Page:VCH Worcestershire 1.djvu/42

 A HISTORY OF WORCESTERSHIRE to a depth of 1,200 feet with unsatisfactory results : salt water filled the bore-hole. Another boring at Arley Colliery, near Bewdley, was carried to a depth of 1,350 feet, and then reached a basaltic rock like that of Shatterford.' Sections of the sandstones and shales are exposed on the banks of the Severn between Bewdley and Upper Arley. At Shatterford the basalt dyke is quarried for road-metal, while some of the sandstones furnish good building-stone. Attention was first called by E, W. Binney to the occurrence of %ror(^/j-limestone : this comprises thin grey, black and brown lime- stones, which contain the Annelide Spirorhis pusillus. In the sandstones, and more particularly in the shales, remains of ferns, also Stigmaria, Calamites, and fish-remains occur. Exposures of Upper Coal Measures occur on either side of Rubery Hill in the Lower Lickey, resting on the Cambrian quartzite and Silu- rian rocks, but they are not of particular economic importance. In this region strata of the age of the Coal Measures probably occur over a larger area than is shown on the map, as certain so-called Permian strata, are now recognized as Coal Measures.^ Portions of the South Staffordshire coalfield, the ' Black Country,' occur in the county of Worcester, between Dudley, Halesowen and Stourbridge. Here the general sub-divisions are thus noted by Prof Lapworth :^ — ( Red and grey shales and sandstones with 'n Feet. Upper J S/i/V«r^if-limestone . . . . ( ^ Coal Measures J Halesowen Sandstones. . . '' ' Red clays with sandstone and conglomerate Lower f Grey and white sandstones, clays, shales, Coal Measures (. and beds of coal and ironstone
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500 to 1,050 Of special interest is the great Ten-yard seam or Thick coal, which in the southern part of the coalfield is made up of about fourteen seams of coal, elsewhere parted by unproductive strata, and attaining 500 or 600 feet in total thickness. Some dykes and sills of igneous rock (dolerite) occur in the Coal Measures near Dudley, as at Rowley Regis, but these are rather outside the boundaries of the county. In this important coalfield, as in the case of the Forest of Wyre, the Coal Measures rest in part directly on Old Red Sandstone, and in part on the Silurian rocks. Prior to the general disturbance of the strata and the production of the anticline of Dudley, the Coal Measures rested in places on the tilted and worn surface of the Silurian, and, as remarked by ' See D. Jones, Trans. Manchester Geol. Soc., vol. x. p. 37 ; Geol. Mag. for 1 87 1, p. 200, for 1873, p. 350 ; and Trans. Fed. Inst. Mining Eng., vol. vii. p. 287 ; G. E. Roberts, Geologist, vol. iv. pp. 421, 468 ; T. C. Cantrill, ' Geol. Wyre Forest,' »/>. cit., and Co//. Guard., vol. Ixxi. (1896) p. 351 ; Symonds, Records of the Rocks, p. 385. ^ See W. Gibson in Summary of Progress of Geo/ogica/ Survey for 1898, p. 124. ^ Proc. Geo/. Assoc, vol. xv. p. 366 ; see also J. B. Jukes, 'The South Staffordshire Coal- field,' Mem. Geo/. Survey, ed. 2, 1859. 12