A HISTORY OF LEICESTERSHIRE 



high ground about Waltham and Croxton Kerrial. The larger part of the 

 area, however, does not rise much above an average of from 300 to 500 ft.; 

 but, nevertheless, forms the watersheds between the tributaries of the Trent 

 flowing north, those of the Avon flowing south-west, and those of the 

 Welland flowing to the east. 



Five main groups of rocks are represented in Leicestershire : (i) the 

 Pre-Cambrian rocks of Charnwood Forest ; (2) the Coal Measures of the 

 Leicestershire and South Derbyshire Coalfield ; (3) the Red rocks, the 

 Permian and Trias, lapping round them and covering a large part of the 

 plain ; (4) the Jurassic rocks, comprising the three divisions of the Lias, and 

 the few small patches of Oolite capping the eastern hills ; and (5) the 

 superficial clays and gravels that overlie the other formation indiscriminately. 

 The following are the subdivisions of the rocks that are exposed at the 

 surface : 



Period 



Formation 



Character of the Strata 



Approximate 

 Thickness in feet 



Recent . . . 

 Pleistocene . 



Alluvium 



Jurassic . . 



River terraces 



Boulder-clay, sand and gravel . 



Inferior f Lincolnshire Limestone 

 Oolite \ Northampton Sand 



'Upper 

 Middle 



Lower 



Triassic . . 



Permian . 



Carboniferous . 



Pre-Cambrian or 

 Archaean 



Rhaetic 



Keuper 



Bunter 



Marl . 



Sandstone . 



Permian (?) . 

 Coal measures 



Millstone Grit . . . 

 Carboniferous Limestone 



Charnian 



Silt, clay, peat and gravel . 



Gravel and loam 



Stony clay, sand and gravel 



Limestone and freestone 



Sands with layers of clay in the 

 upper part, Ironstone below 



Clay and shale with calcareous 

 concretions 



Ferruginous limestone and iron- 

 stone. Sandy shales in lower 

 part 



Clay and shale ; argillaceous lime- 

 stone 



Black shale ; sandstone .... 



Red and variegated marl with 

 bands of gypsum and a little 

 sandstone 



Red sandstones with marl bands . 



Beds of shingle with a little sand- 

 stone 



Breccia and red marl .... 



Shales with seams of coal and 

 fireclay with beds of sandstone 

 and ironstone 



Massive sandstones and coarse grits 

 with beds of shale .... 



Limestone with occasional beds of 

 chert 



Slates, hornstones and agglomerates 

 with intrusive igneous rocks 



Up to 25 

 I Up to 150 



Sc 



Up to 40 



1 10 to 180 



100 to 200 



750 



38 



600 



IOO 



o to 800 

 o to 50 



500 or more 

 zo to 500 



Unknown 



The geology of Leicestershire has been previously treated by many 



writers, but only passing reference to the more general of these publications 



in these pages. 1 It is not, however, until late years that the 



'^ ' 



2 



