266 
The Agriculture of Staffordshire. 
geological structure by the surface configuration alone. The 
"rough rock," or 1st grit, forms the upper bed of the millstone 
series. It is a coarse massive grit, crumbling under the action 
of the air, on account of the decomposition of felspar, which it 
contains in large quantity. The ord grit is called the escarp- 
ment grit. The edges formed by its outcrop often run for miles 
in an unbroken wall of rock. Between the grit and the mountain 
limestone lies a group of shales and sandstones. A close-grained 
grit is largely quarried for foundation-stones, &c. 
In the South Staffordshire coal-fields the mountain limestone 
and millstone grit, on which the Pottery coal measures rest, are 
entirely wanting. The older strata are represented in the range 
of hills thrown up at Sedgeley, Dudley, and Rowley Regis, 
which run in a south-eastern direction, and by their intrusion 
into the centre of the coal-field divide it into two portions. At 
the two first-named places the beds consist of members of the 
Upper Silurian limestone. At Rowley the intrusive rock is of 
basalt. Igneous rocks also appear at Wednesfield, near Wolver- 
hampton, and near Bentley Hall. Around Walsall the Woolhope 
and other limestone beds have also been lifted up from beneath 
the coal strata. The southern coal-field, narrowing as it extends 
northwards, is prolonged through Cannock Chase to Beau Desert 
and Brereton, where it terminates, in what looks, on a map of 
the strata, like the point of a promontory extending into the 
great sea of new red sandstone, which spreads over the gi'cater 
part of Staffordshire. 
The new red sandstone consists of the Bunter conglomerates 
and sandstones, Keuper sandstones and red marls. These beds 
cover the large tract of country lying between the North and 
South Staffordshire coal-fields, and, except the patches of lias in 
Needwood Forest, extend without intermission from Tamworth 
and Burton to Cheadle. Nearly the whole of Cannock Chase, 
east of Cannock, consists of Bunter conglomerates, generally in 
an unconsolidated condition. The surface generally presents a 
curiously rounded appearance. These beds also occur at Whit- 
more and Cheadle. Castle Ring, at Beau Desert, 900 feet above 
the sea-level, is capped with a deposit of drift gravel 24 feet deep. 
The Keuper beds consist of even-bedded sandstones witli 
marly interstratifications, as at Ingestre, Sandon, near Stafford, 
between Lichfield and Beau Desert, and at Alton Towers. The 
lower division of the Keuper beds is quarried at Hollington, 
where it assumes the form of a white siliceous freestone, which is 
largely quarried here and elsewhere for building. 
The marls are a very important deposit in an agricultural 
point of view; they generally occupy broad level tracts of 
country, and in some localities they attain a thickness of 1000 
