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



The marl occurs as the lowest rock, being subordinate to a red 

 sandstone into which it seems to pass, the transition being marked 

 by dark coloured fissile argillaceous beds. At Jutana and in the 

 Chukie Wan near Jubbee, a coarse red sandstone with bands of 

 conglomerate is seen in some places, cropping out under the marl, 

 but as great disturbance occurs among the strata at these localities, 

 and as the sandstone is identical in mineral character with that 

 which in the regular order of things appears above the marl, we are 

 disposed to consider its occurrence under it in the localities above 

 mentioned as the result of an overturn. 



The marl can be recognized at a distance by its most singular 

 brick red colour, totally different from that of any ordinary clay, 

 which immediately impresses one with the idea, that it has been sub- 

 jected to igneous agency. 



It does not disintegrate when treated with hydrochloric acid, but 

 in powder effervesces strongly, the greater part remaining undis- 

 solved, in the shape of a red mud composed of clay and sulphate of 

 lime or gypsum. The portion soluble in acid, consists of carbonate 

 of lime and carbonate of magnesia in about equal proportions with a 

 little alumina and peroxide of iron, to which latter substance the 

 marl owes its colour. The rock is therefore a clay, cemented by 

 gypsum and the carbonate of lime and magnesia into the consistency 

 of stone, the gypsum predominating and frequently appearing in 

 laminae of selenite in the marl, which sometimes presents a radiated 

 aspect, from a peculiar crystallization of the sulphate of lime. 



In many places it is traversed by veins of gypsum, which seem to 

 have been formed in rents in the marl, and give it a most singular 

 honey-combed appearance. These veins often traverse the included 

 irregular beds of gypsum, proving they are more recent than those, 

 though in mineral character the gypsum of both the veins and beds 

 is identical. In several localities thin beds of chert and coarse 

 silicious sinter, containing patches of chalcedony may be observed. 



The marl is extremely tough, and on this account, though by no 

 means hard, the work of sinking shafts or galleries in it, is very 

 laborious. It forms hills, some of which rise to the height of 1,500 

 feet above the sea, of a most jagged appearance, which is in a great 

 measure produced by the heavy falls of rain, dissolving out the 



