ON THE STOCKDALE SHALES. 



'01 



It will be seen that this list 

 is identical with that of the 

 Graptolites from an exposure 

 of the confertus -shalea a little 

 below the Upper Bridge, Skel- 

 gill. As at that place, Dimor- 

 phograptus confertus is rare and 

 D. Sivanstoni abundant. We 

 think it highly probable that 

 the seams containing the abun- 

 dance of D. confertus are crushed 

 out from between these shales 

 and the underlying calcareous 

 band ; but it is just possible 

 that they may be on a higher 

 horizon. Whatever be the 

 relative position of the shales in 

 which D. confertus is abundant 

 and D. Siuanstoni apparently 

 absent, and those in which the 

 latter is abundant and the 

 former rare, there can be no 

 question that the two belong 

 to one Graptolitic zone, occur- 

 ring always between the zone 

 of Atrypa fleccuosa or of its 

 equivalent, that of Diplograptus 

 acuminatus, and the zone of 

 Monograptus Jlmhriatus. 



Kb 1. The actual passage 

 between the confertus-^h2ileB> 

 and the succeeding Graptolitic 

 shales is not seen ; but we are 

 disposed to believe that the 

 junction is here an unfaulted 

 one. If so, this is the only 

 locality we have met with 

 where such is the case. 



There is no great gap be- 

 tween the confertus-^h?lQ^ and 

 the overlying beds, and the 

 two are dipping with perfect 

 conformity. Moreover if a 

 strike-fault did occur here, we 

 believe we should find traces 

 of it, as it is usual to get a 

 considerable breccia developed 

 at that point, and this breccia 

 would ahnost certainly be ex- 

 hibited. Be that as it may, 

 the measured thickness of the 



aJ.G.S. No. 176. 



Calcareous. 



Grit. 

 Ford. 



Aal. 



Ac 4. 



Ac 5. ■ 



-Ac 3. 



• Calcareous 



Beds. 

 Lower Max, 

 -Waterfall. 

 -Upper Max. 





52 



ol. 



Ba2. 



Waterfall. 



■1 





5t4 



Fault? 



CD 



Dyke. 

 C. Grayae, 





Footpath. 



r 





^ 





I-* 





1 



B6. 



3a 



