258 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 19, 



wrought, viz. Corncockle and Templand, differ materially from each 

 other. The former consists of very regularly bedded red sandstone, 

 easily worked ; the latter of a hard red flag, coarser than the Corn- 

 cockle beds, and remarkably durable. I know of no red sandstone 

 which at all approaches the Templand flags in respect of hardness. 

 In these two localities the strata dip to the W., at an angle exceed- 

 ing 30° ; and, as Templand lies a short distance to the S.W. of Corn- 

 cockle, the beds which occur at this spot occupy a higher position 

 than the Corncockle sandstone. 



I learn from Sir William Jar dine, that, like the Corncockle strata, 

 the deposits which occur at Templand afford fossil footsteps. 



There are some circumstances in connexion with the Corncockle 

 area which are matters of interest. One of these is the directions of 

 the inclinations of the strata in the several localities where the sand- 

 stones and breccias are exposed. 



Whenever we find the newer and the older formations near each 

 other, the former in all cases dips from the latter. On the eastern 

 margins of the area we have a westerly dip, on the western an 

 easterly dip, on the northern a southerly, and on the southern a 

 northerly dip ; and in the intermediate positions the same circum- 

 stances occur. 



Had the area been circular, we should have had the dips converging 

 to a central point ; but, as the form of the area is irregular, we have 

 an approximation to this mode of arrangement. The Lower Silurian 

 margins do not appear to present any evidence of the operation of 

 those causes which have given to the sandstones and breccias their 

 inclination; for we have either a continuous N.N.W. or a continuous 

 S.S.E. dip occurring all through the Silurians of Dumfriesshire. 

 The cause of this peculiar mode of arrangement in the Corncockle 

 area seems to have been local ; and I can attribute it to no other 

 circumstance than a subsidence in a small area, which has dragged 

 down the strata towards it in all directions, and so produced a series 

 of inclinations which always dip from the older formation. 



Another circumstance of interest is the sequence of the deposits 

 which form the sandstones and breccias. As concerns the latter, 

 we have seen that it only occurs in certain spots along the margins of 

 the area. When we have higher beds, these are seen to be false- 

 bedded sandstones, as in the Kinnel Section ; and in no case do we 

 meet with any thick deposits of sandstone beneath the breccias, as is 

 the case with the breccias of the Craigs in the Dumfries area. The 

 mode of occurrence of the breccias would therefore lead to the in- 

 ference, that these are the lowest deposits, — that they are succeeded by 

 a series of sandstones to which those wrought at Corncockle appertain, 

 — and that the highest beds consist of the hard flags of Templand. We 

 have therefore three groups, — 1st, and lowest, breccias, with sand- 

 stones, more than 100 feet thick; 2nd, sandstones, the thickness of 

 which has not been ascertained, but which must be considerably 

 thicker than the breccias ; and 3rd, hard flags, the thickness of which 

 is not determined, but is probably less than that of the breccias. 



The age of these several strata is also a matter of great interest ; 



