4 A POPULAR SKETCH OF THE GEOLOGY 



of Leicestershire, have all their sharp angles worn round, but are 

 frequently of all shapes. The fossils and other pieces from the lias 

 are often little altered from their original condition. The perfect 

 smoothness and roundness of the quartz pebbles favours the supposi- 

 tion of their distant origin. 



This dependence of the condition of the masses on their distance 

 from their parent rock may be admirably seen in tracing the boulders 

 derived from the Charnwood Forest district. These seem to have been 

 drifted chiefly in the S.W. direction, as I never observed them to the 

 N. or E. Over all that table land which runs a little west of Lei- 

 cester, the blocks are strewed in great abundance. As you approach 

 the forest, they become more numerous, more angular, and of a larger 

 size, so as in some instances to weigh two or three tons, but in tra- 

 velling southwards their size and number decrease, till at the distance 

 of twelve or fifteen miles, if you find a boulder of Mount Sorrel 

 stone for instance, it will not be larger nor more angular than a 

 man's head. 



The quantity of diluvial materials accumulated in any one place, 

 varies from one to fifty or sixty feet in thickness. The mass some- 

 times assumes a stratified character, beds of fine sand alternating with 

 beds of pebbles or of clay ; these beds, however, are very irregular, 

 being never continuous for more than a few yards, and sometimes all 

 appearance of regularity is lost, and the whole is nothing but a con- 

 fused heap. In the beds of sand it is not unfrequent to see layers of 

 pebbles of coal (derived from the Ashby or Derbyshire coal fields) 

 from the size of a man's fist downwards ; and these having been ob- 

 served in sinking wells and making excavations, have sometimes led 

 to the erroneous supposition that coal existed immediately beneath. 

 Mankind easily believe what they eagerly desire, or it would at once 

 have been perceived that merely from the occurrence of these pebbles, 

 there was no more reason to expect to find coal beneath, than there 

 was to find chalk, oolite, slate, or sienite, pieces of all these being 

 equally found in the diluvium. The superficial water-rolled materials 

 here spoken of, under the general term diluvium, are never, so far as 

 1 am aware, found high upon the hills of Charnwood Forest, but over 

 all the rest of the county they are distributed sometimes so profusely 

 as greatly to obscure its study, masking the inferior rocks from our 

 inspection. We will now, however, suppose all superficial matters to 

 be stripped off, and the regularly bedded rocks exposed to view, the 

 first which rails our attention being 



