305 
The limestone may be observed stretching above and 
across both the sandstone on the one side the Fault and 
the shales and coals on the other. 
The sandstone is the same as that on which the castle is 
built, and, as already stated, the Pontefract and Houghton 
Common Rocks are undoubtedly members of the Coal- 
measures, though they were considered for many years, and 
by eminent geologists, to be New Red Sandstone, or Roth- 
liegende. They are generally of a grey colour, coarse and 
micaceous, or of a brownish tint, sometimes firm and well 
cemented, forming a good building stone ; at others, only 
incoherent sand. There are many quarries near the town, 
and good natural sections beneath the castle. The sand- 
stone extends southwards beyond the river "Went, towards 
Conisborough, and expands westward to the Ackworth and 
Brierley Moors. It is coarse, thick-bedded, or in some cases 
micaceous and flaggy, more or less coloured red or variegated, 
where in conjunction with the limestone, from which it is 
often distinctly separated by beds of red or purple marls. 
Conisborough Castle stands on an eminence composed of 
an outlying piece of Permian Limestone, capping a 
hill of sandstone. The latter has been largely quarried for 
building purposes between Conisborough and Clifton. It is 
coarse and massive. On the hill-side, opposite the town, a 
section is exposed at the Ashfield Fire-clay Works, exhibiting 
the following sequence : — 
PERMIAN LBfESTONE. 
Ft. Ins. 
Variegated Red Marls ... ... liO 0 
Sandstone, coloured Red ... ... ... 5 0 
Yellow Clay ... ... ... ... 2 0 
Blue Clay ... ... ... ... ... 6 0 
Yellow Ferruginous Clay ... ... ... 12 0 
Yellow Sandstone ... ... . • ... 14 0 
Series of Blue Clays, Ac, v^c. 
The variegated marls are probably belonging to the 
