JO 



GEOLOGY OF THE BRISTOL COAL-FIELD. 



The continuity of the Aust'beds is broken by several faults, 

 which are plainly visible from the steamer when crossing the 

 Severn. Through these faults run little streams of water. The 

 second fault from the western end is covered with an enormous 

 quantity of the pretty little diatom Cocconema cymhiforme, forming 

 a gelatinous mass of several hundreds of feet in length. 



As the geologist passes round the western end of the cliff he 

 will notice the dark coloured shales. In and underneath these 

 are beds very rich in fossils, especially Pecten Valoniensis, Avicula 

 mnioi-a, Avicula cygnipes, Cardium Rhmticum^ Pleurophorus, 

 Aximis, &c. 



After walking about half way along the face of the section, large 

 quantities of sulphate of lime, mixed with strontium and barium, 

 arrest the attention at once. On reaching the third point the best 

 locality is found for examining the celebrated Bone Breccia, many 

 tons of which are generally lying on the shore, loosened and 

 detached by the weather. The lumps are full of portions of 



