Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/741

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
1870.]
CODRINGTON—HAMPSHIRE AND ISLE-OF-WIGHT GRAVELS.
539

Near the former place it attains a height of 300 feet above the sea, and undulating with the cliff- section, it falls as low as 50 feet opposite Compton Grange, rising again to 100 feet to the west of this, where the gravel thins out; but the overlying brick-earth is continued for some distance further. The gravel consists of flints, with chert and ironstone; it contains sand-seams, and is overlain by evenly bedded brick-earth. To the east of Brook Chine the gravel is as much as 15 feet thick, and the brick-earth 12 feet.

At two points in this deposit, at about 100 yards east of Grange Chine, between 60 and 70 feet above the sea, and at half a mile east of Brook Chine, and about 96 feet above the sea, Mr. Wilkins informs me that remains of Elephas primigenius have been found. In both cases they were from the gravel continuously capping the cliff, and not in valleys connected with the Chines.

At a small Chine called Sheppard's Chine, a mile west of Brook, are the peaty beds with hazel-nuts and twigs, which have been often described as lying beneath the gravel[1]. In August, 1868, it was plain that these beds were in a hollow in the gravel, which was 2 feet 6 inches thick beneath them. Over the seams of sand containing vegetable matter lies 5 feet of sandy brick-earth.

(c) Within two miles of the western end of the deposit which caps the cliff continuously from Blackgang Chine, are the mammaliferous gravels of Freshwater, which were described by Mr. Godwin-Austen in Forbes' s Memoir; and his description in 1853 corresponds well with the section now exposed. The lower beds contain subangular chalk-flints, with much lower cretaceous ironstone and chert, and bands of coarse sand, the whole stained of a red-brown colour. These beds rest on the chalk, and against a rearranged formation of chalk-flints in a chalky paste, which is perhaps a talus formed by subaërial weathering of the chalk before the deposition of the gravel. A curved line sloping steeply towards the valley separates the lowest beds from a similar gravel of a lighter colour, which is not always to be clearly distinguished from the former. A third gravel is again sharply divided from the second by a curved line sloping towards the valley. It is finer, more sandy, with much cross bedding, and contains many small white chalk-pebbles; and it was in this that the molar of Elephas primigenius, now preserved at the Albion Hotel, was found at a few feet above high-water level. Over all the gravel- deposits lies a stratum of brick-earth from 4 to 13 feet thick, containing seams of angular fragments of flint, which reaches a height of about 60 feet above the sea towards the Fort. On the east side of the valley another molar of Elephas primigenius was found in the gravel, and there are many shells of Succinea and Pupa in the overlying brick-earth.

(d) There is here exhibited in a sea-cliff a complete section across a river-valley with its gravels ; and the direction in which the river flowed was clearly from the southward, and seaward. The

  1. Vide Webster in Sir H. Englefield's 'Isle of Wight;' Geological Survey Map and Memoir; Mr. Bristow in Forbes's Memoir on the Fluviomarine Tertiaries of the Isle of Wight; Mr. Godwin-Austen, Quart. Journ. Geol. Soc. vol. xi. p. 116.