Page:A Treatise on Geology, volume 1.djvu/315

 CHAP. VI. lie abundantly in these deposits. Large portions of England, Wales, Scotland, and Ireland, are covered by irregular aggregations of gravelly sands and pebbly clays, locally stored with the bones of various land quadrupeds, which appear to have lived not far from the spots where they now occur buried. The parts where they occur were therefore dry land, or, at least, not far removed from the native haunts of the animals.

The pebbles constitute the essential and characteristic part of these deposits, and enable the geologist to decide, in some cases very positively, as to the direction in which they have been drifted. Generally, in all the north of England, the diluvial gravel has been transported by the same routes or the same points of origin as the boulders; but there is some variety in this respect worthy of notice. On the eastern side of the island, from the Tyne to the Humber, the gravelly deposits appear partly of local and partly of distant origin. On the Yorkshire coast, local gravel, derived from the chalk wolds or oolitic moors, lies in very irregular beds, distinct altogether from the clays full of pebbles brought from the Cumbrian and Penine mountains; at Bridlington, local chalk and flint gravel lies over the other diluvium, and at Hessle, on the Humber, similar local gravel lies under it.

It might be proper, in these cases, to confine the term diluvium to that portion of the gravelly masses which, by the abundance of the fragments from very distant parts, requires the supposition of extraordinary circumstances for its accumulation. It is not solely, nor, perhaps, even principally, in this proper diluvium, that the bones of elephants, hippopotami, horses, deer, &c. occur; they seem, on the contrary, to be rather more plentiful in the local gravel deposits. Cases, however, occur, as at Brandsburton, and at Middleton on the Wolds, near Beverley, of elephantine and other remains in the midst of erratic gravel derived from great distances.

The most singular circumstance attending the accumulation of the proper diluvium is the extreme