Abstracts of Papers read on Geology. 



457 



The thickest Marine Bed, which also has the richest fauna, occurs 

 in the higher portion of the Middle Coal-measures about 260 yards 

 above the Moira Main Coal ; it crops out at many places in the Moira, 

 Swadlincote, Church -Gresley, and Woodville district, and the outcrop 

 has been laid down on the 6 inch scale. 



Such mapping is of value, since for want of an index bed it has 

 hitherto been impossible to map any seam of coal above the Main 

 Coal owing to the variable character of the beds in the higher portion 

 of the Coal-measures, and the structure of this part of the coal-field 

 was, therefore, imperfectly understood. Using this Marine Bed as an 

 index bed, we can now fix the position in the sequence of the Moira 

 Sandstones and Grits and of the valuable series of pot, pipe, and 

 fireclays on which the prosperity of this district so largely depends. 



The main interest of this Marine Bed is that in stratigraphical 

 position and in faunal contents it is comparable with the Gin Mine 

 Marine Bed of the North Staffordshire Coal-field, with the Mansfield 

 Marine Bed of the Yorkshire and Nottinghamshire Coal-field, and with 

 the Penny stone Ironstone Marine Bed of Coalbrookdale. 



The following is a correlation of the Productive Coal-measures of 

 the East Midland Coal-fields, based upon the chief marine trans- 

 gressions : — 



In conclusion, it is shown that in colour, mode of weathering, and 

 other characteristics these Marine Beds are in every way comparable 

 with modern * Blue Muds '. 



(6) On the Stkeam-courses of the Black Coxtntet Plateau. By 

 Henky Kay, F.G.S. 



THE Black Country plateau is roughly outlined by the 400 feet 

 contour-line between Stajfford, Worcester, Stratford, and Burton, 

 and is identical with the anticline of the South Staffordshire Coal-field, 

 plus the north-western parts of Cannock Chase and the "Warley-Barr 

 area eastward. On its eastern and western sides are synclinal 

 valleys opening to the Trent and Severn. 



