﻿1851.] MURCHISON SILURIAN ROCKS OF SCOTLAND. 141 



would appear that the Silurian loved to dwell amid the relics of the 

 old greywacke of the Scottish region, as well as on that of the head- 

 quarters of his nation along the Welsh frontier. And thus I rejoice 

 at having substituted a pleasing name, full of glorious British re- 

 collections, for the foreign term " grauwacke" which though useful 

 in a mineralogical sense, had led to much confusion in geological classi- 

 fication, by its having been applied to formations of very different age. 

 After the description of the other tracts of the south of Scotland, the 

 historian says* — " Above Gallowaie is Carrike, sometime a portion of 

 the region of the Silures. . . . Silurie is divided into 3 parts ; to wit 

 Carrike, Kile, and Cunningham." Then describing Carrike with its 

 noble city, strong castles, and fair kine, and Kile, so called from Coile, 

 King of the Britons, with its huge " deafe stone" north of Ayr, and 

 its lake and river of Doon, he concludes with Cunningham as the 

 " third part of Silurie, whose inhabitants in times past were most 

 noisome to the Romans." It is the Carrick of this Silurian region 

 that forms the first subject of our consideration. We shall then pass 

 on to Galloway, including the counties of Wigton and Kircudbright, 

 parts of which constitute the Southern division of the Siluria of early 

 Scottish history. 



A. Silurian and Carboniferous Rocks near Girvan, 

 Ayrshire'!*. 



The most fossiliferous Silurian Rocks yet discovered in Scotland 

 lie directly to the east of Ailsa Crag, and to the north and south 

 of the port of Girvan. Whilst these strata rise into hills on both 

 banks of the Girvan Water, the intervening lower grounds in which 

 that stream meanders are composed of carboniferous deposits which 

 extend from the well-known extensive masses of the same age in 

 the northern parts of Ayrshire, and here constitute a narrow and 

 broken trough, the major axis of which is nearly parallel to the pre- 

 vailing strike of the older flanking rocks %. If the fossil remains of 

 the carboniferous system had not been long ago distinguished from 

 those of the Silurian sera, a geologist, judging from rude physical 

 features only, might on a cursory view be led to suppose, that the 

 coal-bearing strata dipped under the older rocks and were really 

 intercalated in them. A brief inspection, however, of the ground, in- 

 dependently of any fossil evidence, would soon convince him, that 

 although at a lower level and in some instances apparently dipping 

 under the adjacent Silurian rocks, the carboniferous strata are wholly 

 unconnected with them, and have been thrown unconformably against 

 them by a great fracture, as represented in the annexed diagram. 

 (See Map, PL XI. and Section, fig. 1.) 



* See Hollinshed's Chronicles, Edition 1808, vol. v. p. 5. " The description of 

 Scotland, written at the first by Hector Boetius in Latine." 



t The accompanying map (PI. XT.) is not offered as being correct in the boun- 

 daries of the formations, but simply as an approximation to assist the reader. The 

 geography is taken from Mr. Keith Johnstone's Map of Ayrshire. 



X See Map, c, Carboniferous. 



