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Chicago Academy of Sciences

ee LICHEN FLORA

OF

CHICAGO AND: VICINITY

BY

WILLIAM WIRT CALKINS

BULLETIN No. 1

OF THE

Geological and Natural History Survey

ISSUED APRIL, 1896

Pe
oy

err

Gee

Chicago Academy of Sciences

ie LICHEN FLORA

CHICXGO ANB VICINIT y

BY

WILLIAM WIRT CALKINS

BULEETIN Noz |

OF THE

Geological and Natural History Survey

ISSUED APRIL, 1896

LETTER OF TRANSMITTAL.

CHICAGO, ILLINOIS, April 1st, 1896.
DEAR SIR:
By direction of the Board of Managers of the Geological and

Natural History Survey ot The Chicago Academy of Sciences, I herewith
submit to you the report on. The Lichen-Flora of Chicago and Vicinity,
prepared by William Wirt Calkins, for publication as Bulletin No. | of
the Survey, to be issued under the rules of the Academy governing such
matters.

Respectfully,

C. M. HIGGINSON, WiuuIAM K. HIGLEY,
Pres’t of The Academy of Sciences. Chairman.

The Board of Managers of the Geological and Natural History
Survey of The Chicago Academy of Sciences :

WILLIAM K. HIGLEY, Chairman,
CHARLES 8, RADDIN, Secretary.
GAYTON A. DOUGLASS.
WILLIAM E. LONGLEY.

THOMAS L. JOHNSTON.

THE GEOLOGICAL SURVEY,

The BuLietin on the Lichen-Flora is the initial number of a
series of publications in which the Geological and Natural History
Survey of the Chicago Academy of Sciences proposes to discuss
the plants, animals and geological formations found in the vicinity
of Chicago. In this first issue it may be well to briefly outline the
history and state the objects and aims of the survey.

On the 10th day of May, 1892, the Academy of Sciences
unanimously adopted the recommendation of its Executive Board
that a committee of three be appointed from its active membership |
to conduct a topographical survey of Chicago and vicinity. At the
June meeting of 1892 the Academy adopted the recommendation of
this committee to enlarge the scope of the work so as to embrace
the natural history of the region; the work to be known as the
Geological and Natural History Survey of the Chicago Academy
of Sciences. Three general departments were decided upon :
Geology and allied sciences, Topography, Zoology and Botany.
It was further decided that the work in the several divisions of
these departments should be entrusted to men recognized as
specialists, and published as bulletins and reports, which should be
as nearly monographic as possible.

Since the organization of the survey, the work has been steadily
progressing, and a large amount of data has been collected. It is
eminently fitting that before studying the rocks and higher forms
of vegetable life, the lichens should be taken from the boulders
and the bark and made the subject of the first issue.

The survey comprises a labor both of economic and scientific
value. The publications on geology and topography are awaited
with great interest by contractors, engineers and scientific men
generally. The co operation of practical men in the preparation of
these reports has been spontaneous and very general. It is pro-
posed to show the character of the rock strata underlying our area,
their distance from the surface in different localities, the nature
of the materials resting on the rock, the depth necessary to reach
water, and such general information as will assist builders, well-
borers and engineers in the prosecution of their professions. With
this will be reports on the geological formations, their origins,
extent and relations to the present condition of affairs in Chicago
and vicinity. There are many features of our local fauna and flora

On

which are either unfamiliar or unknown to the majority of the peo-
ple. Hence to place reliable reports on these subjects in the hand
of older workers and beginners, of educators and students, is not
only to increase facilities for information, but to awaken interest
and stimulate investigation.

The area covered by the survey is peculiar in two distinct
systems of drainage, either of which may, under certain conditions,
prevail over the other. ‘This peculiarity of the drainage is of great
scientific interest. To bring out this relief it was thought desirable
to fix upon the following boundaries: Beginning at the north line
of Cook County and Lake Michigan, thence westward, coincident
with the north line of Cook County to Kane County; thence south-
ward along the east line of Kane and Kendall Counties to the south-
east corner of Kendall County; thence eastward, coincident with
the south line of Cook County to the east line of Lake County,
Indiana; thence northward to Lake Michigan.

This gives an area of about forty-eight or fifty miles square,
which, after deducting the approximate area of the lake-covered
portions, leaves nearly eighteen hundred square miles of land sur-
face. It comprises all of Cook and DuPage Counties, the nine
north townships of Will County and a portion of Lake County,
Indiana. Of the proposed reports now in preparation, a list of
which may be found elsewhere, many will be illustrated and some
will describe species. All will give such notes and information as
will be of scientific interest.

It will be the aim of the Board of Managers of the survey to
have specimens in the Academy collection illustrating the local
rocks, minerals, fossils, animals and plants enumerated in the
reports. This will enable the student to compare and study the
objects and not have to depend solely on descriptions.

The first BULLETIN, on the Lichens, is of especial value, because
the field is practically new in our vicinity. Few of our local
botanists have directed their attention to this class of plants. Mr.
Calkins has deposited a complete collection of local lichens in the
Herbarium of the Academy building, and it is hoped that the
BULLETIN, together with the specimens, will develop interest and
investigation in this form of plant life, and lead to the discovery
of many new species and localities. It is desired that all who are
interested in the advancement of science will co-operate with the
Board of Managers by furnishing any data within their reach.

The Lichen-Flora of Chicago and Vicinity.

WILLIAM WIRT CALKINS.

INTRODUCTION.

The following report, based upon my personal investigations,
collections and studies, during a period of many years, has been
prepared by invitation of the Board of Managers of the Geological
and Natural History Survey of The Chicago Academy of Sciences.

As directed by the Board the report covers an area comprising
all of Cook and Du Page Counties, nine townships in the northwest
part of Will County, and a portion of Lake County, Indiana. This
territory might be thought sufficiently large to furnish an attractive
field and ample material for the investigation and study of lichens,
yet with the exception of the most common species, a few of which
are cosmopolitan in their habits, the explorer will meet with a dis-
appointment not to be experienced further south and west in
regions where the conditions of the soil, the geological features of
the country, and the climate favor a larger development of species.
Hence mountainous districts and the extreme South offer the great-
est variety of forms, those of Florida being largely semi-tropical
and identical with West Indian and Central American species,
especially in certain genera, as Graphis and Arthonia. However, in
the field under our consideration, enough varieties occur to form an
excellent preliminary course of study, fitting the student for larger
views and greater results when he has become familiar with the
Parmelias and Physcias which are so abundant on oaks and other
trees along the lake shore and in the ‘‘ wooded islands of the
prairies.”

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 7

The geological conditions in most of our territory are not
favorable to the growth of a great number of species owing to
the absence of forests and out-cropping rocks of different forma-
tions and ages, all having an important bearing, because these are
the substrates to which lichens attach themselves, and the investi-
gator will note at once that certain strata and trees, or the earth,
contain some species not found elsewhere, while others are indif-
ferent as to substrate. Localities in and around Chicago formerly
rich in lichenose vegetation are now destitute of it. The species
were and are mostly corticolous, with afew on rocks, where exposed,
and even on the boulders of our prairies. But the tidal waves of
civilization have changed the conditions under which lichens grow,
and to find them abundantly we must seek the country where the
air on which they feed is pure and the substrates suitable. The
sandy soil of the lake shore only produces them where it 1s covered
or mixed with vegetable mould. Northwards from the limits of
Chicago the genera Cladonia and Peltigera are found in the woods
on earth. The scarce growth of Birch (Betula papyracea), near
Glencoe, contains two species rare «in this section. These are
Sagediaoxyspora, Tuckerm. and Pyrenula thelena, Tuckerm. The
former is peculiar to that substrate. On trees, notably the oaks,
are abundant growths of Parmelia borreri, Turner, P. caperata,
(L.) Ach., Physcia stellaris, L., Lecanora subfusca, Ach.; and on
hickory, Arthonia lecideella, Nyl. The latter 1s peculiar to this
substrate and the genus rare, in our territory, in species, although
the above and A. spectabilis, Fl., are abundant. Leaving the
vicinity of the lake and the flat-prairies, we find further west and
south the best development of lichen-flora along wooded streams
and on rocks where these are exposed. Gravel, boulders, old
fences, logs and stumps, sustain many species. Newand rare ones
sometimes reward the explorer. At Riverside I found a new
Verrucaria on siliceous deposits and at Joliet, another new spe-
cies, Lecanora perproxima, Nyl., on silurian rocks. Both have
been described by Dr. Nylander, of Paris. The saxicolous
species are the most difficult and many are in confusion. The
occupation and use of nearly all the lands; the denudation of
forests, and drainage of the country, has, as in the case of the
phenogamia, caused many species to disappear entirely from our
territory. The best localities for saxicolous types are in the town-
ship of Lemont and Will County. Hanover and other places
adjacent to streams produce common forms. A few occur on earth

8 THE CHICAGO ACADEMY OF SCIENCES.

and on mosses, which are minute and easily escape detection. On
calcareous soils in Lemont, also in Will County, may be found,
besides Cladonia, the curious Heppia despreauxii, Tuckerm. and
several species of Endocarpon; also a member of the Alge
Nostoc commune, L. The close association of these species,
which I have witnessed in other States on similar strata, 1s worthy
of note. From what has been said it appears that it is not safe to
fix definitely the number or limits of species in any territory,
at this early date of scientific research. The experience of
the author, resulting in the addition of nearly thirty new species of
lichens to botanical science, is proof of the fact that there are
still hundreds of species yet undiscovered.

Some eight years ago Willey estimated that the whole number
of North American species might ultimately reach one thousand,
but that limit has been passed already, as I have the names of over
sixteen hundred, including varieties, and it is not at all probable
that, after the most conservative study and elimination, the number
would be reduced by more than three hundred, if so many.

Having now reviewed in a general way the lichen-flora of the
territory under consideration, it seems proper, as nothing has
ever been published in the West and South regarding Lichens,
beyond mere lists of species, that something should -be said about
the life history of these humble plants, and of the study, develop-
ment and progress of the Science of Lichenology, especially in
the United States. The account must necessarfly be condensed,
but it is believed will be of great utility.

WHAT ARE LICHENS ?

This very natural and primary question may be thus answered:
Lichens are a natural order of aerial plants which are considered as
intermediate between Alga and Fungi, but the limits are still un-
certain. All are Thallophytes destitute of stem, leaf, root, or
flower, and vegetate under the influence of moisture, obtaining the
elements necessary to their growth from the air, and not from their
substrates, as do the Fungi. Consequently lichens are rapid or
slow in growth according to the conditions surrounding them. In
extreme heat they become torpid, or do not fully develop, frequently
appearing on the surface of their substrates as excrescences, wart-

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 9

like or coralloid. This condition gave rise to the pseudo-genus
Lepraria, Isidium, etc., not now recognized. Lichens may grow
for a century or more, and under poor surroundings increase by
bisection, ike Algze. They will be found under these conditions
near towns and cities, where the air is not pure.

The thallus and the apothecium, or fruit, are the parts of the
plant to first attract attention in the higher lichens—for example,
the Parmelias, socommon on our oaks. The thallus is attached
to its substrate by fibrils, or is subcortical, but is absent in certain
species, as the parasitic ones.

In the thallus are green cells called gonidia, and other or-
gans, aS spermogonia and pycnidia. Dr. T. M. Fries constructed
a system based on the gonidia, which are variously formed and
colored. The thallus supports the apothecium, which is the
most important part of the plant. This appears on the
surface, disk-like, lirellate, etc., and of several colors, such
as red, orange, black or brown. In some genera the fruit
appears as minute, wart-like bodies, with only a pore (ostiole-
at the summit. In others, as Cladonia, the fruit is at the
end of thalline stalks (podetia), or as in Cetraria, on the edges
of the thallus. There are, however, various modifications of all
these. One peculiarity of some lichens is the power they have to
burrow into the hardest rocks, even flint and granite, thus making
for themselves homes (foveoli). The poweris furnished by the car-
bonic acid absorbed from the air. As an example, Verrucaria ru-
derella, Nyl., from the limestones of La Salle county, Ill, may be
mentioned. The apothecium contains the germinating cells, or
spores, which are inclosed in sacks, called thekes. There are
many organs, all of which must be examined under the microscope,
and these have been the subject of profound study and discussion
many years, but especially since the microscope came into use. On
them many fanciful theories as to the origin of lichens, whether they
are autonomous or not, have been built. Fries called them aerial
alge. Schwendener gives his views as follows, which seems
marvelous, if true: ‘All these plants are not individuals in
the common sense of the term; they are rather colonies, consisting
of hundreds of thousands of individuals, of which one holds the
mastership, while the others, in eternal captivity, prepare the nour-
ishment for themselves and their master. The master is a Fungus
of the class of Ascomycete, a parasite which lives on the labor of

10 THE CHICAGO ACADEMY OF SCIENCES.

others. It encloses them as a spider its prey, with a network of
delicate tissue, which is gradually transformed into an impervious
integument. But while the spider sucks the life out of its prey,
the Fungus stimulates the alge in its grasp to greater activity, to
a more vigorous increase, and thereby renders possible a more lux-
urious growth, and promotes the welfare of the whole colony.” *

However grand the Schwendener theory, the question of auton-
omy is still open, while new discoveries are being made which may
eventually change the whole aspect of the science. Our best way
now is to effect their classification under the present system as elu-
cidated by Tuckerman, but not ignoring others entirely. _

The student seeking to become acquainted with lichens will
soon learn to distinguish those highest in the scale, as Parmelia and
Physcia, in our vicinity, by the prominent, foliaceous thallus,
and apothecium, and having fixed the external character in his
mind, will soon associate with them others of similar appearance,
yet differing to some extent in thallus and fruit. In the same man-
ner he will identify and bring together species of other genera,
and perhaps stumbling on forms of Lecanora and Pyrenula, lower
in the scale, observe the characters that seem prominent and com-
mon to all. Experience will enable him to determine very many of
our common species from external characters alone, as indeed, the
early lichenologists determined them all, even up to the time of
Webber and Acharius.

THE DIVISIONS OF LICHENS.

All our lichens may be placed in one of the two series into
which they are divided by the fruit. First, the Gymnocarpi, those
with open fruit; second, the Angiocarpi, those with closed fruit
Pyrenocarpous). There are five tribes, Parmeliacei, Lecideacei,
Graphidacei, Caliciacei, Verrucariacei. Only the last belongs to the -
second series. The tribes are based on the apothecia; families on
the thallus and fruit. Genera and species follow. Other sub-
divisions are made for convenience, and sometimes at the caprice
of authors,

* Die Algentypn Flechtengonidien.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 11

THE THALLUS AND APOTHECIUM——SOME OF THEIR ORGANS,

The thallus, when present, and the apothecium, are to be con-
sidered and studied externally, but the organs of the plant must
be examined with the microscope. Some of these have been
mentioned, and I can only refer briefly to others, doing so in order
to guide the first steps of the explorer, who, at every advance, will
meet with new problems and find all aids necessary. In exami-
nation, the membraneous thallus, cut in a thin section, will show
above what is known as the cortical layer of minute aggregated
cellules; next, the gonidial layer of green cells; then will follow
compacted filaments (hyphe), and in this formation rest the goni-
dia. Below is the inferior cortical layer, from which, in many species,
proceed fibrils (hypothallus), attaching the plant to its substrate.
Some lichens, such as the parasitic, and some others, Peltigera and
Collema, have no thallus; either the upper or lower cortical layer
may be absent, or but one scantily represented. The gonidial
and other wart-like eruptions sometimes appearing on the crust
(soredia), constituted the basis of the old pseudo-genera. The
color of the thallus above and below may differ, as in Sticta. The
gonidia of divers forms and colors are variously placed, singly or
grouped, or of conferve-like character. *

The apothecium, which has been slightly noticed, whatever its
shape, has a uniformity of internal structure. The disk-epithecium,
(exciple), contains the other organs, and is enclosed by a margin,
which may be formed from the thallus (thalline margin). It is
then known as lecanorine. When the margin or border is not
thalline the apothecium is lecideine. Then there is the nuc-
eliform apothecium of angiocarpous lichens. The exciple, when
colored or blackened, is biatorine; when composite, zeorine.
Grouped apothecia form a stroma. The perithecium and
amphithecium of the angiocarpous lichens are the outer and
inner coverings; within is the nucleus. A section of the apothecium
viewed under the lens, shows the epithecium to be of colored,
granular matter and borne on the apices of what are termed the
paraphyses—slender filaments growing from the medullary layer.
The apices are globular or clavate. The thalline exciple contain-
ing gonidia, and the hymenium, bearing the thekes, within which
are the spores, will be seen. The hymenium is either colored or

*Th. M, Fries, Dr, Minks and others as to their systematic value,

12 THE CHICAGO ACADEMY OF SCIENCES.

colorless. The thekes vary in shape, linear, clavate, etc., and are
large or small, according to the spores. The latter are variable in
form, size and color, as well as in number; they are either simple
or divided by transverse septa into cells, usually eight, when they
are called eight-locular; if more, pluri or multi localar, but there
may be less. When it is also divided longitudinally it is called
a muriform spore. The examiner will often find no spores, hence
should have fresh plants, particularly of Arthonia. The spore
may be less than a thousandth of a millimetre in diameter, but
some can be seen with an ordinary lens. Much importance is
attached to the colors and shape of the spores. Spermagones
have been mentioned. These will exhibit, arising from them,
small filaments, which if simple are called sterigmata; if articulate,
arthrosterigmata, to which are attached minute bodies (spermatia)
which are various in form. Nylander, Minks and others have
theorized and written learnedly in regard to their functions.

It would be desirable to explain further in regard to the
spores and other organs entering into lichens, but these can be
studied to better advantage after one has acquired some knowledge
of the more obvious characters, besides no one can do much with
any satisfaction until he has studied our greatest American
authority, Tuckerman, and with his works those of the great
Lichenologists of Europe, a few of whom are mentioned hereafter.
Armed with these, a genuine love and adaptability, success is
assured up to a limit, for it is not probable that all the secret
processes of nature can be wrested from her grasp by even the
greatest minds in a single lifetime.

THE DEVELOPMENT AND PROGRESS OF THE SCIENCE OF LICHENOLOGY.

The study of lichens wastor many years, on account of its sup-
posed difficulties, confined in this country to a very few persons,
who lived remote from each other. Thus it has a scattered and
little known literature, which, however meager in quantity and
quality (with the exception of the works of Tuckerman and
Willey), has proved almost inaccessible to students, or those who
otherwise would have become interested in a branch of botany now
assuming more importance among American students. There were,
also, other reasons why so few botanists pursued the study. Until
the late Professor Edward Tuckerman published his great works
upon American Lichens, the results of a life-time of devoted labor,

THE LICHEN-FLORA OF CHICAGO AND VICINITY. Ne

there was not in the United States any lichenological literature
worthy of the name; na system of classification of American origin,
under which our vast and rich lichen-flora could be arranged.
Students were dependent entirely upon the works of Euporean
authors, and these were mostly in foreign languages not easily to be
obtained or understood here, except by the very few, who, like
Tuckerman, lived under the shadow of a great university and had a
liberal education. Thus it was that New England almost wholly
absorbed the study of this branch of science. Also, every Euro-
pean lichenologist had a system of his own, and no two could
agree on a uniform method of classification applicable to the
species known and the many new forms being constantly dis-
covered.

In ancient times nothing was known of lichens as a distinct
order of plants, but one or two species have been found in coffins,
no doubt used for padding. A reference to the old herbalists of the
twelfth and fifteenth centuries show that lichens then went under
and were considered allied

”?

the names of ‘‘fuscus’ or ‘‘ muscus,
to the mosses. They began to attract more attention in the six-
teenth century, and over twenty species were described. The gen-
eral revival of all learning after the dark, middle ages, stimulated
the study of botany, and lichens shared in the benefit. It was
then that Tournefort separated them from the musci, and included
all then known under the general name, Lichens. This distinctive
term was accepted and used by the great Linnaeus. From sixteen
hundred to the Acharian period, about 1802, rapid progress was
made in the study. During this period lived Micheli, Webber,
Dillenius, of Oxford, Hoffman, Linnaeus and Acharius, the
‘« Father of Lichenology.” All these were celebrated for their
learning and published works upon lichens. Over three hundred
species became known up to 1750, and were arranged in natural
groups and genera, many of which still stand. Their chemistry
and economic uses were studied, and collections of lichens made.
But the best thoughts of investigators in the latter part of the
eighteenth and the first years of the nineteenth century found a
truer expression at last in 1803, when Acharius published the re-
sult of his studies in the Methodus Lichenum, followed in 1810 by
his Lichenographia Universalis, and in 1814 by the Synopsis
Lichenum. These gave full accounts of all the then known species,
over nine hundred. A number of American species are mentioned.

14 THE CHICAGO ACADEMY OF SCIENCES,

He made no use of the spores and thekes in his classification. The
system he founded was long used and made his name immortal.
In 1831, Elias Fries, the great Swedish botanist, published the
Lichenographia Europea Reformata, and gave utterance to views —
that have influenced all later studies of the greatest students
of lichens. He divided them into eight tribes, of which five now
stand as given elsewhere. He also made further divisions which
subsequent writers changed or assumed. The views of Fries were
so far in advance of others and his work as a systematist so highly
regarded, that Tuckerman referring to the advances made in the
study of lichens, says: ‘‘ The whole movement took its start from
the results gained by the unsurpassed penetration of Elias Fries.”

But the period was a golden one and prolific of eminent
botanists—Nylander, Eschweiler, Fee, Wallroth, Schaerer, Mon-
tagne and Floerke, all systematists. There were also many others
of great eminence in Lichenology. Of the above Dr. William
Nylander, who still survives, is the most celebrated. He has
not only published many philosophic papers and works, but has
described more new species than any other man, and his knowledge
of lichens exceeds that of all others. Dr. J. Muller is hardly less
distinguished, however, while Dr. Minks, and Schwendener, have
achieved renown by wonderful discoveries as to the anatomy and
growth of lichens, which, if they are confirmed, will overturn all
previous theories. From what has been stated it will be seen that
Europe had monopolized the field of study, and naturally enough,
for America was young.

It was at such a time that Tuckerman, who had turned early to
the investigation of lichens, became an earnest student of the
great European botanists, particularly of Acharius, Fries and
Nylander. Assisted in the field by several enthusiastic workers,
portions of New England were explored and the lichen-flora
studied and made known to the world. As his views enlarged
he gradually came to have conclusions of his own as to the
systematic arrangement of the species in harmonious and natural
relations with each other. The great Swede seems to have
been his guide in part, while Nylander was not disregarded, nor in
later years the new discoveries of Minks, Tulasne, Bayerhoffer and
others. ‘Tuckerman was pre-eminent as a systematist, and the full
elucidation of his views will be found in his works—The Lichens of
California, 1866; General Lichenum, 1872; and his Synopsis,

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 15

Part I., 1882. A close study of these will show how very near he
came to nature in his reading of her laws as applied to the lichens,
and how well he succeeded when he came to their arrangement.
The key to his success may be found in his expression—‘‘ Ap-
prehension of the Habit of Lichens.” This was certainly an in-
spired faculty and led him to forecast the relations of lichens by
which they could be placed in the system he established, as Tribes,
Families, Groups, Genera, Species, etc. The one great American
Lichenologist is dead, but the services performed cannot be over-
estimated. Part II. of his Synopsis, left incomplete at his death,
which occurred March 15, 1886, was edited and published by Henry
Willey, Tuckerman’s life-long collaborator, in 1888. The foregoing
were by no means all of Tuckerman’s works, but they are the most
important, on which rests the solid basis of his fame. As a supple-
ment to the labors of Tuckerman, American Lichenology has been
benefitted by Henry Willey, in his publication, ‘‘ Synopsis of the
Genus Arthonia,” and his introduction to the “ Study of Lichens,”’
but these must be considered rather as aids to be used in connec-
tion with the study of other authors, While the publications
mentioned are the chief ones in this country, monographs upon a
single genus, or species, have appeared from time to time; also
local lists and brief papers, and these evince the interest awakened,
which no doubt received its impelling force from a knowledge of
the genius and labors of Tuckerman.

THE ECONOMIC USES OF LICHENS,

A few remarks on this subject will show how large a part
these seemingly humble plants play in the economy of life. The
Reindeer Moss (Cladonia rangiferina) furnishes not only food for
the reindeer in the Arctic regions, but alcohol and brandy are
distilled from it by the natives of Norway, Sweden and other
countries. The Iceland Moss (Cetraria Islandica) has long been
in use, both for food and medicine. Cetraria nivalis is also eaten.
In Africa Lecanora esculenta is so abundant on sandy plains that
it is gathered for food for man and beast. Many Arctic voyagers
have prolonged and saved their lives by the use of species of
Umbilicaria—rock-lichens (Zripe.de roche). In Japan a species of
the genus Endocarpon,, also common in Illinois, is used as food.
Valuable dyes were formerly obtained from several lichens, such as
Roccella tinctoria, Lecanora tartaraea, Parmelias, etc. The new

16 THE CHICAGO ACADEMY OF SCIENCES.

discoveries in chemistry did away with their use in civilized
nations. Lichens were once valued highly as remedies for various
diseases, and some species are still used, as Peltigera canina.
Theloschistes parietinus, Cladonia aphthosa, and numerous other
forms of various genera, all common to our own country and
easy of investigation by students.

LICHENS OF THE TERRITORY INCLUDED IN THE SURVEY.

The species enumerated are represented in the ‘‘ Exsiccati of
North American Lichens,” deposited in the collection of the Chi-
cago Academy of Sciences by the author. The descriptions of
species are made from studies of the specimens, comparisons, and
study of other authors.

SERIES 1, GYMNOCARPI,

TRIBE 1. PARMELIACEI.

RAMIDY 1: USNEET.

Ramalina, (Ach.) De Not. Thallus fruticulose, or pendulous, sub-
compressed, pale-greenish; apothecia scattered, or marginal,
scutellaform. Spores colorless, bilocular.

1. R, calicaris, (L.) Fr. Thallus tufted, rather rigid; longitudinally
lacunose; apothecia flattish. Spores ellipsoid.
On oaks near Riverside; at Lemont on stony bluff, and in Will
County.

2. R, calicaris, Fr., var. fraxinea, Fr. Phallus wide and long-lobed;
apothecia lateral.
On oaks and old fences near Lemont.

3. R. calicaris, Fr., var. fastigiata, Fr. Lobes short, often straw-
colored, crowded, branched; apothecia terminal, subfastigiate.
Along lake shore and throughout our territory, on oaks.

Cetraria, (Ach.) Fr., Mull. Thallus ascendant with compressed,
turgid, or channelled branches; or may be expanded and
foliaceous-membranaceous; brown, yellowish, or glaucescent;
apothecia marginal or submarginal, scutellaform, often dilate.
Spores sub ellipsoid.

4. C, ciliaris, (Ach.) Thallus membranaceous, foliaceous, sinuate-
laciniate; greenish or brownish; brownish beneath, fibrillose;
lobes crowded, often narrowed and cleft, lacunose; apothecia
marginal, ample; disk chestnut, margin crenulate. Spores
subellipsoid. Ach. L. U., p. 508. Platisma, Nyl. 5, Syn: 308.
On old rails in Lemont Township; on old birch at Glencoe.

5. CG, aleurites, (Ach.) Th. Fr. Thallus membranaceous, foliace-
ous, divided or cleft, isidiod, plicate at centre; beneath pale,
wrinkled, fibrillose; lobes sinuate-laciniate, with crenate tips;
apothecia marginal, granulate on the margin, brown, medium
size. Spores round.

On old rails near Lemont and Joliet.

18 THE CHICAGO ACADEMY OF SCIENCES.

FAMILY 2. PARMELIEI. °

Theloschistes, Norm. (Physcia, Nyl.) Thallus foliaceous or re-
duced, appressed or ascendant; membranaceous, orange or
yellowish, apothecia scutelleform; disk yellow, orange or
greenish-yellow. Spores ellipsoid, polar-bilocular or simple.

6. T, chrysophthalmus, (L.) Norm. Thallus tufted, more or less
erect, spreading; the branches narrow, linear, smooth or
puberulent; tips mostly fibrillose and ramulose; apothecia
few; disk orange, which is often fibrillose. Spores ellipsoid.
Parmelia chrysophthalma. Ach. M. L. 267.

In Hanover Township, Cook County, and Will County; at
Lemont, on old rails in woods. Also on cld oak trees near
the lake shore, Lake View.

i. T, parietinus, (L.) Norm. Thallus, foliaceous, sub-orbicular,

crenate, yellow and orange, lobes appressed, sub-imbricate,

radiant, rounded; apothecia small to ample, orange, border

entire or flexuous. Spores ellipsoid. Parmelia, Fr., L. E. 72;

Manthonias “ahs kine wa Scand 45:

Along the lake shore, on oaks and poplars; also in Lemont
and elsewhere.

8. T, lychneus, (Nyl.) Thallus reduced, substellate, or effuse, yel-
low; apothecia scattered; yellow-orange, entire or granulate.
Spores ellipsoid. -

On walnut and hickories, west part of Cook County and else-
where. It has a numerous synonomy, and is often con-
sidered a variety of No. 7.

9. T, concolar, (Dickson) Tuckerm. Thallus foliaceous, orbicu-
lar, greenish-yellow; divisions narrow, much dissected; beneath
pale, fibrillose; apothecia small, yellow or rufous. Spores
numerous. _Physcia candelaria, Nyl., etc.

On various trees along the lake shore at Glencoe. All the
genus may be distinguished by the golden or yellow thallus.
May be mistaken for Placodium.

Parmelia, (Ach.) De Not. Thallus imbricate-—foliaceous, lobate or
laciniate, appressed, membranaceous; more or less fibrillose,
sometimes densely so; apothecia scutellaform, slightly pedi-
cellate. Spores ellipsoid. _Vzde Schwendener.

10.

Ii,

13.

14.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 19

P, perlata, (L.) Ach. Thallus greenish-glaucescent, or whitish;
dilated; lobes rounded, often sorediate, undulate; black be-
neath, with brown margins; apothecia small to large, rufous,
emtire, Ach. L. U. 459, ete:

Found throughout our territory on oaks and other trees, and
on boulders near Lemont.

P, perforata, (Jacq.) Ach. Thallus whitish, much dilated; cori-
aceous, membranaceous, glaucescent, smooth, sinuate lobed;
beneath black or fuscous; fibrillose; apothecia very large, per-
forate, cyathiform; disk fuscuous or rufous. Spores ellipsoid.
Clee Wi. 459> etc:

On various trees in Cook and Will Counties. A common spe-
cies.

. P, crinitaas Ach. Thallus dilated, membranaceous, surface

covered with minute granules and branchlets; black beneath
and fibrillose; lobes ciliate; apothecia ample, cyathiform; disk
Ghtestmutts Hie, Wes 5358.

On oaks in Hanover Township; on detached rock near Le-
mont; not common.

P, cetrata, Ach. Thallus greenish, dilated, rather thin, smooth;
beneath black and hispid; the sinuate lobes sorediferous on
the margins, narrowed, soon prolonged; apothecia medium size,
caestnut. Ach. Syn. 1, 198) ete.

On trees and stones near Lemont and westward.

P. tiliacea, (Hoffm) Fl. Thallus smooth, closely adnate, much
narrowed, membranaceous, margins crenate; lobes rounded,
sinuate-laciniate; apothecia medium size, few, margins crenu-
letem hain a 59) ete.

On oaks at Riverside, Lemont and Hanover. There are
varieties in the South.

. P. tiliacea, Fl., var. sulphurosa, Tuck. Medullary layer sulphur-

yellow; otherwise like the species. Tuckerm, Syn. 1, 57.

Found near Elgin on oak trees. Will probably be found else-
where.

16.

ie)

THE CHICAGO ACADEMY OJ SCIENCES.

P, borreri, Turner. Thallus cinereous, glaucescent; lobes large
or narrow, rugulose; beset with round soredia; membranace-
ous; pale brown beneath, fibrillose, dense; apothecia large,
badio-rufous, margin entire. Spores rounded. Turner. Linn.
ne lace eo NcheleanO) 4 Gllpmetc:

Very common everywhere in our territory, especially on oaks.

_P. borreri, Turn., var. rudecta, Tuckerm. Thallus isidioid.

Nele Syne 1974) ) Wuckerme sy mess.

Occurs on oaks in the west part of Cook County, and at
Lemont and Joliet.

P, saxatilis, (L.) Fr. Thallus glaucous-cinerascent, membran-
aceous, more or less lacunose, ramose; isidiophorous; beneath
black and densely fibrillose; lobes sinuate-multifid, incised;
apothecia large, disk fuscous, or spadiceous, margin subcrenu-
late: Spores*ellipsoid=—Fr. i. E. 615 NylSyaeesees

Found on trees in Cook County near Elgin and on recent sand-
stones and boulders at Lemont.

19. P, saxatilis, Fr., var. sulcatas Nyl. On bluff boulders and

“stones near Lemont, and in Will County. Very fine specimens
may be gathered in LaSalle County.

The very numerous soredia, which are round or oblong, con-
fluent and reticulate, mark the variety. Tuck. Syn. 58.

20. P. physodes, (L.) Ach. Thallus loosely attached, substellate,

whitish, coriaceous, glaucous; beneath fuscous-black, no fibrils;
lobes many cleft, complicate, often with white soredia; apothe-
cia medium to large, badio-rufescent, margin. nearly entire,
Spores subellipsoid. Ach.S: UL. 218.) Duckernm,. \Syiuees Seeres
Occurs on oaks in Cook and Du Page Counties, and elsewhere,

There are several varieties in other States.

. P. caperata, (L.) Ach, Thallus substramineous, dilated, cor-

iaceous, undulate-plicate, often sorediate; beneath black,
fibrillose; lobes sinuately-laciniate, rounded tips; apothecia

large, chestnut, margin subcrenulate, often sorediate. Ach..
S. ©..896; (etc:

Very common on Oaks everywhere. The fruit is seldom seen
here, but the lichen is conspicuous for size and color.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 21

22.-P, conspersa, (Ehrh.) Ach., Thallus straw-colored, greenish,
laciniate, much divided, appressed, often isidiophorous in the
centre; beneath fuscous-black, sparingly nigro-fibrillose; lobes
sinuate, often crenate, or pinnatifid, complicate; apothecia
large, chestnut, margin subcrenulate. Spores ellipsoid, simple.
Ach. L. U. 486. Muhl. Catal. 1818 Tuckerm. Syn. 64, etc.

In Lemont and Will County on stones; also found near Elgin
on old wood. This species has a wide distribution in the
United States.

23. P, colopodes, (Ach.) Nyl. Thallus coriaceous, glaucescent, be-
neath dark brown, spongy nap, with a few fibrils; lobes sin-
uate-cleft, flat; apothecia large, disk chestnut. Spores numer-
Cisse buck, Syn. Gl; Nyl. Syn-., etc.

On oaks near Lemont. ‘There is a very narrow lobed form not
as yet observed here.

Physcia, (D. C., Fr.) Th. Fr. Thallus foliaceous, variously
divided, stellate, somewhat fibrillose; apothecia scutelle-
form. Spores ellipsoid, bilocular.

24 P, speciosa, (Wulf.) Nyl. Thallus greenish, glaucous, loosely
stellate, appressed, beneath corticate, rhizine whitish; lobes
sinuate, flat, pinnatifid, with powdery margins; apothecia me-
dium size, sessile, margin crenulate; disk fuscous. Spores
bilocilar sParmelia’ speciosa, Ach. L. U. 480; Fr. L. E. 80;

~ Tuck. exs. n. 81; Calkins exs.

Occurs at Riverside on oaks; on hickories, near Elgin and
other localities.

25. P, stellaris, (L.) Nyl. Thallus albo-glaucescent, stellate, ap-
pressed, orbicular; beneath pale, fibrillose, lobes linear, many-
cleft, compaginate, or discrete; apothecia small, sessile;
disk fuscous-black, often grey-pruinose, margin entire or
chemumlate. Parmelia, Pr: Ll. BE. 82.

This, the most common species of the genus, occurs every-
where on oaks, hickories and other trees, as well as on rocks.

26. P, stellaris, (L.) Nyl., var. aipolia, Nyl. Thallus brown be-
coming blackish, beneath black, fibrils hispid; apothecia sub-
qerenace, NivleScand:, Mit. ‘Parmelia, Ach. S. L. 215.

Found on boulders of the prairies and on stones at Lemont.

22 THE CHICAGO ACADEMY OF SCIENCES.

97. P, tribacia, (Ach.) Tuckerm. .Thallus smallish, membranace-
ous, sub-stellate, glaucescent; beneath white, fibrillose; lobes
short, appressed; margins erose, granulate; apothecia small,
sessile, black or pruinose, margin sub-entire. Lecanora, Ach.
Seale ke metic

On elms at Glencoe, and in other localities on hickory.
A variety of P. stellaris, (d.) of Tuck. Syn., 75.

928. P, obscura, (Ehrh.) Nyl. Thallus stellate, orbicular, appressed,
epruinose, glaucous, fuscescent, beneath black, fibrillose, lobes
many-cleft, flatish; ciliate; apothecia rather small; disk nigro-
fuscous, marginentire. Spores bilocular. Th. Fr., Scand. 142.
Harmelia, Fr. L. E. 84.

On hickories and other trees in west part of Cook County; near
Lemont and Joliet on trees and calcareous rocks. Quite
variable everywhere, having several forms.

29. P, adglutinata, (L.) Nyl. Thallus often slightly olivaceous, also
cinerascent and brown, adheres closely to substrate, small;
lobes thin, flat, compaginate; apothecia small, disk nigro-
fuscous, margin entire. Nyl. Syn. 438, etc.

On elms and hickories in Cook and Will Counties. This is a
well marked species.

30. P, granulifera, (Ach.) Tuckerm. Thallus glaucescent and
white, pruinose, be-sprinkled with powdery granules; beneath
pale, corticate, fibrils black; lobes multifid, dentate-crenate;
apothecia small, inflexed margin crenate. Parmelia, Ach.
Syne Lato) tucker: Obs 390:

Found on hickories near Elgin and at Lemont.

A variety
of P. speciosa (e. of Tuck.), but quite marked.

FAMILY 3. PELTIGEREI.

Peltigera, (Willd., Hoffm.) Fee. Thallus membranaceous, lobate,
frondose, foliaceous; beneath somewhat villous, marked with
veins, occasionally cyphels; apothecia pelteform. Spores
fusiform. Cortical layer, in some species consisting of
gonidia, in others, of gonimia.

THE LICHEN-FLORA OF CHICAGO AND VICINITY.

bo
(su)

31. P, rufescens, (Neck.) Hoffm. Thallus large, coriaceous, rotund,
lobate, lobes elevated and crisp, ash colored to reddish-brown;
beneath reticulated with brown veins, fibrillose; apothecia on
lobules, large; disk revolute, rufo fuscous. Spores acicular.
Breet 46.) luck. exs: n- 104.9. Calkins. exs.

Occurs at Glencoe in ravines and on hillsides, on earth and old
mossy logs. Found also at River Forest near the Desplaines
River and throughout our territory.* Tuckerman says this
species stands in embarrassing relations to P. canina.

FAMILY 4. PANNARIEI.

Heppia, Naeg, Thallus squamose-foliaceous, monophyllous, Goni-
mous layer of gonimia; apothecia round, immersed. Spores
ovoid.

32. H, despreauxii, (Mont.) Tuckerm. Thallus small, round,
smooth, or regulose, green; apothecia separate, or in roset-
tes, sunken in thallus, disk reddish or salmon-colored.

Found on calcareous earth near Lemont. This curious lichen
being very small is not easily seen. It seems always to be
associated with Endocarpon hepaticum in habitat, and has
often been mistaken for a fungus.

Pannaria, Delis, Thallus squamulose, subfolaceous or mono:
phyllous, the hypothallus spongy or obsolete; apothecia
scutelleeform, with both thalline and proper margins, frequently
biatorine. Gonimous layer of both gonidia and gonimia.

33. P, nigra, (Huds.) Nyl. Thallus squamulose, minute, lead
colored, and mostly merged into a granuloid crust; apothecia
small, biatorine, sessile; disk black, margin entire.

On calcarieous rocks near Lemont and in Will County.

FAMILY 5.. COLLEMEI.

Collema, (Hoffm.) Fr. Thallus greenish, cortical layer obsolete;
' gonimia in chains; apothecia very small to middle size;
scutelleform. Spores variously shaped.

* Other species of this genius are likely to occur.

00.

Bil

39.

THE CHICAGO ACADEMY OF SCIENCES.

. CG. pycnocarpum, Nyl. Thallus small, pale, green, sub-orbi-

cular, lobes radiate, narrowed, fenestrate, ribbed, the marginal
lobules densely fruited; apothecia small; disk reddish, exclud-
ing margin. Spores ovoid ellipsoid, bilocular, decolorate.
Nive Syne, lls

Found on elms and shrubs in Will County; rare.

C. microphyllum, Ach. Thallus small, fuscous-green, or
olivaceous, orbicular, diffract or effuse, microphylline; lobes
often granulate, crenate at centre; apothecia abundant, small,
urceolate, rufescent, flat; thalline margin entire, concolorous.
Spores sub-muriform. Ach. Syn. L., 310.

On elm bark; Cook and Will Counties; rare.

._ G flaccidum, Ach. Thallus dark-green, or olive-green; lobes

large, expanded, bullate, entire, with concolorous granules, un-
dulate plicate, paler beneath; apothecia small, sessile; disk
rufescent, margin entire. Spores ovoid. Ach. Syn. L., 322;
huckesGens. oil

Occurs near Elgin and Joliet on oaks and elms; rare. May
be found on rocks also.

C. tenax, (Sw.) Ach. Thallus thin, lobes wide, appressed, also
ascendant, lead-colored; apothecia often immersed; disk rufes-
cent, the margin entire or rogose. Var. c. of G, pulposum,
Tuck., exs. n., 148. Calkins, exs:

Found near Joliet on calcareous soil; rare.

GC, limosum, Ach. Thallus thin, dark green, scattered, slightly
crenate, pulpy when wet; apothecia rufous, immersed but
becoming superficial, margin prominent, entire or somewhat
crenulate, Spores in fours in the thekes. Nyl. Syn., 110.

Inhabits clay soil. Waull County; rare.

C, granosum, (Wulf.) Schaerer. Thallus small, rigid, gelatin-
ous when wet; lead-colored; lobes ample, rounded or elong-
gated and divided; apothecia of medium size, sessile; disk
red@ish, dark. C. dermatinum, Ach. L. U., 64.

On mossy rocks near Desplains River, Will County.

Leptogium, (Fr.) Nyl. Thallus Rolaeaawe. or fruticulose, cortical

layer distinct; gonimia in chains; apothecia sub-scutelleform,
lecanorine or sub-biatorine. Spores of various forms.

40.

4].

43.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 25

L. lacerum, (Sw.) Nyl. Thallus plumbeo-fuscescent, lacero-
laciniate, ample, wrinkled, the lobes dilated above and sinuate,
thin, crisped and dentate; apothecia small, pale-red, sub-ses-
sile, margin entire. Spores ovoid-ellipsoid. Ach. L. U. 657.

On elms in Hanover Township, near Elgin; also in Will County.

L, chloromelum, (Sw.) Nyl, Thallus small to large; orbiculate,
rigid; plumbeo-virescent, lobate, plicate, rugose; apothecia
medium size, lecanorine, plane, rufous, the thalline margin
granulate. Spores ovoid. Nyl.Syn. 128. Tuck. Gen. 98.

On elms in Hanover Township, near Elgin; also in Wiil
County. The varieties are found further south.

. L,myochroum, (Ehrh. Schaerer) Tuckerm. Thallus ample, cori-

aceous, membranaceous, sub-monophyllous, also loosely at-
tached, lead colored and blackish; beneath has a whitish nap;
apothecia reddish, border plicate. Spores ellipsoid. Tuck. 99.

On the same substrate as the preceding species, Will County.

L. pulchellum, (Ach.) Nyl. Thallus small to large, rosulate,

‘glaucous green, lobes plicate, papulose, wrinkled above and

beneath and pitted; apothecia medium size, lecanorine, sub-
pedicellate, disk fusco-rufous, finally excluding the smooth or
finally rugose thalline margin. Spores ovoid-ellipsoid, sub-
muriform, decolorate. Collema, Ach. Syn. L. 321. Tuck.
Syaeloles = Calkins; -exs,

Found on calcareous rocks in Will County, and on elms in
Cook County. Better developed further south in this State.

FAMILY 6. LECANOREI.

Placodium, (D C.) Naeg. & Hepp. Thallus crustaceous, lobed,

suffruticulose, or uniform; apothecia sub-scutellaform, leca-
norine or sub-biatorine; disk usually yellow or orange.
Spores ellipsoid, polar-bilocular, colorless.

44 P, cinnabarinum, (Ach.) Anzi. Thallus rimose-areolate, more

often of applanate scales, crenate, and crowded into an
imbricate crust, orange; apothecia minute or small, adnate;
disk orange, margin entire. Spores ellipsoid. Lecanora, Ach,
ane 402= Rarmelia, Hr. 1. Hs 165.

Very common on calcareous and arenaceous rocks in our

territory.

45.

48,

THE CHICAGO ACADEMY OF SCIENCES.

P, microphyllum, Tuckerm. Thallus squamulose; from green-
ish-yellow to orange; scales adnate, crowded and concealed by
granules; apothecia small, adnate, flat, orange; proper
margin entire, the thalline one crenulate. Spores ellipsoid.
Tuck, Syn. 174.

Found near Lemont, on old fence panels, and in Will County.

. P, aurantiacum, (Light.) Naeg. & Hepp. Thallus uneven and

chinky, warted, broken; yellow or variously colored, often

bordered by a dark hypothallus; apothecia fair size, sessile,

zeorine, flat; disk lemon, saffron or tawny colored; proper
margin thin, the thalline one crenulate or may be obsolete.

Parmelia, Fr. > E. 165. Lecanora, Nyl) Scandait2asiuers

Syne el 74.9) Calkins mexs.

On elms and poplars at Glencoe; on hickories and other trees
along the Desplaines river; on rocks at Lemont, and else-
where. Thallus and apothecia lemon color, in our specimens;
abundant.

e

. P, ferrugineum, (Hudson) Hepp. Thallus chinky, verruculose,

ash-colored, upon a black hypothallus; apothecia fair size,
mostly biatorine, sessile, flattish; disk opaque, rust-colored, or
fulvous, bordered by a crisp proper margin, -often enclosed in
a thalline one; Parmelia;, Pr E7170. Caloplacareitnem iia
Sean, Us, Welk, Syria Ia

On oaks along the Desplaines river and near Elgin on
hickories. Not so common as the preceding species, but
plentiful.

P, vitellinum, Ehrh. Thallus effuse, tartareous, squamaceous,
of crenate granules, crowded into heap-like areoles, often
dispersed, greenish-yellow; apothecia small, sessile, flat, yel-
low; thalline margin granulate-crenate. Spores numerous,
simple and bilocular. Fro. EB. 162) NylSeancdaasieoe
ihuck. (Syn. 180).

Found on dead wood and rails in Lemont Township. Not
common for lack of proper conditions.

Lecanora, (Ach.) Tuckerm. Thallus crustaceous; mostly uniform;

apothecia scutelleform, or zeorine.. Spores ellipsoid, or
oblong.

THE LICHEN-FLORA OF CHTCAGO AND VICINITY. Ol

49. L, pallida, (Schreb.) Schaerer. Thallus thin, membranaceous,

50.

53.

54.

Bll,

smooth, cream-colored or darker; apothecia sessile, tumid;
whitish-buff, white-pruinose, the entire margin disappearing.
Spores ellipsoid. Parmelia, Schaer. Spicil. 396. Tuck. Syn.,
185.

On oaks and hickories near Joliet. This species and its
varieties are more abundant in some localities than in ours.
Varies greatly as to the apothecia.

L, subfusca, (L.) Ach. Thallus whitish or cinerascent, smooth,
rimulose, granulate, verrucose, soon diffract; apothecia plano-
convex, disk fuscous, becoming black, often pruinose, the thal-
line margin entire, flexuous or crenate. Spores ellipsoid.
Parmelia, Schaer. Spicil. 389, etc.

Very common in our territory on oaks and other trees and also
on arenaceous rocks. There are several varieties. I have
specimens from Europe, Japan and the West Indies. Many
species, so called, have been made from this cosmopolite.

L. subfusca, (L.) Ach., var. allophana, Ach. Thallus granu-
late, verrucose; apothecia fuscous-black, margin flexuous and
erenates Wich. Uni. Nyl. 395.

On oaks in various localities; not uncommon.

. L, subfusca, (L.) Ach., var. argentata, Ach. Apothecia smaller,

margin entire. Spores smaller. Lich. Univ. Nyl. Syn. 393.

Occasionally found on shrubs and trees in our territory.

L, subfusca, (L.) Ach., var. distans, Ach.

Common on the same substrates as the preceding forms;
apothecia flat and pale, margin crenulate. Spores smaller
fianinenumber a2. le. distans, Ach. LE. U. 397.

L, hageni, Ach. Thallus cinerascent, verruculose or want-
ing; apothecia small or minute, crowded, plane or tumid; pale
to fusco-rufous or sometimes pruinose; margin white, com-
monly crenate or entire; may be excluded. Th. Fr. Scand.
250. L. umbrina, (Massalongo) Nyl.

On rails near Lemont and on calcareous rocks. Some condi-
tions are known as L. umbrina, (Mass.) Nyl. The observer
cannot but see close relations in L. hageni to L. subfusca
and the next following species.

55.

56.

58.

59.

60.

61.

THE CHICAGO ACADEMY OF SCIENCES,

L, hageni, Ach., var. sambuci, (Pers.) Nyl., L. Sambuci, Nyl.
Th: Er

Found rarely on elms, poplars and shrubs in Will County.

L. varia, (Ehrh.) Ny]. Thallus verruculose, greenish or yel-
lowish; apothecia small, the disk yellow to flesh-color or
rufescent, thin; margin entire or crenulate,- often excluded.
Spores oblong-ellipsoid. Nyl. Scand. 163.

On oaks near Elgin, Lemont and elsewheres” Uhereware
numerous varieties.

L, varia, (Ehrh.) Nyl., var. symmicta, Ach. Thallus thin,
whitish; apothecia yellowish, disk swollen, excluding margin;
biatorord:s rics Ie Ny eeneks Syne

On various trees.

L, calcarea, Sommerf. Thallus white, contiguous; apothecia
innate, emerging; disk grey-pruinose. Spores ovoid-ellipsoid.
Nyl. Scand. 154.

On calcareous rocks at Joliet.

L. calcarea, Sommerf., var. contorta, Fr. Areoles discrete, pale
lead-color. L. calcarea, f. Hoffmani, Nyl.

On calcareous rocks at Joliet. A very curious form.

L, cervina, (Pers.) Nyl. Thallus tartareous, areolate, squam-
ulose; scales sub-peltate, from yellowish to chestnut; apoth-
ecia medium size, impressed, becoming superficial; disk
reddish-brown, thalline margin obsolete. Nyl. Scand. 174.
Tuck. 202.

On detached sandstones in Cook and Will Counties.

L, privigna, (Ach.) Nyl. Thailus wanting; apothecia varying
from small to large; sessile, appressed; scattered or aggre-
gated; disk dark red; margin elevated, rugged, contorted.
Spores numerous, minute Lecidea, Ach. M. L. 49)
Sarcogyne, Koerber, Syst. 266. Biatorella, Th. Fr. Scand.
407.

Found on calcareous pebbles near Elgin, on rocks near Joliet.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 29

62. L, privigna, (Ach.) Nyl., var. pruinosa, (Auctt.) Apothecia
small, appressed, sunken; disk gray-pruinose. Sarcogyne,
Koerber. Lecanora, Nyl.

On sandstone boulders near Lemont. This, and the two pre-
ceding forms, are so nearly related that one is puzzled to
distinguish them without a familiar acquaintance with suites
of specimens from different localities. The most perfect
representations of the variety are from the Trenton rocks of
LaSalle County, Illinois, and from Tennessee.

The variety clavus, Koerber, should be found in our limits
also.

63. L, perproxima,* Nyl. Spec. nova. Resembles L. erysibe,
Ach., nevertheless the spores are larger, .014-18 by .007
mm,, and the hymenial gelatine with iodine is a beautiful blue,
becoming deep blue. In appearance it resembles L. cesio-
cinerea, Nyl.

On calcareous rocks at Joliet and elsewhere.

64. L, erysibe, Ach. Thallus cinerous, thin, diffract; apothecia
fusco-rufous, plane or convex.
On calcareous rocks in Will County; abundant.

Rinodina, Mass. Stizenb. Tuckerm. Thallus crustaceous, apoth-
ecia scutellaform, often zeorine, then lecideine. Spores ellip-
soid, bilocular, brown.

65. R, sophodes, (Ach.) Nyl. Thallus gray or cinereo-fuscescent;
apothecia small, appressed; disk flat, fuscous-black; margin
entire waNyl Scand: 148. Th. Fr. Scand. 199, Tuck. Syn.
207,

On boulders near Lemont. I have not met with it elsewhere
so far north.

66. R, bischoffi, (Hepp.) Koerber. Thallus ash-colored or fusces-
cent; thin, farinose; apothecia small, sessile, flat or convex;
margin fuscescent or cinerascent. Spores broad, fruit finally
fecideord: ~ Lh. Pr .Scand, 204, 1Puck. Syn. 209.

On calcareous rocks at Joliet and Lemont. A little known
species. Occurs more abundantly further south and west.

_ *L. perproxima, Nyl. Spec. Nova. Proxima L. erysibe, Ach. Sporis nonnihil
majoribus, long, 0014-18, crass. 0.007 millim., et gelatina hymenialis. lIodo bene
coerulescente, coerulescentia persistente. Facies fere Lecanora cxwsio-cinerea, Ny.

30

THE CHICAGO ACADEMY GF SCIENCES.

Pertusaria, DC. Thallus crustaceous, continuous, smooth or

67.

69.

70,

Hale

verrucose; apothecia globular, difform, closed; enclosed in
thalline verruce, opening by pores (ostioles); explanate,
lecanoroid. Spores generally large, ellipsoid.

P, velata, (Turn.) Nyl. Thallus white, glaucescent, rugose,
chinky, rimose, radiate near the circumference; apothecia
small, adnate, pale yellowish, white powdery; the thalline
margin disappearing in the fruit. Muhl. Br. L. 274. Tuck.
Syn. 212.

On rocks and trees.

. P, multipuncta, (Turner.) Ny]. Thallus ash colored, rugose,

verrucose, zonate at the circumference; apothecia small, in
verruce—2-4; lecanoroid, finally elevated; disk becoming
black, soon excluding the thalline margin and often forming
powdery heaps. P. faginea, Tuck. Syn. N. E. 64.

On oaks and hickories; not rare.

P. communis, DC. Thallus glaucescent, smooth, chinky or
rugose-verrucose, may become zonate at the circumference;
apothecia small, adnate, depressed, sub-globose, difform,
closed, the numerous ostioles sunken and black. Spores gen-
erally in twos, sometimes solitary. Porina pertusa, (L.) Ach.
Syn, Ik, HOB), ike. :

Common on oaks everywhere in our territory.

P, leioplaca, (Ach.) Schaer. Thallus whitish or more com-
monly pale-yellowish; apothecia medium size, globular and
difform, often crowded together; depressed ostioles indistinct,
often blackening. Nyl. Scand. 181. Tuck. Syn. 215.

On oaks near Elgin and elsewhere.

P, pustulata, (Ach.) Nyl. Thallus greenish or whitish; chinky,
or verruculose; apothecia very small, hemispherical and
difform, globular or confluent; ostioles black. Spores in twos.
PRoring yAchi, ve2 Un S005 me Muck S yn lie

On trees; general in distribution here and elsew here.

Conotrema, Tuckerm. Thallus crustaceous, uniform; apothecia

urceolate, truncate-conoid. Spores cylindraceous, pluri-
locular. :

THE LICHEN-FLORA OF CHICAGO AND VICINITY, 31

72. C. urceolatum, (Ach.) Tuckerm, Thallus smooth, becoming

chinky and rugged, whitish; apothecia small, urceolate, from
black to pruinose; prominent, elevated. Lecidea, Ach. L. U.
Galen Gyrostomum, Mr Duck, Gen Ly 120. Conotrema,
picks Sy mie 217.

This, the only species of the genus and has a wide distribution.
Found on maples and poplars in Cook and Will Counties; ~
also further west and south in Illinois. The genus Gyalecta
should occur with this in our territory, affording at least the
two species, G. lutea and G. trivialis, Willey. They are
very small and may have escaped discovery here, though
found in southern Illinois.

Urceolaria, (Ach.) Flotow. Thallus crustaceous, uniform; apothe-

73.

cia urceolate. Spores ovoid-ellipsoid, muriform, pluri-locular;
fuscescent.

U. scruposa, (L.) Nyl. Thallus tartareous, rugose-plicate;

glaucous, ash-colored or white; apothecia immersed, but

emerging, urceolate, large, black; disk somewhat cinereous;

margin denticulate, hidden by the thalline one, if present.

Nyjleocand=76... Duck, Syn. 229. -Muhl Cat) isis.

Found on calcareous earth in Will County and on dead cedars
along the banks of the Illinois; rare.

TRIBE Il. LECIDEACEI.

FAMILY 7. CLADONIEI.

Cladonia, Hoffman. Thallus squamulose, rarely granulose or

74,

deficient; apothecia variously colored, but never black; soon
inflated and cephaloid; podetia fistulous, funnel or tubulose in
Shape, often shrub-like. Spores small. Tulasne, Mem. sur.
les Lich. Tuck. Gen. Lich. and Syn.

C, mitrula, Tuckerm. Thallus of small squamules, minute,
green; podetia short, granulate, glaucescent; apothecia con-
fluent, flesh-colored or brown. Tuck. in Fl. Cestrica. 444,
Nyie Syn. 203,

-On earth and old logs in Cook and Will Counties, Generally

distributed west and south.

32

75.

~T
O

Io:

80.

Slt.

THE CHICAGO ACADEMY OJF SCIENCES.

C, pyxidata, (L.) Fr. Thallus squamulose; podetia cup-shaped,

warty, turbinate, ash-colored; the cups cyathiform; often

proliferous; apothecia brown. Nyl. Syn. 192. Tuck. Syn.

241.

Formerly abundant on earth along the lake shore in woods.
Common elsewhere in our territory, on earth and rocks,

. CG, pyxidata, (L_) Fr., var. Pocillum, Ach. Has foliaceous thal-

lus and reduced podetia.

Occurs rarely in our limits.

. C, fimbriata, (L.) Fr. Thallus squamulose, but reduced; the

podetia elongated, often white-powdery; cups with erect mar-
gins; apothecia brown. Fr. L. E. 222.

Found on rotten logs at Glencoe, and elsewhere on logs and
earth.

. C, fimbriata, (L.) Fr, var. tubaeformis, Fr. Podetia slender,

elongated, tawny-brown, often with squamules; cups smaller,
toothed or entire; proliferous, fimbriate; apothecia confluent.
Tuck. Syn. 241.

Found throughout our territory. Synonomy numerous.

C, gracilis, (L.) Nyl. Thallus squamulose, but often wanting,
ash green; podetia slender to robust, corticate, polished, proli-
ferous; apothecia fuscous. Nyl. Syn 196, C. ecmocyna, Ach.

On earth in Will County.

C. gracilis, (L.) Nyl., var. verticillatas Fr. Cups proliferous
from the centre, dilated.

On earth in Will county,

C, squamosa, Hoffman. Thallus much divided; podetia much
branched; apothecia cymose, fuscous. Fr. L. E. 231. Nyl
Tuck. Syn. 246.

On earth and rotten logs in Will County and the western part
of Cook.

82. C, delicata, (Ehrh.) Fr. Thallus reduced,

83.

84,

85. C. cristatella, Tuck.

86.

THE LICHEN-FLORA OF CHICAGO AND VICINITY.

more often of
crowded white granules; podetia short, slender; apothecia

heaped, fuscous. Nyl. Syn. 210. Tuck. Syn. 6.

C. para-
sitica, Schaer.

Found near Elgin on old stumps, near Lemont, and else-

where. Very closely related to C. squamosa, MHoffm.
Yadererir. wes.

C. furcata, (Hudson) Fr. Thallus squamulose but small;
podetia fruticulose, elongated, corticate; brownish-green, fer-

tile summits corymbose, pervious; apothecia brown. Fr. L.
Ee 27o whuck: Syn. W47.

On calcareous soil near Joliet and elsewhere.

C. rangiferina, (L.) Hoffm., var. sylvatica, L. Horizontal thal-
lus wanting; the podetia two to four inches high; cinerascent,
erect, branched and imbricate, terminal ones divaricated,
corymbose. A more delicate form than the species. Fr.
siincelksa etc.

Occurs on dead wood and sandstones in the Desplaines Valley,

but is more common further west. The species is found

from the arctic circle to the tropics in one form or another.
Known as the ‘‘ Reindeer moss.”

Thallus squamulose, minute, cut and

crenate; podetia fair size, often elongated, cylindrical, corti-
cate; smooth or wrinkled, summits fastigiate; apothecia scar-

letomrasivar b. Tuck. ochrocarpia, ©. fegkiana “luck
Syaee No. 55, ete:

Found occasionally in our territory. on old decaying logs and
stumps.

C, macilenta, (Ehrh.) Hoffm. Thallus squamulose, minute,
crenate, lobate; podetia cylindrical, slender, granulose-

pulverulent above; apothecia terminal, confluent, scarlet. Fr.
e405) thick: Syn. N. Ey 55:

- On earth and logs in woods near Joliet; rare. This and No.

85 may be easily identified by the scarlet fruit.

34 THE CHICAGO ACADEMY OF SCIENCES.

Myriangium, Mont. and Berk. Thallus cellulose, orbiculate,
plicate-striate at the circumference, nodulose; apothecia
lecanoroid. Spores oblong-ovoid.

87. M, duriaei, (M. & B.) Tuckerm. Thallus crustaceous, adnate,
becoming free, fuscous; apothecia elevated, blackish, disk
with depressed, entire margin. Tuck. Gen. L. 140. M.
curtisii, M. & B.

Collected several years ago on Corylus near River Forest;
not observed elsewhere. Common south. Its position
among the lichens is considered doubtful.

FAMILY 8. LECIDEEI.

Biatora, Fr. Thallus various or deficient; apothecia diverse in
color, becoming soft and swollen when wet. Spores ellipsoid
and simple, or assuming different forms, colorless, numerous,

88. B, coarctata, (Ach.) Th. Fr. Thallus cinereous, of minute
squamules, rimose-areolate; apothecia small, fuscous or black-
ish, connivent or open, sometimes flat. Spores ovoid-ellipsoid.
Lecidea, Nyl. Scand. 196. Tuck. Syn. Pt. 2. 15. Parmelia,
BPrek. EE. 104:

On calcareous and arenaceous rocks in Will County; also
found on detached sandstones in Cook County. A widely
distributed and variable species.

89. B, varians, Ach. Thallus of minute granules compacted
into a yellowish or greenish crust, which is granulate or
broken; apothecia very small, yellowish, rufous or black-
ish; disk flat, margin thin, B. exigua, (Chaub: 3) hn gieaeee
278.

On oaks and hickories near Elgin and Lemont.

90. B, rubella, (Ehrh.) Rabenh. Thallus yellowish or grayish-green,
effuse, confluent; apothecia luteo-rufescent, or reddish-brown;
scattered or congregate, becoming tumid and margin excluded,
the latter often whitish. Spores pluri-locular. Lecidea,
Schaer. Spicil. 168. Bacidia, Th. Fr. Scand. 344. Baiatora,
Tuck. Syn. Pt. 2. 44.

nite

93.

94.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 35

This widely diffused species occurs in our county on hickories
and oaks, It is variable, and a number of varieties, fourteen
or more, have been created species. Each has an extensive
synonomy.

B, fusco-rubella, Hoffm. Thallus granulate, rugose, chinky,
ash-colored; apothecia medium size, ‘sessile, flat; disk often
turgid, rust-colored, chestnut, or even black. Bacidia, Th.
Mirmocand., 346.5 Wecidea spadicea, Ach. Syn. 1, 34. Luck:
Syits 1s Be ae (Vere 15)

In same localities as the preceding species.

. B, suffusa, Fr. Thallus the same as in No. 91. Apothecia

ample, reddish brown, suffused partially or wholly with white;

disk rufescent, becoming darker, turgescent, excluding the

margin, suffused with white. Tuck. Gen. Lich. 166. (Var.

ey) buck. Syn. Pt. 2) 43.

On hickories in Hanover, Cook County, and near Lemont and
Joliet.

B, inundata, Fr. Thallus scurfy, greenish, rimose-areolate;
apothecia minute, sessile or adnate, flat or convex; tumid-
brownish, black, often excluding the margin; hypothecium
pale. Spores slender. Secoliga, Stizenb. .Bacidia, Koerb.
Bator buck Syn. Pt.2. 45.

In all our territory on detached rocks or stones along streams;
the thallus is best shown on sandstones.

B, cyphalea, Tuckerm. Thallus thin granulose, cinerascent;
apothecia small, dark reddish or rust-colored. Tuck. Syn. Pt.
Fao and Gen: 1. 168.

Rare on elms near the Fox River; may be found elsewhere.

Lecidea, (Ach.) Fr. Tuckerm. Thallus various, crustaceous,

95.

squamulose or evanescent; apothecia patelleform, horny.
Spores colorless.. Fr. &. E. Duck. Syn.

L, enteroleuca, Fr. Thallus granulose and cinerascent, often
wanting; apothecia small to large, adnate, convex, often ex-

cluding margin, black. Spores ovoid-ellipsoid. Fr. L. E.

Bereich soy ne NE Eom. Niylscand.2 li:

36

THE CHICAGO ACADEMY OF SCIENCES.

This species has many forms and has been described under
various names. Some of them occur on rocks and mosses,
others on trees. It is found on maples in Will County.
It is the only species of the genus within our limits so far as
known. There are six described varieties in the United
States.

Buellia, (De Not.) Tuckerm. Thallus mostly uniform; apothecia

patellaform. Spores ellipsoid, brown or decolorate.

96. B. parasema, (Ach.) Th. Fr. Thallus cinerascent or darker,

OT.

rugose, granulate, glaucescent; apothecia sessile, black; disk

flat, often turgid; margin thin. Lecidea, Fr. Tuck. Syn. N.

E. 67. L. disciformis, Nyl.

On oaks near Elgin and elsewhere on dead wood. Occurs
everywhere in North America; a variable species.

B, schaereri, De Not. Thallus granulose, often wanting, cin-
erascent; apothecia very small, black, flat; disk turgescent
and margin wanting. Lecidea nigritula, Nyl. Scand. 238.
Found on an old stump near Lemont, also on old rails; not
common. Is also found in Grundy and LaSalle Counties.

TRIBE 3. GRAPHIDACEI.

FAMILY 9. OPEGRAPHEI.

Opegrapha, (Humb.) Ach. Nyl. Thallus hypophleous, or, if ex-

98.

JOR

posed, thin; apothecia normally lirelleeform.

O, atra, (Pers.) Nyl. Thallus thin or wanting; apothecia ses-
sile, black, simple, flexuose; disk open, canaliculate, proper.
margin thick, elevated, wavy.

Throughout our territory on oaks, hickories, cherries, etc.

O, varia, (Pers.) Fr. Thallus white, pulverulent; apothecia
prominent, elongate, oblong, elliptical, attenuate at the ends,
brownish-black, dilated in the centre; margin inflexed.

On various trees in Cook and Will Counties.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. Be

_Graphis, (Ach.) Nyl. This genus has been fully discussed by

100.

101.

Nylander, who followed the thought of Acharius, and by
Tuckerman, in his Genera Lichenum, 203; Syn Pt 2. 119.
Thallus crustaceous, uniform; apothecia mostly lirelleform,
and branching, but in some species rounded, difform; the
proper exciple colored or black. Differentiated from Ope-
grapha by the spores.

G, scripta, (L.) Ach. Thallus thin, whitish, even or rugose,

sub-tartareous; apothecia immersed or half immersed, slender,

width uniform, simple or branched, obtuse at ends; proper

margin narrow, wavy; thalloidal margin tumid. Spores color

less. .

Common everywhere on oaks, hickories and other trees;
apothecia variously branched. There are a number of
varieties which may occur here.

G, dendriticas Ach. Thallus white or yellowish, thin, pul-
verulent; apothecia brownish- black, immersed, broad, flexuose-
branched, forked; disk broad, often casio-pruinose; margin
thin.

On oaks and various trees within our limits. These two spe-
cies seem to be the only ones of this genus in northern Illi-
nois. One other can be added for the southern portion of
the State. When compared with the exuberance of forms
in Florida, derived, however, from semi-tropical or tropical
sources, this is asmall number. The limitation of species is
well illustrated by tracing this genus from south to north.

FAMILY 10. GLYPHIDEI.

Arthonia, (Ach.) Nyl. This genus, containing a great number of

species mostly tropical, is one of the most perplexing. Dr.
Nylander, more than twenty years ago, described about one
hundred species. Henry Willey in his ‘‘ Synopsis,” published
in 1890, admits three hundred and forty-eight species, and
mentions a few more that he had not seen. About eighty of
these are from the United States, four or five of which were
discovered by the author. The genus should have been
spelled Ardonia, according to its derivation from the Greek,
but long usage has sanctioned the present spelling. The
genera Chiodecton and Glyphis, which immediately precede

104.

106,

107.

THE CHICAGO ACADEMY OF SCIENCES.

Arthonia, are not found in our territory, but inhabit Florida.
We have several species of Arthonia, two so abundant as to
be easily identified.

. A, lecideella, Nyl. Thallus green, uneven, effuse; apothecia

abundant, small, round, plain, pruinose. Spores oblong-
ovoid. NyloEno337. Muck.-Gen. 2215 | Walleyeassyaemlor

On hickories and Crategus throughout our territory.

. A, spectabilis, Fl. Thallus thin, white; apothecia black,

difform, angulate, plain or convex, often bordered by the

thallus. A. dispersa, Duf. A. polymorpha, of Muhl, Catal.

Homo, WWilbkesy. Syyim. il

On maples at Glencoe, Riverside and elsewhere. It is also
found on other trees. Synonyms numerous.

A. diffusa, Nyl. Thallus white, effuse or wanting; apothecia
round or difform, plane or convex, pruinose. A. willeyi.
Duck invite VWilleyeeSynae36:

On hickories and maples in Will County; not common.

5. A, pyrrhuliza, Nyl. Thallus white, thin; apothecia reddish,

slender, much divided, ramose. Willey, Syn. 15.

On oaks in Will County; rare. Was once considered the A.
meduszea of Tuckerman. May occur on Crategus, in which
case it is more likely to be noticed.

A radiata, (Pers.) Th. Fr. Thallus whitish, darkening, or

obsolete; apothecia dark-brown, stellate, difform or ramulose,

erumpent. Opegrapha, Pers. (1794). Arthontay) Dhjgyeie

Arctic. 240. A. astroidea, Ach. Syn. 6. Willey, Syn. 44.

Has many synonyms, and until lately was known as A. astro-
idea, Ach. Found on oaks near Elgin and elsewhere. The
variety swartziana, Nyl. should also occur within our
limits.

A, taediosa, Nyl. Thallus indeterminate; apothecia erumpent,

linear, heaped, few branched and sometimes round.

On maples in the Desplaines valley; also found on oaks. The
name is very applicable, its habit, as to form, may be called
sportive.

NoteE--Tribe 4, including the genera Siphula, Spherophorus, Acroseyphus,

Acolium, Calicium and Coniocybe, have not been found in our territory. The two
latter genera are possibilities.

SERIES II, ANGIOCARPI,

TRIBE V. VERRUCARIACEI.

FAMILY 11. ENDOCARPEI.

Endocarpon, (Hedw.) Fr. Thallus foliaceous, or crustaceous,. pel-

tate; apothecia imbedded, minute. Spores colorless. For
exposition consult Tuck. Gen. Lich. 246.

108. E, miniatum, (L.) Schaer. Thallus cinereous, large, peltate,

109,

110.

lobate-crenate, umbilically affixed; underside smooth or

rugose, fulvous; apothecia numerous and minute, immersed,

brownish.

On calcareous’ rocks near Lemont and elsewhere. The spe-
cies has a wide distribution; is found in Europe and Japan,
being used in the latter country, as I am informed by Prot.
Minakata, as an article of diet. The thallus is often one
inch or more in diameter. Abundant in Illinois.

E. miniatum, (L.) Schaer., var. complicatum, Schaer. A poly-
phyllous form.

Found on limestone rocks at Lemont and elsewhere.

E, miniatum, (L.) Schaer., var. muhlenbergii, Ach.
Occurs with the first named and is scarcely distinct.

. E, hepaticum, Ach. Thallus fuscous, squamose, small, round

or angular; apothecia numerous, blackish. Ach. L. U. 298.
(USI), INhybs ewer

On calcareous earth at Lemont and in Will County.

. E, pusillum, Tuckerm. Thallus very small, greenish, thin;

apothecia minute, imbedded.

Very abundant throughout our territory on various rocks and
stones. The genus Endocarpon was founded upon this
Speciesy a Ves pallidas-Nyl = Ach: I. U-

40

ibe.

THE CHICAGO ACADEMY OF SCIENCES.
*

E, rufescens, Ach. Thallus rufescent, squamose, lobes rotun-

date; mcised) icomplicate, Ach. WU 304.5 (is hoy:

On earth in Will County. Not easily distinguished from E.
hepaticum, but is darker and thinner, and the spores are
smaller.

FAMILY 12. VERRUCARIEI.

SUB-FAMILY PYRENULEI.

In the following genera we approach the limits marking the
close relations of the lower lichens with the fungi. The
absence or slight indications of a thallus have caused
Lichenologists to doubt whether certain species of Ver-
rucaria and Pyrenula, should be classed under these
names, or as Spherias. The effort has been made to elimi-
nate the myco lichens, all corticolous, from the true ones.
Fries expressed this idea,* and that a distinction be made
between the saxicoline and corticoline groups, which, seeming
a natural arrangement, I have followed. Tuckerman con-
ceived the sub family as naturally divided into two great
classes: ‘‘the one,’’ to quote his own language, ‘“ (confined
to inorganic substrates) of true lichens, with a well marked
thallus, and the other (confined to organic substrates) of
plants, the thallus of which is more or less obsolete, and the
affinity close to Pyrenomycetous Fungi.” But even with a
fair array of evidence in support of this arrangement,
Nylander dissents from this view.}

Sagedia, (Mass.) K’br. Tuckerman, Thallus crustaceous; apothe-

114.

cia innate-superficial. Koerber. Syst. 362. Nyl. Pyrenoc. 36,
classed under Verrucaria. Tuck. Gen. Lich. 263.

S. oxyspora, Tuckerm. Thallus thin, effuse; apothecia black,
ellipsoid, conoid; perithecium black. VV. albissima, Nyl.
Scand.

Occurs on Betula papyracea along the lake shore near Glencoe.
The few native birch will soon disappear and with them this
species.

*Syst. Orbis Viget. 264.
+Nyl. Pyrenoe.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 41

Verrucaria, (Pers.) Tuckerm. Thallus crustaceous, sub-tartareous,
mostly uniform; apothecia globular, black, immersed or
prominent; perithecium black. The synonomy of this genus is
numerous. Tuck. Gen. Lich. 263. Verrucaria is restricted
here to the rock and earth lichens, species taken from Pyrenula
and other genera, which, as Tuckerman remarks, shows a
full and harmonious spore-character. In Europe a large
number of forms have been included under Verrucaria, but
Fries and Nylander have made a great reduction.

115

V. prospersella,* Nyl. Spec. nova. Thallus uninterruptedly white
or scattered, becoming chinky with age reaction; apothecia
pyrenoid, wholly black, small (breadth, .15 mm.), some-
what globose, rather prominent. Spores 8. colorless,
-oviform, 1 septate, .o18-22 by .o08-.011 mm. The para-
physes few or scarcely any. Hymenia gelatinous-reaction.
Occurs on siliceous rocks near Chicago. (Calkins). This spe-
cies. seems to approach V. inconspicuam, Lahm, from which
it differs by its larger spores. Likewise near to V. saxicola,
Mass. The calcicolous species, V. ruderella, Nyl. also occurs
in the same locality. Nyl. Chall. p. 217.

First found at Riverside. Described and published by Dr

Nylander in his ‘*Obs.” Lichens. Japoniz, Paris, 1890
Abundant so far as known.

116. V, pyrenophora, (Ach.) Nyl. Thallus tartareous, chinky, ash-
colored or continuous and rugulose; apothecia prominent,
black, large conoidal, sessile; perithecium dimidiate. Spores
spacoloness... Ach le. Ul 285. (1810).

On rocks at Riverside, Lemont and throught our territory.

117. V, nigrescens, Pers. Thallus nearly black, crustaceous,
uneven, crumbling, and often raised around the apothecia;
apothecia black; perithecium dimidiate. Spores 8, colorless.

On limestone along streams in various localities.

*V. prospersella, Nyl, Spee. nova, Thallus albidus continus, vel passim obso-
lete rimulosus; apothezia pyrenio integre nigro, minuta (latit. 0,15 millim.), subglo-
bulose prominula: sporae 8 nae incolores oviformes 1-septate, long. 0.018-22, crass.
0,008-011 millim: paraphvses graciles parce vel vix ulle. Gel. hym. I. Super saxum
siliceum haud procul a Chicago (Calkins). Accedere videtur ad_V. inconspicuam, Lahm.
aqua mox differt sporis majoribus. C. fr. etiam Y. saxicola, Mass.--Calcicola ibidem
(idem) V. ruderella, Nyl. Chall. p. 217.

THE CHICAGO ACADEMY OF SCIENCES.

118, V, fuscella, Fr. Thallus crustaceous, dark brown, areolate-

12

diffract. black-limitate, smooth: apothecia minute, immersed
in the areolz. Spores 8, colorless. Ach, L. U. 289.

Found on detached calcareous rocks near Joliet; not common
as far as observed. A well defined and interesting species.

. V, muralis, Ach. Thallus whitish, tartareous, mealy or want-

ing; apothecia black, semi-immersed, hemispherical; peri-
thecium dimidiate.

Iound on limestone near Joliet and in Cook County, and
sometimes on old mortar.

. V, viridula) Ach. Thallus greenish olive, areolate-diffract,

areole polygonal, smooth or rugose, effuse; apothecia black,
numerous, semi-immersed. Spores 8, colorless.

On detached calcareous rocks, north bluff at Lemont

Pyrenula, (Ach., N. & H.) Tuckerm. Thallus hypophlceoid, sub-

cortical, rarely ektophlceoid, superficial; apothecia denudate,

perithecium black, ellipsoid-oblong, etc.

121. P, gemmata, (Ach.) Naeg. Thallus whitish, thin; apothecia

—
bo

bo

black, medium to large, prominent, convex; perithecium
black, dimidiate. Spores colorless. Ach. Meth. Lich. 120.
(1803). Acrocordia, K’br.

On oaks and hickories at River Forest and in all our territory
This species is closely related to Spheria mastoidea, Fr.

. P, punctiformis, (Ach.) Naeg. Thallus thin, effuse, brown;

apothecia black, shining, minute, sessile-innate, conoid; pert-
thecium dimidate. V. epidermidis, Nyl. Offers a near ap-
proach to Fungi according to Fries, Wallroth, Tuckerman.

On Quercus alba near Elgin and elsewhere.

. P, thelaena, (Ach.) Tuckerm. Verrucaria, Ach.

On birch trees at Glencoe; on maples and hickories near River-
side.

THE LICHEN-FLORA OF CHICAGO AND VICINITY. 43

124, P, nitida, Ach. Thallus pale yellowish or olive, waxy,

125.

smooth; apothecia black, in size medium to large, though
sometimes small, invested by the thallus, globose; perithecium
black. Spores fuscous. Spheria, Weigel, Obs. 45. (1772).
Verrucaria, Ach. L. U 279. Nyl., etc.

On oaks and maples throughout our territory, perhaps not
abundant, yet it may be in some places. The very pale
thallus will identify its location more easily. American
specimens vary greatly in size.

P, glabrata, Ach. Thallus whitish, thin; apothecia variable

in size, black, hemispherical, conoid; perithecium black.

Spores fuscous. Ach. Syn. 791. Nyl. Pyren. 47.

On oaks near Elgin and Joliet; apparently not common.
Some Florida specimens are of extraordinary size, making
their proper position questionable.

Bibliography of North American Lichenology.

The following is believed to be a nearly complete list of the
publications on the North American Lichens issued previous to
April 15th, 1896:

Acharius, E. Lichenographia Universalis. 1810.
Synopsis Lickenum. 1814.

Numerous species are described in both works.

Arthur, J. C., Bailey, L. H. and Holway, E. W. D. Plants collected
between Lake Superior and the International Boundary, 1896. Geol. and
Nat. Hist. Surv. Minn. Bull, No. 3:31-32. 101887.

Enumerates thirty-seven species.

Bailey, L. H. See Arthur, J. C.

Bell, Robert. A List of Plants Collected on the South and East Shores
of Lake Superior and North Shore of Lake Huron in 1860. Ann. Bot. Soc.
Canada. 1:78. 1861.

Mentions seven species.

Bogue, E. E. Catalogue of the Lichens of Ohio. Jour. Cine. Soc.
Nat. Hist. Ap1893.

Enumerates 166 species.

Bolander, H. N. A Catalogue of the Plants Growing in the Vicinity of
San Francisco, California. 1870:41.

Mentions the Lichens.

Calkins, William Wirt, Catalogue of Lichens Collected in Florida in
1885. Jour. Mycology. 2:112. 1886.

Notes on New Florida Lichens. Bull. Torr. Bot. Club. D1889.
Notes on Rare East Tennessee Lichens. Am. Naturalist. N1890.

Note on a New Edible Lichen. Bot. Gaz. D1892.

L

. Remarks on American Lichenology. Science, 26Ag1892.
—901892.—10F 1893.

The Lichen-Flora of Chicago and Vicinity. Geol. and Nat. .
Hist. Surv. The Chicago Acad, Sci. Bull. No. 1:1-52. Ap1896.

General consideration of the Lichens; deseribes one hundred and twenty-five
species and varieties; notes on the habitat of each species.

See Eekfeldt, John W.

Cragin, F. W. Note on Kansas Lichens. Bull. Washburn Col. Lab.
Nat. Hist. 1:64. Jal885.

Enumerates two species with notes regarding their habitat. Lists fifteen species
and varieties collected by Elihu Hall in Kansas and recorded in Tuckerman’s “North
American Lichens.”’

BIBLIOGRAPHY. 45

Enumerates ten aditional species of Kansas Lichens, collect-
ed by Elilu Halland recorded in Tuckerman’s «North American Lichens.”
Bull. Washburn Col. Lab. Nat. Hist. 1:176. J11886.

Cummings, Clara S. List of Lichens from Alaska. Bull. Torr. Bot.
Club. 10A¢1892.
Enumerates twenty-nine species.

Curtis, M. A. List of Lichens. Geol. and Nat. Hist. Surv. N. Carolina.
3:77-83, 1867.
Enumerates two hundred and seventeen species.

Day, David F, The Plants of Buffalo and Vicinity—Cryptogame.
Bull. Buffalo Soc. Nat. Sci. 4:167-173.
Enumerates forty-five genera and two huadred and four species and varieties.

Drummond, A. T. Additions to the Canadian Lichen-Flora. Can.
Nat. Mr1874.

———, List of Canadian Lichens. Can, Geol. and Nat. O1865.

Drummend, N. T. On the Economical Uses of Sticta Pulmonaria.
Ann. Bot. Soc. Canada. 1:81.

Durand, Elias. Lichens in Plante Kaneanz Groelandice. Jour.
Phila. Acad. Nat. Sci. 1856.

Eckfeldt, John W. An Enumeration of Some Rare N. A. Lichens. Bull.
Torr. Bot. Club. 19:249. 1892.

Lichens from California and Mexico. Contr. Nat. Herb. 1:291.

3101893.

Enumerates forty-two species with short notes.

———. Chemical and Medicinal Properties of Some Lichens. Med.
Bull. Philadelphia. 1894.

. An Enumeration of the Lichens of Newfoundland and Labra-
dor. Bull. Torr. Bot. Club. %2%:25Je1895.

———. Catalogue of Plants found in New Jersey. (By N. L. Britton.)
Geol. Surv. N. J. 91:357-384. 1889.

The list of Lichens is a revision by Dr. Eekfeldt, of the Prelimary Catalogue printed
from the manuscript of C. F. Austin, and based on specimens named by Prof. Tucker-
man. Enumerates fifty-four genera and three hundred and twenty-nine species and
varieties,

Eckfeldt, John W, and Calkins, William Wirt. Catalogue of the Lichen-
Flora of Florida. Jour. Mycology. 9$:121-133. 1887.

An enumeration of three hundred and thirty species, many of which are new.

Fink, Bruce. The Lichens of fowa. Bull. Lab. Nat. Hist. St. Univ.
of Iowa. 33:70-88. 26A¢1895.

Enumerates one hundred and ninety-six species with notes.

Frost, W. D. Determination of some Minnesota Lichens. Bull. Geol.
and Nat. Hist. Surv. Minn. 9:81-85. 21Mr1894.

Gerard, W. R. Note on Omphataria pulvinata, Nyl. Bull. Torr. Bot.
Club. D1875.

Gronovius, D, J. F. Flora Virginica. (Pub. at Leyden). 1739.
This isthe first mention of North American Lichens.

46 THE CHICAGO ACADEMY OF SCIENCES.

Hall, F. W. List of Lichens within Twenty Miles of Yale College.
Am. Nat. 11:170. Mr1877.

Hall, Elihu. See Wolf, J.

Halsey, A. Synopsis of Lichens near New York. Ann. Lyc, Nat. Hist.
1:1-19. f4. 1823.

A valuable work enumerating one hundred and seventy-six species, some of which
are new and described by Schweinitz.

Hitchcock, Edward. Catalogue of Animals and Plants of Massachu-
setts. Geol. Rep. Mass. 1835.

Enumerates one hundred and sixteen species.

Catalogue of Plants Growing near Amherst, Mass. 1829.

Enumerates the Lichens.

Hooker, J. D. Flora Boreali-Americana. (Pub. in London). 1840.

Gives a general view of American Lichens -

Hasse, H. E. List of the Lichens of Los Angeles County, California.
Erythea, Mr1895.

Hnumerates one hundred species.

——. Supplementary List of the Lichens of Los Angeles County,
California. In Litt.

Kellerman, W. A. and Werner, W. C. Cat. of Ohio Plants. Geol. Surv.
Ohio. 7:56-106. 1895.

Enumerates thirty-six genera and one hundred and fifty-eight species and yarie-
ties with their hosts.

Knowlton, F. H. Algo-Lichen Hypothesis. Am. Mo. Mic. Jour. 7:101.

Lapham, L. A. The Lichens of Wisconsin. Trans. Wis. State Agri.
Soc. 1860:8.

Leighton, W. A. Lichens Collected by Sir J. Richardson in Arctic
America. ppl7. pl26. 8, 1867.

Leinhart, Rey. E. Greeley’s Narrative of the Franklin Bay Expedi-
tion. Y%:397.

Seven species are mentioned

——-—-. Additions to the Flora of Washington. Proc. Biol. Soe. 3,

Lindsay, W. L. What to Observe in Canadian Lichens. Ann. Bot.
Soc. Canada. 1:49.

———. The Lichen-Flora of Greenland. 1870.

Macoun, John. Lichens of British Columbia. Rep. Geol. Surv. Canada.
187 7:227.

———. Annotated Catalogue of Lichens of the Dominion of Canada,
Newfoundland and Alaska.

In Litt. to be published during 1896-7.

Michener, KE. Lichens in Darlington’s Flora Cestrica, 3rd, Ed. 1853.

Valuable. Enumerates and describes one hundred and five species.

Millspaugh, C. F. and Nuttall, L. W. Flora of West Virginia. Field
Columbian Museum, Chicago. Bull. 2. 1895.

Enumerates the Lichens with deseriptions of three new species.

BIBLIOGRAPHY, 47

Muhlenberg, Index Flore Lancastriensis. Trans. Am. Phil. Soe.
Philadelphia. 3. 1793.
Enumerates thirty species.

—. Catalogus Plantarum Americe Septentrionalis. 1818.
Knumerates one hundred and eighty-four species; many new.

. Eaton’s Manual, 6th Edition. 1833.
The species enumerated in the preceding catalogue are deseribed.

Muller, J. Lichenes Eckteldtiana, etc. Bull. du L’ Herbier Boissier.
9:89. F1894.

Describe forty species from North and South America, chiefly from Mexico. One
genus and several species and varieties are new.

McClatchie, A. J. Flora of Pasadena. Hist, of Pasadena, Cal. By H.
A. Reid. 1895.

Enumerates forty-one species.

Nuttall, L, W. See Millspaugh, CU. F.

Nuttall, Catalogue of Plants of the Pacific Coast. Phila. Acad. Sci. 7.

Mentions Borrera columbiana.

Nylander, William, Lichenes Insularum Guineensium. Paris. 1889.

Describes, in an appendix, seventeen species mostly from North America, twelve
of which are new Florida discoveries of the author of this Bulletin.

—. lLichenes Japonie. 1890.

Describes thirty-six species from North America, many of which are new, collected
by the author of this Bulletin in Tennessee and Florida.

——. Sertum Lichenee Tropical e Labuanet Singapore. 1891.

Describes twenty-eight species many being new forms, collected by the author
of this Bulletin in Tennessee, Florida and Illinois.

Olney, Catalogue of Rhode Island Plants. Proc. Providence Frank-
lin Soc. 1, 1846.

Enumerates twenty-four species.

Peck, Charles H. Reports of the State Botanist of New York. Ann.
Rep’ts State Mus. Nat. Hist.

In the reports of several years species are enumerated with notes regarding habitat.

Rothrock, J. T. Lichens Collected in Alaska by Dr. T. H. Bean in
1880. Proc. U.S. Nat. Mus. 7:1-10. 01894.

Knumerates one hundred and ten species with copious notes.

Russell, John L. Notices of Lichens. Jour. Essex Co. Nat. Hist. Soc. 1.

Speaks of eight New England species.

—. Notices of Lichens, Proc. Essex Inst. 1] and 8,

Describes the new genus and species, Hydrothyria venosa.

—. Notices of Lichens. Proc. Boston Soc. Nat. Hist. 1840..—-Am.
Jour. Sci. 1840,_-Hovey’s Mag. Bot. 1840.—Hovey’s Mag. Bot. 1850-2.

Stitzenberger, E. List of Lichens Collected by R. Reubeux in Western
North America, Proc. Cal. Acad. Sci. II. §:535. 1895.

Sturgis, William C. On the Carpologic Structure and Development of
the Collemacez and Allied Groups. Contr. Crypt. Lab. Harvard Univ.
25:15-53. pl8. 9Ap1890.

Swartz, Lichen Americani. 1811,

Deseribes twenty-five species. This was the only number of the Journal issued,

48 THE CHICAGO ACADEMY OF SCIENCES.

Torrey, John, A Catalogue of Plants near New York. 1819. (Albany).

——-, Usneafasciata. Am. Jour. Sci. 6,

———. Botanical Report. Expl. and Surv. for R. R. Route from Miss.
River to Pacific Ocean. 73:22. 1856,

Enumerates four species.

Tuckerman, Edward. An Enumeration of Some Lichens of North Am-
erica. Proc. Boston Soc. Nat. Hist. 2, Further communication in 3 and 5,
Observations on Some Interesting Plants of New England.
Am, Jour. Sci. 1843.

Mentlons two Lichens.

-. An Enumeration of North American Lichens. 1845. (Cam-

bridge).

Two hundred and thirty-eight are mentioned; remarks on the systems of Oken,
Fries and others; discusses the structure and general history of Lichens, following the
views of Frles.

Synopsis of the Lichens of New England, the other Northern
States and British America, 1848. (Cambridge).

Two hundred and ninety-five species are described.
. hea’s Catalogue of the Plants of Cincinnati. 1849.
Fifty-three species are classified by Tuckerman.
. Agassiz’s Lake Superior. 1850.
Seventy-three species are classified by Tuckerman,
Botanical Report, Expl. and Surv. for R. R. Route from Miss.
River to Pacific Ocean. 63:94. 1857.

Enumerates ten species and varieties.

———. Supplements to the Enumeration of North American Lichens.
Am. Jour. Sci. 1858-9.

Sixty-six species are described.

———. Observations on North American and Other Lichens. Proce.
Am. Acad. Sci. and Art. 1860-4.

—. Wilke’s Exploring Expedition. 1861.
Contains descriptions of one hundred and four species. e :
—. lLichens of California, Oregon, etc. 1866. (Amherst).
EKnumerates one hundred and eighty-four species.
——-—. Can Lichens be Identified by Chemical Tests? Am. Nat. 9:
104, Ap1868.

——. United States Exploration of the40th Parallel. Rep. 1872:412.

———. Genera Lichenum. 1872. (Amberst).

An arrangement of North American Lichens. A valunble work of two hundred
and eighty-one pages.

——,. Note on Ramalina reticulata. Bull. Torr. Bot. Club. 3:23
Jals72. .

———. Two Oregon Lichens. Bull. Torr, Bot. Club. §:20. Apl874,

——. Catalogue of Plants Growing Within Thirty Miles of Amherst
College. 1875. ;
—. Regensburg Flora. 1875.

Merely a note.
—. Observationes Lichenologice. Proc. Am.Acad. 1876. (Boston),

BIBLIOGRAPHY. 49

———. Report upon the Botanical Collections made in Portions of
Nevada, Utah, California, Colorado, New Mexico and Arizona. U. 8.
Geog. Surv. W. 100d Meridian. 6:350-351. 1878.

Enumerates sixteen genera and twenty-eight species and varieties.

—. Synopsis of the North American Lichens. Pt.1. pp261. 1882,
Part 2 was edited and published by Heury Willey in 1888.

Underwood. Lucien M. List of Cryptogams at Present Known to In-
habit the State of Indiana. Proc. Indiana Acad. Sci. 1893:30-67. Ag1894.

Enumerates thirty species.

Watt, David A. P. A Provisional Catalogue of Canadian Cryptogams,
Can. Nat, 2, 01865.

Enumerates one hundred and fifty-six species.

Williams Thomas A. Flora of Nebraska. Nebraska Agri. Rep. 1889.

Enumerates two hundred and thirty-one species.

--. The Fruiting of Parmelia Molliuscula, Ach. Rept. Mo. Bot.
Gard. 3:169-170. pll 28My1892.

——. Lichens ofthe Black Hillsand heir Distribution. Bull. Torr.
Bot. Soc. 20:349. 81893.

———. Notes on Mexican Lichens. Am. Nat. 29:480. My1895,~

Webber, H. J. Appendix to the Catalogue of the Flora of Nebraska.
Trans, Acad. Sei. St. Louis. 6:12-138. 12Mr1892.

Enumerates twenty-three species, with notes.

Werner, W.C€. See Kellerman, W. A.

Willey, Henry. Note on Biatora lucida. Am. Nat. O18 7.

American Lichenography, 1867.
——. The Spores of Lichens. Am. Nat. 4:720. F1871.
———._ Lichens Under the Microscope, Am. Nat. Jels71.

———. On Lichens Collected by Dr. Coulter. Rept. Geol. Surv. of
the Territories. 6:790. 1872.
. A List of North American Lichens. 1873. (New Bedford).

———., Statistics and Distribution of North American Lichens, Bull.
Buttalo Nat. Hist. Soe. O1873.

——._, List of Illinois Lichens. Bot. Gaz. F1877,—Mr1878.

———. First Contribution to the Knowledge of Kansas Lichens.
Bull. Washburn Col. Lab. Nat, Hist. 1:16-17. $1884,

-Enumerates sixteen species, with notes.

———. Lichens Not Previously Reported from Kansas, Bull, Wash-
burn Col. Lab. Nat. Hist. 1:176. J11886,

Five species are listed, with notes regarding habitat.

———. An Introduction to the Study of Lichens with a Supplement.
1887. (New Bedford). ppd8. pll0.

——. Notes on Dermatiscum Catawbense, (Willey) Nyl. Bull.
Torr, Bot, Club, 14:134. J11887.

———. Notes on Some Lichens. Bull. Torr Bot, Club. 14:222, O1887.

———. Review of Prof, H. Lojka’s Lichenotheca Universalis. Bull.
Torr, Bot. Club, 14:247. N1887.

50 THE CHICAGO ACADEMY OF SCIENCES.

——~—. Notes on Trypethelium Kunzei, Fee. Bull. Torr. Bot. Club.
15 Jel8s8ss.

——. Lichens of Colorado. Syn. Flora Col. U.S, Geol. and Geog.
Surv. Territories Mise. Pub. 4:161-163,

Enumerates fifty-four species and varieties, with notes,
—. ASynopsisofthe Genus Arthonia, pp62. 1890. (New Bedford).

Deseribes three hundred and forty-eight species.

Wolf, John and Hall, Elihu, A List of the Mosses, Liverworts, and
Lichens of Illinois. Bull. Ill, St. Lab. Nat. Hist. 2:27-384. Je1878.

Enumerates forty genera and two hundred and sixteen species and varieties.

Arthonia,
Biatora,
iBwelilta,’ (=.
Cetraria,
Cladonia,
Collema,
Conotrema,
Endocarpon,
Graphis, -
Heppia,
Lecanora,
Lecidea,
Leptogium,
Myriangium,
Opegrapha,
Pannaria,
Parmelia,
Peltigera,
Pertusaria,
Physcia,
Placodium,
Pyrenula,
Ramalina,
Rinodina,

Sagedia,

Theloschistes,

Urceolaria,

Verrucaria,

INDEX TO GENERA.

_ Publications Issued by The Chicago Academy of Sciences.

I, BY THE ACADEMY:
Transactions, Vol. I, Out of print.

Art. I. Description of Fossils from the Palaeozoic Rocks of the
Western States, with Illustrations. By Prof. J, H. McChesney.

_ Art. II. On the Climate of the Country Bordering upon the Great

_ North American Lakes. By Dr. I. A. Lapham.

Art. III. Remarks on the Geology of the Valley of Mackenzie
River, with figures and descriptions of Fossils from that region, in the
_ Museum of the Smithsonion Institution, chiefly collected by the late
_ Robert Kennicott, Esq. By F. B. Meek.
| Art. IV. Descriptions of New Subcarboniferous and Coal Measure
_ Fossils, collected upon the Geological Survey of Iowa, together with
_ a notice of new generic characters observed in two species of Brachio-
_ pods. By Dr. C. A. White and O. H. St. John.

; Art. V. Illustrations of North American Birds in the Museum of
The Chicago Academy of Sciences. By Dr. William Stimpson.

Art. VI. Biography of Robert Kennicott. By a Committee of the
Academy, appointed at the meeting of Nov. 13th, 1866.

Art. VII. Onthe Antiquity of Man in North America. By J. W.
Foster, LL. D.

M Art. VIII. Descriptions of Certain Stone and Copper Implements
- Used by the Mound Builders. By J. W. Foster, LL, D.

a Art, IX. List of Birds of Alaska, with Biographical Notes. By
- Wm. H. Dall and H. M, Bannister.

Art. X. On Additions to the Bird-Fauna of North America, made
by the Scientific Corps of the Russo-American Telegraph Expedition.
By 8. F. Baird. :

i Art, XI. A Preliminary List ofthe Butterflies of Iowa. By Samuel
H, Scudder.

Transactions, Vol. II. Out of Print.

Art, I, The North American Lakes Considered as Chronometers
of Post-Glacial Time. By Edmund Andrews, A. M., M. D.

Bulletins, Volume I,
‘ No, I. Glacial Markings of Unusual Forms in the Laurentian

Hills. By Edmund Andrews, M.D., LL.D. Price, 25.

No, Il. Observations on Fluviatile Deposits in Peoria Lake, Ills.
_ By Rev. Joseph D. Wilson. Price, 25.

No. Ill. List of Batrachia and Reptilia of Illinois. By N.S. Davis,
Jr. and F. L. Rice. Price 25.

PUBLICATIONS—Continued.

No. IV. Report of the Committee on the Microscopic Organisms :
in the Boulder Clays of Chicago and Vicinity. By H. A, Johnson, ‘
D. and B. W. Thomas, F. R. M.S., Committee. Price, 25, is

No. V, The Northern Piteher-Piant or the Side-Saddle Flower,
Sarracenia purpurea, L, By W. K. Higley. Price, 25.

No, VI. Boulder Clays. On the Miscroscopic Structure of Oertail«
Boulder Clays and the Organisms Contained in Them. By Dr. Ceoresy
M. Dawson, D.3S., F. G.S., &c. Price, 25.

No, VII. ers Points on the Micro-Chemistry of Fats. By John
S. Long, Sc, D, Price, 25.

No. VIII. Chicago Artesian Wells. On Their Structure sys Hourgees ,
of Supply. By Leander Stone, A. M. Price, 25, .

No. IX. OnRhizocarps inthe Hrian (Devonian) Period in America
By Sir William Dawson, LL. D., F. R. 8. Price, 25,

No. X. A Paper on Rlophas Primigenius. By W. K. Higley.
Price, 25. Feta ya:

Bulletins, Volume IT.

No. I. The Flora of Cook County, Illinois, and a part of Lake
County, Indiana. By William K. Higley and Charles §. Raddin, Price, ~
cloth 1.00; paper 75. aby:
- No. II, Preliminary Outline of a New Classification of the Family —
Muricide. By Frank Collins Baker, Secretary and Curator, Price, 25-

In Preparation:
Vol. II, No. III. An Historical Sketch of the Chicago Academy oi
Sciences,

II, By THE GEOLOGICAL AND NATURAL Histone SURVEY:

Bulletin No. I, The Lichen-Flora of Chicago and Vicinity. By
William Wirt Calkins. Price, 25. ‘

In Preparation: ‘d

a. The Drift of the Chicago Area, By Frank Leverett, U.S. Geol. —
Surv. ; 5
b. Boring Records of Chicago and Vicinity. A reference bulletin.

c. Palentology. By M. Fischer and W. C. Egan. i

d. Minerals. By C. M, Higginson.

e. Lepidoptera. By W. E. Longley.

f. Mollusca. By Prof, Frank C, Baker,

g. Aves. By Frank M. Woodruff.

h. Reptilia and Batrachia.

i, Alge. By Prof. C. B, Atwell.

j. Pteridophyta and Bryophyta. By Prof. E. J. Hill.

k. Flora of Cook County and Vicinity, (Phenogamia and Vascu- y
lar Cryptogamia). By Prof. W. K. Higley and C. 8, Raddin, 4

1, Ethnology and Archeology. By Dr. W. A. Phillips,

THE

Chicago Academy of Sciences

THE

| Pleistocene Features and Deposits

Chicago Area.

FRANK LEVERETT.

U. S. Geological Survey.

BULLETIN No. II

OF THE

Geological and Natural History Survey

ISSUED MAY, 1897.

THE

Chicago Academy of Sciences

THE

Pleistocene Features and Deposits

Chicago Area.

BY

FRANK LEVERETT.

U. S. Geological Survey.

BULLETIN No. I

OF THE

Geological and Natural History Survey

ISSUED MAY, 1897.

| Davip OLIPHANT, PRINTER, 178 Mo ROE Sr

f; eka ” <

ON, MPC s

LETTER OF TRANSMITTAL.

CuHicaGco, InuInois, April ist, 1897.

DEAR SIR:

By direction of the Board of Managers of the Geological
and Natural History Survey of The Chicago Academy of Sciences, I
herewith submit to you for publication as Bulletin No. II of the
Survey, the report on The Pleistocene Features and Deposits of the
Chicago Area, prepared by Frank Leverett, of the United States ©
Geological Survey, to be issued under the rules of the Academy
governing such matters.

Respectfully,

WiuuIAM K. HIGLEY,

THOMAS C. CHAMBERLIN, Chairman.

Pres’t of The Academy of Sciences.

DEDICATION.

This Bulletin is dedicated to Mr. George H. Laflin,
who, interested in the advancement of science and in the
work of our institutions of learning, has by his generosity

made its publication possible.

The Board of Managers of the Geological and Natural History

Survey of The Chicago Academy of Sciences :

WILLIAM K. HIGLEY, Chairman,
CHARLES §8. RADDIN, Secretary.
THOMAS ©. CHAMBERLIN.
GAYTON A. DOUGLASS.
THOMAS T. JOHNSTON.

THE GEOLOGICAL SURVEY.

The Board of Management of the Geological and Natural
History Survey take pleasure in presenting the second of its
proposed publications, a list of which may be found on the
fourth cover page.

The history and aims of the survey are outlined in the
first bulletin, The Lichen Flora, prepared by Mr. W. W.
Calkins, and published through the generosity of Mr. Albert
Dickinson. It is only necessary, therefore, to repeat here the
extent of the territory covered by the survey. This area
comprises Cook and Du Page Counties, and the nine north
townships of Will County, in Illinois, and a portion of Lake
County, Indiana, giving a surface of about forty-eight or fifty
miles square, or a land surface of nearly 1800 square miles.

The present bulletin on the Pleistocene Features and
Deposits of the Chicago Area, has been prepared by Mr.
Frank Leverett, of the U. S. Geological Survey. The Board
desires to express its appreciation of the time and labor that
must have been taken from the stress of other duties in the
preparation of this very creditable work as well as of the
assistance given to Mr. Leverett by individuals and institu-
tions, recognition of which has been made in the body of
tle) fx.

The Board wishes further to make acknowledgement of
the courtesy extended by the Sanitary District of Chicago,
which, through the kindness of Mr. T. T. Johnston, Assistant
Engineer, prepared the maps and profiles from Mr. Leverett’s
manuscript copy.

All into whose hands this bulletin may come, will join
with the members of the Board in appreciation of the gener-
osity of Mr. George Laflin, whose prompt response to the
request for funds to publish the bulletin is but another’
instance of the liberality which has marked his attitude
towards the Chicago Academy of Sciences.

THE BOoarp.

CONTENTS.

PAGE

LMG ROMUCTOMYOLALEMNE MIE. 5 Jlepelierayetete:sioleicie sietsie ajalerciere ciclo oleic) cleleicterslelcveielete ti ciele 9
Outline of Time Relations or Glacial Succession...................... 11
Albertan, or Oldest Recognized Drift Sheet..................... eke lls,
Aftonian Interval of Recession or Deglaciation.................... 13
Kansan Drift Sheet of the Iowa Geologists.................-.00. .. 14
Second Interval of Recession or Deglaciation...................+. 14
IDUPNGHE yA DE INNA So odgoddoosabooaolG ARE ILA ern eciny lero ENA cievieteas I4
Third or Pre-loessial Interval of Recession or Deglaciation....... 15
Iowan Drift Sheet and Main Loess Deposit.................:...+6-- 16
Fourth or Post-loessial Interval of Recession or Denlaciation Ballade 16
HarhyewasconsineD Tritt SMES. 6 2 occ se. ao o's. 6 ice clvinte winvaicle hele wists hee 17
Shelbyville Morainic System................... ASN AONE Seat 1L2/
Champaign Morainic System................ cee eee ee eee ee eee ee 18
Blooming tone MoOraimi CG) Systemics yee <ereislaicrsicsate eetioteleleieiaieleicrets 19
Marseilles Morainic System................50 cece Kosong HS Uc 20-

Fifth Interval, shown by Shifting of Ice Lobes.................... 20
Late Wisconsin Drift Sheets........... sHehelaratenstesaionsienesccaneieiel'eieuelerenatenarere 21
Great Bowlder Belts and Accompanying Moraines............. 21
Valparaiso Morainic System....... 2.5... cece cette ete ee ees 22

Wake Borders Moraimie Sy Stem y ssa iioietciclhelo is eleislepatel sheleierercimietsie 22

The Lake Beaches........ 0.22. ccc s seer cece e settee eee eecteees 22
General Physiographic Features of the Chicago Area...........seseees 23
The Valparaiso Moraine in [llimois. ... 2.06.5... 23. c ee eee eee cen ses 26
PME PMEOT ATI eyavspelarevorcheneterelercteveleveleieieseclsimlaisierc JOooHGOUOOOUOOOUOOOUD O00 26
IDS OMCs e's da ocaalagonNsodo ods GoGo no oobodeUcboodEK dad 26

FEV M Gites eisstee yar rewe pars al eearey yet erica cu caie Aisin nite) Siselgee topeuetat cone ta Gutcus ds ted ena ote bauer assets 27
SUES CoOmMnowmrsis ces swadauscovauedooadsshonodaguagoodddcdecoo6 28

JhiNGha Ne Ore IDbabijs soe beg ouooDOUDBUeOeDoodsobse Ucadsco don ao ond. 29
SUPUCUHUIIC Of IDR 6 Oe oo ae deuoouupooUooS soaocoddoOdauOeOooUdCouL 31
Flowing Wells........ Beatles Wan cule ailepacehevevatatintes aleNere Gai rel aienabeie eietarelny Muonalbahevete 37
Palatine Flowing Well District.................. eee eeeceeeccoes 37

Salt Creek Flowing Well District...............0..ceesceeecees 38

MV IBOICGEIe IPINSINOMNSING So Kasdbacobondace cocoguoUU KC dooundbUGooUr 38
The Lake-Border Morainic System...............c2 cece cs ce cc cececesees 42
MEO MIMO TEVA'S eater a aeecnchotere usec oleroiate el tcestievs paisiekotelie averse isielebeleloketeneias stede 42
OUI, OIE WES IWNCEE So agoeodoodeedcdddccnnodudsoddgcobuGSobood00 42

ANNE MENG Kliie) IRClee, 66S oodaneo eso od GouodoDUaGDOU UDO Sob MD ODOcOF 42

ANING, IO linGleGIn So Sob dann eo SubonboOoN apoUUduGoUoDOUeOOUGu hcoouD 43

inhi CGaoon anos boodddodURdHOEOUoCUOOOUCKOUEOO MERE aac lca atts ay tee 43
Thickness of the Drift..... See P ears folerencre sioleialaie heteleveve ler eieteretolerre tel 44

Sipposed! Comnelatlomskyie era sieisdeat sen esta Lee Cnet eee 45
Jo SNE nOEL IRIE SAH oaoUbos whoo ns son Sc beeen the tehatol eset ca Catan heeaeae 46
Bowlder Wray sr cer pistes tide wie eters sit ele ooaie. ele rarsiate elect te eee 46
Lakeward Extension of Hast Ridge,...........-.+++.sescssun sus 47

Associated Till iPlaing, cco cae cals as oan ee nee cate eee Ce 47
AILITUAES ANASIOMES oie c eld eke eid nea eee eee oe Saas eee 47
Thickness of DET ye. Fae ties cheseltion alcmadecne asia ee ee 48
Structure of Dritt. Ay ils. bev ogc eee aed ee 48

SUTTON eeies eee valevievey a repelch ey sievorerauaualatewanase ales cual Wiel) tay qomthatodapercbeelt VACGl stetch Sea ata aeaeeae 52

The Chicago Outlet and Beaches of Lake Chicago..................... 55

PPeEV IOUS? WHIGELS es ceiare tauren toukors caesiem tee nustcieheeeiae Mapes aonoAt ous 55

Mhe Chicago Outlet ici oes) hears eee wise ci sihos dere wis oteleae le ba ersteloee eae 57

Maye (Cale yore whi ben ey (Oankee verona eauaacnaouusodsoonocosb0bocccs000ccnc00c 64
Upper, oriGlenwood, Beach.ie maee seen we oie hee eee 66
Interval’ of Emergence ss ii. fn eae os, Ve ea eee 71
Second orCalumeth each crys udev lle elelekel hele een 72
Third; or Lolleston! Beae@hi. 2 evs. psveclaiec sa orrsielloiel keke arene 74

ihesPresent Beachiot Make: Michisan: «nese: teers e mele eerie 79
ACEN OW LER SEM EDIEG, «js ole cere Ne eile le aietaien ctacesa cc Wy aveteky Gece a lavepees Oyane CRS ene nee 85
ILLUSTRATIONS.

PAGE
Pip aGlacial Map ot. NorbhwAmentc ain. cl-ricieus ae cee eit ene ocala
Pls 2s Glacial: Map, Of TINGMOUS sig edie io alei elite steleaele tole takes eee eRe ee emt?
Pi. 3.) Glacial Map of Chicago and Vicinity... ..2....-..-. «-4-se eel 23
Pl. 4, Profile Sections Across the Chicago Area..............0.-..555 . 24
Fig. 1. Bowlder and Peat Bed near Willow Springs..............+...+:: 48
Fig. 2. Disturbed Stratitication near Willow Springs..................- 50
1D Gio (SMENEKE EAE OLY, IPMN, Ha GominacodoncobnebeouMooobebaacadqcuoddo™ 52
Iie eS SEITEN Toy ATMEL eS a agbaaogobdsdcdo tioonboccdoooddooDcoounss 54
Biot 5) Striae at Stony, Island J.\o.).cccssc ee ces se conse ie ee ee 56
Fig. 6, Striae on Bed of Chicago Outlet near Willow Springs.......... 58
Fig.7. Grooves in Bed of Chicago Outlet near Lemont................ 60
Fig. 8, Cut Terrace of the Upper Beach near Galewood..........°***"> 67

Pleistocene Features and Deposits of the Chicago Area,

By FRANK LEVERETT.

SUNT ROWWE ROR We SM Adiee MiNi

The Chicago area here discussed embraces not only the site
of the city, but adjacent territory west and south, nearly to. the
Fox and Kankakee Rivers, and north nearly to the line of Illinois
and Wisconsin. It is made to include the first great moraine which
sweeps around the head of Lake Michigan, as well as several weak
morainic lines lying nearer the lake. It includes also the ancient
beaches of Northeastern Illinois and a portion of the outlet of
the body of water which formed them. It is a country exception-
ally full of varied and interesting features.

Some of the features, especially those pertaining to the old
lake and its outlet, are discussed by Dr. Edmund Andrews, in an
eatly volume of the Transactions of the Chicago Academy (1).

_The same features and some of the leading features of the glacial

deposits were briefly discussed by Dr. H. M. Bannister, in his
official reports to the State Geologist (2). A description of the
principal moraine traversing this district, based upon studies. by
Prof. T. C. Chamberlin and Prof. L. C. Wooster, is given by Pro-
fessor Chamberlin in an early report of the United States Geolog-
ical Survey (3)

The paper which follows aims to discuss these features in the
light of a somewhat detailed study of Pleistocene deposits, which
I have had the privilege of making in this and adjacent districts.

Carried on as this study thas been, under the direction of Prof. T.

a (1) The North American Lakes considered as Chronometers of Post glacial
Gaia, By Dr. Edmund Andrews, Transactions of The Chicago Academy of
ciences. Vol. IT, 1870, pp. 1-23.

(2) Geology of Cook Gounty. By H.M. Bannister. Vol. IIT. 1868, pp. 239-244.
“erik SRT DeKalb, Kane and DuPage Counties. By H. M. Bannister. Vol. IV,
ee Oley of McHenry and Lake Counties. By Dr. H. M. Bannister. Ibid, pp.
e (3) Preliminary Paper on the Terminal Moraine of the Second Glacial Epoch.

y Thos. C. Chamberlin, Third Annual Report, U. 8. Geol. Survey, 1881-82, pp. 322-325.

10 CHICAGO ACADEMY OF SCIENCES.

C. Chamberlin, I have had the benefit of counsel and guidance,
which has been of great service and which it is a pleasure to ac-
knowledge.

The studies in Illinois, upon which the present paper is based,
were entered upon in 1886, near the beginning of my study of
Pleistocene deposits, and the greater part of the work in the Chi-
cago Area was done in that and the following season. The study
in Northern Illinois was carried into greater detail than in most
of the territory subsequently covered, chiefly because of the com--
plexity of the features. Nearly every township was traversed at
intervals so close as to give opportunity to see practically all of
the surface, to examine the best natural exposures, as well as rail-
way cuttings and other artificial exposures, and to collect records
of nearly all the important borings. Portions of the district here
discussed have been recently re-examined. This has in a measure
made good the loss consequent upon the lapse of time, and has
brought the interpretation into harmony with the present state of

knowledge of Pleistocene events or stages.

GEOLOGICAL AND NATURAL HISTORY SURVEY. 11

POUREINE OF TIME RELATIONS OR GLACIAL SUC
CHSSlON:

The complexity of the glacial events is such that it will be
advantageous to outline as clearly as possible at the outset the
recognized glacial succession and thus learn the position of the
drift of the Chicago Area in the series of drift sheets displayed
in the Mississippi Basin and adjacent territory. The outline given
below aims to present simply the recognized subdivisions. These
-may prove to differ widely in rank or importance. The main divi-
sions here outlined seem to be much longer than the secondary
divisions and they may be of very unequal length. They appear
to have the rank of an epoch, or main division of a period, except
the divisions of Lake history, which, perhaps, should be substages.
The outline aims to cover the events between the deposition of the
oldest recognized drift sheet and the final recession of the ice
sheet into the region north of the Great Lakes. That region may
furnish several additional substages and possibly one or more
stages. The outline differs from that published by Prof. T. C.
Chamberlin, in a recent number of the Journal of Geology (1),
only in being a fuller presentation of substages in the Wisconsin
drift series, and in including the lake history of this region.

OUTLINE OF THE DRIFT SHEETS AND INTERVALS.

Oldest recognized drift sheet—the Albertan of Dawson.
First, or Aftonian, interval of recession or deglaciation.
Kansan drift sheet of the lowa geologists.

Second interval of recession or deglaciation.

Hlinoian drift sheet.

Third, or preloessial, interval of recession or deglaciation.
Iowan drift sheet and main loess deposit. ©

Fourth, or postloessial, interval of recession or deglacia-

BPN ON CASES AS) le!

tion.
. Early Wisconsin drift sheets.
Substage 1. Shelbyville morainic system.
Substage 2. Champaign morainic system.
Substage 3. Bloomington morainic system.
Substage 4. Marseilles morainic system.
10. Fifth interval of recession, shown by shifting of ice lobes.

\O

(it) Journal of Geology, Chicago University. Vol. LV, No. 7 October-November,
896, DP. 872-876.

12 CHICAGO ACADEMY OF SCIENCES,

tr. Late Wisconsin drift sheets.
Substage 1. Great bowlder belts and accompanying
moraines.
Substage 2. Valparaiso morainic system.
Substage 3. Lake-border morainic system.

12. Lake Chicago submergence.

13. Emergence ‘of plain, covered by Lake Chicago.

14. Partial resubmergence of plain, covered by Lake Chi-
cago.

15. The present stage of Lake Michigan.

It appears from the above outline that the late Wisconsin |
series covers the entire Chicago Area. A brief discussion of the
several drift sheets which preceded the Late Wisconsin will be of
advantage, however, both for comparison and for the interpreta-
tion of the deposits of earlier drift found beneath the late Wiscon-
sin within the Chicago Area.

Explqnation of Map of North America. —The position of the
four main centers of glaciation is indicated, viz.: The Cordilleran,
confined chiefly to the region west of the Rocky Mountains; the
Keewatin, extending over the area between the Rocky Mountains
and Hudson Bay and reaching Central Missouri at its farthest
point south; the Labrador, extending over the peninsula of Lab-
rador, and the Great Lakes, with its extreme southwest terminus
in Southern Illinois, and the eastern borders of Missouri and Iowa.
(The eastern New England, New Brunswick, Nova Scotia and
Newfoundland glaciation may be from small independent cen-
ters, but this can scarcely be considered as demonstrated.) The
fourth center of glaciation, is the Greenland, which 1s still largely
ice covered. The Driftless Area of Southwestern Wisconsin and
border districts stands between the fields covered by the Keewatin
and Labrador ice sheets. South from this driftless area is a nar-
row belt covered first by the Keewatin and later by the Labrador
ice sheet, as indicated in the text. .

The principal glacial lakes are perhaps sufficiently outlined
to be deciphered. Lake Agassiz is shown clearly. Lake Iroquois
occupies the Ontario basin and border districts. The Warren and
Algonquin Lakes are more difficult to decipher. Lake Warren
is now restricted by several geologists to a body of water that dis-
charged across: Southern Michigan from the Erie-Huron basin.
At that time Lake Chicago was occupying the south end of the
Lake Michigan basin. A small predecessor of Lake Warren,
called Lake Maumee, had southwestward outlet to the Wabash.
A lake discharging southwestward from the Lake Superior basin
was probably a contemporary of Lake Warren. At the Lake
Warren stage the ice sheet was apparently covering the region
about the straits of Mackinac, much of Georgian Bay, and the
eastern end of Lake Ontario. Lake Iroquois, in the Ontario basin,
is of later date than Lake Warren, and is thought to have been
held in on the northeast by the ice sheet, as shown by studies of

Diata

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Showing Glacial Boundaries, Glacial Movements

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MAP OF
NORTH AMERICA

and ae
extent of Glacial Lakes A
Compiled by ay ee
Frank Leverett and Frank B.Taylor re

Plate 1.

John B.Torbert.

MAP OF NORTH AMERICA. (Inland Educator, August, 186.)

GEOLOGICAL AND NATURAL HISTORY SURUEY. 13

Gilbert not yet published in full. Lake Algonquin represents a
stage where an eastward outlet, from Georgian Bay by Trent
River, to Lake Iroquois, was open, the outlet to the St. Clair being
for aitime above lake level. At that time the emergence of the.
south end of the Lake Michigan basin, discussed in the text, may
have occurred. For the use of this map plate we are indéedted
to the Inland Educator Company of Terre Haute, Indiana.

ALBERTAN, OR OLDEST RECOGNIZED DRIFT SHEET.

Dr. George M. Dawson has recently called attention to a very '
aged drift sheet found by him in the province of Alberta, east of
the Rocky Mountains, in Southern Canada (1). Its relation to
drift sheets in the United States 1s not definitely worked out. It is
overlain by a sheet that is probably either the sub-Aftonian (for-
metly Kansan) of Professor Chamberlin, or the somewhat later
sheet to which the lowa geologists have applied the name Kan-
san. Should the lower sheet prove to be the one that overlies the
Albertan drift it will be necessary to place that drift in a still earlier
stage than the sub-Aftonian of Professor Chamberlin, for it is de-
scribed to be of markedly greater age than the drift sheet which
overlies it.

AFTONIAN INTERVAL OF RECESSION.

The interval of recession or deglaciation, following the depo-
sition of the lower till sheet of Southern Lowa, and named by Pro-
fessor Chamberlin the Aftonian, from the type locality near Afton,
Iowa, is characterized by soil and weathering of such a marked
character that it no doubt will be recognized widely as the detailed
study progresses. In the present stage of investigation it scarcely
can be separated from soils of other horizons, except in the dis-
trict which lies outside the Illinoian and the lowan drift sheets.
This district has not as yet received much study, hence the extent
to which the soil remains intact is not known.

In Southeastern Iowa and Western Illinois several instances
of the occurrence of a black soil between beds of till, and thought -
to be the Aftonian, have come to my notice. There is an element
of uncertainty from the fact that it is near the border of the drift
sheet, where minor oscillations of the ice margin are liable to have
occurred, which may have caused the burial of soils whose extent
is limited. It is not yet made certain that they mark a prolonged
interval, such as Professor Chamberlin finds to be exhibited in the
type locality near Afton.

(i) Bulletin Geological Society of America. Vol. 7, pp. 31-66. Issued Nov. 1895

14 CHICAGO ACADEMY OF SCIENCES.
KANSAN DRIFT SHEET OF THE IOWA GEOLOGISTS.

This is a sheet which has much importance in the drift series,
for it constitutes a large part of the drift of Southern lowa and
Missouri and probably remains in extensive sheets beneath the
later drift in districts to the north. It apparently extends into
Western Illinois a'short distance, beneath the Illinoian drift sheet.
It is a sheet that has as yet received but little attention, the chief
study given it being in Southeastern and Southern Iowa.

SECOND INTERVAL OF RECESSION OR DEGULACIATION.

This interval is known not by a recession and readvance of
the same ice sheet, nor a sheet with the same gathering ground, ~
but by the recession of one ice sheet and the advance of another
ice sheet into the region thus abandoned. It has been studied only
in Southeastern Iowa, where the Illinois lobe has encroached
upon the territory which had been occupied by a more western
lobe.

Evidences of the lapse of a long period between the with-
drawal of one ice sheet and the invasion of the other are clear and
decisive. The drift of the earlier sheet is a very calcareous till, yet
its surface had been leached to a depth of several feet before the
Illinois lobe encroached upon it. :

Accompanying the leaching was the formation of a black or
humus stained soil, numerous exposures of which are to be seen
in Southeastern lowa under the drift of the Illinois lobe.

There was also much erosion of the surface by stream action.
Prior to the discovery of the extension of the Illinois lobe into
Southeastern Iowa it had been noted by Professor Chamberlin,
as well as by the writer, that Southern Iowa presents a more
eroded appearance than I\linois and the southeastern counties ot
Iowa. In the former district remnants of the original drift plain
are confined to narrow strips between water courses, while in
the latter district such remnants are far more extensive, compris-
ing much more than half the surface. It is planned to make a
careful measurement of the relative amounts of erosion in the
two districts, for erosion studies made with proper analytical
method promise to furnish the most satisfactory means available
for measuring such time intervals.

’

ILLINOIAN DRIFT SHEET,

Under this name is included the sheet of drift which covers
Western Illinois and extends a few miles into Southeastern Iowa.

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GEOLOGICAL AND NATURAL HISTORY SURVEY. 15

It remains to be determined whether it should be made to include
all the drift of Southern Illinois and the oldest sheet of drift in dis-
tricts to the east from Illinois. Further study is also necessary
to determine whether the drift on the border of the Driftless Area
in Northwestern Illinois and Southern Wisconsin is so recent as
the Illinoian sheet. There may be found in the region referred to
a sheet or sheets of drift corresponding in age with one or both of
the sheets in Towa that are earlier than the Illinoian drift sheet.
The drift of these regions is thus only provisionally referred to the
Tilinoian stage.

The Illinoian sheet has in Southeastern Iowa and Western
Illinois a variable thickness, ranging from ten feet or less up to
fully too feet, with an average of perhaps forty feet. It is scarcely
so thick as the older sheet of Iowa and Northern Missouri, whose
edge it overlaps in Southeastern Iowa. In Southern Illinois, also,
the drift is not so thick as in the old sheets of Iowa and Missouri,
being even thinner than in Western Illinois. The same is true of
the old drift sheets of Southern Indiana and Southern Ohio. In
all these districts the older drift is not so thick as the newer. The
Hlinoian drift sheet has mainly a plane surface, but near its mar-
gin there is a tendency to morainic ridging. The ridging is a sub-
dued form, the ridges being one-half to one mile or more in width,
with a relief of but twenty-five to fifty feet. The extent of the Ill-
noian sheet and the distribution of its ridges are shown on the
accompanying map (plate 2).

Explanation of Map of Lliinots._In this map the extent of
the Ilinoian drift sheet is represented. Its extension into Mis-
souri, near St. Lois, is conjectural, but the extension into Iowa is
well established. The several moraines formed in the early and late
Wisconsin stages are indicated by shading with dots. The extent
of Lake Chicago in Northeastern I!linois and Northwestern In-
diana is also represented. These features have been added to the
map as published by U. S. Geological Survey. The 50 foot

contours appear except in the hilly parts of Illinois and in
western Indiana where only 100 foot: contours are shown.

THIRD OR PRELOESSIAL INTERVAL OF RECESSION OR DEGLACIATION.

There is between the Ilinoian drift sheet and the overlying
mantle of loess and associated silts a well-defined soil horizon.
There is also leaching of the till to depths seldom less than four
feet and often much more. It is, therefore, an interval of con-
siderable importance. Its length, however, appears to be some-
what less than that of either of the two earlier intervals.

16 CHICAGO ACADEMY OF SCIENCES.

Prof. Worthen early recognized this soil horizon at the base
of the loess and made numerous references to it in the Geology of
Illinois. Being situated near the surface, it is much more fre-
quently exposed to view than the soils at lower horizons. Prob-
ably, also, it has been subjected to less disturbance and removal
than soils which were overridden by the ice sheet.

IOWAN DRIFT SHEET AND MAIN LOESS DEPOSIT.

This sheet of drift was brought to notice by Mr. W J
McGee in his early papers on the drift of Northeastern Iowa, where
it is commonly referred to as the “upper till.” It was found by Mr.
McGee to be of the same age as a deposit of loess which covers
Southeastern Iowa, but which was excluded from much of North-
eastern Iowa by the ice sheet (1).

This drift sheet Mr. McGee found to be markedly different in
its stony ingredients from the sheet that underlies it. It is sep-
arated from that sheet by a prolonged interval. This interval, it
now appears, comprises not only the third or preloessial interval
of Western Illinois, but the time covered by the Illinoian stage of
elaciation and the deglaciation interval which preceded it. Com-
prising thus the time of two stages of deglaciation and one of gla-
ciation, the interval shown in Northeastern Iowa is necessarily
very marked.

The Iowan sheet is mae to be represented in Northern
Illinois by a sheet of drift found mainly east of Rock River,
though extending in places west of that stream. This sheet is con-
cealed within a few miles east of Rock River by a later drift sheet
(the early Wisconsin).

Both in Towa and Illinois the sheet referred to the Towan
stage is perceptibly fresher than the sheet of the Illinoian stage
of glaciation. The depth of leaching is, on an average, one to two
feet less than on the IIlinoian drift sheet. The erosion of streams
is also less, apparently not more than half as great as in the IIli-
noian drift sheet. |

FOURTH OR POST-LOESSIAL INTERVAL OF RECESSION OR DEGLACIATION,

This interval is shown to be one of considerable length by
the amount of valley excavation which occurred between the de-
position of the loess and the succeeding stage of glaciation. At
the close of the loess deposition the main valleys, such as the
Missouri, Mississippi, and Illinois, were filled throughout most

{11 See Kleventh annual report U.S. Geological Survey for a full discussion of
this drift sheet,

GEOLOGICAL AND NATURAL HISTORY SURVEY. il

of their lower courses to heights of 75 to 100 feet, or more, above
the present streams. But before deposits from the waters, contrib-
uted by the succeeding glaciation, were poured into these valleys,
‘they had been cut down about to the present level of the streams
- and in some cases, perhaps, to an even lower level.

The cutting down of the valleys indicates a marked change
in altitude or at least in attitude of the land surface, and this
change cannot have been accomplished in a very brief period.

EARLY WISCONSIN DRIFT SHEETS.

Under this term are included several important morainic sys-
tems, which are well displayed in the State of Illinois. The names
applied to these morainic systems are in every case taken from
Illinois localities. Shelbyville is derived from the county seat of
Shelby County, which is situated on the outer belt of moraines.
Champaign is from the city of that name in Eastern Illinois, which
is situated on one of the principal members of the morainic sys-
tem to which the name is applied. Bloomington is situated upon
the principal member of a still later system of moraines, well dis-
played in Central THlinois. Marseilles is situated at a point where
the moraine to which this name is applied crosses the Illinois
River.

It is thought that the several morainic systems just men-
tioned were formed in comparatively rapid succession in the order
named. At least no decisive evidence of a prolonged interval
separating the formation of successive morainic systems has been
discovered. It is probable that some oscillation of the ice front
occurred, so that the moraines do not mark simply halts in the
recession of the ice. They may mark the limits of successive
advances following retreats of minor importance.

Shelbyville Moratnic System.—The Shelbyville morainic
svstem marks the southern limits of a sheet of thick drift, the
thickest, perhaps, formed in Illinois at any stage of the glacial
period. The distribution of the moraine may be seen by reference
to the accompanying map (Plate 2). Whether the outer ridge
throughout the entire extent from the Wabash River, near Terre
Haute, Ind., around to the Wisconsin line, near Harvard, Ill., was
occupied at any one time by the ice sheet, or whether there were
oscillations by which some parts were formed earlier than others,
is not yet definitely settled. Possibly the outer ridge in the vicinity
of the Illinois River should be classed with the Towan rather than
the Early Wisconsin drift. This system has not much relief

18 CHICAGO ACADEMY OF SCIENCES.

above the district lying on its inner or iceward border, since that
district was filled with drift nearly to the level of its crest. But on
the outer, or landward, border there is usually a relief of 75 to 100
feet or more. Viewed from the outer border, the moraine in places
presents the appearance of a bluff or escarpment, though the rise
of 75 to 100 feet usually occupies a mile or more.

By reference to the map, it will be seen that there is a feeble
morainic belt lying a few miles back from the border of this drift
sheet. This is included with the Shelbyville system. It seems to
mark a brief halt of the ice sheet soon after it began its retreat.

The main moraine, though very bulky, has but little surface
expression, much of it being nearly as smooth as the plains to the
north. It consists mainly of a single ridge, but in Edgar and
Coles Counties it has in places a double ridge. The feeble belt just
referred to presents in places a sharper morainic expression than
the main moraine, there being clusters of sharp knolls rising
abuptly thirty to fifty feet, or more, above border tracts. The
ereater part of this belt, however, has a gently undulating surface,
like that of the main moraine.

This sheet of drift, terminated by the Shelbyville moraine, is
composed in the main of a soft, fresh-looking, blue till, markedly
in contrast with the partially cemented brown and gray tills which
underlie it, and extend southward imto the outlying districts. It
has long been recognized by well-drillers as a sheet very distinct
from the underlying tills. From the Shelbyville moraine a sheet
of soft blue till, similar to that in the moraine, is found beneath
plains, as well as moraines northward over much of Northeastern
Illinois. There appears to be but little difference in the structure
of drift in the morainic ridges from that in plane-surfaced tracts.

Champaign Morainic System.—The Champaign morainic
system, though far less bulky, is fully as complex as the Shelbyville
system. It consists of several more or less distinct members sep-
arated by plains, the latter ranging in width from a mile or less up
to three and even five miles. It is exposed to view only in Eastern
Illinois, being combined with or overridden by the Bloomington
system from the vicinity of Bloomington westward. It is poorly
developed in Indiana, though small ridges are traceable across
Vermillion, Parke and Fountain Counties to Montgomery County,
Indiana, where they are overridden by a morainic system of the
Late Wisconsin stage. The complexity of the system and the dis-
tribution of its several members may be seen by reference to the
accompanying map (Plate 2). -

GEOLOGICAL AND NATURAL HISTORY SURVEY. 19

Where best developed the members of this morainic system
have a relief of fifty to seventy-five feet above plains on the outer
border, but, like the Shelbyville system, the relief is less pro-
-nounced on the inner border. In Indiana the belts have less relief,
seldom more than thirty or forty feet. Where best developed, the
members of this morainic system are one to two miles in width.
The surface is usually strongly undulating, a feature which dis-
tinguishes the moraines from the bordering nearly level plains.
The surface expression is on the whole stronger than in the Shelby-
ville moraine.

In structure this morainic system does not differ markedly
from the Shelbyville system. The ridges are composed mainly
of a soft till. The soft till extends to a level somewhat lower
than the base of the ridges, a feature which is thought to indicate
that the Shelbyville drift is here present in considerable thickness.
Beneath the soft till of the Shelbyville drift a black soil is found,
which forms the surface of a drift older than the Shelbyville, pre-
sumably the Illinoian driit sheet.

Bloomington Morainic System.—This is a more prominent
morainic system than the Champaign. It is traceable from West-
ern Indiana westward across Central Illinois in a somewhat indi-
rect course (with a re-entrant angle near Gibson City) nearly to
the Hlinois Valley. Whether this system crosses the Illinois just
above Peoria and becomes combined with an earlier system, or has
its continuation in certain local developments of morainic topog-
raphy along the east side of the Illinois, northward to the bend
near Hennepin, is not fully determined. It is thought that the
moraine leading from the bend of the river northeastward and
passing near Mendota and DeKalb belongs to this system. At the
east this system is overridden by a later moraine in Benton and
Warren Counties, Indiana.

The portion east from the Illinois River has, in places, three,
and elsewhere two well-defined members separated from each
other by narrow plains. The outer member of the system has
generally a relief of 75 to 100 feet above plain tracts south of it,
thus approaching in strength the Shelbyville system.

In structure the drift of this morainic system closely re-
sembles that of the two systems outside of it, being chiefly a soft
blue till. It rests upon a soft till, which is thought to be the
northward extension of the Shelbyville sheet. This in turn is
‘underlain by a hard till, probably of the Illinoian stage.

The topography is of a swell and sag type, rather more pro-

20 CHICAGO ACADEMY OF SCIENCES,

nounced than in eithgr of the earlier systems of the Early Wiscon-
sin stage. The undulations not infrequently extend back for
several miles on the inner border of the morainic system and fade
away gradually into characteristic till plain topography.

Marseilles Morainic System.—TYhe Marseilles morainic sys-
tem consists of a bulky ridge, usually with a single crest, but in
places double, which encircles the basin at the head of the Hlinois:
River, known as the Morris basin. From the north border of
the basin it extends northward along the east side of Fox River
to the vicinity of Elgin, beyond which it has not been separated
from the moraines of the Late Wisconsin stage. At its southeast-
ern end, also, this moraine is concealed by a moraine of the Late
Wisconsin stage.

Aside from the main belt, called the Marseilles, there is a
small moraine, the Minooka, which separates from the Marseilles
moraine near Oswego, IIl., and passes southward into the basin
at the head of the Illinois. It has not been recognized south of
that stream. This moraine probably followed closely the Mar-
seilles moraine in its deposition, and is accordingly included in
the Marseilles system.

The Marseilles moraine stands 50 to 100 feet above the plain
on its outer border and even higher above the basin on its inner
border. Its inner border relief is much more marked than that of
any of the morainic systems yet discussed. This is due largely to
the thinness of the drift deposits on. the inner border, there being
a much smaller amount of drift there than on the inner border of
the other morainic systems.

The surface expression of this moraine is very similar to that
of the Bloomington system, the topography being of a sharply
undulating swell and sag type. The Minooka moraine is much
smoother surfaced than the Marseilles and has a relief scarcely
half as great.

The structure of the drift, both in the Marseilles and the
Minooka moraine, is similar to that in the other morainic syeteins,
being chiefly a soft blue till.

FIFTH INTERVAL SHOWN BY SHIFTING OF IGE LOBES.

The evidence for this interval is based largely on the change
of front or shifting in the position of the ice lobe which invaded
Northeastern Illinois and districts to the north and east. It is
best shown in Western Indiana, where the moraines of the later
stage cross those of the earlier one at a high angle. It is thought

GEOLOGICAL AND NATURAL HISTORY SURVEY, 21

that this change of front could not have taken place in a brief time.

In connection with this change of front there appears a re-
markable increase in the number of surface bowlders, a feature
which may prove to have great significance. The causes for vari-
ations in the number of surface bowlders are so little understood
as yet that we scarcely are warranted even in conjecturing the im-
port of such bowlder belts. They may signify a great recession
of the ice sheet, followed by a fresh advance across the Canadian
highlands, by which a new supply of bowlders was gathered up
and brought down to the extreme limit reached by that advance.
Such bowlders in some cases, as recently suggested by Mr. F. B.
Taylor (1) may be derived from accumulations in interglacial val-
leys. This suggestion, however, can scarcely apply to bowlder
belts of such length as are displayed in Western Indiana and East-
ern Illinois.

LATE WISCONSIN DRIFT SHEETS.

The moraines of the Late Wisconsin series contain generally
a larger amount of assorted material with the till than is found in
the moraines and accompanying till sheets of the Early Wisconsin
series. The topography also is more closely allied to the knob
and basin type than to the gently undulating broad ridged type
of the Early Wisconsin series.

Some attention has been given the subject of comparative
amounts of surface leaching and erosion on the Marseilles mo-
raine and the moraines of the Late Wisconsin series, but no strik-
ing contrast has been observed. A more refined investigation,
however, may bring to light essential differences.

Great Bowlder Belts and Accompanying Moraines.—The
bowlder belts of Northeastern Illinois and Western Indiana have
attracted attention from the earliest days of exploration, as have
also their continuation in Central and Eastern Indiana and West-
ern Ohio. In the early explorations they were observed only as
detached belts, but their connections are now well. established.
Occurring, as the bowlders usually do, in narrow, well-defined
belts, they are readily traced from section to section, even where
unaccompanied by peculiar topographic features. Throughout
much of their course in Ohio and Indiana these bowlder belts are
simply an accompaniment of well-defined belts of morainic drift.
But in Western Indiana and Northeastern Illinois the bowlder

[1] Ina paper presented at the Washington meeting of the Geological Society
of America, December, 1896,

22 CHICAGO ACADEMY OF SCIENCES.

belts often cross smooth plains having only occasional develop-
ments of morainic topography.

The moraines which these bowlder belts accompany are usu-
ally a strong phase of the swell and sag type bordering on the
knob and basin type. They are moraines which in their north-
ward continuation in Eastern Wisconsin assume a pronounced
knob and basin type.

In northern Kane and McHenry Counties there are bulky mo-
raines with strong expression, which do not have definite south-
ward continuation, unless it be in the bowlder belts. It is not cer-
tain whether they are to be correlated with the much feebler,
bowlder strewn moraines of Eastern Illinois and Western In-
diana, with which the bowlder belts give them a possible con-
nection. They may prove to belong to the Early Wisconsin series.
In that case they were overridden without being obscured by
the very bowldery drift sheet.

Valparaiso Morainic System —This system consists of a more
or less complex belt, which sweeps around the head of Lake
Michigan, passing through the western and southern part of the
Chicago Area. It receives its name from the city of Valparaiso,
Ind., situated on its crest. As it is fully discussed on subsequent
pages, further description at this point is unnecessary.

Lake Border Morainic System.—This system embraces a se-
ries of till ridges well displayed along both the western and eastern
borders of Lake Michigan. Those in Lake and Cook Counties,
Illinois, are discussed in detailin this paper. Similar ridges appear
in Porter and Laporte Counties, Indiana, and in the western
counties of Michigan as far north as investigations have been
carried (to the mouth of Kalamazoo River).

THE LAKE BEACHES,

Upon the retreat of the ice sheet from the head of Lake
Michigan a body of water collected in the southern end of the basin
and discharged southwestward by the “Chicago, outlet” to the
Desplaines River. This period of discharge appears to have been
followed by a period in which the water level was too low to dis-
charge in that direction.. There then succeeded another period of
discharge through the southwestward outlet. This period of
discharge was followed by the present lake stage with northward
outlet. Ass this complicated lake history is discussed in some de-
tail farther on, it is left here with this passing word.

Glacial Map of Chi,
and Vicinity.

By Pease Levererr.
1897.

LIST OF CITIES AND VILLAGES.

® Eola
Si Naperville
H Downers Grove
Port Hill SS Hinsdale
Yolo Western Springs
Wauconda La Grange
Premont Willow Sprinus
{vanhoe 7 Summit
Diamond Lake Morgan Park
Libertyville Blue Island
xeeption of a fake Fo Naw Bride
exception of dunes Lake Forest Sag Bridge
sandy beaches on os 13 Highland Lemont
border of Lake Mishi- | 1! Ravinia Romeo
gan the rolling surfges || 15 Deerfield Plainfleld

Straight li =
plains, and the curved
rolling country. With the

Seen Geuvevuwr

test
ue

op

represents morainic

%

Half Day P. O.

topography.

17 Lake Zurie

} 18 Barrington

9 Palatine
Arlington Heights

Lockport
adley

Orland

Bremen

ss

Homewood
Harvey
Thornton
lammond
Whiting
Gibson
Hessville
Griffith
Edgemoor

Wheeling

Northfield
Oak Glen
Glencoe

5 Winnetka

5 Wilmette
Evanston
Niles

o Park Ridge
Des Plaines
Mount Prospect
Schaumberg
Bartlett
Spaulding
Wayne
Ontario
Roselle
Itasca byer
Rensonville Chicago Heights
‘Turner Park Mattison
Austin Frankfort
Oak Park Mokena
Riverside Spencer
Maywood v Lenox

5 Elmhurst Klwood

5 Lombard Monee
Glen Ellys Goodenow

s Wheaton Creto

9 Turner Junction

Wet HK

vty

Pr PPP eee

me
dye)
it

4

Wheeler
Crown Point
Shermerville
St. John
Brunswick

EAEGECZSE SSAA

SCALE OF NILES

LUBE re. Fare~.

ih =

MAP OF THE CHICAGO AREA.

, ‘ Way eran ‘ ; 7 PS ers
1S GeO: MY
Metta yey Wii

gees, ey
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Nea el
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GEOLOGICAL AND NATURAL HISTORY SURVEY. 23

CeNbR AI -eRvSlOGRAPEIC (EF RBATURES : OF) ShEe
CHICAGO RDA

The principal physiographic features of the Chicago Area
were produced by the ice sheet, the rock surface being generally
covered to a great depth by the drift. The variations in altitude
which the region presents are produced by inequalities of drift
accumulations rather than by the underlying rock, the elevation
-of the rock surface being but little, if any, higher in the highest
parts of the area than it is in the lowest.

The most conspicuous physiographic features are the lake
plain, the lake outlet, and the Valparaiso moraine. Less conspic-
uous features are found in the Lake Border Morainic System of
northern Cook and eastern Lake Counties. These are each dis-
cussed in some detail farther on, but a brief outline of their features
may be of service at this point.

The lake plain has its most extensive development in Chi-
cago and its immediate borders as far north as Winnetka. It
extends back some twelve to fifteen miles from the lake, with a
general southward and westward rise, the elevation averaging
about ten feet at the border of Lake Michigan and about fifty
feet at the upper beach. This plain is continued into Indiana, but
is greatly concealed by dunes. North from Waukegan there is
a narrow plain bordering the lake, whose ele ation is but twelve
to thirty feet above the present lake level.

The portion of the shore of Lake Michigan between Win-
netka and Waukegan is occupied by one of the ridges of the Lake
Border morainic system, and the erosion of this ridge by the lake
gives the high banks which are present in that section. Between
this ridge and the Desplaines River there are a series of till ridges
separated by narrow plains. The ridges rise to a height of 100 to

Explanation of Glacial Map of Chieago and Vicinity. —On
this map an attempt is made to give a bird’s-eye view of the area
by means of broken profiles. The moraines appear with undulat-
ing contour, the plains with straight lines, the beaches with abrupt,
step-like descent of the plain. Striae are indicated by arrows and
represent bearings accurately. Some confusion of dunes with
moraines may arise if it is not borne in mind that the belt of ridges
bordering Lake Michigan in Lake County, Indiana, consists of
sand dunes. The dunes are found for eight to twelve miles south
from the lake in that county. The bars in Cook County, Illinois,
also are to be distinguished from the moraines. They are much
lower and narrower ridges, as shown in the discussion.

24 CHICAGO ACADEMY OF SCIENCES.

125 feet above the lake and the plains from 60 to go feet or more.
The general elevation is, therefore, higher than in the lake plain
bordering the city of Chicago. 3

The district between the Des Plainés and Fox Rivers in Lake,
northwestern Cook and Du Page Counties, is largely occupied by
the Valparaiso moraine. This moraine is interrupted by the
Chicago outlet in southwestern Cook and northern Will Counties.
East from this outlet it is developed along the watershed between
the Kankakee River and Lake Michigan in southern Cook and_
eastern Will Counties and continues thence eastward, swinging
gradually to the north around the head of Lake Michigan.

The ‘highest points on the Valparaiso moraine are found in
southern Lake and northwestern Cook Counties. One of these,
just east of the village of Volo, stands 913 feet, and one in the
northwest section of Cook County stands 910 feet above tide, as
determined by the Barometric survey under Professor Rolfe.
Much of the crest of the moraine in the southwestern part of Lake
County rises above 850 feet. In northwestern Lake County and
in northwestern Cook County it rises generally above 800 feet
and a few points exceed 850 feet. In Du Page County the crest
is generally about 750 feet. In Will County a few points rise above
800 feet, but the general elevation is not much above 750 feet,
and this elevation is maintained eastward about to Valparaiso,
Ind., where the moraine rises above 800 feet and continues with
an elevation of 800 to 900 feet from that point to the borders of
the St. Joseph River in Michigan.

From the Valparaiso moraine there is less descent toward
the Fox River Valley than toward Lake Michigan, the elevation
of the immediate border of the valley being 750 to 775 feet in
Lake County and 700 to 750 feet on the borders of Cook and
Kane Counties. But upon approaching the Des Plaines River the
district outside the moraine becomes about as low as that along
the lake, and the immediate valleys of the Des Plaines and Kan-
kakee, in Will County, are lower than the lake surface. Farther
east the district outside the moraine reaches an elevation higher
than the lake level, the altitude of the Kankakee marsh at the

Explanation of Profile Sections—The profile sections given
in Plate 4 are based upon the railway surveys along six lines radi-
ating out from Chicago. The distance to rock is shown by a
series of well borings along each line. In cases where rock is not
struck the depth of well is indicated. The vertical scale being
about thirty times the horizontal, the reliefs of the region are suffi-
ciently well outlined to be readily seen.

6 WAUKEGAN

Ye

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WM

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INDEX MAP

SHOWING

| LINES OF PROFILES

ha Naa berber Pier

Vertical Scale 30 times the horizontal.
|
|

|
|
|
|

4
i
4
‘
’ ; i A
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3 2

= z 4
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x . = 3
i = z =
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SECTION A-A
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2 g s =
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— t ~——_—_ & Fs
— 7 es ae 2 k E ee 4 Cuicaco
aa P —_ +> “
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SECTION B-B
b
S 5 5
s § 3 :
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sr =. ele 5 Cricaso
apalcaer ean rad t ‘
a ee ae — a aE Nitin, ___
Aurora g
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& % i a 3 3
§ § & % © Ss
i Bae 3 e &§ 3
| $$ p= D en | ™ f § 2 Cyicago
Ss
* Be SSS oo anced ~ . i SS a <> $$ Lake Micnican __

SECTION D-D

b
: ¢ x
{ é E j z N
= ra Fa > 8
: Li ii a 5 t oS
i aja ee ag t a eas
Vinee ee iat ay, a a eit, a — ve hanee Manian.
SECTION E-E
t 3 8
& Ey :
‘ * 3 ‘
° 6 2 ‘
x a t 5 Chicaso
1 -
= | oes a Sige pn sae _ ate ee INDEX MAP

BHOWING

SECTIGN REP LINES OF PROFILES
Plate 4. PROFILE SECTIONS RADIATING OUT FROM CHICAGO.

Length of each Profile 45 miles. Vertical Scale 30 times the horizontal.

MOTIIE

Mort aa fice

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Be vise a :
at J sh } ; = + }
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GEOLOGICAL AND NATURAL HISTORY SURVEY. 25

State line being about forty to fifty feet, and its eastern end, near
South Bend, fully 100 feet higher than the lake.
The lake outlet trenches the Valparaiso moraine to a level

- about as low as the surface of Lake Michigan, witha valley nearly

a mile in average width. This is the only drainage line crossing
the Valparaiso moraine in Illinois and no drainage line crosses
the moraine in Indiana, though it is crossed by the St. Joseph
River just north of the Indiana line between Niles and Berrien
Springs in Michigan.

Some of the features just diceHacel are well represented on
the reduced topographic map accompanying this paper. But
the large map sheets of the United States Geological Survey
should be consulted for the full representation of characteristic
features of the plain, the outlet, and the Valparaiso moraine. It
is to be hoped that the map sheets of the entire State, which Pro-
fessor Rolfe has prepared, may soon be published, since they
bring out clearly the main pliysiographic features.

26 CHICAGO ACADEMY OF SCIENCES,

THE VALPARAISO MORAINE IN ILLINOIS.
THE MORAINE.

Distribution.— At the Illinois and Wisconsin line and for
some thirty miles southward the Valparaiso moraine is so closely
associated in its outer or west border with earlier moraines that
that border is not clearly outlined. Just south of Elgin the mo-
raine first becomes distinct, its course there becoming east of
south, while the earlier moraines bear west of south. It covers the
lake region of western Lake and eastern McHenry Counties,
its eastern border in Lake County being nearly coincident with
that of the system of small lakes, and slightly east of the water
parting between the Fox and Des Plaines Rivers.

In Cook and Du Page Counties the moraine has a breadth of
not less than ten miles and in places reaches fifteen miles, its inner
border being somewhat irregular. In northern DuPage County
it lies entirely within the limits of the county, but farther south it _
encroaches on western Cook County, the inner border at the
Des Plaines River being about four miles east of the county line.
The outer border from Wayne to Turner Junction lies just east
of the Chicago and Northwestern railroad. South from Turner
Junction the West Du Page River follows the border. In south-
ern Du Page County there is a separation into rudely parallel
ridges between which are lowlands, which are utilized by the
southward flowing streams, East Du Page River and Salt
Creek. Near the south part of Du Page County the East Du
Page is forced to turn westward into the West Du Page, for the
ridges which are separate in Du Page County coalesce in north-
ern Will County. Salt Creek has, in its lower course, left its old
valley and cut a new one eastward through Proviso Township,
Cook County, to the Des Plaines. The old valley passes south-
ward through the western part of Lyons Township, almost in line
with the upper portion of Salt Creek Valley, crossing the Chicago,
Burlington and Quincy Railway west of Western Springs, and
joining the Des Plaines about seven miles below the present
mouth of the creek.

Through Will and southern Cook Counties the moraine has
a southeasterly course. Its inner border is nearly parallel with

GEOLOGICAL AND NATURAL HISTORY SURVEY. ONT

the shore of Lake Michigan and distant from it about twelve
miles. The Des Plaines River enters this moraine near Mt. Forest
_and the other lake outlet, known as “the Sag,” enters it about five
miles east of Sag Bridge. Between Mt. Forest and the Sag out-
let the moraine covers an island situated between the outlets of
Lake Chicago. The main part of the moraine crosses the Des
Plaines between Lemont and Joliet and thence, continuing south
of east, its crest passes near Frankfort and Monee and enters Indi-
ana from southeastern Will County. There is a somewhat distinct
outer belt following the divide between the Des Plaines and Du
Page southward past Joliet and crossing the Des Plaines three to
five miles below that city. This belt, east from the Des Plaines, is
in places distinct from the main belt, but scarcely merits a separ-
ate name, since it is so generally united with that belt. Where
distinct it is about two miles in width. Throughout much of the
interval between the Des Plaines and the Indiana line this outer
belt is nearly parallel with the Kankakee River and distant from it
about ten miles. Near the Indiana line its border approaches the
Kankakee and in Indiana follows closely the north side ot the
marsh drained by the Kankakee.

Relief —The crest of the Valparaiso moraine is much higher
_ than its outer and inner borders, but the moraine has such broad
slopes that it has not a bold relief on either face. The following
table of elevations is taken from the profiles of several of the rail-
ways which cross the moraine.

TABLE OF ELEVATIONS ON VALPARAISO MORAINE.

Railroad. Inner Border. Crest. Outer Border.
Ie, Je G2) sy they Lake Commis, oa do 720 feet. 880 feet. 770 feet.
Whiscomenin Cemiirally ooocce ds csoneeds O83 S235 778
OV Geno te) MS ener nciine en Rein ee OAOM Tm SIZ 768
(Co Ce, ING NNEC Cling eae 5 aes ane 50/0: S67 772
C. & N. W. (Omaha div.).......... Gana eiva Gols 750
Cap IB. CER OR GS RU ASIA alts Hat 646 “* Hog 700
WYEIDASIA 26 a atia ne atau emer ett O65), 9 FEZ Geto Ga)
(Crag) IRR Toc Ne te a an Go) Cials GSorei eG)
PUTER erate eae eee pews ens aay 650/07 806 * TOM
(Cs. Gree LUNs Coes on Rae uN eae 632)5 a Tin 713

(1) Cuter border of main ridge.

All of the above lines cross the highest part of the moraine
in their respective latitudes, except the Wabash, Chicago, Rock

28 CHICAGO ACADEMY OF SCIENCES.

Island and Pacific, and the Omaha division of the Chicago and
Northwestern. These lines cross low points in the crest, twenty-
five to fifty feet lower than the general altitude of neighboring
portions. The highest parts of the crest in Illinois, as noted above,
are in northwestern Cook and southwestern Lake Counties, and
stand about goo feet above tide.

Surface Contours.——The Valparaiso morainic system pre-
sents notable variations in surface contour, even in the short sec-
tion that lies within the State of Illinois. At the north, in Lake
County, there are numerous basins occupying an area ranging
from a few acres up to several square miles each, and containing
lakes or marshes. ‘They are scattered over the slopes of the mo-
raine, indenting its surface to depths of twenty-five to fifty feet
or more. Basins become rare upon passing southward into Cook
County and the moraine is comparatively free from them through-
out the remainder of its course in Illinois. The few which occur
are very small and shallow. These basins, with their lakelets, add
greatly to the beauty of the scenery of Lake County, furnishing
attractive sites for summer residences and for camping grounds.
Among the lakes there are knolls and irregular ridges, with gentle
slope, ranging in height from ten feet or less up to about fiity
feet. The moraine has also a well-defined crest line in a ridge
twenty to forty feet higher than the border tracts and a mile or
less in width, which leads southward, with a somewhat winding
course, through the western part of Lake County, forming the
water parting between Fox and Des Plaines Rivers:

Passing south into Cook County the crest line continues as
definite as in Lake County. To the east of the crest line there
are only gentle swells seldom more than fifteen feet in height and
-a rapid descent to the plain bordering the Des Plaines. To the
west of the crest line there is an irregular network of ridges and
knolls, inclosing winding sloughs. The height of these knolls and
ridges ranges from ten or fifteen feet up to fully fifty feet. Con-
tinuing south across Du Page County the ridges tend to a paral-
lelism with the crest and the sloughs become less conspicuous.
This topography also characterizes the portion of the moraine in
Will County. In the latter county the tendency to a parallel ar-
rangement of the ridges and of chains of knolls is very marked.
Throughout the course in Du Page and Will Counties the inner
slope has a milder expression than the crest or outer slope, though
the contrast is scarcely so striking as in Cook County.

The outlying belt in Will County carries low knolls twenty

GEOLOGICAL AND NATURAL HISTORY SURVEY. 99

- feet or less in“height. There is not so well-defined ridging as in
the main belt. Though the undulation is not sharp, it is sufficient
to give this belt a strong contrast to the very smooth till plain
‘which borders it on the south. The contrast with the till plain on
the north is not so striking, for that plain is dotted with low swells
ten feet or more in height.

Thickness of the Drift.—Situated as the Valparaiso moraine
is in a district over which there have probably been several suc-
cessive ice advances with intervening recesstons, the drift can
scarcely be expected to belong solely to the advance which formed
‘this moraine. ‘Jt is known that remnants of the partially ce-
mented sheets of the oldest stages of glaciation are present.
There is probably present also a considerable amount of drift of
the Early Wisconsin stage. The drift of the Early Wisconsin
stage is so similar to that of the Valparaiso moraine that it is
doubtful if it can be readily distinguished from it. There does
not appear to be a well-defined soil horizon at the base of the Val-
paraiso sheet to mark the line of junction such as occurs under
wide areas at the base of the Early Wisconsin drift. The thick-
ness of the Valparaiso drift sheet can perhaps be best estimated
by the relief, for it can scarcely be assumed to exceed greatly the
measure of the outer border relief of the moraine. The relief on
that border is estimated to average about sixty-five feet. The
average thickness is probably even less than the relief, since the
sheet is markedly thinner on the, borders of the moraine than on its
crest.

The combined thickness of the several sheets of drift here rep-
resented is also difficult to determine from the fact that the under-
lying rock surface is very uneven. In Cook County alone the rock
‘surface is known to range from about 100 feet above the level
of Lake Michigan to more than 100 feet below the surface of the
Jake. In the table of thickness of drift which follows, the older
deposits as well as those of the Valparaiso moraine are included.

30 CHICAGO ACADEMY OF SCIENCES.

: ae
——s Se

List of deep borings along the re: Moraine in Lake, Cook,
Du Page and Will Counties :

Thickness Approximate

of jlevation

Drift. above Vide.

1) At) Ivanhoe; onereste... 3.02 \- 24> a -. 290 feet 800 feet
9. Near Lake Zurich, on crest.............. 26a ae 900 <<
3. At Lake Zurich, 20 to 30 feet below crest 240+ <“‘ 880 “
4.) Hainesville, meatierest: sce cs. sje secre tee Bstiar 3 880 «
Bl NGilmenr.4 Wear eLesbmi.ei is seicle wal talnya|- cee 21d-P <5 820
6, Crest, east of Wauconda................. 230+, «§ 850 «
7. -Crest, south of Barrington .............. 315+ es 850 ‘“*
8. Barrington, 40 to 45 feet below crest..... 254 of 818 «
9. Hast of Elgin, near crest .............. 220-240 e 850 «
Nien Palatine and va cia bye dere ye yeti 100-170+ « 750 <«
11. Near Schaumberg, along crest........... 190-6 825 «“

12. Arlington Heights, about 150 feet below
CVSS T yarn ie Holete oerdauerele ate tay foled cttevene) cueivene 128 ce 700 <<
13. North of Arlington Heights, 20 to 30 feet

above station......... ate a taave Meh stt sates - 190 Uc 725 «<<
14. Near Spaulding, about 50 feet below crest 120 ae Aen Olegee
15. Bartlett, 10 to 20 feet below crest........ TOO ct oes 800 Ǥ
16, Ontarioville, near crest:-::........ ents 140+ + 815 «*
17. Roselle, about 50 feet below crest........ 100+ « Tih) ce
18. Crest south of Bloomingdale............ 162 Ue 800. Ǥ
AOL MIG AS Caine sree ke Monette eldictate ttarntali eke teres EP An oc 692
XD). ese ye souecocccusosopdpoobdsensos 97 ok OUT ae
MA HMA WHEN Gad ouesdolsosaaqoasecods500doeoCe 98 ts 688 <:
OY AIMbrninpiasiy QUA, gy ooabodacacdodsesgbodes Trace - 660 <<
23. Turner Junction .............-:-.-.+- eiarLlG oe 765 «<
24, Quarries near Naperville................ Trace 700 «°
25. Crest east of Naperville........... peut rs 5+ « 740 <<
26. Downers Grove......... i aise a Nea J Na Tsien ee 720 «
27. Crest east of Downers Grove............ 159 we 750 $6
OshaNear Clarendon | ENILIS yee) clne elses 160+ <Ǥ 755. 1
29. Crest northwest of Lemont.............. 150 “é 740 <<
30. Crest of moraine east of Lockport ...... 115+ « (25 mee:
31. Near Spencer........ sHaGodeooosd aos auld 81 Oe 710. «*
525 IOrest mearebramktOng ieieiisyetiteloistscieicerle WeYiyqe ce 780 «+
33. Hickory Creek, near Frankfort .......... Trace 730 <<
Syl S\eye5 TS, AN, SH 1s WUE Goode duscoscacdn0e oe 760 <é
Sq WONAVEXe), GIN CRA ose odoonconeanonduobddoS 180+ <«§ 804 -«
36. Crest mear Goodenow........0=---+-+-0% = 112+ 780 <<
SY EXXHONGTM A digo wa duo mondo odoDOonomrogdoondS 106+ « 720 <<
38. Sec. 119 Tp. 34, Ro SIV E..:...... eRe teneeasie INGap = £6 720 <é
39: Chicago Helohtsy ey. sie eeecls mls csi ele ie: 30 OG 690 <<

40. Quarry 1 Mi. east of Chicago Heights.... Trace 665 *

GEOLOGICAL AND NATURAL HISTORY SURVEY. 31

Structure. —The drift of the Valparaiso sheet, together with .
that of the Early Wisconsin, which underlies it, consists mainly
of a soit blue till, easily penetrated by the spade or auger. With
‘the till there are local deposits of sand or gravel, which collect the
water that supplies wells. There are also a few places in which
the deposits of sand and gravel occupy nearly the entire drift
section. In following the moraine through Northeastern Ilinois
there will be found occasional townships in which the till, which
is a poor source for water because of its compact matrix, is not ac-
~ companied by a sufficient amount of sand or gravel to furnish water
for strong wells, while in adjoining townships no difficulty may
be experienced in obtaining water. It is more often found neces-
sary to drill wells to great depths in eastern and northern Du
Page, northwestern Cook and southern Lake Counties than else-
where along the moraine in Illinois, many wells in that district
being more than 150 feet in depth. In southern Du Page County,
between the east and west branches of Du Page River, the drift
to a depth of fifty to sixty feet or more (the depth reached by the
deep wells) is mainly sand and gravel, this being an unusually
gravelly part of the moraine. In Will County wells seldom reach
a depth of 100 feet because of the abundance of water-bearing sand
ot gravel at less depth.

In collecting well records there is, I find upon examining my
notes, a larger proportion showing exceptional than normal con-
ditions, it being natural to pass over the usual section after it is
once noted without collecting further records. This should be
borne in mind when examining the specific well records given
below. Scores of wells were found which show a section about as
follows: At surface ten to twelve feet of pebbly yellow till, be-
neath which is a soft blue till extending to the water bed of sand
or gravel at depths ranging from twenty-five feet to 150 feet or
more. Ifa well is carried to a depth much beyond 150 feet it is
ustial to pass out of the blue till into a hard brown till, unless rock
is reached. This hard till presumably belongs to one of the ear-
liest invasions of the ice. In a few cases great depths of sand
have been found beneath the blue till, as noted below. The sec-
tions of wells here given include the deepest which came to my
notice.

32 CHICAGO ACADEMY OF SCIENCES.

5. J. Lewis, a well driller, of Elgin, I11., reports a well about
one mile east of Lake Zurich, in Lake County (in Sec. 20, T. 43
N., R. to E.), which has the following section:

Taw ellows! pebblyatelarperwever aloe aeue cael eae ad ete ree Merah aye ee 12 feet

2y (Grewia ores pSlMDhy Clehy aay ccnesadessecbanonedamessedabesuuc 88 *

Bini’ Nora yu Sac ey Mees nea SE NU eT ICES eae ie ane alan Lee TOV
IDM oso dos 6 BUNA ned Wr Seeal as A ior Da ens EMP Ta AICI icc» if 297 feet

Altitude of well mouth about 900 feet A. T.

Mr. Lewis reports three wells near Lake Zurich which ob-
tain water in gravel beneath the blue till at 138, 140 and 150 feet,
respectively... Near Hlainesyille, in.See\ 28, 1. 45 UN.) Re woul eae
reports a boring to have reached the bottom of the blue till at, 120
feet. Below this till is sand for a depth of 167 feet. The sand
yielded an abundance of water, but was too fine to be screened by
the strainer and no well could be obtained. Near Gilmer, in Sec.
3, I. 43, R. 10 E., Mr. Lewis made a well which penetrates stony
clays 120 feet and sand 93 feet, obtaining water in coarse sand at
a depth of 213 feet. Fora mile or more east of Gilmer wells are
obtained in gravel beneath blue till at a depth of 75 to 100 feet, but
occasionally the blue till extends to a depth of 160 feet. In Bar-
tington Township, Cook County, T. 42 N., R. 9 E., wells usually
penetrate soft blue till to a depth of 100 to 140 feet and occasion-

ally 200 feet before reaching a water bearing gravel or a harder
till.

Mr. W. Spumer, of Lake Zurich, who has had some experi-
ence in boring tubular wells, furnished the following section of his

own well near Lake Zurich, in Sec. 17, T. 43, R. 9 E.:

Te wellowarpebibliy clay. ths Sages soa Sunes sick) CVA oe par One ee 10 feet
A, (Graymisii-paie, jelooiky CleyZ, BlbObhitss cs sesdaococcsdencnocoocce TOW "2
3. Sand, end blue. pebbly clay in alternate layers of various
(WHINE) IMNSSSSS) SoS sled ou gooe Hii te aonicachtye cmctat BlS 0:5 (oleae
4, Sand, becoming coarse and gravelly at bottom............:... LAGS
IDS o ido) FALURL MAAN EL VINCI a Leet aN i Eran a RUIN A Oo 240 feet

Mr. Spumer reports that a boring at Ivanhoe, Sec. 22, T. 44,
R.9 E., strikes rock at 200 feet. A well three miles southeast of -
Wauconda, on the Fletcher Estate, Sec. 32, T. 44, R. 10 E.; is
reported by Mr. Spumer to have the following section:

GEOLOGICAL AND NATURAL HISTORY SURVEY. 33 |

1. Yellow, pebbly clay.........-- ORME GTA HUAN AL ORaY ME ILS UES a ae 12 feet
a GRATES GUISE IO) SLING Letra en in ae HG Sa RT SEUN AU HE VE 2-3
Peebles pepbly: clay, wath’ sand: pockets... 0.1 ats j-)ans alee tee Too “
4. Sand and reddish, pebbly clay, in alternate layers, each 10—15
TOKE | SSSR sc eA RR Ree tN SHS eae UU Ee ARE Arties ai ra 107
B. Worn “Genaahie Clean dan Ga tig nam Slo cG cai oe wo atob a sibla Soran aiciols Ar
©, -Seaiancl guiatral sence nel ey a an aes pose es ete) lbs a ia Sau Rea ec en Be
JD Yeypyielay cs ie wee ee eee a Ai PRR eu LACM eT PAE ra Aa tet 230 feet

Mr. Spumer estimates the depth of the blue till along the
divide between the Fox and Des-Plaines Rivers in southern Lake
County to be 125 to 150 feet and wells occasionally obtain water
in gravel immediately beneath this till.

Mr. William McWendle, a well borer at Oak Glen, reports
two wells at Barrington that strike rock at 254 and 250 feet, re-
spectively. To a depth of about 160 feet in each well the drift 1s
mainly a soft blue till. Considerable cobble was encountered at
this depth. Below the cobble is a lighter colored clay harder and
more pebbly than the blue clay and apparently belonging to an
older drift sheet.

Mr. A. W. Van Dervolgan, of Batavia, reports the following
section of a boring on the crest of the moraine south of Barring-
ton, in Sec. 22, Barringtown Township, which is the thickest sec-
tion of drift yet noted in the Chicago Area:

teoellow, and: blue. pebblyyclays,aboute ss. 100.6 eas se sae eee 160 feet

AD, “Oywniclxeaiaal a vonsheke es eeae soc ais acs a Aas aoe iOIo Saeco ey ola repeeRNs 15

Paeneddish pebbly;clayashandeandydrynabout. ic a. seat seis 140)
TID) Smelt ee aS wana eel cs ois a ce ht eel A ea Se aD 315 feet

The well was abandoned without reaching the bottom of
the drift and a second boring was made only five rods distant
from it, which furnishes a good supply of water at 170 feet.

Mr. M. Sneible, of Palatine, has found in his experience as a
well borer that the yellow surface clays in the vicinity of that vil-
lage vary in depth from six to fifteen feet and that the blue bowlder
clay is 100 to 125 feet in depth. He usually finds sand or gravel
beneath the blue clay and here obtains the wells, but occasionally
a thin bed of cemented gravel is penetrated or limestone is en-
tered just below the blue clay before obtaining a well. In sev-
eral instances he has reached the bottom of the drift at 150 to 165

34 CHICAGO ACADEMY OF SCIENCES.

feet and in one place, near Palatine, at 100 feet. But it should
be borne in mind that the surface elevation in the vicinity of Pala-
tine is.at least 100 feet below the crest of the ridge in Barrington.
Township. Mr. Sneible has found buried soil but once. This
was near Arlington Heights, beneath blue bowlder clay, at a
depth of seventy feet. The soil was underlain by a pebbly clay.
It contained bits of wood and was of an offensive odor.

Mr. R. Ryan, of Bloomingdale, in an extensive experience
as a well borer, has found a buried sofl but a few times. He recol-
lects its depth in but one instance, in a well in the northwestern
part of Schaumberg Township. It occurs at 135 to 139 feet below
the surface. It is of a brownish black color and has an offensive
odor. It is overlain by blue bowlder clay and underlain by
quicksand. Mr. Ryan and also other well borers have found
wood and peaty deposits imbedded at slight depth beneath ponds.
They are covered by swamp muck and pebbleless clays and
have probably been buried in postglacial times. Mr. Ryan re-
ports the soft blue till to have a depth of 100 to 140 feet in the
vicinity of Bloomingdale, Schaumberg and Wheaton.

Mr. Diebold, a well borer at Downers Grove, reports a depth
of 100 to 115 feet of blue bowlder clay in the vicinity of Downers
Grove, Clarendon Hills and Hinsdale. Mr. Diebold furnished
the following section of a well at a brick yard on the crest of the
moraine three miles east of Downers Grove:

Twiellowaclaye (pebtlysc aiipcw sek mons osteo ernee nyaenee ae 7 to 8 feet
2. Grayish-blue, pebbly clay........ SINC Tes Nha GMA URED a tg Pana bice hs
Beataie if DL te, Samia ayes elses cy ale cae) ages ys eT ye ae 20 wa
MPTP SEONG, cleo Me ene cioeat cleat Oke a Mea Ae a Oe AOWe

Depth of drift..... Gyo a HAR AIT. A) ear Ne en a a2 159 feet

Mr. Diebold has frequently found a blue sand beneath the
blue bowlder clay in that vicinity, and if this is not present there
is usually white sand or gravel beneath the blue clay and overly-
ing the rock.

Borings near East Du Page River strike rock at too feet or
less, and the sand and gravel which underlie the blue clay are
but a few feet in depth.

The structure of the drift along the bluffs of the Des Plaines
is well exposed at several points between Lemont and Joliet.
There appears to be much more sand and gravel than is shown by
well sections on the uplands.. There is, however, considerable

Y

- GEOLOGICAL AND NATURAL HISTORY SURVEY. 35

till exposed in the east bluff. Just below Lemont a blue till rests
immediately on the limestone, but frequently in that locality. there
ds sand or gravelvat the base of the drift. In the west bluff, oppo-
site Lemont, there are large accumulations of sand, gravel and
cobble, in portions of which bowlders and bowlderets are im-
bedded, while in other portions assorting is quite perfect. There
are also places where a very fine, partially cemented, sand, almost
as fine as loess, caps the deposit.

In the portion of the moraine east of the Des Plaines River
the yellow clay has a depth of about ten feet. It is underlain by
a grayisn-blue bowlder clay, which carries a sufficient number
of water-bearing veins to furnish abundance of water for wells.
There is less difficulty experienced in getting good wells at slight
depth here* than in the portion of the moraine west of the Des
Plaines River. There are very few tubular wells and these seldom
exceed seventy-five feet in depth, while the majority of those along
the crest of the moraine have a depth of but forty to sixty-five
feet. Consequently there is a less complete knowledge of the
deeper structure of the drift than on the portion wést of the Des
Plaines River. The following represent the deepest wells of which
sections were obtained: _

At Beecher Station a well 106 feet in depth is principally
in blue bowlder clay and obtains water in a gravel at the depth
mentioned.

On the crest of the moraine at C. L. Pease’s residence, one
mile north of Goodenow, a well 112 feet in depth is in blue
bowlder clay to the water-bearing gravel at bottom.

J. O. Piepenbrink, Section 11, Crete Township, has a well
106 feet in depth, which has the following section:

i, Welllows, weolihy Clenys Cr mealahighn Geist, os sababcousiccdaccocsuuedr 20 feet

Pen Gravis plies, pebblygclays valentin a itiad oo sie Jie seuss eras Pineiro ia

Bo (CORBIS Seay G hats eee a Bees sit RIN SIU NO crs RMN an I
Depicts tea a eater La PON RA Sic carn A DP 100 feet

Mr. Piepenbrink finds the blue clay less pebbly than the
yellow clay and the blue clay varies greatly in hardness in differ-
ent wells on his farm and also varies at different depths in the
same well.

In the village of Crete nearly all the wells enter sand at slight
depth, and cellars are frequently drained by boring a few feet in:
their bottoms to a dry sand, which absorbs their water. The

36 CHICAGO ACADEMY OF SCIENCES,

following section of a well in Sec. 8, Crete Township, is represent-

ative:

t. Yellow, pebbly clay.......:-+:2+s.0005. seit I A are 8 MCN ee 15 feet

2. Blue, pebbly clay...--...... EAS Ne eco hai BUN A ase eae Swregs

Ze ND exaust wal Muh Sn einetcn ree Cimino meen Maroy UKM eRe Blobs iB.c cg aicac D.C 12

As Oxevicleeeharalchinal WUE Von dae be seusooeiad Ch OO sa deseclins ooo 0: Ply?
IDAs dwar aa ees Oe comma eran wud Ag ald ore Reus aA Cor, t5 52 feet

In some wells the sand lies within ten feet of the surface and
has no blue clay above it.

The following sections of well borings near Spencer will il-
lustrate the structure and show the general thickness of drift in
that locality:

Section of well at elevator in Spencer—

Tevellowspebblivaclayeeenieceeion Sears ea Bust aN erst 12 to 15 feet
2. Blue, pebbly clay, hard and dry.......... Nog Grey aos Sie) 50
3. Cemented sand ......- reece eee aren uaa See Ain ME SION “oe Rai to mel

Al OyenielkeennGl Sod osbas ous Fou: PASTA Tae ees eleeehen ea eats Mae a eR 5 to 6

5. Limestone at.75 feet ()...... Cie POIs SoC ae a aR ND Panta

Section of well two miles south of Spencer—

TINGE Howes ebiliy, clay Aes nele eels cheweernbohe dee sons vee aaa Ot eo 8 feet
2igsandiand gravelly yawn ie ve sea aie anak janaine oacceetsa len. Gee ai) eee TAN i
Ze Blue pebbly clayy inandeaimcdlcigyue sen nea eue nee ea - 60° —
Ane Pimlestomeracno2miee teste ee: cement: IC Din tIA ean SPAIN SS. ss

Carbonic acid gas has been encountered quite frequently
in wells along this moraine. It is usually found in dry cavities
in the blue clay and is struck at various depths.

In the outlying belt in Will County, from the Des Plaines
River southeastward, the thickness of the drift is much less than
in the main belt, being as a rule between forty and seventy-five
feet. There is usually at surface ten to twenty feet of yellow till,
Beneath this is occasionally found a bed of sand or gravel of
slight depth, but usually blue till immediately underlies the yel-
low. In the blue till beds of blue quicksand are often struck.
These beds are, in this district, sometimes ten feet or more in
depth, and offer great obstruction to well-digging or boring.
Such quicksand is not uncommon in other districts in Northeast-
ern Illinois. Wells are seldom obtained in it, though it is full of

[1] It is thought that rock was struck at the bottom of the well.

GEOLOGICAL AND NATURAL HISTORY SURVEY, Syd

water, for the reason that the sand clogs the strainer of the pump.
‘It is also difficult to case or wall a bored or dug well in this ma-
terial, it being necessary to sink the wall or casing to the bottom
of the sand. Many wells are carried through this sand and a few
feet of the underlying blue clay to a gravel bed or in some instances
into underlying limestone. —

FLOWING WELLS (1).

Palatine. Flowing Well District. —In the vicinity of Palatine,
in northern Cook County, there is a small district having a radius
of about two miles from the village of Palatine as a center, where
flowing wells are obtained. In 1887 there were eight of these wells
in the village of Palatine, and at least twenty-five in the town-
ship. The writer has obtained no later information concerning
this district. The depth of the wells ranges from 70 to 170 feet,
the majority of them being from 125 to 170 feet in depth. Occa-
sionally a well has struck two or more veins from which water
will flow, though usually there is but one vein. The water rises
in the village of Palatine from the three strongest wells about ten
feet above the level of the track at the depot. These wells do not
obtain water from exactly the same depth, but are among the deep-
est wells in the village. The head is lower in the shallow wells,

water rising in some cases only about five feet above the level
of the railway station. It was not determined to what height water
rises in wells outside the village compared with those in the village,
since they are scattered widely and no levelings have been made
between the wells. The rate of discharge varies greatly even in the
village of Palatine. The strongest well, which is at the cheese
factory, has a discharge of sixty gallons per minute. The other
wells in the village ow but one to six gallons per minute, and
the wells at the farm houses outside the village seldom flow more

- than five gallons per minute. -The water is slightly chalybeate in
every well which was examined. The waters vary greatly in
hardness in the different wells. All the water, however, is so hard
that it is necessary to “break” it before using it for laundry pur-
poses.

There are many deep wells in the vicinity of Palatine which
do not flow, even when the surface level is lower than that at
the flowing wells. The water supply is apparently from veins
whose collecting areas vary in altitude, otherwise the water level

would be more uniform.

[1] These flowing wells were first discussed by me in the 17th Annual Report
of the U. 8. Geological Survey.

: weer’ & hy aie
I i ays one

38 CHICAGO ACADEMY OF SCIENCES.

The collecting area is thought to be in the portion of the
moraine west and north of Palatine. The moraine west of Pala-
tine attains an altitude of 100 to 120 feet above the station, and
the crest in Lake County has nearly as great an altitude. The
. superficial drainage is very poor north of Palatine, on the divide
between Salt Creek and Buffalo Creek, and it is also poor west
of Palatine, for there is no stream nearer than Fox River to re-
ceive its waters. Consequently much of the water must evapor-
ate or find outlet by underground passages. There seems to be
a sufficient collecting area and also a sufficient variation in altitude
to account for the wells and the difference in head.

Salt Creek Flowing Well District.—South of Palatine Town-
ship, along Salt Creek and its tributaries, owing wells are fre-
quently obtained. They differ but little from springs which occur
-along the creek. There are at least six such wells along a trib-

utary of Salt Creek in the eastern part of Schaumberg Town-

ship, (T. 41, R. 10 E.), none of which exceed forty-five feet in
depth. Those along Salt Creek, from Plum Grove, in southern
Palatine Township, to the vicinity of Elmhurst, in York Town-
ship, seldom exceed thirty feet in depth.

In Itasca there are a few flowing wells along a tributary of
Salt Creek. Of these the deepest one recorded is but twenty-
eight feet. The water here will rise not more than three feet above
the bed of the creek. This level is sixty-five to seventy feet lower.
than the level of the owing wells in Palatine.

OUTER BORDER PHENOMENA.

While the ice sheet was forming the Valparaiso moraine

there were streams of water issuing from its outer border and

escaping down the Des Plaines River. These streams became over-
burdened with material derived from the ice and in consequence

built up their beds and valley bottoms to a marked degree. The’

filling reached such a stage that the streams were in some cases
forced to find outlet across the present interfluvial tract. Valleys
were formed by these streams which are now abandoned or occu-
pied by insignificant brooks (1).

From the contour maps prepared by the United States Geo-
logical Survey it is possible to ascertain the height to which the
filling extended along the lower part of the Du Page and the
Des Plaines and the elevation of these abandoned channels. From

[1] Perhaps the vallevs here referred to were partially opened by subglacial
streams at the time when the moraine which they cross. was occupied by the
ice sheet.

a ee ae ee

GEOLOGICAL AND NATURAL HISTORY SURVEY. 39

the Joliet sheet, which includes sections of the Des Plaines and
lower Du Page Rivers, immediately outside the Valparaiso mo-
-raine, it appears that on the immediate border of the moraine the
gravel filling reached an altitude approximately 620 feet A. T.
These gravel deposits are extensive along the Du Page River be-
low the junction of the West and East Forks and along the Des
Plaines River below Romeo. Tracing these deposits southward,
there is a marked descent, the altitude at Plainfield being scarcely
610 feet, at Grinton 590 feet, at Joliet Mound 580 feet and at
Channahon 570 feet, a fall of fifty feet in a distance of about
twenty miles.

The abandoned valleys which connect the Des Plaines and
Du Page Rivers are not of the same elevation. The northermost
one, occupied by small streams which drain it in opposite direc-
tions, each of which is known as Isle la Cache Creek, leaves the
Des Plaines opposite Romeo and passes nearly directly westward
to the Du Page Valley just above Plainfield. It has an elevation
between 600 and 610 feet A. T. It opens out toward the south-
west into an extensive gravel plain near Plainfield, having the
same elevation as the channel, which was probably built up in
part by the current which formed this valley. The valley is about

one-half mile in width and is cut to a level forty to fifty feet below
the bordering uplands.

A second valley leaves the Des Plaines about:'two miles south
from the Isle la Cache and leads southwestward to the Du Page,
entering that valley below Plainfield. Its elevation is 620 feet, or
‘about the elevation of the gravel deposits bordering that portion
of the Des Plaines Valley and somewhat higher than the deposits
on the Du Page. It is not so large as the Isle la Cache and prob-
ably was earlier abandoned.

A third valley leaves the Des Plaines about midway between
_ Lockport and Joliet and passes westward into the Du Page Val-
ley just above Grinton. The elevation of its channel is 570 to 580
feet or ten to twenty feet below the level of the bordering gravel
deposit. It is about fifty feet in depth and nearly one-half mile in
width. The contours of its bluffs indicate the line of a vigorous
stream.. This valley was apparently the last of the three to be
abandoned.

The deposits along the Du Page and Des Plaines Rivers con-
sist in the main of coarse gravel and cobble, much of the finer
material having been swept away by the strong current. Excellent
exposures are to be seen in the gravel pits near Plainfield on the

40 CHICAGO ACADEMY OF SCIENCES.

Du Page and in numerous small gravel pits along the border of the
Des Plaines, both above and below Joliet. One of the largest on
the Des Plaines is found in an island-like remnant of the old
terrace known as “Joliet Mound,” about two miles below the city
of Joliet, on the west side of the river. At the southeast end of
this mound the following section is exposed:

iy Sieioeree Comimmose Or silly Ceyyaelsndsassgsessce Fboeccoco~ I to 4 feet
2D, Coenese eacanyell sing! CODD As adogonccgh@asoseo ea oon ec soo - 10) toml2 sea
3. Sandy gravel of medium coarseness, cemented in places. 25 to 30 ~
Hive Bball halGl ovp lohanbai A onal SiMe s o dlacia aa i aiiAON Gi0 aes
5. Blue, pebbleless clay, laminated, calcareous............ 8 to 10

6. Bowlder bed, containing clay balls and a sandy, clay

matrix, extending to river level on east side of mound,

ce

but underlain at slight depth by limestone at west side. a to 20

It is thought that the bowlder belt is a result of interglacial
erosion ofa till sheet. The blue pebbleless clay which overlies it
is apparently a still water deposit formed perhaps before the ice
sheet had reached such a stage of melting as to produce vigorous
drainage. The upper member appears to indicate a deposit by a
stream whose vigor was greatest toward the close of deposition,
for at the top the cobble is swept almost free from sand. The
change, however, may have been brought about by a shifting of
the main current of the stream, the coarse material being deposited
over portions of the bed which had before been outside the main
current.

The deposits of gravel along this valley terminate very ab-
ruptly at the south, near Channahon, there being only a fine sand
on the plain in the Morris basin at the head of the [linois. This
feature 1s apparently due to the presence of a body of still water
in the low country about the head of the Illinois River. The
region is covered by sandy deposits up to a level about 575 feet
A. T., on the border of which there are in places well defined beach
lines. This lake had a western outlet through the Marseilles
moraine down the Illinois. Its beaches are traceable a short dis-
tance beyond Morris. Further west the body of water became
narrowed to the width of the Illinois valley and changed to an
eroding agent.

It is probable that each of the small tributaries of the Kankakee,
which head in the Valparaiso moraine, and also eastern tributaries
of the Des Plaines, were lines for escape of glacial waters, but the
writer has not examined the valleys to determine the effect of such

pn

Rd POs
a a ee —-

GEOLOGICAL AND NATURAL HISTORY SURVEY. 4]

waters, excepting the valley of Hickory Creek, which enters the
Des Plaines at Joliet. This valley has a moraine-headed terrace,
setting in at the outer border of the moraine in Sec. 17, New
Lenox Township. It has a gently undulating surface for a mile or
more out from the border of the moraine; its surface then becomes
plain. This gravel plain is nearly as high as the bordering till
plains 620 to 630 feet A. T. and 60 to 70 feet above the present
stream.

On the east side of the West Du Page River, from Naperville
northward, the gravelly deposits of the moraine graduate into
terraces or gravelly aprons, which lead down the valley. The low
gravelly knolls of the moraine disappear in a nearly plane sur-
faced apron on descending to the border of the river. This gravel
apron is not so extensive as the deposits of the lower Du Page,
above described, and is now seen only as remnants along the valley
border.

The East Du Page throughout its entire length drains a
broad slough, which separates morainic ridges. Its bottom is said
to be underlain by deposits of gravel and cobble.

49 CHICAGO ACADEMY OF SCIENCES.

LAKE BORDER MORAINIC SYSTEM.

THE MORAINES.

Between the Valparaiso moraine and the shore of Lake
Michigan there are, in Cook and Lake Counties, a series of nearly
parallel till ridges. We can perhaps best describe them as the West
Ridge, Middle Ridge and East Ridge. Though usually distinct,
the ridges are in places coalesced as described below.

The Outer or West Ridge.—The outer or west ridge enters
Illinois from Wisconsin on the west side of the Des Plaines River,
its outer border being for a few miles followed by Mill Creek,
while its inner extends to the west bluff of the Des Plaines River.
Just below Gurnee the river passes through the moraine and for
several miles south follows closely the outer border. The river
then bears away from the ridge a short distance and the outer
border of the ridge for the remainder of its course lies a mile or
more east of the stream. In Lake County the ridge is sufficiently
prominent and bully to constitute a marked feature and has a
general width of about two miles. In the south part of the county
it sends out a spur to join the middle moraine belt near Deerfield,
while the main ridge continues south into Cook County, gradually
decreasing in strength and dying out in a plain near Mont Clare,
in the southwestern part of Jefferson Township (T. 40, R. 12 E.).
For five or six miles north from its southern terminus it rises
scarcely ten feet above the bordering plains, and is distinguishable
from them mainly in being more undulatory. Where well de-
veloped, as in northern Lake County, the moraine has numerous
knolls, 20 to 25 feet in height, and these stand upon a basement
ridge whose relief is nearly twenty-five feet. A noticeable feature
of this and also of the other ridges of this system is the difference
in the breadth of the outer and inner slopes, the usual breadth of
the outer slope being scarcely one half that of the inner.

The Middle Ridge.—As already noted, this ridge is joined to
a spur from the west ridge, south from Deerfield. The combined
belt finds its southern terminus near the head of the Chicago
River and at the border of the old lake. A possible continuation
southward is discussed below.. The course of the belt is south to
north, through Northfield Township, Cook County. Upon enter-
ing Lake County it becomes distinct from the spur and remains

Fee tk a

GEOLOGICAL AND NATURAL HISTORY SURVEY. 43

a distinct ridge for a distance of fifteen miles. It there, in Sec. 18,
Waukegan Township (T. 46, R. 12 E.), becomes united with
the east ridge and remains so as far north as it has been examined.
On each side of this ridge there is a narrow sag or slough. The
sag on the east is marshy its entire length from Winnetka, in Cook
County, northward to the latitude of Waukegan, a distance of
nearly twenty miles. For a couple of miles at its southern end it
has a width of one-half mile or more, but the usual width is only
one-fourth mile. The sag on the western, or outer, border con-
tains a marsh from Rondout station south to the Lake and Cook
County line, a distance of about nine miles.

This ridge, like the west ridge, has low knolls along its crest,
8 to 15 feet in height, but the coalesced ridge in Northern Cook
County is more billowy and carries knolls twenty feet or more in
height. There are basins and winding sloughs among the knolls,
which add to the expression of the moraine.

The East Ridge.—The southern terminus of the east ridge is
at Winnetka, where the present lake cuts it off. It has apparently
had its entire east slope and a portion of the crest removed by
the lake, there being a descent immediately from the bluff on the
lake to the slough, which lies west of the ridge. Following the
ridge north to Highland Park the crest and east slope appear.
Continuing north to Lake Forest, a narrow till plain appears on
the east of the ridge, the inner border of the ridge lying back a
half mile or more from the lake front. Still farther north at Wau-
kegan, the inner border lies back about two miles from the lake
front. The usual width of this ridge, where complete, is about
one mile. The crest of the ridge usually stands 110 to 125 feet
above the lake. At Winnetka, the higher portion being removed,
it rises but 80 feet above the lake. The till plain east of the ridge
stands 75 to go feet above the lake.

The rate at which the lake bluff is being encroached upon by
waye action has become a matter of much concern to the residents.
It is estimated by old settlers that from Waukegan to Evanston
there has been, during the thirty years from 1860 to 1890, a strip
about 150 feet in width, undermined and carried into the lake.
This amounts to about 500 acres, representing at present valuation
nearly one million dollars’ worth of property.

Relief —The west ridge rises with a somewhat abrupt slope
about twenty-five feet above the plain along the Des Plaines
River. On the inner (eastern) side there is a gradual descent of

44 CHICAGO ACADEMY OF SCIENCES.

about forty feet to the plain along the Chicago River, and of 20
to 25 feet to the marshy plain in Lake County.

The middle ridge has a relief of 20 to 25 feet above the
marshy plain on its outer border, and a gradual slope of 25 to
40 feet to the sag or slough, which lies on its inner border,

The east ridge has a relief of 20 feet in Northern Lake County
and 35 to 40 feet in Southern Lake and Northern Cook Counties
above the sag on its outer border. The reliefs of all these ridges
are lessened at the northern end because of increase of elevation in
the sags or plains which separate them. The ridges each maintain
a nearly uniform height above Lake Michigan throughout their
course in Illinois.

Thickness of Drift.—In numerous borings, 75 to 100 feet in
depth, no rock is struck and no outcrops of rock occur along this
portion of the lake shore. The drift beneath the level of the base

of these moraines is probably largely of earlier date. The follow-
ing list of borings which have struck rock indicates that in several

places at least the rock surface lies much below the surface of Lake
Michigan. g

t. At Senator C. B. Farwell’s artesian well, in Lake Forest,
rock is struck at 160 feet. The well mouth is 40 to 45 feet below
the crest of the east ridge at Lake Forest and about 75 feet above
Lake Michigan.

2. At Highland Park rock is struck at 160 to 175 feet. The
elevation above the lake is 100 to 115 feet.

3. At Lloyd’s artesian well, in the north part of Winnetka,
rock is struck at 150 feet. The well mouth is by surveyors’ level
78 feet above Lake Michigan.

4. At Ravinia a well strikes rock at 164 feet. The surface
level has not been accurately determined, but it is probably about
100 feet above Lake Michigan.

5. Near Schermerville rock is struck at 147 feet. The surface
elevation does not exceed 100 feet above Lake Michigan.

6. On the crest of the west ridge in Sec. 14, Maine Township
(T. 41, R. 12 E.), rock is struck at 110 feet. The elevation is prob-
ably about the same amount above the lake.

Structure of the Drift.—Along the lake shore the bluffs from
Winnetka to the vicinity of Waukegan rise abruptly 75 to go feet
and present many good exposures of the drift to this depth. There
is at the surface a pebbly yellow clay 8 to 13 feet in depth, which is
similar to that in the Valparaiso moraine. Beneath this clay is a
grayish blue till containing occasional sand pockets saturated with

GEOLOGICAL AND NATURAL HISTORY SURVEY. 45

water. These, however, form but a small part of the drift. The
bulk of the bluff is a compact till, but moderately pebbly and ex-
posing only an occasional imbedded bowlder. It was noted that
the pebbles and bowlders are usually glaciated.

Neither the east ridge nor west ridge nor the northern
portion of the middle ridge has gravel knolls of any consequence,
but the southern portion of the middle ridge lying in Cook County
has many such knolls. Indeed, nearly every prominent knoll
contains gravel. It seldom exceeds 15 feet in depth and ap-
pears to be confined to the knolls, for they are situated on
a basement ridge of till similar to the till exposed along the lake
bluff. But one complete reliable section of the drift could be
obtained, which, though valuable, needs to be supplemented by
other records to furnish a satisfactory knowledge of the lower
portiton of the drift. The well is located at Ravinia. Its section
was furnished by William McWendle, of Oak Glen.

i, JPeloinihy, svolllony Clehveeoccooseddcdcecaesac Sete sisi Stee II feet
2. Grayish-blue, pebbly clay........ BEEN CLARITA et Sak csi CONay
3. Gray, clay, very pebbly........ shal bpavede nel atnive Renner a nate MDAL I 10 to 12
4. Grayish-blue, pebbly clay, lighter color than No. 2....... FO).
&, Clay, irecenmmpvitnes qoiliavadveguoobae Suigecenobodedoes fe go6 ALO) (5
6; ILiimestome, So lelsasoGuammds ude avenace Gare VG een 22

Total \alieies 5 c/o ALE URES SI aE MAU Taare
SUPPOSED CORRELATIONS,

None of these moraines have been found to have connection
at their southern end with the massive Valparaiso moraine, nor do
they admit of continuous tracing around the southern end of the
lake within (north of) that moraine. The weak development in
that district seems the more remarkable since there is on the east
side of Lake Michigan, northward from Porter County, Indiana,
a series of ridges of similar size and complexity to that under dis-
cussion and which are probably its continuation. The conditions
which affected the southern end of the ice lobe at the time these
belts were forming are so poorly known that it may be difficult to
ascertain what caused this wide gap. The question naturally
arises whether the expanded lake and its old outlet may not have
removed the ridges.

In the case of the western ridge this suggestion is inapplica-
ble, since the terminus at Mont Clare is outside the well-defined
beaches and above their level. The ice sheet here, however, may

46 CHICAGO ACADEMY OF SCIENCES.

have terminated in water held between its front and the Val-
paraiso moraine in the brief period required for the cutting down of
the outlet to the level of the upper beach. But in that case, while
wave action may have removed weak morainic features, it seems
scarcely probable that there could have been a complete oblitera-
tion of so strong a belt as is present in districts to the north. In
the case of the Middle and East Ridges, as shown below, there
may have been some erosion by the lake outlet and lake waves.

The Blue Island Ridge.—The Middle Ridge has its southern
terminus as a well-defined ridge at the point where it meets the
Upper beach. There is, however, near the southwestern limit of
the city of Chicago a till ridge, and connected with it a bowlder
belt, which may be correlatives of this morainic ridge.

The till ridge referred to is known as “Blue Island.” It leads
north to south for a distance of about six miles, along the line of
Calumet and Worth Townships. Blue Island village is situated
at its southern end. At that end the ridge stands about 60 feet
above Lake Michigan, but rises northward to an altitude 85 to go
feet above the lake. Its width, including the slopes, is only about
one mile. The northern portion is gently undulating and is
strewn with bowlders, but the remainder of the ridge is smooth
and comparatively free from surface bowlders. Around this ridge
there are shore marks in the form of eroded banks or terraces
and gravelly beaches at an altitude 55 to 60 feet above the present
take level. On its west border sand from the old lake shore is
drifted into dunes that extend nearly to the top of the ridge. Blue
Island ridge owes its elevation to a thickening of the drift deposits,
for the rock surface is as low beneath it as on border plains. A
well at Morgan Park, near the crest, reaches a level 70 feet below
the base of the ridge before entering limestone.

Bowlder Train.—A train of bowlders is traceable north from
the north end of Blue Island through the western part of the city of
Chicago to thevicinity of the Chicago River in Jefferson Township.
Although portions of the line fall within a thickly settled portion
of the city, the bowlders still remain in sufficient numbers to be a
noticeable feature. In the thinly settled district from South Lynne
southward to Blue Island they remain in about their natural
abundance. The belt occupied by the bowlders is a mile or more
in width. There appear to have been several hundred bowlders
to the square mile along this line, while on bordering districts
there are estimated to have been less than 100 to the square mile.
From the north end of this bowldery tract to the south end of the

GEOLOGICAL AND NATURAL HISTORY SURVEY. AT

Middle Ridge the interval is but a few miles and is mainly
covered by heavy deposits of lake sand and gravel which would
obscure any bowlder connection which may have existed. There
seems, therefore, nothing to oppose the correlation of the bowlder
train and Blue Island ridge with the Middle ridge.

From the south end of Blue Island ridge to the till ridges in
Porter County, Indiana, no line of bowlders or indication of the
position of the ice margin has been found. Such features may
however, be concealed in much of that district by the heavy depos-
its of lake sand.

Continuation of Hast Ridge.—The East ridge apparently had
some continuation southward beneath the present lake. Prof. L.
E. Cooley, of the Chicago Drainage Commission, informs me that.
in a series of dredgings in the south end of the lake, made a few
years since under his direction, a bowldery belt was traced for
several miles southeastward from the terminus of the East ridge
at Winnetka. This bowldery belt is perhaps a residue froma ridge
of till which has been cut away by the lake.

ASSOCIATED TILL PLAINS.

The ridges just discussed occupy but a small portion of the
area embraced between the Valparaiso moraine and the shore of
Lake Michigan. The greater part of the area is a plain underlain
by till deposits. On this plain, as is shown later, the lake has built
or carved its shore lines and made thin deposits of sand or gravel.

Altitude and Slopes.—In the portion of the plain west and
south from Chicago the altitude at the border of the Valparaiso
moraine is 620 to 630 feet A: T., or 40 to 50 feet above the lake.
From this border there is a gradual descent toward the present
shore of Lake Michigan, where the altitude is about 590 feet A. T.
This portion of the plain was covered by the lake at the time the
upper beach was formed, the altitude of that beach being 635 to 640
feet Ac.

Upon passing northward along the till plains just described
the narrow plains which separate the ridges soon rise above the
level of the Upper beach. The plain that lies between the Westridge
and the Valparaiso moraine slopes eastward at the rate of several
feet per mile. Its west border next the Valparaiso moraine rises from
635 feet at Ovington station, on the Omaha division of the C. & N.
W.railroad, toabout 690 feet at the line of Cook and Lake Counties,
a distance of 18 miles, and about 725 feet in northern Lake County
at the line of Illinois and Wisconsin, a distance of 24 miles farther.

48 CHICAGO ACADEMY OF SCIENCES.

This rise of 1$ to 3 feet per mile is, of ccurse, not perceptible to
the eye.

The plain between the West and Middle ridges rises from 630
feet at Oak Glen to 680 feet at Deerfield, a distance of six miles.
From Deerfield north to the State line, a distance of 24 miles, it is
shown by the C., M. & St. P. railway survey to stand at 670 to 685
feet A.T. Russell station, near the State line, is 673 feet.

The plain between the Middle and East ridges rises from 630
feet opposite Winnetka to about 670 feet at the point where the
ridges unite, 20 miles north from Winnetka.

Thickness of Drift.—On this plain there is much difference in
the thickness of the drift and since the surface, aside from the till
ridges just described, and the low beach lines, has very little varia-
tion in altitude, the difference in depth is due almost entirely to
the variation in surface of the underlying rock strata. Within the
city of Chicago, where the surface is especially flat, several rocky
prominences come to the surface, or are concealed but slightly by
drift, while among them the drift accumulations extend to depths
of 100 to 125 feet or more (1).

Mr. Samuel G. Artingstall, while City Engineer, prepared a
map of the city giving the distance to rock at many places. This
indicates that a filled valley with rock floor 100 to 125 feet below
lake level passes through the north central part of the city, enter-
ing the lake south of Lincoln Park.

West from the city the rock rises over quite extensive areas
very nearly to the surface of the plain, or to a height of 30 to 60
feet above the level of Lake Michigan. On the border of the Chi-
cago outlet there is a nearly continuous exposure of rock from near
Summit to the head of the Illinois.

In the northern portion of the district, between as well as be-
neath the till ridges, the rock surface has an average altitude slight-
ly lower than in the low plain in the vicinity of Chicago, for the
majority of the wells go about 50 feet below the level of Lake
Michigan before entering rock. It is estimated that the thickness
of drift in this northern portion will average nearly 150 feet, while
in the low plain the average will scarcely exceed 50 feet.

Structure of Drift. —The drift beneath this plain, like that
of the moraine, consists largely of a soft blue till beneath which
are remnants of a hard till of earlier age. The tills appear to be of

fi] A large amount of material has been collected by the Geological and Natural
History Board of The Chicago Academy of Sciences, with a view to preparing a
topographic map of the rock surface underlying the city and border tracts, and
which is designed to be published as a bulletin of the Academy.

[UOISSTMIULOYD oSBUTBACT
Osvoryy) oy} Aq Ydeasoyoyd] ‘step[Moq oy} Jo youq yurq oyy jo ospoa oy UL U9VS oq ABU ywod Jo doadjNO oY, “yeod
JO pod B MOTO STOP[MOG EGIL] SUTMOYS ‘TRURD OSvUTLIC, OSVOIYO Aq OpBUT ‘SSUTAdG MO]TAA cou OINSOdXY *T *Sty

oe

See

GEOLOGICAL AND NATURAL HISTORY SURVEY. 49

direct glacial deposition even in portions of the plain which lie
within the limits of the beaches. The clayey matrix of the soft till
is scarcely so thickly set with stones as that of the underlying hard
till. In both tills many of the stones are glaciated. The rocky
constituents grade from bowlders two to three feet or more in
diameter down to minute pebbles. These in the upper or later till
are made up in large part from the local Upper Silurian rocks,
probably less than ro per cent. being from the pre-Cambrian Cana-
dian rocks. Devonian rocks from ledges to the north of Chicago
are-sparingly represented. The clayey matrix is highly calcareous
and under the microscope it is found that angular or but slightly
rounded grains of limestone constitute a large proportion of the
fine material. With the minute limestone fragments, there appear
quartz grains, bits of shale and fragments from crystalline rocks of
various kinds. Whether the rock constituents of the lower till
differ markedly from the upper has not been ascertained. Its sit-
uation immediately upon the Niagara limestone would in all prob-
ability result in the incorporation of an even larger proportion of
this rock than appears in the upper till. :

One of the most conspicuous instances of the occurrence of
the lower till within the Chicago area is that brought to light in
the excavation of the Chicago Drainage Canal. Immediately east
from Summit the canal for a mile or so extends a few feet into a
very hard, partially cemented till apparently of early glacial age.
Its hardness compared with that of the overlying till is so marked
that the contractors who engaged to, excavate this part of the
channel were obliged to abandon the steam shovel which had been
used in the soft till and resort to blasting. It is probable that this
old drift fills depressions in the rock quite extensively in this dis-
trict, but as no special attention has been given its identification
the instances recorded are not numerous. The well drillers usually
recognize the hard till and apply to it the term hardpan, while the
soft till is called clay.

Although the great body of the drift is till, there are found
numerous thin beds of sand or gravel in which water collects in
sufficient quantity to supply the wells. There are also small pock-
ets of dry sand or gravel occupying but a few cubic feet each.
Such pockets were found in the excavation of the main lake tunnel
for water supply. They were in some cases completely inclosed by
till. .

On the surface of the plain both above and below the level
of the upper beach there is quite generally present a clay, varying

i aN yes * SU elt OR RG
} ' aie :
&

50 CHICAGO ACADEMY OF SCIENCES.

in thickness from a few inches up to several feet, in which pebbles
are far less numerous than in the till. It however carries occa-
sional bowlders. This deposit seems attributable to the combined
agency of water and ice. It was probably a deposit made in a
body of water held between the ice front and the Valparaiso
moraine while the ice sheet was still in the immediate neighborhood
of the moraine.

In the district within the limits of the upper beach there are

deposits of sand and gravel marking the shore lines of the lake.

These deposits form a less regular coating than the clay just men-
tioned. Over much of the plain the deposition was so light as to
leave scarcely a trace of sand in the soil, but in places the deposits
cover the till of the old lake bottom to a depth of 20 to 25 feet. The
heavy deposits are found chiefly along the present lake border
from Evanston southward, where there is a continuous belt of sand
ranging in width from one-half mile to three or four miles, and
having an average depth of not less than to feet. The southwest-
ward lake outlet appears to have carried away much of the sand
which was brought into the southern end of the lake while that
outlet was open.

The depth of leaching and oxidation is markedly less on the
plain covered by the lake than on the till ridges or the Valparaiso
moraine. Numerous tests with hydrochloric acid show the leach-
ing on the plain to extend only to a depth of a few inches, seldom
more than two feet, while on the ridges it is rare to obtain a re-
sponse at less than five or six feet from the surface. On the plain
the surface oxidation of the till is only two to six feet, while on the
ridge it is six to ten feet or more. This difference in the amount
of oxidationand leaching is probably attributable in part to the flat-
ness of the plain and in part to the later date at which the plain
was exposed to atmospheric action.

There have been several deep lines of excavation made in
Chicago and vicinity which have afforded excellent oportunities
for studying the structure of the drift. The longest line is the
drainage canal, now under construction, which opens a channel 25
to 40 feet in depth from the Chicago River at Bridgeport to the
Des Plaines River at Summit, that is entirely in drift. Along the
Des Plaines also the excavation is largely in drift to the vicinity
of Lemont, where the canal becomes a rock channel. From
Bridgeport to Summit there is little besides. till, but from Summit
to Lemont gravel, sand and the coarser material deposited along

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GEOLOGICAL AND NATURAL HISTORY SURVEY. il

the line of the old outlet form a large part of the section. (See
Bigs. t/and 2:)

_ In the Fullerton avenue conduit which leads eastward into the
lake through the north part of Chicago the drift is mainly till, but
the surface sand is a conspicuous deposit. From its western end
to within 2,000 feet of the lake the rock surface is found at a depth
of 43 to 54 feet. Within 100 feet east from this point it drops down
to 80 feet, passes below the conduit, and does not appear further
east. The sand has its greatest thickness at about 1,700 feet from
the lake, where it reaches 25 feet. It decreases westward to 17 feet
at 2,100 feet from the lake, and to 12 feet at 6,000 feet, and entirely
disappears before reaching the Chicago River valley. Toward the
lake shore also it decreases, being about 18 feet in depth for 1,400
feet west from the shore. At the water’s edge the depth is but 10
- feet. The profile continues out 1,100 feet below the lake, and there
is but three feet of sand at its terminus.

The profile of the lake tunnel shows the rock to be at a depth
of 37 feet at the working shaft four miles inland. Eastward from
here the distance to rock gradually increases to a point about two
and four-tenths miles from the lake shore, being between 50 and
60 feet at that point. It there drops down rapidly to a level nearly
go feet below the surface, and is not encountered farther east. For
two miles out beneath the lake the excavation reaches 60 feet or
more below the lake bottom. The tunnel was through till its
entire length. It shows, as noted above, pockets of sand inclosed
in the till. The surface sand, as in the Fullerton avenue conduit, is
of considerable depth.

In Hyde Park Township in the south part of Chicago numer-
ous borings and excavations show the sand deposits to be from
five feet up to about 20 feet in depth. Except where the rock
comes near the surface till is found to underly the sand.

52 CHICAGO ACADEMY OF SCIENCES. A

SARITA:

Exposures of striae are numerous and indicate that the axial
movement of the ice sheet in this district was decidedly west of
south rather than due south. This should be borne in mind in
estimating the amount of divergence in the lateral flowage. The
striae in this region are remarkably well preserved, and that, too,
where conditions for obliteration seem favorable. In some places
there appears to have been no drift protecting the ledges since the
withdrawal of the lake, if not since the time when the ice sheet
withdrew, and yet but few exposures do not preserve the striae.
In similarly exposed situations outside the Valparaiso moraine
striae are seldom preserved. This difference may be due partly to
the greater age of the striae outside the moraine. But aside from
this there appears to have been an original difference in the in-
tensity of glaciation by which ledges more often escaped the rasp-
ing action of the ice sheet outside the moraine than in the district
between the moraine and the lake.

The following embrace the localities where bearings were
observed:

1. Stony Island in south part of Chicago. The rock where
glaciation was observed dips toward the southeast, with an angle
of nearly 40 degrees, and heavy scorings follow the line of strike,
with a bearing S. 44 degrees W. (See Fig. 5.) Associated with
these are striae of feebler development, which vary in direction
fully 10 degrees to the east and west of the heavy scorings, thus
ranging from S. 34 degrees to S. 54 degrees W. An escarpment
of the dipping layers rising about six feet above the remainder of

the quarry is glaciated not only on the upper surface and nearly -

vertical front, but also beneath one of the lower layers, its dipping
under surface being smoothly polished for about 18 inches back
from the front of the ledge. (See Fig. 4, where the glaciated under
surface appears near the sachel.)

2. On Thorn Creek near Thornton. The prominent portions
of arching layers of the Niagara limestone are roche moutonneed
and a few striae have a bearing S. 31 degrees W.

3. Quarries one mile southwest of Blue Island. A few faint
striae were observed bearing S.54 degrees W.

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GEOLOGICAL AND NATURAL HISTORY SURVEY. 53

|

4. On west side of Des Plaines River, one-fourth mile north
of Santa Fe Railway bridge. An area of several square rods of
limestone surface is heavily glaciated. Grooves one-half inch in
width are common and there are a few fully two inches in width.
Fine lines are numerous. ‘The bearing corrected for magnetic
variation is very nearly due west, the magnetic bearing being 3 to
4 degrees south of west. This striated surface slopes perceptibly
toward the southeast, there being a descent of 2 to 3 feet in as
many rods. The glaciation was therefore made on an ascending
surface.

5. Immediately west of Summit on the west side of the Des
Plaines. The striae here observed are faint lines bearing S. 38
degrees W.

6. Between Willow Springs and Sag bridge, in the bed of the
Drainage Canal. The striae here observed consist of faint lines
bearing S. 23 degrees W. They appear over a space of several
square yards. (See Fig. 6.)

7. At Lemont, about 500 feet from the Santa Fe Railway
bridge. Mr. Ossian Guthrie reports that heavy grooves have a
bearing about S. 60 degrees W.. They were exposed in the exca-
vation for the diversion channel for the Des Plaines. A view of
these grooves is given in Fig. 7, but the present writer thinks they
may be the product of the waters of the Chicago outlet rather than
glacial striae.

8. Lyons, quarry in south part of village. Nearly all the
striae bear S. 70 degrees to 75 degrees W., but scattering striae
range from S. 44 degrees to S. 71 degrees 30 minutes W.

9. La Grange quarry. Scattering striae on a planed surface.
Bearing S. 58 degrees 30 minutes W.

10. Hawthorne quarry. There are here two sets, each quite
heavy scorings. The earlier set follow.approximately the line of
strike of the dipping layers, bearing S. 64 degrees to 68 degrees W.
The later set cross the upturned edges of the layers at a small
angle, bearing S. 52 degrees to 54 degrees W.

II. Quarry at crossing of Chicago avenue and Western ave-
nue, Chicago. A few faint striae preserved have a bearing S. 72
degrees W.

12. Excavation for Fullerton avenue conduit in north part of
Chicago. Bearing S. 60 degrees W. (recorded in profile of con-
duit).

54 CHICAGO ACADEMY OF SCIENCES.

13. On Eighteenth and Robey streets, Chicago. The surface
of arching layers is roche moutonneed. The prominent portions
of the surface are striated, the bearing of the striae ranging from S.
52 degrees to S. 57 degrees W.

14: Covel's quarty near Pimburst, Sec. 17, ) lp. 20) danse
The surface is planed quite extensively and covered with a multi-
tude of striae, bearing S. 63 degrees W.

15. Joliet, bearing 20 degrees north of west. An exposure of
striae with this remarkable bearing was found on ledges in the
Des Plaines valley, a short distance southeast of the State Peni-
tentiary. The ledges stand 10 to 20 feet above the valley bottom
and several striated surfaces were found, with small grooves, as
well as fine striae.

16. Du Page bluff, near C., R. 1. & P. Railway bridge, east
of Minooka. Prof. J. A. Udden reports an observation of heavy
glaciation, with grooves bearing about southwest.

17. Near Wilton, quarries are opened, which expose surfaces
heavily glaciated with grooves bearing about S. 40 degrees W.

Pe ee

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GEOLOGICAL AND NATURAL HISTORY SURVEY. 55

THE ChiENGO) (OUTER AND BEACHES OF Nk
CHicAGO:

PREVIOUS WRITERS.

It is perhaps impossible to determine who was the first person
to recognize the evidence or form the conception of a southwest-
ward outlet from Lake Michigan to the Des Plaines. Inquiry
among the old residents of this region shows that many of them
recognized the beaches as products of the lake, and they also
noted that the lake once discharged into the Des Plaines Valley.
Byvidently these conceptions were entertained for many years
beiore any notice appeared in scientific publications.

Bannister.— Probably the earliest scientific account of the
outlet is that given by Dr. H. M. Bannister in the Geology of Cook
County, published in 1868, as a part of the Geology of Illinois.
However, a report upon the survey of the Illinois River, by Col.
James H. Wilson and William Gooding, was published the same
year in the report of the U.S. Army Engineers, which makes ref-
erence to the former southwestward discharge of Lake Michigan.
Dr. Bannister opens his discussion of the old lake outlet and the
raised beaches with the following statement:

“Tt is evident with a very little observation that at a compara-
tively recent period, subsequent to the Glacial epoch, a considera-
ble portion of Cook County was under the waters of Lake Michi-
gan, which at that time found an outlet into the Mississippi Valley
through the present channel of the Des Plaines.”

Dr. Bannister apparently makes no claim to discovery, as is
natural, in view of the fact that the outlet had been recognized as
such by residents for many years.

Andrews. -— One of the early publications of this Academy
presents a discussion of the beaches prepared by Dr. Edmund
Andrews, a publication which has attracted wide notice (1.) This
paper, however, deals mainly with the work of the lake at its
present stage. The ancient beaches are briefly discussed, but the
outlet is not described. A map accompanying the paper shows
the extent of the old lake beyond its present limit from the southern
end northward some distance into Wisconsin and Michigan.

f1]. The North American Lakes Considered as Chronometers of Postglacial

Time, by Dr. Edmund Andrews, Trans. of Chicago Academy of Sciences. Vol I,
1870, Article 1, pp. 1-24. e

56 CHICAGO ACADEMY OF SCIENCES.

Chamberlin. -— Prof. T. C. Chamberlin has presented a brief
discussion of the beaches along the Wisconsin shore of Lake Mich-
igan in the Geology of Wisconsin (1), which includes many im-
portant data concerning the shore phenomena and an interpreta-
tion of the lake history. In the twenty years which have elapséd
since this report was published, the studies of the shores of the
Great Lakes have brought out a more complex history than had
been anticipated, hence the interpretation does not fully meet the
case, though it recognizes important fluctuations of lake level.

Leverett. — Although there have been frequent references to
the southwestward outlet and the ancient beaches, in geological
literature, within the past 20 years, no publication especially de-
voted to them appeared until 1888, when a paper was published by
the present writer in the Transactions of the Wisconsin Academy
of Sciences, entitled “Raised Beaches at the Head of Lake Michi-
gan” (2). This paper gives a somewhat detailed account of each of
the several beaches found south of latitude 42 degrees 30 minutes,
the latitude of the line of Wisconsin and Illinois. It contains but a
brief reference to the outlet. |

Cooley.—Prof. L. E. Cooley, consulting engineer of the
Chicago Drainage Commission, has published two papers which
deal to some extent with the Chicago outlet (3). The first paper
discusses the outlet as a means for improving the sanitary condi-
tions at Chicago. The second paper deals with it as an important
line for navigation and discusses the proper means for obtaining
the best results. This paper contains a large amount of valuable ~
data concerning the regimen of the Illinois and Des Plaines Rivers.

Marshall. —The Report of the U. S. Army Engineers for 1890
contains much material collected by Capt. W. L. Marshall con-
cerning the Chicago outlet as a channel for navigation; also refer-
ences to earlier work by that organization.

Taylor. Mr. F. B. Taylor has published, in the American Geol-
ogist, observations on high beaches in the northern portion of
the basin of Lake Michigan. These beaches he thinks pass be-
neath the present lake level before reaching the southern end of
the basin (4). This being the case they have no connection with
the outlet under discussion. :

{1] Geology of Wisconsin. Vol. 2, 1877, pp. 219-233.

[2] Trans. Wis. Acad. ofSciences. Vol. VII, 1883-87, pp. 177-192. Published in 1888

a at WES Supplies of Illinois in relation to Health. Report of State Board of
ealth, 1889. i
Lake and Gulf Waterway. Private publication, 1890.

[4] American Gtologist. Vol. XIII, May, 1894.

His,

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“cc

No, V. The Northern Pitcher-Plant, or the Side-Saddle Flower,
Sarracenia purpurea, L. By W. K. Higley. Price, 25.

No. VI. Bowlder Clays. On the Miscroscopic Structure of Certain
Bowlder Clays and the Organisms Contained in Them. By Dr. George
M. Dawson, D.8., F.G.8., &e. Price, 25,

No. VII. Seme Points on the Micro-Chemistry of Fats. By John
S. Long, Sc. D. Price, 25.

No, VIII. Chicago Artesian Wells. On Their Structure and Sources
of Supply. By Leander Stone, A, M. Price, 25,

No. IX. On Rhizocraps in the Erian (Devonian) Period in America.
By Sir William Dawson, LL. D., F.R,S. Price, 25,

No. X. A Paper on Elephas Primigenius. By W. K. Higley.
Price, 25.

Bulletins, Volume IJ.

No. I. The Flora of Cook County, L[llinois, and a Part of Lake
County, Indiana. By William K. Higley and Charles S. Raddin. Price,

Cloth, $1.00; paper, 75.

No, Il. Preliminary Outline of a New Classification of the Family
Muricide. By Frank Collins Baker, Secretary and Curator. Price, 25.

In Preparation :

Vol. If, No. III. An Historical Sketch of the Chicago Academy of
Sciences.

Il. By THE GEOLOGICAL AND NATURAL HISTORY SURVEY:

Bulletin No. I. The Lichen-Flora of Chicago and Vicinity. By
William Wirt Calkins. Price, 25.

Bulletin No. II. The Pleistocene Features and Deposits of the
Chicago Area. By Frank Leverett, U.S. Geol. Survey. Price, 25,

In Preparation ;

a. Boring Records of Chicago and Vicinity. By T. T. Johnston.
b. Palzontology.

e. Minerals. By C. M. Higginson and Prof. A. R. Crook.

d. Lepidoptera.

e. Mollusea. By Prof. Frank C. Baker.

f. Aves. By Frank M. Woodrutt.

g. Reptilia and Batrachia.

h. Alge. By Frof, C. B. Atwell.

i, Pteridophyta and Bryophyta. Dy Prof. E, J. Hill.

j. Flora of Cook County and Vicinity, (Phenogamia), By Prof.
W. K. Higley and C.S. Raddin.

k. Ethnology and Archeology. By Dr. W. A. Phillips.

1. Diptera.

m. Noxious Insects.

n. Composition of the Waters of the Deep Wells of the Chicago

Area. By Dr. J, H. Long.
o. Noxious Plants, By Prof. W. K. Higley.
p. The Niagara Formation.

PUBLICATIONS ISSUED BY

THE CHICAGO ACADEMY OF SCIENCES.

I. BY THE ACADEMY:
Transactions, Vol. I. Out of print.

Art. I. Description of Fossils from the Palaeozoic Rocks of the
Western States, with Illustrations. By Prof. J. H. McChesney.

Art. II. On-the Climate of the Country Bordering upon the Great
North American Lakes. By Dr. I. A. Lapham.

Art. III. Remarks on the Geology of the. Valley of Mackenzie
River, with figures and descriptions of Fossils from that region, in the
Museum of the Smithsonian Institution, chiefly collected by the late
Robert Kennicott, Esq, By F. B. Meek.

Art. IV. Descriptions of New Subcarboniferous and Coal Measure
Fossils, collected upon the Geological Survey of Iowa, together with
a notice of new generic characters observed in two species of Brachio-
pods. By Dr. C. A. White and O. H. St. John.

Art, VY. Illustrations of North American Birds in the Museum of
The Chicago Academy of Sciences. By Dr. William Stimpson.

Art. VI. Biography of Robert Kennicott. By a Committee of the
Academy, appointed at a meeting of November 13th, 1866.

Art. VII. On the Antiquity of Man in North America. By J. W.
Foster, LL, D.

Art, VIII. Descriptions of Certain Stone and Copper Implements
Used by the Mound Builders. By J. W. Foster, Li. D.

Art. {X. List of Birds of Alaska, with Biographical Notes. By
Wm, H, Dall and H. M. Bannister.

Art, X. On Additions to the Bird-Fauna of North America, made
by the Scientific Corps of the Russo-American Telegraph Expedition
By 8. F. Baird.

Art. XI. A Preliminary list of the Butterflies of lowa. By Samuel
H. Shudder.

Transactions, Vol. Il.. Out of print.

Art. I. The North American Lakes Considered as Chronometers
of Post-Glacial Time. By Edmund Andrews, A. M., M. D.

Bulletins, Volume I.

No, I. Glacial Markings of Unusual Forms in the Laurentian
Hills. By Edmund Andrews, M. D., LL. D. Price, 25,

No. Il. Observations on Fluviatile Deposits in Peoria Lake, Ills.
By Rev. Joseph D,. Wilson. Price, 25.

No. III. List of Batrachia and Reptila of Illinois. By N.S. Davis,
Jr., and F. L. Rice, Price, 25.

No. IV. Report of the Committee on the Microscopic Organisms
in the Bowlder Clays of Chicago and Vicinity. By H. A. Johnson, M.
D., and B. W. Thomas, F, R. M. S., Committee. Price, 25.

as

Seek

INDEX.

Abandoned Valleys, 38, 39.

Aftonian Deglaciation, 11, 13.-

Agassiz (Lake), 12.

Albertan Drift Sheet, 13.

Alden, W. C., (printed Holden),
cited, 76. >

Algonquin (Lake), 12, 13.

Altitudes in Chicago Area, 24, 27,
47, 69.

Andrews, Edmund, cited, 9, 71, 73,
79, 80, 81, 82, 84, 85.

Artingstall, S. G., cited, 48.

Bannister, H. M., cited, 9, 55.

Beaches, 22, 55, 66, 72, 74.

Blomington Morainic System, 11, 19

Bowlder Belts, 21, 46.

Bowlders, 21, 46, 63.

Buried Soils, 13, 34, 77.

Calumet Beach, 72.

Chamberlin, T. C., cited, 9, 11, 13,
14, 56, 58, 66, 71, 83, 85.

Champaign Morainic System, 11,18.

Chicago Area (outlined), 9.

Chicago (Lake), 12, 15, 27, 55, 64-79.

Chicago Outlet, 22, 24, 48, 55-63,
64, 79.

Cooley, L. E., cited, 47, 56, 59, 61,
62, 79, 81, 82, 85.

Cordilleran Glaciation, 12.

Davis, W. M., cited, 57.

Dawson, G. M., cited, 13.

Diebold, Mr., well data, 34.

Douglass, G, A., aid by, 86.

Drainage Canal, 49, 50, 56.

Drainage Commission Map Sheet,
57.

Drifttless Area, 12, 15,

Dunes, 23, 68, 76.

Early Wisconsin Drift Sheet, 11,
17-21,

Farwell, C. B., Artesian Well, 44.

Flowing Wells, 37, 38.

Fossils, 70, 76, 77.

Fullerton Avenue Conduit, 51, 53, 77

Gas, 36.

Glacial Lakes, 12,

Glacial Succession, 11-22.

Glenwood Beach, 66,

Gooding, William, cited. 55.

Gravel Terraces, 39-41.

Greenland Glaciation, 12.

Guthrie, Ossian, cited, 53, 57.

Haas’ Gravel Pit, 70.

Harrington, M. W., cited, 81, 82.

Higley, W. K., aid by, 85.

Iilinoian Drift Sheet, 11, 14, 15.

Illinois Lobe, 14,

Interglacial Leaching, 14.

Towan Drift Sheet, 11, 16.

Iroquois (Lake), 12, 13.

Joliet Mound, 40.

Kansan Drift Sheet, 1], 14.

Keewatin Glaciation, 12.

Knight, 5. G., measurements by, 83.

Labradorian Glaciation, 12.

Lake Agassiz, 12.

Lake Algonquin, 12, 13.

Lake Chicago, 12,15, 27, 55, 64-79.

Lake Iroquois, 12, 13.

Lake Maumee, 12.

Lake Tunnel, 51.

Lake Warren, 12.

Lapham, I. A., cited, 83.

Late Wisconsin Drift Sheet, 12, 21, 22

Leverett, Frank, cited, 56.

Lewis, S. J., well data, 32.

Loess, 11, 15,

Marcy, Oliver, cited, 76, 77; 85.

Marshall, W. L., cited, 56.

Marseilles, Morainic System, 11, 20,
40, 59. :

Maumee (Lake), 12.

McGee, W. J., cited, 16.

McWendle, well data, 33, 44.

Minooka, Moraine, 20.

Morainic Topography, 19, 23-25, 69
78.

Morris Basin, 20, 60, 63.

Pease, C. L., well data, 35.

Peat, 71, 73, 76, 77.

Penhallow, D. P., cited, 77.

Pipenbrink, J. O., well data, 35.

Rolfe, C. W., map sheets, 14, 25, 58.

Ryan, R., well data, 34.

Sag Outlet, 27, 57, 63; 68, 72, 75.

Simpson, C. T., cited, 77.

Shelbyville Moraine, 11, 17.

Sneible, M., well data, 33, 34.

Spencer, J. W., cited, 79.

Spumer, W., well data, 32, 33.

Striae, 52-54,

Structure of Drift, 31, 44, 48.

Sub-Aftonian Drift Sheet, 13.

Taylor, F. B., cited, 21, 56, 66, 71.

Thickness of Drift, 15, 29, 44, 48.

Tolléston Beach, 74.

Topographic Maps, 58.

Udden, J. A., cited, 54. :

Upper Beach, 66-71.

U.S. Geological Survey Sheets, 58,

Valparaiso Moraine, 12, 22, 24, 20,
26-41, £7, 50, 59, 63, 68.

Van Dervolgan, well data, 33.

Warren (Lake), 12.

Wilson, J. H., cited, 55.

Wisconsin Drift Sheets, 11, 17.

Wooster, L. C., work of, 9.

Worthen, A. H., cited, 16.

ee ee ee

86 CHICAGO ACADEMY OF SCIENCES,

photographs, | am indebted to Mr. Gayton A. Douglass and to
the Chicago Drainage Commission. In the preparation of maps, I
am indebted to several members of the Chicago Drainage Com-
mission; also to the Inland Educator Company for an electrotype
of the map of North America.

GEOLOGICAL AND NATURAL HISTORY SURVEY. 85

occupied its present level. Where the shores are of drift clay the
terrace generally has a breadth of from 2 to 6 miles, but at the
south end of Lake Michigan it is nearly ten miles. The west shore
of Lake Michigan was examined in some detail between Chicago
and Manitowoc and found to have an average width of 3.98 miles.
This terrace slopes gently outward to the depth of about 60 feet,
when the bottom dips more suddenly to the deep water of the
basin. It is thought by Dr. Andrews to be the product of wave
action and is denominated by him the terrace of erosion. The pres-
ent writer, however, has no opinion concerning its origin. The time
required for the formation of this terrace was computed by using
the average width of the terrace as a dividend and the annual rate
of erosion as a divisor. As the outer edge of the terrace is at the
depth of 60 feet, the position of the old shore was assumed to be at
a point where a line drawn from the top of the present bluff of the
lake to the outer edge of the terrace would meet the surface of the
lake. These estimates give the average position of the old shore,
a distance of 2.72 miles from the present shore. Dividing this
distance by the annual rate makes the total age of the terrace 2,720
years, or a duration nearly the same as that computed by the drift:
ing of the sand. Ifthe rate of erosion determined by the Wiscon-
sin Survey be substituted the age would be 4,708 years.

The estimate based upon the rate of erosion of the shore of
the lake is probably much more reliable than that based upon the
drifting of the sand past the piers, but the great variability in the
height of the shore (from 10 feet up to 100 feet or more) and the
variability in the rate of recession (from 0 to 16.95 feet per year)
make it evident that the above computation is at best only a rude
approximation. These-estimates serve, however, as a provisional
measurement of the duration of this stage of the lake and have
much value in its bearing upon the length of postglacial time. Dr.
Andrews remarks that they are useful, in showing that it is impos-
sible to allow, even on the most liberal estimates, any such post-
glacial antiquity as 100,000 years, which has often been claimed.

ACKNOWLEDGIMENTS.

In the preparation of this paper and its illustrations, I am
happy to acknowledge the aid kindly given by many persons,
among whom should be mentioned Prof. Oliver Marcy, Prof. L.
E. Cooley, Prof. W. K. Higley, and,-most of all, Profi. T. C. Cham-
berlin, the President of this Academy. In the preparation of

84 CHICAGO ACADEMY OF SCIENCES,

North line, Syae, ai, Ws My IRW AR donc a clean 6 cena 15.58 14.50 1.08
Wiestilines Sec.22-) Day R23. 000... SCOTS jah 19.39 18.43 0.96
Northline SEC 275 dis AR REI 23 live). eystera ays siete 26.39 ~ 26.39 0.00
INomtholine: Seele4yid Al Re 23.05.50 Se Sees -. 16.04 15.47 0.57
West line, Sec. 34, T. 4, R. 23----- BS CAME autre 31.50 30.00 1.50
INiorpaelines See w4y dag) Ri-235 2. res ae ee) 20:03 26.50 1.53
INomthelines Seo is 3h Re 230 ys eosin rs iene oe 18.82 18.00 0.82
Worn Iltme, Sac 1G, Was IR Ao noses boodosobeoe 27.80 20.60 6.20
North line, Sec. 21, T. 3, R. 23.---- Bil Steeda sr 21.25 18.00 3.25
Nominating, Secy Zisk Wes Is Agoosaucacouhonud Se 31.16 1.66
West line, Sec. 28, T. 3, R. 23........ see ae as 30.20 23.87 6.33
INiorthslime Seer sans 25 0R. 235. 5.7 sono uee duo. BYhiaS 32.40 2.45
Somiun time, See sails BINS Awe ccococcosa ade “LOKO0) 44.73 1.87

Mean of eighteen places, chains........... SOS OBIOn cia Geir ofa alae 1.92

Same in feet, 126.72.

Loss per annum in feet, 3.33.

“The following measurements were made to ascertain the
amount of the abrasion of the west shore of Lake Michigan, in
Milwaukee County, since the Government Survey, made in 1835
and 1836:

Annual

Place. 1835. LO7AN ye LOSS:
Chains. Chains. Feet.
Sutil inne, Seely) aes IR aaa os ei ore a tare 45.01 44.50 1.9
SonbhielinetSecieO, dO wee 2h oe os oh a 15-00 14.40 2.6
Sorin Inne, See, i, Als ©) IRS As Sob souasee ue soe CKO) 18.70 1.0
Sowiltiln lhime, Soe win ts 7p Ik AAs oo cous educeeaoe as: 8.72 8.42 0.5
Sorwisa Iime, "Sac ws, I, Wy IR P@sskoee ones ORION: SAG) 2.82 4.3
Soil Ime, See, WO, W751 Ao ooo Lek e eben cse 43.35 ATaOAN 220
Sow bine, See, sy Ws GA Ao ecscas s AI Sloan ae gH ke 19.34 17.36 3.33
Sowtiln Ibn, See svi) IS IR AAs sos bbonshe 66h a5 PAOD 18.69 5.61
I AUGe rakes Ae aeRO AERTS ely Oona eV UD RR ae MEST oe 2

“The loss in the other counties bordering the lake is less on
the average.”

In view of these measurements reported by the Wisconsin
Survey, the rate for the entire shore is probably scarcely more
than halfthat of Dr. Andrews’ estimates.

Dr. Andrews calls attention to the existence of a submerged
terrace, which, he thinks, furnishes a ready means for determining
approximately the original position of the shore, and conse-
quently the distance which the bluffs have receded since the water

GEOLOGICAL AND NATURAL HISTORY SURVEY, 83

acne) Omit} see esis aT ghee tiesb sina ehensaeethe cee etal 16.00 “ 3
ARRAS Usha Nees OO ON A Wage 8 te REE UR AN Bue Se ad SIL Yolo), a
(Oak “Creek... ...0.2 7 Ce RO le EPs aoc coiile aaa etaghs nee yay ae PAO) s
Onermilegiuntenpaontliner sects eee er A BOP ol hurry ot eke TAOO one fe
Milwaukee ........ Bre trai ay 5 ceil Scien Reicks Ue MaMa teremehs Oi
Rog Wiashimetomemeneere ey cits cre alles oncle nts! diet ele 220i i
Onemniilegiintherm anorthite inci meeice ie tsai eee TE50)) 9 7 p
Place tunther montis sel: BN ne Uren Seb UE Ae an ee Peo tOOP AE i
Place four miles south of Sheboygan......+......0....-. 8.00 “* -
SIMADON Tia Uy Soaea Maly Sones Miao 6 pA aa Ve ar a AEN OMA tn “i
VIATEO WO Coa adie stee Mae ce ty o-oo a aabenatliye i eee Per MU avs Mis ceen ASR EO) ee

From the above table it appears that the average erosion in
the portion of the shore between Milwaukee and Manitowoc is
4.33 feet per year, while between Milwaukee and Evanston it is
6.24 feet per year. . The average erosion of the two sections is 5.28
Reet.

A series of more careful measurements than those given in
the above table appears in the Geology of Wisconsin and covers
part of this section of the shore. The following is the statement
furnished by Dr. Lapham to Prof. Chamberlin (1):

“Mr. S. G. Knight, of Racine, has carefully measured for the
Geological Survey, from the nearest section corner or quarter
post, to the bank of Lake Michigan, along all the section lines in
Racine County, the results of which, compared with the Govern-
ment Survey made in 1836, are given in the following table. Had
these measurements been made at right angles to the shore line
the result would have been a trifle less; but as some portions of the
bank have been artificially protected we may assume the result
as a close approximation to the actual amount of loss, during the
past thirty-eight years in Racine County. These measurements
will have their value many years hence.”

LAKE SHORE IN RACINE COUNTY.

Section Lines. 1836. 1874. Loss.
Chains. Chains. Chains.
IN@retay Ire, See oy ily ain IRS AB ae koe on Soeu So SPFAO) 30.30 2.40
IN@rue ite, Sec, Gy We aly IRS 23)0 bea soo Bae Shape 34.68 33.45 m23
Wiestulime. Secu Silty AGMRe) 2Qr iva hin imine aerate 30.18 29.70. 0.48
North line, Sec. 17, T. 4, R. 23..+...-> alge are 16.38 14.60 1.78
Westie.) Sear TO. Ula VRe age mM Cr iah-lea ae Hens eo ele) 9.75 1 0

(1) Geology of Wisconsin, Vol. II, 1877, pp. 231-232.

«

82 CHICAGO ACADEMY OF SCIENCES.

sion that the effective work on the shores is due to waves and not
to currents, and it is a matter of doubt if this lake has such a system
of currents as are indicated by Professor Harrington’s charts. The
movement of the water seems to depend mainly upon the wind, but
is governed to some degree by the contours of the shores. If the
north winds prevail for a few days, as is often the case in the spring
months, the surface water appears to have a southward move-
ment throughout the breadth of the lake, and return currents must
be at some depth. On the other hand, a prevailing south wind,
such as occurs for short periods during the summer, will induce
a northward movement across the entire breadth of the lake. The
contours of the shore seem to favor a northward movement from
direct west winds in the north half and a southward movement in
the south half of the lake. As the prevailing winds are from the
west these become the most protracted of the movements of sur-
face water. Professor Cooley has found that breakwaters along
the shore support this interpretation. In the southern half of the
lake they are largely constructed to protect the harbors from the
drift on the north side, while in the northern half they are con-
structed to protect them from drift coming from the south. In
view of this apparently changeable course of lake movement, it
seems doubtful if estimates, such as Dr. Andrews attempted, have
the value that some have attached to them.

Dr. Andrews also made an estimate of the age of the lake from
the annual amount of destruction of the bluffs. To determine the
rate of erosion on the west coast of Lake Michigan he gathered a
large number of observations, mostly derived from surveys, and
after rejecting loose or vague estimates, as well as erosions
brought to notice because of remarkable rapidity, he obtained the
results given in the following table:

At Evanston the erosion is.......- sy ie Nee Cs Ele ae 16.95 feet a year
At the Old Pier, two miles further north.............. ARGON in: my
One mile further north..... SS Eat Ls AA GUE N La NM aD aye Aolss "4
ANE, WWitanover elie Bia Gidea sua syechaeial ai tec au apes LRA NISL Na at CE A 4.05
Onesniileeturthennornrthin «ede Bo NG atten Minpine 6.05
Malkeeqhonest.<..-o. BS REY AR aE ar AAR Hoe cy SN TEL Goa 1.65
Wennilcxeriny Giga cise Bone aa eee ole Rd RIAL A Ata ge A Me Meer ec 0.00

IO) mms sae mOimlNe books oosa one eho Sept e aks sa0 OCD

Staren litte wevetssnr titel tere ht iol take barely: s «Vreven teats 16.50
IN@MOSINELS fe Boy Ae beeps ee hl tic etal ert 12.00

Mi wommilespructheratiOnthic ey eideeete eeeieieere 3.00

,

GEOLOGICAL AND NATURAL HISTORY SURVEY. 81

Dr. Andrews estimates that the combined bulk of the beaches
formed by Lake Chicago is nearly equal to that of the beach of the
present lake, the proportion being 16 to 17. In this computation
it was assumed that 656,000,000 cubic yards escaped through the
Chicago outlet. This assumption is based on a comparison of the
relative sizes of the beaches of Lake Chicago in a section outside
the outlet and a section embracing the outlet.

Dr. Andrews attempted to estimate the length of time in-
volved in the accumulation of the beach deposits by measuring the
amount of sand carried southward past the piers at Chicago and
Michigan City. The sand annually stopped by the two piers was
found to be 129,000 cubic yards. If this represented the whole
drift past the piers the period represented in the accumulation of
the sand in all the beaches would be 26,000 years, and the duration
of Lake Michigan at its present stage 13,000 years. He estimates,
however, that not more than one-fourth or one-fifth of the south-
ward drifting sand is stopped by the piers, and thus reduces the
period to less than 6,000 years, with but about 3,000 years for Lake
Michigan.

Dr. Andrews’ estimates were based on the assumption that
there is a southward flowing current on each side of the lake, car-
rying sand to its present head. Investigations made by the
Weather Bureau in 1892 and 1893, under the direction of Prof.
Mark Harrington (1) led him to the conclusion that the currents
on the east shore in the southern portion of the basin are north-
ward instead of southward. He accounts for the accumulation of
sand on the north side of breakwaters along this coast by the action
of the surf, in northerly storms, which is more transient than the
currents proper and would affect the southern part of Lake Michi-
gan only when the wind was northerly. This occasional phe-
nomenon is very efficient when it occurs. He concludes that the
estimates of time involved in the formation of beaches have, there-
fore, less value than would be the case were the accumulations due
more largely to lake currents.

Considerable study of the movement of water in Lake Michi-
gan has been made by the Chicago Drainage Commission, largely
under the direction of Professor Cooley. As a result of these in-
vestigations, which involve not only a study of bottle papers, but
also a thorough canvass of the opinions of lake captains and an
examination of breakwaters, Mr. Cooley has reached the conclu-

(1) Currents of the Great Lakes as deduced from the movements of Bottle

Papers during the seasons of 1892 and 1893, by Mark W. Harrington, Weather Bureau,
Bulletin B, U S. Department of Agriculture, 1894,

. —
. Se
Se ee

Ss

80 CHICAGO ACADEMY OF SCIENCES.

print and copies of it are difficult to obtain, the computations made
by Dr. Andrews are presented below. Dr. Andrews apparently
includes the beachlets referred to above in the present lake stage.

The lake is encroaching upon the district on its west border
from the Wisconsin line southward to Chicago, though piers-
built along the shore in Chicago and for some distance north-
ward now. prevent further encroachment. Along the border
of Hyde Park, in the south part of Chicago, the lake is
building a beach and is tending to fill im rather than to extend the
lake in that region. In Indiana the lake is filling in rather than
extending its borders. In Southwestern Michigan it is eroding the
prominent parts and filling in the bights, thus giving the lake a
more regular outline. In this connection it may be remarked that
the effect of the lake generally is to remove the prominent parts
and fill the bights.

Dr. Andrews computed the bulk of the beach as follows: For
25 miles west from Michigan City it maintains an average cross
section of about 6,000 square yards, and its’contents are 264,-
000,000 cubic yards. In this division the beach is in the form of a
lofty belt of sand dunes, about one-third of a mile wide, and in
places 160 to 200 feet in height. In the next eight miles west this
beach spreads out into a broad belt of low parallel ridges, about
two miles in extreme width. This division has a cross section of
about 16,000 square yards, after deducting the sand which was
deposited by Lake Chicago. Its contents amount to 22 5,280,000
cubic vards. From the Indiana line, near Wolf Lake, to Chicago
River, a distance of sixteen miles, the sand occupies a belt esti-
mated to be seven yards thick on the shore and running out to a
thin edge at the average distance of 2,500 yards inland. It, there-
fore, has a cross section of 8,750 square yards and contains 246,-
409.000 cubic yards. To this should be added the portion of the
beach under water. This, taken for the entire distance from Chi-
cago to Michigan City, is estimated to be about 1,01 1,890,000 cubic
yards. The computation of the subaqueous belt is as follows: The
sand at the shore line is about 10 feet deep, and it extends out to
where the water reaches a depth of 24 to 36 feet. The breadth
varies greatly, ranging from about 1,000 yards to nearly five miles,
the widest part being at the head of the lake. The total bulk of the
lake deposits, both in and out of water, in the section between
Michigan City and the mouth of Chicago River, is estimated to be
1,747,570,000 cubic yards.

GEOLOGICAL AND NATURAL HISTORY SURVEY. 79

this beach distinguishes it so strikingly from the paucity of life
which characterizes the other beaches that a suspicion of a dif-
ferent origin at once arises.

Dr. J. W. Spencer has advanced the view that an uplift at
the Niagara outlet is still in progress, and has suggested that the
recession of the falls of Niagara past Johnson’s Ridge, a ridge
standing higher than the remainder of the gorge and situated
about a mile north of the Falls, would have caused a temporary
partial discharge of the upper lakes, including Lake Erie, into the
Mississippi, a discharge which did not stop the outflow by Niagara.
He maintains that when Niagara Falls had effected the incision
through the Johnson Ridge, the level of Lake Erie fell about 24
feet, reaching a level 17 feet below the Chicago divide, and thus
the full flow of the outlet was returned to Niagara. (1.)

The test of the value of Dr. Spencer’s ingenious suggestion
lies in the occurrence of phenomena immediately south of the
ridge, which will demonstrate that the water stood at a level suf-
ficiently high to have caused outflow through the Chicago outlet.
Such a stage of water should have left shore markings there as
well as on the plain at the head of Lake Michigan. The view that
an uplift is still in progress in the vicinity of the Niagara outlet
also seems to be sustained by very weak evidence.

Prof. L. E. Cooley has called my attention to rapids at the
head of St. Clair River, which he thinks may have a bearing upon
the lowering of the lake level a few feet in recent geological times.
For several miles the St. Clair River has a fall of about 16 inches
per mile, making nearly all the descent of nine feet which is made
between Lake Huron and Lake Erie. This rapid portion is stated
by Professor Cooley to be cutting glacial drift, and it is his opinion
that this drift barrier may have at one time held the lake level even
as high as the second beach. The matter is one worthy of investi-
gation, and Professor Cooley has hoped to give it fuller attention.
The question of the date of this beach and of its relation to uplifts
and barriers must therefore be left open until more substantial
evidence is gathered.

THE PRESENT BEACH OF LAKE MICHIGAN.

Dr. Edmund Andrews has discussed the present beach of
Lake Michigan in his paper published in an early volume of the
Transactions of this Academy, and compared its strength with that
of the beaches of Lake Chicago (2). Since this paper is now out of

(1) Proc. A. A. A. S., Brooklyn Meeting, 1894, pp. 242-243.
(2) Trans. Chicago Academy of Sciences, Vol. II, 1870, pp. 1-23.

"8 CHICAGO ACADEMY OF SCIENCES.

These do not form continuous lines around the head of the lake,
but those in the vicinity of the Chicago University and Jackson
Park die out in the marsh, which sets in a short distance south of
the park, and those in Lake County, Indiana, die out at their
western ends in a sandy plain, which borders Wolf Lake, Lake
Calumet, and other small lakes near the State line. This sandy
plain stands but 5 to 8 feet above the lake and was apparently an
open bay at the time these bar-like features were forming. But it
has now become filled with sand, leaving Lake Calumet and the
other small lakes as its dwarfed representatives. The beachlets
stand only 10 to 12 feet above lake level (except where coated by
wind-drifted sand) and are, as noted above, to be referred to the
action of the present lake rather than to Lake Chicago.

The outlets of the lake at the time the Third beach was form-
ing appear to have been along three lines; one, that occupied by
the mouth of the Chicago River and the south branch of the Chi-
cago River (reversed); a second along the marsh referred to above
as leading from the south part of Hyde Park Township north-
westward between Englewood and South Lynne, which connects
with the south fork of the Chicago River north of the Union Stock

Yards;a third leading westward from Riverdale along the Sag out-

let. The broadest of these outlets is that leading past Englewood
and the Union Stock Yards, and it is possible that the other out-
lets became nearly closed by sand before this outlet was aban-

- doned.

The altitude of this beach is nowhere more than 20 to 22 feet
above the lake (except where wind has drifted sand to higher
levels). The outlets could not well have been cut below a level 8
feet above the lake, that being the altitude of the Chicago outlet for
several miles below its junction with the present Des Plaines River.
The depth of the water in the outlets would, therefore, be 10 to 12
feet or less. As beaches are often built up to a height of 4 or 5 feet
above the ordinary level of the lake, it seems probable that
the ordinary stage of water was not more than 15 feet above the
present stage of Lake Michigan, thus leaving but 7 feet depth
of water in the outlet. The Sag outlet reaches nearly 15 feet
above the level of Lake Michigan, hence it was probably at all
times a minor line of discharge.

As hinted above, the reference of this beach to the same lake
which formed the higher beaches is not made with any degree of
confidence. Indeed, the abundant life of the waters which formed

GEOLOGICAL AND NATURAL HISTORY SURVEY. ae

Ha Coarse sands inot caleaTreo uss sateen ee ser veka erie 6 to 12
So Ov illo mmeronb icy covetianiia che tar yolas MM WANN odie ois bud a 3
6. Yellow clay, very calcareous, with leaves im-

DEUCE dT eiaten ie Geren cheer srciesail teens EEN ONS 3
7. Carbonaceous band, not calcareous........--.. 2
8. Yellow calcareous clay, similar to No. 6........ AV {way 6)
9. Band of carbonaceous material, not calcareous. . 2
10. Brown sand, with twigs and peaty material...... 8 to 10
11. Water bearing sand and talus-covered slope..... 8

Fvle(ehitrotub hati ay ikea jolie, aera ickeen cans ngs ta esse 20 to 22 feet.

The calcareous clays, Nos. 6 and 8, of the last section, and
Nos. 6 and 7 of Dr. Marcy’s section, contain numerous gasteropod
shells. Dr. Marcy has collected a large number of shells from this
horizon, among which there are Unios, apparently of several dif-
ferent species, but not specifically identified. Mr. C. T. Simpson
has identified nine different genera of mollusks, all of existing
species, found in No. 7 of Dr. Marcy’s section. Planorbis and
Lymnea are very abundant. Prof. D. P. Penhallow has identified
two wood specimens, one a new species of Picea (Picea Evanston),
the other a new oak (Quercus Marcyana) (1). The bone of the
deer, found by Dr. Marcy, is a portion of the femur. The writer
has found many localities in the sandy portions of this beach, where
molluscan shells abound. Nearly every exposure in the sandy dis-
trict west of the beach, from the main part of the city of Chicago
southward to Englewood exhibits them. This beach is, therefore,
in striking contrast with the two higher beaches, which contain
few remains of aquatic life. '

An excellent artificial section across this beach, made by the
Fullerton avenue conduit, which leads from the Chicago River
eastward to Lake Michigan, across the north part of Chicago, is
discussed above. The deposit throughout is mainly sand,
but some gravel is encountered. Shells of Unios and other mol-
lusks were noted at frequent intervals throughout nearly the whole

width of the deposit. Beneath these beach deposits there is every-

where a pebbly blue-gray clay, apparently an unmodified glacial
till. Some of the sewer’ ditches in Hyde Park, west of Grand
boulevard, have reached peat deposits below sand, at a level a few
feet above the lake. Wood has often been found in the sand west
of this beach in Chicago.

Reference has been made to the beachlets which occupy the
interval between the main beach and the present shore of the lake.

(1) Trans Royal Society of Canada, 1891, pp. 39-82, plate IT.

‘
’
:

76 CHICAGO ACADEMY OF SCIENCES,

depth of several feet. Excavations have shown, however, that till
usually sets in at a depth of 10 to 20 feet or less (1).

In Indiana this beach, like the present shore of Lake Michi-
gan, is very sandy. Its dunes, however, seldom reach a greater
height than 50 feet, or but one-third to one-quarter the height of
dunes on the present shore. Wells along it have occasionally en-
countered a bed of gravel at the base of the sand at levels, corre- _
sponding with the gravelly beaches of the Illinois portion.

One of the best exposures of this beach in the Chicago area
is found at the border of the campus of the Northwestern Uni-
versity at Evanston. The following sections, one taken by Dr.
Oliver Marcy, of Northwestern University, in 1864, at which time
there was a peculiarly good exposure, the other taken by the
writer in 1887, at which time there was a less extensive exposure,
show a slightly different section. The beach in this interval had
suffered an erosion of perhaps 75 or 100 feet.

Section of Beach at Evanston made in 1864.

TAM TIGLAC ES OU SAIC y shee eee ee ie ae Miata ticreredd sg Ph ale eiermlly steelers 1% feet
2 Brown sand and tinevoravielwss she)... TL Sia wiogaa Bute 6 Ble 22 BE
Bue oarcen otavelasthatitieds sich ec cess Orn tel Cees see 242 5
Al ABT CEN bes ols rece su BEES Be BOO OES Some ROO EOE Unb Bene caceo 2 a
Re Gravel contaimime bones of deer awe =. « ecclece ciechel- ae oe ha yeaers
Omebineasand ss cContainimeom oalkanlOgsuertcstcs sete i ele at 1% ie
7. Peat or carbonaceous earth with a marl bed containing

molluscan shells in the lower portion or interstratified

NW DUE DEIN 1) Cate Biter ear oteliegansU reverent CTR a oc crete sce Nc ei Ver aloes 142 ie
eae Erne VE Linen ear carer irene tate CON pan nvate aro tear acre cosas eat ah gale RL TU 34 i
9. Humus soil, with stumps and logs (coniferous).---......... ye i
to. Yellow clay, laminated and contorted, containing pockets of

(Scie eM ee AR ean Cates ni OIE Ge eA ie eM Rear eet 3u2 i
Teles te veD ebb by eC laiyan eee eriico ae scion eres oneton Sst Neen bal Una shee 2 1g

lel@iesinte Oni IDMiNGr 6 Gus Gu ooo bono ubodeseoooe Sua aN ena 2D feet

‘Section of Beaeh at Evanston in 1887.
Feet. Inches.

i Vellowish-red. inon-stained sand. <3... 25 es.5.0. 2) tol 5
Pe Band On DOrmTon: Oreweramtlateiys emcees 4 to 6
3. Gravel, with beds of sand included (the stratifica-

tion is very irregular in thickness and assorting

Vetya in pertecb)aecem ier. EMSS MBE Wo miar Oa clas SELON,

(1) The writer is indebted to Mr. W. C. Holden of the U. 8S. Geological Survey
for many data concerning the distribution of the sand and for access to the accurate
maps of the Pleistocene deposits in Chicago, which he has prepared for the Survey.

GEOLOGICAL AND NATURAL HISTORY SURVEY, 75

or other accurate data showing its former extent. The bar is pre-
served from the Douglas monument southward to Englewood, a
distance of four or five miles. This portion consists of a series of
overlapping ridges, of which the westernmost or earlier terminate
further north than their successors on the east. At the termination
of each of these ridges a hook turns out to the west into the bay
that was inclosed by the bar. An outlet seems to have béen main-
tained toward the Des Plaines around the southern end of this
bar, until it reached Englewood. This may not have been closed
until the water level had dropped too low for a discharge to the
Des Plaines.

Passing across the outlet marsh from Englewood to South
Lynne, a continuation of this beach is found. It leads in a course
east of south to South Englewood and thence more easterly across
the northwest corner of Calumet Township into Hyde Park, com-
ing to the Illinois Central Railway a short distance north of Pull-
man. From this point a gravelly ridge is traceable southward
past the north border of Lake Calumet, where it dies out in the
marsh. A slight beach is formed to the northeast from here on
Stony Island, between Lake Calumet and South Chicago. But the
main line of this beach is found west of Lake Calumet, running
north and south through the west parts of Pullman and Kensing-
ton, where it usually has the form of a cut terrace, with banks 10
to Ts feet in height, but changes to a gravelly and sandy beach at
the south. This beach comes to the Calumet River at Riverdale,
where it connects with the Sag outlet. It reappears on the south
side of the river at Dolton and passes thence southeastward into
Indiana. Its course in Lake County, Indiana, is eastward through
Hessville and Tolleston and Miller. In Porter County it continues
with a slight deflection to the north, keeping parallel to the shore
of Lake Michigan, and enters LaPorte County near the south edge
of Michigan City. A short distance northeast from Michigan City
it becomes merged with the dunes of the present shore, and no
attempt was made to separate it beyond that city.

The Illinois portion of this beach consists mainly of fine
gravel, which is usually well worn, but in places has considerable
angular material, as if formed rapidly and subjected for but a brief
period to the action of the lake waves. The low district along
the Chicago River back of this beach has received quite generally
a coating of sand several feet in depth, and the marshy tracts in
Hyde Park and Lake Townships are also covered with sand to a

74 CHICAGO ACADEMY OF SCIENCES.

There seems no escape from the conclusion that the lake stood at
a lower stage than the level of the second beach before that beach
and the bar under discussion were formed.

The Third or Tolleston Beach—This beach receives its name
from the village of Tolleston, situated in Northwestern Indiana at
the crossing of the Pittsburg, Ft. Wayne and Chicago Railway and
the Michigan Central Railway, at a point immediately south of the
extreme head of Lake Michigan, and distant only 24 miles from the
head of the lake. It is more complex than either of the higher
beaches, and it becomes a matter of no small difficulty to determine
what beaches should be included with this lake stage. There are,
by actual count, 32 beachlets crossed on a N.-S. line about three
miles east of the State line of Illinois and Indiana. The outer
line of this series is usually much stronger than the others and
stands a few feet higher, and hence is considered the main line.

The village of Tolleston and also Hessville and Miller Station, in
Indiana, are situated on the outermost or main line.

Many of the beachlets situated between the main line and the
shore of Lake Michigan stand only 10 to 12 feet above that lake,
and, as shown further on, seem to have been formed after the
southeastward outlet was abandoned. This being the case they
should not be referred to Lake Chicago. The Third or Tolleston
beach, as here described, includes only such beaches and bars as
have sufficient elevation above the sill of the Chicago outlet to
indicate that they are connected with that outlet—beaches whose

_ elevation is 18 to 25 feet above the level of Lake Michigan.

The portion of the shore of this lake stage, in Lake County,
Illinois, is closely associated with that of the higher lake stages,
and consists of a gravelly deposit flanking the foot of the cut ter-
race. In Cook County this beach appears on the grounds of the
Northwestern University, in Evanston, and for several miles south
it lies near the east border of the bar formed at the next preceding
lake stage. From Rose Hill Cemetery southward it is beyond the
limits of the bar, but is perhaps itself a bar built out southward
into a bay now traversed by, Chicago River. It appears to have
reached some distance south at an early part-of this lake stage, for
no well-defined beach appears on the west side of the bay back of
it. This bar lies within a mile of the present shore of Lake Michi-
gan and is readily traced as far south as Lincoln Park. The bar
is said to have been nearly continuous through the city of Chicago,
but it is now obliterated from Lincoln Park southward nearly to
the Douglas Monument, and I have been unable to obtain a map

GEOLOGICAL AND NATURAL HISTORY SURVEY. vies

marshy. Notwithstanding the presence of this bar the beach back
of it seems to have been acted upon by lake waves with nearly
as much vigor as the portion of the beach farther south, which
was not thus protected. The bar is much stronger than any part
of the beach proper, being 10 to 20 feet in height and nearly one-
fourth mile in average breadth—if the sand and gravel on its
borders are included.

The second beach is, on the whole, characterized by larger
deposition than the upper one, there being throughout much of its
extent a line of sandy gravel, 5 to to rods or more in width and
2 to 5 feet in height, but it has less conspicuous cut terraces. Its
strength is greater in the vicinity of the northern outlet and on the
north side of the southern outlet than at points between or outside
the outlets. In Illinois and Michigan, however, it is heavily cov-
ered with sand, which is probably in large part wind drifted. These
accumulations of sand in places reach the height of 30 to 4o feet.

Occasional reports of the discovery of a molluscan shell in
this beach have come to my notice, but none have been personally
noted. In this respect it is similar to the Upper beach, but ‘in
striking contrast with the next lower beach, which is full of fossils.

An excellent exposure of the structure of the bar noted above
is found immediately north of Evanston, where the lake is under-
mining the bar as well as subjacent deposits. The beach sands
and. gravels rest upon a bed of peat, which was noted by Dr.
Andrews and interpreted by him to be the accumulation of a marsh
or partially summerged land surface. The peat not only underlies
the bar under discussion, but extends eastward across the interval
between it and the Third beach. Its level is no higher than that of
the Third beach, being but 12 to 15 feet above the present level of
Lake Michigan. The peat is in places several feet thick, but at the
point where the bar comes out to the lake shore it has a thickness
of only 3 to6inches. It contains pieces of mangled wood and has
been disturbed by waves. Between the peat and the yellowish blue
till, which ferms the base of the exposure, there is a gravelly sand
6 to 18 inches in thickness, which appears to be a lacustrine deposit.
The peat is immediately overlain by about 5 feet of sand, above
which there is a bed of coarse gravel. The gravel is thin near the
borders of the bar, but has a thickness of 11 to 12 feet beneath the
highest part. It is capped by a thin deposit of sand and has layers
of sand interstratified with it in its thickest part. The presence of
this gravel makes it impossible to suppose that the old land surface
has been buried by the drifting of material from the lower beach.

;

aay? ee ea

SS. ae pee ee

2 CHICAGO ACADEMY OF SCIENCES.

The Second or Calumet Beach.—This beach throughout
much of its course in Indiana and for a short distance in Illinois
follows the south border of the Calumet River, and because of this
close association the name Calumet seems appropriate. It stands
about 20 feet lower than the Upper beach, and its course in the
Illinois portion of the region traversed by it is indicated on the
accompanying map (Plate 3). From the Wisconsin line southward
to Chicago River it is closely associated with the Upper beach,
wherever that beach remains. From the Chicago to the Des
Plaines River it is separated from the Upper beach by an interval
of 14 to 3 miles. The outlet at this stage was at the Des Plaines
River, between the villages of Riverside and Summit, and the
beach gravels are well developed for a short distance below Sum-
mit on the east side of the outlet. The beach leads somewhat
directly southeastward from Summit to the north end of Blue
Island ridge and then southward along the east side of the ridge,
past Washington Heights to the Calumet River, two or three
miles east of Blue Island. The Sag outlet had its head at this time
in a wide opening between the Calumet and Thornton. Immedi-
ately east of Thornton the beach reappears in its customary
strength and passes thence eastward across Lake County, Indiana,
following the south border of Calumet River at an average dis-
tance of perhaps a mile from this stream. In western Porter
County, Indiana, near the line of Portage and Westchester Town-
ships, it crosses to the north side of the river, and its course from
that point eastward across Porter and northwestern Walzorte
Counties is nearly parallel with the present shore of Lake Michi-
gan and distant from it two to three miles. In Michigan it borders
the lake even more closely, as far north as observations were
carried (to latitude 42 degrees, 30 minutes), being found usually
within a mile or two of the lake shore.

This beach extended a conspicuous bar out some distance into
the lake above Chicago. Its northern end is found at the lake
shore between Wilmette and Evanston, and leads thence south-
ward through the west part of Evanston to Rose Hill Cemetery,
and there turns abruptly westward and terminates at the. village
of Bowmanville, on the east bluff of Chicago River. Itis probable
that this bar was attached to the old shore at some point farther
north than its present terminus, a portion of it having been re-
moved by the encroachments of Lake Michigan. The bay back
of this bar had a width of one to four miles and a depth of 15 to 20
feet in its deepest parts. Portions of it were so shallow as to be

GEOLOGICAL AND NATURAL HISTORY SURVEY. a

found, and this negative evidence strengthens the view that the
shells at this pit may be intrusions. Remains of terrestrial life have
also been found here. Mr. Haas preserved fragments of the tooth
of a mammoth found in the gravel pit at a depth of several feet.
These fragments are waterworn, and it seems, therefore, quite
probable that they were imbedded during the formation of the
beach.

Another gravel pit has been opened in the beach between
Salt Creek and LaGrange, in which the excavation extends from
the east side of the beach westward nearly to the outer slope. It
has a depth of 12 to 14 feet in the deepest part, and exposes a series
of beds dipping slightly toward the east. The upper five feet is of
brown stained gravel. The lower portion is a fine gravel, with
very little stain. In the gravel there are sandy pockets and also
thin beds of sand. These sandy portions, in some cases, show a

slight effervescence with acid, but are not nearly so calcareous as

the sand found at similar depths in glacial deposits.

Interval of Emergence. — After the Glenwood beach was

formed the lake appears to have withdrawn from the plain between
the beach and the shore of Lake Michigan, in Illinois. How much
farther north it withdrew is not accurately determined. Professor
Chamberlin recognized evidence of emergence between the forma-
tion of this beach and the second beach, in Southeastern Wisconsin.
That it withdrew so much in the northern end of the Lake Michi-
gan basin as in the southern seems improbable from the evidence
drawn from tilting, it being found by Mr. F. B. Taylor that that
portion of the basin has been uplifted more than the southern.
Whether this emergence is to be connected with the lake stage,
known as the Algonquin, is not yet ascertained, though that seems
a probable correlation.

The evidence for this emergence within the Chicago area is
found in beds of peaty material that occur beneath gravel of the
succeeding lake stage, as long since noted by Dr. Andrews and
discussed in his paper cited above. In Wisconsin the evidence is
in clay beds, which seem to have been left in a retiring water
body, and which are covered by beach deposits of the succeeding
lake stage, as pointed out by Prof. Chamberlin in his official report
of the Wisconsin Geological Survey. There is need for further
study of this interval in the lake history before conclusions of
much consequence can be drawn.

“0 CHICAGO ACADEMY OF SCIENCES.

A few gravel pits have been opened in this beach. Probably
the most extensive is Haas’ pit, near Forest Home Cemetery, one
mile south of Oak Park. This is opened in the bar described
above as leading southward on the east side of the Des Plaines
River. The excavation extends from the east side of the bar west
past the center and shows beds dipping at various angles, but all
towards the east. Some of the beds increase in thickness as they
descend, but the lower bed which is mainly sand decreases in thick-
ness in passing from the higher to the lower part of the bar. It
appears to be a sand bar upon which the coarser beach deposits
are built. The following section was obtained at the south side of
this gravel pit and shows the structure at that particular place
only, for Mr. Haas states that the material of the same bed may
vary greatly in coarseness within the space of a few feet. The dip
of the beds, however, is uniformly toward the east, throughout the
entire extent of the pit, which covers an area of several acres:

mM kW YN

. Brown-stained gravel, capping summit and slope...... T8 to 30 inches
Pine gravel, fresh or stained but little................ 24 to 48
. Sand, very thin at top, but increasing toward side of bar o to 36 “
binesravele micreasime ike NON 245 nese see ee chien 0 to ASE in
. Fine gravel, nearly 4 feet in thickness, which passes
upward from near the east side of the excavation, as-
suming a nearly horizontal position beneath the crest
Olthemnidigies 454. sees ee sisi etl UUM e Runt a ine mitten hae are 4o to 48
6. Sand, thickening toward the higher part of ridge....-- 6 to 36

Mr. Haas reports that shells of the size of unios and also
smaller molluscan shells have been found in the bed of sand at the
bottom of the pit. The larger shells were thought by him to be
unios. A shell, however, which he sent to the writer proved to be
the ordinary oyster. This unexpected development raises the
question whether this particular shell was in situ at the time it was
discovered, if it does not render doubtful the occurrence of any
native shells in this bar. Upon visiting the region again and in-
quiring particularly into the circumstances, there seems little ques-
tion that the shell was picked up near the base of the pit by some
of the workmen, but it was found that there are a few Indian graves
on the bar, which extend down nearly to the level of the base of
the pit. The shell, therefore, may have been introduced at the
time of burial of some brave warrior, or it may have been of more
recent introduction. This is apparently the only place along the
entire length of the upper beach where molluscan shells have been

GEOLOGICAL AND NATURAL HISTORY SURVEY. 69

west from the railway station, and at an elevation 55 to 60 feet
above the lake.

Near the mouth of the Kalamazoo River, in Michigan, there
are extensive sand plains standing go to- 100 feet above the lake,
which seem to have been occupied by lake water. The sand de-
posits extend back nearly to Allegan, on the Kalamazoo, and
southward from the Kalamazoo to Paw Paw River, near
Hartford, occupying a strip of lowlands back of a moraine that lies
near the lake shore. They may have been formed at an earlier
stage than the beach under discussion, in a narrow lake held be-
tween the ice and the higher land to the east. It seems probable
that a small lake would have appeared during the formation of this
moraine. In the present stage of investigation it is scarcely legiti-
mate to assume that Lake Chicago reached so high a level there,
a level about 40 feet above that of the beaches at the south and
west borders of the lake.

There is very little range of altitude shown in the Illinois por-
tion of this beach, the variations being scarcely more than may be
attributed to the fluctuations in the lake or to storms. The follow-
ing presents the railway elevations in succession, from north to
south, at points where this beach is crossed:

Table of Altitudes along the Upper or Glenwood Beach.

STATION. RAILWAY. ELEVATION.

Freer A. 7.
; d 658
Winnetka, O65 CF IS Wo | 640
Oak Glen, (Os INE te (Shits LEY 631
; 640
Norwood, Cc. & N. W. 1 626
Galewood C., M. & St. P. bel
? 623
Maywood, Gos tu, IRS we Tees (Oh. 636
7 645
La Grange, C. B. & Q. | 627
Border of a 658
Moraine, Ce Ee 630
Homewood, Til. Cent. 656
Glenwood, C. & HE. I. 636
Dyer, Ind, L. N. A. & C. 636

In the above table, where two elevations are given, the lower
marks the base of the cut terrace and the upper the brow. It is
probable that the lake level was but a few feet above the base. In
the Illinois portion it may safely be assumed to be 635 to 640 feet
above tide or about 53 to 58 feet above the level of the present lake.

68. CHICAGO ACADEMY OF SCIENCES.

Its faintness in this district is probably due, in part, at least, to the
protection from wave action occasioned by the bar just described.
Upon passing south and crossing Salt Creek, about a mile from
the point where the beach fades out, it reappears as a well-defined
ridge, composed of sand and gravel, rising from Io to 12 feet above
the border of the plain on the east, and having a breadth of 30 to 4o
rods. Following this beach southward, it changes in
about a mile to a cut terrace, which is well defined from that point
southward to the lake outlet, a short distance south of LaGrange.
Its course is through the eastern part of the city of LaGrange,
where it is in the form of a cut terrace, with bank 10 to 15 feet in
height.

Passing to the west side of the outlet, near Willow Springs,
the shore line is found as a cut terrace along the east face of the
prominent morainic tract which occupies the interval between the
two outlets of the lake. Though mainly a cut terrace the moraine
is flanked occasionally by deposits of gravel and sand.

South from the southern, or Sag, outlet the shore is carved on
the inner face of the Valparaiso moraine with banks 5 to 20 feet, or
more, in height, but with only occasional deposits of gravel and
sand. Upon approaching the State line, however, near Glenwood,
the shore bears away from the moraine and deposits of gravel and
sand are built up to a height of 6 to 12 feet or more. These are
sometimes in the form of a single ridge, but not infrequently a
series of parallel ridges occur, separated by narrow sags.

The effect of the waves at this lake stage is discernible on
the borders of Blue Island till ridge, though the western border is
characterized by dunes which conceal to some extent the action of
the lake.

Upon passing into Indiana the beach soon becomes sandy,
like the shore of the present lake, and dunes with an elevation of
10 to 25 feet are formed throughout much of the course in that
State. These dunes, in places, have drifted out for a mile or more
beyond the old lake border, reaching elevations somewhat higher
than the level of the lake. There are occasional points where
gravelly deposits have been found in connection with this shore
in Indiana and also in Michigan, but the sand, as a rule, conceals
the shore products of the lake. One of the best instances noted of
a gravelly beach formed at this stage is at Sawyer, Michigan, a
few miles south of St. Joseph. The beach is well exposed by a
wagon road leading west from the village, about 100 to 120 rods

GEOLOGICAL AND NATURAL HISTORY SURVEY, 67

minus, perhaps one mile from the point where the terrace departs
from the present shore of the lake. From the terminus of this
ridge a bar was built out southwestward five or six miles, ter-
minating about a mile east of Chicago River, in the western part of
T. 41, R. 13, E. The bar sends out two prominent spurs to the
west, a distance of nearly one mile. These probably mark the
termini in its earlier stages. The average width of this bar is about
one-fourth mile, and it was built up to a height of 10 to 20 feet
above the bay back of it. It consists largely of gravel, but has a
liberal admixture of sand. The bay back of this bar extended to the
valley of the Chicago River and had a width of two to three miles.
The northern end finds a narrow extension northward, in Skokie
marsh. The site of this old bay is now largely under cultivation,
though some portions are still marshy.

The question naturally arises whether this accumulation of
gravel and sand was formed by the lake currents and waves, inde-
pendent of the Chicago River, or was largely formed as a delta
from that stream. This deposit is not in the form of a delta built
up at the debouchure of the river into the lake, but lies some dis-
tance to the east of the river valley. Moreover, to make it still
more evident that it was the lake and not the river which con-
tributed the great bulk of the beach deposit, it is found that the
river valley above the point where it entered the old lake has very
little assorted material, such as would accumulate above a delta.

The beach appears on the west side of the Chicago River,
Sec. 19, T. 41, R. 13 E., about a mile northwest from the terminus
of the bar. From this point southward to Oak Park the shore is
usually a cut terrace (see Fig. 8), with a bank ranging from 6 to 25
feet in height, with occasional deposits of beach gravel and sand
along its front. At Oak Park there is an extension of gravel down
the east side of the Des Plaines River similar to that of the bar east
of the Chicago River, noted above. A ridge or bar 20 to 40 rods in
width and to feet or more in height extends from Oak Park south
about two miles to the south part of Secs. 13 and 14, T. 39, R. 12
E., and there terminates abruptly with a level nearly 20 feet above
the plain on its immediate borders.

Passing to the west side of the Des Plaines River, the beach
appears about a mile above the southern end of the bar just de-
scribed and passes in a curving course westward through
the south edge of \|Maywood, in Secs, (14, 22) and) To;
39, R. 12 E. This portion of the beach is only two
to four feet in height, and at the west it fades out completely.

iin os
SS EME, oe:

a ae ee ee oe eee

[Photograph by Gayton A. Douglass.]

Cut terrace formed at upper lake level near Galewood.

ee,

Fig. 8.

jew wen ey i "
a ete SS

66 CHICAGO ACADEMY OF SCIENCES.

The study of the beaches of this glacial lake is not sufficiently
- complete for me to indicate its precise relations to, or points of
connection with, the ice sheet. My study has been carried no
farther north than to the line of Illinois and Wisconsin on the
west side and to a corresponding latitude on the east side of the
lake. Prof. Chamberlin’s studies left the precise extent of the
higher beaches undetermined. Mr. Taylor’s observations have
been confined to the northern portion of the basin, and as yet no
one has examined the intervening district, with a view to determin-
ing the limits of this glacial lake. Probably the most favorable
field for investigation will be found on the Wisconsin side, since
the extensive deposits of wind-drifted sand on the border of the
lake in Michigan make it difficult to determine the extent of water
action. The long stretches of high bluff, however, interrupt the
beaches so greatly that some difficulty is anticipated in making
precise correlations on the Wisconsin side.

The Upper or Glenwood Beach.—This beach receives its
name from the village of Glenwood, on the Chicago and Eastern
Illinois Railroad, a few miles south of the limits of Chicago. The
name has been selected (1) because the beach is especially well
developed at that village and (2) because, being near the State line
of Indiana and Illinois, the name will be familiar to residents of
either State.

In the Illinois portion of Lake Chicago this beach is present,
except for a few miles between Waukegan and Winnetka, where
the lake shore is now farther west than it was at the time this beach
was formed. In Indiana the beach is present throughout the
entire extent of the border of Lake Chicago in that State, being
nowhere less than two and in places twelve miles back from the
shore. In Michigan it is absent for a short distance at the “clay
banks,” north of New Buffalo, where the present shore stands
farther east than the shore of Lake Chicago. It is also absent for
the same reason for a few miles near the line of Berrien and Van
Buren Counties, north of St. Joseph, Michigan. Tracing in detail
the course of this beach is as follows: j

From the Wisconsin line southward to South Waukegan,
it stands only one to two miles back from the shore of Lake
Michigan, and comes otit to that shore at the point where
the bluff of till sets in south of Waukegan. This bluff of
till stands above the lake level as far south as Winnetka.
From Winnetka a cut terrace, nearly 20 feet in height, extends
south along the face of the east till ridge, noted above, to its ter-

GEOLOGICAL AND NATURAL HISTORY SURVEY. 65

When the ice sheet withdrew from the Ontario basin an east-
ward outlet was opened by the Mohawk. The Erie and Huron
basins were then made tributary to the Mohawk and Hudson, and
it is probable that they never afterwards discharged into the Lake
Michigan basin. There are, however, complications not yet fully
understood, arising in large part from the differential uplifts of the
region, which may have resulted in a brief flow of the waters west-
ward along the straits of Mackinac after the ice had withdrawn
from the northern end of the Lake Michigan basin.

The working out of the lake history has also brought evidence
that the Lake Michigan basin was for a time free from water in its
southern end far within the limits of the present shore of the lake.
This low stage of the southern end of the basin, it appears, was
due not so much to the shrinking of the lake as to lower elevation
in the northern latitudes, for at that time the lake apparently stood
above its present level at the north end of the basin. The evidence
now at hand points to a general northeastward elevatory move-
ment, following more or less closely the retreat of the ice sheet.
While, therefore, the retreat of the ice sheet opened low outlets to-
ward the east and thus led to the withdrawal of the water from the
southern and western end of the lake basins, the succeeding uplift
at the northeast, complicated by conditions which cannot well be
entered into here, raised these outlets sufficiently to cause the
water to be thrown back and give these lakes their present extent.

The introduction ofthename Lake Chicago, for the glacial lake,
which was held in the southern end of the Lake Michigan basin,
seems convenient, if not necessary, inasmuch as its area was not
coincident with that of Lake Michigan, and its outlet was in the
reverse direction. It is also in keeping with the custom of students
of glacial lakes, who find it advantageous to have a special name for
each of the temporary bodies of water in the several basins. The
name, Lake Chicago, seems especially pertinent, since the glacial
lake extended about as far beyond the present limits of Lake
Michigan, in the vicinity of Chicago, as at any part of its border.
It is also a name which readily suggests the position of the lake,
and it is in keeping with the name which has come into use for the
outlet, namely, the Chicago outlet.

The name Lake Chicago is applied provisionally to all the
stages at which there was a southwestward outlet, but it is not yet
certain whether they were all formed during the occupancy of a
portion of the Lake Michigan basin by the ice sheet. This ques-
tion is discussed at some length further on.

64 CHICAGO ACADEMY OF SCIENCES.
THE GUACIAL LAKE CHICAGO,

During the past ten or twelve years evidence has been gradu-
ally accumulating which points to the existence of several glacial
lakes held on the north by the ice sheet and having southward dis-
charge over the lowest points in the rims of the basins which they oc-
cupied. The area of these lakes would naturally be variable, since a
part of the boundary was formed by an oscillating ice sheet. The
outlets of the lakes would also be liable to change on account of the
covering of certain low outlets in the early stages which were open
to discharge in later stages. A change in the extent and the outlets
of the lakes, it appears, has also been produced by a warping of the
crust or differential uplift in the region they occupy. The compli-
cations are therefore great, and as yet the full history is not worked
out. Enough is known, however, to make certain that the general
' direction of retreat of the ice sheet was northeastward. The
southern and western portions of the Great Lake basins were,

therefore, the first to become free from ice and occupied by glacial
lakes.

While the ice sheet was covering the present outlets of Lakes
Superior and Michigan, these lakes had no connection with each
other, nor with the lakes to the east, and their discharge was south-
ward or southwestward into the Mississippi, from the present
heads of these lakes. A small district west of Lake Erie was also
occupied by a lake that discharged southwestward to the Wabash.
Upon the withdrawal of the ice sheet from the southern peninsula
of Michigan and the southern portion of the Lake Huron basin,
the lake at the western end of Lake Erie became expanded and a
line of discharge was opened eventually from Saginaw Bay across
the southern peninsula of Michigan to the Lake Michigan basin,
and this being lower than the outlet to the Wabash, that outlet was
abandoned. The waters of the Lake Huron basin being held at
a somewhat higher level than those of the Lake Michigan basin,
the flow of water was from the former to the latter. The glacial
lake, which discharged across the southern peninsula of Michigan
extended over the district between Lake Huron and Lake Erie, as
well as the Lake Erie basin and the low district bordering it on
the south and west. It apparently did not extend far into the
Ontario basin, as a study of moraines indicates that the ice sheet
occupied that basin at the time of this discharge. It thus appears
that the Chicago outlet at one time was the line of discharge for an
-area much larger than the present Lake Michigan basin.

GEOLOGICAL AND NATURAL HISTORY SURVEY. 638

to the surface. (See Figs. 1 and 2.) Below Lemont the bare rock
forms much of the floor as far as Joliet. From Joliet to the head of
the Illinois perhaps half the floor is covered with deposits of drift
and river debris, so that the distance to rock is not known. The
remainder is either bare rock or rock with a very thin deposit of
coarse river debris, with a liberal supply of bowlders of Canadian
derivation. In the Morris basin the rock is largely shale. This
has been eroded in places by the current and the hollows filled with
sand and gravel. From the Morris basin to the bend of the Illinois
the rock floor, mainly sandstone, is generally swept clean. The
St. Peter sandstone of this section is of such a texture as to break
up rapidly into its constituent grains and these, as fast as they
were set free, would have been carried by the strong current down
to the lower Illinois, and. probably on into the Mississippi. The
Lower Illinois has only sand and silt in its bottoms. This section
is now in process of silting up, the current being too sluggish to
carry away the material brought in from the upper portion of the
stream.

In connection with the river debris should be mentioned
accumulations of bowlders. The most conspicuous accumulation
noted is that on the borders of the Sag outlet, just east of the point
where it enters the moraine and northeast of the village of Worth.
An area of perhaps a square mile is so thickly strewn that one
might almost step from stone to stone over its entire extent. There
are, it is estimated, more than 1,000 bowlders per acre. Surface
‘bowlders are not rare in other portions of the old lake bottom,
where sand deposits are thin or wanting, there being, perhaps, 100
per square mile on the part of the lake bottom, where till is ex-
posed. There seems, however, to be a tendency to aggregation
at the entrance to the old outlets. This feature suggests that float-
ing ice has been influential in their distribution, though there may
have been a large number brought by the ice sheet, the head of the
outlets being near the inner border of the Valparaiso moraine.

Some very large bowlders have been found along the Drain-
age Canal, two of which are shown in the accompanying view
(Fig. 1). The large ones occur in most abundance where the
Valparaiso moraine crosses the outlet. Bowlders are very numer-
ous for a few miles above the junction of the Des Plaines with the
Kankakee, both in the lake outlet and the districts south. The
cause for their abundance there is not satisfactorily determined.
They seldom reach the large size which bowlders in the Valparaiso
moraine present. :

62 CHICAGO ACADEMY OF SCIENCES.

plished by the lake outlet. Being the outlet from a lake, however,
its waters probably carried but little sediment in this portion, a
feature which should be weighed in discussing the slight amount
of excavation. Whether a stream of nearly clear water could have
accomplished the slight excavation here displayed in the course of
_ afew thousand years remains to be determined.

Turning to Niagara River, where the work accomplished in
a few thousand years by a clear stream is open to investigation, it -
is found that the recession of the Horseshoe Fall is due almost
wholly to undermining, and that the American Fall, in which there
is little undermining, is nearly stationary. The cutting on the
rapids above the Falls is also very slow and amounts to buta few
feet in average depth.

__ Professor Cooley has called my attention to the deposits at
the head of Lake St. Clair as likely to furnish an index of the
amount of sediment transported by the Chicago outlet. A delta,
with an area of several square miles, has been built in the head of
Lake St. Clair, which must have derived the bulk of its material
from southward moving littoral currents along both the borders
of Lake Huron. In the lake under discussion littoral currents
along the west border would have transported material probably
in as great volume as on either shore of Lake Huron, but those
on the east and south may have contributed less, for wind drifting
there is very effective. It seems legitimate to assume that at least
half as much sediment was being transported down the Chicago
Outlet as is carried by the St. Clair River. The waters of the
Chicago outlet would be probably more turbid than the Niagara
and less turbid than the St. Clair. Prof. Cooley thinks the contri-
butions of sediment to the outlet through the Des Plaines were of
little consequence, for this river has, since the lake waters were
withdrawn, made scarcely any filling of the outlet below River-
side, where its delta would naturally accumulate. The accession
of larger tributaries below may have rendered the stream slightly
more turbid than on the rapids, and the rate of rock excavation
would have been correspondingly accelerated.

It should not be inferred that this outlet is entirely free from
river debris. Beginning at the upper beach, near Summit, there
is for several miles a mass of coarse material, largely limestone
blocks, too large to have been transported by the current, covering
the bed of the outlet. The Drainage Canal exposes excellent sec-
tions of the coarse river debris from Summit to Lemont, there
being only limited areas in this interval, where the solid rock comes

.

GEOLOGICAL AND NATURAL HISTORY SURVEY, | 61

Niagara limestone. Its resistance, therefore, may not be markedly
Ene than that of the beds of glacial drift. |

- As noted above, the level at which excavation by lake waters
began in the section below the great bend of the Hlinois, is less
than 100 feet above the present stream, since the glacial terraces in
which the lake outlet was excavated seldom reach a level 100 feet
above the bed of the outlet, while below the mouth of the Sanga-
mon they rise scarcely 50 feet above that level. If the 30 feet of
filling estimated by Prof. Cooley be added it seems a liberal esti-
mate to allow 75 feet of average excavation in this lower section of
200 miles. It may not have been more than two-thirds that
amount. The width of the outlet in this lower section ranges from
two up to about five miles, with an average of perhaps three miles.
This excavation is in a loose, easily eroded bed of sand and fine
gravel, which had been deposited largely by glacial streams.

Summing up the above estimates, it appears that the outlet
has a width ranging from one mile up to about five miles, and a
depth ranging from 20 feet up to 7o feet. Its length from Summit
to the mouth of the Illinois is 300 miles. The excavation is prob-
ably not less than three cubic miles. With the exception of about
fifteen miles between Lemont and Joliet and forty miles between
Morris and Peru, where rock strata have been eroded, the excava-
tion is almost entirely in beds of drift. The width varies with the
resistance to erosion, being least in the section where the Niagara
limestone was eroded and greatest where there were only drift
beds to remove, while in the sandstone the channel is of inter-
mediate breadth. The breadth is also to some degree dependent
upon the slope of the bed, being narrower in the portions, with
rapid fall, than in portions having a low rate of descent.

Throughout the entire length of the outlet the bluffs are steep,
like a river bank, and deposits made by side streams on the edge
of the valley are very meager, a feature which indicates that the
stream had great volume, probably filling the channel from bluff
to bluff, and a current sufficiently strong to carry away nearly all
the detritus brought into it by the side streams.

The rapids between Romeo and Joliet occur ina section where
the limestone is friable, and it is thought by Professor Cooley that
the friability is such that falls could not have been maintained, or
even established. The removal of this, the main barrier in the
course of the outlet, it is estimated, would require the excavation
of a channel in rock only about 20 miles in length and 25 to 75 feet
in depth. Of this excavation scarcely one-tenth part was accom-

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60 CHICAGO ACADEMY OF SCIENCES,

not markedly greater than in the portion above Joliet. The por-

tion above Joliet is cut to a slight depth into the Niagara limestone,
which there underlies the glacial gravel. The excavation in lime-
stone, however, amounts to not more than one-fourth the size of
the channel, for the limestone seldom rises more than 40 feet above
the bed of the lake outlet and in many places its surface comes
down nearly to the level of the valley floor. Below Joliet there
was even less excavation in the rock than above. It is estimated
that the rock excavation here does not exceed ten per cent. of the
total cutting.

In the low tract at the head of the Illinois (the Morris basin)
the depth of excavation by the outlet is very slight, averaging prob-
ably less than 20 feet in the ten miles between the head of the
Illinois and Morris. The plain appears to have descended nearly
to the 520-foot contour on the borders of the river before modified
at all by lake or stream action.. A low bluff formed on the north
border of the basin has a height of 15 to 20 feet. On the south
border there 1s no bluff, that side of the basin being heavily coated
with sand deposits. These deposits may perhaps have been laid

down in part at the time the lake waters were forming the outlet,

but they are probably largely of earlier date. In this basin the
lake outlet had an average width of four or five miles.

In the section of the I'linois, immediately below (west from)
this basin, erosion, prior to the opening of the Chicago outlet, may
have brought the level of the valley bottom down to that of the
upper beach line of the basin, 550 to 560 feet above tide. The bed
of the Chicago outlet is nearly 500 feet, thus leaving about 60 feet
depth of erosion. Passing westward the broad bed of the Chicago
outlet declines nearly 60 feet in the forty miles between the west
border of the basin, just mentioned, and the bend of the L[llinois
near Hennepin. Whether the valley had the same gradient.at the
time the accession of lake waters occurred is not known, but it
could not have been greatly different, for the glacial terrace just
above Hennepin stands about 30 feet lower than the beach lines
of the Morris basin, and this terrace was, in all probability, eroded
the remaining 30 to 40 feet necessary to give a similar gradient.

The width of the outlet between Morris and Hennepin aver-
ages about 1$ miles. The excavation is largely in a soft sandstone,
there being nearly continuous rock bluffs to a height of 60 to 75
feet above the level of the bed of the outlet. This sandstone
presents much less resistance to stream action than the firm

GEQLOGICAL AND NATURAL HISTORY SURVEY. 59

Plaines and other tributaries entering the basin farther east, thus
permitting the water to issue at the western end of the basin, un-
burdened with glacial material. The stream discharging west-
ward from this basin would therefore have a tendency to deepen
the new valley opened across the Marseilles moraine, and in all
probability would have extended its excavation at least through
the new portion of the valley to Hennepin, there being in that
section a gradient of several inches per mile and possibly at first
a gradient of several feet. It seems not improbable, also, that
some excavation was accomplished by the glacial floods in their
passage over the terraces in the lower portion of the Illinois Valley,
the advantages for erosion being as good for these floods as for the
later ones fed by Lake Chicago.

It is also necessary to estimate the amount of filling which the
lower course of the outlet has received since the lake waters were
withdrawn. Concerning this filling, Prof. L. E. Cooley has made
some investigation and concludes that it will average about 30
feet from Peru to the mouth of the Illinois. (1.)

In the Des Plaines Valley the erosion of the Valparaiso
moraine and of the terraces outside of it was probably very largely
effected by the lake waters. An examination of this portion of the
outlet will therefore be likely to afford a fair understanding of the
size of the channel which it formed.

Turning to the topographic maps, it appears that the bed of
the lake outlet declines from about 590 feet A. T. at Lemont, in
the midst of the Valparaiso moraine, to scarcely 500 feet at the
head of the Illinois, or go feet in a distance of 25 miles. Of this
fall 76 feet is made in a little less than ten miles from Romeo ‘to
Joliet pool. The glacial terraces which border the outlet decline
from about 630 feet to 570 feet between Lemont and the head of
the Illinois. This deepening of the channel is shown by the maps
to be somewhat irregular, ranging from 40 feet to about 7o feet,
but an average erosion of 50 feet may be assumed. This deepen-
ing embraces not only the work at the time the upper beach was
forming, but also that carried on during the formation of the
middle and third beaches, or down to the time of the final abandon-
ment of the lake outlet. The channel above Joliet has a breadth of
one to one and a half miles, averaging perhaps one and a quarter
miles. Between Joliet and the head of the Illinois several island-
like remnants of the glacial terraces remain in the midst of the
channel, making it more difficult to estimate the breadth, but it is

f4] Communicated to the writer,

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58 CHICAGO ACADEMY OF SCIENCES.

which covers nearly all of Cook County and the immediate borders
of the Chicago outlet along the Des Plaines River. This map has
not been published, being merely a study map. The topographic
work carried on by the U. S. Geological Survey in this region is
largely published. The peculiar features of the upper portion of
the outlet are brought out in an effective manner by the following
sheets, viz: The Chicago, Riverside, Calumet, Des Plaines, Joliet,
Wilmington, Morris, Ottawa, Marseilles, La Salle, Hennepin and
Lacon sheets. These sheets cover something over 100 miles of the
former lake outlet or nearly one-third the distance from the head
of the outlet to the Mississippi. The remainder of the outlet is
shown in Professor Rolfe’s map sheets, yet unpublished. The re-
duced contour map (Plate 2) accompanying this paper is based
upon these several surveys. It serves to indicate the comparative
size of the valleys occupied by the outlet and of the main tribu-
_ taries of the Illinois. But to fully appreciate the features produced
by the outlet, reference should be made to the large scale maps
just mentioned. ee Ree

In the interpretation of these features from the maps, care must
be exercised in determining the condition of the valley at the time
the outlet first became operative. The portion of the Illinois below
Hennepin, it will be observed, is a preglacial valley, which is only
partially filled by the glacial deposits. This filling is preserved in
terraces along the borders of the valley. The glacial terraces sel-
dom rise to a height of more than 100 feet, and in the lower 100
miles their average height scarcely exceeds 50 feet above the
present stream. In the portion of the valley above Hennepin the
stream is mainly ina glacial or postglacial course, or the two com-
bined, but even here there are complications which make it no
easy matter to determine the amount of erosion attributable to the
outlet. Before the accession of the lake waters this valley was the
line of discharge for streams issuing from the ice sheet, as possibly
of interglacial streams, some evidence of which has been gathered
by Professor Chamberlin. Although the streams were generally so
heavily charged with detritus as to build up rather than erode
their beds for some distance below the point of emergen¢e from
the ice sheet, it seems scarcely probable that filling would have
exceeded erosion throughout the entire length of the Des Plaines
and Illinois Valleys. The basin at the head of the [llinois, as
noted above, was apparently occupied by a lake at the Valparaiso
stage of glaciation and this would have received the greater part
of the detritus borne down by the glacial floods on the Des

GEOLOGICAL AND NATURAL HISTORY SURVEY. Sh

Davis.—Professor W. M. Davis has published a description
of the Chicago outlet in the Popular Science Monthly (2). His
paper was based upon a personal inspection of the channel with
the topographic maps in hand, and is a remarkably clear discussion
of the features.

Guthrie. —Mr. Ossian Guthrie, of Chicago, has contributed
several newspaper articles and has published two or more pam-
phlets within the past few years which contain popular accounts of
local features in the region under discussion and which have served
to stimulate interest in its geological history. Having been a resi-
dent of the city for about 50 years and an enthusiastic student of
natural features he is in possession of a fund of information which
it is to be hoped will be placed on record in suitable form for refer-
ence.

THE CHICAGO OUTLET.

The name “Chicago Outlet” has come into use by geologists
and engineers without announcement or conference among
writers, to designate the line of southwestward discharge from the
basin of Lake Michigan across the low divides near Chicago and
thence down the Des Plaines and Illinois to the Mississippi. It
may appropriately embrace both the points of discharge from the
lake to the Des Plaines, namely, the one entering at Summit and
the one at Sag Bridge.

When the lake was occupying the highest beach the north or
main outlet was entered about three miles southwest of Summit;
when occupying the second beachthe outlet was entered at Summit;
when occupying the third beach the point of entrance appears to
have been transferred eastward nearly to the present shore of Lake
Michigan, as explained below. Similarly the southern outlet was
lengthened eastward with the lowering of the lake. The point of
entrance at the time of the highest beach being about five miles
east of Sag Bridge, at the time of the second beach near Blue
Island, and at the time of the third beach at Riverdale. This
relationship of the several beaches to the outlets and the eastward
lengthening of the outlets may be readily understood by a glance at
the accompanying map. (Plate 3.)

There have been several surveys which have contributed con-
tour maps of portions of the Chicago outlet and the plain covered
by the lake in the vicinity of Chicago. The Chicago Drainage Com-
mission have prepared an excellent map with five-foot contours

[2] The Aneient Outlet of Michigan,- by Prof, W. M. Davis. Popular Science
Monthly, December, 1894, pp. 218-229,

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