Field Meeting on the Central Malverns Complexes
–
11 May
Saturday 11 May (Field Meeting): Central Malverns Complexes. Led by John Moseley (Gloucestershire Conservation Trust). Meet at 10.00 in Upper Tollgate Quarry (also known as Upper Wyche Quarry) which is used as a car park GR: SO7695 4395. This is the more southerly of the Tollgate Quarries. Parking costs £5.50 for the day, but covers all the Malvern Hills car parks if we need to move. Payment is by card only. Bring a packed lunch.
At the Tollgate quarries we will look at the Upper Silurian and Llandovery/Malvernian unconformity. Here there is a good range of foliated rocks of igneous origins, mainly granitic and dioritic, and evidence of a sheared dyke, and an enigmatic feldspar-hornblende-biotite rock. Here we can open discussion on topics such as metasomatism, and brittle and ductile shearing. From the Tollgate quarries, we will walk through the Wyche cutting, where there is evidence of mylonites and pseudotachylites. Then there will be a short walk onto Perseverance Hill to observe granitic rocks with gneissose and schistose textures. From here there are excellent views, and a chance to put the Malvernian in its regional context.
After lunch there are various options: a section through Upper Silurian on the west side of the Malverns (quite close to Wyche Cutting) and/or Gullet Quarry for the Llandovery-Malvernian unconformity. Total walking: approx 4km. Aim to finish by 4.00.