. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 382 Mr. J. F. Walker on a Phosphatic Deposit At a coprolite-working on the left side of the line, looking towards Cambridge, a few yards from the edge of the cutting, the bed increases in thickness to 2 feet. At a large working on the hill the conglomerate bed is about 6 feet thick; the section is as follows :— .fe^iU-G^MUj-jg^O^aj^. 1. Sandstone, on which conglomerate rests. 2. Conglomerate bed, 6 feet. 3. Flaggy sandstone, not exceeding 1 foot in thickness (often less), and
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. 382 Mr. J. F. Walker on a Phosphatic Deposit At a coprolite-working on the left side of the line, looking towards Cambridge, a few yards from the edge of the cutting, the bed increases in thickness to 2 feet. At a large working on the hill the conglomerate bed is about 6 feet thick; the section is as follows :— .fe^iU-G^MUj-jg^O^aj^. 1. Sandstone, on which conglomerate rests. 2. Conglomerate bed, 6 feet. 3. Flaggy sandstone, not exceeding 1 foot in thickness (often less), and surface soil. The lower part of the conglomerate is here darker in colour and more indurated than the upper. On the other side of the road is another working, where the nodules lie in loose sand, and the phosphatic bed is about 1 foot thick. There are several other workings in the neighbourhood. The conglomerate contains phosphatic nodules and pebbles in about equal proportions. The bed is dug out and sifted, washed and laid in heaps, and then conveyed into sheds, where the no- dules are picked out by hand. The quantity of phosphoric acid in the nodules varies from fifteen to twenty-two per cent. It seems to be the opinion of Mr. H. Seeley that this bed is the southern extension of the Carstone, which, in a former paper*, he has stated to represent the Gault and the Shanklin Sands. But the Gault in this district is represented by a clay lying beneath the Upper Greensand. Therefore, if his views be correct, the term Carstone is inapplicable to this bed. Mr. Seeley states that this deposit " reproduces earlier in time the conditions of the Cambridge ; The Greensand of Cambridge consists of a fine marl which eflPervesces briskly with hydrochloric acid; it also contains green grains, angular boulders, and hard dark-coloured nodules of phosphatic matter, often covered with Plicatulce; lumps of iron pyrites are occasionally found. All the fossil shells are fille
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