RECORD: Buckland, William. 1821. Considerations of the evidences of a recent deluge. Transactions of the Geological Society of London 5: 516–44.

REVISION HISTORY: Transcribed (single key) by AEL Data. RN1

NOTE: This work formed part of the Beagle library. The Beagle Library project has been generously supported by a Singapore Ministry of Education Academic Research Fund Tier 1 grant and Charles Darwin University and the Charles Darwin University Foundation, Northern Territory, Australia.

[page 506]

XXVIII. Description of the Quartz Rock of the Lickey Hill in Worcestershire, and of the Strata immediately surrounding it; with considerations on the evidences of a Recent Deluge afforded by the gravel beds of Warwickshire and Oxfordshire, and the valley of the Thames from Oxford downwards to London; and an Appendix, containing analogous proofs of diluvian action. Collected from various authorities.



[Read December 3, 1819.]

IT was long ago observed by Dr. Kidd, and is mentioned by Mr. Playfair, that the Lickey Hill (Plate 36), between Birmingham and Bromsgrove, in Worcestershire, is the nearest source to which it is possible to trace the origin of the siliceous pebbles which are accumulated in immense quantities over the plains of Warwickshire and the midland counties, and which are found also on the summit of some hills in the neighbourhood of Oxford, and in the valley of the Thames from Oxford downwards to its termination below London. But as neither of these gentlemen had leisure to ascertain the extent and circumstances of this hill, and as its occurrence here is attended with many curious facts calculated to throw light on the geological history of the surrounding country, I undertook its examination with Count Breunner, of Vienna, in the summer of 1819,

[page] 507

and beg to lay before the Society the following results, which with his assistance I was enabled to obtain.

I shall designate the ridge of hills which more peculiarly demand our attention by the name of the Lower Lickey, to distinguish it from the more elevated range of the Bromsgrove or Upper Lickey, which overhangs it on the south-west, forming the highest summit and great land-mark of the surrounding country. This Bromsgrove or Upper Lickey range stretches from north-west towards south-east, at the distance of about eight miles from the bed of the Severn, and, divides the upper part of the vale of Worcester from the more elevated plains of Birmingham; having its north-west termination in the Clint and Hagley hills near Stourbridge, and being continuous thence south-eastward to Tardebig, on the east of Bromsgrove, whence it stretches by Feckenham forest to the Ridgeway on the west of Alcester, and there slopes off into the vale of the Avon above Evesham. It will be seen by reference to the annexed map, that the road from Bromsgrove to Birmingham crosses nearly at right angles through both the Upper and Lower Lickey ridges, and in the valley between them is an inn, from which their examination may be conveniently conducted.

The Upper Lickey ridge is composed chiefly of sand and loose sandstone, belonging to the new red sandstone, or red rock marl formation; and some of its strata are extensively charged with pebbles that agree in substance with the quartz rock of the Lower Lickey, and are mixed with other pebbles of common white quartz, black and variegated jasper, flinty and chloritic slate, many varieties of porphyry, and of grey and variegated compact and granular sandstone. Similar pebbles are also accumulated in vast abundance on the surface of these sandy strata, forming thereon irregular and unstratified masses of diluvian gravel, which being in some cases

[page] 508

derivative from, and similar in substance to, the regular beds immediately subjacent, it is not always easy to distinguish those portions of the latter, which are highly loaded with pebbles, from the diluvian gravel. In this gravel there occur also large boulders of chert, with casts of entrochi, and large blocks of various kinds of porphyry, which latter are most abundant towards the bottom of the hill near Bromsgrove.

The Upper Lickey range, in that part which is intersected by the turnpike road, is composed wholly of new red sandstone and superficial gravel; in other parts it contains also strata belonging to the old red sandstone formation, and affords quarries of the calcareous breccia called cornstone, in several places further westward, along the slope and base of its east frontier. The line of this frontier appears to have been the scene of great disturbances at a period antecedent to the deposition of the new red sandstone.*

Subjacent to this ridge is that of the Lower Lickey, and the most advantageous position for seeing its connection with the surrounding country is the crest of the Upper Lickey, which overhangs it with an escarpment facing nearly the north-east. Its appearance from hence at once marks it to be composed of materials wholly different from any other rock in the neighbourhood. A narrow ridge of camel-back'd hills rises suddenly in the plain beneath us, presenting on a small scale the wavy and pointed outline of a chain of primitive or transition formations, and extending in a straight line about two miles from north to south, whilst the greatest breadth of its base scarcely exceeds a quarter of a mile; it is intersected

* Quarries of corn-stone are wrought to obtain lime for agriculture at four or five spots about three miles north-west of the Lower Lickey, between the village of Frankley and the base of the Clint and Hagley hills, on the south side of the road that leads from Hagley to Hales Owen.

[page] 509

from the summit to its base by four transverse vallies, which contribute to give the camel-back'd appearance to the intermediate eminences, and on the side of the high road which passes through a winding defile formed by the most easterly of these vallies, are quarries that afford the best and almost only sections in the whole ridge.

The surface of these hills is barren and scantily clothed with heath, through which the rock occasionally protrudes in a state of perfect nudity and sterility. Their interior is composed principally of semi-transparent quartz, having disseminated, and as it were floating throughout its substance, small crystals of red and yellowish felspar, which is usually in a state of decomposition. The quartz is stratified in beds varying from an inch to many feet in thickness; and where thickest, often losing all traces of the minor lamin?which generally pervade it. In great part of the rock, however, the planes of the strata are distinctly visible; they are separated by thin laminæ of soft argillaceous slate, highly micaceous, and of a reddish colour. Mica is rarely found disseminated with the felspar crystals through the quartz, but angular flakes and irregular lumps of decomposed yellow felspar abound wherever the slaty laminæ enlarge themselves to any degree of thickness exceeding a quarter of an inch. Similar felspar is also found in most of the larger interstices, and occasionally in minute fissures, that divide the quartzose strata in lines parallel with their planes, and split them into millions of small angular fragments of irregular form, so that it is scarcely possible to find a solid block of one foot in diameter, except in those cases where the felspar is sufficiently tenacious to hold together the quartzose fragments in a kind of breccia. Most frequently these interstices are entirely empty, and the rock, in consequence, falls immediately into small pieces on being moved from

[page] 510

its native bed, so that without artificial fracture it is applicable at once to the purposes of small gravel. These quartzose fragments, into which the entire rock is as it were shattered, are of extreme hardness, and vary in substance from compact transparent glassy quartz to an opake coarse-grained sandstone. An intermediate state between these extremes is however most frequent, presenting on fracture a subgranular structure, the grains being usually more brilliant than the siliceous matrix in which they are set; but the gradation from this state into the two extremes is so insensible, that it seems almost impossible to consider those apparent grains of sand to be any thing more than concretions bearing the form of rounded fragments.

The dip of the strata, where it is most distinct, in the great quarry by the road side, is 30° south-west; at another opening towards the south extremity of the ridge, and near a small projecting mass of trap-rock, they are considerably contorted and bent backwards, but the sections are too few to give any correct idea of the general dip of the whole ridge.

The trap rock just mentioned in substance approaches to the nature of wacke, and occurs precisely at the base of the south-east extremity of the quartzose ridge; but it is so totally covered with soil and grass, that neither its extent nor relative position can be accurately ascertained: it is visible only in two or three small fields, in one of which there occurs also an old quarry of transition limestone, exactly similar to that of Dudley; but its relative position to the older rocks is marked by no decisive section, and its extent seems limited to the single spot just mentioned. Immediately at this point, where the limestone, trap, and quartz rock appear thus confusedly crouded together, the new red sandstone sets on, and throws an impenetrable veil over them all.

[page] 511

The trap is found only at the south-east extremity of the ridge of quartz, but the transition limestone appears once more towards its north extremity, at a place called Colmer's farm, and at the distance of three-quarters of a mile eastwards from the quartz; here again there is no section to guide our conjectures, and we find the space intermediate between the limestone and quartz rock occupied by an insulated patch of coal measures, whilst on the north-east side of Colmer's farm there are quarries of old red sandstone, containing subordinately calcareous beds of cornstone.

On the west side of the ridge of quartz, dividing it from the Upper Lickey, is a triangular valley containing coal measures, which, like those of Colmer's farm, have never yet been wrought on any extensive scale; but there is no section which affords any decided evidence of their dip; the valley being inclosed by the high ridge of quartz projecting suddenly on its east frontier, and the still higher escarpment of young red sandstone which overhangs it on the south-west, and being terminated southwards by the union of these two ridges at an acute angle. From this south point the new red sandstone sweeps round it at a low level, touching the east base of the Lower Lickey up to the spot where the Birmingham road emerges from the great defile, and thence retiring eastwards, so as to leave uncovered the coal and lime, and old red sandstone strata of Colmer's farm; so that the Lower Lickey, with its little group of attendant rocks, more ancient than the new red sandstone, is encircled on every side with an investiture of beds of the latter formation, abutting against and overlying, horizontally, the basset edges and inclined strata of the former. Beyond the north extremity of the Lower Lickey to the base of the Clint and Hagley hills, the country is composed of a fundamental rock of old red sandstone, having the new red sandstone ierrgularly and

VOL. V. 3T

[page] 512

unconformably strewed over it; but, from the similarity of colour and substance in the beds composing these two formations, it is impossible to trace accurately the precise limits of each, the only sections being at a few quarries where the cornstone is extracted from the old red sandstone, to be burnt to lime.*

*I have thought it expedient to apply the local term cornstone to a kind of breccia, known generally by that name in Herefordshire, where it is found perhaps more abundantly than in any other English county. It occurs in the form of subordinate strata in the old red sandstone, and its dip is always conformable to that of the marl or sandstone beds between which it lies. It is composed of marl and marlstone, filled with concretions of compact limestone, presenting the fracture and colour of mountain limestone, and varying in size from that of a pea to blocks of many tons, and sometimes spreading itself out into thick and compact beds, to the almost total exclusion of the marl. The knotted characters which these concretions assume resembles that of a conglomerate animal gland, and the small acini or kernels of which they are composed usually separate under the blow of the hammer. The transfusion of their outer portions and projecting points into the substance of the marlstone, shows them not to be fragments resulting from the destruction of any older rocks of transition limestone, but concretions of contemporaneous origin with the marlstone, in which they are imbedded. The marlstone itself also has occasionally a similar tendency to form concretions, in which the sharpness of the angles shows it to be quite impossible they could ever have been submitted to the process of rolling; and the appearance resulting from the union of the calcareous concretions with the marlstone, is that of an angular breccia, resembling in structure the vert antique, and some of the Sienna and African marbles; in which the fragments have never been submitted to the process of rolling.
From the tubercular knotted condition of these concretions, and the non-appearance in them of any traces of organic remains, we derive a character of high importance in distinguishing cornstone from a calcareous conglomerate which very nearly resembles it in the new red sandstone; the fragments in the latter case being most frequently rolled portions of transition and mountain limestone, which can be identified by their organic remains, and of which various truncated sections are presented on the circumference of the fragments. In those cases where they have been rolled only to a short distance from their native bed, the angles of these fragments have undergone a proportionally small degree of attrition. They occur sometimes loosely mixed with other pebbles and sand, and sometimes united into a firm breccia by a calcareous cement which is highly charged with magnesia, and which in the absence of the pebbles often enlarges itself into extensive beds of dolomite. This calcareous conglomerate occurs subordinately among the mixed pebble beds of the new red sandstone, and like all its other members is disposed in horizontal strata lying unconformably on the basset edges of rocks more ancient than itself, so that it may sometimes rest immediately on the edge of inclined strata of cornstone.
A good section, in which it may be seen reposing on the basset edge of a siliceous conglomerate belonging to the old red sandstone, has been described by Mr. Warburton and Dr. Gilby, in the Banks of the Avon below Bristol, and on the north-west of Kidderminster; at Bircwood Lime-works near Shatterford, there is a thick bed of cornstone, dipping at 45° and lying subordinately in the old red sandstone, near which the calcareous pebble beds of Tremplay Green (being the breccia of the new red sandstone) rest immediately on the edges of strata belonging to the old red sandstone formation.

[page] 513

The quartz rock of the Lower Lickey being thus skirted on each side by a small coal-field, and having on its east frontier two minute patches of transition lime, with a little trap at its south end, and a small portion of old red sandstone containing cornstone near its north extremity, is, together with them, completely insulated and inclosed by a vast extent of new red sandstone, abutting against and covering them up on every side, and dividing them from the nearest trap, lime, and coal formations at Dudley, on the north, at Shatterford near Kidderminster on the west, and at Abberly on the south-west, between which points these small fragments, though apparently so minute, form a valuable connecting link.* On the north-west of Dudley, the chain of these formations is again resumed in the little mountain group of the Wrekin, and in Caer Caradoc, where the quartz rock occurs under circumstances that leave no doubt as to its age and relative position.

As there has been a difference of opinion on this point, as far as relates to the Lickey quartz rock, some geologists considering it of the same formation with the millstone grit of Derbyshire, others thinking it a peculiar variety of the new red sandstone formation,

* I am informed there are the remains of some small neglected coal-works at Apsley heath, on the west of Tamworth; these probably form another link in the same broken chain of dislocated fragments and patches of coal-measures of which we have two cases before us at the Lower Lickey, and of which several examples occur on the west and north-west of Shrewsbury, near the edge of the new red sandstone.

3 T 2

[page] 514

and as there is no decisive section at the Lickey along its line of junction with any of the surrounding strata, we are fortunate in being able to supply this deficiency from the accurate and valuable observations of Mr. Aikin, on a rock which he considers absolutely identical with it at no great distance in Shropshire, where in the well known hills of the Wrekin and Caer Caradoc, the position of the quartz rock is, according to his observations (Geol. Trans. vol. i. p. 208, and Plate annexed) distinctly marked, extending along a considerable line intermediate between the soft grauwacke slate that flanks these chains on their south-east base, and the trap rocks that form their summits; their middle region or south-east slope being composed of quartz rock dipping under the grauwacke slate, and being identical with that of the Lickey in every circumstance of the most minute particulars of its character. Incumbent on the grauwacke slate along great part of this extent, is a thick mass of transition limestone, which terminates suddenly in the steep escarpment of Wenlock Edge overhanging the grauwacke slate, and facing towards the north-west;* the same limestone occurs also in a similar position on the south-east side of the Wrekin, and though it may perhaps be doubtful whether the quartz rock ought to be ranked in the class of primitive or transition formations, it is certainly more ancient than the youngest beds of the grauwacke slate, and probably referable to a place among the older members of the grauwacke formation.

* This soft variety of grauwake slate, which is often found in the neighbourhood of transition limestone, is commonly distinguished in Herefordshire by the name of water-stone, as it decomposes readily into a soft grey clay the surface of which is very tenacious of water. Near Abberley the appellation of mudstone is given to the same slate for similar reasons, and in the Shropshire Coal-field it is known by the name of Dye-earth. In a subsequent paper on the coal-fields of Somerset and Gloucester, I shall give it the name of transition limestone shale, and enter more at large into its history and relations.

[page] 515

At the south-east base of May hill, near Huntley, on the road from Gloucester to Ross, a few siliceous beds, exactly resembling the quartz rock of the Lickey, alternate with strata of coarse grauwacke; and on the summit of a slaty mountain called the Stiper-stones, a few miles west of Caer Caradoc and Church Stretton, there is a considerable mass of naked projecting ledges, composed of a coarse grained variety of this same quartz rock, which from the resemblance of its internal structure, has been sometimes mistaken for the millstone grit of Derbyshire. The same opinion has been entertained also with respect to the quartz rock of the Lower Lickey, and it must be admitted that it is possible to select from each of these formations individual specimens, the resemblance of which to one another is complete; but such resemblances are no proof of the identity in geological position, and I have before stated that the true place of the quartz rock we have been considering, appears to be towards the lower extremity of that series of depositions which are usually associated under the name of grauwacke formations.*

* Pebbles resembling those derivative from the quartzose rock of the Lickey, are by no means confined to the central parts of England; they occur also in Scotland and Ireland; the Hon. Wm. Strangways has found them mixt with the diluvium and large boulders of Petersburg and Moscow. He has also found a native rock at Olonetz, on the Ladoga lake, and another in Catherineburg, from which they may have been derived. The rock at Olonetz being adjacent to the transition strata of the neighbourhood of Petersburg, is probably referable, like that of the Lickey, to the grauwacke series. I have myself found them abundant between Basle and the south extremity of the Vosges, scattered over the surface of the low hills that lie on the east of Altkirk; these are probably derived either from the neighbouring mountains of the Vosges or the Black Forest.

[page] 516

Considerations on the Evidences of a Recent Deluge, afforded by the Gravel Beds, and state of the Plains and Vallies of Warwickshire, and the North of Oxfordshire; and of the Valley of the Thames from Oxford downwards to London.

The extent of the quartz rock of the Lower Lickey, with its attendant fragments of other formations which I have been describing, is altogether so very inconsiderable, that I should have scarcely deemed it worthy the attention I have paid to it, had it not derived much greater importance from the wide dispersion and vast abundance of its ruins. The quantity of wreck we find dispersed over immense tracts of country, under the form of completely rounded pebbles of granular quartz rock, exactly similar in substance to that of the Lower Lickey, warrants us in assuming that there has been an extensive destruction of the masses from which these pebbles were supplied. Hence it seems certain, that before these pebbles were reduced to their present state, the quartz rock extended very far beyond the limits it now occupies, possibly so far as to be uninterruptedly connected with the beds of similar formation in the Caer Caradoc Group, in Salop; this and the Lickey Ridge being but residuary fragments of a once continuous chain, of which the intermediate portions have been broken down, and after violent attrition accumulated in the form of beds of pebbles in the lower

[page] 517

regions of the new red sandstone formation, to the entire bulk of which they often contribute no inconsiderable proportion.*

The pebbles thus imbedded in the regular strata are less exposed to observation than where they occur in their more common and obvious state of superficial gravel, having been again torn up from their lodgement in the new red sandstone, by the last diluvian waters, and spread over the surface of the plains of the midland countries in quantities that are quite enormous, and dispersed indiscriminately without reference to the age or substance of the rock which lies beneath them. At Cannock Chace in Staffordshire, and at Coleshill on the east of Birmingham, the accumulation of these pebbles is particularly striking; nor are these places far distant from the Shropshire chain of the Wrekin and Caer Caradoc, from which it has been suggested a large proportion of them may have been primarily derived; the rocks of Charnwood Forest might also be supposed to have supplied many of the slaty and porphyritic pebbles that are found mixed with those of quartz rock, without obliging us to refer their origin to the more distant mountains of Wales.

* A good example of these pebbles imbedded in regular strata of the young sandstone formation, may be seen three miles east of Kidderminster, on the road to Hagley, where beds of fine grained red sand alternate with others that are full of quartzose pebbles; they may be seen also in the summit of the hills which overhang the Severn on the east of Bridgenorth, and in those immediately south of Bewdly on the road to Stourport; and again in the deep section afforded by the road side immediately under the town of Nottingham. In the hill called Trempley Green, three miles north-west of Kidderminster, and at the quarries at Quatford and Alveley, between Kidderminster and Bridgenorth, are similar strata of siliceous pebbles, mixed with others that are calcareous, and forming with them a pudding-stone united by a strong calcareous cement. The limestone pebbles contain fragments of anomi?and encrinites, and were probably derived from the transition chain of the Wrekin and Wenlock Edge, and broken down by the same disturbing forces that affected the neighbouring quartz rock, with the fragments of which they are intermixed. These calcareous fragments have been already alluded to in the notes on cornstone.

[page] 518

Similar masses of pebbles have been collected (See Plate 37) in enormous quantities along the plains subjacent to the great oolite escarpment on the north-east of Shipston on Stower in Warwickshire, particularly on the south of that town towards the escarpment of Long Compton Hill. The most common varieties here found are rounded fragments of compact granular quartz rock, and common white quartz, Lydian stone, gneiss, porphyry, compact felspar, trap, sandstone of several kinds, lias, chalk, and chalk flints.

Between Shipston and re ton in the Marsh, they have been drifted into a kind of bay, formed by the horn-shaped headland of the Campden Hills, projecting like a pier-head some miles beyond the ordinary line of termination of the escarpment of the great oolite formation of the Cotswold Hills. The mouth of this bay opens directly to the north-east, from which quarter it is probable the current which brought the pebbles had its direction; for on the south-east of Shipston there are pebbles of hard red chalk, such as occurs not unfrequently in the Wolds of Yorkshire and Lincolnshire, but is never met with in the chalk of the south or south-east of England. The nearest possible point therefore to which these pebbles of red chalk can be referred, is the neighbourhood of Spilsby in Lincolnshire, whence a current flowing from the north-east would find an unobstructed passage across the plains of Leicestershire to the Bay of Shipston, and Moreton in the Marsh. With these pebbles of red chalk are others of hard and compact white chalk, such as accompanies the red chalk in the two last mentioned countries, and will be shewn in the appendix to occur also at Ridlington in Rutlandshire.

The diluvian current thus impelled into the Bay of Shipston, from the north-east, appears to have continued its course onwards beyond the head of this bay, near Moreton in the Marsh, bursting

[page] 519

in over the lowest point of depression of the great escarpment of the oolite; and being deflected thence south-eastwards by the elevated ridge of Stow in the Wold, to have gone forward along the line of the vale of the Evenlode by Charlbury, till it joined that of the Thames at Ensham, five miles north-west of Oxford. (See Plate 37.)

This hypothesis affords the most satisfactory explanation of the origin of the great deposits of quartzose pebbles which not only cover irregularly the lower regions of the valley of the Evenlode, but are scattered abundantly over the surface of the oolite strata which rise to a considerable height, and form table-lands on both sides, that valley along its whole extent. It also accounts for the accumulation of beds of similar pebbles on the west and south of Oxford, upon the insulated and almost conical summit of Wytham Hill, and the ridge of Bagley Wood, by their position exactly opposite the mouth of the vale of the Evenlode, at its confluence with that of the Thames, at the very point on which the driftings evacuated from the former valley would be thrown up.* Being thus introduced within the escarpment of the oolite, and having passed down the vale of the Evenlode, into that of the Thames near Oxford, these pebbles may have been forced onwards by the retiring diluvian waters, and mixt up with the gravelly wreck of the neighbouring hills in each successive district along the line of the Thames, from the vale of Oxford downwards to the gravel beds of London, their quantity decreasing with the distance from their source; so that in Hyde Park, and at the Kensington

* Near this same point, pebbles of clear rock crystals occur scattered over the surface at Ensham Heath, and are applied to the purposes of jewellery, like the Bagshot Heath diamonds, as they are commonly called, being merely similar small pebbles of the same substance.

VOL. V. 3 U

[page] 520

gravel, its quartzose pebbles, derivative by the course we have been tracing from the red sand strata of Warwickshire, occur less abundantly, though they are by no means unfrequent. They may be seen on the summit of the chalk hill immediately on the east of Henley and in the valley of Maidenhead, at Dropmore also, and in the gravel pits of Burnham between Beaconsfield and Windsor; in all these last named places the great mass of the gravel is composed of imperfectly rolled flints derived from the neighbouring chalk.

The occurrence of quartzose pebbles in such high situations as the top of Henley hill and Cumnor hill, and again on the highest summit of Witchwood Forest, and the elevated plains that flank the vale of the Evenlode above Oxford, goes far to prove the recent origin of the vallies through which the Thames and Evenlode now flow; and compels us to refer the excavation of them (at least in certain parts) to the denuding agency of the subsiding waters of the most recent deluge that has affected the earth. It seems that the first action of these waters drifted forward the quartzose pebbles within the great escarpment of the oolite, and strewed them over the then nearly continuous planes of strata belonging to that formation; and that the present minor vallies were subsequently scooped and furrowed out by the retiring action of the same waters whose advance drove on before them the pebbles we are now considering; for it is not easy to imagine any other solution of the fact of the pebbles being heaped together on the summit of the insulated, steep, and nearly conical hill of Wytham and the elevated ridge of Bagley Wood near Oxford, or on the highest crest of the oolite ridge of Witchwood Forest, or the chalky summit of Henley hill; unless we adopt that which supposes the excavation of the vallies immediately subjacent to these hills to have taken place

[page] 521

subsequently to the transport of the pebbles to their present situation on the highest summits. Nor is this hypothesis unsupported by the fact, that it is on the elevated plains that flank the vale of the Evenlode, no less than in the lower regions which form its present water-course, that the pebbles are scattered an almost uninterrupted line, marking distinctly the course by which, they have been propelled from Warwickshire into the valley of the Thames, descending along the back of the inclined and once continuous planes of the oolite strata that dip to the south-east, from their highest escarpment in the Cotswold bills.

There is another strong fact tending to prove the excavation of the vallies of the Evenlode and of the Thames near Oxford to have been subsequent to the transport of the Warwickshire pebbles, namely, the total absence of pebbles of oolite in the caps of Warwickshire gravel that crown the summits of Wytham Hill and Bagley Wood. Hence we may infer that the destruction of the oolite strata did not begin with the first rush of the advancing deluge, but was the effect of its subsiding waters returning to the lower levels, excavating combes and vallies on every side of the higher ridges, and covering the bottoms only of these with gravel composed of the wreck of the oolite strata immediately inclosing them, mixt up also with that which its rising waters had transported from more distant regions; and that the lower trunks of the vallies of the Thames and Evenlode, i. e. those portions of them which may be fairly attributed to the exclusive action of denudation, and which lie below the average level of the table-lands which flank their course, did not exist at the time of the first advance of the diluvian waters, which brought the pebbles in from Warwickshire, but were excavated by

3 U 2

[page] 522

the denuding agency which they exerted during the period of their retreat.*

It is here important to remark, that although the valley of the Evenlode from its commencement to its termination is thus strewed over with quartzose pebbles, the parallel valley of the Windrush, which is closely adjacent to it on the west, and separated only by the lofty ridge of Stow in the Wold, affords not a single pebble that is not derivative from the oolite strata by which it is inclosed: this arises from the circumstance of its upper extremities taking their origin entirely within the high escarpment of the elevated ridge of the Cotswold and Campden Hills, whilst an interruption of the continuity, or at least a depression of this escarpment at the head of the vale of Evenlode, has permitted the diluvian current from Warwickshire there to pass on without obstruction into the area of the oolite,† and bring with it the wreck of the districts over which it had advanced. In the upper part also of the valley of the Thames, from that part where the driftings of the Evenlode Gap have fallen into it above Oxford, to the sources of its many tributary streams, no traces of this gravel are to be discovered; nor is there any depression along the line of the Cotswold Hills on the west of Stow in the Wold, by which any such current as that which entered by Moreton and the vale of the Evenlode could have gained admittance.

* For a detailed and excellent description of the gravel beds of the plain of Oxford, I beg to refer to the preface of Dr. Kidd's Elements of Mineralogy, and to Chap. 17, of his Geological Essays.

† Although the oolite vallies which lie on the south-west of that of the Evenlode, are not strewed over like it with quartzose pebbles, they still afford equally convincing proofs of extensive and deep-cutting denudations taking their origin, not from a current rushing in over the high crest of the lofty escarpment that bounds their upper extremities, but simply from the weight and force of an immense volume of water subsiding within it from higher to lower levels along an inclined plane composed of uniform and moderately yielding materials. Any irregular projections that might have existed on such a plane would cause the waters to descend with accelerated velocity over the intermediate depressions, and to excavate that series of sweeping combes and vallies that wind with the regular flexures of a meandrous river, and present masses of land alternately advancing and retiring with all the uniformity of the salient and re-entering angles that usually mark the course of running water.
Striking examples of such, vallies extending upwards far above the highest spring that take their rise in them, and forming vast diluvian furrows along the back of the inclined planes of the great oolite formation, may be seen in passing along the line of the Roman Fossway, from Bath to Stow in the Wold: this line, being parallel to that of the great escarpment of the Cotswold Hills, crosses nearly at right angles all the vallies that descend from them towards the south-east, into the main trunks of the Thames or Avon; and in no part of this line are the features of diluvian action more strongly displayed than between North Leach and Stow in the Wold. It is obvious that such vallies can in no way be attributed to the action of springs or rivers that now flow through them, since they often take their origin many miles above even the highest springs; their magnitude and depth bespeak the agency of a mass of waters infinitely more powerful than even the most violent water-spouts of modern times could produce; their form also differs entirely from the deep and precipitous ravines which are produced by mountain torrents; and if it should be contended that the bursting of a series of water-spouts would be competent to set in action such masses of water as might have been sufficient to excavate them, unless we can suppose these to have fallen universally and contemporaneously, not only over the district under consideration but over the whole earth, they will afford no solution of the phænomena of these and similar contemporaneous systems of vallies which occur on strata that are similarly circumstanced in every part of the known world.
The chalk downs of England, and the upper portions of the chalky and oolitic plains of France, are universally covered with a series of dry vallies exactly similar to those that occur on the back of the inclined planes of oolite of the Cotswold Hills; and the uniform texture and moderate degree of inclination which usually attends both these formations will explain the regularity of the diluvian vallies that have been excavated on them, more especially near their most elevated regions, and terminating escarpments.
In strata of higher antiquity, that have been more shattered and disturbed by violent convulsions (i. e. in rocks belonging to the coal formation, and also in the transition and primitive rocks,) the irregularity in texture and disposition of the strata on which the diluvian waters had to exert their force, has caused the features of the vallies that traverse them to be in a much less degree derivative from the simple action of a retiring flood of waters; and indeed has rendered the form, inclination, hardness, and relative position of the masses on which they had to operate, essential elements of any accurate calculations of the quantity of effect they have produced; and though traces of diluvian action are most unequivocally visible in the features of every valley of the earth, we must not attribute the origin of them, all exclusively to that action. In such cases as we have been describing, the simple force of retiring water on the surface of gently inclined and regular strata of chalk and oolite, is sufficient for the effect produced; but in other cases, more especially in mountain districts, where the greatest disturbances appear generally to have taken place, the original form in which the strata were deposited, and the subsequent concretions to which they have been submitted, the fractures, elevations, and subsidence which have effected them, and their partial destruction at early periods by the violent actions of water, (of which the evidence is contained in the various beds of conglomerate that alternate with the secondary strata and transition rocks;) all these and perhaps, many other causes may have contributed to produce vallies of various age and form upon the surface of the earth, before it was submitted to that last universal and recent deluge, which has finally modified them all.

[page] 523

The excavations produced by the waters entering this lowest lip of the oolite escarpment near Moreton in the Marsh, have been so

[page] 524

great, that the head springs of the Evenlode, taking their rise from the lias strata in the vale of Moreton beyond the termination of the oolite escarpment, flow south-eastward toward Oxford (through the same gap by which the diluvian current drifted in the siliceous pebbles,) instead of falling by the course of the Stour to Stratford on Avon, by what, without this lip, would have been the natural drainage of the vale of Moreton; and it is of importance to observe, that the Evenlode and Cherwell are the only rivers of all those which flow down the back of the inclined planes of the oolite strata into the Thames, which have not their head-springs within this escarpment of the great oolite. The sources of the Cherwell and a few of its earliest tributary streams being similarly circumstanced to those of the Evenlode, are thrown out in consequence of similar denudations cut through die oolite strata into the clay beds of the subjacent lias, even as far down as the town of Banbury and village adjacent to it on the south.

The Warwickshire quartzose pebbles occur in the surface gravel

[page] 525

along this valley of denudation at Claydan and Cherwekon, near the sources of the Cherwell, having been drifted into this indenture or low lip of the oolite escarpment, though not in such quantities as those which entered by the vale of Moreton into that of the Evenlode, where the current was stronger in consequence of the projecting horn of the Campden Hills. The lowness of the oolite escarpment at the lip or gap above Banbury, appears still further from its having been selected as the point by which the Oxford Canal is conducted out into the sandstone plains of Warwickshire.

Miss Morland (to whose exertions in the cause of geology I am under extensive obligations,) has traced the Warwickshire quartzose pebbles mixed with chalk flints and slightly rounded oolitic gravel down the valley of the Cherwell, from Steeple Aston to Heyford, Rowsham, Kirtliagton, and Kidlington, four miles on the north of Oxford; at Kidlington there occur mixed with them numerous shells of gryphites rolled to pebbles and probably drifted in from the lias beds of Warwickshire. She has also found similar quartzose pebbles at Long Hanborough, in the valley of the Evenlode, and below Oxford in the plains that flank the valley of the Thames between Dorchester and Abingdon. In the Abingdon gravel pits, and also in Bagley Wood, there are pebbles of porphyritic greenstone and greenstone slate, usually decomposed and probably derivative from the neighbourhood of Mount Sorrel in Leicestershire.

If we examine the geological structure of that large portion of England which lies south-east of the line of the great escarpment of the oolite formation, along its whole extent, from the coast of Dorset to that of Yorkshire, we shall find in it no one stratum that has the smallest resemblance to the quartzose pebbles which are accumulated near Oxford, and over the other districts which I have

[page] 526

been describing; so that if they were not transported hither by the vallies of the Evenlode or the Cherwell, they must have come over some more elevated point of the oolite escarpment, and from some still more distant part of the red sandstone plains that traverse the centre of the island in a line bearing north-west and south-east, parallel and subjacent to this escarpment.

The probable history of these pebbles then is briefly as follows: Their native bed is the quartz rock of the Lower Lickey, Caer Caradoc and the Wrekin. From this they were broken down and rolled to pebbles, and buried in the new red sandstone, at the period of the deposition of that formation; from this lodgement they were again torn up by the waters of the last deluge, and dispersed by them over the surface of the various rocks on which they are now scattered. The exact identity of substance in the greater part of the pebbles with that of the quartz rock, to which they have been referred, affords a satisfactory corroboration of the hypothesis which has been suggested to explain their origin. They present the same glassy brilliancy of fracture, the same gradation from compact, through subgranular and granular, to sandy structure, the same small crystals of decomposing felspar disseminated throughout, and occasionally the same traces of lines of stratification, which characterise the quartz rock of the Lower Lickey and Caer Caradoc. We find with them several other varieties of pebbles, referable to the transition series, and occasionally to the coal formation; but these also accompany the quartzose pebbles in the beds of the young red sandstone, and are the wreck of rocks which suffered by the same destruction that affected the quartz; and thus we have pebbles of grauwacke, Lydianstone, flinty-slate, porphyry, porphyry-slate, trap, and many kinds of sandstone, dispersed over the oolite strata of Oxfordshire, as well

[page] 527

as imbedded in the pebble strata of the new red sandstone formation in the plains of the Midland counties.

Having endeavoured to establish an identity in point of substance between the quartzose pebbles of Warwickshire and Oxfordshire and the rock of the Lower Lickey, it only remains to mark one circumstance in the character of the latter rock which shews it to be particularly calculated to afford such pebbles as we have been attempting to trace up to it. This consists in the shattered condition in which the quartz occurs in its native bed; being a state calculated to afford the greatest possible quantity of pebbles at the least expense of time and friction, from the smallest bulk of rock destroyed: Whereas many rocks when broken fall into large solid blocks or tabular masses, the strata of the Lickey quartz rock are naturally cracked throughout into millions of small angular fragments of intense hardness, which barely adhere to each other, as they lie in their native beds, and fall to pieces on application of the smallest violence. A rock composed of materials so loosely set together, would be of all others the most liable to destruction by the action of currents that may at any time have been directed against it; and this circumstance may assist to explain the reason why so few portions now remain of a formation which the abundance of pebbles that have been derived from it, shews to have possessed at one time an extent by no means inconsiderable. It is almost impossible to conceive that the millions of pebbles which compose this gravel should have been derived from large blocks ground down to their present average size of a pullet'egg; and the presence of a rock in this neighbourhood which splits spontaneously into such minute fragments as have been described, supersedes the necessity of any such hypothesis. Thus we find in the Lower Lickey ridge and chain of Caer Caradoc, all the elements necessary for the

VOL. V. 3 x

[page] 528

solution of our problem of the origin of two distinct deposits of quartzose pebbles, the one in the new red sandstone formation, the other in diluvian gravel, they contain a mass of quartz naturally divided into minute angular fragments, and these fragments identical in substance with, and easily reducible to, the condition of the pebbles in question. The same force of water which would tear these fragments from their native beds, ought, if continued long enough, reduce them to their present state of roundness by simple attrition, at a period immediately preceding the deposition of the new red sandstone. And we have the analogy of rounded fragments of the older strata of each neighbourhood in other districts throughout England, from the conglomerate beds of Devon and Somerset, Gloucester and Glamorganshire, to those of Nottingham, Yorkshire, and the Valley of Carlisle, to prove the existence of an extensive and violent destruction of the earth's surface by water at the period of the deposition of the new red sandstone; and finally, we have the mass of gravel thus buried in the new red sandstone, and remaining in it undisturbed during the period of the deposition of the succeeding secondary formations, till it was again torn up by the water of the last great deluge, and scattered not only over the surface of strata composed of the same sandstone, but over almost all strata of all ages that occur in England.

When it happens, as it often does in the central plains of England, that masses of diluvian gravel, composed principally of quartzose pebbles, lie immediately on the regular sandstone strata containing subordinate beds of the same pebbles, it is not always easy to discover to which of these deposits the pebbles ought to be referred, the occurrence of a section is usually decisive of this point, and the discovery of a single fragment of any rock more recent than the new red sandstone, is sufficient to shew the mass to be not referable

[page] 529

to that formation; e. g. the presence of pebbles of lias and red chalk in the quartzose gravel near Shipston, shews it to be certainly of more recent origin than both these strata.

It appears certain, that the state of roundness which the quartzose pebbles have attained, has resulted from the friction they underwent before their first lodgement in the red sandstone; and if we had not decisive proof of this fact from the state in which we find them there imbedded, we should have difficulty in referring their rounded condition simply to the friction they have undergone by the act of transport from the Lickey or Caer Caradoc to the plains of Warwickshire, or even to Oxford. For it should seem the waters of the last deluge were of too short duration, or too tranquil, to produce on the fragments of rocks which were torn down and drifted by them, that greatest possible degree of roundness which is so universal in the quartzose pebbles we have been considering. Indeed instances are rare, where fragments even of soft rocks, which have undergone no further attrition than that of the last diluvian waters, have received that total and extreme degree of roundness which is found in the quartzose pebbles we are considering, and which is similar to what we now see produced by the long continued action of violently agitated water on fragments exposed to the waves on the sea shore. This fact is a strong proof of the short duration of the last deluge, and may be illustrated by the state of the angular portions of gravel on the plain of Oxford,* or in Hyde Park.

The same observations which have been made on the quartzose pebbles of the new red sandstone formation in Warwickshire, may be applied to the pebble beds of the plastic clay formation above the

* See Dr. Kidd's account and reasoning on the Gravel of the plains of Oxford, in the preface to his Mineralogy.

3 x 2

[page] 530

chalk, (the indurated varieties of which are well known as the puddingstone of Herts, their common state being that of the loose gravel beds of Blackheath). These pebbles are composed of chalk flints rolled to the same extreme degree as the quartzose pebbles of the new red sandstone formation, and having received their attrition at a period subsequent to the consolidation of the chalk, and long anterior to the last universal deluge. Both these pebble beds, formed at periods far distant from each other, have shared the common fate of all strata, in being broken up and ravaged by the waters of that deluge, and mixed with the angular gravel which was torn by them from rocks which had undergone no other previous attrition. And accordingly we find rounded pebbles derivative from the plastic clay formation mixt with the angular and imperfectly rolled chalk flints which constitute the great bulk of the London gravel; the latter having undergone no further attrition than that to which it was exposed during the short period of the last great deluge that has overwhelmed the earth.

In the gravel of the valley of Oxford we also mark the same distinction between angular and completely rounded pebbles; the fragments of the neighbouring hills being angular, and slightly rolled, and those only being completely rounded that can be traced up to ancient gravel beds, forming part of the new red sandstone strata of Warwickshire, the pebbles of which have been shewn to have received their attrition at an early period in the history of the revolutions that have affected the surface of our planet.

A difficulty occurs frequently along the base of a mountain chain, in marking the exact line which separates the deposits of post-diluvian detritus, which have been and still continue to be drifted down by wintry torrents, from that gravel which is strictly of diluvian origin. The bursting of an Alpine Lake (such as occurred

[page] 531

in June, 1818, in the valley of the Dranse in Switzerland), and the daily action of torrents and rapid rivers in times of flood, is competent to produce partially over a limited district beds of gravel somewhat similar to those of the great diluvian waters; striking examples of this kind are afforded in the Duchy of Venice, along the base of that part of the Alps which lies immediately on the north and north-west of the town of Valvasone, where the flood waters of the Tagliamento, the Meduna, and the Zelline, have strewed the plains to an extent of many miles from the base of the mountains with a beach of pebbles of enormous breadth, which in summer is dry and barren, resembling a naked Chesil bank on the sea shore. Similar features are presented by the Torre and Malina torrents on the north-east of Udina, and by the numerous torrents that descend into the plain of Lombardy from the mountains on the north of Verona and Vicenza. The Trebbia and Taro rivers also, and all the torrents adjacent to them, which fall into the Po from the south, near Parma and Piacenza, cover the lands in the vicinity of their courses with a similar and annually increasing accumulation of detritus, from that part of the Apennines in which they take their origin. And in our own country, the small river of Avon Lwyd or Tor Vaen, which descends from the west side of the Blorenge mountain in Monmouthshire, by the valley of Pontypool, presents, at the point where it leaves the mountains immediately below that town, a naked strand of pebbles, that is perpetually shifting and laying desolate the level regions that succeed immediately to the sudden termination of the steep and precipitous mountain valley, along which the torrent has its course above Pontypool.

At the point where transverse mountain vallies fall into the great ongitudinal vallies, we sometimes find a considerable talus-shaped

[page] 532

accumulation of post-diluvian gravel, partially filling up the diluvian gorge of the transverse valley, and protruding itself to a considerable distance into the main trunk of the longitudinal valley; many striking examples of this latter kind may be seen in ascending the passage of Mont-Cenis on its western side from Aiguebelle upwards. Here, at the termination or mouth of the transverse vallies that fall into the main valley of the Arc, immense talusses of gravel of modern origin project into the latter valley, being often incumbent on, and easily distinguishable from, subjacent beds of diluvian gravel, and sometimes protruding across the great longitudinal valley, so as entirely to obstruct it, with the exception of a small passage which is kept open by the present river, in the lowest edge of the talus. I have seen also similar examples well displayed at the mouths of the transverse vallies that fall into the main valley of the Kiszucza River on the Hungarian side of the pass of Iablunka, at the west extremity of the Carpathians. Deposits of this kind go on accumulating daily under our observation, and may, by careful investigation, be always distinguished from that gravel which is strictly diluvian, as the latter has also been shewn to be decidedly distinct from those more completely rolled pebble beds of antidiluvian origin, that occur among the regular strata which compose the crust of our globe, and which must be referred to periods of still higher antiquity, and long distant from each other, as well as from that last universal deluge which has overwhelmed the earth.

For the purpose of impressing more strongly this distinction. which I have drawn between diluvian and post-diluvian gravel, it will be convenient if geologists will consent to restrict the term diluvium to the superficial gravel beds produced by the last universal deluge; and designate by the term alluvium those local accumulations that have been formed since that period by torrents and rapid

[page] 533

rivers, and the bursting of alpine lakes, and similar minor causes which operate daily, and partially within the sphere of our own observation.

The Hon. Wm. Strangways, in a valuable Synoptic Table of the Formations near Petersburg, published by him during his late residence in that city, has adopted with great advantage this division between diluvian and post-diluvian formations; distinguishing them by the name of diluvium and alluvium. He dates the commencement of the alluvium from the period of the retreat of the last waters that have covered the earth, and includes under it—1, Drift sand marine, or inland; 2, Marsh land, composed of mud deposited by rivers; 3, Peat; 4, Calcareous tuf. All these formations are referable to causes that are still in daily action; under the term diluvium he includes the superficial gravel beds that lie indiscriminately on all strata of anti-diluvian origin, and are composed of a mixt detritus of pebbles, sand, and clay, torn down from formations of all ages, except alluvial, and also the blocks of granite and other fragments of primitive and secondary rocks, that are scattered over the plains and low hills of that part of the north of Europe, either mixt with the superficial gravel, or lying insulated in situations to which they must have been drifted from very considerable distances, as there is no matrix near them from which they could by possibility have been derived. He has omitted to mention beds of gravel produced locally by torrents and rapid rivers, because the flat condition of the district on which his synoptic table is founded, has allowed no gravel of this kind to be transported to so great a distance from the hills or mountains, from the daily detritus of which it is immediately derived.

A well digested and valuable comparative account of the mode of action and effect of rivers and mountain torrents, shewing that the

[page] 534

maximum of their force is wholly incompetent either to excavate the main trunks of the vallies through which they flow, or to produce the gravel beds that cover them at a distance from the hills and mountains whence this gravel has been transported, is given in chap. 20 of Dr. Kidd's Geological Essays, and in the second Essay of Mr. Greenough's Examination of the first Principles of Geology. The same subject has been treated with equal accuracy and ability by M. Brongniart in the latter part of his "Histoire naturelle de l'Ea" published in the 14th volume of the "Dictionaire des Sciences naturelles," and separately as a small pamphlet, which I strongly recommend to the attention of those persons who wish for correct information as to the effects produced by water upon the surface of our globe.

I have now only to add a few words on the organic remains found in the beds of diluvian gravel which we have been describing. In all the gravel pits of the valley of the Thames round Oxford, at Abingdon also, and Dorchester and Wallingford, and Hurley Bottom near Henley, teeth and tusks, and various bones of the mammoth or northern elephant have been found abundantly. There are in the Ashmolean Museum at Oxford, some vertebr?and leg bones of an elephant of enormous size, probably sixteen feet high, and in a delicate state of preservation, which were found in the gravel near Abingdon three years ago; mixt with these occur the bones of the rhinoceros, hippopotamus, horse, ox, hog, and several species of deer, often crouded together in the same pit, and not much rolled, although they are rarely, if ever, united in entire skeletons. Fragments of sixteen horns of deer were dug up lately within a short time in the same gravel-pit, with the great elephant's bones, near Abingdon. These bones are extremely soft and tender whilst they remain wet, and harden by drying. They not in the

[page] 535

least degree mineralised, and retain much of their animal matter.* In the collection of the late Mr. Catcot, in the City Library at Bristol, is the tooth of a rhinoceros found in the gravel-pits of St. Clement's in Oxford, and about two years since a large grinding tooth of an elephant was found in digging gravel in one of the streets of this city, near St. John's College; in London also in digging the grand sewer on the east of Waterloo-place, near Charles-street, at the depth of thirty feet, they found not long ago a similar tooth of the same species of elephant imbedded in gravel; and in a similar matrix at Kingsland near Hoxton, in the year 1806, an entire elephant's scull was discovered, containing two tusks of enormous length as well as the grinding teeth. They have also been found frequently at Ilford, on the road from London to Harwich; and indeed in almost all the gravel-pits round London these teeth are found of all sizes, from the milk teeth to that of the largest and most perfect growth; and in all the intermediate and peculiar stages of change to which the teeth of modern elephants are subject.

In Phil. Trans, for 1813, is a report of the tusk of an elephant nine feet long, and of other remains of the same animal, with those of hippopotamus, ox, and several species of deer, and the horn of an ox four feet and half in length, all of which were found by Mr. Trimmer in the gravel of the valley of the Thames near Brentford. Six tusks of the hippopotamus lay in an area of 120 yards. In all these gravel-beds no two bones lie in immediate contact with each other, and in very few cases are they rounded by attrition.

At Newnham in Warwickshire, near Church Lawton, about two miles west of Rugby, two magnificent heads and other bones of the

* For a farther detail of the gravel beds of Oxford, Wkham Hill, and Bagley Wood, and of the organic remains contained in them, I must again refer to chapter 17 of Dr. Kidd's Geological Essays.

VOL. V. 3 Y

[page] 536

Siberian rhinoceros, and three large tusks and teeth of elephants, with some stags horns and bones of the ox, were found in the year 1815 in a bed of diluvian gravel, connected with that which we have been speaking of near Shipston; this gravel is immediately incumbent on stratified beds of lias; it is composed of a mixture of various pebbles, sand, and clay, in the lower regions of which, where the clay predominates, the bones are found, at the depth of fifteen feet from the surface; they are not in the smallest degree mineralised. One of these heads measuring in length two feet six inches, together with one of the tusks, and a grinding-tooth of an elephant, have, by the kindness of Henry Hakewill, Esq. (of architectural celebrity) been deposited in the Radcliflf Library at Oxford. The other and larger head, with a tooth and leg-bone of the same animal, has been presented by Henry Warburton, Esq. to the Geological Society of London. Of the remaining tusks of elephants, the largest is in the possession of G. Harris, Esq. of Rugby, and the other of J. Caldecot, Esq. of Lawford. These tusks have all of them a considerable curvature outwards towards the point, like those of the fossil mammoth, or extinct elephant, which abounds in the gravel of Russia, of which one specimen was found with its flesh still entire on it, bedded in a mass of ice on the north coast of Siberia, and is now placed in the Museum of the Academy at St. Petersburg, with the dried flesh and skin still adhering to its head.

In the Ashmolean Museum at Oxford there is a similar head of a rhinoceros to those found near Rugby, of the same length and proportions with them, and also resembling that engraved in vol. 2 of Cuvier's Animaux Foss ties, at PI. 4, No. 12, in his chapter on Rhinoceros, and quoted by him as having been found at Lippstadt, in Westphalia, and being in the collection of Adrian Camper. It

[page] 537

appears to have been among the original collection of bones deposited in the Ashmolean Museum, but the place where it was found is not recorded. A fragment of another head of the same species of rhinoceros, fifteen inches long, is mentioned by Dr. N. Green, in p. 254 of his catalogue of the Museum of the Royal Society, (Anno 1681) as having been found at Chartham, near Canterbury. These all belong to the same extinct species of the double-horned fossil Rhinoceros of Siberia,* and appear to have been the contemporaries and compatriots of the extinct elephant or mammoth, which is found so abundantly throughout the northern regions of Europe, Asia, and America, and even in South America in the elevated plains of Peru and Quito, buried in diluvian gravel under circumstances in all respects so similar as to oblige us to refer their origin to a common cause, viz. the latest diluvian catastrophe that has affected the surface of our globe.

* The largest and finest head of this species of Rhinoceros which I have ever seen, has been sent to me lately from Siberia by Mr. J. Prescott, of St. Petersburg, whose kindness on this occasion has fortunately put it in my power to present, through M. Cuvier, to the Museum of the Royal Garden at Paris, a fossil which has hitherto been a desideratum in that rich and splendid cabinet. In the British Museum is a similar head, which was presented by the Emperor of Russia to the late Sir Joseph Banks.
I have lately received from Warwickshire an Os humeri and Os innominatum of Rhinoceros, in a state of preservation as perfect as if they had been dissected from a recent animal.

3 Y 2

[page] 538


As connected with my present subject, I beg to subjoin a few valuable notices on the superficial gravel-beds of the midland districts of Rutland, Leicester and Buckinghamshire, by the Rev. W. D. Conybeare, with further important observations of other gentlemen on similar depositions of diluvian gravel.

The gravel, accumulated in the midland counties of England, is considered by Mr. Conybeare to be a subject worthy of much more attention than it has hitherto received. These accumulations have been observed by him to extend over the plains that lie beneath the north-west escarpment of the great oolite chain, and also over the low tract between these hills and the north-west escarpment of the chalk of Bucks, Herts, and Bedfordshire; but they are more particularly abundant in the former position, where extending many fathoms in depth, they often effectually conceal the subjacent strata, and sometimes by their accervation constitute decided hills. Tracts pf this description are particularly abundant in the borders of Rutland, Warwick and Leicestershire. From Houghton on the Hill near Leicester, to Braunston near Daventry, proceeding by Market Harborough and Lutterworth, the traveller passes over a continuous bed of gravel for about forty miles; near Hinckley, great depositions of gravel, probably connected with this mass, are found, and afford pebbles containing specimens of the organic remains of most of the secondary strata in England; this deposition may probably be traced continuously to that of Shipston on Stour, most of the hillocks scattered over the lias and red marl tract between Southam and Shipston being crowned with this gravel.

[page] 539

These accumulations of pebbles, promiscuously heaped together, are composed of the wreck of rocks of the most distant ages, which exist in their native state only in distant quarters of the island; flints from the chalk formation, accompanied by rounded masses of hard chalk and fragments of the different oolite rocks, seem however decidedly predominant in Leicestershire; and next to these in quantity, are the granular quartz rock pebbles resembling those from the Lickey, with others of white quartz (apparently derived from veins) and dark coloured hard flinty-slate. It would however be not difficult in many places, as for instance on the west of Market Harborough, and in the valley of Shipston on Stour, to form almost a complete geological series of English rocks from among these rounded fragments, which often occur in boulders of very considerable size.

The immense quantities of fragments of chalk flints scattered in this gravel at such a distance from the present limits of the chalk, is a very observable circumstance, and seems decisively to indicate that this formation must once have occupied a much wider space than it does at present. Near Syrwell, six miles north-east of Northampton, on the oolite formation, are some fields as thickly strewed over with fragments of pure white chalk, as the surface of stony arable land is usually with the substance of the subjacent rock. Even as far as Derbyshire, chalk flints are commonly found dispersed over the surface of the country.*

* In the Phil. Trans. for 1791, an account is given of a quarry of chalk having been worked in Rutlandshire at Ridlington. The writer of it is evidently well acquainted with the character and general limits of the chalk formation throughout England; and his account is so very precise and bears so many marks of accuracy (specifying that the chalk is not soft but hard like that of Baldock, with rows of flints lying in it which are shattered and not so black as those in the south of England,) that the extent of the chalk near this quarry must be considered a subject worthy the examination of those geologists who may have opportunity of visiting this spot, where its limits have never been ascertained, and its distance from the great mass of the same formation renders its occurrence and circumstances deserving of further investigation. Its extent is probably very small, and it seems to present an interesting and valuable relic of the great mantle of chalk, whose distant outlying fragments which we find elsewhere, added to the enormous quantities of its wreck which are dispersed over the country in the form of diluvian gravel, shew it to have been once extensively spread out beyond the limits of its present area.

[page] 540

The accumulations of gravel on the low grounds between the oolite and chalk ridges along the valley of Buckingham and Bedford, and skirting the lower or south-east slope of the great oolite range, are almost exclusively composed of fragments of oolite and chalk; older pebbles being there very sparingly intermixed. Examples of this may particularly be seen at Wittlebury Forest in Northamptonshire and near Buckingham. The above observations on this subject, by Mr. Conybeare, are in perfect harmony with my own in other parts of England.

I am informed by Sir Joseph Banks, that he has observed pebbles of porphyry in the gravel used for repairing the roads on the north side of the town of Dunstable, near the escarpment of the chalk; these also are referable to the same era with those which have been traced along the vallies of the Evenlode and Thames from Warwickshire to Hyde Park, and are connected with the gravel which Mr. Conybeare has noticed in the midland districts. The occurrence of granite pebbles and other fragments of distant primitive rocks, which have been transported into the valley of the Seine, near Paris, is another fact precisely of a similar kind.

Mr. Farey, in his Agricultural Report of Derbyshire, gives a long and interesting list of the gravel patches in that county, from which it appears, that fragments of all the English formations from

[page] 541

granite upwards to chalk, are accumulated in the form of diluvian gravel on the surface of all the strata which constitute that midland part of England.

It is mentioned in a paper by Mr. A. Aikin, on the Gravel at Litchfield, printed in the fourth volume of the Geological Transactions, that he found near that town pebbles of granite, syenite, greenstone, schist, limestone, quartz, chalcedony and hornstone, all of which with the exceptions of the quartz have undergone considerable decomposition; amongst these the pebbles of corralline limestone are most abundant, and like those of the chert appear to have been derived from the mountain limestone of Derbyshire, and to have been accumulated at the same period with the gravel beds of Shipston on Stour, and of the valley of the Thames.

In a very able and ingenious paper by Sir James Hall, in vol. 7, of the Transactions of the Royal Society of Edinburgh, he has recorded his discovery of similar traces of the action of a diluvian current on the surface of the hills and vallies near that city. These districts are not only strewed over with the gravelly wreck of rocks that have been drifted to a great distance from their native bed by the force of violent waters; but Sir James has also observed channels and furrows, which he calls dressings, still remaining on the surface of the hard rocks over which these waters passed, driving before them blocks and fragments of every substance that lay in the line of their course, and excavating vallies of denudation analogous to those we have described in Oxfordshire.

Mr. Weaver, in his very valuable memoir on the Geology of the East of Ireland, at p. 294 of the present volume, has discussed the subject of the denudations there displayed, and the gravel produced by the retiring action of a subsiding mass of waters,

[page] 542

with a degree of ability that like the whole of his paper bespeaks the touch of a master's hand; his observations are important to our present subject, as adducing facts in strict unison with those which we have been tracing in England. Dr Richardson has also given important notices on the enormous affects of analogous denudations, in his excellent paper on the Basaltic Area of the North of Ireland, published in the Philosophical Transactions for the year 1808.

Mr. Greenough, in his examination of the first principles of geology, concludes his admirable summary of phœnomena derivative from diluvian action in all quarters of the earth, with the following passages, which are much too important to be omitted in this place. "The universal diffusion of alluvial sand, gravel, &c. proves that at some time or other an inundation has taken place in all countries, and the presence of similar alluvial deposits both organic and inorganic, in neighbouring or distant islands, though consisting often of substances foreign to the rocks of which the islands are respectively composed, makes it highly probable at least, that these deposits are products of the same inundation. The universal occurrence of mountains and vallies, and the symmetry which pervades their several branches and inosculations, are further proofs not only that a deluge has swept over every part of the globe, but probably the same deluge." He also shews it to be highly probable "that the order of things immediately preceding the deluge, closely resembled the present order, and was suddenly interrupted by a general flood, which swept away the quadrupeds from the continents, tore up the solid strata, and reduced the surface to a state of ruin: but this disorder was of short duration, the mutilated earth did not cease to be a planet: animals and plants similar to those which had perished, once more adorned its surface; and nature again submitted

[page] 543

to that regular system of laws which has continued uninterrupted to the present day."

In the works of Calcott and Hutchinson,* a mass of strong evidence is adduced and well set forth in proof of the agency of diluvian currents over large portions of the surface of this island.

De Saussure has recorded a valuable series of observations on the effects of the debacle, or breaking up and transport of rocks and gravel, produced by an enormous rush of subsiding waters in Switzerland. These effects appear to be only a larger feature of that same diluvian action which we have been tracing in the central parts of England, and which in that country are on a scale proportioned to the magnitude of the Alpine masses on which if had to exert itself. For the detail of these effects, I must refer to the author's own descriptions, and also to Sir James Hall's excellent paper in the Edinburgh Transactions before alluded to, in which he offers some most ingenious conjectures as to the probable mode by which the stupendous operations which have taken place in Switzerland were brought about.

In Buffon's History of the Epochs of Nature,† we find his description of the state of the vallies of France, and of their forms as derived from the excavating force of a retiring mas s of waters, to be in perfect harmony with those of the other writers whom I have been quoting, and to whose observation on their own countries, where they had opportunities of conducting the most accurate investigations, I would request all persons who feel an interest in this subject to direct their attention.

* See Calcott on the Deluge, 1768, and Hutchinson's Works, vol. 12.

† Vol. 12. p. 159. Deux Pont Edit. 1782.

VOL. V. 3 Z

[page] 544

But above all I would refer them to the opinions of M. Cuvier, expressed in his inestimable Essay on the Theory of the Earth, in which, after the most enlarged and philosophical view of the state of the question that has ever been taken, he concludes with expressing his conviction, "that if there be any one fact thoroughly established by geological investigations, it is the certainty of the low antiquity of the human race and present state of the surface of the earth, and the circumstance of its having been recently overwhelmed by the waters of a transient deluge."

These united authorities present us a mass of evidence collected from the highest sources that are accessible, all conspiring to establish the important fact, that accumulations of superficial gravel more modern than the most recent of the regular strata are found in all parts of the world, under circumstances of such exact resemblance, that it is impossible not to refer them to one and the same common cause, viz. a recent deluge acting universally and at the same period over the surface of the whole globe.

This document has been accessed 801 times

Return to homepage

Citation: John van Wyhe, editor. 2002-. The Complete Work of Charles Darwin Online. (

File last updated 18 March, 2014