ON THE 8T0CKDALE SHALES. 



693 



Ashgill. 

 The usual depression is continued from Torver Beck to Ashgill 

 Quarry, about two thirds of a mile to the south-west. 

 The section in the quarry is shown in fig. 8. 



N.E. 



Pig. 8. — Section across Ashgill Quarry. 

 (Scale about 50 feet to 1 in.) 



s.w. 



The Dimorphograj)tus-beds are seen in the face of the quarry 

 resting on the Ashgill Beds, the Atrypa-flexuosa limestone being 

 here crushed out. They are hard, ferruginous, well-laminated, 

 grey-black shales, of glossy appearance, and with Graptolites, inclu- 

 ding Monograjptus revolutus, Kurck, in a very indifferent state of 

 preservation. Dimorjpliograptus confertus seems to occur here, but 

 the shales are strongly cleaved, and sufiiciently large pieces cannot 

 be obtained to show the whole of any individual Graptolite. No 

 higher beds of the Skelgill series occur. 



In the south-west corner of the quarry a fault, which runs slightly 

 obliquely to the strike, brings the JDimorphograptus-heds once more 

 against the lowest part of the Ashgill Shales — the Staurocephalus- 

 limestone. They are here seen to be affected by a series of folds, 

 which causes reduplication of the shale. This is the clearest sec- 

 tion we have seen exhibiting this feature ; but we feel convinced 

 that these shales are repeated often many times upon themselves 

 all the way from Yewdale Beck to Appletreeworth Beck. Below 

 the quarry no rock is seen for a considerable distance ; but at the 

 tail of what was once an island (though the south-western branch 

 of the stream is now dry), about halfway between the quarry and 

 Ashgill Bridge, the black shales of the crisjms-zone crop out in the 

 stream, associated with the usual pale shales. The fossils here are 

 in a very tolerable state of preservation amd include : — 



Monograptus crispus, Lajpw. 



exiguus, Nich. 



pandus, Lapw. 



discus, Tornq. 



Monograptus griestonensis, Nicol. 



Hisingeri, Carr. 



Ketiolites Geinitzianus, Barr. 

 Petalograptus palmeus, Barr. 



The Retiolites occurred only in the highest band visible. The 

 whole thickness is about 20 feet. Just above Ashgill Bridge the 



