FAUNAL SUCCESSION OF THE UPPER BERNICIAN 6li 



Oxford Limestone. 



Geographical Distribution. 



Sea Houses, Lowick, and Scremerston districts. 



StratigraJiJiical C/iaracter. 



A compact bed of dark coloured limestone about 15 feet in 

 thickness, rendered conspicuous by the presence of Girvanella 

 in the form of red and black concretionary incrustations 

 surrounding" the corals and encrinite columns. (Pi. xviii., 

 fig. 2). 



Fauna. 



Corals numerous ; their poor condition however renders their 

 determination difficult. Crushed Dibunophyllids abundant in 

 the overlying shale in the Oxford Quarry (near Ancroft). 

 Dil)unophyUum nr. ^, Lithostrotion, Giganteid Prodiicti 

 (Prod, a) and other forms common. 



The "Oxford" is perhaps the most highly encrinital limestone 

 in the Bernician series, although the fragmentary columns of 

 encrinites are abundant in all the calcareous beds. 



Lonsdaleia florifoimis has been found in a thin limestone 30 

 or 40 feet above the Oxford Limestone near Scremerston. 

 This form appears to be rare in Northumberland, the author 

 not having seen it in any of the limestones. Messrs. Carruthers 

 and Maufif found it in the bed mentioned above, in December, 

 1908, and it has been recorded by H.M. Geological Survey 

 from the Eelwell Limestone. 



The " Posidonomya Bed." 



Budle Bay. 



In Budle Bay, between Bamburgh and Holy Lsland, a red 

 calcareous shale is to be seen overlying a thickly bedded 

 limestone. The shale, which is about 15 feet in thickness, 

 passes upwards into sandstone. 



The exact horizon of this shale is doubtful, but geographical 

 and stratigraphical considerations point to its belonging to the 

 Lower Limeston:: group. 



