ON THE

ORIGIN

OF

ALLUVIAL AND DILUVIAL FORMATIONS.

BY PROF.” SEDGWICK.

From rue ANNALS OF PHILOSOPHY ror APRIL sxv JULY, 1825.

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; Snes Retains rat
: eo... abana j

ges 34 bh aoa YUDPOZOMUT WO B,

/

ON THE

ORIGIN, &c.

(To the Editors of the Annals of Philosophy.)

GENTLEMEN, Trinity College, Cambridge, March 11, 1825.

THE existence of widely extended masses of incoherent mate-
rials separating the vegetable soil from the solid strata of the
earth, is a fact which forces itself upon the attention of every
practical geologist. These materials have for many years been
divided into two classes. The first composed of a series of
deposits originating in such causes as are now in daily action.
The second composed of various materials irregularly heaped
together, often transported from considerable distances, and
supposed to have originated in some great irregular inundation.
Since the publication of Cuvier’s great work on fossil quadru-
peds, this distinction has been very generally admitted ; espe-
cially as it seemed to be completely borne out by the zoological
phenomena exhibited by the two separate classes of deposits.

Prof. Buckland was, I believe, the first geologist who adopted
the terms diluvium and alluvium, diluvial detritus and post-
diluvial detritus to designate the two classes of phenomena
above alluded to. The propriety of this separation has been
since confirmed by a long series of well-conducted observations ;
and by the interesting discoveries brought to light by the same
author within the last four years, some important errors have
been corrected, and the whole subject has assumed a form and
a consistency which it unquestionably never had before. Since
the publication of the “ Reliquie Diluviane,” many objections
have been urged against the opinions advanced in that work.
The greater part of the objectors are undeserving of any animad-
version, as they appear entirely ignorant of the very elements of
geology, and far too imperfectly acquainted with the facts about
which they write to have it in their power to turn them to any

~

4

account, or to draw a single just conclusion from them, This
censure does not, however, apply equally to them all. A writer
in the two last numbers of the Edinbur h Philosophical Journal
considers the present classification of the superficial detritus of
the earth to be founded on an imperfect induction, and to be
contradicted, or at least invalidated, by the distribution of the
organic remains contained in it. ‘Though [ am opposed to many
of the conclusions of this author, and think that he has been
misled from a want of a more extended knowledge of the pheno-
mena in question, yet | willingly allow that his arguments are
adduced with a sincere love of truth, and that his facts and
inferences are entitled to a candid examination. It is not, how-
ever, my intention formally to enter the field of controversy.
Prof. Buckland is far too secure in his position, and incompa-
rably too well armed to need any such assistance.

The words alluvial and diluvial detritus designate certain
classes of phenomena which at the same time have a distinct
character, and belong to distinct epochs. ‘The propriety of this
assumption can only be made out by direct observation. If it
appear that alluvial formations commonly rest on dilwvial ; that
the converse is never true; and that the two formations never
altemate: then the distinction just alluded to is completely made
out, and rests on exactly the same evidence as the order of
superposition of any known strata. We may further observe
that this conclusion is quite independent of any zoological
arrangements. When the order of superposition has been once
made out, we may then proceed to examine the zoological pheno-
mena of each successive deposit. Before that time, organic
remains, however interesting in themselves, convey little inform-
ation respecting the revolutions to which the earth’s surface has
been subjected. It has been already observed that the words
diluvial detritus were applied to certain materials brought into
their present situation by great irregular inundations. In what
sense all diduvial formations may be considered contemporane-
ous ; to what extent, and in what manner, diluvial torrents have
acted on the earth’s surface, are simply questions of fact to be
determined by physical evidence, and by physical evidence
alone.

The truth of any physical phenomenon can only be made out
by physical evidence, and no appeal ought to be made to any
other authority before that evidence has been completely inves-
tigated. It is then obvious that every conclusion respecting the
classification of formations, of whatever age, can only rest on the
evidence aflorded by direct observations. For this reason, I
have drawn up, for insertion in the Annals of Philosophy, an
account. of some of the a//wvial and diluvial deposits which 1
have had an opportunity of personally examining. Part of the
succeeding statements may be considered unnecessary, and

—

5

some of the facts may be thought too unimportant to deserve
any notice. If, however, they should throw any light on a dis-
puted subject, or should they in any way strengthen the chain
of evidence by which one of the most important inductions of
geology has been established, they will not be altogether with-
out their use. i have the honour to be, Gentlemen,

Your most faithful servant,

é A. Sepewick.
ODE

Secr. 1.—Alluvial Deposits.

All the principal vallies of England exhibit in their higher
portions occasional examples of nearly horizontal deposits of
comminuted gravel, silt, loam, and other materials accumulated
by successive partial inundations. The nature of these alluvial
deposits and the cause of them are so obvious, that it is unne-
cessary to refer to particular instances. If we descend from the
hilly and mountainous regions, and examine the courses of our
rivers near their entrance into any widely extended plains, we
frequently find their banks composed of incoherent materials of
anew character. They are not made up of thin layers of com-
minuted matter formed by successive inundations, or of silt
turf-bog accumulated in stagnant waters, but of gre
masses of sand, loam, and coarse gravel, containing
ames rounded blocks sometimes of enormous magnitu is
at once evident that the propelling force of the rivers is entirely
inadequate to the transport of such materials as these. We
may ahattve, moreover, that they are not confined to the banks
of the rivers, but spread over all the face of the country, and
often appear at elevations many hundred feet above the level of
any natural inundation. To such materials as these the term
ales (indicating their formation by some great irregular
inundation) is now applied by almost ail the English school of
geologists.

The rivers which descend from the western moors and unite
in the great central plain of Yorkshire, afford a succession of
beautiful illustrations of the appearances which have been just
described. While rolling from the mountain chains, and uniting
with their different tributary branches, they leave masses of
alluvial matter in every place where the form of the vall
admits of such a deposit: and after passing through the infe-
rior region and escaping through many ravines and gorges into
the great plain of the new red sandstone, they then find their
way through enormous masses of diluvial debris which often
mask the inferior strata through considerably extended tracts of
country. If we follow any of these rivers into the central parts.
of the great plain, we may still find (with occasional interrup-
tions) the diluwial detritus descending with the surface of the

6

ground, often forming the channel of the waters, and, where the
level of the country admits of it, sometimes surmounted by an
accumulation of newer alluvial materials. By the ordinary
action of the waters, the two distinct classes of deposits some-
times become mixed and confounded ; but 1 have never seen an
example where their order is inverted, or where, through any
extent of country, they alternate with each other. The instances
adduced are not exceptions to, but examples of, the Chic

rule. There is not, I believe, a single river in England whi
does not afford a more or less perfect illustration of some of the
phenomena above described.
Perhaps the most important class of facts connected with 4

alluvial phenomena, and which at the same time very strikingly
exhibit their relation to all other deposits in this country, are to
be met with in the low marshy regions near the mouths of some
of our larger rivers. In proof of this assertion I shall proceed to
describe some of the physical characters of the fenny tract of
country which stretches from the south part of Lincolnshire to
the base of the chalk hills of Norfolk, Suffolk, and Cambridge-
shire. If a section be made through this region in a direction
which is transverse to the outfall of the waters, its profile will be
___ represented, first, by a line descending from the higher part of

~ Lincolnshire to the level of the fens ; secondly, by a succession
of horizontal lines exhibiting the several levels of distinct fenuy
rep nterrupted here and there by extensive protuberances
of diluvial gravel; * lastly, by an undulating lme ascendiag
from the alluvial region to the top of the hills which form its
south-eastern boundary. Ifa section were made in a direction
transverse to the former, commencing at the south-west boun-
dary of the low lands, and ending in the sea, its profile would
be represented, first, by a line showing the descent of the high
lands to the level of the fens; secondly, by a long line extend-
ing almost ata dead level (except where it is interrupted by some
of the protuberances above-mentioned) to the eastern extremity
of the fens in the immediate vicinity of the coast; lastly, by a
line descending rapidly from the level of the fens to low water
mark. The singular contour indicated by the second section
has unquestionably arisen from the continued accumulation of
alluvial silt which has choked up the mouths of the rivers, and
raised their beds and all the contiguous country far above their
ancient level.

~* During great inundations these diluvial hills resemble islands rising out of an
inland sea. Most of the towns and villages in the Isle of Ely are built upon them,

+ Thus from Peterborough to Sutton Wash below Wisbeach (a distance of more
than twenty miles), the fall of the water is on the average three inches and a half for
each mile. But from Sutton Wash to low-water-mark at Crabhole, the fall is more
ran ac feet for each mile.—(See Rennie’s Report on the Drainage of the Bedford

vel.

$~ Thus Thorney north fen is thirteen feet; Peterborough low fen twelve feet six

7

It is not, however, the external contour so much as the inter-
nal structure of the district, which bears on the subject of this
paper. The whole of the alluvial de/ta exhibits, as might be
expected, a great uniformity in the arrangement of its consti-
tuent beds. hen the vegetable coating is removed from an
part of it, we may generally find below a brownish black eart
which is formed of a variable mixture of common vegetable soil,
of peat, and of alluvial silt. The different qualities of fen land
arise out of the variable proportions of these constituents. In
those tracts which are pent up between high artificial banks
and upon which water sequently stagnates, the soil is almost
exclusively composed of decayed vegetable matter converted
more or less perfectly into the state of peat. In other more
favoured tracts, more especially on the sloping skirts of the
diluvial hills, the soil is of great fertility, and is composed prin-
cipally of the accumulated silt of successive imundations.
Materials possessing some of these characters are in many
places accumulated upon the regular strata of the country tothe
thickness of nearly twenty feet. When they are laid bare by
any artificial sectfon, we may often see various modifications
which are so far interesting as they throw light upon the ancient
history of these deposits. In one part of such a section we
may find the prevailing black earth interrupted by thin beds of
peat, each of which indicates the temporary residence of stag=
nant water. In another part of the same section, the prevailing
soil is seen to alternate with layers of sand and silt which mark
the effects produced by extraordinary land floods. Alternations
like these are so common as hardly to deserve any notice. If
the section descend still further, we not unfrequently find the
whole series of alluvial deposits separated from the true substra-
tum (which in many places is composed of astiff blue clay)* by
a very thin bed of light coloured, unctuous, marly silt.” This
marly silt is, if I mistake not, of great antiquity, and must have
been deposited by the waters prior to the existence of any por-
tion of the alluvial covering.

If all the soil and accumulated detritus were removed from the
district I am considering, it is certain that the surface of the
ground would present many considerable irregularities. It is
further evident that such a surface must in ancient times have

inches ; Peterborough great fen thirteen feet two inches above the level which ought to
form the base of the drainage near the sea.—(See Bower’s Report of the New Drainage
near Boston.) .

* In all the central parts of the fens, the blue substratum contains innumerable
specimens of the characteristic grypha@a dilatata of the Oxford clay ; but near Ely,
under the alluvial and diluvial detritus, there is a bed which contains the ostrea deltot-
dea of the Kimmeridge clay. If I mistake not, the coral-rag formation thins off before
it reaches the fens, where the two clays are probably brought into immediate contact.
Below Cambridge, the tracts of fen land rest on the galt or Folkstone clay.

8

supported many varieties of productions which are now so
deeply buried as to be reached only by occasional artificial
excavations. This remark at once explains the variable thick-
ness of different portions of the fen lands, and the extraordinary
appearances we sometimes meet with in digging through them.
For example: in excavating the foundations of the new lock on
the river Cam between Clay Hithe and Ely, they reached (after
passing through ten or twelve feet of common fen soil) a bed of
considerable thickness composed almost entirely of hazel wood
and hazel nuts. The wood could not, I think, have been drifted
from any great distance; and the enormous accumulation of
nuts (many pecks of which might have been collected in the
space of a few square yards) seemed to be the production of an
ancient period when, year after year, the trees shed their fruit
on the ground, and there were no inhabitants to collect it. In
many other places, after passing through a thick coating of turf
bog and alluvial silt, we meet with the branches, trunks, and
even the roots of large timber trees. Some of these may have
been floated down during great-floods from the neighbouring
high lands ; but the far greater number of them have unques-
tionably grown near the spots where we now findthem. Exam-
ples of this kind are, I believe, supplied by almost all the exten-
sive fen regions in our island,

Lastly, I shall briefly notice a class of facts which, although
admitting ofa very easy explanation, have sometimes led to erro-
neous conclusions. In almost all the marsh lands which border
on the sea, the alluyiwm is separated from the old subjacent
strata by a quantity of marine silt, and sometimes by beds of
sea shells which appear to have lived and died on the spot
where they are now found, The extent of this marine deposit
towards the interior of the country plainly indicates the extent
to which the alluvial materials have been accumulated and
pushed down within the ancient line of the sea coast. But the
case is not always as simple as I have here stated it. The
lower portion of the marsh lands in question sometimes exhibitd
tone distinct alternations of marine silt and shells, with turf -
bog and other freshwater deposits. Facts of this kind were (if
I have not been misinformed) observed in some of the lower
parts of the Eau Brink cut which was lately completed in the
neighbourhood of Lynn. We are not to suppose that such
facts indicate any sudden change in the relative level of land
and sea. All the alternations above described are below the
level of high-water, and naturally result from the manner in
which the fen lands have been formed. We have only to recol-
lect that in the places alluded to, the tides have for many ages
been ebbing ibs wing along a system of planes which have
been perpetually encroaching on the coast, and perpetually

9

changing their inclination. Ofsuch a state of things, the occa-
sional admixture of marine and freshwater deposits, and the
occasional alternation is the inevitable consequence.*

Seer. 2.—Diluvial Formations.

It remains for me briefly to notice the diluvial formations
which appear within the limits of the tract I have been describ-
ing. They seem to have been rapidly and irregularly accumu-
lated by an inundation which acted with extrordinary violence ;
for they are partly composed of broken masses of more ancient
strata, akik are rounded and ground down by attrition, and
which in many instances have been transported from distant
parts of the country ; and they contain no alternations indicating
(as in the case of alluvial deposits) the long continued and tran-
quil operation of the agents by which they have been produced.
They rest on the ancient strata of the country without the inter-
vention of any other deposit whatsoever, and in instances with-
out number they form the basis of the whole alluvial detritus,

The true relations of the diluvial detritus are beautifully
exemplified on the flanks of the chalk hills which skirt the
south-eastern side of the marsh lands above described. It is
constantly seen to rest immediately on the fundamental rock ;
to follow all the irregularities of the surface ; to rise out from
beneath all the alluvial lands, and sometimes to lie in scattered
masses on the very top of the chalk downs. From thence it
may be traced, almost in a continuous mass, still further to the
south-east, where itis heaped up to an enormous thickness, and
overlies the newest tertiary beds which exist in that.part of
England. From all these facts we are justified in concluding,
that the diduvial and alluvial deposits above described are not
only essentially different in their structure, but belong to two
distinct epochs ; the former class of deposits having been pro-
duced by some extraordinary disturbing itcss prior to the exist-
ence of any portion of the other class.

Were the order above given contradicted by the arrange-
ments of the superficial deposits in other parts of our island, we
should of course be prevented from drawing any general conclu-
sion from it. But believe there is no inconsistency in the
order of our superficial deposits, and that the counterpart of the

* A fine instance of this kind of alternation may be seen in the lower Pentowan
stream-tcork near St. Austle. “The diluvial tin ground (which is nearly thirty feet
below the level of high-water) is covered with a deposit (about seven feet thick) of com-
pressed vegetable matter, leaves, roots, and trunks of trees, &c. all of which have eyi-
dently been drifted into their present position by floods, or perhaps by the slide of a half-
formed turf bog. Over this deposit are a suecession of marine beds (above twenty feet
thick) obviously accumulated, while the lower part of the valley was an estuary.
Lastly, a thick formation of peat, containing branches and trunks of trees, ie
the level of high-water, and is surmounted by common vegetable soil. For a-détailed
account of this section, see Geol. Trans. vol. iv, p. 404, &e. “ai

10

facts above stated may be found in every country which is simi-
larly circumstanced with that which has been described. My
object is not, however, to make out a new arrangement, but to
confirm an old one; I shall, therefore, content myself with
referring to one additional class of examples.

In many parts of Cornwall the flanks of the central chain of
hills are covered with a thick deposit of diluvial gravel, which,
after resting immediately on the granitic and schistose rocks of
the country, and following their inclination, often descends into
the lower part of the transverse valleys, and from thence shelve
down below the level of the sea. Near the mouths of these
valleys the diduwvium is always éovered up by beds of a more
recent detritus which in some places are nearly sixty feet thick.
Notwithstanding their great thickness, many large excavations
have been made through them for the purpose of extracting the
tin ore which has been washed down from the mountains at the
time the d/wvial rabbish was formed, and which (in consequence
of its great specific gravity) has naturally subsided to the bot-
tom of the formation. In various excavations of this kind
(provincially called stream-works), conducted in different parts
of the county, we may sec in the clearest manner the true rela-
tions of the several superficial deposits ; and (as far as any thing
can be proved bysingle instances) the sections show; first, that all
the diluvial detritus in that part of England originated in the
same system of causes which, having produced their effects
once, were never repeated; * secondly, that all the alluvial
detritus, of whatever kind, is posterior to the preceding;
because it constantly rests upon it, and never alternates with it.

By the examination of facts like these, we become acquainted
with the natural history of such superficial deposits as I have
been describing. The facts are in strict accordance with every
thing which I have myself observed, and they are, I believe, in
accordance with the observations of all English geologists who
have personally examined the evidence connected with this sub-
ject. We may therefore conclude on an induction founded on
a very wide range of consistent observations; 1. That a//wvial
deposits include a large class of formations which have originated
in causes such as are now in daily action; 2. That the same
causes have acted during a long period ; 3. That during that
period the deposits have not been interrupted by any catastrophe
which has interposed any other deposits of a distinet character ;
4, That diluvial deposits possess a distinct character from the
preceding class, never alternate with them, and, from their posi-
tion, evidently belong to an older epoch; 5. That during the
epoch in question, the dilwvial gravel was produced by extraor-

. > This fact is of great importance and was, I believe, first remarked by Townsend
in his “+ Vindication of Moses.”’ (See vol. i. p. 227, &c.) I had repeated opportunities
of verifying this remark during a tour in Cornwall made in the summer of 1819.

11

dinary inundations; 6. That the disturbing forces which pro-
duced these inundations acted on the earth’s surface after the
deposition of all the regular strata with which we are ac-
quainted,

The separation of the incoherent materials, which are heaped
on the regular strata of the earth, into dé/wvial and post-diluvial
detritus, is, therefore, a natural separation, which is at once
descriptive of the things designated, and founded on the con-
stant relations which they bear to each other. Moreover it is
unconnected with any hypothesis whatsoever, and is indepen-
dent of any argument drawn from the nature of the organic
remains contained in different parts of the several deposits.

Secr.3.—Organic Remains in Alluvial Formations.

I should not have dwelt so long in illustrating the preceding
conclusions, had [not known that the nature of the evidence on
which they are founded has often been entirely overlooked or
misunderstood. In the next place, I shall briefly consider the
organic remains contained in the two classes of deposits, espe-
cially in those localities which have been already described.
The following specimens were derived from the alluvial debris
which rests on the dilwvial tin ground in various parts of Corn-
wall.

1. A human skull buried 36 feet in al/uvium, from the Carnon
stream-work, 2. Horn of an ox 40 feet deep in alluvium, from
the same place. 3. Fragments of a human skeleton, from the
Pentowan stream-work. 4. An ancient earthen vessel, formed
without the potter’s wheel, more than 40 feet deep in alluvium,
and about 10 or 12 feet above the diluvial tin ground, from the
same place. 5. Part of a culinary vessel buried 24 feet in
alluvium, from the Levrean stream-work. A celt and some
other rude works of art were found near the same place. To
the preceding might be added a long list of spoils derived from
the alluvial region which stretches out from the neighbourhood
of Cambridge to the wolds of Lincolnshire, such as various
specimens of trunks and branches of trees; of freshwater and
land shells ; of implements of human workmanship; of horns,
teeth, and sometimes skeletons of animals which have been
either drifted into the marshes, or have perished there by acci-
dentor violence, &e. &c. To which catalogue might be added,
the skeletons of four beavers found near Chatteris in the alluvial
bed of the Old West-water, a river which in former times per-
formed an important part in the drainage of the country, but
which has been choked up for 200 or 300 years.* We look in
vain into these lists for the bones of the cavern-bear, the mam-

¥ See a paper by John Okes, Esq. in the Transactions of the Cambridge Philoso-
phical Society, vol. i. p. 176.

12

moth, the hyena, the rhinoceros, the hippopotamus, and other
animals, the spoils of which are found in almost miraculous’
abundance in many parts of the world buried in the old diéluvial
detritus. ;

When we consider the great extent of the adluvial tract above
described, and the various cuts and drains which have been
made through almost every part of it: and when we further
consider that the same tract of country is the growth and accu-
mulation of at least 2000 or 3000 years ; the negative argument
becomes complete, and we conclude, almost with certainty, that
during this long period not one of the several species of animals
last enumerated existed in the neighbouring parts of our island.
Let these considerations be combined with the admirable details
and illustrations supplied in the writings of Cuvier and Buck-
land, and we readily extend the same conclusion to other parts
of England, and indeed to every part of the world, which has
been rigidly examined.

It may, however, be urged that no accumulation of negative
evidence can stand against the direct evidence of opposing facts.
Is then the preceding conclusion opposed by any incontroyerti-
ble facts? To such a question I should not hesitate to reply by
a decided negative. Rubitaste cases ie occur near the base
of a crumbling sea cliff, or near the bank of a river which is
continually fallmg down from being undermined by the attrition
of the waters; or in the silt and alluvial rubbish of a valley
which for many ages has been modified and ravaged by succes-
sive floods. In such situations the spoils of alluvial and dilu-
vial deposits may be mechanically mixed together so as to render
it impossible to separate them.

A sober-minded naturalist who makes his inductions after an
extended examination of facts, and who does not view all things
through the distorting medium of an hypothesis, will never
derive from such localities as these any argument for the true
arrangement of spoils found in different parts of the superficial
gravel, The only way in which spoils derived from such situa-
tions can be classified, is by comparing them with similar
remains found in other deposits, the relations of which are
clearly exhibited, and which have been modified by no subse-
quent disturbing forces. Had this observation suggested itself
to Dr. Fleming, he might have withheld more than half the
examples he has brought forward in the Edinburgh Philoso-
phical Journal (No. 22, p. 297, &c.) with a view of overturning
the distinction which has been drawn between the organic
remains ofadluvial and diluvial detritus, In regard to the mam-
moth, he has not produced a single example of its remains found
in undisturbed alluvium. Some of his examples may, perhaps,
be ambiguous; but others are derived from localities which,
had he taken the trouble to examine them himself, he would

13

have known to be didwvial, A single example is given of the
bones of the hippopotamus found under a peat-bog. But the
fact is given without details, and without the shadow of a proof
that the bones were buried in alluvium. The case of the great
fossil=elk may perhaps be ambiguous. A gigantic animal of
that family would soon be marked out for destruction; or it
may perhaps have been exterminated by beasts of prey before
the peopling of Western Europe. All the spoils of this creature
which | have myself seen ix stéu do, however, belong to diluvial
deposits. The three examples of horns of the rhinoceros found
in alluvial marl-pits and turf-bogs, and preserved in the museum
of Edinburgh, seem at first sight to throw most formidable diffi-
culties in the way of the received classification. Through the
kindness of Prof. Jameson, I have lately seen the specimens in
question, and I know from the Professor himself that there is
no adequate evidence to prove them genuine fossils. Without
this information, from their Jook and their condition, I should
not have hesitated.a moment in rejecting them as spurious. It
is contrary to my present object to enter into any details con-
nected with the examples to which I have referred. I do, how-
ever, unhesitatingly assert, that as far as regards the purpose
for which they were adduced, they are altogether without weight,
and without importance.

Srcr. 4.— Organic Remains in Diluvial Detritus.

The diduvium in the central parts of the fens of Cambridge-
shire, or on the sides of the low hills by which the region is
skirted, is found to possess a great uniformity of character. It
contains innumerable fragments of gryphites, echinites, shells,
corals, lizards’ bones, and other fossils, all more or less perfectly
mineralized, and all obviously torn up from the regular strata of
the country by the same disturbing forces which formed the
ancient gravel, Among these fragments, and among rounded
blocks of stone chiefly derived from the same strata, are many
minute fragments of bones, and sometimes entire teeth of various
animals, more especially of the horse, the ox, the deer, and
various graminivora. Among these, the remains of animals
(such as the mammoth and the rhinoceros) now unknown as the
inhabitants of any part of Europe are by no means uncommon.
To describe, or even to enumerate, such specimens in detail
would be foreign to my present purpose. I shall only refer, by
way of example, to some of the organic spoils derived from the
undisturbed diduwium in the neighbourhood of Cambridge.
1. Fragments of the pelvis of amammoth, from the gravel south of
St. Ives, Huntingdonshire. 2.Grinder of the mammoth, fromthe
diluvium which stretches from St. Ives towards the centre of
the fens. 3. Fragments of a large mammoth’s tusk, from Foul-
mire. 4, A very large grinder of the mammoth, from the gravel

14

beds at Hinxton. 5. Innumerable fragments of the bones of
various animals from the beds of small flint-gravel, north-west
of Cambridge. 6. Eight or ten fragments of mammoth’s grind-
ers, from the thick gravel beds behind Barnwell. 7. Three or
four large and perfect grinders of the mammoth, from the fine
flint-gravel south of Cambridge; along with which were found
several bones of the horse, and teeth of various graminivora.
8. Many teeth of various graminivora ; humerus of a very large
mammoth ; several teeth of the rhinoceros ; horns and portions
of two enormous skulls of the urus or buffalo; an atlas (probably
belonging to one of the preceding species), in linear dimensions
about twice as large as the atlas of a full grown ox; several
perfect bones of the horse; fragment of the horn of the cervus
giganteus; Ke. &c. all derived from the gravel beds at the north-
west end of Barnwell.*

Such are the organic remains contained in a small part of the
diluvium of this country ; all of them differing in condition, and
many of them differing in kind from the Pa oe aa spoils of
the alluvial beds of the same district; and the distinction is
rendered still more complete by the fact, that not one work of
human art, and not one fragment ofa human skeleton, have yet
been discovered in any part of the numberless excavations which
are conducted in the lower and more ancient deposit. When
we properly estimate these facts (which are but the counterpart
of some of the admirable details given in the “ Reliquiw Dilu-
vianz”), and consider how very smail a portion of the superficial
gravel has yet been turned over even in the most populous parts
of our island. We are compelled to admit that animals almost
without number must have inhabited all thé lower parts of
Europe before the commencement of those destructive opera-
tions which produced the diluvial gravel.+ A further examina-
tion of the facts already stated leads us also to conclude, that
many pre-existing species of animals must have perished during
the operation of the same destructive causes; because we do
not find their remains in any more recent deposit.

It is in vain for any one to attack these conclusions by
demanding how it came to pass that one class of animals
perished during the formation of the diluvial gravel, and another
class survived it. The same difficulty meets us in classing
many of the regular strata of the earth. The suite of fossils
derived from one formation may be widely different from the
suite derived from another; yet we know by experience that
both suites may contain many individuals of a common species,

* Most of the specimens from this locality are in the possession of J, Okes, Esq. of
Cambridge.

+ This conclusion had been completely demonstrated, in the opinion of most geolo-
gists, from the number, the nature, and the condition of the organic remains of the

gravel: had any doubt remained on the subject, it is now set at rest by the details con-
nected with the Kirkdale cavern given in the “ Reliquiz Diluviane.”

15

Still less are the conclusions shaken by the hypothesis, that the
weapons of the hunter completed the extinction of many species
of animals, of whose former existence we have no knowledge,
except through their bones, which are buried in the beds of old
diluvial covering. From the only pac evidence which we
can have on such a subject, we believe that not a single hunter
had ever trodden in the woods of Europe at the time when the
mammoth, the rhinoceros, and the hyena were its inhabitants.
And the records of Europe afford no proof that such beasts ever
inhabited this part of the world in times within the reach of
history. Again, we know by direct evidence, which is inde-
pendent of any zoological details and of =h history, that the
diluvial gravel is of great antiquity ; and we know from history
that in ancient times large tracts of Europe existed in the form
of unreclaimed marsh or almost impenetrable forest. Under
such circumstances, are we to believe that a set of inhabitants,
savage, almost naked, and few in number, should have waged a
war of extermination with large and formidable beasts like the
rhinoceros, the cavern-bear, and the hyena? The hypothesis
which attributes the extinction of such animals to the agency
of hunters in the early ages of the world is at once gratuitous
and incredible.

As the general result of all the preceding details, we may
conclude that the separation of the superficial debris of the
earth into two classes (di/uvial and post-diluvial detritus), formed
by different causes, and during distinct epochs, is completely
made out; first, by the direct evidence of natural sections prov-
ing one formation superior to the other; secondly, by the distinct
suites of organid remains imbedded in the two deposits. The
lower formation containing many organic remains which are
never found in the upper; and the upper also containing many
which are not found in the lower. In these respects, perhaps, no
two contiguous formations in the crust of the earth are sepa-
rated from each other by more clear and decisive characters.

Secr, 5.—On the Causes of Diluvial and Alluvial Phenomena.

The conclusions which I have attempted to vindicate in the
preceding sections, however interesting in themselves, give us
but scanty means of speculating on the causes which have pro-
duced the diluvial deposits. 1t may be asked, by what forces
were the diluvian torrents first put in motion? In what direction
did they sweep over the earth ? On what part of the earth’s sur-
face have they acted? Did they operate almost simultaneously
over all parts of the world, or did they act at intervals and dur-
ing along period of time ? What was the condition of the globe
prior to their action, and what are the modifications in its
external character produced by them? To some of these ques-
tions, no answer can be given, and to none of them can we give

16

a complete answer in the present state of our information. If,
however, a great many well observed facts seem to point to one
conclusion, that conclusion must be considered probable until it
is opposed by some other conflicting facts. One thing at least
is certain, that no hypothesis can be admitted which is not
borne out by that series of facts (however imperfect) with which
we are now acquainted. Pec = 2:

On these grounds I do not hesitate a moment in rejecting the
hypothesis which allows the formation of alluvial deposits in
the manner above described, but accounts for all the di/uvial
phenomena by a succession of partial and transient inundations,
occasioned by the bursting of lakes, and other similar catastro-
phes.* In the first place, the cause assigned is inadequate to
the effects produced. The physical contour and structure of the
central and southern parts of England show the impossibility of
any large lakes ever having existed among our secondary strata,
capable of producing the enormous and almost continuous beds
of gravel which stretch along the eastern coast. Several striking
facts connected with this question have fallen under my own
observation ; and, as far as they go, confirm the eneral views
given in the “ Reliquie Diluviane.” As the description of
these facts will lead me into some details, I hope to resume the
subject in the next number of the Annals of Philosophy.
Secondly, the hypothesis is gratuitous. In many parts of
England, where there is abundance of superar gravel, there
is not the shadow of evidence to prove that any great body of
water was ever pent up among the neighbouring strata, su as to
form alake which afterwards burst the barriers by which it was
confined. Catastrophes of this kind sometimes happen in
mountainous regions, and the effects produced are commensu-
rate to the agents; but these effects have nothing to do with
the great masses of superficial gravel even in the contiguous
districts.| Thirdly, the feeble agents which the hypothesis
allows would require an indefinite extension of time before they
could produce such effects as the earth’s surface plamly exhibits.
But the quantity of marsh land and silt formed at the head of
many lakes, the extent of different deltas, and other similar phe-
nomena, appear to demonstrate that all ad/uvial deposits have
been completed within a very limited period.{ The hypothesis
is, therefore, inadmissible, which makes al/uvial and diluvial
deposits contemporaneous, and implies an indefinite period of

* This appears nearly to agree with Saussure’s opinions, and is still held by some
geologists on the Continent.

+ In consequence of the prevalence of local disturbing forces, such as those alluded
to in the text, the great relations of the superficial detritus cannot be studied to so much
advantage in the immediate neighbourhood ef mountain chains, as in the lower regions
of the earth’s surface.

~ Weowe this conclusion to Deluc who devoted the labours of many years to its con-
firmation. Had his labours terminated here, he had done great service to geology.

17

time for their formation. Fourthly, the hypothesis does not
account for the different suites of organic remains found in each
deposit. Lastly, it does not account for the constant order in
the position of alluvial and diluwal debris. Had they. been
formed in the way which the hypothesis implies, they must
sometimes have alternated. Each of these objections might
be expanded and illustrated by many details; but to enter on
them would be foreign to my present purpose.

The details already given in the preceding sections sufficiently
explain the origin of common ad/uvial formations. But there
are two classes of phenomena exhibited on several parts of the
coast of our and. which are intimately connected wich the
present inquiries, and do not always admit of easy explanation,
viz. 1. Traces of recent marine deposits above the level of high-
water. 2. Extensive traces of ancient forests in situations which
are constantly overflown at high-water.

Phenomena of the first class are generally met with on the
banks of estuaries where the waters of the seanecessarily undergo
great oscillations. By the extraordinary combination of a high
spring tide, and a hurricane blowing in the direction of the cur-
rent, whales and other marine animals have from time to time
been stranded on the banks of estuaries in situations 20 or 30
feet above the reach of common floods.* This is not mere
hypothesis : we know that by the combination of such circum-
stances as these, the sea has two or three times, within the last
600 years, risen to an extraordinary elevation on the coast of
Holland, and overwhelmed large and populous tracts of that
country.

The existence of submarine forests is not so readily accounted
for. Some writers have supposed them to be the effects of
earthquakes, which in ancient times have submerged large tracts
of forest land bordering on the sea coast. Without pretending
to exclude such agents in cases which without them admit of no
explanation, I think that in a vast majority of instances it is
unnecessary to introduce them. The mean elevation of the sea
about every part of our coast is unquestionably constant; but
the actual level of high-water at any given place is dependent on
the velocity and direction of the tidal currents, the contour of
the coast, and a number of circumstances which are entirely
local. In proof of this assertion, it is only necessary to appeal
to the fact, that in extensive bays and estuaries, the sides of
which gradually diverge towards the open sea, the tides occa-
sionally rise (through the operation of a common hydrostatical

* Two examples of this kind are noticed by Dr. Fleming in the last number of the
Edinburgh Philosophical Journal, p. 124. Such cases must be carefully distinguished
from all tertiary deposits ; and fromsuch accumulations of marine shells as are seen in
the crag-pits on various parts of Norfolk, Suffolk, and Essex. These latter instances

unquestionably belong to no natural marine inundation, and are, at least, as old as the
diluvium in that part of England.

18

law) to an elevation which is many times greater than the rise
of the same tides on more open parts of the coast. Any set of
causes which greatly modify the form of a deeply indented
coast, must, therefore, inevitably produce considerable local
effects upon the level of ne eae

Let these remarks be applied to the eastern shores of England.
We know that during the last 1000 years, the sea has made
enormous encroachments on many parts of Suffolk, Norfolk,
Lincolnshire, and Yorkshire; not only modifying the whole con-
tour of the coast, but at the same time forming chains of shoals
and sandbanks by which the velocity and the direction of the
tidal currents must have been more or less affected. The waters
have, therefore, during successive ages, been propelled into the
recesses of the coast by different forces, and up diflerent systems
of inclined planes ; and must in consequence have ascended to
different levels. Such effects as these will reach their maximum
on the shores of large bays and estuaries, like the Humber and
the Wash of Lincolnshire.

The form of the Wash of Lincolnshire must have been greatly
changed since the epoch of the di/uwial detritus, partly by the
degradation of the neighbouring cliffs ; but still more by the
encroachments of ad/uvial silt which has been pushed down into
it by the waters of the Witham, the Glen, the Welland, the
Nene, and the Ouse.* If an undulating line be drawn through
these several rivers a few miles above the estuaries in which
they terminate, it may be taken as an approximation to the form
of a part of the coast in very ancient times before the great accu-
mulation of alluvial matter. The country within this line then
presented a low undulating surface, gradually rising on every
side of the Wash towards the high lands ; and it was probably
almost covered with forest trees, with the exception of a few
very low regions through which the rivers descended to the sea,
and which were partially flooded at the time of high-water. But
in the present state of things, the flood-tides, after filling the
lower part of the Wash, are pushed on towards the ancient line
of coast through a number of estuaries, the sides of which con-
verge towards the interior, and on that account force the waters
up to a higher level than they could reach ona coast which was
less indented. And after the flood-tides have been thus pushed
up into the mouths of the rivers, they do not now, as in former
times, mix with the freshwater and cause a reflux, extending far
into the interior of the country ; but after rising, almost at once,
to a high level,+ they are pent up between artificial banks, and
soon stopped altogether by /ocks and other works connected

* A long note containing some details connected with the drainage of the fens bor-
dering on the Wash, arrived too late for the press, but will be affixed to the continua-
tion of this paper.— Edit.

+ See note 2, p. 6,

< PN maces
Pe es ae

<&

~

z
-

AGS

tg 3-7 oe et
eats ix, 5,

Kage >.
SH

pes AS) ©

ee
i pee’

PASS

19

with the artificial drainage and navigation of the country. It is
almost certain that in such a state of things the tides cannot rise
to the exact level which they reached in ancient times ; and the
change will, I think, be precisely of that kind which will explain
the appearance of submarine forests in many places bordering
upon the Wash. If through a combination of causes such as
have been mentioned, the tides on any part of the coast rise toa
level only a few feet higher than they did in ancient times, the
whole difficulty we have been considering at once vanishes.

The conclusions which have been dedaced from a considera-
tion of certain facts exhibited on the coast of Lincolnshire, may
be extended to every country which is similarly circumstanced ;
and it seems probable that an actual change in the height of the
tides produced by a change in the contour of the neighbourin
coasts, is among the most general and eflicient causes whic
have produced the phenomena of submarine forests. By this
assertion it is, of course, never intended to exclude other agents
from their proper share in producing the phenomenon. Forest
trees may have grown in many low tracts bordering on the sea
while they have been protected from the flood-tides by artificial,
and sometimes, perhaps, by natural embankments ; and in sub-
sequent ages the embankments may have failed, and the forests
may have been submerged by a consequent incursion of the
waters. Fen lands, after being drained and brought under cul-
tivation, may have undergone a natural subsidence, and on that
account have been exposed to the chance cf subsequent inun-
dations. This at least was Deluc’s opinion, founded on obser-
vations made in various parts of Holland. Lastly, large tracts
of low alluvial land may (after the natural destruction of the bar-
riers by which they were held in) be transferred by a slide to a
lower level ; and in that way productions once out of the reach
of the high tides may become exposed to their constant attacks.
By the gradual operation of such causes as have been enume-
rated, the existence of submarine forests may in most instances
be satisfactorily explained without the intervention of earth-
quakes or other irregular disturbing forces.

The phenomena above described (viz. the existence of land
productions below, and of marine productions above the level of
high-water) are after all things suz generis, which are confined to
«small part of the coast; and, however interesting in themselves,
throw no light whatever on the general classification of alluvial

and diluvial deposits.
(To be continued.)

20

On Diluvial Formations. By Professor Sedgwick.
(To the Editors of the Annals of Philosophy.)

GENTLEMEN, Trinity College, Cambridge, May, 1825.

Tue following remarks on certain di/uvial deposits form a
supplement to a paper which you did me the honour to publish
in the Annals of Philosophy for the month of April. Circum-
stances, over which I have had no control, have prevented me
from resuming the subject sooner; but I venture to hope that
the statements which are now offered for insertion in your jou
nal, will be found sufficient to explain and vindicate the opinions
advanced in my former communication,

{ have the honour to be, Gentlemen,
Your most faithful servant,

a A. Sepewick.
ep

Separation of Alluvial and Diluvial Formations.

In my former paper on the origin of alluvial and diluvial
formations, I endeavoured to explain the nature of the evidence
on which the two classes of deposits had been separated from
each other; and [ also endeavoured to show, that diluvial forma-
tions have not originated in a succession of partial and transient
inundations occasioned by the bursting of lakes, or by the ordi-
nary operation of any cause with which we are acquainted. The
last conclusion might, perhaps, be established by showing the
constant order in the position of the two deposits, and the differ-
ent suites of organic remains contained in them. It derives,
however, its most direct support from the two following consi-
derations: 1. That, with very limited exceptions, the earth’s
surface exhibits no traces of ancient lakes capable of producing
any portion of the superficial. gravel. 2 That admitting

21

(although against direct evidence) the existence of such ancient
lakes, we shall not, by that hypothesis, introduce an agent
capable of producing the diduvial debris which is exhibited on
almost every part of the earth’s surface which has been well
examined.

In illustration of the first of these two assertions, I need only
state, after Prof. Buckland, that in none of the higher parts of
ingland out of the reach of ordinary floods, have any traces
been yet discovered of lacustrine terraces, such as those which
are scen in one or two of the glens of Scotland, or of any other
deposits indicating the former presence of extensive tracts of
stagnant water. ‘The hypothesis which ascribes the distribution
of the enormous masses of diluvial gravel existing in so rie
parts of our island to the agency of a series of lakes, whic
from time to time have burst their barriers and descended to
lower levels, may, therefore, at once be rejected as gratuitous.

Diluvian Action proved from the Form of many Valleys of

Denudation.

There is another independent reason for rejecting the hypo-
thesis, which may be properly stated in this place. That most
of our secondary valleys faye been formed by denudation, and
that by the action ef water many portions of the earth’s surface
have been greatly changed in form since the solid strata assumed
their present elevation is universally admitted; the only ques-
tion 1s respecting the manner in which such changes have been
brought about. Now we may venture to assert, that in number-
less instances the present drainage of the earth’s surface could
never have been flected, either by the long continued erosion
of the elements, or by the bursting of any series of lakes once
pent up among its higher regions; and if this statement be true,
the present modifications in the external contour of the earth
must have been effected by the action of water put in motion by
powers which differ altogether with those with which we are
acquainted. It is impossible in this place to enter on a detailed
proof of the preceding assertion. By way of illustration, I shall
only refer to two examples of the kind alluded to, though many
others equally decisive of the question at issue, might be derived
from various parts of our island.*

Wealds of Kent.
The first example to which { shall refer is supplied by the

“ Some excellent observations connected with this subject may be found in the
** Geological Survey of the Yorkshire Coast; by Young and Bird, p. 279, 286.
Many valleys appear to have been formed by an actual disruption of the strata produced
at the time of their first elevation. Valleys of this kind are of course excepted from the
remarks in the text, which apply exclusively to true valleys of denudation, such as those
by which the greater part of the secondary strata of England are intersected.

22

natural drainage ofa portion of the counties of Kent and Sussex.
A number of small rivers take their rise in the central ridge of
the Hastings sands (see Greenough’s Geological Map of a
land), and descend from thence both on the north and south side
into the longitudinal valleys occupied by the weald clay.
Instead of finding their way to the sea through these valleys, the
rivers proceed in adirection nearly transverse to them, and escape
on the one side into the Thames, and on the other side into the
Channel, by deep gorges cut through the escarpments of the
North and South Downs.* In this way the whole region is
intersected by a double system of valleys communicating with
the sea, and crossing each other nearly at right angles. It is,
{ think, physically impossible that this singular contour should
have been produced by the long continued erosion of the waters.
For allowing that the rivers have scoured out the longitudinal
valleys of the weald clay, no reason can be given why they
feoula not flow down those valleys at this moment; and on this
supposition it is inconceivable how they should ever have forced
their way (in no less than eight places) through the high ridges
of the North and South Downs. Again, if we suppose that the
North and South Downs were once prolonged to the south-east
so as to form a continuous ridge, we may shift the difficulty, but
we shall not explain it. On this supposition a large inland lake
might have occupied the region of the weald clay, and such a
lake might have burst the chalk barrier, and formed one or two
swieta of denudation. But it is impossible that such an agent
should ever have formed the complex system of valleys by which
the Downs are now intersected. That all these valleys have
been opened out by the same disturbing forces which have pro-
duced the accumulations of superficial gravel in the neighbour-
ing parts of England cannot admit of doubt. Yet we have the
clearest physical evidence that the drainage could never have
been effected by the ordinary operations of any of those disturb-
ing forces which are now acting on the surface of the earth.

Drainage of the Isle of Wight.
The next example is supplied by the drainage of the Isle of

' Wight.+ Two small rivers which rise on the south side of the —

central Downs might have escaped into the sea by low and direct
channels cut through the incoherent ferruginous sands. Instead
of this, they flow into the north channel, at Cowes and Brading,
through two deep vaileys which have been scooped out of the
central chalk ridge. It is physically impossible that the rivers
should have effected this passage for themselves. And if we
suppose these valleys to be closed, itis incompatible with every

* * See the “ Outlines of the Geology of England and Wales,” p- 145.

+ See the map accompanying Dr. Fitton’s paper published in the Annals uf Philo-
sophy for Nov. 1824,

his Sa pw

EE SS Ns 5

ae

Ky ia

Go 4, anteckies we

23

thing we know of the structure of the country to conceive the
existence of any lake whatsoever, much less of any body of
waters capable of bursting through the high chalk downs, and
of bringing the island into its present form. We are, therefore,
compelled to admit, that the island has been reduced to its pre-
sent form by some more powerful cause than any which is in
ordinary action. A detailed examination of the surface of the
country fully establishes this inference. For we have the most
direct evidence to prove, that diluvian torrents have swept over
every part of the Isle of Wight, its highest as well as its lowest
elevations ; and that they have scooped out deep valleys, and
driven before them enormous masses of gravel, which are heaped
ei the upper freshwater beds and all the other tertiary deposits
which extend to the north channel. °

~

~ Resulting Conclusions.

From a consideration of such facts as these, we may, } think,
unequivocally establish the two following conclusions: 1. That
during a period of time posterior to the deposition of the newest
regular strata which are known to geologists, many parts of our
island have been ravaged by powerful denuding forces. 2. That
the form and direction of the valleys produced by these denuding
forces, cannot be accounted for by any known action of the
waters which are now draining off the surface of the country.
On similar grounds the preceding conclusions might be extended
to many other parts of the world; and they are obviously inde-
pendent of any arguments drawn from the extent and the posi-

tion of the dilwvial detritus. ;

Position and Extent of the Diluvial Detritus.

In the remaining part of this paper I shall proceed to an
examination of the materials which have been torn up by diluvian
currents, and scattered over different parts of our island; and
from the position and extent of these materials, I shall endeavour
to prove that they cannot be accounted for by the ordinary
operation of any known physical agent. It is not, however, m
intention to enter on any general details connected with the
history of this detritus, as they would inevitably lead me into
ground which is already occupied by the author of the “ Reli-
quia Diluviane.” I shall, therefore, only select from the facts
which have come under my own observation, two or three which
seem to bear more immediately on my present object. On this
account I forbear to notice the successive valleys of denudation,
and the almost continuous masses of di/uvium which present
themselves on the south coast; and for the same reason I pass
over all the corresponding phenomena in the central and south-
ern parts of our island. I may, however, express a convictiou,
founded on a very extensive range of observations, that there 's

24

not a single spot in the abovementioned et of England which
has been exempted from the attacks of those destructive forces
which have produced the diluvial gravel. Whatever, therefore,
may have been the origin of the phenomena in question, they
are due to the operation of no partial or local agents,

Diluvium on the East Coast, &c.

I. The eastern parts of England from the chalk downs of Lin-
colnshire to those of Cambridgeshire, offer a series of striking
facts connected with the history of diluvial phenomena. In the
neighbourhood of Cambridge (and I believe also along the whole
escarpment of the chalk in the counties of Norfolk and Suffolk),
the diluvial deposits may be divided into two distinct classes.
The first, composed of coarse materials, often lodged at consi-
derable elevations, and apparently drifted into their present situa-
tion by the first rush of the waters: the second, generally found
in lower elevations, and apparently comminuted~ by the
continued attrition of the retiring waters. The extensive
deposits of transported materials in the low region between
Cambridge and Lynn, generally belong to the latter class; and
the immense abundance of rolled flints contained in them seem
to prove that the neighbouring chalk strata must once have
extended considerably to the west of their present limits. An
examination of the chalk downs themselves completely demon-
strates that the denuding currents have not been confined to
the lower part of the escarpments; but have pushed enormous
masses of gravel over the very top of the downs, and have
modified the whole surface of the district. Lastly, the bluff.
escarpment presented by the chalk on the coast of Norfolk, and
the re-appearance of the same rock ia the*wolds of Lincolnshire,
almost compel us to admit that the formation was once continu-
ous, and that the whole Wash of Lincolnshire has been caused
by denudation. Be this as it may, we may conclude with cer-
tainty that the present form of the chalk downs of Suffolk, Nor-
folk, and Cambridgeshire, could never have been produced by
any known action of the waters which now drain off that part of
England ; and the nature and position of transported materials,
which the denuding currents have drifted over many parts of
the neighbouring region, lead us to exactly the same conclusion.

Diluvium of Huntingdonshire and Cambridgeshire.

The elevated plains, which extend on the confines of Bedford-
shire, Cambridgeshire, and Huntingdonshire, exhibit several par-
tial deposits of such transported materials, from which the Rev.
J. Plumptre, of Great Gransden, has selected a vast variety of
rolled masses derived from almost every known formation in
England. His highly interesting collection, obtained from the
diluvium in the neighbouring district, may be divided into the

25

following classes :—1, Containing many ancient rocks derived
from doubtful or unknown localities. 2. Many primitive and
transition rocks resembling those existing in stu on the western
side of our island. Some of these which are much rounded
have probably, by an ancient catastrophe, been buried in the
conglomerates of the new red sandstone; and afterwards, by
the last catastrophe which has desolated the earth’s surface,
been transported into their present situation. 3. A fine series of
specimens of mountain limestone and sa resembling the cor-
responding rocks of Derbyshire and Staffordshire. 4. An
immense number of blocks drifted from the more recent strata.
Out of this class one might select a good series of specimens
characteristic of all the strata of England from the has to the
chalk.

Extensive deposits of diluvial rubbish similar to those last
described occur in two or three places to the east and south-east
of Cambridge. From the gravel on the top of the Gogmagog
hills, 1 have found rolled masses of granite and porphyry ;
pebbles resembling those imbedded in the new red sandstone ;
masses of trap and mountain limestone; and a fine series of
specimens derived from the oolitic formations. Masses of gravel
ofa nearly identical character lie scattered over several parts of
the downs of Suffolk and Norfolk.* We must not imagine that
the instances here given are indications of mere local operations.
The gravel about Cambridge not only agrees in general charac-
ter, but almost forms a continuous mass with the beds of gravel
which are spread over many parts of the counties of Bedford-
shire, Huntingdonshire, and Northamptonshire. And _ the
patches of coarse diluvium which are scattered over the downs,
are connected with a series of operations which have buried
nearly the whole county of Norfolk and the greater part of the
county of Suffolk under enormous masses of diluvial debris.
Effects such as these are utterly beyond the reach of any known
natural agent.

Plains of Cheshire and Derbyshire Hilts, &c.

II. I intentionally pass over all details connected with the
history of the transported materials in the great plain of the new
red sandstone, and shall content myself with stating, that enor-
mous masses of diluvium extend from the base of the great
oolitic terrace through many parts of Leicestershire and Staf-
fordshire, and through almost every part of the plains of
Cheshire. The diluvial wreck of this region is found at all levels,
for it is seen on the upper part of Charnwood forest as well as in
the neighbouring vallies; and transported bowlders of consider-
able magnitude occur at the very top of several parts of the

* For some further details connected with this subject, see Prof, Hailstone’s paper in
the Geol. Transac, vol. iii. p. 244.

26

Derbyshire chain which overhangs the great plain of Cheshire.
For example, many large smooth bowlders of primitive or tran-
sition rocks lie seattered over the surface of the ground on both
sides of the high pass leading from Buxton to Macclesfield.
These facts speak the same language with those which [ have
already quoted. ‘They show the generality of the causes which
have produced the superficial detritus; and they prove that their
operations have not been confined to the lower parts of our

island.

Western Moors, Central Plains, and East Coast of Yorkshire.

II. In my former paper I briefly noticed the great accumula-
tion of coarse gravel on the plains which skirt the western moors
of Yorkshire. Had this gravel been formed by a number of
lakes which were once pent up among the mountains, and after-
wards burst their way into the lower regions of the district, we
might expect to find traces of such lakes in the interior of the
moorlands, and distinct heaps of gravel Be: the devastations
produced by the discharge of the successive lakes into the plain
of the new red sandstone. We, however, find no indications of
such lakes; and the diluvial rubbish is spread out almost
uniformly over the central plain by some cause which appears to
have acted simultaneously, and which has left traces of its
sore from the southern extremity of Yorkshire to the mouth
of the Tees.

Every part of the Yorkshire coast and whole neighbouring
region. bearf witness to the operation of similar causes. The
numberless valleys of denudation in the eastern moorlands—the
immense accumulation of transported materials on the hills as
well as in the valleys—the whole contour of the vale of Picker-
ing—the enormous cap of diluvium containing rounded masses
of primitive rocks many tons weight, and resting on the chalk
hills near Flamborough Head—the external form of the Wolds
—and the continuous mass of di/wvium extending from Bridling-
ton to Spurn Head, and from the chalk downs to the sea, are
so many monuments of the gigantic powers which were let loose
upon the world during the epoch of the diluvial gravel. In the
summer of 1821, Thad an opportunity of examining all these
ote in detail; and I can bear unqualified testimony to the

aithfulness of the descriptions given of them by the author of
the “ Reliquie Diluviane.”*

The diluvium of Holderness is of great interest, partly from its
immediate connexion with a series of operations which have
affected all the neighbouring districts ; partly also from its occu-
pying the whole line of coast, and from its enormous thickness,
which enable us to examine with detail all the circumstances

* See the “ Reliquie Diluviane,” p- 191, 194.

27

appearing to throw light upon its agit In many places
where it occupies a succession of lofty cliffs, it puts on a rude
appearance of stratification, or at least may be subdivided into -
separate masses which possess distinct characters.

The lower part of the cliffs, to the height of about twenty
feet, generally consists of a stiff bluish clay, which in many
places passes into a dark brown coloured loam.* Through the
whole of this mass are imbedded an incredible number of smooth
round blocks of granite, gneiss, greenstone, mica slate &c. &e. -
resembling none of the rocks of England, but resembling speci-
mens derived from various parts of the great Scandinavian
chain. Irregularly mixed vie the preceding are found, in per-
haps still greater abundance, fragments of carboniferous lime-
stone, of millstone grit, of lias, of oolite, and of chalk, torn up
from the regular strata of the country, and driven into their
present situation by a great eastern current which has left its
traces on every part of the neighbouring district. In regard to
the imbedded fragments above-mentioned, two things appear to
deserve notice. 1. They exist in equal abundance in the upper
as well as in the lower portions of the diluvialloam. This fact,
though difficult of explanation, has been remarked in other simi-
lar deposits, and seems to prove the gigantic nature of the
forces by which the materials have been drifted into their
present position. 2, The bowlders derived from distant coun-
tries are rounded by attrition; but those which are derived from
neighbouring rocks are little altered in form. The hard Norwe-
gian rocks are smooth and spheroidal, but the fragments of
oolite and lias, and still more the fragments of chalk, are often
sharp and angular.

Over the preceding deposit come a set of beds of sand and
comminuted gravel, very variable both in their structure and in
their thickness. They seem to have been formed by a longer
continued and a less violent action than that which produced
the diluvial loam on which they rest.+

Over the sand and gravel we may sometimes find traces of
ancient turf-bogs and of other alluvial deposits, formed in situa-
tions which were once in the interior of the country; but are
brought into their present position by the encroachments of the
coast.

* Large grinders of the mammoth haye been found in several parts of this deposit,

+ Near Bodkingian there is a diluyial covering about sixty feet thick where we may
observe, 1. The clay and loam with large imbedded fragments; 2. The sand and fine
gravel; 3. Over the two preceding, and immediately under the vegetable soil, a bed
composed of rolled fragments of chalk and of chalk flints ; in some places cemented toge~
ther so as to form a hard conglomerate. This bed is diluyial, and must be ascribed to
the last action of the retiring waters. It may be traced to a considerable height on some
parts of the downs wiwem it rests immediately on the chalk ; and following the inclination -
of the ground, it descends towards, and at length covers, the ordinary diluvial deposits
abovementioned,

28

Lastly, over all the preceeding we find in many places a consi-

~~~ derable thickness of blown sand.

Such are the phenomena exhibited in the cliffs of Holderness,

The masses of transported materials on the top of the Wolds,
and still more the enormous masses which, on many parts of the
coast between Filey Bridge and Redcar, are piled upon the
regular strata to the thickness of 150 feet, admit of the same
general subdivisions as the déduvium of Holderness, and
undoubtedly belong to the same epoch. As we advance towards
the north, the fragments of chalk begin to disappear; and frag-
ments of magnesian limestone and of other rocks derived from
the county of Durham begin to be more abundant

Conclusions.

The following conclusions may, | think, be fairly deduced
from the facts srr stated. 1.'The diduvium of Holderness and
of the whole east coast of Yorkshire, is due to a set of causes
which have acted over the western moors, and over all the great
central plain of the county. 2. The diluvial currents which
aeaiat the gravel of Holderness were probably contempora-
neous with other more powerful currents which drove large
masses of primitive rocks from Scandinavia to the plains of
Yorkshire. And it seems probable that the same currents were
contemporaneous with those mighty Propeling forces which
have driven innumerable fragments of the Scandinavian rocks
over the great plains of Russia, Poland, and Germany.

Diluvium at the Base of the Cumberland Mountains, §c. &c.

IV. During the three last years, 1 have examined every part
of the great cluster of mountains which is bounded by the
valleys of the Lune and the Eden, and by the western coast
from Moricambe Bay to Solway Firth. On its eastern side, this
region is united with the great central chain of England ; but on
all other sides through three-fourths of its circumference, it is
skirted bya succession of plains, or lands of low elevation, which
are almost entirely buried under accumulations of diluvial
matter. From the foot of Staimmoor to Solway Firth, through
the whole plain of the new red sandstone, the incoherent mate-
rials under the vegetable soil are spread over the greater part of
the surface, and are often of such an enormous thickness as
entirely to conceal all the subjacent strata. These accumula.
tions are not partial or irregular; but seem to have been rolled
out over the surface of the country by an inundation which
acted at one moment over the whole district; and like all simi-
lar deposits, they contain an incredible number of large bowl-
ders, principally derived from the neighbouring mountains.

On approaching that part of the plain which borders on the
northern extremity of the hilly region, we meet with pebbles and

° }
il enns
. A. tA ,

29

bowlders which have been drifted across the Firth from the rocks
of Dumfriesshire; and in the diduvium still further to the south-
west, near the termination of the new red sandstone at Maryport,
the imbedded fragments of the transition rocks of Cumberland
become rare in comparison with the bowlders derived from the
opposite coast of Scotland. In the diluvial rubbish capping a
hill near Hayton Castle, about four miles north-east of Mary-
port, I found some large granitic bowlders resembling the rocks
of the Criffel. Among them was one spheroidal mass, the
greatest diameter of erhial was ten feet and a half long, and
the part which appeared above the ground was more than four
feet high.

Fron Maryport to St. Bees Head, the cliffs are occupied by a
succession of coal strata; and the diluvial phenomena, though
of constant occurrence, present nothing worth remarking in this

lace.
x West Coast of Cumberland.

From St. Bees Head to the southern extremity of Cumberland,
the region bordering on the coast is formed of one almost conti-
nuous mass of d¢/uvzwm, interrupted here and there by low hills
of blown sand, and by other recent formations. In this part of
the county, the cliffs are of a deep red colour, caused by the pre-
sence of innumerable imbedded fragments of the subjacent new
red sandstone. With these fragments, bowlders of granite, por-
phyry, and greenstone, are scattered through the whole diluvial
covering ; sometimes in such abundance as to give it the appear-
ance of a true conglomerate ; especially in places where, by the
infiltration of a new cementing principle, the whole mass has
begun to assume a coherent form.*

Some of the granite blocks imbedded in the cliffs are of great
magnitude. In the dilavial cliffs near Bootle, I found one of a
rude prismatic form which was twelve feet long, six feet wide,
and five feet and ahalf high. All specimens of this kind of rock
have been drifted to the coast from the granitic region which
extends from Wastdale foot, through Muncaster félf to the
neighbourhood of Bootle; and occupies a part of Wastdale
Head, and all the lower parts of the valleys of the Mite and the
Esk.

Diluvium of Low Furness.

If we cross the estuary of the Duddon to the shores of Low
Furness, we find an exact repetition of the phenomena we have

* When these diluvial conglomerates are not seen in situ, they may be separatéd
from the older conglomerates by the freshness of their imbedded pebbles. Fragments
imbedded in the older conglomerates are generally in a state of decomposition, which
appears frequently to originate in a similar cause to that which so often produces decom-
td in crystals after they have become coated over by a deposition of newer crystal-
ine matter.

Ld

30

left behind. All the country bordering on the western shore is
covered by an enormously thick deposit of red coloured diluvial

ravel containing innumerable rolled fragments of rocks derived
Five every part of the lake mountains ; andall the neighbouring
islands are composed exclusively of the same materials. A
rolled mass of Eskdale granite, which had been imbedded in
the highest portion of the diluvial cliff near Rampside, fell
down upon the strand in the year 1822, It rose nine or ten
feet above the rubbish in which it was at that time partially
buried. At the base of the cliffs of the isles of Barrow and
Foudrey, among innumerable bowlders of granite, and of other
Cumberland rocks, were some specimens of a beautiful variety
of compact felspar which f afterwards found 7 si/u near the top
of Sca-fell and Bow-fell.*

In places where the inferior strata are so completely concealed
it is impossible to ascertain the whole thickness of the diluvial
covering. In many parts of Low Furness, it must, I think, be
considerably more than 100 feet. Near Newbiggin, where they
were searching for coal in the year 1822, they passed through
60 feet of diluvial loam before they reached any rock in situ.

The phenomena above described have obviously been caused
by a violent rush of descending waters. Whatever forces may
have put these waters in motion, it is, | think, obvious, from the
facts already stated, that they have not acted partially, but
have swept over the whole cluster of the neighbouring moun-
tains.

Diluvial Deposits in the Mid Region of the Mountains, &c.

V. If the accumulations of diluvial gravel, such as have been
last described, were produced by descending currents which
brought fragments of rock down from the very crests of the
neighbouring mountains ; we may expect to find some traces of
such currents in the mid regions of the district between the
highest elevations and the surrounding plains. In such situa-
tions, for obvious reasons, we must not look for those accumula-
tions of diluvial loam which are extended over the lower country.
The transported materials will only find a partial lodgment, or
will appear in the form of scattered bowlders which poe propel-

* The direction in which the diluvian currents have swept over the western coast of
Cumberland, is plainly indicated by the immense accumulations of bowlders of Eskdale
ite in Low Furness, and in the whole cluster of the neighbouring islands, and would

ead us to expect the appearance of rolled masses of the same variety of rock on the
plains of Lancashire. Prof. Buckland states (Reliquie Diluviane, p. 199), that they
ave been drifted in great numbers over the plains of Lancashire, Cheshire, and Stafford-
shire. Ina description given by Dr. Hibbert. in the Edinburgh Journal of Science for
last April, of an interesting diluvial deposit containing granite bowlders which occurs
near Manehedters it is conjectured that the transported blocks are derived from the
os ae Dufton ‘near Appleby. Had the author been acquainted with the facts
above, he would probably have referred the bowlders in question tothe Eskdale

granite,

31

ling currents have left behind. Such is the case in the mid
region of the lake mountains, where innumerable scattered bowl-
ders give the clearest indications of the force and of the direction
of the torrents which have swept over it. Any thing like a
regular history of such phenomena would lead me into endless
details. One or two facts bearing upon the subject will be
enough for my present purpose. :

1, On the granitic hills which extend from Bootle into Eskdale
are many large bowlders derived from various parts of the green
slate formation. Among the rest are some specimens of a
striped hornstone, identical with the rocks immediately under
the crest of Sca-fell, the highest mountain in Cumberland.
These blocks are at present separated from the parent rock by
the deep valley of the Esk.

Carrock Bowlders.

2. Millions of large bowlders lie scattered over the hills
which form the north-west boundary of the mountainous region ;
but they are seldem sufficiently characteristic to enable us to
determine the exact spot from which they have descended. The
syenitic blocks of Carrock-fell, principally composed of hyper-
stene and compact felspar, may, however, be traced from the
diluvial loam and gravel of the plains, through the valleys and
over the hills of the mid region, to the very foot of the parent
tock. On the side of High Pike (near the path leading from
Nether-row to the lead mines) are innumerable bowlders of the
Carrock syenite. The largest (which is known in the country
by the name of golden rock) is 21 feet long, more than ten feet
high, and about nine feet wide. The back of Carrock, where
the same kind of rock exists in situ, is about two miles distant
from the great bowlder, and is at present separated from it by a
deep valley.

3. Rolled masses of the porphyry of St. John’s vale almost
cover the ground near Penruddock, and from thence follow the
course of the valleys of denudation which descend into the
Eamont. Blocks derived froma dyke of beautiful red porphyry
which traverses a part of the ridge to the west of Thirlmere, are
found scattered about on the lower part of the hills near Keswick.

Shap Granite.

4. Spherical bowlders of shap granite occur in great abun-
dance on the calcareous hills south of Appleby. Among
them I found one or two which were about twelve feet in diame-
ter. On the south side of the calcareous zone, the granite
blocks are incomparably more abundant; and on approaching
Wastdale Head (a few miles south of Shap), where the granite is
in situ, they literally cover the ground. Near Shap Wells there

is a rolled mass of granite fifteen feet long, ten feet. wide, and
eight feet high.

32

Bowlders on Kendal Fells, &c.

5, Equally striking examples may be found on the south side
of the mountainous region. On the flat tops of the calcareous
hills on the west side of Kendal are many rounded blocks, appa-
rently drifted from the green slate formation at the head of Kent-
meer and Long Sleddale. These calcareous hills are now
separated by deep valleys from every part of the slate formation.
Similar phenomena appear on several parts of the mountains
between Kendal and Sedbergh, and among the rolled masses
are a few bowlders of shap granite. The instances now given
are sufficient for my present purpose; for they completely bear
out the observations by ei, they were preceded.

Proofs of Diluvian Action at the Tops of the Mountains.
VI. It is stated by Buckland (Reliquie Diluviane, p. 221),

“ that all mountain regions he has ever visited bear, in the form
of their component hills, the same evidence of being modified
by the force of water, as do the hills of the lower regions of the
earth.” My own observations, as far as they go, confirm the
truth of this remark. Some of the highest mountains of Cum-
derland and Westmorland, which consist of a soft decomposing
slate, are as plainly modified by the action of denuding currents
as any of the secondary ridges of our island. We must, however,
remember that the earth’s surface has been ravaged by the action
of water during several distinct catastrophes, and that the pre-
sent modifications in the form of some of our mountain chains
may, therefore, have been effected during some epoch long ante-
cedent to that of the diluvial gravel. To prove that the floods
which produced the superficial gravel have swept over the tops
of the highest mountains, requires, therefore, more direct
evidence than that which is afforded by the external forms of
the mountains themselves.* [ think it has already been proved
that diluvian torrents have swept over every part of the Cum-
berland chain ; because we find water-worn masses, derived from
the highest elevations of the country, imbedded in the diluvial
loam which covers almost all the neighbouring plains; and
because we find large bowlders of the same rocks scattered over
many parts of the mid region of the mountains, in situations to
which they could never have been drifted by any less powerful
agent than that to which they have been ascribed. I may also
observe that the bowlders in question, at whatever elevation, are
all in the same state of preservation, and all appear, as far as we
can judge from their external characters, to have been produced
at the same epoch.

Admitting the fact that the waters of a great inundation have

* For the direct evidence offered on this subject by Prof. Buckland, see the “ Reli-
quie Diluviane,”’ p. 221—223,

>

33

swept over some of the highest elevations of the earth, it is still
obvious that true diluvial deposits must necessarily be of rare
occurrence near the crests of mountain chains. On this account
1 thought myself fortunate in being able to discover two or
three examples of such deposits among the mountains of Cum-
berland.

Sca-fell.

l. In the deep water-worn channels which descend from Sca-
fell towards Burnmoor Tarn, are great accumulations of detritus,
which, when I visited the spot in 1822, I considered to be
undoubtedly diluvial. These accumulations are apparently
connected with the transported blocks which are scattered over
the ground between Barnmoor Tarn and Wastdale Head, and
exactly resemble the detritus which still further down is accumu-
lated in the valley of the Mite.

Ridge, near Red Pike.

2. On the very top of the lofty ridge which separates the
valleys of Ennerdale and Buttermere, are most striking and
unequivocal proofs of the action of diluvian torrents. Between
Red Pike and Ennerdale Scaw, the top of the ridge is partly
composed of syenite, and partly of a soft variety of clay slate.
A smooth round-topped hill (called Starling Dod), composed of
the soft slate, forms the highest part of the crest between the two
summits before-mentioned. I was persuaded, before I ascended
this hill, that its singular form must have been produced by the
action of water; and on reaching its summit, which is about
2500 feet above the level of the sea, 1 found it covered with
water-worn bowlders of red syenite and other rocks drifted
from the more lofty eminences of the same ridge near Red Pike.
The same kind of bowlders are found near the top of Mellbreak,
a mountain which overhangs the west side of Crummock lake ;
and they may be traced on the sides of the water-worn hills, and
down the valleys which communicate with Loweswater and
Crummock foot; and from thence the descending currents have
drifted them into the lower regions of the district where they are
mixed with the diluvium of the plains.

Borrowdale Fells, &c.

3. Near the top of Glaramara, one of the mountain crests of
Borrowdale, and at the back of the Hay Stacks, near the top of
the ridge between Ennerdale Head and Buttermere, [ saw seve-
ral bowlders which had been caught among the serrated edges
of those rugged elevations. The transported blocks were not
of a kind to enable one to point out the spot from which they
had been drifted ; but their presence was enough to demonstrate
the former action of violent disturbing forces which had affected
the highest points of the mountain region.

34

‘lo account for such phenomena as those above described, b
the bursting of lakes, of the existence of which we have no
proof; and which, had they ever existed, could only have
existed at much lower levels, would be to adopt an hypothesis
contradicted by the very facts which it is intended to explain,
The condition of the transported blocks, their association with
others which have descended into the mid region, and their
identity with many other masses which are imbedded in the
diluvium of the plains, forbid us to ascribe their appearance to
any of the more ancient catastrophes in the physical history of
the earth. The conclusion then to be drawn from them is
obvious, and is in accordance with the other facts which have

been stated in this paper.

Directions in which the Shap Granite has been drifted.

VII. The great uniformity in the mineralogical character of
the rocks in many parts of Cnaibetionl, often prevents us from
ascertaining the direction in which the diluvial bowlders have
been drifted from their native beds. This difficulty we do not
meet with in following the blocks of Shap granite, as they can-
not be confounded with any other rocks in the north of England,
It has already been stated that they almost cover the ground in
many places near eM ; and that they have been lifted over the
escarpment of the carboniferous limestone, and drifted over the
hills near Appleby. I may now add, that they have been scat-
tered far and wide over the plain of the new red sandstone—
that they have rolled over the great central chain of England
into the plains of Yorkshire—that they are imbedded in the
diluvium on both banks of the Tees—and that a few straggling
blocks have, if I mistake not, found their way to the eastern
coast.

The passage of the same kind of granitic blocks into the
valley of the Kent is, if possible, still more difficult to explain
by the operations of any known agent. For the granite only
exists tm situ on the very outskirts of the mountain group, and
almost abuts against the calcareous zone near Shap wells. Yet
a set of gorges have been opened out of the higher and more
central parts of the group, through which the granite bowlders
have been driven (@n a direction exactly opposite to that in
which they have been already traced), and from which they have
not only descended in great abundance into the valley of the
Kent, but have also been drifted into a part of the ridge between
the Kent and the Lune. With these remarks on the extraordi-
_ nary directions in which masses of Shap granite have been
dnfted from their native bed, I terminate my observations on the
position and extent of the masses of incoherent detritus which
lie scattered over many parts of our island.

35

Concluding Remarks.

As the general result of the facts detailed in this and the pre-
ceding paper, we may conclude ~-that the floods which produced
the opal detritus swept over every part of England—that they
were put in motion by no powers of nature with which we are
acquainted—and that they took place during an epoch which
was posterior to the deposition of all the regular strata of the
earth, and prior to all known accumulations of alluvial matter.

We have evidence enough to justify us in extending the same
conclusions to every part of the European basin, and there is
some evidence which makes it probable that they may be
extended to the remotest parts of the earth’s surface. Indeed
the mighty disturbing forces which produced the accumulations
of diluvial detritus between the western extremities of Europe
and the central plains of Asia, must probably have acted with
sufficient energy to leave some traces of their power over every
quarter of the globe. On the continent of America the succes-
sion of formations seems to be very nearly the same with that of
our own country ; and over all the regular strata, there occur in
many places alluvial and diluyvial formations in every respect like
those of Europe, It is, therefore, to say the least of it, probable,
that the diluvial phenomena of Europe and America belong to
the same epoch.

The actual duration of the diluvian era, it is of course impos-
sible to ascertain ; for as the powers of the agent are unknown,
it is obviously impossible for us to form an estimate of the time
which was necessary to the production of such effects as are
visible on the earth’s surface. The facts which have been
detailed seem, however, to make it prebable that the floods
which produced the diluvial gravel were sudden and transient. :

In the present state of our information, we have certainly no
evidence to prove that all the highest elevations of the globe
were submerged by the diluvian waters; for the form of the
great mountain chains may have been produced by some more
ancient catastrophe, and we have no right to assume the exist-
ence of diluvial detviéus in parts of the world which have not
been examined, or which are inaccessible. We have, however,
direct evidence to prove, that the diluvian floods acted on some
of the highest points of Europe, and it is probable also that they
have acted on some of the highest parts of Asia.

As we are unacquainted with the forces which put the dilu-
vian waters iu motion, we are also, with very limited excep-
tions, unable to determine the direction in which the currents have
moved over the earth’s surface. Many parts of the north of

Jurope seem to have been swept over by a great current which
set in from the north. In some parts of Scotland there has been

36

a great rush of water from the north-west.* The details given
above, show that the currents which have swept over different
arts of England have not been confined to any given direction,
t may, perhaps, be laid down as a general rule, that the
diluvial gravel has been drifted down all the great inclined
planes which the earth’s surface presented to the retiring waters,

That the details given in the preceding papers tend, as far as
they go, to confirm the general argument of Buckland’s
“ Reliquie Diluviane” cannot admit of doubt. Indeed, the
facts brought to light by the combined labours of the modern
school of geologists, seem, as far as | comprehend them, com-
pletely to demonstrate the reality of a great diluvian catastrophe
during a comparatively recent period in the natural history of
the earth. In the preceding speculations, I have carefully ab-
stained from any allusion to the sacred records of the history
of mankind; and | deny that Professor Buckland, or any other
practical geologist of our time has rashly attempted to unite the
speculations of his favourite science with the truths of re-
velation.+ ,

The authority of the sacred records has been established by
a great mass of evidence at once conclusive and appropriate ;
but differing altogether in kind from the evidence of observa-
tion and experiment, by which alone physical truth can ever
be established. It must, therefore, at once be rash an unphi-
losophical to look to the language of revelation for any direct
proof of the truths of physical science. But truth must at all
times be consistent with itself. The conclusions established on
the authority of the sacred records may, therefore, consistently
with the soundest philosophy, be compared with tbe conclusions
established on the evidence of observation and experiment ;
and such conclusions, if fairly deduced, must necessarily be in
accordance with each other. ‘This principle has been acted on
by Cuvier, and appears to be recognized in every part of the
“« Reliquie Diluviane.”’ The application is obvious. The
sacred records tell us—that a few thousand years ago “ the
fountains of the great deep were broken up ”—and that the

arth’s surface was submerged by the waters of a general deluge ;
and the investigations of geology tend to prove that the accu-
mulations of alluvial matter have not been going on many
housand years; and that they were preceded bY a great ca-
tastrophe which has left traces of its operation in the diluvial
detritus which is spread out over all the strata of the earth.

* This is proved in an original and excellent paper, published by Sir James Hall,
in the Transactions of the Royal Society of Edinburgh, vol. vii.

See also the “* Religuie Diluviane,” p. 201—205.

+ See the Edinburgh Philosophical Journal, No. 22, p. 304.

4
"

.
ag

37

Between these conclusions, derived from sources entirely in-
dependent of each other, there is, therefore, a general coinci-
dence which it is impossible to overlook, and the importance
of which it would be most unreasonable to deny. The coin-
cidence has not been assumed hypothetically, but has been
proved legitimately, by an immense number of direct observa-
tions conducted with indefatigable labour, and all tending to
the establishment of the same general truth.

a

APPENDIX.

[The following account of the drainage of a part of the fen
lands bordering on the Wash of Lincolnshire, is principally
abridged from Dugdale on “ The History of Imbanking and
Drayninge,” chap. 54; and from “ Badeslade on the Naviga-
tion of King’s-Lynn, and of Cambridge.” It was imtended to
appear in the form of a note to the fifth section of a paper in
the Annals of Philosophy for April last; but it was not trans-
mitted to the Editors in time for the press. ]

A short account of the drainage of a part of the fens, bor-
dering on the Wash, during a period within the reach of au-
thentic records, will explain and confirm the assertion in the
text.* In the early parts of that period, the drainage was effected
in the following manner: 1, By the channel of the Witham,
which had nearly the same course which it has at the present
time. 2. By the Welland, which, after descending by Stam-
ford, Crowland, and Spalding, united with the waters of the
Glen in the estuary, north of Holland-fen. 3. By the Nene,
which, after passing Wansford and Peterborough, descended
by Whittlesea-meer, Ugg. meer, and Ramsey-meer to Benwick,
where it was joined by the Old West-water, one of the branches
of the Great Ouse ; from Benwick it flowed on the north side
of March and Doddington (which stand, if [ mistake not, on low
diluvial hills) to Upwell, where it was joined by the Welney
river, then the principal branch of the Great Ouse; and from
Upwell the united waters proceeded directly to Wisbeach,
anciently called Ousebeach. 4. By the Great Ouse, which,
after passing Huntingdon and St. Ives, descended to Erith (a
small village at the SW. end of the old and new Bedford
rivers) veében it divided into two branches. One called the Old
West-water ran to Benwick, as before stated, and there united
with the Nene. The other branch, now called the Old Ouse
(sometimes erroneously marked as the Old West-water), de-
scended by Cottenham fen, and was joined by the Cam a few
miles above Ely. After passing Ely, it was joined by the Mil-
denhall river; and it then passed, by the way of Littleport and

* See Annals for April, Editor’s note, sect. 5, qt TE

/

4
ns NLAL

38

Welney, to Upwell; where (as above stated) it joined the
waters of the Nene and descended to the sea at Wisbeach,
5, By the Little Ouse (then a very inconsiderable river),
which (after passing Brandon, and being joined by some small
tributary streams from the Norfolk side) fell into the sea a,
Lynn, In the preceding account, all the old artificial drains,
and several minute bifurcations of the rivers, after they reached
the alluvial delta, are intentionally omitted.

As early as the twelfth century, the accumulations of alluvial
silt near the mouths of the Welland and the Nene, caused a
great back-water; and in the early part of the thirteenth
century (by the great rise of the fen lands near the coast) the
out-fail of the waters by some of the old channels entirely failed,
During this time, the bed of the Little Ouse, not having been
silted up in the same manner, was much below the mean level
of the alluvial delta, extending through the mouths of the other
rivers above mentioned ; and a great drain was consequently
cut from Littleport Chair to Rebeck, making the first direct
communication between the Great and Little Ouse. The effect
was exactly what might have been anticipated. The waters
which had been pent up at a higher level descended with irre-
sistible force through this new drain into the channel of the
Little Ouse, and so escaped into the sea at Lynn. About this
time the out-fall at Spalding had so completely failed, that the
waters of the Welland found their way through the Catswater
into the Nene; and a new direction having been given to all
the currents, in consequence of the channel which was now
opened below the level of the ancient out-fall at Wisbeach,
the united waters of the Nene flowed back into the Great
Ouse through the Old West-water, through the Welney branch,
and through all the other cross drains of the country; and were
then conveyed by the new communication into the Lynn river.
In this way, for many years, nearly all the waters of the alluvial
delta, south of the Witham, found their way into the sea at
Lynn: and the river, which had formerly run between banks
which were not more than twelve perches asunder, was, aftei
the changes above described, more than a mile wide.

Many attempts were made to prevent this great discharge
of waters through the Ouse. In the year 1292, several dams
were constructed near Upwell, to prevent the influx of the
Nene. But they produced such ruinous effects on many parts
of the marsh lands, and on the banks of the Ouse as far as St.
Neots, that in 1532 they were ordered to be destroyed. For
many years afterwards, the great drainage of the delta was
effected nearly in the manner above described.

In the year 1490, the discharge by the Ouse was partially re-
lieved by a great cut (called Morton’s Leam) from Peter-
borough to Guyhirn near Wisbeach. This was intended to

39

convey the waters of the Nene direct to their old channel at
Wisbeach, but was never entirely effective before the year
1638: when Vermuyden, under eng Charles I. erected high
banks on each side of the Leam, and opened out a channel to
the sea. Since that time the Nene has continued to flow down
to the sea by Wisbeach.

Notwithstanding the indirect nature of the new drainage
which conveyed the waters of the Welland, the Nene, and the
Ouse, into the sea by the Lynn channel, the fens appear for
many years afterwards to have been in a good condition; a fact
’ which can only be explained by the low level of the great out-
fall. In course of time, however, the new channels began to
silt up, and new works became necessary. Of these works,
the old and new Bedford rivers were the most important, ex-
tending from Erith to Salters Lode, a distance of about twenty
miles. Soon after the year. 1648, when the new Bedford river was
completed, the waters of the Ouse were shut out by a sluice at
Erith from their old channel, so that they did not mix with the
waters of the Cam and its tributary branches, till they had
been conducted by the new drainage to Salters Lode. These
new works appear from the first to have been injurious to the
natural drainage of the Cam; for the floods of the Ouse by the
new passage reached Salters Lode much sooner than the floods
of the Cam; moreover, the bottom of the new Bedford river
was about eight feet above the bottom of the old Ouse. On
both these accounts, the banks of the Cam were perpetually
flooded by the back-waters of the Ouse. One great flood of
the Ouse in 1720, is said to have backed up the Cam for twenty
days, and to have silted up a part of the old channel below
Ely, to the thickness of three or four feet. These ruinous effects
have been partly counteracted by the erection of different
sluices ; which, although affording a cure for an immediate evil,
have ultimately produced the very evil they were intended to
remedy; for, partly by their agency, the whole bed of the Cam
is now silted up to the level of the Bedford rivers.

If such extraordinary effects as those described in this note
be produced by the accumulation of alluvial matter in course
ofa few hundred years, we may be well assured that the whole
form of the neighbouring coast must have been greatly modified
by the same causes acting without interruption, and without any
modification from works of art, for 3000 or 4000 years.

Printed by C. Baldwin, New Bridge-street, London.