The high level river gravels in Oxfordshire (the Northern Drift Group), whi
ch range in age from Early Pleistocene to around 450 ka, contain pebbles th
at were derived from a source area to the north near Birmingham. The pebble
s could not have been transported across the Upper Triassic and Lower Juras
sic clay outcrops of the Midlands unless the region was at or close to sea
level. The present day Cotswold escarpment ranges from 70 to 215 m: this up
lift must therefore have occurred after deposition of the Northern Drift Gr
oup, when the drainage of the Midlands appears to have shifted from towards
the Thames basin to the Bristol Channel area. It is concluded that lithosp
heric flexure due to the removal of >500 km(3) of soft Late Triassic and Ea
rly Jurassic clays and marls from large areas of the Midlands and their re-
deposition in the Celtic Deep might account for this Late Pleistocene uplif
t. Uplift in the Midlands is the likely explanation for both the tilted (ap
proximately 0.3 degrees) plateau surface in north Oxfordshire and the chang
e in strike of the Jurassic beds SW of Northamptonshire. Although some upli
ft occurred in SE England during the Early Cenozoic and Miocene, we demonst
rate here that there has been significant uplift of the region in the Late
Pleistocene. The tilted plateau surface in north Oxfordshire may therefore
be a relatively young (i.e. post-450 ka) feature related to tectonic uplift
in the Midlands.