"7 



YORKSHIRE NATURALISTS AT CONISBOROUGH 

 AND DONCASTER. 



HERBERT H. CORBETT, M.R.C.S.. 



Doncaster. 



The 162nd meeting of the Yorkshire Naturalists' Union was 

 held on Thursday, 26th September 1901, for the investigation of 

 the Don valley from Conisborough to Doncaster. About forty 

 members and associates met at Conisborough Station at 

 11.30 a.m., and proceeded to the ancient castle. Here those who 

 had their cameras found subjects of antiquarian and geological 

 interest, while the bryologists, coleopterists, and conchologists 

 were busy among the loose, moss-clad stones in the old moat. 

 The castle having been investigated, the party divided into three: 

 one part of the general body of naturalists taking the left bank 

 of the Don, under the leadership of Mr. M. H. Stiles, F.R.M.S. ; 

 the other, led by Mr. E. G. Bayford, following the right side ; 

 and the geologists, conducted by Messrs. H. H. Corbett and 

 H. Culpin, taking a third course. These latter proceeded to the 

 top of Conisborough Common, where a fine view was obtained 

 of the escarpment of the Lower. Magnesian Limestone, with the 

 river Don cutting through it. Turning to the left, along the 

 summit of the escarpment, the South Yorkshire coalfield was 

 seen, with its dense population and smoky air. On going down 

 the steep face of the limestone hill the guides called attention to 

 the fossiliferous bed which is always present near the base of the 

 Permian series in this part of Yorkshire. It varies from a few 

 inches up to 15 feet in thickness, and is crowded with the casts of 

 shells. These are generally very imperfectly preserved, though 

 at some places, e.g., South Elmsall, Hampole, and at the Ash- 

 field Brickworks at Conisborough good specimens are to be 

 found. They consist of species of the genera Schizodus, Mya. 

 Turbo, Terebratula, etc. 



Passing again over the face of the escarpment towards 

 Conisborough the valley of a small tributary of the Don was 

 noted as following the line of a fault which has thrown up the 

 coal measures against the Permian rocks. 



A splendid section of these carboniferous rocks is seen at the 

 Ashfield Brickworks, which were next visited. The section 

 exposes a long series of clays, sandstones, and thin beds ol 

 coal. In some of the beds are vegetable fossils which have been 

 referred by Mr. Hemingway to the horizon of the junction of 



1902 April 1. 



