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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 19, 



Sandstone-area of Maucliliney Ayrshire. — We have now to leave 

 Dumfriesshire and go to near the centre of the adjoining county 

 Ayrshire. In this district, around Mauchline, there is another patch 

 of red sandstone and breccias exhibited. About a quarter of a mile 

 to the south of the Mauchline Station this sandstone is worked. It 

 possesses all the features which characterize the false-bedded sand- 

 stones above the breccias in the several Dumfriesshire areas, and 

 seems to be of considerable thickness. About half a mile further 

 south, at Ballochmoyle, in the course of the Water of Ayr, we have 

 a beautiful section exhibiting these sandstones and the strata upon 

 which they repose. 



Immediately above the bridge over the Railway the red sandstones 

 dip N. 50° W., at an angle of 15° ; and as we go up the Water of 

 Ayr, from newer to older beds, we see a great change taking place 

 in the nature of the deposits. 



The lowest strata of the sandstones are soft, and rest upon a thick 

 series of breccias, which in appearance are like those at the south 

 entrance of the Drumlanrig tunnel, and consist of angular fragments 

 of amygdaloid, in the cavities of which are nests of zeolitic minerals. 

 In the highest portions of these breccias there are thin beds of a 

 siliceous limestone, of a purplish colour, but in these I found no 

 organic remains. See Section, fig. 4. In going up the stream, from 



Fig. 4. — Section near Ballochmoyle, Water of Ayr, Ayrshire. 



c. False-bedded sandstones. 

 b, b. Impure limestone. 

 a, a. Breccia. 



the higher to the lower beds of the breccia, we come upon a trap- 

 dike which cuts off the beds, and from which the fragments entering 

 into the composition of the breccias have been obtained ; and on the 

 eastern side of the dike we have Carboniferous grits, similar to those 

 which surround the sandstones of the Thornhill area. 



The association of the several rocks here is intimately connected 

 with what is seen at the entrance of the Drumlanrig tunnel, the only 

 difference being that at Ballochmoyle we have a more perfect section 



