact of the withdrawal of the
Lake Albany waters but without implication as to whether the
*Ancient Water Levels. N. Y. State Mus. Bul. 84, p. 177 and 242, 1905.
?Merrill, Quaternary ‘Geology of the MHudson River Valley. oth
Annual Rep’t of the State Geol, 1890. Peet, Glacial and Postglacial
History of the Hudson and Champlain Valleys. Journal of Geol., 12:640.
1904. This author considers two alternation hypotheses: (1) the water
body was a lake made by.a barrier at the south, (2) the water body
was an arm of the sea.
* Fairchild. Ann. Rep’t of N. Y. State Geol. 1912, p. 24.
18 NEW YORK STATE MUSEUM
cause of the subsidence was the removal of a barrier at the south
which held in the waters or to regional uplift.
The Lake Albany deposits comprise (1) the mass of stratified
clays and sands whose surface forms the terraced slopes of the
Hudson valley and (2) the sands and gravels of the Hoosic delta.
The clay and sand formation, as already stated, forms the filling
of the ancient rock valley of the Hudson. The lower beds of the
formation consist predominantly of clay and are the source of the
well-known brick clays of the upper Hudson region. As seen in
the pits at the brick-making plants, the clays are fine grained,
evenly laminated and of a bluish color below passing to yellowish
above. As exposed in mass at the slopes fronting the river valley
or along the ravines, the weathered surfaces are of a buff or
yellowish color. The compact clays make up perhaps the lower
100 feet of the formation, above which they grade into sand, clays
or clayey sands. The latter, in certain localities (as 1 mile south-
west of Mechanicville) have the composition requisite for mold-
ing sands.
Farther back from the river the materials of the Lake Albany-
deposits are coarser and consist more largely of sands. In places,
however, the clay constituent still predominates and there are
tracts of considerable extent at or near the 300-foot level, as west
of Melrose, where the lands are of clayey character.
The surface of the clay and sand formations is marked by strik-
ing topographic features. These are (1) the terraces of which an
upper and a lower are distinguished and (2) the ravines which
cross the terraces, dividing them, especially the lower one, into
segments.
The upper terrace is less well defined than the lower. In places
(as west of Cohoes and southwest of Mechanicville) it appears as
a nearly level expanse, one-half of a mile or more in breadth,
bordered at its outward side by a slope toward the uplands and at
its side toward the river by a more gradual slope to the level of the
lower terrace. This description applies generally also to the upper
terrace on the east side of the valley as it appears north of Crandall
Corners and northwest of Melrose. In other places (as west of
Stillwater) the upper terrace is less perfectly expressed, being
narrower and with surface falling toward the river. In places,
also, as at the Saratoga battlefield, the level of the terrace is broken
by hills of till (or till-covered rock hills) which rise above the
lacustrine deposits. East of Lansingburg the upper terrace (as also
the lower) disappears as a distinct form feature, the steep rock
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE £9
wall of the valley here controlling the topography. These modifi-
cations of the terrace form (apart from the effects of underlying
rock features) are clearly due in part to postglacial erosion but
probably in larger part to the conditions under which the materials
were laid down.
EVO FOR vii Ot Sih UPPER) TERRACE
It 1s believed that the sands and clays of the upper terrace were
in large part laid down at that stage of the melting of the ice when
the uplands had been bared, while a broad lobe of ice still lingered
in the Hudson valley. In the lateral depressions, between the
central mass of ice and the bared slopes of the valley, waters
gathered and flowed southward discharging into the open lake
waters along the dwindling southern limit of the ice lobe. These
currents bore sediments partly derived from the debris of the
melting ice and partly received from the tributary streams draining »
the bordering uplands. The finer parts of these sediments were
deposited mainly where the currents were checked by the quiet
waters of the lower end of the marginal channel, or embayment
between the ice lobe and the shore of the lake. The coarser
materials were deposited in the bed of the channels. Also as the
latter shifted in position, due to the shrinking of the lobe of ice,
the deposits were made progressively farther inward from shore.
In this way the accumulations acquired the form of a shoal plat-
form with face sloping toward the middle of the lake. With the
subsidence of the lake waters, at a later time, the shoal became a
terrace of similar slope. (See fig. 3, page 22.) At times bodies of
comparatively static waters were held in portions of the lateral
depressions conforming to topographic features of the adjoining
slopes and to irregularities of the ice border. When tributary
streams from the uplands discharged into’ these quiet waters
. deposition took place, forming deltas. With the subsidence of the
waters, at a later time, these deltas emerged as terraces of more even
and level surfaces than those described in the preceding paragraph.
It is believed that an example of a terrace form developed in this
way is the flat area northwest of Melrose at the 300-foot level at
its outer border.
On the north side of the Mohawk river and both north and south
of Anthony kill the plain of the upper terrace becomes continuous
with that of Lake Albany deposits bordering these streams and
extending westward to the general sand plain region of the Schenec-
20 NEW YORK STATE MUSEUM
tady quadrangle. The terrace surface, in these westward exten-
sions, Shows a gradual increase in elevation.
The general or average elevation of the upper terrace may be
stated as 300 feet. For the most part the 300-foot contour line of
the sheet marks the outer border of the terrace plain, although, in
places, the lacustrine deposits rise to a higher level. As a rule no
definite line of contact of the clays and sands with the till of the
uplands can be observed in the field, and in mapping this boundary
has been drawn somewhat arbitrarily. As pointed out by Fair-
child, the summit level of the body of glacial waters was often
higher than the plain of the deposits built into it. In the Lake
Albany waters the deltas formed at the mouths of the larger
streams, now represented by extensive sand plains, as that south
of Schenectady (Mohawk delta), north of Ballston (Hudson delta)
and that of the Hoosic delta, described below, probably indicate
closely the height of the lake waters. (Present differences in ele-
vation are to be accounted for by postglacial deformation.)? But
the deposits made in Lake Albany, other than the great deltas,
were not usually built up to water level. Thus the plain of the
Hoosic delta near its head, as in the broad expanse northwest of
Schaghticoke, stands 340 to 360 feet elevation, while the upper
terrace which extends northward from the delta has an elevation
of 320 feet. This difference is interpreted as due to a less amount
of deposition taking place in the marginal channels, in the early
stages of the development of the lake, as above described, than at
the mouth of the large rivers, at the later stage when the deltas
were built. Also differences in elevation of the upper terrace in
different localities are understood as due primarily to differences
in amount of sedimentation. .
The lower terrace is a quite definite topographic feature. On the
west side of the river it is continuous from the northern to the
southern margin of the sheet, except as broken by the numerous
ravines that cross it and where, in the localities of Mechanicville
and Waterford, broad stretches of the terrace were swept away by
the flooded Mohawk waters of late glacial times. On the east side
of the river the terrace shows as a distinct form feature except
where interrupted by the Hoosic delta and by the steep rock wall
of the valley at Lansingburgh. The terrace is best developed in
the middle part of the sheet where it attains a breadth on each
* Bul. Geol. Soc. of Amer., 27 :230.
*Stoller. Glacial Geology of the Saratoga Quadrangle. N. Y. State
Mus. Bul. 183.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 21
side of the valley,of a mile or more. These terrace plains form
evident and striking features of the landscape. In the field, to the
observer looking north and south and ignoring the depressions of
the gullies, the terrace surface appears as one level expanse; or,
looking across the valley, as a bench broken by the ravines and
with the upper terrace slope and plain and the rising hills of the
uplands in the background.
DEVELOPMENT Ob THE LOWER TERRACE
_ The conditions under which the lower terrace was developed are
believed to be as follows: With the disappearance, through melt-
ing, of the ice lobe from the Hudson valley, the middle portion of
the valley became the seat of sedimentation. It had already
received debris derived from the melting of the ice lobe, together
with some accessions of finer sediments borne by the currents flow-
ing in the marginal channels and checked by the quiet waters of
the embayments lateral to the terminal portion of the ice lobe. The
conditions of an established body of lake waters now permitted
deposition from the currents normal to the lake. As the outlet of
the lake was at its southern end, we may assume constant south-
ward flowing midlake currents. These currents, moving in a body
of water of considerable magnitude, were of low velocity and car-
ried only fine sediments. Under the fluctuations incident to varying
seasonal, climatic and other physical factors, deposition of these
sediments took place and thus layers of silts and fine sands were
laid down on the floor of the middle portion of the lake.
At length came the time of the subsidence of the Lake Albany
waters. At the first stage of subsidence the lateral portions of the
lake bottom had emerged as land surface, forming the upper ter-
races, above described. The erosion of the surfaces of these ter-
races immediately began and many small streams, heading in the
uplands, extended their courses across the terraces and discharged
into the shrunken lake. The sediments brought by these streams
to the lake were distributed over the same area of the lake floor
that had received deposits from the midlake currents. From these
two sources were derived the silts now forming the clays of the
lower terrace. The emergence of these deposits, thus giving rise
to the present terrace, was due to a further subsidence of the Lake
Albany waters.
The accompanying diagrams are believed to represent the suc-
cessive steps in the development of the upper and lower terraces.
ending with the production of the present features of the valley.
22 NEW YORK STATE MUSEUM
REDROCK SAND WITH aay CLAY
LYING TIL
Fig. 3 Diagrams showing the conditions of deposition of the sands and
clays of the Hudson valley ‘and the development of the terraces
No. 1 shows the ice lobe occupying the inner preglacial valley of the
Hudson and the waters (embayments of Lake Albany) filling the depressions
hetween the lateral margins of the ice lobe and the rim of “the outer valley.
Deposits made in these waters were largely of sands. No. 2 shows the
shrunken ice lobe and the consequent broader embayments. Depositions of
finer sediments, mainly clays, were made in the deeper and more quiet waters.
No. 3 shows the conditions when Lake Albany was at the height of its
development. In the quiet mid-waters of the lake abundant clay sediments
were deposited. No. 4 shows conditions at the end of the first stage of
marked subsidence of the lake waters. The outer portions of the lake
bottom have emerged forming the present upper terrace. No. 5 shows the
conditions after the second stage of marked subsidence. The lower terrace
has emerged. No. 6 shows the deposits in their present relations and the
present topographical features of the valley.
GLACIAL GEOLOGX OF THE COHOES QUADRANGLE 23
The Hoosic delta. The Hoosic delta, like the other deltas
built by large streams which discharged their sediments into Lake
Albany, in its present surface features bears the character of a
sand plain. The continuity of the plain is broken, however, by the
valley of the present river which has sunk its bed deeply into the
sands and, through meandering, swept away a broad path through
the delta. The marginal limits of the delta plain are indicated
partly by differences in the topographic features of the delta, as
contrasted with the terraced deposits above described, and partly
by differences in the character of the materials of the two forma-
tions. ‘In general, the delta materials as seen at the surface are
coarser and less coherent than those of the terraced areas, the
proportion of sands and fine gravels being much larger.
The shape of the delta is that characteristic of this type of con-
structional formation. The materials are spread out fanlike from
the original head of the delta or place where the river debouched
into the lake. This may be taken as at Schaghticoke. The outward
margin of the delta mass, fronting the Hudson valley, is somewhat
of the form of an arc but this has been considerably modified by
river erosion. The Hudson currents, deflected eastward from
Bemis Heights, have cut deeply into the northward extension of
the delta border. Also, at an earlier time, the Iroquois-Mohawk
currents which followed the present course of Anthony kill, sweep-
ing across the subsiding waters of Lake Albany, cut deeply into the
marginal lobe of the delta at Reynolds forming the upper and
lower erosion terraces to be described below. (Further reference
to this stage of Pleistocene history will be given below.)
The surface of the delta plain varies much as to composition of
materials and minor topographic features. The soils are for the
most part too deficient in clay constituents to be valuable for agri-
culture. Considerable areas are left uncultivated and there are
tracts of coarse sands where wild vegetation is scanty. The lack
of coherence of the soil particles has resulted in extensive gullying
of the surface over considerable areas. In the region east of
Reynolds the plain is deeply dissected by many ravines producing
the irregularities of surface indicated by the contour lines of the
sheet.
The above description applies to the surface materials and
features of the delta where the plain has not been reduced by river
24 NEW YORK STATE MUSEUM
erosion. Where the Hoosic river has cut deep into the delta, form-
ing a succession of terraces on either side of the valley, thus expos-
ing the materials of the delta at different levels and at varying dis-
tances from the head of the delta at Schaghticoke, they differ con-
siderably from the materials of the surface of the plain. In gen-
eral, the terraces of the lower levels are of mixed clay and sand
composition, forming soils which are well adapted for farming and
gardening. For instance, the extensive flat at the 100-foot level
crossed by the road running northeasterly from Reynolds is com-
posed of fine-grained soils of high fertility. The materials of the
terrace plain on the opposite side of the river, beyond the alluvial
flat and rising to the 140-foot level, are also finely divided and
include a considerable proportion of clay in their composition.
The fine sands and clays, lying at the base of the delta deposits
and far out from the head of the delta, are interpreted as the
bottom-set beds of the formation. They were laid down at an
early stage in the building up of the delta, representing the finer
sediments borne by the Hoosic river and dropped where the cur-
rents were checked by the quiet waters of the body of the lake.
The materials of the higher terraces become progressively
coarser in order of elevation and of nearness to the head cf the
delta. This is well shown to the observer who follows the road
south of the river, beginning where the road crosses Tomhannock
creek and continuing eastward and southward to the 360-foot level
of the delta plain beyond where the highway crosses the railroad.
360 ft
== 310.0 tia
= 200 “
——— O10
Fig. 4 Profile of terraces in delta of Hoosic river. The terraces south
of the river are shown on a line extending from the delta plain west of
East Schaghticoke to the Hocsic river at the mouth of the Tomhannock
creek; the terraces north of the river on a line extending from the latter
point northeasterly to the delta plain northwest of Schaghticoke. See lines
on map.
Thus the materials of the successive terrace plains were noted as
follows: 140-foot terrace, sandy loam; 180-foot terrace, coarse
sandy or loamy soil; 220-foot terrace, fine to coarse gravel; 320-
foot terrace, gravel, largely uncultivated; 360-foot level (south of
railroad), sand and fine gravel. The materials of the terrace plains
on the opposite side of the river are predominantly sand and gravel,
although the extensive plain at the 340-foot level has a considerable
admixture of clay. To the east of the ravine, however, this plain
gradually merges into an area of blown sands,
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 25
The coarse sands and gravels making up the middle layers of
the delta formation and rising well toward its stirface are inter-
preted as the fore-set beds. They are the coarser sediments which
were deposited at first at the head of the delta and then successively
added to, thus building up the delta progressively toward the body
of the lake.
A section of the lower and middle beds of the delta, together
with the underlying till, is shown on the right bank of the river
about 1 mile below the gorge west of Schaghticoke. At the base
there is a thickness of about 40 feet of materials of bluish color,
mixed composition, including boulders, and without evident strati-
fication. Above this and somewhat sharply defined from it, though
without evident unconformity, are beds of yellow sands with
approximately horizontal stratification, as seen in this section.
There is an exposure of perhaps 30 feet of these sands as seen in
nearly vertical section, and at a higher level the sands are con-
tinued on a sloping surface.
The elevation of the highest terrace plain of the delta is about
360 feet. The extensive plain northwest of Schaghticoke, bisected
by the ravine, is 340 feet at its inner margin and rises to 360 feet
at its outer margin. Southwest of Schaghticoke there is a narrow
but distinct plain (crossed by the road to Schaghticoke hill) which
is at 360 feet elevation. It is believed that these plains represent
the level of the waters of Lake Albany. The former has an areal
extent of several square miles and it is scarcely open to question
that its materials were laid down below or at the level of the lake
waters. It evidently consists of the top-set beds of the delta which
were spread out horizontally over the fore-set beds. It will be
noted that this elevation is considerably above that of the general
or average elevation of the upper terrace of the body of deposits
in the lake north and south of the area of the delta.
We have now to consider the sand and gravel deposits which
border the Hoosic valley for several miles eastward from Schaghti-
coke. At East Schaghticoke these deposits are 380 feet in eleva-
tion and the village of Valley Falls, one and one-half miles to the
east, is built on a river terrace of the same elevation. Also on the
north side of the river and farther to the east there is a distinct
terrace of sand and fine gravel. This terrace is sharply distinguish-
able, both in regard to materials of composition and topographic
form from the hill of till adjoining it to the east and which formed
a part of the dam of glacial debris behind which were ponded
the waters which formed the glacial lake north of Johnsonville.
26 NEW YORK STATE MUSEUM
These deposits are interpreted as a valleyward extension of the
delta and as representing that portion of the delta which was built
up above the level of the general delta platform of the lake. This
principle of delta growth has been stated as follows: “At the
same time the channel of the stream above the original head of the
delta is aggraded, for the current there is checked by the aggrada-
tion of the delta. Thus alluvial deposits continuous with the delta
are extended landward.”?
IDS VIDIO WOSING (Oe Wists. IslOOSWIC Wi SIKUAVCIE S
The river had built into Lake Albany a great delta, the plain
of which had been raised above the level of the water at the head
of the delta, near Schaghticoke, and stood very slightly below the
water level for a considerable distance outward from the head.
When at length Lake Albany began to subside this portion of the
delta plain, covered by shallow water, emerged as land surface.
During the emergence the river maintained its channel across the
added area but as the extent of the level or slightly sloping surface
increased, the stream was gradually thrown into a winding course
and eventually broad meanders were developed. The continued
degradation of the bed of the river resulted in lowering the level
of the plain within the belt of meandering. In the shifting of the
channel of the stream from side to side terraces were left at the
outer limit of each meander. These terraces were formed at suc-
cessively lower levels according to the level of the lowering plain
at each successive swing of the river.
The subsidence of Lake Albany by stages, bringing to the sur-
face at different times added areas of the delta surface, was
undoubtedly an important factor in the development of the terraces.
It is possible that the slopes bounding some of the terraces repre-
sent in fact abandoned shore lines of the lake. The terrace on the
north side of the river at the 280-foot level at its inner margin and
bounded at its outer margin by the slope that separates it from the
340-foot level of the delta plain lends itself to this explanation. The
contour lines that mark the 20 feet of slope trend abruptly to the
northeast and can scarcely be interpreted as indicating the limit of
a meander. The writer has not found it possible, however, on the
basis of topographic evidence, to differentiate between the effects
to be immediately connected with subsidence and those due to
erosion and meandering as described above.
_*Chamberlin and Salisbury. Geology, 1:189.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 27
Fig. 5 Diagram showing terraces in delta of Hcosic river
EROSION TERRACES
Near Mechanicville on either side of the Hudson valley there
is a well-defined terrace at the 200-foot level. These terraces are
quite certainly of different origin from the other terraces bordering
the valley and described above as the upper and lower terraces
of the Lake Albany deposits. The terrace west of the river (south-
west of Mechanicville) stands 40 feet below the lower lake terrace
and is separated from the latter by a steep slope. It was evidently
formed by the cutting down of the inner portion of the area of the
lake terrace. The terrace on the east side of the river is likewise
evidently a terrace of erosion having been carved out of the Hoosic
delta deposits.
It is evident that the currents which formed these symmetrical
erosion terraces issued from the valley now followed by Anthony
kill. The west terrace has the location and trend of outlines which
would result from erosion by a western tributary river occupying
28 NEW YORK STATE MUSEUM
this valley and discharging into waters flowing southward in the
udson valley. The east terrace likewise has the location and
form relations which would result from currents from the same
tributary river sweeping across the Hudson valley waters and
impinging against a frontal lobe of the delta mass.
o oO ©
ge ae . :
S ees es - =
a om) + (Be » a
a= Arenson S = uo
\ ome oO oe) ne) a,
O CG o a mn
Qu s fe) O oO ie)
5 rs)
am fe) S S
i SY teh ae J |
300ft— | |
200 i5—=
100 a
Fig. 6 Surface profile across the Hudson valley at Mechanicville showing
the symmetrical erosion’ terraces. Horizontal scale and relief scale cor-
respond to those of topographic sheet. The line on which the profile is
drawn is shown on the map.
These terraces are therefore interpreted as follows: When the
waters of Lake Albany had so far subsided as to bring to the
surface the deposits which now form the lower, or brick-clay, ter-
. race of the Hudson valley, the Iroquois-Mohawk ‘waters still dis-
charged into the lake through the northern (Anthony kill) channel.
In the progress of the subsidence the river currents, shifting east-
ward, cut down the inner portion of the clay terrace at Mechanic-
ville and, due to the deflection of the Iroquois-Mohawk currents,
southward through confluence with the southward-flowing lake
currents, the area of reduced clay surface developed southeasterly.
This process of erosion was brought to an end by a renewed and
more rapid subsidence of the lake waters, thus causing the eroded
area to emerge as land surface and forming the present terrace.
This terrace and the corresponding one on the opposite side
of the valley are therefore features due to the destructive (degrad-
ing) work of river currents in contrast with the clay terraces which
were built up through the deposition of sediments in Lake Albany.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 29
In both cases, however, the marginal slope, de‘ermining the front
of the terrace, is due to downcutting by currents shifted from a
broader to a narrower range of erosion consequent upon the sub-
sidence of the Lake Albany waters.
The downcutting which attended the renewed subsidence of the
lake waters is definitely recorded in the steep slopes which bound
the erosion terraces at their inner margins. As shown by the
contour lines of the sheet the slope, or bluff, of the west terrace
(facing the flattened area on which Mechanicville is built) is 60
feet in height and the bluff of the east terrace (extending northwest-
erly from Reynolds) is 80 feet. The trend of the lines of these bluffs
is quite evidently such as would be caused by currents issuing from
the Anthony kill channel. And these currents must have been of
considerable power, seeing that their force was not spent in their
diagonal course across the lake waters. It is therefore inferred
that the Iroquois-Mohawk was still discharging into Lake Albany
at Mechanicville when the waters of the lake had subsided to
the level of the eroded area at the foot of the bluff west of
Mechanicville. The eroded area just referred to has the physio-
graphic form of a terrace normal to the river at the present level ©
of its channel. The corresponding terrace on the east side of the
river is the level tract extending toward the river from the foot of
the bluff running northwesterly from Reynolds. These symmetrical
terraces may be designated the lower erosion terraces in contra-
distinction to the upper erosion terraces described above.
EVIDENCE (BEARING ON POSTGLACIAL HISTORY OF
EDSON CEAVIPO AN VALE
These topographic features, due to erosion by the Iroquois-
Mohawk currents, afford a datum for determining the time ot
subsidence of Lake Albany with reference to the location of the
front of the ice sheet in its retreat from the Hudson and Cham-
plain valleys. The outlet of the interior glacial lakes (Algonquin-
Iroquois stage) continued through the Mohawk valley until such
time as the receding ice front opened an outlet along the northward
slope of the Adirondacks. It follows that the subsidence of Lake
Albany had proceeded to the extent that its waters had lowered
from the 360-foot level (that of the Hoosic delta) to the 100-foot
level (that of the lower erosion terraces at Mechanicville) within
the period of time the ice front was in process of retreat to the
northern end of the Champlain region. For during the continuance
30 NEW YORK STATE MUSEUM
of the Iroquois-Mohawk outlet its currents lowered their bed in the
Lake Albany deposits pari passu with the subsidence of the lake
waters from the surface of the deposits to the level of 100 feet.
There is no evidence that the waters of the Hudson valley, after
their subsidence to the level indicated by the eroded area at Mechan-
icville, rose again to a higher level. The present major topographic
features of the valley (the terraces and their slopes) have certainly
not been modified by overflowing waters since their origin. If
therefore a water connection existed between the Champlain arm
of the sea and the ocean at New York, this strait had a breadth at
Mechanicville not greater than approximately the space between
the 100-foot contour lines on the opposite sides of the valley; that
is a breadth not greater than that of the present valley bottom.
These deductions, drawn from the facts of topography, are
opposed to the conception of a body of marine waters filling the
Hudson valley to a height indicated by the river deltas and con-
tinuous with marine waters in the Champlain depression.
If we suppose that the Hudson valley waters in which the sands
and clays were deposited were estuarine, opening into the sea at
New York, then that portion of the estuary included in the area
of the Cohoes quadrangle had become changed to a fresh-water
river while yet the St Lawrence basin was filled with ice. We are
thus led to conclude that at no time was there a continuous body
of marine waters connecting the St Lawrence arm of the sea with
the ocean at New York.
Clays, sands and gravels on the floor of the Hudson valley.
The materials of the floor of the Hudson valley are varied in char-
acter and over considerable extents of the surface are not readily
resolvable into areas of distribution according to their composition
and origin. This complexity is due to the varied factors that have
determined deposition of materials and their subsequent degrada-
tion during the successive stages of Pleistocene history.
The strong currents which through downcutting brought into
relief the clay bluffs bordering the valley floor did not sweep away
all the deposits laid down on the middle portion of the basin of
Lake Albany. In places, therefore, the soil is made up largely ot
clays representing original lacustrine deposits. Where these clays
thin out or where they have been largely removed by erosion,
glacial till appears, often with boulders at the surface. Where the
erosion has gone on to the extent that the till has been removed,
areas of bare rocks, or rocks covered with postglacial residual
soils, occur.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 31
At the base of the clay bluffs and in places extending well out
toward the middle line of the valley there are low heaps or sloping
banks of mixed clays and sands that have been washed down or
have slidden in loosened masses from the slope. At a number of
places there are evidences that landslides of considerable propor-
tions have occurred. Thus on the left bank of the river above
Stillwater, near the Washington-Rensselaer county boundary lines,
the broken slope and partially detached masses of the clayey
materials are quite evidently the result of landslides. Also 2 miles
north of Waterford there is a conspicuous sloping bank, marked by
the curve of the Champlain canal, which is believed to represent a
landslide. The conditions and factors determining the occurrence
of landslides of the Hudson valley clays have been carefully studied
by Newland.*
It is quite probable that a considerable proportion of the fine-
grained materials of the soils of the valley floor have been derived
as silts washed from the numerous ravines that open into the val-
ley. There are, however, no well-formed alluvial fans fron’ing
_ the mouths of the ravines. In explanation of this it is to be remem-
bered that the development of the ravines began as soon as the
terraces emerged from the Lake Albany waters and that the sedi-
ments washed from the ravines were for a long time spread out
on the bed of the lake when its shore line corresponded with the
present bluffs of the lower terrace.
There occur here and there on the valley floor deposits of gravels ;
that is, rounded pebbles and cobbles, usually mingled with coarse-
grained sands. Some of these occurrences admit of ready explana-
tion. For instance, on the eroded tract crossed by the road that
runs southwesterly from Reynolds the gravels, forming much ot
the soil of the fields, have evidently been derived from the materials
of the Hoosic delta. The currents which reduced this portion of
the front of the delta mass left behind the coarser parts which
were too heavy to be transported.
There are frequent occurrences of masses of gravel in which
there is a stratified arrangement of the materials. Immediately
north of Waterford, in the angle between the canal and the highway,
there is a conspicuous gravel bank in which the following features
of composition and structure were noted: (1) Layers of coarse
gravel mixed with dark sand 3 to 15 feet thick and Io to 15 feet
Newland. Landslides in Unconsolidated Sediments. 12th Rep’t of
the Director of the State Mus., p. 79. 1916.
Re NEW YORK STATE MUSEUM
in length; these layers mostly dipping to south. (2) Layers of dark
sand mixed with pebbles and worn fragments of shale rock 3 to 10
feet thick. (3) Thinner layers of stratified yellow sands a few
inches to 3 or 4 feet thick.
A gravel pit and slope showing a thickness of about 40 feet
occurs along the road that crosses the eroded area northwest of
Waterford near where the small stream crosses the road. This is
apparently an exposure of the same gravel mass described in the
preceding paragraph. Also on the northern part of Peobles island,
south of Waterford, sand and gravel are obtained from deposits
which apparently fill depressions of the rock surface. The materials
show a stratified arrangement and consist of water-worn fragments
of rock, ranging from the size of pebbles to cobbles, with irregularly _
-interstratified layers and lenses of coarse sand, mingled with worn
fragments of local rock.
These bodies of gravel are interpreted as representing kames,
or morainic accumulations formed at the ice front in the retreat
of the ice lobe which occupied the general valley of the Hudson
after the melting of the ice from the uplands. As lacustrine condi- |
tions supervened these ice deposits were covered over with the
clay sediments but in the localities mentioned, as elsewhere on the
floor of the Hudson, they have been stripped of the clays and more
or less reduced by stream erosion.
An interesting occurrence of gravels is that found on Green
island and on the east side of the river, south of Lansingburg.
Here the surface materials are limited to a thin layer of coarse
sand and fine gravel immediately overlying bedrock. The thick-
ness of this deposit, as observed, is nowhere in excess of 3 or 4
feet and in places it thins out to a few inches: The deposit lies
unconformably on the rock surface, filling and smoothing over
depressions in the rock. These sands and fine gravels are inter-
preted as outwash deposits from the morainic accumulations to the
north and referred to in the preceding paragraphs.
The Willow Glen gravel bank. At Willow Glen the north
slope of the valley now followed by Anthony kill presents an
exposure of a thick mass of sand and gravel. The materials are
utilized for building purposes and a spur of the railroad extends
to the bank. The general composition and structural features are
similar to those of the sand and gravel bank at North Albany. In
general, the entire mass shows irregular stratification: layers of
coarse gravels intermixed with coarse sands are clearly marked off
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 33
from layers of less coarse compesition. Some of the layers are
of dark color, due mainly to water-worn fragments of the local
rock. At the base of the bed there are cobbles and boulders that
have been separated from the sands in the work of excavation.
It is believed that these deposits are morainic in character and
were laid down under conditions of standing water. They evidently
occupy a preglacial depression and the retreating ice front may
have halted or entered upon a phase of slow recession at this place.
At the same time waters gathered in the depression and the
materials derived from the melting ice were partially sorted as they
were laid down.
This formation of sands and gravels, and others of similar com-
position and structure as they occur in the Hudson valley where
lacustrine conditions immediately supervened upon the withdrawal
of the ice sheet, may be designated as subaqueous recessional
moraines.
Residual clays of postglacial age. The Mohawk waters which
coursed through the Anthony kill channel swept from their path
the Lake Albany deposits and laid bare the underlying rock. Much
of this rock surface thus exposed to weathering is now covered
with residual clay soils. In general, the floor of the valley from
Willow Glen eastward to the river (except where bare rock is now
exposed) is mantled with a thin layer of rock detritus soils of post-
glacial age. They are well shown in cuttings made in grading the
macadamized road, and the transition from the fine-grained surface
soil to the slightly altered rock below is readily noticeable. The
depth of the soil, as observed, varies from a few inches to several
feet. The park area of the city of Mechanicville is composed of
this residual clay soil with some additions of materials from the
lacustrine clays and sands that have been washed down from the
slope bounding the erosion terrace.
When the Mohawk river became established in its present course
(the Aqueduct-Cohoes channel) its flooded waters likewise swept
away a broad path through the Lake Albany deposits. In this way
was formed the broad depression extending southeastward from
Crescent to the islands at the mouth of the Mohawk. The greater
portion of the floor of this depression lies east of the present course
of the river and is marked by striking irregularities of surface.
The larger features are clearly due to the effects of weathering and
stream erosion, mainly in preglacial times, of steeply tilted rocks
composed of unequally resistant strata. The topography of this
34 NEW YORK STATE MUSEUM
area is therefore essentially preglacial and represents, in fact, a
portion of the ancient rock valley of the Hudson stripped of its
Pleistocene covering and somewhat modified by postglacial erosion
and weathering.
The same area shows in its minor surface features the action of
strong currents laden with fragments of hard rock as cutting tools.
There are numerous depressions marking ancient potholes, now
partially or wholly filled with the residual clays. Some of these are
exposed where the clay is thin or has been removed; for example,
on the left bank of the river near the falls.*
The surface materials of this area consist mainly of residual
clays derived from the underlying shale (or slate) rocks. The
section of the state barge canal which extends from Waterford
to the Mohawk, at a point about 1 mile above Cohoes falls, crosses
this area and is everywhere cut in bedrock. The layer of residual
soil overlying rock is thus clearly exposed. Along the gorge of
the Mohawk the weathered rock surface, forming a dark-colored
clay soil, is also well shown. ‘The thickness of the clay mantle is
nowhere great, varying from a few inches to perhaps 5 or 6 feet.
These clays have certainly originated as the products of rock-
weathering since the end of the epoch of flooded Mohawk waters.
While the covering of this area consists predominantly of residual
clays, there occur in places materials of the glacial till which escaped
removal by flood erosion. These are scattered boulders and cob-
bles; also, in places, especially in the eastern portion of the area,
some of the less coarse materials of the till still persist in the covy-
ering of the bedrock.
Areas of residual clays also occur on the floor of the Hudson
valley.. The largest of these forms a broad tract lying west of the
curve of the river between Bemis Heights and Stillwater and
extending in narrower development southward to near Mechanic-
ville. This area includes many patches of outcropping or thinly ~
covered rock, the distribution of which corresponds in general with
the highest parts of the surface. In that portion of the area which
lies east of the abandoned canal (which follows a line of drainage
depression) the parts of highest elevation are shown by the looped
contours marking the 1oo-fcct level. But west of the road that
runs northerly from Stillwater there is an elongated hill of rock
with thin covering of detritus which is 160 feet in elevation. There
*For a full description of these potholes with measurements, see paper
by G. K. Gilbert (Deposition of the Mastodon at Cohoes), N. Y. State
Cabinet Nat. Hist., 21st Annual Report, 1871. p. 129-48.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 35
is a depression of surface between this hill and the clay bluff which
bounds the lower lacustrine terrace.
The interpretation placed upon these features is as follows: In
the course of the lowering of the Lake Albany waters to the level
marked by the base of the bluff fronting the lower terrace, the
character of this body of waters had gradually become changed
from lacustrine to fluviatile. Strong currents from the north flowed
in the channel formed by the shrunken bed of the lake. At Bemis
Heights these currents sweep southwestward along the clay bluff;
subsequently the line of strongest currents shifted easterly, denuding
the broad tract now covered with residual soils, and finally occupy-
ing the present channel of the Hudson.
In a number of places farther to the south there is like evidence
of the erosive work of strong currents which flowed over the floor
of the Hudson valley. The rock surfaces thus laid bare. are now
covered mainly by residual clays. The attempt has been made to
map these areas, but in some places there are no clear delimitations
and the boundaries as shown on the map are to be taken as
approximate.
Areas of bared rocks. The areas of exposed rock surface on
the floor of the Hudson valley and the two tributary valleys from
the west are not sharply separable from the areas of residual clays
described above. Both were originally swept bare by the same
flood currents and it is probable that, excepting the rock islands
of the Hudson river and other small exposures adjacent to the
present streams, much of the area now bare was formerly cov-
ered with residual clays. The larger towns of the valley, Cohoes,
-Lansingburg, Waterford and Mechanicville, are built wholly or in
part on rock and it is evident that human agencies have played a
part in denuding these areas.
Postglacial gorges. The Mohawk river from near Crescent
to its mouth has its bed on rock and in the last 3 miles of its course
occupies a rock gorge marked by the well-known falls at Cohoes.
A dam has been built across the upper portion of the gorge, in
order to supply power for the industries of Cohoes. The level of
the water in the dam is 156 feet. From the dam to the falls the
river has the character of a rapids descending 20 feet in the dis-
tance of three-fourths of a mile. It then falls 70 feet over a preci-
pice of rock. The water does not descend abruptly as a vertical
sheet but flows over the steeply inclined rock declivity. The slope
of this declivity corresponds in general to the dip of the rocks but
36 NEW YORK STATE MUSEUM
in the middle portion of the falls the rocks have been worn and
broken so that the angle of fall is less than that of the dip and in
places the falling water has the character of a cascade. At about
one-third of the width of the river from the left bank there is a
projecting mass of smoothed rock over which little water passes.
At the inner side of this mass the volume of falling water is greater
than elsewhere and at the base there is a deep pool of water
occupying a depression worn into the rocks.
|
—
if
1
|
CAS
<
Z Residual é cya WS
Mi
On 6
“TT
“|
of
Yaa, «0° diy, <
TL) |(\\S COONS
[7 =
Mii p ian \
|
A\\\\ \\,
# MAS
: 1
>
=
Se
7
°
Fig. 7 Block diagram of the Cohoes region of the lower Mohawk. The
development of the topographic features here shown is explained in the
Lex
Below the falls the river flows on a bed of jagged rock but with
slower currents, descending in the course of a mile from the level
of 60 feet at the foot of the falls to 51 feet at the head of the
lower rapids where the river divides into three streams forming
the islands on the floor of the Hudson valley. In the summer
when the river is low most of the water below the falls is confined
to a deep-water channel which extends from the deep-water pool
at the falls.
In interpreting these features it is to be remembered that in
this portion of its course the Mohawk flows across the ancient
rock valley of the Hudson. The outer boundary of this rock valley
is clearly indicated by the ridge (although now mostly covered)
extending north and south from Crescent station. The postglacial
Mohawk river broke through this boundary at Crescent. Then
bending southward, its course partly determined by the strike of
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 37
the rock beds and partly by the slope of the old valley floor, the
river eroded its present channel. Where it passed over the rim
of the narrower inner portion, or gorge (see page 7), of the
ancient rock valley, rapids were formed and, owing to the steep
dip of the rocks, the rapids developed into a waterfall. This was
the origin of the Cohoes falls.
The height of the rock wall of the gorge below the falls as seen
on the east side is 120 feet. About three-eighths of a mile below
the falls this wall falls away to a height of 40 feet. The contours
of the upper portion of the wall, representing 80 feet, here become
continuous with the slope extending northeasterly and bounding
the present valley floor of the Hudson. This slope (crossed by
the road a short distance back from the summit of the gorge) is
composed of rock covered with residual clays. The continuation
of this escarpment is seen on the opposite side of the gorge though
much reduced in height and angle of slope for some distance back
from the river. This is due to the flooded Mohawk waters of late
glacial times, which laid bare the rocks on which the lower
(northern) portion of the city of Cohoes is built. The trend of
the currents southward due to their confluence with the Hudson
waters, caused a greater reduction of the scarp immediately south
of the gorge. But farther to the south, west of the railway tracks,
where the surface of the rock is exposed in a ravine, the scarp
shows at its full height.
It is quite evident that this slope of rock is the rim of the inner
portion of the ancient rock valley and that the place where the
height of the wall of the gorge below the falls abruptly lessens
marks the original location of the falls of the river. The present
Cohoes falls is located approximately 2000 feet back from this
landmark, showing that a recession of the falls has taken place
to that extent in postglacial times and subsequent to the with-
drawal of the Lake Albany waters.
This small amount of recession compared with other postglacial
falls (Niagara Falls has receded 7 miles in postglacial times) is -
explained, at least as to the main factors concerned, by the
materials and structure of the rocks through which the gorge has.
been cut. The rock consists of indurated shales (slates) and sand-
stones, dipping steeply in a general direction to the east. The
amount and direction of dip varies locally, due to contortions of
the strata resulting from compression. In general, the sandstone
layers predominate in the rock and layers of a thickness of from
38 NEW YORK STATE MUSEUM
several inches to a foot or more occur interbedded with the thinner
layers.
The direction of flow is with the dip so that in general the wear
of the rocks at the front of the precipice is on the faces of their
bedding planes. Because of this the process of wear goes on
slowly. But at the summit of the falls the water flows over the
edges of the rocks and the destructive process is more rapid. The
erosive agents lodge in the depressions resulting from unequal
wear of alternating soft and hard strata and deepen them into pot-
holes. There are very many of these in the bed of the river imme-
diately above the falls. Due to the more rapid wear of the strata
on their upper ends than on their faces, the angle of slope of the
falls is greater than that of the dip of the strata.
At the base of the falls where the impetus of the falling water
is greatest somewhat rapid wear takes place, forming pools, and
the eddies in these pools, through undermining, may contribute
somewhat to the recession of the falls.
The Hoosic gorge. A postglacial gorge of interesting physi-
ographic and scenic features is that of the Hoosic river west of
Schaghticoke. The river has here sunk its bed through the mass
of delta deposits and into the underlying bedrock. Where the
stream enters the gorge at Schaghticoke its course turns abruptly
northward, evidently in conformity to the strike of the rocks.
After emerging from the first gorge the river turns westward and
its slopes consist of the delta materials. It then enters the second
rock gorge and its further course describes the shape of the letter
U, the direction of the arms of the U corresponding to the dip of
the strata. There is a fall of 120 feet from the head of the upper
gorge to the foot of the lower rock gorge, furnishing abundant
power. This has long been utilized for manufacturing industries
and, in recent years, for the generating of electric energy.
East of Schaghticoke the general valley of the Hoosic has the
appearance of a preglacial valley although the shallow rock gorge
at Valley Falls may mark a diversion of the river from its old bed.
The course of the preglacial Hoosic from near Schaghticoke to
the Hudson is unknown.
In that portion of the course of Tomhannock creek which crosses
the delta formation, the stream has in places sunk its bed into the
underlying rock forming gorges and cascades. One of these occurs
a short distance northwest of Schaghticoke hill and another of pic-
turesque scenic features about one and one-half miles farther on.
Plate 2
Falls of the Mohawk at Cohoes. The amount of rock erosion both
above and below the falls on the left bank of the river is shown in
the picture.
The gorge of the Hoosic river below Schaghticoke. The building in
the middle background is the power house.
GLACIAL GEOLOGY O& THE COHOES QUADRANGLE 39
RECENT DEPOSITS
The deposits representing the recent period of geological history,
or epoch that has elapsed since the final subsidence and disappear-
ance of glacial waters, are (1) wind-blown sands, (2) stream allu-
vium and (3) vegetable debris or peaty accumulations in swamps.
Wind-blown sands. In the western and northwestern parts
of the quadrangle there are extensive areas of country thickly
mantled with loose sands. These sand fields are the eastern por-
tions of a broad belt of sands that extends southwest from the
region of Saratoga lake to the Mohawk river. To a large extent
the sand is heaped in dunes, although, along the eastern margins
of the tracts, there are stretches of nearly level country where the
sand has been distributed somewhat evenly over the underlying
till or lacustrine deposits. Many of the dunes are of live sand
and show evidence of constantly changing size and position. They
exhibit no general uniformity of shape but in individual cases it
may be observed that their present growth is toward the form of
a ridge with axis corresponding to the direction of the prevailing
strong winds.
For the most part these sand tracts, especially the one extending
southward from Saratoga lake, are uncultivated. Only the marginal
portions of the areas where the depth of sand is not great are of
any important agricultural value. The native vegetation consists
of coarse grasses and of trees — pines, white birches and occasional
oaks and maples. These trees are of second growth and are mostly
undersized and often of stunted character.
The source of these blown sands is undoubtedly from deposits
originally made in Lake Albany. To the westward from the sand
fields south of Saratoga lake there is a nearly ‘level plain (the
Malta plain, Schenectady sheet) which bears evidence of having
undergone denudation. The inference seems warranted that much
of the sand of this field has been transported by the winds from
the area of this plain to its present location. There is a similar
relation between the sand region north of Crescent and a leveled
tract to the west on the area of the Schenectady quadrangle. It
is, of course, also to be considered that the prevailing strong winds
of this general region are west or northwest.
There are two areas of wind-blown sands with well-developed
dunes on the surface of the Hoosic delta deposits. Both of them
lie near the eastern border of the delta region and are evidently
composed of fine sands that have been sorted from the delta
40 NEW YORK STATR MUSEUM
materials by winds blowing from the west. Their locations are
shown on the map. In other portions of the surface of the delta
there are occasional dunes, but in general the materials of the
delta are too coarse to be lifted by the winds.
Alluvium. The Hudson river is bordered by broad valley flats
in its course from the northern edge of the sheet as far as Still-
water. The surface materials of these flats are the fine sediments .
or silts that have been deposited at times of high water when the
river overflowed its banks. From Stillwater south to the head of
tide water at Troy the work of the river in the recent epoch has
been rather to lower its bed by erosion than to build up a flood
plain. Some narrow areas of alluvial lands occur along the banks
and in the curve of the river north of Lansingburg there are two
islands of alluvial origin.
Along the Hoosic river the flats east and south of Schaghticoke
constitute an interesting physiographical feature. It is evident that
at a former time the river described a meander both on its right
and its left bank. A factor in this shifting of its course was the
rock barrier west of Schaghticoke which in times of flood held
back the waters, causing the river to overflow its banks and divert-
ing its currents against the valley slope. As this barrier was
gradually reduced through erosion, forming the present gorge, the
river straightened its course. The meanders were cut off from
the main channel leaving, however, as a remnant, the present
linked channels on the north flat.
An extensive alluvial flat, representing a recent meander of the
river, occurs along the Hoosic in its lower course. As observed
on the left bank of the river, the soil of this area is an alluvium
with admixture of mold; it is of a high degree of fertility and is
cultivated for market gardening products.
Swamps. Areas of swampy or partially drained lands, repre-
senting glacial lakes or ponds which have been filled in by sedi-
ments and overrun by vegetation, have been indicated on the map
as far as observed.
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE Al
REVIEW AND SUMMARY
The following is a classification of stages of the pleistocene
period and present period as recorded on the area of the Cohoes
quadrangle:
NAME OF STAGE PROCESS RECORD
PPR CCeNL eyes ha ee og es Stream and wind Alluvium, wind-
= erosion and depo- blown sands, swamp
ag sition muck
S Glacio-lacustrine
2 Substage e.... Erosion by fluviatile waters. Erosion terraces and eroded
AY bottom of present Hudson
: valley
~~ Substage d.... Later subsidence of Lake
‘$ ANDEAN 5h ay 5 Gan nee Lower terrace
S Substage c.... Earlier subsidence of Lake
S PAINTING ele oy oes Sere ce tocar Upper terrace
S Substage b.... Lacustrine waters occupy
8 iEtudsonivalley. = oe... 4.0) Lake Albany deposits
= Substage a.... Ice lobe occupies Hudson
8 SINS oes canoer eee Marginal moraines
R&R, Wisconsin...... Last general glaciation..... Till
Pre-Wisconsin... (Interglacial interval)...... noe Gm of Saratoga
lake (:
In a previous report? the writer has presented what seems con-
clusive evidence that the Hudson river in its course across the
southeastern spur of the Adirondack mountains, from Corinth to
west of Glens Falls, occupies a valley cut during an interglacial
epoch, immediately preceding the last or Wisconsin period of glacia-
tion. On the area of the Cohoes quadrangle, however, no certain
evidence of an earlier period of glaciation has been found. But
mention may be made of the possibility that the rock depression
occupied by Saratoga lake is a part of the valley eroded by the
interglacial Hudson in its course southward from the place of
emergence from the Adirondack region onto the Hudson plain
west of Glens Falls. It has been thought permissible, in the classi-
fication above given, to recognize, in a tentative way, this inter-
pretation of the rock basin of Saratoga lake with which may be
connected that of Round lake, 4 miles farther to the south. Wood-
worth has suggested as follows: “It seems probable that Round
and Saratoga lakes are unfilled depressions marking the site of an
old’ valley west of the present Hudson gorge.’”
* Glacial Geology of the Saratoga Quadrangle. N. Y. State Mus. Bul.
183, p. 30-35.
* Woodworth. Op. cit. p. 76.
42 NEW YORK STATE MUSEUM
The effects of a general ice sheet moving in a north-south direc-
tion, whether representing only the last invasion of the ice or the
last, together with previous invasions, are recorded on the area of
the Cohoes quadrangle in the smoothed surfaces of rock hills and
in glacial scratches. The drumlinized forms of many of the rock
hills are conspicuous to the eye in the field and are also clearly
indicated by the contour lines of the topographic sheet. The char-
acter of the rocks (indurated shales and sandstones) and their
steeply inclined planes of stratification are unfavorable for register-
ing the ice movements by glacial scratches and they were observed
only in two localities, as follows: about 124 miles northwest of
Stillwater, on the surface of a projecting mass of rock in a field
south of the highway (see map), 10° west of south; about 1%
miles south of Valley Falls on rock at roadside, 5° east of south.
The close of the latest period of general prevalence of ice, marked
by the retreat of the ice sheet to the north) 1s 1econdedsammnie
materials left from the melting ice and forming the till sheet, or
ground moraine of the uplands portions of the quadrangle. The
recession of the ice front appears to have been relatively steady
and uninterrupted. This is inferred from the fact that there is no
recessional moraine of any considerable continuity. In a few local-
ities on the eastern uplands areas, groups of hills of definite mor-
ainic character occur, evidently marking temporary and local stand-
ings of the ice front.
In the gradual process of the melting of the ice sheet the uplands
were bared before the thicker ice filling the broad valley of the
Hudson had wasted. A broad and deep lobe of ice thus lingered
in the valley, probably for a long time after the upland areas were
ice-free. South of the southern limit of the valley ice, and con-
stantly extending northward with the retreat of the ice lobe, as
well as spreading laterally over depressed areas adjacent to the
Hudson valley, gathered and for a long time stood at a permanent
level the body of waters which formed Lake Albany.
Due to the more rapid melting of the ice in its lateral portions
than in the thicker middle portion, the ice lobe narrowed gradually
toward its southern end and thus were formed two embayments
of the lake waters, lying on either side of the elongated wedge of
ice. These embayments received sediments derived from the melt-
ing ice and especially from streams from the north which developed
in the depressions between the lateral margins of the lobe of ice
and the bared land slopes. The coarser sediments were deposited
in the upper and narrower parts of the embayments while the finer
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 43
materials were carried farther and laid down in the quiet waters
lateral to the dwindling end of the ice lobe. As a general result
of this sorting of the sediments, the materials deposited on the
floor of the upper and outer portion of the preglacial valley of the
Hudson are coarser (sands and clays of the upper terrace) than
those which form the filling of the inner portion of the valley
(brick clays of the lower terrace). The latter were added to, how-
ever, at a later time, by depositions of fine sediments from the
midcurrents of Lake Albany.
Fig. 8 Sketch map showing the distribution of land and water on the
areas of the Schenectady and \Cohoes quadrangles when Lake Albany was
at the height of its development, its level corresponding to the present 360-
foot contour
When the ice lobe had melted back beyond the northern limit of
the quadrangle, all parts of the area the elevation of which is
below approximately 360 feet on the northern portion of the present
map and 320 feet in the southern were covered by the waters of
Lake Albany. The lake waters rose beyond the height of the
western marginal boundary of the preglacial rock valley of the
Hudson and extended in two broad sheets westerly, communicating
with the expanse of Lake Albany that overspread the eastern and
southern portion of the area of the Schenectady quadrangle. The
body of waters thus developed received the Hoosic river at its
eastern border and the flooded Iroquois-Mohawk (then the outlet
44 NEW YORK STATE MUSEUM
of the great interior glacial lakes) at its western border. Each of
these streams built extensive deltas into the lake. The magnitude
of these deltas affords evidence of a prolonged period of stable con-
ditions of the Lake Albany waters.
When at length the waters of Lake Albany began to subside the
great deltas emerged as land surfaces. The emergence of the delta
of the Mohawk influenced greatly the subsequent drainage history
of the Mohawk-Hudson region. As the waters shallowed at the
head of the delta near Schenectady, the checked Iroquois-Mohawk
| (Viecher a om:
Pe
Fig. 9 Sketch map showing areal extent of Lake Albany and drainage
courses on the areas of the Schenectady and Cohoes quadrangles at the
time when the Lake Albany waters had subsided to the level represented
by the present 320-foot contour
currents, impeded by their own deposits, were diverted northeast-
ward through the Ballston channel, the latter opening into Lake
Albany in the Saratoga-Round Lake region. At the same time,
due to partial obstruction of the Ballston channel by sediments, a
spillway across the barrier of rocks at Aqueduct was formed and
a portion of the Mohawk waters discharged into Lake Albany at
Vischer Ferry.
The northward course of the Mohawk waters continued for a
long time. As the subsidence of Lake Albany progressed, bringing
to the surface the lake bottom in the region of East Line, the cur-
rents eroded channels in the lacustrine deposits and eventually
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 45
the main course became established in the channel extending south-
easterly to the Round Lake inlet of Lake Albany. At a later time,
with a further subsidence of the lake waters, the Iroquois-Mohawk
eroded out the broad and deep valley now followed by Anthony
kill.
The Hoosic river, unlike the Mohawk, maintained its course
across the emerged area of the delta, repeatedly shifting its channel
from side to side and thus building a series of terraces.
The subsidence of the Lake Albany waters took place inter-
mittently, as is shown by the distinctly terraced forms of the
Fig. 10 Sketch map showing Lake Albany and drainage courses on the
areas of the Schenectady and Cohoes quadrangles when the lake waters had
subsided to the level represented by the present 240-foot contour
deposits. With the withdrawal of the waters to the level now
represented by the 300-foot contour, or somewhat lower, the outer
portions of the lake bottom in which the coarser sediments had
been deposited emerged as land surface. Thus originated the
present upper terrace of the Hudson valley.
At the next stage of marked subsidence, when the water had
receded to the level represented by the 240-foot contour, or some-
what lower, the more even portion of the lake bottom which had
been built up by deposition of the finer sediments, emerged as land
surface, forming the plain of the lower or brick clay terrace.
46 NEW YORK STATE MUSEUM
The lake, then greatly narrowed, began to take on the char-
acter of a broad river and strong currents, coming both from the
north and from the Iroquois-Mohawk which still discharged into
the Hudson waters at Mechanicville, cut deeply into the sediments
still filling the midportion of the general Hudson valley.
As a result of downcutting, symmetrical erosion terraces were
developed at two levels on opposite sides of the valley at Mechanic-
ville. The locations and configurations of these terraces show
(S) tound Lake
Anth
7? on, Liz,
(Mechanicville
SS) (Aqueduct )
Schenectady
Basin \e
°
a Se
rong
Fig. 11 Sketch map showing drainage of the areas of the Schenectady
and Cohoes quadrangles and breadth of waters occupying valleys when Lake
Albany had receded to the level represented by the present 100-foot contour
line and had taken on the character of a broad river. The Mohawk river
had lowered its gorge at Aqueduct to the 300-foot level.
conclusively that they were the work of the Iroquois-Mohawk
currents and establish the fact that the postglacial body of waters
of the Hudson valley became greatly diminished prior to the time
of the opening of the channel northward to the Adirondack region
as the outlet of the waters of the great interior lakes.
The spillway across the rock barrier at Aqueduct gradually deep-
ened, through erosion, into a gorge of capacity sufficient to contain
the volume of the Mohawk waters. The flooded currents cut a
broad path through the lacustrine deposits southeast of Crescent,
laying bare the rock floor of the preglacial Hudson valley. Where
the river flowed over the rocky slope which marked the rim of the
GLACIAL GEOLOGY OF THE COHOES QUADRANGLE 47
ancient valley a falls developed which, through recession, formed
the present falls and gorge of the Mohawk at Cohoes.
The stage of flooded waters in the Mohawk valley lasted until
the general ice sheet had retreated to the north so far as to open
a passage for the overflow waters of the great interior lakes north
of the Adirondack region, thus diverting the outlet to the sea from
_ the Mohawk valley.
Whether flooded waters continued for a still longer time in the
Hudson valley depends upon whether the northern outlet of the
great lakes, when first opened, connected with the sea through the
St Lawrence basin as now or, for a time, found a course to the sea
through the Champlain-Hudson valley. Assuming the latter case,
there is no evidence that the flooded waters ever rose to a level
higher than the foot of the clay bluffs bordering the present valley
floor of the Hudson.
IN De xX
Albany Lake, 42; deposits, 17-19;
sketch map, 43, 44, 45
Alluvium, 40
Anthony kill, 10, 23
Aqueduct, 46
Ballston lake, Io
Chamberlin, cited, 26
Clays, Lake Albany deposits, 18;
on floor of Hudson valley, 30-32;
residual, of postglacial age, 33-35
Cohoes quadrangle, sketch map
showing drainage, 46
Crescent, 35, 46
Drumlins, 13
East Schaghticoke, 15
Erosion terraces, 27-29
Fairchild, cited, 10, 17, 20
Gilbert, G. K., cited, 34
Glacial lakes, 15
Gorges, postglacial, 35-38
Gravel, hills of, 14; Willow Glen
gravel bank, 32
- Gravels, of Hoosic delta, 18; on floor
of Hudson valley, 30-32
Ground moraine, I2
Haynersville, 16
Hoosic delta, 23-26
Hoosic gorge, 38
Hoosic Lake, 16
Hoosic river, 10
Hoosic terraces, development of, 26
Hudson river, 6, 41
Kames, 14
Lake Albany, 42; deposits, 17-19;
sketch map, 43, 44, 45
Lake Hoosic, 16
Lake Tomhannock, 6, 15
Lakes, glacial, 15
Lower terrace, development of, 21-26
Mechanicville, 27
Melrose, 15
Merrill, cited, 17
Mohawk valley, 9
Moraine, ground, 12
Mount Rafinesque, II
Newland, cited, 31
Physical geography, 6-12
Poesten kill, 16
Postglacial history of
Champlain valley, 29-40
Hudson-
Quacken kill, 16
Raymertown, 15
Rice mountain, II
Ridges, 14
Rocks, areas of bared rocks, 35
Round lake, 10, 41
Salisbury, cited, 26
Sand, hills of, 14
Sands, Lake Albany deposits, 18; of
Hoosic delta, 18; on floor of Hud-
son valley, 30-32; wind-blown
sands, 39
Saratoga lake, 41
Schaghticoke, 23, 25, 38
Schenectady quadrangle, sketch map
showing drainage, 46
Speigletown, 14
Stoller, cited, 9, 10, 20
Swamps, 40
Dili x12
Tomhannock creek, 12, 14, 38
Tomhannock, Lake, 6, 15
Upper terrace, development of, 19-21
Valley Falls, 25
Waterford, 31
Willow Glen gravel bank, 32
Woodworth, cited, 41
JOHN M, CLARKE UNIVERSITY OF THE STATE OF NEW YORK
STATE GEOLOGIST STATE MUSEUM
BULLETIN 215-16
COHSES QUADRANGLE
LEGEND
Swamps or artially
drained areas; mainly
vegetable debris.
Areas of wind blown
sands with well defined
dunes; overlying till or
Lake Albany deposits:
Rooks Jald bare by late
glactal or post glacial
Streim erosion; gorges
are indicated by Mnes
at right angles tostream
COUrSeS:
Residual olays; derived
from rocks laid bare by
powerful currents of
Water (Mohawk and
Hudson rivers) of Inte
glacial times.
Olays, sands and gravels;
in part original deposits
made in Lake Alban
and) tn part materials
washed from gullies or
moved by landslides and
deposited on the floor
of the Hudson channel.
In places till (boulders)
occurs.
and’ slopes of the
emerged basin of Lake
bany.
Olays ays); de-
posits made Lake
Albany and emerged
(Schenectady)
(Hoosick)
dnoring the later stages
of subsidence. of the
lake waters thelr sur-
face forming a lower
terrace.
Fine gravels, sands and
clayey sands; delta de-
posits in Lake Albany
made by Hoosie river.
Sunds or clayey sands;
deposits made in Lake
Albany and emerged
during the carly stages
of the subsidence of the
lake waters, thelr sur-
face forming an upper
terrace and slope.
Deposits mai
of glacial lak:
uplands tne
silts thinly ov
ing glactal rill;
Hoosle Valley, sands
aud fine gravels.
Hills of sand and gravel;
@) Kames, marking, re-
Gesstonal moraines, (2)
Ridges, marking
moraines as lateral to
the Hudson Valley ice
lobe.
11) or ground moraine;
(lacking or scanty where
rocks or rock detritus
solls form the surface
materials).
Glacial soratohes
Mi Rafines
Geology by James H. Stoller.
Scale #3600 1916-1917
~ 3 o a a A. » Milew
"
“ 3 o 2 = 2 re |, Hilometers
Contour interval 20 feet
Darurn in mean sex levet
oh cwnsce ies aR aS
\
‘
Re:
|
{
‘ew York State Museum Bulletin
it Entered as second-class matter November 27, 191s, at the) Post Office at Albany, N Y,
“under the act of August 24, T912 i
Published monthly By The University of the > State of New York ©
Nos. 217, 218 o AEP ANG) ee 1919
The University of the State of New York
New York State Museum
Joun M. Crarke, Director Si) a
_ THE PALEOZOIC ROCKS OF THE CANTON
| QUADRANGLE
BY 4
yg . ‘ -G, H. CHADWICK
fs |
wh
: PAGE PAGE,
‘ Patrotuction : I ok EER Re a =5 | The geological history. . . aan ot 42
_ The geological formations ....... 8 Interpretation of the Paleozoic
- General statements...........- 8 TECorG. ht. itiue athe Om a 42
_ Potsdam sandstones ........-.-. 11'| Subsequent geclogic history .... 47
fhe basal contact. .:... ... 3... 07 | Surface geology . 2). yc ase ae 48
The concealed zone........-.-- 20 Preglacial and glacial.......... 49
"Theresa mixed: beds...........- 24 Postglacial shorelines.......... 50
' Heuvelton white sandstone..,.. 26 | Later features ..............-. 51
_ Bucks Bridge mixed beds....... *28) |’ Economic resources... 5 oie 52
Beekmantown (Ogdensburg) Sandstones and limestones ..... 52
; BNCHIthe hs ania Waele oe oe eS 36 | ‘Iromvore....)......6.0 20 tae Pe NE
_. PossibleTrentonlimestoneoutlier 39 Literature and maps............ 53
Resumé of stratigraphy ........ Vis Gy pects a>. a immane my MTA Na 4 5 | 59.
ALBANY
THE UNIVERSITY OF THE STATE OF NEW YORK
*
, oat ‘Warrér,Gurst Kettoce B.A. LL. DB. —
Col alan cg Director of State Library
CE he 3 _ JAMEs I. Wyer, Jr, M.S. PAD. ey
:
f Pals PLiny TE EXTON L! [
“19 30 Cee N. OTTINGHAM M. yt Ph. ce iy
| ge 5 ‘Cuartes B. ALEXANDER M. A. ies, iD
1929 Hersert L. BRIDGMAN Tee bag es
1931 Tuomas J. Manean M.A. = ae ape
Juan H. Fintey M.A. LL.D. LHD.
eo
eee ALBERT VANDER VEER I
ie
De He ;
1923 Asram I. Evxus LEB LL. D. D.C.L. =" - ey -N
©
—1924 “ADELBERT Moor MEAD. Liner) oe 2
Lit. D. - - ---- - ie
1920 James Byrne B.A. LL.B. LL.D. Se
arch ( President of the University and Commissioner of Education ;
Deputy Commissioner and Counsel — ed eS ie
= 4PRaNK Bs GILBERT BoA. 0 7) Gee
; Assistant Commissioner and Director of Professional Education! a
; _ Aucustus S. DowNINnG M.A. L.H.D. LL: D. Pd. ee
_ Assistant Commissioner for Secondary Education -
Cartes F. WHEELOCK B.S. LL.D.
‘radars Assistant Commissioner for Elementary dueation a
Grorce M. Winey M.A. Z. om 4
Director of Science and State Museum
Joun M. CuarkE D.Sc. LL.D.
: i Chiefs and Directors of Divisions
Administration, Hiram C. CasE .
Agricultural and Industrial Education, Lewis A. Witson” “es
Archives and History, James Suttivan M.A. Ph.D. 4 ; 5,
Attendance, James D. SULLIVAN | ee
- Educational Extension, Witttam R. Watson B.S.” Pa Ey
Examinations and Inspections, Gzorcz M. WILEY M. A, Staten
Law, Frank B. GILBERT B.A., Counsel BEY
Library Sehool.iites 1. Wika Jean LG Pe meee
School Buildings and Grounds, Frank H. ‘Woop M. JAS,
School Libraries, SHERMAN WitiaMs Pd. D.
Visual Instruction, ALFRED Ww. ens. Ph Pe
lags
4, int 5. ps
The University of the State of New York
Science Department, November 9, 1918
Dr John H. Finley
President of the University
SIR:
I beg to communicate herewith and to recommend for publica-
tion, as a bulletin of the State Museum, a manuscript entitled The
Paleozoic Rocks of the Canton Quadrangle, which has been pre-
pared, at my request, by Prof. George H. Chadwick.
Respectfully yours
Joun M. CLARKE
Director
THE UNIVERSITY OF THE STATE OF NEW YORK
THE STATE DEPARTMENT OF EDUCATION
Approved for publication this 12th day of November 1918
[Raia
President of the Umversity
beeen ar.)
— 3
New York State Museum Bulletin
Entered as second-class matter November 27, 1915, at the Post Office at Albany, N. Y., under
the act of August 24, I912
Published monthly by The University of th: State of New York
Nos. 217, 218 ALBANY, N. Y. JANUARY—FEBRUARY. 1919
The University of the State of New York
New York State Museum
Joun M. CLARKE, Director
THE PALEOZOIC ROCKS OF THE CANTON
QUADRANGLE
BY G. H. CHADWICK
INTRODUCTION?
The Canton quadrangle lies in the St Lawrence valley,? between
the parallels of 44° 30’ and 44° 45’ north and the meridians of
75° and 75° 15’ west. In its southeast corner begin to rise the
hills that mark the declining north edge of the Adirondack upland.’
Of the two physiographic areas mentioned, the valley is a drift-
mantled peneplain cut in the softer, Paleozoic sedimentary rocks;
the upland is a dissected Cretaceous peneplain of the hard, Pre-
cambrian gneisses. A third, vastly older (pre-Potsdam) and sub-
sequently deformed, peneplain is represented here at the contact
of the Paleozoic rocks with the underlying crystalline Precambrians,
and is now reexposed over a part of the quadrangle by removal of
the Paleozoic cover. The village of Canton is situated at the
approximate merging point of all three of these plains, the signifi-
cance and history of which are discussed on a later page. (See
figure 2.)
*To Doctor Martin, interpreter of the crystalline rocks of the same
area, to Doctor Ruedemann and Doctor Ulrich, paleontologists respec-
tively of the state and national surveys, to Professor Cushing, his prede-
cessor, and to Doctor Clarke, his chief, the writer gladly acknowledges his
indebtedness. Valuable aid has been received also from the residents of
the territory studied, particularly the following: Prof. and Mrs C. S.
Phelps, Rev. C. H. Fenton, G. A. Manley and Alexander Veitch of Can-
ton, O. A. Babcock of Madrid, and two of my students who served with-
out pay in the field, Erle M. Billings and John A. Shea. To these and
all others who assisted I would record my gratitude.
Ge EL Gs
7N. Y. State Mus. Bul. 168, p. 22, fig. 2, opp. p. 15.
6 NEW YORK STATE MUSEUM
The present relief of the surface is moderate. In the northern
portion of the map the irregularities are seldom due to rock but
represent almost entirely a drumlinized morainal blanket, the work
of the latest ice sheet. In the southern part they are rock hills,
with a few conspicuous exceptions like the Waterman Hill drum-
lin. Benway hill, the highest point, in the extreme southeast corner,
constitutes a ““monadnock” or erosional remnant rising above the
Cretaceous peneplain and giving a minimum measure for the
earlier pre-Potsdam peneplain in that direction.
Fig. t Key map of northern New York showing location of the Canton
quadrangle and the belts of Paleozoic HOES adjacent thereto (Geology
after Logan and Merrill)
While there are many eccentricities in the water courses, in gen-
eral the drainage lines are controlled at the south by the rock
topography, which is in turn largely influenced by rock structure
and hardness; whereas at the north even the larger streams wander
in fortuitous pathways among the drumlins and are let down upon
bedrock at irregular intervals, thus giving rise to waterpowers
determining the location of the early settlements.1 The gradually
‘The broader story of the geography and settlement of the county has
been set forth by Edgar G. Blankman in his ‘‘ Geography of St Lawrence
County.”
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE Zi
curving courses of the Grass and Raquette rivers to their mouths,
after leaving the crystalline rocks, agree so nearly with the curving
orientation of the drumlins as to need no better explanation, though
within the map limits the Raquette is for a space bandied back and
forth among the drumlins. The lowest point on the map is not
on either of these principal rivers but at the exit of Trout brook,
intermediate between them. Even in the southern part the drain-
age is not wholly adjusted to the rock belts, for its devious chan-
nels there are determined in part by glacial and postglacial deposits,
including the delta sand plains built by the streams themselves
awhile ago into the lowering series of glacial lake and marine water
levels whose history is summarized beyond.
In the nature of its Paleozoic rock geology the Canton district
is intermediate or transitional in type from an extensive belt on
the east where the Paleozoics are said* to abut continuously against
a rather abrupt Precambrian front from which they decline quite
steadily northward presenting linear zones of outcrop, to a mark-
edly different area at the southwest where* the Paleozoic rocks, at
least the so-called Potsdam, are somewhat folded and now largely
cut up by erosion into scattered outliers among the crystallines.*
yt ADIRONDACK
: UPLAND REY
SDM FRE
Qu
ST LAWRENCE § VALLEY
i) 4
"TERTIARY" PENEPLA/NY __-—--- ee
Fig. 2 Diagrammatic north-south profile showing the relations of the three
peneplains in the vicinity of Canton; drift omitted. The peneplains are
numbered in order of age. (Vertical scale greatly exaggerated)
The transition is accompanied by a sharp offset in the formation
boundaries as they enter our quadrangle from the east (see the
key map, figure 1), signifying the emergence at this point of a
rugged sub-Potsdam surface that seems to be deeply buried in
*16th Rep’t N. Y. State Geologist, p. 5~6, 15, and the map. Also N. Y.
State Mus. Bul. 95, p. 433—34.
“19th Rep’t N. Y. State Geologist, map opp. p. r85. Also 13th Rep’t
ibid., p. 496 and map opp. p. 492.
316th Rep’t cit, p. 6. Also s5oth Rep’'t N. Y. State Mus., p. 10, and
N. Y. State Mus. Bul. 145, p. 112-15; maps. Compare also the paper by
Brooks in Amer. Jour. of Sci., 4:24 (1872).
8 NEW YORK STATE MUSEUM
that direction. In short, whereas the Paleozoic frontier corresponds
with the margin of the St Lawrence valley as far west as the
Raquette river, there these two suddenly part company, the Pre-
cambrian exposures extending down into and becoming a part of
the valley floor but preserving many Paleozoic remnants in their
hollows. At the same time, as noted by Cushing,* a folded group
of weaker Grenville metasediments appears intercalated in the
massive Saranac gneisses that have alone formed the Precambrian
on the east; and it is probably these weaker crystalline zones yield-
ing more readily to compression that have occasioned the undula-
tions in the overlying strata.” Smooth zones of outcrop with incon-
spicuous dips therefore give way to vigorous zigzags and visible
tiltings while both outliers and inliers become frequent. With the
more nearly complete substitution of Grenville rocks for gneiss as
we pass southwestward into the town of Gouverneur the Paleozoic
embed is again offset toward the St Lawrence and the archipelago
of outliers reaches its fullest development. It will be seen that
the transition span accordingly includes also the Ogdensburg quad-
rangle next west, recently mapped by Professor Cushing.*
THE GEOLOGICAL FORMATIONS
General Statements
Five divisions are recognized in the Paleozoic rocks of the Can-
ton quadrangle as colored on the map.* These are, in ascending
order:> the Potsdam sandstones, the Theresa mixed beds, the
Heuvelton white sandstone, the Bucks Bridge mixed beds, the
Ogdensburg dolomite.
In age, these rocks range from Cambrian (Ozarkian of Doctor
*On p. 6 of the 16th report, before cited.
* Geol. Soc. of Amer. Bul. 26, p. 290-94.
*N. Y. State Mus. Bul. 191.
“Two other possible formations are suggested in the text, one the
upper or white Potsdam, which may require separate recognition, the
other the mass of Trenton shaly limestone at locality 4, recorded on
page 39.
°Geol. Soc. of Amer. Bul. 26, p. 289. For convenience of the reader
the position of these divisions in the standard time-scale is indicated by
the italics below:
Precambrian time (Rocks described in Bulletin 185)
Paleozoic time
Cambrian period: Georgian epoch
Acadian epoch
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 9
Ulrich*) to early Ordovician (Canadian?). The Potsdam and
Theresa formations are currently referred to the former and the
Ogdensburg or upper Beekmantown limestone is a typical repre-
sentative of the latter, but there is still some doubt as to the exact
position of the intervening two, as explained beyond. Briefly it
may be said that the Heuvelton seems linked stratigraphically with
the Theresa below, though its few fossils suggest a later age; while
the Bucks Bridge beds are approximately what has been called
“Tribes Hill” in Jefferson county and are therefore probably
Canadian, though they may prove not to be a unit.
These Paleozoic formations occupy in general the northern two-
fifths of the Canton quadrangle (localities 1 to 68 of our map) but
under a nearly unbroken drift cover so that exposures there are
very few. In the southern half of the quadrangle where outcrops
are more frequent are also several outliers of the Potsdam sand-
stones (localities 69 to 89) resting upon the crystallines, but these
sandstones are either absent or thoroughly concealed in the northern
belt, so that the sequence between them and the Theresa beds is
here interrupted and must be inferred from neighboring areas,
where they are found to pass gradually up into the latter without
break or unconformity.’
Over the northern area the general attitude of the beds is nearly
horizontal, with dips averaging I or 2 degrees and seldom exceed-
ing 4 or 5, though a dip of 12 degrees has been measured; but these
-dips are in all directions and continually changing. They thus
indicate a series of gentle undulations of irregular character, low,
pitching folds and domes, which it becomes practically impossible
- Saratogan epoch (Potsdam, Theresa and
Little Falls)
Ordovician period: Canadian epoch (Tribes Hill, Beekman-
town and Chazy)
Mohawkian epoch (Black River and
Trenton)
Cincinnatian epoch
Silurian period
Devonian period
Carboniferous period
Mesozoic time (Triassic, Jurassic and Cretaceous).
Cenozoic time (Tertiary, Glacial, Postglacial and Recent).
But Doctor Ulrich proposes to insert an Ozarkian period between the
Cambrian and Ordovician, and to refer to it our Saratogan rocks. He also
considers the Canadian, exclusive of the Chazy, as a distinct period. See next
footnote.
*Geol. Soc. of Amer. Bul. 22, p. 627, 647.
7,N. Y. State Mus. Bul. 145, p. 66.
IO NEW YORK STATE MUSEUM
to trace in detail across the concealed spaces. Away from the
actual outcrops the map boundaries have to be generalized, with
a result far from satisfactory. But the dominant strike is every-
where northeast and southwest, showing that the axes of the
stronger system of folds correspond roughly with the belts of the
underlying crystalline rocks and are approximately parallel to the
general direction of the St Lawrence valley. It is these stronger
folds that are apparent in the zigzags of the geologic map and
in the colored cross section diagrams, in which is also evident
the gradual decline of the whole series to the northward, where
although the land is lower the higher beds appear. But another
set of weaker waves is gridironed across these, shown by the fact
that at several points (for example, localities 52 and 59) upward
domings of the strata (particularly where unroofed by stream
trenching) reveal inliers* of the layers or formations below, while
at others (as localities 30 and 23) occur erosional remnants or
outliers of the higher formations filling sags in those beneath. Could
the obscuring drift mantle be lifted the number of such isolated
patches, inliers or outliers, would undoubtedly be found much
greater than now known, and the actual boundaries of the forma-
tions far more complex than portrayed on the basis of the visible
evidence. This is likely the real reason why in the map the strata
appear so much more involved along the eastern margin of the
sheet where the Raquette river unmantles them than along the
riverless western border.
It is to be noted in passing that these rocks represent but the
basal portion, spared by erosion, of a great series of sedimentary
strata perhaps thousands of feet thick that have been eroded away
from over this region. Only beneath such a superincumbent
“load” could the layers have been so folded or the lower sand-
stones so thoroughly consolidated. These beds rested upon the
more ancient Precambrian crystallines, as they do today over the
areas from which they have not since been stripped by erosion.
The smaller residual patches (70 to 89) in the southern half of
the quadrangle, beyond the edge of the main mass, prove the former
extension of the Paleozoic cover in this direction. These consist
entirely of the Potsdam sandstones, now to be described, and
they are considerably more disturbed than the strata to the north,
dips of 30 degrees being not uncommon.
‘A suggestive paper on inliers, by Doctor Ruedemann, is contained in
N. Yo State Muss Bulsng3) ps 104:
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE II
Potsdam Sandstones
This name is here used in the plural because of the growing
probability that the formation as at present understood is not a
unit, and also because of its varied lithologic expression.
The exposures of these rocks within the quadrangle are limited
entirely to outliers, unless those in the Grass river near the county
house (locality 69) are connected with the main mass of Paleozoic
rocks on the north. The remaining outcrops are isolated from
the general embed, forming scattered patches whose relations and
character are of peculiar interest.
One of the most extensive of these Potsdam outliers lies about
two miles south-southeast from Canton village (localities 76 to
80) but is badly drift covered, with the outcrops in five or six
separated groups that bear little resemblance to one another. At
locality 77 all the exposures show the white saccharoidal sand-
stone of the upper ‘“ Potsdam” dipping uniformly southward about
5 degrees, without any sign of faulting. The actual contact with
the vertical reddish quartzose Grenville rocks beneath is seen at
the north end. One-half of a mile south, at locality 76, are glaciated
ledges of a much more indurated red quartz sandstone full of micro-
faulting, forming an “autoclastic”’ rock. The lowest ledge is very
red typical Potsdam; higher up are hematitic iron spherules in a
whitish layer; banding is common and some of the most brecciated
portions are gray rather than red. In the field to the east a small
surface just above the soil is flesh pink, its glacial polish like glass
indicating intense induration. In attitude, these beds of locality 76
appear to surmount the white layers of the previous locality, but
in every other way they look to be much older and it seems safe
to assume that the dip changes in the interval, if indeed the two
formations are not totally unconformable.
One and one-fourth miles due east, at locality 80, it is possible
to work out a fairly strong anticline and syncline in rather similar
indurated and microfaulted beds of various red, buff and leaden
colors, as is shown in the cross-section diagram of this locality in
pocket. This diagram, drawn to scale without exaggeration, shows
the true dips, at some points exceeding 30 degrees. A core of red
jaspery quartzite protrudes through layer C at the east end north
of the line of section. Not far southwest of the west end, across
the brooklet, is a small exposure of white to pnk sandstone more
12 NEW YORK STATE MUSEUM
nearly horizontal and perhaps belonging to the upper series. The
total section here was measured as follows:
M 1 foot Light red sandstone
L 2 feet White or gray sandstone
K Concealed (unknown amount)
J 10 feet Conglomerate, red-brown matrix, with pebbles of
white quartz and red sandstone
I 5 “. Brownish orange sandstone with black and white
specks
Lot shown in diagram
ce
ly 3 Uniformly dark leaden purple sandstone
Goo .. f Brilliant orange-red sandstone
1d] Concealed, combined with preceding in total estimate
E 5 “ Reddish, buff etc., rather banded sandstone, containing
ID LO ©? occasional white quartz pebbles
Ci@ ~ “Sioa
B 15 Concealed, estimated
A 10 “ Similar to C, rather light colored. Base concealed
Total 78 feet, not including K, L and M
Special attention should be called to the conglomerate J, which
although represented as conformable in the diagram, has not been
proved to be so, and by carrying some pebbles of red sandstone
similar to the undoubted Potsdam beneath adds one more point
to the accumulating evidence that there is a break between this
and the widely distributed upper so-called “ white Potsdam ” beds.
A sandstone closely resembling G of the above section has been
quarried at the most northerly of the group of outcrops included
in locality 79, north of the preceding. The other outcrops of this
group on the south side of the road do not in fact show any sand-
stone at all, in place, though fragments abound in the plowed fields,
but we have here the remains of some of the ferruginous basal
contact masses that are presently to be described, half veiling an
islandlike knoll of Grenville marble and quartzite and carrying a
workable body of red iron ore, by the roadside.
Northwest of this group is an old quarry in red or purplish-
banded sandstone of ordinary Potsdam type on Judge Hale’s farm,
locality 78. This rock also is faulted, and the color bands show a
secondary intersecting set running steeply across the bedding ones,
as in the Unkpapa sandstone of the Black hills. Some at least of
the multitudinous little faultslips at this quarry appear to have
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 1035
‘occurred while the sand was as yet unconsolidated, so that all the
layers have been stretched or dragged, along a zone of appreciable
width. In the glacial kame sands of Cobb’s hill, Rochester, similar
faulting is demonstrably due to ice thrust; but it does not follow
that the same agency operated in these Paleozoic sands.
A mile south, at Mr Martin’s place, locality 81, there crops up
a vitreous exceedingly tough cream-white sandstone or quartzite,
without visible bedding. Its relations to all other exposures are
unknown, but it is not to be confused with the more mctamorplosed
Grenville quartzites.
The above outcrops have been eccrine in detail because they
afford many of the chief types of rocks included under the name
“Potsdam sandstones” and illustrate the rapidity of variation in °
short distances or in successive layers. Together they constitute
an instructive and easily accessible group, presumably a single out-
lier, closely surrounded on all sides by the outcrops of the crystal-
lines and underlaid mostly by the weaker Grenville limestones.
Beginning with the area just described and extending thence
southwestward in a direct line up the strike valley of the Grass
river and Harrison creek, following the marble belt, is a chain
of at least five other Potsdam remnants, four of them (72-75)
within the limits of the quadrangle and the fifth (71) just outside.
Doctor Martin reports another a mile farther up the valley. The
suggestion that these remnants sketch the course of a pre-Potsdam
valley is strengthened as one sees the old gneissic rocks rising,
sometimes a hundred feet higher, on either hand and the sand-
stone abutting against their slopes with interesting contact
phenomena.
Each member of this chain is individual. At the nearest (locality
75), on the south bank of the Grass river a mile southwest of the
large area already described, there is a heavy ledge of white Pots-
dam with small dip to south running almost “end on” into a steeply
dipping mass of deep red basal Potsdam striking approximately
at right angles to the white, with merely a shallow gully intervening.
There are suggestions of a coarse conglomerate (see plate 3) at
the base of the white beds, quite different from the talus breccia
(plates 5 and 6) at the bottom of the red immediately adjoining.
But the question of an unconformity here between white and red
is still debatable. Just south of the white ledge lies a large rec-
tangular block that shows a few sinuous worm trails, the only
fossil seen in the “ Potsdam” rocks of our area.
14 NEW YORK STATE MUSEUM
A mile and one-half above on the same side of the river, due:
north of Pyrites, is a varied display of the basal contact stuff
shading off into red sandstone (locality 74). Some of the rock
is deep blood red with large pebbles of pure white quartzite. A
mile farther, at the road corners on the north side of Harrison
creek (locality 73) a small bit of the same contact material is
reported by Doctor Martin. Another mile above, on the south bank
and protruding barrierlike across the valley (locality 72), is a
plicated mass of considerable thickness, chiefly of very light or
red sandstone somewhat microfaulted, without conglomerates, but
in part weak and thin-bedded. Although this area is isolated from
the surrounding crystallines by a valley on all sides (contouring
erroneous), a quartzite core appears in it as usual, consisting as
so frequently of the red jaspery variety, though ordinary white
vitreous quartzite is also present. Presumably these quartzite
cores have retarded glacial removal of the Potsdam patches. In
the western outcrops of this area the beds are pink or cream color
like those of the upper division. The highest dips measured, some
as high as 30 degrees, were in the redder layers and toward the
southeast, alternating repeatedly with lesser dips in the opposite
direction which indicate a succession of anticlines and synclines.
This plication seems to have resulted from compression of the
underlying marble belt.1 The two remaining areas (71 and one
not shown) outcrop off the map, as learned from Doctor Martin.
The prolongation of this chain northeastward is covered by drift,
except the tiny occurrence of iron-charged contact stuff in the
state road gutter at the cemetery crossing east of Canton (locality
70). The remaining exposures lie well to the east and southeast,
that near the county house excepted. Old quarries in red to whitish
layers are located on the Bullis farm at the foot of Waterman hill
(83) and on the Spaulding farm (82) a mile and one-third north.
A mile northeast of the latter the bed of Grannis brook is on Pots-
dam above the mouth of Boyden brook as far as the road to Crary
Mills? (locality 89). The strata are much disturbed, with dips
in various directions, making discontinuous exposures in the bed
of the brook visible at low water. The chief interest in the locality
* Geol. Soc. of Amer. Bul. 26, p. 292-93.
*I am indebted to Mrs C. S. Phelps for the notes on this locaJity, which
had been overlooked.
A. Basal Potsdam conglomerate resembling a tillyte, at Mr Dillabaugh’s
(locality 85), south of Pierrepont
The main ledge lies just behind, in the trees. (Looking north by east)
See pages 15 and 43.
B. Potsdam boulder in rear of Mr Dillabaugh’s
One of a large cluster derived from the ledge of the preceding view, which
lies to the left (across the road) in the trees, at the foot of the Precambrian
cliff.
The knoll on which the house stands is Grenville limestone. (Looking south-
east )
' See pages I5 and 50.
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adoge ‘(9g Ayr[ed0]) Yaet0 Javjessuey ueA Fo Yuq yyNos uo d}eIBWO[SUOD Weps}od [eseq Jo Japjnog
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PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 15
lies in the occurrence here of the “tree trunk” concretions
described by Hough,’ Ells,” Cushing? and others from other regions.
A mile east of the last, well drillers on the Henry Douglas farm
just northeast of Crary’s Mills (88) struck sandstone of rather
light color about 45 feet below the surface, and penetrated it for
some distance. Though the extent of this area is unknown, the
find emphasizes the fact that Potsdam strata are likely to be
encountered anywhere in the drift-mantied places and that their
actual distribution may be much more general than has been sup-
posed. More surprising proof of this was afforded by the well at
Frank J. Crary’s (locality 84’) one and one-half miles west of
Pierrepont, where the drill passing through 28 feet of till found
about 150 feet of typical red Potsdam sandstone, at the bottom of
which it dropped into a water pocket believed to mark the basal
contact. In the brook channel three-fourths of a mile west, below
the falls (600 foot contour), there are hematite-charged schists
indicating that the Potsdam has been but recently removed, while
one and one-fourth miles northward (84) in the brook bed north
of the brick schoolhouse is a close pavement of red, purple and
saffron sandstone blocks that have been quarried for foundation
stones. All these circumstances point to a large area of sandstone
underlying this big morainal hill.
The most interesting Potsdam locality of all is the out-of-the-
way one at Mr Dillabaugh’s (85) in the southeast corner of the
quadrangle (plate 1). Here stowed away under Benway hill at
an elevation of over 800 feet is a little ledge and glaciated knoll
(figure A) on the east side of the road and a quantity of loose
masses (figure B) on the other side, of the ferruginous basal Pots-
dam breccia, whose cavities contain elegant crystallizations of
hematite and quartz. The rock is highly indurated, hardly clastic
in appearance, and but little of the ordinary sandstone is seen.
Beneath are Grenville limestones, while behind are nearly vertical
‘cliffs of gneiss embracing and sheltering the ledge within the sig-
moidal curve described by Doctor Martin.* Two miles southwest
(86) in the same valley of Van Rensselaer creek large loose blocks
of somewhat similar stuff (plate 2) are piled thickly for many
13d Ann. Rep’t, N. Y. State Mus. (1850), p. 32-33, figure; and Proc. Am.
Assn. for Adv. of Sci. 4 (1851), p. 352-54.
airove soc. ot Can. Irans., Ser. 2), 9 (no. 4),ep. 103: (Geol. Sur. of Can.
Ann. Rep’t for 1901, 14:176A (1905).
*N. Y. State Mus. Bul. 145, p. 61, pl. 13.
4N. Y. State Mus. Bul. 185, p. 96.
16 NEW YORK STATE MUSEUM
rods along the stream with a wall of quartzose Grenville rising
behind; but actual outcrops are lacking.
There remains the area (locality 69) exposed only at low water
in the bed of the Grass river north of Canton, as diametrically
opposite to that at Mr Dillabaugh’s (85) in lithologic character
as in location, altitude and stratigraphic position. As those beds
are the highest in present altitude but probably the lowest strati-
graphically, these are the lowest in altitude but probably the highest
beds of the series. They are white saccharoidal sandstone, contain-
ing a few white quartz pebbles up to 5 inches diameter, like the first
described outcrops of locality 77. The area is cut off down stream
by a heavy mass of red granite-gneiss and it is hard to believe
that the sandstone can extend itself over this beneath the drift to
connect with the main belt of sandstone on the north, though this
may happen.
The surprising thing about these outliers is the variability of
color, structure and texture in passing from one to another. It is
almost incredible that they can all represent a single formation.
The range of colors includes pure white, ashen, creamy, buff mot-
tled, faint pink striped, light to dark garnet red and deep wine color
either uniform or variously striped, bright orange-brown, dark
grizzled purple, light tan with violet stripes, rosy gray, hematite
red, and many intervening shades and combinations. The textures
range all the way from fine, uniform arenytes through pebble con-
glomerates to reconsolidated talus breccias, the medium to coarse
sandstone types (arenytes) being the most common. In degree of
induration the beds vary from rather crumbling saccharoidal rocks,
usually light colored or white, through excellent building stones
of clean fracture and great durability, usually bright colored and
chiefly red, to light flesh-colored white or creamy quartzites of
exceeding toughness and vitreous surface, and to a calico con-
glomerate with red jasperized matrix very difficult to distinguish
from the Grenville jasperite though the amorphous jasper can
apparently be traced directly into the ordinary red, sandy matrix
by perfect gradations. The conglomerates, as might be expected,
seldom show much stratification and the quartzitelike portions
appear almost wholly structureless, but the commoner sandstones
vary from coarsely to closely stratified or even thin-laminated and
generally display more or less cross-bedding or flow-and-plunge
structure (see figure A of plate 4).
a
Boulder of “middle Potsdam” conglomerate in field south of “The
Bunch” cottage (locality 75) on the east bank of the Grass river south of
Canton (Looking northeast)
The pebbles consist chiefly of red jasper which has been bleached to milk
white by pre-‘‘ Potsdam” weathering, except at the hearts of the larger
pieces. The sand-matrix also is decolorized. Contrast the basal beds.
See pages 13 and 44.
A. Cross-bedding and a pebble band in upper (white) “ Potsdam” sandstones
south of “The Bunch” cottage (locality 75), on east bank of Grass river
south of Canton. (Piece tipped out of the ledge for photographing)
(Looking southeast)
See pages 16 and 44.
B. General view of exposures at “The Bunch” shown in detail in the two
following plates. Professor Fairchild sits on the ledge of plate 5. The
ledge of plate 6 is behind Mrs Phelps’s camera. Deep-red Potsdam sand-
stone caps the knoll to left; main ledge of white sandstone is in trees
behind. (Looking east-northeast )
See pages 13 and 18.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 77,
The Basal Contact
The interesting nature of the Potsdam-Precambrian contact has
already been suggested. Marking as it does the greatest hiatus and
unconformity in the entire known geological record, it would in any
case attract attention but the variety of forms which it assumes in
the outliers south of Canton is remarkable. Following the post-
Laurentian uplift, which completed the metamorphism of at least
such. parts as now remain of the Grenville and associated rocks,
our region was approximately base-leveled. But either the process
of peneplaination lacked completion or was followed by some reju-
venation, for the irregularity of the sub-Potsdam surface, already
described by Professor Cushing for the Theresa region’ and else
where in northern New York, is equally well shown hereabouts.
As today, so then, the Precambrian crystallines standing at high
angles outcropped in long belts or strike ridges, the stronger gneisses
and quartzite upstanding, the softer marbles and schists mostly
excavated by shallow stream-valleys or wind-erosion hollows.
The suggestion is strong that at least the closing phases of this
land cycle were arid, and probably cold. Rock destruction by
atmospheric and solar agencies probably went on unhindered, the
resulting residual soil becoming charged with the insoluble red
oxide of iron derived from the various iron-bearing minerals of
these older rocks, whose other stable products were chiefly quartz
sand and clay. The removal of the latter product was quite likely
effected by wind work comparable to that now going on over the
Great Plains, and its final resting place may be in part the Georgian
(Lower Cambrian) red shales in Vermont. The sand remained,
in part at least, and furnished material for the overlying forma-
tions. There are points (as at locality 75; summit of the quartzite
knoll southeast of the main mass) where the sandstone may be
found fitting into undercut spaces beneath the old crystalline ledges,
hinting at wind erosion of the desert type. Similar cases are
described by Cushing. There are other places (as at locality 74)
where the basal Cambrian is a reconsolidated talus breccia banked
against the foot of a steep quartzite ledge and showing a com-
pletely residual, nonassorted character. There are even places
(localities 74, 75, 70, 79) where through some 10 to 20 feet of beds
a complete gradation exists between ordinary fresh Grenville rocks
1N. Y. State Mus. Bul. 145, p. 54. See also footnote 3, page 20.
18 NEW YORK STATE MUSEUM
beneath and the normal stratified red Potsdam sandstone above
through a Grenville regolith constituting a basal Potsdam breccia.
This is comparable to the gradations existing today in our southern
states from live rock below through various intensities of rock
disintegration into residual soils and finally to reworked surface
materials above. In the process of Potsdam consolidation these
disintegration products were reconverted into solid rock, furnish-
ing many puzzling phenomena. At many points merely a faint
veneer of this material remains coating the Precambrian surfaces,
or in glaciated ledges of the quartzite it is sometimes removed
from all but the tiny corrosion hollows and pittings of the ancient
surface, or is found filling ancient joint cracks so as to simulate a
vein. These phenomena are displayed in wonderful variety at the
two outliers along the Grass river north of Pyrites (localities 74
and 75). In particular at the more northerly of these, in the knoll
behind ‘The Bunch” cottage, a peculiar thin-laminated silicious
Grenville rock, weathering with strong reddish color banding, has
been uncovered by late erosion (chiefly glacial?) in such a way as
to show its face in part plastered over with a mosaic of its own
small fragments, which fill also its former joint fissures, and pass
upward into a sand-matrix breccia and finally into ordinary red
Potsdam. The illustrations (plates 5 and 6) give but an inade-
quate idea of this occurrence. Twenty rods west of this, and again
on the summit of the (second) knoll 80 rods south, are fine
examples of basal breccias filling weather-widened joints in the
crystallines.
Apart from the revelations of the past afforded by these contact
deposits, they have a more general interest from the red iron ores
they contain.2 These usually occupy slight pre-Potsdam hollows
*To this sort of deceptive gradation undoubtedly we may ascribe
Brooks’s belief that the Grenville and Potsdam were conformable mem-
bers of one continuous Cambrian (Taconic) series; Amer. Jour. of Sci.,
4 (1872) : 22-26.
? The divergent views of various writers as to the origin of these ores
may be gleaned from Emmons 1842 (Second District, p. 97), Vanuxem
1842 (Third District, p. 267), T. S. Hunt 1871 (N. Y. State Mus. Rep’t 21,
p. 88-89), Brooks 1872 (just cited), Smock 1889 (Bulletin 7, p. 10, 43-48),
the note by Dr U. S. Grant in Winchell 1893 (21st Minnesota, p. 106-8),
Smyth 1894 (13th Rep’t N. Y. State Geologist, p. 495-09) and D. H. New-
land 1907 (N. Y. State Mus. Bul. 112, p. 38-39). While these writings
pertain to the Antwerp-Rossie district, which the writer has not visited,
the observations given here, as they were written before any of this litera-
ture had been examined, serve as independent corroboration of Smyth’s
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PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 19
at the meeting of Grenville quartzite and marble, and consist mostly
of a reconsolidated ferruginous earth, with some silicious frag-
ments, or else of a silicious regolithic breccia whose cracks and
interstices often gleam with “combs” of crystalline quartz and
hematite. Some of the most beautiful of these mineralizations
come from the tiny outlier at Mr Dillabaugh’s (locality 85) in the
southeast corner of the quadrangle.
Where there has been some reworking of the talus adjacent to
a cliff, we have brilliant ‘“ calico conglomerates,’ with a deep-red
or blood-red sand-matrix inclosing all-sized rounded to angular
fragments of white, yellowish and reddish quartzite, or dull-red
jasper. In some cases the sand-matrix becomes jasperized and
the rock closely approaches certain portions of the Grenville in
appearance, possibly because the jasperization of both rocks was
accomplished simultaneously. This may have been by hot alkaline
waters working up from beneath through the limestone, but whether
these were the same mineralizing solutions that put the zinc in the
latter at Edwards and converted its tremolite into talc, or whether
they were of later date, can not now be said. In any case they
have not lightened the task of mapping the frayed and tattered
contact line in which no real division plane exists. A visit to
localities 74 and 75 will show how hopeless is the attempt to por-
tray the facts on a map, even where the rocks are completely bare.
But there are other localities, for example 77, where the contact
of the two rocks is abrupt, suggesting an ancient sea-cliff slowly
drowned and silted over by advancing waves. It is noteworthy
that such occurrences are chiefly in the upper white beds of the
Potsdam series, a division that bears more evidence of construc-
tion in and under water than do the lower, possibly anemoclastic
and continental, red beds. Yet even here the Potsdam is always
so thoroughly bonded to the rock beneath that only closest scrutiny
reveals the division line; and nowhere has the writer seen the two
rocks tending to separate smoothly from each other on weather-
ing, as do all the higher formations. The one has arisen largely
from the dissolution of the other in situ.
interpretations so far as they are applicable to our deposits. It may be
safely asserted (a) that the ore was residual from the crystallines, likely
including the oxidation of pyrite as Smyth surmised, (b) that it was
washed down into the marble valleys and there precipitated, probably by
reaction with the limestone, and (c) that to the associated quartzite bands
we owe in our region the preservation of the existing patches from
erosion long subsequent.
20 NEW YORK STATE MUSEUM
Over the entire area explored, no contacts approaching the hori-
zontal have actually been seen between the Potsdam and the Pre-
cambrian. Everywhere the former is found resting upon steeply
sloping hillsides of the latter and thus is rapidly cut out, often
along the strike. Such relations, if the contact were not visible,
would readily suggest a faulted condition, but no actual faults,
other than the microfaulting, have been seen anywhere in the
quadrangle.1 The Potsdam outlier at locality 83 dips inward under
the north face of Waterman Hill, whereas Mr Bullis’s well on
the top of the hill (locality 87) entered gneiss (overlaid by till)
at 96 feet depth, which is over 140 feet higher, while gneiss also
outcrops in the summit due south of the outlier, 250 feet above it.
A fault was suspected here, and again in the exposures northwest
of West Potsdam (localities 44 to 50) there are some puzzles
possibly due to a minor slip; but in view of all the other evidence,
especially Doctor Martin’s Precambrian investigations, any consid-
erable faulting in our region appears to be out of the question.’
We may safely look upon Waterman hill, then, as indicating a pre-
Potsdam or sub-Potsdam relief of at least 250 feet magnitude.
The presence of a deep pre-Potsdam valley to the north of this hill,
thus denoted, ties in with other facts to be presented.
The Concealed Zone
In contrast with the outliers, when we turn to the northern embed
for the main mass of the Potsdam strata we find, clear across the
quadrangle, a mile and one-half wide zone without outcrops between
the outposts of the Precambrian rocks and the nearest Paleozoic
ledges. The first outcrops are invariably well up in the Theresa
formation or higher.
It is within this concealed zone that the main belt of Potsdam
must lie, if it exists across our map area. Eastward from the Oswe-
gatchie Professor Cushing maps a narrowing wedge of Potsdam
*Cushing’s belief in major faulting at Hannawa, just east of our map,
(16th Rep’t N. Y. State Geol. (1808), p. 14, 24), seems to be purely infer-
ential, with another explanation equally plausible.
7Dr R. W. Ells, who studied and mapped the faults in the Paleozoics
about Ottawa, specifically remarks their absence in these same rocks
along the Canadian side of the St Lawrence, a district also mapped by
him. Trans. Roy. Soc. Can., 6, (no. 4), p. 118, (1900).
*Since the above was written a masterly treatment of the whole prob-
lem of pre-Potsdam topography has appeared in Mus. Bul. 18, Canada
Dep’t of Mines, by Kindle and Burling (1915).
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 21
(the upper white portion alone present), with its last exposure
‘at ““ The Ledges” in the Indian Creek swamp, about a mile west
of our borders. Here these sandstones vanish under glacial drift
together with a large part of the thickness of the Theresa, of which,
with one possible exception, not more than the top 20 feet have
been positively seen on the quadrangle. At locality 42, southwest
of West Potsdam, in the bottom of a small brook valley, among a
great mass of stream-washed boulders, is a disrupted ledge about
a rod long of white sandstone, varied buffy and reddish, that is |
quite massive and with brilliantly glittering surfaces due to
recrystallization of quartz, like the higher Potsdam; but its south-
erly dip and proximity to extensive Heuvelton and even Bucks
Bridge outcrops favor a reference to one of the lower hard sand-
stones in the Theresa west of our district.
It would seem that if present, so resistant a formation as the
Potsdam ought to outcrop, as it does both east and west. At
Rensselaer Falls it is extensively displayed in the bed of the Oswe-
gatchie, making rapids, whereas both the Grass and the Raquette
cross from the Precambrian to the Theresa without a ripple. On
the Raquette moreover there is scant room for any Potsdam
between the gneiss at Potsdam village and the topmost Theresa
beds above Sissonville (locality 33). Cushing? noted this fact but
invoked faulting and considered the gneiss at Potsdam an isolated _
knob or “inlier ” with the main belt of Potsdam sandstone passing
behind (south of) it. This is conjectural, for the nearest outcrops
to the southwest, though remote, are of Grenville tied up with
numerous Precambrian masses beyond, while the accumulating ©
evidence is contrary fo major faulting in our area.
Just at the point where the Potsdam belt enters the east edge of
the Canton sheet, the Precambrian outcrops begin to protrude far
-to the north (see the key map, figure 1), narrowing the space
between them and the Beekmantown across the Canton quadrangle,
while the space between the Heuvelton and the Beekmantown is
not similarly compressed. That this great Precambrian promon-
tory cuts out the Potsdam for a few miles is therefore not incred-
ible. There is no question that the lower part of the sandstone
series, including at least the entire thickness of the typical red
beds, is thus interrupted, since the white layers of the upper division
‘
*16th Rep’t N. Y. State Geol., p. 24. Cushing’s observations along the
Raquette were of the pioneer type, just at the close of the field season.
See page 55.
22 NEW YORK STATE MUSEUM
--T- —_—<——-— 4
PlrerrepoA¢
aa Pont we
Fig. 3 Outline map of the Canton quadrangle to illustrate possible distribu-
tion of the Potsdam sandstones
= Ogdensburg Heuvelton [ee3ese.] “ White Potsdam ”
aolomite; sandstone; Ltege’e® sandstone;
geeeae] Red Potsdam ene Possible limit Limit of known
29 0G sandstone; of Theresa; Precambrian
outcrops; _— Limit of abundant Precambrian exposures
Between these two limits there may be extensive concealed areas of the
Potsdam sandstones
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 23
rest directly upon the crystallines in the more northerly outliers,
whereas southward the outliers become mostly red beds, at feast
75 feet in thickness at locality 80 and 150 feet at Frank Crary’s
a Potsdam Bie 4 TES It Precambrian
No JZ
Fig. 4 Cross sections showing variant possibilities as to the presence or
absence of the Potsdam beds within the concealed zone south of Morley.
No. I is a portion of figure B—B of the colored sections, with the Pots-
dam “lapped out” by the Theresa beds. No. 2 shows the alternative
mapped in figure 3. No. 3 represents an intermediate interpretation.
(Scale is one and one-fourth times that of the colored map.)
(locality 84’), with the summit and white beds removed by erosion.
Evidently the sub-Potsdam floor was higher:at the north than at
the south when they were laid down, and it is believable that its
summits were not wholly buried under the accumulating sediments
before Theresa time; in which case the presence or absence today
24 NEW YORK STATE MUSEUM
of a mappable belt of Potsdam on the north side of this crystalline
ridge depends on whether the overlapping Theresa has been suf-
ficiently stripped away to reexpose it.
It must be observed that the concealing drift is not in the nature
of a morainal ridge, but that the outcropless zone is mostly low
and extensively swampy, giving the impression of a refilled valley.
That a belt of Potsdam of considerable thickness and of resistant
character might lie buried in such a valley is shown by its occur-
rence along the shores of Black lake on the Brier Hill quadrangle,
with the Precambrian and Theresa rising above on either side.
(Compare the alternative cross sections in figure 4.) There is
even a possibility that the Potsdam underlies the drift throughout
nearly all the area mapped as undifferentiated Precambrian, with
the crystalline outcrops merely fenestrated through it. (Com-
pare figure 3.) The deep wells at Mr Cranys and) MasSsizers
(localities 84’ and 88) both found sandstone, and there are abund-
ant drift blocks of it all over the district. New outcrops may
reward further search both here and in the blank zone, and well
records will be of incalculable aid.
Theresa Mixed Beds
The series of alternating beds of blue dolomitic limestones and
rather weak grayish white or creamy sandstones that succeed the
Potsdam is the Theresa formation of Professor Cushing.t On
the Canton quadrangle these beds are seldom well exposed, and
are nowhere seen in contact with the Potsdam sandstone. Their
thickness here is therefore unknown though probably somewhere
between 50 and 100 feet. The well at Mr Cunningham’s on the
Ogdensburg state road one mile west of our limits (Woodbridge’s
Corners) starting below the summit of. the Theresa, which crops
out in the adjacent road-gutter, was still in these mixed beds at
50 feet depth.
About 20 feet of the top beds, in contact with the overlying Heu-
velton sandstone, show on the west bank of the Raquette above
the Sissonville dam (localities 31 to 33). This is a short distance
below Potsdam village, with no exposure of Potsdam sandstone
known between these Theresa outcrops and those of the Pre-
cambrian gneisses in the falls at that village (see figure 3). It
is then 3 miles farther up the Raquette, without intervening out-
1 Geol. Soc. of Amer. Bul. 10, p. 160. N. Y. State Mus. Bul. 121, p. 12.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 25
crops, to the quarries of the type red Potsdam sandstone below
Hannawa Falls (on the Potsdam quadrangle).
Between the Raquette and the Grass are found only occasional
small sometimes doubtful exposures of the Theresa beds, usually
immediately beneath the Heuvelton ledges (localities 45, 48, 49,
42°). Of these, the most interesting is that at locality 42, West
Potsdam, already described. On the Grass river just above Morley
a rather strong anticline brings up these beds, chiefly in the river
itself and on the west bank above the cemetery (locality 61; com-
pare figure A of plate 7). Immediately below the Morley bridge
(locality 59) they are again unroofed for a few rods on the west
side of the stream. Finally the latter phenomenon is repeated
one-fourth of a mile below the ruined dam at Bucks Bridge, where
typical Theresa strata are seen on the east bank in a little slough
(locality 52). Much better exposures occur on the Oswegatchie
river above Heuvelton, several miles west of our map.
The rocks of the Theresa formation are generally blue-gray when
fresh. This color is usually retained, on weathering, by the strictly
calcareous layers, while the sandy portions turn either ashen or
more commonly brownish. On long rotting, the color deepens to
a chocolate and the beds become very weak; but the calcareous
layers may slowly dissolve away without rotting. Calcite is the
cementing material throughout, so that fresh specimens foam freely
in dilute acid. The gleaming surfaces described by Cushing, due
to cleavage of this crystalline calcite cement, are frequently seen
on fresh fracture, and are usually slightly warped or curving; but
these occur also in higher strata.
The stratification in the Theresa is crude and irregular; usually
not in very heavy beds. Small lentils or pockets of the soluble blue
limestone show at intervals throughout the sandy layers, which are
inclined to be crudely cross-bedded, while stringers and knots of
sand break the calcareous portions. ‘Pittings of the size of a finger
tip frequently develop on the weathered surfaces of the coarsely
sandy streaks. In general these rocks tend to become very craggy
on exposure, furnishing an admirable foothold for mosses and
small herbs.
No organic remains have been found. The pittings above men-
tioned are the surface expression of tubular chocolate-colored
stains extending irregularly through the rock in fucoidal fashion;
but whether these are really of organic origin (burrows or alga
stems) remains to be determined. In Jefferson county a brachiopod
*N. Y. State Mus. Bul. 145, p. 65.
26 NEW YORK STATE MUSEUM
shell, Lingulepis acuminata,’ is said to be common in
this formation. This fixes the age of the beds as Upper Cambrian
(Saratogan, Ozarkian of Ulrich).
While actual outcrops of the Theresa are few across this quad-
rangle, boulders from the formation are abundant along the same
belt and to the southward. Sometimes, as at Slab City (locality
41, old dam site below the bridge), and in the brook bed three-
fourths of a mile northeast (locality 40), these boulders from the
blue calcareous layers are so massed that an outcrop closely adjoin-
ing seems inevitable, whereas none is found. The boulders clearly
recognized as Theresa are usually chunky, while those from the
rather similar Bucks Bridge formation are frequently slabby and
sometimes of large area.
Heuvelton White Sandstone
Without any marked stratigraphic break, the lower Theresa beds
give place above to the “twenty-foot sandstone” of Professor
Cushing which according to him? is shown by its relations farther
west to be merely a lentil in the Theresa, though on our meridian
it constitutes the apparent summit of that formation. From the
resistant character of this rock, and of the beds just overlying,
it has furnished the most important index to the rock structures
in the northern area. It forms extensive ledges in the Grass river
at Morley (locality 59) as shown in plate 7, and again on the west
bank below Bucks Bridge (locality 53), being responsible for the
water power at both places. It is conspicuous at several points
north of Casey Corners (localities 51, 50, 48), and three times
comes to the surface on Trout and Stony brooks (localities 46, 38,
35), besides affording the water power on the Raquette at Sisson-
ville (locality 31). And it is this same rock that, rising again in
a low anticline at Norwood (localities 19, 20), once more barricades
the Raquette. Westward of this quadrangle the same strong sand-
stone ledges appear to furnish the only conspicuous outcrops as
far as the Oswegatchie river, on the south bank of which they are
strikingly developed at Heuvelton, the type locality.®
*Lingula antiqua Hall, Paleontology of N. Y. 1:3-4; pl. 1, fis. 3a-e.
?'N. Y. State Mus. Bul. 173, p. 61.
* Geol. Soc. of Amer. Bul. 26, p. 280.
A. Heuvelton sandstone ledge above Morley on the east bank of the Grass
river (locality 61). Block undermined by solution of the Theresa beds.
(Actual dip of the strata here is to the right.) (Looking east of north)
See pages 25 and 206.
B. Summit of the Heuvelton at Pollock’s ledge, east bank of Grass river below
Morley (locality 57’), showing laminated structure and marked contrast with
overlying basal Bucks Bridge, above Mr Billings’s hand. (Looking northerly)
See page 26, and compare plate 8.
4
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 27
The Heuvelton formation consists of white, vitreous sandstone
often with a decided platy structure and much ripple-marking and
minor cross-bedding. In stream beds the surface of the rock is
usually strongly stained with reddish brown iron rust or is even
nearly black, and the lamination is clearly brought out; but the
glaciated ledges commonly show the rock in about three heavy
benches of glistening whiteness. The cement is clearly silicious,
with the original sand grains fine and uniform, so that these polished
surfaces are nearly indestructible and essentially a quartzite. Very
rarely there is a small lentil or even a thin stratum of slightly cal-
careous material. At Sissonville especially (locality 31) the number
and liminess of such lentils is more marked than to the westward.
This sandstone may, therefore, become less pronounced eastward
of our area. Yet at Norwood the masses thrown out in construct-
ing the concrete dam (locality 19)* indicate no loss of strength at
this point, and the full thickness of 20 feet is said to have been
encountered; also that it was an exceedingly difficult rock to drill
on account of its flintiness.
Unlike the formations below, the Heuvelton is fossiliferous,
though its fossils are poorly preserved as in general with our for-
mations.. A large, flatly coiled shell not unlike the Eccyliopterus
types of the Beekmantown (Ogdensburg) and sometimes reaching
a diameter of three and one-half inches, occurs sparingly, especially
near the summit. Doctor Ulrich suggests that this species may pos-
sibly be Helicotoma uniangulata,? “which is char-
acteristic of the Chepultepec (upper) series of the Ozarkian.” It
is possible, however, that more than one form is represented by the
crude molds that have been seen.
Besides the shells, a characteristic burrowlike or fucoidal struc-
ture is oftentimes pronounced. This consists of tubular windings,
about the size of a slate pencil, and filled with either the same
white or a bluish sand, or rarely weathering more rusty. They
penetrate the strata at all angles, and by a tendency to radiate in
twos or threes from a center frequently give to the weathered
surfaces the appearance of being covered with turkey tracks. This
*The new dam is situated about 25 rods farther up the stream than the
dam shown on the map, in line with the end of the street on the east
side of the river.
*Euomphalus uniangulatus Hall, Paleontology of N. Y. 1:9;
pl. 13, fig. 1, 1a. There is a very fine specimen of this species in the col-
lection of St Lawrence University, besides some poorer ones, all in loose
rotten rock of the glacial drift; but these are evidently out of the succeed-
ing Bucks Bridge formation.
28 NEW YORK STATE MUSEUM
fossil has been described and figured in the “ Geology of Canada,”
page 101, as Scolithus canadensis. A vety similangon
identical form occurs in the Upper Cambrian (St Croixan) Eau
Claire sandstone of Minnesota.
That the Heuvelton sandstone may furnish a valuable building
stone is shown in the school building and the Episcopal chapel at
Morley. The rock used is ashen gray with a tendency to a rusty
buff stain, and was quarried on the river bank just behind the
chapel, the trimmings being from the Hannawa Potsdam quarries.
Quarries have also been opened in this rock elsewhere, as at Heu-
velton and near Sissonville (locality 32), the latter for road metal
and extending downward into the Theresa beds.
The Heuvelton sandstone varies somewhat in thickness, appar-
ently through irregularity of its summit plane, certain upper layers
being sometimes present and sometimes absent. It is thinnest at
the old mill site below Bucks Bridge (locality 54) where the over-
lying beds are thickest, and has its full thickness at the Stony
Brook falls (localities 35, 36) where the overlying ledge is thin.
(See figure A, plate 9.) At the latter locality there is even some
appearance of calcareous (rotten) upper Theresa sediments above
the Heuvelton, exposed on the north-south roadway, but too thin for
mapping. If correctly so interpreted, this is the only locality vet
known on our quadrangle where there remains any trace of the
upper Theresa beds that lie above the Heuvelton lentil on the Brier
Hill and Ogdensburg quadrangles. They seem otherwise to have
been removed by erosion, together often with some portions of the
top of the Heuvelton, before the succeeding Bucks Bridge beds
were deposited.
Bucks Bridge Mixed Beds
The Heuvelton sandstone is succeeded by another white, sandy
mass of different aspect, considerably more calcareous, passing
gradually upward into heavy, dark, silicious dolomites with only
rare sandstone layers, and these in turn becoming more quartzose
again as the summit of the group is approached. No complete
section is available for measurement, but the total thickness may be
safely put at over 50 feet and perhaps nearer 70, though a cursory
view of the occasional thin exposures would not at once suggest
so great a bulk.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 29
Basal division. The lowest beds of this series have a tendency
to form a solid ledge, 5 or 6 feet high, rising abruptly from the
broad surfaces of the Heuvelton with a rounded and glittering
white forehead, followed sometimes by one or two other tiers of
similar aspect. There may be in all 15 or 20 feet of such beds.
They consist of frequent alternations of somewhat calcareous (or
dolomitic) sandstones with purer sandstones, and are mostly of fine
texture, usually rather weak and granular within but vitrifying
and bleaching on the surface into a nearly pure white resistant crust
about 3 millimeters thick, just beneath which the oxides of iron
form dark stains. Like the Theresa, the limiest bands sometimes
6
show the characteristic “sand crystal” cleavages of the calcare-
ous cement noted by Cushing’ as common in these mixed or transi-
tion beds between the Potsdam and the Beekmantown; and nodules
of crystalline calcite are not lacking. The color of the fresh rock
is a mouse-gray or drab-gray, stained as it leaches with various
rusty colors (especially wood-browns) arranged in striking patterns,
marbled or clouded. Weathering develops more buffy tones in
cracks and seams, but often bleaches the exposed faces as above
stated to an ashy white, frequently overgrown with dark
Protococcids. |
_ As compared w:.th the Heuvelton, these layers are darker within
and whiten on exposure, while the former is whiter within and gener-
ally develops a dark crust on the surface. Moreover that rock tends
to maintain angular edges because of its silicious character, whereas
these beds become more rounded, with solution along joint planes,
and otherwise give testimony of their more calcareous nature.”
The cross-bedding too, while still abundant, is smaller and even
more irregular, while the rock when thoroughly weathered is a
rottenstone full of closely interwoven, branching, fucoidal struc-
tures, the Palaeophycus beverleyense of Billings.°
The contact of these basal beds with the underlying Heuvelton
shows many signs of disconformity, indicating a break in the
IN. Y. State Mus. Bul. 145, p. 64.
? They furnish a foothold for such rare lime-loving plants as the slender
cliff-brake (at locality 57’), the bulblet bladder-fern, and the walking-leaf
(locality 35), besides many commoner forms.
Canadian Paleozoic Fossils, 1:97, fig. 86.
30 NEW YORK STATE MUSEUM
process of deposition. Its irregular character is seen in the ledge
on the Grass river at Pollock’s woods below Morley (local.ty 57’),
illustrated in plates 7 and 8. At the old mill site below Bucks
Bridge (locality 54) several inches of soft, deeply undercut shaly
layers are present at the contact, immediately followed by the rotten
fucoidal stuff. There seems reason to think, also, that the layers
making the base of the formation at some localities are not identical
with those at other localities, several feet of the lowest beds being
present or absent as the case may be. A similar difference in the
top of the Heuvelton below this contact has already been mentioned.
Besides the localities marked on the map along the Heuvelton
contact (namely, 57’, 55, 54, 38, 35,28), these white basal layers
are exposed also in broad surfaces, the summit of a low, domed
uplift, east of Madrid depot (locality 7) near the north edge of
our quadrangle; and again similarly on the west bank of the
Raquette between Hewittville and Norwood (locality 22) mostly
just east of our limits. They appear also at and above the Hewitt-
ville upper dam (localities 26 and 27), and a mass of boulders of
‘this horizon occurs just south of Madrid (locality 9).
The maximum thickness of these basal layers appears to be repre-
sented at Bucks Bridge in the beds of Nettle creek and the Grass
river (locality 55), where a hurried estimate indicated from 20 to
25 feet of crass-bedded, ripple-marked and sun-cracked, fucoidal,
partly calcareous sandy strata. Where these ledges cross the river,
making a considerable rapid (locality 54), gastropod shells of the
Ophileta type occur in them, especially at the old millrace on the
west bank (See figure B, plate 9). A good specimen from here bears,
according to Doctor Ruedemann, a considerable resemblance to Cle-
land’s Pleurotomaria hunterensis? of the Mohawk
valley Tribes Hill beds. Similar gastropods, though usually poorly
preserved and infrequent, characterize all levels of the Bucks Bridge
formation at practically all localities visited, and thus often furnish
a means of distinguishing isolated outcrops from those of the
Theresa. They appear to represent Vanuxem’s Ophileta
complanata,! to which Cleland’s species is probably equivalent.
Bul. of Amer. Paleontology, 33252; pl: 17, fis: 1) 2) 7, 8; ibider4 16;
pl. 4, fig. 1-2. According to U. S. Nat. Mus. Bul. 92, p. 1020, the present
name is Polygyrata hunterensis. But see the next footnote.
A. Basal contact of the Bucks Bridge beds disconformably on the Heuvelton
at Pollock’s ledge, east bank of Grass river below Morley (locality 57’).
Irregular, wavy contact at Mr Billings’s hand. (Looking east)
See page 30, and compare plate 7.
B. Detail of the preceding, retouched to emphasize the wavy nature of the
contact
Plate 9
ee)
Bot by Mrs C. S. Phelps
A. Ledge of basal Bucks Bridge calcareous sandstone with Heuvelton sand-
stone surface in foreground, at Stony Brook falls east of West Potsdam
(locality 35). (Looking east)
See pages 26 and 28.
©
"Photo by Mrs C. S. Phelps
B. Higher layers of the lower Bucks Bridge beds in the old mill race on west
bank of the Grass river at Bucks Bridge (locality 54) where gastropods
were secured. (Looking southeast)
See page 30.
a
*
<
Los)
atin)
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 31
Middle division. The transition to the more calcareous or,
rather, dolomitic beds of the middle Bucks Bridge is not abrupt
though fairly rapid, and some heavy uniform bluish dolomites not
unlike the Beekmantown make their appearance. But they are
harder, darker and more sandy, with the “ sand-crystal” cleavages
. of the passage beds and without the soft, velvety surface of the
true Ogdensburg dolomite. They are exposed at but few localities
and their relations to the lower beds are poorly shown at most
of these, while their exact relation to the upper beds is still unsatis-
factorily determined. The best development of these layers is seen
(at low water) in the bed of the Raquette river just above the
Hewittville bridge (locality 24), where the exposures are nearly
continuous with those of the lower beds just upstream from them,
adjoining the dam (locality 26). Gastropod shells are abundant in
the upper surface of the bottom layer and continue frequent through
the 10 feet or so of beds here shown. Some of them are of large
size and suggest Eccyliopterus. A vitreous, white, cross-bedded
sandstone layer (about 2 feet thick) caps the series at the east end
of the bridge, and fucoidal rottenstones follow not far below
the bridge; the latter being thought to correlate with the beds else-
where referred to the upper division.
To this middle division belong apparently the beds formerly quar-
ried south of Madrid bridge (locality 8), of which the bridge itself
and the “twin mills’? beside it were built. They reappear at Nor-
wood both above the railway bridge (locality 17) and in the brook
bed back of the Episcopal church (locality 18), 120 rods over on
the Potsdam quadrangle. On Stony brook they make picturesque
ledges northeast of West Potsdam (locality 37), while the layers
at their base cause a small fall in Trout brook at locality 44. Above
Geolmortnersc) Dist.) p..360, fey 2) (Hall, Pal: of N. Yours. plas:
fig. 6). Doctor Ulrich assures me that Cleland’s shell is the same as
the O. complanata of Vanuxem, but the “O. complanata and
O. compacta (both younger fossils) of Salter, Billings and Whitfield
and all subsequent authors” are not the same species but are even of
different genera. In this case our shell would appear to stand correctly
i Polyeyrata complanata (Vanuxem), since the type of
Ophileta is clearly O. levata (loc. cit., fig. 1) and not this species
as sometimes asserted.
*It is to be regretted that the reconstruction of the west m'‘ll after a
recent fire was not carried out on the original lines, hence they are no
longer twin.
32 NEW YORK STATE MUSEUM
Bucks Bridge they are best seen at very low water in the Grass
river (at locality 57). Again on the Raquette below Sissonville
they have a small exposure 10 feet above the basal beds at locality
29. West of our limits about one-half of a mile (locality 68)
similar beds occur on the James Dandy farm and in the adjacent
road gutters; while north of the quadrangle some 60 rods (locality
15; Waddington sheet) layers resembling those at Madrid appear
in the brook that runs near Dailey Ridge church, but this last iden-
tification 1s not wholly certain.
Upper division. What are believed to be the highest beds of the
Bucks Bridge formation are splendidly shown in the bare ledges
on Trout brook at the Rutland Railway (locality 12), where
approximately 25 feet of these strata are present below the Ogdens-
burg dolomite with a disconformable contact. These beds are sandy
and silicious dolomites, rather flaggy in structure and highly fucoi-
dal as they weather, but still distinguishable from the basal division.
They seem much like the beds that immediately succeed the middle
division below Hewittville bridge, and it is likely that the base of
this Trout brook section actually ties to the top of that one, though
of course still other unknown beds may intervene. Inasmuch as
there are, below the Ogdensburg at the Hewittville lower mills,
some quite different calcilutites next to be described, it would seem
that these ought to be present somewhere at this locality. A very
small development of similar calcilutites does appear on the east
bank just north of the preceding (locality 13) about 50 rods below
the railway bridge, dipping under the basal Ogdensburg on the
opposite side of the brook. Again in the railway cutting next west
(locality 11) are sandy layers and calcilutites forming a low anti-
cline, which may be in part of the Hewittville horizon, but the
examination of these was hurried and they may really be Ogdens-
burg. These beds are surely absent from the exposure by the rail-
way bridge, thus indicating an unconformity by pre-Ogdensburg
erosion. ‘The fucoidal beds reappear in several exposures farther
down Trout brook (localities 13 and 14), with a short, concealed
interval between them and the Ogdensburg rocks at the road bridge
(13). No “ Hewittville° layers are seen here, though they may
possibly occupy the covered space.
Fossiliferous and fucoidal beds like the above form the hill slope
east of Brandy brook not far below the Andrew Walker bridge
(locality 5), just over on the Waddington quadrangle. These beds
dip strongly west by north, indicating one limb of a fold that in
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 33
conjunction with the valley of the brook produces a deep reentrant
in the Ogdensburg front. A second similar reentrant is formed
by the coincidence of the Grass River valley with a second similar
low anticline that brings up the basal Bucks Bridge at Madrid depot
(locality 7; see previous, page 30). A third reentrant is developed
along the Trout brook depression, with its Dailey Ridge tributary ;
while the Raquette valley is the occasion for a fourth. It will be
seen by the map that these sinuosities aline well with the ins and
outs manifested by the outcrops of the lower formations, and that
finally they all bear some relation to the belts of Precambrian rocks
that pass under them.* See map in Museum bulletin 185.
In the exposure at the Hewittville lower mills (locality 23)
described on page 34, the lowest four and one-half feet are consid-
ered to belong to the division just defined.
To the already mentioned gastropods and fucoids (Palaeophy-
cus) of the Bucks Bridge fauna, which are even better displayed
in the upper division than below, these upper beds contribute a
more significant element in a little graptolite from the highest layers
of the formation at locality 12 on Trout brook just north of the
Rutland bridge. Concerning our provisional reference of the speci-
mens to his Deep Kill species Dictyonema rectilinea-
tum,? Doctor Ruedemann writes: ‘“ The Dictyonema is, in the best
preserved specimen, finer than the typical D. rectilineatum,
though having all the characters of it. It has 18 branches in 10
mm against 12 to 14 of that species. Another fragment has 14
to 16. Also the branches themselves are finer; otherwise, however,
they are alike in form. Probably these differences are due to the
preservation in different matrices.” But the species may also be
compared with D. sociale of Salter, generally made a synonym
of D. flabelliforme, a widespread horizon-marker that Doc-
tor Ruedemann has recognized’ in the Schaghticoke shale of the
Hudson valley, below the Deep Kill.
Hewittville beds.* Capping the Bucks Bridge formation on the
west bank of the Raquette river just below the concrete dam of
the lower mills at Hewittville (locality 23) and so just east of this
*Geol. Soc. of Amer. Bul. 26, p. 287-94, “ Post-Ordovician Deformation
in the Saint Lawrence Valley.”
7N. Y. State Mus. Memoir 7, p. 607, fig. 29; pl. 3: fig. 9, 10.
°N. Y. State Mus. Bul. 60, p. 934-58.
*This name is not intended in a formational sense, but is used kere for
convenience only.
34 NEW YORK STATE MUSEUM
quadrangle, are a few feet of beds lithologically more peculiar than
any others above the red Potsdam in our Paleozoic section. These
are rather argillaceous, lightish (smoky) gray, firm and compact
dull limy mudstones (calcilutites or exceedingly fine calcarenites).
They weather to vivid tones, light clay-buffs and mud colors, some-
times gaily banded or streaked with brown, indicating zones full
of rounded quartz grains. The distribution of these sand grains
in streaks or winnowings, the curdled (pebbly) or breccialike
appearance of certain of the beds, and the irregular bedding dis-
continuous horizontally, with the absence of fossils,’ are all remin-
iscent of shoal water conditions within a lagoon (barachois) at
tide level. The variable nature of the deposits is expressed in the
following section:
Section on west bank of Raquette river at Hewittville lower mills
Ogdensburg formation
Ft. In.
T Coarsely ribboned geodiferous dolomite............... Bo iit
S Deeply weathered contact; contains fragments of R,
Cie eer ee Ae aes SMT ye eos Moana Gg oO Ob ETD 2 SOON
Ft. In.
4 5
Bucks Bridge formation
(Hewittville beds)
R Exceedingly fine, flaggy, light gray colomarenite;
Weathenrssto (Ciminamon.. cease errata te aero Oc arr
Q Massy, argillaceous dolomilutite, with small scattered
Pebbles omlichter colons ee ose ee cee eee o 7%
P Exceedingly fine, ribboned, calcarenite, with some
Sand esramspandwarshalemscaniemee ieee oO 10
O Exceedingly fine, platy, calcilutite, with scattered
sand grains; weathers banded............ PE Metta On PAs
N Similar to M but with closer irregular alternations
Of Satrdy:sursacey . Slashedmcn sa eee eeemnne eee 0) 50
M Heavy stratum; more or less breccialike and rib-
boned, fine calcarenite and dolomilutite, with many
nodules of pinkish calcite; base banded........... 2s
EP Avidagk shalyjseamn simitlatyeto mailers tae One
K Lutite alternating with very fine dolomarenite con-
taining coarser grains; weathers ribboned......... Onn
J Weak, thin-shaly, exceedingly fine dolomarenite..... Onna
I Thin-layered coarse calcilutite, ribboned.............. Ome
H Like J but more variegated; weathers dark......... Om Id
*A single, small, poorly preserved and dubious gastropod, perhaps a
Maclurites, was seen in bed N.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 35
G Solid layer of calcilutite with conchoidal tough frac- Ft. In.
ture; white ‘chert: ticar baSess.ceccse. csc er ue seus oO II
(Greenish shale film)
F Compact lutite; weathers gaily ribboned................. Qo ul
(Greenish shale film)
E Banded lutite and fine calcarenite; weathers strongly
banded) bister and clove DrOwilscccess seceoone oes o 6
(Greenish shale film)
D Banded as above, with much medium to coarse quartz
sand grains in both parts, the grains sparkling on
WISAPMERECUSibACE) cc iarctelatietthc sien aie bioreien era rea o 6
(Greenish shale film)
Motalelvewittville! yc Reet cn cee eee 8 8%
C Very fine tough calcarenite with 30 to 50 per cent
of medium quartz sand; wpper surface with flat
Pennles or very, fine buffy calcarenites...¢ meen if 2
B Similar but not so tough; weathers “pocked”’...... Tas
A Like last; base of Clift. “ine Waters cas vacmocee eee o «68
X In midstream; medium grained, calcareous sandstone;
WUC A LITEGS RD ILLOON ws, fae Fide 4.5: seis iene a e'vad alu e & atecore meee 1) aco)
4 6
MO TalmSeChiOniMEx POSE: £1,504 ss earache ta ee Le
Beds C and below are referred to the summit of the normal
Bucks Bridge terrane. They are light, neutral gray, rather lustrous
calcarenites or calcareous sandstones, weathering brown.
Elsewhere than at Hewittville these 8 or 9 feet of yellow-weather-
ing waterlimes fail to appear, either because concealed beneath
ledges of the Ogdensburg or because discontinuous through: erosion
or through lateral change. Abundant fragments occur in the glacial
drift at Bucks Bridge and some other points, but the sources of
such strays are unknown.
It is questionable whether these strata do or do not belong in
the Bucks Bridge formation, but since no break is evident at the
supposed contact it has not seemed wise to separate them until
they can be traced farther east.
Summary. Combining the measurements or estimates for the
different divisions, we obtain the following sums:
Minimum estimate Maximum estimate
Calcilutites at Hewittville.... 8 feet g feet
Upper fucoidal layers......... 25 feet or more 27 feet (perhaps more)
Middle dolomites ............ TOL Me aeih ? AE nde
Basal quartzose beds......... Shah: SO ab B25 sae
36 NEW YORK STATE MUSEUM
Of these the maximum figures are the more probable. These
strata thus constitute a formation of considerable thickness, with a
fauna essentially the same throughout, and distinct both litholog-
ically and faunally from the formations above and below, from each
of which it appears to be set off by an erosional break (discon-
formity). They appertain to the Theresa or “ passage” beds as
originally defined by Professor ‘Cushing, and are the equivalents
roughly of. the upper portion which on the Theresa and adjacent
quadrangles he and Doctor Ulrich have more recently referred to
the Tribes Hill.t Considering the absence here of the rich Tribes
Hill fauna, the isolation of these northern New York strata from
the typical beds of that horizon in the Mohawk valley, and their
very different lithologic constitution and local subdivisions, a dis-
tinctive local name is needed for them. No satisfactory type locality
having as yet offered, the name here used owes its selection chiefly
to the fact that it was not likely to be preoccupied, and it should
be permitted to lapse as soon as a permanent one can replace it.
Beekmantown (Ogdensburg) Dolomite
The rocks occupying the area that was assigned to the “ Calci-
ferous”’ (now called Beekmantown) on the state geologic map
are, in our region, fine-grained, firm, fairly uniform, gray to drab
dolomites and dolomarenites usually with a rather dull, velvety
surface when fresh and often a coarsely ribboned or thin-lamellated
appearance when weathered. Sand grains are absent except in
restricted layers, and while the rock is sometimes slightly argillace-
ous it is seldom silicious. The magnesian content varies; most lay-
ers effervesce poorly, but some strongly and some not at all in dilute
acid.2 The sand-crystal cleavages so frequent in beds below
(Theresa and Bucks Bridge) are here wanting or at least very rare.
Like the Lockport dolomite of western New York, this rock usually
consists of tiny sandlike crystal grains of dolomite in a calcite or
dolomite cement, and like that rock it furnishes an excellent build-
ing stone.
Masses and nodules of cleavable crystalline calcite occur more
or less commonly, as also exactly similar ones of dolomite, dis-
tinguishable only by failure to foam with dilute acid. These masses
*N. Y. State Mus. Bul. 145, p. 64-66.
*The larger the percentage of magnesia (dolomite instead of calcite)
in a limestone, the less readily it will effervesce (foam) with weak acid.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 37
range from a few millimeters up to several inches in size, or some-
times become veinlike and parallel to the bedding. They vary
from white to salmon or flesh colors, buff, or even gray like the
matrix. Less commonly, but specially near the base of the forma-
tion, small geode cavities are found, lined with dogtooth calcite,
dolomite rhombohedrons, or clear, sparkling quartz crystals.
Although a firm rock when fresh, even running quite tough and
hard to work, it usually weathers rather weak or even very soft,
with rounded edges. In the typical sections near Ogdensburg occur
two or three lentils of hard, creamy white sandstone abruptly inter-
calated in the limestones, each in turn overlaid by a bed composed
of the peculiar spongelike fossil, Cryptozoon. These may be mostly
of higher horizons than the basal stuff that appears on our map
area; but Cryptozoon masses are so abundant in the drift of the
northwest corner (locality 3) as to suggest a local derivation, and
a Cryptozoon stratum in place occurs in the Rutland Railway cut
at the Madrid-Potsdam turnpike crossing (locality 10). The under-
lying sandstone lentils have not, however, been observed here.
“ Black” shaly partings in the lower beds, such as are shown
well in the Cedar Croft quarry on the state road west of Ogdens-
burg, have been noted in the old quarry north of the Rutland Rail-
way a mile west of Norwood (locality 16) and also in the state
road quarry on the east bank of the Raquette river 2 miles south
of Norwood (on the Potsdam quadrangle) where one of the shale
seams divides this formation from that next below (Hewittville
beds). Dark (“black”) chert nodules have been found along the
Raquette river in loose blocks apparently from these lower beds,
associated with or replacing Cryptozoa and Orthocerata.
The dolomitization of the rock, or perhaps rather its recrystalliza-
tion during dolomitization, has fairly obliterated what must once
have been an abundant fauna,’ judging from the faint traces of
fossils common in many of the layers. Occasionally something of
interest has withstood the process. A loose block in the river at
*Doctor Ulrich comments (in litt.): “According to my observations
there is no warrant for the common belief that dolomitization has oblit-
erated any considerable part of the fossil contents of dolomitic forma-
tions.” Blackwelder, however, in his study of the Bighorn dolomite
(Geol. Soc. Amer. Bul. 24, p. 624 et ante) has reached a different con-
clusion; and the writer knows of no other explanation for the facts seen
repeatedly in dolomites, such, for example, as the Lockport of western
New York. Compare also Van Tuyl in Science No. 1141, Nov. 10, 10916,
especially p. 688.
38 NEW YORK STATE MUSEUM
Yaleville (Waddington quadrangle), furnished a closely chambered
cephalopod shell resembling Cameroceras tenuiseptum
of the Chazy.* This may be merely a well-grown specimen of
Proterocameroceras brainerdi, a Fort Cassin Beek-
mantown fossil* with which silicified specimens in poor condition
were provisionally identified from the basal beds below the Rutland
Railway bridge over Trout brook (locality 12). Gastropods are
more abundant; species of Eccyliopterus (?)* with solute body-
whorl in the old quarry south of the Rutland tracks at locality 16
a mile west of Norwood, besides many loose specimens that Doctor
Ruedemann calls ““Maclurea compare sordida and matu-
tina’ the former of Fort Cassin and the latter of Tribes Hill
age elsewhere; also an Ophileta like O. levata,® numerous in a
loose slab below the Hewittville lower dam (locality 23) on the
Potsdam sheet.
In a gutter exposure along the Rutland tracks just beyond the
old quarry above mentioned, a single layer contained a small,
pointed ‘Linguloid, probably Linguwlepis = acunmmare
sequens’ described from the Beekmantown of Ticonderoga, and
two other poorly preserved species of brachiopods which Doctor
Ruedemann assigned to Syntrophia lateralis® and Poly-
*Orthoceras tenuiseptum Hall, Paleontology of N. Y. 1:35;
pl. 7, fig. 6. See N. Y. State Mus. Bul. 90, p. 408; pl. 3-6. Doctor Ulrich
suggests that this specimen may represent a species, “like Endoceras
montrealense, that is common about this horizon and distinct from
C. tenuiseptum.” (See Orthoceras montrealensis Bil-
lings, Geol. of Can., p. 121, fig. 37 a-c. )N..Y: State Mus. Bulb compinos
?Orthoceras brainerdi Whitfield. See N. Y. State Mus. Bul.
90, p. 405; pl. 1-2.
*Doctor Ulrich thinks this shell may be his E. planidorsalis
(unpublished?), “‘a characteristic and very widely distributed species.”
‘Hall, Paleontology of N. Y. 1:10; pl. 3, figs. 2-2a and 3, respectively.
Maclurites sordidus and matutinwus, in U. S. Nat. Mus.
Bul. 92, p. 780.
* Both, according to Ulrich, occurring in division D of the Beekman-
town, however. "
*Vanuxem,. 3d Dist., p. 36, fig. 1. See Pal) of N. Yo 1:11, fo. neplaes
fig. 4-5. Given as from the Little Falls formation in U. S. Nat. Mus.
Bul. 92, p. 879. This may be one of the various forms called O. com-
planata or perhaps more likely the O. compacta of Salter (see
Geol. of Can., p. 102, fig. 9a-b; and p. 115, fig. 23a-b).
7 Walcott, Smithsonian Misc. Coll. 53, p. 72, pl. 8, fig. 4. Lingula
acuminata in Pal. of N. Y. 8, pt 1, pl. 1, fig. 1-2, not of Conrad.
*Triplesia lateralis? Whitheldis | SeerRaly tom s\n emo Dee
p. 216, pl. 62, fig. I-10.
Plate Io
A. Disconformity(?) in the Beekmantown beds in old quarry on Raquette
river, west of Yaleville one mile north of Norwood (Waddington quad-
rangle). The locality where Winchell and Schuchert collected. (Looking
. northeasterly )
See page 38.
B. Perspective view of same ledge. The beds above and below this break
appear to be alike, supposedly Ogdensburg; but unless those below are
actually Bucks Bridge, or some new member, this may be a “ pseudo-
disconformity.”
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 39
toechia apicalis(?)* of the Fort Cassin fauna. Two or
more species of Cryptozoon” from localities already specified, and
a finely branching structure supposed to be a nullipore (calcareous
seaweed) from the townline road bridge over Trout brook 2 miles
east of Madrid (locality 13), complete the forms collected by the
writer on the Canton quadrangle. The higher portions of the
formation on the Ogdensburg and Waddington sheets contain a
larger number of species and beiter preserved, yet the forms enu-
merated here are sufficient to show in these lowest beds the pres-
ence of the Ogdensburg fauna and its near relations to that of the
“ division D” Beekmantown or Cassin formation of Cushing.°
With the exception of the Cryptozoon layers previously men-
tioned, it seems possible that all our exposures fall within the basal
10 or 15 feet of the formation, though this base may not be the
same at all localities on account of unconformity with the subfloor.
This unconformity may be seen on the west bank of Trout brook
(locality 12) in the joint faces of the beds, and is emphasized by
the discontinuous distribution of the Hewittville calcilutites, as well
as by the abrupt lithologic change. At Hewittville the contact zone
is rendered conspicuous by being a water-bearing plane with sec-
ondary solution and recrystallization, while in the quarry farther
downstream it consists of a strong shale parting as before noted.
The hiatus corresponds to the absence of at least “ division C” of
the Beekmantown.
Possible Trenton Limestone Outlier
On Thomas Veitch’s farm just southwest of the road bridge over
Brandy brook (locality 4) may be seen by the roadside large slabs
of undoubted Trenton shaly limestone full of finely preserved shells
of the brachiopod Rhynchotrema increbescens,* and
*Hemipronites apicalis Whitfield. See ibid. 8, pt 1, p. 230,
pl. 7A, fig. 26-30.
*The species .described from the Beekmantown formation are C.
steeli, C. wingi, and C. saxiroseum of Seely from the Cham-
plain valley (5th Vermont Rep’t), C. lachutense of Dawson from
Quebec, C. giganteum of Chaney and C. minnesotense of
Winchell (with var. libertatis) from Minnesota (Shakopee dolom-
ite). The columnar form from locality 10 is a new species, Doctor Ulrich
says.
*N. Y. State Mus. Bul. 95, p. 363.
eiialiveqas Atrypa), Pal. (of (NY. «12146; (280; pl. 33, “fig. orga:
Rhynchotrema inaequivalve of Schuchert and others, but see
U. S. Nat. Mus. Bul. 92, p. 1124-25. Identified by courtesy of Doctor
Ruedemann.
40 NEW YORK STATE MUSEUM
with other characteristic Trenton bryozoa and brachiopods such as
stictopora elegantula’) and )Dianort hismepcenae
nella.” Now Mr Veitch and his sons state that these fragments
were removed as an originally single and continuous slab about Io by
15 feet but only 5 inches thick, from a ledge which lay so near the
surface as to interfere with the plow. They say that this was
lifted with crowbars and afterwards broken for removal, and that
similar shaly and shelly rock formed a supposedly solid ledge under
it. The spot is now recovered with earth, the location being marked
only approximately by a swell of ground. |
It is difficult to believe that this thin-bedded material could have
been glacially transported in such broad slabs from the nearest
known exposures in Canada without disruption, since these are fully
25 miles away (see the outline map on page 6). All the other Tren-
ton drift fragments known to the writer in this region are small (not
over 3 feet) and well rounded. To be sure, Bucks Bridge slabs
up to 12 feet square are known, but these have not traveled far
and are both thicker and tougher. On the other hand it is entirely
contrary to expectation that there should be here any Trenton
strata in place or other than erratic. The Trenton limestone belongs
far above the Ogdensburg, with the Chazy and other formations
intervening. But this mass lies in one of the anticlinal reentrants
of the Beekmantown front and close down to lower Bucks Bridge
rocks (perhaps not in place but nevertheless significant) in the
bed of the brook hard by. If not a glacial erratic, then a great
post-Beekmantown, pre-Trenton erosion is here indicated. The
little knoll on which Mr Veitch’s house stands is a small drumloid,
as shown by a well he was digging, but just possibly its core may
be a tiny Trenton outlier resting down on Bucks Bridge with entire
absence by erosion of the Ogdensburg beds (the Chazy and Black
River may not have been deposited in this area). In that case it
would be a most interesting link between the now sundered Trenton
limestones of Jefferson county and Canada. The spot where it lies
is well suited for preservation of such a remnant. It must be
admitted, however, that the facts fail to prove this theory, though
they justify directing the attention of others thus to the locality.
* Hall, Pal. N. Y. 1:75, pl. 26, fig. ga-g. Identified by the writer.
SOietiiis MPeECtimelila Idurmnems, Acl IDsisi,, D, dou, we 2 See lPzill.
ING NG5, 1083, joll, Bar ies, ior
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE Al
Resumé of Stratigraphy
Inasmuch as the Heuvelton sandstone is the only one of the
Paleozoic formations on the Canton quadrangle that can be seen
in anything like continuous section from base to summit with both
contacts exposed, our knowledge of the thickness of the others
must finally depend on intelligent and accurately kept records of
deep wells or borings. Such records will be of great public service
if the drillers will cooperate with the State Geologist in making
them available. The composite section obtained by the uncertain
patching together of many scattered outcrops gives the following
recognizable divisions, in ascending order, with these approximate
thicknesses :
Cambrian or Taconic
Age uncertain, perhaps older than Saratogan
Typical Potsdam (red) sandstones and conglom-
SMCS eae Vil 5 lees lay sie es rap ahen ce pilioh e! Giss Re Fageeeneee o-150++ ft.
(Possible unconformity )
Saratogan or Ozarkian
“Potsdam” (Keeseville?) sandstone (mostly
TRVIOUUES Pave ee sea Ree mete eM Pr o?-100? ft.
(Sequence interrupted; conformable else-
where)
Theresa mixed beds, dolomites and _ sand-
SHOE Ay Oe oc Gat De EMR RPC CRE CRORE at least 50 ft.
Age uncertain, probably Ozarkian
lcimeltom winter saimdStOne. wes -mmeiae ee acne 10-25? ft.
(Disconformity )
Ordovician or Champlainic
Canadian (Beekmantownian )*
Bucks Bridge mixed beds, dolomite and sand-
SOMME es ee a cacs Weise aia etovauer « Lodisicpity «iodo at a, ar aie ahaa 50-75 ft.
(Unconformity )
Ogdensburg dolomite, basal part only...... perhaps 30 ft.
(Section continued on the Waddington sheet)
*Dr P. E. Raymond has advanced the suggestion that the Tribes Hill
beds are Ozarkian rather tham Canadian, so that our Bucks Bridge, if
equivalent, may need to be reclassified above. See Amer. Jour. of Sci.,
30:344.
42 NEW YORK STATE MUSEUM
A well drilled in the northwest corner of the quadrangle might
therefore pass through 400 or 500 feet of Paleozoic strata before
reaching the Precambrian crystallines. The supposed underground
relations of these rocks are shown, with great exaggeration of thick-
nesses and dips, in the diagrammatic colored cross-sections.
Ogdensburg dolomite
Hewittville calcilutites
Trenton limestone?
Bucks Bridge mixed beds
Heuvelton sandstone
Theresa mixed beds
(Sequence concealed)
“White Potsdam ’’ sandstone
Precambrian rocks
(gneiss, schist,
marble, quartzite,
gabbro etc.)
Typical red
Potsdam sandstone
Precambrian
Fig. 5 Columnar diagram of strata, showing the relations to one another, and
to the Precambrian, of the Paleozoic formations described on the Canton
quadrangle
THE GEOLOGICAL HISTORY
Interpretation of the Paleozoic Record
To reclothe the bones of the dead past is the primary purpose
of geology. So closely are fact and interpretation interwoven that
the latter has inevitably obtruded here and there into the discussion
of the rocks and their distribution. For an orderly presentation of
the strangely varied past of our region yet other items must now
be elicited, and the narrative must involve some repetition of what
has already been said.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 43
The sandstones of the Potsdam represent the residuum of insolu-
ble, perdurable quartz sand from prolonged deep and thorough
weathering of the Precambrian gneisses and quartzites. Their red
color marks the complete oxidation of the iron content of those
rocks freed by the total destruction of the amphiboles (hornblende
etc.), pyroxenes and dark micas of the gneisses. At favored points
this iron was concentrated in the regolith of the rotting crystallines,
and incorporated as ore deposits in the basement of the Potsdam
sands accumulating above. The sands themselves bear evidence
at many places of being wind-drifted, more particularly in their
lower portions. The cross-beddings in the Hannawa quarries are
quaquaversal, on a giant scale and at depositional angles too steep
for water-saturated sands. Quite confidently these are petrified
sand dunes. The total absence of fossils, the undercut erosion,
so evidently of a sandblast character, in the Grenville quartzites
at some of the contacts, and the fine, even nature of the sand itself
right up to the contacts, all suggest eolation. In short, our early
Potsdam land was a vast desert of wind-shifting sands when it
sank slowly beneath the advancing Cambrian sea. Its surface was
not flat, but rather it had the form of a corroded peneplain above
which rose, often steeply, knobs and ridges of the more resistant
quartzites and granite-gneiss, sometimes to heights of 200 or
300 feet. These summits were probably bare rock, rounded or
etched by the wind and exfoliating under the glare of the sun. Quite
possibly they had been not long since glaciated by the Cambrian
glaciers. They bore little or no vegetation even of the low types
such as mosses and lichens then in existence, and rainfall upon
them would appear to have been scant and infrequent.
The suggestion of glaciation, made less improbable by the dis-
covery of unquestioned tillite (boulder-clay rock with striated peb-
bles) in the Cambrian strata of Norway, Australia etc., is drawn
partly from the frequent association of glacial conditions with red-
rock accumulations, and partly from the tillitelike nature of the
curious deposit at Mr Dillabaugh’s (locality 85). Here, in the pro-
tection of an almost overhanging encircling ledge of the gneiss,
is a mass that consists at base of a regolithic or talus-heap breccia
with residual-earth matrix and secondary quartz and hematite
crystallizations of great beauty; but above this lies an indurated
quartzose conglomerate of very perplexing nature. In lack of
Stratification, complete jumbling of material of all sizes, and com-
pact character of the matrix this closely resembles a glacial ground-
moraine, but the convincing witness of striated pebbles has not
vet been secured.
AA NEW YORK STATE MUSEUM
The order of events now indicated is (a) peneplaination, then
(b) slight uplift and further deep weathering or rotting under
moist and warm climate, next possibly (c) glaciation, followed by
(d) arid, cold, desert conditions with free sweep to the winds,
finally (e) slow submergence under an encroaching sea.
That this sea came in from the northeast is well known.’ It
appears to have first invaded our quadrangle from the east as a
bay making westward from Hannawa and finally penetrating nar-
rowly through the Harrison Creek strait as far as Dekalb (Gou-
verneur sheet). Whether it was simultaneously entering the north-
ern border of the quadrangle as the edge of a large and deeper
bay occupying the primitive St Lawrence valley can not be certainly
told until well-drilling proves the existence of the red beds there,
but such is the general assumption and our cross-sections are
based upon it.
The sea continued to advance and red sandstones to be deposited
until probably the most of the southern third of the quadrangle
was submerged and a hundred feet or more of strata had been laid
down in the deeper hollows. At this juncture a slight uplift with
some disturbance, crushing and faulting, of the unconsolidated
sands seems to have taken place; and the time interval appears to
have been sufficient for induration of the sands into firm sandstone.
In places, heated waters seemingly percolated up through the beds,
jasperizing the sand matrix of the basal breccias and possibly some
of the adjacent Grenville quartzites at the same time. Mineraliza-
tion of the residual iron ores at Dillabaugh’s and elsewhere may
also be the work of this time. The extent of this disturbance and
the length of time it consumed can not now be affirmed. There
are some reasons for thinking it was a break of major importance,
so that the true red Potsdam sandstones would be much older than
the upper white division which carries the Saratogan fossils —
possibly even Lower Cambrian (Georgian) or Keweenawan. But
other facts seem to point to a lesser import.
However great or however slight the interruption, the returning
sea found a change in climate, with vegetation decolorizing the
sands now supplied to it. Its waters reoccupied the Hannawa-
Canton bay spreading a thin basement of pebbly sands, and crept
upon us also from the north and west (Rensselaer Falls), gradually
*TIt is highly desirable that the reader should become familiar with
Professor Cushing’s conclusions in Bulletins 95 (pages 272 to 294) and
145 (pages 8 to 60) of the N. Y. State Museum, without which these
pages would not likely have been written.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 45
burying the intervening irregular promontory of granite-gneiss that
now became mostly a group of islands. Thus the upper “ white”
Potsdam strata were deposited. At the close of this stage the quad-
rangle had changed into a sandy tidal flat many miles across,
inhabited by wormlike creatures of which our knowledge is limited,
and the burrowing Lingulas.
As the shore pushed farther south and west, giving more open,
deeper waters hereabouts, various lime-secreting organisms of the
ocean found living conditions on the clean, sandy bottom no longer
churned by the waves. These may have been mostly calcareous
algae, precipitating magnesium, as well as calcium, carbonates.
Thus the white sands began to have thin interbedded layers of
dolomitic muds washed inshore from the reefs. The amount of
such calcareous inwash soon about equaled the landwash of sand,
and fluctuating currents built up the alternating beds of the Theresa
formation.
Submergence, perhaps always intermittent and oscillating, event-
ually gave place to renewed elevation, and once more a beach deposit
of white, cross-bedded, ripple-marked sand was spread out across
several quadrangles with a rather remarkably uniform thickness of
about 20 feet, the Heuvelton sandstone. In these sands the waves
sowed large sea-snails’ shells, drifted gas-buoyed from deeper
haunts, and burrowing “ worms ” still found sustenance.
The immediate sequel is not decipherable on our quadrangle, but
before very long afterward the area again became land for a short
time. Whatever deposits lay above the Heuvelton were swept off,
and the summit of the latter more or less pared away in places.
This paring may have been mostly the work of waves during the
return of the sea in the next period.
Submergence was resumed at no remote time, and somewhat the
same succession of events was repeated; the advancing sea spread
beach-sands, the basal Bucks Bridge, this time more calcareous
from the presence of the Theresa dolomites in the area undergoing
erosion and of gastropods along the strand, followed by fairly
heavy sandy dolomites carrying plenty of molluscan shells, suc-
ceeded in turn by the sandier sediments of the withdrawing waters
as uplift again ensued. Finally we have barachois (“lagoon”)
conditions and the precipitation of fine lime-muds streaked with
storm sands — the Hewittville beds.
The sequel again is not recognizable until areas to the east are
better known. Land was finally established and a distinct erosion
46 NEW YORK STATE MUSEUM
was effected before the ocean came back. But land detritus seems
by this time to have been largely exhausted or the rivers turned
elsewhere, for great beds of nearly pure magnesian limestone, the
Ogdensburg, now accumulated, Cryptozoon reefs grew widely and
a normal marine fauna of molluscs and brachiopods thrived. Yet
in the very midst of these limestones an occasional thin bed of pure
sandstone marks a sudden flood or sweep of current, and upon each
such sand waste a new Cryptozoon colony sprang up.
The continuation of the Paleozoic sedimentary record lies north-
ward (see the key map, figure 1) across the St Lawrence. Here
we find evidence of further oscillations,’ the Chazy limestones with
a basal (Aylmer) sandstone resting upon eroded surfaces of the
Beekmantown, while above these follow the Black River and Tren-
ton series of limestones and calcareous shales. ‘Whether the Chazy
beds ever reached into our quadrangle is unknown. If the Trenton
mass at Mr Veitch’s (see page 39) 1s a true outlier, then deep erosion
of the Beekmantown dolomites was proceeding in our area during
Chazy and Black River time; and the Trenton sea transgressed
over the beveled edges of the Chazy and Ogdensburg strata, already
arched into the undulations of today, and laid its sediments down
upon those of the Tribes Hill division and possibly on still lower
beds.
After the completion of sedimentation in our region, or perhaps
(if the preceding is correct) immediately at the close of Beek-
mantown time, the rocks laid down in originally horizontal strata
were thrown into the gentle undulations they now exhibit. This
movement may not have been single and simple. More likely it was
renewed from time to time with each doming of the Adirondack
massif, and perhaps in slightly different directions. The total
result, conditioned in part by the belted and uneven Precambrian ©
floor, is complicated, and by the drift covering rendered most per-
plexing. The colored cross sections show diagrammatically (with
a vertical exaggeration of eleven times) the simplest possible inter-
pretation of the observed data. Southward, in the Potsdam out-
liers, the amount of compression becomes clearly greater, perhaps
because in part referable to a disturbance older than the upper
white sandstones (see page 44), but also in part involving these
(as at locality 75). The colored cross section at locality 80
*Consult N. Y. State Mus. Bul. 145, p. 17-20; Geol. of Can., p. 123-97;
G. S. of Can! Rep't, for 1890))voli 12, n: s.(10902)),) Reps Gijiee Ame oumson
Sci. (1905) 20:353-66.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 47
shows the actual dips there observed, without the exaggeration of
the other sections. Brecciation, or microfaulting, is among the
other evidences of the crushing to which these brittle sandstones
have been subjected, apparently through being squeezed between
the jaws of a Precambrian vise that consisted of an older synclinal
fold of gneiss with a marble core.
Subsequent Geologic History
The complete induration of the Potsdam sandstones seems to
imply that they were for a long time under the “load” of many
hundreds of feet of overlying strata. What these strata could
have been is not so easy to answer. Discounting the conjectural
Trenton outlier, they may have consisted in part of the Beekman-
town, Chazy, and perhaps Black River, Trenton, Utica and less
probably the Lorraine and Queenston formations. To these, or
without them, it is even possible there were added now vanished
Silurian and Devonian deposits. In fact we can not be sure that
all marine deposition ceased in the upper St Lawrence valley until
the end of Middle Devonian time, and unknown continental fillings
may have continued to be heaped in from the wasting Adirondacks
only to be carried on out again.”
By general consent the area has come to be looked upon as one
that has remained moderately near to sea level throughout the long
post-Precambrian times, but this may be erroneous. It may have
been much depressed, and also much elevated, though today (per-
haps accidentally) back at about the same stand. But at the close
of the Mesozoic? it, and the areas adjacent even far into the Adi-
rondacks, had reached the flatness of surface that comes from long
erosion at one level and which is called a peneplain. The surface
of this peneplain (figure 2) is that of the present high land from
Waterman hill southward, visible from Canton as a nearly smooth
sky line but far more impressive when seen from the standpipe hill
south of Gouverneur. Into this peneplain, after its elevation, the
rivers of Tertiary time cut deep and often not very wide valleys.
But at the same time they opened out a wide flat-bottomed valley
(figure 2) along the belt of Paleozoic rocks for the St Lawrence
*Geol. Soc. of Amer. Bul. 26, p. 292-04, figs. 7-0.
"A summary of the evidence bearing on the former thickness and
extent of the Paleozoic strata is contained in Museum Bulletin 18 of the
Canada Department of Mines, pages 19 to 22 (1915), by % M. Kindle
and L. D. Burling.
48 NEW YORK STATE MUSEUM
of today, and the character of this flat bottom as a late Tertiary
peneplain is also manifest when one views it from the summit of
Waterman hill. It is interesting to note how closely this series of
events parallels those that preceded the Potsdam deposition, when
a mature Precambrian peneplain was gently elevated and corroded,
just prior possibly to glaciation. Once again that sort of a mature
peneplain, hewed mostly across the same crystalline rocks and at
very nearly the same level in them, is gently uplifted and incised
just before glaciation. In our immediate region the coincidence
of the two planes is so intimate that one can not be sure it is not
actually the reuncovered sub-Potsdam peneplain that we see from
Gouverneur or Canton. The writer would be unwilling to assert
too confidently that it is not just that, though theoretically the
Mesozoic plain should control as one goes southward. On account
of the warping and probable disfiguration of the older plain (figure
2) by the later movements already discussed, it seems more likely
that this very conspicuous, smooth, upland surface is the product
of the much later period of erosion which elsewhere has given
us the well-known late Mesozoic (Cretaceous) peneplains.*
Over this surface, then, probably wandered the huge dinosaurian
reptiles of those days, and above them flew the dragonlike ptero-
saurs. But the morasses and river silts into which their skeletons
fell have long since disappeared from here by erosion, and nothing
remains of their gruesome occupancy. After them came the great
mammals of the Cenozoic (Tertiary); and they too have passed
away, along with the land surface on which they trod. Yet the
St Lawrence region as they saw it must have been in many ways
a good deal like the present, with many of the same hills and
valleys.
The closing chapters are those of the ice invasions and their
aftermath of glacial lakes and marine submergence, a brief account
of which follows.
SURE ACH GEOBO G4
The Pleistocene geology of the Canton quadrangle is fully as
complex in its mappable elements as is that of the rocks, and since
these can not therefore be shawn on the present map, they will be
merely summarized here.
*The currently assigned ages of these peneplains (preferably spelled
“peneplanes”’) has been lately (1916) questioned by Eugene Wesley Shaw
at the Albany meeting of The Geological Society of America. Mr Shaw
believes them to be of much more recent date. G. S. A. Bul. 28:128.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 49
Preglacial and Glacial ;
Preglacial erosion and drainage. Whatever form erosion took
during the long stretches of later Paleozoic, Mesozoic and Tertiary
time, whether canyon-cutting through rapidly uplifted strata with
subsequent reduction of the divides, or slow, continuous, base-
leveling of a slowly rising surface, its net preglacial product could
not have differed much from that of today. Professor Fairchild
believes that the stream adjustment on this northwestern side of
the Adirondacks was similar to that now existing on their south-
western flank, namely, that a major valley was developed in a
tangential direction along the surface contact of the crystallines
with the edge of the overlapping Paleozoics, and that this received
the radial flow from the highland within.1 Our concealed zone
with its absence of outcrops along the Paleozoic frontier may be
a local remnant of the course of this ancient trunk valley through
this heavily ice-scoured trough. More certain is it that the ancient
rock-valley of the Raquette past South Colton continues northwest
from Higley Falls into the southeast corner of our sheet, where
it is now occupied by only tiny Conner (Leonard) brook. The
present deflection of the Raquette toward Colton and Potsdam is
maintained merely by a weak remnant of its gravelly delta built
in Lake Iroquois (see beyond). Since the other known rock-valleys
on the map, except that of the Grass at and above Pyrites, are in
belts of weak rock accordant with the direction of glacial flow, it
seems unsafe to assert for them any preglacial significance. Some
are more truly resurrected pre-Potsdam. Over the Paleozoic area
the rock surface appears to be almost featureless, the present relief
being wholly that of the glacial drift.
Glaciation. The Pleistocene glaciation of this district was
from the northeast, and the heavier movement seems always to have
been influenced, at least the basal currents, by the course of the
St Lawrence trough and its included strike ridges. The thin edge
of the waning ice appears, however, to have had a spreading flow,
and as this gave the rocks their final polishing, the compass direc-
tion of the striations is generally about south, frequently two or
three degrees east of south. The drumlinized hills show a similar
orientation, as they too were the product of this thin spreading
ice margin. The drumlins in particular reveal a curving aline-
ment, swinging slowly and regularly from southwest in the northern
*N. Y. State Mus. Bul. 145, p. 141-45.
50 NEW YORK STATE MUSEUM
part of the sheet (Morey Ridge for example) to a trifle east of
south on the parallel of Canton. All this accords with theoretical
expectation.
Over most of the quadrangle the depth of moraine is great, and
exposures are very few. On the entire Paleozoic area, all the hills
are drumlins, or at least drift in some form. This drift is very
stony, with crystalline boulders from Canada, and slabs of Pale-
ozoic limestones and sandstones. It is also very sandy, lacking
clayey stiffening because of absence of shales to contribute such.
In the southern third of the sheet, the crystalline district, the rock
surfaces are more extensively bared and scrubbed, but occasional
drumlins and much ground moraine exist all through. Waterman
hill is one of the largest of these drumlinized masses. Kame gravels
are found chiefly in small patehes, but the Beach plains (see
beyond) and its feeding esker represent constructional work by
waters of glacial melting, such as exists more abundantly in the
Colton region immediately east of our sheet. Erratic boulders
reach huge proportions along the southern margin of the map,
sometimes as large as haystacks. (Plate 11; also plate 2.)
Nearly all the glacial constructional features have been subse-
quently softened or modified by the action of static waters about
to be mentioned.
Postglacial Shorelines?
The blockade of the lower St Lawrence valley by the waning
ice sheet produced a lowering succession of glacial lakes, whose
beaches encircle our steeper hill slopes and blend with delta plains
at the crossings of the stream valleys. These beaches are those
of ‘“ Lake Iroquois,’ at 860 to 890 feet present altitude, and lower,
“Lake Emmons” at 690 feet, and ‘‘ Lake Vermont ” ranging down-
ward from 600 to about 500 feet. At still lower levels, from about
460 feet downward, are the undoubtedly marine beaches of “ Gil-
bert gulf” (Woodworth’s Hochelagan sea) representing a slow
postglacial uplift of our region out of the ocean.? Professor Fair-
*Attention should be called here to Cushing’s acute early observations
on these phenomena (50th Rep’t N. Y. State Mus., 2:7) which consider-
ably antedated those of Professor Fairchild and the writer but were not
known to the latter when he entered the region ten years later.
* These have furnished salt-water shells such.as Macoma, Saxicava
etc., and even barnacles, at Massena, Norwood, Ogdensburg, and other
points adjacent to our quadrangle.
"oS ased 20S
‘SIOp[NOg BSOO] 1B MoTA 9} UL Sosseur
aq} [[V ‘osuripenb uojzue) jo ulsivm yInos jo YNOs jsnf ‘JuodaIIoT| jsaA\ Je stop[nog [ewes IsnyT
yooysuroyg “yf Aq oj0y4g
II 331d
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 51
child has recently presented strong evidence that the “ Lake Ver-
mont” shore (or Vermont-New York, as he calls it in our region)
is really only a higher (earlier) stage of the marine levels, but with
possibly still fresh or brackish waters because of the narrowness
of its connection with open ocean and the large influx from the
melting glacier. Such questions of interpretation do not, however,
affect the fact that these ‘several beach lines are distinct features
marking fairly prolonged stands of wide and deep bodies of water,
with heavy wave action.
The Beach Plains represent an esker-fan (proglacial delta) in —
Lake Iroquois, whose feeding esker is seen along the road to
Boyden’s Corners. Good beaches of Lake Emmons may be seen
just on the south margin of the quadrangle above North Russell.
The Vermont beach skirts Waterman hill, with deltas at Boyden’s
Corners, the North Russell mill and Pyrites village, especially west
of the last. Some of the best beaches on this shore line are a mile
southeast of Langdon’s Corners, and again 2 miles south of west
from Little River settlement.
The Gilbert Gulf beaches are in general best displayed on the
high drumlins in the northern third of the quadrangle. Splendid
examples exist on the hills about Norwood (especially at the stand-
pipe), north of West Potsdam, and east of Morley; also on
Morey ridge.
Characteristic diversions of the streams have been wrought by
their own deltas at Pyrites, North Russell and elsewhere, thus
making available water power at these places.
Later Features
Abandoned channels. Several rather interesting abandoned
channels exist along the course of the Grass river, especially at
Canton and Madrid. They range from occupancy at present by
flood waters, up to 20 feet or more above present river level. The
most remarkable one begins just northwest of the “345” road
corners, opposite the sharp bend in the river below Canton; that is
at the corners where the road to the county house turns off from
Water street, 2 miles out from Canton. It continues (plate 12, figure
A) for a mile along the northeast side of the Morley road, from
which it may occasionally be seen, and loses itself finally in the broad
marshes east of that road. A huge rib of the red granite-gneiss
crosses it at the north end of the first hill that it skirts, forming
a dry cataract. This channel agrees in level with the sand plain
52 IBA Z MEOMRORS SAAMI, MEIGS MAUI AL
extending behind it south and east for a mile or more, for which
it is probably responsible.
Wind work. Sand dunes are common throughout much of the
qttadrangle. Usually they are small, 3 to 10 feet high, and grassed
over. Three miles east of Canton, north of the Crary Mills road,
they constitute a drifting area. No such conspicuous dune areas
as those on the Potsdam quadrangle to the east have been found
on our sheet, the best bit seen being shown in plate 12, figure B.
Recent ferruginous conglomerates. Along the right bank of
the Grass river below Morley, the rock exposures in the river
bed are coated with a firm conglomerate containing millions of
old iron nails cemented by their own rust. Rev. C. H. Fenton
states that an “ ashery ” was conducted at this point by his grand-
father. The deposit extends for many yards, has a thickness of
several inches, and successfully resists removal by the stream.
A more extensive iron-conglomerate was found by Doctor Martin
in the river bed above the mills at Pyrites. This is an indurated
mass of talus or shingle, containing boulders up to half a ton in
weight, with a limonitic matrix derived probably from the tailings
of the old pyrite mine. It covers many square rods, often to a
depth of 2 or 3 feet, thus mask.ng a part of the rock exposures.
ECONOMIC RESOURCES
Sandstones and Limestones
Active quarrying on the Canton quadrangle, except for road
metal is not going on today, though everywhere are the remains
of past workings and many sightly structures have arisen from their
output. The reason for this decadence is the expansion of the
Potsdam sandstone quarries at Hannawa just over the one border,
and of the marble at Gouverneur not far over the other. The red
Potsdam is not likely to be again exploited on our- quadrangle,
nor is the white (upper) sandstone favorable for building stone,
but that at the old south quarry of locality 77, near Canton vil-
lage, ought to be tested as an abrasive.
The Theresa sandy dolomites are good road metal, fairly tough
and inclined to “ bind,” but deteriorate on weathering. The Heu-
velton, though too silicious and brittle for the roads, has been used
as a building stone at Morley (page 28). The middle limestones
in the Bucks Bridge, which have been quarried and used at Madrid
(locality 8) in the stone bridge and mills, are the most satisfactory
and enduring rock in the quadrangle. The Ogdensburg formation
Plate 12
A. Abandoned channel of the Grass river two miles north-northwest of Canton
(north of locality 69), east of the road to Morley. Looking south-south-
west obliquely down upon the channel, which appears darker than the side
slopes.
See page 51.
_ B. Wind-drifted sand burying a cedar grove south of the Rutland Railway
three miles east of Madrid depot (north from Burnham Corners). (Look-
ing easterly)
See page 52.
‘ ve
; y
i? i
4
'
A
=
Sate
5
1
*
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 5
io)
also carries good stone for buildings and for lime, but the better
localities are somewhat beyond our boundaries. This stone was
burned on the “ Jake to farm (locality 6), 2 miles west of
Madrid depot.
Iron Ore
The iron ore workings are also but vestiges. The deposits, how-
ever interesting scientifically, proved altogether too limited and
uncertain for extraction. ‘The principal prospect holes were at
localities 74 and 79 with other occurrences of the ore at 70 and 85,
the material in all cases being red, earthy hematite, accompanied
by more or less of the shining black crystals in cracks and vugs.
LITERATURE AND MAPS
1836. In the apportionment of the State among the geologists
of the original survey, northern New York (the “ second district ’’)
fell to Prof. Ebenezer Emmons of Williams College.t| In common
with his colleagues, Emmons submitted annual reports of progress
which were published as legislative matter, but their contents were
assembled in the final reports. The pages special to our area are
from the following Assembly documents: 1837, no. 161, p. 29-32
(Beck on iron ores) ; 1838, no. 200, p. 209, 214-19 (Emmons on
iron ore and Potsdam sandstone) ; 1839, no. 275, p. 62-63 (Conrad’s
classification of the “ New York System” of rocks) ; 1840, no. 50,
Pp. 347-49 (Emmons on Potsdam sandstone).
1842. In 1842 appeared Emmons’s final “ Report on the Geology
of the Second District” as volume 2 of part 4 Geology, of the
“ Natural History of the State of New York.’ Our Paleozoic
rocks were all included in the two divisions “‘ Potsdam Sandstone ”
and “ Calciferous Sandrock”’ of the ‘Champlain group” and are
described in detail on pages 99 to 106,? their distribution in St
Lawrence county being given in pages 360 to 363 and in the sec-
1Consult State Museum Bulletin 56, page 8, etc. Interesting accounts,
with portraits, of many of the men mentioned in this chapter will be
found in the History of American Geology by Dr George P. Merrill in
the 1904 report of the U. S. National Museum, pages 180-734. Two earlier
papers are worth mention, namely John Finch’s “Essay on the Mineralogy
and Geology of St Lawrence County,” Amer. Jour. Sci., 19:220-28 (1831),
and the “ Sketch of the Mineralogy of a Portion of Jefferson and St Law-
rence Counties” by Dr J. B. Crawe and Asa Gray, ibid. 25:346-50 (1834).
?Emmons made the curious mistake of locating Hannawa on the Grass
river (page 360), a slip that has been followed by several subsequent
writers on our building stones.
54 NEW YORK STATE MUSEUM
tion diagrams on plates VII and IX, as well as depicted on the
separately published 1842 “Geologic Map of the State of New
York” by Emmons, Vanuxem, Mather and Hall. Emmons’s ideas
on the origin of the red iron ore (pages 97-98) have already been
mentioned. i
1863. Across the river lies Canada, and the dividing line
although a river is not a geologic boundary, as the key map (figure
1) clearly shows. In 1863 appeared Sir William E. Logan’s “ Geol-
ogy of Canada,’ using Emmons’s names for the formations and
giving much detail of their distribution just over the line (pages
87, to 122). Tt is easy to! recognize, im the carefull scetioms arue
various members to which we are now supplying names. The map
in the atlas accompanying this book (not printed until 1865) covers
New York State also, this portion contributed by our own State
Geologist, Dr James Hall. But this map was only a reduced prelim-
inary copy of the large “ Geological Map of Canada” issued the fol-
lowing year, copies of which are very rare. A few years later
T. B. Brooks examined the iron mines of Rossie, near Keene, and
published his observations already commented on (American
Journal of Science, July 1872, 4:22-26).
1875. Except for a map of the eastern United States by Hall
in the 27th Museum Report (1875), and the notes in Macfarlane’s
“ Geological Railway Guide” (1879), nothing further of conse-
quence was printed concerning our area until 1888, when the New
York State Museum bulletins began to appear. In bulletins 3, 7
and 10 (1888, 1889, 1890) Prof. J. C. Smock of Rutgers College
reviewed the economic aspects of our building stones and iron ores,
but without specific mention of any workings within our quad-
rangle. Charles D. Walcott’s papers on the correlation of the
Cambrian in bulletin 81 of the U. S. Geological Survey include
several mentions of our rocks, especially pages 203-5, 244, 341-42,
363, 381, and the maps of plates I and II (1891). Incidental value
attaches also to the papers by Prof. C. H. Smyth, jr, then of Ham-
ilton College, ‘““A Geological Reconnoissance in the Vicinity of
Gouverneur” in the Transactions of the New York Academy of
Science, 12: 97-108 (1893), especially pages 102-4; and “ General
and Economic Geology of Four Townships in St Lawrence and
Jefferson Counties” in the 13th Report of the State Geologist
(1894), pages 491 to 515, especially pages 500-11; and by Prof.
N. H. Winchell, geologist of Minnesota, on “The Potsdam Sand-
stone at Potsdam, N. Y.” in the 21st Minnesota report, pages 99
to 112 (1893), all of which have been cited in the preceding pages.
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 55
1894. Map work was resumed in 1894 with the appearance of
Hall’s “ Preliminary Geologic Map of New York,” a large wall
map compiled by W. J. McGee of the U. S. Geological Survey,
followed by Dr F. J. H. Merrill’s “Economic and Geologic Map”
of the State, which was reissued in Bulletins 15 (1895) and 85
(1905). The latter marks no advance in the knowledge of our
area, while the former recognizes the inadequacy of previous work by
leaving most of our region blank! Attention thus being directed to
our needs, results soon followed.
1895. Mention may be made here of the fourth edition of Dana’s
“Manual of Geology” for its improved classifications and its con-
cise summary of previous knowledge, which render it a starting
point for future work (1895), and of an important paper by Dr
R. W. Ells on “ The Potsdam and Calciferous formations of Que-
bec and Eastern Ontario” (Can. Roy. Soc. Proc. and Trans., 12,
sect. 4, p. 21-30, 1895), in which he argues for the union and even
(citing Emmons, p. 347) partial contemporaneity of these two
groups (a view later urged by Grabaw), and assigns the Potsdam
to the base of the Ordovician (“Cambro-Silurian”). Ells’s
remarks apply, of course, to the fossiliferous “ white Potsdam.”
In the same year, Winchell again declared his belief in the Keween-
awan age of the true (red) Potsdam at Hannawa (American
Geologist, 16: 205-13) and in 1897 Merrill discussed the road
metals of the State (bulletin 17) with maps still based on the old
surveys. More important was Merrill’s “ Guide to the Study of the
Geological Collections of the New York State Museum” published
in 1898 as Bulletin 19 of the museum; particularly pages 141-47,
187-88, 216 and 219. The handsome map in this bulletin adds little
to the early work on our area. ;
1598. In 1898 appeared Mr Edgar G. Blankman’s ‘ Geography
of St Lawrence County,’ with a section on its geology (pages 29
to 31) and a small colored map based on that of 1842. A new
era began, however, with the advent of Prof. H. P. Cushing of
Western Reserve University, whose “Report on the Boundary
between the Potsdam and Precambrian Rocks North of the Adi-
rondacks” constituting pages 5 to 27 of the 16th Report of the
State Geologist (1898) recorded the first detailed formation trac-
ing in this region since the days of Emmons. Professor Cushing
worked into the Canton quadrangle from the east, but did not cross
it, being interrupted by the close of his field season. He recog-
nized, however, the great difficulties presented by the drift-laden
56 NEW YORK STATE MUSEUM
area encountered here (page 26), together with the irregularity
of the sub-Potsdam surface (pages 6 and 14); he also pointed out
the distinction between the lower and upper portions of the “ Pots-
dam” and the upward gradation of the latter into the “passage
beds” to the “ Calciferous”” (page 13). While he noted some dis-
turbance of the strata, he ascribed it to the faulting with which he
had been familiar in the Champlain valley, applying this explana-
tion to thé gneiss exposed at Potsdam village and the red sandstone
area at Hannawa Falls (pages 13, 14, 24). Hus statement (page
24) that the rocks along the Raquette from Potsdam to Norwood
“are all with the same dip [northwesterly], and manifestly in a
continuous and undisturbed section” shows that time limitations
prevented his seeing all the exposures, and must today be qualified.
1899. The epochal nature of the times was signalized in two
other quarters. Through three different media Dr John M. Clarke
and Prof. Charles Schuchert wrought a revolution in the classifi-
cation and naming of the New York Paleozoic formations
(Science 10:874-78, December 15, 1899; Amer. Geol., 25 :114-10,
February 1900; Memoir 3 of the New York State Museum: pages
8 to 12,1900). For “Calciferous sandrock ” of Eaton and Emmons
they propose the name Beekmantown limestone, and restore the
early names Taconic and Champlainic in place of Cambrian and
Ordovician. In the following year (1901) Director Merrill of
the Museum put out the present standard “ Geologic Map of New
York State” on the same scale as the McGee map of 1894, which
it was intended to replace. For our area Cushing’s boundaries and
unpublished work by Smyth were used. This represents the last
mapping done on the Canton district until Doctor Martin and the
writer entered the field.
toor. In directions other than mapping much, however, has been
accomplished in the past sixteen years. In the 19th Report of the
Geologist, pages r9g8 to r103 (1901) Smyth described minutely the
character of the Potsdam sandstones and of the surface on which
they were laid down, in the Thousand Islands region; and in the
20th report page r37 (1902) the existence of the Adirondack pene-
plain is suggested by Cushing for our county. The character of the
Potsdam invasion is discussed by Dr E. O. Ulrich and Professor
Schuchert in Museum Bulletin 52, pages 636-37 (1902). In. Bul-
letin 56 of the same year, Merrill describes the new state map (of
I9Q0I), reviewing in a table the classifications of our rocks from
1823 to date. Walcott in 1903 (Journal of Geology, 11:318) pro-
posed Saratogan (“Saratogian’’) to replace Potsdamian for the
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE 5
NI
Upper Cambrian, and in the same year the Museum issued a Hand-
book (no. 19) on the Classification of the New York Series of
Geologic Formations, followed in the next year by one (no. 17)
on Economic Geology, and an important short paper on the “ Eco-
nomic Products of St Lawrence County” in the 22d Report of the
Geologist, pages r118 to r124, by Prof. W. N. Logan, then of
St Lawrence University. The activity of this first five years of the
new century culminated in the appearance of Cushing’s great bul-
letin (95 of the State Museum) on the “ Geology of the Northern
Adirondack Region,’ indispensable companion of all subsequent
workers. The pages that bear particularly on the problems of
our own quadrangle are 276-89, 354-64, 386-94, 403, 406 and
418. Since this is available at a nominal price to all, it is useless
here to do more than acknowledge again our great indebtedness
to it.
1906. Fire tests of the Potsdam sandstone were reported by
W. E. McCourt in Museum Bulletin 100 (1906) and D. H. New-
land summarized Smyth’s theory of the origin of the red iron ores
in Bulletin 112, page 38 (1907). The name Theresa for the
“passage beds ” was proposed by Cushing in the Geological Society
of America Bulletin 19, page 160 (1908) and coincidently in the
Director’s Report (Bulletin 121), page 12, together in the former
journal with a resumé of the Paleozoic stratigraphy and geography
of our region, a subject which was also assailed by Dr A. W.
Grabau of Columbia University (Science, new series, 29: 351-56,-
358; Journal of Geology 17: 211-26; 1909) who readvanced the
theory of Emmons and Ells. In 1909 also, H. Leighton published
in the Director’s Report (Bulletin 133, p. 115-55) a list of geologic
maps of the State and a color reproduction of Amos Eaton’s New
York State map of 1830, the first geologic map of the State. This
five-year period culminates with the reentry of Doctor Ulrich in
the field of New York stratigraphy (Museum Bulletin 140, pages
II, 127 to 140, in which the name Tribes Hill limestone is pro-
posed).and the publication of the “ Geology of the Thousand Islands
Region” (Bulletin 145; 1910) by Cushing and others (see pages
14-24, 53-68, 78 footnote 2, 92-97, 112-18, 120-26). A note by
Dr P. E. Raymond in the American Journal of Science for the same
year (30:344) suggests the Ozarkian rather than Canadian age of
the Tribes Hill.
ro1r. The last five-year period opens with Ulrich’s “ Revision
of the Paleozoic Systems” (Geological Society of America Bul-
letin 22: 281-680, 1911) and the geologic map of North America
58 NEW YORK STATE MUSEUM
by Bailey Willis (Washington, 1911) followed in i912 by its
description in professional paper 71 of the U. S. survey: “Index
to the Stratigraphy of North America” which gives a summary of
everything to date (consult pages 120-27, 183-86 for our area).
The State Museum also put forth a revised edition of its Hand-
book 19 on “ Classification of New York Series,’ which is the
present standard. In 1914 came Prof. W. J. Miller’s “ Geological
History of New York State” (Bulletin 168), in which special
reference may be made to pages 41 to 51 and others; and Cushing,
Martin and Chadwick reported progress on their respective fields
in the Director's Report (Bulletin 173) pages 61-67. The last
papers to mention are Chadwick's “ Post-Ordovician Deformation
im the Saint Lawrence Valley” (Geological Society of Amer.ca
Bulletin 26:287-94; 1915) in which the names Heuvelton and
Bucks Bridge were first employed and a black and white map of
the Canton quadrangle Paleozoics was given, and the stratigraphic
tables in Bulletin 92 of the U. S. National Museum, by Bassler.
In addition to these, Professor Cushing’s bulletin on the Ogdens-
burg and Brier Hill quadrangles will probably be issued before this
paper is printed.
In the above catalog no account has been taken of publications
on the surface geology, that being reserved for the time when the
Pleistocene formations of our quadrangle shall receive the special
description that they merit. Papers purely paleontologic have been
omitted for citation in the text.
Of the works named, the most indispensable to local student
or amateurs are probably Bulletins 95, 145 and 168 of the State
Museum, which may be secured at small cost from Albany, Logan’s
economic report in the 22d of the State Geologist (56th of the
Museum), the revised edition of Handbook 19 which is free on
request, and the U. S. Geological Survey professional paper 71.
Emmons’s 1842 Report on the Second District and the 1863
Geology of Canada are still useful and may be obtained at old book
stores. The last state map (1901) is now sold in atlas form only.
INDEX
Abandoned channels, 51
Babcock, O. A., acknowledgments
LOWS
Basal contact, 17-20
Beekmantown (Ogdensburg) dolo-
mite, 8, 30-30
Benway hill, 6
Billings, Erle M., acknowledgments
to, 5
Black lake, 24
Blackwelder, cited, 37
Blankman, Edgar G., cited, 6
Boyden brook, 14
Brandy brook, 32
Brooks, cited, 18
Bucks Bridge, 26, 28, 30
Bucks Bridge mixed beds, 8, 28-36
Burling, L. D., cited, 20, 47
Cameroceras tenuiseptum, 38
Canton, 5, II, 16
Casey Corners, 26
Clarke, Dr John M., acknowledg-
ments to, 5
Concealed zone, 20-24
Crary Mills, 14, 15
Cryptozoon, 39
giganteum, 39
lachutense, 30
minnesotense, 39
saxiroseum, 39
steeli, 39
wingi, 39
Cushing, Prof., acknowledgments to,
Becited os, 15, 172 2024) AA
Dictyonema flabelliforme, 33
rectilineatum, 33
sociale, 33
Dinorthis pectinella, 40
Eccyliopterus, 31
planidorsalis, 38
Economic resources, 52
Ells, Dr-R. W., cited, 15, 20
Emmons, cited, 18
Endoceras montrealense, 38
Euomphalus uniangulatus, 27
Fenton, Rev. C. Hk,
ments to, 5
Ferruginous conglomerates, 52
acknowledg-
Geological history, 42-48
Glaciation, 49
Grannis brook, 14
Grassy fiver, 7. 133) LO.255 2m Geese
Grass River valley, 33
Hannawa Falls, 25
Harrison creek, 13, 14
Helicotoma uniangulata, 27
Hemipronites apicalis, 39
Heuvelton, 25, 20
Heuvelton ledges, 25
Heuvelton white sandstone, 8,
Hewittville, 30, 33, 30
Hewittville beds, 33-36
Hough, cited, 15
Hunt, i. S5 ‘citeds 18
26-28
Indian Creek swamp, 21
Iron ore, 53
Kindle, E. M., cited, 20, 47
Limestones, 52
Lingula acuminata, 38
antiqua, 26
Lingulepis acuminata, 26
sequens, 38
Literature, 53-58
Maclurea compare sordida and
matutina, 38
Maclurites sordidus and matutinus,
38
Madrid, 30, 39
Manley, G. A., acknowledgments to,
5
[59]
60 NEW YORK STATE MUSEUM
Maps, 53-58
Martin, Dr, acknowledgments to, 5
Morley, 25, 26, 30
Nettle creek, 30
Newland, D. H., cited, 18
Norwood, 26, 27, 30, 31, 37
Ogdensburg dolomite, 8, 36-390
Ophileta compacta, 31
complanata, 30, 31
levata, 31, 38
Orthis pectinella, 40
Orthoceras brainerdi, 38
compacta, 38
complanata, 38
montrealensis, 38
tenuiseptum, 38
Oswegatchie river, 25, 20
Palaeophycus beverleyense, 29
Paleozoic record, 42-47
Phelps, Mrs C. S., acknowledgments
to, 5, 14
Phelps, Prof.
ments to, 5
Pierrepont, 15
Pleurotomaria hunterensis, 30
Polygyrata complanata, 31
hunterensis, 30
Polytoechia apicalis, 39
Postglacial shorelines, 50
Potsdam sandstones, 8, 11-16, 43
Potsdam village, 21
Preglacial erosion and drainage, 49
Proterocameroceras brainerdi, 38
Pyrites, 14
C. S., acknowledg-
Raquette river, 7, 24, 26, 30, 31, 32
Raquette valley, 33
Raymond, Dr P. E., cited, 41
Rensselaer falls, 21
Rhynchotrema inaequivalve, 30
increbescens, 39
Ruedemann, Dr,
to, 5; cited, 10
acknowledgments
Sandstones, 52
Scolithus canadensis, 28
Shaw, Eugene Wesley, cited, 48
Shea, John A., acknowledgments to,
5
Sissonville, 21, 26, 27, 28, 32
Sissonville dam, 24
Slab City, 26
Smock, cited, 18
Smyth, cited, 18
Stictopora elegantula, 40
Stony brook, 26
Stony Brook falls, 28
Stratigraphy, resumé of, 41
Surface geology, 48-52
Syntrophia lateralis, 38
Theresa mixed beds, 8, 24-26, 36
Trenton limestone outlier, 8, 390
Tribes Hill beds, 9, 36, 41
Triplesia lateralis, 38
Trout brook, 7, 26, 31;)32) sauce
Ulrich, Dr, acknowledgments to, 5;
cited, 9, 27, 36, 37
Van Rensselaer creek, 15
Vanuxem, cite’, 18
Veitch, Alexander, acknowledgments
to, 5
Waterman hill, 14, 20
Waterman Hill drumlin, 6
West Potsdam, 21, 25, 31
Winchell, cited, 18
Wind work, 52
ee a ee er < = ee : a EE ee Se eet eee - a
-PALEOZOIC R
it
JOHN M, CLARKE
STATE GEOLOGIST
UNIVERSITY OF THE STATE OF NEW YORK
STATE MUSEUM
~ 2978
Ting Coding . aXe
im
BULLETIN 217-18
PALEOZOIC ROCKS OF THE CANTON QUADRANGLE
Scale axs60
St
o a 2 3
: 3 o a 2 > “
Geology by George H. Chadwick.
= Miles
Kilometers
3
(er ee
Contour interval 20 feet.
Dane ix mean 20a level.
CHAMPLAINIC
CAMBRIC (OZARKIAN)
SYMBOLS
CONVENTIONAL
i
1
'
1
1
t
{
|
1
1
1
t
Bucks Bri
mixed re
DISCONFORMITY
pene
Houvelton sandstone.
Rio
Chie
Theresa mixed bods.
(Probably Including
some Potsdam in the
concealed area.)
Potsdam sandstones.
UNCONFORMITY
f =|
[essa
Less]
Known contacts,
feo
[ers]
Inferred contacts
[ye]
Dip and strike of
neared oUtorop,
43
Numbors refer to
descriptions tu the coxt.
x
Quarries.
A
A
Lines of sections
Wells.
Actual exposures are
shown by red spots:
i
a
.
|
aa
4
4
a
Hd
NEW YORK STATE MUSEUM BULLETIN 217-18
CANTON QUADRANGLE
GEOLOGIC CROSS SECTION DIAGRAMS
(Slightly enlarged)
ALONG LINES A-A TO E-B, SHOWN ON MAP
WITH MUCH ENLARGED SECTION
AT LOCALITY 80 ,
= MOREY RIDGE
—, Ao
ip LZ, Zy, v
ARLE
Wf eo ees)
BUCK Ss BRIDGE
Norwoop
ue
v eases
Section at 80
(WEST)
SCALE C= et — 100 FEET
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voles | a& yi" Si bhatt L Aa—.* 8 oa A a ant el
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: as z PF
YT kien rats 338
ar ao >; %,
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Va
3 9088 01300