264 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 19, 



the Corncockle area, the Thornhill district, at Mauchline, and in the 

 neighhourhood of Dumfries ; 3rd, hard thick breccias, best seen at 

 the Craigs, Dumfries ; and 4th, thin-bedded sandstone, only slightly 

 developed; occurring at Castledikes, Dumfries, above the breccias*. 

 The Dumfries area presents, so far as can be seen, the same phy- 

 sical geology as the other patches ; it appears to dip from the higher 

 hills, and forms a trough through which the River Nith flows. 



Since my memoir on the New Red Sandstone of the southern 

 portion of the Vale of the Nith was written, there has been another 

 quarry opened immediately under the south-eastern end of the 

 Maiden-Bower Craigs. See Section, fig. 5. Among the sandstones of 



Fig. 5. — Sectio7i near Dumfries, from Lochar Moss {S.E.) to the 



River Nith {N.E.). 



Georgetown 

 Craig. 



Mid- Craig. 



Maiden's Bower 

 Craig. 



N.W. 



Castledikes 

 sandstone. 



Fault 



e. Castledikes sandstone. 



d. Breccias. 



c. False-bedded sandstones. 



b. Flaggy beds with footprints . 

 a. False-bedded sandstones. 



this quarry, which occupy a higher position than those in which the 

 footsteps occur, there are seen features which, so far as I am aware, 

 are peculiar to this spot. The lithological characters of some of the 

 strata here show their intimate connexion with the overlying breccias, 

 since some of the beds have fine breccias mixed up among them. On 

 the surfaces of a few of the higher of these sandstones we have 

 singular markings, which, at first sight, are so remarkable that there 

 is a difficulty in knowing what to make of them. They consist of 

 sunken impressions on the upper faces of the beds. These markings 

 are in some cases somewhat rhomboidal in form, with sharp angles. 

 In other cases they have a rib-like appearance ; sometimes they are 

 sinuous, and at other times they are cylindrical ; and might be taken 

 for either portions of stems of trees, or fragments of large Orthocerata. 

 I was at one time disposed to regard them as the result of a peculiar 

 mode of rippling, such as would arise from the action of a small rill 

 over a muddy beach ; but the angular character of some of the 

 markings is hostile to this opinion ; and the cylindrical form which 

 they sometimes present is also opposed to this idea. I am indebted 

 to my friend Sir William Jardine for the correct explanation as to 



* Loc. cit. p. 396. 



