88 Dr. Verchere on the Geology of Kashmir, [No. 2, 



It is hardly necessary to add that the rolling of this great wave of 

 •melted minerals, under a certain part of the earth's crust, would set all 

 the deep-seated waters to boil, would sublimate certain metals and 

 elements, and that steam at a great heat, and occasionally impregnated 

 with various vapours, would add its metamorphic influence to that of 

 the heat disengaged from the molten granite underneath, and would 

 here and their percolate and alter certain distant beds which would 

 have otherwise escaped metamorphosis. 



It has been advanced that steam alone was sufficient to account for 

 the metamorphism ; to me it appears inadequate to the work, when we 

 come to consider the extensive beds of metamorphic rocks seen in 

 several parts of the world. No Geyser, ever so hot, has yet been 

 reported to have changed shales in its vicinity into gneiss or crystalline 

 schists, though, I admit, the influence is often evident enough in beds 

 of limestone. On the other hand, we know that dykes of greenstone, 

 of basalt, or of amygdaloid have often converted sandstone into horn- 

 stone or quartzite, and slate clay into flinty-state or jasper. It appears 

 therefore evident, that heat is one of the most powerful, if not the 

 principal agent of metamorphism ; it appears also necessary that the 

 heat should be long sustained to produce such a great extent of metamor- 

 phosed beds as those we are considering, and that it should be equally 

 and uniformly distributed. It does not appear likely that this persistent 

 and uniform heat was supplied by bursts of vapours, nor indeed have we 

 any analogy in the present days of large tracts of country being sensibly 

 modified by the permeation of steam. The slow cooling of a mass of 

 molten mineral under pressure would be admirably adapted to the work 

 of metamorphosing the superincumbent crust, over several hundred 

 square miles of country. 



If the hypothesis advanced just now. be accepted, we have no 

 difficulty in understanding the graduating of granite into volcanic 

 rocks ; it is indeed what we would naturally expect to see, wherever 

 subsequent upheavals have exposed extensive granitic and trappean 

 regions. 



To facilitate the application of these remarks to the Himalaya 

 mountains, let us make a theoretical section from the south-west to 

 the north-east across the Silurian Archipelego of Kashmir and the 

 sea to the north-east of it. 



