cxxiv Report of the Mineralogical Survey [No. 126*. 



origin. The ground is still the same granan, equally soft, equally abound- 

 ing in felspar as at the two former places ; but the blocks are of superior 

 hardness, and have not any sign or trace of disintegration. The 

 crusts may be seen in every stage, just beginning to separate, or having 

 made considerable progress ; a large layer, of a thickness seldom exceed- 

 ing half an inch seems waiting any impulse, or perhaps the further 

 action of the same cause to detach it entirely. These form the only 

 means of obtaining specimens, so hard and so round are the blocks 

 where this phenomenon is going on. The view of the process in all 

 its different stages satisfied me at once that these boulders originated 

 in the granan being but the harder and more durable nodules of a soft 

 rock, which has gradually wasted away, and left them as monuments 

 of the extensive waste the surface has undergone. This view is con- 

 firmed by an examination of a very large one that lies to the S. W. 

 of the temple, and which presents a set of appearances worth recording. 

 It is of an irregular sphero-rhombohedral shape, and not less than 

 60 feet in diameter. It rests on the granan, and its connection with 

 the latter is the circumstance which forms the interest. The block 

 itself is very hard at its base ; it is well-defined by a seam which se- 

 parates it from a layer of a softer granite that is divided by seams into 

 numerous flakes, which all follow the curvature of the boulder. It is 

 not the change of hardness that forms the boundary of the latter, but 

 a distinct seam or separation. The flakes immediately adjoining it 

 are very thin ; they gradually increase in thickness as they diminish in 

 hardness, till in a space of five or six feet the seams disappear, and the 

 soft granan of the surrounding surface is established. The rock is in 

 some measure overhanging, the soft layers having been cleared away 

 probably for the purpose of forming a cave or shelter for the numerous 

 flocks and herds that graze here at particular seasons, so that the struc- 

 ture and arrangement of the thing is perfectly exhibited. My figure 

 may give a clearer idea than any verbal description can. 



267. The correct boundaries of this granan tract have not yet been 

 fixed on every side, but it is inferred that the extent of it is very 

 limited in a North and South direction. In proceeding to visit the 

 iron mine at Muglig, which is in the latter quarter, I found it pass 

 into a very regular micaceous schist, in a distance of 6 miles. This 

 schist dips to the North, that is, towards the granite, and at rather a 



