Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/279

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1869.]
WILTSHIRE—HUNSTANTON RED CHALK.
185


2. On the Red Chalk of Hunstanton. By the Rev. T. Wiltshire, M.A., F.L.S., F.G.S.

Section of Hunstanton Cliff

Section of Hunstanton Cliff
Section of Hunstanton Cliff

* A thickness of upwards of 30 feet is here omitted for convenience.

Not far from the apex of the angle which the Wash, opening out into the German Ocean, forms on the western coast of Norfolk, is situated a cliff of about a mile in length and 50 or 60 feet in height, on which, at its greatest elevation, is erected the Hunstanton Lighthouse. This headland, which gradually rises from the low ground on the north, and finally sinks towards the south through the effect of local denudation, is remarkable, even when viewed from a distance, from the circumstance that its face is marked by three parallel coloured bands, slightly inclined, and cropping out in succession on the surface soil, of which bands the uppermost is white, the next bright red, and the lowest yellow, each division being sharply defined, without any intermingling of tints at the lines of contact. A close inspection shows that the highest stratum, the white, consists of a hard calcareous substance, compact in texture, and much shattered and fissured, originally deposited in such a manner that its materials were arranged in definite layers, two of which (a, b), those forming the base, are represented in the annexed section drawn to scale. The first of these (a), in thickness about 2 feet 6 inches, is noticeable for the presence of an enormous quantity of fragments of Inocerami dispersed throughout its whole extent, and which under the influence of weathering impart to this portion of the cliff a jagged and rough appearance. Its characteristic fossils are spines of Cidaris vesiculosa, Holaster planus, Vermicularia umbonata, Terebratulina