TRACES OF THE GREAT ICE AGE IN I lERl'.VSHIRE. 27 



sand, or brick-earth. The boulders contained within these clays 

 are derived from the Derbyshire hills lying to the north, and 

 would seem to be the debris brought down by local glaciers at 

 the commencement of the Glacial Epoch. The Quartzose Sand 

 indicates submergence and a temporary relaxation of the arctic 

 conditions. A section of the Older Pleistocene Boulder-clay 

 occurs on Waterloo Hill, near Burton-on-Trent. It contains 

 erratics, "probably of Cumbrian origin." Interesting exposures 

 also occur at Spondon, at Chaddesden, and Sheldon Wharf. 

 Spondon itself is built on it, and it is exposed in several other 

 places. It contains Carboniferous boulders, and rests on a 

 surface of contorted Keuper marl. One of the erratics weighs at 

 least six tons, and many exhibit fine glacial polishing and striae. 

 Finely glaciated Carboniferous boulders also occur in the de- 

 posits at Chaddesden and Sheldon Wharf. 



The deposits of the Middle Pleistocene Epoch are' of particular 

 interest, and indicate a remarkable change in the physical con- 

 ditions. Widely distributed over the area occupied by the Trent 

 basin are deposits known as the Great Chalky Boulder-clay, and 

 these deposits indicate the passage of an ice-sheet from the east. 

 The evidence is this : the deposits contain numerous boulders 

 and fossils which must have been derived from rocks which lie 

 far to the east. Thus we find on Chellaston hill a deposit of 

 Boulder-clay overlying the Keuper strata, which here is being 

 worked for gypsum. This deposit contains well-glaciated boulders 

 which have been derived from Cretaceous rocks. Chalk and 

 chalk flints are to be found, together with Gryphaea and other 

 Liassic fossils. But there are no hills to the east capable of 

 giving rise to glaciers. From whence then did the ice come ? 

 An exhaustive study of these deposits and of the phenomena on 

 the coast of Norfolk (notably around Cromer) has led geologists 

 to the conclusion that during this period intense cold prevailed, 

 and that an enormous ice-sheet, fed frorn the Scandinavian 

 mountains, moved across and filled the shallow North Sea, 

 and, joining and brushing aside the ice from north-east 

 Britain, brought fragments of Scandinavian rocks to our shores. 



