126 WYNNE : GEOLOGY OF THE SALT RANGE IN THE PUNJAB. 



extend but a short way, the mass of these beds having* been removed 

 or never deposited. 



From Rotas to Mount Tilla the Upper Siwalik beds are all on 

 From EotSs towards edge, running in a south-westerly direction either 

 "Ti^l^- straight for the hill, or so as to pass along its 



southern side^ occupying a width of about three miles. In these rocks 

 contortions may exist, but the tops of the arches having been removed 

 by denudation, the structure of the ground is obscured; the main 

 anticlinal, however, as at Rotas, lies well to the south-east side of the 

 broken rising ground. In a southerly direction the country near the hills 

 is covered by debris, apparently derived from very soft underlying rocks 

 in which clays predominate. Just along the foot of the tertiary hills are 

 conglomeratic beds with limestone pebbles, pseudo-conglomeratic and 

 grey sandstones, with light brown clays. Ascending the slopes, purple 

 and red clays alternate with grey soft sandstones; while about the 

 reo-ion of the anticlinal, and on the north-eastern side of this, brownish 

 clays, and soft, coarse and fine sandstones, with some gravelly beds, 

 again appear. Near the middle of the ridge, where the road from 

 Jhelum to Mount Tilla meets the old one from Rotds, a zone of 

 ossiferous sandstones is intercalated with the brownish clays and sand- 

 stones. Bone fragments are locally numerous in 

 this, but as they are embedded in a very frag- 

 mentary state, the finding of good specimens must be quite accidental. 



The thickness of the tertiary beds of this ridge and its neighbour- 

 hood must be great, but calculations regarding it 



THirkiicss 



are affected by uncertainty as to the existence of 

 compressed and concealed contortions. Beneath the Rotas fort these 

 beds dip to the north-west steadily for more than a mile at 60° and 70°, 

 giving a thickness of 4,700 to 5,000 feet. In the event of plications not 

 occurring, that thickness might be fairly doubled, while the softer beds 

 beyond the ridge may be at least 5,000 feet more. Hence 10,000 feet 

 does not seem too large an estimate for this portion of the tertiary rocks. 

 ( 126 ) 



