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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 19, 



Thornhill area is in the course of the Creechope Burn, at Creechope 

 Linn, the scene of the retreat of Balfour of Burley in * Old Mor- 

 tality.' Here a small rapid streamlet has cut itself a deep channel 

 among soft sandstones, leaving steep cliffs on either side. At the 

 entrance of the Linn, a short distance above where the Creechope 

 joins the Cample Burn, we have purplish flagstones, which belong to 

 the Carboniferous age, dipping atN. 4° S.E. at an angle of 15°; and 

 the same flagstones are seen in the bed of the stream higher up the 

 Linn, at a spot called the Sutor's Seat. The deposits, which at this 

 spot occur immediately above the Carboniferous flagstones, cannot 

 be seen owing to debris ; but at about 9 feet above the flagstones 

 purple clays make their appearance, with cream-coloured spots, 

 devoid of lamination, and fracturing very irregularly. These have a 

 thickness of about 6 feet ; and above them are seen the soft red sand- 

 stones, attaining a considerable thickness, and very much false-bedded. 

 See Section, fig. 2. In the purple clays I was unable to detect any 



Fig. 2. — Section at Sutor's Seat, Creechope Linn, near Thornhill, 



Dumfriesshi re . 



d. False-bedded sandstones. 



c. Purple clays. 



b. Not seen. 



a. Carboniferous grits. 



fossils. The sandstones extend through the whole of the Linn, and 

 present the same false-bedded aspect, so much so that their apparent 

 directions and dips are not to be depended on. At Gatelaw Bridge, 

 about a mile north from Creechope Linn, the sandstone is extensively 

 worked ; and is here also false-bedded, but not to the same extent as 

 at the latter locality. Where the inclination is regular the dip is 

 N.N.W., at an angle of 15° ; and at a short distance, higher up the 

 Cample Water, breccias are seen, which seem to underlie the sand- 

 stone of Gatelaw Bridge. Columnar basalt, with layers of amygdaloid, 

 occurs further to the east than the breccias, and has furnished the 

 latter with a considerable portion of their contents. 



