DESCRIPTION OF SECTIONS. 239 



recent conglomerates hardened into a compact mass; these gravels 

 are of fluviatile origin, the ground generally having a very gentle 

 slope in the direction of the drainage, but as pointed out in a previous 

 chapter, the very regular differences of level between these recent 

 conglomerates, the lowest being the newest, no doubt represent 

 corresponding differences of level of the water surface in the 

 gradually dwindling lakes. 



Throughout the considerable width of the Siwalik outcrop the 

 dip is everywhere northward, often at high angles, the sub-recent 

 gravels resting horizontally upon the denuded edges of the tilted 

 strata. The Siwaliks consist of the same rocks as elsewhere : clays 

 often bright-coloured, loose sandstones, conglomerates. No definite 

 succession can be made out, although it is probable that the clays 

 are generally older, the conglomerates generally newer. The clays 

 are often intersected by a perfect network of veins of gypsum, 

 the mineral occurring both in clear mica-like plates, and in an earthy 

 form. It is often associated with very clear crystals of calcite, 

 which take the shape of obtuse rhombohedra. 



North of these Siwaliks is the Gatt-i-Hamun or " Cliff of the 

 n .. . „ Marsh."" It may be regarded as the continuation 



Uatt-i-Hamun. y ° 



of the folded band of rocks extending south of 

 the Lora river and through the Chapar range. The cliffs are formed 

 by the scarped face of a thick limestone mass (c in Fig. 8). It is 

 underlaid by olive-green shales which are visible up to a certain 

 distance south of the escarpment, being very highly contorted (a in 

 Fig. 8). They contain numerous veins of gypsum. The limestones 

 are associated with volcanic tuffs. These rocks greatly resemble 

 those to be described at the (i Malik Gatt " (page 63), which are of 

 Cardita beaumonti age, but in the present instance I did not meet 

 with any distinct fossils. 



The hills in the neighbourhood of Mirui may be looked upon as 

 „. . a further continuation of the same range. Thev 



Hills at Mirui. » x ,c / 



consist of folded strata, greenish-grey shales 

 and calcareous sandstones petrologically identical with those that form 

 the great range east of Nushki (page 41). Just as at Nushki, there 



( 61 ) 



