88 
Records of the Geological Survey of India. 
[VOL. VI. 
a stream which joins the Pasang near the Jainnuggur and Kumda road. It there contains 
1' 6" of good coal (vide p. 39j. The top is much weathered, and covered with soil, but 
geam the base is well seen. Another seam is badly exposed west of 
the road, after which up to the junction with the Rehr the only 
l'ocks seen are horizontal sandstones. In the Ivhoa and Gambadia rivers west of Pilka the 
Barakar sections contain grits and sandstones only; the latter are sometimes of a somewhat 
pinkish coloi', as also are some of those in the Pasang associated with the coal. 
Oobri River Section, &c .—The character of the sections in the Gobri, with its tribu¬ 
taries the Damunda, Patpuria, and Ivadaria, can be best gathered from the map. In so far 
as the Barakars are concerned, there are no points of sufficient interest to be made the 
subject of special detail. No traces of coal were met with in any of them. 
IV.— Upper Sandstones (Loweb Mahadeyas ?) 
Within the limits of the Bisrampur coal-measure area, the only locality in which 
sandstones referable to any of the groups higher than the 
Barakars occur, is in the Pilka hills, a remarkable looking cluster 
which stands out isolated in the centre of the Sirglija plains. 
These hills are formed of hard quartzose sandstones, grits and pebble conglomerates, the 
beds of which are horizontal; and the elevation of the top of the 
highest hill above its base, or about 1,000, may therefore be taken 
as giving the total thickness. 
The evidence here afforded of great unconformity between the rocks of this and the 
older fonnations is singularly conclusive. The basal bed of grit 
laps from Barakars across Talckfrs on to inetamorpkics, the 
relations between which had been first established by faults. A doubtful case—not yet fully 
examined--of similar faulting having taken place in the Barakars previous to the deposition 
of the upper sandstones, occurs in the hills to the north-east. 
In the Karanpura field too, a fault has been mapped as running under the Upper 
Panchets. 
In describing these rooks, I follow what appears to be now the accepted belief, viz., that 
the Upper Panchets of the Damuda fields are of Lower Mahadeva age, and the genex-al 
lithological resemblance between the Pilka grits, Ac., and the Upper Panchets, is so strong 
that I think their identity may be safely asserted. 
The only difference that 1 could detect between the pebbly beds of Pilka, and those of 
Panchet and Lugfi* was that the former are somewhat less ferruginous, in which respect 
they resemble the Rajmahdl grits, which appear to be also referable to Mahadeva age. 
On the level top of the hill there is a little soil, but no ti-ace of either laterite or trap. 
Judging from the similar hills and the plateaus, both to the north 
and south, trap in all probability at one time did also exist here. 
Pilka hills. 
Thickness. 
Unconformity. 
No laterite or trap. 
Tbap Dykes. 
In addition to the general horizontality of the beds, and the small throws of the few 
faults in the Bisrampur coal measure area, the scarcity of trap dykes affords evidence that 
the rocks have been subjected to a very small amount of disturbance, as compared to that 
which has affected the more eastern fields. 
One trap dyke is exposed in the Mahan section, two miles east of Durti. A possible 
continuation of it is seen in the Talchirs and metamorpliics, in the 
,MAAn dyke. Jojhoa stream, seven miles to the west, hut no other ti-ace of 
its continuance beyond the bed of the Malian was discovered. 
* Hills situated respectively in the Raniganj and Bok£ro fields. 
