Page:VCH Worcestershire 1.djvu/53

 GEOLOGY An immense break in the series occurs between the Great Oolite and the succeeding deposits which are now found in Worcestershire. We miss all the Middle and Upper Oolites, the whole of the Cretaceous and Tertiary strata, and our next records are those of a time when man had probably appeared on the scenes. In the meanwhile the changes that took place must have been enormous, both as regards the deposition of great masses of strata and their subsequent removal by rain, rivers and sea. There can be little doubt that the Oolites were spread over the Malvern and Lickey areas, in fact over the entire county ; and that they suffered denudation during Upper Cretaceous times, when the Chalk extended far and wide over the country in general. Since then the Chalk has been removed, and the great vale between Malvern and the Cotteswold Hills carved out. GLACIAL DRIFT, VALLEY DEPOSITS AND ALLUVIUM We have at present but very imperfect knowledge of the Drift de- posits of Worcestershire, or indeed of the Vale of Severn. The latest deposit, the ordinary Alluvium, is composed of silt and mud and gravel brought down by the river since it commenced to flow, much in its pre- sent form. It is now liable to be swollen by heavy rains and by rapid thaw after snow, though it is more hampered than at one time by the works of man. Bordering the river at higher levels are beds of gravel, which extend in patches over a wide area in the Vale of Severn and in the Vale of Evesham.^ The gravels are made up of quartzite, quartz, slaty rock, flint and Jurassic material. Some of these patches are old river gravel and brickearth ; they contain Unio and other freshwater mollusca, as well as hippopotamus, rhinoceros, mammoth and other mammalian remains. Sections have been opened up at Cropthorne, Fladbury, Bengeworth, Little Comberton, Eckington, Defford, and Pull Court, near Bushley. Remains of mammoth have been found at Droitwich, and of reindeer at Upton Snodsbury. Again, in what Prestwich has called the ' Rubble Drift,' remains of mammoth and rhinoceros were found in digging the foundations of the Imperial Hotel at Malvern.^ Other deposits of gravel and sand in the Severn Vale contain marine shells, or fragments of marine shells, as well as mammaUan remains. Among the shell-fragments are those of Cyprina islandica, Cardium edule, Lucina borealis, Rissoa, Turritella terebra and Purpura lapillus. One of the localities is Beckford, and here have been found remains of mammoth. Rhinoceros antiquitatis. Bos taurus var. primigenius and reindeer. At Kempsey, near Worcester, and other places along the Severn Valley below Bewdley, both mammoth and rhinoceros have been found. It is by no means unlikely p. 262. 23
 * See T. G. B. Lloyd, Quart. 'Journ. Geol. Soc, vol. xxvi. p. 204.
 * Quart. Journ. Geol. Soc, vol. xlviii. p. 317 ; see also Life and Letters of Prestwich, 1899,