Page:A Treatise on Geology, volume 1.djvu/210

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194
A TREATISE ON GEOLOGY.
CHAP. VI.

ton, in Wharfdale, a distance of 110 miles.[1]

whole of the somewhat

rectangular tract of included between the northern Depressed region. Tymedale. ELEVATED REGION. Penine fault.

(Tynedale), southern (Craven), and middle (Penine) portions of this fault, is elevated above the corresponding strata in the depressed surrounding regions, not less than from 1200 to 4000 feet; in consequence of which silurian rocks show themselves along the Penine and Craven portions, while small coal fields appear on the parts at h and i thrown down 2000 feet below the summits of millstone grit!

On the south side of the Craven branch of this great fault are found many anticlinal ridges, severally ranging north-east and south-west, or nearly, and throwing the whole Craven country into a series of parallel undulations. Through Derbyshire runs an axis, from which the rocks dip eastward and westward; and this ridge, continued northwards towards Colne, effects a complete disunion of the great coal field on the east (Yorkshire, Derbyshire, Nottinghamshire), from that on the west (Lancashire, Cheshire) which it appears most probable were once united on the bed of the sea. It is only by considering the effects of subterranean movements, that we can at all account for the disjointed and fragmentary condition of the central coal fields of England. Their disunion is sometimes real, but very frequently only apparent, since they often dip towards each other, as c c, and would perhaps be seen to unite

  1. See separate Memoirs by Sedgwick and Phillips in Geological Transactions; also Geology of Yorkshire, vol. ii., and Geol. Proceedings, Dec. 1851.