Geology Reference
In-Depth Information
Weathered chalk
Weathered sand
()
a
PALAEOCENE SANDS
CHALK
Red Crag Sea
()
b
Red Crag sediments
()
c
()
d
()
e
Late Neogene surface
Chalk
escarpment
Sub-Palaeogene
surface
Chalk uplands
Backslope bench
Figure 15.6
Cartoon depiction of a possible evolutionary model for the prominent backslope bench of the London
Basin involving modified etchplanation. (a) Neogene duricrusted surface of low relief. (b) Red Crag incursion (see
Figure 15.5) following downwarping to the east. (c) After marine regression. (d) Accentuated weathering beneath
former marine platform leads to the development of an etchsurface. (e) Differential uplift in the Pleistocene leads to
dissection and the removal of much regolith with the remainder greatly disturbed and mixed by periglaciation.
Source:
After Jones (1999). Reproduced by permission of the Geological Society, London, and David Jones
of the late Palaeogene Summit Surface. In
some areas, including the West Country table-
lands and the Chilterns, the limited scale of
deformation aided the survival and continuing
development of the late Palaeogene Summit Sur-
face, sometimes to such a negligible degree that
the
morphostasis
during
the
Neogene
seems
likely.