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The quadrupedal remains which have been found in this lacustrine formation, belong principally to deer. Bones of oxen, likewise, occur in it. Of deer, at least, three species have been discovered in the peat and clay; the great Irish elk, (C. giganteus,) the red deer, (C. elaphus) and the fallow deer, (C. dama.) A doubtful skull, (found at Owthorne,) in the possession of the Yorkshire Philosophical Society, has some resemblance to the cranium of the chamois goat.

The extensive accumulations of peat and trees, along the shores of the Humber and its tributary rivers, happened, probably, at the same period of time as those which have contributed to fill up the ancient lakes of Holderness. This is inferred, with the highest probability of truth, from the position of the peat with respect to the diluvial clay and pebbles; for, wherever these occur together, the former is invariably uppermost. The opinion of the peat extending under the whole district of Holderness, was probably founded on the very considerable depth at which it is, in some places, buried under sediment deposited by the sea. But this silt, accumulated by the action of the tide, which composes the surface of the level land in Holderness, may be easily distinguished from the more ancient aggregations of clay, sand, and pebbles, which indicate the action of the deluge. No fresh-water shells, nor any such alternations of argillaceous marls as those which lie in the site of former lakes, accompany the peat deposit of the marshlands; but it is covered by a marine deposit of silt and clay, such as now drops from the muddy waters of the Humber. The depth of this covering is, in some instances, not less than thirty feet, and the peat lies below the low-water mark ; under what circumstances it was collected together, it is not easy to conjecture. That at the time of its aggregation the sea flowed up the channel of the Humber, appears probable, because the first deposits which cover it are of the same kind as those now dropped by the tide; that its formation happened soon after the deluge, may be inferred from the fact that it rests almost immediately upon the diluvial detritus ; that some remarkable general agency, probably a great land-flood, was concerned in the production of the phenomena, is evident from the extent of the vegetable accumulation.

The following statement of substances found in sinking a well at the Block-house mill, on the east side of the town of Hull, derived from two accounts communicated at different times by my friends, will shew what are the accompaniments of this remarkable layer of peat in Holderness.

Feet.
Soil

1)
Clay

6 Alluvial deposit. Silt sand

23

32 Moor or peat, with large

2

Feet.

trees, &c.

[blocks in formation]

In Ottringham marsh the layer of peat, one yard thick, was found forty-one yards beneath the surface; thirty-six yards of various diluvial matter lay beneath, and the chalk was found at the depth of seventyeight yards.

These accounts are interesting in another point of view, for, by means of them, we can determine correctly the dip or declination of the chalk. The nearest situations where this stratum sinks below the marshland, are at Hessle and Cottingham. The distance between Hessle and the Blockhouse mill, in a straight line, is between four and five miles ; and as the upper plane of the chalk was found in the latter instance ninety-four feet deep, whilst at the former point it appears at the surface, the dip towards the east is twenty feet per mile. The distance from Hessle to Ottringham marsh is nearly fourteen miles, and the declination two hundred and twenty-four feet, or sixteen feet per mile. If this moderate declination be constant, the chalk rock may be reached by wells in many parts of Holderness; and thus, as in similar districts of Lincolnshire, unfailing supplies of water be obtained.

CHAPTER III.

Strata of the Yorkshire coast. Geological description of the Coast of Yorkshire, from Spurn Point to Redcar; including the

heights and stratification of all the Cliffs,

Before entering on a particular description of all the cliffs on the seacoast of Yorkshire, it seems necessary to give a general explanation of the section which is drawn to represent them: for this is not a hasty sketch, designed merely to give a rude notion of the height and stratification of the cliffs, but carefully constructed from many and repeated measurements. It was originally drawn on a much larger size than it would have been practicable to publish ; but it is hoped the scale hereadopted, will be found at once sufficient and convenient. A mile in length of the coast, allowing for its principal flexures, occupies in the section, one inch and a

and four hundred feet of altitude are represented by one inch. This is quite sufficient to allow of expressing all details necessary to a proper exhibition of the strata, in their relative order and thickness. Wherever the nature of the subject requires it, enlarged drawings are added, with proper marks of reference to their place in the general section. For this purpose, the junctions of rocks have been very carefully studied and copied on the spot, and all their minuter peculiarities recorded, Upwards of fifty such detailed sections have been drawn, but it has not been deemed requisite to engrave so many. Such of them have, therefore, been selected as seemed to be most illustrative; and these, with the accompanying explanations, will, it is hoped, be found sufficient to give an accurate knowledge of the coast, With regard to the colouring, the natural prevailing hues of the strata have been generally imitated; but where two rocks could not be thus well discriminated, the difference of their tints has been necessarily exaggerated. It is a common opinion that all geological works should be coloured upon one model ; but what model shall we follow ? No geological map can possibly be so filled with colours as to embrace all the minor subdivisions of rocks which, in local sections, it would be unpardonable to omit. Besides, the colours of rocks vary, and circumstances may make it desirable that sometimes a stratum should be coloured strongly to mark its importance, though at other times it would be better represented by a fainter shade. However, to increase as little as possible the confusion of colours which already exists, I have followed in the colours of the colitic rocks the works of Mr. Smith, and have preferred, with Mr. Greenough, to leave the chalk white. Where rocks were to be thus represented for the first time, I have used such colours as have not been before appropriated.

The heights of the cliffs are represented above the level of high water at spring tide, because this is, upon the whole, the most convenient line that can be referred to; and though it is too variable to serve for the rigid determination of altitude by graduated instruments, it will be found accurate enough for geological purposes. The tides rise on this coast about fifteen or eighteen feet, and as they very generally lay up much sand at the foot of the cliffs, and as at this level we commonly find much debris accumulated, it seemed, upon the whole, better, except in a few instances, to confine the colouring to the level of high water. It

It remains to state that the following description is in every particular original ; and was mostly executed on the spot.

SPURN POINT,

The southernmost part of the coast of Yorkshire, is a low peninsula of gravel and sand, accumulated by the sea and the wind, and laid in its peculiar forms by the united action of currents from the sea and the Humber. The materials which fall from the wasting cliffs between Bridlington and Kilnsea, are sorted by the tide according to their weight and magnitude ; the pebbles are strewed upon the shore, beneath the precipice from which they fell; the sand is driven along and accumulated in little bays and recesses; whilst the lighter particles of clay are transported away to the south, making muddy water, and finally enter the great estuary of the Humber, and enrich the level lands under the denomination of warp. The sand and pebbles, which were at first deposited near the place where they fell, are afterwards removed further and further south by the tide, and the cliffs are left exposed to fresh destruction. Thus the whole shore is in motion, every cliff is hastening to its fall, the parishes are contracted, the churches washed away, and not unreasonable fears are entertained that at some time the waters of the ocean and the Humber may join, and the Spurn become an island. At present, however, the isthmus stands firm, and though composed only of a heap of pebbles and sand, and exposed to two strong currents, may, perhaps, be little changed for ages to come. Such is the efficacy of long equal slopes and a pebbly, sand, in repelling the rage of

the sea,

Among innumerable pebbles derived from the wasted cliffs of Holderness, which are here thrown up by the sea, we observe diallage rock, and mica slate with garnets, and a great variety of sienites, green-stones, and porphyries, which have been derived from Scotland, and perhaps Norway; much granite from Shap fell, sienite from Carrock fall, breccia from Kirby Stephen, and other Cumbrian rocks; limestone and sandstone from the western part of Yorkshire, and lias fossils from the neighbourhood of Whitby

From Spurn Point to Kilnsea, the shore is very low, and, being composed only of gravel and sand, presents little that requires remark. The ruins of Kilnsea church stand upon a low ruinous cliff, of very peculiar composition. Not a single pebble is to be seen in it, but the whole height is a mass of loam or warp, disposed in regular laminæ, whose parallel surfaces are undulated like the broadest ripple-marks on a level sand. (A) is a sketch to shew the peculiar arrangement of these laminæ, and it must be noticed that, in the sharper curves, the laminæ are separated a little from each other. (a)

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