Page:VCH Warwickshire 1.djvu/59

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GEOLOGY flints, and was apparently derived from the north-east and east. The third or local drift lies at the foot of some of the Oolitic hills and appears to be made of exclusively local materials. Lastly comes the jiuviatile type, a mixture of the other three ; it occurs in patches along the Avon valley and is traceable from Lawford to Defford at heights ranging up to 40 feet above the river, and is the only drift containing organic remains of contemporaneous origin ; from it have been obtained shells of mollusca and bones of mammalia at various places, including Lawford and Shottery, at the latter of which were found teeth of elephants. Brodie's papers added much to our knowledge, and he has recorded details 1 of an extensive deposit of drift over the tableland lying to the north-west of Warwick and extending thence in the direction of Birmingham. Occasional large rounded boulders of sandstone occur, but generally the pebbles are small and consist of sandstone and quartz. Flints are present, especially at Hazeley and Hatton, ' where masses of large unrolled flints occur, looking as fresh as if they had lately come from a chalkpit.' At Rowington the soil of a small field contained little bits of very hard chalk rounded and scratched, and there were present also flints, pieces of greensand, and fragments of various Jurassic rocks, together with Carboniferous sandstone with plant remains, and several boulders of igneous rocks such as granite and syenite. The Lias outlier of Brown's Wood, south-west of Henley-in-Arden (see p. 18), is covered with drift derived from districts lying to the north. At the same time Brodie pointed out that fossils similar to those then recently found in the Lower Silurian pebbles of the Trias of Budleigh Salterton in Devonshire are to be found in some of the quartzose pebbles of the Warwickshire drift, and this observation has since been confirmed by Mr. W. J. Harrison. 2 Mr. T. G. B. Lloyd 3 in 1870 recorded certain observations on the drift of the Avon valley and pointed out the occurrence on the higher ground of a bed of chalky boulder clay, a stiff" compact mass of sandy unstratified clay or earth, from slaty-blue to purple in colour, full of grooved and striated pieces of Lias limestone, white chalk, quartzite pebbles, flints and syenite boulders. This seems to be specially preva- lent over the outcrop of the Lias, changing its colour to red where it overlies the Trias. Associated with this typical boulder clay are irregu- lar and impersistent beds of sand and gravel. On the lower grounds are beds of quartzose flinty gravel and local drift containing shells and bones of mammals. Chalky boulder clay to a depth of 30 feet has been described by Mr. W. Andrews 4 as occurring in a railway cutting at Berkswell. The deposits of the neighbourhood of Rugby have been described by Mr. J. M. Wilson & under two heads high level deposits and valley 1 Brodie, Quart. Journ. Geol. See. xxiii. (1867), 208. 8 Proc. Birm. Phil. Soc. (1882), p. 157. 3 Quart. Journ. Geol. Soc. xxvi. (1870), 202.

  • Proc. Warw. Field Club, 1884. Quart. Journ. Geol. Soc. xxvi. (1870), 192.

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