﻿56 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Dec, 4, 



River Urr. 



Castle 

 Douglas. 



found much metamorphosed, and deprived 

 of all traces of organic remains. 



Concluding Remarks on the Silurian 

 Rocks of Dumfriesshire, and of the 

 South of Scotland generally. 



On the south side of the porphyritic 

 district of Kirkcudbright the prevailing 

 dip is southward ; the same direction also 

 obtains on the south side of the granite 

 of Criffel, amongst the Silurian rocks. 

 On the north side of these igneous masses 

 the usual N.N.W. inclination occurs, and 

 this inclination is the common dip of the 

 stratified deposits of Kirkcudbrightshire, 

 except where they are disturbed by the 

 intrusion of igneous rocks. Following 

 this south dip in an easterly direction we 

 meet with it in Dumfriesshire, in the 

 parishes of Torthorwald, Mousewald, 

 Lochmaben, and Dalton, in which loca- 

 lities the Silurians have their southern 

 limit. The range of hills here is distinctly 

 marked by characters which show that 

 some change takes place in the inclina- 

 tion, their steep and precipitous sides 

 being towards the north with gentle slopes 

 southward. At Barlouth, in the parish 

 of Torthorwald, about a mile south of the 

 high road, the dip is southward, at an 

 angle of 75°, the rock consisting of a fine- 

 grained greywacke, with intercalated 

 shales, considerably metamorphosed, the 

 shale being disposed to break at right 

 angles to the planes of deposition rather 

 than to split along the laminae. At 

 Cleugh Erae, in the parish of Mousewald, 

 we have a section of the Silurians well 

 shown in a small brook. Here the rock 

 dips S.S.E. at an angle of 75°, and consists 

 of the same altered shale and greywacke 

 sandstone as occurs in the parish of Tor- 

 thorwald. On the hills above Rammer- 

 scales, in the parish of Dalton, the same 

 dip and rock prevail, and these may be 

 traced eastward until they cross the river 

 Annan at Linn Mills, where the strata are 

 exposed, and have an inclination towards 

 the south at an angle of 72°. At Lockerby, in the railway cutting, 

 the same dip is seen, and from thence it appears to extend eastward 

 along the course of the Silurians. 



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