1002 DB R. KIDSTON, MR T. C. CANTRILL, AND MR E. E. L. DIXON. 



Shropshire, where the Coalbrookdale Coal Field reaches its southern limit. There is 

 no complete break between the two, but the outcrop of the Coal Measures is reduced 

 to a narrow band between the Old Red Sandstone on the west and the so-called 

 Permian rocks on the east. From Bridgnorth the Coal Field extends southward, 

 broadening out till it reaches the latitude of Bewdley, in Worcestershire, beyond 

 which it is cut off on the south by the emergence of the Lower Old Red Sandstone 

 of Heightington. In the south-west a narrow neck of Coal Measures, half a mile 

 broad, connects this main northern area with a peninsular portion, which extends 

 in a south-eastward direction from Bayton as far as the Silurian ridges of the 

 Abberley Hills. 



To these two portions must be added the anticlinal tract of Trimpley, where a 

 broad fold of the Old Red Sandstone is bounded on each side by a narrow strip of 

 Coal Measures. These strips run from near Bewdley in a north eastward direction 

 for about 5 miles, and unite in the neighbourhood of Compton, where the Coal 

 Measures of the Forest of Wyre are separated from those of South Staffordshire by 

 a distance of only 5^ miles. 



The broad outlines of the geological structure are shown on the accompanying 

 sketch-map (text-fig. l), which is based on that of the Geological Survey. The out- 

 crops of the coals and Spirorbis-lime&tone have been taken partly from that authority 

 and partly from the maps published by Mr Daniel Jones in 1894 and by myself in 

 1895. As the base of the Sulphur Coal Group has not yet been defined, the line on 

 the map has been taken at or not far below the Main Sulphur Coal. From 

 Billingsley to Kingswood and thence to Button Oak the line is purely diagrammatic, 

 and must remain so till the district is properly surveyed. 



On the west and south the Coal Field is bounded by the Lower Old Red Sandstone, 

 on which the Coal Measures rest unconformably. The Carboniferous Limestone is 

 absent. The so-called Millstone Grit, shown on the Geological Survey map at one 

 spot only, near Bagginswood, is believed by Mr E. E. L. Dixon to be merely a white 

 sandstone in the Coal Measures. Eastward, the Coal Measures pass under, or are 

 faulted against, various subdivisions of the Trias. 



Between the Triassic rocks on the east and the Old Red Sandstone on the west 

 the following descending sequence has been established : — 



Coal Measures 



" Permian " and Keele Beds. 



Sulphur Coal Group, with pyritous coals, and Spirorbis-limestone. The 



chief seams are the Brock Hall and the Main Sulphur Coals. 

 Sweet Coal Group, with non-pyritous (" sweet ") coals and good ironstones. 



At the present time the sweet coals are being raised in the Highley region at the 

 Billingsley, Kinlet, and Highley Collieries. In the Mamble region the sulphur 

 coals are worked at three or four collieries between Bayton and Abberley. In the 

 past the coals of both groups have been worked over most of the Coal Field, hut 

 generally in a small way, and not far from their outcrops. 



