350 Be/port on the Geological Structure of the Salt Range. [No. 4, 



served. In the limestone they are generally mere casts of shells, 

 and those obtained were generally much weathered. 



In superficial extent, the nummulite limestone formation covers 

 a larger space in the Salt Range, than any of the rocks hitherto de- 

 scribed. In the eastern part of the Range it is first observed on the 

 northern flank of mount Tillah, a little above the village of Bhet, as 

 a band of yellow marly shell limestone, not more than twenty feet 

 in thickness, resting on upper Devonian red shales, and covered by 

 thick beds of Miocene (?) strata. Preserving the same relations, it 

 may again be seen at Jalalpoor on the North side of the Range, and 

 from thence may be traced uninterruptedly to Baghanwalla, where 

 it has a thickness of from seventy-five to eighty feet. 



West of this it seems rapidly to increase in thickness and from 

 the top of the Range when it crops out in the escarpment, it stretches 

 north in nearly horizontal strata forming the table-land of Besharut, 

 Here it skirts the flank of mountains Kuringuli and Drengun, the 

 ridges of which, formed of Devonian rocks, have been forced up 

 through the nummulite limestone, and throw it off with an anticli- 

 nal dip from either side. On the west end of mount Drengun, it 

 entirely conceals the Devonian rocks, and from thence dips north 

 under the narrow valley which separates mount Drengun from Del- 

 jubba. In this valley it is covered up by Miocene strata, but on the 

 north side of the Deljubba ridge, again crops out dipping to the 

 south-east under the Miocene strata at a high angle. At the west 

 end of the escarpment on the north side of Deljubba it appears rest- 

 ing on the Devonian rocks, but on proceeding eastward it seems to 

 thin out and to be covered over by the Miocene strata. The lime- 

 stone can however be traced projecting here and there through the 

 latter on to the Gharigulla Pass where it appears in a nearly verti- 

 cal wall, some thirty feet thick, crossing the pass from south-west 

 to north-east, and gradually disappearing under the Miocene strata, 

 which are thrown off from it, from either side of an anticlinal axis. 



"We are not aware that the limestone is anywhere seen, between 

 the Gharigulla Pass and Bulerala. 



Prom the neighbourhood of mountains Kuringali and Drengun, the 

 nummulite limestone stretches westward, and forms the superficial 



