STRATIGRAPHICAL ELEMENTS: CRYSTALLINES, ETC. 8l 



No. 6 Js, 4 miles north-west of Gudwaliyan, Gundgurh range, in 

 dykes banded with limestone belonging to the Slate series. A rock 

 similar to the above and evidently part of the same intrusive band. 

 The original structure of the rock has been completely obliterated 

 with development of epidote in large irregular grains, and of calcite. 



No. B f 5 , Sunvai near Lalo Gulee, associated with the gneissose- 

 granite. A crushed foliated rock of greenish colour. Contains 

 hornblende and plagioclase among the original constituents ; but the 

 rock has been partly serpentinised with production of picrolite, giving 

 deep violet polarisation colours. Calcite and epidote are also well 

 represented. The rock might doubtless have become an ophicalcite 

 if more crushing and dynamo-metamorphism had supervened. 



Appendix : Rocks found as river boulders in the Indus river-bed. 



The country to the north and north-west of Hazara and the Black 



Mountain, alon? the course of the Indus river, is 

 Remarks. . , r . , 



inhabited by a number of independent hill- 

 tribes, and up to the present is impossible of access to anything but an 

 armed force. I, therefore, made a collection of the river boulders near 

 Lalo Gulee, with the object of illustrating, as far as possible, the nature 

 of the parent rocks in that inaccessible region. I give below a list of 

 these, with a few remarks about the most important of them. 



No. g| T is an example of the most common rock found in the river- 

 bed, vi2. t the gneissose-granite which I have already described as 

 being the rock most in evidence at the surface forming the high 

 hills round about. It is present in the river-bed in immense blocks of 

 several thousand cubit feet content, and slightly rounded, which lie 

 along certain reaches of the river. Microscopically it exactly corre- 

 sponds to the most typical examples of gneissose-granite described 

 above. The orthoclase is specially beautiful as regards the inclu- 

 sions or schillerization products (probably sericite) which appear in 

 it crossing one another in regular lines parallel to the cleavage. 



The next set of rocks, which can be made out from the boulders, are 

 a series of rocks, mottled white, and dark-green, sometimes foliated 

 G ( 8l ) 



