256 Report on the Geological Structure of the Salt Range. [No. 3. 



surface of its beds, it is grooved and channeled in a most peculiar 

 way by the rain water, which passing through the vegetation, ac- 

 quires carbonic acid in considerable quantity, and becomes a most 

 powerful natural solvent of lime and magnesia. 



The only mineral which we have observed in this formation de- 

 serving of notice is galena or sulphuret of lead. 



This occurs in the dolomitic sandstone, forming the summit of 

 mount Kuringali, and in the same rock in a ravine near the temple 

 on the right side of the Keurah gorge above Pind Dadun Khan. In 

 these localities small cubical crystals are found scattered throughout 

 the rock, but in very small quantity, and no where are there indica- 

 tions of a vein of any consequence. It is in great request among the 

 natives as a cosmetic, to whom it is known by the name of Soorma. 



Obscure carbonaceous markings are of frequent occurrence among 

 the green micaceous sandstones, but too indistinct to be identified. 

 They probably are the remains of fuci. In the dolomitic sandstone, 

 no traces of organisms of any kind were detected. 



d. Upper, red, variegated Sandstones, Grits, Conglomerates and 



The dolomitic sandstone last described is succeeded by a series of 

 dark red shales, argillaceous sandstones, including nodules of green 

 clay, and quartzose grits with bands of conglomerates of primitive 

 rocks, among which the same red syenite as occurs in the lower red 

 sandstone is most abundant. 



These beds are highly charged with peroxide of iron which gives 

 them a blood-red colour, and magnesia may be detected in all the 

 sandstones, grits, and conglomerates of the group in considerable 

 abundance. All the sandstones are extensively ripple-marked, and 

 along the water courses which intersect the beds, present on their 

 surface a saline efflorescence. 



Between Jelalpore and Pind Dadun Khan, they are largely deve- 

 loped, while towards the Indus they seem to be in a great measure 

 replaced by a series of red, green, purple and chocolate-coloured 

 shales which weather into clays, and from yielding small concretion- 

 ary masses of copper ore, present considerable interest. These are 

 invariably superior to the sandstone grits and conglomerates. Thin 

 beds of white quartzose grit occasionally traverse the shales, and 



