‘ 
ON THE CIRCULATION OF UNDERGROUND WATERS. 389 
xe Feet from surface, Feet thickness, 
_- about about 
( Lower 
) Permian 
1900 0 Red sandstone P ? p : fp ; | See 16 0 
stone 
Earthy limestones, shales, with Anthra- [ Carboni- 
2030 0 cosia, coarse grit, breccia, and marls_. ferous 4 aS0 0 
2030 0 
Tabulating these figures gives the following totals :— 
ft. in. 
Brith av. ‘ ; : 10 0 
Lias : ; : : 65 0 
Rhetic . : ; : 66 0 ft. ins 
Keuper marls : , 573 0 y - 736 OV o- 
Bi iat otomet : : ; 244 0 ; y 142 0 ¢ 878 
Bunter . : F ‘ 542 0 
Permian . : ; 400 0 
Carboniferous ~ : 130 0 
2030 0 
Mr. Dalton, F.G.S., late of the Geological Survey of England and 
Wales, has given some different thicknesses as the result of his examina- 
tion of the cores which he has had the opportunity of inspecting, his 
alternative figures are given in the second column above. He refers to 
_ this boring as the Collingham boring, and regards the locality as a centre 
_ of subsidence in Triassic times, and considers the beds there to be of 
abnormal thickness. 
Yorkshire Coal Measures.—The following information as to the thick- 
ness of the intercalated sandstones, in the Yorkshire Coal-measures, and 
their water-bearing capacity, which is of considerable value both as to 
quantity and quality, have been obtained from Professor Green, M.A., 
?.G.S., of the Leeds University. 
The ‘Oakenshaw’ or ‘ Clifton’ rock is generally a massive false- 
_ bedded sandstone, much divided by joints; it is close in grain and gritty 
intexture; it furnishes an excellent and durable building stone. In some 
_ districts it is separated into two beds; in this case the upper bed is 
called the ‘Shertcliffe Bed Seatstones.’ In the Clifton district the two 
beds, with intervening shales, together form the ‘ Clifton rock.’ 
The ‘Thornhill rock,’ the most important middle coal-measure sand- 
stone in the northern part of the field, is the chief source of building-stone 
. 
_ in the district ; it is generally close grained and thin bedded, but is some- 
times coarse; in places it is much traversed by vertical joints. It 
urs below the Haigh Moor coal, and also bears the names of the Dews- 
bury Bank, Morley, Middleton, Robin Hood, and Oulton rock ; below it 
is the Joan coal. 
‘Parkgate rock,’ ‘ Croppergate,’ or ‘ Birstall rock’ occurs above the 
Parkgate coal. At Scholes Colliery it is 80 feet thick; at the Nunnery 
sinking 90 feet; at the old Pits Moor OCollieries it is nearly 170 feet, 
where it is thickest ; itis thickly bedded, rather coarse, and much jointed, 
and yields abundance of water, necessitating heavy pumping to work the 
coal when there is no intervening bind above the seam, as is sometimes 
‘the case. It is largely quarried at the village of Bradgate, and hence 
William Smith called it the ‘ Bradgate rock.’ 
_ The ‘Woolley Edge rock’ is believed to have been deposited in an 
area bounded by a line running west between Pontefract and Castleford, 
