TY  - UNPB
Y1  - 1971///
A1  - Brown, MJF
AV  - public
EP  - 548
N1  - Thesis digitised by British Library EThOS
N2  - During the last glaciation the area was invaded by two
distinct ice sheets. One, from the Irish Sea basin, pushed
southwards across the Cheshire - Shropshire Plain and sent
a lobe down the Vale of Stretton and onto the northern
slopes of the Long Mynd. The other was nourished in the
Plynlimon massif and advanced from the west.
Directions of ice movement, inferred from the orientation
of ice-moulded landforms, drumlins, striations and the
distribution of erratics, are complex, but the broad valleys
were the main avenues of advance.
Drift generally occupies valleys and covers the lower
hillslopes, while erratics and scattered patches of till are
found at higher altitudes.
At the glacial maximum all save perhaps the highest
hill summits were ice-covered. The Stiperstones tors are
unreliable indicators of an inglaciated enclave.
Deglaciation was characterised by a gradual downwastage,
retreat and stagnation of the margins of the ice. Complex
systems of subglacial drainage channels were cut in the Vale
of Strettoa, and on all the major hill masses up to 1,300ft.
Kaure moraines deposited across the Onny valley at Lydham Heath
and the Mule - Caebitra valley at Sarn, indicate pauses in
the ice retreat. Kamiform topography is also a feature of the
northern slopes of the Long Mynd and the Vale of Stretton.
Several important changes in, the drainage pattern resulted
from glaciation. The Mule and Camlad were diverted across
pre-glacial watersheds through meltwater channels, while the
Onny was diverted through an ice-breached col and meltwater
channel at the southern end of the Long Mynd.
Radiocarbon dating of shells in the drifts at Iron Bridge,
and of other drifts on the margins of the Welsh massif, indicate
that the last glaciation of southern Shropshire was of Main
Wurm age.
TI  - The glacial geomorphology of parts of South West Shropshire and Montgomeryshire
PB  - University of London
UR  - https://discovery-pp.ucl.ac.uk/id/eprint/1350024/
ID  - discovery1350024
M1  - Doctoral
ER  -