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PRINCIPLES

OF

GEOLOGY:

BEING

AN INQUIRY HOW FAR THE FORMER CHANGES OF
THE EARTH’S SURFACE

ARE REFERABLE TO CAUSES NOW IN OPERATION,

\

BY

CHARLES LYELL, Ese. F.R.S.

PRESIDENT OF THE GEOLOGICAL SOCIETY. OF LONDON.

i

“ The stony rocks are not primeval, but the daughters of Time.”
LINNÆUS, Syst, Nat., Ed. 5. Stockholm, 1748, p. 219.

i a pk ts =

IN FOUR VOLUMES.
VOL. IV.

THE FIFTH EDITION.

SS

LONDON:
JOHN MURRAY, ALBEMARLE STREET.
1837.

PRINCIPLES OF GEOLOGY.

BOOK IV.

CHAPTER X.

NEWER PLIOCENE FORMATIONS — MARINE AND VOLCANIC.

Tertiary formations of Campania — Comparison of the recorded
changes in this region with those commemorated by geological
monuments — Dikes of Somma — Parallelism of their opposite
sides (p. 6.)— Age of the volcanic and associated rocks of
Campania — Organic remains — No signs of diluvial waves —
Marine Newer Pliocene strata chiefly seen in countries of earth-

: quakes (p. 16.) — Illustrations from Chili — Peru — Paralle
roads of Coquimbo — West Indies (p. 21.) — East Indian
archipelago — Red Sea.

Tertiary Formations of Campania.

Comparison of recorded changes with those commemo-
rated by geological monuments.—In the second volume
I traced the various changes which the volcanic region
of Naples is known to have undergone during the last
two thousand years; and, imperfect as are our histori-
cal records, the aggregate effect of igneous and aqueous
agency, during that period, was shown to be far from
insignificant. The rise of the modern cone of Vesu-

vius, Since the year 79, was the most memorable event
VOL. Iv. B

Z NEWER PLIOCENE PERIOD. [Book IV.

during those twenty centuries ; but, in addition to this
remarkable phenomenon, I enumerated the production
of several new minor cones in Ischia, and of the Monte
Nuovo, in the year 1538. The flowing also of lava
currents upon the land and along the bottom of the
sea was described, — the showering down of volcanic
sand, pumice, and scorie, in such abundance that whole
cities were buried, —the filling up or shoaling of
certain tracts of the sea, and the transportation of
tufaceous sediment by rivers and land floods. I also
explained the evidence in proof of a permanent alter-
ation of the relative levels of the land and sea in
several places, and of the same tract having, near
Puzzuoli, been alternately upheaved and depressed to
the amount of more than twenty feet. In connection
with these convulsions, I pointed out that, on the
shores of the Bay of Baiz, there are recent tufaceous
strata filled with fabricated articles, mingled with
marine shells. It was also shown that. the sea has
been making gradual advances upon the coast, not only
sweeping away the soft tuffs of the Bay of Baiz, but
excavating precipitous cliffs, where the hard Ischian
and Vesuvian lavas have flowed down into the deep.
These events, it may be objected, although interest-
ing, are the results of operations on a very inferior
scale to those indicated by geological monuments.
When we examine this same region, it will be said we
find that the ancient cone of Vesuvius, called Somma,
is larger than the modern cone, and is intersected by
a greater number of dikes, — the hills of unknown
antiquity, such as Astroni, the Solfatara, and Monte
Barbaro, formed by separate eruptions, in different
parts of the Phlegrean fields, far outnumber those of

Ch. X.] TERTIARY FORMATIONS OF CAMPANIA. 3

similar origin, which are recorded to have been thrown
up within the historical era. In place of modern tuffs
of slight thickness, and single flows of lava, we find,
amongst the older formations, hills from 500 to more
than 2000 feet in height, composed of an immense
series of tufaceous strata, alternating with distinct lava
currents. We have evidence that, in the lapse of past
ages, districts, not merely a few miles square, were up-
raised to the height of twenty or thirty feet above their
former level, but that extensive and mountainous coun-
tries were uplifted to an elevation of more than 1000
feet, and at some points more than 2000 feet, above
the level of the sea.

These and similar objections are made by those who
compare the modern effects of igneous and aqueous
causes, not with a part but with the whole results of
the same agency in antecedent ages. Thus viewed in
the aggregate, the leading geological features of each
district must always appear to be on a colossal scale,
just as a large edifice may seem an effort of super-
human power, until we reflect on the innumerable
minute parts of which it is composed, the number of
the builders, and the time required to raise it. A
mountain mass, so long as the imagination is occupied
in contemplating the gigantic whole, must appear the
work of extraordinary causes ; but when the separate
Portions of which it is made up are carefully studied,
they are seen to have been formed successively ; and \
the dimensions of each part, considered singly, are
Soon recognized to be comparatively insignificant, so
that it appears no longer extravagant to liken them to
the recorded effects of ordinary causes.

B 2

Å NEWER PLIOCENE PERIOD. . [Book 1¥

Difference in the composition of Somma and Vesuvius.

As no traditional accounts have been handed down
to us of the eruptions of the ancient Vesuvius, from
the times of the earliest Greek colonists, the volcano
must have been dormant for many centuries, perhaps
for thousands of years, previous to the great eruption
in the reign of Titus. But it will be shown hereafter
that there are sufficient grounds for presuming this
mountain, and the other igneous products of Cam-
pania, to have been produced during the Newer Plio-
cene period.

We have seen that the ancient and modern cones
of Vesuvius were each a counterpart of the other in
structure *; and I may now remark that the principal
point of difference consists in the greater abundance
in the older cone of fragments of altered sedimentary
rocks ejected during eruptions. We may easily con-
ceive that the first explosions would act with the
greatest violence, rending and shattering whatever
golid masses obstructed the escape of lava and the
accompanying gases, so that great heaps of ejected
pieces of rock would naturally occur in the tufaceous
breccias formed by. the earliest eruptions. But when
a passage had once been opened and an habitual vent
established, the materials thrown out would consist of
liquid lava, which would take the form of sand and
šcoriæ, or of angular fragments of such solid lavas as.
may have choked up the vent.

Among the fragments which abound in the tuface-
pus breccias of Somma, none are more common than
a saccharoid dolomite, supposed to have been derived

* Vol. II, p. 87.

tt

Ch. XJ DIKES OF SOMMA. H

from an ordinary limestone altered by heat and vol-
canic vapours.

_ Carbonate of lime enters into the composition o-
so many of the simple minerals found in Somma, that
M. Mitscherlich, with much probability, ascribes their
great variety to the action of the volcanic heat on
subjacent masses of limestone.

Dikes of Somma. — The dikes seen in the great es-
carpment which Somma presents towards the modern
cone of Vesuvius are very numerous. They are for
the most part vertical, and traverse at right angles the
beds of lava, scoriæ, volcanic. breccia, and sand, o.
which the ancient cone is composed. They project in
relief several inches, or sometimes feet, from the face
of the cliff, like the dikes of Etna already described
(see Fig. 102.), being, like them, extremely compact,
and less destructible than the intersected tuffs and
porous lavas. In vertical extent they vary from a few
yards to 500 feet, and in breadth from one to twelve
feet. Many of them cut all the inclined beds in the
escarpment of Somma from top to bottom, others stop
short before they ascend above half way, and a few
terminate at both ends, either in a point or abruptly.
In mineral composition they scarcely differ from the
lavas of Somma, the rock consisting of a base of leucite
and augite, through which large crystals of augite and
some of leucite are scattered.* Examples are not
rare of one dike cutting through another, and in one
instance a shift or fault is seen at the point of intersec-
tion. I observed before, when speaking of the dikes
of the modern cone of Vesuvius, that they must have

* Consult the valuable memoir of M. L. A. Necker, Mém. de

la Soc. de Phys. et d’Hist. Nat. de Généve, tome ii. parti., Nov.
1822,

B 3

6 NEWER PLIOCENE PERIOD. [Book IV.

been produced by the filling up of open fissures by
liquid lava.* In some examples, however, the rents
seem to have been filled laterally.

The reader will remember the description before
given of the manner in which the plain of Jerocarne,
in Calabria, was fissured by the earthquake of 1783,
so that the academicians compared it to the cracks in
a broken pane of glass.t If we suppose the side
walls of the ancient crater of Vesuvius to have been

Fig. 109.

Dikes or veins at the Punto del Nasone on Somma.

cracked in like manner, and the lava to have entered
the rents and become consolidated, we can explain the
singular form of the veins figured in the accompanying
wood-cut.t
Parallelism of their opposite sides. — Nothing is more
remarkable than the parallelism of the opposite sides
of the dikes, which usually correspond with as much

* Vol. II. p. 86.
+ See Vol. II. p. 223. Fig. 47.
ł From a drawing of M. Necker, in Mém. before cited.

Ch. XJ PARALLEL SIDES OF DIKES. T

regularity as the two opposite faces of a wall of ma-
sonry. This character appears at first the more inex-
plicable, when we consider how jagged and uneven
are the rents caused by earthquakes in masses of
heterogeneous composition like those composing the
cone of Somma; but M. Necker has offered an in-
genious and, I think, satisfactory explanation of the
phenomenon. He refers us to Sir W. Hamilton’s
account of an eruption of Vesuvius in the year 1779,
who records the following facts: — “ The lavas, when
they either boiled over the crater, or broke out from
the conical parts of the volcano, constantly formed
channels as regular as if they had been cut by art,
down the steep part of the mountain; and, whilst in
a state of perfect fusion, continued their course in
those channels, which were sometimes full to the brim,
and at other times more or less so, according to the
quantity of matter in motion.

“ These channels, upon examination after an erup-
tion, I have found to be in general from two to five or
six feet wide, and seven or eight feet deep. They
were often hid from the sight by a quantity of scoriæ
that had formed a crust over them; and the lava,
having been conveyed in a covered way for some
yards, came out fresh again into an open channel.
After an eruption I have walked in some of those sub-
terraneous or covered galleries, which were exceed-
ingly curious, the sides, top, and bottom being worn
perfectly smooth and even in most parts, by the violence
of the currents of the red-hot lavas, which they had
conveyed for many weeks successively.”

In another place, in the same memoir, he describes
the liquid and red-hot matter as being received “ into
a regular channel, raised upon a sort of wall of scoriz

B 4

8 NEWER PLIOCENE PERIOD, [Book IV.

and cinders, almost perpendicularly, of about the
height of eight or ten feet, resembling much an ancient
aqueduct.” *

Now, if the lava in these instances had not run out
from the covered channel, in consequence of the de-
clivity whereon it was placed —if, instead of the space
being left empty, the lava had been retained within
until it cooled and consolidated, it would then have
constituted a small dike with parallel sides. But the
walls of a vertical fissure through which lava has as-
cended in its way to a volcanic vent, must have been
exposed to the same erosion as the four sides of the
channels before adverted to. The prolonged and uni-
_ form friction of the heavy fluid, as it is forced and
made to flow upwards, cannot fail to wear and smooth
down the surfaces on which it rubs, and the intense
heat must melt all-‘such masses as project and obstruct
the passage of the incandescent fluid.

I do not mean to assert that the sides of fissures
caused by earthquakes are never smooth and parallel,
but they are usually uneven, and are often seen to
have been so where volcanic or trap dikes are as regu-
lar in shape as those of Somma. The solution, there-
fore, of this problem, in reference to the modern dikes,
is most interesting, as being of very general applica-
tion in geology.

Varieties in their texture. — Having explained the
origin of the parallelism of the sides of a dike, we have
next to consider the difference of its texture at the
edges and in the middle. Towards the centre, observes
M. Necker, the rock is larger grained, the component
elements being in a far more crystalline state ; while at

* Phil. Trans., vol. lxx. 1780,

Ch. X.] VARIETIES IN THE TEXTURE OF DIKES. 9

the edge the lava is sometimes vitreous, and always
finer grained. A thin parting band, approaching in its
character to pitchstone, occasionally intervenes on the
contact of the vertical dike and intersected beds. M.
Necker mentions one of these at the place called
Primo Monte, in the Atrio del Cavallo; I saw three
or four others in different parts of the great escarp-
ment. These phenomena are in perfect harmony with
the results of the experiments of Sir James Hall and
Mr. Gregory Watt, which have shown that a glassy
texture is the effect of sudden cooling, and that, on
the contrary, a crystalline grain is produced where
fused minerals are allowed to consolidate eee: and |
tranquilly under high pressure. K

It is evident that the central portion of the lava in
a fissure would, during consolidation, part with its heat
more slowly than the sides, although the contrast of
circumstances would not be so great as when we com-
pare the lava at the bottom and at the surface of a
current flowing in the open air. In this case the up-
permost part, where it has been in contact with the
atmosphere, and where refrigeration has been most
rapid, is always found to consist of scoriform, vitreous;
and porous lava, while at a greater depth the mass
assumes a more lithoidal structure, and then becomes
more and more stony as we descend, until at length
we are able to recognize with a magnifying glass the
simple minerals of which the rock is composed. On
penetrating still deeper, we can detect the constituent
parts by the naked eye, and in the Vesuvian currents
distinct crystals of augite and leucite become ap-
parent.

The same phenomenon, observes M. Necker, may
readily be exhibited on a smaller scale, if we detach

BS

10 NEWER PLIOCENE PERIOD. [Book IV.

a piece of liquid lava from a moving current. The
fragment cools instantly, and we find the surface
covered with a vitreous coat, while the interior, al-
though extremely fine grained, has a more stony
appearance.

It must, however, be observed, that although the
lateral portions of the dikes are finer grained than the
central, yet the vitreous parting layer before alluded to
is extremely rare. This may, perhaps, be accounted
for, as the above-mentioned author suggests, by the
great heat which the walls of a fissure may acquire
before the fluid mass begins to consolidate, in which
case the lava, even at the sides, would cool very
slowly. Some fissures, also, may be filled from above ;
and in this case the refrigeration at the sides would
be more rapid than when the melted matter flowed
upwards from the volcanic foci, in an intensely heated
state.

The rock composing the dikes of Somma is far more
compact than that of ordinary lava, for the pressure of
a column of melted matter in a fissure greatly exceeds
that in an ordinary stream of lava ; and pressure checks
the expansion of those gases which give rise to vesicles
in lava.

There is a tendency in almost all the Vesuvian dikes
to divide into horizontal prisms*, a phenomenon in
accordance with the formation of vertical columns in
horizontal beds of lava ; for in both cases the divisions
which give rise to the prismatic structure are at right
angles to the cooling surfaces.

Minor cones of the Phlegrean Fields. — In the vol-
canic district of Naples there are a great number of

* See Fig. 109. p. 6.

Ch. X.J MINOR CONES OF CAMPANIA. Ii

conical hills with craters on their summits, which have
evidently been produced by one or more explosions,
like that which threw up the Monte Nuovo in 1538.
They are composed of trachytic tuff, which is loose
and incoherent, both in the hills and, to a certain
depth, in the plains around their base, but which is in-
durated below. It is suggested by Mr. Scrope, that
this difference may be owing to the circumstance of
the volcanic vents having burst out in a shallow sea,
as was the case with Monte Nuovo, where there is a
similar foundation of hard tuff, under a covering of
loose lapilli. The subaqueous part may have become
solid by an aggregative process like that which takes
place in the setting of mortar, while the rest of the
ejections, having accumulated on dry land when the
cone was raised above the water, may have remained
in a loose state. *

Age of the voleanic and associated rocks of Campania.
— If we inquire into the evidence derivable from or-
ganic remains, respecting the age of the volcanic rocks
of Campania, we find reason to conclude that such
parts as do not belong to the Recent are referable to
the Newer Pliocene period. In the solid tuff quarried
out of the hills immediately behind Naples, are found
recent shells of the genera Ostrea, Cardium, Buccinum,
and Patella, all referable to species now living in the
Mediterranean.+ In the centre of Ischia the lofty
hill called Epomeo, or San Nicola, is composed of
greenish indurated tuff of a prodigious thickness, inter-
Stratified in some parts with argillaceous marl, and
here and there with great streams of indurated lava.
Visconti ascertained by trigonometrical measurement

* Geol. Trans., vol. ii. part iii, p.351. Second Series. _
tł Scrope, ibid.
B 6

12 NEWER PLIOCENE PERIOD. [Book IV.

that this mountain was 2605 feet above the level of
the sea. In mineral composition and in form, as seen
from many points of view, it resembles the hill to the
north of Naples on the summit of which stands the
convent of Camaldoli, which is 1643 feet in height. I
collected in 1828 many recent marine shells from beds
of clay and tuff, not far from the summit of Epomeo,
about 2000 feet above the level of the sea, as also at
another place, about 100 feet below the first, on the
southern declivity of the mountain, and others still
lower, not far above the town of Moropano. At Casa-
micciol, and several places near the sea-shore, shells
have long been observed in stratified tuff and clay.
From these various points I obtained, during a short
excursion in Ischia, twenty-eight species of shells, all
of which, with one exception, were identified by M.
Deshayes with recent species. *

It is clear, therefore, that the great mass of Epo-
meo was not only raised to its present height above
the level of the sea, but was also formed, since the
Mediterranean was inhabited by the existing species
of testacea.

In the Ischian tuffs we find pumice, lapilli, angular
fragments of trachytic lava, and other products: of
igneous ejections, interstratified with some deposits of
clay free from any intermixture of volcanic matter.
These clays might have resulted from the decompo-
sition of felspathic lava like that so abundant in Ischia,
the materials having been transported by rivers and
marine currents, and spread over the bottom of the
sea where testacea were living. All these submarine
tuffs, lavas, and clays of Campania, very much, ré-

* See the list of these shells, Appendix II. first ed.

Ch.X.] OUTLINE OF COUNTRY, HOW CAUSED. 13

semble those around the base of Etna, and in parts of
the Val di Noto before described.

_ External configuration of the country, how caused.—
When once we have satisfied ourselves by inspection of
the marine shells imbedded in tuffs at high elevations,
that a mass of land like the island of Ischia has been
raised from beneath the waters of the sea to its present
height, we are prepared to find signs of the denuding
action of the waves impressed upon the outward form
of the island, especially if we conceive the upheaving
force to have acted by successive movements. Let us
suppose the low contiguous island of Procida to be
raised by degrees until it attains the height of Ischia ;
we should in that case expect the steep cliffs which
now face Misenum to be carried upwards, and to be-
come precipices near the summit of the central moun-
tain. Such, perhaps, may have been the origin of those
precipices which appear on the north and south sides
of the ridge which forms the summit of Epomeo in
Ischia. The northern escarpment is about 1000 feet
‘in height, rising from the hollow called the Cavo delle
Neve, above the village of Panella. The abrupt man-
ner in which the horizontal tuffs are there cut off, in
the face of the cliff, is such as the action of the sea,
working on soft materials, might easily have produced,
undermining and removing a great portion of the mass.
A heap of shingle which lies at the base of a steep
declivity on the flanks of Epomeo, between the Cavo
delle Neve and Panella, may once, perhaps, have been
a sea-beach, for it certainly could not have been brought
to the spot by any existing torrents.

There is no difficulty in conceiving that if a large
tract of the bed of the sea near Ischia should now be

Stadually upheaved during the continuance of volcanic

14 NEWER PLIOCENE PERIOD. [Book IV.

agency, this newly raised land might present a coun-
terpart to the Phlegræan Fields before described.
Masses of alternating lava and tuff, the products of
submarine eruptions, might on their emergence be-
come hills and islands; the level intervening plains
might afterwards appear, covered partly by the ashes
drifted and deposited by water, and partly by those
which would fall after the laying dry of the tract.
The last features imparted to the physical geography
would be derived from such eruptions in the open
air as those of Monte Nuovo and the minor cones of
Ischia.

No signs of diluvial waves.— Such a conversion of a
large tract of sea into land might possibly take place
while the surface of the contiguous country underwent
but slight modification. No great wave was caused by
the permanent rise of the coast near Puzzuoli in the
year 1538, because the upheaving operation appears to
have been effected by a succession of minor shocks. *
A series of such movements, therefore, might produce
an island like Ischia without throwing a diluvial rush
of waters upon low parts of the neighbouring continent.
The advocates of paroxysmal elevations may, perhaps,
contend that the rise of Ischia must have been anterior
to the birth of all the cones of loose scoriz scattered
over the Phlegrzan Fields ; for, according to them, the
sudden rise of marine strata causes inundations which
devastate adjoining continents. But the absence of
any signs of such floods in the volcanic region of
Campania does not appear to me to warrant the con-
clusion, either that Ischia was raised previously to the
production of the volcanic cones, or that it may not

* See Vol. II. p. 267.

Ch. X.J NO SIGNS OF DILUVIAL WAVES, 15

have been rising during the whole period of their
formation.

We learn from the study of the mutations now in
progress, that one part of the earth's surface may, for
an indefinite period, be the scene of continued change,
while another, in the immediate vicinity, remains sta-
tionary. We need go no farther than our own country
to illustrate this principle ; for, reasoning from what
has taken place in the last ten centuries, we must an-
ticipate that, in the course of the next four thousand
or five thousand years, a long strip of land, skirting the
line of our eastern coast, will be devoured by the
ocean, while part of the interior, immediately adjacent,
will remain at rest and entirely undisturbed. The
analogy holds true in regions where the volcanic fires
are at work ; for part of the Philosopher's Tower on
Etna has stood for the last two thousand years, at the
height of more than nine thousand feet above the sea,
between the foot of the highest cone and the edge of
the precipice which overhangs the Val del Bove, whilst
large tracts of the surrounding district have been the
Scenes of tremendous convulsions. The great cone
above has more than once been destroyed, and again
renewed ; the earth has sunk down in the neighbour-
ing Cisterna*; the cones of 1811 and 1819 have been
thrown up, on the ledge of rock below, pouring out of
their craters two copious streams of lava; the watery
deluge of 1755, descending from the desert region
into the Val del Bove, has rolled vast heaps of rocky
fragments towards the sea; fissures, several miles in
length, have opened on the flanks of Etna; towns and
villages have been laid in ruins by earthquakes, or

* See Vol. III. p: 425.

16 NEWER PLIOCENE PERIOD. [Book IV.

buried under lava and ashes ;— yet the tower has
stood, as if placed there to commemorate the stability
of one part of the earth’s surface, while others in im-
mediate proximity have been subject to most wonder-
ful vicissitudes.

In concluding what I have to say of the marine and
volcanic formations of the Newer Pliocene period, I
| mdy notice the highly interesting fact, that the marine
strata of this era have been found at great elevations,
chiefly in those countries where earthquakes have
occurred during the historical ages. On the other
hand, it is a still more striking fact, that there is no
example of any extensive maritime district, now ha-
bitually agitated by violent earthquakes, which has not,
when carefully investigated, yielded traces of marine
| strata, either of Recent or Newer Pliocene eras, at a
considerable height above the sea.

-Chili— Conception Bay.— In illustration of the above
remarks, I may mention that on the western coast of
South America marine deposits occur, containing pre-
cisely the same shells as are now living in the Pacific.
In Chili, for example, as before stated, micaceous
sand, containing the fossil remains of such species as
now inhabit the Bay of Conception, are found at the
height of from.1000 to 1500 feet above the level of the
ocean.* It is impossible to say how much of this rise
may have taken place during the Recent period. One
earthquake appears to have raised this part of the
Chilian coast, in 1750, to the height of at least twenty-
five feet above its former level. If we could suppose
a series of such shocks to occur, one in every century,
only 6000 years would be required to uplift the coast

* Vol. II. p. 256.

Ch. XJ PERU. 17

1500 feet. But we have no data for inferring that so
great a quantity of elevation has taken place in that
space of time; and although there is no evidence that
the micaceous sand may not belong to the Recent
period, I think it more probable that it was deposited
during the Newer Pliocene period.

Peru. — I have been informed by Mr. A. Cruck-
shanks, a naturalist who resided for several years in
South America, that in the valley of Lima, or Rimao,
where the subterranean movements have been so vio-
lent in recent times, there are indications not only
of a considerable rise of the land, but of that rise
having resulted from successive movements. Distinct
lines of ancient sea-cliffs have been observed at various
heights, at the base of which the hard rocks of green-
stone are hollowed out into precisely those forms
which they now assume between high and low water
mark on the shores of the Pacific. Immediately below
these water-worn lines are ancient beaches strewed
with rounded blocks. One of these cliffs appears in
the hill behind Baños del Pujio, about seven hundred
feet above the level of the sea, and two hundred above
the contiguous valley. Another occurs at Amancaes,
at the height of perhaps two hundred feet above the
Sea ; and others at intermediate elevations.

Mr. Freyer also states that the Isle of San Lorenzo,
in the Bay of Callao, appears to have been raised up
by volcanic action, and partially so at a comparatively
recent period; for he found at considerable heights
above the sea the shells of Concholepas, Pecten pur-
bureus, Sigaretus concavus, and others, in great abund-
ance, retaining their colours almost as fresh as those
now living in the Pacific. *

* Proceedings of Geol. Soc. No. 40, p. 179.

18 NEWER PLIOCENE PERIOD. [Book IV.

Parallel Roads of Coquimbo.— We can hardly doubt
that the parallel roads of Coquimbo, in Chili, described
by Captain Hall, owe their origin to similar causes.
These roads, or shelves, occur in a valley six or seven
miles wide, which descends from the Andes to the
Pacific. Their general width is from twenty to fifty
yards, but they are, at some places, half a mile broad.
They are so disposed as to present exact counterparts `
of one another, at the same level, on oppesite sides of
the valley. There are three distinctly characterized
sets; the upper one lies about three or four hundred
feet above the level of the sea; the next twenty yards
lower ; and the lowest about ten yards still lower. Each
resembles a shingle beach, being formed entirely of
loose materials, principally water-worn rounded stones,
from the size of a nut to that of a man’s head. The
stones are principally granite and gneiss, with masses
of schistus, whinstone, and quartz, mixed indiscrimin-
ately, and all bearing marks of having been worn by
attrition under water. *

The theory proposed by Captain Hall to explain
these appearances is the same as that which had been
adopted to account for the analogous parallel roads of
Glen Roy in Scotland.+ The valley is supposed to
have been a lake, the waters of which stood, originally,
at the level of the highest road, until a flat beach was
produced. A portion of the barrier was then broken
down, which allowed the lake to discharge part of its
waters into the sea, and, consequently, to fall to the
second level; and so on successively till the whole

* Captain Hall’s South America, vol. ii. p. 9.
+ See Sir T. D. Lauder, Ed. Roy. Soc. Trans., vol. ix.; and
Dr. MacCulloch, Geol. Trans., 1st Series, vol. iv. p. $14.

Ch. XJ PARALLEL ROADS OF COQUIMBO. 19

embankment was washed away, and the valley left as
we now see it.

As I did not feel satisfied with this explanation, I
applied to my friend Captain Hall for additional details,
and he immediately sent me his original manuscript
notes, requesting me to make free use of them. In
them I find the following interesting passages, omitted
in his printed account: — « The valley is completely
open towards the sea; if the roads, therefore, are the
beaches of an ancient lake, it is difficult to imagine a
catastrophe sufficiently violent to carry away the bar-
rier, which should not at the same time obliterate all
traces of the beaches. I find it difficult also to ac-
count for the water-worn character of all the stones, .
for they have the appearance of having travelled over
a great distance, being well rounded and dressed. They
are in immense quantity too, and much more than one
could expect to find on the beach of any lake, and
seem more properly to belong to the ocean.”

I had entertained a Strong suspicion, before reading
these notes, that the beaches were formed by the
waves of the Pacific, and not by the waters of a lake ;
in other words, that they bear testimony to the suc-
cessive rise of the land, not to the repeated fall of the
waters of a lake. M. Boblaye has discovered four or
five distinct ranges of ancient sea-cliffs, one above the
other, at various heights, in the Morea, which attest
that that country has been upheaved at as many suc-
Cessive periods. He found inland terraces or beaches,
Covered with shells, at the base of precipices worn like
the modern sea-cliffs by the waves, and having, like
them, many caverns and lithodomous perforations in
the hard limestone. *

* Journ. de Géol., No. x. Feb, 1831; Bull, de la Soc. Géol.
de France, tom. ii. Pp: 236,

20 NEWER PLIOCENE PERIOD. [Book IV,

Near the northern gate of the town of St. Mihiel,
south of Verdun, in France, I have examined a series
of markings on the face of the limestone cliffs, much
resembling some of those described by M. Boblaye.
There are three and sometimes four distinct horizontal
grooves, which have been scooped out of a white semi-
crystalline rock, or marble, of the oolitic period. This
ancient cliff, which is near the right bank of the Meuse,
is in part broken into a number of detached rocks, the
upper parts of which present in some cases precipitous
sides towards all points of the compass, round which
the grooves pass in a circular course, just as if the
summit of a rocky islet had been worn by the waves.*

Captain Bayfield, in his survey of the coast of the
Gulf of St. Lawrence, traced in several places, espe-
cially in the Mingan Islands, a succession of shingle
beaches, the most distant from the shore being sixty
feet above the level of the highest tides. He also ob-
served water-worn pillars of limestone accompanying
these beaches, which bear evidence of having been
worn and scooped out at different periods; the marks
of the successive action of the water agreeing in level
with the successive ridges of limestone shingle. The

* I have no data for speculating on the period at which these
cliffs may have emerged from the sea. I was directed to the spot,
which I visited in June, 1833, by M. Deshayes; and I stated in
the second edition, on his authority, that the worn rocks were eaten
into by marine lithodomous shells, but I was unable to discover
any of these; and I believe that the fossils of the genus Saxicava,
which M. Deshayes procured from this place, were of the age of
the corals of the limestone, not of the date of the excavation of
the grooves. The fossil corals of this formation (coral rag) fre-
quently contain lithodomous shells, which seem to have pierced
the zoophytes while they were still growing in the sea.

Ch. XJ PARALLEL UPRAISED BEACHES. 2}

drawings of the pillars, made to illustrate his memoir,

convince me that they are counterparts of the worn

rocks which I have seen at St. Mihiel.* I have also

been favoured with other views of rocks on the same

coast, drawn by Lieut. A. Bowen, R.N. (see Fig. 110.).
Fig. 110.

Limestone ns in Niapisca Island, in the Gulf of St. Lawrence. Height
of the second column on the left, 60 feet.

If there exist lines of parallel upraised cliffs, we
ought to find parallel lines of elevated beaches on
those coasts where the rocks are of a nature to retain
for a length of time the marks imprinted on their sur-
ace. We may expect such indications to be pecu-
liarly manifest in countries where the subterranean

force has been in activity within comparatively modern

times,

and it is there that the hypothesis of paroxys-
mal el

ai elevations, and the instantaneous rise of moun-

‘ain-chains, should first have been put to the test,
efore it was too hastily embraced and extended.

West Indian Archipelago.— According to the sketch

* Proceedings of Geol. Soc., No, 33. p. 5.

99 NEWER PLIOCENE PERIOD. [Book IV.

given by Maclure of the geology of the Leeward
Islands, the western range consists in great part of
formations of the most modern period.* It will be
remembered, that many parts of this region have been
subject to violent earthquakes; that in St. Vincent's
and Guadaloupe there are active volcanos, and in some
of the other islands boiling springs and solfataras. In
St. Eustatia there is a marine deposit, estimated at
1500 feet in thickness, consisting of coral limestone
alternating with beds of shells, of which the species
are, according to Maclure, the same as those now
found in the sea. These strata dip to the south-west,
at an angle of about 45°, and both rest upon, and are
covered by, cinders, pumice, and volcanic substances.
Part of the madreporic rock has been converted into
silex and calcedony, and is, in some parts, associated
with crystalline gypsum. Alternations of coralline
formations with prismatic lava and different volcanic
substances also occur in Dominica and St. Christo-
pher’s ; and the American naturalist remarks, that as
every lava-current which runs into the sea in this
archipelago is liable to be covered with corals and
shells, and these again with lava, we may suppose an
` indefinite repetition of such alternations to constitute
the foundation of each island.

I do not question the accuracy of the opinion, that
the fossil shells and corals of these formations are of
recent species; for there are specimens of limestone
in the Museum of the Jardin du Roi at Paris, from
the West Indies, in which the imbedded shells are all
or nearly all identical with those now living. Part of
this limestone is soft, but some of the specimens are
very compact and crystalline, and contain only the

* Quart. Journ. of Sci., vol. v. p. 311.

Re nt a

Ch, X.] EAST INDIAN ARCHIPELAGO, ETC. 23

casts of shells.
Deshayes from th
a recent.

Of thirty species examined by M.
is rock, twenty-eight were decidedly

Honduras. — Shells sent from some of the recent
strata of Jamaica, and many from the nearest adjoining
continent of the Honduras, may be seen in the British
Museum, and are indentified with species now living
in the West Indian seas.

East Indian Archipelago. — We have seen that the
Indian Ocean is one of the principal theatres of vol-
canic disturbance ; it is to be expected, therefore, that
future researches in this quarter of the globe will
bring to light some of the most striking examples of _
marine strata upraised to great heights during com-
paratively modern periods.

From the observations of Dr. Jack,

in the island of Pulo Nias, off the west coast of
Sumatra, masses of corals of recent species can be
traced from the level of the sea far into the interior,
where they form considerable hills. Large shells of
the Chama gigas (Tridacna, Lamk.) are scattered
over the face of the country, just as they occur on the
Present reefs. These fossils are in such a state of
Preservation as to be collected by the inhabitants for
the purpose of being cut into rings for the arms and
Wrists,*

Madeira. — The island of Madeira is placed be-
tween the Azores and Canaries, in both of which
8Toups there are active volcanos; and Madeira itself
Was violently shaken by earthquakes during the last
Century. It consists in great part of volcanic tuffs
and porous lava, intersected in some places, as at the

it appears that

* Geol. Trans., Second Series, vol. i, part ii. p. 397.

24. NEWER PLIOCENE PERIOD. [Book IV

Brazen Head, by vertical dikes of compact lava.*
Some of the marine fossil shells, procured by Mr.
Bowdich from this island, are referable to recent
species.

These examples may suffice for the present, and
lead us to anticipate with confidence, that in almost all
countries where changes of level have taken place in
our own times, the geologist will find monuments of a
prolonged series of convulsions during the Recent and
Newer Pliocene periods. Exceptions may no doubt
occur where a particular line of coast is sinking down;
yet even here we may presume, from what we know
of the irregular action of the subterranean forces, that
some cases of partial elevation will have been caused
by occasional oscillations of level, so that modern sub-
aqueous formations will, here and there, have been
brought up to view.

- I shall conclude by enumerating some exceptions to
the rule above illustrated, — instances of elevation
where no great earthquakes have been recently ex-
perienced.

Scandinavia. — The first and most important is that
of Sweden, before described.t This country, although
free from convulsions, was shown to be the theatre
of unceasing changes in the relative level of land and
sea. We accordingly discover in it deposits of sand,
marl, and clay, several hundred feet in thickness, and
containing recent species of marine shells raised to the
height of 200 feet, and even in Norway 400 feet
above the sea, and extending at some points far into
the interior.

Groswil, near Nice.— At a spot called Grosceil, near

* MS. of Captain B. Hall. t Book ii. chap. xvii.

Ch. XJ BORDERS OF THE RED SEA. 25

Nice, east of the Bay of Villefranche, in the peninsula
of St. Hospice, a remarkable bed of fine sand occurs
at an elevation of about fifty feet above the sea.*
This sand rests on inclined secondary rocks, and is
filled with the remains of marine species, all identical
with those now inhabiting the neighbouring sea. No
less than two hundred Species of shells, and several
crustacea and echini, have been obtained by M. Risso,
in a high state of preservation, although mingled with
broken shells. The winds have blown up large heaps
of similar sand to considerable heights, upon ledges of
the Steep coast farther westward; but the position of
the deposit at Grosceil cannot be referred to such
agency, for among the shells may be seen the large
Murex Triton, Linn, anda species of Cassis, weighing
a pound and a half,

West of England. — The proofs lately brought to
light of analogous elevations of deposits containing
recent shells on our western shores, and between Lan-
cashire and the Bristol channel, have been already
pointed out.+

Western borders of the Red Sea. — Another excep- |
tion may be alluded to, for which we are indebted to
the researches of Mr. James Burton. On the western
Shores of the Arabian Gulf, about half way between
Suez and Kosire, in the 28th degree of north latitude,
a formation of white limestone and calcareous sand is
Seen, reaching the height of 200 feet above the sea.
It is replete with fossil shells, all of recent species,
which are in a beautiful State of preservation, many of

= I examined this spot, with Mr. Murchison, in 1828.

T See description of the Map, Vol. I. p. 215.
VOL. Iv, c

26 NEWER PLIOCENE PERIOD. [Bock IV.

them retaining their colour.* The volcano of Gabel
Tor, situate at the entrance of the Arabian Gulf, is
the nearest volcanic region known to me at present.

But the reader must not infer, from the facts above
detailed, that marine strata of the Newer Pliocene pe-
riod have been produced almost exclusively in countries
of earthquakes, or where changes of level are known
to be taking place, as in Sweden. If our illustrations
have been drawn chiefly from modern volcanic regions,
it is simply because these formations have been made
visible in those districts only where the conversion of
sea into land has occurred in times comparatively
modern. Other continents have, during the Newer
Pliocene period, suffered degradation, and rivers and
currents have deposited sediment in other seas; but
the new strata remain concealed wherever no subse-
quent alterations of level have taken place.

Yet, to a certain limited extent, the growth of new
subaqueous deposits may have been greatest where
aqueous causes have co-operated with earthquakes.
It is there that the degradation of land is most rapid;
and it is there only that materials ejected from below,
by volcanic explosions, are added to the sediment
transported by running water.t

* These fossils are now in Mr. Greenough’s museum in Lon-
don, and duplicates, presented by him, in the cabinets of the
Geological Society. A list was given in App. II., first edition.

+ See Book ii, chap. xv. ; and Book iii. chap. xviii.

CHAPTER XI.

NEWER PLIOCENE FORMATIONS — FRESHWATER AND

ALLUVIAL.

Newer Pliocene freshwater formations — Valley of the Elsa —
Travertins of Rome — Loess of the Valley of the Rhine— Con-
tains recent terrestrial and aquatic shells — Its origin —
Osseous breccias of the Newer Pliocene era (p. 38.) — Fossil
bones of Marsupial animals in Australian caves — Newer Plio-
cene alluviums (p, 44.) — European alluviums chiefly tertiary

— Erratic blocks of the Alps — Theory of their transportation
by ice,

Freshwater Formations. — IN this chapter I shall treat
of the freshwater formations, and of the cave breccias
and alluviums of the Newer Pliocene period.

In regard to the first of these, they must have been
formed, in greater or less quantity, in nearly all the
existing lakes of the world ; in those, at least, of which
the basins were formed before the earth was tenanted
by man. If the great lakes of North America origin-
ated before that era, the sedimentary strata deposited
therein, in the ages immediately antecedent, would,
according to the terms of our definition, belong to the
Newer Pliocene period.

Valley of the Elsa.— As an example of the strata
ot this age, which have been exposed to view in con-
Sequence of the drainage of a lake, I may mention
those of the valley of the Elsa, in Tuscany, between

lorence and Sienna, where we meet with freshwater
Cc?

he) NEWER PLIOCENE PERIOD. [Book IV.

marls and travertins full of shells, belonging to species
which now live in the lakes and rivers of Italy. Val-
leys several hundred feet deep have been excavated
through the lacustrine beds, and the ancient town of
Colle stands on a hill composed of them. The subja-
cent formation consists of marine Subapennine beds,
in which more than half the shells are of recent spe-
cies. The freshwater shells which I collected near
Colle are in a very perfect state, and the colours of
the Neritine are peculiarly brilliant.*

Travertins of Rome. — Many of the travertins and
calcareous tufas which cap the hills of Rome may also
pelong to the same period. The terrestrial shells in-
closed in these masses are of the same species as
those now abounding in the gardens of Rome, and the
accompanying aquatic shells are such as are found in
the streams and lakes of the Campagna. On Mount
Aventine, the Vatican, and the Capitol, we find abund-
ance of vegetable matter, principally reeds, mcrusted
with calcareous tufa, and intermixed with volcanic
sand and pumice. The tusk of a mammoth has been
procured from this formation, filled in the interior with
solid travertin, wherein sparkling crystals of augite are
interspersed, so that the bone has all the appearance
of having been extracted from a hard crystalline
rock.+

These Roman tufas and travertins repose partly on
marine tertiary strata, belonging, perhaps, to the Older
Pliocene era, and partly on volcanic tuff of a still later

* The following six pieces, all of which now inhabit Italy,
were identified by M. Deshayes: — Paludina impura, Neritines
frwiatils, Succinea amphibia, Limnea auricularis, L. peregra, and
Planorbis carinatus.

+ This fossil was shown me by Signor Riccioli at Rome.

Ch. XL] LOESS OF THE VALLEY OF THE RHINE. 29

date. They must have been formed in small lakes and
marshes, which existed before the excavation of the
valleys, which divide the seven hills of Rome, and they
must orginally have occupied the lowest hollows of the
country as it then existed ; whereas now we find them
placed upon the summit of hills about 200 feet above
the alluvial plain of the Tiber. We know that this
river has flowed nearly in its present channel ever
since the building of Rome, and that scarcely any

changes in the geographical features of the country
have taken place since that era.

When the marine tertiary strata of this district were
formed, those of Monte Mario for example, the Medi-
terranean was already inhabited by a large proportion
of the existing species of testacea. Ata subsequent
period, volcanic erruptions occurred, and tuffs were
superimposed. The marine formation then emerged
from the deep, and supported lakes wherein the fresh-
water groups above described slowly accumulated, at
a time when the mammoth inhabited the country.
The valley of the Tiber was afterwards excavated, and
the adjoining hills assumed their present shape; and
then a long interval may, perhaps, have elapsed before
the first human settlers arrived. Thus we have evi-
dence of a chain of events, all regarded by the geolo-
gist as among the most recent, but which, nevertheless,
may have preceded, for a long series of ages, a very
remote era in the history of nations.

Loess of the valley of the Rhine.* —A remarkable

* Having re-examined a much greater extent of the country
covered by the loess in the years 1833 and 1835, I have modified
and retracted some opinions which I expressed in regard to it in
former editions. For a full account of my observations see
Jameson’s Ed. New Phil. Journ., No. 33. July 1834.; Pro-

c 3

80 NEWER PLIOCENE PERIOD. [Book IV.

deposit of ancient silt, containing land and freshwater
shells of living European species, occurs, here and
there, throughout the valley of the Rhine, from the
plains below Cologne up to the borders of Switzerland,
near Schaffhausen, and in the valleys of the principal
tributaries of the Rhine. This deposit of yellow cal-
careous loam is provincially termed “loess” by the
Germans, and in Alsace “lehm,” and it partakes
partly of an alluvial and partly of a lacustrine cha-
racter. It exhibits almost every where the same mi-
neralogical characters and fossil shells, and is usually
found in detached patches, but sometimes forming
lines of low hills which rest on the gravel of the allu-
vial plain of the Rhine. Occasionally it reposes on
the flanks of the mountains bounding the great valley,
where it rises to various elevations above the river,
sometimes to 300 or 400 feet, as near Basle, where it
is more than 1200 feet above the sea.

In an excursion through part of the Duchy of
Darmstadt by Mayence, Oppenheim, Alzey, Flonheim,
Eppelsheim, and Worms, I found the loess spread al-
most every where over the country. On the opposite
side of the Rhine, in the elevated table land above the
Bergstrasse between Wiesloch and Bruchsal, I ob-
served it attaining a thickness of 200 feet. It extends
also far into Wurtemberg, up the valley of the Neckar,
and from Frankfort, up the valley of the Mayne, to
above Dettelbach. Near Strasburg large masses of it
are seen at the foot of the Vosges mountains, on the
left of the great plain of the Rhine, and at the base of
the mountains of the Black Forest on the other side.

ceedings of Geol. Soc., No. 36. p. 83., and No. 43. p. 221. ; and
Anniv. Address to Geol, Soc. 1836.

Ch, XL] LOESS OF THE VALLEY OF THE RHINE. 31

It occurs not only at Basle, as above stated, but still
higher up the Rhine at Waldshut, and it is said to
terminate between that place and Schaffhausen. It
is important to remark that all the above-mentioned
places, however distant from each other, have a direct
hydrographical communication with the main valley
of the Rhine.

When the loess is first observed lying on the gravel
of the great plain near Bonn, Heidelberg, Strasburg,
and other places, we naturally suppose it to be of very
modern origin, especially as it contains recent land
and freshwater shells of species which are, for the
most part, very abundant in the adjacent country.
Even the colour of some of these shells, as that of the
Helia nemoralis, is occasionally preserved. But, when
we have extended our investigations, we find that al-
though the present system of hills and valleys must |
have existed previously to the formation of the loess,
yet the whole country has undergone many great geo-
graphical changes during the accumulation of the de-
posit — so great, indeed, that there has probably been
a sinking down to the amount of many hundred feet,
and afterwards a re-elevation of all the land between
Switzerland and Holland since this silt began to accu-
mulate. No changes of less magnitude seem adequate
to explain the phenomena about to be described.

The loess at Heidelberg, according to M. Leon-
hard, consists chiefly of argillaceous matter, combined
with a sixth part of carbonate of lime, and a sixth of
quartzose and micaceous sand. It is a pulverulent
loam, of a dirty yellowish-grey colour, often containing
calcareous sandy concretions or nodules, rarely ex-
ceeding the size of a man’s head. Its entire thickness,
in some places, amounts to between 200 and 300 feet;

cC 4

352 NEWER PLIOCENE PERIOD. [Book IV.

yet there are often no signs of stratification in the
mass, except here and there at the bottom, where there
is occasionally a slight intermixture of drifted materials
derived from subjacent rocks.

As the pure loess exhibits no division into strata,
I at first imagined, in common with other observers,
that this deposit was thrown down suddenly from the
muddy waters of a transient flood, in the same manner
as the moya of the Andes, or as the trass of the Rhine
volcanos is generally believed to have been formed.
But on re-examining the places where loess and allu-
vium, or loess and layers of volcanic matter, alternate,
I am compelled to renounce this view. In the deep
gravel pits without the Manheim gate of Heidelberg,
loess is seen interstratified with gravel; and here more
than one bed containing entire land and freshwater
shells rests upon, and is covered by, a stratum of
gravel, showing the effects of successive accumulation.
I observed the same fact in the valley of the Lahn,
north of Limburg, near the village of Elz; and Pro-
fessor Bronn informs me, that the calcareous concre-
tions of the loess are sometimes arranged in horizontal
layers, marking a difference in the carbonate of lime
with which the sediment must have been charged at
different periods.

It should also be observed that many of the ter-
restrial and aquatic shells preserved in this silt are of
the most fragile and delicate structure, and must, for
the most part, have been broken to-pieces if they had
been swept along by a violent inundation of force suf-
ficient to transport pebbles; whereas the shells are
almost invariably perfect and uninjured, even in those
places where the loamy beds of loess alternate with
gravel.

~ @9
Ch. XI.] LOESS OF THE VALLEY OF THE RHINE. 33

The most widely spread and abundant fossils in this
formation are Helix plebeium, Pupa muscorum, and Sue-
cinea elongata (see Figs. 111, 112,113.). The last-men-

Fig. 111. Fig. 112.

Succinea elongata. Pupa muscorum. Helix plebeium.

tioned shell is amphibious, and such as may have been
washed away from the banks of streams during floods.
The proportion of land shells of the genera Helix, Pupa,
and Bulimus, is very large; but in many places aquatic
species of the genera Limnea, Paludina, and Planorbis
are also found. Ihave never detected the Unio or
Neritina among the rest, but, with these exceptions,
there is a great generic resemblance between the as-
semblage of fossils in the loess and the shells which
the Rhine carries down in our own time to the sea.
With a view of ascertaining this point I collected, in
the summer of 1833, several hundred shells, which
were exposed on the margin of the Rhine on the fall
of the waters, or had been cast ashore by large waves
raised by the steam boats; and they proved to be, for
the most part, terrestrial species of the genera Helix
and Pupa, with some shells of Limnea, Paludina, and
Planorbis, which may have been washed away during
floods from pools and marshes bordering the river.

Bones of vertebrated animals are rare in the loess,
but those of the mammoth, horse, and some other
quadrupeds have been met with. At the village of
Binningen, and the hills called Bruder Holz, near
Basle, I found the vertebre of fish together with the
usual shells. These vertebre, according to M. Agassiz,

c 5

BA NEWER PLIOCENE PERIOD. [Book IV.

belong decidedly to the Shark family, perhaps to the
genus Lamna; and although it seemed, at first, extra-
ordinary that they should occur among land and fresh-
water shells, I am informed, in explanation of the fact,
that certain fish of this family ascend the Senegal,
Amazon, and other great rivers, to the distance of
several hundred miles from the ocean.*

The reader is probably aware that on both sides of
the Rhine, between Bonn and Coblentz, there is a
region of extinct volcanos. Now, on visiting part of
this country, near Andernach, and examining the
sections which have been well described by MM.
Steininger, Hibbert, and others, I perceived clear evi-
dence that some of the last volcanic eruptions of the
Lower Eifel took place both during and since the de-
position of the loess. The loamy sediment may be
seen in the Kirchweg, above Andernach, alternating
with volcanic matter, over which is a mass of pure
and unmixed loess, thirty feet and upwards in thick-
ness, containing the usual shells; and over the whole
are strewed layers of pumice, lapilli, and volcanic sand,
from ten to fifteen feet thick, very much resembling
the ejections under which Pompeii lies buried. There
is no passage at this upper junction from the loess into
the pumiceous superstratum ; and this last follows the
slope of the hill, just as it would have done had it
fallen in showers from the air on a declivity partly
formed of loess.

In general, however, the loess overlies almost all the
volcanic products, even those between Neuwied and
Bonn, which have the most modern aspect; and it has
filled up in part the crater of the Roderberg, a volcanic

* Proceedings of Geol. Soc. No. 43. p.

Ch. XI] LOESS OF THE VALLEY OF THE RHINE. 35

hillnear Bonn. It was in 1833 that a well was sunk at
the bottom of this crater through seventy feet of loess,
in part of which were the usual calcareous concre-
tions.

It has been ascertained that the waters of the Rhine,
when evaporated, leave a residuum of calcareous loam,
not distinguishable from loess * ; so that if these waters
should now overflow the low lands adjoining the river,
they might give rise to a deposit having the same
mineral characters as the loess, and which would con-
tain, as I have already shown (p- 33.), fossil shells for
the most part of the same genera.

The first idea which has probably occurred to every
one, after examining the loess between Mayence and
Basle, is, to imagine that a great lake once extended
throughout the valley of the Rhine between those two
places. Such a lake may have sent off large branches
up the course of -the Mayne, Neckar, and other tri-
butary valleys, in all of which large patches of loess
are now seen. The barrier of the lake might be placed —
somewhere in the narrow and picturesque gorge of the
Rhine between Bingen and Bonn. But this theory is
insufficient to explain the phenomena ; for that gorge
itself has once been filled with loess, which must have
been tranquilly deposited in it, as also in the lateral
valley of the Lahn, communicating with the gorge.
The loess has also overspread the high adjoining plat-
form near the village of Plaidt, above Andernach.
Nay, on proceeding farther down to the north, we
discover that the hills which skirt the valley between
Bonn and Cologne have loess on their flanks, which

* See Mr. Horner, on the Sediment of the Rhine: Proceed.
ings of Geol. Soc. 1834,

c 6

36 NEWER PLIOCENE PERIOD. [Book iV.

also covers here and there the gravel of the plain as
far as Cologne.

Besides these objections to the lake theory it will be
remembered, that the loess is met with near Basle,
capping hills more than 1200 feet above the sea, su
that a barrier of land capable of separating the sup-
posed lake from the ocean would require to be at least
as high as the mountains called the Siebengebirge,
near Bonn, the loftiest summit of which, the Oehlberg,
is only 1209 feet above the Rhine and 1369 feet above
the sea. It would be necessary, moreover, to place
this lofty barrier somewhere below Cologne, that is to
say, precisely where the level of the land is now lowest.

Instead, therefore, of supposing one continuous lake
of sufficient extent and depth to allow of the simul-
taneous accumulation of the loess, at various heights,
throughout the whole area where it now occurs, I
conceive that, subsequently to the period when the
countries now drained by the Rhine and its tributaries
acquired nearly their actual form and geographical
features, they were again depressed gradually by a
movement like that now in progress on the west coast
of Greenland. In proportion as the whole district was
lowered, the general fall of the waters between the
Alps and the ocean was lessened; and both the main
and lateral valleys, becoming more subject to river
inundations, were partially filled up with fluviatile’
silt, containing land and freshwater shells. When a
thickness of many hundred feet of loess had been
thrown down slowly by this operation, the whole region
was once more upheaved gradually, but perhaps not
equally in all parts. During this upward movement most
of the fine loam would be carried off by the denuding’
power of rains and rivers ; and thus the original valleys

pe
Ch. XI] LOESS OF THE VALLEY OF THE RHINE. 3%

may have been re-excavated, and the country almost
restored to its pristine ‘state, with the exception of
some masses and patches of loess still remaining,
which, from their frequency and remarkable homoge-
neousness of composition and fossils, attest the ancient
continuity and common origin of the whole. By in-
troducing such general fluctuations of relative level,
we dispense with the necessity of erecting, and after-
wards removing, a mountain barrier sufficiently high
to exclude the ocean from the valley of the Rhine
during the period of the accumulation of the loess.
The hypothesis above suggested may, perhaps, be
better understood if we consider what would happen
if similar alterations of level should occur in another
part of the world. It has been shown (Vol. I. p. 290.)
that several large lakes have recently been formed in
the basin of the Red River, in Louisiana, and that trees
are still standing there under water. One of these
lakes is no less than thirty miles long, into which, as
into others, the waters of the Red River flow up dur-
ing floods, the main stream at such seasons invading
some of the valleys of its tributaries. Whatever
may be the causes of this singular state of things
in Louisiana, it is clear that analogous effects might
arise from partial depressions of land. It is also evi-
dent that if a general subsidence should take place in
the hydrographical basin alluded to, the fall of the
waters between the Rocky Mountains and the ocean
would be lessened, and, consequently, there would be
an increased liability to river inundations in all the
plains and valleys of the same basin. Under these cir-
cumstances, the red ochreous sediment from which the
Red River derives its name would be deposited in the
main and partially in the lateral valleys; and as the

38 NEWER PLIOCENE PERIOD. [Book IV.

course of the Red River is double in length that of
the Rhine, the area covered by red fluviatile silt might
be vast in proportion. It may also be observed that
the number of temporary lakes and marshes, occa-
sioned by frequent overflowings and partial subsidences
of land, would favour greatly the growth of amphibious
mollusks of the genus Succinea; while, at the same
time, land and freshwater shells would annually be
swept away and imbedded in mud, which, like that of
the Nile in Egypt, would be thrown down periodically
on the plains. The thickness of the muddy deposits
would depend on the quantity of time during which
the country continued to sink, provided the rate of
sinking be sufficiently slow to allow of the water being
charged again and again with fresh sediment. The re-
elevation of the district at a subsequent period would
be attended with extensive denudation, or removal of
fine sediment. The colour of the loam might, in this in-
stance, be as uniformly red as it is yéllow in the valley
of the Rhine ; while, in other respects, the phenomena
would be analogous, and such as might appear, at first
sight, to indicate the former existence of an enormous
lake more than 1000 feet deep and several hundred
miles in length.*

Osseous breccias — Sicily. — The breccias latel
found in several caves in Sicily belong evidently to
the period under consideration. I have shown, in the
sixth chapter, that the cavernous limestone of the
Val di Noto is of very modern date, as it contains a
great abundance of fossil shells of recent species ; and

* For particulars concerning the loess of the Rhine, consult
the works of MM. Bronn, Leonhard, Boué, Voltz, Noeggerath,
Steininger, Merian, Rozet, Von Meyer, Hibbert, and Horner.

Ch, XL] BRECCIAS*IN SICILIAN CAVES. 39

if any breccias are found in the caverns of this rock,
they must be of still later origin. : sar
We are informed by M. Hoffmann, that the bones
of the mammoth, and of an extinct species of hippo-
potamus, have been discovered in the stalactite of
caves near Sortino, of which the situation is repre-
sented in the annexed diagram at 6. The same au-

4 ue A xa} containing remains of extinct quadrupeds,
C. Limestone containing remains of recent shells,

thor also describes a breccia, containing the bones of
an extinct rhinoceros and hippopotamus, in a cave in
the neighbourhood of Syracuse, where the country
is composed entirely of the Val di Noto limestone.
Some of the fragments in the breccia are perforated
by lithodomi, and the whole mass is covered by a
deposit of marine clay filled with recent shells. *
These phenomena may, I think, be explained by sup-
Posing such oscillations of level as are known to occur
on maritime coasts where earthquakes prevail — such,
in fact, as have been witnessed on the shores of the
Bay of Baie within the last three centuries. + For
it is evident that the temporary submergence of a
cave filled with osseous breccia might afford time for

* Hoffmann, Archiv fiir Mineralogie, p. 393. Berlin, 1831,

Dr. Christie, Proceedings of Geol. Soc., No, xxiii. p. 333.
T Vol. II. p. 267.

=

ers

40 NEWER PLIOCENE PERIOD. [Book IV.

the perforation of the rock by boring testacea, and
for the deposition upon it of mud, sand, and shells.
The association in these and other localities of
shells of living species with the remains of extinct
mammalia is very distinct, and corroborates the in-
ference adverted to in a former chapter, that the lon-
gevity of species in the mammalia is, upon the whole,
inferior to that of the testacea. I am by no means
inclined to refer this circumstance to the intervention
of man, and his power of extirpating the larger qua-
drupeds ; for the succession of mammiferous species
appears to have been in like manner comparatively

eo Fi Be
OA a ay

EFI

a. Monte Grifone. , b. Cave of San Ciro, *
c. Plain of Palermo, in which are Newer Pliocene strata of
limestone and sand. d. Bay of Palermo.

rapid throughout the older tertiary periods. Their
more limited duration depends, in all probability, on
physiological laws, which render warm-blooded qua-
drupeds less capable, in general, of accommodating
themselves to a great variety of circumstances, and,
consequently, of surviving the vicissitudes to which the
earth’s surface is exposed in a great lapse of ages. +

* Section given by Dr. Christie, Edin. New Phil. Journ.,
No. xxiii., called by mistake the Cave of Mardolce, by the late
M. Hoffmann. See account by Mr. S. P. Pratt, F. G.S., Pro-
ceedings of Geol. Soc. No. 32. 1833.

t See Vol. III. p. 100., and book i. chap, vi.

Ch. XL] BRECCIAS IN SICILIAN CAVES, 4l

Caves near Palermo. — The caves near Palermo
exhibit appearances very analogous to those above
described, and much curious information has been
lately published respecting them. According to Hoff-
mann, the grotto of San Ciro is distant about two
miles from Palermo, and is twenty feet high and ten
wide. It occurs in a secondary limestone, in the
Monte Grifone, at the base of a rocky precipice about
180 feet above the sea. From the foot of this preci-
pice an inclined plane, consisting of horizontal tertiary
strata, of the Newer Pliocene period, extends to the
sea, a distance of about a mile.

The limestone escarpment was evidently once a
sea-cliff, and the ancient beach still remains formed of
pebbles of various rocks, many of which must have
been brought from places far remote. Broken pieces
of coral and shell, especially of oysters and pectens,
are seen intermingled with the pebbles. Immediately
above the level of this beach, serpule are still found
adhering to the face of the rock, and the limestone is
perforated by lithodomi. Within the grotto, also, at
the same level, similar perforations occur; and so
numerous are the holes, that the rock is compared by
Hoffmann to a target pierced by musket balls. But
in order to expose to view these marks of boring-shells
in the interior of the cave, it was necessary first to re-
Move a mass of breccia, which consisted of numerous
fragments of rock and an immense quantity of bones
imbedded in a dark brown calcareous marl. Many of
the bones were rolled as if partially subjected to the
action of the waves. Below this breccia, which is
about twenty feet thick, was found a bed of sand filled
with sea-shells of recent species; and underneath the
and, again, is the secondary limestone of Monte Gri-
fone. The state of the surface of the limestone in the

49 NEWER PLIOCENE PERIOD. [Book IV.

cave above the level of the marine sand is very differ-
ent from that below it. Above, the rock is jagged and -
uneven, as is usual in the roofs and sides of limestone
caverns; below, the surface is smooth and polished, as
if by the attrition of the waves.

So enormous was the quantity of bones, that many
ship-loads were exported in the years 1829 and 1830,
in the hope of their retaining a sufficient quantity of
gelatine to serve for refining sugar; for which, how-
ever, they proved useless. The bones belong chiefly
to the mammoth (E. primigenius), and with them are
those of an hippopotamus, distinct from the recent
species, and smaller than that usually found fossil.
Several species of deer, also, and, according to some
accounts, the remains of a bear, were discovered.

It is easy to explain in what manner the cavern of
San Ciro was in part filled with sea-sand, and how the
surface of the limestone became perforated by litho-
domi; but in what manner, when the elevation of the
rocks and the ancient beach had taken place, was the
superimposed osseous breccia formed? For want of
more exact local details, it would be rash to speculate
on this subject; but by referring to what was previ-
ously said of caverns near the sea-shore of the Morea,
from which rivers escape, the reader may conceive
that caves, after having been submerged and filled
with sea-sand, may afterwards be upraised and flooded
by the waters of engulphed rivers washing down
animal remains from the land.* ‘

Two other caverns are described by Dr. Christie as
occurring in Mount Beliemi, about four miles west of
Palermo, at a higher elevation than that of San Ciro,
being more than three hundred feet above the level of -

* See Vol. III. p. 206.

Ch. XL} AUSTRALIAN CAVE-BRECCIAS. 43

the sea. In one of these places the bones are found
only in a talus at the outside of the cavern; in the
other, they occur both within the cave and in the talus
which slopes from it to the plain below. These caves
appear to be situated much above the highest point
attained by the tertiary deposits in this neighbourhood ;
nor is there the slightest appearance in the caves
themselves of the sea having been there.*

Australian cave-breccias.— Ossiferous breccias have
lately been discovered in fissured and cavernous lime-
stone in Australia, and the remains of the fossil mam-
malia are found to be referable to species now living in
that country, mingled with some relics of extinct animals.
Some of these caves have been examined by Major
Mitchell, in the Wellington Valley, about 210 miles
west of Sydney, on the river Bell, one of the principal
sources of the Macquarie, and on the Macquarie itself.

The fissures and caverns appear to correspond
closely with those which contain similar osseous brec-
cias in Europe; they often branch off in different
directions through the rock, widening and contracting
their dimensions, the roofs and floors being covered
with stalactite. The bones are often broken, but do
not seem to be water-worn. In some caves and fissures
they lie imbedded in loose earth, but usually they are in-
cluded ina breccia, having ared ochreous cement as hard
as limestone, and like that of the Mediterranean caves.

The remains found most abundantly are those of
the kangaroo. Amongst others; those of the Wombat,
Dasyurus, Kaola, and Phalangista, have been recog-
nized. The greater part of them belong to existing,
but some to extinct, species. One of the latter bones,

bel Ss Christie, Jameson, Edin. New Phil. Jour., No. xxiii.
PHL

44: NEWER PLIOCENE PERIOD. [Book IV,

of much greater size than the rest, is supposed, by
Mr. Clift, to belong to an hippopotamus. *

In a collection of these bones sent to Paris, Mr. Pent-
land thought he could recognize a species of Halma-
turus, exceeding in size the largest living kangaroo.

These facts are full of interest, for they prove that
the peculiar type of organization which now character-
izes the marsupial tribes has prevailed from a remote
period in Australia; and that in that continent, as in
Europe, North and South America, and India, some
species of mammalia have become extinct. It also
appears, although the evidence on this point is still
incomplete, that among the extinct were land qua-
drupeds far exceeding in magnitude any of the wild
animals now inhabiting New Holland. t

Newer Pliocene Alluviums.— Some writers have
attempted to introduce into their classification of
geological periods an alluvial epoch, as if the trans-
portation of loose matter from one part of the surface
of the land to another had been the work of one par-
ticular period.

With equal propriety might they have endeavoured _
to institute a volcanic period, or a period of marine
or freshwater deposition; for alluvial formations must
have originated in every age, since the surface of the |
earth was first divided into land and sea, but most
rapidly in any given district at those periods when

* Mr. Clift, Edin. New Phil. Journ., No. xx. p. 394. Major
Mitchell, Proceedings of Geol. Soc., 1831, p. 321.

+ Journ. de Géologie, tome iii. p. 291. The bone mentioned
as that of an elephant by Mr. Pentland, was the same large bone
alluded to by Mr. Clift.

¢ For remarks on the mode in which these caverns may have
been filled with osseous breccias, see Vol. III. p. 203.

Ch, X1] NEWER PLIOCENE ALLUVIUMS. 4

land has been upheaved above, or depressed below,
its former level.* ;

If those geologists who speak of an “alluvial epoch”
intend merely to say that a great part of the Euro-
pean alluviums are tertiary, there may undoubtedly
be much truth in the opinion; for the larger part of
the existing continent of Europe has emerged from
-beneath the waters during some one or other of the
tertiary periods+; and it is probable, that even those
districts which were land before the commencement
of the tertiary epoch, may have shared in the subter-
ranean convulsions by which the levels of adjoining
countries have since been altered. During such sub-
terranean movements new alluviums might be formed
in great abundance, and those of more ancient date so
modified as to retain scarcely any of their original
distinguishing characters.

During the gradual rise of a large area, first from
beneath the waters, and then to a great height above
them, several kinds of superficial gravel must be
formed and transported from one place to another.
When the first islets begin to appear, and the breakers
are foaming upon the new raised reefs, many rocky frag-
ments are torn off and rolled along the bottom of the sea.

Let the reader recall to mind the action of the tides
and currents off the coast of Shetland, where blocks
of granite, gneiss, porphyry, and serpentine, of enor-
mous dimensions, are continually detached from wast-
ing cliffs during storms, and carried in a few hours to
a distance of many hundred yards from the parent
rocks. Suppose the floor of the ocean, after being

* See definition of alluvium, Vol. III, p. 196.

t See map, Vol. I. p. 214,
f See Vol. I. p- 391.

46 NEWER PLIOCENE PERIOD. [Book IV.

thus strewed over with detached blocks and pebbles,
to be converted partially into land, the geologist might
then, perhaps, search in vain for the masses from
which the fragments were originally derived, since part
of these may have been consumed by the waves, and
the rest may remain submerged beneath them.

If this new land be then uplifted to a considerable
height, the marine alluvium before alluded to would
be raised up on the summits of the hills and on the
surface of elevated platforms. It might still constitute
the general covering of the country, being wanting
only in such valleys and ravines as may have been
caused by earthquakes, or excavated by the power of
running water during the rise of the land; for the
alluvium in those more modern valleys would consist
partly of pebbles washed out of the older gravel be-
fore mentioned, but chiefly of fragments derived from
the rocks which were removed during the erosion of
the valleys themselves.

Erratic blocks. — Blocks of extraordinary magnitude
have been observed at the foot of the Alps, and at
a considerable height in some of the valleys of the
Jura, exactly opposite the principal openings by which
great rivers descend from the Alps. These fragments
have been called “ erratic,” and many imaginary causes
have been invented to account for their transport-
ation. Some have talked of chasms opening in the
ground immediately below, and of huge fragments
having been cast out of them from the bowels of the
earth. Others have referred to the deluge, an agent
in which a simple solution is' so often found of every
difficult problem exhibited by alluvial phenomena ;
and more recently, the sudden rise of mountain-chains
has been introduced as a cause which may have given
rise to diluvial waves, capable of devastating whole

Ch. XL] ERRATIC BLOCKS. 4&7

continents, and drifting huge blocks from one part of
the earth’s surface to another.

It seems necessary to suppose that the Jura once

| formed a prolongation -of the Alps, and that large frag-

\ ments of rock were, at a remote period, detached from

\the Alpine summits, and transported to lower hills or
platforms, which were destined afterwards to be up- |
\ Yaised and to form the independent chain now called j
the Jura. Ice, as has been often suggested, may have |

contributed its aid to the transfer of such blocks ;
some of the masses are so enormous,

flood like that in the valley of Bagnes
be supposed to have conveyed them
distances by the power of water alone.

That the Alps must have been moved and shaken
by earthquakes at periods comparatively modern, is
evident from the fact that they are skirted on their
northern, southern, and eastern flanks by marine ter-
tiary strata. When these were raised into their present
Position, to the height of many hundred feet above the

sea, the whole of the older chain must have partici-
pated in the convulsions. i

for
that not even a
» in 1818*, can
to considerable

It is important, therefore, to consider what would
w happen if regions like that of Mont Blanc were

no

subjected to earthquakes.
detached by the action of
` Peaks or « needles,”
fall annually on the
gradually transported
leagues into the vall
farthquake would th
Similar but far heavi
anches of snow and

Large fragments of rock,
rain and frost from the
as they are called, of Chamouni,
surface of the glaciers, and are
by ice to the distance of many
eys below.+ The shock of an
row down a prodigious load of
er masses, accompanied by ava-
ice, by which the moraine of the

* See Vol. I. p. 295. + Vol. I. p. 269.

48 NEWER PLIOCENE PERIOD. [Book IV.

glacier would be greatly enlarged. If the shocks took
place on the eve of a thaw in spring, when the accu-
mulated snows of winter were beginning to melt, they
would cause almost every where immense avalanches,
by which many narrow gorges might be choked up, so
that the valleys above such barriers of snow, ice, and
rock would be converted into lakes. Portions of the
rent glaciers, moreover, would at their lower extre-
mities be covered with water, and might be floated
off together with incumbent and included fragments of
rock. At length, on the bursting of the temporary
barrier, the whole mass of waters, together with huge
rocks buoyed up by ice, would descend with tremen-
dous violence into the lower country.

The manner in which the ice of rivers and of the
sea itself contributes, in the Baltic and other northern
regions, to transport large blocks, as well as smaller
pieces of stone, to vast distances, has been treated of
in a former chapter.

Sicily. — Assuming, then, that almost all the Eu-
ropean alluviums are tertiary, we have next to inquire
which of them are of Newer Pliocene origin. It is
clear that, when a district like the Val di Noto, is
composed of rocks of this age, all the alluvium upon
the surface must necessarily belong either to the
Newer Pliocene or the Recent epoch. If, therefore,
the elevation of the mountains of the Val di Noto was
chiefly accomplished antecedently to the Recent epoch,
we must at once pronounce all alluviums, in the posi-
tion indicated at a, Fig. 114. (p. 38.), to belong to the
Newer Pliocene era. I saw gravel so situated at
Grammichele in Sicily, and was informed that it con-
tained the bones of the mammoth.

* See Vol, I. p. 271.

ane eS

SETENE a ance

CHAPTER XII.

OLDER PLIOCENE FORMATIONS.

Geological monuments of the older Pliocene period — Subapen-
nne formations — Opinions of Brocchi — Different groups
termed by him Subapennine are not all of the same age—
Mineral composition of the Subapennine formations — Marls
— Yellow sand and gravel — Subapennine beds, how formed
(p. 56.) — Illustration derived from the Upper Val d’ Arno —
Organic remains of Subapennine hills — Older Pliocene strata
at the base of the Maritime Alps — Genoa (p. 63.) — Sa-
Vona — Albenga — Nice — Conglomerate of Valley of Mag-
nan — Its origin — Tertiary strata at the eastern extremity of
the Pyrenees.

Subapennine strata. — WE must now carry our re-
trospect one step farther, and treat of the monuments
of the era immediately antecedent to that last con-
Sidered, The Apennines, it is well known, are com-
Posed chiefly of secondary rocks, forming a chain which

ranches off from the Ligurian Alps and passes down
the Middle of the Italian peninsula. At the foot of
these mountains, on the side both of the Adriatic and
ti a Mediterranean, are found a series of tertiary strata
hs ich form, for the most part, a line of low hills occu-
Pying the Space between the older chain and the sea.

rocchi, the first Italian geologist who described this
newer group in detail, gave it the name of the
Subapennines ; and he classed all the tertiary strata of
taly from Piedmont to Calabria, as parts of the same

S E ki
ystem. Certain mineral characters, he observed, were
VOL. Iv. D

50 . OLDER PLIOCENE PERIOD. ' [Book IV.

common to the whole ; for the strata consist generally
of light brown or blue marl, covered by yellow calca-
reous sand and gravel. There are also, he added, some
species of fossil shells which are found in these de-
posits throughout the whole of Italy.

In a catalogue, published by Lamarck, of five hun-
dred species of fossil-shells of the Paris basin, a small
number only were enumerated as identical with those
of Italy, and only twenty as agreeing with living spe-
cies. This result, said Brocchi, is wonderful, and ve y
different from that derived from a comparison of the

fossil-shells of Italy, more than half of which agree with
species now living in the Mediterranean, or in other
seas chiefly of hotter climates. *

He also stated, that it appeared from the observ-
ations of Parkinson, that the clay of London, like that
of the Subapennine hills, was covered by sand (alluding

to the crag), and that in that upper formation of sand
in England the species of shells corresponded much
more closely with those now living in the ocean than
did the species of the subjacent clay. Hence he in-
ferred that an interval of time had separated the origin
of the two groups. But in Italy, he goes on to say,
the shells found in the marl and superincumbent sand
belong entirely to the same group, and must have been
deposited under the same circumstances. +
Notwithstanding the correctness of these views,
Brocchi conceived that the Italian tertiary strata, as a
whole, might agree with those of the basins of Paris
and London; and he endeavoured to explain the dis-
cordance of their fossil contents by remarking, that the

* Conch. Foss. Subap., tom. i. p. 148.
t Ibid., p. 147.

Ch. XIL] SUBAPENNINE STRATA. 5]
testacea of the Mediterranean differ now from those
living in the ocean.* In attempting thus to assimilate
the age of these distinct groups, he was evidently in-
fluenced by his adherence to the anciently received
theory of the gradual fall of the level of the ocean, to
which, and not to the successive rise of the land, he
attributed the emergence of the tertiary strata ; all of
which he consequently imagined to have remained
under water down to a comparatively recent period.
Brocchi was perfectly justified in affirming that there _
Were some species cf shells common to all the strata
Called by him Subapennine; but I have shown that this
fact is not inconsistent with the conclusion, that the
Several deposits may have originated at different pe-
Tiods, for there are species of shells common to all the
tertiary eras. He seems to have been aware, however,
of the insufficiency of his data; for in giving a list of
Species universally distributed throughout Italy, he
candidly admits his inability to determine whether the
shells of Piedmont were all identical with those of
scany, and whether those of the northern and south-
_ 1 extremities of Italy corresponded. +
€ have already satisfactory evidence that the
Subapennine beds of Brocchi belonged, at least, to
three periods. To the Miocene we can refer a portion
of the Strata of Piedmont, those of the hill of the
“perga, for example; to the Older Pliocene belong the
Sreater part of the strata of northern Italy and of
UScany, and perhaps those of Rome; to the Newer
locene, the tufaceous formations of Naples, the cal-
“Areous strata of Otranto, and probably the greater
Part of the tertiary beds of Calabria.

* Conch. Foss. Subap., tom. i, p. 166. T Ibid., p. 143.
D 2

52 OLDER PLIOCENE PERIOD. -[Book IV.

That there is a considerable correspondence in the
arrangement and mineral composition of these different
Italian groups, is undeniable; but not that close re-
semblance which should lead us to assume an exact
identity of age, even had the fossil remains been less
dissimilar.

Very erroneous notions have been etertained re-
specting the contrast between the lithological charac-
ters of the Italian strata and certain groups of higher
antiquity. Dr. MacCulloch has treated of the Italian
tertiary beds under the general title of “ elevated
submarine alluvia;’ and the overlying yellow sand
and gravel may, according to him, be wholly, or in
part, a terrestrial alluvium.* Had he visited Italy, I
am persuaded that he would never have considered the
tertiary strata of London and Paris as belonging to
formations of a different order from the Subapennine
groups, or as being more regularly stratified. He
seems to have been misled by Brocchi’s description,
who contrasts the more crystalline and solid texture of
the older secondary rocks of the Apennines with the
loose and incoherent nature of the Subapennine beds,
which resemble, he says, the mud and sand now de-
posited by the sea.

I have endeavoured, in a former chapter, to restrict
within definite limits the meaning of the term allu-
vium+; but if the Subapennine beds are to be de-
signated “marine alluvia,” the same name might,
with equal propriety, be applied not only to the argil-
laceous and sandy groups of the London and Hamp-
shire basins, but to a very great portion of our se-

* Syst. of Geol., vol. i. chap. xv.
+ Vol. III. p. 196.

Ch. XIL] SUBAPENNINE MARLS. 53
Condary series, where the marls, clays, and sands are
as imperfectly consolidated as are the tertiary strata
of Italy in general.

They who have been inclined to associate the idea
of the more Stony texture of stratified deposits with a
- Comparatively higher antiquity, should consider how
dissimilar, in this respect, are the tertiary groups of
London and Paris, although admitted to be of con-
temporaneous date 3 or they should visit Sicily, and
behold a soft brown marl, identical in mineral cha-
racter with that of the Subapennine beds, underlying
amass of solid and regularly stratified limestone, rival-
ling the chalk of England in thickness.. This Sicilian
marl is older than the superincumbent limestone, but
newer than the Subapennine marl of the north of Italy;
for in the latter the extinct shells rather predominate
Over the recent, in the Sicilian strata the recent spe-
cies predominate almost to the exclusion of the extinct.

Subapennine marls.—I shall now consider more
particularly the characters of those Subapennine beds
which may be referred to the Older Pliocene period.

The most important member of the Subapennine
formation is a marl which varies in colour from grey-
ish brown to blue. It is very aluminous, and usually
Contains much calcareous matter and scales of mica.

t often exhibits no lines of division throughout a
considerable thickness, but in other places it is thinly
aminated. Near Parma, for example, I have counted
thirty distinct laminæ in the thickness of an inch. In
Some of the hills near that city the marl attains,
according to Signor Guidotti, a thickness of nearly
two thousand feet, and is charged throughout with
shells, many of which are such as inhabit a deep sea.
D 3

54 OLDER PLIOCENE PERIOD, [Book IV.

They often occur in layers in such a manner as to
indicate their slow and gradual accumulation. They
are not flattened, but are filled with marl. Beds of
lignite are sometimes interstratified, as at Medesano,
four leagues from Parma; subordinate beds of gypsum
also occur in many places, as at Vigolano and Bar-
gone, in the territory of Parma, where they are inter-
stratified with shelly marl and sand. At Lezignano,
in the Monte Cerio, the sulphate of lime is found in
lenticular crystals, in which unaltered shells are some-
times included. Signor Guidotti, who showed me
specimens of this gypsum, remarked, that the sulphu-
ric acid must have been fully saturated with lime
when the shells were enveloped, so that it could not
act upon the shell. According to Brocchi, the marl
sometimes passes from a soft and pulverulent substance
into a compact limestone, but it is rarely found in
this solid form.* ‘It is also occasionally interstratified
with sandstone.

The marl constitutes very frequently the surface of
the country, having no covering of sand. It is some-
times seen reposing immediately on the Apennine
limestone; more rarely gravel intervenes, as in the
hills of San Quirico.+ Volcanic rocks are here and
there superimposed, as at Radicofani, in Tuscany,
where a hill composed of marl, with some few shells
interspersed, is capped by basalt. Several of the
volcanic tuffs in the same place are so interstratified
with the marls as to show that the eruptions took
place in the sea during the Older Pliocene period. At
Acquapendente, Viterbo, and other places, hills of the
same formation are capped with trachytic lava, and

* Conch. Foss. Subap., tom. i. p. 82. T Ibid., p. 7g,

Ch. XIL] SUBAPENNINE YELLOW SAND. 55

with tuffs which appear evidently to have been sub-
aqueous.

Yellow sand.— The other member of the Sub-
apennine group, the yellow sand and conglomerate,
constitutes, in most of the places where I have seen
it, a border formation near the junction of the tertiary
and secondary rocks. In some cases, as near the town
of Sienna, we see sand and calcareous gravel resting
immediately on the Apennine limestone, without the
intervention of any blue marl. Alternations are there
seen of beds containing fluviatile shells, with others
filled exclusively with marine species ; and I observed
oysters attached to many of the pebbles of limestone.
This appears to have been a point where a river, flow-
ing from the Apennines, entered the sea in which the
tertiary strata were formed.

Between Florence and Poggibonsi, in Tuscany,

there is a great range of conglomerate of the Sub-
apennine beds, which is seen for eleven miles continu-
ously from Casciano to the south of Barberino. The

Pebbles are chiefly of whitish limestone, with some
Sandstone.

On receding from the older Apennine
- rocks, the conglomerate passes into yellow sand and
sandstone, with shells, the whole overlying blue marl.
In such cases we may suppose the deltas of rivers and
torrents to have gained upon the bed of a sea where
blue marl had previously been deposited.
; The upper arenaceous group above described some-
times passes into a calcareous sandstone, as at San
ignone. It contains lapidified shells more frequently
than the marl, owing probably to the more free per-
Colation of mineral waters, which often dissolve and
Carry away the original component elements of fossil
odies, and substitute others in their place. In some
D 4

56 OLDER PLIOCENE PERIOD. [Book IY.

cases the shells imbedded in this group are silicified,
as at San Vitale, near Parma, from whence I saw two
individuals of recent species, one freshwater and the
other marine (Limnea palustris, and Cytherea concen-
trica, Lamk.), both perfectly converted into flint.

On the other hand, the shells of Monte Mario, near
Rome, which are probably referable to the same form-
ation, are changed into calcareous spar, the form being
preserved notwithstanding the crystallization of the
carbonate of lime.

Mode of formation of the Subapennine beds, — The
tertiary strata above described have resulted from the
waste of the secondary rocks which now form the
Apennines, and which had become dry land before the
Older Pliocene beds were deposited. In the territory
of Placentia we have an Opportunity of observing the

kind of sediment which the rivers are now bringing

down from the Apennines. The tertiary marl of that

district being too calcareous to be used for bricks or
pottery, a substitute is obtained by conveying into
tanks the turbid waters of the rivers Braganza, Parma,
Taro, and Enza. In the course of a year a deposit of
brown clay, much resembling some of the Subapennine
marl, is procured, several feet in thickness, divided
into thin laminze of different shades of colour.

In regard to the sand and gravel, we see yellow
sand thrown down by the Tiber near Rome, and by
the Arno, at Florence. The northern part of the
Apennines consists of a grey micaceous sandstone
with dn argillaceous base, alternating with shale, from
the degradation of which brown clay and sand would
result. If a river flow through such strata, and some
one of its tributaries drains the ordinary limestone of
the Apennines, the clay might become marly by the

Ch. XIL] SUBAPENNINE STRATA, HOW FORMED. 57

intermixture of calcareous matter. The sand is fre-
quently yellow from being stained by oxide of iron;
but this colour is by no means constant.

The similarity in composition of the tertiary strata
in the basins of the Po, the Arno, and the Tiber, is
merely such as might be expected to arise from their
having been all derived from the disintegration of the
Same continuous chain of secondary rocks. But it
does not follow that the latter rocks were all upheaved
and exposed to degradation at the same time. The
Correspondence of the tertiary groups consists in their
being all alike composed of marl, clay, and sand; but
we might say as much of the beds of the London and
Hampshire basins, although the English and Italian
groups, thus compared, belong nearly to the two
opposite extremes of the tertiary series.

The similarity in mineral character of the lacustrine
deposit of the Upper Val d’ Arno, and the marine
Subapennine hills of northern Italy, ought to serve as
a caution to the geologist, not to infer too hastily a
Contemporaneous origin from identity of mineral com-
Position. The deposit of the Upper Val d’ Arno oc-
curs nearly at the bottom of a deep narrow valley,
Which is surrounded by precipitous rocks of secondary
Sandstone and shale (the macigno of the Italians, and
Steywacké of the Germans). Hills of yellow sand, of
Considerable thickness, appear around the margin of
the small basin; while, towards the central parts,
Where there has been considerable denudation, and
Where the Arno flows, blue clay is seen underlying
the yellow sand. The shells are of freshwater origin,
but I shall speak more particularly of them when dis-
cussing the probable age of this formation in the six-
teenth chapter. I desire at present to call attention

D5

See

58 OLDER PLIOCENE PERIOD,

[Book vz

to the fact, that we have here, in an isolated basin,
such a formation as would result from the waste of the
contiguous secondary rocks -of the Apennines, frag-
ments of which rocks are found in the sand and con-
glomerate. We might expect that, if the freshwater
beds were removed, and the barrier of the lake-basin
closed up again, similar sediment would be again de-
posited; since the aqueous agents would operate in
the same manner, at whatever period they might be in
activity. Now, the only difference in mineral compo-
sition, between the lacustrine deposit and the ordinary
marine Subapennine strata, consists in the absence of
calcareous matter from the clay; and this may be
ascribed to the circumstance that the torrents flowing
into the lake had passed over no limestone rocks.

The lithological character of the Subapennine beds
varies in different parts of the Peninsula both in colour
and degree of solidity. The presence, also, or ab-
sence of lignite and gypsum, and the association or
non-association of volcanic rocks, are causes of great
local discrepancy. The superposition of the sand and
conglomerate to the marl, on the other hand, is a
general point of agreement, although there are ex-
ceptions to the rule, as at San Quirico before men-
tioned. The cause of this arrangement may be, as I
before hinted, that- the arenaceous groups were first
formed on the coast where rivers entered; and when
these pushed their deltas farther out, they threw
down the sand upon part of the bed of the sea already
occupied by finer and more transportable mud.

Captain Bayfield, in his Survey of the Coast of
St. Lawrence, mentions horizontal strata of sand and
gravel, and a subjacent deposit of clay, as reposing in
depressions in the older rocks near the shore. The

TEGT (9A. VOLS? WLY Lad 14 PAYS IMT Upu T

LEF

UDA UDT “WyP]OII

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DIANA) PI Tj PT

MUAS | UNUTING, U IOA OPORO QULOQOLMMAZT OTTE UNIIUSLAL AUTUN G E
Mog SNAS PAT o SOSS OROL pympedyna = WULOZOLMATT `L T j MOT OOV SOL OQUI] 9
gT UNO BINADA UTIADJOS GAT OI SUOR P ETET SNSOBNA OQAMJ ZT

OL id

UL

Ch. XIIL] ORGANIC REMAINS OF SUBAPENNINES. 59

clay invariably occupies the lowest position, and the
gravel the highest; and this arrangement, he says,
may be explained by considering that the rivers where
they now bring down alluvial matter on several parts
of this coast, carry gravel over a bottom previously
occupied by clay, the finer sediment having first been
drifted farther from the shore.*

When Captain Bayfield proposed this theory, he had
not seen my work; and it was satisfactory to observe
the exact coincidence of his views with my own,
his having been suggested by the modern changes
going on in the St. Lawrence, mine by reasoning on
appearances in the interior of Italy.

Organic remains. — Figures of some of the most
abundant shells of the Subapennine formations are
given in the accompanying plate. (Pl. X.) The greater
Part of them are common both to the Older and Newer
Pliocene periods of this work. Eight of the species,
Nos. 1, 3, 5, 6, 7, 9, 13, and 14, are now living, but
are also common in the older Pliocene formations.
Fusus crispus has not been found either recent, or in
the Miocene or Eocene formations, but occurs both in
; the Older and Newer Pliocene formations. Mitra
E aa ias hoan- abserved only in the Older Pliocene
deposits. The Turbo rugosus was formerly considered
aS exclusively Pliocene; but M. Boué has since found
= ın the Miocene strata at Vienna and Moravia. Buc-
“inum semistriatum is also a Miocene shell, but has

fen inserted as being peculiarly abundant in the
liocene Strata.

The Subapennine testacea are referable to species

: :
Att abstract of this paper will be found in the Proceedings
of the Geol, Soc., No. 33. p. 4.
pd 6

60 OLDER PLIOCENE PERIOD, [Book Iv.

and families of which the habits are extremely diver-
sified, some living in deep, others in shallow water,
some in rivers or at their mouths. I have seen a
specimen of a freshwater univalve (Limnea palustris),
taken from the blue marl near Parma, full of small
marine shells. It may have been floated down by the
same causes which carried wood and leaves into the
ancient sea.

I have been informed, by experienced collectors of
the Subapennine fossils, that they invariably procure
the greatest number in those winters when the rains
are most abundant; an annual crop, as it were, being
washed out of the soil to replace those which the
action of moisture, frost, and the rays of the sun soon
reduce to dust upon the surface.

The shells, in general, are soft when first taken from
the marl, but they become hard when dried. The
superficial enamel is often well preserved, and many
shells retain their pearly lustre, and part of their ex.
ternal colour, and even the ligament which unites the
valves. No shells are more usually perfect than the
microscopic, which abound near Sienna, where more
than a thouand full-grown individuals are sometimes
poured out of the interior of a single univalve of mo-
derate dimensions. In some large tracts of yellow
sand it is impossible to detect a single fossil, while in
other places they occur in profusion.

Blocks of Apennine limestone are found in this
formation drilled by lithodomous shells. The remains
not only of testacea and corals, but of fishes and crabs,
are met with, as also those of cetacea, and even of
terrestrial quadrupeds.

A considerable list of the mammiferous species has
been given by Brocchi and some other writers ; and,

h.XIL] STRATA AT BASE OF MARITIME ALPS. 61
although several mistakes have been made, and some
bones of cetacea have been confounded with those of
land animals, it is still indubitable that some remains of
land animals were carried down into the sea when the
Subapennine sand and marl were accumulated. The
Same causes which drifted skeletons into lakes, such as
that of the Upper Val d'Arno, may have carried down
others into firths or bays of the sea. The femur of an
elephant has been disinterred with oysters attached to

it, showing that it remained for some time exposed
after it was drifted into the sea.

Strata at the base of the Maritime Alps. —If we pass
from the Italian peninsula, and, following the borders
of the Mediterranean, examine the tertiary strata at
the foot bf the Maritime Alps, we find formations
agreeing in zoological characters with the Subapennine
beds, and presenting many points of analogy in their
mineral composition. The Alps, it is well known, ter-
minate abruptly in the sea, between Genoa and Nice,
and the steep declivities of that bold coast are con-
tinued below the waters; so that a depth of many
hundred fathoms is often found within stone’s-throw of
the beach. Exceptions occur only where streams and
torrents enter the sea; and at these points there is
always a low level tract, intervening between the
mouth of the stream and the precipitous escarpment
of the mountains.

In travelling from France to Genoa, by the new
Coast road, we are conveyed principally along a ledge
excavated out of a steep slope or precipice, in the
Same manner as on the roads which traverse the great
interior passes of the Alps, such as the Simplon and
Mont Cenis ; the difference being that, in this case, the
traveller has always the sea below him, instead of a

62 OLDER PLIOCENE PERIOD. [Book IV,

river. But we are obliged occasionally to descend by
a zigzag course into those low plains before alluded to,
which, when viewed from above, have the appearance
of bays deserted by the sea. They are surrounded on
three sides by rocky eminences, and the fourth is open
to the sea.

These leading features in the physical geography of
the country are intimately connected with its geological
structure. ‘The rocks composing the Alpine declivities
belong partly to the primary formations, but more
generally to the secondary, and have undergone im-
mense disturbance; but when we examine the low
tracts before mentioned, we find the surface covered
with great beds of gravel and sand, such as are now
annually brought down by torrents and streams in the
winter, and which are spread in such quantity over the
wide and shifting river-channels as to render the roads
for a season impassable. The first idea which naturally
suggests itself, on viewing these plains, is to imagine
them to be deltas or spaces converted into land by the
accumulated sand and gravel brought down from the
Alps by rivers. But, on closer inspection we find that
the apparent lowness of the plains, which at first glance .
might be supposed to be only just raised above the
level of the sea, is a deception produced by contrast.
The Alps rise suddenly to the height of several thou-
sand feet with a bold and precipitous outline ; while
the country below is composed of horizontal strata,
which have either, a flat or gently undulating surface,
The strata consist of gravel, sand, and marl, filled
with marine shells, and they are considerably elevated,
attaining sometimes the height of two hundred feet,
or even more, above the level of the sea; there must,
therefore, have been a rise of the coast since they were

Ch. XIL] TERTIARY STRATA AT GENOA. ` 63
deposited, and they are not mere deltas or spaces re-
claimed from the sea by rivers. Why, then, are such
‘Strata found only at the points where rivers enter ?
We must imagine that, after the coast had nearly
acquired its present configuration, the streams which
flowed down into the Mediterranean produced shoals
opposite their mouths by the continual drifting in of
gravel, sand, and mud. The Alps have since been
raised to a sufficient height to cause these shoals to
become land; while the corresponding elevation of the
intervening parts of the coast, where the sea was of
` great depth near the shore, has not been perceptible.
The disturbing force appears to have acted very
irregularly, and to have produced the least elevation
towards the eastern extremity of the Maritime Alps,
and a greater amount as we proceed westward. Thus a
we find the marine tertiary strata attaining the height | |
of about 100 feet at Genoa, 200 and 300 feet farther | \

westward at Albenga, and 800 or 900 feet in the \

neighbourhood of Nice.

renoa.__ At Genoa the tertiary strata consist of

Monte Fi ETO.
@’ Origina.- 8

SS NSS
NS

TAN
KN

:

/
trae k
a., /X b

[3 i
fe A E E

#

Position of tertiary strata. at Genoa.
@ Ancient sea-beach. b. Blue marl with shells,
C. Inclined secondary strata of sandstone, shale, &c.

Ee SAO —

64 ' OLDER PLIOCENE PERIOD. [Book IV,

blue marls like those of the northern Subapennines
and contain the same shells. On the immediate site
of the town they rise to the height of only twenty feet
above the sea; but they reach about eighty feet in
some parts of the suburbs. At the base of a moun-
tain not far from the suburbs there is an ancient beach,
strewed with rounded blocks of Alpine rocks, some of
which are drilled by the Modiola lithophaga, Lamk.,
the whole cemented into a conglomerate, which
marks the ancient sea-beach at the height of 100 feet
above the present sea. *

Savona. — At Savona, proceeding westwards, we
find deposits of blue marl like those of Genoa, and
occupying a corresponding geological position at the
base of the mountains near the sea. The shells, col-
lected from these marls by Mr. Murchison and myself,
in 1828, were examined by Signor Bonelli, of Turin,
and found to agree with Subapennine fossils.

Albenga. — At Albenga these formations occupy a
more extensive tract, forming the plains around that
town and the low hills of the neighbourhood, which
reach in some spots an elevation of 300 feet. The
encircling mountains recalled to my mind those which
bound the plain and bay of Palermo, and other bays
of the Mediterranean, which are surrounded by bold
rocky coasts. ;

The general resemblance of the Albenga strata to
the Subapennine beds is very striking; the lowest
division consisting of blue marl which is covered by
sand and yellow clay, and the highest by a mass of
stratified shingle, sometimes consolidated into a con-

* I have here to acknowledge my obligations to Professor
Viviani, and Dr. Sasso, who called my attention to these phe-
nomena when I visited Genoa in Jan. 1829.

Ch. XIL] TERTIARY STRATA AT NICE. 65
glomerate. Dr. Sasso has collected about 200 species
of shells from these beds ; and it appears, by his cata-
logue, that they agree, for the most part, with the
northern Subapennine fossils, more than half of them
belonging to recent species. *

Nice. — At Nice the tertiary strata are upraised to
4 much greater height, but they may still be said to
lie at the base of the Alps which tower above them.
Here, also, they consist principally of blue marl and
yellow sand, which appear to have been deposited in
Submarine valleys previously existing in the inclined
secondary strata. In one district, a few miles to the
West of Nice, the tertiary beds are almost exclusively
composed of conglomerate, from the point of their
junction with the secondary strata to the sea.

The river Magnan flows in a deep valley, which ter-

Minates at its upper extremity in a narrow ravine.
early vertical precipices are laid open on each side,
varying from 200 to 600 feet in height, and composed

of inclined beds of shingle, sometimes separated by

layers of sand, and more rarely by blue micaceous
marl. The pebbles in these stratified shingles agree
“Composition with those now brought down from the
Alps by the Var and other rivers on this coast.

The dip of these strata is remarkably uniform, being
always southwards, or towards the Mediterranean, at
a angle of about 25°. I examined this section in
company with Mr. Murchison in the summer of 1828,
When the bed of the river was dried up. The geolo-
Sist has then a good opportunity of examining a sec-
tion of the strata, as the channel crosses for many
miles the line of bearing of the beds, which may be

* Giornale Ligustico, Genoa, 1827.

66 OLDER PLIOCENE PERIOw. [Book IV.

traced to the base of Monte Calvo, a distance of about
nine miles in a straight line from the Mediterranean.
It is usually impossible to determine the exact age of
such accumulations of sand and gravel, in consequence
of the total absence of organic remains. Their non-
existence may depend chiefly on the disturbed state of
the waters, where great beds of shingle are formed,
which are known to prevent testacea and fishes from
living in Alpine torrents; partly on the total destruction
of shells by the same friction which rounded the peb-
bles; and partly on the permeability of the matrix to
water, which may carry away the elements of the de-
composing fossil body, without substituting any other
substance in their place which might retain a cast of
their form.

But it fortunately happens, in this instance, that in
some few seams of loamy marl, intervening between
the pebble-beds, and near the middle of the section,
shells have been preserved in a very perfect state;
and these may furnish a zoological date to the whole
mass. The principal of these interstratified masses of
loam occurs near the church of St. Madeleine (at ¢,
diagram No. 117.), where the active researches of M.
Risso have brought to light a great number of shells
which agree perfectly with the species found in much
greater abundance at a spot called La Trinita, and
some other places nearer Nice. From these fossils it
clearly appears that the formation belongs to the Older
Pliocene era.

Such alternations of gravel with the usual thin
layers of fine sediment may easily be explained, if we
reflect that the rivers now flowing from the Maritime
Alps are nearly dried up in summer, and have only
strength to drift along fine mud to the sea; whereas

Ch, XIL] TERTIARY STRATA AT NICE. or
in winter, or on the melting of the snow, they roll
along large quantities of pebbles. The thicker masses
of loam, such as that of St. Madeleine, may have been
Produced during a longer interval, when the river
shifted for a time the direction of its principal channel
of discharge ; so that nothing but fine mud was for a
Series of years conveyed to that point in the bed of
the sea opposite the delta. |

Monte Calvo,

Fig. 117.

Section from Monte Calvo to the sea by the valley of Magnan, near Nice.

A. Dolomite and sandstone. (Green-sand formation ?)
a, b, d. Beds of gravel and sand.
c. Fine marl and sand of St. Madeleine.

Uniform and continuous as the strata appear ponia
general view, in the ravine of the Magnan, we discover,
if we attempt to trace any one of them for some dis-
tance, that they thin out and are wedge-shaped. We

elieve that they were thrown down originally upon a
Steep slanting bank or talus, which advanced gradually
rom the base of Monte Calvo to the sea. The dis-
tance between these points is, as before mentioned,
about nine miles; so that the accumulation of super-
imposed strata would be a great many miles in thick-

MBSE, LE they were placed horizontally upon one another.

68 OLDER PLIOCENE PERIOD. [Book IV.

The strata nearest to Monte Calvo, which may be ex-
pressed by 4, are certainly older than those at b, and
the group b was formed before e. The aggregate thick-
ness, in any one place, cannot be proved to amount to
1000 feet, although it may, perhaps, be much greater.
But it may never exceed 3000 or 4000 feet ; whereas,
if we did not suppose that the beds were originally
deposited in an inclined position, we should be forced
to imagine that a sea, many miles in depth, had been
filled up by horizontal strata of pebbles thrown down
one upon another.

At no great distance on this coast the Var is an-
nually seen to sweep down into the sea a large quan-
tity of gravel, which may be spread out by the waves
and currents over a considerable space. ‘The sea at
the mouth of this river is now shallow, but it may
originally have been 3000 feet deep, as it is now close
to the shore at Nice. Here, therefore, a formation
resembling that of the Magnan above described may
be in progress.

In confirmation of the above reasoning,
to the modern delta of the river Kander in the lake
of Thun in Switzerland. The Kander formerly ran
parallel to that lake, until it was artificially turned
into it about the year 1713, when the government of
Berne caused two parallel subterranean galleries or
tunnels to be excavated through the land which separ-
ated the course.of the river from the lake; a distance
of nearly a mile. The Kander, on being admitted,
shot with the violence of a Swiss torrent through the
tunnels, burst the arches of the galleries, and formed
a ravine, which is now open to the day, about fifty
feet in depth. A large quantity of mud and rock was
swept into the lake, and an alluvial tract was formed

I may refer

Ch XIL] TERTIARY STRATA OF THE PYRENEES. 69

of a semicircular shape, which now extends for a mile
along the original shore, and projects about a quarter
of that distance into the lake. Its annual advance is
Said to amount to several. yards*, and the delta ter-
minates in a talus, the slope of which is inclined at
angles varying between 15° and 25°. Such was
the result of my own observations, in 1836, when I
Sounded the lake opposite the mouth of the Kander.
© greatest inclination which I found gave an angle
of 29°, the least 6°.t It follows, therefore, that the
Strata have successively accumulated on a plane thus `
highly inclined; so that, if the Lake of Thun, which
is 600 feet deep}, beyond the recently formed shoal,
Were drained, a vertical section might be laid open,
00 feet in height, in which strata would be seen
‘aving a considerable dip like those of the Magnan,
although they had remained undisturbed from the
Period of their original deposition.
ertiary Strata at the eastern extremity of the
Yrenees, I shall conclude this chapter with one
More example, derived from a region not far distant.
n the borders of the Mediterranean, at the eastern
extremity of the Pyrenees, in the south of France, a
considerable thickness of tertiary strata is seen in the
Valleys of the rivers Tech, Tet, and Gly. They bear
much resemblance to those already described, consist-
™ partly of a large proportion of conglomerate, and

* Rev. J. Yates, on Alluvium, Edin. New Phil. Journ. 1834.
t Lord Cole and the Rev. Mr. Egerton measured the dip in

1833, and concluded that it was still more considerable (Pro-

ceedings of Geol . Soc. 1834.) ; but they tell me that they had not
Sufficient time or implements to insure accuracy in their sound-
ings,

¢ Mr. Yates, ibid.

70 OLDER PLIOCENE PERIOD. : [Book IV.

partly of clay and sand, with subordinate beds of
lignite. They abut against the primary formation of
the Pyrenees, which here consists of mica-schist.
Between Ceret and Boulon these tertiary strata are
seen inclined at an angle of between 20° and 30°.
The shells which I procured from several localities
were recognized by M. Deshayes as agreeing with
Subapennine fossils.

Spain — Morea. — It appears, from the recent ob-
servations of Colonel Silvertop, that marine strata of
the Older Pliocene period occur in patches at Malaga,
and in Granada in Spain. They have also been dis-
covered by MM. Boblaye and Virlet in the Morea.

CHAPTER XIII.

OLDER PLIOCENE FORMATIONS — CRAG.

Crag of Norfolk and Suffolk — Appears by its fossil contents to
belong to the Older Pliocene period. — Divisible into coralline
and red crag. — Superincumbent deposits — Forms of stratifi-
Cation (p. 78.) — Oblique layers— Cause of this arrangement—

islocations in the strata produced by subterranean movements
°verlaying the shelly crag— Protruded masses of chalk (p. 85.)
~ Similar appearances in the cliffs of Moen in Denmark.

Tur Older Pliocene strata, described in the last chap-
ter, are all situated in countries bordering the Medi-
‘erranean; but there is a group in our own island,
Probably belonging to the same era, which I shall now
Consider. I have already alluded to this deposit under
the provincial name of crag *, and pointed out its
Superposition to the London clay, a tertiary formation
of much higher antiquity.+ The crag is chiefly de-
veloped in the eastern parts of Norfolk and Suffolk,
from whence it extends into Essex.

lis relative age.— A collection of the shells of the
“crag” beds, which I formed in 1829, together with
à much larger number sent me by my friend Mr.
Mantell, of Brighton, were carefully examined by M.
Deshayes, and compared with the tertiary species in
lis cabinet. More than half of these were considered
by him to be of extinct species, not agreeing in general
with the fossils of Touraine or other Miocene deposits.
The remainder were of recent species, and considered

* Vol. III. p. 336. + See Fig. 84. Vol. III. p. 338,

Je OLDER PLIOCENE PERIOD. [Book IV.

to be identical with testacea now living in the German
Ocean. For these reasons it was inferred that the
crag was older than the Miocene period, and about as
far removed in conchological character from the shells
of our seas, as are the Subapennine strata from the
shells now inhabiting the Mediterranean. Out of 111
species examined in Paris in 1829, sixty-six were re-
garded as extinct, and forty-five as recent*; and when
I lately submitted to the inspection of M. Deshayes
sixty other species, procured from the lowest or coral-
line crag, he still retained the same opinion in regard
to the proportion of recent species. A larger number,
however, of organic remains has of late years been
obtained from the crag, principally by Mr. Wood of
Hasketon, in Suffolk, who states that he has in his col-
lection, exclusive of Polypi, Radiaria, and Crustacea,
no less than 450 species of invertebrated animals from
the crag, among which there are of annulata 13, cirrhi-
peda 11, conchifera 189, mollusca 257.

But these fossils have not yet been examined with
sufficient attention to enable me to say, whether the
results to which they lead should modify the conclu-
sions previously deduced from more limited data.+

* M. Deshayes is now aware that he was mistaken in supposing
one of these crag fossils, Voluta Lamberti, to be identical with a
recent species.

+ Dr. Beck, of Copenhagen, well known for his profound
knowledge of recent shells, has lately seen 260 species of crag
shells in Mr. Charlesworth’s cabinet in London, and informs me,
that although a large proportion of the species approach very
near to others which now live in our northern seas, he regards
them as almost all of distinct species, and not recent. T attribute
this discordance of opinion between the Danish naturalist and
M. Deshayes, chiefly to the different estimate which they have
formed of the amount of variation necessary to constitute a dis-

Ch, XIIL] CRAG OF ENGLAND. 73

From the labours of Mr. Charlesworth, it appears
that the crag may be divided into two distinct masses,
one of which may be termed the lower or “ coralline
crag,” and the other the “red crag.” The lower
division iş composed of calcareous sand, chiefly derived
from decomposed corals, in which are imbedded shells,
Corals, and Sponges, in a good state of preservation,
and which must evidently have lived on the spot.

This coralline formation is often without distinct
Stratification, and in some places forms a soft stone
Used in building: it is said to attain a thickness of
More than 50 feet at Orford, and was not pierced
through even at that depth. The coralline crag rests
immediately on the London clay, and may be studied
at several places in Suffolk, as at Tattingstone, Rams-
holt, Sudburn Park, Orford, and Aldborough.

The red crag is distinguished from the coralline,
upon which it lies in some places unconformably, by
the deep red ferruginous or ochreous colour of its sands
and fossils. It consists in great part of numerous
layers of siliceous sand containing shells, which are
usually broken and worn. Among these are many of

l i

è

tinct Species. It seems natural that those who, like M. Deshayes,

have been long engaged in the study of fossils, should acquire a

More enlarged conception of the modifications which time and
Circumstances may produce in species, even though they reject
the Lamarckian doctrine of transmutation. This subject, how-
ever, requires a thorough re-examination, as respects the crag
fossils, Mr. Milne Edwards tells me that he has seen a small
humber of corals or polypifera from the crag, none of which are,
in his Opinion, recent. On the other hand, Dr. Fleming, as I
Mentioned in a former edition, considers the Eschara retiformis,
and several other zoophytes of this formation, as perfectly a
with living species. Both M. Deshayes and Dr. Beck agree in
Pronouncing the crag shells to be those of a northern climate.
VOL. IV. E

Ay OLDER PLIOCENE PERIOD. [Book 1V.

the genera Buccinum and Fusus, which have never
been met with in the coralline crag.

Some haye imagined the red crag to consist in
great measure of transported materials derived from
the breaking up of the coralline crag; but I can fully
confirm the observation of Mr. R. E. Taylor and others,
that this deposit has been gradually formed, as may be
inferred from stratification, and from the fact of certain
shells occurring at intervals in groups and genera, and
being by no means diffused everywhere, nor scat-
tered at random, through the beds.

Another question has also arisen respecting the
coralline and the red crag, namely, whether both of
them belong to the same tertiary period. Of the
fossil shells in Mr. Wood’s collection, 235 species are
said to have been procured from the red crag, and 353
from the coralline beds, and out of these 150 species
are common to the two divisions. Mr. Charlesworth
suggests that, even of these 150 species, many may
have belonged originally to the lower bed, and have
been washed into the newer one, in the same manner
as some fossil shells of the chalk have certainly been
imbedded in the crag, and as crag shells are now daily
washed into the sea on our coast, and mixed with re-
cent shells. But, although such accidental mixtures
have doubtless occurred, I see no sufficient reason at
present for believing that the two divisions of the crag
should be referred to distinct tertiary periods. It is
not disputed that many fossils are truly common to
both divisions of the crag, and equally abundant in
each. The remarkable want of correspondence in
the genera of shells, and even in some other classes
and families of organic remains, characteristic of each
division, affords by no means a strong argument in

Ch SURI + . CRAG OF ENGLAND, 75

favour of a wide difference in epoch. It is said that
there are few indications of fish in the coralline crag ;
Whereas in the red crag, the teeth and bones of fish of
the genera Carcharias, Myliobates, Galeus, Lamna,
Notidanus, and Platax, are found abundantly. So also
it is remarked that mammalian remains, as those of
the Elephant, Horse, and others, are chiefly confined
to the upper or red crag, whereas corallines and other
200phytes, as also microscopic foraminifera (of which

r. Wood has obtained fifty species), belong almost
exclusively to the lower or coralline division. *

Now these distinctions are precisely of a kind which
Would depend on differences of a local rather than a
chronological nature. Thus in one part of the sea
Wwe may suppose a region, where the water is deep
and tranquil, to be favourable to the growth of corals,
Sponges, echini and microscopic cephalopods, such as
Characterize the lower crag; whilst in another and
Somewhat shallower region, where currents prevailed,
and to which sand and shingle were often drifted, no
20ophytes might exist, although certain kinds of tes-
tacea abounded. According to this hypothesis, a cer-
tain Space where the coralline crag was first formed
might afterwards have been converted into a shallower
S€a, or exposed to the action of waves and currents,
So as to become the receptacle of deposits like the red
Crag,

It is only when we can compare fossils of the same
e ass, as shells with shells, corals with corals, and fish
With fish, and when we find that a large proportion of
the species thus compared are dissimilar, that we can
refer two groups of strata to different periods.

ji Charlesworth, Phil. Mag., June, 1836, vol, viii. P. 535,
E 2

"6 OLDER PLIOCENE PERIOD. [Book IV.

There may nevertheless have been a long interval
of time, and some amount of change in the marine
fauna, between the times of the deposition of the lower
and upper crag ; for when we adopt only four tertiary
periods, as proposed in this work, the number of ages
probably comprised in any one of them, as for instance
in the Older Pliocene, may be indefinitely great.

The shelly beds of Norfolk appear to belong exclu-
sively to the red crag; but on the northern limits of
that county they are said to be occasionally covered
by astill newer stratum, containing exclusively species
now living in the adjoining sea. This is doubtless the
marine formation described by Mr. Phillips as occur-
ing throughout Holderness, in Yorkshire.* Accord-
ing to this view, the succession of tertiary formations,
in following our eastern coast from the estuary of
the Thames to that of the Humber, will be, first, in
Essex, the Eocene or London clay ; secondly, in
Suffolk, the coralline crag, probably belonging to the
Older Pliocene period; next, the red crag of Suffolk
and Norfolk, also of the same era; and lastly, on the
extreme northern boundary of Norfolk and in Holder-
ness, a marine Newer Pliocene deposit.

Superimposed upon the fossiliferous crag in the
cliffs of Norfolk and Suffolk, is a formation of much
greater thickness, and of more uncertain age. It has
been sometimes classed with the crag and sometimes
distinguished from it under the name of diluvium. A
large portion of it is regularly stratified, but other
parts consist of a confused heap of mud and rubbish
entirely without stratification, and containing frag-
ments of various rocks, some derived from the oolitic

* See Phillips’s Geol. of Yorksh.

Ch. XIIL], CRAG OF ENGLAND. 7

Series with their characteristic fossils, others from the
chalk and London clay, together with granitic and
other pebbles transported from a great distance. In
Some places this formation consists of sand and shingle
in alternate beds destitute of organic remains, and
of considerable thickness, as in the Suffolk cliffs be-
tween Dunwich and Yarmouth. Elsewhere it is com-
Posed of blue or brown marl, sand, loam, and clay, con-
taining bones of terrestrial quadrupeds with drift wood
and beds of lignite. |

Above this deposit of uncertain age, are occasional
patches of lacustrine strata, filling up small cavities
Which must have once been lakes or ponds on the sur-
face of the country, and in which strata of loam and peat
accumulated, including recent freshwater testacea.

The annexed section may give a general idea of

Fig, 118.

@ Chalk, b. Shelly crag and overlying strata of uncertain age.
c. Lacustrine deposit (newer pliocene).
D. Trimmingham beacon.
E. Interior and higher part of Norfolk.*

the manner in which the crag and the superimposed
Sravel, sand, and marl rest on the chalk as we pass from
the Norfolk cliffs, at Trimmingham, into the interior,
Where the country rises gradually.

The outline of the surface of the subjacent chalk,
in this section, is imaginary, but is such as might ex-

* This section is compiled principally from one by Mr. Mur-
chison ; the others in this chapter are from sketches which I
made in 1899,

E 3

78 OLDER PLIOCENE PERIOD, » [Book IV.

plain the relations of those protruded masses of chalk,
three of which appear in the cliffs near Trimmingham,
and which some geologists have too hastily assumed to
be unconnected with the great mass of chalk below.
I shall treat of these presently, when describing the
disturbances which the tertiary strata of the Norfolk
cliffs have suffered since their original deposition.

In the interior, at x, there is a thick covering of
sand and gravel upon the chalk, having the characters
of an alluvium, but which seems to pass gradually into
the regular strata of sand, shingle, and loam before
described as covering the shelly crag.

Forms of stratification. — In almost every formation
the individual strata are rarely persistent for a great
distance, the superior and inferior planes being seldom
precisely parallel to each other; and if the materials
are very coarse, the beds often thin out if we trace
them for a few hundred yards. There are also many
cases where all the layers are oblique to the general
direction of the strata, and the crag affords most in-
teresting illustrations of this phenomenon.

In the sea-cliff near Walton, in Suffolk, opposite the
Martello Tower, called R, the section represented in
the annexed diagram is seen. The vertical height is
about twenty feet, and the beds of crag consist alter-
nately of sets of inclined and horizontal layers of sand

Fig. 119.

Section of shelly crag near Walton, Suffolk.

Ch. XIIL] CRAG OF ENGLAND. 79

and comminuted shells. The sand is siliceous, and of
a ferruginous colour; but the layers are sometimes
made up of small plates of bivalve shells, arranged with
their flat sides parallel to the plane of each layer, like
mica in micaceous sandstones. |

The number of Jaminz in the thickness of an inch,
both in the siliceous and shelly sand, varies from
Seven to ten, so that it is impossible to express them
all in the diagram. The height of the uppermost
Stratum is, in this instance, remarkable, as it extends
to twelve feet. The inclination of the laminz is about
30°; but in the cliffs of Bawdesey, to the eastward,
they are sometimes inclined at an angle of 45°, and

€ven more.

" Section at the lighthouse near Happisborough. Height sixteen feet.
a. Pebbles of chalk flint, and of rolled pieces of white chalk. —
_ 6, Loam overlying a. c, c. Blue and brown clay.

This diagonal arrangement of the layers, sometimes
Called « ‘false stratification,” is not confined to deposits
of fine sand and comminuted shells; for we find beds
of shingle disposed in the same manner, as is seen in
the annexed section (Fig. 120.).

The direction of the dip of the inclined layers,
throughout the Suffolk coast, is so uniformly to the
South, that I only saw two or three instances of a con-
trary nature, where the inclination was northerly. One
of the best examples of this variation is exhibited
in a cliff between Mismer and Dunwich (Fig. 121.).

E 4

80 OLDER PLIOCENE PERIOD. | [Book IV.

In this case, there are about six layers in the thick-

ness of an inch, and the part of the cliff represented is
about six feet high.

Fig. 121.

SES

Section of part of Little Cat cliff, composed of quartxose sand, showing the
inclination of the layers in opposite directions.

Another example may be seen near Walton, where
the layers, which are of extreme tenuity, consist of
ferruginous sand, brown loam, and comminuted shells. :
It is not uncommon to find in this manner sets of per-
fectly horizontal strata resting upon and covered by
groups of wavy and transverse layers.

Fig. 122.

=

Lamination of shelly sand and loam, near the Signal-house, Walton.
Vertical height four Sect,

The appearances exhibited in the diagrams are not
peculiar to the crag: they may be found in almost
every gravel-pit; and I have seen sand and pebble-
beds of all ages, including the old red sandstone, grey-
wacké, and clay-slate, exhibit the same arrangement.

If we now inquire into the causes of such a disposi-
tion of the materials of each bed or group of layers, it
may, in the first place, be remarked, that, however

Ch. XIIL] CRAG OF ENGLAND. 81

Fig. 123. numerous may be the succes-

, sive layers a, b, c, the layer a
Cyr“ a must have been deposited be-
i fore b, b before c, and so of the

rest.

We must suppose that each thin seam was thrown
down on a slope, and that it conformed itself to the
side of the steep bank, just as we see the materials of
a talus arrange themselves at the foot of a cliff when
they have been cast down successively from above. If
the transverse layers are cut off by a nearly horizontal
line, as in many of the above. sections, it may arise
from the denuding action of a wave which has carried
away the upper portion of a submarine bank, and
truncated the layers of which it was composed. But I
do not conceive this hypothesis to be necessary ; for
if a bank have a steep side, it may grow by the suc-
Cessive apposition of thin strata thrown down upon its
Slanting side, and the removal of matter from the top
May proceed simultaneously with its lateral extension.
The same current may borrow from the top what it
gives to the sides; a mode of formation which I had
lately an opportunty of observing on the rippled sur-
face of the hills of blown sand near Calais. The undu-
lating ridges and intervening furrows on the dunes of
blown sand resembled exactly in form those caused by
the waves on a sea-beach, and were always at right
angles to the direction of the wind which had produced
them. Each ridge had one side slightly inclined, and

Fig. 124.
d

a —> e — > e

the other steep; the lee side being always steep, as
E 5

82 OLDER PLIOCENE PERIOD, [Book IV.

b, c, d, e ; the windward side a gentle slope, as a, b, c, d.
When a gust of wind blew with sufficient force to drive
along a cloud of sand, all the ridges were seen to be
in motion at once, each encroaching on the furrow
before it, and, in the course of a few minutes, filling
the place which the furrows had occupied. Many
grains of sand were drifted along the slopes a b and
e d, which, when they fell over the scarps 6 c and d e,
were under shelter from the wind; so that they re-
mained stationary, resting, according to their shape
and momentum, on different parts of the descent. In
this manner each ridge was distinctly seen to move
slowly on as often as the force of the wind augmented.
We shall not strain analogy too far, by supposing that,
in such cases, the same laws may govern subaqueous

and subaérial phenomena; and if so, we may imagine

a submarine bank to be nothing more than one of the
ridges of ripple on a larger scale, which may increase

in the manner before suggested, by successive additions
to the steep scarps.

The set of tides and currents, in opposite directions,
may account for sudden variations in the direction of
the dip of the layers,

in the first volume*,
gement of the sub-
o that exhibited by
f rivers where a con-
siderable transportation of sediment is in progress,
Derangement of strata. —In the above examples I

* P 378, Fig. 13,

Ch. XIIL] DERANGEMENT OF STRATA. ‘ 83
have explained the want of parallelism or horizon-
tality in the subordinate layers of different strata, by
reference to the mode of their original deposition ;
but there are signs of disturbance which can only be
accounted for by subsequent movements. The same
blue and brown clay, or loam, which is often perfectly
horizontal, and as regularly bedded as any of our older
formations, is, in ‘other places, curved and even folded
back upon itself, in the manner represented in the an-
nexed diagrams.
Fig. 125. Fig. 126.

Noes

Bent strata of loam in the cliffs Folding of the strata between East and
between Cromer and Runton. West Runton.

In the last of these cuts a central nucleus of sand
is surrounded by argillaceous and sandy layers. This
phenomenon is very frequent ; and there are instances
where the materials thus enveloped consist of broken
flints mingled with pieces of chalk, forming a white
mass, encircled by dark laminated clay. The diameter
of these included masses, as seen in sections laid open
in the sea cliffs, varies from five to fifteen feet.

East of Sherringham, a heap of partially-rounded
flints, about five feet in diameter, is nearly enveloped
by finely laminated strata of sand and loam, and some
of the loam is entangled in the midst of the flints.

In this and similar instances, we may imagine the

E 6

OLDER PLIOCENE PERIOD, [Book IV.

Section in the Cliffs east of Sherringham.
a. Sand and loam in thin layers.

yielding strata, a, to have subsided into a cavity, and
the flints belonging to a superincumbent bed to have
pressed down with their weight, so as to cause the
strata to fold round them.

That some masses of stratified sand and loam have
actually sunk down into cavities, or have fallen like
landslips into ravines, seems indicated by other appear-
ances. Thus, near Sherringham, the argillaceous beds,
a, represented in the annexed diagram (Fig. 128.), are
cut off abruptly, and succeeded by the vertical and
contorted series 6, c. The face of the cliff here repre-

Fig. 128.

Section east of Sherringham, Norfolk.

a, Sand, loam, and blue clay.

b, b. Sand and gravel,
c. Twisted beds of loam,

sented is twenty-four feet in height.
ers in b, b, are composed of pebbles, and these alternate
with thin beds of loose sand. The whole set must
once have been horizontal, and must have moved in a
mass, or the-relative position of the several parts would
not have been preserved. Similar appearances may,

Some of the lay-

Ch. XIII] PROTRUDED MASSES OF CHALK. 85

perhaps, be produced when chasms open during earth-
quakes, and portions of yielding strata fall in from
above and are engulphed.

Protruded masses of chalk. — But whatever opinion
we may entertain on this point, we cannot doubt that
Subterranean movements have given rise to some of
the local derangements of this formation, particularly
Where masses of solid chalk pierce, as it were, through

Fig.129.

Z

Side view of a promontory of chalk and tertiary strata, Trimmingham, Norfolk.

% Gravel and ferruginous sand, rounded and angular pieces of
chalk flint, with some quartz pebbles, 3 feet.

6. Laminated blue clay, 8 feet.

¢. Yellow sand, 1 foot, 6 inches.

d. -Dark blue clay, with fragments of marine shells, 6 feet.

e. Yellow loam and flint gravel, 3 feet.

J- Light blue clay, 1 foot. g. Sand and loam, 12 feet.

h. Yellow and white sand, loam, and gravel, about 100 feet.

the tertiary strata. Thus, between Mundesley and
Trimmingham we see the appearances exhibited in the
accompanying view (Fig. 129.). The chalk, of which
the strata are highly inclined, or vertical, projects in a

g peee eA
™ i TERE Lang nase MEET Tae
SPS Neh a ee aaa

s
an a E At asic

86 OLDER PLIOCENE PERIOD, EBook IV.

promontory, because it offers more resistance to the
action of the waves than the tertiary beds which, on
both sides, constitute the whole of the cliff. The
height of the soft strata immediately above the chalk

is, in this place, about 130 feet. Those which are in

contact (see the wood-cut) are inclined at an angle of
45°, and appear more disturbed than in other parts of
the cliffs, as if they had been displaced by the move-
ment by which the chalk was protruded.

Very similar appearances are exhibited by the
northernmost of the three protuberances of chalk, of
which a front view is given in the annexed diagram.

Northern protuberance of chalk, Trimmingham.
a. Chalk with flints,
6. Gravel of broken and half-rounded flints.

c. Laminated blue clay. d. Sand and yellow loam.

It occupies a space of about one hundred
the shore, and projects about sixty yards in advance of
the general line of cliff. One of its edges, at c, rests
upon the blue clay beds, in such a manner as to imply
that the mass had been undermined when the clay
was deposited, unless we suppose, as some have d one,
that this chaik is a great detached mass enveloped by

yards along

Ch. XIIL] PROTRUDED MASSES OF CHALK. 87

tertiary strata. For, as one of the “ Needles,” or in-
Sulated rocks of chalk, which stood 120 feet above
high-water mark, at the western extremity of the Isle
of Wight, fell into the sea in 1772*, so a pinnacle of
chalk may have been precipitated into the tertiary sea,
at a point where some beds of clay had previously ac-
cumulated. The strata of chalk with flint in the above
diagram appear nearly horizontal ; but they are in fact
highly inclined inwards towards the cliff, and it is quite
evident that the chalk and overlying deposit have both —
been subjected to the same movement, and have been
Violently disturbed. |

Since I first published my observations on these
Phenomena, I have visited Denmark, and seen similar
appearances, but on a much grander scale, in the cliffs
of the island of Moen. The white chalk with flnts,
Which there forms cliffs from 300 to 400 feet high, is
Covered with tertiary sand, clay, and loam, exactly re-
Sembling in form, colour, and mineralogical character,
the deposit overlying the crag of Norfolk. The chalk
in Méen exhibits curved, vertical, and shifted strata,
upon the whole more deranged than those of Purbeck
or the Isle of Wight. They have been so fissured and
dislocated, that large masses of overlying clay and sand
have subsided bodily into large chasms, intersecting
the chalk to the depth of several hundred feet. Some
of these intercalations and intermixtures of tertiary
clay and sand with chalk can only be explained by
Supposing engulphments of superincumbent matter,
Such as are known to have occurred during modern
earthquakes.

I have stated that the Danish tertiary deposit re-

* Dodsley’s Annual Register, vol. xv. p. 140.

———— = ae
SS EE

Lee

SSS SS

Se ae

ae

88 OLDER PLIOCENE PERIOD. [Book IV.

sembles that of uncertain age, which rests upon the
crag in Norfolk and Suffolk. The correspondence ex-
tends not merely to the nature of the clay, sand, gravel,
and mud, but to many other peculiarities. Thus in
Denmark, especially in Holstein, as seen in sections on
the banks of the Elbe, we find in some places a total ab-
sence of stratification, while masses in immediate con-
tact are regularly divided into thin layers of sand and
loam extending to the thickness of several hundred feet.
In Denmark also, as in Norfolk, we find here and there
the wreck of many secondary formations included in
the newer deposit, especially chalk, together with
some pebbles of granite, porphyry, and other rocks.
Organic remains are rare in Denmark, except those
derived from older strata, and hence the age of the
formation is on the whole very doubtful; but it has
been supposed by Dr. Forchhammer and Dr. Beck to
have been in progress throughout more than one ter-
tiary period. Be this as it may, it is ascertained that
one portion of it is extremely modern, and belongs to
the latest part of the Newer Pliocene period, contain-
ing shells identical with those now living in the Ger-
man Ocean. Whether the beds of the Norfolk cliffs
which, together with the chalk, have been so much dis-
turbed, are of equally modern date, or belong rather to
a more remote part of the great Pliocene epoch, is a
point which we cannot yet determine; and indeed we
cannot hope to solve this problem, until we have com-
pared more attentively the newer tertiary strata of
Denmark, and the south of Sweden, with those of the
eastern coast of England.

CHAPTER XIV.

VOLCANIC ROCKS OF THE OLDER PLIOCENE PERIOD.

Igneous rocks of this period in Italy — Volcanic region of Olot,
in Catalonia— Lava currents— Ravines — Ancient alluvium
— Jets of air called “ Bufadors” (p. 98.)— Age of the Ca-
talonian volcanos uncertain — Earthquake of Olot in 1421 —
Sardinian voleanos — District of the Eifel and Lower Rhine—
Peculiar characteristics of the Eifel volcanos — Lake craters
(p. 102,) — Trass — Age of the Eifel volcanic rocks how far

> Uncertain (p. 109.) — Brown coal formation.

Ttaly.—Ir is part of my proposed plan to consider the
igneous as well as the aqueous formations of each
Period; but I am far from being able as yet to assign
to each of the numerous groups of volcanic origin scat-
tered over Europe a precise place in the chronological
Series, It has been already stated, that the yolcanic
Tocks of Tuscany belong, in part at least, to the Older
Pliocene period, — those, for example, of Radicofani,
Viterbo, and Aquapendente, which have been chiefly
€rupted beneath the sea. The same observation
Would probably hold true in regard to the igneous
Tocks of the Campagna di Roma.

But several other districts, of which the dates are
still uncertain, may be mentioned in this chapter as
being possibly referable to the period now under con-
Sideration. It will at least be useful to explain the
Points which require elucidation before the exact age

of the groups about to be described can be accurately
determined,

90 OLDER PLIOCENE PERIOD. [Book IV.

Volcanos of Olot, in Catalonia. —I shall first de-
scribe a district of extinct volcanos in the north of
Spain, which is little known, and which I visited in
the summer of 1830.

The whole extent of country occupied by volcanic
products in Catalonia is not more than fifteen geogra-
phical miles from north to south, and about six from
east to west. The vents of eruption range entirely
within a narrow band running north and south ; and
the branches, which are represented as extending
i Fig. 131.

spa.

DOT
OLOY

ys

ey,
sy

fa ZH al

|

Volcanic district of Catalonia.

7, S¢ Michel. 2, Monte Oliveto. 3, Montsacopa. 4, Puig Sacourona. 5, Garrinada.
; >

UW of Me 5 jf Bet Z Ae l Ud Lh CLEP Se

ary rocks ig Secondary pra “| Volcanic R
y TPS : ey Joleanic Rocks.
ences. 2 (SY formations. 3 ie | ie Rocks

Ch, XIV.] VOLCANOS OF CATALONIA. 91

eastward in the map, are formed simply of two lava-
Streams — those of Castell Follit and Cellent.

Dr. Maclure, the American geologist, was the first
Who made known the existence of these volcanos * ;
and, according to his description, the volcanic region
extended over twenty square leagues, from Amer to

assanet, I searched in vain in the environs of Mas-
Sanet, in the Pyrenees, for traces of alava-current; and

can say, with confidence, that the adjoining map gives
à Correct view of the true area of the volcanic action.

Geological structure of the district. —The eruptions
lave burst entirely through secondary rocks, composed
great part of grey and greenish sandstone and con-
5 merate, with some thick beds of nummulitic lime-
Stone. The conglomerate contains pebbles of quartz,
Mestone, and Lydian stone. The limestone is not
only replete with nummulites, but occasionally in-
cludes oysters, pectens, and other shells. This system
Of rocks is very extensively spread throughout Cata-
onia; one of its members being a red sandstone, to
Which the celebrated salt-rock of Cardona is subor-

Mate. It is conjectured that the whole belongs to
the age of our green-sand and chalk.

Near Amer, in the Valley of the Ter, on the south-
em borders of the region delineated in the map, pri-
mary rocks are seen consisting of gneiss, mica-schist,
and clay-slate. They run in a line nearly parallel to

e Pyrenees, and throw off the secondary strata from

eir flanks, causing them to dip to the north and
north-west. This dip, which is towards the Pyrenees,
i Connected with a distinct axis of elevation, and pre-
Vails through the whole area described in the map, the

* :
Maclure, Journ. de Phys., vol. Ixvi. p. 219., 1808 ; cited by
aubeny, Description of Volcanos, p. 24.

SS a L =
=

=a =

92 OLDER PLIOCENE PERIOD. [Book IV.

inclination of the beds being sometimes at an angle of
between 40 and 50 degrees.

It is evident that the physical geography of the
country has undergone no material change since the
commencement of the era,of the volcanic eruptions,
except such as has resulted from the introduction of
new hills of scorize, and currents of lava upon the sur-
face. If the lavas could be remelted and poured out
again from their respective craters, they would descend
the same valleys in which they are now seen, and re-
occupy the spaces which they at present fill. The only
difference in the external configuration of the fresh
lavas would consist in this, that they would nowhere
be intersected by ravines, or exhibit marks of erosion
by running water.

Volcanic cones and lavas, — There are about four-
teen distinct cones with craters in this part of Spain,
besides several points whence lavas may have issued;
all of them arranged along a narrow line running north
and south, as will be seen in the map. The greatest
number of perfect cones are in the immediate neigh-
bourhood of Olot, some of which are represented in
the annexed plate (Pl. XI.); and the level plain on
which that town stands hag clearly been produced

by the flowing down of many lava-streams from those
hills into the bottom of a valley,
considerable depth, like
country.

In this plate an attempt is made to represent by
colours the different geological formations of which
the country is composed.* The blue line of moun-

probably once of
those of the surrounding

* This view is taken from a sketch which I made on the spot
in 1830.

Ch xiv]. VOLCANOS OF CATALONIA. 93

tains in the distance are the Pyrenees, which are to
the north of the spectator, and consist of primary
and ancient secondary rocks. In front of these are
the secondary formations described in this chapter,
Coloured grey. Different shades of this colour are
introduced, to express various distances. The flank
of the hill, in the foreground, called Costa de Pujou,
is composed partly of secondary rocks, and partly of
Volcanic, the red colour expressing lava and scorie.
The Fluvia, which flows near the town of Olot, has
Cut to the depth of only 40 feet through the lavas of
the plain before mentioned. The bed of the river is
hard basalt; and at the bridge of Santa Madalena are
Seen two distinct lava-currents, one above the other,
Separated by a horizontal bed of scorie eight feet
thick. l
In one place, to the south of Olot, the even surface
of the plain is broken by a mound of lava, called the
“ Bosque de Tosca,”. the upper part of which is scori-
aceous, and covered with enormous heaps of fragments
of basalt more or less porous. Between the numerous
hummocks thus formed are deep cavities, having the
„appearance of small craters. The whole precisely re-
Sembles some of the modern currents of Etna, or that
of Côme, near Clermont; the last of which, like the
Bosque de Tosca, supports only a scanty vegetation.
Most of the Catalonian volcanos are as entire as
those in the neighbourhood of Naples, or on the flanks
of Etna. One of these, figured in the plate, called
Montsacopa, is of a very regular form, and has a cir-
cular depression or crater at the summit. It is chiefly
made up of red scoriz, undistinguishable from that of
the minor cones of Etna. The neighbouring hills of
Olivet and Garrinada, also figured in the plate, are of

94 OLDER PLIOCENE PERIOD, [Book IV.

similar composition and shape. The largest crater of
the whole district occurs farther to the east of Olot,
and is called Santa Margarita. It is 455 feet deep,
and about a mile in circumference. Like Astroni,
near Naples, it is richly covered with wood, wherein
game of various kinds abounds.

Although the volcanos of Catalonia have broken out
through sandstone, shale, and limestone, as have those
of the Eifel, in Germany, to be described in the sequel,
there isa remarkable difference in the nature of the
ejections composing the cones in these two regions.
In the Eifel, the quantity of pieces of sandstone and
shale thrown out from the vents is often so immense
as far to exceed in volume the scoria, pumice, and
lava; but I sought in vain in the cones near Olot for
a single fragment of any extraneous rock; and Don
Francisco Bolos, an eminent botanist of Olot, informs
me that he has never been able to detect any. Vol-
canic sand and ashes are not confined to the cones,
but have been sometimes scattered by the wind over
the country, and drifted into narrow valleys, as is seen
between Olot and Cellent, where the annexed section
is exposed. The light cindery volcanic matter rests
in thin regular layers, just as it alighted on the slope
formed by the solid conglomerate. No flood could

Fig. 132.
xs a. Secondary conglo-

merate.
b. Thin seams of vol-
canic sand and scoriæ.

have passed through the valley since the scoriæ fell, or
these would have been for the most part removed.
The currents of lava in Catalonia, like those of

3 ;
h. XIV.] RAVINES IN LAVA EXCAVATED BY RIVERS. 95

Auvergne, the Vivarais, Iceland, and all mountainous
countries, are of considerable depth in narrow defiles,
2e Spread out into comparatively thin sheets in places
4 ere the valleys widen. If a river has flowed on
“arly level ground, as in the great plain near Olot,
© water has only excavated a channel of slight depth;
ut where the declivity is great, the stream has cut
“ep section, sometimes by penetrating directly
Si the central part of a lava-current, but more
oY by passing between the lava and the se-
ke ary rock which bounds the valley. Thus, in the
—°Mpanying section, at the bridge of Cellent, six
miles east of Olot, we see the lava on one side of the

Fig.133,

Section above the bridge of Cellent.
Scoriaceous lava. d. Scoriz, vegetable soil, and alluvium.
chistose basalt. e. Nummulitic limestone.
columnar basalt. J- Micaceous grey sandstone,

Sin j Pee A
aal] Stream ; while the inclined stratified rocks con-

Sie channel and opposite bank. The upper part

t the lava at that place, as is usual in the currents of
Bie te Vesuvius, is scoriaceous ; farther down it be-
stil Io ess porous, and assumes a spheroidal structure;
Dei wer it divides in horizontal plates, each about

0 inches in thickness, and is more compact. Lastly,

96 OLDER PLIOCENE PERIOD. ` [Book 1V:

at the bottom is a mass of prismatic basalt about five
feet thick. The vertical columns often rest immediately
on the subjacent secondary rocks; but there is some-
times an intervention of such sand and scoria as covet
the country during volcanic eruptions, and which whe?
unprotected, as here, by superincumbent lava, is
washed away from the surface of the land. Some
times, the bed d contains a few pebbles and angulat
fragments of rock; in other places fine earth, which
may have constituted an ancient vegetable soil.

Ty several localities, beds of sand and ashes are in-
terposed between the lava and subjacent stratified
rock, as may be seen if we follow the course of thé
lava-current which descends from Las Planas towards
Amer, and stops two miles short of that town. The
river there has often cut through the lava, and through
eighteen feet of underlying limestone. Occasionally
an alluvium, several feet thick, is interspersed between
the igneous and marine formation; and it is interesting
to remark that in this, as in other beds of pebbles
occupying a similar position, there are no rounded
fragments of lava; whereas in the most modern gravel-
beds of rivers of this country, volcanic pebbles aré
abundant.

The deepest excavation made by a river through
lava, which I observed in this part of Spain, is that
seen in the bottom of a valley near San Feliu de Pal-
leróls, opposite the Castell de Stolles. The lava theré
has filled up the bottom of a valley, and a narroW
ravine has been cut through it to the depth of oné
hundred feet. In the lower part the lava has ĉ
columnar structure. A great number of ages wer?
probably required for the erosion of so deep a ravine;
but we have no reason to infer that this current is of

Ch, XIV.] RAVINES IN LAVA EXCAVATED BY RIVERS. 97

higher antiquity than those of the plain near Olot.
The fall of the ground, and consequent velocity of the
Stream, being in this case greater, a more considerable
Volume of rock may have been removed in the same
time,

I shall describe one more section to elucidate the
Phenomena of this district. A lava-stream, flowing
from a ridge of hills on the east of Olot, descends a
Considerable slope, until it reaches the valley of the
river Fluvia. Here, for the first time, it comes in
Contact with running water, which has removed a
Portion, and laid open its internal structure in a pre-
“ipice about 130 feet in height, at the edge of which
Stands the town of Castell Follit.

By the junction of the rivers Fluvia and Teronel
the mass of lava has been cut away on two sides; and
the insular rock g (Fig. 134.) has been left, which was
Probably never so high as the cliff a, as it may have
“onstituted the lower part of the sloping side of the
original current.

From an examination of the vertical cliffs, it appears
that the upper part of the lava on which the town is

uilt is scoriaceous, passing downwards into a sphe-
řoidal basalt; some of the huge spheroids being no
“88 than six feet in diameter. Below this is a more
compact basalt with crystals of olivine. There are in
a about four distinct ranges of prismatic basalt, separ-
ated by thinner beds not columnar, and some of which
àre schistose. The whole mass rests on alluvium, ten
or twelve feet in thickness, composed of pebbles of
“Mestone and quartz, but without any intermixture of
Igneous rocks; in which circumstance alone it appears

to differ from the modern gravel of the Fluvia.
VOL. -Iv. F

SSNS pa oS

as ¥ nD

OLDER PLIOCENE PERIOD. [Book IV.

Fig. 134.

LLN

fi l mt Nui
|

UAI

River luva
ne

Section at Castell Follit.

A. Church and town of Castell Follit, overlooking precipices of
basalt.

B. Small island, on each side of which branches of the river
Teronel flow to meet the Fluvia.

c. Precipice of basaltic lava, chiefly columnar, about 130 feet in
height.

d. Ancient alluvium underlying the lava-current.
e. Inclined strata of secondary sandstone.

Bufadors.— The volcanic rocks near Olot have often
a cavernous structure, like some of the lavas of E tna
and in many parts of the hill of Batet, in the environs
of the town, the sound returned by the earth, when
struck, is like that of an archway. At the base of the
same hill are the mouths of several subterranean
caverns, about twelve in number, which are called in
the country “ bufadors,” from which a current of cold
air issues during summer, but which in winter is said
to be scarcely perceptible. I visited one of these
bufadors in the beginning of August, 1830, when the
heat of the season was unusually intense, and found a
cold wind blowing from it ; which may easily be ex-

Ch, XIV,] AGE OF CATALONIAN VOLCANOS. 99

plained; for as the external air, when rarefied by heat},
ascends, the pressure of the colder and heavier air ok
the caverns in the interior of the mountain causes if.
to rush out to supply its place.

Age of the Catalonian volcanos uncertain. — It now
only remains to offer some remarks on the probable
age of these Spanish volcanos. Attempts have been
Made to prove, that in this country, as well as in Au-
vergne and the Eifel, the earliest inhabitants were eye-
Witnesses to the volcanic action. In the year 1421, it
is said, when Olot was destroyed by an earthquake,
an eruption broke out near Amer, and consumed the
town, The researches of Don Francisco Bolos have,
l think, shown, in the most satisfactory manner, that
there is no good historical foundation for the latter
Part of this story ; and any geologist who has visited

Mer must be convinced that there never was any
“Tuption on that spot. It is true that, in the year above
Mentioned, the whole of Olot, with the exception of a
‘ingle house, was cast down by an earthquake ; one
of those shocks which, at distant intervals during the
ast five centuries, have shaken the Pyrenees, and par-
ticularly the country between Perpignan and Olot,
Where the movements, at the period alluded to, were
Most violent.

Some houses are said to have sunk into the earth;
and this account has been corroborated by the fact

at, within the memory of persons now living, the

uried arches of a Benedictine monastery were found
at the depth of six feet beneath the surface ; and still
ater, Some houses were dug out in the street called

‘Sua. Don Bolos informed me, that he was present
When the latter excavation was made, and when the
“Oof of 9 buried house was found nearly entire ; the

F 2

ORS SEE
ee ee ss

100 OLDER PLIOCENE PERIOD, [Book IV.

interior of the building being in a great part empty, so
that is was necessary to fill it up with earth and
stones, in order to form a sure foundation for the new
edifice. ;

The annihilation of the ancient Olot may, perhaps,
be’ ascribed, not to the extraordinary violence of the
movement on that spot, but to the cavernous nature of
the subjacent rocks ; for Catalonia is beyond the line
of those European earthquakes which have, within the
period of history, destroyed towns throughout exten-
sive areas. |

As we have no historical records, then, to guide us
in regard to the extinct volcanos, we must appeal to
geological monuments. I have little doubt that some
fossil land-shells, and bones of quadrupeds, will here-
after reward the industry of collectors. If such re-
mains are found imbedded in volcanic ejections, the

period of the eruptions may be inferred ; but at pre-
sent we have no evidence beyond that afforded by
superposition, in regard to which the annexed diagram
will present to the reader, in a synoptical form, the
results obtained from numerous sections.

Superposition of rocks in the volcanic district of Catalonia.
a. Sandstone and nummulitic limestone.
b. Older alluvium without volcanic pebbles.
c. Cones of scoriz and lava, d. Newer alluvium.
The more modern alluvium, d, is partial, and has
been formed by the action of rivers and floods upon the

Ch. XIV.] VOLCANOS OF THE EIFEL. 101

lava; whereas the older gravel, b, was strewed over
the country before the volcanic eruptions. In neither
have any organic remains been discovered ; so that we
can merely affirm, as yet, that the volcanos broke out
after the elevation of some of the newest rocks of the
Secondary series, and before the formation of an allu-
vium, d, of unknown date. The integrity of the cones
Merely shows that the country has not been agitated
by violent earthquakes, or subjected to the action of
any great transient flood since their origin.

East of Olot, on the Catalonian coast, marine tertiary
‘Strata occur, which, near Barcelona, attain the height
of about five hundred feet. It appears probable, from
a small number of shells which I collected, that these
Strata may correspond with the Subapennine beds;
So that if the volcanic district had extended thus far,
We might be able to determine the age of the igneous
Products, by observing their relation to these Older
Pliocene formations. *
_ Sardinian volcanos. — The line of extinct volcanos
m Sardinia, described by Captain Smyth }, is also of
uncertain date, as, notwithstanding the freshness of
Some of the cones and lavas, they may be of high an-
tiquity. They rest, however, on a tertiary formation,
Supposed by some to correspond to the Subapennine
Strata, but of which the fossil remains have not been
fully described.

Volcanic rocks of the Eifel. — The volcanos of the
Lower Rhine and the Eifel are, for the most part, of no

* For some account of the Olot volcanos, see ‘“ Noticia de los
Estinguidos Volcanes de la Villa de Olot,” by Francisco Bolos.
arcelona. No date; but the observations, I am told, preceded
those of Dr. Maclure.
t Present State of Sardinia, &c. pp. 69, 70.
F 3

102 OLDER PLIOCENE PERIOD. [Book IV.

less uncertain date than those of Catalonia; but I am
desirous of pointing out some of their peculiar charac-
ters, and shall, therefore, treat of them in this chapter,
trusting that future investigations will determine their
chronological relations more accurately.

For the geographical details of this volcanic region
the reader is referred to thea nnexed map (Fig. 136.),
for which I am indebted to Mr. Horner, whose resi-
dence in the country has enabled him to verify the
maps of MM. Noeggerath and Von Oeynhausen, from
which that now given has been principally compiled.

There has been a long succession of eruptions in
this country, and some of them must have occurred
when its physical geography was in a very different
state, while others have happened when the whole dis-
trict had nearly assumed its present configuration.

The fundamental rock of the Eifel is an ancient
secondary sandstone and shale, to which the obscure
and vague appellation of “ greywacké” has been given.
The formation has precisely the characters of a great
part of those gray and red sandstones and shales,
which are called “ old red sandstone ” in England and
Scotland, where they constitute the inferior member
of the carboniferous series. In the Eifel they occupy.
the same geological position, and in some parts alter-
nate with a limestone, containing trilobites and other
fossils of our “mountain” and « transition” limestones.
The strata are inclined at all angles, from the hori-
zontal to the vertical, and must have undergone re-
iterated convulsions before the country was moulded
into its present form.

Lake-craters. — The volcanos have broken out some-
times at the bottom of deep valleys, sometimes on
the summit of hills, and frequently on intervening

103-

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Ch. XIV.]

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104 OLDER PLIOCENE PERIOD. [Book IV.

platforms. The traveller often falls upon them unex-
pectedly in a district otherwise extremely barren of
geological interest. Thus, for example, he might
arrive at the village of Gemund, immediately south of
Daun, without suspecting that he was in the imme-
diate vicinity of some of the most remarkable vents of
eruption. Leaving a stream, which flows at the bottom
of a deep valley in a sandstone country, he climbs the
steep acclivity of a hill, where he observes the edges
of strata of sandstone and shale dipping inwards to-

d. Schalkenmehren Maar.

=
3
a
=
ia
Vv
KS.
$
S
E
S

The Gemunder Maar.

Ah DME

a. Village of Gemund.
6. Gemunder Maar

Ch. XIV.] LAKE-CRATERS OF THE EIFEL. 105

wards the mountain. When he has ascended to a con-,
siderable height, he sees fragments of scoriz’ sparingly

Scattered over the surface ; till, at length, on reaching
the summit, he finds himself suddenly on the edge of
à tarn, or deep circular lake-basin.

; This, which is called the Gemunder Maar, is the
first of three lakes which are in immediate contact,
the same ridge forming the barrier of two neighbouring
Cavities (see Fig. 137.). On viewing the first of these
We recognize the ordinary form of a crater, for which
we have been prepared by the occurrence of scoriæ
Scattered over the surface of the soil. But on examin-
ing the walls of the crater, we find precipices of .
Sandstone and shale which exhibit no signs of the
action of heat; and we look in vain for those beds of
lava and scoriz, dipping in opposite directions on every
Side, which we have been accustomed to consider as
Characteristic of volcanic craters. As we proceed,
however, to the opposite side of the lake, and after-
Wards visit the craters c and d (Fig. 138.), we find a
onsiderable quantity of scoriæ and some lava, and
See the whole surface of the soil sparkling with vol-
Canic sand, and strewed with ejected fragments of
half-fused shale, which preserves its laminated texture
m the interior, while it has a vitrified or scoriform
Coating,

_A few miles to the south of the lakes above men-
tioned occurs the Pulvermaar of Gillenfeld, an oval
take of very regular form, and surrounded by an un-
broken ridge of fragmentary materials, consisting of
“jected shale and sandstone, and preserving a uniform

eight of about 150 feet above the water. The side

Stope in the interior is at an angle of about forty-five

“grees ; on the exterior, of thirty-five degrees. _ Vol-

F5

106 OLDER PLIOCENE PERIOD. [Book IV.

canic substances are intermixed very sparingly with
the ejections, which in this place entirely conceal from
view the stratified rocks of the country.*

The Meerfelder Maar is a cavity of far greater size
and depth, hollowed out of similar strata; the sides
presenting some abrupt sections of inclined secondary
rocks, which in other places are buried under vast
heaps of pulverized shale. I could discover no scoriz
amongst the ejected materials, but balls of olivine
and other volcanic substances are mentioned as having
been found.+ This cavity, which we must suppose to
have discharged an immense volume of gas, is nearly

- a mile in diameter, and is said to be more than one

hundred fathoms deep. In the neighbourhood is a
mountain called the Mosenberg, which consists of red
sandstone and shale in its lower parts, but supports
on its summit a triple volcanic cone, while a distinct
current of lava is seen descending the flanks of the
mountain. The edge of the crater of the largest cone
reminded me much of the form and characters of that
of Vesuvius.

If we pass from the Upper to the Lower Eifel, we
find the celebrated lake-crater of Laach, which has a
greater resemblance than any of those before men-
tioned to the Lago di Bolsena, and others in Italy —
being surrounded by a ridge of gently sloping hills,
composed of loose tuffs, scoriæ, and blocks of a variety
of lavas.

One of the most interesting volcanos on the left
bank of the Rhine is called the Roderberg. It forms
4 circular crater nearly a quarter of a mile in diameter,
and one hundred feet deep, now covered with fields of

* Scrope, Edin. Journ. of Sci., June, 1826, p. 145.
+ Hibbert, Extinct Volcanos of the Rhine, p, 24,

MeT e ce i

i
f {
iN -

Ch. XIV.J LAKE-CRATERS OF THE EIFEL. ‘107

corn. The highly inclined greywacké strata rise even
to the rim of one side of the crater ; but they are over-
spread by quartzose gravel, and this again is covered
by volcanic scoriæ and tufaceous sand. The opposite
wall of the crater is composed of cinders and scorified
rock, like that at the summit of Vesuvius. It is quite
evident that the eruption in this case burst through
the greywacké and alluvium which immediately over-
lies it; and I observed some of the quartz pebbles
mixed with scoriz on the flanks of the mountain, as if
they had been cast up into the air, and had fallen again
with the volcanic ashes.

I have already observed, that a large part of this
crater has been filled up with loess, and I have pointed
out how far we may thus obtain a relative date for the
Period of its eruption.*

The most striking peculiarity of a great many of the
craters above described, is the absence of any signs of
alteration or torrefaction in their walls, when these are
composed of regular strata of greywacké-sandstone and
shale. It is evident that the summits of hills formed
of the above-mentioned stratified rocks have, in some
cases, been carried away by gaseous explosions, while
at the same time no lava, and often a very small quan-
tity only of scoriæ, has escaped from the newly formed.
Cavity. There is, indeed, no feature in the Eifel vol-
canos more worthy of note, than the proofs they afford
of very copious aériform discharges, unaccompanied
by the pouring out of melted matter, except, here and
there, in very insignificant volume. I have seen no
assemblage of extinct volcanos in France, Italy, or
Spain, where gaseous explosions of such magnitude

* See p. 34.
F 6

108 OLDER PLIOCENE PERIOD. [Book IV.

have been attended by the emission of so small a
quantity of lava. Yet I looked in vain in the Eifel for
any appearances which could lend support to the hy-
pothesis, that the sudden rushing out of such enormous
volumes of gas had ever lifted up the stratified rocks
immediately around the vent, so as to form conical
masses, having their strata dipping outwards on all
sides from a central axis. In the Gemunder Maar
the beds, as before stated, have an inward dip on one
side of the hill; and in the walls of this and other cra
ters, there are strata which are inclined at all angles,
just as may be observed in the greywacké, far from the
points of eruption. Those who favour the theory of
the elevation crater might naturally expect, that in a
district where so many tremendous explosions have
occurred, they would find masses of greywacké tower-
ing several thousand feet above the surrounding plat-
form, whereas the height of these ancient rocks has
not been visibly affected by the sites of the extinct
volcanos.*

Trass and its origin. — It appears that in the Lower
Eifel eruptions of trachytic lava preceded the emission
of currents of basalt, and that immense quantities of
pumice were thrown out wherever trachyte issued.
In this district, also, we find the tufaceous alluvium of
the Rhine volcanos called trass, which has covered
large areas, and choked up some valleys now partially
re-excavated. This trass is unstratified; and its base
consists almost entirely of pumice, in which are in-
cluded fragments of basalt and other lavas, pieces of
burnt shale, slate, and sandstone, and numerous trunks
and branches of trees.

* See Vol. II, p. 152.

Ch. XIV.] AGE OF THE EIFEL VOLCANOS. 109

We may easily conceive the manner of its origin, if
we reflect on what would happen if an eruption, at-
tended by a copious evolution of gases, should now
occur in one of the lake basins. The water might re-
main for weeks in a state of violent ebullition, until it
became of the consistency of mud, just as the sea con-
tinued to be charged with red mud round Graham’s
Island, in the Mediterranean, in the year 1831.* If
a breach should then be made in the side of the cone,
the flood would sweep away great heaps of ejected
fragments of shale and sandstone, which would be
borne down into the adjoining valleys. Forests might
be torn up by such a flood; and thus the occurrence
of the numerous trunks of trees dispersed. irregularly
through the trass, can be explained. :

Age of the volcanic rocks. — It will be seen by the
map (Fig. 136.), that the volcanic rocks extend also to
the opposite or right bank of the Rhine, where they
are spread over parts of the Westerwald, and form the
great mass of the mountains called the Siebengebirge.
They consist partly of basaltic and partly of trachytic
lavas, the latter description being, in general, the more
ancient of the two. There are many varieties of tra-
chyte, some of which are highly crystalline, resem-
bling a coarse-grained eranite, with large separate
crystals of felspar. Trachytic tuff is also very abund-
ant. It is a difficult task to determine the age of all-
these igneous rocks, although their position, relatively
to the stratified formations with which they are asso-
ciated, has been clearly made out. The accompanying
table presents in a synoptical view the series of rocks
of the district delineated in the map (Fig. 136.).

* See Vol. II. p.147.

110 OLDER PLIOCENE PERIOD, [Book IV.

- Volcanic.
Loess.

. Gravel. A. Newer Pliocene,
. Loess.
. Volcanic.

a
b.
c
b
a
d. Volcanic.

e. Gravel, oy j

£ Brown coal, B. AR ak uncertain periods, but older
g. Volcanic,

J- Brown coal.

Greywacké, C.

It will be seen that the greywacké C, before alluded
to (p. 102.), is the lowest rock of the series, which is
usually in highly inclined Strata; upon this reposes a
nearly horizental tertiary formation f, which has been
called “brown coal.” This deposit consists of beds of
loose sand and sandstone, clay with nodules of clay-
ironstone, and siliceous conglomerate. Beds of light
brown and sometimes black lignite, of various thick-
ness, are interstratified with the clays and sands, and
often irregularly diffused through them, They are
extensively worked for fuel, and hence the name given
to the whole formation: they contain numerous im-
pressions of leaves and stems of trees.

i?
period of the accumulation o

products (g) were ejected.

A vast deposit of gravel, e chiefly composed of
pebbles of white quartz, but containing also a few
fragments of other rocks, lies over the brown coal
formation, forming sometimes only a thin covering, at
others attaining a thickness of more than 100 feet.

o

AGE OF EIFEL. VOLCANOS. ill

Ch. XIV] ©

This gravel is very distinct in character from that now
forming the bed of the Rhine. It is called « Kiesel
Serolle” by the Germans, often reaches great eleva-
Hons, and is covered in several places with volcanic
ections. It is evident that the country has under-
sone great changes in its physical geography since

IS gravel was formed, whereas no inconsiderable
Proportion of the volcanic rocks, d, were produced
after the country had nearly attained its present con-

Suration.

The aqueous and igneous formations above enume-
rated, constituting the group B, may be declared to be
tertiary, from the character of the organic remains of
the brown coal f; for they are seen to be either of the
Same age as f, or newer, and the members of the group

ave been shown to be so intimately connected with

e loess *, that we may, without hesitation, declare
them to belong to the Newer Pliocene period. It
Should be recollected, however, that the whole series

Only forms, in the aggregate, a very insignificant
“ature in the district, and the great mass of the vol-
“aniic products, d, may, possibly, belong to the Older

locene, or some still more remote era.

The varieties of wood found in the brown coal strata
are said to belong entirely to dicotyledonous trees;

ut among the impressions of leaves, collected by
“ar. Horner, some were referred by Mr. Lindley to a
Palm, perhaps of the genus Chamerops, and others re-
‘Sembled the Cinnamomum dulce, and Podocarpus ma-
“ophylla, which would also indicate a warm climate.+
he other organic remains of the brown coal are

* See pp. 32. 34.
} Trans. of Geol. Soc., 2d ser. vol. v.

112 OLDER PLIOCENE PERIOD. [Book IV.

principally fishes; they are found in a bituminous
shale, called paper-coal, from being divisible into ex-
tremely thin leaves. The individuals are extremely
numerous; but they appear to belong to about five
species, which M. Agassiz informs me are all extinct,
and hitherto peculiar to this brown coal. They belong
to the freshwater genera Leuciscus, Aspius, and Perca
The remains of frogs also, of an extinct species, have
been discovered in the paper-coal; and a complete
series may be seen in the museum at Bonn, from the
most imperfect state of the tadpole to that of the full-
grown animal. With these a salamander, scarcely
distinguishable from the recent species, has been found,
and several remains of insects.

The brown coal was evidently a freshwater form-
ation; but the extreme rarity of shells renders it diffi-
cult to form any conjecture as to the subdivision of
the tertiary period to which it may belong. Near
Marienforst, in the vicinity of Bonn, large blocks are
found of a white opaque chert, containing numerous
casts of freshwater shells, which appear to belong to
Planorbis rotundatus and Limnea longiscata, two spe-
cies common both to the Eocene and Miocene periods,
but which have not been found in any newer deposits.
M. Deshayes, to whom I showed the specimens, said
he felt as confident of the above identifications as mere
casts would warrant. These blocks of chert are not
in situ, but they probably belong to the brown coal
formation, of which the hills at Marienforst consist.
The brown coal is well known to contain, at other
places, subordinate beds of silex. It is to be hoped,
that a comparison of the organic remains of the brown
coal with those of the tertiary formation of Mayence,
which appears to be of Miocene date, will throw some

Ch. XIV] AGE OF EIFEL VOLCANOS. 113

light on the chronological relations of the igneous and
freshwater formations above considered. *

* For fuller details consult Noeggerath’s. Rheinland West-
Phalen, Memoirs of Von Dechen, Oeynhausen, and Von Buch,
Steininger (erloschenen Vulkane in der Eifel, &c., Mainz, 1820),
Van der Wyck (Uebersicht der Rheinischen und Eifeler
erlosch, Vulkane, Bonn. 1826), Scrope (Edin. Journ. of Sci.
1826, p, 145.) Daubeny (Volcanos, p. 45.), Leonhard (Ueber

asalt-Gebilde), Hibbert (Extinct. Volcs. of Rhine), and the

moir above cited by Mr. Horner, in the Trans. of Geol. Soc.
Vol. v. 2d ser.

CHAPTER XV.
MIOCENE FORMATIONS — MARINE.

Miocene period — Marine formations — Faluns of Touraine —
compared to the English crag — Basin of the Gironde and
Landes — Freshwater limestone of Saucats (p. 121.)—Eocene
strata in the Bordeaux basin. — Position of the limestone of
Blaye —Inland cliff near Dax — Montpellier — Strata of
Piedmont — Superga — Valley of the Bormida — Molasse of
Switzerland (p. 128.) — Basin of Vienna — Styria — Hun-
gary — Volhynia and Podolia — Mayence.

Havine treated in the preceding chapters of the Older
and Newer Pliocene formations, I shall next consider
those members of the tertiary series for which I have
proposed the name of Miocene. The distinguishing
characters of this group, as derived from its imbedded
fossil testacea, have been explained in the fifth chap-
ter.* In regard to the relative position of the strata,
they underlie the Older Pliocene, and overlie the
Eocene, formations, when any of these happen to be
present.

The area covered by the marine, freshwater, and
volcanic rocks of the Miocene period, in different parts
of Europe, can already be proved to be very consider-
able; for they occur in Touraine, in the basin of the
Loire, and still more extensively in the South of

* Vol. IIL. p. 370.

"zgor Boty Uyar Nd PIYSYGny UPUT

‘nig UDF VUPI AO 9- IOG VSOPOLTU OCUAGMAT L

YSI SaPOOUUBLY VIL] TWIST QT WY NOA OUPRLNJ, G — CUOL SPUN YT ORN F

290g OMIQUIP PUNOJ ET IO PUMI VATE E 4 UPT NASIDA OMA T

ap 'IAOPNO àT

ar E FALUNS OF TOURAINE 115

France, between the Pyrenees and the Gironde. ‘They
| “ve also been observed in Piedmont, near Turin, and
m the neighbouring valley of the Bormida, where the
Apennines branch off from the Alps. They are largely
veloped in the neighbourhood of Vienna and in
Styria they abound in parts of Hungary; and they
*Yerspread extensive tracts in Volhynia and Podolia.
Shells characteristic of the Miocene strata are found
n all these countries, figures of some of which are
> in Plate XII., the species here selected abounding
. almost all the deposits of this era, and not occurring
any Eocene or Pliocene formations. Cardita Ajar,
°Wever, is also a recent species, but has been admitted
account of its abundance in Miocene strata, and
“cause it has never yet been observed in any Pliocene
oo and is confined in a living state to tropical
Utries, as Senegal.
dic Shall now proceed to notice briefly some of the
itries before enumerated as containing monuments
© era under consideration.
°uraine.——I have already alluded to the proofs
SUperposition adduced by M. Desnoyers, to show
t the shelly strata provincially called “ the Faluns
€ Loire,” were posterior to the most recent fresh-
ater formation of the basin of the Seine. Their
aion; therefore, shows that they are of newer
Sm than the Eocene strata, — more recent, at least,
i the uppermost beds of the Paris basin. But an
mination of their fossil contents proves also that
“J are referable to that type which distinguishes
iocene period. When 300 of the Touraine
collected by M. Desnoyers were compared by
Speci €shayes with more than 1100 of the Parisian
les, there were scarcely more than 20 which could

tha

e
Shells

116 MIOCENE PERIOD. [Book IV:

be identified; and on the other hand, the fossil shells
of the Touraine beds agree far less with the testace?
now inhabiting our seas than do the shells of the Olde
Pliocene strata of Northern Italy.

It is not merely in the basin of the Loire that the
superposition of the Miocene to the Eocene strata has
been observed; but in the Cotentin (see Map, chap’
xx.), and in the environs of Rennes, in Brittany.

The Miocene strata of the Loire have been observe
to repose on a great variety of older rocks betwee?
Sologne and the sea, in which line they are seen to res!
successively upon gneiss, clay-slate, coal-measure®
Jura limestone, greenstone, chalk, and lastly upon thé
upper freshwater deposits of the basin of the Sein®
They consist principally of quartzose gravel, sand, and
broken shells. The components are generally inco
herent, but sometimes agglutinated together by a cal-
careous or earthy cement, so as to serve as a building
stone. Like the shelly portion of the crag of Norfolk
and Suffolk, the faluns and associated strata are 0
slight thickness, not exceeding seventy feet. They
often bear a close resemblance to the crag in appeat
ance, the shells being stained of the same ferruginov
colour, and being in the same state of decay ; serving
in Touraine, just as in Norfolk and Suffolk, to fertilize
the arable land. Like the crag, also, they contain mam
miferous remains, which are not only intermixed with
marine shells, but sometimes incrusted with serpul@
flustra, and balani. These terrestrial quadrupeds
belong to the genera Mastodon, Rhinoceros, Hipp?
potamus, &c., the assemblage, considered as a wholes
being very distinct from those of the Paris gypsum.*

* Desnoyers, Bull. de la Soc. Géol. de France, tome ii. p. 44%

Ch. Xv.] CRAG AND FALUNS COMPARED. 117

The faluns and contemporary strata of the basin of
the Loire may be considered generally as having been
ormed in a shallow sea, into which a river, flowing
Perhaps from some of the lands now drained by the

oire, introduced from time to time fluviatile shells,
Wood, and the bones of quadrupeds, which may have

een washed down during floods. Some of these
Ones have precisely the same black colour as those

ound in the peaty shell-marl of Scotland; and we
might imagine them to have been dyed black in Mio-
sie peat, which was swept down into the sea during

© waste of cliffs, did we not find the remains of
Cetacea in the same strata—bones, for example, of

© lamantine, morse, sea-calf, and dolphin, having
Precisely the same colour.

The resemblance which M. Desnoyers has pointed
rut as existing between the English erag-and they

tench faluns is one which ought by no means to in-

Uce us to ascribe a contemporaneous origin to-these
= groups, but merely a similarity of geographical -
“cumstances at the respective periods when each

Was deposited. In every age, where there is Jand and

Sea, there must be shores, shallow estuaries, and rivers;

and near the sea-coasts banks of marine shells and

corals may accumulate. It must also be expected
that rivers will drift in freshwater shells, together

with sand and pebbles, and occasionally, perhaps,

Sweep down the carcasses of land quadrupeds into the

Sea. If the sand and shells, both of the “crag” and

7 faluns,” have each acquired the same ferruginous

Colour, such a coincidence would merely lead us to

“ier that, at each period, there happened to be springs

Charged with iron, which flowed into some part of the

118 MIOCENE PERIOD. [Book 1V

sea or basin of the river, by which the sediment wa
carried down into the sea.

Even had the French and English strata which we
are comparing shared a greater number of mineral
characters in common, that identity could not havé
justified us in inferring the synchronous date of thé
two groups, where the discordance of fossil remains
is so marked. The argument which infers a contem”
poraneous origin from correspondence of mineral con”
tents, proceeds on the supposition that the materials
were either washed down from a common source, 0%
being derived from different sources, were mingled
together in a common receptacle. If, according 1
the latter hypothesis, the crag and the faluns wer?
thrown down in one continuous sea, the testace#
could not have been so distinct in two regions not
more distant from each other than Essex and thé
mouth of the Loire, unless we assume that the law®
which regulated the geographical distribution of spe-
cies were then very different from those now prevail-
ing. But if it be said that the two basins may have
been separated from each other, as are those of thé
Mediterranean and Red Sea, by an isthmus, and that
distinct assemblages of species may have flourished
in each, as is now actually the case in those tw?
seas *, I may reply, that such narrow lines of demar
ation are extremely rare now, and must have bee?
infinitely more so in remoter tertiary epochs; becaus¢
there can be no doubt that the proportion of land t0
sea has been greatly on the increase in European Jati-
tudes during the more modern geological eras.

In the faluns, and in certain groups of the same ag®

* See above, chap. x,

Ch, Xv] BASIN OF THE GIRONDE. 119

Which occur not far to the west of Orleans, M. Des-
noyers has discovered the following mammiferous
quadrupeds :— Paleotherium magnum, Mastodon an-
Justidens, Hippopotamus major and H. minutus,
inoceros leptorhinus and R. minutus, Tapir gigas,
nthracotherium (small species), Sus, Equus (small
Species), Cervus, and an undetermined species of the
odentia.
The first species on this list is common to the Paris
SYpsum, and is therefore an example of a land qua-
Tuped common to the Miocene and Eocene formations,
n exception perfectly in harmony with the results
obtained from the study of fossil shells.*
Basin of the Gironde and district of the Landes.+ —
Streat extent of country between the Pyrenees and
the Gironde is overspread by tertiary deposits, which
ave been more particularly studied in the environs

of Bordeaux and Dax, from whence about six hundred
Species of shells have been obtained. These shells be-
ng to the same zoological type as those of Touraine.
Most of the beds near Dax, whence these shells
are procured, consist of incoherent quartzose sand, -
Mixed for the most part with calcareous matter, which
48 often bound together the sand into concretionary

* For further details respecting the basin of the Loire, see

4 Desnoyers, Ann. des Sci. Nat., tome xvi. pp. 171. 402.,
Where full references to other authors are given.

t Since this account was first written in 1832, M. Dufrénoy’s
article on the tertiary strata of the south of France, has been pub-
lisheq With lists of shells by M. C. Desmoulins. See Mémoires

Pour servir à une Descrip. Géol. de la France, tom. iii. p. 1.
aris, 1836,

h M. de Basterot has given descriptions of more than three
Undred shells of Bordeaux and Dax, and figures of the greater
number of them. Mém. dela Soc. d’Hist. Nat. de Paris, tome ii,

120 MIOCENE PERIOD. [Book IV.

nodules. A great abundance of fluviatile shells occurs
in many places intermixed with the marine; and i2
some localities microscopic shells of the order fora
minifera are in great profusion.

The tertiary deposits in this part of France vary
much in their mineralogical character, yet admit ge-
nerally of being arranged in four groups. See diagram.

Fig. 139. Adour R. Luy R. Puy Arzet.

t)

Tertiary strata overlying chalk in the environs of Dax.

a. Siliceous sand without shells. c. Sand and marl with shells.
. Gravel. d. Blue marl with shells.
E. Chalk and volcanic tuff.

In some places the united thickness of these groups
is considerable ; but in the country between the Py-
renees and the valley of the Adour, around Dax, the
disturbed secondary rocks are often covered by a thin
pellicle only of tertiary strata, which rests horizontally
on the chalk, and does not always conceal it.

In the valleys of the Adour and Luy, sections of all
the members of this tertiary formation are laid open ;
but the lowest blue marl, which is sometimes tw0
hundred feet thick, is not often penetrated. On the
banks of the Luy, however, to the south of Dax, the
subjacent white chalk is exposed in inclined and ver-
tical strata. In the hill called Puy Arzet the chalk,
characterized by its peculiar fossils, is accompanied by
beds of volcanic tuff, which are conformable to it, and
which may be considered as the product of submarine
eruptions which took place in the sea wherein the chalk
was formed. ‘These tuffs must once have been nearly

Ch, XV.] STRATA NEAR DAX. 121

horizontal, but, like the chalky strata, have been sub-
Jected to great subsequent derangement.

About a mile west of Orthés, in the Bas Pyrénées,
the blue marl is seen to extend to the borders of the
tertiary formation, and rises to the height probably of
SIX or seven hundred feet. In that locality many of

e marine Miocene shells preserve their. original
Colours, This marl is covered by a considerable
thickness of ferruginous gravel, which seems to in-
“tease in volume near the borders of the tertiary basin
n the side of the Pyrenees. 5

In an opposite direction, to the north of Dax, the
shelly sands often pass into calcareous sandstone, in
Which there are merely the casts of shells, as at Car-
“ares; and into a shelly breccia, resembling some .
tocks of recent origin which I have received from tlie
“oral reefs of the Bermudas.

Freshwater limestone at Saucats. — Associated with

e Miocene strata near Bordeaux, at a place called
“aUcats, is a compact freshwater limestone, of slight
: ickness, which is perforated on the upper surface by
Marine shells, for the most part of extinct species.
tis evident that the ancient surface must at this
Place have been alternately occupied by salt and fresh

Water. The ground, perhaps, may have been alter-

nately raised and depressed, or a lagoon may have been
ormed, in which the water became fresh; then a bar-
“ler of sand, by which the sea was excluded for a
time, may have been breached; so that the salt water
again obtained access. |

- Dufrénoy has classed this freshwater limestone
as Pliocene (tertiaire supérieur), but, from the fresh-
Water shells contained in it, as well as from the marine

Ossils on which it rests and by which it is immediately
VOL. Ivy, G

122 MIOCENE PERIOD. [Book EY-

covered, M. Deshayes and I conclude that it is Mio-
cene. Among the shells determined by M. C. Des-
moulins, we find Cyrena Brongniarti, Bast., Planor-
bis rotundatus, and Limnea longiscata, species found
elsewhere m beds older than the Pliocene.*

Eocene strata in the Bordeaux basin. — The rela-
tions of some of the members of the tertiary series,
in the basin of the Gironde, have of late afforded
matter of controversy. A limestone, resembling the
calcaire grossier of Paris, and from one hundred to
two hundred feet in thickness, occurs at Pauliac and
Blaye, and extends on the right bank of the Gironde,
between Blaye and La Roche. It contains many species
of fossils identical with those of the Paris basin. This
fact was pointed out to me by M. Deshayes before I
visited Blaye in 1830; but although I recognized the
mineral characters of the rock to be very different
from those of the Miocene formations in the imme-:
diate neighbourhood of Bordeaux, I had not time to
verify its relative position. J inferred, however, the
inferiority of the Blaye limestone to the Miocene
strata, from the order in which each series presented
itself, as I receded from the chalk and passed to the
central parts of the Bordeaux basin.

Upon leaving the white chalk with flints s, In travel-
ling from Charante by Blaye to Bordeaux, I first found
myself upon overlying red clay and sand (as at Mi-
rambeau): I then came upon the tertiary limestone
above alluded to, at Blaye; and lastly, on departing
still farther from the chalk, reached the strata which,
at Bordeaux and Dax, contain exclusively the Miocene

shells.

See M. Dufrénoy’s Paper, p. 341.

Ch.xvj BORDEAUX BASIN. 123

The occurrence both of Eocene and Miocene fossils 3
in the same basin of the Gironde, had been cited by
M. Boué as a tact which detracted from the value of
Zoological characters as a means of determining the
chronological relations of tertiary groups. But on
farther inquiry, the fact has been found to furnish
additional grounds of confidence in these characters.

M. Ch. Desmoulins replied, to M. Boué’s objections,
that the assemblage of Eocene shells are never inter-
Mixed with those found in the “ moellon,” as he calls
the Sandy calcareous rock of the environs of Bordeaux
aid Dax; and M. Dufrénoy farther stated, that the
hills of limestone which border the right bank of the
Gironde, from Marmande as far as Blaye, present
S€veral sections wherein the Parisian (or Eocene)
limestone is seen to be separated from the shelly
Strata called “faluns,” or “ moellon,” by a freshwater
formation of considerable thickness. It appears, there-
ore, that as the marine faluns of Touraine rest on a
freshwater formation, which overlies the marine cal-
Caire grossier of Paris, so the marine Miocene strata
of Bordeaux are separated from those of Blaye by a
freshwater deposit.* .

The following diagram will express the order of
Position of the groups above alluded to.

Fig. 140.

| Chath — Le a
l > oe R ee

a,
Red clay and sandy
` “M™mestone like calcaire grossier, sometimes alternating with
Steen marl, and containing Eocene shells.

* Bulletin de la Soc. Géol. de France, tome ii. 7 440.

G 2

Wi MIOCENE PERIOD. [Book 1V.

c. Freshwater formation, same as that of the department of Lot

and Garonne.
d:i Tertiary strata of the Landes, same as Fig. 139., with Miocene

fossils.

M. Dufrénoy considers the upper sands without fos-
sils, which cover the low flat countries of Médoc and
the Landes, to be of the age of the Subapennine beds. *
But there appears as yet to be scarcely sufficient data
to enable us to draw such an inference. It is, however,
clear that the true Subapennine or Older Pliocene
formation exists between Perpignan and the Pyre-
pees}; so that in one region, in the south of France,
we have the Eocene, Miocene, and Pliocene form-
ations all represented: an important fact, as directly
opposed to the theory which endeavours to explain
away the distinctness of the fossils of different tertiary
groups, by supposing them to have been all deposited
in contemporaneous basins belonging to independent
zoological provinces, not in lakes and seas inhabited
successively by distinct species.

Inland cliff near Dax.— A few miles west from
Dax, and at the distance of about twelve miles from
the sea, a steep bank is seen running in a direction
nearly north-east and south-west, ‘or parallel to the
‘contiguous coast. This steep declivity, which is about |
fifty feet in height, conducts us from the higher plat- A

Section of Inland Cliff at Abesse, new Daz.
g. Sand of the Landes. 6. Limestone,

* See his paper above cited, tome iii. p. 11,
f 35220 above; pe 69.

rà
Ch. XV.] INLAND CLIFF NEAR DAX. 125

form of the Landes to a lower plain which extends to
the sea. The outline of the ground might suggest to
every geologist the opinion that the bank in question
Was once a sea-cliff, when the whole country stood at
a lower level relatively to the sea. But this can no
longer be regarded as matter of conjecture. In making
excavations recently for the foundation of a building at
Abesse, a quantity of loose sand, which formed the
slope de, was removed; anda perpendicular cliff, about
fifty feet in height, which had hitherto been protected
from the agency of the elements, was exposed. The
bottom of this cliff consists of limestone 6, which con-
tains tertiary shells and corals. Immediately below
the limestone is the clay, c; and above it the usual
tertiary sand, a, of the department of the Landes. At
the base of the precipice are seen large partially
rounded miasses of rock, evidently detached from the
Stratum b. The face of the limestone is hollowed out
and weathered into such forms as are seen in the cal-
Careous cliffs of the adjoining coast, especially at
Biaritz, near Bayonne. It is evident that, when the
Country was at a somewhat lower level, the sea ad-
Vanced along the surface of the argillaceous stratum c,
Which, from its yielding nature, favoured the waste by
undermining the more solid superincumbent lime-
Stone 4, Afterwards, when the country had been
elevated, part of the sand, a, fell down, or was drifted
by the winds, so as to form the talus, d e, which
Masked the inland cliff until it was artificially laid
Open to view.

The situation of this cliff is interesting, as marking
ne of the pauses which intervened between the suc-
cessive movements of elevation by which the marine

G 3

Jkt

ec

1

adit.

126 MIOCENE PERIOD. [Book IV¥-

tertiary strata of this country were upheaved to their
present height, a pause which allowed time for the
sea to advance and strip off the upper beds a, b, from
the denuded clay e.

Monitpellier.—The tertiary strata of Montpellier con-
tain many of the Dax and Bordeaux species of shells,
so that they are probably referable to the Miocene
epoch ; but in the catalogue given by M. Marcel de
Serres, many Pliocene species, similar to those of the
Subapennine beds, are enumerated. M. de Christol
mentions Mastodon angustidens, Rhinoceros lepto-
rhinus, a Tapir, a Palaotherium, and an Anthracothe-
rium, together with many other mammifers, besides
cetacea and reptiles. *

It would be highly interesting if, upon fuller inves-
tigation, the Montpellier beds should be found to
indicate a passage from the fossils of the Miocene
type to those of the Older Pliocene. We may expect
the discovery of such intermediate links, and I have
endeavoured to provide a place for them in the ‘clas-
sification proposed in the fifth chapter, +

Hills of Mont Ferrat and the Superga. — The late
Signor Bonelli of Turin was the first who remarked
that the tertiary shells found in the green sand and
marl of the Superga.near Turin differed, as a group,
from those generally characteristic of the Subapennine
beds. The same naturalist had also observed, that
many of the species peculiar to the Superga were
identical with. those occurring near Bordeaux and
Dax. ‘The strata of which the hill of the Superga is
composed are inclined at an angle of more than

* Résumé de M. Boué, p.128. Bull. de la Soc. Géol. de
France, tom. iii. + Vol. II.

€h.XV.] MONT FERRAT AND THE SUPERGA. 127

Seventy degrees, as I found when I examined the
Superga in company with Mr. Murchison in 1828.

hey consist partly of fine sand and marl, and partly
of a conglomerate composed of primary boulders,
which forms a lower part of the series, and not, as
fepresented by M. Brongniart by mistake, an un-
conformable and overlying mass.* The same series of
beds is more largely developed in the chain of Mont
Ferrat, especially in the basin of the Bormida. The
high road which leads from Savona to Alessandria
intersects them in its northern descent, and the form-
ation may be well studied along this line at Carcare,
Cairo, and Spinto, at all which localities fossil shells
Occur in a bright green sand. At Piana, a conglo-
Merate, interstratified with this green sand, contains
founded blocks of serpentine and chlorite schist, larger
than those near the summit of the Superga, some of
them being not less than nine feet in diameter.

When we descend to Aqui, we find the green sand
Siving place to bluish marls, which also skirt the plains
of the Tanaro at lower levels. These newer marls are
associated with sand, and are nearly horizontal, and
*ppear to belong to the Older Pliocene Subapennine
Strata, + The shells which characterize the latter
abound in various parts of the country near Turin; but
that region has not yet been examined with sufficient
“are to enable us to give exact sections to illustrate
the Superposition of the Miocene and Older Pliocene
beds, It is, however, ascertained, that the highly
inclined green sand, which comes immediately in con-
tact with the primary rocks, is the oldest part of the
Series,

* Terrains du Vicentin, p. 26.
t See section, Fig. 84. Vol. III. p. 338.
G 4

128 i MIOCENE PERIOD. [Book IV.

Molasse of Switzerland. —If we cross the Alps,
and pass from Piedmont to Savoy, we find there, at
the northern base of the great chain, and throughout
the lower country of Switzerland, a soft green sand-
stone much resembling some of the beds of the basin
of the Bormida, above described, and associated in a
similar manner with marls and conglomerate. This
formation is called in Switzerland “molasse,” said to
be derived from “mol,” « soft,” because the stone is
easily cut in the quarry. It is of vast thickness; but
shells have so rarely been found in it, that they do not
supply sufficient data for correctly determining its
age. M. Studer, in his treatise on the « molasse,”
enumerates some fossil shells found near Lucerne,
agreeing, apparently, with those of the Subapennine
hills. The correspondence in mineral character be-
tween the green sand of Piedmont and that of Switzer-
land can in nowise authorise us to infer identity of
age, but merely to conclude that both have been
derived from the degradation of similar ancient rocks.

Until the place of the “molasse” in the chrono-
logical series of tertiary formations has been more
rigorously determined, the application of this provincial
name to the tertiary groups of other countries must
be very uncertain, and it will be desirable to confine
it to the tertiary beds of Switzerland.

Styria, Vienna, Hungary. — Of the various groups
which have hitherto been referred to the Miocene
era, none are so important in thickness and geogra-
phical extent as those which are found at the eastern
extremity of the Alps, in what have been termed the
basins of Vienna and Styria, and which spread thence
into the plains of Hungary. The collection of shells
formed by M. Constant Prevost, in the neighbourhood

4

Ch. XV.] STYRIA— VIENNA — HUNGARY. 129

of Vienna, and described by him in 1820*, was alone
Sufficient to identify a great part of the formations of
that country with the Miocene beds of the Loire,
Gironde, and Piedmont. The fossil remains subse-
quently procured by that indefatigable observer M.
Boué have served to show the still greater range of
the same beds through Hungary and Transylvania.

It appears from the recently published memoirs of
Professor Sedgwick and Mr. Murchison}, that the
formations of Styria may be divided into groups cor-
Tesponding to those adopted by M. Partsch for the
Vienna beds ; the basin of Styria exhibiting nearly the
Same phenomena as that of Vienna. These regions
have evidently formed, during the Miocene period,
two deep bays of the same sea, separated from each
other by a great promontory connected with the cen-
tral ridge of the eastern Alps.

The English geologists above mentioned describe a
long succession of marine strata intervening between
the Alps and the plains of Hungary, which are divi-
sible into three natural groups, each of vast thickness,
and affording a great variety of rocks. All these
groups are of marine origin, and lie in nearly horizontal
strata, but have throughout a slight easterly dip; so
that, in traversing them from west to east, we com-
mence with the oldest, and end with the youngest
beds, . l

At their western extremity they fill an irregular
trough-shaped depression, through which the waters
of the Mur, the Raab, and the Drave, make their way
to the lower Danube.{ Here the first group is de-

* Journal de Physique, Novembre, 1820.
+ Geol. Trans., Second Series, vol. iii. p. 301.
¢ Ibid., p. 382.

G 5

130 MIOCENE PERIOD, [Book IV.

veloped, consisting of conglomerate, sandstone, and
marls, some of the marls containing marine shells.
Beds also of lignite occur, showing that wood was
drifted down in large quantities into the sea. In parts
of the series there are masses of rounded siliceous
pebbles, resembling the shingle banks which are form-
ing on some of our coasts.

The second principal group is characterized by
coralline and concretionary limestone of a yellowish
white colour ; it is finely exposed in the escarpments
of. Wildon, and in the hills of Ehrenhausen, on the
right bank of the Mur.* This coralline limestone is
not less than 400 feet thick at Wildon, and exceeds,
therefore, some of the most considerable of our se-
condary groups in England.

Beds of sandstone, sand, and shale, and calcareous
marls, are associated with the above-mentioned lime-
stone.

The third group, which occurs at a still greater dis-
tance from the mountains, is composed of sandstone
and marl, and of beds of limestone, exhibiting here
and there a perfectly oolitic structure. In this system
fossil shells are numerous.

In regard to. the age of the formations above de-
scribed, it is by no means clear that the coralline lime-
stones of the second group are posterior in origin to
all the beds of the first division ; they may possibly
have been formed at some distance from land, while
the head of the gulf was becoming filled up with
enormous deposits of gravel, sand, and mud, which
may, in that quarter, have rendered the waters too
turbid for the fullest development of testaceous and
coralline animals.

* Geol.. Trans., Second Series, vol. iii. p. 385. + Ibid., p. 390.

Ch. XV.J STYRIA — VIENNA — HUNGARY. 131

The middle group, both in the basins of Styria and
Vienna, belongs indisputably to the Miocene period ;
for the Species of shells are the same as those of the
Loire, Gironde, and other contemporary basins before
Noticed. Whether the lowest and uppermost systems
are referable to the same, or to distinct tertiary epochs,
'S the only question. We cannot doubt that the accu-
mulation of so vast a succession of beds required an
Immense lapse of ages, and we should expect to find
Some difference in the species characterizing the differ-
ent members of the series; nevertheless, all may be-
long to different subdivisions of the Miocene period.
Professor Sedgwick and Mr. Murchison have suggested
that the inferior, or first group, which comprises the
Strata between the Alps and the coralline limestone of

ildon, may correspond in age to the Paris basin ; but
the list of fossils which they have given seems rather
to favour the supposition that the deposit is of the

Miocene era. They mention four characteristic
Miocene fossils, — Mytilus Brardii, Cerithium pictum,
C. pupæforme, and C. plicatum : — and though some
few of the associated shells are common to the Paris

asin, such a coincidence is no more than holds

true in regard to all the European Miocene form-
ations,

On the other hand, the third or newest system,
Which overlies the coralline limestone, contains fossils
Which do not appear to depart so widely from the
Miocene type as to authorize us to separate them.

hey appear to agree with the tertiary strata of a
Sreat part of Hungary and Transylvania, which are
referable to the Miocene period. *

* See tables of shells by M. Deshayes, in Appendix I. of the
Octavo edition.

z

G6

132 MIOCENE PERIOD. [Book IV.

Volhynia and Podolia.— We may expect to find
many other districts in Europe composed of Miocene
strata; and there is already sufficient evidence that
the marine deposits of the platform of Volhynia and
Podolia were of this era. The fossils of that region,
which is bounded by Galicia on the west, and the
Ukraine on the east, and comprises parts of the basins
of the Bog and the Dneister, has been investigated by
Von Buch, Eichwald, and Du Bois; and the latter has
given excellent plates of more than one hundred fossil
shells of the country, which M. Deshayes finds to agree
decidedly with the fossils of the Miocene period.*

The formation consists of sand and sandstone, clay,
coarse limestone, and a white oolite, the last of which
is of great extent.

Mayence. — The tertiary strata near Mayence con-
tain in abundance the Mytilus Brardii, and several other
characteristic Miocene fossils. They occupy a tract
from five to twelve miles in breadth, extending along
the left bank of the Rhine from Mayence to the neigh-
bourhood of Manheim, and are again found to the east,
north, and south-west of Frankfort. In some places

“they have the appearance of a freshwater formation;
but in others, as at Alzey, the shells are for the most
part marine. Cerithia are in great profusion, which
indicates that the sea where the deposit was formed
was fed by rivers; and the great quantity of fossil land
shells, chiefly of the genus Helix, confirm the same
opinion. The variety in the species of shells is small,
scarcely eighty having yet been discovered, as I learn
from Professor Bronn, of Heidelberg, while the indi-
viduals are exceedingly numerous; a fact which accords

* Conch. Foss. du Plateau Wolhyni-Podol., par F. du Bois.
Berlin, 1831.

Ch. XV.] MAYENCE— OSNABRUCH. 133

Perfectly with the idea that the formation may have
originated in a gulf or sea which, like the Baltic, was
brackish in some parts and almost frésh in others. A
Species of Paludina, very nearly resembling the recent
Littorina ulva, is found throughout this basin. These
shells may be compared in size to grains of rice, and
often are in such quantity as to form almost entiré
Strata of marl and limestone. I have seen them as
thick as grains of sand, in stratified masses fifteen feet
thick; and Professor Bronn has observed a succession
of beds thirty feet in thickness, of which they are the
Principal constituent.
I was unable to find any natgral sections which ex-
ibited the relations of the Mayence strata above de-
Scribed to the sandy beds of Eppelsheim, wherein the
new genus Deinotherium, and the bones of the Mas-
todon avernensis, and other mammifers, have been dis-
Covered. But I think it most probable that they all
belong to the same era, and that the freshwater beds
of Georges Gemund, in Bavaria, as well as several
ther detached lacustrine groups of that country and
of Wurtemburg, may be referred to the Miocene period.
At Georges Gemund, as in Touraine, we find an asso-
“lation of the genera Palæotherium, Mastodon, and
hinoceros.

Osnabruch. — From the fossils which I have seen in
the cabinet of Count Munster at Bayreuth, I have little
doubt that strata of the Miocene period are largely

veloped between the mountains of the Teutobour-
Serwald and Wesergebirge, including the environs of
Snabruch, Münster, Astrupp, and other places.

ta
Ii
)

TLRS

CHAPTER XVI.

MIOCENE FORMATIONS — ALLUVIAL — FRESHWATER —
VOLCANIC,

Miocene alluviums — Auvergne — Mont Perrier — Extinct qua-
drupeds — Velay — Orleanais — Alluviums contemporaneous
with Faluns of Touraine — Miocene freshwater formations —
Upper Val @ Arno — Extinct mammalia (p. 138.) — Coal of
Cadibona — Miocene voleanic rocks — Hungary — Transyl-

vania — Styria — Auvergne — Velay.

‘ig
In the present chapter I shali offer some observations
on the alluviums and freshwater formations of the
Miocene era, and shall afterwards point out the coun-
tries in Europe where the volcanic rocks of the same
period may be studied.

Miocene Alluviums.
Auvergne.— The annexed drawing will explain the
position of two ancient beds of alluvium, ¢ and e, in

Fig. 142,

Position of the Miocene aliuviums of Mont Perrier (or Boulade).
Descending series.
a. Newer alluvium. b. Second trachytic breccia.
. Second Miocene alluvium with bones.
d, First trachytic breccia.
e. First Miocene alluvium with bones.
Jf. Compact basalt. & Eocene lacustrine strata.

Ch, XVL] AUVERGNE. 135-

Auvergne, in which the remains of several quadrupeds
Characteristic of the Miocene period have been ob-
tained. In order to account for the situation of these
beds of rounded pebbles and sand, we must suppose
that after the tertiary strata g, covered by the basaltic
ava f, had been disturbed and exposed ‘to aqueous
€nudation, a valley was excavated, wherein the allu-
vium e was accumulated, and in which the remains of
quadrupeds then inhabiting the country were buried.
The trachytic breccia d was then superimposed; this
"eccia is an aggregate of shapeless and angular frag-
Ments of trachyte, cemented by volcanic tuff and
Pumice, resembling some of the breccias which enter
mto the composition of the neighbouring extinct vol-
ĉano of Mont Dor in Auvergne, or those which are
found on Etna. Upon this rests another alluvium, e,
Which also contains the bones of Miocene species, and
this is covered by another enormous mass of tufaceous
treccia.. The breccias have probably resulted from the
Sudden rush of large bodies of water down the sides of
a elevated volcano at its moments of eruption, perhaps
when snow was melted by Java. Such floods occur in |
Celand, sweeping away loose blocks of lava and ejec-
“ons surrounding the crater, and then strewing the
Plains with fragments of igneous rocks, enveloped in
Mud or « moya.” The abrupt escarpment presented
by the above-described beds, b, c, d, e, towards the
Valley of the Couze, must have been caused by subse-
{Went erosion, which has carried away a large portion
of those masses.*

For an account of the position and age of the volcanic brec-
aS of Mont Perrier and Boulade, see Lyell and Murchison on

the Beds of Mont Perrier, Ed. New Phil. Journ., July, 1829,
P. 15,

Ci

156. . MIOCENE PERIOD. [Book IV.

In the alluviums c and e, MM. Croizet, Jobert,
Chabriol, and Bouillet have discovered the remains
of about forty species of extinct mammalia, the greater
part of which are peculiar as yet to this locality; but
some of them are characteristic of the Miocene period,
being common to the faluns of Touraine, and asso-
ciated in other localities with marine Miocene strata.
Among these species may be enumerated Mastodon
minor and M. arvernensis, Hippopotamus major;
Rhinoceros leptorhinus, and Tapir arvernensis. ‘The
Elephas primigenius, a species common to so many
tertiary periods, is also stated. to accompany the rest.
In some cases the remains are not sufficiently charac-
teristic to indicate the exact species, but the follow-
ing genera can be determined : — The boar, horse, ox;
hyena (two species), felis (three or four), bear
(three), deer (many species), canis, otter, beaver,
hare, and water-rat.*

Velay. — In Velay a somewhat similar group of
mammiferous remains were found by Dr. Hibbert t
in a bed of volcanic scoriæ and tuff, inclosed between
two beds of basaltic lava, at Saint Privat d’ Allier-
Some of the bones were found adhering to the slaggy
lava. Among the animals were Rhinoceros lepto-
rhinus, Hyzena spelza, and another species allied to
the spotted hyæna of the Cape, together with four
undetermined species of deer. t

At Cussac and Solilhae, one league from Puy en

* Recherches sur les Oss. Foss. du Dépt. du Puy de Dome;
4to. 1828. Essai Géol. et Minéral. sur les Environs d’Issoire
Dépt. du Puy de Dome, folio, 1827.

+ Edin. Journ. of Sci., No. iv. New Series, p- 276.

ł Figures of some of these remains are given by M. Bertrand
de Doue, Ann. de la Soc. d’ Agricult. de Puy, 1828.

Chey . UPPER VAL D’ ARNO. 137

Velay, M. Robert discovered, in an ancient alluvium
overed with lava, the remains of Elephas primigenius,

hinoceros leptorhinus, Tapir arvernensis, horse (two
Species), deer (seven species), ox (two species), and
a antelope.

Orleanais. — In the Orleanais, at Avaray, Chevilly,
es Aides, and les Barres, fossil land quadrupeds have
“en found associated with fluviatile shells and rep-
tiles, identical with those found in the marine faluns
of Touraine.” These are supposed with great pro-
ability, by M. Desnoyers, to mark the passage of
Streams which flowed towards the sea in which the

aluns were deposited.

Miocene Freshwater Formations.

Upper Val d Arno. — There are a great number of
isolated tertiary formations, bf freshwater origin, rest-
mg on primary and secondary rocks in different parts
of Europe, in the same manner as we now find small
akes scattered over our continents and islands, wherein
“posits are forming, quite detached from all contem-
Porary marine strata. To determine the age of such
Stoups, with reference to the great chronological :
Series established for the marine strata, must often be
à matter of difficulty, since we cannot always enjoy an
°pportunity of studying a locality where the fresh-
Water species are intermixed with marine shells, or
SN they occur in beds alternating with marine

rata,

The deposit of the Upper Val d’ Arno before alluded

* MM. Desnoyers and Lockart, Bulletin de la Soc. Géol.,
tom, ii, P. 336.

Sa

138 \ MIOCENE PERIOD. ; . [Book IV.

to (p. 57.), was evidently formed in an ancient lake;
but, although the fossil testaceous and mammiferous
remains preserved therein are very numerous, it is
scarcely possible, at present, to decide with certainty
the precise era to which they belong. I collected
six species of lacustrine shells, in an excellent state
of preservation, from this basin, belonging to the ge-
nera Anodon, Paludina, and Neritina; but M. Deshayes
was unable to identify any one of them with any
recent or fossil species known to him. If the beds
belonged to the Older Pliocene formations, we might
expect that several of the fossils would agree specifi-
cally with living testacea ; and I'am therefore disposed
to believe that they belong to an older epoch. If we
consider the terrestrial mammilia of the same beds,
we immediately perceive that they cannot be assimi-
lated to the Eocene type, as exhibited in the Paris
basin, or in Auvergne and Velay : but some of them
agree with Miocene species. Mr. Pentland - has
obligingly sent me the following list of the fossil
mammifers of the upper Val d’Arno which are in the
museums of Paris. —— Fer@ — Ursus cultridens, Vi-
verra Valdarnensis, Canis lupus (?), and another of the
size of the common fox. Hyeena radiata, H. fossilis-
Felis (a new species, of the size of the panther). Ro-
dentia — Histrix, nearly allied to dorsalis, Castor.
Pachydermata — Elephas Italicus, Mastodon angusti-
dens, M. Taperoides, Tapir , Equus , Sus
scrofa, Rhinoceros leptorhinus, Hippopotamus major;
fossilis. Ruminantia — Cervus megaceros (P), C. Val-
darnensis, C. (new species), Bos, bubalo affinis,
B. urus and B. taurus.

Cuvier also mentions the remains of a species of
lophiodon as occurring among the bones in the Upper

g
b. XVII CADIBONA. 139

Val d'Arno. * The elephant of this place has been
called by-Nesti + meridionalis, and is considered by
him as distinct from the Siberian fossil species Æ. pri-
"genius, with which, however, some eminent com-
Parative anatomists regard it as identical. The skele-
tons of the hippopotamus are exceedingly abundant ;
= no less than forty had been
procured when I visited Flo-
rence in 1828. Remains of
the elephant, stag, ox, and
horse, are also extremely nu-
_ merous. In winter the super-
ficial degradation of the soil
is so rapid, that bones which
the year before were buried
are seen to project from the
surface of the soil, and are
described by the peasants as
growing. In this manner the
tips of the horns of stags, or
of the tusks of hippopota-
muses, often appear on the —
surface, and thus lead to the
discovery of an entire head
or skeleton.

Cadibona. — Another ex-
ample of an isolated lacus-
trine deposit, belonging pos-
sibly to the Miocene period,

Dns ; is that which occurs at Cadi-

» between Savona and Carcare; a place which I

Sea

Savona
if

b. Sand, shale, and coal o

F aie <3
D
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Q
O

a

La)

=

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=

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v

ia
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S

ra)

a

Fo
=
g
wn
=|
v
g

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we IR
LPO HSE

”

é A
Section of the freshwater formation of Cadibona.

d. Chloritic and Micaceous schist, serpentine, &c.

a. Blue marl and yellow sand (Older Pliocene).
Cadibona (Miocene ?).

* Os
8s. Foss., vol. v. p. 504.

Seana sopra alcune Ossa Fossili del Val d’ Arno, &c. Pisa,

140 MIOCENE PERIOD. [Book IV.

visited in August, 1828, in company with Mr. Murchi-
son. Its position is described in the annexed section;
which does not, however, pretend to accuracy in regard
to the relative heights of the different rocks, or thé
distances of the places from each other. The lacus-
trine strata are composed of gravel, grit, and micaceous
sandstone, of such materials as were derivable from
the surrounding primary rocks; and so great is the
thickness of this mass, that some valleys intersect it
to the depth of seven or eight hundred feet without
penetrating to the subjacent formations. In one part.
of the series, carbonaceous shales occur, and several
Seams of coal from two to six feet in thickness; but
no impressions of plants of which the species could be
determined, and no shells have been discovered. Many
entire jaws and other bones of an extinct mammife!,
called by Cuvier Anthracotherium, have been found
in the coal-beds, the bone being itself changed into 4
kind of coal; but as this species has not as yet oc-
curred elsewhere in association with organic remains of
known date, it affords us no aid when we attempt t0
assign a place to the lignites of Cadibona.

Miocene Volcanic Rocks.

Hungary. — M. Beudant, in his elaborate work on
Hungary, describes five distinct groups of volcanic
rocks, which, although nowhere of great extent, form
striking features in the physical geography of that
country, rising as they do abruptly from extensive
plains composed of tertiary strata, They may have
constituted islands in the ancient sea, as Santorin and
Milo now do in the Grecian Archipelago ; and M. Beu-

Ch. XVI] = VOLCANIC ROCKS HUNGARY. 141

dant has remarked that the mineral products of the
last-mentioned islands resemble remarkably those of
the Hungarian extinct volcanos, where many of the
Same minerals, as opal, calcedony, resinous silex (silex
resinite), pearlite, obsidian, and pitchstone abound.
The Hungarian lavas are chiefly felspathic, con-
‘isting of different varieties of trachyte ; many are
Cellular, and used as millstones; some so porous and
Sven scoriform as to resemble those which have issued
-the open air. Pumice occurs in great quantity; and
there are conglomerates, or rather breccias, wherein
“agments of trachyte are bound together by pumiceous
tuff, or sometimes by silex.

It is probable that these rocks were permeated by
tl

üe waters of hot springs, impregnated, like the Gey-
» with silica; or, in some instances, perhaps, by
Aqueous vapours, which, like those of Lancerote, may

Serg

lave precipitated hydrate of silica. *

By the influence of such springs or vapours the
trunks and branches of trees washed down during
ods, and buried in tuffs on the flanks of the moun-
tains, may have become silicified. It is scarcely pos-
“ible, says M. Beudant, to dig into any of the pumiceous

“posits of these mountains without meeting with
Palized wood, and sometimes entire silicified trunks
of trees of great size and weight.

: It appears from the species of shells collected prin-
“pally by M. Boué, and examined by M. Deshayes,

at the fossil remains imbedded in the voleanic tuffs,
Mad in strata alternating with them in Hungary, are
of thé Miocene type, and not identical, as was formerly
‘Upposed, with the fossils of the Paris basin.

* See Vol. II. p. 142.

149 MIOCENE PERIOD. [Book IV.

Transylvania. — The igneous rocks of the easter”
part of Transylvania, described by M. Boué, are pro-.
bably of the same age. They cover a considerable
area, and bear a close resemblance to the Hungarian
lavas, being chiefly trachytic. Several large craters;
containing shallow lakes, like the Maars of the Eifel,
are met with in some regions; and a rent in the tra-
chytic mountains of Budoshagy exhales hot sulphureous
vapours, which convert the trachyte into alum-stone ;
a change which that rock has undergone at remote
periods in several parts of Hungary.

Styria.— Many of the volcanic groups of this country
bear a similar relation to the Styrian tertiary deposits,
as do the Hungarian rocks to the marine strata of that
country. The shells are found imbedded in the vol-
canic tuffs in such a manner as to show that they lived
in the sea when the volcanic eruptions were in progress;
as many of the Val di Noto lavas in Sicily, before de-
scribed, were shown to be contemporaneous with the
Newer Pliocene strata. *

Auvergne— Velay.—I believe that part of the volca-
nic eruptions of Auvergne took place during the Mio-
cene period; those, for example, which cover, or are
interstratified with, the alluviums mentioned in this
chapter, and some of the ancient basaltic cappings of
hills in Auvergne, which repose on gravel characterized
by similar organic remains. A part also of the igneous
rocks of Velay must belong to this epoch ; but these
will be again referred to when I treat more fully of
the volcanic rocks of Central France, the older part of:
which are referable to the Eocene period.

* Sedgwick and Murchison, Geol. Trans., Second Series, yol.ilis
p. 400. Daubeny’s Volcanos, p. 92,

-CHAPTER XVII.

EOCENE FRESHWATER FORMATIONS.

Eocene period — Freshwater formations — Central France—Map
~ Limagne d’ Auvergne—Sandstone and conglomerate — Ter-
tiary red marl and red sandstone — Green and white foliated
Marls (p. 149.) — Indusial limestone—Gypseous marls — Tra-
Vertin — Freshwater formation of Puy en Velay (p. 157.) —
Of Cantal — Resemblance of Aurillac limestone and flints to

Sur upper chalk — Concluding remarks.

W

$ E have now traced back the history of the European
‘mations to that period when the seas and lakes were

‘thabited by testacea, of which a few only belonged

? Species now existing; a period which I have de-
“Snated Eocene, as indicating the dawn of the present
e of the animate creation. But although a small
. mber only of the living species of animals were then
: being, there are ample grounds for inferring that all
1€ great classes of the animal kingdom, such as they
ae exist, were then fully represented. In regard to
he testacea, indeed, it is no longer a matter of infer-
ence; for more than 1200 species of this class have
fen obtained from that small number of detached
ene deposits which have hitherto been examined
n Europe.
The celebrated Paris basin, the position of which
Me pointed out in the former part of this book (see
od-cut, Vol. III. p. 332.), first presents itself, and

144 EOCENE PERIOD. [Book IV.

seems to claim our chief attention when we examine
the phenomena of this era. But in order the more
easily to explain the peculiar nature and origin of that
group, it will be desirable, first, to give a brief sketch
of certain deposits of Central France, which afford
many interesting points of analogy to that of Faris,
both in organic remains and mineral composition, and
where the original circumstances under which the
strata were accumulated may more easily be dis
cerned.

Auvergne. — The deposits alluded to, which I ex-
amined in the summer of 1828, in company with Mr.
Murchison, are those of the lacustrine basins of AU- ’
vergne, Cantal, and Velay, and their sites may be
seen in the annexed map. They appear to be the mo-
numents of ancient lakes, which may have resembled
in geographical distribution some of those now existing
in Switzerland, and may like them have occupied the
depressions in a mountainous country, and have bee?
each fed by one or more rivers and torrents. The
country where they occur is almost entirely composed
of granite and different varieties of granitic schist, with
here and there a few patches of secondary strata much
dislocated, and which have probably suffered great de-
nudation. ‘There are also some vast piles of volcanic
matter (see the map), the greater part of which is
newer than the freshwater Strata, and is sometimes
seen to rest upon them, whilst a small part has evi-
dently been of contemporaneous origin. Of these
igneous rocks I shall treat more particularly in the
nineteenth chapter, and shall now speak only of the
lacustrine beds.

The most northern of the freshwater groups is sitd-
ated in the valley-plain of the Allier, which lies within

Fig. 144,

Freshwater

a
4

S
NORE:
D LTAL

146 EOCENE PERIOD. [Book IV-

the department of the Puy de Dome, being the tract
which went formerly by the name of the Limagne
d’ Auvergne. It is inclosed by two parallel primitive
ranges, — that of the Foréz, which divides the waters
of the Loire and Allier, on the east; and that of the
Monts Domes, which separates the Allier from the
Sioule, on the west.* The average breadth of this
tract is about twenty miles; and it is for the most part
composed of nearly horizontal strata of sand, sandstone,
calcareous marl, clay, and limestone, none of which
observe a fixed and invariable order of superposition: —
The ancient borders of the lake wherein the fresh-
water strata were accumulated, may generally be
traced with precision, the granite and other ancient
rocks rising up boldly from the level country. The
precise junction, however, of the lacustrine and granitic
beds is rarely seen, as a small valley usually intervenes
between them. The freshwater strata may sometimes
be seen to retain their horizontality within a very
slight distance of the border-rocks, while in some
places they are inclined, and in a few instances ver-
tical. The principal divisions into which the lacus-
trine series may be separated are the following : —
Ist, Sandstone, grit, and conglomerate, including red
marl and red sandstone. 2dly, Green and white
foliated marls. 3dly, Limestone or travertin, oolite-
4thly, Gypseous marls.

1. a. Sandstone and conglomerate. — Strata of sand
and gravel, sometimes bound together into a solid rock»
are found in great abundance around the confines of
the lacustrine basin, containing, in different places:
pebbles of all the ancient rocks of the adjoining ele-
vated country; namely, granite, gneiss, mica-schists

* Scrope, Geology of Central France, p. 15.

Ch. XVII] LACUSTRINE STRATA— AUVERGNE. 14:7

clay-slate, porphyry, and others. But the arenaceous
Strata do not form one continuous band around the
Margin of the basin, being rather disposed like the
dependent deltas which grow at the mouths of tor-
rents along the borders of existing lakes.*

At Chamalieres, near Clermont, we have an ex-
ample of one of these littoral groups of local extent,
Where the pebbly beds slope away from the granite as
if they had formed a talus beneath the waters of the
lake near the steep shore. A section of about fifty
feet in vertical height has been laid open by a torrent,
and the pebbles are seen to consist throughout of
rounded and angular fragments of granite, quartz, pri-
Mary slate, and red sandstone ; but without any inter-
Mixture of those volcanic rocks which now abound
in the neighbourhood. Partial layers of lignite and
Pieces of wood are found in these beds, but no shells ;
à fact which probably indicates that testacea could
Rot live where the turbid waters of a stream were
frequently hurrying down uprooted trees, together
With sand and pebbles, or that, if they existed, they
Were triturated by the transported rocks.

There are other localities on the margin of the basin
Where quartzose grits are found, composed of white
Sand bound together by a siliceous cement.

Occasionally, when the grits rest on granite, as at
Chamalieres before mentioned, and many other places,
the Separate crystals of quartz, mica, and felspar, of
the disintegrated granite, are bound together again by
the Silex, so that the granite seems regenerated in a
New and even more solid form; and thus so gradual a
Passage may easily be traced between a crystalline

* See book ii. chap. v.
H 2

148 EOCENE PERIOD. [Book 1V-

rock and one of mechanical origin, that we can scarcely
distinguish where one ends and the other begins.

In the Puy de Jussat, and the neighbouring hill of
La Roche, are white quartzose grits, cemented by
calcareous matter, which is sometimes so abundant as
to form imbedded nodules.: These sometimes consti-
tute spheroidal concretions six feet in diameter, and
pass into beds of solid limestone resembling the Italian
travertins, or the deposits of mineral springs.

In the hills above mentioned, we have the advan-
tage of seeing a section continuously exposed for about
seven hundred feet in thickness. At the bottom are
foliated marls, white and green, about four hundred
feet thick; and above, resting on the marls, are the
quartzose grits before mentioned, with the associated
travertins. This section is close to the confines of the
basin; so that the lake must here have been filled up
near the shore with fine mud, before the coarse super-
incumbent sand was introduced. There are other
cases where sand is seen below the marl.

1. b. Red marl and sandstone. — But the most re-
markable of the arenaceous groups is one of red sand-
stone and red marl, which are identical in all their
characters with the secondary new red sandstone and
marl of England. In these secondary rocks, the red
ground is sometimes variegated with light greenish
spots, and the same may be seen in the tertiary form-
ation of freshwater origin at Coudes, on the Allier-
The marls are sometimes of a purplish-red colour, as
at Champheix, and are accompanied by a reddish lime-
stone like the well-known “ cornstone,” which is asso-
ciated with the old red sandstone of English geologists-
The red sandstone and marl of Auvergne have evi-
dently been derived from the degradation of gneiss

Ch. XVIL] LACUSTRINE STRATA AUVERGNE 149

and mica-schist, which are seen én situ on the adjoin-
ing hills, decomposing into a soil very similar to the
tertiary red sand and marl. We also find pebbles of
SNeiss, mica-schist, and quartz, in the coarser sand-
Stones of this group, clearly pointing to the parent
rocks from which the sand and marl were derived.

he red beds, although destitute themselves of organic
remains, pass upwards into strata containing Eocene
ossils, and are certainly an integral part of the lacus-
trine formation.

2. Green and white foliated marls.— A great portion
of what we term clay in ordinary language consists of
the same materials as sand, but the component parts
are in a finer state of subdivision. The same primary
rocks, therefore, of Auvergne which, by the partial

gradation of their harder parts, gave rise to the
Wartzose grits and conglomerates before mentioned,
Would, by the reduction of the same materials into
Powder, and by the decomposition of their felspar,
Mica, and hornblende, produce aluminous clay ; and, if
à sufficient quantity of carbonate of lime was present,
Calcareous marl. This fine sediment would naturally
be Carried out to a greater distance from the shore, as
are the various finer marls now deposited in Lake
Uperior.* And, as in the American lake, shingle and
Sand are annually amassed near the northern shores,
Šo in Auvergne the grits and conglomerates before
Mentioned were evidently formed near the borders.
_ The entire thickness of these marls is unknown; but
it certainly exceeds, in some places, seven hundred
eet. They are for the most part either light-green
% white, and usually calcareous. They are thinly

* See Vol. I. p. 344.
H 3

150 EOCENE PERIOD. [Book IV.

foliated, —a character which frequently arises from the
innumerable thin plates or scales of that small animal
called Cypris; a genus which comprises several species;
of which some are recent, and may be seen swimming
swiftly through the waters of our stagnant pools and
ditches. The antennæ, at the end of which are fine

Cypris unifasciata, a living species, greatly Cypris vidua, a living species
magnified. greatly magnified.*

a. Upper part. 6. Side view of the same.

pencils of hair, are the principal organs for swimming;
and are moved with great rapidity. This animal re-
sides within two small valves not unlike those of a
bivalve shell, and moults its integuments annually,
which the conchiferous mollusks do not. This cir-
cumstance may partly explain the countless myriads
of the shells of cypris which were shed in the Eocene
lakes, so as to give rise to divisions in the marl as thin
as paper, and that too in stratified masses several
hundred feet thick. A more convincing proof of the
tranquillity and clearness of the waters, and of the
slow and gradual process by which the lake was filled
up with fine mud, cannot be desired. But we may

* See Desmarest’s Crustacea, plate 55

Ch. XVIL] LACUSTRINE STRATA — AUVERGNE. ‘151

easily suppose that, while this fine sediment was
thrown down in the deep and central parts of the
basin, gravel, sand, and rocky fragments were hurried
into the lake near the shore, and formed the group
described in the preceding section.

Not far from Clermont, the green marls, containing
the cypris in abundance, approach to within a few yards
BA

\ ie 147.

SETS

Vertical strata of marl near Clermont.

i ;

A. Granite. B. Space of sixty feet, in which no section is seen.
C. Green marl, vertical and inclined. D. White marl.

of the granite which forms the borders of the basin.
The annexed section occurs at Champradelle, in a
Small ravine north of La petite Baraque, and above
the bridge. .

The occurrence of these marls so near the ancient
Margin may be explained by considering that, at the
bottom of the ancient lake, no coarse ingredients were
deposited ‘in spaces intermediate between the points
Where rivers and torrents entered, but finer mud only
Was drifted there by currents. The verticality of some
of the beds in the above section bears testimony to
Considerable local disturbance subsequent to the de-
Position of the marls; but such inclined and vertical
Strata are very rare.

3. Limestone, travertin, oolite. — Both the preceding
Members of the lacustrine deposit, the marls and grits,

H 4

152 EOCENE PERIOD. [Book IV.

pass occasionally into limestone. Sometimes only
concretionary nodules abound in them ; but these,
where there is an increase in the quantity of cal-
careous matter, unite, as already noticed (p- 148.), into
regular beds. Fe

On each side of the basin of the Limagne, both on
the west at Gannat, and on the east at Vichy, a white
oolitic limestone is quarried. At Vichy, the. oolite
resembles our Bath stone in appearance and beauty;
and, like it, is soft when first taken from the quarry;
but soon hardens on exposure to the air. At Gannat,
the stone contains land-shells and bones of quadru-
peds, resembling those of the Paris gypsum. In
several places in the neighbourhood of Gannat, at
Marculot among others, this stone is divided by layers
of clay. |

At Chadrat, in the hill of La Serre, the limestone is
pisolitic, and in this and other respects resembles the
travertin of Tivoli. It presents the same combination
of a radiated and concentric structure, and the coats
of the different spheroids have the same undulating
surface.*

Indusial limestone. — There is another remarkable
form of freshwater limestone in Auvergne, called
« indusial,” from the Cases, or indusi@, of the larvee of
Phryganea, great heaps of which have been incrusted,
as they lay, by carbonate of lime, and formed into a
hard travertin. Several beds of this rock, either in
continuous masses, or in Concretionary nodules, are
seen superimposed one upon another, with layers of
marl interposed. We may often observe in our ponds
some of the living species of this kind of insect, covered

* See Fig. 12. Vol. I. p. 323,

Ch. XVIL] LACUSTRINE STRATA — AUVERGNE. 153

with small freshwater shells, which they have the

Power of fixing to the outside of their tubular cases, in
order, probably, to give them weight and strength.

Fig. 148. The individual figured in

the annexed cut, which be-

longs to a species very abun-

dant in England, has hap-

Eee pened to cover its case

Larva of recent Phryganea. * with shells of a small Plan-

orbis. In the same manner a large species which

‘warmed in the Eocene lakes of Auvergne was accus-

tomed to attach to its dwelling the shells of a small

Spiral univalve of the genus Paludina. A hundred of

these minute shells are sometimes seen arranged

around one tube, part of the central cavity of which is

often empty, the rest being filled up with thin concen-

tric layers of travertin. The cases have been thrown

together confusedly, and often lie, as in Fig. 149., at
"ight angles one to the other. When we consider
that ten or twelve tubes are packed within the com-
Pass of a cubic inch, and that some single strata of this
Mestone are six feet thick, and may be traced over a

a. Indusial limestone of Auvergne.
6. Fossil Paludina magnified.

* S . o . .
a I believe that the British specimen here figured is P. rhom-
ica, Linn.

H 5

~ 7

154 EOCENE PERIOD. [Book TV.

considerable area, we may form some idea of the count-
less number of insects and mollusca which contributed
their integuments and shells to compose this singularly
constructed rock. It is unnecessary to suppose that
the Phryganee lived on the spots where their cases
are now found; they may have multiplied in the shal-
lows near the margin of the lake, or in the streams by
which it was fed, and their buoyant cases may have
been drifted by a current far into the deep water.*
The calcareous strata of the Limagne, like the other
members of this lacustrine formation, are for the most
part horizontal, or inclined at a very slight angle, but
instances of local dislocation are sometimes observable.
At the town of Vichy, for example, in an ancient
quarry behind the convent of Celestines, the strata
dip at an angle of between thirty and forty degrees;
and near the hot spring at the same place, the beds
of limestone are seen, in one part of the section, in-
clined at an angle of eighty degrees, and in another
vertical. :
4. Gypseous marls.— More than fifty feet of thinly
laminated gypseous marls, exactly resembling those in
the hill of Montmartre, at Paris, are worked for gypsum
at St. Romain, on the right bank of the Allier. They
rest on a series of green cypriferous marls which
alternate with grit, the united thickness of this inferior
group being seen, in a vertical section on the banks of
the river, to exceed 250 feet,
General arrangement and origin of the freshwater
formations of Auvergne.— The relations of the different
groups above described cannot be learnt by the study

* For remarks on the floating of empty land shells by rivers,
see above, p. 33., and Vol. ITI. p. 360,

Ch. XVIL] LACUSTRINE STRATA'—AUVERGNE. 155

of any one section, and the geologist who sets out with
the expectation of finding a fixed order of succession
May perhaps complain that the different parts of the
asin give contradictory results. The arenaceous
division (i. p-146.), the marls (2. p. 149.), and the
limestone (3. p. 151.), may all be seen in some places
to alternate with each other ; yet it can by no means
be affirmed that there is no order of arrangement. The
Sands, sandstone, and conglomerate, constitute in ge-
Neral a littoral group; the foliated white and green
Marls, a contemporaneous central deposit; and the
limestone is for the most part subordinate to the
Newer portions of both. The uppermost marls and
Sands are rnore calcareous than the lower; and we
Never meet with calcareous rocks covered by a con-
Siderable thickness of quartzose sand or green marl.
From the resemblance of the Eocene limestones of
Auvergne to the Italian travertins, we may conclude
that they were derived from the waters of mineral
Springs, — such springs as now exist in Auvergne, and
Which, rising up through the granite, precipitate tra-
Vertin. They are sometimes thermal, but this cha-
Tacter is by no means constant.

It seems that, when the ancient lake of the Li-
Magne first began to be filled with sediment, no vol-
Canic action had yet produced lava and scoriz on any
Part of the surface of Auvergne. No pebbles, there-
fore, of lava were transported into the lake, — no
fragments of volcanic rocks imbedded in the conglo-
merate. But at a later period, when a considerable
thickness of sandstone and marl had accumulated,
eruptions broke out, and lava and tuff were deposited,
at some spots, alternately with the lacustrine strata.
Proofs of this will be given in the 19th chapter. It is

H 6

156 EOCENE PERIOD. [Book 1V-

not improbable that cold and thermal springs, holding
different mineral ingredients in solution, became more
numerous during the successive convulsions attending
this development of volcanic agency, and thus deposits
of carbonate and sulphate of lime, silex, and other
minerals were produced. Hence these minerals pre-
dominate in the uppermost strata. The subterranean
movements may then have continued until they altered
the relative levels of the country, and caused the waters
of the lakes to be drained off, and the farther accumu-
lation of regular freshwater strata to cease. The oc-
currence of these convulsions anterior to the Miocene
epoch, and their continuance during a succession 0
after-ages, may explain why no freshwater formations
more recent than the Eocene are now found in this
country.

We may easily conceive a similar series of events
to give rise to analogous results in any modern basin,
such as that of Lake’ Superior, for example, where
numerous rivers and torrents are carrying down the
detritus of a chain of mountains into the lake. The
transported materials must be arranged according to
their size and weight, the coarser near the shore, the
finer at a greater distance from land; but in the
gravelly and sandy beds of Lake Superior no pebbles
of modern volcanic rocks can be included, since there
are none of these at present in the district. If igneous
action should break out in that country and produce
Java, scoriz, and thermal springs, the deposition of
gravel, sand, and marl might still continue as before;
but in addition, there would then be an intermixture
of volcanic gravel and tuff, and of rocks precipitated
from the waters of mineral springs.

Although the freshwater strata of the Limagne ap-

Ch. XVIL] LACUSTRINE STRATA—PUY EN VELAY. 157

Proach generally to a horizontal position, the proofs of
local disturbance are sufficiently numerous and violent
to allow us to suppose great changes of level since the

Ocene period. We are unable to assign a northern
darrier to the ancient lake, although we can still trace
its limits to the east, west, and south, where they were
formed of bold granitic eminences. But we need not

© surprised at our inability to restore the physical
Seography of the country after so great a series of
volcanic eruptions ; for it is by no means improbable
that one part of it may have been moved upwards
bodily, while others remained at rest, or even suffered
à movement of depression.

Puy en Velay.—In the department of the Haute
Loire, a freshwater formation, very analogous to that
= Auvergne, is situated in the basin of the Loire, and
'S exposed in the valley in which stands the town of

e Puy. Since the deposition of the lacustrine strata,
there have been so many volcanic eruptions in this
“ountry, and such immense quantities of lava and
‘coria have been poured out upon the surface, that
the aqueous rocks are almost buried and concealed.

ut we are indebted to the researches of M. Bertrand
de Doue, for having distinctly ascertained the succes-
‘ton of strata, and I have myself had opportunities of
Verifying his observations during a visit to Le Puy.

th this basin we find, as in Auvergne, two great
Visions, consisting of grits and marls; the former
composed of quartzose grit, in some places resembling
Stanite, and of reddish and mottled sands and conglo-
Merates, All these were evidently derived from the
degradation of granitic rocks, and are very like the
drenaceous group of the Limagne before described.
hey are almost confined to the borders of the basin,

1638 EOCENE PERIOD. [Book IV.

and were evidently a littoral deposit. The othe!
member of the formation, the maris, are more or less
calcareous, and are associated with limestone and
gypsum, which last exactly resembles that of Paris,
and is worked for agricultural uses.

The analogy in the mineral charater of the Velay
and Paris basins is rendered more complete by the
presence in both of silex in regular beds. In the
limestone I found gyrogonites, or seeds of the Chara
of the same species as those most common in the
Paris basin; and M. Bertrand de Doue has discovered
the bones of several mammiferous animals of the same
genera as those which characterize the basins of Au-
vergne and Paris.* The species of shells also of this
formation are the same as those of Eocene formations
in other parts of France.

The sand and conglomerate of the freshwater basi?
of Velay are entirely free from volcanic pebbles, agree-
ing in this respect with the analogous group of the
Limagne; but the fact is the more striking in Velay»
because the masses of trachyte, clinkstone, and other
igneous rocks now abounding in that country, have an
aspect of very high antiquity, and constitute a most
prominent feature in the geological structure of the
district. Yet the non-intermixture of volcanic pro-
ducts with the lacustrine sediment, is just what we
should expect when we have ascertained that the im-
bedded organic remains of those strata are Eocene;
whereas the lavas belong in part, if not entirely, to the
Miocene period.+

Cantal. — Near Aurillac, in Cantal, another series
of freshwater strata occurs, which resembles, in mi-

* Descrip. Géognos. des Env. du Puy en Velay, 1823.
+ See p. 136., and chap. xix.

Ch, XVIL] LACUSTRINE STRATA — CANTAL. 159

neral character and organic remains, those of Auvergne
and Velay already described. The leading feature of
this group, as distinguished from the two former, is
the immense abundance of silex associated with the
calcareous marls and limestone, which last constitute,
like the limestone of Auvergne, an upper member of
the freshwater series. l
The formations of the Cantal may be divided into
two groups, the lower composed of gravel, sand, and
clay, such as might have been derived from the wear-
ng down and decomposition of the granitic schists of
the Surrounding country ; the upper system, consisting
of siliceous and calcareous marls, contains subordin-
ately gypsum, silex, and limestone — deposits such as
the waters of springs charged with carbonate and sul-
Phate of lime, and with silica, may have produced.
Freshwater limestone and Jlints resembling chalk. —
-0 the English geologist, the most interesting feature
‘NX the Cantal is the resemblance of the freshwater
limestone, and its accompanying flint, to our upper
Chalk ; a resemblance which (like that of the red sand-
Stone of Auvergne to our secondary “ new red”) is
the more important, as being calculated to put the
Student upon his guard against relying too implicitly
0n lithological characters as tests of the relative ages
frocks. When we approach Aurillac from the west,
We pass over great heathy plains, where the sterile
Mica-schist is barely covered with vegetation. Near
trac, and between La Capelle and Viscamp, we find
the Surface strewed over with loose broken flints, some
of them black in the interior, but with a white externa!
Coatings; others stained with tints of yellow and red,
‘nd in appearance precisely like the flint gravel of our
chalk districts. When heaps of this gravel have thus

160 a EOCENE PERIOD. [Book IV:

announced our approach to a new formation, we arrivé
at length at the escarpment of the lacustrine beds. At
the bottom of the hill which rises before us, we see
strata of clay and sand resting on mica-schist ; and
above, in the quarries of Belbet, Leybros, and Bruel,
a white limestone, in horizontal strata, the surface of
which has been hollowed out into irregular furrows
since filled up with broken flint, marl, and dark vege
table mould. In these cavities we recognize an exact
Counterpart to those which are so numerous on the
furrowed surface of our own white chalk. Advancing
from these quarries, along a road made of the white
limestone, which reflects as glaring a light in the sun,
as do our roads composed of chalk, we reach, at length,
in the neighbourhood of Aurillac, hills of limestone and
calcareous marl, in horizontal Strata, separated in some
places by regular layers of flint in nodules, the coat-
ing of each nodule being of an Opaque white colou!;
like the exterior of the flinty nodules of our chalk.
This hard white substance has been ascertained i”
England to consist, in some instances, wholly of sili-
ceous matter, and sometiines to contain a small admix-
ture of carbonate of lime*, and the analysis of the
similar rocks in the Cantal would probably give the
same results. The Aurillac flints have precisely the
appearance of having separated from their matrix after
the siliceous and calcareous matter had been blended
together. The calcareous marl sometimes occupies
small sinuous cavities in the flint ; and the siliceous
nodule, when detached, is often as irregular in form as
those found in our chalk.

ze Phillips, Geol. Trans., First Series, vol. y. p. 22, — Outlines
of Geology, p. 95.

Ch. XVIL] LACUSTRINE STRATA—CANTAL. 161

By what means, then, can the geologist at once
decide that the limestone and silex of Aurillac are
referable to an epoch entirely distinct from that of
the English chalk? It is not by reference to position ;
r we can merely say of the lacustrine beds, as we
Should have been able to declare of the true chalk had
it been present, that they overlie the granitic rocks of
this part of France. It is from the organic remains
only that we are able to pronounce the formation to
elong to the Eocene tertiary period. Instead of the
Marine Alcyonia of our cretaceous system, the silici-
€d seed-vessels of the Chara, a plant which grows at
the bottom of lakes, abound in the flints of Aurillac,
oth in those which are im situ and those forming the
Stavel. Instead of the Echini and marine testacea of
the chalk, we find in these marls and limestones the
shells of the Planorbis, and other lacustrine testacea,
all of them, like the gyrogonites, agreeing specifically
With Species of the Eocene type. .

Proofs of the gradual deposition of marl. — Some
ections of the foliated marls in the valley of the Cer,
Near Aurillac, attest, in the most unequivocal manner,

© extreme slowness with which the materials of the
*Custrine series were amassed. In the hill of Barrat,
x example, we find an assemblage of calcareous and
siliceous marls, in which, for a depth of at least sixty
“et, the layers are so thin that thirty are sometimes
“ontained in the thickness of an inch; and when they
“Te separated we see preserved in every one of them
e flattened stems of Charæ, or other plants, or some-
‘Mes myriads of small paludine and other freshwater
shells, These minute foliations of the marl resemble
P "ecisely some of the recent laminated beds of the
Cotch marl lakes, and may be compared to the pages

162 EOCENE PERIOD. [Book IV.

of a book, each containing a history of a certain period
of the past. The different layers may be grouped
together in beds from a foot to a foot and a half in
thickness, which are distinguished by differences of
composition and colour, the tints being white, greens
and brown. Occasionally there is a parting layer of
pure flint, or of black carbonaceous vegetable matte!
about an inch thick, or of white pulverulent marl.
We find several hills in the neighbourhood of Aurillac
composed of such materials for the height of moré
than 200 feet from their base, the whole sometimes
covered by rocky currents of trachytic or basaltic
lava. *

Thus wonderfully minute are the separate parts
of which some of the most massive geological mont-
ments are made up! When we desire to classify
it is necessary to contemplate entire groups of strata
in the aggregate; but if we wish to understand
the mode of their formation, and to explain theif
origin, we must think only of the minute subdi-
visions of which each mass is composed. We must
bear in mind how many thin leaf-like seams of matte!
each containing the remains of myriads of testace@
and plants, frequently enter into the composition of 4
single stratum, and how vast a succession of these
strata unite to form a single group! We must re-
member also, that volcanos like the Plomb du Cantal,
which rises in the immediate neighbourhood of Au-
rillac, are themselves equally the result of succes
sive accumulation, consisting of reiterated flows of
lava and showers of scoriæ ; and I have shown, whe?

* Lyell and Murchison, sur les Dépôts Lacust. Tertiaires 44
Cantal, &c. Ann. des Sci. Nat., Oct. 1829.

c
h. XVIL] LACUSTRINE STRATA — CANTAL. 163

treating of the high antiquity of Etna, how many dis-
tinct lava-currents and heaps of ejected substances
are required to make up one of the numerous conical
envelopes whereof a volcano is composed. — Lastly,
Re Must not forget that continents and mountain-
Chains, colossal as are their dimensions, are nothing
more than an assemblage of many such igneous and
aqueous groups, formed in succession during an

por lapse of ages, and superimposed upon each
er,

CHAPTER XVIII..
EOCENE FORMATIONS — PARIS BASIN.

Marine Eocene strata — Paris basin how far analogous to deposits
of Central France — Connexion of Auvergne and Paris basin’
— Groups in Paris basin — Observations of M. C. Prevost—
Contemporaneous marine and freshwater strata — Abundant?
of Cerithia (p. 169.) — Upper marine formation — All th?
Parisian groups Eocene — Microscopic shells (p. 17 6.)— Bon
of quadrupeds in gypsum — Strata with and without organit
remains alternating — Extent of our knowledge of thé

physical geography, fauna, and flora of the Eocene period ~
Concluding remarks.

THE geologist who has studied the lacustrine form-
ations described in the last chapter cannot enter thé
tract usually termed “the Paris Basin” without im-
mediately recognizing a great variety of rocks witb
which his eye has already become familiar. The green
and white marls of Auvergne, Cantal, and Velay»
again present themselves, together with limestones and
quartzose grits, siliceous and gypseous marls, nodules
and layers of flint, and saccharoid gypsum ; lastly, 1”
addition to all this identity of mineral character, he
finds an assemblage of the same species of fossil ani-
mals and plants,

When we consider the geographical proximity of
the two districts, we are the more prepared to ascribe
this correspondence in the mineral composition of
these groups to a combination of similar circumstances

Ch, Xvi PARIS BASIN. i 165

at the same era. From the map (Fig. 144. p. 145.) in
the last chapter, it will be seen that the united waters
* the Alier and Loire, after descending from the
valleys occupied by the freshwater formations of
“ntral France, flow on till they reach the southern
“<tremity of what is called the Paris basin. M. Oma-
‘Us d’Halloy long ago suggested the very natural idea
àt there existed formerly a chain of lakes, reaching
“om the highest part of the central mountain-group
rance, and terminating in the basin of Paris, which
è Supposes was at that time an arm of the sea.
: Notwithstanding the great changes which the phy-
“ical Seography of this part of France must since have
Pi €rgone, we may easily conceive that many of the
Principal features in the configuration of the country
~~ have remained unchanged, or but slightly modified.
ills of volcanic matter have indeed been formed since
© Eocene formations were accumulated, and the
Svels of large tracts have been altered in relation to
> Sea; lakes have been drained, and a gulf of the
N turned into dry land, but many of the reciprocal
ations of the different parts of the surface may still-
“Main the same. The waters which flowed from the
Sanitic heights into the Eocene lakes may now
“Scend in the same manner through valleys once the
“Sins of those lakes. Let us, for illustration, suppose
the; Steat Canadian lakes, and the gulf into which
w waters are discharged, to be elevated and laid
"Y by subterranean movements. The whole hydro-
“aphical basin of the St. Lawrence might be upraised
eg these convulsions, yet that river might continue,
1 after so extraordinary a revolution, to drain the
© elevated regions, and might still convey its
“ters in the same direction from the interior of the

166 EOCENE PERIOD. [Book 1V

continent to the Atlantic. Instead of traversing thé
lakes, it would hold its course through deposits of
lacustrine sand and shelly marl, such as we know to bè
now forming in Lakes Superior and Erie; and thes?
freshwater strata would occupy the site, and bea"
testimony to the pristine existence of the lakes. Ma-
rine strata may also be brought into view in the spac?
where an inlet of the sea, like the estuary of the St.
Lawrence, had once received the continental waters?
and in such formations we might discover shells of
lacustrine and fluviatile species intermingled with
marine testacea and zoophytes.

Subdivisions of strata in the Paris basin.— The are?
which has been called the Paris basin is about 180
miles in its greatest length from north-east to south-
west, and about ninety miles from east to west. This
space may be described as a depression in the chalk
(see Fig. 82. Vol. IIT. p. 332.), which has been filled up
by alternating groups of marine and freshwater strat
MM. Cuvier and Brongniart attempted in 1811 to dis-
tinguish five different formations, and to arrange them!
in the following order, beginning with the lowest: —
Plastic clay.

Lignite.
First sandstone.

1. First freshwater
formation ..ccecccceceeceees

2, First marine form- : 3
Calcaire grossier.

3. Second kad Siliceous limestone.

formation Gypsum, with bones of animals.

Freshwater marls.

Gypseous marine marls.

Upper marine sands and sandstones.
Upper marine marls and limestones.
g. Third freshwater Siliceous millstone, without shells.
£ ORPA = : ° ¥ Siliceous millstone, with shells.

a i *** | Upper freshwater marls.

4. Second marine
formation

Ch'XVIIL] PARIS BASIN. 167

These formations were supposed to have been de-
Posited in succession upon the chalk; and it was
Magined that the waters of the ocean had been by
turns admitted into and excluded from the same
"egion. But the subsequent investigations of several
S€ologists, especially of M. Constant Prevost *, have
ed to great modifications in the theoretical views en-
tertained respecting the order in which the several
S'oups were formed ; and it now appears that the form-
ations Nos. 1, 2, and 3. of the table of MM. Cuvier and

Tongniart, instead of having originated one after the
Other, are divisible into four nearly contemporaneous
Soups.

Superposition of different formations in the Paris
asin. — A comparison of the two accompanying dia-
8tams will show at a glance the different relations

Fig. 150. Fig. 151.
~ *tongniart. M. Constant Prevost.
a k.

=

J, Upper Freshwater

4. Upper Marine
L
7 EE ETE
3 Z
Cale. Sil. ale. Gros.

l d. Plastic Clay

UM Chalk

* Bulletin des Sci. de la Soc. Philom., May, 1825, p- 74

168 EOCENE PERIOD, [Book IV:

which the several sets of strata bear to each other
according to the original as well as the more moder?
classification. I shall now proceed to lay before the
reader a brief sketch of the several sets of strata re”
ferred to in the above systems.

Immediately upon the chalk a layer of broken chalk
flints, often cemented into a breccia by siliceous sand
is very commonly found. These flints probably indi-
cate the action of the sea upon reefs of chalk when 3
portion of that rock had emerged, and before the
regular tertiary beds were superimposed. To this
partial layer no reference is made in the annexed
sections.

Plastic clay and sand. — Upon this flinty stratum;
or, if it be wanting, upon the chalk itself, rests fre”
quently a deposit of clay and lignite (No. 1. of the
above tables). It includes the remains of freshwate!
shells and drift-wood, and was, at first, regarded as 4
proof that the Paris basin had originally been filled
with fresh water. But it has since been shown that
this group is not only of very partial extent, but is bY `
no means restricted to a fixed place in the series ; fot
it alternates with the marine calcaire grossier (No. 2:
of the tables), and is repeated in the very middle of
that limestone at Veaugirard, Bagneux, and other
places, where the same Planorbes, Paludinæ, and Lim-
neæ occur.* M. Desnoyers pointed out to me a sec-
tion in the suburbs of Paris, laid open in 1829, where
a similar intercalation was seen in a still higher part
of the calcaire grossier. These observations relieve US
from the difficulty of seeking a cause why vegetable
matter, and certain species of freshwater shells and 3

* Prevost, Sur les Submersions Itératives, &c. Mém. de 12
Soc. @Hist. Nat. de Paris, tome iy, p: 74.

Ch XVIIL] PARIS BASIN, 169

Particular kind of clay, were at first introduced into
the basin, and why the same space was subsequently
Usurped by the sea. A minute examination of the phe-
nomena leads us simply to infer, that a river charged
with argillaceous sediment entered a bay of the sea
and drifted into it, from time to time, freshwater shells
aad wood.
Caleaire grossier. — The calcaire grossier above al-
uded to, is a coarse limestone, often passing into sand,
Such as may perhaps have been in part derived from
© aqueous degradation of a chalk country. It con-
ains by far the greater number of the fossil shells
Which characterize the Paris basin. No less than 400
istinct species have been procured from a single spot
Near Grignon. They are imbedded in a calcareous
Sand, chiefly formed of comminuted shells, in which,
nevertheless, individuals in a perfect state of preserv-`
ation, both of marine, terrestrial, and freshwater spe-
“es, are mingled together, and were evidently trans-
Ported from a’ distance. Some of the marine shells
May have lived on the spot ; but the Cyclostoma and
‘Mnea must have been brought thither by rivers and
Currents, and the quantity of triturated shells implies
“siderable movement in the waters.
thing is more striking in this assemblage of
*ssil_testacea than the great proportion of species
~ferable to the genus Cerithium. (See fig. 152.)
“te occur no less than one hundred and thirty-seven
‘Pecies of this genus in the Paris basin, and almost all
them in the calcaire grossier. Now the living tes-
acea of this genus inhabit the sea near the mouths of
"Wets, where the waters are brackish, so that their
abundance in the marine strata of the Paris basin is in

rfect harmony with the hypothesis before advanced,
VOL. ty. I

EOCENE PERIOD. - pBook 1%

Fig. 152. that a river flowed into the gulf, and gave risë
to the beds of clay and lignite before me?”
tioned. But there are ample data for infer-
ring that the gulf was supplied with fresh
water by more than one river; for while the
calcaire grossier occupies the northern part
of the Paris basin, another contemporaneous
deposit, of freshwater origin, appears at the
southern extremity.

Calcaire siliceux.— This group (No. 3. of
the foregoing tables) is a compact siliceo¥®
limestone, which resembles a precipitate from

ee pa the waters of mineral springs. It is often tra

cinctum.* versed by small empty sinuous cavities; #
for the most part devoid of organic remains, but in
some places contains freshwater and. land species
and never any marine fossils. The siliceous lime-
stone and the calcaire grossier occupy distinct parts ®
the basin, the one attaining its fullest development iB
those places where the other is of slight thickness

They also alternate with each other towards the cent"?

of the basin, as at Sergy and Osny; and there are eves

points where the two rocks are so blended togethet
that portions of each may be seen in hand specimens

Thus in the same bed, at Triel, we have the compact

freshwater limestone, characterized by its Limne®

mingled with the coarse marine limestone throug?
which the small multilocular shell, called milliolite, is
dispersed in countless numbers. These microscopi?
testacea are also accompanied by Cerithia and other
shells of the calcaire grossier. It is very extraordinay
that in this instance both kinds of sediment must have
been thrown down together on the same spot, 4”

* This species is found also in the Paris and London pasins-

Ch. XVIIL] PARIS BASIN. “ rik

each has still retained its own peculiar organic remains.
his limestone was pointed out to me by M. Prevost,
oth ôn situ at Triel, and in hand specimens in his
Cabinet,

These facts lead irresistibly to the conclusion, that
While to the north, where the bay was probably open
to the sea, a marine limestone was formed, another

eposit of freshwater origin was introduced to the
Southward, or at the head of the bay ; for it appears _
that during the Eocene period, as now, the ocean was
to the north; and the continent, where the great lakes
existed, to the south. From that southern region we
may suppose a body of fresh water to have descended
charged with carbonate of lime and silica, the water

eing perhaps in sufficient volume to convert-the upper
€nad of the bay into fresh water, like some of the gulfs
of the Baltic.

_ Gypsum and marls. — The next group to be con-
Sidered is the gypsum, and the white and green marls,
Subdivisions of No. 3. of the table of Cuvier and

rongniart. These were once supposed to be entirely
Subsequent in origin to the two groups already con-

Sidered ; but M. Prevost has pointed out that in some
°calities they alternate repeatedly with the calcaire
Siliceux, and in others with some of the upper mem-

“ts of the calcaire grossier. The gypsum, with its
"sociated marl and limestone, is in greatest force
towards the centre of the basin, where the two groups

fore mentioned are less fully developed; and M.

"evost infers, that while those two principal deposits
Were gradually in progress, the one towards the north,
Ad the other towards the south, a river descending
rom the east may have brought down the gypseous
and marly sediment.

r2

172 EOCENE PERIOD. [Book 1V-

It must be admitted, as highly probable, that a bay
or narrow sea, 180 miles in length, would receive, at
more points than one, the waters of the adjoining
continent ; at the same time I may observe, that if the
gypsum and associated green and white maris of
Montmartre were derived from a hydrographical basin
distinct from that of the southern chain of lakes before
adverted to, this basin must nevertheless have been
placed under circumstances extremely similar; for the
identity of the rocks of Velay and Auvergne with the
freshwater group of Montmartre, is such as can scarcely
be appreciated by geologists who have not carefully
examined the structure of both these countries.

Some readers may think that the view above give!
of the arrangement of four different sets of strata iD
the Paris basin is far more obscure and complicated
than that first presented to them in the system of
MM. Cuvier and Brongniart. Undoubtedly ‘the rela-
tions of the several groups are less simple than thé
first observers supposed, being much more analogous
to those before described in the lacustrine deposits
of Central France. The simultaneous deposition of
two or more groups of strata in one basin, some of
them freshwater and others marine, must always pro-
duce very coraplex results; but in proportion as it ÍS
more difficult in these cases to discover any fixed
order of superposition in the associated mineral masses
so also is it more easy to explain the manner of their
origin, and to reconcile their relations to the agency of
known causes. Instead of the successive irruptio?®
and retreats of the sea, and changes in the chemical
nature of the fluid and other speculations of the earliet
geologists, we are now simply called upon to imagine
a gulf, into one- extremity of which the sea entere%

Ch. XVIIL] PARIS BASIN. 173

and at the other a large river, while other streams may
have flowed in at different points, whereby an inde-
finite number of alternations of marine and freshwater
beds would be occasioned.

Second or Upper marine group. — The next group,
called the second or upper marine formation (No. 4. of
the tables), consists in its lower division of green marls,
Which alternate with the-freshwater beds of gypsum
and marl last described. Above this division the pro-
ducts of the sea exclusively predominate, the beds

eing chiefly formed of micaceous and quartzose sand,

eighty feet or more in thickness, surmounted by beds
of sandstone, with scarcely any limestone. The sum-
mits of a great many platforms and hills in the Paris
basin consist of this upper marine series.

I fully agree with M. C. Prevost that the alternation
of the various marine and freshwater formations before
described admit of a satisfactory explanation without
Upposing different retreats and subsequent returns
of the sea; yet I think that a subsidence of the soil
Would best account for the position of these upper
Marine sands. Oscillations of level may have oc-
“urred, in consequence of which the sea and a river
may have prevailed each in their turn for a time, until
àt length, by a more considerable sinking down of part
of the basin, a tract previously occupied by fresh
Water was converted into a sea of moderate depth.

Th one part of the Paris basin there are decisive
Proofs that during the Eocene period, and before the
UPper marine sand was formed, parts of the calcaire
Stossier were exposed to the action of denuding
Causes, At Valmondois, for example, a deposit of the
“pper marine sandstone is found, in which rolled

locks of the calcaire grossier with its peculiar fossils,
1 3

174 EOCENE PERIOD. [Book IV-

and fragments of a limestone resembling the calcaire
siliceux, occur.* These calcareous boulders are rolled
and pierced by perforating shells belonging to no less
than fifteen distinct species. Both the blocks and
many worn shells washed out from the calcaire gros-
sier, are found mingled with the ordinary fossils of the
upper marine sand.

We have seen that the same earthquake in Cutch
could raise one part of the delta of the Indus and
depress another, and cause the river to cut a passage
through the upraised strata, and carry down the mate-
rials removed from the new channel into the sea. Al
these changes, therefore, might happen within a short
interval of time between the deposition of two sets of
strata in the same delta.+

It is not improbable, then, that the same convul-
sions which caused one part of the Paris basin to sink
down, so as to let in the sea upon the area previously
covered by gypsum and freshwater marl, may have
lifted up the calcaire grossier and the siliceous lime-
stone, so that they might be acted upon by the waves,
and fragments of them swept down into the contiguous
sea, there to be drilled by boring testacea.

It is observed that the older marine formation at
Laon is now raised three hundred metres or nearly
one thousand feet above the sea, whereas the upper
marine sands never attain half that elevation. Such
may possibly have been the relative altitude of the
two groups when the newest of them was deposited.

* M. Deshayes, Mémoires de la Soc, d’Hist. Nat. de Paris
tom. i. p. 243. The sandstone is there called, by mistake, grés
marin inférieur, instead of supérieur, to which last the author ba$
since ascertained it to belong. :

+ Vol. II, p. 194

Ch. XVII] PARIS BASIN. 175

Third freshwater formation.— We have still to con-
Sider another formation, the third freshwater group
(No. 5. of the preceding tables). It consists of marls
Interstratified with beds of flint and layers of flinty
nodules. One set of siliceous layers is destitute of
organic remains, the other replete with them.

Gyrogonites, or fossil seed-vessels of charz, are
found abundantly in these strata; and all the animal
and vegetable remains agree well with the hypothesis,
that after the gulf or estuary had been silted up with
the sand of the upper marine formation, a great number
of marshes and shallow lakes existed, like those which
frequently overspread the newest parts of a delta.
These Jakes were fed by rivers or springs which con-
tained, in chemical solution or mechanical suspension,
Such kinds of sediment ‘as we have already seen to
have been deposited in the lakes of Central France
during the Eocene period.

The Parisian groups all Eocene.— Having now given
à rapid sketch ‘of the different groups of the Paris
basin, I may observe generally that they all belong
to the Eocene epoch, although the entire series must
doubtless have required an immense lapse of ages for
its accumulation. The shells of the different fresh-
Water groups, constituting at once some of the lowest
and uppermost members of the series, are nearly all
referable to the same species, and the discordance
between the marine testacea of the calcaire grossier
and the upper marine sands is very inconsiderable.

A curious observation has been made by M. Des-

ayes, in reference to the changes which one species,
the Cardium porulosum, has undergone during the long
Period of its existence in the Paris basin. Different
Varieties of this cardium are characteristic of different

` r4

176 EOCENE PERIOD. [Book IV.

strata. In the older sand of the Soissonais (a marine
formation underlying the regular beds of the calcaire
grossier), this shell acquires but a small volume, and

Fig.153. ge

S

if) iOS
3 | \ N \ S X
VANNY NENN
Cardium porulosum. Paris and London basins.

has many peculiarities, which disappear in the lowest
beds of the calcaire grossier. In these the shell attains
its full size, and many peculiarities of form, which are
again modified in the uppermost beds of the calcaire
grossier; and these last characters are preserved
throughout the whole of the “ upper marine” series.*
Miliolite limestone and microscopic shells. — In some
parts of the calcaire grossier round Paris, certain
‘beds occur of a stone used in building, and called by
the French geologists miliolite limestone. It is almost
entirely made up of millions of small shells of the size
of minute grains of sand, which all belong to the same
class, but are of distinct species from those found in
the Older Pliocene beds of Italy. These minute fossil
bodies consist of multilocular shells, which were for-
merly referred to the order Cephalopoda, by M.
D’Orbigny, but M. Dujardin has shown that some of
them do certainly not belong to that order. They
were separated by D’Orbigny from the nautilus and
ammonite, by their having no siphon or internal tube
connecting the different chambers, and were called by
him Foraminifera. They are often in an excellent

* Coquilles caractérist. des Terrains, 1831.

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Ch. XVIIL] MAMMIFEROUS REMAINS IN GYPSUM. 177

State of preservation, and their forms are singularly
diferent from those of the larger testacea.

A plate of some of these is given, from unpublished

Tawings by M. Deshayes, who has carefully selected

© most remarkable types of form. The natural size
% each species figured (Plate XIII.) is indicated by
ch minute points, that it is necessary to call atten-
tion to them, as they might otherwise be overlooked.

t should also be mentioned that the genus miliolite of
' ~amarck has since been subdivided into several genera,

“hong which are the Triloculina and Quinqueloculina

‘gured in the plate (Pl. XIIL).

Characteristic shells. — The species of shells figured
the annexed plate are common in the Paris basin,
and may be considered as characteristic of the Eocene
Period generally. They appear as yet to be exclu-
Sively confined to deposits of that period, and are for
the most part abundant in them wherever they have

ĉen attentively studied. (P1 XIV.)

Bones of quadrupeds in gypsum.— I have already
“Onsidered the position of the gypsum which occurs in
the form of a saccharoid rock “in the hill of Mont-
Martre at Paris, and other central parts of the basin.
At the base of that hill it is seen distinctly to alternate
With soft marly beds of the calcaire grossier, in which
“erithia and other marine shells occur. But the great
Mass of gypsum may be considered as a purely fresh-
Water deposit, containing land and fluviatile shells,
together. with fragments of palm-wood, and great
Ambers of skeletons of quadrupeds and birds, an
*ssemblage of organic remains which has given great
“elebrity to the Paris basin. The bones of freshwater
sh, also, and of crocodiles, and many land and fluvia-
tile reptiles, occur in this rock. The skeletons of mam-

15

178 EOCENE PERIOD. [Book IV.»

malia are usually isolated, often entire, the most deli-
cate extremities being preserved, as if the carcasses»
clothed with their flesh and skin, had been floated
down soon after death, and while they were still swoln
by the gases generated by their first decomposition-
The few accompanying shells are of those light kinds
which frequently float on the surface of rivers together
with wood.

M. Prevost has therefore suggested that a river may
have swept away the bodies of animals, and the plants
which lived on its borders,xor in the lakes which it
traversed, and may have carried them down into the
centre of the gulf into which flowed the waters im-
pregnated with sulphate of lime. We know that the
Fiume Salso in Sicily enters the sea so charged with
various salts that the thirsty cattle refuse to ital of
it. A stream of sulphureous water, as white as milk,
descends into the sea from the volcanic mountain of
Idienne, on the east of Java; and a great body of hot
water, charged. with sulphuric acid, rushed down from
the same volcano on one occasion, and inundated @
large tract of country, destroying, by its noxious pro-
perties, all the vegetation.* In like manner the Pu-
sanibio, or “ Vinegar River,” of Colombia, which rises
at the foot of Puracé, an extinct volcano, 7500 feet
above the level of the sea, is strongly impregnated
with sulphuric and muriatic acids, and with oxide of
iron. We may easily suppose the waters of such
streams to have properties noxious to marine animals,
and in this manner the entire absence of marine re”
mains in the ossiferous gypsum may be explained.t

* Leyde Magaz. voor Wetensch Konst en Lett., partie Y»
cahier i. p. 71. Cited by Rozet, Journ. de Géologie, tom. i. p, 4%
+ M..C.. Prevost, Submersions Itératives, &c. Note 23.

Ch. XVIII] MAMMIFEROUS REMAINS IN GYPSUM. 179

There are no pebbles or coarse sand in the gypsum ;
à circumstance which agrees well with the hypothesis
that these beds were precipitated from water holding
sulphate of lime iw solution, and floating the remains

“of different animals. The bones of land quadrupeds,
Owever, are not confined entirely to the freshwater
formation to which the gypsum belongs; for the re-
Mains of a Paleotherium, together with some fresh-
Water shells, have been found in a marine stratum be-
nging to the calcaire grossier at Beauchamp.

Tn the gypsum the remains of about fifty species of
quadrupeds have been found, all extinct, and nearly
four-fifths of them belonging to a division of the order
Pachydermata, which is now represented by only four
living species ; namely, three tapirs and the daman of
the Cape. With them a few carnivorous animals are
*Ssociated, among which are a species of fox and gen-
Ret. Of the Rodentia, a dormouse and a squirrel; of
the Insectivora, a bat; and of the Marsupialia (an
rder now confined to America, Australia, and some
“ontiguous islands), an opossum, have been discovered.

Of birds, about ten species have been ascertained,
the skeletons of some of which are entire. None of
them are referable to existing species.* The same
“emark applies to the fish, according to MM. Cuvier
d Agassiz, as also to the reptiles. Among the last
are crocodiles and tortoises of the genera Emys and
Trionix. :

The tribe of land quadrupeds most abundant in this
formation is such as now inhabits alluvial plains and
marshes and the banks of rivers and lakes, a class most

* Cuvier, Oss. Foss., tom. iii. p. 255.

1 6

180 EOCENE PERIOD. [Book IV.

exposed to suffer by river inundations. Whether the
disproportion of carnivorous animals can be ascribed
to this cause, or whether they were comparatively
small in number and dimensions, as in the indigenous
fauna of Australia, when first known to Europeans, 18
a point on which it would be rash, perhaps, to offer an
opinion in the present state of our knowledge.

We have no reason to-be surprised that all the
species of vertebrated animals hitherto observed are
extinct, when we recollect that out of 1122 species of
fossil testacea obtained from the Paris basin, thirty-
eight only can be identified with species now living:
I have more than once adverted to the fact, that ex-
tinct mammalia are often found associated with assem-
blages of recent shells, a fact from which I have inferred
the inferior duration of species of the mammalia as com-
pared with the testacea ; and it is not improbable that
the higher order of animals in general may more readily
become extinct than the marine mollusca. Some of
the thirty-eight species of testacea above alluded to;
as having survived from the Eocene period to our ow?
times, have now a wide geographical range, as, for ex-
ample, Lucina divaricata*, and are therefore fitted to
exist under a great variety of circumstances. On the
other hand, the great proportion of the Eocene marine
testacea which have become extinct sufficiently de-
monstrates that the loss of species has been due t0
general laws ; and that a sudden catastrophe, such as
the invasion of a whole continent by the sea — a cause
which could annihilate only the terrestrial and fresh-

water tribes, — is an hypothesis wholly inadequate to
account for the phenomenon,

* See Fig. 85. Vol. III. p. 372.

Ch. XVIII] CONCLUDING REMARKS. 181

Strata with and without organic remains alternating.
— Between the gypsum of the Paris basin and the
Upper marine sands a thin bed of oysters is found,
Which is spread over a remarkably wide area. From
the manner in which they lie, it is inferred that they
did not grow on the spot, but that some current swept
them away from a bed of oysters formed in some other
Part of the bay. The strata of sand which immediately
Tepose on the oyster-bed are quite destitute of organic
“emains ; and nothing is more common in the Paris ba-
Sin and in other formations, than alternations of shelly
beds with others entirely devoid of them. The tempo-
‘ary extinction and renewal of animal life at successive
Periods have been inferred from such phenomena,
Which may nevertheless be explained, as M. Prevost
justly remarks, without appealing to any such extra-
ordinary revolutions in the state of the animate cre-
ation, A current one day scoops out a channel in a
bed of shelly sand and mud, and the next day, by a
Slight alteration of its course, ceases to prey upon the
Same bank. It may then become charged with sand
Unmixed with shells, derived from some dune, or
brought down by a river. In the course of ages an
definite number of transitions from shelly strata to
those without shells may thus be caused.

Concluding remarks. — It will be seen by our ob-
Servations on Auvergne and other parts of Central
France, and-on the district round Paris, that geologists
have already gained a considerable insight into the
State of the physical geography of part of Europe during
the Eocene period. We can point to some districts
Where lakes and rivers then existed, and to the site of
Some of the lands encircling those lakes, and to the po-

Sition of a great bay of the sea, into which their surplus

182 EOCENE PERIOD. [Book IV.

waters were discharged. We can also show, as I shall
endeavour to explain in the next chapter, the points
where some volcanic eruptions took place. Much
information has been acquired respecting the quadru-
peds which inhabited the land at that period, and con-
cerning the reptiles, fishes, and testacea which swarmed
in the waters of lakes and rivers; and we have a col-
lection of the marine Eocene shells more complete
than has yet been obtained from any existing sea 0
equal extent in Europe. Nor are the contemporary
fossil plants altogether unknown to us, which, like
the animals, are of extinct species, and indicate 4
warmer climate than that now prevailing in the same
latitudes.

When we reflect on the tranquil state of the earth,
implied by some of the lacustrine and marine deposits
of this age, and consider the fulness of all the different
classes of the animal kingdom, as deduced from the
study of the fossil remains, we are naturally led to
conclude, that the earth was at that period in a per-
fectly settled state, and already fitted for the habitation
of man.

The heat of European latitudes during the Eocene
period does not seem to have been superior, if equal,
to that now experienced between the tropics; some
living species of molluscous animals, both of the land,
the lake, and the sea, existed when the strata of the
Paris basin were formed; and the contrast in the of-
ganization of the various tribes of Eocene: animals,
when compared to those now co-existing with man,
although striking, is not, perhaps, so great as between
the living Australian and European types. At the
same time, we must be fully aware that we cannot
reason with any confidence on the capability of our

Ch. XVIIL] © CONCLUDING REMARKS. 183

wn, or any other contemporary species, to exist under
“ircumstances so different as those which might be
“aused by an entirely new distribution of land and sea;
and we know that in the earlier tertiary periods the
Physical geography of the northern hemisphere was
very distinct. Our inability to account for the atmo-
Spheric and other latent causes, which often give rise
to the most destructive epidemics, proves the extent
of our ignorance of the entire assemblage of conditions

"equisite for the existence of any one species on the
globe,

CHAPTER XIX.

EOCENE VOLCANIC ROCKS.

Volcanic rocks of Auvergne—Eruptions at successive periods —
Mont Dor an extinct volcano — Velay — Plomb du Cantal,
(p. 191.)— Train of minor volcanos stretching from Auverg?® —
to the Vivarais — Monts Domes’— Ravines excavated throug}
lava — Alluviums of distinct ages (p. 195.) — Age of mor?
modern lavas of Central France — No eruption during the bis-
torical era — Division of volcanos into ante-diluvian and post-

' diluvian inadmissible — Theories respecting the effects of thë
Flood considered (p. 201.) — Recapitulation.

In treating of the lacustrine deposits of Central Francés
in the seventeenth chapter, I omitted, in order t0
avoid confusion, all details respecting the associated
volcanic rocks, to which I now recall the reader’s at-
tention. (See the Map, p. 145.)

It was stated that, in the arenaceous and pebbly
group of the lacustrine basins of Auvergne, Cantal,
and Velay, no volcanic pebbles had ever been detected;
although massive piles of igneous rocks are now found
in the immediate vicinity. As this observation has
been confirmed by minute research, we are warranted
in inferrmg that the volcanic eruptions had not com
menced when the older subdivisions of the freshwater
groups originated.

In Cantal and Velay no decisive proofs have yet
been brought to light that any of the igneous out-
bursts happened during the deposition of the fresh-

Ch. XIX] VOLCANIC ROCKS OF AUVERGNE. 185

Water strata; but there can be no doubt that in
Auvergne some volcanic explosions took place before
the drainage of the lakes, and at a time when the
Ocene species of animals and plants still flourished.
shall first advert to these proofs, as relating to the
‘Story of the period under consideration, and shall then
Proceed to show that there are in the same country
Volcanic rocks of much newer date, some of which
*Ppear to be referable to the Miocene era.

Volcanic rocks associated with lacustrine in Au-
terne, — The first locality to which I shall call the
Teader’s attention is Pont du Chateau, near Clermont,
Which spot, as well as others in Auvergne, mentioned
N this chapter, I examined, with Mr. Murchison, in

828. The section is seen in a precipice on the right
ank of the river Allier. Here beds of volcanic tuff
“ternate with a freshwater limestone, which is in some
ces pure, but in others spotted with fragments of
Volcanic matter, as if it were deposited while showers

Sand and scoriæ were projected from a neighbouring
Yent.* This limestone contains the Helix Ramondi
“hd other shells of Eocene species. It is immaterial
0 the present argument whether the volcanic sand was
‘howered down from above, or drifted to the spot by a
Wer; for the latter opinion must presuppose the
ntry to have been covered with volcanic ejections
Wing the Eocene period.

Another example occurs in the Puy de Marmont,
ĉar Veyres, where a freshwater marl alternates with
volcanic tuff containing Eocene shells. The tuff or
D in this locality is precisely such as is known to

Sult from volcanic ashes falling into water, and sub-

* See Scrope’s Central France, p. 21.

186 EOCENE PERIOD. [Book IV.

siding together with ejected fragments of marl and
other stratified rocks. These tuffs and marls are highly
inclined, and traversed by a thick vein of basalt, which,
as it rises in the hill, divides into two branches.

_ Gergovia.— The hill of Gergovia, near Clermont,
affords a third example. I agree with MM. Dufrénoy
and Jobert that there is no alternation here of lav@
and freshwater strata, in the manner supposed by some
other observers *; but the position and contents 0
some of the tuffs prove them to have been derived
from volcanic eruptions which occurred during thé
deposition of the Eocene formations.

The bottom of the hill consists of slightly inclined
beds of white and greenish marls, more than thre
hundred feet in thickness, intersected by a dike of
basalt, which may be studied in the ravine above thé
village of Merdogne. The dike here cuts through the

marly strata at a considerable angle, preducing, ™
general, great alteration and confusion in them fo!

Fig. 154,
bokal e Pit iste? ah

ee

Feet e . p
Z Limest? & Peéperinn
eee ona

Hill of Gergovia.

* See Scrope’s Central France, p. 7.

a
h. XIX.] VOLCANIC ROCKS OF AUVERGNE. 187

“ome distance from the point of contact. Above the
White and green marls, a series of beds of limestone
ad marl, containing freshwater shells, are seen to
âlternate with volcanic tuff. In the lowest part of
S division, beds of pure marl alternate with compact
Ssile tuff, resembling some of the subaqueous tuffs of
taly and Sicily called peperinos. Occasionally frag-
Ments of scoriz are visible in this rock. Still higher
S seen another group of some thickness, consisting
*Xclusively of tuff, upon which lie other marly strata
‘termixed with volcanic matter.
here are many points in Auvergne where igneous
"ocks have been forced by subsequent injection through
“lays and marly limestones, in such a manner that the
Vhoie has become blended in one confused and brec-
“ated mass, between which and the basalt there is
‘metimes no very distinct line of demarcation. In
© cavities of such mixed rocks we often find calce-
y, and crystals of mesotype, stilbite, and arragonite.
0 formations of this class may belong some of the
"eccias immediately adjoining the dike in the hill of
“€eovia; but it cannot be contended that the vol-
“tic sand and scoriæ interstratified with the marls
“hd limestones in the upper part of that hill were in-
troduced, like the dike, subsequently, by intrusion from
elow.. They must have been thrown down like sedi-
ment from water, and can only have resulted from
'8neous action, which was going on contemporaneously
With the deposition of the lacustrine strata.
The reader will bear in mind that this conclusion
grees well with the proofs, adverted to in the seven-
fenth chapter, of the abundance of silex, travertin,
“nd gypsum precipitated when the upper lacustrine

188 EOCENE PERIOD, [Book IV:

strata were formed; for these rocks are such as the w4”
ters of mineral and thermal springs might generate.

The igneous products above mentioned, as ass0-
ciated with the lacustrine strata, form the lowest
members of the great series of volcanic rocks °
Auvergne, Cantal, and Velay, which repose for the most
part on the granitic mountains (see Map, p. 145.)
There was evidently a long succession of eruption®
beginning with those of the Eocene period, and ending
so far as can yet be inferred from the evidence 4e-
rived from fossil remains, with those of the Miocene
epoch. The oldest part of the two principal volcani?
masses of Mont Dor and the Plomb du Cantal may
perhaps belong to the Eocene period, — the new
portion of the same mountains to the Miocene; just
as Etna commenced its operations during the New
Pliocene era, and has continued them down to thé
Recent epoch, and still retains its energy undiminished
There are some parts of the Mont Mezen, in Velaj
which are perhaps of the same antiquity as the oldest
parts of Mont Dor.

Besides these ancient rocks, of which the lavas at@
in a great measure trachytic, there are many mino!
cones in Central France, for the most part of poste
rior origin, which extend from Auvergne, in a directio”
north-west and south-east, through Velay, into the
Vivarais, where they are seen in the basin of th?
Ardéche... This: voleanic.line does not pass by the
Plomb du Cantal; it was formed, as nearly as can be
conjectured in the present imperfect state of 0U"
knowledge, during the Miocene period; but theré
may probably be found, among these cones and the!
accompanying lavas, rocks of every intermediate 48°

Ch Ixy MONT DOR. _ 189

between the oldest and newest volcanic formations of
€ntral France.

l shall first give a brief description of the Mont Dor

Md the Plomb du Cantal, and then pass on to the train
ML newer cones, examining the evidence at present
tained respecting their relative ages, and the light
Which they throw on the successive formation of allu-
“tums and on the excavation of valleys.

ont Dor. — Mont Dor, the most conspicuous of
© volcanic masses of Auvergne, rests immediately on
© granitic rocks standing apart from the freshwater
Strata. x This volcano rises suddenly to the height of
Several thousand feet above the surrounding platform,
nd retains the shape of a flattened and somewhat irre-
Sular cone, all the sides sloping more or less rapidly,
"Mtil their inclination is gradually lost in the high
Plain around. This cone is composed of layers of sco-
mi pumice-stones, and their fine detritus, with inter-
sed beds of trachyte and basalt, which descend often
ù uninterrupted currents, till they reach and spread
‘emselves round the base of the mountain.- Con-
Slomerates also, composed of angular and rounded
"agments of igneous rocks, are observed to alternate
With the above; and the various masses are seen to
'P off from the central axis, and to lie parallel to the
; ping flanks of the great cone, in the manner I have
described when treating of Etna.
The summit of the mountain terminates in seven or
“ight rocky peaks, where no regular crater can now
è traced, but where we may easily imagine one to
ave existed, which may have been shattered by earth- |
Wakes, and have suffered degradation by aqueous
* See the Map, p. 145.
+ Scrope’s Central France, p. 98.

190 EOCENE PERIOD, [Book IV

agents. Originally, perhaps, like the highest crater of
Etna, it may have formed an insignificant feature =
the great pile, and may frequently have been destroy®
and renovated.

We cannot at present determine the age of the
great mass of Mont Dor, because no organic remall®
have yet been found in the tuffs, except impressions
of the leaves of trees of species not determine®™
Some of the lowest parts of the mountain are formé
of white pumiceous tuffs, in which animal remains maY
perhaps be one day found. In the mean time, we may
conclude that Mont Dor had no existence when the
grits and conglomerates of the Limagne, which conta”
no volcanic materials, were formed; but some of thé
earliest eruptions were, perhaps, contemporary with
those described in the commencement of this chapter”
To the latest of these eruptions, on the other hand;
refer those trachytic breccias of Mont Perrier which
were shown in the sixteenth chapter (p. 134.) ©
alternate with Miocene alluviums.

Velay. — The observations of M. Bertrand de Dov®
have not yet established that any of the most ancie”t
volcanos of Velay were in action during the Eocen?
period, although it is very probable that some of the™
may have been contemporaneous with the oldest of tP?
Auvergne lavas. There are beds of gravel in Velay
as in Auvergne, covered by lava at different height’
above the channels of the existing rivers. In the high
est and most ancient of these alluviums the pebbles
are exclusively of granitic rocks; but in the newe”
which are found at lower levels, they contain an inte™
mixture of volcanic substances. Ihave already show
in the sixteenth chapter, that, in the volcanic ejection’
and alluviums covered by the lavas of Velay, the bones

Ch, XIx.] PLOMB DU CANTAL ” 191

f animals of Miocene species have been found, in
Which respect the phenomena accord perfectly with
those of Auvergne. i
_ Plomb du Cantal. — In regard to the age of the
'Sneous rocks of the Cantal we are still less informed,
and at present can merely affirm, that they overlie the
Ocene lacustrine strata of that country. (See Map,
p. 145.) They form a great dome-shaped mass, which
3S evidently been accumulated, like the cone of Etna,
Uting a long series of eruptions. It is composed of
"achytic, phonolitic, and basaltic lavas, tuffs, and con-
8 %Merates, or breccias, forming a mountain several thou-
Sand feet in height. Dikes also of phonolite, trachyte,
“nd basalt are numerous, especially in the neighbour-
lood of the large cavity, probably once a crater, around
Which the loftiest summits of the Cantal are ranged
circularly, few of them, except the Plomb du Cantal,
"Ising far above the border or ridge of this supposed
“Tater, A pyramidal hill, called the Puy Griou, occu:
Pies the middle of the cavity.* It is evident that the
volcano of the Cantal broke out precisely on the site
f the lacustrine deposit before described (Chapter
D, which had accumulated in a depression of a
tract composed of micaceous schist. In the breccias,
ven to the very summit of the mountain, we find
ejected masses of the freshwater beds, and sometimes
“agments of flint, containing Eocene shells. Valleys
“adiate in all directions from the central heights of the
ountain, increasing in size as they recede from those
‘eights. Those of the Cer and Jourdanne, which are
Nore than twenty miles in length, are of great depth,
“nd lay open the geological structure of the mountain.

* Mém. de la Soc. Géol. de France, tom. i. p. 175.

192 EOCENE PERIOD. Book IV
No alternation of lavas with undisturbed Eocene strata
has been observed, nor any tuffs containing freshwater
shells, although some of these tuffs include fossil T°
mains of terrestrial plants said to imply several distinct
restorations of the vegetation of the mountain in the
intervals between great periods of eruption. On the
northern side of the Plomb du Cantal, at La Vissier®
near Murat, is a spot, pointed out on the Map (p- 145-))
where freshwater limestone and marl are seen covet?
by a thickness of about eight hundred feet of volcanic
rock. Shifts are here seen in the strata of limesto®?
and marl.*

Although it appears that the lavas of the Cantal at?
more recent than the freshwater formation of that
country, it does not follow that they may not belong
to the Eocene period. The lake may possibly hav?

been drained by the earthquakes which preceded o
accompanied the first erùptions, but the Eocene apl
mals and plants may have continued to exist for a 1088
series of ages, while the cone went on increasing in

dimensions.

Train of minor volcanos. —I shall next consid
those minor volcanos, before alluded to, which stret¢
in a long range from Auvergne to the Vivarais, a?
which appear for the most part to be of newer origi"
than the mountains above described. These volcan?’
were faithfully described, so early as the year 1802
by M. de Montlosier.t They have been thrown up in
a great number of isolated points, and much resemblé
those scattered over the Phlegrzean fields and the flanks
of Etna. They have given rise chiefly to currents °

er
h

* See Lyell and Murchison, Ann. des Sci. Nat., Oct. 1829.
+ Théorie des Volc, d’ Auvergne. — Clermont, An X.

Ch. x1xJ VOLCANOS OF AUVERGNE. 193

basaltic lava, whereas those of Mont Dor and the
Cantal are in great part trachytic. There are perhaps
about 300 of these minor cones in Central France; but
à part of them only occur in Auvergne, where some
wW are found at the bottom of valleys excavated
through the more ancient lavas of Mont Dor, as the

uy de Tartaret, for example, whence issues a current
of lava which, flowing into the bed of the river Couze,
Save rise to the lake of Chambon. Here the more
{cient columnar basalts of Auvergne are seen form-
Ng the upper portion of the precipices which bound
the valley.

But the greater part of the minor cones of Auvergne
àre placed upon the granitic platform, where they
orm an irregular ridge, about eighteen miles in length
id two in breadth. They are usually truncated at
the summit, where the crater is often preserved entire,
the lava having issued from the base of the hill. But
equently the crater is broken down on one side,
Where the lava has flowed out. The hills are composed
of loose scoriæ, blocks of lava, lapilli, and puzzuolana,
With fragments of trachyte and granite.

The lavas may be often traced from the crater to
the nearest valley, where they usurp the channel of
the river, which has often excavated a deep ravine
through the basalt. We have thus an opportunity of
Contrasting the enormous degradation which the solid
and massive rock has suffered by aqueous erosion, and
the integrity of the cone of sand and ashes which has,
n the mean time, remained uninjured on the neigh-

uring platform, where it was placed beyond the reach
of the power of running water.

Puy de Céme.—The Puy de Côme and its lava cur-
"ent, near Clermont, may be mentioned as one of the

VOL, Iv. K

194 i EOCENE PERIOD. [Book IV-

numerous illustrations of the phenomenon here alluded
to.* This conical hill rises from the granitic platform
at an angle of about 40°, to the height of more tha?
900 feet. Its summit presents two distinct crater
one of them with a vertical depth of 250 feet.
stream of lava takes its rise at the western base of the
hill, instead of issuing from either crater, and descends
the granitic slope towards the present site of the
town of Pont Gibaud. Thence it pours in a broa
Sheet down a steep declivity into the valley of thé
Sioule, filling the ancient river-channel for the distanc?
of more than a mile. The Sioule, thus dispossessed 0
its bed, has worked out a fresh one between the lav?
and the granite of its western bank; and the excav®
tion has disclosed, in one spot, a wall of columna"
basalt about 50 feet high.+ :

The excavation of the ravine is still in progress
every winter some columns of basalt being undermined
and carried down the channel of the river, and in the
course of a few miles rolled to sand and pebbles
Meanwhile the cone of Côme remains stationary, if
loose materials being protected by a dense vegetatio™
and the hill standing on a ridge not commanded by
any higher ground whence floods of rain-water may
descend.

Puy Rouge. —At another point, farther down the
course of the Sioule, we find a second illustration of
the same phenomenon in the Puy Rouge, a conical hill
to the north of the village of Pranal. The cone ís
composed entirely of red and black scoriæ, tuff, and
volcanic bombs. On its western side there is a worn“

* Montlosier, Théorie des Volc: d’ Auvergne, ch. ii.
+ Scrope’s Central France, p. 60., and plate.

Ch, XIX.] ALLUVIUMS OF DIFFERENT AGES. 195

down crater, whence a powerful stream of lava has
‘sued, and flowed into the valley of the Sioule. The
“Wer has since excavated a ravine through the lava
‘nd subjacent gneiss, to the depth of 400 feet.

_On the upper part of the precipice forming the left
Side of this ravine, we see a great mass of black and
"ed scoriaceous lava; below this a thin bed of gravel,
“vidently an ancient river-bed, now at an elevation of
fifty feet above the channel of the Sioule. The gravel
ain rests upon gneiss, which has been eroded to the

pth of 50 feet.* It is quite evident in this case,
that, while the basalt was gradually undermined and

“arried away by the force of running water, the cone
Whence the lava issued escaped destruction, because it
stood upon a platform of gneiss several hundred feet
bove the level of the valley in which the force of
“inning water was exerted. 28

It is needless to multiply examples, or the Vivarais

Would supply many others equally striking. Among
Many I may instance the cone of Jaujac, and its lava
Current, which is a counterpart of that near Pranal
ast mentioned.+ —

Lavas and alluviums of different ages. —We have
‘een that on the flanks of Etna, since the commence- .
‘tent of the present century, several currents of lava

ave flowed at the bottom of the Val del Bove, at the

t of precipices formed of more ancient lavas and
tuffs, So we find in Auvergne that some streams of
melted matter have flowed in valleys, the sides of
Which consist partly of older lavas. These are often

%

Ra; See Lyell and Murchison on the Excavation of Valleys,
In

- New Phil. Journ., July, 1829.
Scrope’s Central France, plate 14.

Keg

196 EOCENE PERIOD, © [Book IV.

seen capping the hills in broad sheets, resting some
times on granite, sometimes on freshwater strata-

Many of the earlier lavas of Auvergne flowed out
upon the platform of granite before all the existing
valleys had been excavated; others again spread them-
selves in broad sheets over the horizontal lacustri2é
deposit, when these had been covered with gravel
probably soon after the drainage of the lakes. Grea!
vicissitudes in the physical geography of the count!Y
must have taken place since the flowing of these a
cient lavas ; and it is evident that the changes we!
gradual and successive, caused probably by the unite
agency of running water and subterranean movements:
We frequently observe one mass of lava capping #
hill, and a second at a lower elevation, forming a te!”
race on the side of a valley; or sometimes occupyins
the bed of a river.

It is a most interesting fact, that in these cases beds
of gravel almost invariably underlie the successiv?
currents of lava, as in Catalonia before described
(pp- 95. 98.). Occasionally, when the highest plat-
form of lava is seven hundred or eight hundred feet
above the lowest, we cannot fail to be struck with the

Fig. 155.

>=

Bed of River

Lavas of Auvergne resting on alluviums of different ages.

Ch. X1x.] ALLUVIUMS OF DIFFERENT AGES. 197

Wonderful alterations effected in the drainage of the
ountry since the first current flowed; for the most
elevated alluviums must originally have been accumu-
lated on the lowest levels of the then existing surface.
As some geologists have referred almost all the super-
ficial gravels to one era, and have supposed them to
© the result of one sudden catastrophe, the pheno-
Nena of Auvergne here alluded to are very important.
he flows of volcanic matter have, in fact, preserved
Portions of the surface in the state in which they ex-
Sted at successive periods ; so that it is impossible to
Confound together the alluviums of different ages.
he reader will see at once by reference to the wood-
Cut (Fig. 155.), that a considerable interval of time
Must have occurred between the formation of the up-
Permost bed of gravel and that next below it; during
Which interval the uppermost lava was poured out, and
a Valley excavated, at the bottom of which the second
ved of gravel accumulated. In like manner the pour-
Ne out of a second current of lava and a further
epening of the valley, took place between the date
of the second gravel and that of the modern alluvium
Which now fills the channel of the river.*

When rivers are dispossessed of their channels by
ava, they usually flow between the mass of lava and
One side of the original valley. They there eat out a
Passage, partly through the volcanic and partly through

€ older formation; but as the soft tertiary marls

* For localities in Central France where lavas or sheets of
asalt repose on alluviums at different elevations above the present
Valleys, and for the inferences deducible from such facts, consult
the works of MM. Le Grand d’Aussi, Montlosier, Ramond,
Crope, Bertrand de Doue, Croizet, Jobert, and Bouillet.
K 3

198 EOCENE PERIOD, [Book IV.

in Auvergne give way more readily than the basalt,
it is usually at the expense of the marls that the e”
larging and deepening of the new valley is effected;
so that all the remaining lava is then left on one sid&
in the manner represented in the above woodcut.

Alluviums in ancient Jissures. —It might have bee”
expected, from the analogy of modern changes in vol-
canic countries, that we should find in Auvergne somé
signs of ancient fissures caused by earthquakes. AC
cordingly M. Fournet has observed in the course °
excavations made for mining in the valley of the Sioul®
near Clermont, some curious and decisive proofs of the
former existence of open rents which must have coo”
municated with the surface, and have been filled fro™
above with alluvium, after the commencement and '
before the end of the period of volcanic eruptions. It
appears that a metaliferous vein traversing gneiss (iB
other words, a mass or dike of matter, partly metalli¢
and partly not, filling an old fissure in the gneiss) had
been dislocated by later convulsions, so that a ne
rent was formed in it which reached the surface
Sand and gravel like that of a river-bed were the?
washed in, together with pieces of wood, which até
now found fossil with the gravel, in a good state of pre
servation. The rounded pebbles are partly of granitic
rocks, partly of basaltic and augitic lava, showing that
the last filling up of the fissure occurred after some
lavas had flowed over the adjacent country. But tw?
of the most modern lava streams near Pont Gibau4s
have passed over the top of the dike, and they must
evidently have been poured out after it was filled with
alluvium.*

* See Fournet, Traité de Géog., D’ Aubuisson, tom. iii. p. 544

Ch. XIX.] AGE OF AUVERGNE VOLCANOS. 199

Age of the more modern lavas.—The only organic
temains found as yet in the ancient alluviums appear
to belong to the Miocene period; but I have heard of
Rone discovered in the gravel underlying the newest
avas, — those which either occupy the channels of the
existing rivers, or are very slightly elevated above
them, I think it not improbable that even these may
9% of Miocene date, although the conjecture will ap-
Pear extremely rash to some who are aware that the
ones and craters whence the lavas issue are often as
fresh in their aspect as the majority of the cones of
the forest zone of Etna.

The brim of the crater of the Puy de Pariou, near
Clermont, is so sharp, and has been so little blunted

Y time, that it scarcely affords room to stand upon.
this and other cones in an equally remarkable state of
Ntegrity have stood, I conceive, uninjured, not in spite
f their loose porous nature, as might at first be na-
‘urally supposed, but in consequence of it. No rills
an collect where all the rain is instantly absorbed by
the sand and scorie, as was shown to be the case on
Etna (see Vol. IIL. p. 431.); and nothing but a water-
Spout breaking directly upon the Puy de Pariou could
Carry away a portion of the hill, so long as it is not
tent or engulphed by earthquakes.

Attempt to divide volcanos into ante-diluvian and
Post-diluvian. — The opinions above expressed are ent
tirely at variance with the doctrines of those writers
Who have endeavoured to arrange all the volcanic cones
of Europe under two divisions, those of ante-diluvian
nd those of post-diluvian origin. To the ante-diluvian’
Class they attribute such hills of sand and scorize as
exhibit on their surface evident signs of aqueous de-
nudation; to the post-diluvian, such as betray nO marks

K 4

” $ Vv.
200 EOCENE PERIOD, [Book I

of having been exposed to such aqueous action. Ac-
cording to this classification, almost all the minor cor®$
of Central France must be called post-diluvian ; 4
though, if we receive this term in its ordinary accept-
ation, as denoting posteriority of date to the Noachian
deluge, we are forced to suppose that all the volcanlé
eruptions occurred within a period of little more tha?
twenty centuries, or between the era of the 004
which happened about four thousand years ago, a0
the earliest historical records handed down to us 1°"
Specting the former state of Central France. D"
Daubeny has justly observed, that had any of thes?
French volcanos been in a state of activity in the ag®
of Julius Cæsar, that general, who encamped upon the
plains of Auvergne, and laid siege to its principal city
(Gergovia, near Clermont), could hardly have failed
to notice them. Had there been even any record 0
their existence in the time of Pliny or Sidonius Apol-
linaris, the one would scarcely have omitted to make
mention of it in his Natural History, nor the other t°
introduce some allusion to it among the descriptio?’
of this his native province. This poet’s residence wa®
on the borders of the Lake Aidat, which owed its very
existence to the damming up of a river by one of the
most modern lava-currents,*

The ruins of several Roman bridges, and of the
Roman baths at Royat, confirm the conclusion that 2
sensible alteration has taken place in the physical geo-
graphy of the district, not even in the chasms ex¢®
vated through the newest lavas since ages historically
remote. We have no data at present for presuming
that any one of the Auvergne cones has been pro-

* Daubeny on Volcanos, p. 14.

Romtordo

=... Mochtorde nC) eo
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Plate ls.
i|
|

MOUTH of the

Baa” S

Brenttordo

Staines

Havant Op Chichester
eBrighton

Mar gater N Foreland

msgate

oBarham ` /
f S.Foreland

thang

olkestone

; ofenterden $
E New Romnev
EB
> Denge
P R Ness’ es
Winchelsere . , Gk oLOGICAL Ma P
ee of the South East of
ENGLAND,
Exhibiting the Denudation
oF THE WEALD.

5 :
Lop ss ; sgg

STe
|Peaza day

___ Seale of Miles ___
70 75

2
fe ea leat

i
lech and
iwestone

Ch, XIX.] DILUVIAL THEORIES. 201

duced within the last four or five thousand years; and
the same may be said of those of Velay; and, until
the bones of men or articles of human workmanship
àre found buried under some of their lavas, instead of
the remains of extinct animals, which alone have
Utherto been met with, we are justified in regarding
tas probable that the latest of the volcanic eruptions
may have occurred during the Miocene period.

Supposed effects of the Flood.

They who have used the terms ante-diluvian and
Post-diluvian, in the manner above adverted to, pro-
“eed on the assumption that there are clear and une-
Wivocal marks of the passage of a general flood over
all parts of the surface of the globe. It had long been
à question among ‘the learned, even before the com-
mencement of geological researches, whether the de-
We of the Scriptures was universal in reference to the
Whole surface of the globe, or only so with respect to

at portion of it which was then inhabited by man.
f the latter interpretation be admissible, it will appear
tom other parts of this work that there are two
“lasses of phenomena in the configuration of the earth’s
‘urface, which might enable us to account for such an
“vent. First, extensive lakes elevated above the level
of the ocean; secondly, large tracts of dry land de-
Pressed below that level. When there is an immense
ake, having its surface, like Lake Superior, raised six

Undred feet above the level of the sea, the water may

© Suddenly let loose by the rending or sinking down

°F the barrier during earthquakes, and thereby a region

S extensive as the valley of the Mississippi, inhabited
K 5

202 _ EOCENE PERIOD. [Book 1V-

by a population of several millions, might be deluged-*
On the other hand, if there be any country place

beneath the mean level of the ocean, as some hav®
supposed to be the case with part of Asiat, the
depressed region must be entirely laid under wate!
if the tract which separates it from the ocean be fis-
sured or depressed to a certain depth. Humboldt
inferred, from the observations of Parrot, that a gre
cavity existed in Western Asia, eighteen thousa?

Square leagues in area, and occupied by a considerable
population. The lowest parts, surrounding the Cas
pian Sea, were said to be about 350 feet below the
level of the Euxine, — here, therefore, the diluvi@
waters might overflow the summits of hills rising 350
feet above the level of the plain; and if depressio?’
still more profound existed in any former time ”
Asia, the tops of still loftier mountains may hav?
been covered by a flood. §

* Vol. I. p. 133. + Vol. III. p. 126.

+ Fragmens Asiatiques, Paris, 1831.

§ Since the above passage was first written, Professor Parrot
of Dorpat, has published his “ Reise zum Ararat,” in which he
doubts, nay, appears wholly to have disproved, the fact so long
believed on his authority,‘of a difference of level between the
Black Sea and the Caspian. The opinion was originally adopté
on the authority of barometrical measurements, made by him 4?
M. Engelhardt in 1811. M. Parrot, however, on revisiting the
country in 1829 and 1830, was led to suspect the correctness ©
his former observations on several grounds, one of which only *
shall now quote. Russian engineers had ascertained, by accurat?
measurements, that the Don, at the place called Katschalins&s
where it is only sixty wersts distant from the Wolga, is 130 Paris
feet higher than the latter river, and that the Don flows with much
greater rapidity to the Black Sea than the Wolga does tO the
Caspian ; consequently, if there be a difference of level of the tw?
seas, it must be considerably less than 130 feet. Parrot according}?

Ch. XIX.] DILUVIAL THEORIES. ` 203

But the great majority of the older commentators
ave held the deluge, according to the brief account of
the event given by Moses, to have consisted of a rise
of waters over the whole earth, by which the summits
f the loftiest mountains on the globe were submerged.
. “ty have indulged in speculations concerning the
Mstruments employed to bring about the grand cata-
ysm ; and there has been a great division of opinion
3 to the effects which it might be expected to have
Produced on the surface of the earth. According to
ne school, of which De Luc formerly, and in our
Wn times Dr. Buckland, have been zealous supporters,
the passage of the flood worked a considerable alter-
“tion in the external configuration of our continents.

Y Dr. Buckland the deluge has been represented as

having determined to ascertain the true state of the case, made a

“ties of levellings from the mouth of the Wolga to Zarytzin,
409 Wersts up its course, and from the mouth of the Don to the
ike distance. As the result of these observations, he made the
Routh of the Don to be between three and four feet lower than
'at of the Wolga! Baron Humboldt, who with other geographers
ad given full credit to the former statement of Parrot, refused to
admit the validity of these new results, unless the professor was
Prepared to show that his former observations were less worthy of
“Onfidence. In reply to this, Parrot, in an Appendix, admits

at their barometrical instruments used in 1811 were imperfect,

at errors had crept into his calculations, that he was suffering
tom ill health, &c. &c.

Notwithstanding this recantation, M. Erman, of Berlin, in his
$ eise um die erde,” &c. 1828-29-30., infers from independent
. servations that the Caspian is lower than the Black Sea by 42.8

tses, or about 280 feet; and Meyer and Lenz, in a paper read
° the Academy of Sciences in St. Petersburgh in 1835, mention

at Mr. Goebel, by his barometrical measurements in 1833, found
è difference of 50 feet.
K 6

204: EOCENE PERIOD. [Book 1V:

a violent and transient rush of waters which tore UP
the soil to a great depth, excavated valleys, gave rise
to immense beds of shingle, carried fragments of roc
and gravel from one point to another ; and, during its
advance and retreat, strewed the valleys, and even the
tops of many hills, with alluvium.*

But I agree with Dr. Fleming, that in the narrative
of Moses there are no terms employed that indicat?
the impetuous rushing of the waters, either as they
rose or when they retired, upon the restraining of thé
rain and the passing of a wind over the earth.+ Op
the contrary, the olive-branch, brought back by thé
dove, seems as clear an indication to us that the vege-
tation was not destroyed, as it was then to Noah that
the dry land was about to reappear.

I have been led with great reluctance into thi
digression, in the hope of relieving the minds of som®
readers from groundless apprehension respecting thé
bearing of many of the views advocated in this work
They have been in the habit of regarding the diluvial
theory above controverted as alone capable of affording
an explanation of geological phenomena in accordan©®
with Scripture, and they may have felt disapprobatio?
at an attempt to prove, in a.former chapter, that thé
minor volcanos on the flanks of Etna may, some °
them, be more than 10,000 years old.t How, they
would immediately ask, could they have escaped thé
denuding force of a diluvial rush of waters? The samê

* Buckland, Reliquiz Diluviane. These opinions, howevel
have been candidly renounced in a note in his Bridgewater Treatise

+ Rev. Dr. Fleming, on the Geological Deluge, Edin. Phil-
Journ., vol. xiv. p. 205.; and remarks by myself in the Quarterly
Review, Oct. 1827, No. lxxii. p. 481.

ł Vol. III. p. 430.

Ch, X1x.] DILUVIAL THEORIES. 205

objection may have presented itself when I quoted,
With respect, the opinion of a distinguished botanist,
that some living specimens of the Baobab tree of

frica, or the Taxodium of Mexico, may be 5000 years
*. The: reader may also have been astonished at
the high antiquity assigned to the greater part of the

Uopean alluviums, and the many different ages to
Which I have referred them t, as he may have been
taught to consider the whole as the result of one recent
d simultaneous inundation.

Professor Sedgwick is inclined to adopt the hypo-
thesis of M. Elie de Beaumont, that the sudden ele-
Yation of mountain-chains “has been followed again
and again by mighty waves desolating whole regions
of the earth ¢;” a phenomenon which he thinks has
“taken away all anterior incredibility from the fact of
à recent deluge.” § i

But I cannot admit that there are sufficient geolo-
Štcal data for inferring such instantaneous upheavings
of Submerged land as might be capable of causing a

ood over a whole continent at once. I may also ob-
‘erve, that the reasoning above alluded to seems to
Proceed entirely on the assumption that the flood of
oah was brought about by natural causes, just as
‘ome writers have contended that a volcanic eruption
Was the instrument employed to destroy Sodom and.

Morrah. If we believe the flood to have been a
temporary suspension of the ordinary laws of the
natural world, requiring a miraculous intervention of

lvine power, then it is evident that the credibility of

* See Vol. III, p. 428.
Vol. IV. p. 45. ¢ Vol. III. p. 481.

os Sedgwick, Anniv, Address to the Geol. Soc., Feb. 18th,
oly

206 EOCENE PERIOD. [Book 1¥-

such ap event cannot be enhanced by any series of P
undations, however analogous, of which the geologist
may imagine that he has discovered the proofs.

For my own part, I have always considered thé
flood, when its universality in the strictest sense of thé
term is insisted upon, as a preternatural event far be-
yond the reach of philosophical inquiry, whether as t°
the causes employed to produce it, or the effects most
likely to result from it. At the same time, it is clea"
that they who are desirous of pointing out the coin-
cidence of geological phenomena with the occurren©®
of such a general catastrophe, must neglect no one 0
the circumstances enumerated in the Mosaic history:
least of all so remarkable a fact as that the olive te
mained standing while the waters were abating.

Recapitulation.—I shall now briefly recapitulat?
some of the principal conclusions to which we hav

been led by an examination of the volcanic districts
Central France.

Ist. Some of the volcanic eruptions of Auvergn®
took place during the Eocene period; others at 2
era long subequent, probably during the Miocene

period.

2dly. There are no proofs as yet discovered that
the most recent of the volcanos of Auvergne and Velay
are subsequent to the Miocene period, the integrity
of many cones and craters not Opposing any soup
objection to the opinion that they may be of very
great antiquity.

3dly. There are alluviums in Auvergne of very
different ages, some of them belonging to the Miocen®
period. Many of these have been covered by lava-
currents which have been poured out in successio”
while the excavation of valleys was in progress.

Ch, XIX. RECAPITULATION. 207

4thly. There are a multitude of cones in Auvergne,
Velay, and the Vivarais, which have never been sub-
J€cted to the action of a violent rush of waters capable
“i Modifying considerably the surface of the earth..

Sthly. If, therefore, the Mosaic deluge be repre-
‘ented as universal, and as having exercised a violent

“nuding force, all these cones, several hundred in
Number, must be post-diluvian.

Sthly. But since the beginning of the historical era,
r the invasion of Gaul by Julius Cæsar, the volcanic
action in Auvergne has been dormant; and there is
Nothing to countenance the idea that, between the date
Usually assigned to the Mosaic deluge and the earliest
traditional and historical records of Central France

à Pericd of little more than twenty centuries), all or
Uy one of the more entire cones of loose scoriæ were
thrown up.

Lastly. It is the opinion of some writers, that the
“arth’s surface underwent no great modification at the
“ta of the Mosaic deluge, and that the strictest inter-
Pretation of the Scriptural narrative dees not warrant
Us in expecting to find any geological monuments of

€ catastrophe ; an opinion which would be consistent
With the preservation of these volcanic cones, however

gh their antiquity.

aR TTT
SS ee

CHAPTER XxX.

EOCENE FORMATIONS — continued.

Basin of the Cotentin, or Valognes — Rennes — Basin of the
Netherlands — Aix, in Provence — Fossil insects — Vicentiv®
— Tertiary strata of England — Basins of London and Hamp-
shire— Different groups — Plastic clay and sand — Londo”
clay (p. 214.) — Bagshot sand — Freshwater strata of the Isle
of Wight — Palzotherium and other fossils of Binstead —E03"
lish Eocene strata conformable to chalk — Outliers on tP?
elevated parts of the chalk (p. 218. ).

In addition to the Eocene formations treated of in thé
last three chapters, there are others in the north °
Europe, the geographical position of which is de-
lineated on the annexed map.*

Basin of the Cotentin, or Valognes. — The strata 1”
the environs of Valognes, in the department of 14
Manche, consist chiefly of a coarse limestone rese™
bling the calcaire grossier of Paris; of which M. Des“
noyers has given an elaborate description. It is occ?
sionally covered with a compact freshwater limestoP?
alternating with freshwater marls. In these Eocene
strata more than 300 species of fossil shells have bee?
discovered, almost all identical with species of the

* This map is copied from one given by M. Desnoyers, Mém.
de la Soc. d’Hist. Nat. de Paris, 1825, pl. 9. ; compiled partly
from that author’s observations, and partly from Mr, Webster 5
map, Geol. Trans., First Series, vol. ii. plate 10.

Ch, : k
XX] EOCENE FORMATIONS. 209

Paris hac: ; -
aris basin. Superimposed upon the Eocene strata of
l DE 3 é

S basin is a newer marine deposit, extending over a

Ma
p OF THE PRINCIPAL TERTIARY BASINS OF THE EOCENE
PERIOD.

Fig. 156.

WY,

J =
=

CEM =
Fa po Z A 7 ——
—S)— = fap a @
— is C p a“

med Primary rocks and WA, Eocene formations.
a 3 :
‘a older than the carbonife- .

5 series,

r

a8. The space left blank is occupied by secondary formations
3 the old red sandstone to the chalk inclusive.

ited area, the fossils of which agree with those of
Sit aluns of the Loire.* Here, therefore, the geolo-
of AS an opportunity of observing the superposition
ae Miocene deposits upon those of the age of the
aris basin.
ennes. — Several small patches, also, of marine
ta, have been found by M. Desnoyers, in the
Shbourhood of Rennes, which are characterized by
pa fossils, and repose on ancient rocks, as will be
n in the map.

Stra
Nej

5

* A
Desnoyers, Mém. dela Soc. d’Hist, Nat. de Paris, 1825.

vV.
210 EOCENE PERIOD, [Book 1

Basin of Belgium, or the Netherlands.— The greate”
part of the tertiary formations of the Low Countré
consist of clay and sand, much resembling those of the
basin of London, afterwards to be described; and t ;
fossil shells are of the same species. d

Aix in Provence. — The tertiary strata of Aix 4?
Fuveau, in Provence, are of great thickness and extent
the lower members being remarkable for containing
coal grit and beds of compact limestone, such a$ K
England are found only in ancient secondary group”
Yet these strata are for the most part of freshwate!
origin, and contain several species of Eocene shells
together with many which are peculiar to this bas™
It will require a fuller comparison than has yet pee?

' made of the fossil remains of Aix and Fuveau, pefot?
we can determine with accuracy the relative agé a
this formation. Some of the plants seem to agree wit?
those of the Paris basin, while many of the insect
have been supposed identical with species now living
These insects have been almost exclusively procul?
from a thin bed of grey calcareous marl, which passe?
into an argillaceous limestone found in the quarries i
gypsum near Aix. The rock in which they are ™™
bedded is so thinly laminated, that there are someti™m®’
more than seventy layers in the thickness of an inch
The insects are for the most part in an extraordiaa"y
state of preservation, and an impression of their for?
is seen both on the upper and under laminæ, as in the
case of the Monte Bolca fishes. M. Marcel de Set!
enumerates sixty-two genera, belonging chiefly to sa
orders Diptera, Hemiptera, and Coleoptera. On ¥

24: de
* M. Marcel de Serres, Géog. des Ter. Tertiaires du Mid!

Ja France. -

h. Xx] ENGLISH EOCENE FORMATIONS. 211
ming a collection brought from Aix, Mr. Curtis
‘ iin that they are all of European forms, and most
e em referable to existing genera.* With the
E e exception of an Hydrobius, none of the species
ra] aquatic. The antenne, tarsi, and trophi are gene-
W very obscure, or distorted; yet in a few the
S are visible, and the sculpture, and even some
Bere of local colouring, are preserved. The nerves
a Wings, in almost all the Diptera, are perfectly
nct, and even the pubescence on the head of one
oe Several of the beetles have the wings ex-
ed beyond the elytra, as if they had made an effort
p escape by flying, or had fallen into the water while
n the wing
Vicentine. —On the Southern flank of the Alps to
€ north of Vicenza, in Italy, a limestone occurs con-
aning shells of Eocene species, and in the basaltic
S associated with this limestone (as at Ronca and
“er Places) shells are found which are also identical
th species of the Paris basin. f

Basins of London and Hampshire.

The reader will see in the small map above given

ig 156. p.209.), the position of the two districts
‘ually called the basins of London and Hampshire,
° Which the Eocene formations of England are con-
. These tracts are bounded by rising grounds
“wae of chalk, except where the sea intervenes.
E the chalk passes beneath the tertiary strata, we

not only infer from geological data, but can prove

$ Murchison and Lyell. Ed. New Phil. Journ., Oct. 1829.
Curtis, ibid., where figures of some of the insects are given.

a list of species collected by M. Boué, and named by M.
ayes, Bull, de la Soc, Géol. de France, tomeili. p. 91.

e N
212 EOCENE PERIOD. [Book I

by numerous artificial sections at points where wells
have been sunk, or borings made through the over”
lying beds. The Eocene deposits are chiefly marin’)
and have generally been divided into three groups’
Ist, the Plastic clay and sand, which is the lowe
group; 2dly, the London clay; and, 3dly, the Bagshot
sand. Of all these the mineral composition is vet
simple, for they consist almost entirely of clay, sand
and shingle, the great mass of clay being in the middle
and the upper and lower members of the series beit
more arenaceous.

Plastic clay and sand.— The lowest formation, which
sometimes attains a thickness of from four hundred
five hundred feet, consists principally of an indefinit
number of beds of sand, shingle, clay, and loam, irre’
gularly alternating, some of the clay being used E
potteries, in reference to which the name of Plast!”
clay has been given to the whole formation. The be®
of shingle are composed of perfectly rolled chalk flin™
with here and there small pebbles of quartz. Heap?
of these materials appear sometimes to have remain?
for a long time covered by a tranquil sea. Dr. Buck
land mentions that he observed a large pebble in part
of this formation at Bromley, to which five full-grow”
oyster-shells were affixed, in such a manner as to show
that they had commenced their first growth upon ih
and remained attached through life.*

In some of the associated clays and sand, perfect
marine shells are met with, which are of the sa”?
species as those of the London clay. The line °
separation, indeed, between this superincumbent blv®
clay and the Plastic clay and sand is quite arbitrar}?
as any geologist may be convinced who examines the

* Geol, Trans., First Series, vol. iv. p. 800.

“h XX.) ENGLISH EOCENE FORMATIONS. 213
°elebrated section in Alum Bay, in the Isle of Wight,
ere a distinct alternation of the two groups is ob-
Yable, each marked with their most characteristic
Peculiarities,* In the midst of the sands of the lower `
om amass of clay occurs two hundred feet thick,
ting septaria, and replete with the usual fossils
the neighbourhood of London.+
© arenaceous beds are chiefly laid open on the
nes of the basins of London and Hampshire, in
Owing which we discover at many places great
eds of perfectly rounded flints. Of this description,
% the Southern borders of the basin of London, are
© hills of Comb Hurst and the Addington hills,
ich form a ridge stretching from Blackheath to
"oydon. Here they have much the appearance of
“tks of sand and shingle formed near the shores of a
“ttiary sea; but whether they were really of littoral.
"gin cannot be determined, for want of a sufficient
“ther of sections, which might enable us to compare
` tertiary strata at the edges with those in the cen-
Parts of each basin.
e have ample opportunities in the basin of Paris
*Xamining steep cliffs of hard rock, which bound
ny of the valleys, and innumerable excavations
ave been made for building-stone, limestone, and
ms but when we attempt to obtain a connected
W of any considerable part of the tertiary series
` € basin of London, we are almost entirely limited
a single line of coast-section ; for in the interior

Sey

Conf

* .
E. See Mr. Webster’s Memoir, Geol. Trans., vol. ii., First
tes, and his Letters in Sir H. Englefield’s Isle of Wight.

Fi See Mr. Webster’s Sections, plate 11. Geol. Trans., vol. ii.,
"St Series, i :

x
214 EOCENE PERIOD. [Book IV

the regular beds are much concealed by an alluvial
covering of flint gravel spread alike over the summits
and gentle slopes of the hills, and over the bottoms °
the valleys. a

Organic remains are extremely scarce in the Plasti¢
clay ; but when any shells occur, they are of Foce”?
species. Vegetable impressions and fossil wood are
sometimes met with, and even beds: of lignite ; put
none of the species of plants have, I believe, as J `
been ascertained.

London clay.— This formation consists of a plucish
or blackish clay, sometimes passing into a calcareo
marl, rarely into a solid rock. Its thickness is VOY
great, sometimes exceeding five hundred feet.*
contains many layers of ovate or flattish masses °
argillaceous limestone, which, in their interior, #
generally traversed in various directions by crack
partially or wholly filled by calcareous spar. Thes?
masses, called septaria, are sometimes continUé
through a thickness of two hundred feet.+

A great number of the marine shells of this da
have been identified with those of the Paris basin; 2”
it is quite evident that the strata of these two basi
belong to the same epoch.

No remains of terrestrial mammalia have as yet be”
found in this clay ; but the occurrence of bones 2”
skeletons of crocodiles and turtles prove, as Mr. Conf"
beare justly remarks, the existence of neighbouring
dry land. The shores, at least, of, some islands we”
accessible, whither these creatures may have resorte
to lay their eggs. In like manner, we may infer the cO™

* Con. and Phil. Outlines of Geol., p. 33.
t Outlines of Geol., p. 27.

XX] LONDON AND HAMPSHIRE BASINS, 215
tiguity of land from the immense number of ligneous
Sced-vessels of plants, some of them resembling the
'9coa-nut, and other spices of' tropical regions, which
"Ve been found fossil in great profusion in the Isle of
“Ppey. Such is the abundance of these fruits, that
they have been supposed to belong to several hundred
'Stinct species of plants.
agshot sand. — The third and uppermost group,
“ually termed the Bagshot sand, rests conformably
"Pon the London clay, and consists of siliceous sand
è Sandstone, devoid of organic remains, with some
P ln deposits of marl associated. From these marls a
RY Marine shells have been obtained which are in an
Perfect state, but appear to belong to Eocene species
“Mon to the Paris basin.*
"eshwater strata of the Hampshire basin.—In the
“orther part of the Isle of Wight, and part of the

Posite coast of Hampshire, freshwater strata occur
cs on the London clay. They are composed
ely of calcareous and argillaceous marls, inter-
"atified with some thick beds of siliceous sand, and
w layers of limestone sometimes slightly siliceous.

© marls are often green, and bear a considerable

St

M adblance to the green marls of Auvergne and the
"ts basin. The shells and gyrogonites also agree
p cifically with some of those most common in the
the ch deposits. Mr. Webster, who first described
% freshwater formation of Hampshire, divided it
an upper and lower series, separated by inter-
a8 beds of marine origin. There are undoubtedly
À "tain intercalated strata, both in the Isle of Wight

oast of Hampshire, marked by a slight inter-

Venj

® . ae
Warburton, Geol. Trans., vol, i., Second Series.

216 EOCENE PERIOD. [Book 10

mixture of marine and freshwater shells, sufficient to

imply a temporary return of the sea, before and afte!
which the waters of the lake, or rather, perhaps, 5° 7
large river, prevailed.* The united thickness of th?
freshwater and intercalated upper marine beds, at
posed in a vertical precipice in Headen Hill, in the
Isle of Wight, is about four hundred feet, the mar”?
series appearing about half way up in the cliff.

Eocene mammiferous remains. — Very perfect a
mains of tortoises and the teeth of crocodiles hav?
been procured from the freshwater strata; but a still
more interesting discovery has recently been ma i
The bones of mammalia, corresponding to those °
the celebrated gypsum of Paris, have been disintetT®
at Binstead, near Ryde, in the Isle of Wight. In t
ancient quarries near this town a limestone, belong
ing to the lower freshwater formation, is worked if
building. Solid beds alternate with marls, whereid®
tooth of an Anoplotherium, and two teeth of #°
genus Paleotherium, were found. These remains were
accompanied not only by several other fragments °
the bones of Pachydermata (chiefly in a rolled 4”
injured state), but also by the jaw of a new species °
Ruminantia, apparently closely allied to the ge®”
Moschus.+ Mr. T. Allan of Edinburgh had seve”
years before found the tooth of an Anoplotherium °
the same spot. $

These newer strata of the Isle of Wight beat’
certain degree of resemblance to some of the gre”

* See Memoirs of Mr. Webster, Geol. Trans., vol. ii- First
Series; vol. i. parti., Second Series; and Englefield’s Isle °
Wight. — Professor Sedgwick, Ann. of Phil., 1822; and LY”
Geol. Trans., vol. ii., Second Series.

+ Pratt, Trans. of Geol. Soc., vol. iii. part iii. p. 451.

Ch, XX] EOCENE STRATA CONFORMABLE TO CHALK, 217

marls and limestones in the Paris basin; yet, as a whole,
o formations can be more dissimilar in mineral cha-
“acter than the Eocene deposits of England and Paris.
n Our own island the tertiary strata are more exclu-
ively marine ; and it might be said that the Parisian
series differs chiefly from that of London in the very
Points in which it agrees with the formations of Au-
vergne, Cantal, and Velay. The tertiary formations
. “hgland are, in fact, almost exclusively of mecha-
lcal origin, and their composition bespeaks the ab-
ence of those mineral and thermal waters to which
ave attributed the origin of the compact and sili-
Ceoug limestones, the gypsum, and beds of pure flint,
ommon to the Paris basin and Central France.
‘nglish tertiary strata conformable to the chalk. —
© British Eocene strata are nearly conformable to
the chalk on which they rest, being horizontal where
© strata of the chalk are horizontal, and vertical
“here they are vertical. On the other hand, there
. © evident signs that the surface of the chalk had,
_ many places, been furrowed by the action of the
Wes and. currents, before the Plastic clay and its
"nds were superimposed. In the quarries near Ro-
‘ester and Gravesend, for instance, fine examples
“Seen of deep indentations on the surface of the
“nalk, into which sand, together with rolled and
Sular pieces of chalk-flint, bave been swept.* But
"hese appearances may be referred to the action of
ster when the chalk began to emerge during the
Ocene period, and they by no means warrant the
y nclusion that the chalk had undergone any con-
erable change of position before the tertiary strata
{Ere superimposed.

N

* Con. and Phil., Outlines of. Geol., p. 62.

VOL. ty. L

218 EOCENE PERIOD. [Book 1V

In this respect there is a marked difference betwee?
. the reciprocal relations of our secondary and tertiary

rocks, and those which exist between the same groups
throughout the greater part of the Continent, espe-
cially in the neighbourhood of mountain-chains. Ne®
the base, for example, of the Alps, Apennines, 3?
Pyrenees, -we find the newer formations reposing U?
conformably upon the truncated edges of the older
beds; and it is clear that, in many cases, the oldet
strata had been subjected to a complicated series °
movements before the more modern set was forme
The newer beds rise only to a certain height on the
flanks of the mountains which usually tower abové
them, and are recognized at once by the geologist as
having been already converted into land when tb?
tertiary deposits were still forming in the sea. Th®
ancient borders, also, of that sea can often be define
with certainty, and the outline of some of its bays ant
sea-cliffs traced.

In England, although undoubtedly the greater po
tion of the tertiary strata is confined to certain space*
we find outlying patches here and there at great dis-
tances beyond the general limits, and ab great height’
upon the chalk which separates the basins of Lond
and Hampshire.* I have seen masses of clay extend-
ing in this manner to near the edge of the weste”
escarpment of the chalk of Wiltshire, and Mr. Mant”!
has pointed out the same to me in the South Down’:
Near the escarpment at Lewes, for example, there ®
a fissure in the chalk filled with sand, and with a fet
ruginous breccia, such as usually marks the lowe?
members of the Plastic clay formation. From thé
occurrence of these tertiary outliers Dr. Buckland i”

* Dr. Buckland, Geol. Trans., Second Series, vol, ii. p» 125

Ch, Xx] TERTIARY OUTLIERS ON CHALK. 219

ferred, “ that the basins of London and Hants were

Mginally united together in one continuous deposit
cross the now intervening chalk of Salisbury Plain in
ilts, and the plains of Andover and Basingstoke in
‘nts; and that the greater integrity in which the
&rtiary Strata are preserved within the basins has re-
“uted from the protection which their comparatively
wis Position has afforded them from the ravages of
lluvia] denudation.” *
agree so far with this conclusion as to believe that
€ basins of London and Hampshire were not sepa-
tateq until part of the tertiary strata were deposited ;
ut I do not think it probable that the tertiary beds
“Ver extended continuously over those spaces where
the Outliers above mentioned occur, nor that the com- -
ative thinness of those deposits in the higher chalk
“untries should be attributed chiefly to the greater
gree of denudation which they have there suffered.

* Dr. Buckland, Geol. Trans., Second Series, vol. ii. p. 126.

CHAPTER XXI,

ORIGIN OF THE ENGLISH EOCENE FORMATIONS AND.
DENUDATION OF THE WEALD.

Manner in which the English tertiary strata may have’ originat?

— Denudation of secondary strata during their deposition ~
Valley of the Weald — Secondary rocks of the Weald divisibl?
into five groups — North and South Downs — Section acto
the valley of the Weald —-Anticlinal axis — Chalk escarpmen™
once sea-cliffs (p. 226.) — Rise and denudation of the stt@™
gradual — Parallel ridges and valleys formed by harder 4”

softer beds — No ruins of the chalk on the central district °
the Weald (p. 234.) — Double system of valleys, the longit™
dinal and the transverse (p. 237.).

Preliminary views.— In explanation of the phenome”?
described in the last chapter, I shall now endeavour t°
lay before the reader a view of the series of even!
which may have produced the leading geological a
geographical features of the south-east of England.
conceive that the chalk, together with many subjace™*
rocks, may have remained undisturbed and in horizont?
stratification until after the commencement, of th?
Eocene period. When at length the chalk was UP”
heaved and exposed to the action of the waves and cu"
rents, it was rent and shattered, so that the subjacent
secondary strata were soon after exposed to denudatio™
The waste of all these rocks, composed chiefly of sa2®
stone and -clay, supplied materials for the tertiary

Sh, XX1] ‘DENUDATION OF THE WEALD. 221

Sands and clays; while the chalk was the source of
flinty shingle, and of the calcareous matter which we
nd intermixed with the Eocene clays. The tracts
Ow separating the basins of London and Hampshire
Were those first elevated, and which contributed by
their gradual decay to the production of the newer
‘trata. These last were accumulated in deep submarine
ollows, formed probably by the subsidence of certain
Parts of the chalk, which sank while the adjoining
tracts were rising.

Denudation of the Valley of the Weald.—In order to
Understand this theory, it will be necessary that the
teader should be acquainted with the phenomena of

fnudation exhibited by the chalk and some of the
older secondary rocks in parts of England, most nearly
“Onticuous to e basins of London and Hampshire.

t will be sufficient to consider one of the denuded

istricts, as the appearances observable in others are
Strictly analogous; I shall, therefore, direct attention
to what may be called the Valley of the Weald, or

€ region intervening between the North and South

Owns.
Map. — The district alluded to is delineated in the
coloured map, given in Plate XV., which has been
chiefly taken from Mr. Greenough’s Map of England ;
“nd it will be there seen that the southern portion of

€ basin of London, and the north-eastern limits of that
$ Hampshire, are separated by a tract of secondary
*ocks, between, forty and fifty miles in breadth, com-
p rising within it the whole of' Sussex, and parts of the
“ounties of Kent, Surrey, and Hampshire.

There can be no doubt that the tertiary deposits of
the Hampshire basin formerly extended much farther
long our southern coast towards Beachy Head, for

L 3

229 EOCENE PERIOD. [Book 1V:
j

patches are still found near Newhaven, and at othe!
points, as will be seen by the map. These are now
wasting away, and will in time disappear, as the sea ®
constantly encroaching and undermining the subjacent
chalk.

The secondary rocks, depicted on the map, may be

divided into five groups : —

1. Chalk and upper green-sand. — This group ”
the uppermost of the series; it includes thé
white chalk with and without flints, and an i
ferior deposit, called, provincially, “ Firestone
and by English geologists, the « Upper gree
sand.” It sometimes consists of loose siliceous
sand, containing grains of silicate of iron, bY
often of firm beds of sandstone and chert.

2. Blue clay or calcareous marl, called, provinciallys
Gault.

`3. Lower green-sand, a very complex group, co”
sisting of grey, yellowish, and greenish sandsi
ferruginous sand and sandstone ; clay, chet’
and siliceous limestone.

4. Weald clay, composed for the most part of clay
without intermixture of calcareous matter, bu!
sometimes including thin beds of sand at
shelly limestone.

5. Hastings sands, composed chiefly of sand, sand-
stone, clay, and calcareous grit, passing int?
limestone. * ;

The first three formations above enumerated are of

marine origin ; the last two, Nos. 4. and 5., conta?

* For an account of these strata in the south-east of England,
see Mantell’s Geology of Sussex, and Dr. Fitton’s Geology %
Hastings, where the memoirs of all the writers on this part 0
England are referred to.

Ch, XXIL] DENUDATION OF THE WEALD. 223
almost exclusively the remains of freshwater and am-
Phibious animals. But it is not my intention to enlarge,
i present, upon the organic remains of these form-
ations, as the rocks are merely adverted to in order
that I may describe the changes of position which they
Mave undergone, and the denudation to which they
lave been exposed since the commencement of the
Ocene period, —mutations which, if the theory about
to be explained be well founded, belong strictly to the
istory of tertiary phenomena.
i By a glance at the map, the reader may trace at
once the superficial area occupied by each of the five
formations above mentioned. On the west will be
Seen a large expanse of chalk, from which two branches
are sent off ; one through the hills of Surrey and Kent
to Dover, forming the ridge called the North Downs ;
and the other through Sussex to the sea at Beachy
Head, constituting the South Downs. The space com-
Prised between the North and South Downs, or, “ the
Valley of the Weald,” consists of the formations Nos.
2, 8, 4, 5. of the above table. It will be observed that
‘the chalk terminates abruptly, and with a well-defined
ine towards the country occupied by those older
Strata. Within that line is a narrow band, coloured
blue, formed by the gault ; and within this again, is
the Lower green-sand, next the Weald clay; and then,
in the centre of the district, a ridge formed by the
astings sands. |
Section of the Valley of the Weald.—It has been as-
Certained by careful investigation, that if a line be
drawn from any part of the North to the ‘South Downs,
Which shall pass through the central group (No. 5.),
the beds will be found arranged in the order described
m the annexed section (Fig. 157.).
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Ch. XX1] DENUDATION OF THE WEALD. 225

The reader is referred at present to the dark lines
of the section, as the fainter lines represent portions
of rock Supposed to have been carried away by denu-.
dation,

At each end of the diagram the tertiary strata, 4,
are exhibited reposing on the chalk. In the centre
ate seen the Hastings sands (No. 5.), forming an an-
Uclinal axis, on each side of which the other form-
ations are arranged with an opposite dip. It has been
Necessary, however, in order to. give a clear view of
the different formations, to exaggerate the propor-
tional height of each in comparison to its horizontal
*Xtent; and a true scale is therefore subjoined- in
another diagram (Fig. 158.), in order to correct the
“roneous impression which might otherwise be made
°n the reader’s mind. In this section the distance

tween the North and South Downs is represented

to exceed forty miles ; for the Valley of the Weald is
“te intersected in its longest diameter, in the direc-
tion of a line between Lewes and Maidstone.

In attempting to account for the manner in which

€ five secondary groups above mentioned may have

“en brought into their present position, the following

Ypothesis has been very generally adopted : — Suppose
‘he five formations to lie in horizontal stratification
at the bottom of the sea; then let a movement from

Clow press them upwards into the form of a flattened

Ome, and let the crown of this dome be afterwards
“ut off, so that the incision should penetrate to the
west of the five groups. The different beds would

‘en be exposed on the surface, in the manner ex-
hibited in the map, Pl. XV.*

y See illustrations of this theory by Dr, Fitton, Geol. Sketch
astings,

L 5

296 EOCENE PERIOD. iBook IV

It will appear, from former parts of this work, that
the amount of elevation here supposed to -have taken
place is not greater than we can prove to have 0
curred in other regions within geological periods of 29
great duration. On the other hand, the quantity of
denudation or removal by water of vast masses which
are assumed to have once reached continuously fro™
the North to the South Downs is so enormous, that thé
reader may at first be startled by the boldness of thé
hypothesis. But he will find the difficulty to vanish
when once sufficient time is allowed for the gradua
and successive rise of the strata, during which the
waves and currents of the ocean might slowly accom”
plish an operation, which no sudden diluvial rush °
waters could possibly have effected.

Escarpments of the chalk once sea-cliffs.—In order t°
make the reader acquainted with the physical struc
ture of the Valley of the Weald, I shall suppose him
first to travel southwards from the London basin. O”
leaving the tertiary strata he will first ascend a gently
inclined plane, composed of the upper flinty portion of
the chalk, and then find himself on the summit of a
declivity consisting, for the most part, of diferent
members of the chalk formation; below which thé
upper green-sand, and sometimes also the gault, crop
out.* This steep — is called by geologists “ the
escarpment of the chalk,” which overhangs a. valley
excavated chiefly out of the argillaceous or marly bed:
termed Gault (No. 2.). The escarpment is continuous
along the southern termination of the North Dow»®
and may be traced from the sea at Folkstone, west-

* This term, borrowed from our miners, is used to express the
coming up to the surface of one stratum from beneath another:

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228 EOCENE PERIOD. [Book 1V.

ward to Guildford and the neigbourhood of Peters-
field, and from amy: to the termination of the South

The castle and village

of Bramber in the foreground.

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Downs at Beachy
Head. In this pre
cipice or steep
slope the strata at?
cut off abruptly,
and it is evident
that they must
originally have €%-
tended farther. 2
the accompanying
wood-cut, (Fig:
159.), part of the
escarpment of thé
South Downs is
faithfully repre
‘sented, where thé
denudation at the
base of the dedi-
vity has been some
what more exte!
sive than usual, 12
‘consequence of the
upper and lowe!
green-sand being

formed of very incoherent materials, the upper, indeed»
being extremely thin and almost wanting.

The geologist cannot fail to recognize in this vie™
the exact likeness of a sea-cliff; and if he turns 22
looks in an opposite direction, or eastward, towards
Beachy Head (see Fig. 160.), he will see the same lin?
of height prolonged. Even those who are not accus-
tomed to speculate on the former changes which thé

Sh. Xxi] DENUDATION OF WEALD VALLEY. 229

“Urface has undergone may fancy the broad and level
Plain to resemble the flat sands which were laid dry by
€ receding tide, and the different projecting masses
chalk to be the headlands of a coast which separated
© different bays from each other.
Lower terrace of jirestone. —I have said that the
Yp per green-sand (“ firestone,” or “ malm-rock,” as it
i Sometimes: called) is almost absent in the tract here
Wuded to, It is, in fact, seen at Beachy Head to thin
ut to an inconsiderable stratum of loose green-sand ;
it farther to the westward it is of great thickness,
and Contains hard beds of blue chert and limestone.
‘te, accordingly, we find that it produces a corre-
‘Ponding influence on the scenery of the country ; for -
$ "uns out like a step beyond the foot of the chalk-
hills, and constitutes a lower terrace, varying in breadth
= a quarter of a mile to three miles, and following

of

*Sinuosities of the chalk escarpment. *

% Chalk with flints. b. Chalk without flints.
" Upper green-sand, or firestone. d.. Gault.

It is impossible to desire a more satisfactory proof
àt the escarpment is due to the excavating power of
Water during the rise of the strata; for I have shown,
My account of the coast of Sicily, in what manner
€ encroachments of the sea tend to efface that suc-

. ay
Mr. Murchison, Geol. Sketch of Sussex, &c., Geol. Trans.,
“cond Series, vol, ii. p. 98.

4
230 EOCENE PERIOD. : [Book J

cession of terraces which must otherwise result from
the successive rises of a coast preyed upon by the
waves.* During the interval between two elevator)
movements, the lower terrace will usually be de-
stroyed, wherever it is composed of incoherent ma!
rials; whereas the sea will not have time entirely ©
sweep away another part of the same terrace, or lowe!
platform, which happens to be composed of rocks of?
harder texture, and capable of offering a firmer resist
ance to the erosive action of water.

Valleys where softer strata, ridges where harder & u
out. — It is evident that the gault No.2. (see the MaP
could not have opposed any effectual resistance t0 the
denuding force of the waves; its outcrop, therefor
is marked by a valley, the breadth of which. is of”
increased by the loose incoherent nature of the upp?”
most beds of the lower green-sand, which lie next .
it, and which have often been removed with eg”?
facility.

This formation (the lower green-sand) has pee?
sometimes entirely smoothed off like the gault ; bu
in those districts where chert, limestone, and othe
solid materials enter largely into its composition
forms a range of hills parallel to the chalk, which some”
_ times rival the escarpment of the chalk itself in heig”’
or even surpass it, as in Leith Hill. This ridge ofte”
presents a steep escarpment towards the Weald clay
which crops out from under it. (See the strong linc?
in Fig. 157. p. 224.)

The clay last mentioned forms, for the most part, 7
broad valley, separating the lower green-sand from the
Hastings sands, or Forest ridge; but where subordinat?

* See Vol. ITI. p. 440. and wood-cut Fig. 107.

“WXXL] DENUDATION OF WEALD VALLEY. 231
beds of sandstone of a firmer texture occur, the uni-
mity of the plain is broken by waving irregularities
“nd hillocks,* :

In the central region, or Forest ridge, the strata
a been considerably disturbed, and are: greatly

Ctured and shifted. One fault is known where the
Eo shift of a bed of calcareous grit is no less than

Y fathoms.+ It must not be supposed that the
Mticlinal axis, which is described as running through
. - Centre of the Weald, is by any means so simple as
s Usually represented in geological sections. There
are, on the contrary, a series of anticlinal and syn-
Clinal + lines, which form ridges and troughs running
"early parallel to each other.

uch of the picturesque character of the scenery

this district arises from the depth of the narrow
Meys and ridges to which, the sharp bends and
. “tures of the strata have given rise; but it is also
~*~ to be attributed to the excavating power ex-
cd by water, especially on the interstratified argil-
*Ceous beds.

A
ý rom the above description it will appear that, in
© tract intervening between the North and South

Wns, there are a series of parallel valleys and ridges ;

~ Valleys appearing evidently to have been formed
“Neipally by the removal of softer materials, while
€ ridges are due to the resistance offered by firmer
“dS to the destroying action of water.

ise and denudation of the strata gradual. — Let us
ĉn consider how far these phenomena agree with the

*
tin Martin, Geol, of Western Sussex. Fitton, Geol. of Has-
88) p. 31.

T Fitton, Ibid. p. 55.
For explanation of these terms, see Glossary, Vol. I.

Y.
232 EOCENE PERIOD. [Book Í

changes which we should naturally expect to occu!
during the rise of the secondary strata. Suppose the
line of the most violent movements to have coincides
with what is now the central ridge of the Weald valley:
in that case the first land which emerged must have
been situated where the Forest ridge is now place™
Here a number of reefs may have existed, and isla? ;
of chalk, which may have been gradually devoured PY
the ocean in the same manner as Heligoland and othe!

The dotted lines represent the sea-level.

h. xxr] DENUDATION OF WEALD VALLEY. 233
European islands have disappeared in modern times,
M related in the second book.*
"ppose the ridge or dome first elevated to have
een so rent and shattered on its summit as to give
ore fasy access to the waves, until at length the
Masses represented by the fainter lines (Fig. 162.)
c Tmored, Two strips of land might then remain
the each side of a channel, in the same manner as
of °pposite coasts of France and England, composed
4 chalk, present ranges of white cliffs facing each
Nt A powerful current might then rush, like that

ich now ebbs and flows through the Straits of Dover,

Might scoop out a channel in the gault. We must
ĉar in mind that the intermittent action of earth-
Na es would accompany this denuding process, fis-
nng rocks, throwing down cliffs, and bringing up,
m time to time, new stratified masses, and thus
"eatly accelerating the rate of waste. If the lower

of chalk on one side of the channel should be

; ; €r than on the other, it would cause an under ter-
fen, as represented in the diagram (Fig. 162.), re-
ling that presented by the upper green-sand in.
"tts of Sussex and Hampshire. When at length the
Sault Was entirely swept away from the central parts
the channel, the lower green-sand (3. Fig. 163.)
po be laid bare, and portions of it would become
during the continuance of the upheaving earth-

€s. Meanwhile the chalk cliffs would recede far-

1 *t from one another, whereby four parallel strips of

» Or perhaps rows of islands, would be caused.

Y a continuance of these operations the edges of
€ argillaceous strata, No. 2. (Fig. 163.), would be

* Vok- 2. 75

= SS ee

ee

es E
———

234 EOCENE PERIOD. [Book 1%

exposed to farther erosion by the waves; and a portion
of the clay, No. 4., would be also removed, and a$ j
gradually rose, would be swept off from part of the
subjacent group, No. 5. This last would then ™ K
turn be laid bare, and afterwards become land by 5%
sequent elevation. 4
Why no ruins of chalk on central district. — BY thë
theory of the successive emergence and denudation ?
the groups, 1, 2, 3, 4, 5., we may account for a? j í
whic?
ob
esis"
the

. vial phenomenon
seems inexplicable
any other hypoth

S The summits of

e
s chalk downs are cov
p

Barcombe

every where with #
gravel, which is A
entirely wanting O” ‘
surface of the clay z
the foot of the ch®
escarpment, and /
traces of chalk flint hav?
ever been found if
alluvium of the cent”?
5 district, or Forest ridg”
It is rare, indeed, t° n
any wreck of the cha,

even at the distanc?
fro?

(upper green-sand wanting),
green-sand.

Lower

Offham

two or three miles

—

= he
= the escarpments oft
wv

Section from the North escarpment of the South Downs to Barcombe.

Gravel composed of partially rounded chalk flints.

2. Chalk with and without flints.
3. Lowest chalk or chalk marl

O 5
. North and South pop

1.

a
‘5 gene!
To this 8 be

h, xxr] ALLUVIUM OF WEALD VALLEY. | 235
‘bout three miles to the north of Lewes, a place which
Visited with Mr. Mantell, to whom I am indebted
4 the accompanying section (Fig. 164.). It will be
£2 that the valley at the foot of the escarpment ex-
“nds, in this case, not only over the gault, but over
i “lower green-sand ” to the Weald clay. On this
Y a thick bed of flints, evidently derived from
© waste of chalk, remains in the position above
“scribed,
When I say that there is no detritus of the chalk
its flints on the central ridge of the Weald, I may
ate that I have sought in vain for a vestige of such
"8gments ; and Mr. Mantell, who has had greater
PPortunities of minute investigation, assures me that
as never been able to detect any. Now, whether
. embrace or reject the theory of the former con-
Muity of the chalk and other groups over the whole
aCe intervening between the North and South Downs,
iy Certainly cannot imagine that any transient and
E uous rush of waters could have swept over this
ORA which should not have left some fragments of
-S Chalk and its flints in the deep valleys of the Forest

“ige. Indeed, if we adopt the diluvial hypothesis of
" Buckland, we should expect to find vast heaps of
"oken flints drifted frequently into the valleys of the
{ult and Weald clay, instead of being generally con-
"ed to the summit of the chalk downs.

n the other hand, it is quite conceivable that the
Py agency of oceanic currents may have cleared

Way,
lanat

in the course of ages, the matter which fell into
a from wasting cliffs. But in order that this ex-
tion should be satisfactory we must suppose that
i rise of the land in the south-east of England was

Y gradual, and the subterranean movements for the

a al ea a
SS

ee

v:
236 EOCENE PERIOD. [Book }

most part of moderate intensity. During the last cen’
tury earthquakes have occasionally thrown down ?
once whole lines of sea-cliffs, for several miles ©
tinuously ; but if this had happened repeatedly during
the waste of the ancient escarpments of the chalk now
encircling the Weald, and if the shocks had beer 4
companied by the sudden rise and conversion of larg?
districts into land, the Weald would have been covet?
with the ruins of those wasted rocks, and the sea Co"
not possibly have had time to clear the whole aw)’
The reader will recollect the account before given f
the manner in which the sea has advanced, within the
last century, upon the Norfolk coast at Sherr ingha™

Fig. 165.

Section of cliffs west of Sherringham.

a. Crag.
b. Ferruginous flint breccia on the surface of the chalk-
c. Chalk with flints,

The beach, at the foot of the cliff, is composed of
bare chalk with flints, as is the bed of the sea 0°
the shore. No one would suspect, from the appeara
of the beach at low water, that a few years ago b°
of solid chalk, together with sand and loam of *
superincumbent crag, formed land on the very sp?
where the waves are now rolling; still less that thes

* Vol. I. p. 405.

“Xx TRANSVERSE VALLEYS. 237
‘ame formations extended, within the last fifty years,
° a considerable distance from the present shore,
ver a Space where the sea has.now excavated a
Channel twenty feet deep.

S in*this recent instance the ocean has cleared
"ay part of the chalk, and its capping of crag, so the
“tiary sea may have swept away not only the chalk
“rounding the valley of the Weald, but the layer of
"oken flints on its surface, which was probably a
“tine alluvium of the Eocene period. Hence these
mts might naturally occur on the ‘downs, and be
Panting in the valleys below. ;

f the reader will refer to the preceding diagrams

igs, 162. and 163. p. 232.), and reflect not only on
“successive states of the country there delineated,
ut on all the intermediate conditions which the dis-
"ct must have passed through during the process of

'adual elevation and denudation before supposed, he
understand why no wreck of the chalk (No. 1.)

uld occur at great distances from the chalk escarp-
“nts; for it is evident that when the ruins of the
PPermost bed (No. 1. Fig. 162.) had been thrown
own upon the surface of the bed immediately below,
’se ruins would subsequently be carried away when
NS inferior stratum itself was destroyed. And in pro-
"tion to the number and thickness of the groups,
ls removed in succession, is the probability lessened
ur finding any remnants of the highest group
“tewed over the bared surface of the lowest.
Transverse valleys. — There is another peculiarity in
the Seographical features of the south-east of England,
“aich must not be overlooked when we are consider-
Mg the action of the denuding causes. By reference
‘0 the map (Plate XV.), the reader will perceive that

f.
238 EOCENE PERIOD. [Book IV

the drainage of the country is not effected by wate™
courses following the great valleys excavated out 0
the argillaceous strata (Nos. 2. and 4.), but by valley’
which run in a transverse direction, passing throug”
the chalk to the basin of the Thames on the one sid
and to the English channel on the other.

In this manner the chain of the North Downs *
broken by the rivers Wey, Mole, Darent, Medway
and Stour; the South Downs by the Arun, Adu’
Ouse, and Cuckmere.*

If these transverse hollows could be filled up;
the rivers, observes Mr. Conybeare, would be fore
to take an easterly course, and to empty themselv®”
into the sea by Romney Marsh and Pevensey levels

Mr. Martin has suggested that the great cross frat’
tures of the chalk, which have become river chan?® fi
have a remarkable correspondence on each side of the
valley of the Weald; in several instances the gorge i
the North and South Downs appearing to be direct
opposed to each other. Thus, for example, the defil®
of the Wey, in the North Downs, and of the Arun, ™
the South, seem to coincide in direction ; and, in Jis?
manner, the Ouse corresponds to the Darent, and t f
Cuckmere to the Medway. $ }

Although these coincidences may, perhaps, be act
dental, it is by no means improbable, as hinted by *”
author above mentioned, that the great amount of e”
vation towards the centre of the Weald district 32”
rise to transverse fissures. And as the longitudinal m Í
leys were connected with that linear movement wh!
caused the anticlinal lines running east and west a

* Conybeare, Outlines of Geol., p. 81. + Ibid., p- 145.
¢ Geol. of Western Sussex, p. 61. )

‘weyoIoyg PIO 9 ‘mpy TAN “9 “suruks}g Jo UMOT,

"SUMOM YING IY} UL ANPP IY4 SO hayDA ISLIASUV.LI,

991 ‘SL

v.
240 EOCENE PERIOD. [Book 1

com

the cross fissures might have been occasioned by tP?
intensity of the upheaving force towards the centre ?
the line, whereby the effect of a double axis of elev™
tion was in some measure produced. :
In order to give a clearer idea of the manner ™
which the chalk-hills are intersected by these transvers?
valleys, I subjoin a sketch (Fig. 166.) of the gorg?
of the river Adur, taken from the summit of the cha!
downs, ata point in the bridle-way leading from the
towns of Bramber and Steyning to Shoreham. If the
reader will refer again to the view given ina forme?
wood-cut (Fig. 159. p. 227.), he will there see the esa%
point where the gorge, of which Iam now speaking?
interrupts the chalk escarpment. A projecting hil
at the point a, hides the town of Steyning, near whit
the valley commences where the Adur passes direct
to the sea at Old Shoreham. The river flows throug
a nearly level plain, as do most of the others whit
intersect the hills of Surrey, Kent, and Sussex ; a”
it is evident that these openings, so far at least ®
they are due to aqueous erosion, have not been pl
duced by the rivers, many of which, like the Ous?
near Lewes, have filled up arms of the sea, instead °
deepening the hollows which they traverse.

In regard to the origin of the transverse ravine
Fig. 167.

¢

Supposed section of Transverse Valley.

there can be no doubt that they are connected with
lines of fracture, and perhaps, in some places, there

S
h. XXI THE COOMB, NEAR, LEWES. 241

oy be an anticlinal dip on both sides of the valley,
Suggested by Mr. Martin.* But this notion requires

confirmation.

a he ravine, called the Coomb, near Lewes, affords
fautiful example of the manner in which narrow

near Lewes

<
>
Š
Š
v
=
SN

ae :
nings in the chalk may have been connected with
ifts and dislocations in the strata. This coomb is

* Geol. of Western Sussex, p. 64. Plate III. fig. 3.
VOL. Iv. M

242 EOCENE PERIOD. [Book 1V-

seen on the eastern side of the valley of the Ous®
in the suburbs of the town of Lewes. The steep
declivities on each side are covered with green tu™
as is the bottom, which is perfectly dry. No outwat
signs of disturbance are visible; and the connexio”
of the hollow with subterranean movements wow!
not have been suspected by the geologist, had not thé
evidence of great convulsions been clearly exposé
in the escarpment of the valley of the Ouse, and ™
the numerous chalk pits worked at the termination °
the Coomb. By aid of these we discover that the
ravine coincides precisely with a line of fault, on 02°
side of which the chalk with flints, a, appears at the
summit of the hill, while it is thrown down to the bot
tom on the other. I examined this spot in compa)
with Mr. Mantell, to whom I am indebted for the
accompanying section.

Fig. 169.

Fault in the clifPhilis near Lewes.

a. Chalk with flints. b. Lower chalk.*

The fracture here alluded to is one of those whieh
run east and west, and of which there are many ™
the Weald district, parallel to the central axis of th?
Forest ridge.

In whatever manner the transverse gorges origi”
ated, they must evidently have formed ready channe’
of communication between the submarine longitudin®

_ * For farther information, see Mantell’s Geol. of S. E. ob
England, p. 352.

Ch, XX1] THE COOMB, NEAR LEWES. 243
valleys and those deep parts of the sea wherein the
ertiary strata may have accumulated. If the strips
of land which first rose had been unbroken, and there
ad been no free passage through the cross fractures,
e currents would not so easily have drifted away
© materials detached from the wasting cliffs, and it
Would have been more difficult to understand how the
Wreck of the denuded strata could have been so en-
"rely Swept away from the base of the escarpments.

n the next chapter I shall resume the consideration
of these subjects, especially the proofs of the former
“Ntinuity of the chalk of the North and South Downs,
“hd the probable connexion of the denudation of the

'eald valley with the origin of the Eocene strata.

CHAPTER XXIL
ORIGIN OF THE ENGLISH EOCENE FORMATIONS AND peN”
DATION OF THE WEALD — continued.

The alternative of the proposition that the chalk of the North and
South Downs was once continuous, considered — Dr. Bucs
land on Valleys of Elevation (p. 246.) —If rise and den”
dation of secondary rocks gradual, so also the deposition °
tertiary strata (p. 254.) — Composition of the latter such
would result from wreck of denuded secondary rocks
Central parts of the London and Hampshire basins nea!
as high as Weald — Why — Curved and vertical strata Ta
Isle of Wight — Eocene alluviums (p. 263.) — Formation °
valleys — Recapitulationu.

Extent of denudation in the Valley of the Weald.—“ is
would be highly rash,” observes Mr. Conybeare, spea
ing of the denudation of the Weald, “to assume that
the chalk at any period actually covered the who
space in which the inferior strata are now expose’
although the truncated form of its escarpment ev
dently shows it to have once extended much farthe*
than at present.” *

I believe that few geologists who have considered
the extent of country supposed to have been denuded
and who have explored the- hills and valleys of te
central or Forest ridge, without being able to discov’
the slightest vestige of chalk in the alluviumt, Y
fail to participate, at first, in the doubts here express?

* Outlines, p- 144. + See above, p: 234

Ch. XXIL] DENUDATION OF WEALD :VALLEY. 945

aS to the original continuity of the upper secondary
formations over the anticlinal axis of the Weald. For
MY own part, I never traversed the wide space which
Separates the North and South Downs, without de-
Siring to escape from the conclusions advocated in the
last chapter; and yet I have been invariably brought
ack again to the opinion, that the chalk was origin-
aly continuous, on a more deliberate review of the
Whole phenomena.

It may be useful to. consider the only other alter-
Native of the hypothesis before explained. If the
Marine groups, Nos. 1, 2, 3., were not originally con-

Fig. 170.

soe —
se

L Chalk and Upper 4, Weald clay.
9 green-sand.
` Nault,

” Lower green-sand. 5. Hastings sands.

Marine. Freshwater.

tinuous, it is necessary to imagine that they each
terminated at some point between their present out-
Soings and the secondary strata of the Forest ridge.
hus we might suppose them to have thinned out one
after the other, as in the above diagram, and never to
®ve covered the entire area occupied by the fresh-
Water strata, Nos. 4. and 5.
tt must be granted, that had such been the original
Sposition of the different groups, they might, as they
Stadually emerged from the sea, have become denuded
ù the manner explained in the last chapter, so that the
“ountry might equally have assumed its present con-
"guration. But although I know of no invincible ob-
J€ction to such an hypothesis, there are certainly no
M 3

246 EOCENE PERIOD. [Book iV:

appearances which favour it. If the strata Nos: *
and 5. had been unconformable to the lower green-
sand No. 3., then, indeed, we might have imagine
that the older groups had been disturbed by a series 0
movements antecedently to the deposition of No. 3°
and, in that case, some parts of them might be sup
posed to have emerged or formed shoals in the ancient
sea, interrupting the continuity of the newer marine
deposits. But the group No. 4. is conformable to No. 3+:
and the only change which has been observed to take
place at the junction is an occasional intermixture 0
the Weald clay with the superior marine sand, such 4
might have been caused by a slight superficial move-
ment in the waters when the sea first overflowed thé
freshwater strata.

On the other hand, the green-sand and chalk, 3°
they approach the central axis of the Weald, are nof

found to contain littoral shells, or any wreck of the
freshwater strata, such as might indicate the exist
ence of an island with its shores or wasting cliffs-
Had any such signs been discovered, we might hav®
supposed the geography of the region to have on?
borne some resemblance to that exhibited in the dia

gram, Fig. 170.

Dr. Buckland on Valleys of Elevation. — We a
indebted to Dr. Buckland for an able memoir in illus
tration of several districts of similar form and structu"?
to the Weald, which occur at no great distance in the
south of England. His paper is intitled, “ On the
Formation of the Valley of Kingsclere and other Val
leys, by the Elevation of the Strata which inclos®
them.” *

* Geol. Trans. Second Series, vol, ii. p. 119.

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* Copied by permission from Dr. Buckland’s Plate XVII.,

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Ch. XXIL]
bury,
bread

248 EOCENE PERIOD. [Book IV.

more nearly approaches to that of nature, although the
altitudes, in proportion to the horizontal extent, are
even in this, perhaps, somewhat in excess. On each
side of the valley we find escarpments of chalk, thé
strata of which dip in opposite directions, in the north
ern escarpment to the north, and in the southern t?
the south. At the eastern and western extremities
of the valley, the two escarpments become confluent
precisely in the same manner as do those of the North
and South Downs, at the eastern end of the Weald
district, near Petersfield. And as, a few miles east of
the town last mentioned (see Map, Plate XV.) the fire-
stone, or upper green-sand, is laid open in the sharp
angle between the escarpment of the Alton Hills avd
the western termination of the South Downs * ; so in
the valley of Kingsclere the same formation is seen t0
crop out from beneath the chalk.

The reader might imagine, on regarding the sectio”
(Fig. 173.), where, for the sake of elucidating the ge

Fig. 173.

I. Chalk with flints, 2. Lower chalk without flints.

3. Upper green-sand, or firestone, containing beds of chert-

N. B. The lines here are not intended to represent strata.

logical phenomena, the heights are exaggerated i?
proportion to the horizontal extent, that the solution °

* See Mr. Murchison’s Map, Plate XIV., Geol. Trams
Second Series, vol. ii.

Ch. XXIL] _ VALLEY OF KINGSCLERE. 249

continuity of the strata bounding the valley of Kings-

Clere had been simply due to elevation and fracture,
Unassisted by aqueous causes; but by reference to the

truer scale (Fig. 172.), it will immediately appear that
a Considerable mass of chalk must have been removed
Y denudation.

If the anticlinal dip had been confined to the valley
of Kingsclere, we might have supposed that the
Upheaving force had acted on a mere point, forcing
Upwards the superincumbent strata into a small dome-
Shaped eminence, the crown of which had been sub-
Sequently cut off; but Dr. Buckland traced the line
of Opposite dip far beyond the confluence of the chalk
“scarpments, and found that it was prolonged in
à more north-west direction far beyond the point «
(Fig, 171.). In following the line thus extended, the
Strata are seen in numerous chalk-pits to have an op-
Posite dip on either side of a central axis, from which
We may clearly infer the linear direction of the move-
Ment,

Many of the valleys having a similar conformation
to that of Kingsclere, run east and west, like the
anticlinal ridge of the Weald valley. Several of these
occur in Wiltshire and Dorsetshire, and they are all
“rcumscribed by an escarpment whose component
Strata dip outwards from an anticlinal line running
‘long the central axis of the valley. One of these, dis-
tant about seven miles to the north-east of Weymouth,
8 nearly elliptical in shape, and in size does not much
Xceed the Coliseum at Rome. Their drainage is ge-
erally effected in a manner analogous to the drainage
of the Weald, by an aperture in one of their lateral
“scarpments, and not at either extremity of their longer

mM 5

250 EOCENE PERIOD. [Book 1”.

axis, as would have happened had they been simply
excavated by the sweeping force of rapid water.*

“It will be seen,” continues Dr. Buckland, « if we fol”
low on Mr. Greenough’s map the south-western escap’
ment of the chalk in the counties of Wilts and Dorse®
that, at no great distance from these small elliptic?
valleys of elevation, there occur several longer an
larger valleys, forming deep notches, as it were, in thé
lofty edge of the chalk. These are of similar struc’
ture to the, smaller valleys we have been considering
and consist of green-sand, inclosed by chalk at one e*
tremity, and flanked by two escarpments of the sam
facing each other with an opposite dip; but they differ
in the circumstance of their other and broader extre
mity being without any such inclosure, and gradually
widening till it is lost in the expanse of the adjacent
country.

“The cases I now allude to are the Vale of Pew-
sey, to the east of Devizes; that of the Wily, to the
east of Warminster; and the Valley of the Naddet
extending from Shaftesbury to Barford, near Salisbury’
in which last not only the strata of green-sand a?
brought to the surface, but also the still lower for™
ations of Purbeck and Portland beds, and of Kimmé
ridge clay.

“It might at first sight appear that these valleys
are nothing more than simple valleys of denudation '
but the fact of the strata composing their escarpment?
having an opposite and outward dip from the axis 9

the valley, and this often at a high angle, as nea"
Fonthill and Barford, in the Vale of the Naddets
and at Oare, near the base of Martinsell Hill, in the

* Dr. Buckland, Geol. Trans., Second Series, vol. iis p. 122

Ch. XXIL] PROOFS OF DENUDATION. 251

Vale of Pewsey, obliges us to refer their inclination
to some antecedent violence, analogous to that to
Which I have attributed the position of the strata in
the inclosed valleys near Kingsclere, Ham, and Bur-
Sage, Nor is it probable that without some pre-exist-
Mg fracture or opening in the lofty line of the great
Chalk escarpment, which is here presented to the
North-west, the power of water alone would have
forced open three such deep valleys as those in ques-
tion, without causing them to maintain a more equable
breadth, instead of narrowing till they end in a point
in the body of the chalk.” *
Now, in the Weald, the strata of the North Downs
are inclined to the north at an angle of from 10° to 15°,
r even 45°, in the narrow ridge of the Hog’s Back,
West of Guildford, in Surrey; while those in the South
Downs dip to the south at a slight angle. It is super-
fluous to dwell on the analogy which, in this respect,
the two escarpments bear to those which flank the
valleys above alluded to; and in regard to the greater
distance which separates the hills of Surrey from those
of Sussex, the difficulty may be reduced simply to a
Westion of time.
If the rise of the land was accomplished by an
indefinite number of minor convulsions, or by a slow
‘ad insensible upheaving like that now taking place in
Sweden, the power of the ocean would be fully ade-
quate to perform the work of denudation in the lapse
of many ages. If, on the other hand, we embrace the

Ypothesis of paroxysmal elevation; or, in other words,
Suppose a submarine tract to have been converted
stantaneously into high land, we may seek in vain

* Br. Buckland, Geol. Trans. Second Series, vol. ii. p. 125.
M 6

252 EOCENE PERIOD. [Book IV

for any known cause capable of sweeping away eve”
those portions of chalk and other rocks which, all are
agreed, must once have formed the prolongation of
the existing escarpments. It is common in such cases
to call in one imaginary cause to support another; and
as the upheaving force operated with sudden violence,
so a vast diluvial wave is introduced to carry away,
with almost equal celerity, the mountain mass of strata
assumed to have been stripped off.

Some geologists have endeavoured to account fot
the structure of the districts described as “ valleys of
elevation,” by the aid of Von Buch’s theory of
“elevation craters,” in which case they can dispens®
both with time and denudation. It would be supe!
fluous to repeat what has been already said of thé
hypothetical agency here referred to*; but it may
be well to consider whether the upheaving of small
dome-shaped masses, such as those described PY
Dr. Buckland, implies the development at a cor
siderable depth of volcanic forces acting with great
violence on limited areas, or mere points of the earth”
crust.

_ A theory suggested by Dr. Fitton appears to me fa!
more probable. Suppose a series of horizontal strat”
composed in great part of sand and soft clay, to repos?
on a foundation of older and more solid rocks present
ing an uneven surface, varied by hills, valleys, a?
ridges, like many parts of the land and bed of the s€%
If a force acting from beneath should then elevate t°
whole mass, the protuberances of the subjacent rocks
would be forced up against the more compressible
strata which coveredthem. The effect of the pressure

* Vol. II. p. 152.

Ch. XXIL] ORIGIN OF TERTIARY STRATA. . 953

Might be the same as that which happens on a small
Scale in a bound book, when a minute inequality or
knob in the paper of some page is propagated through
à great number of others, imparting its shape to all,
Without piercing through them.* The observations \
of Dolomieu on the manner in which the more yielding |
tertiary strata of Calabria were displaced by the granite
uring the earthquake of 1783, lends some countenance
to this theory. +

In the last chapter I pointed out the phenomena
Which seem to indicate that the elevation and denud-
ation of land in the south-east of England were
Stadual. t The same arguments are in a great degree
applicable to the basins of Hampshire and the Isle of
Wight ; but Mr. Conybeare has contended that the
Verticality of the strata in the Isle of Wight and in
Purbeck compels us to admit that the movement
there was so violent, that the vertical strata, which
‘ave been traced through a district nearly sixty miles
m length, were brought into their present position by a
Single convulsion.

_ It may well be asked what ground is there for as-
Suming that a single effort of the subterranean force,
‘ather than reiterated movements, produced that sharp
flexure of which the vertical strata of the Isle of Wight
ae supposed to form a part, the remainder of the arc
aving been carried away by denudation? §

It is not improbable that the Cutch earthquake
of 1819, before alluded to, may have produced an
Ncipient curve, running in a linear direction through

i * Dr. Fitton, Geol. Trans., Second Series, vol. iv. pe 244.
834,

t See above, Vol. II. p. 215. } Page 231.
$ See Webster, Englefield’s Isle of Wight, Plate XLII. fig. 1.

254: EOCENE PERIOD. [Book IV:

a tract at least sixty miles in length.* The strat@
were upraised in the Ullah Bund, and depressed
below the level of the sea in the adjoining tract
where the fort of Sindree was submerged. (See Plate
V.) It would be impossible, if the next earthquake
should raise the Bund still higher, and sink to a lowe!
depth the adjoining tract, to discriminate, by aY
geological investigations, the different effects of thé
two earthquakes, unless a minute survey of the effec
of the first shock had been made and put on record:
In this manner we may suppose the strata to be bent
again and again, in the course of future ages, until
parts of them become perpendicular.

To some it may appear that there is a unity of
effect in the line of deranged strata in the Isles 9
Wight and Purbeck, as also in the central axis of thé
Weald, which is inconsistent with the supposition 9
a great number of separate movements recurring afte!
long intervals of time. But we know that earthquake’
are repeated throughout a long series of ages, in thé
same spots, like volcanic eruptions. The oldest lav4
of Etna were poured out many thousands, perhap’
myriads of years, before the newest, and yet they
have produced a symmetrical mountain ; and if rivel®
of melted matter thus continue to flow in the sa™®
direction, and towards the same points, for an in
definite lapse of ages, what difficulty is there in c0”
ceiving that the subterranean volcanic force, occasioni”
the rise or fall of certain parts of the earth’s crus
may, by reiterated movements, produce the most per
fect unity of result ?

Tf denudation of secondary rocks gradual, so also de-
position of tertiary. — It follows, then, from the fact?

* See Vol. II. p. 194., and Vol. III. p. 253.

Ch. XXIL] ORIGIN OF TERTIARY STRATA. 255

*xamined in this and the. preceding chapter, that
Subsequently to the deposition of the chalk a large
region composed of secondary strata has been denuded,
and that the lapse of many ages must have been
required for the entire removal of the materials from
the denuded district.

t is no less evident that the transported matter
Must have been deposited by degrees somewhere else.
Are there any tracts in the south-east of England,
Where we find derivative strata composed of a mixture
of such mineral ingredients as would result from the
degradation of the secondary groups Nos. 1, 2, 3, 4,
5.? The tertiary strata of the London and Hamp-
shire basins answer well to the conditions required by
Such an origin, for they consist of alternations of va-
tiously coloured sands and clays, as do the secondary
‘trata from the group No. 5. to No. 2. inclusive. Some
tertiary green-sand, which occurs in parts of the
Plastic clay formation in the basins of London and

ants, cannot be distinguished mineralogically from
à large part of that which is found in the secondary
formations below the chalk.

If it be asked, where do we find the ruins of the
White chalk among our Eocene strata? — the answer is,
“tst, that the flint pebbles which are associated in such
‘timense abundance with the sands of the plastic clay,
‘re derived evidently from the destruction of chalk,
“nd contain the same fossils: secondly, that as to the
Soft, white, calcareous matrix, we may suppose it to
ave been easily reduced to fine sediment, and to have
“ontributed, when in a state of perfect solution, to
orm the shells of Eocene testacea; or when mixed
With the waste of the argillaceous groups, Nos. 2. and 4.,
Which have been peculiarly exposed to denudation, it

256 EOCENE PERIOD. [Book 1V:

may have entered into the composition of the London
clay, which contains no slight proportion of calcareous
matter. In the crag of Norfolk, undoubtedly, we find
great heaps of broken pieces of white chalk, with
slightly worn and angular flints; but, in this case, We
may infer that the attrition was not continued for 4
Jong time; whereas, the large accumulations of pet
fectly rolled shingle, which are interstratified with ou
Eocene formations, prove that they were acted up?”
for a protracted period by the waves. We have many
opportunities of witnessing the entire demolition of thé
chalk on our southern coast, as at Seaford, for example
in Sussex, where large masses are, year after year, de
tached from the cliffs, and soon disappear, leaving 29
thing behind but a great bank of flint shingle.*

It may also be remarked that the white chalk ™
the north of England, as in Yorkshire, for example, is
much harder than the corresponding formation in thé
southern counties, where it is now so soft that we may
imagine it to have been in the state of mud whe?
submerged beneath the waters of the sea. An original
difference of this kind in the degree of induration may
explain the fact, that in certain districts gravel co™
posed of chalk-flint occurs without any pebbles of white
chalk, while in other regions rounded boulders of whit?
chalk are plentifully intermixed with pebbles of flint-

The similarity, then, of the mineral ingredients °
the Eocene secondary strata affords alone some p*®
sumption in favour of this newer group having bee?
derived from the wreck of the older series. But it ®
also natural to expect, that when the formations of the
Weald were emerging, there would be some contiguo™®

* Vol. I. p. 424.

Ch. XXII] AMOUNT OF DENUDATION. 257

Parts of the sea sufficiently deep to receive the drift
Matter,
Fig. 174.

We may suppose, that while the waves and cur-
tents were excavating the longitudinal valleys, D
wd C (Fig. 174.), “the deposits a were thrown down
© the bottom of the contiguous deep water E, the
Sediment being drifted through transverse fissures, as

efore explained. In this case, the rise of the form-
ations Nos. 1, 2, 3, 4, 5. may have been going on
“ontemporaneously with the excavation of the valleys
C and D, and with the accumulation of the strata a.

here must be innumerable points on our own coast
Where the sea is of great depth near to islands and
Cliffs now exposed to rapid waste, and in all these the
“enuding and reproductive processes must be going on
N the immediate proximity of each other.

English Eocene strata rise nearly as high as the de-
nuded secondary districts. — Those geologists who have
Atherto regarded the rise and denudation of the lands
u the south-east of England as events altogether pos-
terior in date to the deposition of the London clay,
will object to the foregoing reasoning, that not only
*ettain outlying patches of tertiary strata, but even

€ central parts of the London and Hampshire basins,
Attain very considerable altitudes above the level of
the sea, Thus the London clay at Highbeach, in

Ssex, reaches the height of 750 feet; an elevation
“Xceeding that of large districts of the chalk and other

`

258 EOCENE PERIOD. [Book 1

denuded secondary rocks. But these facts do not, J
think, militate against the theory above proposed
since I have endeavoured to show that there must
have been a long-continued series of elevatory mov
ments in a region where both the degradation aP
reproduction of strata were in progress.

In order to explain this view, I shall assume that,
in the region A (Fig. 175.), the chalk and associate

strata are raised and converted into land; while in t°
adjoining district, B, a contiguous part of the sam®
beds remains submerged beneath the sea. Durg
the elevation in A, the mass c c is gradually remove
by denudation, and its ruins drifted to B, forming
the tertiary deposit d. The force of water has tb¥
exerted an antagonist power; so that, in spite of the
upheaving movement, the general outline of the so!
surface, or the relative levels of its various parts, are
| not greatly altered; for the uppermost part of thé
newer deposit d rises nearly as high as the remainiPS
summits of the denuded country A. After all thes?
changes and levelling operations, an elevation to the
amount of eight hundred feet in both the regions
and B, would cause the secondary rocks of A tô of
quire much the same height above the level of th®
sea, as the tertiary beds would attain in B.

The estimate of Mr. Martin is not, perhaps: exp
aggerated, when he computes the probable thickness

Ch. XXII.) VERTICAL STRATA OF ISLE OF WIGHT. 259

o£ Strata removed from the highest part of the Forest
“dee to be about 1900 feet: so that, if we restore to
Towborough Hill, in Sussex, the beds of Weald clay,
Ower green-sand, gault, and chalk, which have been
*emoved by denudation, that hill, instead of rising
t0 the height. of eight hundred feet, would be more
than trebled in altitude, and be about 2700 feet high.*
t would then tower far above the highest outliers
of tertiary strata which are scattered over our chalk ;
% Inkpen Hill, in Berkshire, the greatest elevation
of chalk in England, rises only 1011 feet above the
vel of the sea.
Some geologists, who have thought it necessary to
‘uppose all the strata of the London and Hampshire
asins to have been once continuous, have estimated
the united thickness of the three marine Eocene groups
fore described, as amounting to 1300 feet, and have
ĉen bold enough to imagine a mass of this height to
ve been once superimposed upon the chalk which
merly covered the axis of the Weald.t Hence they
Were led to infer that Crowborough Hill was once
four thousand feet high, and was then cut down from
Ur thousand to eight hundred feet by diluvial action.
But by adopting the view above explained, that the
Ocene deposits originated while the chalk and other
Secondary rocks were rising from the sea and wasting
“Way, we shall find it unnecessary to suppose any re-
Noval of formations newer than the chalk, from the
“entral parts of the Weald.
_ Vertical strata of the Isle of Wight. — A line of ver-
ical and inclined strata, running east and west, or

* Phil. Mag. and Annals, No. 26., New Series, p. 117,
t Martin, ibid. i

260 EOCENE PERIOD. [Book 1V.

parallel to the central axis of the Weald, extends, 3$
has been stated, through the Isles of Wight and Pur-
beck, and through Dorsetshire, and has been observed
by Dr. Fitton to reappear in France, north of Boulogh®
The same strata which are elevated in the Weal
valley are upheaved on this line also; and in the Isle
of Wight, all the tertiary strata appear to have pa
taken in the same movement.* ;
From the horizontality of the freshwater series ”
Alum Bay, as contrasted with the vertical position 0
the marine tertiary beds, Mr. Webster was at first l€
very naturally to conclude, that the marine had unde?
gone great derangement before the deposition of the
freshwater strata. It appears, however, from the sub”
séğjuent observations of Professor Sedgwick +, th
/ these appearances are deceptive; and that at thé
eastern extremity of the Isle of Wight, part of th?
freshwater series is vertical, like the marine. Henc?
it is now ascertained that, as the chalk is horizontal at
the southern extremity of the Isle of Wight, while i
is vertical in the centre of that island, so the Eoce?®
strata are horizontal in the north of the island, 2”
vertical in the centre.
An important corollary is deduced from the dis-
covery above mentioned ; namely, that the convulsio”?
which brought the Isle of Wight group into their Pr”
sent position were, in a great part if not entirely, sub-
sequent to the deposition of the freshwater beds, %
upper members of the Eocene formation. They may?

* See Mr. Webster’s section, Geol. Trans., vol. ii. pirs
Series, PlateX I, i ;

t Anniv. Address to the Geol. Soc., Feb. 1831, p. 9 "i
fessor Sedgwick informs me that his observations, made in 187”
have recently been confirmed by Professor Henslow.

Ch, XXIL] ELEPHANT BED, BRIGHTON. 261

however, have been contemporaneous with those move-
Ments which raised the central parts of the London
‘nd Hampshire basins to their present height. Re-
fering again to the diagram, Fig. 175. p. 258., we may
magine the series of elevatory movements in the S. E.
of England to be divided into two parts: first, that
Which casused the elevation and denudation of the
tentral axis of the Weald in A; secondly, that which
lifted the denuded surface E, together with the
tertiary formations d, to their actual height. Now,
this last set of movements may have occured before
the close of the Eocene period, and may have pro-

Uced that curve in the stratified rocks of the Isle
of Wight, in which the freshwater beds there have
Participated.

At the same time great movements of elevation
have been experienced in the south of England, at
Periods decidedly post-Eocene; as, for example, those
Y which the crag strata attained their present posi-
Non in Norfolk, Suffolk, and Essex. The formation
also called by Mr. Mantell the Elephant Bed, at the
t of the chalk cliffs at Brighton, is not merely a
talus of calcareous rubble collected at the base of an
‘Nand cliff, but exhibits every appearance of having
ĉen spread out in successive horizontal layers by
Water in motion.

The deposit alluded to skirts the shores between
‘ighton and Rottingdean, and another mass appa-
t tently of the same age occurs at Dover. The pheno-
Mena appear to me to suggest the following conclu-
‘lons ; — First, the south-eastern part of England had
quired its actual configuration when the ancient
chalk clif A a was formed, the beach of sand and
shingle b having then been thrown up at the base of

v.
262 EOCENE PERIOD. [Book I

the cliff. Afterwards the whole coast, or at least that
part of it where the elephant bed now extends, sub-
Fig. 176.

A. Chalk with layers of flint dipping slightly to the south.

b. Ancient beach, consisting of fine sand, from one to four ie
thick, covered by shingle from five to eight feet thick °
pebbles of chalk-flint, granite, and other rocks, with proke”
shells, &c.

c. Elephant bed, about fifty feet thick, consisting of layers °
white chalk rubble, with broken chalk flints, in which depo"
are found bones of ox, deer, horse, and mammoth. *

sided to the depth of fifty or sixty feet, and during
the period of submergence successive layers of whit?
calcareous rubble ¢ were accumulated, so as to c0Y®
the ancient beach 6. Subsequently, the coast W”
again raised, so that the ancient shore was elevated *
a level somewhat higher than its original position. t
_* Mantell’s Geol. of S. E. of England, p. 32. |
+ See Mantell’s Geol. of S. E. of England, p. 32-
re-examining the elephant bed in 1834, I was no longer in d
of its having been a regular subaqueous deposit.

oubt

Ch. xxi y EXCAVATION OF VALLEYS. 263

Eocene alluviums. — The discovery, before men-
tioned, of the genera Paleotherium and Anoplotherium
A Binstead, associated with fossil shells of well-known.
Ocene species, is interesting, as showing that England,
® rather the space now occupied by part of our island,
38 well as the country of the Paris basin, and Auvergne,
‘ital, and Velay, were all inhabited, during the
cene period, by a class of land animals of a very
Peculiar type.
€t we have never found a single fragment of the
nes of any of these quadrupeds in our alluviums or
“Ve breccias. In these formations we find the bones
the mastodon and mammoth, of the rhinoceros,
tippopotamus, lion, hyana, bear, and other quadru-
Peds, all of extinct species. Where, then, are the
“restrial alluviums of that surface which was inha-
ted by the Paleothere and its congeners?
It is difficult to answer this question ; but it seems
“ear that a peculiar and rare combination of favour-
© circumstances is required to preserve mammifer-
Us or, indeed, any remains in terrestrial alluviums, in
Wicient quantity to afford the geologist the means of
‘signing the date of such deposits. For this reason
“are scarcely able, at present, to form any conjec-
te as to the relative ages of the numerous alluviums
ich cover the surface of Scotland; a country which
"obably became land long before the commencement
*t the tertiary epochs.
teavation of valleys. —It will be seen that the
Xcavation of the valleys in the S. E. of England has
“en referred chiefly to the ocean.
those geologists who contend that the valleys in
"gland are not due to what they term “ modern
“Uses,” are in the habit of appealing to the fact, that

A
264 EOCENE PERIOD. [Book IV

the rivers in the interior of England are working g
sensible alterations, and could never in their present
state, not even in millions of years, have excavate
the valleys through which they now flow. A false
theory seems to be involved even in the term “mode™
causes,” as if it could be assumed that there We
ancient causes, differing from those which are now, y
operation. But if we substitute the phrase “ existing
causes,”» we shall find that the argument now contr”
verted amounts to little more than this,—“ that in y
country free from subterranean movements, the actio?
of running water is so trifling, that it could neve?
hollow out, in any lapse of ages, a deep system °
valleys, and, therefore, no known combination of exist
ing causes could ever have given rise to our prese”
valleys !”

"The advocates of these doctrines, in their an
to point out the supposed absurdity of attributing
ordinary causes those inequalities of hill and 4 j
which now diversify the earth’s surface, have too ofte”
kept entirely out of view the many recorded exa™mP "
of elevations and subsidences of land during eart 4
quakes; the frequent fissuring of mountains and ope
ing of chasms; the temporary damming up of rivers
landslips, followed by their sudden and impetuo”
escape; the deflexion of streams from their origi”?
|| courses; and, more important, perhaps, than all thes”
|| the denuding power of the ocean, during the rise °

continents from the deeps. Few of the ordinary cals”
H of change, whether igneous or aqueous, x
served to act with their full intensity in any one
at the same time: hence it is easy to persuade t he
who have not reflected long and profoundly 9 ;
working of the numerous igneous and aqueous a8°

xiety

pts,

Ch. XXIL] RECAPITULATION. 265

that they are entirely inadequate to bring about any
portant fluctuations in the configuration of the
farth’s surface.

Recapitulation. —1 shall now briefly recapitulate
Some of the principal conclusions to which I have
arrived respecting the geology of the south-east of

ngland, in reference to the nature and origin of the

Ocene formations considered in this and the two
Preceding chapters.

l. In the first place, it appears that the tertiary
‘trata rest exclusively upon the chalk, and consist,
With some trifling exceptions, of alternations of clay
and sand.

2. The organic remains agree with those of the

aris basin ; but the mineral character of the English
tertiary deposits is extremely different, those rocks in
Particular which are common to the Paris basin and

entral France being wanting, or extremely rare in
England.

3. The English Eocene deposits are generally con-
rmable to the chalk, being horizontal where the beds
of chalk are horizontal, and vertical where they are
Vertical; so that both series of rocks appear to have
Participated in nearly the same movements.

4. It is not possible to define the limits of the
àncient borders of the tertiary sea in the south-east of

hgland, in the same manner as can be frequently —

One in those countries where the secondary rocks are
“Xconformable to the tertiary.

5. Although the tertiary deposits are chiefly confined
to the tracts called the basins of London and Hamp-
Shire, insulated patches of them are, nevertheless,
Und on some of the highest summits of the chalk
intervening between these basins.

VOL. Iv. N

'

266 _ EOCENE PERIOD. . [Book IY:

6. These outliers, however, do not necessarily prov’
that the great mass of tertiary strata was once Conti
nuous between the basins of London and Hampshire:
and over other parts of the south-east of England now
occupied by secondary rocks.

7. On the contrary, it is probable that these second-
ary districts were gradually elevated and denude®
when the basins of London and Hampshire were stil
submarine, and while they were gradually becoming
filled up with tertiary sand and clay.

8. If, in illustration of this theory, we examine one
of the districts thus supposed to have been denude®
we find in the valley of the Weald decided proofs
that an immense mass of chalk and other seconda'Y
formations has been removed by the force of water.

9. We may infer, from the existence in the Wert
of large valleys along the outcrop of the softer beds
and of parallel chains of hills where harder rocks co™®
up to the surface, that water was the removing caus@’
and from the shape of the escarpments presented by
the harder rocks, and the distribution of alluvium; ©
may also conclude that the denudation was success!”
and gradual during the rise of the strata.

10. The materials carried away from the denuded .
districts were probably conveyed into the depths of t°
contiguous sea, through channels produced by cros
fractures which have since become river-channels, 2”
which now intersect the chalk in a direction at 18
angles to the general axis of elevation of the count®y’

11. The analogous structure of the valley of King?
clere, and of other valleys:which run east and west,
like the valley of the Weald, but are much narrowe”
accords with the hypothesis, that they were all Py

Ch. XXII] RECAPITULATION. 267

duced by the denuding power of water co-operating
With elevatory movements. >

12. The mineral composition of the materials thus
Supposed to have been removed in immense abundance
from the valley of the Weald, are such as would, by
degradation, form the English Eocene strata.

13. The movements which threw the chalk and the
tertiary strata of the Isles of Wight and Purbeck into
à Vertical position, were subsequent to the formation
of the Eocene freshwater strata of the Isle of Wight,

ut may possibly have occurred during the Eocene
Period.

14. But some movements of land in the south of

Ngland must have been posterior to the deposition of
the crag; and the ancient beach, together with the
å elephant bed” at Brighton, seem to imply a subsi-
dence and elevation of comparatively modern date.

15. The masses of secondary rock which have been
"emoved by denudation from the central axis of the

eald would, if restored, rise to more than double the
“eight now attained by any patches of tertiary strata
England. l

l6. If, therefore, the Eocene strata do not appear to
*ccupy a much lower level than the secondary rocks
“0m the destruction of which they have been formed,
Mis, perhaps, because the highest summits of the
Secondary formations have been cut off during the rise
oÈ the land, and thrown into those troughs where we
now find the tertiary deposits.

CHAPTER XXIII.

FORMATIONS COMMONLY CALLED SECONDARY AND
TRANSITION.

Ancient and modern classification of fossiliferous strata — For™
ations commonly called secondary and transition — The di-
visions usually adopted not of equivalent value — Sketch of the
principal groups — Cretaceous group (p. 271.) — No species
common to the secondary and tertiary rocks — Chasm betwee?
the Eocene and Maestricht beds — Duration of seconda
periods— Wealden strata— Their relation to the marine group ;

above and below — Portland “dirt bed” — Oolitic gro”?
(p. 287.)— Lias — New red sandstone — Zechstein — Carbo?” .
iferous group — Old red sandstone — Transition formations <

Rock called Greywacké.

Ir was stated in a former chapter that the first rude
attempt to classify rocks in chronological order was
that according to which they were arranged in four

groups called primitive, transition, secondary, and te"
tiary —the transition and secondary comprising all the
stratified fossiliferous formations older than the tertia?’
These ancient divisions, although not yet obsolete
have gradually become less and less fitted to repres?”
the present state of our knowledge. It was neve!
supposed that each of the four sections were of equiv
lent importance, or, in other words, that they °°
comprised a series of monuments relating to ed”
portions of the ancient history of the earth. It wa®
however, imagined that they followed each other ”

Ch. XXII] CLASSIFICATION OF STRATA. 269

tegular chronological order, and that the primary were
always older than the transition; that the transition
Were more ancient than the secondary, and the second-
ary than the tertiary strata. That this opinion, though
8enerally correct, is not strictly true in regard to the
€ntire series called “ primary,” whether stratified or
unstratified, will appear in the sequel.*

The fossiliferous strata have been variously grouped,
according to the comparative value which different
8eologists have attached to different characters; some
having been guided chiefly by the thickness, geogra-
Phical extent, and mineralogical composition of par-
ticular sets of strata; others, by their organic remains.
All, however, seem now agreed that it is by a com-
bination of these characters that we must endeavour
to decide which sets of strata should be entitled to
tank as principal or independent groups. The fol-
lowing is an outline of the arrangement adopted in
this work, which will be more fully explained by the
Tables at the end of this and the 27th chapter : —

. Tertiary, or supracretaceous + - Tertiary.
. Cretaceous - - Rees
Wealden - - - -

. Oolite, upper, middle, and lower
Lias - = 3 - -

. New red sandstone and muschelkalk
. Magnesian limestone and zechstein
. Carboniferous - - -

Old red sandstone -

? Secondary.

ODWAA PS OD

3 Chap xxvii.

t -For tertiary, Mr. De la Beche has used the term “supracre-
‘aceous,” a name implying that the strata so called are superior
'M position to the chalk.

aS

270 CLASSIFICATION OF STRATA. [Book 1V.

10. Ludlow rocks 7 Upper
11. Wenlock limestone Silurian
12. Caradoc sandstones Lower $ Transition:
13. Llandeilo flags Silurian*
14. Fossiliferous Greywacké -

The third group, however, of the above list, or thé
Wealden formation, although locally of great thicknes*
in the south-east of England, is so partial a deposit
that some geologists think it should be merged in the
oolite, others in the cretaceous system; to both of
which propositions there are objections, as will after-
wards appear. The fifth group, or lias, would by maby
be included in the oolites. The old red sandstone ba
usually been classed as the lower part of the carboni-
ferous series; but the fossils recently found in it are
so distinct from those of the coal, and, on the othe
hand, from those of the underlying Ludlow rocks, that
it seems fairly entitled, on these grounds as well aS
from its great thickness in parts of England and Seot
land, to stand as a separate section.

Among other objections to the above classificatio®
it may be said that the tertiary group, comprehending
all the deposits from the Eocene strata to the New
Pliocene inclusive, is of greater importance than man}
of the other divisons. It may also be suggested that
the oolitic formation might admit of three subdivisio®®
each as much entitled to rank as an independent form-
ation as the lias. The following would, perhaps, be ®
nearer approximation to an arrangement in which the
leading divisions would be of equivalent value, as est
mated by the successive changes in organic life implied
by the imbedded fossil remains and by the geographica
extent and thickness of the strata: —

* For explanation of the term « Silurian,” see p. 298

Ch. XXIIL] ` CRETACEOUS GROUP.

> Pliocene. ` 11. New red sandstone and

» Miocene. _. Muschelkalk.

- Eocene. 12. Magnesian limestone and
» Maestricht and Chalk. _ Zechstein.
© Green sand. 13. Carboniferous formation.
» Wealden. 14. Old red sandstone.

: Upper Oolite. © 15. Ludlow rocks.

» Middle Qolite. 16. Wenlock limestone.

- Lower Oolite. 17. Caradoc sandstone. ,

E Tias. 18. Llandeilo flags.

19. Fossiliferous Greywacké.

COOWND MW Wh

~
©

“It is not my intention to enter at present upon a
detailed description of the fossiliferous formations older
than the tertiary, the elucidation of which might well
Occupy another volume. The observations about to be
Offered have chiefly for their object to show how far the
tules of interpretation adopted: for the tertiary form-
ations are applicable to the phenomena of the older

Sedimentary rocks.

PRINCIPAL GROUPS. (Descending Series.)

L. Cretaceous Group.—WStrata from the Chalk of Maes-
> tricht to the Lower Green-sand inclusive. — F, Table I.
í P. 802.
- The principal subdivisions of this group, as it occurs
m England and in several countries of the North of
Europe, will be found on consulting Table I. Group F.
ey are six in number, namely ;—1. the Maestricht
beds, —2. the chalk with flints, — 3. the chalk without
ints, — 4. the upper green-sand,— 5. the gault, —
6. the lower green-sand. The newest of these deposits
is well seen at St. Peter’s Mount, Maestricht, and at
ai near Mons, reposing on the upper flinty chalk
of England and France. It is a soft yellowish stone,
Not very unlike chalk, and “ includes siliceous masses,
N 4

272 CRETACEOUS GROUP. [Book 1V.

which are much more rare than those of the chalk, of
greater bulk, and not composed of black flint, but °
chert and calcedony.”*

It is characterized by a peculiar assemblage of
organic remains, perfectly distinct from those of the
tertiary period. M. Deshayes, after a careful comp?
rison, and after making drawings of more than tw?
hundred species of the Maestricht shells, has bee?
unable to identify any one of them with the numerous
tertiary fossils in his collection. On the other hand
there are several shells which are decidedly commo”
to the calcareous beds of Maestricht and the whité
chalk ; as, for example, the twelve following species, 0
which the names have been communicated to me PY
M. nc SDENT Cuvieri (Fig. ise (spe

Catillus Cuviert. Syn. Inoceramus Cuvieri, Sow. nae with fin
cimens imperfect), Plagiostoma spinosum (Fig. 180: )
P. Hoperi (Fig. 179.), Pecten fragilissimus, Ostrea Ye
sicularis (see Fig. 186.), O. carinata os 182.), on

CrantaParisiensis, Ak aes ogo mf:
inferior or attached Plagiostoma Plagiostoma"
value. Hoperi. spinosum. £

* Fitton, Proceedings of Geol. Soc. 1830.

Ch, XXIL] ` MAESTRICHT BEDS.

Patisiensis (Fig. 178.), Terebratula octoplicata (Fig.

Fig, 181.

Ostrea carinata,
efrancii. characteristic of Upper Green-sand.

183.), T. carnea (Fig. 185.), T.pumilus (Magas, Sow.)
m Fig.184. Fig. 185.

Terebratula E Terebratula
(Wa, CCtoplicata. Terebratula pumilus. carnea,
Gr, of T. plicatilis). ( Magas pumilus, Sow.)

(Pig.184.), T. Defrancii (Fig.181.), Belemnites mucro-
Matus (Fig. 187.).
ut the fossils of the Maestricht beds extend not
Merely into the white chalk of the French geologists,
ùt into their “ chloritic, or green-sand,” which corre-
‘Ponds with the upper green-sand of the English geolo-
Šlsts, The following five species of shells have been
“ognized by M. Deshayes as common to the Maes-
“cht beds and the upper green-sand of France : —
8giostoma spinosum (Fig. 180.), Ostrea vesicularis

Fig, 186.

Ostrea vesicularis (Gryphea globosa, Sow.)

N 5

CRETACEOUS GROUP.

a. Belemnites mucronatus,
. Same, internal structure

Fig. 189.

Se = ja
=n L 5
5

Baculites Faujasii. Baculites anceps; Chalk.
(Fig. 186.), O. carinata (Fig. 182.), Belemnites mut”
natus (Fig. 187.), and Baculites Faujasii (Fig. 188-):
Count Munster has shown me, among the fos%
which he himself collected at Maestricht, three speci®?
of ammonite, among which is A. Rhotomage™
(Defrance) ; also a species °
Hamite, and Hippurites Des
moulinsi (Golf). The sa“
eminent naturalist has dis”
vered no less than forty spe
cies of microscopic fora”
F nifera in the same formati”
Ammonites Bhotomagensis. all of species distinct fro
any known either as recent or tertiary, and madY y
new genera. There is also an ammonite, obtai”?
from the Maestricht limestone by Dr. Fitton, 20” i
the museum of the Geological Society of Londo”
The occurrence of these ammonites and species
kindred genera, such as the Baculite and Hamite, p
also the Belemnite, is important, as showing that t
subdivision (No. 1.) now under consideration shou
be classed as the newest member of the secon f
series, rather than as a link between it and the "A
tiary. No shell hitherto found, even in the oldest °

Ch, XXIIL] CHALK. 275

Eocene tertiary formations, minutely as these have
ĉen investigated, could be mistaken, either for the
Ammonite or belemnite, the nearest approach to the
Mmonite being the nautilus, and the tertiary fossil
Which comes nearest to the belemnite being the
Beloptera of the London and Paris basins (Fig. 191.).
We can scarcely expect, therefore,
to discover in existing tropical seas
any living representatives of those `
curious cephalopoda, ammonites and
belemnites, which evidently swarmed
in the ocean when the cretaceous
and many preceding groups of strata
were formed. They even seem to
ndon and Paris basins. haye become entirely extinct, at
least in European latitudes, before the commencement
the Eocene period.

The rock commonly known as chalk preserves its
Peculiar mineral character throughout a considerable
‘tea in Europe, but it is rarely of such thickness as in
Many parts of the south-east of England, where hori-
“ontally stratified masses about one thousand feet
: ick, are composed of it. Its upper member in this
“Ountry is usually called the “ Chalk with flints ;” but
“Dove this mass there is in some places another de-
Posit of white chalk without flints, which was found, by
oring at Diss, in Norfolk, to attain a thickness of
00 feet.* The chalk stretches over a large part of
our island, and recurs in the north of Ireland, is found
t Denmark and the south of Sweden, and even in

oland and part of Russia. In France it surrounds
“hd underlies the strata of the Paris basin before de-

* Proceedings of Geol. Soc., vol. ii. p. 93.
N 6

276 CRETACEOUS GROUP. [Book 1V.

scribed (see Map, Fig. 156. p. 209.), from whence it
stretches northward into Belgium and the north °
Germany, and southward to the basin of the Gironde-
I have seen it, still retaining nearly all the same char
racters, between Bordeaux and Dax; but it chang®
its aspect greatly on the flanks of the Pyrenees, wher?
its identity can only be established by the similarity
of its fossil remains. Even the white chalk, howeve”
varies considerably in its texture, in proportion as W°
depart from the great central deposit of Europe- In
some parts, for example, of the south of France, it
becomes oolitic. Here also it contains, together wit

shells which abound in the north, many other spec
peculiar to more southern districts, especially of the

genera spherulite, hippurite, and nummulite.
Fig. 192. a shaba

ai Hippurites bioculata, Lamk.

ancl
. H. radiosa, Desmoulins, Opercular valve. ? Lower chalk, South of Fr

The other divisions of the cretaceous group, Nos: hy
5, and 6., consist of sands and clays, which have also
a wide geographical range. The position of the gat
and lower green-sand, relatively to the formations °
the white and flinty chalk before alluded to, has bee?
elucidated in diagram Fig. 157. p. 224. The fossils

Fig. 193. Fig. 194. gf

i a

= > 5.
> j qat!
f ‘it. n 5 COS? og
4 E es ojile. ? Upper green-sand, taper and log,
green-

* Dufrénoy, Bulletin de la Soc. Géol. de France, tom. i p> 1”

Ch. XXIL] - CRETACEOUS GROUP.

@. Turrilites costatus, Gault. A
. Same, shewing the indurated border of the partition of the chambers.

of the inferior arenaceous and argillaceous groups are
Yon the whole very different from those of the chalk

fore described, but there are many species common
to these two great divisions.

The testacea obtained from the entire cretaceous
System amount to about one thousand ; and if, for the
Sake of classification, we refer every set of strata in |

Urope which are characterized by these organic re-
Maing to one period, we immediately comprehend in
t rocks of every variety of mineral composition, yet
Which always occupy a determinate place in the order
of Superposition intervening between the tertiary strata
4nd those of the Oolitic period.

In the cretaceous group, thus distinguished, we
behold in the Pyrenees and in Spain compact and
crystalline marbles, masses of gypsum and salt, pud-
ingstones, red sandstone, thin shales and grits, con-
taining impressions of marine plants, and other rocks,
to which there is nothing analogous in formations of
the same age in northern Europe.

Tt appears, by the researches of MM. Boblaye and

irlet, that in the Morea a great cretaceous system
Occurs, composed of compact and lithographic lime-
Stones of great thickness ; also of granular limestones,
With jasper; and in some districts, as in Messenia, a
Puddingstone with a siliceous cement more than 1600
feet in thickness.*

* Bull. dela Soc. Géol. de France, tom. iii. p. 149.

278 CRETACEOUS GROUP. [Book IV.

It is evident, observe these geologists, from the great
range of the hippurite and nummulite limestone, a rock
belonging to the same era, that the South of Europe w35
occupied at the period of the cretaceous deposition
by an immense sea, which extended from the Atlantic
Ocean into Asia, and comprehended the South of
France, together with Spain, Sicily, part of Italy, and
the Austrian Alps, Dalmatia, Albania, a portion of
Syria, the isles of the Ægean, coasts of Thrace, and
the Troad.

The plants found in the chalk of England and Franc?
are chiefly marine. Some wood has been occasionally
met with, both in the chalky rock and its flints, having
the appearance of being drifted, and commonly marke
with the perforations of boring shells, such as thé
Teredo and Fistulana.* In Sweden, M. Nilsson a®
found beds of lignite associated with our commo”
chalk fossils}; so that we may conclude that forests
grew on the lands of this period, wherever these may
have been placed ; but as yet their site is mere matte”
of conjecture.

The testacea, zoophytes, crustacea, and fishes, at?
marine, and no bones of mammiferous quadrupeds
or birds have yet been discovered ; but in the Maes-
tricht beds large turtles have been found, and #
gigantic reptile, the Mosasaurus, or fossil Monitor, °
Maestricht, some of the vertebrae of which appe®
also in the English chalk.t The osteological chara
ters of this oviparous quadruped prove it to have bee?
intermediate between the living Monitors and Iguanas +
and, from the size of the head, vertebrae, and othe"

* Mantell, Geol. of S. E. of England, p. 96.
+ Petrificata Suecana, 1827.
$ See Mantell’s Geol. of S. E. of England.

Ch, XXIIL] _MAESTRICHT FOSSILS. 279

bones, it is supposed to have been twenty-four feet in
length. :
In reviewing the facts above enumerated, I may first.
Call attention to the important circumstance that no
Species of fossil shell has yet been found common to
the secondary and tertiary formations ; a fact stated on
the authority of M. Deshayes, who assures me that
he has seen no tertiary shells in the Gosau beds, sup-
Posed by some geologists to be intermediate between
the secondary and tertiary formations. On the other
hand, some of the most characteristic species of
Gosau -occur in the green-sand beneath the chalk, at
Ciply, south of Mons, in Belgium, and at some
Neighbouring places which I have visited. Count.
unster also informs me, that the zoophytes which
he possesses from the Gosau beds differ specifically
from any which he knows as tertiary. I mention this
in the hope that the identifications which have been
made of Gosau and tertiary species may be re-examined
With scrupulous care, for, if confirmed, they would be of
the greatest theoretical interest.

This marked discordance in the organic remains of
the two series is not confined to the testacea, but
extends, so far as a careful comparison has yet been
instituted, to all the other departments of the animal
kingdom, and to the fossil plants. Dr. Agassiz, whose
Streat work on fossil fish is now in progress of publi-
Cation, has discovered no species of fish common to
the secondary and tertiary rocks.

There appears, then, to be a greater chasm between

e. organic remains of the Eocene and Maestricht

eds, than between the Eocene and Recent strata ;
or there are some living shells in the Eocene form-
ations, while there are no Eocene fossils in the newest

280 WEALDEN STRATA. -Book IV:

secondary group. It is not improbable that a longe"
interval of time may be indicated by this greate"
dissimilarity in fossil remains. In the 3d and 4th
chapters I endeavoured to point out that we have °
right to expect, even when we have investigated £
greater extent of the earth’s surface, that we shall Þe
able to bring to light an unbroken chronological series
of monuments from the remotest eras to the present:
but, as we have already discovered a long successio”
of deposits of different ages, between the tertiary
groups first known and the recent formations, so W?
may, perhaps, hereafter detect an equal, or eve?
greater, series intermediate between the Maestricht
and Eocene strata.

The different subdivisions of the cretaceous group
(No. 1.), extending from the chalk of Maestricht t°
the lower green-sand inclusive, may, perhaps, relate
to a lapse of ages as immense as the united tertiary
periods, of which the eventful history has bee?
sketched in this work. Such a conjecture, at leash
seems warranted, if we can form any estimate of the
quantity of time, by comparing the amount of vicis-
situde in animal life which has occurred during i
lapse.

2. The Wealden, or the Strata from the Weald Clay @
the Purbeck Limestone inclusive.—G, Table I. pe 302.

It will be seen by the Table I. p. 302., that in the
South of England this group may be divided into three
formations — the Weald clay, the Hastings sands, 29
the Purbeck beds, which are all characterized by thé
remains of freshwater animals; whereas the cretaceo™ -
strata which are superitnposed upon the Wealden, in

xxi] WEALDEN. STRATA. 281

the south-east of England, contain fossils of marine
Decies,*
The position of these beds has been indicated in
agram Fig. 157. page 224., and the map (Plate XV.)
Will show the superficial area occupied by them in
€nt, Sussex, Surrey, and Hampshire. It must not
© supposed, however, that they terminate at the
Points where they happen to be covered by the creta-
“eous system. The same group has been ascertained
0 extend from west to east (from Lulworth Cove to
© boundary of the Lower Boulonnois), about 200
Nglish miles; and from north-west to south-east
(from Whitchurch to Beauvais), 220 miles; the depth
total thickness of the beds, where greatest, being
‘bout 2000 feet.t The general appearance of the
Clays and sands, and of the subordinate beds of lime-
‘tone, grit, and shale, and of the imbedded shells,
tecalls so precisely that of many tertiary formations of
"eshwater origin, that it is only after having deter-
mined the species of organic remains that we recognize
à discordance in character as great as might have been
“ticipated when strata above and below the chalk
Vere compared.
The vegetable remains belong, some of them, to `
Plants which appear to have held an intermediate place
tween the Equiseta and Palms, as the Clathraria
‘covered by Mr. Mantell; while others approach to
‘tborescent ferns, the species being very peculiar, and
“ot known in any other deposit, whether of higher or
‘ferior antiquity. t

b * The term Wealden was suggested by Mr. Martin, and will
e fo

t Fitton’s Geol. of Hastings, p. 58.
ł Mantell, Geol. of S. E. of England, chap. xi.

und of great convenience.

282 WEALDEN STRATA. [Book 1V:

The shells of the Wealden are almost exclusively
fluviatile; and, as is usual in assemblages of freshwat®"
testacea, a few species only are found, while the 1™
dividuals are very numerous, sometimes forming the
principal component of entire beds of limestone. Shells
of the Cypris, also, a freshwater animal, befor?
mentioned as occurring in the lacustrine deposits °
Auvergne, are profusely distributed throughout the
Wealden. Of this genus several species have bee?
discovered, named and figured by Dr. Fitton.* (Se
figures. )

Fig. 198.

Cypris Cypris Valdensis, Fitton. Cypri tuberculatts
a ge C. faba, Min. Con, 485.) A “Fitton. :
itton.

Some fish, also, of forms resembling known fuviatile
genera, have been met with; but the remains °
reptiles present the most remarkable feature in #®
group. Some of these belong to turtles, such ast
Trionyx, a genus now occurring in freshwater in t%
pical regions: others are referable to the genus Emy?
Of Saurian lizards there are at least five genera; f
Crocodile, Plesiosaur, Megalosaur, Iguanodon, ap
Hyleosaur. The Iguanodon, of which the remain’
- were first discovered by Mr. Mantell,.was an herbi”
rous reptile, and was regarded by Cuvier as more e
traordinary than any with which he was acquainte’’
for the teeth, though bearing a great analogy t° * a

y in the
* See Trans. of Geol. Soc., vol. iv., Second Series, now ™ f
press.

i

h xxr] 7 WEALDEN STRATA. sn RS

Modern Iguanas which now frequent the tropical
Woods of America and the West Indies, exhibit many
tiking and important differences. It appears that
€y have been worn by mastication; whereas the
isting herbivorous reptiles clip and gnaw off the
Vegetable productions on which they feed, but do not
“ew them. Their teeth, when worn, present an ap-
Pearance of having been chipped off, and never, like
the fossil teeth of the Iguanodon, have a flat ground
'urface, resembling the grinders of herbivorous mam-
malia From the large bones, found in great num-
ts near these teeth, a fairly presumed to belong
the same animal, it is computed that the entire
“gth of this reptile could not have been less than
*venty feet.

The bones of birds have been found in the Wealden ;
ùt in no part has any fragment of the skeleton of a
Mammiferous quadruped been obtained. With this
‘ception, to which I shall presently revert, the strata

the Wealden present such characters as we might
k for in the deposits of the deltas now forming at
the mouths of large rivers in tropical climates.

The Wealden, as was before explained, is covered
Y the marine cretaceous system, and reposes upon
Nother, which is, in like manner, a purely marine
pt: namely, the uppermost member of the Oolite,

e H, Table I. p. 303..

n This intercalation of a great freshwater formation
tween two others of marine origin is a remarkable
Act, and attests, in a striking manner, the great extent
former revolutions in the position of sea and land.
A those sections where the junction of the freshwater
Cretaceous system is seen, the beds of the lower

* Mantell, Geol. of S. E. of England, p. 277.

y.
284 PORTLAND DIRT-BED. [Book !

green-sand have been observed to repose conformably
upon those of the subjacent Weald clay. There is ™°
indication of disturbance: “To all appearance the,
change from the deposition of the freshwater remains
to that of the marine shells may have been effect?
simply by a tranquil submersion of the land to a greate"
depth beneath the surface of the waters.” * l
At the point of contact of the inferior division of the
Wealden or “ Purbeck beds,” with the more ancien”
marine system, a very curious phenomenon is observe"
the freshwater calcareous strata repose, both in port
land and Purbeck, upon the oolitic limestone, ¢4!
the Portland stone, which abounds with Ammonite
Trigoniæ, and other marine shells, Between the tw?
formations there intervenes “a layer, about a foot
thickness, of what appears to have been an anclé?
vegetable soil ; it is of a dark brown colour, contains ’
large proportion of earthy lignite, and, like the mode”
soil on the surface of the island, many water-wo
stones. This layer is called the ¢dirt-bed’ by E
quarrymen ; and in, and upon it, are a great num”
of silicified trunks of coniferous trees, and plants albe
to the recent cycas and zamia. Many of the stems °
the trees, as well as the plants, are still erect, as
petrified while growing undisturbed in their nati”
forest ; the trees having their roots in the soil n
their trunks extending into the superincumbent $t!?
of limestone.” + r
Traces of this vegetable earth, occupying the sa

* Dr. Fitton, Geol. of Hastings, p. 28.

+ Mantell, Geol. of S. E. of England, p. 336. —
papers by Mr. Webster, Dr. Buckland, and Mr. De la Be j
Geol. Trans., Second Series, vol. ii. Mr. Webster was, ÍI belie
the first to notice the erect position of the stems.

Ch, XXL PORTLAND DIRT-BED. x 285

'elative situation, have been observed by Dr. Fitton in
e cliffs of the Boulonnois, on the opposite coast of
tance. * Dr. Buckland and Mr. De la Beche have

‘lo ascertained that many of the stumps of trees re-

Nain erect, with their roots attached to the black soil

n which they grew, their upper part being imbedded

N the limestone; from which they infer, “that the

“Urface of the subjacent Portland stone was for some

lhe dry land, and covered by a forest, and probably

Na Climate such as to admit the growth of the modern
amia and Cycas.” +
It seems a legitimate deduction from the data above

Xplained, that the marine formations of an antece-
“at period (that of the oolite) had become land
toughout a portion of the space now occupied by the
Wuth of England, and the opposite coast of France ;

"Nd that this land then sank down, with its forests, and

“Came submerged beneath the waters of a great river,

st as the region around Sindree, in Cutch, subsided

"1819, and was permanently laid under water, being
tone time occupied by the fresh water of the Indus.

© country may then have continued to subside, until |
thickness of one or two thousand feet of fluviatile
diment had been gradually accumulated ; and this

*Posit, or delta, by a continuation of the same de-
"essing operations, may, in its turn, have become

ried deep beneath the sea in which the chalk was
med,

I shall not enter farther into these speculations at
sent, but proceed to inquire how far the Wealden
` connected by its fossil remains with the overlying or

: Geol. of Hastings. Geol. Proceedings, vol. i. p. 9.
P toceedings of Geol. Soc., April, 1830.
+ See Vol. II. p. 196., and Vol. III. p. 254., and Plate V.

286 WEALDEN STRATA. Book 1%"

subjacent formations. First, we may ask whether ther?
are any species of fossil animals or plants commo”
the freshwater group and to the oolitic system. ! aw
aware of one example only, the Megalosaurus Buo
landi; for the teeth and bones of this great sauria”
occur in the Stonesfield oolite and the Hastings sand
the remains in both cases having been referred b
Cuvier to the same species. There are also some
generic forms both of reptiles and fish common tO si
Oolite and Wealden, and not yet discovered in the chalk
Vertebræ, for example, of the Plesiosaurus are m
confined to the oolite and lias, but have been also fow?

in the Wealden; and the Lepidotus, a genus of fis

very characteristic of the Wealden, is unknown in the
cretaceous group, while it is abundant in the oolitl?
‘series. On the other hand, the same Iguanodon Ma
telli, which is so conspicuous a fossil in the Wealde™
has recently been discovered near Maidstone in ‘

overlying Kentish rag, a marine limestone of f

lower green-sand. From this fact we may infer tha
some of the saurians which inhabited the country °
that great river, which by its sediment produced ;

Wealden strata, continued to live when part of t
country had become submerged beneath the sea. Thu
in our own times, we may suppose the bones of larg?
alligators to be frequently entombed in recent fresi
water strata in the delta of the Ganges. But if part s
that delta should sink down so as to be covered byi
sea, marine formations might begin to accumulate jn the
same space where freshwater beds had previously bat

formed; and yet the Ganges might still pour dow?’ f
turbid waters in the same direction, and caltTy v

carcasses of the same species of alligator to the 5€%

Ch XXII] OOLITIC GROUP. : 287

Which case their. bones might be included in marine
3S well as in subjacent freshwater strata.
Near Beauvais, in France, there is a small valley of
“evation and denudation, closely resembling in struc-
ture that of the Weald, and called the country of Bray,
Where the green-sand crops out from beneath the chalk,
Md where strata, for the most part like those of the
falden, appear beneath the green-sand. One mem-
®t of the series, a fine whitish sand, contains impres-
sions of ferns, considered by M. Adolphe Brongniart
à identical with Lonchopteris Mantelli, a plant found
"equently in the Wealden. I examined part of the
‘alley of Bray in company with M. Graves, in 1833,
"hd I observed that the sand last mentioned, with its
Vegetable remains, was intercalated between two sets
marine strata, containing trigoniæ, and referred, by
"nch geologists, to the lower green-sand. In the
“ame country of Bray, and associated with the same
mation, is a limestone resembling the Purbeck mar-
< > and containing a Paludina which seems specifically
entical with that of Purbeck. z
There are some few species, therefore, of the Weal-
ĉn common on the one hand to the overlying creta-
Moug group, and on the other to the subjacent oolite ;
ùt the connection hitherto established is so slight
àt the era of the freshwater deposit may have been
“barated by a wide interval of time from the periods
€n the animals either of the oolitic or cretaceous
Periods predominated.

288 i OOLITIC GROUP. [Book 1V

3. Oolite, or Jura Limestone Formation. — H, Table I
- p- 303.

The different subdivisions which have been made f%
the classification of the rocks of this group in Engla”
are enumerated in Table I. p. 303. It consists °
limestone, clay, marl, and sand; which, considered H
the aggregate, retain the same lithological characte"
throughout a considerable part of England, France, #”
Germany. It is not to be expected that we sbo”
be able to follow the different members of the Eng!
series throughout Europe, as they vary greatly, bot
in mineral and organic characters, in their cow"
throughout different parts of our own island ; bub ie
the fossils of the higher, middle, and lower parts :
the series are not the same, it may be possible,
their aid, to establish subordinate groups of gre
utility.

Among the fossils known to have a wide rang? J
Europe, and peculiar to the upper division, 1 ™
mention Gryphea virgula, as occurring in France, ne?

Oxford, and elsewh”

(Fig. 199.), and O%

deltoidea (Fig. 900: )

common in part of th

upper Oolite or kr

meridge clay, throug i

eas out England and E

virgula. , Ostrea deliotdea. north of France ap

found also in Scotland, at Brora.

The coral rag of England, and analogous zoophY
limestones of the oolitic period in different pat
Europe, bear a resemblance to the coralline formatio”
now in progress in the seas of warmer latitudes.

tic

Ch. XXIILJ OOLITIC GROUP. 289

Fig. 201, A A member of the oolite of the Jura,
: corresponding to part of the English
coral rag (H. 3. Table I. p- 303.), has
been called «“ Nerinægan limestone”
(Calcaire à Nérinées) by M. Thirria ;
Nerinæa being a genus of univalve shells,
much resembling the Cerithium in ex-
ternal form. The annexed section (Fig.
201.) of one from the coral rag shows
j the curious form of the hollow part of
Seu; .£& each whorl, and also the perforation
ection of Nerinea A : A
hierogłyphica. which passes up the middle of the co-
Coral rag.
lumella.
Fig. 202. A division of the oolite in the
Alps, referred by most geologists
to the coral rag, has been often
named “ Diceras limestone,” or
“ Calcaire à Dicerates,” from its
containing abundantly a bivalve
a ee shell (Fig. 202.) of a genus allied to
Coral rag. ` the Chama.
- In the lithographic limestone of Solenhofen, belong-
Ng to one of the upper members of the series, a great
Variety of organic remains is found. Among these I
ave seen in the museum of Count Munster no less
than seven species of flying lizards, or Pterodactyls, six
‘aurians, three tortoises, sixty species of fish, forty-six
of crustacea, and twenty-six of insects. The number
of testacea is comparatively small, as also of plants,
Which are all marine. Count Munster had determined
237 species of animal and vegetable remains from the
Olenhofen slate when I saw his collection in 1833.
the extreme fineness of the sediment has, in this
"stance, allowed impressions of some of the most
XOL. TV. (0)

290 LIAS. [Book IV.

1

delicate and soft parts of various animals to be pre-
served; as of the belemnite and several insects.

In the Stonesfield slate (see Table), the remains of
reptiles have been found associated with marine shells,
and with them the jaws of at least two species of small
mammiferous quadrupeds of a genus allied to the
Didelphys, or Opossum.* It is very remarkable, that
these fossils afford the only exception yet known t°
the apparent absence of all terrestrial mammalia fro™
the islands and continents which existed anteriorly t°
the Eocene period.

Among the characteristic shells of the oolite I may
instance Terebratula spinosa (Fig. 203.), Pholadomy®
fidicula (Fig. 204.), and Belemnites hastatus, (Fig. 205.)

Terebratula spinosa. a. Pholadomya fidicula. Inferior Oolite. t
Inferior Oolite. b. Heart-shaped anterior termination of the same:

Fig. 205.

Belemnites hastatus.

4. Lias. I., Table I., p. 304.

The English provincial name of Lias has been very
generally adopted for a formation of argillaceous lim®
stone, marl, and clay, usually found in conformable
stratification to the rocks of the oolite group before de-
scribed. Some geologists regard the lias as the lowest
member of the oolite group, several species of organ?

* For figures of these, see above, Vol. I. pp. 237, 238.

Ch. XXIIL] LIAS. 291

remains being common to it and to the inferior oolite.
If we draw a line between these formations, the sepa-
ration will be somewhat arbitrary, but may be, never-
theless, convenient ; as both the oolite group and the
lias will still comprehend a great thickness of strata,
Characterized, when viewed on the great scale, by
assemblages of distinct fossils. The lias retains a uni-
form mineralogical character throughout a great part of
England, France, and Germany; and this circumstance
_ May facilitate the attempt to ascertain the contempo-
Taneous existence of a sufficiently numerous set of fos-
sil plants and animals to enable us to determine the
equivalent groups of distant countries.

A principal member of this formation has been
Sometimes called on the Continent “ Calcaire à gry-
Phytes,” or “ Gryphyte limestone,” from the great
abundance of a species of shell of a genus allied to

Fig. 206.

Grypheaincurva, Sow.

Syn. G. arcuata, Lam. — Nauitlus truncatus, Lias.
the oyster. (See Fig. 206.) :

The remains of reptiles, those of saurians in par-
ticular, are very common in the liassic rocks in several
Parts of England, especially of the genera Ichthyo-
Saurus, Plesiosaurus, and Crocodile.

The fish are, for the most part, of the same genera
as in the oolite. (See Figs. 208, 209.).

Hybodus reticulatus. Lias, Lyme Regis.

a. Part of the fin, commonly called Ichthyodorulite.
b. Tooth of the same.

Fig. 209.

Acrodus nobilis, tooth ; commonly called fossil Leach.
Lias, Lyme Regis, and Germany.

5. New Red Sandstone group, K., Tab. I., p. 304. (1
cluding the Muschelkalk of the Germans).

The deposits which are referable to the interval
which separated the lias from the great coal formatio?
may be divided into two principal groups : first, the
New Red Sandstone ; secondly, the Magnesian Lime-
stone. The New Red Sandstone of England, accom
panied by beds of gypsum and rock salt, is almost
entirely destitute of organic remains ; but the Musch-
elkalk of Germany, which is referable to the” same
period, and has no precise equivalent among the English

strata, contains many fossils of species distinct from
a b

a. Avicula socialis. b. Side view of same.
Characteristic of the Muschelkalk.

those of the lias, or subjacent magnesian limestone-

Ch. XXIILJ ” MAGNESIAN LIMESTONE. 293

This calcareous formation (Muschelkalk) is inter-
posed in Bavaria and Wurtemburg, between two others;
the overlying “ Keuper,” or variegated marls, with
which it alternates at the junction, and the red mottled
sandstone (“ bunter sandstein”) on which it rests.
The plants found by Count Munster in this last, and
in the “ Keuper,” ,” are so similar, as to induce that geo-
logist to regard all the three groups thus connected
as belonging to one period ; and in confirmation of the
Same opinion, M. Agassiz finds the same species of fish
to be common to the three groups.

6. Magnesian Limestone ( Zechstein of the Germans).
L., Tab. I., p. 305.

This formation consists in England for the most
part of a yellowish limestone, in which a small number
only of organic remains are preserved, but these are
referable to peculiar and characteristic species.

So also in the zechstein of the Germans, a limestone
of this period, and in its accompanying copper slate,
the same or very similar fossils occur. At Mansfeld
in Upper Saxony, for example, fish are found of the
extinct genus Palaothryssum, only known in strata of
this group. Dr. Agassiz informs me that he has not
as yet been able to identify any species from Mansfeld
With any one of those found in England, but the genus
. appears characteristic of the era under consideration.

7. Carboniferous Group, comprising the Coal-measures,
and the Mountain Limestone. M., Tab. I., p. 305.

The rocks of this group consist of limestone, shale,
Sandstone, and conglomerate; interstratified with which
are large beds of coal, a substance now universally
admitted to be of vegetable origin. Several hundred

o 3

294 CARBONIFEROUS GROUP, [Book IY-

species of plants have been found in the shales and
sandstones associated with the coal, and all are, with
few exceptions, of species differing widely from those
which mark the vegetation of other eras. Some re-
marks have been offered in the first book *, respecting
the known geographical extent of the coal formation
and the tropical character of its flora, and of the shells
and corals of the carboniferous or mountain lime-
stone. Ithere adduced arguments for inferring that
the lands in northern latitudes consisted, for the most
part, at that remote era, of small islands; and men-
tioned the absence of large saurian remains, the insula!
character of the flora, and the deposition of the strata
as favouring that opinion.

But although the higher latitudes of the norther?
hemisphere probably formed at that time a great archi-
pelago, they must have contained some islands of sufi-
cient magnitude to allow of the existence of rivers
and estuaries, where freshwater strata were accumU-
lated. A freshwater limestone has been discovered
and described by Dr. Hibbert at Burdiehouse nea!
Edinburgh, as lying beneath marine strata of the cat
boniferous group. Instead of containing fossil coral-
lines or encrinites, like the mountain-limestone, thé
formation in question contains land plants in great
abundance, and minute entomostraca supposed to be
allied to the genus Cypris and several fish.}

Mr. Hutton states that, in part of the coal-field 0f
Northumberland and Durham, fossil shells of a species
of Unio occur in considerable abundance in a shalé
containing plants of the carboniferous period, and ove!

* Vol. I. pp. 201. to 203. T VoL I. p. 158.

ł Hibbert, Trans. R. S. Edinb. vol. xiii, and L. Horne!
Edinb. New Phil. Journ. April 1836.

Ch. XXIII] OLD RED SANDSTONE. aS

lying a bed of coal. The coal has been worked out
from beneath the shells, which have been already
proved to extend over an area five thousand feet
Square. The shelly stratum is about eighteen inches
thick ; and the animals have evidently died at various
ages, the shells being of every size. This accumu-
lation of bivalves of one species, and of this form,
seems clearly to indicate the continuance on the spot
of a body of fresh water, such as might be found in
the estuary of a river.*

In the Shropshire coal-field near Bridgnorth, and in
other places, Mr. Murchison has shown that the upper
coal-measures contain a subordinate bed of limestone,
which he has termed lacustrine, as a small species of
shell, supposed to be a Planorbis, is plentifully im-
bedded in it.+

The fossils of the mountain limestone, above al-

luded to, are marine, and contain, among other genera
of shells not discovered in newer deposits, the Ortho-
cera (see Fig. 211.), a chambered univalve, sometimes
many feet in length.

Orthoceras laterale, Phillips. O. giganteum, Sow’
Mountain limestone. . Section shewing the siphuncle.

Old Red Sandstone. N., Table I., p. 306.

Beneath the coal-series in the northern part of
Fifeshire in Scotland, and the southern half of Forfar-

* Fossil Flora, by Lindley and Hutton, No. 10,
+ Proceedings of Geol. Soc., No. 38. p. 119.
o 4

296 OLD RED SANDSTONE. [Book IV.

shire, a formation occurs of great thickness, composed
of red marl, conglomerate, red and white sandstone;
and shales of various colours, for the most part devoid
of organic remains. In some of the shales, however;
impressions of plants, apparently marine, have been
met with; and in the flaggy sandstones containing @
slight admixture of carbonate of lime, the scales and
other remains of fish are not unfrequent. They belong
toa genus named by Dr. Agassiz “ Cephalaspis,” or
“ buckler-headed,” from the extraordinary shield which
covers the head. (See Fig. 213.) This peculiar form
Fig. 213.

at Glammis in Forfarshire. The species, which Dr. Agassiz has
named after me, will be described in his work on Fossil Fish.

of fish, which is quite unknown in the coal-strata,
seems characteristic of the old red sandstone generally;
for it is found in Herefordshire and other counties of
England and Wales, where the old red sandstone is
largely developed. All the animal and vegetable
remains hitherto discovered. in this series are dis-
tinct from those of the overlying coal, or subjacent
transition strata.

Ch. XXIII] TRANSITION FORMATIONS.

9. Transition, or Greywacké Formations. O.& P.,
Table I., p. 306.

Continental and English authors have not always `

been agreed where the line of separation should be
drawn between the secondary and transition form-
ations. Some of them, for example, have included the
carboniferous group in the secondary, others in the
transition system. But in England the old red sand-
Stone has been generally considered as the lowest
member of the secondary series.

The name of transition was first given by Werner to

Certain sedimentary deposits consisting, in the Hartz “ \

and many parts of Germany, of arenaceous and brec-
Ciated rocks which alternate with argillaceous schist,
and are sometimes associated with coralline and shelly
limestones. These were supposed to have been the
earliest formed strata when the ocean first became
habitable by aquatic beings. Although the principal
members of this group, where it is largely developed,
are evidently of mechanical origin, they often alter-
Nate with beds of quartz and argillaceous schist, not
distinguishable mineralogically from crystalline rocks
classed by Werner as primitive. Hence, as was before
Stated, the term transition was adopted to express the
theory that, at this period, the causes which had given
rise to crystalline formations were still in action ; while
those which produced stratified sedimentary rocks,
including organic remains, were also beginning to
Operate.

The characteristic group called in German “ Grau-
Wacke,” an old miner’s term, is an aggregate of small
fragments of quartz, flinty slate (or Lydian stone),
and argillaceous schist, cemented together by argil-

o 5

s

298 TRANSITION FORMATIONS. [Book IV.

laceous matter. But far too much importance bas
been attached to this kind of rock, as if it were pe-
culiar to a certain epoch in the earth’s history, whereas
it is only an accidental variety of argillaceous sand-
stone, probably in some cases altered by heat. There
are parts of England and Sweden where fossiliferous
strata more ancient than the old red sandstone ar
largely developed, and yet where no rocks answeriD$
mineralogically to the Greywacké of the Germans are
discoverable.

The first great step towards a general table of supe?
position of the British fossiliferous groups below the
old red sandstone, each distinguished by certain mi-
neral characters and organic remains, has recently
been made by Mr. Murchison, and his arrangement
has been adopted in Table I., p. 306.

Mr. Murchison has had an opportunity of tracing
the succession of deposits in a regular descending
series, from the old red sandstone with which they at?
in part covered, to the subjacent and unconformabl?
greywacké rocks of South Wales. As far as his e%
amination has hitherto proceeded, all the species of
zoophytes and shells differ from those of the carboni-
ferous limestone ; while the fossils of his four grea
subdivisions are distinct from each other.*

He has proposed the term “ Silurian,” as a general

name for this whole system of rocks, derived fro
« Silures,” the principal tribe of Celts or ancient Bri-
tons, who occupied part of Wales and the bordering
counties of England, where these ancient fossiliferous
strata are most distinctly exhibited. The Ludlow
rocks and the Wenlock limestone may be classed 3°
the Upper Silurian group, being the deposits which
* Proceedings of Geol. Soc. London, No. $4. 1834

Ch. XXIIL] ` TRANSITION FORMATIONS. -299

are immediately below the old red sandstone ; while
the Caradoc sandstones and Llandeilo’ flags form the
Lower Silurian group. Below all these there are other
fossiliferous rocks which, in Wales, are unconformable
to the Silurian strata. |

Among the fossils of the Silurian formations, zoo-
phytes and crinoidea are the most numerous ; and some
of the limestones, which are in great part composed of
them, agree in their general character with those now
in progress in seas where stone-corals are abundant.
The Trilobite (see Figs. 214, 215.), a singular crus-

Fig. 214.

Calymene Blumenbachit, Asaphus Buchit.
Brongniart, Pl. 1. fig. 1. commonly called Brongniart, Pl. 2, fig, 2.. A.
* Dudley trilobite.” Lower Silurian,
Upper Silurian rocks.

taceous animal, of which no species is known in form-
ations newer than the mountain limestone, is also
Characteristic of the rocks of this period; so also the
‘Orthocera, a chambered univalve, found also in the
Carboniferous limestone (see Fig. 211. p. 295.), but
hitherto in no newer deposit. On the other hand,
some of the shells belong to recent genera, as the
Terebratula, of which there is a great variety, The
only vertebrated remains hitherto found are a few
bones of fishes. The shells and zoophytes of these
formations have been studied in Germany by Count
Munster, Professor Goldfyss, and M. Steininger. In
Nassau, M. Stift has endeavoured to classify the dif-
ferent subdivisions of the same series chiefly by refer-
ence to their mineralogical characters. M. Hisinger
0 6

300 TRANSITION FORMATIONS, [Book 1V.

t

also, who has recently published a geological map of
the south of Sweden, as well as Professor Wahlenberg
and the late M. Dalman, have described and figured
many fossil productions from these strata in Sweden.

With this “ Silurian ” group I shall conclude; for it
_ does not appear that any antecedent periods can yet
be established on the evidence of a distinct assemblage
of fossil remains. Traces of organization do undoubt-
edly occur in rocks of still higher antiquity, for some
of which Professor Sedgwick has proposed the name
of “ Cambrian ;” but they can scarcely be referred to
a distinct geological period, until we have obtained
more data for determining the specific characters of 4
considerable number of fossils.

The annexed table will explain the order of super-
. position of the successive groups of fossiliferous strata
hitherto established in Europe; it should be remem-

bered, however, that it is in a small part of western
Europe only that almost all this series of monuments
has been discovered.

2K CENT PERIOD-

A

f

Ll, TERTIARY PERIOD-

Newer
Pliocene.

Older
= Q
Pliocene, °

o

Miocene.

301

TABLE I.

Showing the Order of Superposition, or Chronological Suc-
“ession, of the principal European Groups of Sedimentary
‘nd Fossiliferous Strata.

This Table is also referred to in the Glossary.

Names of the principal

Members and Mineral

Nature of the Formation, in Countries where it

has been most studied.

Some of the Localities
where the Form-
ation occurs.

The deposits of this period are for the most part concealed under
existing lakes and seas.

Consolidated sandy and gravelly beds(a),
travertin limestones (b), calcareous sand-
stones with broken shells (c), coral- lime-
stone, consisting of corals, shells, &c. (d),

compact limestone (e).

a. Delta of the
Rhone.

6. Tivoli, and other
parts of Italy.

c. Shore of Island
of Guadaloupe.

d. Coral reefs in
Pacific, &c.

e. Bermudas.

[

ji

MARINE.
Limestone, sands,
clays, sandstones,
conglomerates, marls,
with gypsum; con-
taining marine fos-

sils (a).

FRESHWATER.
Sands, clays, sand-
stones, lignites, &c. ;
containing land and
freshwater fossils (b).

a. Sicily, Ischia.
b. Colle in Tus-
cany. :

Subapennine marl,
Subapennine yellow
sand, English “crag,”
and other deposits,
as in B., containing
marine-fossils (a).

Faluns of the Loire,
and other deposits
varying in mineral
composition, as those
in B. and C., con-
taining marine fos-
sils (a).

Similar deposits to
B.; containing land
and freshwater fos-
sils (b).

a Subapennine
formations, Per-
pignan, Nice,
Norfolk, and
Suffolk.

b. NearSienna, &c.

Similar deposits to
B. and C.; contain-
ing land and fresh-
water fossils (b).

a. Touraine, Bor-
deaux, Valley of
Bormida, Super-
ga near Turin,
Basin of Vienna.

b. Saucats, twelve
miles south of
Bordeaux.

TABULAR VIEW

TABLE 31.2 ‘contiined,

tied
Periods | Names of the principal Members and Mineral | Some of the Loe

Nature of the Formation, in Countries where where
it has been most studied. ation occurs.

Calcaire grossier | Calcaire siliceux — | a. - Paris pasin ondo”
(a), London clay, | sandstones and con- | b. Paris, pire
sands, sandstones, | glomerates, red marl, and Hams of
&c., with marine | green and white basins, Isl
fossils (b). marls, limestone,

gypseous marls—
with land and fresh-
water fossils (c).

continued.

If. Tertiary Prrrop—|

1. Maestricht Beds. — Soft | St. Peter’s Mount,
yellowish-white limestone with | tricht. `
siliceous masses, resembling | . Ciply, near Mons.

chalk (marine). a

2. Chalk with flints (marine).

8. Chalk without flints (ma-
rine).

4. Upper green sand (ma-
rine). — Marly stone, and sand
with green particles; layers of North and South Dow we"
calcareous sandstone. and parts of the inte? te’
ing Weald of Kent, 9”

5. Gault (marine). — Blue | and Sussex. pe
clay, with numerous fossils, |i, Yorkshire; Northo
| passing into calcareous marl land.
in the lower parts. Beauvais, Franc®

.

Cretaceous Group.

6.. Lower green sand (ma-
rine). — Grey, yellowish, and
greenish sands, ferruginous
sands and sandstones, “clays,
cherts, and siliceous lime
stones,

III. Seconvary PERIOD.

1. Weald Clay (freshwater).
— Clay for the most part with-
out intermixture of calcareous
matter, sometimes including
thin beds of sand and shelly
limestone. |

dev?

1, 2, Extensively

OF FOSSILIFEROUS STRATA.

TABLE I. — continued.

Names of the principal Members and
Mineral Nature of the Formation,
in Countries where it has been most
studied,

Some of the Localities where the
Formation occurs.

G

alden Group —

continued.

ig

2. Hastings sands (fresh-
water). — Grey, yellow, and
reddish-brown sands, sand-
stones, clays, calcareous grits
passing into limestone.

3. Purbeck beds (freshwater).
— Various kinds of limestones
and marls.

| loped in the central parts of
7 Kent, Surrey, and-Sussex.

3. Isle of Purbeck, in
Dorsetshire.

N
N
$
N
N
Y
3
3
Ny
N
3
<
A
4a
$
Š
a
3
N

Oolite, or Jura Limestone Group.

m

1. Portland beds (marine). —
Coarse shelly limestone, fine-
grained white limestone, com-
pact limestone — all more or
less of an Oolitic structure ;
beds of cherts.

Isle of Portland, Tisbury
in Wiltshire, Aylesbury.

2. Kimmeridge clay (marine).
—— Blue and greyish-yellow
slaty clay, containing gypsum,
bituminous slate (Kimmeridge
coal).

Near Kimmeridge on
coast of Dorsetshire — Sun-
ning Well, near Oxford.

3. Coral rag (marine). — Cal-
careous shelly freestones,
largely oolitic; coarse lime-
stone, full of corals; yellow
sands; calcareous siliceous
grits.

Headington, near Oxford
— Farringdon, in Berkshire
— Calne and Steeple Ash-
ton, in Wiltshire — Somer-
setshire.

4. Oxford clay (marine). —
Dark blue tenacious clay, with
septaria, bituminous shale,
sandy limestone (Kelloway
rock), iron pyrites, gypsum.

New Malton, in Yorkshire
— Lincolnshire Cam-
bridgeshire — Huntingdon-
shire, and midland counties
— abundantly near Oxford
— Somersetshire — Dorset-
shire.

5. Cornbrash (marine). —
Grey or bluish rubbly lime-

stone, separated by layers of |.

clay. ©

Malmsbury; Atford, Wrax-
all, Chippenham.

TABULAR VIEW

TABLE I. — continued.

here the

3 Names of the principal Members and

Periods and{ Mineral Nature of the Formation, | Some of the Localities ¥
Groups. ms pupities where it has been most Formation occurs.
studied.

s
H. | 6. Forest marble(marine).—| Whichwood Forests S
Calcareo-siliceous sand and | fordshire — Frome,
gritstone; thin fissile beds of | east of Bath.
limestone, with clay partings ;
coarse shelly limestone.

ito
7. Great oolite (marine). —| Bath— Burford in odii
White and yellow oolitic cal- | shire— Bradfordin Wil od
careous freestone, coarse shelly | a. Stonesfield, near
limestone, layers of clay. stock, Oxfordshire.

Oolitic limestone, with re-
mains of land animals, birds,

amphibia, plants, sea-shells(a).

COPLLLIE LCL

8. Fuller’s earth clay (ma-| Near Bath.
rine). — Clay containing in
some places fuller’s earth.

LR LOD

ee : ' u
9. Inferior oolite (marine).— | Cotteswold Hills — p
Soft freestone, sand with cal- | dry Hill, near Bristol.
careous concretions. f r

SECONDA TEN

Limestones of various qualities, clays, sands, and i
stone, containing the same fossils as those occurring” jin
series of the oolitic group of England, constitute the rat
body of the Jura chain of mountains, and cover vast
of country in Germany.

Oolite, or Jura Limestone Group — continued.

PEPA

Y
S
3

2
3
S
©
A
©
kari
[a4
fy

met

p
[4
4
A
z
©
Q
i}

N

—

leon!

~

t
Lias (marine). — Shale and | Lyme Regis in Dorf
sandy marlstone. shire, and in many pa pis?
Blue, white, and yellow | Somersetshire — forks e
earthy limestone, usually in|— in Sutherlandshire, pe
thin beds, interstratified with | Hebrides, and North %
clay, often slaty and bitumin- | land.
ous. In France, asat Metz, oy
a considerable extent 1” Jut
many, as in the Swabia”

5
1. Keuper, or variegatedmarls. | Neighbourhood of Vose
— Red, grey, green, blue, and | mountains, and many west
white marls, sandstones, con- | of Wurtemberg and
glomerates,and shells, contain- | phalia, Nuremberg.

ing gypsum and rock-salt.

O

}
ty,
(San

ng

ee

N
N
y
Š
Š
Ñ
à
§
N
a
N
N
N
X
R

4

TEF

f Carboniferous Group.

“oups,

New Fed Sandstone
Group — continued.

A

OF FOSSILIFEROUS

STRATA.

TABLE I.—continued.

Names of the principal Members and
Mineral Nature of the Formation,
in Countries where it has been most
studied.

Some of the Localities where the
Formation occurs,

2. Muschelkalk (marine). —
Grey, blue, and blackish lime-
stone, with alternating clay and
marl, and with silicedus layers,
and nodules.

Extensively developed in
Germany and France.

Hitherto no beds in Eng-
land have been identified with
the formation.

3. Variegated (Bunter) sand-
stone. — Red, white, blue, and
green siliceo-argillaceous sand-
stone, often micaceous and con-
taining gypsum and rock-salt.

Nottinghamshire — York-
shire.
Stuttgardt.

E

Magnesian Limestone

and marls.

1. Magnesian limestone (a)
(marine). — Marl-slate, shelly
limestone, variegated marls,
yellow magnesian limestone.

Zechstein of Germany (b) —
limestone — marl-slate, con-
taining copper ore, and im-
pressions of fish.

a. Nottinghamshire, Derby-
shire, Yorkshire, Durham,
Northumberland,

b. Mansfeld in Thuringia.

2. Red conglomerate.—Sand-
stones, conglomerates, sands,

Neighbourhood of Exeter.

=

1. Coal measures (fresh-
water and marine). — Sand-
Stones, grits, conglomerates,
clays, with ironstone, shales,
and limestone, interstratified
with beds of coal.

Northumberland, Durham,
Yorkshire, Lancashire, Staf-
fordshire, Somersetshire,
South Wales, Valleys of the
Forth and Clyde.

District of Liege, West-
phalia, Silesia, Bohemia, &c.

2. Mountain limestone (ma-
rine). — Grey, compact, and
crystalline limestone, abound-
ing in lead ore in North of
England, and alternating with
Coal measures in Scotland.

Mendip Hills, Derbyshire,
Yorkshire, Durham, North-
umberland, Lanarkshire,
Linlithgowshire, many parts
of Ireland.

North-west of Germany,
Belgium, North of France.

TABULAR VIEW OF STRATA.

TABLE I, — continued.

Periods and
Groups.

zZ

Old red sand-
stone Group.

Names of the principal Members and
Mineral Nature of the Formation,
in Countries where it has been most
studied. ;

th
i exe
Some of the Localities wi
Formation occul

1. Old red sandstone—Coarse
and fine siliceous sandstones
and conglomerates of various
colours, red predominating.

+

ip
Extensively develop g
Shropshire and Her i
shire, Brecknockshu®
fries-shire, Forfarshit®
Silesia, Bohemia-

—

©

Silurian Group.

4
©
kani
a]
S]

Ay
Z
=
=
I
n
Z
<
%
mg

>

from

1. Ludlow rocks (marine), —
Argillaceous limestone, sandy
shale.

pit
Ludlow Castle, Sr op
Aymestry and vee
Herefordshire.

2. Wenlock limestone (ma-
rine). — Coralline limestone
and argillaceous shale, with
nodules of earthy limestone.

pi
Wenlock Edge, shroks
Dudley, Worcestersh

pe

3. Caradoc sandstones (marine).

— Shelly limestone and mica-
ceous sandstone, quartzose
grits, and sandy limestones.

a + RA

Horderly, Shropsbi” pje
May Hill, Glouceste pa
East flank of Wre*. g

4. Llandeilo flags (marine).
— Calcareous flags, sandstone
and schist,

pit
Caer Caradoc, Shrop?

‘Llandrindod, nea dei”
Radnorshire. ; [Llar

care
si

Fossiliferous greywacké, and rocks older than e.i w
rian, but in which no distinct assemblage of orga gst
mains have as yet been specifically determined. se Ni
Sedgwick has proposed the name of “ Cambrian” £

formations.

CHAPTER XXIV.

AN i
NALOGY OF THE OLDER FOSSILIFEROUS TO THE TERTIARY
STRATA.

That land as well as sea existed at each successive period — Some
former continents placed where it is now sea—Secondary fresh-
Water deposits, why rare (p. 313. )—Persistency of mineral com-
Position, why apparently greatest in older rocks—Supposed uni-
Yersality of red marl formations — Secondary rocks, why more
Consolidated — why more fractured and disturbed (p. 318.) —
Secondary volcanic rocks of many different ages.

Ù the last chapter I stated that no detailed account of
A older fossiliferous formations would be attempted
t this work, and that I should confine myself almost
*Xclusively to the inquiry how far the rules of inter-
Pretation previously adopted for the tertiary groups
‘ight be applied to the phenomena of more ancient
“tata. "To this point the following remarks are chiefly
tected ; — .

Position of former continents. — The existence of
“td as well as sea, at every geological period, is
attested by the remains of terrestrial plants imbedded -
U the deposits of all ages, even the most remote. We
hd fluviatile shells not unfrequently in the secondary
‘trata, and here and there some freshwater form-
‘tions; but the latter are less common than in the
ĉrtiary series. For this fact the reader’s mind has
ĉen prepared, by the views advanced in the third

a
308 SECONDARY FORMATIONS. [Book

chapter respecting the different circumstances un
which the secondary and tertiary strata appear to hav
originated. The secondary, it was suggested, may
have been accumulated in an ocean like the Paci#®
where coralline and shelly limestones are forming +, ;
in a basin like the bed of the western Atlantic, Ww)”
may have received, for ages, the turbid waters of oe
rivers, such as the Amazon and Orinoco, each ats
ing a considerable extent of continent. The tertia?
deposits, on the other hand, very probably accumula”
during the growth of a continent, by successive ae
gence of new lands, and the uniting together of isla”
During such changes, inland seas and lakes would i
caused, and their basins afterwards filled up with $ê
ment, and then raised above the level of the waters
That the greater part of the space now occupied f
the European continent was sea when some of £
secondary rocks were produced, must be inferred f%
the wide areas over which several of the marine group 7
are diffused; but we need not suppose that the que
tity of land was less in those remote ages, but me?
that its position was very different. „Jk
It has been shown that, immediately below the ch ;
and green-sand, a fluviatile formation, called the We
den, occurs, which has been ascertained to extend #° ;
-west to east about 200 English miles, and from nort
west to south-east about 220 miles, the depth or u
thickness of the beds, where greatest, being abo"
2000 feet.* These phenomena clearly indicate th?
there was a constant supply in that region, for @ mie
period, of a considerable body of fresh water, such ®
might be supposed to have drained a continent, %

of

* Fitton’s Geology of Hastings, p. 58.

ae
h, XXIV.] POSITION OF FORMER CONTINENTS. 309

itge island, containing within it a lofty chain of moun-
“Ins. Dr. Fitton, in speaking of these appearances,
"ecalls to our recollection that the delta of the newly
Stovered Quorra, or Niger, in Africa, stretches into
Ae interior for more than 170 miles, and occupies,
is supposed, a space of more than 300 miles along
€ coast; thus forming a surface of more than 25,000
‘quare miles, or equal to about one half of England. *
If asked where the continent was placed from the
ins. of which the Wealden strata were derived, we
“ght be almost tempted to speculate on the former
“Xistence of the Atlantis of Plato as true in geology,
“though fabulous as an historical event. We know
at the present European lands have come into exist-
Uce almost entirely since the deposition of the chalk
‘ee map, Plate II.); and the same period may have
‘iced for the disappearance of a continent of equal
{nitude, situated farther to the west.
But among the numerous fossils of the ancient delta
the Wealden no remains of mammalia have been
“tected; whereas we should naturally expect, on
amining the deposits recently formed at the mouths
“t the Quorra, Indus, or Ganges, to find, not only the
nes of birds and of amphibious and land reptiles, but
50 those of the hippopotamus, and other mammalia
‘hich frequent the banks of rivers. Mr. Mantell
‘tems to have demonstrated +, that the remains of the
imals and plants found fossil in the Wealden have;
vith the exception of the testacea and other aquatic
“bes, been transported for a considerable distance,
€ stems of the plants being, for the most part, torn

* Fitton, Geol. of Hastings, p. 58 , who cites Lander’s Travels.
t Geol. of S. E. of England, p. 232.

k
}

. g
310 SECONDARY FORMATIONS. [Book f

5, °

and intermingled with pebbles of quartz, slate; and
jasper; while the bones of lizards, turtles, and fish, ®°
detached from the skeleton, and more or less broke?
and rolled. But, admitting that these fossils W%
drifted for many a league, we might fairly expect that
at least, some fragments of mammiferous bones wY
have reached the delta.

It is certainly a startling proposition to suppose» that
a continent covered with vegetation, which had p
forests of palms and tree-ferns, and its plants allied ©
the Dracæna and Cycas, which was inhabited by Jarg?
saurians, and by birds, was, nevertheless, entire
devoid of land quadrupeds. If the proofs were con"
fined to the Wealden, we might hesitate to lay mut
stress on mere negative evidence, since extensive
posits of the Eocene period, such as the London 4)’
have as yet yielded no mammiferous fossils.
when we find the same general absence of mami”
in strata of the Oolitic and Liassic eras, we can hat i
refuse to admit that the highest order of quadrup® ;
was very feebly represented in those ages, when t é
small Didelphys of Stonesfield was entombed. S0%
of the bones, indeed, collected by Dr. Buckland fro”
the oolitic series, have been pronounced by Cuviet
be cetaceous; but that naturalist has himself remat*°
how closely the vertebree of the larger reptiles pi
semble those of certain dolphins; so that it is hig”
desirable that the fossils alluded to should be ™
examined with great care. *

So far, then, as our present inquiries enable YS i
judge, there are strong indications that, during i

* Mantell, Geol. of S, E. of England, p. 282, ; and see abov’ |
Vons Te pn 332, {

€ n. ; ;
à XXIV.] ABSENCE OF MAMMALIA. ” 31E

tiods of the Wealden, the Oolite, and Lias, there
àS a large development of the reptilia, at the ex-
Pense, as it were, both of the cetaceous and terrestrial
ammalia.

It may be well, then, te inquire whether this differ-
“ce in the state of animal life in the northern hemi-
Phere, at these remote periods, is irreconcileable with

© notion of the constancy and uniformity of the laws
“hich govern the changes of the organic world. Would
€ almost entire suppression of one important class of
a tebrated animals, and the larger development of
Nother, if fully established on farther investigation,

‘ply that there are no fixed rules according to which
the form, structure, and attributes of animals are
®commodated to the endless vicissitudes of the earth’s
wtface ? Or are the rules, if any, made to endure for

* time only, new ones being substituted at each suc-

sive period? Or, is it conceivable that the distinct
n logical characters. of certain secondary groups, as
Stpared to others of the tertiary epoch, may depend
laws as uniform as those which, from one century

° another, appear to determine the growth of certain
Tibes of plants ome animals in the arctic, and of others
i tropical regions ?

ln Australia, New Zealand, and many dhg parts of
the Southern hemisphere, where the indigenous land
Vadrupeds are comparatively few and of small dimen-
‘Ons, the reptiles do not predominate in number or size.
e deposits formed at the mouth of an Australian
er, within the tropics, might contain the bones of
ia e afew small marsupial animals, which, like those
Ë Stonesfield, might hereafter be discovered with diff-
i tY by geologists; but there would, at the same
€, be no megalosauri and other fossil remains, show-

aes W
312 SECONDARY FORMATIONS. [Book Í

ing that large saurians were plentiful on the land and
in the waters when mammalia were scarce. '
No precise analogy, therefore, can here be foun?
to the state of the animal kingdom supposed to hav?
prevailed during the secondary periods when a M8
temperature pervaded European latitudes. But it may
be useful to consider whether any of the anomalies pow
caused by climate in the relative number and
portance of different classes of the vertebrata may if
in some degree illustrate this topic. In the Arctic j
gions, for example, reptiles are small, and sometim?
wholly wanting, where birds, large land quadrupe™
and cetacea abound. We meet with bears, wolve®
foxes, musk oxen, and deer, walrusses, seals, whale”
and narwals, in regions of ice and snow, where #
smallest snakes, efts, and frogs are rarely if ev?
seen. i .
On what grand laws in the animal physiology th
remarkable phenomenon depends, cannot, in the P i
sent state of science, be explained; nor could we pre
dict whether any opposite condition of the atmosphe™
in respect to heat, moisture, and other circumstan@
would bring about a state of animal life which m8
be called the converse of that above described ; a $t?
of things in.which large mammalia might abound, ”
reptiles disappear. We ought, however, to recolle?”
that a mean annual temperature like that now ®
perienced at the equator, co-existing with the uneg”
days and. nights of European latitudes, and with 3
distinct distribution of sea and land, would imply ;
climate to which we have now no parallel. Co?
sequently, the type of animal and vegetable existen”
required for such a climate might deviate as wi?
from that now established in any part of the globe; f

Ch, XXIV.]° PERSISTENCY OF MINERAL CHARACTER. 313

do the Flora and Fauna of our tropical differ from
those of our arctic regions.

Secondary freshwater deposits, why rare. — If there
Were extensive tracts of land in the secondary period,
We may presume that there were lakes also ; yet I am
Not aware of any pure lacustrine formations inter-
Stratified with rocks older than the chalk. Perhaps
their general absence may be accounted for by the
Adoption of the theoretical views above set forth; for
l the present ocean coincides for the most part with
the site of the ancient continent, the places occupied

y lakes must have been submerged. It should also
be recollected, that the area covered by lakes, at any
One time, is very insignificant in proportion to the
cean; and, therefore, we may expect that, after the
farth’s surface has undergone considerable revolutions
in its physical geography, the lacustrine strata will be
“oncealed, for the most part, under superimposed ma-
trine deposits.

Persistency of mineral character. —In the same man-
ter as it is rare and difficult to find ancient lacustrine
Strata, so also we can scarcely expect to discover newer
Marine groups preserving the same lithological charac-
ters continuously throughout wide areas. The chalk
Now seen stretching for thousands of miles over differ-
“tt parts of Europe has become visible to us by the
fect, not of one, but of many distinct series of move-
Ments, Time has been required, and a succession of
8eological periods, to raise it above the waves in so”
any regions; and if calcareous rocks of the Eocene
°r Miocene periods have been formed, preserving a

°mogeneous mineral composition throughout equally
extensive regions, it may require convulsions as nume-
tous as all those which have occurred since the origin

VOL. Iv, P

_ but in some places, as on the northern flanks 9
Pyrenees, and in Catalonia, a saliferous re

34 SECONDARY FORMATIONS. [Book IV:
of the chalk to bring them up within the sphere of
human observation. Hence the rocks of more moder?
periods may appear of partial extent, as compared me
those of remoter eras, not because there was any
original difference of circumstances throughout the
globe when they were formed, but because there Þa
not been sufficient time for the development of a gre?
series of subterranean volcanic operations since thet
origin.

At the same time, the reader should be warne
to place implicit reliance on the alleged persi
of the same mineral characters in secondary rocks
When it was first ascertained that an order of sue
cession could be traced in the principal groups
strata above enumerated, names were given to eat”
derived from the mineral composition of the rocks f
those parts of Germany, England, or France, whet?
they happened to be first studied. When it was after”
wards acknowledged that the zoological and phy”
logical characters of the same formations were far mo
persistent than their mineral peculiarities, the ola?
names were still retained, instead of being exchange
for others founded on more constant and essent?
characters. The student was given to understand #4
the terms chalk, green-sand, oolite, red marl, coal, an
others, were to be taken in a liberal and exten?
sense; that chalk was not always a cretaceous al

d no!

stenty
*

d ma!

Green-sand, it was said, was rarely green, and fe"
quently not arenaceous, but represented in parts .
the south of Europe by a hard dolomitic limesto?®
In like manner, it was declared that the oolitic textul?

* See some remarks on this subject, Vol. I. p- 135+

Ch. XXIV.] PERSISTENCY OF MINERAL CHARACTER. 315

was rather an exception to the general rule in rocks of
the oolitic period, and that no particle of carbonaceous
Matter could often be detected in the true coal form-
ation of many districts where it attains great thickness.
It must be obvious to every one, that inconvenience
and erroneous prepossessions could hardly fail to arise
from such a nomenclature ; and accordingly a fallacious
Mode of reasoning has been widely propagated, chiefly
by the influence of a language so singularly inappro-
Priate.

After the admission that the identity or discordance
of mineral character was by no means a sure test of
agreement or disagreement in the age of rocks, it was
Still thought, by many geologists, that if they found
à rock at the antipodes agreeing precisely in mineral
Composition with another well known in Europe, they
Could fairly presume that both are of the same age,
until the contrary could be shown.

Now, it is usually difficult or impossible to combat
‘uch an assumption on geological grounds, so long as
We are imperfectly acquainted with the geology of a
distant country, inasmuch as there are often no or-
Sanic remains in the foreign stratum; and even if
these abound, and are specifically different from the
fossils of the supposed European equivalent, it may be
objected that we cannot expect the same species to

ave inhabited very distant quarters of the globe at
he same time.

Supposed universality of red marl. —I shall select a
"emarkable example of the erroneous mode of general-
Zing now alluded to. A group of red marl and sand-
Stone, sometimes containing salt and gypsum, is found
m England interposed between the lias and the car-

Oniferous strata. For this reason, other red marls
P 2

`~

316 SECONDARY FORMATIONS. - [Book IV

and sandstones, associated some of them with salt, and
others with gypsum, and occurring not only in different
parts of Europe, but in Peru, India, the salt deserts °
Asia, those of Africa, in a word, in every quarter °
the globe, have been referred to one and the same
period. The burden of proof is not supposed to rest
with those who insist on the identity of age of al
these groups; so that it is in vain to urge as an ob-
jection the improbability of the hypothesis which
would imply that all the moving waters on the globe
were once simultaneously charged with sediment °
a red colour.

The absurdity of pretending to identify, in ages al
the red sandstones and marls in question, has at lengt
been sufficiently exposed, by the discovery that, evii
in Europe, they belong decidedly to many differe™
epochs. We have already ascertained, that the re
sandstone and red marl, with which the rock-salt °
Cardona is associated, may be referred to the period?
our chalk and green-sand. I was led to this opinio”
when I visited Cardona in 1830, and before I was awal?
that M. Dufrénoy had arrived at the same conch
sions.* Ihave pointed out that in Auvergne there até
red marls and variegated sandstones, which are und" -
tinguishable in mineral composition from the new ty
sandstone of English geologists, yet which were dep”
_ sited in the Eocene period: and, lastly, the gypse"
red marl of Aix, in Provence, formerly supposed tO
a marine secondary group, is now acknowledged t°
a tertiary freshwater formation. f

Secondary rocks, why more consolidated. — One °
the points where the analogy between the secondary
and tertiary formations has been supposed to fail, is t

* Ann. des Sci. Nat., Avril, 1831, p. 449.

Ch. XXIV. ] CONSOLIDATION. 317

greater degree of solidity observable in the secondary
Series. Undoubtedly the older rocks, in general, are
More stony than the newer; and most of the tertiary
Strata are more loose and incoherent in their texture
than the secondary. Many exceptions, however, may
be pointed out, especially in those calcareous and sili-
Ceous deposits which have been precipitated in great
Part from the waters of mineral springs, and have been
Originally compact. Of this description are a large
Proportion of the Parisian Eocene rocks, which are more
Stony than most of the. English secondary groups.

But strata in general have evidently been consoli-
dated subsequently to their deposition by a slow lapidi-
fying process. Thus loose sand and gravel are bound
together by waters holding carbonate and oxide of
iron, carbonate of lime, silica, and other ingredients in
Solution. These waters percolate slowly the earth's
crust in different regions, and often. remove gradually
the component elements of fossil organic bodies, sub-
Stituting other substances in their place. It seems,
Moreover, that the draining off of the waters during
the elevation of land may often cause the setting of

‘Particular mixtures, in the same manner as mortar
hardens when desiccated, or as the recent soft marl of
Lake Superior becomes highly indurated when ex-
Posed to the air.* The conversion of clay into shale,
and of sand into sandstone, may, in many cases, be
attributed to simple pressure, produced by the weight
of superincumbent strata, or by the upward heaving of
Subjacent masses during earthquakes. Heat is another
Cause of a more compact and crystalline texture, which
Will be considered when I speak of the strata termed
“primary.” All the changes produced by these various

* Vol. I. p. 344. *
P 3

318 SECONDARY FORMATIONS, [Book 1V.

means require time for their completion; and this may
explain, in a satisfactory manner, why the older rocks
are most consolidated, without entitling us to resort t0
any hypothesis respecting an original distinctness i
the degree of lapidification of the secondary strata.

Secondary, why more disturbed.— As the older form-
ations are generally more stony, so also they are moré
fractured, curved, elevated, and displaced, than the
newer. Are we, then, to infer, with some geologists:
that the disturbing forces were more energetic in re-
moter ages? No conclusion can be more unsound;
for as the moving power acts from below, the newer
strata cannot be deranged without the subjacent rock
participating in the movement; while we have evidenc®
that the older have been frequently shattered, raised,
and depressed, again and again, before the newer rocks
were formed. It is evident that if the disturbing
power of the subterranean causes be exerted with
_ uniform intensity in each succeeding period, the quan
tity of convulsion undergone by different groups of
strata will generally be great in proportion to theif
antiquity. But exceptions will occur, owing to thé
partial operation of the volcanic forces at particula"
periods; so that we sometimes find tertiary strat@
more elevated and disturbed, in particular countries
than the secondary rocks in others.

Some of the enormous faults and complicated dis-
locations of the ancient strata may probably hav?
arisen from the continued repetition of earthquakes i
the same place, and sometimes from two distinct
series of convulsions, which have forced the same
masses in different, and even opposite, directions i
sometimes by vertical, at others by horizontal, mov
ments,

Ch, XXIV,] VOLCANIC ROCKS. 319

Secondary volcanic rocks of different ages. — The
a8sociation of volcanic rocks with different secondary
strata is such as to prove that there were igneous
€ruptions at many distinct periods, as also that they
Were confined during each epoch, as now, to limited
areas, Thus, for example, igneous rocks contempora-
neous with the carboniferous strata abound in some
Countries, but are wanting in others. So it is evident |
that the bottom of the sea, on which the oolite and its
Contemporary deposits were thrown down, was, for the
Most part, free from submarine eruptions ; but at some
Points, as in the Hebrides, it seems that the same
Ocean was the theatre of volcanic action. It was before
remarked *, that, as the ancient eruptions occurred
in succession, sufficient time usually intervening be-
tween them to allow of the accumulation of many
Subaqueous strata, so also should we infer that sub-
terranean movements, which are another portion of

the volcanic phenomena, occurred separately and in
Succession.

* Booki. chap. v.

CHAPTER XXV.

RELATIVE ANTIQUITY OF MOUNTAIN-CHAINS.

Theory of M. Elie de Beaumont — His opinions controverted —
His method of proving that different chains were raised at dis-
tinct periods, and that the rise of others was contemporaneous)
not conclusive — His doctrine of the parallelism of contem-
Poraneous lines of elevation — Objections (p. 326.) —How fat
anticlinal lines formed at the same period are parallel —
Difficulties in the way of determining the relative age of
mountains.

Tuar the different parts of our continents have bee”
elevated, in succession, to their present height abové
the level of the sea, is an opinion which has been gra
dually gaining ground with the progress of science?
but no one before M. Elie de Beaumont had the merit
even of attempting to collect together the recorded
facts which bear on this subject, and to reduce the
to one systematic whole. The above-mentioned ge0
logist was eminently qualified for the task, as one wh?
had laboured industriously in the field of original ob-
servation, and who combined an extensive knowledgé
of facts with an ardent love of generalization.

But, as I cannot admit the accuracy of an import
ant part of his method of reasoning on this topic, a2
as his principal conclusions appear to me very uncer
tain, I must explain the reasons of my dissent, having
first given a brief summary of the most prominent fea
tures of his theory.

Ch. XXV.] ANTIQUITY OF MOUNTAIN-CHAINS, _ 321

Ist. M. de Beaumont supposes, “ that in the history
of the earth there have been long periods of compara-
tive repose, during which the deposition of sedimentary
Matter has gone on in regular continuity ; and there
have also been short periods of paroxysmal violence,
during which that continuity was broken.

“ Qdly. At each of these periods of violence or
‘revolution’ in the state of the earth’s surface, a
Steat number of mountain-chains have been formed
Suddenly.

“ 3dly. All the chains thrown up by a particular
revolution have one uniform direction, being parallel
to each other within a few degrees of the compass,
€ven when situated in remote regions ; but the chains
thrown up at different periods have, for the most part,
different directions.

« 4thly. Each ‘revolution,’ or, as it is sometimes
termed, ‘frightful convulsion,’ has fallen in ‘with the
date of another geological phenomenon ; namely, ‘the
Passage from one independent sedimentary formation
to another,’ characterized by a considerable difference
0 ‘organic types.’ :

“Sthly. There has been a recurrence of these
Paroxysmal movements from the remotest geological
Periods; and they may still be reproduced, and the
epose in which we live may hereafter be broken by
the sudden upthrow of another system of parallel
Chains of mountains.

“6thly. We may presume that one of these revo-
Utions has occurred within the historical era, when
the Andes were upheaved to their present height ;
for that chain is the best defined and least obliterated
ature observable in the present exterior configuration
of the globe, and was probably the last elevated.

P9

322 RELATIVE ANTIQUITY [Book 1V.

“ 7thly. The instantaneous upheaving from the
ocean of great mountain masses must cause a violent
agitation in the waters; and the rise of the Andes
may, perhaps, have produced that* transient deluge
which is noticed among the traditions of so many
nations.

“ Lastly. The successive revolutions above men-
tioned cannot be referred to ordinary volcanic forces,
but may depend on the secular refrigeration of the
heated interior of our planet.” *

I need not enter here into an examination of all
these topics, as the discussion of several of them has
been in some degree anticipated in former chapters.
Respecting the alternation of periods of general rê-
pose and disorder, I have before suggested that ge”
logical phenomena indicate merely that each regio?

„of the globe has in succession been a great theat!t?
of subterranean convulsions, as some districts are now
while others remain at rest. Before we can reaso?”
ably attribute extraordinary energy to any known caus
we must be sure that its usual force would be i”
adequate, though exerted for indefinite ages, to produc?
the effects required.

The geologist, therefore, who assumes that conti-

nents and mountain-chains have been heaved up sud-
denly by paroxysmal violence, may be considered %5
pledging himself to the opinion that the accumulate

effects of ordinary volcanic forces could never in 9Y

series of years produce appearances such as we WE

ness in the earth’s crust. Time and the progress °

* Ann. des Sci. Nat., Septembre, Novembre, et Décembré
1829. Revue Francaise, No. 15. May, 1830. The last edition by
M. de B. is in De la Beche’s Manual, 3d. edit. ; and p’ Aubuls
son, Traité de Géognosie, tom. iii, p, 282., 1835.

Ch, Xxv.] OF MOUNTAIN-CHAINS. 3

Science can alone decide whether such an assumption
ig warranted, or whether, on the contrary, it does not
Spring from two scources of prejudice: — first, the
difficulty of conceiving the aggregate results of a great
Number of minor convulsions ; secondly, the habit of
Viewing geological phenomena without any desire to
explain them as the effects of moderate forces, such
as we know to act, instead of that intense degree of
energy, the occasional development of which, however
Possible, is entirely conjectural.

The speculation of M. de Beaumont concerning the
“secular refrigeration” of the internal nucleus of the
globe, considered as a cause of the instantaneous rise
of mountain-chains,, appears to me obscure, and is
mainly founded on that part of the doctrine of central
heat which has been controverted in the second
Volume. *

In regard to the connection of the rise of mountain-
chains with revolutions equally sudden in the animate
World, I have endeavoured to show, in the third book,
that changes in physical geography, which are un-
Ceasingly in progress, are among the causes which
Contribute, in the course of ages, to the extermination
of certain species of animals and plants; but the in-
fluence of these causes is slow, and, for the most part,
indirect, and has no analogy with those sudden cata-
Strophes which are introduced into the theory now
Under review. An explanation of the probable cause
of the abrupt transitions from one set of strata to
another, containing distinct organic remains, has been
Siven at length in the third and fourth chapters of
this book. +

* Book ii. chapters xviii. and xix.
t See particularly from p. 345, to p. 355. of Vol. IIT.
P 6

324: RELATIVE ANTIQUITY [Book IV

When the protrusion of the Andes from beneath the
sea is proposed as a possible cause of the historical
deluge, we naturally inquire, what proofs there are of

that chain having started up at once within the last
4000 or 5000 years from a great depth of sea; foritis
necessary that a large body of water should be dis-
placed, in order that a diluvial wave, capable of in-
undating a previously existing continent, should be
raised. If it were reasonable to refer deluges to what
have been called paroxysmal elevations, it would surel¥
be a fairer speculation to point to a line of shoals 0"
reefs, consisting of shattered and dislocated rocks, and
surrounded on all sides by an unfathomable ocean, tha?
to select a mountain-chain as the site of the upthroW>
for the rapid conversion of the bed of a deep sea int?
a shoal would evidently cause a much greater displace
ment of water than the rise of a large shoal into ®
mountain-chain.

Without dilating further on these subjects, I shall
now endeavour to analyze the proofs by which th?
successive elevation of different chains, and the sup“
posed parallelism of lines of contemporaneous eleva"
tion, are supported.

M. de Beaumont's proofs that different chains we”
raised at different epochs. —‘“We observe,” says #*
Elie de Beaumont, “along nearly all the mountail”
chains, when we attentively examine them, that th?
most recent rocks extend horizontally up to the foot °
such chains, as we should expect would be the case ?
they were deposited in seas or lakes, of which thes?
mountains have partly formed the shores; whilst tP?
other sedimentary beds, tilted up, and more or less
contorted, on the flanks of the mountains, rise in cer”

Ch. RXV] OF MOUNTAIN-CHAINS. ' 325

tain points even to their highest crests.”* There are,
therefore, in and adjacent to each chain, two classes of
Sedimentary rocks, the ancient or inclined beds, and
the newer or horizontal. It is evident that the first
appearance of the chain itself was an event “ inter-
Mediate between the period when the beds now up-
Taised were deposited and that when the strata were
Produced horizontally at its feet.” ?
A Fig. 216.

b

Thus the chain A assumed its present position after
the deposition of the strata b, which have undergone

Sreat movements, and before the deposition of the

Stroup c, in which the strata have not suffered derange-
Ment.

If we then discover another chain B, in which we

Fig. 217.

find not only the formation 6, but the group c also,

disturbed and thrown on its edges, we may infer that

the latter chain is of subsequent date to A; for B

Must have been elevated after the deposition of c, and
efore that of the group d; whereas A had originated
Fore the strata c were formed.

* Phil. Mag. and Annals, No, 58., New Series, p. 242.

326 RELATIVE ANTIQUITY _ [Book IY.

In order to ascertain whether other mountain ranges
are of contemporaneous date with A and B, or are re
ferable to distinct periods, we have only to inquire
whether the geological phenomena are identical;
namely, whether the inclined and undisturbed sets °
strata in each correspond to those in the types abov®
mentioned.

Objections to M. de Beaumont's theory. — Now all
this reasoning is perfectly correct, so long as thé
periods of the deposition of the particular local group®
of strata 6 and c are not confounded with the period
during which the animals and plants found fossil in
and c may have flourished, and provided also that du®
latitude is given to the term contemporaneous ; for
this term must be understood to allude, not to a
moment of time, but to the interval, whether brief #
protracted, which elapsed between two events, namely
between the accumulation of the inclined and that °
the horizontal strata.

But, unfortunately, no attempt seems to have bee?
made to avoid this manifest source of confusion, 27
hence the very terms of each proposition are equi
vocal; and the length of some of the intervals is
so vast, that to affirm that all the chains raised #
such intervals were contemporaneous, is an abuse °
language.

In order to illustrate this argument, I shall select
the Pyrenees as an example. This range of mou”
tains, says M. de Beaumont, rose suddenly (à un $€"
jet*) to its present elevation at a certain epoch in the

* In the last edition of M. de B.’s system (see note above
p. 323.), he only speaks of the convulsion which raised the PS
renees, as “one of the most violent which the land of Eur0P
ever experienced,”

Ch xxvj OF MOUNTAIN-CHAINS. 327

“arth’s history, namely, between the deposition of the
chalk and that of the tertiary formations; for the
Chalk is seen in vertical, curved, and distorted beds on
the fanks of the chain, while the tertiary formations
Test upon them in horizontal strata at its base.

The only proof offered of the extreme suddenness
Of the convulsion is the shortness of the time which
Ntervened between the formation of the chalk and
that of the tertiary strata. *

Now the beds called chalk on the flanks of the Pyre-
Nees differ widely in mineral composition from the
White chalk with flints of England and France; but as
they contain for the most part the same species of
fossi] shells, I grant that they may on that evidence be
Teferred to the cretaceous system.+ On the other
hand, the horizontal tertiary strata at the western end
of the Pyrenees, near Bayonne, are certainly of the

locene period. The reader will find, when he re~
fects on these data, that we can only infer that the
Steat movement took place after the cretaceous period

ad commenced, but we cannot assume that it oc-
Curred after the close of that period. So also we may
Say, that the Pyrenees rose before the close of the

locene epoch, but not that the event happened
€fore its commencement. We cannot permit M. de
€aumont to exclude the whole of either of these
Periods (the Cretaceous and Miocene) from the pos-
Sible duration of that interval during all or any part of
Which the elevation may have taken place.

* Phil. Mag. and Annals, No. 58., New Series, p. 243-

t The fossils which I collected in company with Captain S. E,
Cook, R. N., from the newest secondary beds on the flanks of the

Yrenees, near Bayonne, were examined by M. Deshayes, and
found identical with species of the chalk near Paris.

328 RELATIVE ANTIQUITY [Book IY:

The upheaving of the Pyrenees, therefore, may have?
been going on before the animals of the chalk period
ceased to exist, or when the Maestricht beds were 1”
progress, or during the indefinite ages which may
have elapsed between the extinction of the Maestricht
animals and the introduction of the Eocene tribes, 0"
during the Eocene epoch, or between that and thé
Miocene, or at the commencement of the Mioce?®
epoch. Or the rise may have been going on throug)”
out one, or several, or all of these periods.

It would be a purely gratuitous assumption to saf
that the chalk strata c, Fig. 217., p. 325., were the last
which were deposited during the cretaceous period, 0"
that, when they were upheaved, all or nearly all the
species of animals and plants which are now fou®
fossil in them were suddenly exterminated; ye
unless this can be affirmed, we cannot say that the
chain B was not upheaved during the cretaceo™®
period. Consequently, another range of mountai™®
(A, Fig. 216.), at the base of which cretaceous rock
c, may lie in horizontal stratification, may have be®
elevated during the same period; because, in t"
case, the particular group ¢ may have been formed 1005
after the animals and plants which are characterist'®
of them, in a fossil state, began to flourish, and during
those antecedent ages the chain A may have risen-

The Newer Pliocene strata in Sicily have be?”
raised to the height of nearly 3000 feet in some place”
with great derangement; yet the testacea and 20%
phytes inclosed in these still exist, or nine tenths ° |
them at least, in the Mediterranean. The same per!
still continues, if we speak of periods in the same €%
tended sense in which they are understood by geolo”
gists, and by M. de Beaumont, in the memoir ”°

Ch xxv OF MOUNTAIN.CHAINS. 329

before us. So the chalk in the Pyrenees may have

ĉen raised to the height of many thousand feet, when
the animals found fossil in the upheaved strata still
“ontinued to inhabit the sea.

In like manner the sea may have been inhabited by

iocene testacea for ages before the deposition of
‘hose particular Miocene strata which occur at the
oot of the Pyrenees.

To illustrate the grave objections above advanced,
Which go to affect the whole of De Beaumont’s reason-
ing, let us suppose, that in some country three styles
of architecture had prevailed in succession, each for a
-Period of one thousand years; first the Greek, then
the Roman, and then the Gothic; and that a tremen-

ous earthquake was known to have occurred in the
Same district during one of the three periods, — a con-
Yulsion of such violence as to have levelled to the
Stound all the buildings then standing. If an anti-
ary, desirous of discovering the date of the cata-
Strophe, should first arrive at a city where several
Greek temples were lying in ruins and half engulphed
the earth, while many Gothic edifices were stand-
‘Ng uninjured, could he determine on these data the
“ta of the shock? Could he even exclude any one of
the three periods and decide that it must have happened
Wing one of the other two? Certainly not. He

“ould merely affirm that it happened at some period
“iter the introduction of the Greek style, and before
the Gothic had fallen into disuse. Should he pretend
to define the date of the convulsion with greater
Precision, and decide that the earthquake must have
Occurred after the Greek and before the Gothic period,

at is to say, when the Roman style was in use, the
allacy in his reasoning would be too palpable to escape

*tection for a moment.

330 RELATIVE ANTIQUITY. | rBook IV

Yet such is the nature of the erroneous inductio”
which I am now exposing. For as, in the example
above proposed, the erection of a particular edifice ®
perfectly distinct from the period of architecture ™
which it may have been raised, so is the deposition °
chalk, or any other set of strata, from the geologicé
epochs characterized by certain fossils to which they
may belong.

It is superfluous to enter into any farther analysis of
this theory, because the force of the whole argument
depends on the accuracy of the data by which the
contemporaneous or non-contemporaneous date of the
elevation of two independent chains can be demo”
strated. In every case, this evidence, as stated by
M. de Beaumont, is equivocal, because he has not we
cluded in the possible interval of time between the de-
position of the deranged and the horizontal formations
part of the periods to which each of those classes °
formations are referable. By the insufficiency, tho”
of the above proofs, the doctrine of the parallelism °
lines of contemporaneous elevation is destroyed ; P%
cause all the geological facts may be true, and Y°
the conclusion that certain chains were or were 3%
simultaneously upraised is by no means a legitimat?
consequence.

As the hypothesis of parallelism, however, ha
quired some popularity, I may remark, that it appeal”
as stated by the author, to be in some degree at variant?
with itself. When certain European chains were 4
sumed to have been raised at the same time, oP t
data already impugned, it was found that several
these contemporaneous chains had a parallel directio”
Hence it was immediately inferred to be a general A
in geological dynamics that the chains upheavé

s ac

Ch, xxv OF MOUNTAIN-CHAINS. 331

the same time are parallel. For example, it was said
that the Pyrenees and northern Apennines have a
direction about W. N. W. and E. S. E.; to this line the
Alleghanies, in North America, conform, as also the

hauts of Malabar, and certain chains in Egypt, Syria,
XOrthern Africa, and other countries; and from this
Mere conformity in direction it was presumed that all

€se mountain-ranges were thrown up simultane-
ously, |

To select another example, the principal chain of
the Alps, differing in age and direction from the Py-
tenees, is parallel to the Sierra Morena, the Balkan,
the chain of Mount Atlas, the central chain of the

aucasus, and the Himalaya. All these ridges, there-
ore, are assumed to have been heaved up by the same
Paroxysmal convulsion. The Western Alps, on the
‘ther hand, rose at a still earlier period, when the
Parallel chains of Kiol, in Scandinavia, certain chains
m Morocco, and the littoral Cordillera of Brazil, were
Med !

Not only do these speculations refer to mountains
ever yet touched, as M. Boué remarks, by the ham-
Rep of the geologist, but they proceed on the suppo-
‘tion, that in these distant chains the geological and
8€ographical axis always coincide. Now we know

àt in Europe the sérike+ of the beds is not always

“In regard to the Alleghanies, see De Beaumont, 1833. French
e of De la Beche’s Manual, p. 657. But in fact this thain

S from N. E. to S. W.

The term “ strike” has been recently adopted by some of

jo Most eminent geologists from the German “ streich,” to

Shify what our miners call the “ line of bearing” of the strata.

à “à a term was much wanted ; and, as we often speak of striking

i Ma given direction, the expression seems sufficiently consistent
analogy in our language.

332 RELATIVE ANTIQUITY [Book IV

parallel to the direction of the chain. As an exception:
we may instance the Hartz mountains, where Von De-
chen * states that the direction or strike of the strat?
of slate and greywacké is sometimes from E; and W.,
and frequently N. E. and S. W.; the geographical di-
rection of the mountain-chain being decidedly from
E. S. E. to W. N. W.

In addition to these considerations, the important
admission is made by M. de Beaumont himself, that
the elevating forces, whose activity must be referré
to different epochs, have sometimes acted in Europ?
in parallel lines. “It is worthy of remark,” he say”
“that the directions of three systems of mountaia®
—namely, first that of the Pilas and the Côte gori
secondly, that of the Pyrenees; and thirdly, that s
the islands of Corsica and Sardinia,— are respectiv?
parallel to three other systems, namely, first, that °
Westmoreland and the Hunsdruck; secondly, that °
the Ballons (or Vosges) and the hills of the Bocag®
in Calvados ; and thirdly, the system of the north °
England. The corresponding directions only diffe! a
a few degrees, and the two series have succe? ý
each other in the same order, leading to the supp?”
tion, that there has been a kind of periodical ree
rence of the same, or nearly the same, directions
elevations.” +

Here then, we have three systems of mountain
A, B, C, which were formed at successive epochs; m
have each a different direction; and we have th
other systems, D, E, F, which, although they ar p
sumed to have the same strike as the series first ™
tioned (D corresponding with A, E with B, a"

* Trans. of De la Beche’s Geol. Manual, p. 41. 56:

+ Phil. Mag. and Annals, No. 58., New Series, pp- 255s?

Ch. XXV] OF MOUNTAIN-CHAINS; 333

With C), are nevertheless declared to have been formed
at different periods. On what principle, then, is the
äge of an Indian or transatlantic chain referred to one
of these European lines rather than to another ?—
Why is the age of the Alleghanies, or the Ghauts of

alabar, determined by their parallelism to B rather
than to E, to the Pyrenees rather than to the Ballons
of the Vosges ? *

Modern volcanic lines not parallel.—The analogy of
Yolcanic operations in our own times would lead us to
Suppose that the lines of convulsion, at former epochs,
Were far from being uniform in direction; for that the
trains of active volcanos are not parallel, every one is
aware who has studied Von Buch’s masterly survey of
the general range of volcanic lines over the globet;
While the elevations and subsidences caused by mo-
dern earthquakes, although they may sometimes run
t parallel lines within limited districts, have not been
observed to have a common direction in distant and
‘dependent theatres of volcanic action.

I doubt not that in many regions, yet only within a
imited range of country, the ridges, troughs, and fis-
Sures caused by modern earthquakes, are, to a certain
extent, parallel to each other; and such appears to

ave been the case in many districts at former eras.

_ * The substance of the last objection has been anticipated by

M. Boué (Journ. of Geol., tom. iii. p. 338.) Ishall not re--

Peat here minor points and facts, enumerated, in a former edition,

às disputed by several geologists, because they are of no import-

ance if the basis of the theory is unfounded. See Mr. Cony-
®are’s remarks, Phil. Mag. and Journ. of Sci., No. 2., Third

i ries, p, 118. Studer, Bulletin de la Soc. Géol. de France, ii.
' 68.

t Physical. Besch. der Canarischen Inseln, Berlin, 1825.

334 RELATIVE ANTIQUITY [Book IV.

The anticlinal lines of the Weald valley, before alluded
to, and of the Isle of Wight, may, in this manner, have
been contemporaneous; that is to say, both may have
been formed in some part of the Eocene period, — 2” :
hypothesis which does not involve the theory of thel!
having been due to a paroxysmal convulsion at the
same moment of that vast period. It should be ob:
served, that, as some trains of burning volcanos 4
parallel to each other, so at all periods some inde
pendent lines of elevation may be parallel accidentally i
not in obedience to any known law of parallelism, bu
on the contrary, as exceptions to the general rule-

The speculations of M. de Beaumont will, I trust
be useful, in inducing geologists to inquire how far the
uniformity in the direction of the beds, in a regio”
which has been agitated at any particular period, ™
extend; but, in the present state of our scienc’
cherish no sanguine expectations of fixing a chron? j
gical succession of epochs of elevation of differ?”
mountain-chains, or of making more than a loose ap
proximation to such a result. The difficulty depe” j
chiefly on the broken and interrupted nature of E
series of sedimentary formations hitherto brought
light, which appears so imperfect that we can vel.
seldom be sure that, between the groups now class?
as consecutive, the memorials of some great interv?
time may not be wanting. Another great sourc®
ambiguity arises from the small progress which ©
have yet made in identifying strata in countries some
what distant from each other.

There may be instances, perhaps, where the
set of strata, preserving throughout a perfect identit
of mineral character, may be traced continuously f°
the flanks of one independent mountain-chain tO

gam?

Ch, XXV.] OF MOUNTAIN-CHAINS 335

base of another, the beds being vertical or inclined in
ne chain, and horizontal in the other. We might
then decide with confidence, according to the method
Proposed by M. de Beaumont, on the relative periods
at which these chains had undergone disturbance: and
ftom one point thus securely established, we might
Proceed to another, until we had determined the eras
of many neighbouring lines of convulsion.

CHAPTER XXVI.

ON THE ROCKS COMMONLY CALLED “ PRIMARY.”

Relation of rocks called “ Primary” to volcanic and sedimenta
formations — Unstratified rocks called ‘* Plutonic” — Granit?
veins — Their various forms and mineral composition — P" oo"
of their igneous origin — Granites of the same character ri
duced at successive eras (p. 343.) — Some of these newe" than
certain fossiliferous strata— Volcanic, trappean, and plutoni?

rocks.

I sHALL now treat of the class of rocks usually termed
“primary,” a name which, as I shall afterwards show
is not always applicable, since the formations so desig”
nated sometimes belong to different epochs, and ar?
not, in every case, more ancient than the fossilifer™
strata. In general, however, this division of rocks mô,
justly be regarded as of higher antiquity than i
secondary and transition groups above described ; n
they may, therefore, with propriety be spoken 0 ;
these concluding chapters, as I have hitherto proce? >
in my retrospective survey from the newer to the mo"
ancient geological monuments.

In order to explain the relation which I con
the rocks termed “ primary” to bear to the tertiary?
secondary, and transition formations, I shall res”,
that general view of the component parts of the earth
crust of which I gave a slight sketch in the pret
minary division of the subject in the second chapte"

ceive

* See Vol. III. pp. 313, 314.

Ch XXVI] PLUTONIC ROCKS. SAT

It was there stated that sedimentary formations,
containing organic remains, occupy a large part of the
Surface of our continents ; but that here and there vol-
anic rocks occur, covering, alternating with, or break-
ing through, the sedimentary deposits; so that there
àre two orders of mineral masses formed at the surface
which have obviously a distinct origin, — the aqueous
and the volcanic.

a. Formations called primary (stratified and unstratified).
b. Aqueous formations. c. Volcanic rocks.

Besides these, however, there is another class, which
“annot be assimilated precisely to either of the pre-
eding, and which is often seen underlying the sedi-
mentary, or breaking up to the surface in the central
Parts of mountain-chains, -constituting some of the
highest lands, and, at the same time, passing down and
Orming the. inferior parts of the crust of the earth.

his class, usually termed “ primary,” is divisible into
two groups, —the stratified and the unstratified. The
Stratified consists of the rocks called gneiss, mica-schist,
{gillaceous-schist (or clay-slate), hornblende-schist,
Primary limestone, and some others. The unstratified,
EP lutonic, is composed in great measure of granite,
d rocks closely allied to granite. Both these groups
"Sree in having, for the most part, a highly crystalline
*xture, and in not containing organic remains.

lutonic rocks. — The unstratified crystalline rocks
Ve been very commonly called Plutonic, from the
YOU. Iv, Q

338 GRANITE VEINS. [Book IV-

opinion that they were formed by igneous action at
great depths ; whereas the volcanic, although they also
have risen up from below, have cooled from a melted
state upon or near to the surface. Granite, porphyry
and other rocks of the same family, often occur 1}
large amorphous masses, from which small veins 2
dikes are sent off, which traverse the stratified rocks
called “primary,” precisely in the manner in which
lava is seen in some places to penetrate the secondary
Strata.

Granite veins. — We find also one set of granite
veins intersecting another, and granitiform porphyrie®
intruding themselves into granite, in a manner analo”
gous to that of the volcanic dikes of Etna and Vest
vius, where they cut and shift each other, or pass
through alternating beds of lava and tuff.

Fig. 219.

Granite veins traversing stratified rocks.

The annexed diagram will explain to the readet the
manner in which these granite veins often branch °
from the principal mass. Those on the right-bay
side, and in the middle, are taken from Dr. Mact#

Ch. XXVI] GRANITE VEINS, 339

loch’s representation of veins passing through the
Sneiss at Cape Wrath, in Scotland.* The veins on
the left of the same diagram are described, by Captain
Basil Hall, as traversing the argillaceous schist of the
Table-Mountain at the Cape of Good Hope. +

I subjoin another sketch from Dr. MacCulloch’s in-
teresting representations of the granite veins in Scot-
land, and in which the contrast of colour between the

Fig. 220.

Granite veins traversing gneiss at Cape Wrath, in Scotland.

Vein and some of the dark varieties of hornblende-
Schist associated with the gneiss renders the phenomena
More conspicuous.
The following sketch of a group of granite veins in
Cornwall is given by Messieurs Von Oeynhausen and
on Dechen.{ ‘The main body of the granite here is
of a porphyritic appearance, with large crystals of fel-
Spar ; but in the veins it is fine-grained, and without
these large crystals. The general height of the veins

a from sixteen to twenty feet, but some are much
higher,

* Western Islands, plate 31.

Account of the Structure of Table-Mountain, &c. Trans.
0J. Soc. Edin., vol. vii.

ł Phil, Mag. and Annals, No. 27., New Series, March, 1829.
Q2

GRANITE VEINS,

Granite veins passing through hornblende slate, Carnstlver Cove, Cornwall

The vein-granite of Cornwall very generally assume®

a finer grain, and frequently undergoes a change in
| mineral composition, as is very commonly observed i”
other countries. Thus, according to Professor Sedg’ »
i wick, the main body of the Cornish granite is-an a8
gregate of mica, quartz, arid felspar ; but the veins at?
‘sometimes without mica, being a granular aggregal®
‘of quartz and felspar. In other varieties quartz pre
| vails to the almost entire exclusion both of felspar a?

| mica; in others, the mica and quartz both disappe@”
and the vein is simply composed of white granular
felspar. *

Changes are sometimes caused in the intersected
strata very analogous to those which the centact of 4
fused mass might be supposed to produce.

The annexed diagram, from a sketch of Dr. Mac-

-Culloch, represents the junction of the granite of Gler
Tilt, in Perthshire, with a mass of stratified limesto°

* On Geol. of Cornwall, Trans. of Cambridge Soc., vol, ™
p. 124, Z

Ch. XXVI.] JUNCTION OF GRANITE AND LIMESTONE. 34]

and schist. The granite, in this locality, often sends
forth so many veins as to reticulate the limestone and
Schist, the veins diminishing towards their termination
to the thickness of a leaf of paper or a thread. In
Some places fragments of granite appear entangled, as it
Were, in the limestone, and are not visibly connected
With any larger mass ; while sometimes, on the other
hand, a lump of the limestone is found in the midst of
the granite. The ordinary colour of the limestone of

Fig. 222.

Junction of granite and limestone in Glen Tilt:
a, Granite. b. Limestone.

c. Blue argillaceous schist.

Glen Tilt is lead blue, and its texture large-grained
@nd highly crystalline ; but where it approximates to
Q 3

342 © GRANITE VEINS. [Book IV-

the granite, particularly where it is penetrated by the
smaller veins, the crystalline texture disappears, and it
assumes an appearance exactly resembling that °
hornstone. The associated argillaceous schist ofte®
passes into hornblende slate, where it approaches very
near to the granite.*

The conversion of the limestone in these and many
other instances into a siliceous rock, effervescing
slowly with acids, would be difficult of explanation, wer?
it not ascertained that such limestones are always im
pure, containing grains of quartz, mica, or felspat
disseminated through them. The elements of thes?
minerals, when the rock has been subjected to great
heat, may have been fused, and so spread more un!
formly through the whole mass. ;

In the plutonic, as in the volcanic rocks, there
every gradation from a tortuous vein to the most re-
gular form of a dike, such as I have described inte!
secting the tuffs and lavas of Vesuvius and Etna. J
these dikes of granite, which may be seen, among
other places, on the southern flank of Mount Battoc!»
one of the Grampians, the opposite walls sometimes
preserve an exact parallelism for a considerable ®5
tance. It is not uncommon for one set of granite veins
to intersect another; and sometimes there are thre?
sets, as in the environs of Heidelberg, where the
granite on the banks of the river Necker is seen t°
consist of three varieties, differing in colour, grain, 2”
various peculiarities of mineral composition. One g
these, which is evidently the second in age, is seen t°
cut through an older granite ; and another, still newe”
traverses both the second and the first. These phe?”

* MacCulloch, Geol. Trans., vol. iii. p. 259.

Ch. XXV] GRANITES OF DIFFERENT AGES. 343

mena were pointed out to me by Professor Leonhard
at Heidelberg.

In Shetland there are two kinds of granite. One
of these, composed of hornblende, mica, felspar, and
quartz, is of a dark colour, and is seen underlying
gneiss. The other is a red granite, which penetrates
the dark variety every where in veins. *

Granites of different ages. — It was formerly supposed
that granite was the oldest of rocks, the mineral pro-
duct of a particular period or state of the earth, formed
long antecedently to the introduction of organic beings
into our planet. But it is now ascertained that this
rock has been produced again and again, at successive
eras, with the same characters, penetrating the stra-
tified rocks in different regions, but not always asso-
ciated with strata of the same age. Nor are organic
remains always entirely wanting in the formations in-
vaded by granite, although they are usually absent.
Many well-authenticated exceptions to the rule are
now established, on the authority of numerous ob-
Servers, amongst the earliest of whom we may cite
Von Buch, who discovered in Norway a mass of granite
overlying an ancient secondary limestone, containing
orthocerata and other shells and zoophytes. +

A considerable mass of -granite in the Isle of Sky is
described by Dr. MacCulloch as incumbent on lime-
Stone and shale, which are of the age of the English
lias.t The limestone, which, at a greater distance
from the granite, contains shells, exhibits no- traces of

* MacCulloch, Syst. of Geol., vol. i. p. 58.

+ Travels through Norway and Lapland, p. 45. London,
1813,

+ See Murchison, Geol. Trans., Second Series, vol. ii. part ii.
Pp. 311—321.

Q4

344 GRANITES OF DIFFERENT AGES. [Book IV.

them near its junction, where it has been converted
into a pure crystalline marble.*

This granite of Sky was at first termed “ Syenite,”
by which name some authors have denominated the
more modern granites; but they have entirely failed
in their attempt to establish a distinction betwee?
granites and syenites on geological grounds. Syenite
has been defined to be a triple compound of felspat,
‘quartz, and hornblende; but the oldest granitifor™m
rocks are very commonly composed of these ingre-
dients only. In his later publications Dr. MacCul-
loch has, with great propriety, I think, called the
plutonic rock of Sky a granite. +

In different parts of the Alps a comparatively moder?
granite is seen penetrating through secondary strata
which contain belemnites, and other fossils, and aré
supposed to be referable to the age of the English
lias. According to the observations of MM. Elie de
Beaumont and Hugi, masses of this granite are some-
times found partially overlying the secondary beds;
and altering them in a manner analagous to the
changes superinduced upon sedimentary deposits 1?
contact with rocks of igneous origin. { (See Fig. 225:
p. 369.)

In such examples we can merely affirm, that the
granite is newer than a secondary formation containing
belemnites ; but we can form no conjecture when it
originated, not even whether it be of secondary or tef-
tiary date. It is not to be inferred that a granite i$

* Western Islands, vol. i. p. 330.

+ Syst. of Geol., vol. i. p. 150.

¢ Elie de Beaumont, sur les Montagnes de l’ Oisans, Mém. de
la Soc. d’Hist. Nat. de Paris, tome v. Hugi, Natur. Historische
Alpenreise, Soleure, 1830.

Ch. XXVI] TRAP ROCKS. 345

usually of about the same age as the group of strata
Into which it has intruded itself; for in that case we
should be inclined to assume, rashly, that the granite
found penetrating a more modern rock, such as the
lias, for example, was much newer than that which
is found to invade greywacké. The contrary may
often be true; for the plutonic rock which was last in
a melted state may not anywhere have been forced
up so near to the surface as to traverse the newer
Sroups, but may be confined exclusively to the older
Sedimentary formations.

“In a deep series of strata,” says Dr. MacCulloch,
“the superior or distant portions may have been but
slightly disturbed, or have entirely escaped disturb-
ance, by a granite which has not emitted its veins far

€yond its immediate boundary. However certain,
therefore, it may be, that any mass of granite is pos-
terior to the gneiss, the micaceous schist, or the argil-
laceous schists, which it traverses, or into which it
intrudes, we are unable to prove that it is not also pos- `
terior to the secondary strata that lie above them.” *

There can be little doubt, however, that some gra-
Nites are more ancient than any of our regular series
Which we identify by organic remains; because there
are rounded pebbles of granite, as well ds gneiss, in
the Conglomerates of very ancient fossiliferous groups.

Distinction between volcanic and plutonic rocks —
Trap.— When geologists first began to examine at-
tentively the structure of the northern parts of Europe,
they were almost entirely ignorant of the phenomena
‘ad €xisting volcanos; and when they met with basalt

* Syst. of Geol., vol. i. p. 136.
Qs

346 TRAP ROCKS. [Book IV

and other rocks composed chiefly of augite, hornblende,
and felspar, which are now admitted by all to havé
been once in a state of fusion, they were divided i
opinion whether they were of igneous or of aqueous
origin. In the sketch of the history of geology in the
first volume, it was shown how much the polemical
controversies on this subject retarded the advance-
ment of the science, and how slowly the analogy °
the rocks in question to the products of active volcanos
was recognized.

Most of the igneous rocks first investigated in Ger-
many, France, and Scotland were associated with ma
rine strata, and in some places they occurred in tabulat
masses or platforms at different heights, so as to form
on the sides of some hills a succession of terraces of
steps; from which circumstance they were calle
“trap” by Bergman (from trappa, Swedish for a Aight
of steps), —a name afterwards adopted very generally
into the nomenclature of the science.

When these trappean rocks were compared with
lavas produced in the atmosphere, they were found
be in general less porous and more compact : and fro
this character, and their association with subaqueo™
deposits, the connection of their origin with ordinat}
volcanic action was overlooked. In this instance the
terms of comparison were imperfect; for a set of rock®
formed almost entirely under water, was contrast?
with anothèr which had cooled in the open air.

Yet the products of the ancient volcanos of Cen
France were classed, in reference, probably, to th
antiquity, with the trap rocks, although they afo"
perfect counterparts to existing volcanos, and we
evidently formed in the open air. Mont Dor and the
Plomb du Cantal, indeed, differ in many respects from

tral
ei!

+

Ch. XXVI] TRAP ROCKS. 347

Vesuvius and Etna in the mineral constitution and
structure of their lavas ; but it is that kind of differ-
ence which we must expect to discover when we com-
pare the products of any two active volcanos in distant
regions, such as Teneriffe and Hecla, or Hecla and
Cotopaxi.

The amygdaloidal structure in many of the trap
formations proves that they were originally cellular
and porous, like lava; but the cells have been subse-
quently filled up with silex, carbonate of lime, zeolite,
and other ingredients which form the nodules. The
absence of this amygdaloidal structure may be said to
be one of the negative characters of granite and other
Plutonic rocks.

Dr. MacCulloch, after examining with great atten-
tion the igneous rocks of Scotland, observes, “that it
is a mere dispute about terms to refuse to the ancient
eruptions of trap the name of submarine volcanos, for
they are such in every essential point, although they
No longer eject fire and smoke.”* The same author
also considers it not improbable that some of the vol-
tanic rocks of the same country may have been poured
Out in the open air. +

The recent examination of the igneous rocks of
Sicily, especially those of the Val di Noto, has proved
that all the more ordinary varieties of European trap
have been produced under the waters of the sea in the

ewer Pliocene period ; that is to say, since the Me-
diterranean has been inhabited by a great proportion
of the existing species of testacea. We are, therefore,
entitled to expect, that if we could obtain access to
the existing bed of the ocean, and explore the igneous

* Syst. of Geol., vol. ii. p. 114. + Ibid.
Qa 6

348 RELATIONS OF GRANITE AND TRAP. [Book IV.

rocks poured out within the last five thousand years
beneath the pressure of a sea of considerable depth,
we should behold formations of modern date very
similar to the most ancient trap rocks of our island.
We cannot, however, expect the identity to be perfects
for time is ever working some alteration in the com-
position of these mineral masses, as, for example, PY
converting porous lava into amygdaloids.

Passage from trap into granite.—If a division be
attempted between the trappean and volcanic rocks, it
must be made between different parts of the same
volcano, — nay, even the same rock, which would be
called “ trap,” where it fills a fissure and has assumed
a solid crystalline form on slow cooling, must be
-termed volcanic, or lava, where it issues on the flank
of the mountain. Some geologists may, perhaps, P?
of opinion that melted matter, which has been pouré
out in the open air, may be conveniently called vol-
canic; while that which appears to have cooled at thé
bottom of the sea, or under pressure, but at no gre@!
depth from the surface, may be termed “ trap:” put it
is very doubtful whether such distinctions can be made
without confusion, and whether we shall not be oblige
to consider trap and volcanic as synonymous. On the
other hand, the difficulty of discriminating the volcani?
from the plutonic rocks is sufficiently great ; there
being an insensible passage from the most commo”
forms of granite into trap or lava.

« The ordinary granite of Aberdeenshire,” s4Y*
Dr. MacCulloch, “ is the usual ternary compound °
quartz, felspar, and mica; but sometimes hornblend?
is substituted for the mica. But in many places j
variety occurs which is composed simply of felspar an
hornblende; and in examining more minutely this

Ch. XXVI] RELATIONS OF GRANITE AND TRAP. 349

duplicate compound, it is observed in some places to
assume a fine grain, and at length to become undistin-
Suishable from the greenstones of the trap family. It
also passes in the same uninterrupted manner into a
basalt, and at length into a soft claystone, with a
Schistose tendency on exposure, in no respect dif-
fering from those of the trap islands of the western
Coast.”* The same author mentions, that in Shetland
a granite composed of hornblende, mica, felspar, and
quartz graduates in an equally perfect manner into
basalt. +

It would be easy to multiply examples to prove that
the granitic and trap rocks pass into each other, and
are merely different forms which the same elements
have assumed, according to the different circumstances
under which they have consolidated from a state of
fusion. What has been said respecting the mode of
€xplaining the different texture of the central and ex-
ternal parts of the Vesuvian dikes may enable the
reader in some measure to comprehend how such dif-
ferences may originate. + {i

The lavas, which are porous where they have flowed
Over the crater, and cooled rapidly under compara-
tively slight pressure, appear compact and porphyritic
in the dike. Now these dikes evidently communicate
With the crater and the volcanic foci below; so that
We may suppose them to be continuous to a vast
depth; and the fluid matter below, which cools and
Consolidates slowly under so enormous a pressure,
May be conceived to acquire a very distinct and more
Crystalline texture, like granite.

If it be objected that we do not find in mountain-

* Syst. of Geol., vol. i. p. 157. t Ibid, p. 158,
ł See p. 8,

350 ORIGIN OF GRANITE. [Book IV.

chains volcanic dikes passing upwards into lava, and
downwards into granite, we may answer, that our ver-
tical sections are usually of small extent; and if we
find in certain places a transition from trap to porous
lava, and in others a passage from granite to trap, it Í$
as much as could be expected of this evidence. H
should also be remembered, that a large proportion of
the igneous rocks, when first formed, cannot be sup”
posed to reach the surface, and these may assume the
usual granitic texture without graduating into trap, 9
into such lava and scorie as are found on the flanks 0

a volcanic cone.

Theory of the origin of granite at all periods. — It '8
not uncommon for lava streams to require more tha?
ten years to cool in the open air; and where they al
of great depth, a much longer period. The melted
matter poured from Jorullo, in Mexico, in the yea!

1759, which accumulated in some places to the heigh!
of 550 feet, was found to retain a high temperatur?
half a century after the eruption.* For what immens¢
periods, then, may we not conceive that great masse’
of subterranean lava in the volcanic foci may remain
in a red-hot or incandescent state, and how gradual
must be the process of refrigeration! This proces’
may be sometimes retarded for an indefinite period,
by the accession of fresh supplies of heat; for we fin

that the lava in the crater'of Stromboli, one of thé
Lipari islands, has been in a state of constant ebullitio?
for the last two thousand years; and we must suppoS®
this fluid mass to communicate with some cauldron 0"
reservoir of fused matter below. In the Isle of Bourbo™
also, where there has been an emission of lava once ™

* See Vol. II. p. 134.

Ch. XXVI] ORIGIN OF GRANITE. 351

every two years for a long period, we may infer that
the lava below is permanently in a state of lique-
faction.

The great pressure of a superincumbent mass, and
exclusion from contact with the atmosphere, and per-
haps with the ocean, are some of the conditions which
May be necessary to produce the granitic texture ; but
what I have before said of the causes of volcanic heat
Operating at considerable depths, will show how com-
plicated may be the processes going on in the interior
of the earth, and how different from any within the
Sphere of our observation at the surface.*

If plutonic rocks, such as granite or porphyry, have
Originated far below as often as the volcanic have been
generated at the surface, it will follow that no small
quantity of the former class has been forming in the
recent epoch; since we suppose that about two thou-
sand volcanic eruptions may occur in the course of
€very century, either above the waters of the sea or
beneath them. +

We may also infer, that during each preceding

Period, whether tertiary or secondary, there have been
granites and granitiform rocks generated; because we
have already discovered the monuments of ancient
Volcanic eruptions of almost every period.

In the next chapter I shall endeavour to show, that,
in consequence of the great depths at which the plu-
tonic rocks usually originate, and of the manner in
Which they are associated with the older sedimentary
Strata of each district, it is rarely possible to determine
With exactness their relative age. It may be true that
the greater portion of them now visible are of higher

* Book ii, chapters 18. and 19. + See Vol. II. p. 178.

352 AGE OF PLUTONIC ROCKS. [Book 1.

antiquity than the oldest secondary strata; and yet
they may have been produced in nearly equal quanti-
ties during equal periods of time, from the earliest t0
the most modern epochs, instead of diminishing in
quantity at each successive epoch, as some geologists
pretend. :

CHAPTER XXVII.
ON THE STRATIFIED ROCKS CALLED “ PRIMARY.”

Whether any “primary” rocks are truly stratified — Difference
between stratification and cleavage — Professor Sedgwick on the
Slaty and the Jointed Structure — Alteration of sedimentary
Strata by dikes (p. 364.) — Manner in which heat may be con-
veyed through rocks — Conversion of sedimentary into crystal-
line strata—The term “ Hypogene”’ proposed as a substitute for
s Primary (p070) Metamorphic” for “ stratified primary”
rocks — No regular order of succession of hypogene rocks —
Cause of the high relative antiquity of visible hypogene forma-
tions (p. 383.) — They may have been produced at each succes-
Sive period in equal quantities — Volume of hypogene rocks
Supposed to have been formed since the Eocene period — Con-
cluding remarks,

Whether any primary rocks are stratified. —Ir has been
‘tated that the rocks usually called “ Primary,” are
Visible into the stratified and the unstratified; but
‘ome geologists have entertained doubts as to the pro-
Priety of applying the term stratified to any rocks of
© crystalline or “ primary” class. They admit that
€ latter are often made up of thbular masses, or beds
Maced one upon the other, something in the manner
true strata; but they deny that the analogy is so
Perfect as to indicate a similarity of origin: in other
oe they do not believe the distinct beds into which
Ystalline rocks, such as gneiss, mica-schist, and horn-
“nde-schist, are divided, to have been the result of
“dimentary deposition from water.

354 CLEAVAGE OR SLATY STRUCTURE. [Book 1V:

Now it must be conceded that even in rocks which
are unequivocally of sedimentary origin, and which
contain organic remains, there are many lines of part
ing, that might easily be mistaken for strata, yet whic?
have no connection with stratification. Of these part
ings some‘have been distinguished by miners undef
the name of “joints,” others by that of the “ planes °
cleavage.”

Cleavage or slaty structure. —In an admirable essa}
recently published on this subject, Professor Sedgw!
has described the ordinary forms, and speculated o
the probable origin, of these different kinds of strut
ture.* His descriptions are derived from an extensiv
series of original observations, made on the slate r0? :
of Cumberland and Wales, and will be read by all wh?
are desirous of obtaining a clear and thorough know”
ledge of this important class of phenomena.

Some of these Cumbrian and Welsh rocks are de
cidedly of mechanical origin ; and some strata cont®™
marine organic remains, so that they must have pee”
deposited from water. But, besides being stratifie®
they are intersected by cleavage planes, which ar
usually inclined at a very considerable angle to t :
planes of the strata, and appear to be in no instan?
exactly coincident with them. In some cases i $
difference is so smali that these planes might easily ;
supposed parallel; but their inclination to each ot 4
in the Welsh chains, is upon an average as much #
30° to 40°, Sometimes the cleavage planes dip tows
the same point of the compass as those of stratificati?
but more frequently they dip to opposite points. »

«In that variety of slate which is used for ro0fN8?

* Geol. Trans., vol. iii. Second Series, p. 461

Ch. XXVII] CLEAVAGE OR SLATY STRUCTURE. 355

Says Professor Sedgwick, “the structure of the rock
has been so modified that the traces of its original de-
Position are quite obliterated; and this remark does
hot apply merely to single quarries, but sometimes to
Whole mountains. We can, however, in many slate
quarries, and even in hand specimens of slate, discover
à number of parallel stripes, sometimes of a lighter, and
Sometimes of a darker colour than the general mass;
and in rocks of the age I am considering, these stripes
are universally parallel to the true bedding of the rocks. _
The proof of this is established by the fact that the
assumption leads to consistent results; that these
Stripes are always parallel to true beds whenever such
beds can be discovered, whether by organic remains, by
the alternations of dissimilar deposits, or by any other
ordinary means. Sometimes, however, all these means
fail, and we may ramble for miles among mountains of
Slate without seeing a single trace of their original
Stratification.

“I think it obvious,” continues the same author,
“that the contortions of slate rocks are phenomena
Quite distinct from cleavage, and that the curves pre-
‘ented by such formations are the true lines of dis-
turbed strata.” *

In the accompanying section, given by the Professor

Parallel planes of cleavage intersecting curved strata.

to illustrate these appearances in the Welsh slate rocks,
We see the cleavage planes preserving an almost geo-

* . ose . r
: Sedgwick, Geol, Trans., vol. iii, Second Series, p. 474.

356 CLEAVAGE OR SLATY STRUCTURE. [Book JV:

metrical parallelism, while they pass through contorted
strata of “hard greenish slate, obviously of sediment
ary origin.” A region more than thirty miles in length,
and eight to ten in breadth, exhibits this structure of
a magnificent scale. Many of the contorted strata
“ are of a coarse mechanical structure ; but subordinat?
to them are fine, crystalline, chloritic slates. But the
coarser beds and the finer, the twisted and the straight
have all been subjected to one change. i

« The slaty cleavage, however, is only brought out g
perfection where the materials of the rock are fine an
homogeneous. Yet although the coarser beds are not
slaty, they are said to have usually a grain parallel te
the cleavage planes of the finer beds, and it is onl
when the materials are very coarse that the cleavag®
planes entirely vanish.” *

It is admitted by Professor Sedgwick, that some peds
of greywacké are subdivided into very thin Jamin?
which resemble slate, and are used for the same po”
poses, yet have been produced by aqueous depositio?”
Nay, in certain cases, “ these laminæ cannot be disti”
guished by their mineral structure from the slates :
cleavage.” It is proposed, however, to call such slate?
of deposition “ flagstones,” by reference to their $ê j
mentary origin. A flagstone, it is said, may general)
be distinguished from a true slate of cleavage by slig
deviations in its plane ; occasionally by what is calle
the ripple mark ; by a dull granular surface ; by scat
tered flakes of mica, entirely unlike the continuo”
chloritic flakes of a true cleavage ; and sometimes
organic remains studded on its surface.

Some confusion will, I fear, arise from attempti?
restrict the term slate to those cases alone where t

0
gt

* Proceedings of Geol. Soc. No. 44. p. 360.

Ch. XXVIL] CLEAVAGE OR SLATY STRUCTURE. 357

slaty laminæ are oblique to the stratification; espe-
Cally as we have seen that diagonal lamination may be
Produced by sedimentary deposition, and that too in
Some instances with considerable regularity. But,
Whatever nomenclature we adopt, it is clear that three
distinct forms of structure are exhibited in certain
tocks throughout large districts: viz.— first, stratifi-
“ation ; secondly, joints ; and thirdly, slaty cleavage ;
the two last having no connection with true bedding,
and having been superinduced by causes absolutely in-
dependent of gravitation. All these different structures
Must have different names, even though there be some
Cases where it is impossible, after carefully studying the
Phenomena, to decide upon the class to which they
elong,

Before treating of joints, it may be well to speak of
the probable origin of slaty cleavage in those cases
Where it is decidedly unconnected with sedimentary
deposition. Professor Sedgwick is of opinion that “no
'etreat of parts, no contraction in dimensions, in pass-
Ne to a solid state, can account for the phenomenon.”
‘t must be referred to crystalline or polar forces acting
simultaneously and somewhat uniformly, in given di-
"ections, on large masses having a homogeneous com-
Position,

“There is at first sight a difficulty in comprehending

€ vastness of those forces which nature must have
*Pplied in producing such effects. But, in crystalliza+
‘on, there is something like a definite polarity in each
Particle, by which it is compelled to turn in a given

ection, and group itself with other particles in defi-
Ute forms ; and if this modification of internal structure
© Carried on through a very large mass of matter, is it
ot Probable that there is an accumulated intensity of

358 JOINTED STRUCTURE IN ROCKS. [Book 1V

crystalline action in each part, so that the whole inte?
sity of crystalline force modifying the mass js not
equal to the sum of the forces necessary to crystallize
each part independently, but is some function of that
sum, whereby it may be increased almost indefinitely’
I see nothing improbable in this kind of accumulat?

attraction.”* .

Sir John Herschel, in allusion to this subject, has
suggested to me, “that if rocks have been so heate
as to allow a commencement of crystallization ; that 5
to say, if they have been heated to a point at which
the particles can begin to move amongst themselves a
at least on their own axes, some general law must the?
determine the position in which these particles wil
rest on cooling. Probably, that position will have some
relation to the direction in which the heat escape
Now, when all, or a majority of particles of the sam?

nature have a general tendency to one position, tha
must of course determine a cleavage plane. The
we see the infinitessimal crystals of fresh precipitat?
sulphate of baryte, and some other such bodies, arrang
themselves alike in the fluid in which they float ; s0 as
when stirred, all to glance with one light and give **
appearance of silky filaments. Some sorts of soap ‘

which insoluble margarates exist, exhibit the sam?

phenomenon when mixed with water; and what occu!
in our experiments on a minute scale, may occur }
nature on a great one, &c.” t

Jointed structure.—“ Besides the planes of clea”
age,” observes Professor Sedgwick, “ we often find ©
large slate quarries one or more sets of cross joint®
418

* Sedgwick, Geol. Trans., vol. iii. Second Series, pp- 477; ;
g g

+ Letter to the author, dated Cape of Good Hope, Feb.
1836.

Ch. XXVILJ JOINTED STRUCTURE IN ROCKS. 359

Which, combined with cleavage, divide the rock into
thombohedral solids. These solids are not capable of
definite subdivision into similar solids, except in one
tection, namely, that of true cleavage ; and in this
Way, even in hand specimens, we may generally dis-
tinguish the true cleavage planes from the joints.
hese last are fissures placed at definite distances from
“ach other, the masses of rock between them having,
Seherally speaking, no tendency to cleave in a direc-
tion parallel to them. Such a structure seems in most
“ses to have been produced mechanically, either by a
‘train upon the rock from external force, producing
More or less regular sets of cracks and fissures, or by
à mechanical tension on the mass, produced probably
Y Contraction, during its passage from a fluid, or semi-
uid, into a solid state. Cleavage planes are, on the
“ntrary, the results of the ultimate chemical arrange-
Ment of the particles of a rock, and appear in most
“ases to be unconnected with any direct mechanical
tion,
“A slaty and jointed structure are, however, often
*xhibited together; and cases may arise where it is
Ost impossible to decide whether a certain set of
Sures are to be called joints, or cleavage planes: but
culties of this kind are the exception, and not
the Tule.” *
The jointed structure is common both to the strati-
êd and unstratified rocks ; but is best seen in the un-
stratified, as in granite, or columnar basalt. In the
Wiss and Savoy. Alps, Mr. Bakewell has well remarked
that €normous masses of limestone are cut through so
"egularly by nearly vertical partings, and these are

š Sedgwick, Geol. Trans., vol. iii. Second Series, pp. 480, 481.

of j
360 JOINTED STRUCTURE IN ROCKS. [Book 1Y

often so much more conspicuous than the seams of
stratification, that an unexperienced observer will a
most inevitably confound them, and suppose the strata
to be perpendicular when in fact they are almost
horizontal. *
The cause of this tendency to a jointed structure Ë
by no means understood ; but it appears, from recent
observations, that ice sometimes presents a similat
arrangement of parts. Scoresby, indeed, when speak
ing of the icebergs of Spitzbergen, had long ago stat?”
« that they are full of rents, extending perpendicularly
downwards, and dividing them’ into innumerable ©
lumns.” Colonel Jackson has lately investigated th
subject more attentively, and has found that the ic?
on the Neva, at St. Petersburg, at the bèginning g
a thaw, when two feet in thickness, is traversed by
rows of very minute air-bubbles extending in stralg
lines, sometimes a little inflected, from the upper sul
face of the ice towards the lower, within from two?
five inches of which they terminate. “ Other bloe 3
presented these bubbles united, so as to form cyl”
drical canals, a little thicker than a horse-hair. ~ ;
serving still further,” he says, “ I found blocks in wh”
the process was more advanced, and two, three s
more clefts, struck off in different directions from t
vertical veins, so that a section perpendicular tO j
vein would represent in miniature the star-forme
cracks of timber. ` Finally, in some pieces, thes
cracks united from top to bottom of the veins, sepa"
ating the whole mass into vertical prisms, having
greater or less number of sides. In this state a slig
shock was sufficient to detach them; and the ploc

* Introduction to Geology, chap. iv.

a be

fi
y

Ch. XXVILJ GRANITIC SCHISTS. 361

With. its scattered fragments was in all respects the
€xact miniature resemblance, in crystal, of a Giants
Causeway. The surface was like a tessellated pave-
Ment, and the columns rose close, adhering and pa-
tallel, from the compact mass of a few inches at the
Under surface. More or less time is required for the
Process, which I have since seen in all its different
Stages,” *

Stratification of granitic schists. —If we examine
Sneiss, which consists of the same materials as granite,
r mica-schist, which is a compound of quartz and mica,
or hornblende schist, which is formed of hornblende and
felspar, or any other member of the so-called primary

lvision, we find that they are each made up of a suc-
Cession of beds, the planes of which are, to a ‘certain
€xtent, parallel to each other in a manner analogous to
that exhibited by sedimentary formations of all ages.

hey may occasionally exhibit, in addition, both a
Jointed anda slaty structure; but they are also divided
into uneven foliated layers, or in some cases into thick
beds which resemble strata of deposition.

The: resemblance to stratification in the granitic
Schists often extends very far ; for the beds are oc-
“asionally contorted, or they are made up of lamine
Placed diagonally, as in many sedimentary formations

®fore described +, such laminæ not being regularly
Parallel like the planes of cleavage.

This disposition of the layers is illustrated in the
*Ccompanying diagram, in which I have represented
“arefully the stratification of a coarse argillaceous
Schist, which I examined in the Pyrenees, part of
Which approaches in character to a green and blue

* Journ. of Roy. Geogr. Soc., vol. v. p. 19. (|

t See above, p. 79.
VOL. Iv. R

GRANITIC SCHISTS.

Lamination of clay-slate, Montagne de Seguinat, near Gavarnie, in the
Pyrenees.

roofing slate, while part is extremely quartzose, the
whole mass passing downwards into micaceous schist
The vertical section here exhibited is about three feet
in height, and the layers are sometimes so thin that
fifty may be counted in the thickness of an inch.
Some of them consist of pure quartz.

Another ‘striking point of analogy between thé

stratification of the crystalline formations and that 0
the secondary and tertiary periods, is the alternation, #
,each, of beds varying greatly in composition, colow”
and thickness. We observe, for instance, gneiss al-
, ternating with layers of black hornblende-schist, %
with granular quartz or limestone ; and the interchan8?
of these different strata may be repeated for an inde
finite number of times. In like manner, mica-schist
alternates with chlorite-schist, and with granula!
limestone in thin layers.

As we observe in the secondary and tertiary for™
ations strata of pure siliceous sand alternating wit
micaceous sand and with layers of clay, so in thé
“primary” we have beds of pure quartz rock alte"
nating with mica-schist and clay-slate. As in the
` secondary and tertiary series we meet with limeston®
alternating again and again with micaceous or argilla-

Ch. XXVII] PASSAGE OF GNEISS INTO GRANITE. 363

Ceous sand, so we find in the “ primary” gneiss and
Mica-schist alternating with pure and impure granular
limestones.

Passage of gneiss into granite. — But if we attribute
the stratification of gneiss, mica-schist, and other as-
Sociated rocks, to sedimentary deposition from a fluid,
We encounter this difficulty, — that there is often a
transition from gneiss, a member of the stratified and
therefore sedimentary series, into granite, which, as I
have shown, is of igneous origin. Gneiss is composed
of the same ingredients as granite, and its texture is
equally crystalline. It sometimes occurs in thick beds,
and in these the rock is often quite undistinguishable,
in hand specimens, from granite; yet the lines of
Stratification are still evident. These lines, it is con-
Ceived, imply deposition from water ; while the passage
into granite would lead us to infer an igneous origin.
th what manner, then, can these apparently conflicting
Views be reconciled? The Huttonian hypothesis offers,
l think, the only satisfactory solution of this problem.
According to that theory, the materials of gneiss were
Originally deposited from water in the usual form of
àqueous strata; but these strata were subsequently
altered by subterranean heat, so as to assume a new
texture. The reader will be in some degree prepared,
by what has been stated in the preceding pages, to
“onclude, that when voluminous masses of melted and
incandescent rock, accompanied by intensely heated
Sases under great pressure, have been for ages in con-
tact with sedimentary deposits, they may produce great
alterations in their texture; and this alteration may
admit of every intermediate gradation between that
resulting from perfect fusion and the slightest modifi-
Cation which heat can produce.

R 2

364 ALTERATIONS IN STRATA PRODUCED [Book IV-

Some light has been thrown on the changes which
stratified masses may undergo subsequently to their
original deposition by direct experiment on the fusio?
of rocks in the laboratory; and still more by observ-
ations on strata in contact with igneous veins and dikes
In studying the latter class of phenomena, we have
the advantage of examining the condition of the sam®
continuous rock at some distance from the dike, wher?
it has escaped the influence of heat, and its state whet
it has been near to, or in contact with, the fused mas*
The changes thus exhibited may be regarded as the
results of a series of experiments, made by nature on f
greater scale than we can imitate, and under evely
variety of condition, in respect to the mineral ingredi-
ents acted upon, the intensity of heat or pressure, a?
the celerity or slowness of the cooling process.

Strata altered by volcanic dikes — Plass Newydd.
One of the most interesting examples of alteration ”
the proximity of a volcanic dike occurs near Plas
Newydd, in Anglesea, described by Professor Henslow-
The dike is 134 feet wide, and consists of a rock which
is a compound of felspar and augite (dolerite of som?
authors). Strata of shale and argillaceous limesto®®
through which it cuts perpendicularly, are altered to ĉ
distance of thirty, or even, in some places, to thirty”
five feet from the edge of the dike. The shale, a5 a
approaches the basalt, becomes gradually more co™™
pact, and is most indurated where nearest the junctio?
Here it loses part of its schistose structure, but the
separation into parallel layers is still discernible. In
several places the shale is converted into hard porcel-
lanous jasper. In the. most hardened -part of the
mass the fossil shells, principally Producte, are nea! y
obliterated; yet eyen here their impressions may fre-

See ite epee

Ch. XXVII] BY.VOLCANIC DIKES. 365

quently be traced. The argillaceous limestone under-
goes analogous mutations, losing its earthy texture as
it approaches the dike, and becoming granular and
Crystalline. But the most extraordinary phenomenon
is the appearance in the shale of numerous crystals of
analcime and garnet, which are distinctly confined to
those portions of the rock affected by the dike.* Gar-
Nets have been observed, under very analogous cir-
Cumstances, in High Teesdale, by Professor Sedgwick,
where they also occur in shale and limestone, altered
by a basaltic dike. This discovery is most interesting,
because garnets often abound in mica-schist; and we
See in the instance above cited that they did not pre-
Viously exist in the shale and limestone, but have
€vidently been produced by heat or heated gases in
Yocks in which the marks of stratification have not
been effaced.
Stirling Castle.— To select another example of
alteration by dikes: the rock of Stirling Castle is a
Calcareous sandstone, fractured and forcibly displaced
by a mass of green-stone, which has evidently invaded
the strata in a melted state. The sandstone has been
indurated, and has assumed a texture approaching to
hornstone near the junction. So also in Arthur's Seat
and Salisbury Craig, near Edinburgh, a sandstone is
Seen to come in contact with green-stone, and to be
Converted into a jaspideous rock, +
Antrim. —In several parts of the county of Antrim,
in the north of Ireland, chalk with fints is traversed
by basaltic dikes. The chalk is there converted into
Sranular marble near the basalt, the change sometimes

* Trans. of Cambridge Phil. Soc., vol. i. p. 406.
t Ilust. of Hutt. Theory, §§ 253. and 261. Dr. MacCulloch,
Geol, Trans., First Series, voi. ii. p. 305.

R 3

366 ALTERATIONS IN STRATA PRODUCED [Book IV.

extending eight or ten feet from the wall of the dike,
being greatest near the point of contact, and thence
gradually decreasing till it becomes evanescent. “ The
extreme effect,” says Dr. Berger, “ presents a dark
brown crystalline limestone, the crystals running ™
flakes as large as those of coarse primitive limestone?
the next state is saccharine, then fine-grained 2?
arenaceous ; a compact variety, having a porcellanovs
aspect and a blueish-grey colour, succeeds: this, t07
wards the outer edge, becomes yellowish white and iP-
sensibly graduates into the unaltered chalk. The fin’
in the altered chalk usually assume a grey yellowish
colour.” * All traces of organic remains are effaced ip
that part of the limestone which is most crystalline.

As the carbonic acid has not been expelled, in this
instance, from that part of the rock which must b°
supposed to have been melted, the change probably
took place under considerable pressure ; for Sir Jame
Hall proved, that, under ordinary circumstances; it
would require the weight of about 1700 feet of se%
water, which would be equivalent to the pressure of 3
column of liquid lava about 600 feet high, to preve™
this acid from being given off. The experiments °
Faraday have recently shown that, if carbonate of lim®
be perfectly dry, it may be melted under a very slight
pressure, without the carbonic acid assuming a 94°
eous form; but it is probable that in the earth’s crust
calcareous rocks are rarely, if ever, entirely free from
moisture.

Another of the dikes of the north-east of Ireland
has converted a mass of red sandstone into hornstone-t
By another, the slate-clay of the coal-measures has

* Dr. Berger, Geol. Trans., First Series, vol. iii. p. 172-

+ Rev. W. Conybeare, Geol. Trans., First Series, vol.iii, p.201»

Ch. XXVIL] BY VOLCANIC DIKES. 367

been indurated, and has assumed the character of flinty
Slate * ; and in another place the slate clay of the lias
has been changed into flinty slate, which still retains
Numerous impressions of ammonites. One of the
green-stone dikes of the same country passes through
a bed of coal, which it reduces to a cinder for the space
of nine feet on each side.{ Yet there are places in
the north of Ireland, where the chalk is scarcely, if at
all, altered by the contact of basaltic dikes, and a
Similar phenomenon is not unfrequent in other districts,
at the junction of trap with different kinds of strata.
This great inequality in the effects of the igneous rocks
May often arise from an original difference in their
temperature and in that of the entangled gases, such
as is ascertained to prevail in different lavas, or in the
Same lava near its source, and at a distance from it.
The power also of the invaded rocks to conduct heat
may vary according to their composition, structure,
and the fractures which they may have experienced,
and, perhaps, as I shall hint in the sequel, the quantity
of steam or hot water they contain. It should also be
borne in mind that in some cases the melted rock may
- begin to cool from the first; whereas, in other cases,
although parting constantly with its heat, it may receive
fresh accessions of caloric from below.

The secondary sandstones in Sky are converted into
Solid quartz in several places where they come in con-
tact with veins or masses of trap ; anda bed of quartz,
says Dr. MacCulloch, has been found near a mass of
trap, among the coal strata of Fife, which was in all

* Rev. W. Conybeare, Geol. Trans., First Series, vol. iii. p. 205.
} Ibid., p. 213.; and Playfair, Illust. of Hutt. Theory, §253.
} Ibid., p. 206.

R4

368 ALTERATIONS OF STRATA [Book IV-

probability a stratum of ordinary sandstone subse-
quently indurated by the action of heat.*

Alterations of strata in contact with granite.— Having
selected these from innumerable examples of changes
produced by volcanic dikes, we may next conside!
those caused by the contiguity of plutonic rocks. To
some of these I have already adverted, when speaking
of granite veins, and endeavouring to establish the
igneous origin of granite. It was stated that the mail
body of the Cornish granite sends forth veins throug?
the killas of that country +,— a coarse argillaceous
schist, which is converted into hornblende-schist nea
the contact with the veins. These appearances até
well seen at the junction of the granite and killas i£
St. Michael's Mount, a small island nearly 300 feet
high, situated in the bay, at a distance of about three
miles from Penzance,

The granite, says Mr. De la Beche, of Dartmoor
in Devonshire, has intruded itself into the greywacké;
twisting and contorting the strata, and sending veins
into them. Hence some of the slate rocks have be
come “ micaceous, others more indurated, and with
the characters of mica-slate and gneiss, while others
again appear converted into a hard-zoned rock strongly

. impregnated with felspar.” t

We learn from the investigations of M. Dufrénoy;
that in the eastern Pyrenees there are mountain masses
of granite posterior in date to the lias and chalk of that
district, and that these secondary rocks are greatly
altered in texture, and often charged with iron ore, i?
the neighbourhood of the granite. Thus in the en-
virons of St. Martin, near St. Paul de Fénouillet, the

* Syst. of Geol., vol, i. p. 206.

f See diagram, Fig. 221, ł Geol. Manual, p. 479.

Ch. XXVILJ IN CONTACT WITH GRANITE. 369

chalky limestone becomes more crystalline and sac-
Charoid as it approaches the granite, and loses all
traces of the fossils which it previously contained in
abundance. At some points also it becomes dolomitic,
and filled with small veins of carbonate of iron, and
Spots of red iron-ore. At Rancié the lias nearest the
granite is not only filled with iron-ore, but charged with
Pyrites, tremolite, garnet, and a new mineral somewhat
allied to felspar, called, from the place in the Pyrenees
where it occurs, “ couzeranite.”

In the department of the Hautes Alpes, in France,
Near Vizille, M. Elie de Beaumont traced a black
argillaceous limestone, charged with belemnites, to

Within a few yards of a mass of granite. Here the
Fig. 225.

Eg?

a
bt
`

?

-
¢

Junction of granite with Jurassic 07 oolite strata in the Alps, near Champoicon.

limestone begins to put on a granular texture, but is

extremely fine-grained. When nearer the junction, it

€comes grey and has a saccharoid structure. In

nother locality, near Champoleon, a granite com-
ee aS,

370 ROCKS, HOW ALTERED BY [Book 1V

posed of quartz, black mica, and rose-coloured felspar
is observed partly to overlie the secondary rocks, pro
ducing an alteration which extends for about thirty
feet downwards, diminishing in the beds which lie
farthest from the granite. (See Fig. 225.) In the
altered mass the argillaceous beds are hardened, thé
limestone is saccharoid, the grits quartzose, and in the
midst of them is a thin layer of an imperfect granite
It is also an important circumstance, that near thé
point of contact, both the granite and the secondary
rocks become metaliferous, and contain nests and small
veins of blende, galena, iron, and copper pyrites. The
stratified rocks become harder and more crystalline:
but the granite, on the contrary, softer and less pe?
fectly crystallized near the junction.*

It will appear from sections in the Alps, described
by MM. Hugi and Studer, that some of the secondaty
beds of limestone and slate, which are in a similat
manner overlaid by granite, have been altered int?
gneiss and mica-schist.+ Some of these altered sedi
mentary formations are supposed, by M. Elie de Beat”
mont, to be of the age of the lias of England, and
others to be even as modern as the Jurassic or oolit€
formations.

We can scarcely doubt, in these cases, that the heat
communicated by the granitic mass, accompanied, pe!
haps, by gases at a high temperature, have reduce
the contiguous strata to semifusion, and that, on coo!
ing slowly, the rock assumed a crystalline texture
The experiments of Gregory Watt prove, distinctly

* Elie de Beaumont, sur les Montagnes de I’Oisans, &?
Mém, de la Soc. d’Hist. Nat. de Paris, tome v.

+ Hugi, Natur. Historische Alpenreise, Soleure, 1830. Stude":
Westlichen Alpen.

Ch. XXVIL] PERMEATION OF HEAT AND GASES. 371

that a rock need not be perfectly melted in order that
a re-arrangement of its component particles should
take place, and that a more crystalline texture should
ensue.* We may easily suppose, therefore, that all
traces of shells and other organic remains may be de-
Stroyed, and that new chemical combinations may
arise, without the mass being so fused as that the
lines of stratification should be wholly obliterated.

In allusion to the passage from granite to gneiss,
above described +, Dr. MacCulloch remarks, that, “in
numerous parts of Scotland, where the leading masses
of gneiss are schistose, evenly stratified, and scarcely
ever traversed by granite veins, they become contorted
and irregular as they approach the granite; assuming
also the granitic character, and becoming intersected
by veins, numerous in proportion to the vicinity of the
mass. The conclusion,” he adds, “is obvious; the
fluid granite has invaded the aqueous stratum as far as
its influence could reach, and thus far has filled it with
Veins, disturbed its regularity, and generated in it a
new mineral character, often absolutely confounded
with its own. And if the more remote beds, and
those alternating with other rocks, are not thus af-
fected, it is not only that it has acted less on those ;
but that, if it had equally affected them, they never
Could have existed, or would have been all granitic
and venous gneiss.” f

It should, however, be understood, that the alter-
ations caused by volcanic dikes, granite veins, and
even large masses of granite, can only afford us some
analogy to those which have given rise to the meta-

* Phil. Trans., 1804. See p. 364.
F Syst. of Geol., vol. ii. p. 145. .
R 6

372 ROCKS, HOW ALTERED BY [Book IV.

morphic structure ; for, according to the views ex-
plained in the second book (chaps. 18 and 19.), vol-
canic heat itself may be derived from chemical and
electrical action pervading large portions of the earths
crust. This action, which, when most intense, may
reduce the elements of rocks to fusion, and give rise
to the most perfect granitic structure, may perhaps
when less energetic, give rise to a crystalline texture,
without destroying stratification.

As to the degree of heat required to superinducé
| such changes, it must, in the present state of science
be matter of conjecture; but some geologists object t0
the metamorphic theory, on the ground that rocks are
extremely bad conductors of heat. Now it is wortby
of consideration, how far heat, instead of being con-
ducted through the solid parts of rocks, may be
carried by heated gases through their pores; for we.
have seen that volcanic eruptions are attended by the
evolution of steam and other gases, which rush out i?
enormous volume, and ata high temperature, for days
weeks, or years continuously, and which are given off
by lava even after it has begun to assume a solid form
These aériform fluids, if unable to force their way
into the atmosphere, may, nevertheless, when brought
into contact with rocks, pass through their pores
According to the experiments of Henry, water, unde!
an hydrostatic pressure of ninety-six feet, will absor?
three times as much carbonic acid gas as it can unde!
the ordinary pressure of the atmosphere. Althoug!
this increased power of absorption would be dimi-
nished, in Consequence of the higher temperature
found to exist as we descend in the earth, ye!
Professor Bischoff has shown that the heat. by 2°
means augments in such a proportion as to counteract

Ch. XXVIL] PERMEATION OF HEAT AND GASES. 373

the effect of augmented pressure.* ‘There are other
gases, as well as the carbonic acid, which water
absorbs, and more rapidly in proportion to the amount
of pressure. Now even the most compact rocks may
be regarded, before they have been exposed to the air
and dried, in the light of sponges filled with water ;
and it is conceivable that heated gases brought into
Contact with them, at great depths, may be absorbed
readily, and transfused through their pores. Although
the gaseous matter first absorbed would soon be con-
densed, and part with its heat, yet the continued
arrival of fresh supplies. from below, might, in the
Course of ages, cause the temperature of the water,
and with it that of the containing rock, to be mate-
tially raised.

M. Fournet, in his description of the metaliferous
Sneiss near Clermont, in Auvergne, states that all the
Minute fissures of the rock are quite saturated with
free carbonic acid gas, which rises plentifully from
the soil there and in many parts of the surrounding
Country. The various elements of the gneiss, with
the exception of the quartz, are all softened; and new
Combinations of the acid, with lime, iron, and man-
Sanese, are continually in progress.+

Another illustration of the power of subterranean
8ases is afforded by the stufas of St. Calogero, situated
in the largest of the Lipari Islands. Here, according
to the description lately published by Hoffmann, hori-
Zonta] strata of tuff, extending for four miles along
the coast, and forming cliffs more than 200 feet high,
lave been discoloured in various places, and strangely
altered by the “ all-penetrating vapours.” Dark clays

* Poggendorf’s Annalen, No. XVI. Second Series, vol. iii,
+ See Vol. I. p. 331.

374: ROCKS, HOW ALTERED BY [Book IV.

have become yellow, or often snow-white; or have as-
sumed a chequered and brecciated appearance, being
crossed with ferruginous red stripes. In some places
| the fumeroles have been found by analysis to consis!
| partly of sublimations of oxide of iron; but it also
_ appears that veins of calcedony and opal, and others
_ of fibrous gypsum, have resulted from these volcanic
exhalations.*

I have before referred to M. Virlet’s account of the
corrosion of hard, flinty, and jaspideous rocks neat
Corinth, by the prolonged agency of subterranea?
gases +; and to Dr. Daubeny’s description of the de-
composition of trachytic rocks in the Solfatara, nea
Naples, by sulphuretted hydrogen and muriatic acid
gases. |

Although in all these instances we can only study
the phenomena as exhibited at the surface, it is clea
that the gaseous fluids must have made their way
through the whole thickness of porous or fissured
rocks, which intervene between the subterranean re“
servoirs of gas and the external air. The extent
therefore, of the earth’s crust, which the vapours hav?
permeated and are now permeating, may be thousands
of fathoms in thickness, and their heating and modi-
fying influence may be spread throughout the whole °
this solid mass.

The study of metaliferous veins, also, especially
those which are admitted to be fissures filled from
below, is calculated to throw light on the manner iP
which heated vapours and aqueous solutions may find

* Hoffmann’s Liparischen Inseln, p. 38. Leipzig, 1832.

+ See Vol. III. p.203.; and Bulletin de la Soc. Géol. 4°
France, tom. ii. p. 330.

+ See Vol. II. p. 90. ; and Daubeny’s Volcanos, p. 167-

Ch. XXVII] PERMEATION OF HEAT AND GASES. 375

their way up.through the interstices of rocks, raising
their temperature, and sometimes transfusing into
them new mineral substances. A great number of these
fissures have evidently been filled in the first instance
with rubbish, resulting from fragments of the adjoining
rocks; and through this rubbish various siliceous, cal-
careous, and metallic vapours or solutions appear to
have risen, causing precipitates of quartz, hornstone,
calcareous spar, lead, zinc, and other metals, often
perfectly distinct in their composition from any of the
elements of the rocks which form the walls of such
fissures. Proofs are not wanting that these rents have
been caused and filled at different epochs. Thus, for
example, some of the silver and cobalt veins in Bohemia
appear, from the observations of Mayer and Fournet,
to be of the age of the chalk *, while other metaliferous
veins, in the same district, were contemporaneous with
a tertiary basalt.+ M. Necker has also shown that a
relation exists between the position of numerous me-
tallic veins in various countries and subjacent masses
of plutonic rock; so that the emanations rising from
such igneous masses may, in many instances, have
given rise to the more crystalline substances, whether
Metallic or not, which constitute the contents of the
veins.

If, after more fully reflecting upon those various
causes of change in the composition and structure of
rocks, which have only been glanced at in the above
Sketch, the reader conceives the possibility of a very
great amount of alteration being induced in the course
of time, he may be prepared to conjecture that gneiss
and mica-schist may be nothing more than altered mi-

* D’Aubuisson, Traité de Géog., tom. iii. p. 497.
+ Ibid., p. 508.

376 _ THE GRANITIC SCHISTS Book IV.

caceous and argillaceous sandstones, and,that granular
quartz may have been derived from siliceous sandstone;
and compact quartz from the same materials. Clay-
slate may be altered shale, and shale appears to be clay
which has been subjected to great pressure. Granular
marble has probably originated in the form of ordinary
limestone, having in many instances been replete with
shells and corals now obliterated, while calcareous
sands and marls have been changed into impure crys-
talline limestones. .

“ Hornblende-schist,” says Dr. MacCulloch, “may
at first have been mere clay; for clay or shale ‘is found
altered by trap into Lydian stone, a substance differing
from hornblende-schist almost solely in compactness
and uniformity of texture.’* “In Shetland,” remarks
the same author, “ argillaceous-schist (or clay-slate)»
when in contact with granite, is sometimes converted
into hornblende-schist, the schist becoming first sili-
ceous, and ultimately, at the contact, hornblende-
schist.” +

Associated with the rocks termed primary, we meet
with anthracite, just as we find beds of coal in sedi
mentary formations; and we know that, in the vicinity
of some trap dikes, coal is converted into anthracite.

This theory, if confirmed by observation and ex-
periment, may enable us to account for the high
position in the series usually held by clay-slate re-
latively to hornblende-schist, as also to gneiss and mica-
schist, which so commonly alternate with hornblende-
schist ; for we must suppose the heat which alters the -
strata to proceed, in almost all cases, from below up-
wards, and to act with greatest intensity on the inferior
strata. If, therefore, several sets of argillaceous strata

* Syst. of Geol., vol. i. p. 210. + Ibid., p. 211-

Ch. XXVILJ MAY BE ALTERED STRATA. 377

or shales be superimposed upon each other in a vertical
Series of beds in the same district, the lowest of these
will be converted into hornblende-schist, while the up-
Permost may continue in the condition of clay-slate.

It has been objected that the chemical composition
of the secondary strata differs essentially from that of
the crystalline schists into which they are supposed to
be convertible.* The “ primary” schists, it is said, ,
usually contain a considerable proportion of potash or
of soda, which the secondary clays, shales and slates do
Not, these last being the result of the decomposition of
felspathic rocks, from which the alkaline matter has
been abstracted during the process of decomposition.
But this reasoning proceeds on insufficient and ap-
parently mistaken data; for a large portion of what is
usually called clay, marl, shale, and slate does actually
Contain a certain and often a considerable proportion of
alkali ; so that it is difficult in many countries to obtain
clay or shale sufficiently free from alkaline ingredients
to allow of their being burnt into bricks or used for
Pottery.

Thus the argillaceous shales, as they are called, and
Slates of the old red-sandstone, in Forfarshire and other
parts of Scotland, are so much charged with alkali,
derived from triturated felspar, that, instead of harden-
ing when exposed to fire, they melt readily into a
glass. They contain no lime, but appear to consist of
extremely minute grains of the various ingredients of
8ranite, which are distinctly visible in the coarser-
rained varieties, and in almost all the interposed
Sandstones. These laminated clays, marls, and shales
hight certainly, if crystallized, resemble in composition
Many of the primary strata.

* Dr. Boase, Primary Geology, p. 319.

378 ALTERED STRATA. [Book IV:

Another objection to the metamorphic theory has
been derived from the alternation of highly crystalline
strata with others having a less crystalline texture.
The heat, it is said, in its ascent from below must hav?
traversed the less altered schists before it reache
a higher and more crystalline bed. In answer t°
this, it may be observed, that if a number of strata
differing greatly in composition from each other be
subjected to equal quantities of heat, there is every
probability that some will bélmore fusible than others
Some, for example, will contain soda, potash, lime, or
some other ingredient capable of acting as a flux ; while
others may be destitute of the same elements, and $0
refractory as to be very slightly affected by a degre?
of heat capable of reducing others to semi-fusion. Nor
should it be forgotten that, as a general rule, the less
crystalline rocks do really occur in the upper, and the
more crystalline in the lower part of each metamorp?
series.

To some it appears a phenomenon very difficult of
explanation, that detached masses of granite, and eve?
layers of it, should often occur in the midst of strat®
near their contact with granite. This appearance °
isolation is usually deceptive, arising from the inte™
section in a vertical precipice of tortuous veins °
granite, as Professor Henslow has shown to be the
case in several places in the cliffs of Anglesea.* I may
also remark, that if unaltered sedimentary strata COP”
tained here and there layers or nests of the ingredients
of granite, the rest of the mass consisting of different
| materials, and if the temperature of the whole has
been sufficiently raised by plutonic action, the result

* Camb. Trans., vol. i.

Ch. XXVII] HYPOGENE STRATA. 379

might be, that nodules and threads of granite might
be formed in certain spots only. /

The term “ Hypogene” proposed instead of Pri-
mary.— It will appear from the reasoning explained in
this and the preceding chapter, that the popular no-
menclature of Geology, in reference to the rocks called
“primary,” is not only imperfect, but in a great degree
founded on a false theory ; inasmuch as some granites
and granitic schists are of origin posterior to many
Secondary rocks. In other words, some primary form-
ations can already be shown to be newer than many
secondary groups — a manifest contradiction in terms.

Yet granite and gneiss, and the families of stratified
and unstratified rocks connected with each of them,
belong to one great natural division of mineral masses
having certain characters in common ; and it is there-
fore convenient that the class to which they belong
Should receive some common name — a name which
must not be of chronological import, and must express,
on the one hand, some peculiarity equally attributable
to granite and gneiss (to the plutonic as well as the
altered rocks ), and which, on the other, must have refer-
ence to characters in which those rocks differ, both
from the volcanic and from the unaltered sedimentary
Strata. I propose the term “hypogene” for this pur-
pose, derived from imo, subter, and yivones, nascor ; a
word implying the theory that granite and gneiss are
both nether-formed rocks, or rocks which have not as-
sumed their present form and structure at the surface.
It is true that gneiss and all stratified rocks must have
been deposited originally at the surface, or on that part
of the surface of the globe which is covered by water ;
but, according to the views explained in this and the
foregoing chapter, they could never have acquired

380 METAMORPHIC STRATA. [Book IV.

their crystalline texture, unless acted upon by heat and
chemical forces under pressure in those regions, and
under those circumstances where the plutonic rocks
are generated.

The term “ Metamorphic” proposed for stratified
primary.— We may divide the hypogene rocks, then»
into the unstratified, or plutonic, and the altered stra-
tified. For these last the term “ metamorphic” (from
pera, trans, poody, forma,) may be used. The last-
mentioned name need not, however, be often resorted
to, because we may speak of hypogene strata, hyp
gene limestone, hypogene schist; and this appellatio”
will suffice to distinguish the formations so designate
from the plutonic rocks. By referring to the table
(No. II. p. 395.), the reader will see the chronological
relation which I conceive the two classes of hypoge®?
rocks to bear to the strata of different ages.

No order of succession in hypogene formations. —
When we regard the tertiary and secondary forma-
tions simply as mineral masses ‘uncharacterized bY
organic remains, we perceive an indefinite series 0
beds of limestone, clay, marl, siliceous sand, sandston®
coal, and other materials, alternating again and ag@?
without any fixed or determinate order of position
The same may. be said of the hypogene formations:
for in these a similar want of arrangement is manifest,
if we compare those occurring in different countries.
Gneiss, mica-schist, hornblende-schist, quartz-rock, bY
pogene limestone, and the rest, have no invariable orde"
of superposition, although, for reasons above explained,
clay-slate must usually hold a superior position rela-
tively to hornblende-schist. j

I do not deny that, in a particular mountain-cham,
a chronological succession of hypogene formations may

SSS ee eee
a mca a Sealer —

Ch, XXVII] METAMORPHIC STRATA. 381

be recognized, for the same reason that in a country
of limited extent there is an order of position in the
Secondary and tertiary rocks, limestone predominating
in one part of the series, clay in another, siliceous sand
in a third, and so of other compounds. It is probable
that a similar prevalence of a regular order of arrange-
ment in the hypogene series throughout certain dis-
tricts led the earlier geologists into a belief that they
Should be able to fix a definite order of succession for
the various members of this great class throughout
the world.

That expectation has certainly not been realized ;
yet was it more reasonable than the doctrine of the
universality of particular kinds of rock which were
admitted to be of sedimentary origin; for there is
undoubtedly a remarkable identity in the mineral cha-
tacter of the hypogene formations, both stratified and
unstratified, in all countries; although the notion of a
uniform order of succession in the different groups
must be abandoned.

The student may, perhaps, object to the views above
given of the relation of the sedimentary and metamor-
phic rocks, on the ground that there is frequently,
indeed usually, an abrupt passage from one to the other.
This phenomenon, however, admits of the same expla-
nation as the fact that the beds of lakes and seas are
how frequently composed of hypogene rocks. In these
localities the hypogene formations have been brought |
Up near to the surface, and laid bare by denudation. |
New sedimentary strata are thrown down upon them,
and in this manner the two classes of rocks, the aque-
Sus and the hypogene, come into immediate contact,
Without any gradation from one to the other. As we.
Suppose the plutonic and metamorphic rocks to have

382 METAMORPHIC STRATA. [Book IV.

been uplifted at all periods in the earth’s history, s0 4
to have formed the bottom of the ocean and of lakes;
by the same operations which have carried up marine
strata to the summits of lofty mountains, we must
suppose the juxtaposition of the two great orders of
rocks, now alluded to, to have been a necessary result
of all former revolutions of the globe.

But occasionally a transition is observable from strata
containing shells, and displaying an evident mechanical
structure, to others which are partially altered ; and
from these again we sometimes pass insensibly into the
hypogene series. Some of the argillaceous schists in
Cornwall are of this description, being undistinguish-
able from the hypogene schists of many countries, a?
yet exhibiting, in a few spots, faint traces of organic
remains. In parts of Germany, also, there are schists
which, from their chemical condition, must be called
metamorphic; yet which are interstratified with grey”
wacké, a rock probably modified by heat, but which
contains casts of shells, and often displays unequivoe
marks of being an aggregate of fragments of pre-exist-
ing rocks.

The same observation holds true in respect to the
Cumbrian and Welsh slate rocks before alluded to 35
described by Professor Sedgwick.* They are meta-
morphic slates alternating with a few mechanical a?
fossiliferous beds. If it be asked by what characte"
we can draw the line and determine where the meta-
morphic series ends, and the sedimentary begins;
reply that, if this be difficult or impossible, it ony
strengthens the argument adduced in the preceding
part of this chapter; for, according to the theory
proposed, we must expect to find strata in every inter-

* See p. Boo.

Ch. XXVII.J AGE OF HYPOGENE STRATA. 383

Mediate condition between the most and the least
altered.

Had Werner’s term “transition” been restricted
exclusively to certain peculiarities of mineral struc-
ture, and never connected with the presence of par-
ticular species of fossils, in consequence of which it
Soon acquired a chronological import, that term might
have been conveniently retained to designate an
intermediate condition of strata when they exhibit the
Characters of rocks of the metamorphic series with
Occasional traces of a mechanical structure and organic
remains.

Some geologists, who shrink from the theory that `
all the hypogene strata, beautifully compact and crys-
talline as they are, have once been in the state of
ordinary mud, clay, marl, sand, gravel, and limestone,
Such as are now forming beneath the waters, resort, in
their desire to escape from such conclusions, to the hy-
Pothesis, that chemical causes once acted with intense
nergy, and that by their influence purely crystalline
Strata were precipitated ; a theory which to me appears
as mysterious and unphilosophical as the doctrine of a
“plastic virtue,” introduced by the earlier writers to
€xplain the origin of fossil-shells and bones.

Relative age of the visible hypogene rocks.—It was
Stated, at the close of the last chapter, that a great
Portion of the plutonic rocks now visible are of higher
antiquity than the oldest secondary strata; the same
May be said of the stratified hypogene formations,
Which are therefore entitled to the appellation of pri-
Mary, in the strict sense of the word, as anterior in age
to the greywacké, or oldest known fossiliferous group.

ut we can, in some instances, demonstrate that there
are granites of posterior origin to certain secondary

384 RELATIVE AGE OF [Book 1V-

strata, and that secondary strata have been converted
into the metamorphic. Examples of such phenomena
are rare, and their rarity is quite consistent with the
` theory, that the hypogene formations, both stratified
and unstratified, may have been always generated
in nearly equal quantities during periods of equal
duration.

I conceive that the granite and gneiss of periods
more recent than the carboniferous and ereywacké
formations are still, for the most part, concealed; a2
those portions which are visible can rarely be show?
by geological evidence, to have originated during
secondary periods. It is very possible, for example
that considerable tracts of hypogene strata in the
Alps may be altered oolite, altered lias, or altered
secondary rocks inferior to the lias; but we ca?
scarcely ever hope to substantiate the fact, becaus®
whenever the change of texture is complete, no chara&
ters remain to afford us any insight into the probable
age of the mass. Where granite happens to have in-
truded itself in such a manner as partially to overlie ®
amass of lias or other strata, as in the case before alluded
to (Fig. 225., p- 369.), we may prove that fossiliferous
strata have been converted into gneiss, mica-schists
clay-slate, or granular marble ; but if the action of the
heat upon the strata had been more intense, thes?
inferences could not have been drawn; and it might
then have been supposed that no alpine hypoge?®
strata were newer than the oldest secondary rocks.

- Considerable difficulty and misapprehension, in Te
gard to the antiquity of the metamorphic rocks, may
arise from the circumstarice of their having been de
posited at one period, and having assumed their crys
talline texture at another. Thus, for example, if a°

Ch. XXVII] HYPOGENE STRATA. 385

Eocene granite should invade the lias, and superinduce
a hypogene structure, to what period shall we refer the
altered strata? Shall we say that they are metamorphic
rocks of the Eocene or Liassic eras? They assumed
their stratified form when the animals and plants of
the lias flourished; they have become metamorphic
during the Eocene period. It would be preferable, in
such instances, I think, to consider them as hypogene
Strata of the Eocene period, or of that in which they
were altered; yet it would rarely be possible to esta-
blish their true age. For this purpose we ought to
know the granite, to which the change of texture was
due, to be newer than the lias which it penetrated ;
but there would rarely be any data to show that this
granite might not have been injected at the close of
the Liassic period, or at some much later era.

The metamorphic rocks must in all cases be the
oldest, that is to say, they must lie at the bottom of
each series of superimposed strata; but the hypogene
Strata of one country may be, and frequently are, of a
Very different age from those of another. The greater
part, however, of the visible hypogene rocks are, pro-
bably, more ancient than the oldest fossiliferous form-
ations. In the latter we frequently discover pebbles
of hypogene rocks, namely, granite, gneiss, mica-
Schist, and clay-slate; and the carboniferous rocks
often rest upon the hypogene, without exhibiting any
marks of change at the junction. According to the
Views before explained of the operations of earth-
quakes, we ought not to expect plutonic and metamor-
Phic rocks of the more modern eras to have reached
the surface generally; for we must suppose many -
$eological periods to elapse before a mass, which has
assumed its particular form far below the level of the

VOL. Iv. S

386 RELATIVE AGE OF [Book IV.

sea, can have been upraised and laid open to view
above that level. Beds containing marine shells some-
times appear in the principal mountain-chains, at the
height of two or three miles above the sea; but they
' always belong to formations of considerable antiquity *
still more, then, should we be prepared to find the
hypogene rocks now in sight to be of high relative
antiquity, since, before they could be brought up to
view, they must probably have risen from a site fat
inferior to the bottom of the ocean.

The cause of the great age of the plutonic a
metamorphic rocks, now in sight, may be elucidate
by a familiar illustration. Suppose two months to be
the usual time required for passing from some tropical
country to our island, and that an annual importatio®
takes place of a certain species of insect which can be
reared only in the climate of that equatorial county
and the ordinary term of whose life is two months
It is evident that no living individuals of that speci
could ever be seen in England except in extreme ol
age. The young may come annually into the world in
great numbers ; but, in order to see them, we must
travel to lands near the equator.

In like manner, if the hypogene rocks can originate
only at great depths in the regions of subterranea?
heat, and if it requires many geological epochs to raise
them to the surface, they must be very ancient before
they make their appearance in the superficial parts °
the earth’s crust. They may still be forming in every
century, and they may have been produced in equ?
quantities during each successive geological period 0
equal duration; but in order to see them in a nascent
state, slowly consolidating from a state of fasion, 0

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Ch, XXVII.J

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388 RELATIVE AGE OF [Book IV.

semi-fusion, it would be necessary to descend into the
« fuelled entrails” of the earth.

In the accompanying diagram, Fig. 226., an attempt
is made to show the inverted order in which the sedi-
mentary and plutonic formations may occur in the
earth’s crust ; subterposition in the plutonic, like super-
position in the sedimentary rocks, being for the most
part characteristic of a newer age.

The oldest plutonic rock, No. I., supposed to have
consolidated from a state of fusion before any of the
fossiliferous rocks now on the surface were deposited,
has been upheaved at successive periods until it has
become exposed to view in a mountain-chain. ‘This
protrusion of No. I. has been caused by the igneous
agency which produced the new plutonic rocks Nos. Il.
II. and IV. Part of the metamorphic rocks No. 1.
have also been raised to the surface by the same gradual
process. It will be observed that the Recent strata
No. 4. and the Recent plutonic rock No. IV. are the
most remote from each other in position, although of
contemporaneous date. According to this hypothesis
the convulsions of many periods will be required be-
fore Recent granite will be upraised so as to form the
highest ridges and central axes of mountain-chains.
During that time the Recent strata No. 4. might be
covered by a great many newer sedimentary form-
ations.

As the progress of decay and reproduction by
aqueous agency is incessant on the surface of the
continents, and in the bed of the ocean, while the
hypogene rocks are generated below, or are rising
gradually from the volcanic foci, there must ever be
a remodelling of the earth’s surface in the time inter-
mediate between the origin of each set of plutonic

SE DNIE I IN OTT

Ch. XXVILJ HYPOGENE STRATA. 389

and metamorphic rocks, and the protrusion of the same
rocks into the atmosphere or the ocean. Suppose
the principal source of the Etnean lavas to lie at
the depth of ten miles, we may easily conceive that
before they can be uplifted to the day several distinct
series of earthquakes must occur, and between each of
these there might usually be one or many periods of
tranquillity. The time required for so great a develop-
ment of subterranean movements might well be pro-
tracted until the deposition of a series of sedimentary
rocks, equal in extent to all our secondary and tertiary
formations, had taken place.

The relative age, therefore, of the visible plutonie/4\
and metamorphic rocks, as compared to the unältered
sedimentary strata, must always be determined by the |
relations of two forces — the power which uplifts the i“ Fa
hypogene rocks, and that aqueous agency which de- "
grades and renovates the earth’s surface; or, in other // |
words, the relative age must depend on the quantity A
of aqueous action which takes place between two YA
periods — that during which the heated and melted
rocks are cooled and consolidated in the nether regions, |
and that of their emergence at the earth’s surface.

Volume of hypogene rocks supposed to have been
formed since the Eocene period.— If we were to indulge
in speculations on the probable quantity of hypogene
formations, both stratified and unstratified, which may
have been formed beneath Europe and the European
seas since the commencement of the Eocene period, it
might be conjectured that the mass has equalled, if
not exceeded in volume, the entire European con-
tinent. The grounds of this opinion will be under-
stood by reference to what I have said of the causes
which may have upheaved part of Sicily to its present

s 3

390 RELATIVE .AGE OF [Book IV:

height above the level of the sea since the beginning
of the Newer Pliocene period.* If the theory which,
in that instance, attributes the disturbance ‘and up-
heavings of the superficial strata to the action of sub-
terranean heat be deemed admissible, the same argu-
ment will apply with no less force to every other
district, elevated or depressed, since the commence-
ment of the tertiary period.

But the remarks on the map of Europe, in the first
book, have shown, that the conversion of sea into land,
since the Eocene period, embraces an area equal to
the greater part of Europe ; and that even those tracts
which had in part emerged before the Eocene era,
such as the Alps, Apennines, and other mountain-
chains, have risen to the additional altitude of from
one thousand to four thousand feet since that era. I
have also suggested the probability of a great amount
of subsidence, and the conversion of considerable
portions of European land into sea, during the same
period, — changes which may be supposed to arise
from the influence of subterranean heat.

From these premises we may conclude, that the
liquefaction and alteration of rocks, by the operation
of volcanic heat at successive periods, has extended
over a subterranean space, equal at least in area to the
present European continent, and has often pervaded 2
portion of the earth’s crust four thousand feet or more
in thickness.

The principal effect of these volcanic operations in
the nether regions, during the tertiary periods, or
since the existing species began to flourish, has been
to heave up to the surface hypogene formations of an
age anterior to the carboniferous. The repetition of

* See Vol. III. p. 437.

Ch. XXVIL] HYPOGENE STRATA. 391

another series of movements, of equal violence, might
upraise the plutonic and metamorphic rocks of many
of the secondary periods ; and if the same force should
still continue to act, the next convulsions might bring
up the tertiary and recent hypogene rocks ; by which
time we may imagine that nearly all the sedimentary
strata now in sight would either have been destroyed
by the action of water, or have assumed the meta-
morphic structure, or would have beén melted down
into plutonic and volcanic rocks.

At the end of this chapter will be found a table of
the chronological relations of the principal divisions of
rocks, according to the views above set forth. The
sketch is confessedly imperfect ; but it will elucidate
the theory above suggested, of the connection which
may exist between the hypogene rocks of different
_ periods, and the alluvial, volcanic, and sedimentary
formations.

Concluding Remarks.

In the history of the progress of geology, it has
been stated that the opinion originally promulgated
by Hutton, “that the strata called primitive were
mere altered sedimentary rocks,” was vehemently
opposed for a time, on the ground of its supposed
tendency to promote a belief in the past eternity of
our planet.* Before that period the absence of animal
and vegetable remains in the so-called primitive
strata had been appealed to, as proving that there
had been an era when the planet was uninhabited by
living beings, and when, as was also inferred, it was

* Vol. I. p. 92.
S 4

392 ' CONCLUDING REMARKS. [Book IV.

uninhabitable, and, therefore, probably in a nascent
State.

The opposite doctrine, that the oldest visible strata
might be the monuments of an antecedent period,
when the animate world was already in existences
was declared to be equivalent to the assumption that
there never was a beginning to the present order of
things. The unfairness of this charge was clearly
pointed out by Playfair, who observed, “that it was
one thing to declare that we had not yet discovered.
the traces of a beginning, and another to deny that the
earth ever had a beginning.”

I regret, however, to find that the bearing of my
arguments in the first book has been misunderstood in
a similar manner ; for I have been charged with en-
deavouring to establish the proposition, that “the ex-
isting causes of change have operated with absolute
uniformity from all eternity.” *

It is the more necessary to notice this misrepresent-
ation of my views, as it has proceeded from a friendly
critic, whose theoretical opinions coincide in general
with my own ; but who has, in this instance, strangely
misconceived the scope of the argument. With equal
justice might an astronomer be accused of asserting
that the works of creation extended throughout in-
Jinite space, because he refuses to take for granted
that the remotest stars now seen in the heavens are
on the utmost verge of the material universe. Every
improvement of the telescope has brought thousands
of new worlds into view ; and it would, therefore, be
rash and unphilosophical to imagine that we already
survey the whole extent of the vast scheme, or that

* Quarterly Review, No. 86., Oct. 1830, p. 464,

Ch. XXVIL] CONCLUDING REMARKS. 393

it will ever be brought within the sphere of human
observation.

But no argument can be drawn from such premises
in favour of the infinity of the space that has been
filled with worlds; and if the material universe has ~
; any limits, it then follows that it must occupy a minute

and infinitesimal /point in infinite space.

Soe fi tracing back the earth’s history, we arrive
` at the monuments of events which may have happened
millions of ages before our times, and if we still find
no decided evidence of a commencement, yet the
arguments from analogy in support of the probability
of a beginning remain unshaken; and if the past
duration of the earth be finite, then the aggregate of
geological epochs, however numerous, must constitute
a mere moment of the past, a mere infinitesimal por-
tion of eternity.

It has been argued, that, as the different states of
the earth’s surface, and the different species by which
it has been inhabited, have all had their origin, and
many of them their termination, so the entire series
may have commenced at a certain period. It has also
‘been urged, that, as we admit the creation of man to
have occurred at a comparatively modern epoch — as
we concede the astonishing fact of the first introduc-
tion of a moral and intellectual being—so also we may
conceive the first creation of the planet itself.

I am far from denying the weight of this reasoning
from analogy; but, although it may strengthen our
conviction, that the present system of change has not
gone on from eternity, it cannot warrant us in pre-
Suming that we shall be permitted to behold the signs
of the earth’s origin, or the evidences of the first
introduction into it of organic beings. We aspire in

$5

394 CONCLUDING REMARKS. [Book IV.

vain to assign limits to the works of creation in space,
whether we examine the starry heavens, or that
world of minute animalcules which is revealed to us
by the microscope. We are prepared, therefore, ta
find that in time also the confines of the universe lie
beyond the reach of mortal ken. But in whatever
direction we pursue our researches, whether in time
or space, we discover every where the clear proofs of
a Creative Intelligence, and of His foresight, wisdom,
and power.

As geologists, we learn that it is not only the pre-
sent condition of the globe which has been suited to

the accommodation of myriads of living creatures, but ++
that many former states also have been adapted to the +?
organization and habits of prior races of beings: :-The* ’
disposition of the seas, continents, and islands, and the’ ~’
climates, have varied; the species likewise have bee! `°

changed ; and yet they have all been so modelled, on- _
types analogous to those of existing plants and animals, _
as to indicate throughout a perfect harmony of desig?” -
and unity of purpose. To assume that the evidence -
of the beginning or end of so vast a scheme lies within
the reach of our philosophical inquiries, or even of out
speculations, appears to be inconsistent with a just
estimate of the relations which subsist between the
finite powers of man and the attributes of an Infinite
and Eternal Being.

TABLE II.

Showing the Relations of the Alluvial, Aqueous, fe
Hypogene Formations of different Ages.

\
\
leanic, and

|
|

Periods. Formations.

Some of the Localities where

the Formations occur.

m

f Alluvial.

Aqueous. |

Volcanic.

a. Plutonic. l
| Hypogene.

b. Metamor-
phic.

a, Marine.
b. Freshwater.

e

“Alluvial.

a. Marine.
Be

is
Newer
Pliocene.

B.
Table I.
p. 301.

Aqueous. fe:
Volcanic.

a. Plutonic.

L Hypogene.

b. Metamor-
phic.

|
¥
=
=i

II. TERTIARY.

Beds of existing rivers,
&c. book iii. ch. xiv.
Coral reefs of the Pacific,

book iii. ch. xviii.
Bed of Lake Superior,
&c., book ii. ch. iy.
Etna, Vesuvius, book ii.
chs: x. xi, Šu.
Concealed ; foci of active ~
volcanos, book iv, ch.
XXVI.
Concealed; around the
foci of active volcanos,
book iv. ch. xxvii,

Gravel covering the
Newer Pliocene strata
of Sicily.

Val di Noto, Sicily.

Colle, in Tuscany.

Val di Noto, Sicily.

Concealed; foci of Newer
Pliocene volcanos —
underneath the Val di
Noto, Vol. IIL. p.437.,
and book iv. ch. xxvii.

Concealed ; near the foci
of Newer Pliocene vol-
canos—underneath the
Val di Noto, Vol. III.
p. 437., and book iv.
ch, xxvii,

CHRONOLOGICAL RELATIONS

TABLE IL. — continued.

Periods.

Some of the Localities where

: >
Formations. the Formations occur.

Tl. Terrrary. — continued.

2.
Older
Pliocene.
Gi
Table I,
p- 301.

3

Miocene.
D.
Table I.
p. 301.

4.
Eocene.

Table I.
p- 302.

(Alluvial. ae aa

| Hypogene.

¢ Alluvial. =< >

a Plutonic.
Hypogene.

Norfolk? Vol. IV. p.78-
Subapennine formations;
Vol. IV. p. 49.
Near Sienna, Vol. 1V-
p. 55.
Volcanic. - - - Tuscany, Vol. IV. p. 54
Concealed ; foci of Older
a. Plutonic. f

; a. Marine.
Aqueous.

b. Freshwater.

Pliocene volcanos —
beneath Tuscany.
Concealed ; probably neat

the same foci.

f Mont Perrier, Auvergne
—Orleanais, Vol. IV.
pp. 134. 137.

Bordeaux. Dax.

Saucats, near Bordeau3s

Vol. IV. p.-121.

Hungary, Vol. IV. p.140-

Concealed ; foci of Mio-
cene volcanos — be-
neath Hungary.

Concealed ; probably
around the same foci.

b. Metamor-
phic.

a. Marine.

Aqueous. b. Freshwater.

Volcanic. apes ay

b. Metamor-
phie.

r Summit of North and

<

South Downs? Vol.I V-
p. 263.
Paris and London basins:
Isle of Wight — Au-
vergne.
Ronca, Vicentine, Vol.
IV. p. 211.; oldest
' volcanic rocks of the
Limagne d’Auvergne
book iv. ch. xix.
Concealed ; fociof Eocene
` volcanos—beneath Vi-
centine and the Li-

Alluvial. aa Ë

Aqueous fo Marine.

b. Freshwater.

Volcanic.

a. Plutonic.

Hypogene.

magne d’ Auvergne.
Concealed; probably nea
the same foci.

b. Metamor-
phic.

OF THE PRINCIPAL FORMATIONS.

TABLE II. — continued.

oe

SECcONDARY-

III.

Periods.

Formations.

Some of thé Localities where
the Formations occur,

“Alluvial.

Aqueous,

Volcanic.

Alluvial.
2
Wealden
group.

G

Aqueous.

<
Table I. Volcanic.
p- 302.

- Alluvial.
ae
Oolite
group. <
H.
Table I.
p- 303.

Aqueous.

Volcanic.

p “Alluvial.

Lias
group.
I. < Volcanic.
Table I.
p. 304.

Aqueous.

5e { Alluvial.
New Red
Sandstone
and eae
nesian
nian
group.

Aqueous.

Pygipadd

K.& L. \Hypogene.

Table I.
p. 304,

| Hypogene.

Lu ypogene.

L Hypogene.

| Hypogene.

Wiltshire, North Downs.

feds Flamborough Head.

b. Freshwater.
Northern Flanks of the
Pyrenees? Near Dax?

= ~ æ

a. Plutonic,
fi Metamor-
phic.
Portland Dirt-bed”
(containing pebbles).

a, Marine. i '
Weald of Surrey, Kent,
b. Freshwater, and Sussex, book iv.

ch. XXi.
a. Plutonic.
b. Metamor-

phic.

Oxford.

chain.

Bath, Jura

be Marine.

b. Freshwater.

a. Plutonic.
f, Metamor-

phic.

Hebrides ?
{ Concealed ; beneath the
Hebrides.

Lyme Regis.

Whitby.
Aberthaw.

a. Marine.

b. Freshwater,

Hebrides?

a. Plutonic.
b. Metamor-
phic.

Alps? book iv. ch. xxvii.
Valorsine in Savoy.
Cheshire. Staffordshire.
te Marine. Vosges. Westphalia.
(Muschelkalk.)
b. ee

Near Exeter, Devon.
Concealed ; beneath De-
vonshire ?

Metamora
phic

m Plutonic.

TABULAR VIEW OF STRATA.

TABLE II. — continued,

7 e
Some of the Localities wher

Periods. Formations, the Formations occur

f Alluvial.

i i din-

a. Marine. eae Mendip, E
burgh. ;
Coal measures of Nort

6. ;
Carbo ni- | Aqueous.
ferous & 6. Freshwater, of England and ne"
Old Red Edinburgh.
Sand- < e orfarshire. Edinburg!

stone Volcanic. Fife. Durham. Hig
group. Teesdale. Sie
M.& N. Concealed ; beneath Edi?”
Table I. a. Plutonic. burgh, Northumbe

p. 305, Hypogene. land, Durham. ks
& bM Near the Plutonic ro?

Oa of the same period-

oes a phic. P

Silu- Alluvial, :
rian & A { a. Marine. Wenlock, Shropshire-

queous.

III. Szconpary—continued.

Grey- b. Freshwater,
wacké < Volcanic. ei a a Shropshire.

group. r Concealed;beneathShrop-
O. & P. Hypogene. + Plutonic, shire.

Table I. b. Metamor- .f Near the Plutonic rock
L p. 306. | phic. of the same period. d
Alluvial. | f yaen all destroy?

Z
©
Ean f
2
=
mn
Z
<
kaa
Em
>
t

Aqueous. by denudation, or c”
Volcanic. verted into hypogen’
Perhaps a consideraP s
Plutonic. part of the granit
now visible.
Hypogene. Probably a large propor
tion of the gneiss, ei
Metamorphic. .ca-schist, © and er
stratified crystallin
rocks now visible.

=e

V, Primary Rocxs.*

* By primary formations are meant those, whether stratified or Y”
stratified, which are older than the most ancient European rocks (#°
transition or greywacké), in which distinct fossils have as yet bee?
discovered,

A.

ABERDEENSHIRE, passage from trap into
granite in, iv. 348.

Abesse, inland cliff at, iv. 124.

Abich, M., on slope on which Java con-
geals, ii. 173.

Abo, ii, 291, 292."

Acquapendente, volcanic tuffs at, iv. 54.

Adams, Mr., on fossil elephant, i. 151.

Adanson on age of the baobab tree, iii,

428.

Addington hills, iv. 213.

Addison on Burnet’s theory, i. 56.

Adernd, dip of strata near, iii. 401.

Adige, embankment of the, i. 280. ; iii.
170.

œ, delta of the, i. 350.

Adour, R., new passage formed by, ii. 24.

—., tertiary strata of, iv. 120.

Adria, formerly a sea-port, i. 351.

Adriatic, deposits in, i. 64. 67. 128. 351. ;
ii. 272.

—, gain of land in, i. 351.

—, its form and depth, i. 351.

Adur, R., transverse valley of, iv. 238.

Africa, fossil shells of, mentioned by
ancients, i. 25.

——., heat, radiated by, i. 168,

—, currents on coast of, ii. 20. 32.

——, drift sands of deserts, iii. 188.

—, shaken by earthquake, ii. 253.

—, devastations of locusts in, iii. 95.
~—, strata forming off coast of, ili. 272.
, desert of, its area, iii, 131.

ate, M., on fossil fish, i. 203. 235. ;
iii, 358.; iv. 33. 112. 179. 279. 293. 296.

Agricola on fossil remains, i, 37.

Ahmedabad town, destroyed by earth-

. quake, ii, 194.

Aidat, lake, how formed, iv. 200.

Air, circulation of, i. 188.

Airthrey, fossil whale found at, iii,
267.

Airy, Professor, i. 185.
Aix, in Provence, tertiary strata of,
iv. 210.
——. fossil insects of, iv. 210,
Albenga, tertiary strata at, iv. 64.
Aldborough, incursions of sea at, i. 414.
Alderney, Race of, i. 385.
Aleppo, earthquake of, ii. 194.
Aleutian isles, eruptions, &c. in, ii. 47.
204.
Alge, depth at which some species live,
iii. 9.
Allan, Mr. T., on mammiferous fossils
of Isle of Wight, i. 241. ; iv. 216.
Allier, R., volcanic tuff, &c. on its
banks, iv. 185.
Alloa, whale cast ashore at, iii. 266.
Alluvium, definition of, iii. 196.
iv. 44,
—, aE of organic remains in,
iii. 197.
——, marine, iii. 198.
—, volcanic, ii. 94.
——-, in Scotland, ii. 241.
——, stalagmite alternating with, in
French caves, iii. 210.
——, European, in great part tertiary,
iv. 45.
——, of newer Pliocene period, iv. 38.
44, 48.
——, of Miocene era, iv. 134.
—, of Eocene period, iv. 234. 263.
——, under lavas, iv. 95, 98. 195.
—, in ancient fissures, i iv. 198.
Alps, Saussure on the, i. 80.
——, tertiary rocks of the, i. 210.

400

Alps, greatly raised during tertiary
epoch, i, 219.

-——, shells drifted from the, iii, 360.

——-, erratic blocks of the, iv. 46.

——, maritime, tertiary strata at base
of, iv. 61.

——, secondary strata penetrated by
granite in the, iv. 344,

——, strata of oolite altered in the, iv,
369.

Altered strata in contact with granite,
iv. 368.

——, enumeration of the probable.con-
versions of sedimentary strata into
well-known metamorphic rocks, iv.

O10;

Alting, on the Zuyder Zee, ii. 6.

Alum Bay, alternation of London and
plastic clay in, iv. 213.

Alzey, tertiary strata of, iv. 132.

Amalfi, i, 126.

Amazon, R., sea discoloured by waters
of, ii. 33.

=—, land formed by its deposits, ii. 33.

——, animals floated down on drift
wood by; iii. 42.

Amer, structure of country near, iv. 91.

America, its coast undermined, ii. 9,

——, lakes of, may cause deluges, i. 133.

——, recent strata in lakes of, i. 344. ;
iii. 262. $

~=, specific distinctness of animals of,
L 827.

—, domesticated animals have run
wild in, ii. 894, ; iii. 113.

Amiata, Mount, i. 314.

Amici, Vito, on Moro’s system, i. 67.

Ammonia in lavas, ii. 351.

Amonoosuck, flood in valley of, i. 294.

Ampère, M., on currents of electricity
in the earth, ii. 324.

Anapo, valley of, iii. 442.

Andernach, loess and voltanic ejections
alternating at, iv. 34.

Andes, changes of level in, iii. 253,

——, height of perpetual snow on, i.
194,

==, volcanos of, ii. 41..43,

Anglesea, changes caused by a volcanic
dike in, iv. 364. 378.

Animals, Lamarck’s theory of the pro-
duction of new organs in, ii. 368.

—, imported into America, have run
wild, ii. 394. 5 iii. 113.

mem, aptitude of some kinds to do.
mestication, ii, 408. 417.

INDEX,

Animals, hereditary instincts of, 1i- 409)

——, domestic qualities of, ii. 408. 442°

—, their acquired habits rarely trans-
missible, ii. 413, 421.

+, changes in the brain of the foetus
in vertebrated, i. 439.

—, plants diffused by, iii. 17.

——, their geographical distribu!
i. 204. ; iii. 27.

——, migrations of, iii. 33. 36.

——, causes which determine the
tions of, iii. 86. 98. 3

——.,-influence of man on their distribu
tion, iii. 109.

—, fossil, in peat, caves, &c., iii. 182
187. 197. 201. 231. 236.

Anio, R., food of the, i. 298. ame

—, once flowed through a chain °
lakes, i. 324. ad

Anning, Miss M., on waste of cliff:
i. 429.

Annus Magnus, duration of, i. 12.

Anoplotherium in freshwater form4
tion of I. of Wight, iv. 216. 263.

Anthracite, whence derived, iv. 376-

Anticlinal axis of Weald valley, 1%
224, 231.

Anticlinal lines ; how far those formed
at the same time are parallel, iv. 394%

Antilles, earthquake in the, ii. 207.

Antissa, i018.

Antrim, chalk in, converted into ma!
ble by trap-dike, iv. 365.

——, altered coal and lias in, iv. 366:

Apennines, their relative age, i. 209. 21%

——, tertiary strata at foot of, iv. 49-

Aphides, White’s account of a show
of, iii, 65.

—, their multiplication, iii, 93.

Apoilinaris cited, iv. 200.

Apure, R., horses drowned in, iii. 234

Aqueous causes, i. 259. f

Aqueous lavas, description of, ii. 78. %3
iii. 192,

Arabian Gulf, filling with coral, iii. 280.

——, volcano at its entrance, ii, 58.

Arabian writers, i. 24. 29.

Arago, M., on influence of forests 07
climate, iii. 168.

==, on solar radiation, i. 226.

—, on level of Mediterranean and Red,
sea, i. 387.

Arbroath, houses, &c. swept away PY
sea at, i. 400:

Arduino, memoirs of, 1759, i. 72.

—~, on submarine volcanos, i. 73.

i0Ns

sta-

INDEX.

Aristarchus, i. 299.

Aristophanes, i. 16.

Aristotelian system, i. 21.

~ theory of spontaneous generation,
1. 38,

Arno, R., yellow sand like Subapennine
deposited by, iv. 56.

Arso, volcanic eruption of, in Ischia,
ii. 70.

Artesian wells, phenomena brought to
light by, i. 302.

~, depth from which water rises in,
i. 303.

Arun, transverse valley of the, iv. 238.

Arve, sediment transported by the, i.
345.

~, section of débris, deposited by, i.
378.

Asama-yama, eruption of, ii. 209.

Ascension, island of, fossil eggs of tur.
tle from, iii. 267.
Shes, volcanic, transported to immense
distances, ii. 201.

Asia, subject to earthquakes, i. 14.

—, coast of, changed, i. 30.

~, causes of extreme cold of part of,

i, 168.

~ Minor, gain of land on coast of,
i, 32,

~, Western, great cavity in, iii 126,

~, this now doubted, iv. 202.

Ags, wild in Quito, iii. 115.

—, wild in Tartary, iii. 38.

Astroni, crater of, iv. 94.

Astruc on delta of Rhone, i. 346.
tchafalaya, R., drift-wood in, i. 286.

~., section of the banks of, i. 365.

Athabasca lake, drift-wood in, iii, 222
antic, mean depth of, i. 185,

“—, its relative level, i. 387.

>, rise of the tide in, i. 388.
tlantis, submersion of, i. 14. ; iv. 309.
trio del Cavallo, ii. 88. ; iv. 9.
Ubenas, fissures filled with breccia
Near, iii. 210.
Urillac, freshwater formation of, iv.
158

»

Australia, kangaroo and emu thinning

Ih, iii. 112,

» Coral reefs of, iii. 280.

> breccias of, bones of marsupial
animals in, iv. 43.

Uergne, salt deposited by springs in,
i, 331.
2 carbonic acid gas disengaged in, i.

4

401

Auvergne, lavas of, iii. 422.

——, alluviums of, iv. 134. 195.

——. volcanic rocks of, i. 86, 87.5 iii.
365. ; iv. 142. 184.

—, lacustrine deposits of, iv, 144.

——, map of lacustrine basins and vol-
canic rocks of, iv. 145,

——, tertiary red marl and sandstone of,
like new red sandstone, iv. 148, 316.

—, indusial limestone of, iv. 152,

» connexion of Paris basin and, iv.
165.
——, igneous rocks ‘associated with la-

custrine in, iv. 185.
——, volcanic breccias of, iv. 134. 187.
——, minor volcanos of, iv. 188, 192,
—, ravines in lavas of, iv. 194, 195.
Ava, fossils of, i. 49.
Aventine, Mount, tufa on, iv. 28, `
Avernus, lake, ił 65.
Avicenna on cause of mountains, i. 30.
Azof sea, said to have been united with
Caspian, ii. 52. 3
=—, new island thrown up in, ii. 53.
Azores, icebergs drifted to the, i. 177.
271.
—, siliceous springs of, i. 327. .

B.

Babbage, Mr., on the coast near Puz-
zuoli, ii. 268.

—, on Temple of Serapis, ii. 280.

——, on expansion of rocks by heat, ii.
339.

Bacon, Lord, cited, iii. 257.

Baden, gypseous springs of, i, 326.

Baffin’s Bay, icebergs in, i. 172.

Bagnes, valley of, bursting of a lake in
the, i. 295,

Bagneux, strata near, iv. 168.

Bagshot sand, its composition, &c., iv.
215.

Baiæ, changes on coast of the bay of, ii.
267.

—, ground plan of the coast of, ii. 267.

——-, sections in bay of, ii. 269. 271.

Bakewell, Mr., on formation of soils,
iii. 156.

—, on fall of Mount Grenier, iii. 200.
——, on jointed structure in rocks, iv.
59. j
Bakewell, Mr., Jun., on Falls of Nia.

gara, i. 276.
Bakie loch, charæ fossil in, iii, 260, .

402

Baku, inflammable gas of, i. 19.; ii, 51.
Balaruc, thermal waters of, i. 347.
Baldassari, on Sienese fossils, i. 68,
Ballard, M., on state of buried bones,
iii, 214,
Baltic sea, deltas of the, i. 344,
—, lowering of level of the, i, 345. ;
ii. 286.
—, drifting of rocks by ice in, i. 271.
—, currents on its shores, ii. 12.
Banos del Pujio, elevated sea-cliff near,
We i.
Baobab tree, its size, probable age, &c.
iii. 428. ; iv. 205.
Barbadoes, rain diminished by felling of
forests in, iii. 165.
Barcelona, tertiary strata of, iv. 101.
Barcombe, in Sussex, iv. 234.
Bargone, gypsum in marls near, iv. 54.
Barren island, a supposed crater of ele-
vation, ii. 159.
Barrow, Mr., on a bank formed in sea
by locusts, iii. 96. 4
Barrow, Mr., Jun., on the Geysers of
Iceland, i. 329. ; ii. 342.
- Barsoe, loss of land in island of, ii. 12.
Barton, Mr., on geography of plants,
iii. 2.
Basalt, opinions of the early writers
on, i. 85, 86. ; iii. 307.
Basterot, M. de, on fossil shells of Bor-
deaux and Dax, iii. 338. ; iv. 119.
Batavia, effects of earthquake at, ii. 259.
Battoch, Mount, granite veins of, iv.
342,
Baumhauer, Mr., on a river-flood in
Java, iji. 235.
Bauza, his chart of Gulf of Mexico, ii,
34.
Bawdesey, crag strata near, iv. 79. 4
Bay of Bengal, its depth, i. 359.
Bayfield, Capt., on gealogy of Lake Su-
perior, i. 342.
—— on bursting of a peninsula by Lake
Erie, ii. 12.
a=, on elevated beaches in Gulf of St.
Lawrence, ii. 47. ; iv. 20.
~, on earthquakes in Canada, ii. 208.
——, on arrangement of strata in Gulf of
St. Lawrence, iv. 58,
Bayonne, strata near, iv. 124. 327.
Beachy Head, i, 423.5 iv. 228.
Bears, once numerous in Wales, iii.
TH.
——, black, migrations of, iii. 36,
-—, drifted on ice, iii, 103,

INDEX.

Beauchamp, palzotherium of, iV- 179.

Beaufort, Capt., on gain of land on coast
of Asia Minor, ii. 32.

——, on rise of tides, i, 382.

Beaumont, M. Elie de, on greyW
fossils, i. 201.

——, on the Great Canary, ii. 158.

——, on elevation craters, ii. 171.

——, on force of modern earthqu
ii. 357.

—, on cause of the deluge, iv. 205. ;

—, his theory of contemporaneo"
origin of parallel mountain cham
considered, iv. 320. f

—, on modern granite of the Alps:
344, A

Beaver, once an inhabitant of Seotla?
and Wales, iii. 110. i

—, remains of, in shell-marl, in pert
shire, iii. 236. ‘a

Beck, Dr., on distribution of testace
iii. 56.

—, on fossils of the Crag, iv. 72 , r)

—, on tertiary strata of Denmark, 1"
88.

Bee, migrations of the, iii. 64.

Beechey, Capt., on elevation of
Conception, ii. 256.

—, on drifting of canoes in
iii, 72.

——, on temple of Ipsambul, iii. 10) 9

—, on coral islands in Pacific, it
987, 297. ae

——, on recent changes of level 19
cific, ili. 296. of;

Beginning of things, supposed proofs
iv. 392.

Behat, buried town near, iii. 199.

Belbet, near Aurillac, iv. 160. `” ep-

Belcher, Capt., on elevation of Con?
tion Bay, ii. 256.

=, on strata forming off C035
Africa, iii. 273. E

Belgium, tertiary formations of, 1°

Beliemi, Mount, caves in, iv. 4%

Bell rock, large stones throw?
storms on the, i..400.

Belzoni, on temple of Ipsambul,

—, on a flood of the Nile, iii. 230-

Benin, currents in bay of, i. 383.

Bérard, M., on depth of Mediterra
ii. 18. f

Bergmann, on waste of Yorkshire coasts
i, 404,

Berkeley, on recent origin of ™
255.

acké

akes,

pay%

Pacifics

t of

jji. 189-

peah»

ans ji

Bermudas, coral reefs of the, iii, 279.

Berthelot, M., on the Great Canary, ii.
58,

Berzelius, on density of sea-water, i,
72,

Beshta, earthquakes in, ii. 250.
€udant, M., on volcanic rocks of Hun-
8ary, iv, 140.
Wick, cited, i. 413. ; iii, 47. 111.
00j, town of, destroyed by earth-
quake, ii. 195.
s» Volcanic eruption at, during Cutch
pe thquake, ii, 195. 5 iii. 194,
tes Bosch; new bay formed in Hol-
lang, ii. 5.
Bigsby, Dr., on North American lakes,
i. 343. ; iii. 262.
Ingen, gorge of, iv. 35,
instead, fossils of, iv, 216. 263.
Itds, diffusion of plants by, iii. 18.
—, geographical distribution of, iii.
45. 74.

—- their powers of diffusion, iii, 47.
“, migrations of, iii. 47.
~, recent extermination of some spe-
ĉies of, iii, 111.
NS, bones of, in Gibraltar breccia, iii.
209,
™, rarity of their remains in new
pi ttata, iii, 290.
ischoff, Professor, cited, iv. 372.
'Scoe, Capt., his discoveries in the
South Polar Seas, i. 175.
ison, fossil, in Yorkshire, i, 145.
‘sons, in Mississippi valley, iii. 35.
\stineau, a lake formed by Red River,
i, 290,
Bitumen, oozing from the bottom of the
Sea, near Trinidad, i. 334.
Bituminous springs, i. 334.
| >, shales, i. 335.
Bize, cave at, iii. 213.
zona, town submerged, i, 27,
lack Lake, i. 290.
S Sea, calcareous springs near, i.

B

™. waste of cliffs in the, ii. 12.
Ž, evaporation of the, ii. 15.
Rn. see Euxine.
prier, M., on peat, iii. 179.
toS limestone of, iv. 122.
oomfield, bursting of peat-moss near,
ni, 186.
Blown sand, imbedding of organic re-
Mains, &c. in, iii, 188.

re

INDEX.

403

Blue mountains in Jamaica, ii. 264,

Bluffs of Mississippi described, i, 283,
285. 3

Boa Constrictor, migration of, iii. 51.

Boase, Mr., on inroads of sea in Corn-
wall, i. 429, 430.

—, on drift-sand in Cornwall, iii. 191.

——, on chemical composition of rocks,
iv. 377.

Boate, Dr., on Irish peat-bogs, iii. 178.

Boblaye, M., on ceramique, in Morea,
iii. 200.

——, on engulphed rivers in Morea, iii.
204. 3

—, on caves of the Morea, iii. 204.

——, on earthquakes in Greece, iii. 207.

——,on successive elevations of the
Morea, iv. 20.

——, on tertiary strata of Morea, iv. 70.

—, on cretaceous rocks of Morea, iv.
277.

Bog iron-ore, whence derived, iii. 182,

Bogota, earthquake of, ii. 189.

Bohemia, age of metallic veins of, iv.
375.

Bolos, Don Francisco, on volcanos of
Catalonia, iv. 94. 99. 101.

—, on destruction of Olot by earth.
quake, in 1421, iv. 99,

Bonajutus, on subsidence of coast of.
Sicily, ii, 261.

Bonaparte, C., on birds, iii. 47.

Bonelli, Signor, on fossils of the Superga,

_ ii. 364, ; iv. 126.

=, on fossil shells of Savona, iv. 64.

Bonn, casts of freshwater shells in
quartz, near, iv. 112.

Bonpland, on plants common to Old and
New World, iii. 5.

Bordeaux, tertiary strata of, iii. 338. ;
iv. 119.
Bore, a tidal wave frequent in the Bris-
tol Channel and the Ganges, ii. 10.
Bormida, tertiary strata of valley of the,
iii. 364. ; iv. 127.

Bory de St. Vincent, M., on isle of San.
torin, ii, 161. 164.

Boscomb chine, i. 497,

Bosphorus, ii, 15. 52.

Botanical Geography, iii. 3.

——, provinces, their number, iii. 7.

——, how caused, iii. 80.

——, why not more blended together,
ili, 82.

Bothnia, Gulf of, gradual elevation of
the coast of, i. 217. 345. 5 ii. 287. |

{

|
|
|
|
|

EL BORE I I A

404 i INDEX;

Bothnia, Gulf of, drifting of rocks by

Gace in, 2

Botley Hill, height of, iv. 224.

Boué, M.. on the Pyrenees, i. 211,

—,, on the coal strata, i. 202,

—, on loess of the Rhine, iv. 38.

-——, on value of Zoological characters

. in determining the chronological re-
lations of strata, iv. 193,

——-, on tertiary formations of Hungary
and Transylvania, iv. 129. 141.

——, on the Vicentine, iv. 211.

——, on theory of M. de Beaumont, iv.
331. 333, t

Bouillet, M., on extinct quadrupeds of

. Mont Perrier, iv. 136. 197.

——, on alluviums of different ages in
Auvergne, iv. 197.

Boulade, alluviums of the, iv. 134.

Boulon and Ceret, dip of tertiary strata
between, iv. 70.

Bourbon, island, volcanic, ii, 58,; iv.
350.

Bourdones, R., shoal upheaved at its
mouth, ii, 208.

Bournmouth, submarine forest at, iii.
228.

Boussingault, M., on volcanos of the
Andes, ii. 43, 44.

——, on gases evolved by volcanos, ii.

Bowdich, Mr., on fossil shells of Ma-
deira, iv. 24.

Bowen, Lieut. A., on limestone columns
near Mingan, iv. 21.

Boyle on bottom of the sea, i. 44,

Bracini on Vesuvius before 1631, ii. 77.

Brahmins, their doctrines, i, 9.

Brand, Rev. J. F., on birthplace of man,
lii. 68.

Brander on fossils of Hampshire, i. 77.

Bray, valley of, iv. 287.-

Breaks in series of superimposed form-
ations, causes of, iii. 345. 351.

Breccias, in Val del Bove, iii. 422,

=, in caves, iv. 38, 43.

——, NOW in progress in the Morea, iii.
205.

—, volcanic, of Auvergne, iv. 134. 187.

Brenta, delta of the, i. 350,

Brieslak, on the temple of Serapis, ii.
276. 278.

-—, on lavas of Vesuvius, ii. 90.

Briggs, Mr., his discovery of water in
African desert, i. 304,

Brighton, waste of cliffs of, i, 424,

Brighton, strata at base of cliffs at *
422.3; iv. 261. 267.

Brine springs, i. 330.

Bristol Channel, currents in,

Britany, a village in, buried
blown sand, iii. 191.

—, marine tertiary strata of, i. 216.

Brocchi on fossil conchology, i. 34

——, on Burnet’s theory, i. 59. er

——.,, his account of writers on delt#
Po;4. 351. 3 w

—, on extinction of species, iii. 83- jji

—, on the Subapennines, i. 209-5 *
335, ; iv. 49. 60. yi

Broderip, Mr., on opossum of Ston®
field, i. 238.

—, on shells from Conception Baf»
257.

——, on lanthina fragilis, iii. 56,

—, on bulimi restored to life
long abstinence, iii. 58.

-—, on moulting of crabs, iii. 60. ie

—, on naturalization of a foreign 12
shell, iii. 76. aug

Bromberg, a vessel and two anchors
up near, iii, 247. .

Bromley, pebble with oysters in
clay at, iv. 212.

Brongniart, M. Ad., on fossil plant
the coal formation, i. 158.

—-, on plants in islands, i. 196. if

Brongniart, M. Alex., on modern lava
streams, ii, 132. 3 i.

—, on elevated beaches in Swede?
216. ; ii. 299.

—, on the Paris Basin, iii. 3323
166..172.

——, on conglomerate of the Supe
iv. 127. ge

Bronn, Prof., on fossil shells of
Superga, iii. 367. :

, on tertiary formations of Italys

a0)s

——, on loess of the Rhine, iv. 32. pe

„on tertiary strata of Mayenc®

133, me

Bronte, eruption of Etna, near, 1. if of

Browallius, on filling up of GU
Bothnia, ii. 291. Af

Brown, Mr., on plants eommon we
rica, Guiana, and Brazil, iii. 15- sill

Brown coal formation near the Rhi
iv. 110.

Bruel, quarry of, iv. 160. Rls

Buckland, Dr., on fossil elephants:
in India, i. 9,

it.

after

jasti¢

of

iv.

ga

ii

INDEX.

| Bucklana, Dr., on fossils from Esch-

Scholtz’s Bay, 1. 153.
“=: on the Bristol coal-field, i. 205.
> on mammiferous remains of Isle of
ight, i. 241.
™-, on fossils in caves and fissures, iii.
208, 210, 212.
= on Val del Bove, iii. 407.
~ on effects of the deluge, iv. 203.
- on the Plastic clay, iv! 212.
» on former continuity of London
and Hampshire basins, iv. 219.

~~, on valleys of elevation, iv. 246. 249.

|

|

~, on fossil forest of I. of Portland,
iv, 285, ‘
©, On oolite fossils, iv. 310.
Budoshagy, solfatara of, iv. 142.
Ufadors, jets of air from subterranean
Caverns called, iv. 98.
Buffon, his theory of the earth, i. 68.
—,, reproved by the sorbonne, i. 69. :
~, on geographical distribution of ani.
Mals, iii. 2. 27.
~, on extinction of species, iii. 143.
Butimus montanus drifted from Alps,
üi, 360.
ùra and. Helice, submerged Grecian
towns, i. 27.’ ii. 56. ; iii. 255.
Urckhardt cited, iii. 189, 190.
Urdiehouse fossils, i. 203. ; iv. 294.
Buried cones on Etna, sections of, iii.
415,
Burkart, Mr., on Jorullo, iix 137.
urnes, Capt. A., on earthquake of
Cutch, 1819, ii. 196.

_™, on earthquake in valley of the

Oxus, ii. 50.

ürnet, his theory of the earth, i. 55.
Burntisland, whale cast ashore near,

li, 266.

Urrampooter, bodies of men, deer, &c.

floated off by, iii, 234.

| X, delta of the, i. 558.

“Urton, Mr. J.,on tertiary strata near
Red Sea, iv. 25.

Bustaras, recently extirpated in Eng-
land, iii. 111.

Pitter, Burnet’s theory ridiculed by, i.
6.

Byron, Lord, on permanency of the
Ocean, ii. 285,

C.

Cadibona, lignites of, iv. 139.
ado lake, i, 290,

Cæsar cited, i. 27.3 iv. 200.

Cairo, fossil shells at, iv. 197.

Caithness schists, fossils any 235. ý

Calabria, geological. description of, ii
14.

~ earthquake of 1783 in, ii. 210.

—, animals preserved in fissures in,
iii. 209. ,

—,, tertiary strata of, i. 141. 5 iii, $40,

Calais, ripple marks formed by the
winds on dunes near, iv, 81,

Calanna, lava of Etna turned from its
course by hill of, iii. 412.

——, valley of, iii. 411. 419,

Calcaire grossier of Paris basin, iv. 167:
169. 173. 179.

Caleaire siliceux of Paris basin, iv. 170.

Calcareous springs, i. 311. ane

Calcutta, beds cut through in sinking 4
well at, i. 361.

Caldcleugh, Mr.,on earthquake in Chili,
1835, ii. 185.

Caldeira, siliceous sinter of the, i. 327.

Caldera, in Isle of Palma, ii. 155.; iti.
200.

California, volcanos in, ii. 45,

Callao, town destroyed by sea, ii. 53,

——, changes caused by earthquakes in,
ii. 258, 259. ; iii. 253,

Caltabiano, R., lava excavated by, i.
274.

Caltagirone, blue shelly marl of, iii, 886.

Caltanisetta, tertiary strata at, iii, 387.

Cambrian formations, iv. 300. 306.

Camden cited, i. 431. >

Camels, carcasses of, imbedded in drift
sand, iii. 190.

Campagna di Roma, calcareous deposits
of, i. 320,

—-, volcanic rocks of, iv. 89.

Campania, aqueous lavas in, iii. 192,

——- tertiary formations of, iv. 1,

——— Comparison of recorded changes in,
with those commemorated by geolo.
gical monuments, iv. 1.

——, age of volcanic and associated
rocks of, iv. 11.

——, external configuration of the coun-
try, how caused, iv. 13.

——, affords no signs of diluvian waves,
iv. 14,

Campbell, Mr., on migration of quaggas
in South Africa, iii. 38.

Camper, on facial angle, ii. 437,

Canada, earthquakes frequent

in, ii.
46, 203.

v

“406

+

Canary islands, eruptions in, ii, 58.

——., shells between lavas in, ii, 158.

Cannon in calcareous rock, iii. 249.

=, account of one taken up near the
Downs, iii. 249,

Canoes drifted to great distances, iii. 71.

=, fossil, iii, 248,

Canopus, formerly an island, i. 354.

——, overwhelmed by the sea, i. 356.

Cantal, Plomb du, ii. 170.

—, freshwater formations of, iv. 158.

Capellbacken, shelly deposit at, ii. 299.

Cape May, encroachment of sea at, ii.
10.

~ of Good Hope, icebergs seen off,
Syg

—— Wrath, granite veins of, iv. 346.

Capitol, hill, calcareous tufa on, iv. 28,

Capo Santa Croce, shelly limestone
resting on lava at, iii. 390. `

Capra, rock of, iii. 420.

Caraccas, earthquakes in, ii. 202. 208.

Caradoc sandstones, iv. 270, 271. 299.

Carang Assam volcano, ii. 202.

Carbonated springs, i. 331.

Carbonic acid gas; its effects on rocks,
i. 331. 333. ; iv. 374.

Carboniferous series, i. 201. 235.; iv.
293.

——, freshwater strata in, iv. 294.

——, see Coal.

Carcare, tertiary strata of, iv. 121. 127.

Cardiganshire, tradition of loss of land
in, i. 431.

Cardium porulosum, iv. 175.

Cardona, rock salt of, its relative age,
iv. 316.

Carelli, Signor, on temple of Serapis, ii.
273.

Carew on St. Michael’s mount, i. 430.

Cariaco, bed of sea raised near, ii, 250.

Caribbean sea, tides in, i. 388. ;

Caridi, R., its course changed by earth-
quakes, ii. 230.

Carlingford bay, raised beaches in, i. 216.

Carpenter, Dr., on encroachment of sea
at Lyme Regis, i. 429.

Casalmaggiore, island at, carried away
by the Po, i. 280.

Casamicciol, shells in tuff at, iv. 12.

Caspian, Pallas on former extent of, i.
80.

=, calcareous springs near the, i. 396.

==, evaporation of the, i. 350.

——, earthquakes on its borders, ii. 51,

=, inflammable gas, &c. near, ii. 51.

INDEX.

Caspian, its level, ii. 51.; iii. 126.5 iV- ee

—, said to have been united i i
Black Sea and sea of Azof, ii. 9%?
iii. 45.

Cassander cited, i. 13. in

Castell de Stolles, ravine excavated
lava opposite, iv. 96. op de

Castell Follitt, lava stream of, 1Y" iv.

—, lava cut through by ‘river 44
97.

Castello d’ Aci, iii. 405. . Not

Castrogiovanni, section of Val di N°
series at, iii, 385.

—, hill of, its height, iii, 386.

——, fossils of, iii. 389. saat

Catalonia, devastation of torrents 1s
164.

——, volcanic district of, iv. 90.

——, ravines excavated through lav!
iv. 95. 97.

——, age of volcanos of, iv. 99.

——, superposition of rocks in volc
district of, iv. 100. sais

Catania, overwhelmed by lava, Íi- pog
iii. 193. de

——, destroyed by earthquakes, 1! ~ ell

—, tools discovered in digging 4
at, iii. 246, :

, volcanic conglomerates formiD

beach at, iii. 396.

— plain of, iii. 397.

——, marine formation near, iii. wt 3

Catastrophes, theories respecting; t “^?
iii. 309. 353.

Catcliff, Little, section of, iv. 80.

Catcott on the deluge, i. 74. x

—— on traditions of deluges in differ
countries, i. 74.

Catodons, stranded, iii. 266.

Cattegat, devastations caused by cut
in the, ii. 12.

Catwyck, loss of land at, ii. 5. a

Caucasus, calcareous springs of, 1. 3 250

—, earthquakes frequent in, ii. 3%

—, abounds in hot springs, ii. 59- yi

Cautley, Capt., on buried Hindoo t°
iii, 199. «ai 008:

—, on bones in ancient wells, HL 4i,

Cavalaccio, Monte, shells in tuffs ©
402. :

Cavanilles on earthquake of Quito
207. ‘

Caves, organic remains in, iii.
iv. 38. 42, 43,

——, alternations of sediment a”!
lagmite in some, iii. 210.

aih

anit

op

ent

ent

ji.
gi. 215

q sta

INDEX.

Caves on Etna, ii. 120.

Cavo delle Neve, in Ischia, iv. 13.

Cayambe, volcano, ii. 43.

Cellent, lava current of, iv. 91.

—, section above -bridge of, iv. 95.

Celestial mountains, i. 147.

Celsius on diminution of Baltic, 1. 58. ;
ii. 286,

Censorinus, i. 21. é

Central France, lavas excavated in, i.
272.

—, comparison between lavas of Ice-
land and, ii. 129, 131.

~, volcanic rocks of, iv. 142. 184.

~, freshwater formations of, iv. 144.

——, analogy of tertiary deposits of, to
those of Paris basin, iv. 164. 172.

Central heat and fluidity, theory of, i.
221. ; ii, 313.

Centrifugal force, ii. 309. 329.

Cephalaspis, fish fossil in old red sand-
stone (see fig.), iv. 296.

Cephalonia, earthquakes in, ii. 214.

Cer, valley of, sections in the, iv. 161.

' Ceret and Boulon, tertiary strata be.

tween, iv. 70.

Cesalpino on organic remains, i. 38.

Cetacea, geographical range of, iii. 33.

—, migrations of the, iii. 44.

—, imbedding of their remains in re-
cent strata, iii. 266.

~, stranded on low shores, iii. 266. '

Chabriol, M., on fossils of Mont Per-
rier, iv. 136.

Chadrat, pisolitic limestone of, iv. 152.

Chagos coral isles, iii. 280.

Chalk, protruded masses of, in the crag
Strata, iv. 85.

—, indentations filled with sand, &c.,
on its surface, iv. 217.

—, tertiary outliers on, iv. 218.

—— and upper green sand of Weald
valley, iv. 223.

—— escarpments of Weald valley, once
sea-cliffs, iv. 227, 228.

——, why no ruins of, on central district
of the Weald, iv. 234.

—— of North and South Downs, its
former continuity, iv. 244.

——., furrows on the, how caused, iv.
217,

—, greatest height of, in England,
iv. 259.

~—., area covered by, iv. 275.

———, converted into marble by trap dike
in Antrim, iv. 366.

407

Chalk-flints, analysis of, iv. 160.

Chaluzet, calcareous spring at, i. 312,

—, volcanic cone of, i. 332.

Chama gigas, growth of, iii. 282.

Chamaliéres, near Clermont, iv. 147.

Chambon, lake of, how formed, iv. 193.

Chamisso, M., on coral islands, iii. 278. `

Chamouniy, glaciers of, iv. 47.

Champheix, tertiary red marls of, iv.
148.

Champoleon in the Alps, strata altered
near, iv. 369.

Champradelle, vertical marls at, iv. 151.

Chare, fossilized, iii. 259.

Charlesworth, Mr., on the crag strata,
iv. 73, 74.

Chemical changes, whether volcanic
heat is produced by, ii. 320.

Chepstow, rise of tides at, i. 382.

Cheshire, brine springs of, i. 330.

——, waste of coast of, i. 431.

Chesil bank, i. 427.

Chesilton, overwhelmed by sea, i. 428.

Chili, earthquakes in, i. 117. ; ii, 183.
189.

——, numerous volcanos in, ii, 41.

—, Newer Pliocene marine strata at
great heights in, iv. 16.

Chimborazo, height of, i. 181.

China, climate of, i. 169.

—, earthquakes violent in, ii, 50.

Chinese deluge, i. 10.

Chines, or narrow ravines, described,
i. 427.

Chittagong, earthquake at, ii. 250.

Chockier, cave at, iii. 211.

Christ Church. head promontory, i. 426.

Christie, Dr. T., on caverns in Sicily,
iv. 39, 41, 42.

Christol, M. de, on fossils of Montpel-
lier, iv. 196.

—, on caves, iii. 214, 215.

Cicero cited, i. 42.

Cimbrian deluge, ii. 13.

Cinquefrondi, changes caused by earth-
quake at, ii. 232.

Ciply, Maestricht beds seen at, iv. 271.

Cirque of Gavarnie, in Pyrenees, iii.
415.

Circular hollows formed by earthquakes,
ii. 234,

Cisterna on Etna, how formed, iii. 425. ;
iv. 15.

Civita Vecchia, springs at, i. 320.

Clarke, Dr., on appearance, &c. of lava
in motion, ii. 83.

408

N
\

Clay-slate in Pyrenees, iv. 362. \

——, may be altered into shale, and
hornblende schist, iv. 376.

Clayton, Bishop, on the deluge, i. 74,

Cleavage, or slaty structure of rocks, iv.
354.

Clermont, sections near, iv. 147. 151.
185.

——, calcareous springs at, i. 312.

Clift, Mr., on bones of animals from
Australian caves, iv. 44.

Climate of Europe, Raspe on former, i.
7.

==, change of, in northern hemisphere,
i, 138,

—, on causes of vicissitudes in, i. 164.

~, astronomical causes of fluctuations
in, i. 224,

——, its influence on distribution of
plants, iii. 3.
—~, effect of alterations in, on distri-
bution of species, iii. 134. 138. 331.
——, influence of vegetation on, iii.
165.

Climates, insular and excessive, i. 169. ;
ii. 390.

Coal, formation of, at mouths of Mac-
kenzie, iii. 222.

—, reduced to cinder by trap dike, iv.
367.

——. See Carboniferous.

Coal formation, fossil plants of the, i.
158. 202. 231. 243.

Cole, Viscount, on delta of the Kander,
iv. 69.

Colebrooke, Mr. H. T., on crocodiles of
Ganges, i. 362.

Colebrooke, Major R. H., on the Ganges,
i, 361. ; iii. 170.

Colle, travertin of, i. 313.

——, freshwater formation of, iv. 28.

College, R., transportation of rocks by
the, i. 268.

Collini on igneous rocks, i. 86.

Colombia, earthquakes in, ii. 250.

Colonna on organic remains, i. 39.

Comb Hurst, hills of, iv. 213.

Côme, lava currentiof, iv, 93.

Conception, earthquakes at, ii. 185. 256.;
iii. 253.

—, recent fossils at great heights in
Bay of, iv. 16.

Conglomerates, tertiary, of Nice, iv. 65.

——~, now formed by rivers near Nice,
i, 375.5 iv. 65. 68.

omen, VOlcanic, ii. 143, ; iii, 396,

INDEX.

Contemporaneous origin of rocks, how
determined, iii. 322.
—, remarks on the term, iii. 363. _
Continents, position of former, iV. 307
Conybeare, Rev. W. D., on Lister, + ***
——, on Bristol coal-field, i. 205.
——, on earthquakes, ii, 357.
—, on the English crag, iii. 337,
——, on the London clay, iv. 214
——, on indentations in the chalk, 1%
DAME:
—, on transverse valleys, iv. 238.
—, on vertical strata of Isle of Wight
iv. 253.
,on former continuity of chal
North and South Downs, iv. 244.
„on theory of M. E. de Beaumont,
iv. 333.
Cook, Captain, on drifting of canoes t°
great distances, iii. 71.
——, on existence of high land neat the
South Pole, i. 177.
Coomb, ravine called the, near Lewes
iv. 241. s
Copernican theory, edicts against, Tee
pealed at Rome, i. 100. a
Copiapo, raised banks of shells at, ™™
191:
Coquimbo, parallel roads of, iv. 18.
Coral between lava currents in Wes
Indies, iii. 294. `:
Coral islands, iii. 274.
—, beds of oysters, '&c., on, in the
Pacific, iii. 276.
—, their extent, iii. 280. 294. 298.
—, linear direction of, iii. 280.
, rate of growth of, iii. 282.
Cordier, M., on rate of increase of heat
in mines, ii. 313. 317.
—, his theory of central heat and
fluidity, i. 222. ; ii. 314.
——, on tides in the internal melted
ocean, ii. 319. mn
Cordilleras shaken by earthquakes, »
189. 203, 3
Corinth, decomposition of rocks in, }”
203. ; iv. 374.
Cornwall, waste of cliffs of, i. 429. —
—, land inundated by drift sand ín,
iii. 191.
——, temperature of mines in, ii. 313.
—, granite veins of, iv. 340. 308.
Corémandel, inundations of sea on coast
of, iii. 198.
Cortesi, i. 79.
Cosmogony distinct from geology, i. 9

k of

INDEX.

Cosmogony of the Hindoos, i. 6,

——, Egyptian, i. 12.

-—— of the Koran, i. 31.

Costa de Pujou, hill of, iv. 93.

Costantini, deluge vindicated by, i. 60.

Cotentin, tertiary formation of the, iv.
208.

Cotopaxi, ii. 43. 337.

Coudes, tertiary red sandstone of, iv.
148. ;

Covelli, M., on increase of temperature
of a hot spring in Ischia by earth-
quake, ii. 188.

Cowper, i. 98.

Couze, R., lake formed by fillin
its ancient bed by lava, iv, 193.

Crag of England, fossils of the, iii. 336. ;
Iv. Pls 72. fas

—, its'age, composition, &c., iv. 71,

——, lacustrine deposits resting on the,
iv. 77.

—, stratification of the, iv. 78.

——, compared to Faluns of Touraine,
iv. 116, 117.

-——, its resemblance to formations now
in progress, iv. 82.

Cramer, Mr., on earthquake of New
Madrid, ii. 204.

Crantz on drift-wood, iii. 224.

Craters of elevation, Von Buch’s theory
of, considered, ii. 152.

Crawfurd, Mr., his discovery of fossils
in Ava, i. 50.

Creation, supposed centres or foci of,
iii. 81.

Cremona, lakes filled up near, i. 279.

Creta, argillaceous deposit called, iii.
387. 397. 401.

Cretaceous group, iv. 271.

Crimea, waste of cliffs in the, ii. 12.

Crocodile taken in the Rhone, iii. 50.

Crocodiles imbedded by a river inunda-
tion in Java, ii. 260. ; iii. 230. 234.

Croizet, M., on extinct quadrupeds of
Mont Perrier, iv. 136.

——, on alluviums of Auvergne, iv. 197,

Cromer, waste of cliffs of, i. 406.

—, section near, iv. 83.

Cropthorn, fossils found at, i. 145.

Crowborough hill, height of, iv. 224.

——, thickness of strata removed from
summit of, iv. 259.

Cruckshanks, Mr. A., on earthquake of
Chili in 1822, ii. 190.

——, on lines of ancient sea-cliffs on
coast of Peru, iv. 17.

g up of

VOL. IV.

T

409

Cuckmere, transverse valley of the, iv.
238.

Culver cliff, i. 495.

Cumana, earthquake of, ii. 207.

Cumberland, slate rocks of, iv. 354. 389.

Cuming, Mr., on earthquake at Valpa-
raiso, 1822, ii. 19].

Currents from equatorial regions, i. 170.

——, from the Pole to the Equator, i.
189,

—, section of débris deposited by
opposing, i. 378. :
——- Causes and velocity of, i. 382. 385.
—, destroying and transporting power

of, i. 392. ; ii. 30. 32. 34.

——, in estuaries, their power, i. 400.

—, in the Straits of Gibraltar, ii. 14.

——-» reproductive effects of, ii. 22.

—, on the British shores, ii, 22,

—, distribution of drift-timber by, iif.
225; $

Curtis, Mr., on ravages caused by
aphides, iii. 93.

Curtis, Mr. John, on power of the ti-
pulæ to cross the sea, iii. 67.

—, on number of British insects, iii .
148.

——, on fossil insects, iii. 229. ; iv. 211,

Curves of the Mississippi, i. 283. :

Cussac, fossils in alluvium under lava
at, iv. 136.

Cutch, changes caused by earthquake of
1819 in, ii. 194. ; iii. 253. 435. ; iv. 174.
253. 285.

—, map of (see plate 5.), ii. 194. .

Cuvier, on durability of bones of men,
i. 246. ; iii. 245. ;

——-,, on variability in species, ii. 391. 394.

—, on identity of Egyptian mummies
with living species, ii. 397.

—, on number of fishes, iii. 149.

—, on extinction of the dodo, iii. 113.

—, on oolite fossils, i. 237.; iv. 310.

——,on mammiferous remains of the
Upper Val d’ Arno, iv. 138.

—, on tertiary strata of Paris basin,
iii. 332. ; iv. 166. 172. 179.

Cuvier, M. F., on aptitude of some ani-
mals to domestication, ii. 408.

——, on influence of domestication, ii.
413.

Cyclops, island of, in bay of Trezza, iii.
401.

Cypris, fossil, iii. 262.; iv.. 150. 282.

——, habits of living species of (see

figs.) iv. 150. ‘

INDEX.

D

Dalman, M., on greywacké rocks of
Sweden, iv. 300.
Dangerfield, Captain F., on buried cities
in Central India, iii. 194.
Daniell, Professor, on the trade-winds,
i. 188.
——, on melting point ofiron, ii. 314.
__—., on fusion of metals, ii. 317.
—_—, on deoxidating power of hydrogen,
ij. 328.
Danish Archipelago, undermined by
currents, ii. 12.
Dante, embankment of rivers noticed
by, i. 281.
Dantzic, waste of land near, ii. 12.
D’ Anville, M., on gain of land in Red
Sea, ii. 28.
Darby on drift-wood of Mississippi, 1.286.
——, on lakes formed by Red River, i.
290.
__—, on marine strata of Lower Louis-
iana, i. 291.
—, on delta of Mississippi, i. 365.
Darent, transverse valley of the, iv. 238.
Dartmoor granite, iv. 368.
Paubeny, Dr. on mineral springs, i. 309.
__—, on country round the Dead Sea, i.
331.
, on Mount Vultur, ii. 57.
——,on decomposition of trachyte, ii.
90. ; iv. 374.
—— , on flowing of lava under water, ii.
94.
——, on vicinity of volcanos to the sea,
ii. 347.
—, on agency of air and water in vol-
canos, ii. 349. 351.
——., on nitrogen in mineral springs, iii.
158.
—, on Val di Noto limestone, iii. 387.
——, on eruption of Vesuvius in 1834,
iii. 424.
ses for volcanic region of Olot, iv. 91.
—, on volcanic district of Lower
Rhine and Eifel, iv. 113.
__—, on Auvergne volcanos, iv. 200.
D Aubuisson cited, i. 103. 5 ili, 422.
Daun, lake-craters near, iv. 104.
Davis, Mr., on the Chinese deluge, i.
ibe
Davy, Sir F., onlake of the Solfatara,
44, 320.
——-, on formation of travertin, i. 321.

Davy, Sir H., his theory of progressive
development, i. 297.

—, on eruption of Vesuvius, ii. 85-

——, on chemical agency of electricity,
ii. 323.

——, his theory ofan unoxidated Me-
tallic nucleus, ii. 327.

—, on agency of air and water in vol-
canos, ii. 349. 351.

—, his analysis of peat, iii. 177.

Davy, Dr., on Graham Island, ii. 152.
348.

—, ona helmet taken up from the sea
near Corfu, iii. 251.

Davy, Rev. C., on Lisbon earthquake,
ii. 352.

Dax, tertiary formations of, iil. 338.5
iv. 119.

—, inland cliff near, iv. 124.

Dead Sea, waters of, i. 331. ‘

—, the country around it volcanic, i.
331. ; ii. 54. i

De Candolle on hybrid plants, ii. 491.

—, on distribution of plants, iii. 4, 5.

—, on agency of man in dispersion of
plants, iii. 22.

—, on stations of plants, iii. 87.

—, on the barriers which separate dis-
tinct botanical provinces, iii. 144.

—, on number of land plants, iii. 148-

—, on longevity of trees, iii. 428.

Dee, R., bridge over, swept away by
floods, i. 267. K

Deer, their powers of swimming, jji. 39-

—, formerly abundant in Scotland,
iii. 110.

—, remains of, in marl lakes, iii. 936.

Deguer on remains of ships, &¢- in
Dutch peat-mosses, iii. 187.

De la Beche, Mr., on greywacké fossils,
1. 201.

——, on delta of Rhone in Lake of Ge
neva, i. 338. .

—, on storm of Nov. 1824, i. 429.

——, on earthquake of Jamaica, 1692,
ii. 263.
——, on action of rain in the tropics»

iii. 165.
=, On

drifting of plants to sea by
hurricanes, iii. 225.

—, on coral formations, iii. 288. :

—, on alternation of coral and lava 3?
Isle of France, iii. 294.

——., on fossil forest of I. of
iv. 285.

Portland,

INDEX.

Dela Beche, Mr., on granite of Dart-
moor, iv. 368.

De la Hire on fossil wood from Ava,
1692, i. 49.

Delhi territory, elephants in, i. 152,

Delille on wheat in Egyptian tombs,
ik 398. i

-—— on native country of wheat, ii,
399.

Delta of the Adige, i. 350.

—— of the Brenta, i. 350.

— of the Burrampooter, i. 358,

—— of the Ganges, i. 358.

—, its stratification, i. 376.

—— of the Isonzo, i, 350. ,

—— of the Mississippi, i. 364, 376,

— of the Niger, size of, iv. 309,

— of the Nile, i. 353. ; iii. 348,

— of the Po, i. 350.

—_—of Rhone, in Lake of Geneva, i.
337. ; iii. 346.

of Rhone, in Mediterranean, i,

346.

of the Tagliamento, i. 350.

Deltas, chronological computations of
age of, i. 339.

——, of Lake Superior, i. 342.

——, of the Baltic, i. 344.

——, oceanic, i. 357.

——, grouping of strata in, i. 371.

——, independent in same basin, i. 373.

De Luc, his treatise on geology, 1809,
i. 99,

——, on origin of granite, i. 102.

—, on age of deltas, i. 342.

——, on conversion of forests into peat.
mosses, iii, 181.

——, on the deluge, iv. 203.

De Luc, M. G. A., his natural chrono-
meters, iii. 188.

Deluge, ancient theories on causes of,
i. 32. 46. 53. 55. 57, 58. 60. 74.

—, fossil shells referred to the, i. 34.
57. ;

—, on changes caused by the, iv. 201.

——, M. de Beaumont on cause of his-
torical, iv. 218.

Deluges part of the present course of
Nature, i. 133.

——., local, how caused, i. 10. 292.

——, traditions of different, i. 10. 21.74. ;
ii. 52. ;

Demaillet, speculative views of, ii. 373.

Denmark, tertiary strata of, iv. 87.

Denodur volcano, ii. 195.

Denudation, effects of, iii. 165. 349. 352.

`

Alt

Denudation of valley of the Weald,iv.221,

Deposition of sediment, rate at which
the finer kinds subside, ii. 34.

—, shifting of the areas of, iii, 345,

Derbyshire, Whitehurst on, i. 79.

Descartes, iii, 426.

Deshayes, M., on fossil shells, iii. 339
369. 374. 387. 402. ; iv. 23, 28. 71. 131.
141. 175. 272. 279. 327.

——, 0n subdivisions of the tertiary
strata, iii. 366.

=, on limestone of Blaye, iv. 129.

Desjardin, M., bones of the dodo found
under lava by, iii. 113.

Desmarest considered geology a branch
of physical geography, i. 5. $

—, on Auvergne, i. 86.

——, on the separation of England from
France, i. 420.

Desmoulins, M. Ch., on Eocene depo.
sits near Bordeaux, iv. 123,

—, on fossils of S. of France, iv, 119.

Desnoyers, M., on human remains in
caves, iii, 215. =

—, 0n tertiary formations of Touraine
iii. 338. 366. ; iv. 115. 117. i

—, on fossils ofthe Orleannais, iy, 137,

——- on alternation of plastic clay and
calcaire grossier in Paris basin, iv. 168,

——, on the Cotentin, iv. 208. `

Deucalion’s deluge, i. 21.

Diceras limestone, iv. 289.

Didelphis, fossil, in oolite, i. 237.

Dikes, composition and position of, ij,
85. ; iü. 390. 392. 417, 421.'; iv. 5. 24, °

— how caused, iii. 85.; iv. 6. _

——, changes caused by, iii. 392, 417.3 iv.
364. 378. i

Diluvial theories, iv. 201.

—— waves, whether there are signs of
their occurrence on Etna, iii. 431,

—, no signs of in Campania, iv. 14,

Dimlington height, waste of, i. 402.

Diodorus Siculus cited, ii. 53. 115.

Dion Cassius cited, ii. 68.

Dodo, recent extinction of the, iii. 119.

Dog, varieties of the, ii. 367. 393.

——, its distinctness from the wolf, ii,
394.

——, hybrids between wolf and, ii, 494.

——, examples of acquired instincts hee
reditary in the, ii. 409,

—— has run wild in America, iii. 115,

Doggerbank, Capt. Hewett on the, ii.
30.

Dollart, formation of estuary of the, jiy.

TZ

412

Dolomieu on the Val di Noto, Vicentin,
and Tyrol, i. 87.

— on lavas of Etna, i. 87.

_ on decomposition of granite, i. 333.

—— on earthquake of 1783-in Calabria,
ii. 213. 215. 229. 242.

Domestication, aptitude possessed by
some animals to, ii. 408. 419.

——., influence of, ii. 413.

Dominica, coral between two lava eur-
rents in, iii. 294. 5 iv. 22.

Don, R., transportation of rocks by, i.
267.

Donati on bed of Adriatic, i. 68, 127.
Soin iy 272; j

D’Orbigny cited, iv. 176.

Dorsetshire, landslip in, i. 427.

—, waste of cliffs of, i. 429.

—, valleys of elevation in, iv. 249.

Doue, M. Bertrand de, on tertiary strata
of Velay, iv. 136. 157, 158, 190.

—, on Auvergne alluviums, iv. 197.

Dover, waste of chalk cliffs of, i, 419.

——, depth of sea near, i. 420.

——, formation of Straits of, i. 420. -

——, strata at foot of cliffs of, i. 422. ; iv.
261.

Downham buried by blown sand, iii. 191.

Dranse, R., i. 295. 297.

Drift-sand of African deserts, iii. 188.

Drift-wood of Mississippi, i. 284. 287-
365.

—, imbedding of, iii. 219.

~—, abundant in North Sea, iii, 224.

Drinkwater, Mr., i. 100.

Drongs, granitic rocks of Shetland,worn
by the sea, i. 397.

Drontheim, ii. 302.

Druids, their doctrines, i. 27.

Du Bois, M., on tertiary strata of Vol-
hynia and Podolia, iv. 152. .

Dufrénoy, M., on the Pyrenees, i. 211. ;
iv. 368.

—, on tertiary strata of S. of France,
iv. 119. 121. 124.

——, on limestone of Blaye, iv. 123.

—, on hill of Gergovia, iv. 186.

——., on age of red marl and rock-salt of
Cardona, iv. 316.

—, on chalk of S. of France, iv. 276.

Dujardin, M., on shells, &c. brought up
by artesian well at Tours, i. 307.

——, on foraminifera of Paris basin, iv,
176.

Dunes, hills of blown sand, i. 404. ; ii.

BL; iv. 815

INDEX.

Dunwich, destroyed by the sea, i. 411.

—, crag strata in cliffs near, iv. 77. 79-

Durance, R., land-shells drifted by thes
iii, 360.

Dureau dela Malle, M., cited, ii. 393-
408.

Durham, waste of coast of, i. 402.

E.

Earth, antiquity of the, i. 35.

—, on changes in its axis, i. 53. 57.

——, proportion of land and sea on its
surface, i, 221.

—, spheroidal form of the, ii. 309.

——, mean density of the, ii. 311.

—, electric currents in the, ii, 324.

—, sections of the (see figs. 59, 60.)s ii.
316. 333.

—, effects produced by the powers of
vitality on its surface, iii. 153.

Earth’s crust, signs of a succession of for-
mer changes recognizable in, iii. 303.

——, arrangement of materials com-
posing the, iii. 311. S

Earthquakes, energy of, probably uni-
form, i. 94. 132.

—, earth’s surface continually Te-
modelled by, i. 181.

, all countries liable to slight shocks

of, ii. 59.

—— chronologically described, see Vol.
Il. p. 181. e¢ seq.

——, phenomena attending, ii. 182.

—, in Cutch, 1819, see map, ii. 194.

___, in Calabria, 1783, ii. 210.

—, difficulty of measuring the effects
of, ii. 217.

—, chasms formed by, ii. 224, ie

—, excavation of valleys aided by, 1!
237. ; iii. 442.

—, renovating effects of, ii. 353. 358.

—, cause of the wave-like motion of,
ii, 335. i

——, cause of retreat of sea during, 1+
254. A

— , ravages caused by sea during, }
198.

—, several thousand people entombed
in caverns during, iii. 207.

_—, their effects in imbedding
and forests, iii. 252. i

—, in the Pacific, iii. 296.

—, causes of volcanos and, ii. 307.

East Indian Archipelago, tertiary form
ations of, iv. 23. a

ji.

cities

SS a aS Se Deen tne enema

INDEX.

Ecchellensis, Abraham, i, 23.

Edmonstone Island, i. 360. ex

Edwards, Mr. M., on corals of the crag,
iv. 73.

Eels, migrations of, iii. 53.

Egerton, Rev. Mr., on delta of the Ran.
der, iv. 69.

Egypt, nearly exempt from earthquakes,
is G57: ‘

—-, cities and towns buried under drift.
sand in, iii. 188.190.

` Egyptian cosmogony, i. 12. 249,

— mummies identical with species
still living, ii. 395.

Ehrenberg, M. C. G., found Bengal tiger
in Siberia, i. 147.

— on corals of Red Sea, iii. 275. 283.
288. 293. 359.

Ehrenhausen, coralline limestone of, iv.
130.

Eichwald, M., on tertiary deposits of
Volhynia and Podolia, iv. 132.

Eifel, volcanos of the, iv. 101.

—, lake-craters of the, iv. 102.

~—., trass of the, and its origin, iv. 108.

Electricity, a source of volcanic heat,
ii. 323.

——, whence derived, ii. 326.

Elephant, fossil, in ice on shores of
North Sea, i. 80. 151.

€ Elephant Bed’ at Brighton, i. 422. ; iv.
261. 267. :

Elephants covered with hair in Delhi, i.
152.

——, their sagacity not attributable to
their intercourse with man, ii. 418.

=, their powers of swimming, iii. 33.

Elevation of land, how caused, i. 50. ;
ji. 184. 189. 256. 339. 5 iii. 436.

——., proofs of successive, iii. 440.

Elevation and subsidence, proportion of,
ii. 355.

Elevation craters, Von Buch’s theory
of, considered, ii. 152.

Elevation valleys, ii. 176. ; iv. 246.

Elizabeth or Henderson’s Island de
scribed, iii. 295.

Elsa, travertin formed by the, i. 312.

——, freshwater formations of the, iv.
ae

Embankment, system of, in Italy, i.
280.

——, gain of land in Adriatic more rapid
in consequence of, i. 351.

Emu in Australia will become extermi.
nated, iii, 112.

T

neon

413

Engetharat on the Caspian Sea, ii, iis
iii. 126,

England, waste of cliffs on coast of, i.
402.

——, slight shocks of earthquakes felt
in, ii. 59.

—, height of tides on east coast of, i.
381. 409,

»——, tertiary strata of, iii. 335, 336. ; iv.

E E Oil,

—, excavation of valleys in S.E. of, iv.
263,

——, geological map of S.E. of, iv. 221.

Eocene period, derivation of the term,
iii. 370.

——, fossils of the, iii. 371. 373,

—, freshwater formations of, iv. 143.

, marine formations of, iv. 164.

—, physical geography, fauna and

flora of the, iv. 181.
—, volcanic rocks of, iv. 184.

——-, map of principal tertiary pasina of,
iv. 209.

—, alluviums of, iv. 263.
—, chasm between secondary form-
ations and those of, iv. 279,
~—, hypogene rocks formed since, iv.
889.
Epomeo, Monte, height, &c., iv. 11.
—, shells in tuff near summit of, iv.12.
Equatorial current, i. 170.
Equinoxes, precession of the, i. 178.
Erhebungscratere, theory of, considered,
ii. 159;
Erie, lake, rapidly filling up, i. 278.
—-, peninsula cut through by, ii. 11.
Erman, M., on specific gravity of sea.
water, i, 172.
—, on level of Caspian, ili. 126.; iv.
203.
Erratic blocks of the Alps, iv. 46.
—, transported by ice, i. 269, ; iv. 48.
Eruptions, volcanic, number of, per
year, ii. 178.
—, cause of, ii. 307. 341.
Erzgebirge, mica slate of the, i. 84.
Escarpments, manner in which sea de.
stroys successive lines of, iii. 440. ; iv,
229.
— of chalk in Weald valley, once
sea cliffs, iv. 227, 228.
Escher, M., on flood in valley of Bagnes,
i. 296.
Eschscholtz Bay, fossils of, i. 153,
Escrinet, Pass of, conglomerate forming
at, iii. 210, .
/

414

Essex, inroads of sea on coast of, i. 415.

Estuary, deposits, arrangement of, iii.
Bie

Estuaries described, i. 401.

——, new ones in Holland, ii. 7

—, how formed, ii. 23.

—, tides in, ii. 24.

——, gain of land in, does not compen-
sate loss of coast, ii. 25.

——., imbedding of freshwater species
in, iii. 262.

Eternity of the earth, or of present sys-
tem of changes, nof assumed in this
work, iv. 392.

Etna, description of, ii. 71. 111.3 iii
397. 407. 421.

—, lavas of, i. 272. 371.5 11) 175.

-——, minor volcanos on, ii. 113.

——., buried cones on flanks of, ii, 114.5
iii. 415.

——, eruptions of, ii. 115. 120.; iii. 413.

——, towns overflowed by lava of, ik:
118. ; iii. 193.

—, subterranean caverns on, ii. 120.

——, great floods on, ii. 123.
—, glacier under lava on, ii. in

__, marine formations at ite er al.
158. ; iii. 397. 401.

—, great valley on east side of, ili. 407.

_—, form, composition, and origin of
the dikes on, iii. 417.

——, subsidences on, iii, 424,

—, antiquity of cone of, iii. 426.

——, whether signs of diluvial waves are
observable on, iii. 431.

Euganean Hills, lavas of, ii. 60.

Europe, newest tertiary strata of, iii.
339.

—, geological map of (see plate 2.), i.
214.

——., large portions of, submerged when
secondary strata formed, iii. 341.

European tertiary strata, successive
origin of, iii. 335.

European alluviums in great part ter-
tiary, iv. 45.

Euxine burst its barrier, according to
Strabo, i. 25.

—, gradually filling up, i. 25.

-—, see Black Sea.

Evaporation, quantity of water carried
off by, i. 350. 386.; ii. 14.

—, currents caused by, i. 386.

Everest, Mr., on island of Munkholm,
ii, 302.

INDEX.

Everest, Rev. R., on climate of fossil
elephant, i. 152.

—, on sediment of Ganges, i. 367.
Excavation of valleys, ii. 237.3; iv. 263.
Extinction of species, successive, part of

the economy of nature, iii..134. 142.
Eyderstede overwhelmed by sea, ii. 13.

F.

Fabio Colonna, i. 39.

Facial angle, ii. 437.

Fair Island, action of the sea on, i. 399.

Falconi on elevation of coast of Bay of
Baiæ, ii. 281.

Falloppio on fossils, i. 36.

Falls of Niagara, i. 275.

— of St. Mary, i, 343.

Faluns of Touraine, iv. 115.

——, compared to the English crag, iv-
LEG SEI:

——, how formed, iv. 117.

—, fossils of, iv. 116. 119.

Faraday, Mr., on water of the Geysers,
i. 328.

—, on slow deposition of sulphate of
baryta powder, ii. 35.
—, on electric currents in the earth,

ii, 325.

—-, on metallic reduction by voltaic
agency, ii. 328.

—, on liquefaction of gases, ii. 337.

—, experiments of, on carbonate of
lime, iv. 366.

Faroe Islands, deposits forming near thes
Tits, ofc

Farquharson, Rev. J., on floods in Scot-
land, i. 267.

Fasano, marine strata near, iii. 401.

Faujas, on Velay and Vivarais, 1779
i. 86.

Ferishta, i. 9.

Ferrara on lavas of Etna, i. 371.

—— on floods on Etna, ii.124.

— on earthquake in Sicily, ii. 208.

Ferruginous springs, i. 330.

Férussac on distribution of testacea,
iii. 56.

Fetlar, effect of lightning on rocks of,
i, 394.

Fez, earthquakes in, ii. 57.

Fife, coast of, submarine forests ON,
i. 401.

——, encroachments of sea on, i. 401.

Findhorn, town swept away by se»
i. 399,

INDEX.

Finochio, rock of, iii. 420.

Firestone of Weald valley, iv. 222,

——, terrace formed by, iv. 229.

Fish, their geographical distribution,
iii. 52.

—, migrations of, iii, 53.

——, fossil, 1, 235.5 ili. 272. 358.5. iv.
292, 296.

Fissures, sulphur, &c. ejected by, ii, 209.

—— caused by earthquake of 1783 in
Calabria, li. 218. 222. 225,

—, cause of the opening and closing
of, ii, 262.

—, preservation of organic remains in,
iii. 201.

Fitton, Dr., on history of English geo-
logy, i. 73.

—, on valley of the Weald, iv. 229,
225. 231. 252. 281, 282. 284.

——, on a line of vertical and inclined
strata from I. of Wight to Boulogne,
iv. 260.

—, on Maestricht beds, iv. 272. 274.

——, on delta of Niger, iv. 309.

FitzRoy, Capt., on earthquake in Chili,
1835, ii. 185. 187. 192.

Fiume Salso, in Sicily, iv. 178.

Flagstones and slates, difference be-
tween, iv. 356.

Flamborough Head washed into caves,
i. 402.

Fleming, Dr., on uniformity in climate,
i, 140.

——,, on food of fossil elephant, i. 146.

——-, on submarine forests, i. 401. ; iii.
BRT:

——, on rapid flight of birds, iii. 48.

——, on turtles taken on coast of Eng-
land, iii. 50.

, on changes in the animal king-
dom caused by man, iii. 109.

—, on stranding of cetacea, iii. 266.

——, on fossils of the crag, iv. 73.

——, on effects of the deluge, iv. 204.

Flinders on coral reefs, iii. 275. 280.
291. i

Flint on course of Mississippi, &c., i.
289. 285. ;

—— on earthquakes in Mississippi val-
ley, ii. 204.

Flood, supposed effects of the, iv. 201.

—, hypothesis of a partial, iv. 201.

Floods, bursting of lakes, &c., i. 292.

—— in North America, i. 293.

—— in valley of Bagnes, i. 295.

—— in Scotland, i, 266. ; iii, 233.

Floods at Tivoli, i, 298.

— on Etna, ii. 123.

Floridia, limestone of, iii. 387.

Fluvia, R., ravines in lava excavated
by, iv. 93. 97.

Foah, advance of delta of Nile near, i.
354.

Folkestone, subsidence of land at, i. 422.

Fontenelle, his eulogy on Palissy, i. 39.

Foraminifera of the crag, iv. 75.

—— of the Paris basin, iv. 176.

Forbes, Mr., on Bay of Baia, ii. 277.

——, on temple of Serapis, ii. 279.

Forchhammer, Dr., on tertiary strata of
Denmark, iv. 88.

Forest ridge of Weald valley, iv. 231.

—, faults in strata of the, iv. 231.

——, thickness of masses removed from
the, iv. 259.

Forests, influence of, iii. 163. 165. 168,

, sites of, now covered by peat, iii.

180.

—, destroyed by insects, iii. 173.

——, submarine, i. 400. ; iii, 296.

Forfarshire, encroachments of sea on
coast of, i. 400.

——, mar] lakes of, iii. 259. 300.

——, composition of secondary rocks of,
iv. 377.

Forio, earthquake near, ii. 188. .

Formosa, earthquakes in, ii. 48.

Forster, Mr., on coral reefs, iii. 275.

Forsyth on climate of Italy, ii. 110.

Fortis on Arabian doctrine of new ge.
nera and species, i. 24.

, Views of Arduino confirmed by, i.

85.

—— and Testa on fossil fish of Monte
Bolca, i. 78.

Fossa Grande, section of Vesuvius seen
in, iii. 410.

Fossilization of organic remains on
emerged land, iii. 177.

—— in peat mosses, iii. 182.

—— in caves and fissures, iii. 201.

— in alluvium and landslips, iii. 197.

—— in volcanic formations on land, iii.
191.

—— in subaqueous deposits, iii, 218.
238.

—— by river floods, iii. 231.

—— in marl lakes, iii, 236.

—— of plants ,and animals partial, iii,
350.

Fossils, speculations concerning their
nature, i, 42, 45. 47.

T 4

416

Fossils, formerly all referred to the
deluge, i. 43.

— of the coal strata, i. 158. 201. 231.

—,, distinctness of secondary and ter-
tiary, i. 211. ; iv. 279.

——, mammiferous, of successive ter-
tiary eras, iii. 379.

——. See Organic Remains.

Fourier, Baron, on temperature of
spaces surrounding our atmosphere, i.
192,

—, on central heat, i. 222.

——, on radiation of heat, i. 223.

Fournet, M., on alluvium in ancient
fissures, iv. 198,

——, on disintegration of rocks, iv. 373.

——, 0n mineral veins, iv. 375.

Fox, Mr., on heat in mines, ii. 313.

——, on electric currents in the earth,
ii. 324.

France, waste of coast of, i. 431.

——, caves of, iii. 213,

Franconia, caves of, iii. 210.

Frankfort, tertiary strata near, iv. 132.

Franklin on a whirlwind in Maryland,
iii. 11,

Freshwater formations, species of tes-
tacea few in, ili. 265.

——, secondary, why rare, iv. 314.

Freshwater plants and animals fossil-
ized, 1N'268,.202)

Freyberg, school of, i. 81. 92.

Freyer, Mr., on earthquake in Chili, ii.
191.

—-, on Isle of San Lorenzo, iv. 17.

Fries on dispersion of cryptogamic
plants, iii. 13.

Frisi on influence of vegetation, iii.
163.

Fuchsel, opinions of, 1762, i. 76.

Funchal, rise of sea during earthquake
at, ii. 254, `

Fuveau, in Provence, tertiary strata of,
iv. 210.

G.

Gabel Tor, volcano of, ii. 58.; iv. 96,

Galieri, a bed of corals among igneous
formations at, iii, 396.

Gambier coral island, iii. 290.

Ganges, delta of the, i. 358. 376.

——, its ancient mouths, i. 358.

———, inundations of the, i, 363. ; iii
234,

INDEX.

Ganges, quantity of sediment in waters
of, i. 367.

—— and Burrampooter not yet com-
pletely united, i. 376.

——, islands formed by the, iii. 170.

—, bones of men found in delta of, iii.
245.

Gannat, freshwater limestone of, iv.
Tos

Gardner on destruction of Dunwich by
the sea, i. 412. ©

Gardner, Mr., cited, i. 177. 221.

Garnets, in altered shale, iv. 365.

Garrinada, hill of, iv. 93.

Gases, liquefaction of, ii. 337.

—, evolved by volcanos, ii. 348.

—, passage of, through rocks, iv. 372.

Gaulish Druids, i, 27.

Gault of Weald valley, iv. 222.

—, valley formed at its out-crop, iv.
230. :

Gavarnie, cirque of, iii. 415.

—, lamination of clay-slate near, iv. —
362.

Gay-Lussac, M., on the vibration of
solid bodies, ii. 337.

——, on agency of water in volcanos, ii,
348,

Gefle, upraised shelly deposit near, ii.
298. 301.

Gemmellaro on eruption of Etna in
dof it Lon

— or ice under lava, ii. 124.

Gemunder Maar, view of, iv. 104.

Generation, spontaneous, theory of, 1.
38.

Generelli, on state of geology in Europe
in middle of 18th century, i. 62.

—, on effects of earthquakes in recent
times, i. 65, 66. 93.

Geneva, lake of, men drowned above
Martigny floated into, i. 296.

— , delta of Rhone in, i. 337. 372. ; iii.
347.

Genoa, tertiary strata at, iv. 63.

Geognosy of Werner, i. 81.

Geographical distribution of plants, ii.
3.

A Paimas, it: 27,

— of birds, iii. 45.

— of reptiles, iii. 49,

—— of fishes, iii. 52.

—— of testacea, iii, 55.

——. of zoophytes, iii. 61,

—— of insects, iii. 62.

—— of man, iii. 68,

INDEX.

Geography, proofs of former changes in
physical, i. 199. 214.

—, effect of changes in, on species, iii.
122;

Geological Society of London, i. 104.

Geological theories, causes of error in,
i. 110.

Geology defined, i. 1.

—— compared to history, i. 1.

——, its relation to other physical
sciences, i, 2.

—— distinct from cosmogony, i. 5.

—— considered by Werner as part of
mineralogy, i. 5.

—, causes of its retardation, i, 42, 97.
110.

, state of, in Europe, before middle

of last century, i. 63.

——, modern progress of, i. 104,

Georges Gemund, freshwater strata of,
iv. 133.

Georgia, in island of, perpetual snow to
level of sea, i. 175. 193.

Gerbanites, an Arabian sect, their doc-
trines, i. 24.

Gergovia, section of hill of, iv. 186.

German Ocean, filling up, ii. 29.

Gesner, John, en organic remains, i. 71.

Geysers of Iceland, i. 328. ; ii. 342.

, cause of their intermittent action,

ii. 344,

Giacomo, St.,
411, 412. 419.

Gian Greco, fall of cliffs during earth-
quake, ii. 236,

Gibbon cited, i. 120.

Gibraltar, birds’ bones in breccia at, iii.
209.

——,, Straits of, ii. 14. :

„supposed under-current in, ii. 15.

Gillenfeld, Pulvermaar of, iv. 105.

Girard, M., on mud of the Nile, i. 355.

—, on former union of Mediterranean
and. Red Sea, ii. 31.

Girgenti, tertiary strata at, iii. 385.

Gironde, tides in its estuary, ii. 24.

—, tertiary strata of basin of, iv. 119.

Glacier, under lava, on Etna, ii. 124.

Glaciers, formation of, i. 156. 269.

—— of Spitzbergen, i. 172.

——., transportation of rocks by, i. 269. ;
iv. 47.

Glen Roy, parallel roads of, iv. 18.

Glen Tilt, granite veins of, i. 90.

——., junction of limestone and granite
in, iv. 340.

valley of, described, iii.

417

Gloger, M., cited, iii. 75,
Gloucestershire, gain of land in, i. 430. -
Gly, R., tertiary strata in valley of tiles
iv. 69.
Gmelin on distribution of fish, iii. 54.
Gneiss, mineral composition of, iv. 361.
363.
» passage of, into granite, iv. 363.
371.
, whence derived, iv. 363. 375.
Goats, multiplication of, in South Ame-
rica, iii, 115.
Godman on migrations of rein-deer, iii.
41.
Goebel, Mr., on level of Caspian, iv.
203.
Golden age, doctrine whence derived, i.
13.
Goldfuss, Professor, on the greywacké,
iv. 299,
Goodwin Sands, i. 418.
Goree on new island, ii. 163.
Gothenburg, rise of land near, ii. 297.
Gozzo degli Martiri, dikes at, iii. 390.
——, View of valley of, iii. 439,
Graah, Capt., on subsidence of Green-
land, ii. 302.
Graham, Mrs., on earthquake of Chili
in 1822, ii. 190.
Graham Island, ii. 146. ; iii. 393.
—, Views of, see wood-cuts, ii; 147,
148, 149.
—, depth of sea from which it rose, ii.
146.
——, arrangement of the ejected ma.
terials on, ii. 148.
Grammichele, strata near, iii. 387.
» bones of mammoth in alluvium at,
iv, 48,
Grampians, granite veins of the, iv. 342.
Granada, tertiary strata of, iv. 70,
Granite of the Hartz, greywacké slate
with organic remains found in, i. 84.
—, disintegration of, in Auvergne, i,

—, junction of limestone and, in Glen
Tilt, iv. 340.

——, formed at different periods, iii,
317. 3 iv..343.

—, passage from trap into, iv. 348.

—, origin of, iji. 316.; iv. 350.

——., passage of gneiss into, iv. 363. 371.

——, changes produced by its contact
with strata of lias and oolite in the
Alps, iv. 369.

Granite veins, their various forms and

Tg

418

mineral compésition, i. 90.3 iv. $38.
368.

Graves, Lieut., on diffusion of insects
by the wind, iii. 66.

Graves, Mr., on distribution of the bus-
tard, iii, 111.

Graves, M , on Valley of Bray, iv. 287.

Gravesend, indentations in chalk filled
with sand, &c., near, iv. 217.

Grecian Archipelago, new isles of the,
i. 76.

——,, volcanos of the, ii. 58.

—, chart and section of, ii. 161.

Greece, earthquakes in, iii. 207.

Greenland, why colder than Lapland, ï.
168.

——, earthquakes in, ii. 58.

—, gradual subsidence of, ii. 302. 340.

—, timber drifted to shores of, iii.
24.

Greenough, Mr., on fossil shells from
borders of Red Sea, iv. 26.

Greville, Dr., on drift sea-weed, iii. 16.

Greywacké formations, fossils of, 1. 200.
932.3 iv. 297.

—— of the Eifel, iv. 102.

——., classification of the, iv. 298.

Grifone, Monte, caves in, iv. 41.

Grimaldi on earthquake of 1783 in Ca-

labria, li. 212. 225. 228.

Grind of the Navir, passage forced by
sea in Shetland Islands, i. 596.

Grosceil tertiary strata at, iv. 24.

Grosse, Dr., on baths of San Filippo, i.
316.

Grotto del Cane, i. 332.

Gryphyte limestone, iv. 291.

Guadaloupe, human skeletons of, iii.
245.

—, volcanos in, iv. 22..

Guatimala, active volcanos in, ii. 45. »

, town of, swallowed up by earth-

quakes, ii. 248.

Guettard, on the Vivarais, i. 86.

Guiana, its maritime district formed by
sediment of the Amazon, ii. 33.

Guidotti, Signor, on Subapennine fossils,
iii, 364.

——, on shells in gypsum of Monte
Cerio, iv. 54.

Guilding, Rev. L., on migration of boa.
constrictor, iii. 51.

Guinea current, i. 383.

Güldenstädt on distinctness of the dog
and wolf, ii. 394.

Gulf stream, i. 170, 384. 391. ;

iii, 14.

INDEX».

Gulholmen, island of, gradually rising,
ii. 297.
Gun-barrel, with shells attached, found
in sands, iii. 250.
Gunnell, Mr., on loss of land in Sheppey»
i. 415. 3
Gypsum and marls of Paris basin,
EiL
—, bones of quadrupeds, &c., in, iv-
177.
, of St, Romain on the Allier, iV:
154. j
, Subapennine, iv. 54.
Gyrogonite described, iii. 259.

iv.

H.

Habitations of plants described, iii. 5..

Hall, Sir J., his experiments on rocks,
4..0023.3v4.9,

Hall, Capt. B., on Falls of Niagara, i
275.
, on width of Mississippi, i. 282.
——, on islands in Mississippi, i. 284.
—, on drift-wood in Mississippi, i. 287-
365.

—,on flood in valley of Bagnes, i.
296.

——, on the trade winds, i. 389.

——, on volcanic eruption in Tierra del
Fuego, ii. 41.

—, on temple of Serapis, ii. 274.

—-, on isle of Cyclops, iii. 403.

——, on parallel roads of Coquimbo, iv-
18.

—, on dikes in Madeira, iv. 24.

—, on veins in the Table Mountain,
Cape of Good Hope, iv. 339.

Hall, Mr. J., on temple of Serapis, ii.
Q74.

Hallstrom, Col., on rise of land in Gulf
of Bothnia, ii. 291.

Hamilton, Sir W., on mass covering
Herculaneum, ii. 99.

—, on earthquake of 1783, in Cala-
bria, ii, 213. 229, 232.

_——., on earthquakes attending eruption
of Monte Nuovo, ii. 281.

——, on eruption of Vesuvius in 1779;
ti. 82. 174.3 iv. 7.

Hamilton, Sir Charles, on submerged
buildings of Port Royal, iii. 255.

Hampshire, Brander on fossils of, i. 77.

—, submarine forest on coast of, t1-
227.

INDEX.

Hampshire, tertiary formations of, iii.
335.3 iv. 211. 215.

——, on former continuity of the basins
of London and, iv. 219.

Happisborough, crag strata near, iv, 79,

Harcourt, Rev. W. V. V., on bones of
mammoth, &c. in Yorkshire, i. 145.

Harlbucht bay, ii. 8.

Harris, Hon, C., on sunk vessel off
Poole harbour, iii. 246.

——, on a submarine forest on coast of
Hampshire, iii. 228.

Hartmann, Dr., on greywacké fossils in
granite of the Hartz, i. 84.

Hartsoeker on sediment in waters of
Rhine, i. 366.

Hartz mountains, i. 84. ; iv: 332.

Harwich, waste of cliffs at, i. 415.

Hastings sands, their composition, iv.
222.

——, anticlinal axis formed by, iv. 225,

Hatfield moss, trees found in, iii. 180.

Haute Loire, freshwater formation, iv.
157,

Headen Hill, section of, iv. 216.

Heat, laws which govern the diffusion
of, i. 166.

——, its influence on consolidation of
strata, iv. 317.

Heber, Bishop, on animals inhabiting
the Himalaya mountains, i, 152.

Hebrides, volcanic rocks of the, iv.
319.

Hecla, columnar basalt of, i. 85.

—, eruptions of, ii. 126.

Heidelberg, loess and gravel alternating
at, iv. 31.

——, granites of different ages near, iv.
342.

Helice and Bura, submerged Grecian
towns, ii. 56. ; iii. 255.

Heligoland destroyed by sea, ii. 7.

Helix, range of species of, iii. 57.

Helmet, changes of submerged, iii. 251.

Henderson on eruption of SkaptarJokul,
1783, ii. 127.

Henderson’s Island described, iii. 295.

Henry, Mr., on absorption of carbonic
acid by water, iv. 372.

Henslow, Rev. Prof., on the cowslip, ii.
403.

——, on diffusion of plants, iii. 19.

——, on changes caused by a dike in
Anglesea, iv. 364, 378.

Herbert, Hon. Mr., on varieties and
hybrids in plants, ii. 403, 431.

T

419

Herculaneum, silence of contemporary
historians concerning, ii. 67.

—, how destroyed, ii. 94.

——, objects preserved in, ii. 100.

—, stalactite formed in galleries of, ii.
101.

Herne Bay, waste of cliffs in, i. 416.

Herodotus cited, i. 353. 355.

Herschel, Sir J., on annual quantity of
light and heat received by the two
hemispheres, i, 178.

——, on the sun, i. 224.

——, on astronomical causes of changes
in climate, i. 224.

—, on the trade winds, i. 391.

, on height of Etna, ii. 111.

—, on form of the earth, ii. 309.

—, on Geysers of Iceland, ii. 344,

——, on the effects of heat on seeds, iii, 14.

——-, on cleavage planes, iv. 358.

Herschel, Sir W., on the elementary
matter of the earth, ii. 308.

Hewett, Capt., on rise of tides, i. 382.

—, on currents, i. 385,

—, on banks in North Sea, ii. 29.

Hibbert, Dr., on the Shetland Islands,
i, 393, 395. 397.

—s, on Rhine volcanos, iv. 106.

—, on loess of the Rhine, iv. 34. 38.

——, on fossils of Velay, iv. 136.

——,on fossils of the carboniferous
Strata, i. 203. 235. ; iv. ‘294.

Hiera, new island, ii. 162.

Highbeach, height of London clay at,
iv, 257.

Hilaire, M. Geof. St., on uninterrupted
succession in animal kingdom, ii. 362.

Hillswick Ness, action of sea on rocks
of, i. 398,

Himalaya mountains, animals inhabit-
ing the, i. 152.

-—, height of perpetual snow on, i.
194.

Hindoo cosmogony, i. 6.

Hindoo town, buried, iii. 199.

Hindostan, earthquakes in, ii. 58. 250.

Hisinger, M., on greywacké rocks o
Sweden, iv. 299, :

Hodgson, Mr., cited, i, 147.

Hoff, Von, on level of Caspian, i. 30.

—, on Omar, i. 31.

—, on springs near Lake
326.

——, on encroachments of sea, ii. 10. 12,

——, on gain of land in Red Sea, ii. 28,

——-, on earthquakes, ii 54. 184. 249.

Urmia, i.

420

Hoff, Von, on buried city of Oojain, ii.200.

——, on human remains in delta of
Ganges, iii. 245.

—, on a buried vessel, iii. 24T.

Hoffmann, M., on new island in Medi-
terranean, ii. 147. ; tii. 393.

—, on elevation craters, ii. 152.

———, on Sicily, tii. 390. ; iv. 39. 41.

——, on agency of subterranean gases,
iv. 373.

Holbach, his theory, 1753, i. 58.

Holderness, marine strata of, iv. 76.

Holland, inroads of the sea in, ii. 5.

——, submarine peat in, iii. 265.

Holm sand, near Lowestoff, i. 411.

Holstein, iv. 88.

Homer cited, i. 354.

Honduras, recent strata of, iv. 23.

Hooke, his “ Discourse of Earthquakes,”
i. 47.

—— on distribution and duration of
species, i. 48, 49.

—— on earthquakes, i. 51. ; ii. 258. 260.
282. :

—— on the deluge, i. 51.

Hooker, Dr., on eruption of Skaptar
Jokul, ii. 127.

—, his view of the crater of the great
Geyser, ii. 343.

—, on drifting of a fox on ice, iii. 105.

Hordwell, loss of land at, i. 426.

Hornblende schist, altered clay or shale,
iv. 376.

Horner, Mr., on sediment of Rhine, i.
366. ; iv. 35.

——., on brine springs of Cheshire, i. 331.

——, on limestone of Burdiehouse, iv.
294.

——, on geology of Lower Rhine and
Eifel, iv. 38. 102. 111.

Hornitos on Jorullo, account of, ii. 135.

Horsburgh, Capt., on icebergs in low
latitudes, i. 177. %

—, on coral islands, iii. 280. 291.

Horses, wild, drowned in rivers in South
America, iii. 234,

Horsfield, Dr., on earthquakes and erup-
tions in Java, ii. 209. 249.

——., on distribution of Mydaus meliceps
in Java, iii. 39.

Horticulture, changes in plants pro.
duced by, ii. 399.

Hugi, M., on altered secondary strata
in the Alps, iv. 370.

—, on modern granite inthe Alps, iv.
344.

INDEX.

Human remains, changes in puried, iii.
214.

—— in peat-mosses, iii. 183.

— in caves, iii. 205. 207. 212.

—, their durability, i. 246. ; iii. 245.

—— in delta of Ganges, iii, 245.

— in calcareous rock at Guadaloupe
iii, 245. ;

—— in breccias in the Morea, iii. 205.

Humber, warp of the, i. 377.5 ii. 27.

—, encroachment of sea in its estuary,
i. 403.

Humboldt on laws which regulate the
diffusion of heat, i. 166.

— on preservation of animals in frozen
mud, i, 154.

— on distribution of land and sea, i.
194.

— on transportation of sediment by
currents, ii. 33.

—, his definition of volcanic action, ii-
40.

—— on mud eruptions in the Andes, ii.
44.

— on eruption of Jorullo, ii. 134.

— on earthquakes, ii. 203. 208, 209.

—— on distribution of species, iii. 3. 5. 29-

— on migrations of animals, iii, 48. 65-
112.

— cited, i. 11. 147. 154. 174.

Humming-birds, distribution, &c., iii.46.

Hungary, tertiary formations of, iv. 128.

—, volcanic rocks of, iv. 140.

Hunstanton, its cliffs undermined, i-
404.

Hunter, John, on mule animals, ii. 423.

Hunter, Mr., on buried city of Oujeins
iii. 193.

Huron, Lake, recent strata of, iii. 262.

Hurricanes connected with earthquakes,
iii, 198.

——, plants drifted to sea by, iii. 225.

Hurst Castle shingle bank, i. 425.

Hutchins on a landslip in Dorsetshire,
i. 427.

Hutchinson, John, his ‘“ Moses’s Prin-
cipia,” 1724, i. 58.

——, on Woodward's theory, i. 58.

Hutton, first to distinguish between
geology and cosmology, i. 5. 89.

— on igneous rocks, i. 90.

— on granite, i. 90.

— represented oldest rocks as deri-
vatives, i. 92.; iv. 391.

Hutton, Mr. W., on fossil plants of the
coal strata, i. 202. 231,

INDEX,

Hutton, Mr. W., on freshwater strata
of the coal period, iv. 294.

Huttonian theory, i. 89. 92. 95. 101.

Hybrid races, Lamarck on, ii. 372,

m animals, ii, 422,

— plants, ii. 426.

Hydrogen, deoxidating power of, ii. 328.

——. why not found in a separate form
among volcanic gases, ii. 349.

Hydrophytes, distribution of, iii. 8. 16.

Hypogene, term proposed as a substitute
for primary, iv. 379.

—— formations, no order of succession
in, iv. 380.

—— rocks, their identity of character
in distant regions, iv. 381.

—— produced in all ages in equal quan-
tities, iv. 384.

—, their relative age, iv. 383.

—, volume of, formed since Eocene
period, iv. 389.

Hythe, encroachments of sea at, i. 422.

I,

Lanthina fragilis, its range, &c., iii. 56.
Ice, animals imbedded in, i. 156.
—, drift, influence of, on temperature,
i. 169,
——, predominance of,
cirele, i. 175.
—, formation of field, i. 191.
——, transportation of rocks by means
couse Of, i. 269.5 ii. 289.5 iv. 47, 48,
——, jointed structure of, iv. 360.
Icebergs, formation of, i. 156, 172.
- ——, distance to which they float, i. 173.
ang, S71,
——, their influence on temperature,
i. 173.
——-, plants and animals transported by,
lii. 16. 40.
-——, rocks transported by, i. 270. ; ii.
289. ; iv. 47, 48. ,
Iceland, icebergs stranded on coast of,
i 173.
—, geysers of, i. 328. ; ii. 342.
——~, volcanic region of, ii. 58.
—, volcanic eruptions in, ii. 126.
——, comparison between the lavas of
Central France and, ii. 129.
—, new island near, ii. 127. 145.
——, polar bear drifted to, iii. 103.
idienne, volcanic mountain of, iv. 178.
Igloolik, fossils of, i. 163.

in antarctic

Igneous action. See Volcanic.

Igneous causes. See Book ii.

——., the antagonist power to action of
running water, i. 260.; ii. 354. ; iii.
161.

Iguanodon, fossil in Wealden and Kent-
ish rag, iv. 286.

Imbaburu volcano, fish ejected from, ii.

Imbedding of organic remains. See Fos-
silization. :

Imperati, theory of, 1590, i. 39.

India, Central, buried cities in, iii. 193.

Indus, recent changes in delta Of:
194. 5 iii. 254. 265.

—, sections of the new-raised land
formed by, ii. 197. `

Indusial limestone of Auvergne, iv. 152.

Inkpen Hill, highest chalk in England,
iv. 259,

Inland cliff, near Dax, iv. 124.

——, on east side of Val di Noto, iti.
440.

Inland seas, deltas of, i. 344.

Insects, geographical distribution of, iii.
62.

—, migrations of, iii. 63.

——, certain types of, distinguish par-
ticular countries, iii. 64.

—, their agency in preserving an
equilibrium of species, iii.89. ~

—, fossil, iii. 229. ; iv. 210.

Instincts, migratory, occasional develop-
ment of, in animals, iii. 36.

—, hereditary, ii. 409. 415.

—, modified by domestication, ii. 413.

Insular climates, description of, i. 169.

Inverness-shire, inroads of sea on coast
of, i, 399. `

Ionian Isles, earthquake in, ii. 194.

——, new island near, ii. 194.

Ippolito, Count, on earthquake of 1783
in Calabria, ii. 212.

Ipsambul, buried temple of, iii, 189.

Irawadi, R., silicified wood of, noticed
in 1692, i. 49.

—, recent discoveries of fossil animals
and vegetables, i. 49.

——, its supposed petrifying power, i.
329.

Ireland, raised beaches on east coast of,
Tes

—, rise of sea, during Lisbon earth.
quake, on coast of, ii. 254.

——., reptiles of, iii. 50.

——, its flora little known, iii. 50,

422

Ireland, peat of, and fossils of peat in,
iii. 178. 183. 185.

——, deposits in progress off coast of,
ail, Ae

—, rocks altered by dikes in, iv. 365.

Iron, melting point of, ii, 314.

— in wood, peat, &c., iii. 182.

—— instruments, taken up from sea,
iii. 249.

Irtish, R., fossil bones on banks of, i.
148.

Irving, Mr. W., on migrations of the
bee, iii. 65.

Ischia, recent fossils of, i. 140. ; iv, 11.

——, hot springs of, i. 329. ; ii. 188,

——, eruptions and earthquakes in, ii.
62. 71. 188.

——, volcanic conglomerates forming on
shores of, iii. 396.

——, configuration of, how caused, iii.
297.3 iv. 13.

Islands, vegetation of small, i. 195. ;
iii. 6. 81.

—, animals in; i. 204. ; iii, 31.

—— in the Mississippi, i. 284.

—— formed by the Ganges, i. 360, 361.

——, migrations of plants aided by, iii.
15.

——, new volcanic, i. 76.3 ii. 127. 145,
146. 205.

—, coral, iii. 274.

— of drift-wood, iii. 41.

Isle of Bourbon, volcanic eruptions in,
iv. 350.

Isle of Cyclops, in bay of Trezza, iii.
401.

——, contortions in strata of, iil. 403.

——, lavas of, not currents from Etna,
iii. 405.

Isle of France, alternation of coral and
lava in, iii. 294.

Isle of Palma, description of, ii. 155.

Isle of Purbeck, line of vertical chalk
in, i. 425. ; iv. 260.

Isle of Wight, geology of the, iii. 335.

—, fall of one of the Needles of, iv.
87. A = <

—, freshwater strata of, iv. 215.

——, mammiferous remains of, iv. 216.
263.

——., vertical strata of, iv. 253. 259.

——, action of the sea on its shores, i.
425.

Isonzo, R., delta of the, i. 350.

—, its present mouth several miles
from its ancient bed, i. 352.

INDEX,

Isonzo, R., conglomerate formed by the,
Taooe

Isothermal lines, Humboldt on, i. 166.

Isthmus of Sleswick, action of sea On,
ii. 8. ; iii. 129.

Italian geologists, their priority, i. 39.

— of the 18th century, i. 59.

Italy, tertiary strata of, i. 59. 141.3 iii.
335. 564.

——, volcanic rocks of, iv. 89.

J.

Jack, Dr., on island of Pulo Nias, iv. 23.

Jackson, Col., on jointed structure of
ice, iv. 360.

Jahde, new estuary of, ii. 8.

Jamaica, earthquakes in, ii. 46. 262. 278-

——, subsidence in, ii. 262.; iii, 125-
PAARA

——, rain diminished in, by felling of
forests, iii. 165.

, a town swept away by sea in, iil.
199.

—, fossil shells of, iv. 23.

James, Mr., on bisons in Mississippi
Valley, iii. 35.

Jampang village engulphed, ii. 209.

Jan Mayen’s island, volcanic, ii. 58.

Japan Isles, earthquake in, ii. 209.

Java, number of volcanos in, ii. 49.

—, earthquakes in, ii. 209. 249. 259.

——, subsidence of volcano of Papan-
dayang in, ii. 249. ; iii. 424.

——, vegetation destroyed by hot sul-
phuric water from a mountain in, iv-
178.

——, river-floods in, ii. 259. ; iii. 230-
234.

Jesso, volcanos in island of, ii. 48.

Jobert,"M., on extinct quadrupeds of
Mont Perrier, iv. 136.

—, on hill of Gergovia, iv. 186.

, on Auvergne alluviums, iv. 197.

Johnston, Mr., on sinking of the waters
of Lake Maeler, ii. 294.

Jointed structure in rocks, iv. 358.

Jones, Sir W., on Menii’s Institutes, i. 6-

Jorio, Andrea de, on Temple of Serapis,
ii. 274. 280. -

Jorullo, eruption of, ii. 45. 133.

——, its height, &c., ii. 133.5 iv. 350.

Juan Fernandez, ii. 185. ; iii. 115.

Jura, Saussure on the, i. 80.

—, relative age of the, i. 211.

INDEX,

Jura, erratic blocks of the, iv. 46.

Jutland, its northern part converted into
an island in 1825, ii. 9.

——, inundations in, ii, 14.

K.

Kamtschatka, active volcanos in, ii. 47.
—, earthquakes in, ii. 259.
—, new island near, ii, 205. 5
Kander, R., delta of, in lake of Thun,
iv. 68. i
Kangaroo giving way in Australia, iii.
112.
Katavothrons of plain of Tripolitza
filled up with osseous breccias, iii. 205.
Kazwini on changes in position of land
and sea, i. 32.
Keferstein, M., on Fuchsel, i. 76.
Keill refutes Burnet’s and Whiston’s
theories, i. 58.
Keith on dispersion of plants, iii. 13.
Kent, loss of land on coast of, i. 415.
Kentucky, caves in limestone, iii. 202.
Kerguelen’s land, quadrupeds in, i. 204.
Killas of Cornwall, iv. 368.
Kimmeridge clay, i. 427. .
Kincardineshire, village in, washed
away by sea, i, 399.
King, Captain P., on currents in Straits
of Magellan, i. 385.
===, on coral reefs, iii. 280. 291.
King, Mr., on cattle lost in bogs in Ire.
land, iii. 185.
——, on submerged cannon, iii. 249,
Kingsclere, valley of, iv. 246.
_ Kinnordy, Loch of, insects in marl in,
iii. 229.
——, canoe in peat of, iii. 248.
Kirby, Rev. Mr., on insects, ii. 433.; iii,
63. 66. 93. 95.
Kirwan, his Geological Essays, i. 99.
——on connection of geology and reli-
gion, i. 99.
—— on age of deltas, i. 342.
Knight, Mr., on varieties of fruit trees,
ii. 401.
Kölreuter on hybrid plants, ii. 426.
Konig, Mr.,on rock in which the bu-
man skeletons from Guadaloupe are
imbedded, iii, 246,
——, on fossils from Melville Island, i.
159.
Koran, cosmogony of the, i. 31.
Kossa cited, i. 32, _ E

423

Kotzebue on drifted canoe, iii. 71.

—— on coral islands, iii. 279,

Krantz on migrations of seals, iii. 45.

Kupffer, M., on increase of heat in
mines, ii. 313.

Kured, upraised shelly deposits of, ii,
299.

Kurile Isles, active volcanos in, ii. 48.

L.

Laach, lake-crater of, iv. 106.

Labrador, drift-timber of, iii, 224,

Laccadive Islands, iii. 280.

Lacépède on Egyptian mummies, ii. 397.

Lagoons, or salt lakes, in delta of Rh one,
i. 348. -

——, of coral islands, iii. 288.

Lagullas current, i. 169.

Lahn, valley of the, iv. 35.

Lake Aidat, how formed, iv. 200.

Lake Erie. See Erie, Lake.

— of Geneva. See Geneva, Lake of.
—— Maeler, ii. 294. 301.

— Mareotis, i. 354.

—— Superior. See Superior, Lake.
Lakes, bursting of, i. 292. 295,

—, filling up of, i. 337. 340.

— formed by landslips in Calabria, ii.

233. .

—, formation of, in basin of Missis-
sippi, i. 290.

-— formed by eartcquakes, ii. 203. 225.
233. 263.

——., arrangement of deposits in, iii. 312_

L’ Altar volcano, ii. 43.

Lamarck, his definition of species, ji.
363.

—— on transmutation of species, ii. 363.
398.; iii. 134. 139.

——‘on conversion of the orang-outang
into the human species, ii. 377.

——- on abundance of polyps, iii. 149.

—— on’ fossils of Paris basin, iv. 50.

La Motta, in Sicily, iii. 400. 406.

Lamouroux on hydrophytes, iii. 8.

Lancashire, submarine forests on coasts
of, i. 431.

——., fossil canoes in, iii. 247.

—, tertiary strata of, i. 215.; iv. 25.

Lancerote, volcanic eruptions in, ii. 139,

* 144.

Land, irregular distribution of, i. 193.

—, quantity of, in northern and
southern hemispheres, i. 176. 193,

424:

Land, proportion of sea and, i. 220.

——., elevation of, how caused, ii. 339. ;
iii. 436.

Landers on delta of Niger, iv. 309.

Landes, tertiary strata of the, iv. 124.

Landguard Fort, waste of the point on
which it stands, i. 414. i

Land-shells drifted to the sea by rivers,
iii. 360.; iv. 33.

Landslips, i. 427. ; ii. 229. 231. 263.

——, imbedding of organic remains by,
iii. 200.

—, Villages and their inhabitants bu-
ried by, iii. 200.

Langsdorf on new island, ii. 48. 205.

Languedoc, deposits on coast of, i. 349.

Lapidifying juice, i. 37.

Laplace on change in the earth’s axis,
1. 57.

—— on mean depth of Atlantic and Pa-
cific Oceans, i. 185.

—— proved that no contraction of the
globe had taken place for 2000 years,
i. 222, x

—— on mean density of the earth, ii. 312.

Lapland, why milder than Greenland,
i. 168.

——, migrations of animals in, iii."36, 37.

Larivière, M., on drifting of rocks by
ice, i. 271.

La Roche, section of hill of, iv. 148.

Las Planas, lava current of, iv. 96.

Latham on range of birds, iii. 47.

Latitude influences climate, i. 176.

Latrielle on distribution of insects, iii,

63.

La Trinità, fossil shells of, iv. 66.

Latta, Dr., on glaciers of Spitzbergen,
1..172.

Lauder, Sir T. D., on floods in Scotland,
i. 267.3 iii. 34. 197. 230. 233.

——, on parallel roads of Glen Roy, iv.
18. :

Laureana, ravines filled near, ii. 234.

Lava excavated by rivers, i. 272. ; iv.
93. 96. 193.

—, effects of decomposition on, ii. 90.

——., flowing of, under water, ii. 94.

—, shells between two currents of, ii.
158. ; iii. 396.

—-, slope on which it congeals, ii. 173.

—— and coral alternating, iii. 294.

—, minerals in cavities of, iii. 405.

—, veins of. See Dikes.

—, length of time which it requires
to cool, iv, 350.

INDEX.

Lava, solid externally while in motion,
iii. 413,

—— and alluvium of different ages in
Auvergne, iv. 195.

—— of Iceland and Central France, ii.
129. 131.

——, comparative volume of ancient
and modern, ii. 132.

——, pretended distinction between an-
cient and modern, ii. 142.

—, mineral composition of, ii. 175. 177-
s51.

La Vissière limestone, iv. 192.

Lawrence on causes which enable malt
to live in all climates, ii. 438.

Lazzaro Moro. See Moro.

Leeward Islands, geology of the, iv. 22.

Le Grand d’Aussi, M., on Auvergnes
iv. 197.

Lehman, treatise of, 1759, i. 71.

Leibnitz, theory of, i. 46.

Leigh on fossil canoes, iii. 247.

Leith Hill, height of, iv. 230.

Lemings, migrations of, iii. 37.

Lena, R., fossil bones on banks of, i-
148, 149.

Lentini, limestone near, iii. 396.

—, valleys near, their origin, iii. 442-

Lenz, M., on level of Caspian, iv. 203.

Leonhard, M., on loess of the Rhine, iv-
3 sto

——, on volcanic district of Lower
Rhine, iv. 113.

——,on granites of different ages, iv. 345.

Lepére, M., on level of Mediterranean
and Red Sea, i. 387. i

Lesbos, Antissa joined to, by delta, i. 18.

Lewes, human bones in tumulus near,
ili. 214.

—, estuary of the Ouse recently filled
up near, iii. 263.

— Levels, iii. 229. 262.

—, fissures in chalk filled with sanë
near, iv. 218.

—, ravine called the Coomb near, iv.241.

——, fault near, iv. 242.

Leybucht, bay of, ii. 8.

Lias, strata of the, iv. 290.

—— altered by trap dike and by granite,
iv. 367. 370. 384.

Licodia, basalts of, iii. 406.

Liege, caves near, iii. 211.

Light, influence of, on plants, i. 159.

Lightning, effect of, in Shetland Islands,
i. 394. ;

Lignite, conversion of wood into, iii. 248-

INDEX.

Lima destroyed by earthquake, ii. 258,

——, Valley of, proofs of its successive
rise, iv. 17.

Limagne d’Auvergne. See Auvergne,

Limburg, loess near town of, iv. 32.

Limestone, origin of, iii. 299,

Lincolnshire, incursions. of the sea on
coast of, i. 404.

Lindley, Mr. J., on fossil plants of Mel-
ville Island, i. 159,

——, on effect of light on plants, i. 159.

——, on fossil plants of the coal Strata,
i. 231.

——, on number of plants, iii, 148.

——-, on dispersion of cryptogamic plants,
iii, 13.

Linnzus on filling up of Gulf of Both-
nia, ii. 288,

—— on constancy of species, ii, 363,

—— on real existence of genera, ii. 383.

—— on diffusion of plants, iii, 18, 23,

—— on introduction of species, iii, 77,

—— cited, iii. 89.

Lionnesse tradition in Cornwall, i.
430,

Lipari Islands, rocks altered by gases in,
iv. 373.

Lippi on destruction of Herculaneum
and Pompeii, ii. 97,

Lipsius, i. 21.

Lisbon, earthquakes at, Ji, 57, 251. siti,
959.

Lister the first to propose geological
maps, i. 46.

—— on fossil shells, i. 46,

Lloyd, Mr., on relative levels of Atlantic
and Pacific, i. 387,

Lioyd’s List, number of wrecked vessels
as shown by, iii. 243.

Lochead on gain of land on coast of
Guiana, ii. 33.

Loch Lomond, agitation of its waters
during Lisbon earthquake, ii. 253.

Lockart, M., on fossils of the Orleanais,
iv. 137.

Locke on Whiston’s theory, i. 58.

Locusts, devastations by, iii, 95.

» bank formed in sea by, iii, 96,

Loess of the Rhine, iy. 29,

Loffredo cited, ii. 279, 280.

Loire, tertiary strata of the, iii. 338. $
iv. 115.

London basin, tertiary deposits of, i,
214. ; iii. 335. ; iv. 211.

—, on former continuity of Hampshire
and, iv. 219,

425

4

London clay, its fossils, composition,
thickness, &c., i. 240. ; iv. 213.

Long, Mr., on earthquake at New Ma.
drid, ii. 204,

Long Point peninsula cut through by
Lake Erie, ii. 11.

Lough Neagh, supposed petrifying power
of, i. 329.

Louis de Foix, ii. 24,

Louisiana, Lower, marine strata of, i.
292.

Lowe, Mr., on shells of Madeira, iii. 58.

Lower green-sand described, iv. 222, 27.

Lower Rhine. See Rhine.

Lowestoff, current off the coast of, i. 411,

—— Ness, description of, i. 411.

—, cliffs undermined near, i. 411.

Lowland of Siberia, i. 153. 219.

Lubbock, Mr., i. 185.

Lubeck, ii. 288.

Lucina divaricata, wide geographical
range of, iii. 372. ; iv. 180.

Luckipour, its inhabitants swept away
by the Ganges, i. 363.

—, new islands formed near, i. 362,

Luckput, subsidence near, ii. 195,

Ludlow rocks, fossils of, i, 234,

—, classification of, iv. 270, 298.

Ludwig, Baron, cited, iii. 15, 4

Luleo, gain of land at, i. 345, 3 li, 289,

Luy, tertiary strata of, iv. 120.

Luzon, active volcanos in, ii, 48.

Lybian sands, caravans overwhelmed
by, iii. 190, 4

Lyme Regis, waste of cliffs at, i. 429.

Lym-Fiord, a breach made by the sea
into, ii. 9.

Lyon, Capt., on imbedding of camels in
African sands, iii. 190.

`M.

Maars, or lake-craters of the Eifel, iv.
104, 105.

MacCulloch, Dr., on gradation from
peat to coal, iii. 178.

—, on origin of limestone, iii. 299.

—, on parallel roads of Glen Roy, iv.

—, on Subapennine strata, iv. 52.

—, on granite veins, iv. 338.

—, on junction of granite and lime.
stone in Glen Tilt, iv. 340.

——-, on granitic rocks, iv. 342, 349, 348.
371,

426

MacCulloch, Dr., on trap rocks, iv. 347.

Macedonia, earthquakes in, ii. 56.

Macgregor, Mr., on earthquakes in Ca-
nada, ii. 208. ‘

Mackenzie, Sir G., his supposed section
of the pipe of a geyser, ii. 346.

, on reindeer in Iceland, iii. 116.

Mackenzie, R., drift-wood of, i. 162. ; iii.
221,

——, calcareous formation near its
mouth, i. 201.

Maclaren on quantity of useful soil in
America, iii. 117.

—, 0n position of American forests, iii.
166.

Maclure, Mr., on coral and lava in
‘West Indies, iii. 294. 5 iv. 22.

—, on volcanic district of Olot, iv. 91.

Macmurdo, Captain, on earthquake of
Cutch, ii. 195. 199.

Madagascar said to contain active vol-
canos, ii. 58.

—, extent of coral near, iii. 280.

Madeira, ii. 58. ; iv. 23.

Maeler, lake, ii. 294. 301.

Maestricht beds, fossils of, iv. 273.

—, chasm between Eocene and, iv.
274.

—, shells common to.the chalk, green-
sand, and, iv. 272,273.

Magellan, Straits of, currents in, i. 385.

Magnesia deposited by springs, i. 316.

Magnesian limestone and travertin com-
pared, i. 317.

Magnetism, terrestrial, phenomena of,
li. 323.

Magnan, R., section in valley of, iv. 65.

Mahomet, his cosmogony, i. 32.

Majoli, opinions of, i. 38.

Malabar, coral near, iii. 280.

Malaga, tertiary strata of, iv. 70.

Malcolm, Sir J., on buried cities in Cen-
tral India, iii. 194.

Maldivas, chain of coral islands, iii, 280.

Mallet, Captain, on petroleum of Tri-
nidad, i. 334.

Malpais, theories to account for con-
vexity of the plain of, ii. 135.

Malte-Brun cited, i. 168. 181. ; iii. 42, 53.
71. 191. 224. 234.

Mammalia, different regions of indi-
genous, ili. 27.

——, fossil, importance of remains of,
ili, 358.; iv. 40. s

——, of successive tertiary periods, iji.
379.

INDEX.

Mammalia, remains of, rare in the older
rocks, iv. 310.

Mammoth, climate, &c., probably Te-
quired by the, i. 144.

——-, bones of, in Yorkshire, i. 145.

—, in tufa near Rome, iv. 28.

Man, unfavourable position of, for ob-
serving changes now in progress, }
121.

—, recent origin of, i. 244.; iii, 117-
O56. :

, remarks on the superiority of, 1-
247.

—, causes which enable him to live in
all climates, ii. 438.

—, his agency in dispersion of plants
and animals, iii. 21. 74.

—, diffusion of, iii. 68.

—, probable birthplace of, iii. 68.

——, changes caused by, i. 252. ; iii. 106-
165.

—, durability of the bones of, i. 246. 5
iii. 245,

—, remains of, in osseous breccias of
the Morea, iii. 205. $

——, his remains and works fossil, iii-
234, 238.

Manetho, i. 113.

Manfredi on sediment in river water,
i. 366.

Mansfeld, fossils of, iv. 293.

Mantell, Mr., on bones from Saxon tu-
mulus, iii. 214.

—, on Lewes Levels, iii. 229. 263.

—, on fossil shells of the crag, iv. 71.

__—, on tertiary outliers on chalk, iv-
218.

——, on the Weald Valley, iv. 222. 224.
235. 282,

——,on “elephant bed” at Brighton,
iv. 261.

——, on fossils of the chalk, iv. 278.

——, on fossil forest of I. of Portland,
iv. 284.

——, on a fault in the cliff-hills near
Lewes, iv. 242. é

Manwantaras, oriental cycle of ages, i, 7.

Maracaybo, lake, ii. 203.

Marble deposited from springs, i. 326.

Marculot, limestone of, iv. 152.

Marienforst, blocks of quartz, with casts
of shells near, iv. 112.

Marine alluviums, iii. 198.

Marine testacea, range of, iii. 361.

Marine and freshwater strata, alterna-
tions of, iii. 264.

INDEX.

Marine deposits, imbedding of fresh-
water species in, iii. 265.

——, contain in general a great variety
of species, iii. 265.

Marine plants and animals, imbedding
of remains of, iii, 265. `

Marine vegetation, iii. 8. 16.

Maritime Alps, conglomerates forming
at base of, i. 376.

~—-, tertiary strata at base of, iv. 61.

Marl lakes of Scotland, animals and
plants fossilized in, iii, 236, 259.

Marsilli, on arrangement of shells in
Adriatic, i. 64. 67.

——, on deposits of coast of Languedoc,
i. 349.

Marstrand, island of, ii. 297.

Marsupial animals, distribution of, iii.
29.

——,in breccias in Australian caves,
iv. 43.

Martigny destroyed by floods, i. 297.

Martin, Mr., on Valley of the Weald,
ive 231,98.

—, on transverse valleys of North and
South Downs, iv. 238.

——, on thickness of strata removed from
summit of Forest ridge, iv. 258.

Martinique, earthquake in, ii. 259. 4

Martin Meer, fossil canoes in, iii, 247.

Martius, on drifting of animals by the
Amazon, iii. 42.

——, on Brazil, iii. 108.

Maryland, whirlwind in, iii. 11,

Mascalucia, subsidence near, iii. 425.

Mathers, village of, swept away by sea,
i. 399.

Matilda coral island, iii. 290.

Mattani on fossils of Volterra, i. 60.

Mattioli on organic remains, i. 37.

Mayence, tertiary strata of, iv. 132.

Mayer, M., on mineral veins, iv. 375.

Mayne, Valley of the, iv. 35.

Medesano, lignite at, iv. 54.

Mediterranean said to have burst
through the columns of Hercules, i.25.

—, microscopic testacea of, i. 78.

—, deposition of salt in the, ii. 15.

——, its former union with the Red
Sea, ii. 31.

——, new island in, ii. 146,

——, organic remains of, iii. 327. ; iv.
118.

~—, shells drifted into, iii. 360.

——, its temperature, depth, level, SoCs,
i. 79. 353. 387.5 ii. 14. 16. 272. |

427

Medway, transverse valley of the, iv. 238.

Meerfelder Maar described, iv. 106.

Megalosaurus Buckland?, iv. 286.

Melania inquinata, iii. 372.

Melilii, circular valley near, iii. 439.

——-, inland cliffs near, iii. 440.

Melville Island, fossils of, i. 159.

—, Migrations of animals into, iii. 41.

Mendip hills, caves of, iii. 212.

Menw’s Institutes, i. 6. 8.

Mercati on organic remains, i. 37.

Merdogne, marls intersected by a dike
near, iv. 186.

Mersey, vessel in bed of, iii. 247.

Meryon, Mr., on Romney Marsh, i. 423.

Mese, formerly an island, i. 347.

Messenia, conglomerate of, iv. 277.

Messina, tide in Straits of, i. 381.

——, earthquake at, ii. 218. 236.

Mesua Collis described. by Pomponius
Mela, i. 347.

Metallic nucleus, theory of an unoxid.
ated, ii. 326.

Metallic substances changed by submer-
sion, iii. 249.

Metamorphic, the term proposed and
defined, iv. 380.

—— rocks of the Alps, iv. 369.
——, Sometimes pass into sedimentary,
iv. 382. A
—, in what manner their age should
be determined, iv. 383.

—, why those visible to us are for the
most part ancient, iv. 384.

Methone, eruption in, ii. 56.

Metshuka, hill of, ii. 250.

Mexico, tides in Gulf of, i. 364.

— volcanic chain extending through,
li. 45.

Meyen, Mr., on earthquake in Chili,
1822, ii. 191.

Meyer, Mr., on level of Caspian, iv.
203.

Mhysir, buried city, iii. 195.

Micaceous schist, whence derived, iv.
375.

Michell on cause and phenomena of
earthquakes, 1760, i. 73.

——, originality of his views, i. 73,

— on the geology of Yorkshire, i. 73.

— on earthquake at Lisbon, ii. 57.
254.

— on retreat of the sea during earth-
quakes, ii. 255.

—— on cause of the wave-like motion
of earthquakes, ii, 335.

428

Microscopie fossil shells of Sienna, iv.
60. :

—~, of the Crag, iv. 75.

—— of Paris basin, see plate, iv. 176.

Migrations of animals, iti. 36.

—— of cetacea, iii. 44.

— of birds, iii. 45.

— of fish, iii. 52.

——- of insects, iii. 62.

Migratory powers indispensable to ani-
mals, iii. 120.

Mileto, subsidence near, ii. 232.

Milford Haven, rise of tides at, i. 382.

Miliolite limestone, iv. 176.

Millennium, i. 35. 55.

Mindinao volcano, ii. 48.

Mineral waters, their connection with
volcanic phenomena, i. 308.

—, ingredients most common in, i.
311. See Springs. :

Mines, heat in, augments with the
depth, ii. 313.

Miocene period, term whence derived,
iii. 370.

—, proportion of living species in fossil

shells of the, iii. 370.

——, mammiferous remains of, iii. 379.

——, marine formations of, iy. 114.

—, freshwater formations of, iv. 137.

—, volcanic rocks of, iv. 140,

——, alluviums of, iv. 134.

Mirambeau, red clay and sand of, iv.
122.

Mismer, crag strata near, iv. 79.

Mississippi, its course, depth, velocity,
KEG bode 235;

— , drift-wood of the, i. 284. 287. 365. ;
iii. 42. 223.

——, earthquakes in valley of, i. 291.;
ii. 46. 203.

——, delta of, i. 364. 376,

‘Missouri, R., i. 282.

Misterbianco, valleys of, iii. 400.

Mitchell, Dr., on waste of cliffs, i. 415,
418.

Mitchell, Major, on Australian caves,
iv. 44.

Mitscherlich, M., on minerals found in
Somma, iv. 5.

Mocha, elevation of land at, ii, 188.

Modern causes, remarks on the term,
iv. 264.

Moel Tryfane, recent marine shells on,
pe Zio;

Moen, chalk and tertiary strata of, iv:
87.

INDEX.

Molasse, its place in series of tertiary
formations not yet known, iv. 128.

Mole, R., transverse valley of, iv. 238.

Molino aee Caldane, travertin, i. 313.

Moluceas, eruption in the, ii. 261.

Moliemotes animals, superior longevity
of the species of, i. 145. ; iii. 361. 372-5
iv. 40.

Mompiliere, articles preserved under
lava in, ii. 119.

Monfalcone, baths of, i. 352.

Mons, secondary strata near, iv. 271.

Mont Blane, glaciers of, i, 269.

—— Dor, volcano of, ii. 170. 173. ; iv. 189-

— Ferrat, tertiary strata of, iii. 338.

m Mezen, age of the, iv. 188.

— Perrier, alluviums and breccias ofs
iv. 134.

Monte Barbaro, description of, ii. 75.

— Bolca, fossil fish of, . 78.

—— Calvo, section from, to the sea, iY-
67.

— Cerio, shells in gypsum of, iv. 54-

—— Grifone, caves in, iv. 41.

— Mario, strata of, iv. 29. 56.

—— Minardo, its height, &c., ii. 113.

— Nucilla, ii. 113.

—— Nuovo, formation of, ii. 72.5 ii
435.3 iv. 11. 14.

— coast of Bay of Baie elevated dur-
ing eruption of, i. 51. ; ii. 72. 280.

— Peluso, ii. 114,

— Rotaro, ii. 63.

—— Somma, structure of, ii. 86. 168.

— Vico, siliceous incrustations of,
329. .

Monticelli and Covelli on Vesuvian ™-
nerals, ii. 92.

Monti Rossi described, ii. 116.

Montlosier on Auvergne, i. 87.3 iv. 192
197.

Montmartre, gypsum of, iv. 172.

—, fossils of, iv. 179.

Montpellier, cannon in crystalline rock
at, i. 349.

—, tertiary strata of, iv. 126.

Montsacopa, volcanic cone of, iv. 98.

Morayshire, town in, destroyed by sea, i.
399.

—, effect of floods in, iii, 197. 233.
Morea, cities submerged in the, ii. 55.
—— Céramique of, iii. 200.

——, osseous breccias now forming ™

the, iii. 203.
——, closed basins and engulphed rivers
in the, iii, 204.

INDEX,

Morea, human remains imbedded in the,
lii. 205.

——, sea-cliffs at various elevations in
the, iv. 19.

——, tertiary strata of, iv. 70.

—, cretaceous rocks of the, iv. 277.

Morren, M., on peat, iii. 187,

Moro, Lazzaro, on earthquakes, 1740, i.
60.

——, on new island in Mediterranean, i.
61. Í

—, on nature of organic remains, i. 61.

——, on faults and dislocations, i. 61.

—, on secondary strata, i. 62.

——, on origin of stratified rocks, i. 67.

——, on primary rocks, i. 91.

Morocco, earthquakes at, ii. 57. 255.

Moropano, shells in tuff near, iv. 12.

Mosasaurus of Maestricht found in the
English chalk, iv. 278.

Mosenberg, extinct volcano, iv. 106.

Mountain chains, on the elevation of, i-
116.

——, on relative antiquity of, iv. 320.

——., difficulty of determining the rela-
tive ages of, iv. 334.

Mountain limestone formation, i. 201. ;
iv. 293.

Mount Vultur, ii. 57.

Mud eruption in Quito, 1797, ii. 206.

Mules sometimes prolific, ii. 424.

Mundane egg of Egyptian cosmogony,
i. 16.

Mundesley, chalk near, iv. 85.

Munkholm, Island of, ii. 302.

Munster, Count, on Maestricht fossils,
iv. 274.

——, on fossils of Solenhofen, iv. 289.

——, on Gosau fossils, iv. 279.

Murat, deposits near, iv. 192.

Murchison, Mr., on the Hartz moun-
tains, j. 184.

——, on tertiary deposits of the Alps, i.
210.

—, on the coal strata, i. 202.; iv. 295.

——, on transition fossils, i. 234.

—, on schists of Caithness, i. 235.

——, on tertiary strata of Lancashire, i.
219

—, on raised beaches in Ireland, i.
216.

~— on tertiary strata of Nice, iv. 25.

—— of maritime Alps, iv. 64. 65.

—— of the Superga, iv. 127.

—— of Styria, iv. 129, 131. 142.

s= of Cadibona, iv. 140.

429

Murchison, Mr., on tertiary strata of
Central France, iv. 144. 162. 185, 199.

— of Aix, iv. 211. j

— his'section of crag resting on chalk,
iv. 77.

——, on excavation of valleys, iv. 195.

——, 0n upper green-sand, iv. 248.

——. his new arrangement of the tran-
Sition strata, iv. 298.

Murcia, earthquake of 1829, ii. 183.

Murphy, Lieut. H., on height of North
Downs, iv. 224.

Musara, buried cones near, iii. 415.

—, flowing of lava round, iii. 490,

Muschelkalk, iv. 292.

Mydaus meliceps, iii. 39,

N.

Nadder, valley of the, iv. 250.

Nakel, fossil ship found at, iii. 247.

Nantucket, banks of, i. 384.

Naples, history and map of yolcanic
district round, ii. 61. ; iv. 1.

—, recent tertiary strata in district
round, iii. 340.

——, recent shells in tuffs near, iv. 11.

Narwal stranded near Boston, iii, 266,

— fossil, near Lewes, iii. 263.

Nature, as defined by Lamarck, ii. 375,

Necker, M. L. A., on Somma, ii, 168.
iv. 5: 3; “

Needles of Isle of Wight, i. 425.

—, fall of one of them, iv. 87.

Neill on whales stranded, iii. 266. |

Nelson, Lieut., on coral reefs, iii. 279,

Neptune, temple of, under water, ii. 276,

Neptunists and Vulcanists, rival factions
of, i. 88. 98.

Nerbuddah, R., iii. 194.

Nerinzan limestone, iv. 289,

Nesti, M., on fossils of UpperVal d’*Arno,
iv. 139.

Netherlands, tertiary formations of the,
iv. 210.

Newcastle coal-field, i. 202.

Newer Pliocene period.
period, newer.

Newfoundland, cattle mired in bogs of,
1. 130:

Newhaven, its cliffs undermined, i, 423.

—, tertiary strata on chalk near, iy,
222. =

New Holland, plants of, i. 196.5 iii. 5.

See Pliocene

4.30

New Holland, animals of, iii. 29.

~—,, coral reefs of, iii. 280.

New Kameni, formation of, ii. 163.

New Madrid, earthquakes at, ii. 203.

New York, excessive climate of, i. 169.

New Zealand, animals in, i. 204.

Niagara, excavation caused by the cata.
ract of, i. 134. 277.

——, falls of, i. 275.

——, probable time which they will re-
quire to reach Lake Erie, i. 278.

Niapisca Island, worn limestone co-
lumns in, iv. 21.

Nicaragua, volcanos in, ii. 45.

Nice, depth of Mediterranean near, i.
353. 376. 3 ii. 18.

—, tertiary strata of, i. 353. ; iv. 63. 65.

Nicolosi destroyed by earthquake, ii.116.

Niebuhr cited, i. 109.

Niger, delta of, its size, iv. 309.

Nile, delta of the, i. 353. ; iii. 348.

—, its ancient mouths, i. 354,

—, analysis of mud of the, i. 355.

——, cities buried under blown sand
near the, iii. 188.

——, men swept away by flood of, iii.
239.

Niisson, M., on lignite of the chalk pe-
riod, iv. 278.

on migrations of eels, ili. 54.

Nipon, volcanos numerous in, ii. 48.

Nitrogen in springs, iii. 158.

Noeggerath, M., on volcanic district of
the Rhine, iv. 102. 113.

Norfolk, waste of cliffs of, i. 404. ; iv.
236.

——., gain of land on coast of, i. 407.

~—, crag strata of, iv. 71.

Norte, R., transportation of sediment
by the, ii. 33.

North Cape, drift-wood on, iii. 224.

North Downs, chalk ridge called the, iy.
293.

——-, section across valley of Weald
from south to, iv. 224.

—, highest point of, iv. 224.

——,on former continuity of chalk of
the, with that of the South Downs,
iv. 244.

Northmavine, rocks drifted by sea at, i.
394. ;

Northstrand destroyed by sea, ii. 9.

Northumberland, land destroyed by sea
in, i. 402. .

‘Noto, Val di, formations of the, iii. 383.

Notre Dame des Ports, i. 347.

INDEX.

Norway free from earthquakes, ii. 304.
—, rise of land in, i. 216. ; ii. 298. 301.
Norwich once situated on an arm of the

sea, i. 407.
Nugent, Dr., on Pitch Lake of Trinidad,
i. 334.

Novera, hill of, in Sicily, iii. 392.

Nymphs, temple of, under water, ii-
276.

Nyée, a new island formed in 1783, ii.
197. 145.

O.

Obsequens on eruption in Ischia, ii. 71.

Oby, R., fossils on shores of, i. 148.

Ocean, permanency of its level, ii. 284.

Oceanic deltas, i. 357.

Odoardi on tertiary strata of Italy, i-
74. 5 ili. 336.

Oersted, discoveries of, ii. 324.

Ogygian deluge, ii. 52. 69.

Ohio, junction of, with Mississippi, i. 282.

Olafsen on drift-wood, iii. 225.

Older Pliocene period. See Pliocene pe-
riod, older.

Old red sandstone formation, iv. 295.

—, fossils of, i. 235. ; iv. 296.

Olivet, volcanic cone of, iv. 93.

Olivi on fossil remains, i. 38.

— on sediment in Adriatic, i. 352.

Olot, volcanic district of (see Pl. xi.), iv-
90.

——, destroyed by earthquake, iv. 99.

Omalius d’Halloy on former connection
of Auvergne and Paris basin, iv. 165.

Omar, an Arabian writer, i. 30.

Oojain. See Oujein.

Oolite, or Jura limestone formation, iv-
287.

—, converted into hypogene rock in
the Alps, iv. 370.

——., fossils of the, i. 237. ; iv. 288.

Oolitic structure in Auvergne, iv. 152.

—— in Hungary, iv. 130.

——, recent, in Lancerote, ii. 144.

Opossum, fossil, at Stonesfield, i. 237.

Oppido, changes caused by earthquake
near, ii. 215. 224.

Orang-outang, Lamarck on its conver-
sion into the human species, ii. 377.
Organic life, effect of changes in land

and sea on, i. 182.
Organic remains, controversy as to real
nature of, i. 34. ; iii. 306.

INDEX,

Organic remains, imbedding of.
Fossilization.

— importance of the study of, i. 106.

——, abrupt transition from those of
the secondary to those of the tertiary
rocks, i. 212.

—, contemporaneous origin of rocks
proved by, iii. 325.

See

——, comparative value of different

classes of, iii. 357.

——. See also Fossils,

Orinoco, R., subsidence in, ii. 250.

Orkney Islands, promontory cut off by
sea in, i. 399.

Orleanais, fossils of the, iv. 137.

Orpheus cited, i. 13.

Orthés, tertiary strata of, iv. 121.

Orust, island of, ii. 300, 301.

Orwell river, i. 415.

Osnabruch, tertiary strata of, iv. 133.

Osseous breccias, formation of, iii. 231,

, in caves, iv. 38. 43. `

——, now forming in the Morea, iii. 203.

Otaheite, volcanos in, iii. 288.

—, coral at great height in, iii, 297.

Otranto, tertiary strata of, i. 141. ; iii.
340.

Oujein, buried city of, ii. 200. ; iii. 193.

Ouse, R., transverse valley of, iv. 238.

——, has filled up an arm of the sea, iii,
263.3 iv. 240. . =

Outlying patches of tertiary strata on
chalk hills, iv. 218.

Ovid cited, i. 16.

Owen, Mr., on bones of turtles, iii. 269.

Owbyhee, iii. 288.

Owthorne, encroachment of sea at, i. 403.

Oxus, earthquake in valley of the, ii. 50,

Oxygen, its action on rocks, i. 262,

Oysters, &c., thrown ashore alive by
storm, ii. 270.

——, migrations of, iii. 60.

Li

Pachydermata abundant in Eocene pe-
riod, iii. 379.

Pacific Ocean, depth of, i. 185

—, its height above the Atlantic, i. 387.

——, animals in islands of, iii, 32.

——, subsidence greater than elevation
in, iii. 294.

——, earthquakes in, iii. 296.

——, coral and volcanic islands of, ii
49. ; iii, 284, 287. 296.

431

Pacific Ocean, lines of ancient sea cliffs
on shores of, iv. 17.

Pestum, formation of limestone near, i.
319,

Pakefield, waste of cliffs at, i. 411.

Palzotherium in freshwater strata of
Isle of Wight, iv. 216. 263.

Palagonia, dikes at, iii. 391.

——-, section to Paterno from, iii. 399.

Palermo, caves containing osseous brec-
cias near, iv. 41.

Palestine shaken by earthquakes, ii. 54.

Palissy on organic remains, i. 39,

Pallas on mountains of Siberia, i. 79.

— on Caspian Sea, i. 80. ; ii. 52,

—— on fossil bones of Siberia, i. 80. 148,
149.

—— on calcareous springs, i. 325.

e ted u. 12°53! 820.3 ait, 75.

Palma, description of Isle of, ii. 155.

Palmer, Mr., on shingle beaches, i. 428.

Panama, tides in Bay of, i. 388.

Panella, in Ischia, iv. 13.

Papandayang, eruption of, ii. 249.

——, its cone truncated, ii, 249. Gait
424.

Papa Stour, waste of rocks of, i. 398.

Papyrus rolls in Herculaneum, ii. 104.

Paradise, Burnet on seat of, i. 56.

Parallel roads of Coquimbo, iv. 18.

— of Glen Roy, iv. 18.

Paris basin, formations of the, i. 214. 5
iii, 332. ; iv. 164.

—, fossils of the, i. 240. ; iii. 333. 379. $
iv. 176, 177.

-——, all tertiary formations at first re.

ferred to age of, iii. 334.

—, analogy of deposits of Central
France to those of the, iv. 164.

—, comparison between English Eo-
cene deposits and those of, iv. 217.

Parkinson, Mr., on the crag, iii. 336. ;
iv. 50.

Parma, tertiary strata near, i. 141.353, ;
iii. 364. ; iv. 53.

Paroxysmal elevations, theory of, iv. 14.

Parrot on Caspian Sea, ii. 51. ; iii. 126.

——., retraction of his opinion on level
of Caspian, iv. 202.

Parry, Captain, highest northern lati-
tude reached by, i. 175.

—— on migration of Polar bear, iii. 40,

—— on animals of Melville Island, iii,
41.

Partsch, M., on tertiary strata of Vi-
enna, iv, 129. k

432

Passo Manzanelli, waterfalls in lava at,
i. 274.
Pasto, volcanos in, ii. 45.
Paternd, section from, to Palagonia, iii.
399.
—, valleys of, iii. 400.
— _, age of basalts of, iii. 406.
Patrizio? s dialogues, i. 59,
Pauliac, limestone of, iv. 122.
Paviland cave, iii. 212.
Peat, on its growth and preservation of
fossils in it, iii. 160. 177. 182.
— bogs, bursting of, iii. 186.
—, submarine, iii. 187. 265,
Padamentina, description of the, ii. 87.
Pembrokeshire, tradition of loss of land
in, i. 431.
Pennant on encroachments of sea on
Yorkshire coast, i. 403, 404.
—— on distribution and migration of
animals, i. 147. ; iii. 31.37.
Pentalica, limestone of, iii. 384, 385.
Pentland, Mr., on fossils from Australian
caves, iv. 44.
——, on fossils of Upper Val d’ Arno, iv,
138.
Pentland Frith, currents in the, i. 385.
Penzance, loss of land near, i. 429.
Peperino, dikes in, iii. 390.
——, how formed, iii. 393.
——, dikes of, how formed, iii. 392.
Péron on distribution of animals, iii. 52.
61.
Perpignan, iv. 99.
Persian Gulf, coral in, iii. 280.
Persian Magi on the deluge, i. 32.
Peru, volcano in, ii. 42.
——, earthquakes in, ii. 42. 258.
——, proofs of successive elevation of
coast of, iv. 17.
Peterhead, whale stranded near, iii, 266.
Petroleum, springs, i. 334,
Pewsey, Vale of, iv. 250.
Pharos joined to Egypt by delta of Nile,
i, 18. 354.
Phillips, Mr, J., on waste of Yorkshire
coast, i. 403.
—, on tertiary strata in Yorkshire, iv.
76.
Phillips, Mr. R., on slow deposition of
some kinds of sediment, ii. 35.
Phillips, Mr. W., his analysis of chalk
flints, iv. 160.
_ Philosopher’s tower on Etna, iv. 15.
Phlegræan fields, volcanos of, ii. 74. ;
iv. 10.

INDEX.

Physical Geography. See Geography-

Piana, conglomerate of, iv. 127.

Piazza, tertiary strata at, iii, 396.

Pichinea volcano, ii. 43.

Piedmont, tertiary strata of, iii. 338.5 iv-
126.

Pietra Mala, inflammable gas of, i. 19.

Pignataro on earthquake of Calabria, ii.
212. :

Pigs, instincts of, ii. 413.

— swim to great distances, iii, 34.

—, fossil, iii. 183.

Pindar cited, ii. 115.

Pingel, Dr., on subsidence of Greenland,
ii. 342,

Pitch lake of Trinidad, i. 334.

Pitchstone, formed by dikes of Somma;
iv. 9.

Piteo, gain of land at, i. 345. ; ii. 289.
Pius VIL, edict against Galileo and Co-
pernican system repealed by, i. 100.

Piz, fall of mountain of, iii. 200.

Plants, varieties in, produced by horti-
culture, ii. 399.

—, extent of variation in, ii. 401.

, their geographical distribution,

iii. 3

—— in islands, iii. 6. 15.

—, dispersion of, iii. 10.

—, stations of, iii. 5. 86.

—, equilibrium among, kept up by in-
sects, iii. 89.

—, number of terrestrial, iii. 148.

—, imbedding of, in subaqueous de-
posits, iii. 219. 258. 265.

——, on number which are now becom-
ing fossil, iii. 226.

—, their fossilization partial, iii. 350.

—, fossil, importance of, in geology»
iii. 357. 359.

——, fossil, of the coal strata, i. 158. 202.
231.

Plas Newydd, changes caused by a dike
near, iv. 364.

Plastic clay and sand of the London ba-
sin, i. 240. ; iv. 212.

—— of the Paris basin, iv. 168.

Plastic force, fossil shells ascribed to, i.
34.

Plato on Egyptian cosmogony, i. 13.

Playfair on Huttonian theory, i. 94. 101.

—— on instability of the earth’s surface,
i, 299.

—— on gradual rise of Sweden, ii. . 291.

—— on formation of ‘vegetable soil, iji-
156.

í

INDEX.

Playfair cited, ii. 320.

Pleurs, town of, and its inhabitants bu-
ried by a landslip, iii, 201.

Pliny the Elder, i. 27.

——, on delta of Rhone, i. 346.

» ON islands at the mouth of the
Texel, ii. 7.

-—, killed by eruption of Vesuvius,
A. D. 79, ii, 67.

Pliny the Younger, on eruption of Ve.
suvius, A. DÐ. 79, ii. 67.

——, does not mention the overwhelm.

ing of Herculaneum and Pompeii, ii.

67.

Pliocene period, newer,
the term, iii. 368,

——, proportion of living
sil shells of, iii. 369, 373.

— marine formations of, iii. 382,

—, volcanic rocks of, iv, 2,

~—, subterranean rocks
formed during, iii. 436.

—, freshwater formations of, iv. 27.

~, OSseous breccias and cave deposits
of, iv. 38.

——, alluviums of, iv. 44.

Pliocene period, older, proportion of
living species in fossil shells of, iii.
369. 373.

——, Mammiferous remains of, iii. 379,

——, formations referable to the, iv. 49,

——., volcanic rocks of, iv. 89.

Pliocene strata of Sicily, origin of, iii.
433.

——, changes of surface during and
since their emergence, iii. 438.

——, ewer, chiefly visible in countries
of earthquakes, iv. 16. 26,

Plomb du Cantal, successively accumu-
lated, iv. 162.

——, volcanic rocks of, iv. 188, 191,

——, limestone covered by volcanic
rocks on, iv. 199.

—, not an elevation crater, ii. 170.

Plot on organic remains, i, 45,

Pluche, theory of, 1732, i. 58.

Plutarch, i.'12.

Plutonic rocks, iv. 337,

— distinction between volcanic and,
iv. 345.

——, their relative age, iv. 351. 383.

—, changes produced by, iv. 368.

Po, R., frequently shifts its course, i, 279,

———; embankment of the, i. 280.

——, delta of the, i, 350, 374.; iii. 170.

Podolia, tertiary formations of, iv. 182,

VOL. Lv.

derivation of

Species in fos-

of fusion,

U

433

Polistena, changes caused by earth-
quakes near, ii. 219. 226. 231.

Polyps, see Zoophytes.

Pomerania, fossil ships in, iii. 247.

Pompeii, how destroyed, ii. 94. 98.

—— section of the mass enveloping,
ii. 95, ;

—, depth to which’ the ashes of erup- '
tion of 1829 covered, ii. 25.

——, objects preserved in, ii. 100.

Pomponius Mela, cited, i, 347. ; ii. 6.

Pondres, cave at, if. 214,

Pontanus on eruption in Ischia, ii. 71.

Pont du Chateau, tuff and limestone at,
iv. 185.

Ponte Leucano, travertin at, i. 321.

Pont Gibaud, gneiss rocks decomposed
by carbonic acid at, i. 332.

——-, calcareous springs near, i. $12.

Poole Bay cut into by sea, i. 426,

Popayan, volcanos in, ii, 45, :

——, shaken by earthquake, ii. 189.

Port-au-Prince destroyed by earthquake,
li. 255.

Portland, fossil ammonites of, i. 49.

——, its peninsula wasting, i. 497.

——, fossil forests in, iv. 284.

Port Royal, subsidence Of; 2620 seat
125.252. 255, ;

Portugal, earthquakes in, ii. 57. 251;

Port Vallais, ancient town in delta of
Rhone, i. 338.

Po Vecchio, i. 280.

Pratt, Mr., on fossils of Isle of
i. 241. ; iv. 216.

— 0n cave of San Ciro, iv. 40,

Precession of the equinoxes, i. 179,

Prevost, M. C., on fossil mammalia
of Stonesfield, i. 237.

[2,0 gypseous springs of Baden, i.
3827.

Wight,

——, on new island in Mediterranean,
ìi. 148,

—— on elevation craters, ij, 159, 154,
170.

~>, on geological causes, iii, 176,

—, on drifting of plants, iii. 229,

—, on filling up of caves with osseous
breccias, iii. 210. ge
—, on tertiary strata of Vienna, iii,

339. ; iv. 128. i
~—, on tertiary strata of Paris
iv. 167. 171. 173. 178.
Prevost, M. P., on radiation of heat, i. 167,
Prevost, Mr. J. L., on number of wrecked
vessels, iii, 243.

basin,

434:

Pressure, effects of, on consolidation of
strata, iv. 317.

Prichard, Dr., on Egyptian cosmogony,
i, 12. 250.

—=, on recent origin of man, i. 246.

——, on distinct origin of dog and wolf,
ii. 394.

__—, on hybrid races, ii, 425.

Seon facial angle, ii. 437.

——, on distribution of animals, iii. 28.
Si

Primary, on the rocks usually termed,
iii. 313. ; iv. 336.

——, their relation to volcanic and sedi-
mentary formations, iv. 336.

——, divisible into two groups, iv. 337.

~——-, on the stratified rocks called, iii.
317. ; iv. 358.

——, the term why faulty, iv: 379.

_— strata, how far entitled to the ap-
pellation, iv. 383.

Primitive, term now abandoned, iii. 318.

Primosole, limestone at, iii. 397.

Prinsep, Mr., on sediment of Ganges, i.
367.

Priory of Crail, swept away by sea,
i, 401.

Procida, island of, remarks of ancient
writers on, ii. 62.

_ would resemble Ischia if raised,
iv. 13.

Progressive development of organiclife,
theory of, i. 227. ; Ï. 363.

Promontories, their effect in protecting
low shores, i. 399. `

Psalmodi, formerly an island, i. 347.

Puglia, fossil elephant found at, i. 37.

Pulo Nias, fossil shells of, iv. 23.

Pulvermaar, described, iv. 105.

Punto del Nasone, dikes at, iv. 6.

Punto di Guimento, veins of lava at,
iii. 419.

Puracé volcano, iv. 178.

Purbeck, its peninsula wasting, i. 427.

Pursh on Plants of United States, iii. 5.

Pusanibio, R., sulphuric acid, &c. in
waters of, iv. 178.

Puy Arzet, chalk with beds of tuff in,
iv. 120.

Puy de Come, ravine in lava of, iv: 193.

Puy de Jussat, quartzose grits of, iv. 148.

Puy de Marmont, tuff and marl in, iv.

“185.

Puy de Pariou, iv. 199.
Puy Griou, iv. 191.
Puy Rouge, ravine in lava of, iv.

194.

INDEX.

Puy de Tartaret, iv. 193.

Puy en Velay, fossils in alluvium under
lava near, iv. 136.

—, freshwater formation of, iv. 157.

Puzzuoli, Temple of Serapis near, ii. 267.

inland cliffs near, ii. 268. 970. 5
iii. 441.

—, date of re-elevation of coast of, ii.
278.

—, encroachment of sea near, ii. 282.

——, no great wave caused by rise of
coast near, iv. 14.

Pyrenees, their relative age, height, &c.,
i. Q11.; iv. 326. 368.

—, tertiary formations of, iv. 69. 121.
327.

——, lamination of clay-state in, iv. 361.

——, chalk of the, iv. 276, Q77.

Pythagoras, system of, i. 16.

—, on Etna, ii. 39.

Q.

é

Quadrumanous animals, not found fos-
sil, i. 242.

Quadrupeds, domestic, multiply rapidly
in America, iii. 113.

—, imbedding of terrestrial, iii, 231.

Quaggas, migrations of, ili. 38.

Quartz, whence derived, iv. 376.

Quebec, climate of, i. 169.

—, earthquakes in, ii. 908.

Quero destroyed by earthquake, ii. 207.

Quilotoa, Lake, cattle killed by vapours
from, ii. 207.

Quintero elevated by earthquake of
1822, ii. 190.

Quirini, theory of, i. 44.

Quito, earthquakes in, ii. 206. 261. >

Quorra, or Niger, delta of the, iv. 309-

Quoy, M., on coral zoophytes, iii. 281.

R

Rabenstein cave, iii. 210.

Race of Alderney, its velocity, i. 385.

Radicofani, marls capped by basalt at,
iv. 54.

——4, age of volcanic rocks of, iv. 89.

Radusa, fossil fish of, iii. 389.

Raffles, Sir S., cited, ii. 200. 419.

Rafts, drift-timber in Mississippi, &°-»
i. 286.

Rain, action of, iii. 164.

Ra

Enns

INDEX. 435

Rain diminished by felling of forests,
iii. 165. ;

Ramazzini on Burnet’s theory, i. 59,

Ramond, M., on Auvergne, iv. 197.

Rancié, altered lias at, iv. 369.

Raspe on islands shifting their position

` (note), i. 19.

—, his theory, 1763, i. 75.

—, on earthquakes, i. 75.

—, on new islands, i. 76.

—, on basalt, i. 85.

——, on elevation of coast of Chili, ii.
258.

Rats, migrations of, iii. 37.

—— introduced by man into America,
iii, 74. 115.

Ravenna, formerly a sea-port, i. 351.

Ray, his physico-theology, i. 52. 54.

——-, 0n earthquakes, i. 53.

——, on encroachments of sea, i. 53. 413.

—, on Woodward’s theory, i. 55.

—,, cited, iii. 50.

«Reaumur on insects, iii. 94.

Recent formations, term explained, iii.
363.

—, form a common point <f departure
in all countries, iii. 378.

Recent and tertiary formations, synop-
tical table of, iii. 381.

Reculver cliff, encroachment of sea on,
i. 416.

Recupero on fiowing of lava, ii. 119.

Red marl, supposed universality of, iv.
315. s

—— and sandstone of Auvergne, iv.
148. 316.

. Red River, formation of new lakes by,

THOS WIV. O75 f

—, drift-wood in, i. 286. ;

Red River and Mississippi, their junc-
tion recent, i. 374.

Red Sea, gain of land in, ii. 28.

——, level of, i. 387.

——, coral reefs of, iii, 275, 282. 288. 292.

—, on former union of Mediterranean
and, ii. 31.

— and Mediterranean, distinct spe.
cies in, iii. 328. ; iv. 118.

—, tertiary strata on borders of, iv. 25.

Refrigeration, Leibnitz’s theory of, i.
46.

——, causes which might produce the
extreme of, i. 186.

Rein-deer, geographical range of, iii. 36.

——, migrations of, iii, 41.

——, imported into Iceland, iii. 116,

Rennell, Major, on delta of Ganges, i.
358. 362.

—, on icebergs, i. 173.

— on delta of Nile, i. 353.

——, on sediment in waters of Ganges,
i. 367. ;

——, on currents, i. 170. 382. 384. 386.

——, on the tide-wave called the Bore,
ii. 10. $

Rennes, tertiary strata near, iv. 209.

Rennie, Rev. Dr., on peat, and fossils in
peat, iii. 177, 178. 182, 188.

Reptiles, their geographical distribution,
iii, 49.

—, their powers of diffusion, iii. 50.

—, in Ireland, iii. 50.

—, imbedding of, in subaqueous depo-
sits, iii. 230. 234. 267.

Resina, overflowed by lava, ii. 77.

Rhine, R., desċription of its course, ii.
Qs

—, its delta, ii. 2,

——., Lower, volcanos of the, iv. 101.

—, origin of trass of, iv. 108.

Rhinoceros, fossil, in Siberia, i. 150,

Rhone, delta of, in Mediterranean, i.
345.

, delta of, in Lake of Geneva, i. 337.

372. iii, 346.

——, debris deposited at its confluence
with the Arve, i. 378.

—, shells drifted by the, iii. 360.

——, acannon imbedded in calcareous
rock in its delta, iii, 249.

Riccioli, Signor, on travertin, iv. 28.

Richardson, Dr., on formation of ice-
bergs, i. 156.

—, on a calcareous formation near the
Mackenzie River, i. 201.

——, on drift-timber in the Mackenzie
and Slave Lake, iii. 221. 293.

Richardson, Mr. W., on Herne Bay, ii.
416. ’

Riobamba destroyed by earthquake, ii.
207.

Rimao, valley of, ancient sea-cliffs in
Tod:

Ripple marks, how formed, iv. 81.

Risso, M., on fossil shells, iv. 25, 66,

Rita, hot spring of, its temperature
raised by earthquake, ii. 188.

Rive, M. dela, on terrestrial magnetism 3
ii, 324.

Rivers, difference in the sediment of
i. 135. 345. 349. 373. ; iii. 326.

—, sinuosities of, i. 263,

t2

436

Rivers, two equal, when they become
confluent, do fiot occupy bed of dou-
ble surface, i. 265.

Robert, M., on fossils of Cussac, iv. 137.

Rocco di Ferro, shells in tuffs of, iii.

402. *
Rochester, indentations in the chalk

filled with sand, &c. near, iv. 217.

Rockall bank, recent deposits on, iii,
271.

Rocks, specific gravity of, i. 264.

——., altered by subterranean gases, i.
332. 3 iv. 373.

——, distinction between sedimentary
and volcanic, iii. 313. ; iv. 337.

=, origin of the primary, iii. 314. ; iv.
350.

—, distinction between primary, Se-
condary, and tertiary, iii. 313.

— persistency, of mineral character,
why apparently greatest in the older,
iv. 313.

——., older, why most consolidated and
disturbed, iv. 316. 318.

——, secondary volcanic, of many dif-
ferent ages, iv. 319.

——, relative age of, how determined,
iii, 319.

——, transportation of, by ice, tbs
ii. 289. ; iv. 48.

—, cleavage planes and jointed struc-
ture of, iv. 354.

——, how altered by permeation of heat
and gases, iv. 372.

——, chemical composition of different,
iv. 377.

Roderberg, crater of the, iv. 34. 106.

Rogvarpen, Lake, strata near, ii. 301.

Roman roads under water in Bay of
Baie, ii. 276.

Rome, travertins of, iv. 28.

Romney Marsh, gained from sea, i. 422.

Ronca, tertiary limestone of, iv. 211.

Ronchi, Roman bridge of, buried in
silt, i. 352.

Rose, M. G., on hornblende and augite,
ii. 178. $

Ross, Captain, on icebergs in Baffin’s
Bay, i. 172.

Rossberg, slide of the, iji, 200.

Rotaro, Monte, structure of, ii. 63.

Rotation of the earth, currents caused
by, i. 390.

Rother, River, vessel found in its old

bed, i. 423.5 iii. 247.
Royat, near Clermont, iv. 200,

INDEX.

Royle, Mr., i. 152.

Rozet, M., on loess of the Rhine, iv. 38.
Runn of Cutch described, ii, 198.
Runton, crag strata in cliffs near, iv. 83.
Rye formerly destroyed by sea, i. 423.

S.

Sabine, Captain, on well at Chiswick, i.
303.

—— on distance to. which waters of
Amazon discolour the sea, ii. 33.

——, on current crossing the mouth of
the Amazon, ii. 33.

Sabrina, island of, ii. 145. 205.

Saco, flood on the River, i. 293.

Saharunpore, buried town near, iii. 199.

St. André destroyed by a landslip, iii.
200.

St. Andrews, loss of land at, i. 401.

——, a gun-barrel, fossil, with shells at-
tached to it, near, iii. 250.

St. Christopher’s, alternations of coral
and volcanic substances in, iv. 22,

St. Domingo, subsidence of coast of, ii.
255;

~=—, hot springs caused by earthquake
in, ii. 250.

——, fossil vases, &c. in, iii. 246.

St. Eustatia, tertiary formations in, iv.
Oe: a

St. George, banks of, i. 384.

St. Helena, tides at, i. 381.

St. Hospice, tertiary strata of, iv. 25.

St. Jago, earthquake at, ii. 189.

St. Katherine’s Docks, a fossil vessel
found in, iii. 247.

St. Lawrence, Gulf of, elevated beaches
in, ii. 47.3) iv. 20.

——, earthquakes in, ii. 208.

St. Madeleine, near Nice, fossil shells of,
iv. 66.

St. Maura, earthquakes in, ii. 194. 214.

St. Michael, siliceous springs of, i. 327.

St. Michael’s Mount, i. 430. ; iv. 368.

St. Mihiel, limestone cliffs of, iv. 20.

St. Ouen, five sheets of water intersected
in a well at, i. 306.

St. Peter’s Mount, Maestricht, fossils of,
iv. 271. i

St. Romain, gypsum of, iv. 154.

St. Sebastian overflowed by volcanic al-
luvions, ii. 94.

St. Ubes engulphed by earthquake, ii.
253.

INDEX.

St. Vincent’s, volcanos of, ii. 203. ;“iv. 22.

——, counter currents in the air proved
by eruption in, i. 188.

—, boa constrictor conveyed on drift-
wood to, iii. 51.

Salisbury Craig, altered strata in, iv. 365.

Salt, on its deposition in the Mediter-
ranean, ii. 15.

Salt springs, i. 30. 330.

Saltholm, island of, ii. 288.

Samothracian deluge, ii. 52.

San Ciro, fossils in cave of, iv. 41.

Sand, estuaries blocked up by blown, i.
408. ; ii. 21.

—, cones of, thrown up during earth-
quake, ii. 235,

—, drift, imbedding of towns, organic
remains, &c. in, iii. 188. 190.

Sanda, its promontory cut off by the sea,
i. 399.

Sandown Bay, excavated by sea, i. 425,

Sandstone, old red, fish found fossil in,
i, 234, 241.

Sandwich Land, perpetual snow to level
of sea-beach in, i, 175.

San Feliu de Pallerdéls, ravine in lava
near, iv. 96.

San Filippo, travertin of, i. 316.

- Sanguinolaria rugosa, range of, iii. 56.

San Lio, on Etna, fissures in plain of, ii.
116. f

San Lorenzo, isle of, recent fossils in, iv.
Ta

San Lucido, torrents of mud caused by
earthquake at, ii. 234.

Santa Croce, Cape of, limestone on lava
at, iii. 390.

Santa Madalena, section at, iv. 93.

Santa Margarita, crater of, iv. 94.

Santa Maria, island, of raised 10 feet, ii.
187.

Santorin, geological structure of, ii. 160.

——, chart and section of, ii. 161.

—, new islands in Gulf of, ii. 162.

San Vignone, travertin of, i. 313.

Saracens, learning of the, i. 29.

Sardinian volcanos, iv. 101,

Sasso, Dr., on tertiary strata of Genoa,
iv. 64.

——, on fossil shells of Albenga, iv. 65.

Saucats, freshwater limestone of, iv. 134,

Saussure on the Alps and Jura, i. 80.

—— on glaciers of Mont Blanc, i. 259.

Savanna la Mar, swept away by sea, iii.
199.

Savona, tertiary strata of, iv. 140.

U

437

Saxony, Werner on the geology of, i.
83.

Scandinavia represented as an island by
the,ancients, ii. 287.

——, gradual rise of, i. 217.; ii. 286. 340. ;
iii. 435.5 iv. 24.

——. See Sweden.

Scarpellini, Professor, i. 100.

Scheuchzer, his theory, 1708, i. 58.

Scheveningen, waste of cliffs of, ii. 5.

Schist, siliceous, clay converted into, by
a lava dike, iii. 392. 404.

Schlegel, M. de, i. 24, |

Schmerling, Dr., on cavern of Chockier,
L211;

— on human remains in caves, iii. 212.

Sciacca, island of. See Graham Island.

Scilla on organic remains, 1670, i. 42.

Scilla, rock of, ii. 236.

Scoresby, Captain, on the gulf HET
ERVAN

——, onthe formation of field ice, i. 191.

——, on weight of rocks transported by

icebergs, i. 270.

—, cited, iii. 41. 219. ; iv. 360.
Scotland, floods in, i. 266. ; iii. 232.
—, fossil fishin old red sandstone of,

i. 235. ; iv. 296,

—, waste of coast of, i. 400.

——, slight earthquakes felt in, ii. 60.
——, thickness of alluvions in, ii. 241. .
——, peat-mosses of, iii. 179. 185.
=, marl-lakes of, iii. 236, 259. 265.
—, granite veins of, iv. 339.

Scrope, Mr. G. P., on eruption of Vesu-
vius in 1822, ii. 80.

=, on columnar basalts of Vesuvius,
ii. 90.

—, on formation of pisolitic globules at
Pompeii, ii. 97.

—, on eruption of Etna in 1811, ii. 121.

——., on advance of lava of 1819, ii. 122.

—, on cause of convexity of plain of
Malpais, ii. 135.

——, on elevation craters, ii. 152.

—, on volcanic district of Naples, iv.
il.

——, on volcanos of the Rhine, iv. 10 .

——, on geology of Auvergne, iv. 185,
186. 194. 197.

Sea does not change its level, but land,
i. 26.

——, Moro on manner in which it ac-
quired its saltness, i. 62.

——, its influence on climate, i. 174

—, area covered by, i. 221.

3

438

Sea, its encroachment on different
coasts, i. 392. 402. 431. '
e , cause of its rise and retreat durin
earthquakes, ii. 254. :
Sea.cliffs, successive elevations proved
by, iii. 440.

=, manner in which the sea destroys
successive ranges of, iii. 440.; iv. 229.

~—-, ancient, in the Morea, iv. 19.

—, in Peru, iv. 17.

Seaford, waste of cliffs at, i. 424. ; iv.
256.

Seals, migration of, iii. 45. `

Sea-water, density of, i. 172.

Sea-weed, banks formed by drift, iii. 16.
265,

Seckendorf, M. de, on greywacké slate,
with organic remains in granite, i. 84.

Secondary rocks, iii. 319.3 iv. 268.

—— of Weald Valley, iv. 222.

——, their rise and degradation gradual,
iv. 251.

——, fossils of the, i. 157. 231.

——, no species common to tertiary and,
iv. 272. 274. 279.

——, circumstances under which they
originated, iii. 319.

——, why more consolidated and dis-
turbed, iv. 316. 318.

——, volcanic, of different ages, iv. 319.

Secondary freshwater deposits, why rare,
iv. 313.

Secondary periods, duration of, iv. 280.

Sedgwick, Professor, cn the Hartz moun-
tains, i. 84.

——, on tertiary deposits of the Alps, i.
210.

——, on raised beaches in Ireland, i. 216.

——, on Caithness schists, i. 235.

——, on magnesian limestone, i. 318,

—, on the antagonist power of vegeta-
tion, iii. 159,

——, on preservation of organic remains
in fissures, iii. 208.

——, on diluvial waves, iii. 431; iv. 205.

——, on tertiary formations of Styria,
iv. 129. 131. 142.

——., on Isle of Wight, iv. 216. 260.

—, on transition rocks, iv. 300. 306.

——, On granite veins, iv. 340.

——, On cleavage and jointed structure
of rocks, iv. 354.

——, on garnets in altered shale, iv. 365.

Sediment, its distribution in the Adri-
atic, i. 352.

= in river water, i. 366.

INDEX.

Sediment of Ganges compared to lavas
of Etna, i. 369.

——, rate of subsidence of some kinds of,
ii. 34. i

——, area over which it may be trans-
ported by currents, ii. 34.

Sedimentary deposition, causes which
occasion a shifting of the areas of, iii.
345.

— rocks, distinction between volcanic
and, iii. 313.

Selside, fissure in limestone at, iii. 208.

Seminara, effects of earthquake near,
11225,

Seneca on a future deluge, i. 23.

Septaria of London clay described, iv.
214.

Serapis, temple of, ii. 267.

—, ground plan of environs of, ii. 267.

—, date of its re-elevation, ii. 278.

Serre del Solfizio, buried cones in cliffs
of, iji. 415.
——, dikes at the base of, iii. 418.
Serres, E. R. A., on changes in brain of
foetus in vertebrated animals, ii. 439.
Serres, M. Marcel de, on changes in bu-
ried human bones, iii. 214.

, on human remains in French

caves, iii. 213. 215.

—, on drifting of land shells to the
sea, iii, 360.

—, on tertiary strata of Montpellier,
iv. 126.

—, on fossil insects of Aix, iv. 210.

Seven Sleepers, legend of the, i. 119.

Severn, tides in estuary of, i. 382.

—, gain of land in its estuary, i. 430.

Shakspeare cited, i. 233.

Shakspeare’s cliff decays rapidly, i.
419,

Shales, bituminous, i. 335.

Sheep, multiplication of, in South Ame-
Tica, iii. 115. 7

Shell marl, fossils in, iii. 259. 300.

Shells. See Testacea.

Sheppey, fossils of, i. 243.

——, waste of the cliffs, i. 415.

Sherringham, sections in cliffs of, iv. 84.

, waste of cliffs at, i. 405. ; iv. 236.

Shetland Islands, action of the sea on,
i. 392. ; iv. 45.

—, rock masses drifted by sea in, i. 393.

—-, effect of lightning on rocks in,
i, 394.

——, granites of different ages in, iv.
343.

INDEX.

Shetland Islands, passage of trap into |
granite in the, iv. 349. ;
—, formations now in progress near,
aa, 212:

Shingle beaches, i. 428.

Ships, number of British, wrecked annu-
ally, iii. 240. 243.

—, fossil, i. 423. ; ifi. 188. 246.

Shropshire coal-field, i. 202.

Sibbald cited, iii. 50. 266.

Siberia, rhinoceros found entire in the
frozen soil of, i. 80. 150.

—, the Bengal tiger found in, i. 147.

——, Lowland of, i. 153. 219.

—, drift-timber on coast of, iii, 224.

Siberian mammoths, i. 144.

Sicily, fossils of existing species in, i. 140.

——, earthquakes in, ii. 54 208. 261. 5
iii. 207.

—, geological structure of, iii. 340. 383.

——, map of part of, iii. 382.

— _, origin of newer Pliocene strata of,
ili. 433.

—, form of valleys of, iii, 438.

——, no peculiar indigenous species
found in, iii. 445.

——, caves in, iv. 38.

—, alluviums of, iv. 48.

Sidon, ancient site of, two miles from
sea, ii. 31.

Siebengebirge, volcanic rocks of the, iv.
36. 109.

Sienna, fossil shells of, i. 68. 141. ; iv. 74.

—, Subapennine strata near, iv. 55. 60.

Silex deposited by springs, i. 327.

——, piles of Trajan’s bridge said to be
converted into, i. 329.

Silla, subsidence of the mountain, ii.
202, 203.

Silliman, Professor, cited, iii. 247.

Silurian group of rocks, iv. 270. 298.

Silvertop, Colonel, on tertiary strata of
Spain, iv. 70.

Simeto, R., lava excavated by, i. 272.

—, plain of the, iii. 399.

Sindree, changes caused by earthquake
of 1819 near, ii. 196. ; iii. 254.

—, view of the fort of, before the
earthquake (see Pl. 6.), ii. 196.

Sioule, R., ravines cut through lava by,
iv. 194.

Sipparah, R., its course changed, iii. 194.

Skapta, R., its channel filled by lava, ii.

128.
Skaptar Jokul, eruption of, ii. 128.

Sky, granite of, iv. 343.

439

Slate rocks, cleavage planes of, iv. 354.

Slave Lake, drift-timber im, iii. 221.

Sleswick, waste of coast oL O

Sligo, bursting of a peat-moss in, iii. 186.

Sloane, Sir H., on earthquake in Ja-
maica, ii. 264.

—, on dispersion of plants, iii. 214.

Smeaton on effect of winds on the sur-
face of water, i. 386.

Smith, William, agreement of his sys-
tem with Werner’s, i. 84.

——, his ‘ Tabular View of the British
Strata,’ 1790, i. 102.

—, his Map of England, i. 103.

— , priority of his arrangement, i. 103.

Smith, Sir J., cited, ii. 401. ; iii. 19.

Smyrna, volcanic country round, ii. 54.

Smyth, Capt. W. H., on the Mediterra-
nean, i. 78. 348. 5 ii. 272.

—, on height of Etna, ii. 111.

——, on Straits of Gibraltar, ii, 15. 18.

——, on depth of sea from which Gra-
ham Island rose, ii. 146.

—, on floating islands of drift-wood,
iii. 43,

—, on drifting of birds by the wind,
jii. 49,

——., on diffusion of insects, iii. 66.

—, on average number of British
ships lost from 1793 to 1829, iii. 243.
——, found shells at great depths be-
tween Gibraltar and Ceuta, iii. 271.

—, on volcanos of Sardinia, iv. 101.

Snow, height of perpetual, in the Andes,
i, 194.

—, in Himalaya mountains, i. 194.

Sddertelje, canal of, ii, 294.

—, recent strata of, ii. 300.

——, buried hut in, ii. 303.

Sodom, catastrophe of, mentioned by
Hooke, i. 51.

Soil, its influence on plants, ii. 402.

Soils, on formation of, iii. 155.

—, influence of plants on, iii, 87.

Soldani, theory of, 1780, i. 78.

———on microscopic testacea of Medi-
terranean, i. 78.

— on the Paris basin, i. 78.

Solenhofen, fossils of, iv. 289.

Solent, its channel widening, i. 425.

Solfatara, lake of, i. 320.

—, volcano, ii. 65. 70. 74. 78.

—, effects of the exhalations on its
structure, ii. 90. ; iv. 374.

—, temple of Serapis probably sub-
merged during eruption of, ii. 279. _

U 4

44.0

Solon on Island of Atlantis, i. 14.

Solway Moss, a man and horse, in ar-
mour, found in, iii. 186.

—, bursting of, iii. 186.

Solway Firth, animals washed by river-
floods into, iii, 232.

Somersetshire, land gained in, i. 430.

Somerville, Mrs., on depth of Atlantic
and Pacific Oceans, i. 185,

—, on effects of compression at earth’s
centre, ii. 319.

Somma, escarpment of, iii, 410, 411. 414.

——, dikes of, ii. 88.5 iv. 5,
——; changes caused by dikes in, iii.
418. s

—— and Vesuvius, differences in com-
position of, iv. 4.

—, section of, ii. 87.

Somme, peat-mosses in valley of, iii. 187.

Sorbonne, College of the, i. 69,

Sorea, eruption in island of, ii. 261.

Soriano, changes caused by earthquake
near, ii. 219. 230.

Sortino, limestone formation in valleys
of, iii, 385.

——, Caves near, iv. 39.

Sortino Vecchio, several thousand peo-
ple entombed at once in caverns at,
iii. 207.

South Carolina, earthquake in, ii. 203.

South Downs, waste of plastic clay on,
i. 424.

——, chalk ridge called the, iv. 223.

——, section from, to the North Downs
across Weald Valley, iv. 224,

——, highest point of, iv. 224.

—, section from, to Barcombe, iv. 234,

—, on former continuity of chalk of
North and, iv. 244.

Souvignargues, cave at, iii. 314.

Spaccaforno limestone, iii. 386.

Spada, his theory, i. 60,

Spain, earthquakes in, ii, 57.

—, tertiary formations of, iv. 70.

——, extinct volcanos of, iv. 90.

-——, lavas excavated by rivers in, iv.
93. 97.

Spallanzani on effects of heat on seeds
of plants, iii. 14.

—— on flight of birds, iii, 48.

Species, definition of the term, ii. 361.

——, Linnzus on constancy of, ii. 363.

——-, Lamarck’s theory of transmut-
ation of, ii. 363. 386. ; iii. 139.

«=, reality of, in nature, ii. 391. 407, 441.

-

INDEX.

Species, geographical distribution of, iii.
korik

——, theories respecting their first in-
troduction, iii. 77. 145.

===, Brocchi on extinction of, iii. 83.

——, reciprocal influence of aquatic and
terrestrial, iii. 98.

——, their successive destruction part
of the order of nature, iii. 101. 132.
142. 150.

—, effect of changes in geography,
climate, &c. on their distribution, i.
182. ; iii. 122. 134. 138. 331. 350.

——, superior longevity of molluscous,
i, 145. ; iii. 361. ; iv. 40.

—, necessity of accurately determin-
ing, iii, 361.

—, living, proportion of, in different
tertiary periods, iii. 369. 373.

‘~ in Sicily older than country they

inhabit, iii. 445.

——, none common to secondary and
tertiary formations, iv. 272. 274,

Spence, Mr., on insects, cited, ii. 433. ;
iii. 63. 93.

Spina, ancient tity in delta of Po, i. 351.

Spinto, fossil shells at, iv. 127.

Spitzbergen, glaciers of, i. 172.

Spix, M., on drifting of animals by the
Amazon, iii. 42.

——, on Brazil, iii. 108.

Spontaneous generation, theory of, i, 38.

Sprengel, M., on numbers of plants, iii.
148. “t

Springs, origin of, i. 300.

——-, the theory of, illustrated by bored
wells, i. 302.

—— most abundant in volcanic regions,
i. 309.

—— affected by earthquakes, i. 309. ; ii.
188. 228, 250.

—, transporting power of, i. 136. 311.

——, calcareous, i. 311. 325.

——, sulphate of magnesia deposited by,
i. 316.

—, sulphureous and gypseous, i, 326.

—, siliceous, i. 327.

——, ferruginous, i. 330.

——, brine, i. 330.

—, carbonated, i. 331.

——, petroleum, i. 334.

Spurn Point, its rapid decay, i. 403.

Squirrels, migrations of, iii. 36.

Stabie, buried city of, ii. 106.

Stalagmite alternating with alluvium in
caves, iii. 210, :

INDEX.

Start Island separated from Sanda by
sea, i. 399.

Statical figure of the earth, ii. 309. 329.

Stations of plants, description of, iii. 5.

— of animals, iii. 100.

Staunton, Sir G., on sediment in Yellow
River, i. 366. ©

Staveren, formation of Straits of, i. 491.;
ii. 6.; iii. 130.

Steele on Burnet’s theory, i. 56.

Steininger, M., on loess of the Rhine,
iv. 34. 38.

——, on volcanic district of the Eifel,iv.
113 `

——, on greywacké rocks, iv. 299.

Stelluti on organic remains, i. 39.

Steno, opinions of, i. 40.

Stephensen on eruption in Iceland, ii.127.

Steppes, Russian, geology of the, ii. 51.

Sternberg, Count, on the coal strata, i.
202. '

Stevenson, Mr., on drift stones thrown
on the Bell Rock, i. 400.

„on the German Ocean, i. 420. ; ii.

29.

——, on waste of cliffs, i. 431.

Stewart, Dugald, cited, i. 249.

Steyning, chalk escarpment above, iv.
228.

Stirling Castle, altered strata in rock of,
iv. 365.

Stockholm, rise of land near, ii. 294.

——, upraised deposits of shells near, ii.
299. 301.

Stonesfield, fossils of, i. 237. ; iv: 290.

Storm of November, 1824, effect of, i.
424. 426. 428.

Stour- and Avon, cliffs undermined, i.
426.

Strabo cited, i. 24. 346, 354. ; ii. 56. 62.

Straits of Dover, formation of, i. 420.

—, their depth, i. 420, 421.

Straits of Staveren, formation of, i. 421. ;
ii. 6;

Straits of Gibraltar, currents in, &c.,
ii. 14, 16. 20.

Stralsund, ii. 288.

Strata, cause of limited continuity of,
iii. 312.

——., order of succession of, iii. 318.

—, origin of European tertiary, at
successive periods, iii. 335.

——-, recent, form a common, point of
departure in all countries, iii. 378.

——, with and without organic remains

- alternating, iv. 181.

44]

Strata, fossiliferous, classification of the,
iv. 269.

——., on consolidation of, iv. 316.

Stratification in deltas, causes of, i. 376.

—— of débris deposited by currents, i.
378. 5 ii. 36.

——, unconformable, remarks on, iii.
349.

—— of the Crag, iv. 78.

—— of primary rocks, iv, 353,

——, difference between cleavage and
iv. 354.

Strato, hypothesis of, i. 25,

Stratton, Mr., on buried temples in
Egypt, iii. 189.

Strickland, Mr., on tertiary strata hear
Cropthorn, i. 145. ` .

Strike of beds, explanation of term, iv.
332.

Stromboli, its appearance during . Cala-
brian earthquakes, ii. 237.

—, lava of, iv. 350.

Studer, M., on molasse of Switzerland,
iv. 128, :

——, on theory of M. E. de Beaumont,
AV SBou2 5

——, on altered strata in the Alps, iv.
370,

Stufas, jets of steam, in volcanic re-
gions, i. 308.

Stutchbury, Mr., on coral islands, iii.
279. 281, 282. 296.

Styria, tertiary formations of, iv. 128.
142.

3

Subapennine strata, i. 141. 209. 241. ; ii.
216. ; iv. 49.

—, early theories of Italian geologists
concerning, i. 74. 127.

——-, Opinions of Brocchi on the, iv. 49.

——-, subdivisions of, described, iv. 53.

——., how formed, iv. 56.

——, organic remains of the, iv. 59.

Subaqueous strata, imbedding of fossils
in, iii, 258.

—, our continents chiefly composed
of, iii, 313.

——., how raised, iii. 435.

—, distinction between alluvium and,
iii. 196.

Submarine forests, i. 400. 431.5 iii. 226.

Submarine peat, iii. 187. 265.

Submarine volcanos, ii. 145,

Subsidence of land, ii. 195. 201, 202. 208.
218. 233, 252. 256. 262. 268.5; iii. 124,
952, 255. 295. 424.

——, permanent, ii, 339.

442

Subsidence of land, greater than eleva-
tion, ii. 356.; iii. 295.

Subterranean lava causes elevation of

land, iii. 436.

Successive development of organic life,
i. 227.

Suez, Isthmus of, ii. 31.

Suffolk, cliffs undermined, i. 410.

—-, inland cliff on coast of, i. 410.

—, tertiary strata of, iii. 336.; iv. 71.

Sullivan’s Island, waste of, ii. 10.

Sulphur Island, ii. 48,

Sulphureous springs, i. 326.

Sumatra, volcanos in, ii. 49.

Sumbawa, subsidence in island of, 1815,
li, 200. ; iii. 254.

Sunderbunds, part of delta of Ganges, i.
358.

Sunderland, magnesian limestone of, i.
319.

Superga, fossil shells of the, iii. 364. 5 iv.
126,

Superior, Lake, deltas of, i. 342.

——, recent deposits in, i, 3445 iii. 262.

—, its depth, extent, &c., i. 342. 344.

——, bursting of, would cause a flood,
iv. 201.

Superposition of successive formations,
causes of the, iii. 345.

—, proof of more recent origin, iii. 320.

—, exceptions in regard to volcanic
rocks, iii. 321.

—, no invariable order of, in Hypo-
gene formations, iv. 380.

Surface, state of, when secondary and
tertiary strata were formed, iii. 341.

Sussex, Weald formation of, i. 206.

—, waste of its coast, 1. 423.

Swanage Bay excavated by sea, i. 425.

Swatch in Bay of Bengal, i. 359.

Sweden, gradual rise of, ii. 286. 353. gh
217. ; iv. 24. 26. 251.

——, earthquakes in, ii. 304.

—, lignite of chalk period in, iv. 278.

` =>, greywacké rocks of, iv. 300.

——. See also Scandinavia. ;

Swinburne, Capt., on Graham Island,
ii. 147. 150.

Switzerland, towns destroyed by land-

- slips in, iii. 200.

—, *‘molasse’ of, iv. 128,

Symes on petroleum springs, i. 33%.

Syenites not distinguishable from gra-
nites, iv. 344.

Syracuse, section at, iii, 385.

o—, inland cliffs north of, iii. 440.

——, Caves near, iv. 39.

INDEX.

Syria, gain of land on its coasts, ii. 31.
—, earthquakes in, ii. 54.

T:

Table-Mountain, intersected by veins,
iv. 339.

Tacitus cited, ii. 68. ;

Tadeausac, earthquakes at, ii. 208.

Tagliamento, R., delta of the, i. 350.

—, conglomerates formed by, i. 352.

Talcahuano, recent elevation of, ii. 187.

Tampico, sediment transported by, ii.
33.

Tanaro, plains of the, iii, 364. ; iv. 127.

Tangaran, R.s stopped up by, Jandslips,
ii. 260.

Targioni on geology of Tuscany, i. 70.

——, on origin of valleys, i. 70.

—_, on fossil elephants, i, 71.

==, on deposits of springs, i. 313.

Taro, R., iv. 56.

Tay, encroachment of sea in its estuary,
i. 400..

Taylor, Mr., on art of mining in Eng-
land, i. 81.

Taylor, Mr. R. C., on waste of cliffs, i.
406.

—, on gain of land on coast of Nor-
folk, i. 408.

——,on the formation of Lowestoft
Ness, i. 410.

Tech, R., valley of, iv. 69.

Teissier, M., on human bones in caves,
&c., iii. 215.

Temminck cited, iii, 30. 149.

Temperature, great changes in, i. 163.

—, difference of, in places in same la-
titudes, i. 167. 3

——, causes of change in, i. 180.

——. See Climate

| Temples, buried, in Egypt, iii. 188.

Temruk, earthquakes near, ii. 53.

Teneriffe, its peak an active solfatara,
ii. 138.

—, volcanic eruptions of, ii. 139.

Ter, R., valley of the, iv. 91.

Terni, limestone forming near, i. 319.

Teronel, R., lava excavated by, iv. 97.

Terraces, manner in which the sea de-
stroys successive lines of, iii. 440. ; iv
229,

Terranuova, subsidence near, ii. 208.

—, fault in the tower of, ii. 219.

—, landslips near, ii. 229.

—, tertiary strata at, iii. 396.

INDEX.

Tertiary formations, general remarks on
the, i. 239. ; iii. 319.

—, origin of the European, at succes-
sive periods, iii. 335.

—, circumstances under which these
and the secondary formations may
have originated, iii. 342. ; iv. 308.

——, state of the surface when they
were formed, iii. 342.

——, Classification of, in chronological
order, iii. 356.

——, new subdivisions of the, iii. 362.

——, numerical proportion of recent
shells in different, iii. 369. 373.

——, mammiferous remains of succes-
sive, iii. 379.

——, -Synoptical Table? of Recent and,
ili. 381.

——, identity of their mineral com-
position no proof of contemporaneous
origin, iv. 57.

—, no species common to secondary
and, iv. 272. 274. 279.

—, of Auvergne, iv. 134. 144.

_—, of England, iii. 335, 336.5 iv. 25.
71, 211.

_—, of the Paris basin, iii. 332. ;

— _, of Sicily, iii. 382.

——, marine, iii. 332. 335. 383. 397. 433. 5
iv. 1. 49. 114. 164. 208.

——, freshwater, iv. 27. 137. 143.

——, volcanic, iii. 389. 400.; iv. 4 89.
140. 184.

Testa and Fortis on fossil fish of Monte
Bolca, i. 78.

Testacea, their geographical distribu-
tion, iii. 55.

tH, fossil, importance of, iii. 359.

—, marine, imbedding of, iii. 269. 327.
359.

—, freshwater, iii. 265.

—, burrowing, iii. 270.
—, parasitic, iii. 283.

——., longevity of species of, i. 145. ; ili,
361. 372. 3 iv. 40.

ay atdet number of, in different ter-
tiary periods, iii. 369. 373.

Tet, valley of, tertiary strata in, iv. 69.

Texel, waste of islands at its mouth,
Het-

Thames, gain and loss of land in its es.
tuary, i. 415.

—, tide in its estuary, ii. 24.

_—., buried vessel in alluvial piain of
the, iii. 247.

—, basin of the, iii. 335.

iv. 164.

443

Thanet, Isle of, loss of land in, i. 418.

Theorizing in geology, different methods
of, iii. 303.

Thermo-electricity, ii. 324.

Thirria, M., cited, iv. 289.

Thompson, Dr:, on siliceous incrust-
ations near Monte Vico, i. 329.

Thrace subject to earthquakes, ii. 56.

Thucydides on Etna, ii. 115.

Thun, Lake of, delta of the Kander in,
iv. 68.

Thury, M. Hericart de, on Artesian
wells, i. 303.

Tiber, growth of its delta, i. 321.

-—, valley of the, iv. 29.

Tide wave of the Atlantic, i. 409.

Tides, height to which they rise, i. 360.
381.

—, effect of winds on the, i. 385.

—, effects of, on wells near London,
i. 301.

—, their destroying and transporting
power, i. 380.

—, their reproductive effects, ii. 22.

—— and currents, drifting of remains
of animals by, iii. 237.

Tiedemann on changes in the brain in
the foetus of vertebrated animals, ii.
439.

Tierra del Fuego supposed to contain
active voleanos, ii. 41.

Tiflis, earthquakes at, ii. 53.

Tiger of Bengal found in Siberia, i.
146.

Tigris and Euphrates, their union a
modern event, i. 375.

Tiganux, tower of, i. 347.

Tilesius on Siberian mammoth, i. 153.

Time, prepossessions in regard to the
duration of past, i. 112. ; iii. 426.

—, error as to quantity of, fatal ‘to
sound views in geology, i. 115.

—, great periods required to explain
formation of sedimentary strata, i.
130. j

Tivoli, flood at, i. 298.

—, travertin of, i. 322.

Toledo, Signor, on elevation of coast of
Bay of Baie, ii. 282.

Tomboro, volcano, eruption of, ii, 200.

——, town of, submerged, ii. 201.

Torneo; gain of land at, i. 345. ; ii. 289.

Torre del Annunziata, columnar lava
at, ii. 89.

Torre del Greco overflowed by lava, ii.
107.

444

Torre del Greco, columnar lavas of Vesu-
vius seen at, ii. 89.

Torrents, action of, in widening valleys,
1. 268.

Torum, overwhelmed by sea, ii. 8,

Tory Island, living testacea at great
depths off, iii. 271.

Totten#Col., on expansion of rocks by
heat, ii. 339.

Touraine, tertiary strata of, iii. 337.: iv.
ibs

Tournal, M., on French caves, iii. 213,
215

Tours, shells, &c. brought up in a bored
wellat, i. 307.

Towns destroyed by landslips, iii. 200.

Trade winds, i. 188. 389.

Traditions of losses of land, i. 430, 431.

Transition formations, fossils of, i. 201.
234. : iv. 297.

——, their extent, i. 200.
wacké, í `

Transverse valleysin North and South
Downs, iv. 238.

Transylvania, tertiary formations of, iv.
129. 131. 142.

Trap rocks, origin of the term, iv. 346.

——, passage of, into granite, iv. 348.

Trass of Rhine volcanos, iv. 108.

Travertin of the Elsa, i. 312. ; iv. 97.

—— of San Vignone, i..313.

—— of San Filippo, i. 316.

——-, spheroidal structure of, i. 317.

——, compared to the English magne-
sian limestone, i. 318.

—— of Tivoli, i. 322.

—— oolitic, recent formation of, in Lan-
cerote, ii. 144.

—— in Forfarshire, iii. 259. \

—— of Rome, fossils in, iv. 28.

Trees, longevity of, iii. 428. ; iv. 205.

Trezza, travertin formed by spray of the
sea on rocks of, ii. 144.

——, Bay of, sub-Etnean formations in
the, iii. 401.

——, submarine eruptions in, iii. 401,
405.

Trimmer, Mr., on recent marine shells
in Wales, i. 215.

Trimmingham, sections near, iv. 77. 86.

Trinidad, subsidence in, i. 334.

——, pitch lake of, i. 334.

—— earthquakes in, ii. 250.

Tripolitza, plain of, breccias forming in,

~ iii. 205.

Trollhattan, ii. 343.

See Grey-

INDEX.

Truncated volcanic cones, ii. 167. 249.
Tubal, elevation of land at, ii. 188.
Tufa. See Travertin.

Tuff, dikes of, how formed, iii. 392.
——, shells in, iv. 11.

Tunguragua volcano, ii. 43, 44. 206.
Tunza, R., ii. 189.

Turin, tertiary formations of, iv. 126.
Turtles, migrations of, iii. 50.

—, eggs of, fossil, iii. 267.

Turton cited, iii. 41. 51.

Tuscany, geology of, i. 40. 70.

——, calcareous springs of, i. 312.
——, freshwater formations of, iv. 27.
——, volcanic rocks of, iii. 365. ; iv. 89.
Tyre now far inland, ii. 31.

Tyrol, Dolomieu on the, i. 87.

U:

Uddevalla, upraised deposits of shells at.
ii. 299.

Ullah Bund, formation of the, ii. 197.

Ulloa cited, ii. 257. : iii. 115.

Unalaschka, new island near, ii. 205.

Unconformability of strata, remarks on
the, iii. 349. 353.

Uniformity of Nature, i. 128. 255.; ii.
TI

Universal formations of Werner, i. 84.

—— remarks on theory of, iii. 323. : iv.
315.

Universal ocean, theory of an, i. 46. 60.

—— disproved by organic remains, i.137.

Upsala, strata near, ii. 301.

Urmia, Lake, springs near, i. 326.

——, its size, &c., ii, 54.

V.

Val d’Arno, Upper, lacustrine strata of,
iv. 57. 137.

—, fossils of the, i. 249, ; iv. 138.

—, effect of destruction of forests in,
iii. 163.

Val del Bove on Etna described, iii.
407. 413.

—, section of buried cones in, iii, 415.

——, form, composition, and origin of
the dikes in, iii. 414. 417.

—, lavas and breccias of the, ii. 121. ;
iii, 422.

—, origin of the, iii. 423. -

——, floods in, ii. 123. ; iii, 425.

INDEX.

Valdemone, formations of, iii. 397.

Val di Calanna, its shape, &c., iii. 411.”

~—,‘began to be filled up by lava in 1811
and 1819, ii. 122. ; iii. 413.

Val di Noto, Dolomieu on the, i. 87.

——, formations of the, iii, 383.

——, volcanic rocks of the, iii. 384. 389.;
iv. 347.

——, volcanic conglomerates of, iii. 396.

——, form of valleys of, iii, 438.

——, inland cliffs on east side of, iii.
440.

Vale of Pewsey, iv. 250.

Valle das Furnas, hot springs of, i. 327.

Valley of the Nadder, iv. 250.

Valleys, Targioni on origin of, i. 70.

——, excavation of, in Central France,
i, 272.

— of elevation, ii. 176, ; iv. 246.

~— on Etna, account of, iii. 407.

—— of Sicily, their form, iii. 438.

==», the excavation of, assisted by
earthquakes, ii. 237. iii, 442.

—, transverse, of North and South
Downs, iv. 238, 239.

— of S. E. of England, how formed,
iv. 263.

Vallisneri on origin of springs, i. 59.

~=» on marine deposits of Italy, i. 59.

—— on the danger of connecting theo-
ries in physicaljscience with the sacred
writings, i. 59.

=, universal ocean of, i. 60.

—— on primary rocks, i. 91.

Valmondois, tertiary strata of, iv. 173.

Valognes, tertiary strata of, iv. 208.

Valparaiso, changes caused by earth-
quakes at, ii. 189. 192. 278. ; iii.-253.

Van der Wyck, M., on the Eifel. iv.
113.

Van Diemen’s Land, climate of, i. 175.

Var, R., gravel swept into sea by, iv.
65. 68.

Vatican, hill of the, tufa on, iv. 28.

Veaugirard, alternation of calcaire gros-
sier and plastic clay at, iv. 168.

Vegetable soil, why it does not increase,
iii, 155,

——, how formed, iii. 157.

Vegetation, centres of, iii. 144.

——, its conservative influence, iii, 158,
162.

——, its influence on climate, iii, 165.

Veins, mineral, on their formation, ii.
997. ; iv. 373.

—— of lava. See Dikes,

445

Velay, extinct quadrupeds in volcanic
scorie in, iv. 136, 190. i

—, freshwater formations of, iv. 157.

——, volcanic rocks of, iv. 142. 188. 190.

Vera Cruz destroyed by earthquake, ii.
259.

Verdun, markings on cliffs near, iv. 20.

Verona, fossils of, i. 34. 38. 60.

——, Arduino on mountains of, i. 72.

Vertebrated animals in oldest strata, i.
237.

Vessels, fossil. See Ships.

Vesta, temple of, i. 299.

Vesuvius, excavation of tuff on, i, 972.

——, history of, ii. 66. 79.

——, eruptions of, ii. 66. 77. 79. ; iii, 424.

——, dikes of, ii. 85.; iv. 5. 7.

——, lava of, ii. 89. 94,

—, volcanic alluvions on, iii, 192.

——and Somma, difference in their
composition, iv. 4.

—, probable section of, ii, 86.

Vicentin, Dolomieu on the, i. 87.

——, submarine lavas of the, i. 128.

——, tertiary strata of the, iv. 211.

Vicenza, mountains of, i. 72.

Vichy, tertiary oolitic limestone of, iv.
iy

Vidal, Captain, on Rockall bank, iii.
Dit

Vienna, gypseous springs of, i. 23.

——, tertiary formations of, iii. 339. ; iv
128.

Vigolano, gypsum and maris at, iv. 54.

Villages and their inhabitants buried by
landslips, iii. 200.

Villarica volcano, ii, 42.

Villasmonde, limestone of, iii. 385.

Villefranche, Bay of, strata near, iv. 25.

Vinegar R., sulphuric acid, &c. in waters
of, iv. 178.

Virgil cited, i. 249.

Virlet, M., on deluge of Samothrace, ii.
53. ;

—, on volcanos of Greece, ii. 56.

——, on greywacké fossils, i, 201.

——-, on island of Santorin, ii. 161. 165,
166.

——, on corrosion of hard rocks by sub- -
terranean gases, iii. 202.; iv. 374.

——, on imbedding of human bones in
the Morea, iii. 205. |

on geology of the Morea, iv. 70.

>

277.
Viterbo, travertin of, i. 319.
—, tuffs and marls at, iv. 54.

446

Viterbo, volcanic rocks of, iv. 89.

Vito Amici on Moro’s system, i. 67.

Vivarais, basalts of the, i. 86.

Vivenzio on earthquake of Calabria in
1783, ii. 212. 233.

Viviani, Professor, on Sicilian flora,
iii. 444.

——,on tertiary strata of Genoa, iv.
64.

Vizzini, tuff and limestone near, iii.

——., changes caused by a dike of lava
at, iii. 392. i

——, oyster-bed between two lava cur-
rents at, iii. 395.

Volcanic action, defined, ii. 39.

——, uniformity of, iiis 161.

Volcanic breccias, how formed,, iv. 117.

Volcanic cones, truncation of, ii. 167.
249.

——, their perfect state no proof of their
relative age, iii. 164.

Volcanic conglomerates, ili. 396.

Volcanic dikes, See Dikes.
Volcanic eruptions, causes of, ii. 320.
——, average number of, per annum, ii.
178.
Volcanic
191.
Volcanic lines, modern, not parallel,
iv. 333.

Volcanic products, mineral composition
of, ii. 177.

Volcanic regions, their geographical
boundaries, ii. 41. 3

—-, map showing extent of (see
Plate 3.), ii. 47.

Volcanic rocks, subterranean, ii. 179.

—, distinction between sedimentary
and, iii. 313.

—, distinction between plutonic and,
iv. 345.

——, age of, how determined, iii. 321.

— of the Val di Noto, iii. 389.

— of Campania, iv. 1.

___ of Italy, iv. 89.

—— of Hungary, Transylvania,
Styria, iv. 140.

_— of Central France, ii. 170. 175. ; iv.
184.

—— secondary, of many different ages,
iv. 319.

Volcanic vents, remarks on their posi-
tion, ii. 40. 347.

Volcanos, safety valves according to
Strabo, i. 27.

formations, fossils in, iii.

and

' INDEX.

Volcanos, duration of past time proved
by extinct, i. 132.

——, agency of water in, ii. 347.

——, mode of computing the age of;
iii. 426.

—— sometimes inactive for centuries,
iii, 427.

— the result of successive accumu-
lation, iv. 162.

Volhynia, tertiary formations of, iv. 132.

Voltaire, his dislike of geology, i. 96.

on systems of Burnet and Wood-

ward, i. 96.

Volterra, Mattani onffossils of, i. 60.

Voltz, M., on loess of the Rhine, iv. 38.

Von Buch on rise of land in Sweden,
1.216. ; ii. 292. 299.

—— on volcanos of Greece, ii. 56.

—— on eruption in Lancerote, ii. 139.

——, his theory of elevation craters con-
sidered, ii. 152. `

—— on volcanic rocks, ii. 175.

— on new island near Kamtschatka,
ii. 205.

—— on the Eifel, iv. 126.

—— on tertiary formations of Volhynia
and Podolia, iv. 132.

—— on volcanic lines, iv. 333.

Von Dechen, M., on volcanic district of
Lower Rhine, iv. 113.

—, on the Hartz mountains, iv. 332.

—, on granite veins, iv. 339.

Von Hoff. See Hoff.

Von Oeynhausen on the Eifel district,
iv. 102. 113.

— on granite veins, iv. 339.

Vosges, loess near their base, iv. 30.

Vulcanists, persecution of, in England,
i. 98.

Vulcanists and Neptunists, factions of,
i. 88.

Vultur, Mount, fi. 57.

Vultures, range of, iii. 46.

W.
Waal, R., ii. 3, 4. *
Wahlenberg, Professor, on greywacké
of Sweden. iv. 300.
Wales, slate rocks of, iv. 354. 382.
Wallerius, theory of, i. 79.
Wallich, Dr., on Ava fossils, i. 50.
Walton, sections near, iv. 78. 80.
Walton Naze cliffs, undermined, i. 415.
Warburton, Mr., on Bagshot sand, iv
215.

INDEX.

Ward, Mr., on Kentucky caves, iii. 202.

Warp of the Humber, i. 377. ; ii. 27.

Warton, his eulogy on Burnet, i. 56.

Washita, R., raft on, i. 286,

Water, action of running, i. 261.

——, its power on freezing, i. 262.

—, solvent power of, i. 262.

—, excavating power of, i. 263.

—, transporting power of, i. 264.

—, agency of, in volcanos, ii. 347.

—, absorption of carbonic acid by, iv.
3/2.

Watt, Gregory, his experiments on
rocks, iv. 9. 370.

Weald, denudation of valley of the, iv.
221. 259.

——-, secondary rocks of the, iv. 222.

——-, section of valley of the, iv.* 223,
224. i

—, alluvium of valley of the, iv. 234.

Wealden, secondary group, called the,
iv. 280.

——., organic remains of the, iv. 281. 286.

, its extent, thickness, &c., iv. 508.

Weaver, Mr., on coal of Munster, i. 201.

Webb, Mr., on the Great Canary, ii. 158.

Webster, Dr., on hot springs of Furnas,
i. 328.

Webster, Mr., on waste of Sussex cliffs,
i. 423.

——, on geology of I. of Wight, iii. 335. ;
iv. 253. 260.

„ On formations of London and

Hampshire basins, iv. 213. 215.

——, on fossil forest of I. of Portland,
iv. 284.

Weddell, Captain, latitude reached by,
L0:

Wellington Valley, Australia, fossils in
breccias in, iv. 43.

Wells, influence of the tides on, near
London, i. 301.

——, Artesian, i. 302.

Wener, Lake, strata near, ii. 300.

Wenlock rocks, iv. 270, 271. 298.

Werner, Professor of Mineralogy at
Freyberg, 1775, i. 81.

- ——, his lectures, i. 83.

——, universal formations of, i. 84.

—— on granite of the Hartz, i. 84.

—-, principal merit of his system, i. 84.

—, his theory of basalt, i. 85.

——, taught that there were no volcanos
in the primeval ages, i. 85.

—, technical terms of, i. 103.

——, on transition rocks, iii. 318.

447

West Indies, Hooke on earthquake in,

VOL
, active volcanos in, ii. 46.

——, tertiary formations of, iv. 21.

Wey, transverse valley of the, iv. 238.

Whales stranded, iii. 266.

Whewell, Rev. Mr., on modern progress
of geology, i. 105.

—, on the tides, ii. 10.

—, Cited, i. 185. ; iii. 369.

Whirlwinds, violent, during eruption in
Sumbawa, ii. 200.

——, dispersion of seeds by, iii. 11.

Whiston, his Theory of the Earth, i. 56.

—, refuted by Keill, i. 58.

White Mountains, landslips in the, i.
293.

Whitehurst, theory of, 1778, i. 79.

——. on rocks of Derbyshire, i. 79.

——, on subsidence at Lisbon, ii. 252.

Whitsunday Island, description of, iii,
286.

Wiegmann on hybrids, ii. 425, 426.

Wildon, coralline limestone of, iv. 130.

Willdenow on diffusion of plants by
man, iii, 23.

—— on centres of vegetable creation,
iii, 144,

Williams on Hutton’s theory, i. 98.

Wiltshire, valleys of elevation in, iv.
249, á

Wily, valley of the, iv. 250.

Winchelsea destroyed by sea, i. 423.

Winds, trade, i. 188. 389.

——, currents caused by the, i. 385.

——, sand drifted by the, ii. 21.

Wismar, ii. 288. é

Wodehouse, Captain, on Graham Island,
ii. 147.

Wokey Hole, human remains in, iii. 212.

Wolf, and dog, distinct species, ii. 395,

——., hybrids between the, ii. 424.

—— drifted to sea on ice, iii. 41.

—— extirpated in Great Britain, iii,
110.

Wollaston, Dr., on water òf Mediter-
ranean, ii. 15.

——, cited, ii. 112.

Wood, Mr., on fossils of the Crag, iv.
72. 74.

Wood impregnated with salt water when
sunk to great depths, ili. 219.

——, drift, È 161. 284. 287. 365.5 iii. 41.
22i

—— converted into lignite, iii. 248.

Woodward, theory of, i. 54. 59. 96. 118,

448

‘Wrecks, average number of, per year,
ili. 240, 249,
Wrotham Hill, height of, iv. 224.

X.

Xanthus, the Lydian, his theory, i. 25.

Ys

Yaou, flood of, i. 10,

Yarmouth, estuary silted up at, i. 407.

——, rise of the tide at, i. 381. 407.

——, strata near, iv. 77.

Yates, Rev. J., on delta of the Kander,
iv. 69.

Yellow R., sediment in, i. 366,

Yenesei R., fossil bones on banks of, i.
148.

Yorkshire, bones of mammoth in, i. 145,

——, waste of its coasts, i, 402.

——, chalk of, iv. 256.

INDEX.

Young, Dr., on effects of compression at
earth’s centre, ii. 312. F
Ytrac, freshwater flints at, iv. 159.

Z.

Zaffarana, valleys near, iii. 410.

Zante, earthquakes in island of, ii. 214,

Zechstein formation, iv, 293.

Zingst peninsula converted into an is-
land, ii. 12.

Zocolaro, hill of, lava of Etna deflected
from its course by, iii. 413.

Zoological provinces how formed, iii. 79,

——, why not more blended together,
iii. 82.

——great extent of, iii, 325.

Zoophytes, their geographical distribu-
tion, iii. 61.

——-, their powers of diffusion, iii. 61.

——, abundance of, iii. 149.

——, which form coral reefs, iii.°276.

Zuyder Zee, formation of, ii. 5.

THE END.

Lonvon :

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