This month's talk will be given by Professor Peter Styles of Keele University. He notes:
'The United Kingdom has a complicated Geological History with
records of almost all parts of the geological record for such a small country
as it has been the site of much more dramatic tectonic episodes than we might
suspect now from its tranquil repose.
It may not be surprising that Wales and Scotland did not
originally form part of what we Geologist call Avalonia but have been forcibly cemented
onto the main central block with associated Volcanoes, earthquakes and faulting
in the relatively recent past of 500 Million years!
The Cheshire Basin is a consequence of one of those periods
of faulting as it sits in a lopsided basin which deepens south-east from the Chester
area toward the south and east where the basin may be more than 7 kilometres
deep against the Wem-Bridgmere-Red Rock Fault which bounds the basin. A fringe
of coal again surrounds this in the Macclesfield area.
Most of the geology of Cheshire has been controlled by this subsiding
basin where thick Coal deposits are followed by Red Sandstones and thick Salt
deposits , the basis of the Cheshire Chemical Industry, formed as the basin
progressively subsided. Later rocks were mostly scraped away by the Ice Age
ice sheets which have sculpted the surface leaving the Cheshire plain with occasional
interruptions such as the Peckfortons and Alderley Edge where Copper deposits
have been exploited along faults.
This lecture will show how the British Isles have formed and
specifically how the Geology and Landscape of Cheshire has been superimposed on
the framework that Plate Tectonics left us.'
Usual time 7:30 in Tiverton village hall. Visitors welcome.
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