309 
CHAPTER XII. 
ECONOMIC GEOLOGY (continued). 
AGRICULTURE, SPRINGS, AND WATER SUPPLY. 
Physical Features. 
THE physical features being dependent on the nature and 
inclination of the rocks, we find the more prominent ridges or 
escarpments formed by the Lower Lias Limestones and by the 
Marl stone. 
The Lias in Dorsetshire is more or less masked by coverings 
of Cretaceous rocks, but further north the Lower Lias forms 
a marked escarpment near Curry Rivell on the borders of the 
Vale of Taunton, and again in the Polden Hills. These are per- 
haps the most conspicuous features in the entire area, formed by 
the Lower Lias ; minor escarpments are formed in North Glou- 
cestershire, Worcestershire, and Warwickshire. The more 
elevated tracts found in other places, as on the Leicestershire 
Wolds, are largely formed of Glacial Drift. 
The Marlstone and underlying sandy beds, form a marked 
escarpment between Ilminster and Yeovil, but onwards along the 
main Oolite escarpment, the Middle Lias is nowhere very promi- 
nent, except near Dursley and Stinchcombe, where it forms a 
platform beneath the main escarpment of the Cotteswold Hills. 
It reaches its highest elevation in the fine scarp of Edge Hill 
(710 feet), and in Northamptonshire and Leicestershire it stands 
out more or less prominently, rising to a height of 755 feet at 
Tilton-on-the-Hill, and forming a conspicuous hill in the Vale of 
Belvoir, crowned by Belvoir Castle. 
The main mass of Lias Clays, comprising the higher portions 
of the Lower Lias and the lower portions of the Middle Lias, 
forms a succession of vales. These include the vales of Marsh- 
wood, in Dorsetshire ; of Ilchester and Sedgemoor (in part), in 
Somersetshire ; of Glamorgan ; of Berkeley, Gloucester, Chelten- 
ham, Winchcomb, and Moretou, in Gloucestershire ; of Evesham, 
in Worcestershire and Gloucestershire ; of Shipston and of the 
" Red Horse," in Warwickshire ; and of Catmos, Mowbray, and 
Belvoir, in Rutlandshire, Leicestershire, and Nottinghamshire. 
Further remarks on the character of the scenery and the causes 
influencing it, are reserved for a subsequent volume dealing with 
the Oolitic rocks. 
Drift Deposits, 
In the south-western counties the Liassic rocks are compara- 
tively free from Drift, and it is not until we pass to the north and 
