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



iiortli-eastern flanks of the hills. The origin of this gypseous clay is not 

 clear. It appears ajrain in the neighbourhood of faulted ground^ on 

 the northern side of the gap which separates these hills from those 

 near Mari, and it may be traced at intervals on the north-east flaiiks of 

 the Tredian hills as far as the petroleum spring behind Jaba (west). 



The north-eastern aspect of the Tredian hills is generally abrupt 

 North-eastern side of ^^^^ steep, the undulating nummulitic limestone 

 Tredian hills. dipping at high angles beneath the tertiary 



sandstones of the Potwar or Rawalpindi plateau. The latter rocks are 

 exposed at several places close to the flanks of the hills, those beds nearest 

 the nummulitic limestone being as usual greenish and grey sand- 

 stones ; in places containing small pebbles, purple pseudo-conglomerate 

 and red and greenish-grey shales, of the (locally) lower division of the 

 tertiary sandstone group. These beds extend with many alternations 

 along the base of the hills ;* they are about 1,000 feet thick and are 

 overlaid by the red, soft, clayey zone, here having a thickness of 1,200 or 

 1,400 feet. The softer grey sandstone and orange clay beds succeed, 

 occupying the rocky portion of the neighbouring plateau and forming 

 the sides and mass of many of its kJmdderas. 



Towards the base of the red tertiary zone in the lower sandstones 

 and pseudo-conglomeratic beds, only imperfect fragments of bone and 

 one part of a reptilian tooth were found, the search for fossils in these 

 rocks being generally almost fruitless. 



In the neighbourhood of Jaba west, on the north-east side of the 



Tredian hills, and five miles from their termination, 



are the two petroleum localities referred to by 



others and fully reported upon by Mr. Lyman (Report on the Oil 



Lands of the Punjab, p. 38 et seq.). The oil comes from that part of the 



* Detailed sections of these rocks measuring about 1,000 feet each are given by Mr. 

 Lyman and Mr. Theobald, the former near Jaba west, the latter near Jabbi (see Mr. 

 Lyman's report, p. 39, and Mr. Theobald's paper, p. 671). As the word " alternation " 

 expresses almost the whole character of sections in these greenish-grey and red sandstones 

 and clays, time was not taken up in measuring them. 



( 264 ) 



