Page 216 - Fundamentals of Geomorphology

KARST LANDSCAPES 199

3 Suffossion dolines form in an analogous manner breakage of soil or rock (Figure 8.7d). Natural dolines
to subjacent karst-collapse dolines, with a blanket of subsidence origin are rare and are found where the
of superficial deposits or thick soil being washed dissolution of underground evaporite beds occurs, as
or falling into widened joints and solution pipes in Cheshire, England, where salt extraction fromTri-
in the limestone beneath (Figure 8.7c). In England, assic rocks has produced depressions on the surface,
the ‘shakeholes’ of Craven, near Ingleborough, locally known as flashes.
northern England, are conical suffossion dolines 5 Alluvial stream-sink dolines form in alluvium
in glacial moraine laid upon the limestone dur- where streams descend into underlying calcareous
ing the ultimate Pleistocene glaciation (Sweeting rocks. The stream-sink is the point at which a stream
1950). disappears underground. Several examples are found
4 Subsidence dolines form gradually by the sagging or in the White Peak District of Derbyshire, England
settling of the ground surface without any manifest (Figure 8.8).

Nan Tor Cave N

100 m

S S
Hoo Brook Wetton Mill
W
etton
Mill
Streamsink
Streamsink

elpersley
Y Yelpersley Old Hannah
Hannah
Old
ave
C
T Tor Cave
or
Wo m a n ’ s H a l l
Woman’s Hall
S S
Redhurst
Redhurst
Swallet
Swallet
Reef limestone
Bedded limestone
Permanent stream
Intermittent stream
Dry valley
S Streamsink
Inflow cave
Outflow cave
Figure 8.8 Stream-sinks on the River Manifold in the English Peak District.
Source: Adapted from Warwick (1953)