l62 ON SECTIONS IN THE LOWER PERiMJAN ROCKS. 



which the lower beds have been thrust out at Claxheiigh 

 and from the sand pit"*^. On the opposite side of the hill in a 

 small old quarry to the east of the Church at West Boldon (in 

 a field immediately behind the school) breccias belonging to 

 the Middle Limestone have been thrust into the beds of the 

 Lower Limestone, which are disturbed in a peculiar way 

 (photograph No. 6). On the top of the hill near West Ijoldon 

 non-fossiliferous calcareous breccias occur, which originally 

 formed part of the highly-magnesian limestone of the Reef. 

 They are pecuihar in being cut into blocks by a series of 

 sloping fissures. 



Both of the areas described are fossiliferous. Fish remains 

 can be obtained from the small exposure of Marl Slate in 

 the Down Hill sand pit, one of the few fossiliferous exposures 

 of Lower Limestone in the district occurs in the railway cutting 

 at Claxheugh, while from the unbedded limestones of the 

 Bryozoa Reef excellent collections of the typical fossils of that 

 formation can be made. 



* A general section of this hill is given in the paper on the Stratigraphy 

 and Tectonics of the Permian of Durham, page 260. 



