London and the Thames Valley Region - Southern England - page 197

FIG 186. Location map for Area 10.
FIG 187. Natural and man-made features of Area 10.
The bedrock of Area 10 ranges from Jurassic to Early Tertiary in age (Fig. 189),
and the distinctive patterns of hills and valleys in each of the four Landscapes cor-
respond directly to the different bedrocks that underlie them. Each Landscape is con-
sidered in turn below.
Landscape A: The Cotswold Hills of Middle Jurassic limestone
The upper Thames and Avon valleys are bordered in the northwest by the Cotswold
Hills, which trend roughly northeast from Bath (see Area 8), across the corner of Area
10 towards Northamptonshire (see Area 9). The Cotswolds are formed of Middle Jur-
assic layers, often oolitic and shelly limestones with an average thickness of about 100