Hind : Carhonijerous Geology. 1 55 



Dr. Silby * obtained very similar results in his study of the 

 southern part of the district, and filled in several details. 

 I have not been abb to satisfy myself that any beds of a lower 

 facies than the Dihunophylhim zone exist in Derbyshire, but 

 the exposure of Settle reveals some Seminida beds underlying: 

 beds with a typical Dihunophyllum fauna. 



The interesting point in Dr. Sibly's paper is the recognition 

 of the wide vertical expansion of the Dihunophyllum zone in the 

 North Staffordshire-Derbyshire district, which measures, accord- 

 ing to him, at least 1700 feet ; whereas in the Bristol district, 

 the whole zone is represented by only between 400 — 500 feet of 

 limestones. 



The Limestone with cherts, characterised by the presence of 

 Cyathaxonia and other small corals, is well developed on the 

 Staffordshire side of the anticlinal, and reaches near Warslow 

 and Wetton 100-150 feet in thickness. At Wetton (Pepper 

 Inn), and Butterton, North Staffordshire, these beds are 

 overlaid conformably by black shales and Limestones, with a 

 typical Pendleside fauna, Pterinopecten papyraceus, Posidonomya 

 becheri, Nomismoceras rotiforme, Glyphioceras striatum, indicating 

 the lowest zone of that series. Here the succession in the 

 L'pper Dihunophyllum Series is very similar to North Wales. 

 Cherty in places, it is succeeded by a Cyathaxonia zone also 

 cherty, passing conformably into the lowest Pendleside zone. 



Beds with a similar faunal sequence are to be seen at 

 many places further North. The Hodder Valley, Winterburn, 

 Lothersdale, the Cracoe Hills and near Settle. 



This large Derbyshire-Staffordshire Carboniferous area is 

 also remarkable because of the enormous development of the 

 Series of rock to which Mr. Howe and I gave the name 

 Pendleside Series. This Series, in the Midlands, consists of 

 a group of dark limestones and shales at the base, passing up 

 into their well bedded dark limestones, which are succeeded 

 by a black shale group, Then the shales become sandy, and 

 pass up into standstones, ganister-like grits, and are overlaid 

 by the Millstone Grit series. I estimate the extreme thickness 

 of these beds to be about 1200 feet, and the greatest thick- 

 ness seems to be at Pendle Hill. 



The Series is of interest because it can be accurately zoned 

 by a succession of cephalopod forms, which appear to indicate 

 definite horizons which can be traced from the centre of Europe 

 to the West coast of Ireland. 



1909 April I 



