Monday, 15 March 2010

27th March - Charterhouse & Burrington Combe

Do join us on Saturday 27th March for this excellent field trip to the Mendip Hills to be led by Dr. Peter Hardy.
Field trip assembly point is at the roadside at the stile into Ubley Warren, ST 504 554 at 10.30 a.m.
Further details about car parking and for the day can be found on the Bath Geological Society website.
At Charterhouse we shall observe the relationship between the land-forms and the geology, especially the three main rock types, i.e. Devonian clastic sediments, Lower Carboniferous shales and limestones. The additional feature which is well seen here is the site of extraction of lead ore over the past two millennia, dating back at least to the Roman occupation of Britain, and the more recent evidence for local smelting of lead from the mineral veins.
At Burrington we shall examine in greater detail the lithologies and fossil content of the above-mentioned sediments, especially those of the limestones, but also a little of the shales. Loose specimens of the Devonian sandstone are also present in the lowest parts of the combe, and in addition we shall see sedimentary deposits from the Palaeozoic/Mesozoic transition of the Triassic sequence, represented here by coarse conglomerates which rest on an early valley floor formed when the combe was a desert wadi on the slopes of the newly elevated hills.
Everyone is welcome - visitors £2.00.
(The photo is from the British Geological Survey - click here for more details)

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