334 Report on the Geological Structure of the Salt Range. [No. 4. 



films of a coal having all the characters of a lignite. The shales 

 contain much pyrites, and large and small crystals of Selenite are 

 abundant throughout them. In many places they are undergoing 

 rapid decomposition from the oxidation of the pyrites. In the 

 neighbourhood of Kalibagh the chemical action is so violent, and 

 often produces such intense heat, as to cause the combustion of the 

 shales and their conversion into red claystone. In some of the old 

 shale pits (from which the alum shales are dug) the combustion is 

 most violent, and volumes of smoke issue with considerable force 

 from their mouths charged with the vapours of sulphurous acid 

 which taints the air all around. On tracing the shales upwards 

 they become arenaceous and marly, and pass by a coarse yellow marly 

 limestone full of nummulites and other shells into a compact grey 

 limestone, the lower beds of which appear as if made up of rounded 

 masses of the same limestone arranged in horizontal layers and 

 cemented in a calcareous paste. This appearance has probably been 

 produced by the breaking up of the deposit shortly after its forma- 

 tion, and the subsequent recementing of the fragments by the infil- 

 tration of calcareous mud. 



Both the limestone and the cementing paste abound in nummu- 

 lites, fragments of Echinidae, &c. Above, the limestone becomes of a 

 grey argillaceous character and when bruised emits a foetid smell. 

 It gradually passes into blue marls which are succeeded by an upper 

 deposit of bituminous alum shales. Argillaceous limestone beds 

 then follow of a light grey colour, having a striking resemblance to 

 chalk, and are succeeded by a thick deposit of a very compact light 

 grey limestone in which irregular shaped masses and rounded nodules 

 of flint closely resembling those found in chalk are abundant. They 

 are particularly so, in the district between Nummul and the north 

 side of mount Likesur, and were there collected in large quantity by 

 the Sikhs for the preparation of musket flints. They seem to be 

 arranged generally in layers, and are of a dark grey or black colour, 

 their surface being covered with a white chalky crust, and sometimes 

 with an incrustation of peroxide of iron, which, both in nodules and 

 in small veins, is of frequent occurrence in the limestone. These 

 are apparently decomposed pyrites. 



The limestone in many places seems formed entirely of the shells 



