Abstract
During the new geological survey of the Hampshire Basin fresh evidence was discovered of the westerly extension of certain of the deposits, in the form of Eocene river-gravels. This evidence tended to link more closely the Eocene deposits of Devon with those of the Hampshire Basin; but it did not seem to throw any light on the Eocene geology of Cornwall, nor of any part of the area west of Dartmoor. Some years since (in 1897) during a holiday-visit to the Lizard, I was much impressed by the character of the material which forms the extensive shingle-beach at Gunwalloe, on the western side of the Lizard promontory, not far from Mullion. The shingle, which was being extensively carted away for gravel, was so perfectly rounded, and in appearance was so unlike anything that I had expected to find in Cornwall, that I examined it closely, taking away samples to give to the Museum of Practical Geology, Jermyn Street. The coarser beach proved to consist largely (about 70 per cent. by weight.) of Chalk-flint and Greensand-chert, only 30 per cent. being Palaeozoic at the spot where it was examined. A large quantity of the fine shingle yielded :— At the time, I was unable to carry the matter further; for, although well aware that scattered Chalk-flints were not uncommon in Cornwall, I could not understand why so many had collected at this spot, almost to the exclusion of the local rocks. The absence of Chalk-flints from the Pliocene gravels of St.
Published Version
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