THE GEOLOGIST. 



49 



On the Geology of tie Beaufort and Ellw Yale District of the South 

 Wales Coal-field, By Geoege Phillips Beyan, Esq., M.D., E.G.S. 



"With the exception of the very able memoirs drawn out bv Sir H. de la 

 Eeche, in the Geological Survey," Vol. I, and the sections of the same 

 survey, as compiled by Mr. David TVilliams, no coal-field has been so 

 little described or worked out as that of the South Wales basin. 

 Although the work of a master geologist, yet the very nature of these 

 memoirs, describing the general arrangements of the rocks in the south- 

 west of England, altogether precludes any attempt at minute geology, 

 which, indeed, should mostly be supplied by local workers. Other 

 coal-fields have been ably and intimately described, but this particular 

 field only in very general terms. Why it should be so I know not, 

 unless it is that only of late years its vast resources have been opened 

 up, and that its many romantic vallies, teeming with beauty above and 

 brimful of coal and mine beneath, have been made accessible either to 

 the tourist or the mining adventurer. Every year, however, sees new 

 railways opened in Monmouthshire and Glamorganshire ; and I have 

 little doubt but that the completion of that magnificent work, the 

 Crumlin viaduct, has done more than anything else to attract persons 

 to that part of South Wales, either from a love of the beautiful, or the 

 scientific interest attached to it. Eor the study of practical geology in 

 its several aspects, this coal-field possesses many advantages, particu- 

 larly in physical geology and the peculiar manner in which sections 

 are obtained, owing to the nature of the ground. In the important 

 branch of palseontology, also, it is by no means deficient ; for, at least 

 in this distiict, plants of the coal, as well as shells, fresh water and 

 marine fish-remains have been discovered most abundantly. I propose, 

 therefore, to give a brief sketch of this portion of the field, feeling 

 assured that it is by local and minute investigation that the truths of 

 the first great principles are upheld, and any new difficulties solved. 

 The greatest length of the South Wales coal- basin is from east to west, 

 extending from Pontypool to Kidwelly, a distance of about seventy 

 miles, while the greatest breadth is about twenty-five miles fromMerthyr 

 or Hirv ain to Cardifi". In this measurement I have excluded the Pern- 



