|
This was billed as The Ice Age in Warwickshire, but as Dr Bradley
has now agreed to lead a field trip for the Society on this subject, he said he would prefer to leave that period for discussion
on the ground at the appropriate time, and instead, he showed by means of very ingenious floor-standing, roll-away illustrated
posters the Geology of Warwickshire and the locations at which rocks of all ages, from the pre-Cambrian period to the Quaternary
may be seen. South of Atherstone are some of the oldest rocks in the English
Midlands. Pre-Cambrian volcanic tuffs and ashes are layered in Mancetter Quarry and Purley Quarry
has the Nuneaton Ridge of hard Cambrian rock standing out above the flat farmland lying on Triassic rocks. There are Ordovician sills of dark, hard lamprophyre which has been found in axe hammers, but is now quarried for
road surfacing with asphalt.
To the west of this is a small strip of Devonian Old Red Sandstone. East
of Coventry an old coal mine of the Carboniferous is now a Wild Life Trust site and fossilised plants can be found. Around Atherstone are Permo-Trias rocks. The desert dust was
so fine it gave us loess – like a Saharan dust deposit – which settled in the lakes as Mercian Mudstone (the old
Keuper Marl). In the south of the county, towards the Cotswolds, there is
Jurassic, with all its associated fossils.Henry Moore used Hornton Stone for many of his sculptures. There are patchy, thin deposits of Tertiary rocks over much of the county, especially
in river valleys. Hand axes are found in the sand and gravels of Quaternary drift. At this point, there was a break for tea, coffee and the Christmas foodstuffs brought by members.Recalcitrance
on the part of the computer controlled video allowed this to be longer than usual! On resumption, the Ice Age was briefly touched upon, but the mysteries of
Lake Harrison await the field trip!
Jean Baxter
|
