GEOLOGY 



lying about, appears to be at least 300 yards long and 100 yards across. The 

 nearest point from which this mass can have come is at Waltham-on-the- 

 Wolds, about 5 miles to the north-east. Other large transported masses of 

 rock occur near Belton, Ashby Magna, and south of Lutterworth. 



VALLEY DRIFT 



A later deposit of clay and stones is found in many of the valleys. This, 

 although not a true Boulder-clay, appears to have been formed in late glacial 

 times, as the material is often thrust into the underlying beds, showing that 

 some ice existed at the time. It is of no great thickness, and is only found 

 along valleys that have been cut through the older Boulder-clay. These beds 

 evidently mark a very late period merging into the time when the terraces of 

 the existing rivers were laid down ; and consequently the separation of them 

 from the river beds is very obscure. They in fact form a connecting link 

 between beds of glacial age and the alluvial deposits of the present rivers. 

 They are best seen at Barrow-on-Soar, but occur also in the neighbourhood of 

 Market Bosworth and other places. 



RIVER-GRAVELS AND ALLUVIUM 



All the main rivers of the district are flanked by well-marked river 

 terraces, composed of well-stratified gravel and loam. They form terraces at 

 from fifteen to twenty feet above the present alluvium of the rivers, from 

 which they usually rise in a sharp bank. These gravels make considerable 

 spreads at the junction of the Wreak and Soar at Syston, and along the 

 Trent Valley north of Kegworth and other places. They extend in many places 

 up the lateral valleys, and in the upper part join on to the alluvium of the 

 present streams. A great number of mammalian remains have from time to 

 time been found in these gravels. 1 These beds have been deposited at a time 

 when the rivers flowed at a higher level, and when there was a greater volume 

 of water than at the present time. 



With regard to the modern alluvium which flanks all the larger streams 

 there is little to be said beyond that it forms fertile meadows and pastures, 

 while the gravel terraces above are mostly arable land. 



The general inference to be drawn from the Drifts of this district is that 

 the glaciation which produced these deposits of Boulder-clay and gravels 

 emanated from two distinct sources. The earliest had its origin somewhere 

 to the north-west, and derived its material solely from rocks older than the 

 Trias. This glaciation, however, does not appear to have been so extensive as 

 that which succeeded, and which, bearing Cretaceous and Jurassic rocks mingled 

 with material from the earlier Boulder-clay, must have come from an easterly 

 direction. The large quantity of gravel and sand associated with this Boulder- 

 clay seems to point to the fact that the termination of the glacier cannot at 

 times have been far from this district, although it varied somewhat at different 

 periods. In fact there is every probability that the Midland counties occupied 

 what was the fringe of the great glaciation that occurred at this period ; and 

 that the frequent advance and retreat of the ice-sheet over this district 

 produced along its edge the complicated series of torrential and swampy 

 deposits which now form the Glacial beds of this part of England. 



1 Montagu Browne, The Vertebrate Animals of Leicestershire and Rutland. 

 1 17 3 



