Dr. H. Preiswerk—Oil Region of the Northern Punjab. 19 
At the time of my visit (beginning of August) the river was rather 
high, and nothing could be seen of the oil-outflow. I was able, 
however, to determine the existence of calcareous marls richly 
impregnated with oil. I noticed them in the crevasses and flanks of 
the limestone ridge right in the Sil River. 
B.S. Lyman ? says of these oil-springs :— 2 
“ The oil rises up through the extremely shallow water of the 
river ; one drop at a time every minute or two gives rainbow colours 
to the surface of the river for the space of a few inches, then floats 
away and disappears. At a distance of about 20 yards north- 
easterly, apparently on the outcrop of the same bed of shales, is 
another like show of oil; also at one or two other places between 
these extremes.” 
The oil-springs of the Sil and Basala Rivers are important on 
account of their geological situation. The rocks accompanying 
them are represented in Fig. 6b. These rocks are typical repre- 
sentatives of the ‘“ Upper Nummulitic”’, which forms here a narrow 
zone (running N. 60° E.) between the sandstones of the Murree 
beds. The character of the oil formation is here entirely similar 
Lundegar- Hill 
Limestone blocks Sw 
Loess~/ike Deposit 
Rack-Tar with Congiomerates 
Washed Fed Clays 
mT and Loess with 
HHLt 
/ i i} | Ci onglomerates , 
Hi. WY 
ee Gray and Red Sandstones and Sandy lays (Murree beds) Fig.7 
Tie 
Ht 
to that of Golra and Saidpur. Bituminous limestones and marls 
are found along the strike of the beds on both sides of the oil-springs : 
to the west of the river in a steep channel in the plateau-margin 
about 30m. above the river, to the east about 120m. distant 
from the oil-springs. also in a narrow gorge in the steep slope. 
Farther east on the plateau, the ‘‘ Upper Nummulitic ”’ can still 
be identified by the appearance of limestone lenticles (for the length 
of about half a mile). Farther on to the east only sandstones of the 
Murree beds are exposed. 
Near the oil-springs, as shown by the sections, almost vertical 
bedding is found, and to the south and north there follow thick 
masses of also very steep Murree sandstone, which dip only a little 
less steeply north and south at a considerable distance from the 
: springs, thus allowing us to recognize the anticlinal structure of 
: the oilfield (Fig. 62). 
\ We can follow the anticlinal core to the east for not quite a mile 
: in the sandstone ; farther east isoclinal stratification predominates, 
~ 
* B.S. Lyman, General Report on the Punjab Oil Lands, Government Press, 
\ Lahore, 1870. 
