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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 5, 



Although I have no intention to describe these coal strata in detail, 

 I may still say a few words on some of their dominant features 

 * which have not yet been developed. The diagram (fig. 1) expresses 



Fig. 1. — Section across Mulloch Hill. 



N.N.W. § S.S.E. 



1 ? 2 c** c* c \ 



c. Carboniferous strata. c*. Coal-beds. c**. Carboniferous timestone. 



1. Trilobite shale = Orthoceratite flags? No. 1. fig. 2. 



2. Shelly sandstone with some pebble beds. 



the fact, that on the right bank of the Girvan Water, and particularly 

 near the Home of Dalquharran, opposite to New Daily, light-coloured 

 carboniferous sandstones (c) prevail. These form, in my opinion, 

 the upper division of a very thick sandstone series, the lower parts of 

 which are of a red colour, and rise up in undulations at Maybole, in 

 the interior, and form the coast ledges that are well exposed at low 

 water between Girvan and Turnberry Castle*. 



In the valley of the Girvan Water, the yellowish and light-coloured 

 sandstones have been irregularly broken up upon an anticlinal line 

 trending from E.N.E. to W.S.W., and the beds having been tilted off to 

 the N. as well as to the S. (see also fig. 2, p. 147), abut against the Si- 

 lurian rocks, from which they are separated by a powerful line of fault. 

 On the north side of the valley, and above Dalquharran Home, the coal- 

 bearing strata (fig. 1, c*) consist of sandstone and shale dipping 25° 

 to the N.N.W. and enclosing four seams of coal, which have recently 

 been laid open by galleries driven along the incline, and exposing 

 many impressions of characteristic plants. In the upper or eastern 

 portion of the valley, near Lammy Lane, courses of concretionary red 

 and white mottled limestones are intercalated in this series, and are 

 extracted for use ; and, although we detected no organic remains in 

 them, it was manifest to us, that they were lithologically quite distinct 

 from certain limestones of Silurian age hereafter to be described. 

 Fortunately, since the visit of my friend and self, the successful fossil- 

 collector of Girvan, Mr. Alexander MacCallum, of whom I shall have 

 occasion to speak in the sequel, has forwarded to me organic remains 

 which he has detected in courses of this bastard carboniferous lime- 

 stone and shale (see Map) which clearly overlie the coal-bearing strata 



* It is much to be desired that a competent geologist would endeavour to define 

 what is really the base of the sandstones to which the term ' carboniferous ' ought to 

 be restricted in the South of Scotland. The red sandstones here adverted to are 

 designated ' Old Red ' in MacCulloch's map, and are therein confounded with the 

 Silurian rocks about to be described ! The distinctions of the Old Red Sandstone 

 (Devonian) have been so ably and clearly delineated in the North Highlands, through 

 their fossil distinctions established by Mr. Hugh Miller and Prof. Agassiz, that the 

 discovery of any of those types in Ayrshire would at once reveal to us whether any 

 portion of this Red Sandstone should be classed as Upper Old Red, or whether, 

 as I am disposed to think, it is all of the lower carboniferous age. 



