6 Dr. H. Preiswerk—Oil Region of the Northern Punjab. 
the plain are hardly less intensely folded than the limestone hills. 
But the sandstone folds have been almost wholly removed by 
erosion. 
Taking into account the great thickness of the sandstones and the 
steep folding, we must suppose that the Nummulitic limestones and 
the oil-bearing beds covering them are mostly some miles below 
the surface in the plain about Rawalpindi. Places where they 
might be expected to exist at an attainable depth have up to this 
time not been found, excepting the east end of the Kairi-Murat 
ridge. 
About 50 miles south of the Kairi-Murat ridge the Nummulitic 
limestones rise again from below the sandstones of the Murree 
beds, on the northern border of the Salt Range. It forms the north 
side of this long drawn-out range of mountains for more than a 
hundred miles, and still continuesin the Trans-Indus extension of the 
Salt Range (see Fig. 1). In the eastern and central parts of the Salt 
Range no gypsiferous marls occur between the Nummulitic lime- 
stones and the overlying Murree sandstones. Only in the western 
part the marls appear again, together with cellular limestones 
(cargneule). And here, too, the oil-springs of Jaba appear, in the 
roof of the Nummulitic limestones, just as in the district of Rawal- 
pindi and Fatehjang. In the same horizon south-east of Jaba 
a series of pitch occurrences is reported. We further have to 
mention the pitch-beds of Alagad, situated in the part of the Salt 
Range lying west of the Indus. 
Further details of the stratigraphical development of the oil- 
horizon in the Salt Range are given later. 
The structure of the western Salt Range differs from that of the 
ranges near Rawalpindi insomuch as the folds of the Salt Range are 
less tightly compressed and more normally built, therefore showing 
on the average a smaller inclination of the strata. 
In 1914 R. Zuber! published some notes referring partly to the 
same districts which I have examined. Zuber is of opinion that the 
different Nummulitic limestone ranges of the Potwar (outliers, 
Wynne) are thrust over the Murree beds, and now represent: 
“durch spitere Denudation zerrissene Ueberreste der Hazar- 
Decken.” The same would bé the case with the Salt Range, the 
strata of which are probably thrust over the Tertiary salt-formation. 
I do not want to discuss the new points of view Zuber has on the 
problem of the Salt Range, but only to put forward an opinion 
differing from Zuber’s idea about the structure of the Nummulitic 
limestone ranges of the Potwar, especially of the Chitta Pahar and 
of the Kairi-Murat ridge, which I know more thoroughly. I 
certainly must agree with Zuber that at the south margin of the 
steep limestone hills of the Margala Hills overthrusts can be observed 
by which the Murree and Kuldana beds are overlain by the older 
1 Rudolf Zuber, ‘‘ Beitrage zur Geologie des Punjab’: Jahrbuch k.k. geol. 
Reichsanstalt, Wien, 1914, pp. 327-56. 
