1850.] HARKNESS NEW RED SANDSTONE, DUMFRIESSHIRE. 395 



There are no distinct traces of joints in the conglomerate, and fis- 

 sures are few and far removed from each other. This almost total 

 absence of joints and fissures seems to be due to the great cohesion 

 and excessive hardness of the conglomerate. When the forces which 

 gave the underlying sandstone its joints and fissures were in action, 

 it is probable that the conglomerate existed, and in a state similar to 

 that in which it now occurs, since to this force the elevation of both 

 the deposits is referable. In the sandstone, its cohesion being but 

 comparatively small and its hardness being much less than that of 

 the conglomerate, the joints and fissures are such as commonly occur. 

 But in the conglomerate, when the elevatory power was sufiicient to 

 overcome the cohesion of the rock, perpendicular fissures were pro- 

 duced at such intervals from each other that the faces of the rock were 

 in some instances so far separated that chasms were formed. 



The conglomerate is found at other localities in the neighbourhood 

 of Dumfries besides the Craigs. It occurs at the foot of the Dock, 

 at Castledikes, and also at the New Quay. From this latter locality 

 it appears to extend southward, and forms a considerable portion of 

 the western side of the adjoining parish of Caerlaverock, where it is 

 usually covered with till. 



At a short distance south of Glencaple in this parish the conglo- 

 merate occurs on the shore. Here the direction of its dip is irregular, 

 varying from west to north, but the inclination is uniform, being about 

 15°. The conglomerate here consists of whin rock, both slaty and 

 compact, syenite, and red granite ; the two latter prevailing to a much 

 greater extent than the former : the whole is cemented together by a 

 fine and remarkably hard, dark-coloured sandstone. 



In the coarser kinds of conglomerate the whin rocks occur more 

 abundantly than in the fine varieties, which are commonly composed 

 of syenite and granite in small angular fragments about a quarter of 

 an inch in size, and approaching in form to rhomboids. So angular 

 are these fragments that the fine-grained conglomerate might at first 

 sight be taken for coarse-grained granite. This fine conglomerate is 

 more susceptible of the action of sea-water than that which is com- 

 posed of the larger fragments, and many places on the shore are co- 

 vered with fine red gravel, the result of its disintegration. 



On the farm of Banks which lies a little to the south-east of the 

 spot where the conglomerate abounds on the shore, it is likewise met 

 with. Here the fine-grained variety is most abundant. 



The same deposit also makes its appearance on the banks of the 

 Cleuden, about three miles west by north of Dumfries. At Cleuden 

 Mills, where it is first seen, it offers all the characters of the deposit 

 at Craigs, except that here it appears to be composed of slaty and 

 compact whin to the almost total exclusion of other kinds of rocks. 



In this locality the conglomerate is interstratified with beds of fine 

 sandstone, some of which are fully four feet in thickness, and their 

 dip is about 16° south. These beds of sandstone do not appear to 

 have any relation to those already described as occurring in and below 

 the lower portion of the conglomerate at the Craigs. The river, 

 running in a direction nearly west and east, passes over the strata at 



VOL. VI. PART I. 2 F 



