﻿36 ME. T. r. SIBLY OX THE FATJJfAL SIJCCESSIOK- IN THE [Feb. 1908^ 



associated with the Carboniferous Limestone, by Mr. Arnold- 

 Bemrose, whose results are embodied in a recent paper/ has laid 

 the foundations for such an investigation ; and, moreover, the 

 structure of the south-eastern portion of the area is now being 

 worked out by Mr. C. B. Wedd, of H.M. Geological Survey, in the 

 course of the re-survey of the East Derbyshire coalfield. 



No systematic attempt to zone the Carboniferous Limestone of 

 the Midland area was made until Mr. C. B. Wedd commenced his 

 examination of the Matlock district, an investigation which is now 

 approaching completion. In the ' Summary of Progress of the 

 Geological Survey ' for 1904, pp. 8 & 9, Mr. Wedd gave a prelimi- 

 nary account of the faunal sequence in the Matlock district, and in 

 the same publication for 1905, p. 14, he stated that 



' The corals and brachiopods show that the bulk of the limestone of the district, 

 at least down to the second toadstone, belongs to the Upper Bihiinophylluin- 

 Zone (D^) of Dr. Vaughan's classification.' 



My own work in this area, carried out in 1906 & 1907, during 

 the tenure of an 1851-Exhibition Science-Eesearch Scholarship,, 

 has had for its object the investigation of the faunal succession 

 in the Carboniferous Limestone throughout the area. The account 

 here presented deals mainly, therefore, with the palaeontological 

 features of that formation ; but a few important tectonic features, 

 which came under my notice are described, and I have also attempted 

 a brief description of those striking lithological changes which take 

 place, between different parts of the area, in certain portions of the 

 sequence. 



The base of the Carboniferous Limestone is not visible in the 

 Midland area, and the whole of the series exposed constitutes a 

 greatly-expanded development of the uppermost zone of the typical 

 Avonian succession of the South- Western Province, namely, the 

 Dihunopliyllura-TiOnQ. In this Midland development three subzones. 

 can be distinguished : these are as foUows, in descending order : — 



D3 = Subzone of Cyathaxonia rushiana. 

 Do = Subzone oi Lonsdalia floriformis, 

 Dy = Subzone of Bihunoiyhyllura 9. 



The scheme of the present paper is as follows. The section along 

 the line of the Midland Railway, between Longstone and Buxton,, 

 being the most extensive in the area, is selected as typical, and 

 is described in some detail. The general faunal succession in the 

 Midland area is then described, and the fauna ^ of each subzone 

 analysed in detail. In this connexion, the marked variation of 

 faunal facies exhibited by the Lonsdalia-subzone is discussed. 

 Certain important sections of the Loiisdalia-suhzone are next 



1 ' The Toadstones of Derbyshire : their Field-Eelations & Petrography '^ 

 Quart. Journ. Geol. Soc. -vol. kiii (1907) p. 241. 



^ Throughout this paper attention is confined entirely to the corals and 

 brachiopods, in interpreting the faunal succession. These two groups alone are- 

 sufficiently abundant to be reliable in zoning. 



