19th May - Geological wander around Failand

Saturday, 19th May 10am-5pm. Cost £20
Many people will be familiar with the Failand Ridge, even though they may not live nearby! It is the prominent wooded ridge to the left (east) as you drive south along the M5 past Gordano Services after crossing the Avon bridge, and whose continuation you drive up and over on the split-level section of the motorway with the large limestone cliff on the left. Travelling northeast, the same ridge forms both sides of the Avon Gorge, where it is cut through by that river. Geologically, it forms the southern limb of the Westbury (-on-Trym) Anticline, a limb much broken by thrust faults formed at the same time as the folding. The overlying Coal Measures, to the south, and the underlying Lower Old Red Sandstone to the north, were both much less resistant to erosion than the Upper Old Red Sandstone and Carboniferous Limestone which make up the ridge and were quickly worn down following folding at the end of the Carboniferous period (about 300 Ma). These lowland areas became the focus for deposition during the Triassic period of hot deserts, before complete burial of the whole landscape by Jurassic and Cretaceous rocks. The modern landscape is essentially much the same as the Triassic one, now exhumed from beneath the eroded Mesozoic cover.
To enrol, contact Dave Green, via  the  Geostudies website, preferably before this Saturday (12th May), to ensure the course runs. He will then contact you with details of meeting point and itinerary for the day.