PUXJAB OIL REGIOX. 



5 



at Guncla, must rest upon the lime rock of those hills, however much steep and 

 even somewhat reversed dips may make the eontrar}^ seem proV)able. The apparent 

 dips did, indeed, mislead me at first. But if the Choor Hill lime I'ock lies really above 

 the Gunda rocks, then lioth must be above the Salt Rano-e nunnnulitic lime I'oek ; 

 and this is possibly so. 



2. Looking closer than at the mere heig-ht of the land, the forms of its surface have 

 three different characters according as the rocks (a) lie level, or (/>) dip steeply, or 

 (c) genth''. 



a. The central tal)le land of the region is mainly made up of I'ocks of quite late 

 age, perhaps old alluvium, possibly passing without break into Siwalik (Miocene) 

 rocks below. These rocks lie nearly oi* quite level, and this fact here, as in other re- 

 gions, gives rise to characteristic forms. The general slo])e of the country is com- 

 parativel}^ level, and the ground is generally flat; but near the streams, high vertical 

 cliffs are common, connecting the fiat tables above with the fiat valleys below. This 

 might be called square-edged topography. The rocks are generally jjretty soft or 

 tender, some of them especially so ; and the growth of a narrow gully into a good 

 sized valley is quite rapid. 



h. The surface of this part of the region is not, however, exclusively of this square- 

 edged cliaracter, for it is somewhat affected by the older rocks below, which rise to 

 to the light in many places both in the valleys and on the higher lands. Tliese I'ocks 

 are of numniulitic age, and are generall}'^ harder and firmer than those above, and 

 often remain standing where they may have once l)een covered by them. In the 

 northern part of the region the lower rocks generally have also a steep dip, and are 

 folded into numerous sharp saddles and basins. This makes it not uncommon here 

 for harder layers of rock to stand up like a knife-edge, so sharp, in fjxct, that some of 

 the Cheerpar hills, 150 feet or more in height above the plains, are so thin as to have 

 holes and long horizontal slits quite through them at some distance from the top. 

 Such topography might be called shar]3-edged. Owing to the great exjiosure of the 

 softer layers to the falling rain, they have been much worn a way, so as to leave the 

 harder ribs standing out, and the topograpliy has a skeleton-like, bony look. This 

 fact often enables the geological structure to be seen very easily from the uiere topog- 

 graphy, and the basins and saddles to be made out from the map. The tojiography 

 has this sharp-edged character, in places where the streams have cut (i<^wn to the 

 low^er rocks, as far south at least as the Sohan River. It is shown by the little, sharp, 

 narrow, parallel valleys of the small streams that empty into the Sohan on the north. 

 It is probable that the same sharp folding of the lower rocks continues for some distance 



A. p. S.— VOL. XV. B. 



