Note on some Geological Features observable at the Carpalla China-Clay Pit in the Parish of St. Stephen's, Cornwall

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Abstract
This clay-work is situated on the Burngullow branch of the Great Western Railway, about a mile and a half north-west of Burngullow Station, at an elevation of about 550 feet above sea-level. The land slopes generally from the east towards a rather deep valley, the railway running from nearly south to north along the eastern edge of the valley, on a low embankment across two fields where the inclination is very gentle. About the middle of its length, the embankment is traversed from east to west by an accommodation-road, over which the line is carried by an arch of masonry. East of the railway and also on the southern portion of the west side, the ground has been very thoroughly explored by means of pits and shafts, while the northern portion of the west side is fully exposed by the great clay-excavation (the Carpalla clay-pit), now over 100 feet deep. The surface-soil or ‘ meat-earth,’ generally almost black and of a peaty character, covers or has covered the whole estate to a depth of 6 inches or more. Beneath this is everywhere a ‘ growan’ 1 or stratum of subsoil, varying in depth from 2 up to 10 or 12 feet. On each side of the railway from the hedge marked NN on the accompanying plan (fig. 1, p. 156), as far as the accommodation-road above mentioned, this growan rests upon a stratified rock locally known as killas, which is here really a well-marked tourmaline-schist ; beyond the road, it

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