1848.) | ORMEROD ON THE SALT-FIELD OF CHESHIRE. 269 
of this equals a portion of the thickness of the carboniferous limestone, 
the whole of the thickness of the millstone and coal-measures, and 
the greater part of the thickness of the new red sandstone. The red 
sandstone at Meer Lake has been already noticed. From this point 
to Madley and Whitmore the district is so covered with drift that the 
eastern basset of the new red sandstone is not exposed. 
The broad valley extending from near Malpas to Congleton, sweep- 
ing in a crescent between the red sandstone hills of Shropshire and 
the Staffordshire coal-field on the one side, and the high ground of 
the Peckforton hills and Delamere range on the other, appears to be 
occupied by the saliferous and gypseous beds, lying as it were in a 
trough, to which the adjoining portions of both the above ranges dip. 
At but few places in this valley, or trough of the salt-measures, do 
natural or artificial sections extending down to the rock occur. The 
country is mostly level and covered with deep drift. In the absence 
of sections we are compelled to have recourse to other clues. In 
the northern part of the county, as at Winsford and Northwich, the 
melting of the beds of rock-salt by the overlying brine causes subsi- 
dences of the ground. Similar subsidences have taken place in the 
southern districts, few indeed in number, but sufficient to connect the 
points where the presence of brine is proved. 
The most southerly point at which brine has been worked is at 
Dirtwich, or Foulwich, situate on the boundary of Cheshire, about 
two miles to the south of Malpas. 
The last pit was sunk through clay to the depth of 450 feet (or by 
estimation 300 feet below sea-level). The brine comes into the shaft 
at the depth of 60 feet in a small stream about the thickness of a 
finger. 
Proceeding in a north-easterly direction, at Bickley, situate about 
three miles to the east of Malpas, a subsidence of the ground took 
place on the 8th of July 1659. (Ormerod’s ‘ Cheshire,’ vol. ii. p. 361.) 
The place is called the Barrel-fall, and is now dry and overgrown with 
brush-wood. 
At Combermere Abbey, about four miles to the south-east of Bick- 
ley and the same distance to the north-east of Whitchurch, a subsi- 
dence took place and the pool was filled with brine, which was worked 
about 1533. 
At Audlem, further to the east, the brine-springs rise to the surface. 
At Moss-hall Farm near Audlem, and other places im that vicinity, 
the red marls crop out from under the lias shale and dip S.W. and S. 
5° to 7°. To the south-east of the country just noticed, which occu- 
pies the valley lying to the south-east of the Peckforton range, lias 
and lias shale occur. They form a slightly elevated pear-shaped 
district, the northern side reaching from Wem by Whixall, Tilstock, 
Burley Dam and Brooks Mill to near Audlem, and overlying the sa- 
liferous or gypseous marls. This district is described in Murthison’s 
‘Silurian System,’ vol. i. p. 25. This continuous bed of lias is an 
additional proof of the continuance of the subjacent beds of salt- 
measures. Through the eastern edge of the lias shales (as described 
