Geology Reference
In-Depth Information
3
Suffossion dolines form in an analogous manner
to subjacent karst-collapse dolines, with a blanket
of superficial deposits or thick soil being washed
or falling into widened joints and solution pipes
in the limestone beneath (Figure 8.7c). In England,
the 'shakeholes' of Craven, near Ingleborough,
northern England, are conical suffossion dolines
in glacial moraine laid upon the limestone dur-
ing the ultimate Pleistocene glaciation (Sweeting
1950).
breakage of soil or rock (Figure 8.7d). Natural dolines
of subsidence origin are rare and are found where the
dissolution of underground evaporite beds occurs, as
in Cheshire, England, where salt extraction from Tri-
assic rocks has produced depressions on the surface,
locally known as flashes .
5 Alluvial stream-sink dolines form in alluvium
where streams descend into underlying calcareous
rocks. The stream-sink is the point at which a stream
disappears underground. Several examples are found
in the White Peak District of Derbyshire, England
(Figure 8.8).
4
Subsidence dolines form gradually by the sagging or
settling of the ground surface without any manifest
Nan Tor Cave
N
100 m
S
Hoo
Wetton Mill
Streamsink
Yelpersley
Tor Cave
Old Hannah
Woman's Hall
S
Redhurst
Swallet
Reef limestone
Bedded limestone
Permanent stream
Intermittent stream
Dry valley
Streamsink
Inflow cave
Outflow cave
S
Figure 8.8 Stream-sinks on the River Manifold in the English Peak District.
Source: Adapted from Warwick (1953)
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