434 LUPTON : SOME NOTES ON THE YORKSHIRE COALFIELD. 
Figure III. is a section drawn from the north-western corner of 
the Coalfield at Denholme, through Batley, Wakefield, Hemsworth, 
Doncaster and past Gainsborough. 
The faults are not shown on the section, but the dip is averaged 
from the outcrop to the deepest point. The writer thinks it quite 
reasonable to omit the faults from this section because he has 
observed that in this Coalfield a seam of coal descends from the 
outcrop to the deepest place where it has been proved sometimes by 
a general dip and sometimes in steps. These steps are the faults, 
but for the purpose of a general section such as this it does not 
matter whether the dip is shown as proceeding along a slope or 
whether the detail of the steps or faults is shown. 
One of the most interesting questions is that of the level of the 
upper surface of the Carboniferous formation where this formation is 
covered up by the Permian. In the section the present average 
inclination of the Carboniferous land surface is shown having a gentle 
dip from west to east. Another dotted line shows the possible 
inclination of the Carboniferous land surface before the Permian was 
deposited and the denudation of the Coalfield was completed down 
to its present level. If that inclination should continue there must 
be an enormous thickness of more recent formations. It is, however, 
possible and probable that the easterly dip of the ancient surface is 
less rapid, and it is possible that there may be a ridge of the Carboni- 
ferous formation under Gainsborough. That the inclination of the 
old land surface flattens appears to be now proved by the boring near 
Haxey. 
The total thickness of the Yorkshire Coal Measures has not yet 
been definitely ascertained. It may be that east of the Permian out- 
crop the dip of the Coal Measures may in some places be steeper than 
the dip of the Permian, in which case there will be room for a greater 
thickness of Coal Measures above the Barnsley bed than has yet been 
proved. It is believed that the section line No. III. is taken along 
the deepest or one of the deepest troughs of the Coalfield. 
At Deholme there is the greatest westerly extension ; along the 
northern outcrop of the Coalfield there is a southerly dip, for instance, 
