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



in their several changes of type. A dark grey almost amorphous rock, 

 with fine granular composition, conchoidal fracture, very hard, but rather 

 brittle, which occurs near Burakot, is one of the most remarkable. Were 

 it not for the decided absence of the arenaceous structure, I should be 

 inclined to term it a greywacke. It contains, I think, carbonate of lime 

 as one of the ingredients. It passes into a perfect roofing slate, which 

 is found in great abundance just below the cantonment. Here we come 

 upon the line of route which belongs to the description of the granite 

 formation, and we must therefore return to Petorahgurh, to finish the 

 details of the route thence to Almorah. 



253. In the ascent to the ridge just above Petorah, the new road 

 gives excellent views of the strata, and it were much to be wished, 

 we could elsewhere gain the same access to the rocks as we do here. 

 The soft and clayey rock of the cantonment appears to pass into a dark 

 black rock of sublaminar structure. It breaks with an uneven, irregu- 

 lar, rather than a conchoidal fracture. It is often stained in the interior 

 of a light ash grey colour, very similar in appearance to a piece of half- 

 burned charcoal. At the summit of the Pass dolomite of a large 

 crystalline grain occurs. It contains veins of indurated talc, (var. 

 prismatic talc mica,) and also of very fine large rhombohedral crystals 

 of dolomite, (macrotypous lime haloide.) The indurated talc is of various 

 colours, but most commonly jet black, a variety not noticed by any of our 

 mineralogical writers. It assumes a very good polish, and would form 

 a very beautiful material for small ornaments for a table or chimney 

 piece. It is not however in any quantity. 



254. The dolomite is evidently a bed in the slate, for almost imme- 

 diately on descending the Pass, the latter rock again occurs. It is here 

 of a white colour, and of micaceous composition, but still slaty in structure. 

 It is again exchanged for the black rock with light grey stains. The 

 debris here consists of a very fine ochrey clay of a good colour, and 

 which might be useful in the arts if prepared properly ; besides the bed of 

 dolomite, beds of talc slate are found, and in this rock is situated the 

 copper mine, which is, however, worked on a very small scale, producing 

 only 50 Rupees per annum. The argillaceous schist continues down 

 this valley, (Shor Goorung,) irregularly intermixed with dolomite, which 

 is very often compact, containing veins of the crystallised mineral, and 

 very often appears to pass into the slate. It can seldom be seen in 



