A HISTORY OF DERBYSHIRE 



and massive variety called alabaster, which is capable of being sculptured, 

 is obtained at Chellaston. The Lower Keuper Sandstone series consists 

 of laminated micaceous sandstones, intercalated with beds of red marl. 

 Under these are beds of sandstone, breccia and a conglomerate with 

 red marls. In this district the lowest beds are generally a band of red 

 clay or marl. The term Waterstones applied to these sandstones origi- 

 nated from their watered-silk-like appearance, though now it is used to 

 denote their water bearing qualities, which are due to the alternation of 

 sandstones and marls. 



We have seen that the Permian rocks are unconformable with the 

 Coal Measures. The Keuper beds were deposited unconformably on the 

 more or less tilted and denuded edges of the carboniferous rocks. They 

 cover in one place the Millstone Grit, in another the Yoredale Rocks 

 and in another the Mountain Limestone ; and in the neighbourhood of 

 Charnwood Forest rest on still older rocks. Hence before the Keuper 

 period earth movements took place which raised the Palaeozoic rocks 

 and exposed them to denudation. 



PLEISTOCENE 

 SOUTH OF THE PENNINE CHAIN 



The deposits of the Pleistocene or Glacial Period consist of clays, 

 sands and gravels resting unconformably upon the rocks which form the 

 solid floor of the country. This mantle of drift is almost continuous 

 from the northern part of our country to the Midlands, where it dies 

 away into ordinary sands and gravels and disappears before we reach the 

 Thames valley. The drift varies locally in character, and is generally 

 composed of masses of clay, sand and gravel, with or without any signs 

 of stratification. Boulders which vary considerably in size and character 

 are often found embedded in the clay. Some of them consist of rocks 

 derived from the district, others are foreign to it and must have travelled 

 hundreds of miles from the places where they were once in situ. These 

 boulders are frequently scratched, grooved and polished as if they had 

 been pressed and rubbed against the rocks of the country over which 

 they have passed. Often when the rocky floor is laid bare by the re- 

 moval of the clay by which it has been overlain, it has been found to be 

 covered with scratches and grooves whose bearings indicate the direction 

 from which the boulders and clay have been brought. 



At present very little information has been published about the 

 glacial deposits of the uplands of Derbyshire, but those of the Trent 

 basin have received a considerable amount of attention. Mr. Deeley, 

 after some years' work, gave in 1886 a general description and classifica- 

 tion of the Pleistocene deposits which occur south of the Pennine Chain. 

 The following information is abstracted from his paper. The deposits 

 consist of Boulder Clays, gravels and sands of various kinds and ages. 

 They vary very much in thickness, and are most greatly developed on 

 the plains to the south and east of the Pennine axis. The oldest Pleisto- 



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