242 Dr Hibbert on the Limestone of Burdiehouse 



beds. In other localities of the sandstones which hold a similar 

 place in the carboniferous group of the Lothians, vegetable re- 

 mains have been found, though sparingly. 



To this system of strata may be referred an outcrop of lime- 

 stone, which is of a marine rather than of a fresh- water origin. It 

 is to be found in the burn near Moredun Mill, about a mile to 

 the north of Burdiehouse. A bed not many feet in thickness, and 

 containing producti, encrinites, &c. is alternated with shale ; but 

 I suspect that more than one bed may be found to thus alter- 

 nate. This limestone and the strata associated with it dip vari- 

 ously, and shew marks of disturbance. The inclination is to the 

 south-east, at angles varying from 44° to 50°, and in some places 

 it is even greater. 



This limestone of marine origin is cut off, by the great fault 

 described, from the strata connected with the Burdiehouse lime- 

 stone, and hence their exact relative position cannot be well as- 

 certained. But I am of opinion that the epoch at which the 

 Burdiehouse and the Moredun Mill limestones were severally 

 formed, cannot be widely different. 



The limestone of Moredun Mill is interesting in this respect, 

 — as shewing that a contiguous and shallow sea had subsisted 

 about the time when the Burdiehouse limestone was deposited. 



A similar knowledge I have also acquired from studying the 

 strata near New Cumnock in Ayrshire, where there is a very 

 deep-seated bed of marine limestone, which, when compared with 

 another similar limestone much higher up in the series of carbo- 

 niferous beds, holds the same relative place as that of Burdie- 

 house ; and, when compared with the Moredun Mill limestone, 

 maintains the same deep seated position, in reference to a far 

 higher and newer marine limestone, which is that of Gilmerton. 



NOTES TO SECTION III. 



I have to thank Mr Charles Maclaren of Edinburgh, who is well known for 

 the sensible descriptions which he has at various times given, in the Journal which 

 he conducts, of the geology of Edinburgh, as well as for the perspicuous and popular 



