Clapha7n : Its Geology and Natural History. 431 



shows current-bedded gravel, containing a large quantity of 

 stones, some very large, and many of them ice-scratched, all 

 apparently of local origin. There is a similar exposure a little 

 further to the west, and the leader said these puzzled him more 

 than any others of the many and intricate problems of the dis- 

 trict. 



But this was only a * side-line,' the main object being to 

 examine the sections of pre-Carboniferous rocks so well exposed 



^Godfrey Bingley.] Austwick Beck Head. [Photo 



at Wharfe Mill Dam, and in the adjacent bed of the Austwick 

 Beck, which shew a sequence from the Bala or Coniston Lime- 

 stone series of the Ordovician (or Lower Silurian of the Geolo- 

 gical Survey) through the Silurian (or Upper Silurian), to the 

 Carboniferous. An obscure exposure in the dam yielded some 

 interesting fossils, including graptolites (probably the first to 

 be found in this particular bed), IllcEnus, and Strophomena 

 siluriana. The rocks are mudstones and volcanic ash. The 

 amount of water running in the beck interfered somewhat with 

 the examination of the higher beds of the series, but several 

 fossils were found, some of such interest as to warrant being 

 sent to the specialists for identification. 



J908 December i. 



