42 



TALCHEKR COAL FIELD. 



seen in the bank of the Brahmini opposite the village of Santapara. 

 (Fig. S.) 



It is only in the more felspathic varieties of the gneiss that this decom- 

 position has been observed to any extent, and principally in the 

 neighbourhood of faults, or on the borders of the coal measures, where 

 the broken and porous nature of the adjoining rock would allow the free 

 access of water. The rounded hummocks produced by the weathering 

 and exfoliation vividly recal the Roches Moutonnees of the glaciers. 

 Indeed, these rocks occur under circumstances in which we might 

 expect to see all the results of glacial action simulated, if any other 

 cause than ice were capable of producing them. A rapid river, carrying 

 down pebbles of considerable size, its rapidity augmented here and there 

 by the very bands ofrocks over which it sweeps, must surely exercise most 

 of the powers of those famous debacles to which glacial appearances have 

 been referred.* 



And if, as has been lately asserted,-f- many of the Roches Mou- 

 tonnees have been produced by exfoliation, we have here a case in which 



* Russia and the Ural Mountains, by Sir E. Murohison. 



t A. Schlagintweit on Bavarian Alps, Quar. Jour. Geol, Soc. 1851, p. 346. 



