Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/740

538 beach-rolling, it would seem that the implements are derived from the white gravel. At Bournemouth also they are generally white, so that it would appear that on the Hampshire coast the implements lie near the top of the gravel, and not, as is generally the case, near the base.

The general features of the Isle of Wight are well known. A chalk range running east and west, and attaining an elevation of nearly 700 feet, divides the island into two nearly equal parts, and is traversed by three river-valleys, at Freshwater, at Newport, and at Brading. More than three quarters of the island is drained by the rivers thus flowing northward to the Solent and Spithead.

(a) In the northern part of the island the flat-topped hills are capped with flint-gravel at from 100 to 300 feet above the sea; and though the evidences of a once continuous gravel-covered tableland are not so plain as on the mainland, section No. 10, from St. George's Down to Norris, shows how the gravel covering the hills coincides with a plain having a uniform slope towards the north. Detached patches of similar gravel on Hempstead Cliff, 200 feet, and on Headon Hill, 390 feet above the sea, may also be looked upon as remnants of a tableland comparable to that on the mainland, but sloping northwards.

The gravel differs but little from that on the mainland. It contains, however, besides chalk-flints and tertiary pebbles, Upper-Greensand chert and materials from the Lower-Greensand beds. In the gravel on the cliff near Egypt, to the west of Cowes, at about 130 feet above the sea, I found a large liver-coloured pebble evidently derived from the New Bed Conglomerate beds. This, with the white quartz and granitic pebbles already noticed as occurring in the gravel at Lymington and on Poole Heath, establishes a connexion with country far to the westward, which is worthy of notice.

As on the mainland, neither shells nor bones of any sort have been found in this gravel, though the valley-gravels have afforded mammalian remains in some abundance; Mr. E. P. Wilkins, of Newport, records the discovery in the gravels of the Medina valley of teeth and bones of the mammoth, rhinoceros, horse, ox, deer, and hog.

(b) To the south of the chalk range there are gravels which, though lying at considerable elevations, do not appear to be fragments of a tabular surface, but rather to be high-level gravels connected with the rivers which drain the southern part of the island, and flow northward through the chalk range. Such is the gravel on Blakedown, 270 feet above the sea and 170 feet above the adjacent stream, and that at Whitcomb, 260 feet above the sea and 160 feet above the stream.

With them may be also classed the deposit of gravel and loam which caps the cliffs between Blackgang Chine and Compton Bay.