466 Notices of Memoirs — The Barnsley Seam. 



been collected by a committee of the Midland Institute of Mining, 

 Civil, and Mechanical Engineers, and were published by that institution 

 in volume form in 1914, the sites at which the information was 

 obtained being plotted on a half-inch map. The depths to the coal 

 have been corrected for the height of the surface location above sea- 

 level, and, after the manner of Dr. Gibson's map (plate i) in the 

 Geological Survey Memoir on the Concealed Coalfield (1913), contour- 

 lines have been drawn among the spot-levels so obtained. Other 

 contour-lines similarly obtained from the records of borings which 

 have passed through Permian strata show the character of the surface 

 of the Coal-measures where they underlie the Permian strata. 



In drawing the contour-lines no attempt has been made to 

 distinguish between those changes of level in the seam between 

 neighbouring pits which are due to faulting, and those due to the 

 folding of the strata. Since, however, over most of the coalfield the 

 faults tend to nullify the change of level which the dip has accom- 

 plished, it is maintained by the author that to plot contours which 

 show the average rate of change of level is a statistical method which 

 yields a useful presentation of the truth. 



1. From an analysis of the results as plotted it appears that the 

 underground contours of the Barnsley Bed (strike lines) in Yorkshire 

 in detail generally range either N.E.-S.W. or N.W.-S.E., and that 

 within the area under which the Barnsley Bed has actually been 

 proved by working it is difficult to find either a N.-S. or an E.-W. 

 strike constant over more than a very few miles of country. This 

 circumstance, if general over the coalfield, would seem to demand 

 some revision of current views respecting the origin and structure of 

 the Pennine Chain. 1 



2. The greatest structural division of the coalfield ' basin ' is by 

 the equivalent of a N.E.-S.W. anticline of which the southern limb 

 is along the line of the Don faults from Sheffield by tlotherham and 

 Conisborough to Doncaster. North of this line there is some evidence 

 for the existence of a completed syncline, with its axis central near 

 Frickley. In ground from which the Permian rocks have been 

 denuded, the Barnsley coal attains a depth exceeding 1,800 feet 

 below sea-level. The general line of this northern trough follows 

 aN.W.-S.E. trend from Wakefield to South Kirkby, whence, displaced 

 perhaps by the Don anticline, it bends somewhat eastward through 

 Bulcroft. South of the Don a wider trough, also trending N.W.-S.E. 

 through Yorkshire Main Colliery (Edlington) and Bawtry, carries 

 the Barnsley Bed (at Bossington) below 2,600 feet. 



3. The inclination of the Barnsley Bed is at its steepest near the 

 outcrop, and after the manner of gentle folds the measures flatten 



1 These views were admirably expressed by Professor E. Hull, who in 

 advocating them in 1868 succinctly remarked (Q.J.G.S., 1869, p. 331) : 

 ' ' Immediately upon the close of the Carboniferous period the northern limits 

 of the Yorkshire and Lancashire Coalfields were determined by the upheaval 

 and denudation of the beds along east and west lines, while the coalfields 

 themselves remained in their original continuity across the region now formed 

 of the Pennine bills from Skipton southwards, and that at the close of the 

 Permian period these coalfields were dissevered by the uprising of the area now 

 formed of the Pennine range by lines of upheaval ranging from north to south." 



