The Geology of Scotland and Its Islands Author:William Rhind Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: GEOLOGY OF THE COUNTIES. GREYWACKE DISTRICT. This district includes the southern portion of Scotland, commencing with Wigtonshire, and terminating with Ber... more »wickshire on the east . It consists chiefly of greywacke conglomerate, with slates, analogous to the upper beds of the Cambrian system of Wales, of old red sandstone, and mountain limestone, with granite, porphyries, and greenstone. Wigton And Kirkcudbright Shires.—The counties of Wigton and Kirkcudbright belong to this greywacke district. The surface of these counties is extremely irregular, consisting of a series of elevations and depressions, with no large valleys or very elevated mountains. This surface consists of greywacke schist, greywacke conglomerate, and, in some situations, patches of sandstone conglomerate and grit belonging to the old red formation. A mass of granite intersects New Galloway, and a similar mass stretches from the sea coast, near theburgh of Kirkcudbright, south and south-westward, to form the Criffle range. Feldspar porphyry also abounds in various localities, and the intrusion of this igneous rock seems to be the cause of the great disturbance of the undulated surface. At Port Mary on the coast, a few miles south of Kirkcudbright, a greyish sandstone, with layers of shale and conglomerate, are seen to rest unconforma- bly on the greywacke. This sandstone continues to skirt the coast, and evidently belongs to the old red formation. At Colvend is exhibited the following succession of strata, onwards along the coast to Sau- terness. SECTION FEOM COL VEND TO 8AUTERNESS. A Colvend. A, granite—B, porphyry— C, trap rocks—d, gneiss, dipping nearly vertically with numerous veins of granite and porphyry interposed, e, greywacke conglomerate, coarse greyish sandstone, with bands of shal...« less