804 
shale, wMcli may be seen by tracing the shales in the bed of 
the stream nearer its source westwards. The shales are 
sandy, and contain a good quantity of mica. 
In the bed of the river Cock, a short distance east of 
Bar wick, beneath beds of thick Yellow Limestone, there is a 
hard sandstone, close-grained, like Calliard; this is not 
coloured, but, where the joints occur in the stone, they are 
often found filled with crystals of Carbonate of Lime. The 
shales, which also occur near the same place, are coloured a 
deep purple. The most probable reason why the sandstone 
is not coloured is its fine, close-grained texture, rendering it 
impervious, or nearly so, to the passage of water percolating 
from the limestone. That water-bearing Carbonate of Lime 
in solution has been present is proved by the lime being 
crystallised and deposited in the cracks of the stone. 
At Gfarforth, the thin-bedded Lower Limestone rests on 
about 12 feet of yellow sand, rather pebbly at the base, 
and very false-bedded. Beneath this are Coal shales, either 
grey or a reddish colour. Towards the south and south-east 
the beds of sand thin out and disappear. 
Passing Kippax, where the sinking of pits beyond the 
Limestone Escarpment have shown the limestone to rest on 
various beds of shale and sandstone, with seams of coal 
belonging to the Coal-measures, at Pontefract a fine section 
has been exposed in making the new line of railway from 
Pontefract to Swinton. A Fault has brought together a 
thick-bedded, soft, yellow sandstone with red marly partings, 
and a series of shales with two beds of coal near the top, in 
the following sequence : — 
Shale 
Coal 
Blue Shale 
Coal 
Yellow Clay, or Shale 
Sandstone, Ferruginous 
Blue Shale 
Sandstone 
Ft. in. 
0 G 
2 0 
0 G 
2 0 
8 0 
10 0 
8 0 
