1S14.] Mineralogical Observations in Gallouay. 421 



space includes about ten miles by four. The river Dee traverses 

 tills district of granite from west to east, and affords a very fine 

 opportunity of otjserving the meeting of it with the neighbouring 

 rocks, at both the western and eastern side. 



In the month of August last I spent some time in examining this 

 granite ma?s. My object principu'ly was to ascertain as accurately 

 as possible the rocks with which it comes in contact, and the manner 

 in which they and it meet one another. I was anxious to determine, 

 1st, Whether the greywacke or greyv.acke slate could anywhere be 

 seen in contact with the granite, and if not, what the nature of the 

 rock or rocks was which intervened between them, and whether 

 any thing like primitive rocks intervened, such as gneiss, mica 

 slate, or clay slate. 2dly, I was anxious to determine whether any 

 appearance could be observed of granite resting on any other rock. 

 3dly, Whether there was any appearance of the stratified rocks in 

 the'neigiibourhood being lapped round this mass of granite so as 

 to give them what is called the mantle shape. 4thly, 1 had in 

 view to observe the appearances of the granite veins. 



In prosecution of these objects I left New Galloway on the 7th of 

 August, 1813 : and, 1. On the brink of Loch Ken, about four 

 miles down, or towards the S. S. E., I found a rock very much 

 resembling mica slate resting on the rock which lies immediately 

 over the granite (afterwards to be spoken of), and running in a 

 direction N. E. by N., dipping to the eastward, and at an angle of 

 about 80". The ends of the strata of this rock are to be seen on 

 the high road close to the brink of the lake. 



2. Half a mile farther south I found a rock which I shall for the 

 present take the liberty to call fine-grained or compact gneiss, rest- 

 ing immediately on the granite, and running in the direction of 

 E. N. E. ; dip to the eastward ; inclination about 70°- 



3. One quarter of a mile farther to the south-west, on a third 

 observation, found the compact gneiis running E. N. E. ; dip and 

 inclination as before. 



4. Two hundred yards farther to the west, found the gneiss run- 

 ning N. by E. ; dip and inclination as before. 



5. A little way west of this I found ironshot gneiss running 

 nearly north and south, still dipping away from the hill, that is, 

 easterly, and inclined about 60° or 70°. 



6. Half a mile to the south found the strata of the compact 

 gneiss running N.N. E. nearly vertical. This observation was taken 

 in the strata of a height nearly to the south of the Louran, and 

 about half a mile from the north bank of the river Dee. 



7. A quarter of a mile S.W. from this, compact gneiss running 

 N.N.E. Here I observed a granite vein in the line-grained gneiss, 

 18 inches wide, running nearly cast and west. It is about 200 

 yards from the bank of the Loch of Strone, and half a mile east of 

 the house of Clachrum. The strata of compact gneiss at this ])lacc 

 seemed to be all much in the above direction, viz. N.N.E. ; 

 di])ping to the south-eastward; elevation about H0°. 'I'hese strata 

 of compact or fine-grained gneiss seem to alternate with the granite 



