1853.] Report on the Geological Structure of the Salt Range. 241 



gypsum, and its earthy carbonates, and forming in it deep ravines 

 and channels. These by luidermining the marl frequently produce 

 extensive slips, which cause serious annoyance in the working of the 

 salt. 



On tracing up some of the ravines, where the marl is well develop- 

 ed, it seems to form the centre of an anticlinal axis, the rocks 

 superior to it (see Table JNo. 7) dipping away from either side of its 

 out crop at a considerable angle. At the end of some of the gorges, 

 it often presents an amphitheatre of small hills surrounded by scarp- 

 ed precipices of the superior rocks. This may be well seen at the 

 upper part of the Milawan ravine below Nurpur and in the Serai 

 Eavine at Surdee, in both of which localities it has a remarkably 

 eruptive aspect. 



In the eastern part of the Eange, the marl presents scarcely any 

 traces of stratification. Towards the Indus, however, in the neigh- 

 bourhood of Chooa, Yurcha and Futtypur, where it is extensively 

 developed, thin beds of argillaceous dark red sandstone occur in the 

 marl, and indicate its being a stratified deposit. 



At several places, but particularly around Pind Dadun Khan, the 

 marl for some depth from the surface has much the character of a 

 breccia; angular masses of salt gypsum, sandstone and limestone 

 similar to those occurring in situ, being diffused through it. As the 

 numbers of the fragments appear to decrease the further from the 

 surface we examine the breccia, and as they are most numerous 

 where there is evidence of the greatest disturbance in the surround- 

 ing rocks, it is most probable that the breccia marl, which we have 

 seen in some ravines fully 200 feet thick, has been formed on the 

 surface of the regular marl at the time of, or subsequent to, the 

 upheaval of the Eange to be hereafter noticed. Indeed its formation 

 may be observed after every heavy fall of rain, which washes large 

 quantities of red mud and fragments of rock into hollows in the 

 marl, which ultimately become cemented by the infiltration of sul- 

 phate and bi-carbonate of lime, held in solution by the rain-water, 

 and derived from the strata over which it passes in its downward 

 course. 



"We have hinted that the marl in some places has a singularly 

 eruptive appearance, but the distinct proofs of stratification which it 



