# Quarterly Journal of the Geological Society of London/Volume 35/On a Mammaliferous Deposit at Barrington, near Cambridge

During the latter part of the summer of 1878 I heard from Mr. Griffith, of Christ's College, Cambridge, that large bones were being met with in a "coprolite-pit" at Barrington, on land belonging to Trinity College. Accompanying him there, we found the workmen had reserved for him fragments of three canines of a Hippopotamus, with some of the molars, a tooth of Rhinoceros, and other specimens. Further discoveries were made; and in September, when the work had been discontinued for harvest, I went there with two friends, and, armed with no tool better than a knife, obtained an excellent specimen of an incisor of the Hippopotamus. Upon this I advised Mr. Keeping, of the Woodwardian Museum, to get permission to commence a regular search for fossils, which, term not having commenced, and the Professor being in the country, he took upon himself the responsibility of doing, and through the kindness of Messrs. Smith and Badcock, the lessees of the coprolite-works, began a systematic exploration of the deposit. This was carried on after the Professor's return under his authority, and has been rewarded with great success.
The locality is easily recognized upon the Ordnance Map as being just south of where the final n in the word Barrington is printed. It is on the edge of a nearly level tract of ground at the foot of the hill between Haslingfield and Barrington, at an elevation of about 20 feet above the alluvial ground of the present stream of the Rhee. This tract of ground does not, however, form quite a flat terrace, but falls again very gradually northward towards the small streamlet, which, lower down, is crossed by the road near the church. The streamlet is not marked in the Ordnance Map, which wrongly represents the slope of the hill as extending to the lane which leads to the pit. The pit is nearly on the highest part of this tract; and consequently the bone-bearing deposit does not belong to the existing drainage-system, but, though at only a small altitude, may be still considered a high-level gravel.
The exposed section at present extends from north to south about 70 yards. The "coprolites" have been obtained in the deepest part at 22 feet. The section presents a superficial covering of soil and fine gravelly "trail," which, in the southern half, rests immediately on disintegrated chalk-marl; but towards the centre of the pit a thin bed of coarse gravelly silt with large pebbles comes in (see fig., p. 671), dipping slightly towards the north, and when it has descended to about 8 feet from the surface it rather suddenly expands downwards, forming a mass of grey gravelly silt, with many large stones towards the bottom, some of which may weigh from twelve to sixteen pounds. Above the stony bed the material is without large pebbles, otherwise of a similar character. Throughout these ​silty gravels bones and shells occur. Mr. Keeping carried his work a few feet further north beyond where the "coprolite-bed" runs out, and the base of the silt has there begun to rise.
Diagram of the northern end of Barrington Pit.
a. Trail of fine gravel in which are pits with ashes and bones. b. Grey gravelly silt with bones and shells. c. Chalk-marl. d. Greensand with "coprolites" (i.e. phosphatic nodules). e. Gault.
There is another smaller coprolite-pit, not yet quite filled up, lying a few yards to the south-west of the present one. It exhibits a little similar stony and gravelly silt, but in patches only, and not in situ as deposited, but forming pockets of "trail" with festoon-like arrangement and the axes of the pebbles not horizontal. Those remnants still existing in the "trail" in this southern pit, as well as the manner in which the deposit occurs in the first pit, show that the gravel is a portion of a more extended mass, of which the upper parts have been denuded away.
[Since this paper was read a similar deposit, equally rich in bones, was laid open for a short time half a mile further up the valley, opposite to the blacksmith's shop on the Green.]
The materials of which the bone-bearing deposit consists are peculiar. The matrix is a grey sand with a slight admixture of clay. The pebbles consist of flint in subangular pieces of no great size, sometimes ochreous, sometimes grey, sometimes black. These are not rounded, but have their surfaces worn, polished, and the angles rubbed off. There are rolled lumps of chalk-marl and a considerable admixture of "coprolites," as might be expected, seeing that the coprolite-bed is abraded by the deposit itself. The remaining pebbles are well-rounded pieces of crystalline rocks, consisting of quartz, quartzite, syenite, jasper, and trap. These old rocks contribute a large part of the pebbles, so that the material cannot be called a flint-gravel, in that it appears to consist of the least destructible parts of the Boulder-clay, mixed with materials from the Chalk-Marl and Greensand.
There are splinters of bone worn smooth at their fractured edges; but most of the bones and teeth are scarcely abraded at all, though not often associated. There seems, however, to be reason to think that portions of the same individuals have also occurred in proximity, although mixed up with fragments of others. Thus one might find, ​one after another, bones of a Bos, but among them a tooth of Hyæna or tusk of Hippopotamus. In some instances it is clear that the ligaments had not decayed when the limbs subsided. Thus my son exhumed an entire set of associated bones of a hind limb of Bos primigenius.
What we have here, then, appears to have been a deposit in a deep hole of a stream, where it swept round against the south side of the hill. This stream was probably no other than the present one called the Rhee, and drained the same district then as now. This district is occupied by the Lower Chalk, the Gault, and the Boulder-clay; it contains none of the Upper Chalk within its area, nor any observed beds of flint-gravel. Accordingly we find the materials of the deposit to be such only as those rocks would supply, consisting as it does almost entirely of the debris of the Boulder-clay. That it is newer than the Boulder-clay is also shown by its lying beneath a hill which is capped by a thin tabular bed of that clay. There appear to be very few remnants of the Oolitic rocks among the pebbles, except a few fragments of Gryphæa. The pebbles are, for the most part, not at all decomposed, as those are which one now picks up in the neighbouring ploughed fields, and the glacial scratches are well preserved. This would lead to the inference that the river flowed between rather deep banks of Boulder-clay, abrading much at a depth beyond the reach of atmospheric influences.
Some peculiar circumstances must have caused so considerable an accumulation of bones. Probably the carcasses, inflated with the gases of decomposition, were detained here and there in the stream by quiet eddies, such as usually occupy deep holes in the elbows of a stream when the water is not in flood. The prevalent south-westerly winds would also assist in detaining any floating body in such situations.
Taking departure from the pit, and crossing the valley from north to south, towards Foxton railway-station, the levels give:—
yards
—— 651
At this point we are again upon the level of the mammalian deposit. There are at the present time two sections open in this interval where coprolites have been dug. One is in the level alluvial ground just south of the middle stream. Here a low-level fine ​river-gravel is seen, well washed, with many small bean-shaped calcareous pebbles wholly soluble in acid. No shells were seen in it. The other section is given by a coprolite-pit in work, north of the corner of the road, not quite on so high a level as the Barrington pit, where there are shallow pocket-like patches of a fine flint-gravel; but they have not the appearance of a river-gravel, but rather of a trail or denudation gravel. Towards the station, however, the surface of the ploughed ground gives indications of a subsoil of flinty gravel, and there have been extensive pits of flint-gravel on the north side of the railway between Foxton and Shepreth stations. These pits are not far from on a level with the Barrington deposit, certainly not lower. We find, then, that the terrace-gravel of the same, or nearly the same, level on the south side of the alluvium of the pre- sent rivercourse consists of quite different materials from that under consideration on the north. The cause may probably be that the former occupy a line of drainage from the south, as may be seen by a small stream crossed by the railway between Foxton and Shepreth, in which direction lies the chalk escarpment, with its beds of flint and of capping flint-gravels. Whether these Foxton gravel-beds are of the same age as the Barrington deposit is a point on which I have no other evidence to offer; but the circumstance referred to may seem to remove any difficulty arising from their different composition. I have from these Foxton gravels what I believe to be a portion of a flint implement of the rudest type, similar to one which I have from Brandon Hill, given me by Dr. J. Evans, and to a portion of another which I found myself in a railway-cutting at Broomhill, near Brandon.
The shells which have been found at Barrington do not render much assistance towards fixing the age of the deposit. Though abundant enough, the species are few, and the number of strictly aquatic shells remarkably limited. By far the most abundant kind is Helix fasciolata (or caperata); Helix virgata is also common; Helix nemoralis also occurs, but is rare. The aquatic species are Succinea(?) oblonga, Limnæa palustris (one specimen), and Pisidium amnicum. This is a meagre list. No specimens or fragments of Unio or Cyrena have been met with.
The Mammalia hitherto discovered at Barrington are:—
Catalogue of Remains of above.
(3.) 1 ulna.
(4.) 1 skull and part of mandible, 1 detached tooth, 1 vertebra, 1 scapula, 1 rib, 2 metatarsals.
(7.) 1 brow-antler, 1 base and burr, 1 tibia.
(8.) 1 astragalus and broken end of tibia, probably of a young animal. It is larger than Roebuck, but much smaller than Red Deer.
(9.) 1 fragment of skull, which fell to pieces, 1 horn-core preserved (3 feet long on the outer curve, and 1 foot 5 inches round the base), 33 vertebræ, 1 fragment of pelvis, 1 fragment of femur, 10 tibiæ, 9 calcanea, 10 astragali, 1 complete hind limb, 5 metatarsals, 4 portions of scapulæ, 9 fragmentary or complete humeri, 1 radius and ulna attached, 10 portions of radii, 4 ulnæ (olecranon portions), 9 metacarpals (belonging to two or three species of Bos), 26 detached bones of feet.
(10.) 4 horn-cores. (Probably some of the bones in the last list may belong to Bison.)
(11.) At least two individuals; one probably entire. 1 skull (fragments of), 4 pieces of jaws, 15 molars and a few fragments, 10 canines (or pieces of), 9 incisors (or pieces of), 24 vertebræ, several caudal belonging to a series, 2 pelves (portions of), 2 kneecaps, 4 femora (portions of), 2 tibiæ, 2 calcanea, 1 astragalus, 4 humeri (or portions of), 2 radius and ulna, 8 detached bones of feet.
(12.) Probably five individuals. 19 molar teeth and some fragments, 1 back of skull, 3 vertebræ, 1 fragment of femur, 1 kneecap, 1 tibia, 6 portions of humerus, 5 radii, 3 ulnæ, 13 detached bones of feet.
(13.) 4 molars of two individuals.
There are likewise a few bones of birds hitherto undetermined. There is no river-deposit mentioned in Prof. Dawkins's paper on British Postglacial mammals, which is credited with so large a number of species, except Fisherton, where the number is likewise fourteen. The assemblage, however, is not the same.
The specimens have been compared at the University Museum of Comparative Anatomy, and determined by Mr. Tawney, who has labelled and catalogued the whole of them. There is a fine skull of Hyæna, which would have been perfect had it not been broken off by the pickaxe just behind the canines; it belonged to an adult, but not aged, individual. A magnificent pair of horn-cores of the Bos primigenius were found, with the forehead attached; but unfortunately the horn-cores were so decayed and permeated with mud that only one of them could be saved. The most remarkable fact observed was the abundance of the bones and teeth of the Hippopotamus, also abundant at the "Green." Some very fine specimens of the tusks have been, with much labour, built up out of the very numerous fragments into which they fell when removed. Four teeth of Elephas antiquus had been previously obtained in another pit in the same field, at a short distance up the course of the old stream, and were presented to the Museum by Mr. F. W. Smith. Mr. Griffith also gave his specimens. I saw only one tooth of Elephant in our working; it was so decayed that it could not be brought home. I believe it belonged to E. primigenius. Had I known at the time that the other specimens belonged to E. antiquus I should have examined it more closely.
Only one worked flint was found. It is of an oval form, extremely small, being about an inch and a half long by an inch wide. It is ​thick for its size. Mr. Keeping picked it up out of the debris, but did not notice having dug it out. I have myself little doubt about its belonging to the deposit. It is of a blackish hue, polished, with white porcellanous mottling, and has specks of botryoidal limestone adhering to it; all which characters mark many of the flint fragments in the silt.
The area excavated for the large collection was about 14 yards from north to south, by about 6 yards from east to west.
If we compare the above list of Mammalia with that given by Mr. Jukes-Browne for Barnwell, we find the following species common to Barrington and Barnwell:—
At Barnwell, but absent from Barrington, Equus fossilis.
It is observable that a small undetermined Cervus is mentioned also at Barnwell.
It will be seen, then, that the Mammalia belong to the same group at these two localities. We have, however, at Barrington neither of the distinctive shells Cyrena fluminalis and Unio litoralis. The absence of either, or both, of these might be accidental; for it is only in places, even at Barnwell, that they are found; but I think the greater distance from the sea would be sufficient to account for the absence of the Cyrena. On the evidence I am disposed to correlate this deposit with that of Barnwell.
Let us compare the conclusions which have been drawn from an examination of this deposit with those arrived at by Mr. A. J. Jukes- Browne respecting the age of the valley of the Rhee, which he thinks of a later age than any of the other tributary valleys of the Cam. If I understand him rightly, he considers the gravel at Barnwell, which is about seven miles below Barrington, to be the oldest "terrace"-gravel in the district; for he does not apply that term to the still older "Observatory" gravel. And he thinks it "possible" (p. 68) that the gravels about Foulmire and Foxton were deposited about the same time as those about Barnwell and Trumpington; but he says that, "on the whole, it seems likely that they belong to a somewhat later period."
As to the age of the Foxton and Foulmire gravels, if the two are to be regarded as contemporary (upon which point I have no opinion to offer), the argument from equality of level is rather in favour of the Foxton gravel being of the same age as that of Barrington. But the deposit at Barrington is, in my opinion, due to the ancient Rhee, and it contains a mammalian fauna similar to that of Barnwell, certainly an ancient one; and consequently the Rhee must still occupy a very ancient line of drainage. The absence from it of ​decided flint gravels, which are so conspicuous in the other tributary valleys, may be probably accounted for, as I have said, by the paucity of materials out of which such gravels could be formed; so that I doubt whether, from that circumstance, any conclusion can be drawn that this valley is more modern than the others.
The measurements referred to in the table of levels show three different levels, of which records still remain, at which the Rhee has run. Starting from the present stream, we find the next older level to have been lower than the present one; it is marked by the lowest-level fine river-gravel in a pit sunk through the present alluvium. The deposit next older than that is the mammalian gravel of Barrington. There may have been deposits of intermediate age, of which no records are left, unless the flint gravel of Foxton be such an intermediate gravel.
If we go lower down the river to Cambridge we find three gravel-levels; the highest and oldest the Barnwell gravel, the next lower the Chesterton gravel, the next the gravel beneath Jesus College and Midsummer Common, which I recollect being formerly largely extracted. These are all noted in Mr. Griffith's section.
Now I think there can be no doubt that a considerable spread of gravel marks a stationary level, or pause in the eroding action of a river in deepening its channel. Gravel is deposited when the river is occupied in meandering from side to side of the valley; and whenever an elbow of the stream reaches the side of the valley, it undermines it and widens the valley at that point. But when the valley is in process of being deepened, the river confines itself more closely to its course, and any gravels which it may then deposit are rearranged during the next stationary period. To what, then, are these stationary periods due, if such there be? It seems that they must be due to alterations in the relative level of sea and land. This is clearly put by Prof. Powell in his Report on the Exploration of the Colorado River, p. 203. He says, "we may consider the level of the sea to be a grand base-level, below which dry lands cannot be eroded; but we may also have for local and temporary purposes other base levels of erosion, which are the levels of the beds of the principal streams which carry away the products of erosion."
I would inquire, then, can we find any records of marine base-levels corresponding to these river-terraces? It is obvious from the silting up of our estuaries, such as the Fens, and the clean gravels to be found below the bottoms of our present streams, that the present sea-level is not so low as it was at a not very distant period. Now we have an indication of such a former lower level of the sea in the submarine forests. Thus we may account for the low gravels beneath our present alluvium.
The high-level gravels, on the other hand, simply intimate that the fall of the stream at the place where they were deposited was not, at the time, too great, and not so great as it became afterwards, when they were cut through. The former condition may have been ​fulfilled in two ways—(1) the coast may have been more distant at the time when the stream ran at its higher level; (2) the sea may have stood at a higher level upon the present, or nearly the present, coast. Of the two it is most probable that the condition which allowed of the deposition of the terrace-gravels was the former, under which a lesser gradient may have coexisted with even higher land; for it is generally believed that this island then formed part of the continent of Europe; and the Pleistocene mammalian remains constantly dredged off our east coast point in the same direction.
But not only must the sea-coast have been further off, but the land must have been also higher, not merely less denuded down, but physically lifted up in relation to the sea-level; or, what amounts to the same thing, the sea must have been lower. Otherwise we cannot account for deposits on the sea-level, and even below high- water mark, such as occur at Clacton and at Walton-on-the-Naze, and on the dredging-grounds in Essex—the former being, according to Prof. Dawkins, one of "the first terms of the Postglacial series," the latter having nothing to separate it from a somewhat early postglacial deposit.
If this supposition is correct it will rather militate against the opinion of Prof. Seeley, which is referred to by Mr. Jukes-Browne, that the marine gravel of March is of the age of the Barnwell gravels. The coast at the time the latter were deposited ought to have been more distant than March is.
As regards the climate at the period of the Barrington deposit, the occurrence of Elephas antiquus and Hippopotamus point to a somewhat warm climate. The Elephants and Rhinoceros being the same as at Lexden, in Essex, and the gravel terrace of about the same altitude, it is likely the gravels are of the same age. At that place the remains of beetles, which are abundant, have been attributed by Mr. Wollaston to a warm climate, probably Mediterranean. The Unio and Cyrena of Barnwell have a like significance; and Helix nemoralis is impatient of great cold.
We learn, then, that there was an interval since the Glacial period (for there is no question that both Barrington and Lexden deposits are Postglacial) when the climate of this island was somewhat warmer than it is at present. There are indications in the disappearance of Elephas antiquus and Rhinoceros leptorhinus, as well as of Cyrena fluminalis and Unio litoralis, that it became afterwards colder, and probably colder than it is now; and my own belief is that a still colder period supervened, which is evidenced by the mechanical accumulation of that drift covering which I have denominated "trail".
(For the Discussion on this paper, see p. 734.)
* ↑ There is a remarkable deposit of bones beneath the row of houses called "The Terrace" at Walton-on-the-Naze, in Essex. At this place the sea is encroaching on what was probably the eastern corner of a sheet of water occupying the same general position that "Walton Creek" now holds. The writer's opinion is, that the accumulation of carcasses at this place was caused by the south-west winds blowing nearly every thing that floated on the southern portion of this sheet of water to this particular part of its shore.
* ↑ Quart. Journ. Geol. Soc. vol. xxv. p. 192.
* ↑ 'The Post-tertiary Deposits of Cambridgeshire,' 1876, p. 64.
* ↑ Geol. Mag. dec. ii. vol. v. p. 400; figured in Camb. Ant. Soc. vol. iv. p. 177, pl. a.
* ↑ The Barnwell specimens in the Museum properly belong to this species.
* ↑ Loc. cit.
* ↑ Published at Washington, 1875.
* ↑ Quart. Journ. Geol. Soc. vol. xix. p. 400.
* ↑ Ibid. vol. xxii. p. 554.