A HISTORY OF BERKSHIRE anywhere near Berkshire, and a great deal of ice work may take place in a river without a glacial period. All that can at present be said is that the Glacial period covers a portion, perhaps a large portion, of the time during which the present surface features of Berkshire were carved out and its gravels deposited. The valley gravel is very sandy in places and often contains an abundant supply of water, which Mr. Blake remarks is of good quality but very liable to pollution. The quartzite boulders above mentioned are very hard, and often used as cobbles. CHALK RUBBLE. In some of the valleys in the chalk district and on the sides of the chalk downs there have accumulated patches of gravel consisting of fragments of chalk and irregular or broken flints. In one. of these patches at Chilton, nearly 400 feet above the sea, Sir Joseph Prestwich found a quantity of mammalian remains and land shells, with which were associated two species of mollusca, Planorbis albus, Ltnncea truncatula, which are of amphibious habit. He compares this interesting deposit to the beds of angular rubble overlying the raised beaches of Sangatte and Brighton. 1 ALLUVIUM is the modern deposit of our rivers. It is muddy or silty, and small sections may be seen in the river banks. In Lyson's Magna Britannia (1806), i. 192, it is noted that peat is found in the vale of the Kennet on both sides of the river for several miles above and below the town of Newbury. ' The stratum of peat lies at various depths below the surface of the ground, and varies in thickness from i to 8 or 9 feet. Horns, heads and bones of various animals have been found in the peat.' Professor Rupert Jones in 1879 referred to a place near Newbury where the peat had been excavated a comparatively few years previously, and which had become entirely rilled up with fresh accumulations of vegetable growth, Equisetum having been an active agent among the plants. 2 A well in London Road, Newbury, passed through 15 feet of drift. At the bottom there was 3 feet of gravel, above it z feet of peat and 6 feet of malm, and then more gravel forming the surface of the ground. Speaking of the river Kennet near Hungerford and the soil around that place Dr. Stukeley, writing as long ago as 1724, says : ' I have often wished that a map of soils was accurately made, promising to myself that such a curiosity would furnish us with some new notions of geography and of the theory of the earth.' 3 An interesting and early suggestion in favour of a geological map. 1 J. Prestwich, Quart. Journ. Geol. Sac. (1882), xxxviii. 127 ; A. J. Jukes-Browne, Proe. Geol. Atsoc. (1889-90), xi. 204. 2 Proc. Geol. Assoc. (1879-80), vi. 188 ; see also T. R. Jones, A Lecture on the Geological History of Netobury, Berks (8vo, London, 1854), where lists of the fossils are given. 3 Itinerant* Curiosum (1724, fol. London), p. 60. 22
