Stockingford Shales - Hartshill Quartzite GEOLOGY Merevale Shales. Oldbury Shales. Purley Shales. Camp Hill Quartzite with Hyolite Limestone. Tuttle Hill Quartzite. Park Hill Quartzite. The Hartshill Quartzite consists of well bedded highly siliceous sandstones, usually of a pale pinkish colour ; the rock is very hard, and according to Mr. Strahan 1 a prepared cubic inch crushes at a pressure of 24,000 Ib. The beds vary in thickness from a few inches to four or five feet. Frequent thin seams of shales occur ; a double band marks the summit of the Park Hill Quartzite, and another separates the middle and upper sub-divisions. ' Worm-burrows ' are the only fossils found in the two lower sub-divisions, but the Camp Hill Quartzite has yielded a small but interesting fauna. The Lower or Park Hill Quartzite is opened up in numerous large quarries, the rock being extensively wrought for roadstone. The lowest layers are best seen at the entrance to Mr. Abel's new quarry near Harts- hill Grange. In this cutting ' the Caldecote tuffs rise in a low anticlinal form, and are visibly overlain to the westwards by the basement bands of the quartzite.' 2 At the entrance to Mr. Boon's quarry the quartzite for some distance upwards from its base ' contains large rounded blocks of Caldecote volcanic rocks, while the matrix is mainly composed of the rounded wash of similar material.' s The Middle or Tuttle Hill Quartzites are being worked in only two quarries, one at Tuttle Hill opposite the Midland Railway station at Nuneaton, and another near Caldecote Windmill. The rocks resemble those of the lower sub-division. The Upper or Camp Hill Quartzite is exposed in the Camp Hill Grange quarry belonging to Messrs. Trye. The base of the sub- division is formed by a shaly band some 50 feet thick, at the top of which occurs a seam, 2 feet thick, of red-coloured hard and tough lime- stone, the Hyolite Limestone, above which the sub-division is completed by 50 feet of hard quartzose and glauconitic sandstone. The fossils of the Hyolite Limestone and its associated shales include several species of Hyo/it&us, Orthotbeca, and Stenotheca, and the brachiopod Kutorgina cingulata. This fauna corresponds in part to that of the Ole- nellus-zone. of other regions ; and Professor Lapworth therefore considers that the Camp Hill Quartzite is probably equivalent to the Comley Sandstone of Shropshire and the Hollybush Sandstone of Malvern. The Stockingford Shales succeed to the uppermost beds of the quartzite. Their outcrop attains its greatest width at Merevale, the highest beds there coming to the surface from beneath the unconform- able Coal Measures. They consist throughout of fine-grained shales and mudstones. 1 Geol. Mag. (1886), p. 544. * Lapworth, Pnc. Geol. Assoc. xv. (1898), 340. 8 Lapworth, op. cit. p. 332. See also Strahan, Geol. Mag. (1886), p. 543. 7
