Walcot Gibson — Carboniferous Bods in N. Stajfordshire. 505 



The Purbeck-Wealden beds also show a considerable thickening 

 to the west, if the boring at Ottinge be compared with that of 

 Penshurst, near Tonbridge, wbere the boring began low down in 

 the Ashdown Sand, the lowest member but one of the group. 



It remains for us to sum up the results of these borings, which 

 are likely to effect the same economic revolution in Kent as was 

 brought about in France by the extension of the coalfield of 

 Valenciennes and Mons, about ninety-five miles to the west of its 

 original outcrop at the surface, and to within some thirty miles of 

 Calais. The coalfield has been proved at Dover. Its range for eight 

 miles to the north has been also proved at Ropersole. Its southern 

 boundary, as yet ill-defined, is marked by the Pembroke-Mendip 

 anticline, ranging under the southern scarp of the chalk downs. 

 Its range in other directions is unknown, and awaits further 

 investigation. To the south of this anticline the Paleeozoic floor is 

 probably composed of pre-Coal-measure rocks. If, however, tbe 

 Coal-measures do occur, they are buried under such great thicknesses 

 of superincumbent rock — largely sands and loams full of water — 

 that it will be difficult to work them. We know now by experiment 

 not only where to seek, but also where it is advisable not to seek 

 for the Coabmeasures. The difficult problem of the buried Coal- 

 measures in South-Eastern England, now being worked out by 

 private enterprise, is likely to add greatly to the resources of 

 this country, as it bas already added to the wealth of geological 

 knowledge. 



V. — Some Eecent Work among the Upper Carboniferous Eocks 

 OF North Staffordshire, and its bearing on concealed 

 Coalfields.^ 



By Walcot Gibson, F.G.S. 

 (Communicated by permission of the Director-General of the Geological Survey.) 

 n^HERE is every reason to believe that in tbe near future tbe 

 JL supplies of coal lying beneath the Red Rocks of the Midland 

 counties will have to be relied upon to meet the increasing demand. 

 Workable seams of coal bave been met with at reasonable depths 

 beneatb the Red Rocks surrounding the Soutb Staffordshire Coal- 

 field, but there i-emain large areas lying between the known coalfields 

 of Shropshire, North Staffordshire, and Nottinghamshire, whicb 

 bave not at present been explored. Within tbis region, as shown 

 on the published maps of the Geological Survey, there are consider- 

 able areas of so-called Permian rocks, which recent investigations 

 have proved to be conformable to the Upper Coal-measures and to 

 contain a Coal-measure flora. Thus Mr. T. C. Cantrill has sbown 

 that in the Forest of Wyre the so-called Permian rocks contain thin 

 coal-seams and bands of Spirorbis limestone.- 



Exceptional facilities afforded by numerous marl- and brick-pits 

 and other artificial and natural exposures in North Staffordshire 



1 A paper read before Section C (Geology), British Association, Dover Meeting, 

 September, 1899. 

 ''' Quart. Jouru. Geol. Soc, vol. li (1895), p. 528. 



