110 THE TRENTHAM GRAVEL BEDS. 



is held, and with some degree of truth, that these beds 

 gradually become thinner and occupy a less important and 

 definite position towards the south and east. This being the 

 case, it is reasonable to conclude that the rocks from which 

 they were originally derived are situated to the north and 

 west, and that by the agency of waves and currents they 

 became scattered in broad thick masses over the floor of 

 the Triassic sea. But where was the shore line, and 

 what formation constituted the land surface of this remote 

 period ? If among the gravels we could but find well- 

 defined fragments of contemporaneous organisms, either 

 of plant or animal, the answer would be there, but 

 the gravels are in this respect silent. Neither are we clear 

 as to whether there were periods of tranquillity or rest 

 during the deposition of these beds, nor even by approxi- 

 mation as to the geological time occupied in the collection 

 of such enormous masses of gravel and shingle. But 

 however our wonder may be excited by speculating on 

 these subjects, it is equally striking when we consider 

 that the exposed area of the Bunter gravels represents 

 but a tithe of their original extent ; and that of this 

 hundreds of square miles have been subsequently subjected 

 to denuding agencies by which, in following the law of 

 redistribution, they have so largely contributed to the 

 infilling of the great valley systems of the midland 

 counties. 



