§ 24. THE CUMBRIAN OR SCHISTOSE SYSTEM. 795 



part of Cumberland, Westmoreland, and Lancashire, reach- 

 ing to elevations of three thousand feet, and giving rise to 

 the grand scenery of the Lakes and of North Wales. 

 Similar strata flank the Grampians, and the range of 

 Lammermuir, and occur in Argyleshire, and in the west of 

 Scotland. Schistose rocks, referable to the Silurian and 

 Cumbrian systems, extend through the country from the 

 sea-coast of Wigton washed by the Irish sea, over Dum- 

 friesshire and Berwickshire, to the North Sea beyond 

 Berwick-upon-Tweed ; being flanked here and there by 

 Devonian deposits. In the Shetland Isles, which, with this 

 exception, consist of primary rocks, the southern pro- 

 longation is made up of slaty deposits, bordered by Old 

 Ked strata. 



The coast of Ireland, opposite to that of Wales and 

 Cumberland, is formed by Silurian and Cumbrian strata, 

 which spread over Wexford, and part of Wat erf or d and 

 Wicklow ; an enormous intrusion of igneous rocks rising 

 up in Carlo w, and reaching to the shore of Dublin Bay, at 

 Kingstown. From Drogheda Bay to Belfast Lough similar 

 deposits appear, covering a great portion of Armagh, Mo- 

 naghan, and Louth ; the whole sinking westward beneath 

 the vast region of mountain limestone, which occupies 

 more than one-half the entire area of Ireland.'' 



Wales may be described as a grand slate formation, with 

 a considerable expansion of indurated conglomerate or 

 Greywacke. v In Charnwood Forest j" slate rocks appear 

 beneath the triassic strata, and they form a considerable 

 part of Anglesea and the Isle of Man. 



* Mr. Knipe's Geological Map of the British Isles presents a coup 

 cVceil of the geographical distribution of these formations over England, 

 Scotland, and Ireland. 



f The Charnwood Forest hills are syenitic rocks protruded through 

 schistose strata, before the deposition of the triassic sandstones and 

 clays, which are disposed in horizontal layers around their base. See 

 Medals of Creation, p. 974. 



