6 
Records of the Geological Surrey of India. 
[vOL. XII. 
interval. Of such di.stinct interval, however, no more direct stratigraphical 
evidence is found in Palamow than elsewhere, beyond the original fact of the 
intercalation of deposits not found away from the Damuda area: the apparent 
sequence of the upper sandstone (iMahadeva.s of Mr. Ball’s report) on the Bara- 
kars here being at least as rcgnlav as in the south-eastern Gondwana regions; 
so that the expectation to find lower Gondwana fossils in this rock here woulil 
still he Justified. Thus, the question stands pretty much as before, save that we 
know exaetly where this change of petrological characters takes place. 
It had been surmised that thi.s change would coincide with tlie limits of the 
Damuda valley; hut Mr. Ball has found that it is not so. A barrier of gneiss, 
between the Kiirunpnra and Aurunga coal-basins, divides the waters of the 
Damuda and the Aurunga, which is a tributary of the Koel; and in the eastern 
part of the Aurunga field the Panchot and Raniganj groups arc about as well 
developed as in the Kilrunpura field, their combined thickness being about 1,700 
feet, and they are covered by the ujiper sandstone. Notwitlrstanding thi.s great 
develojmient in thickness, the exten.sion of these two lower Gondwana groups is 
strangely limited. The feature under notice is, indeed, brought within a compa.ss 
of two miles in the hills south of Latehar, at the west end of which the upper 
(Mahadova) sandstone rests on Barakars, and at the east end on Panchets. Both 
the north and south bouudarie.s are represented as faulted, so that the overlap 
cannot be follo^ved out; but this case gives at least the assurance that the 
covering sandstone, so differently cii’eumstanced at its base, is one and the same 
formation. The absence of fossils in the.se sections is deplorable. Without 
them the position of this top sandstone in the general scries must remain doubt¬ 
ful: in the west of the Aurunga field its relation to the coal-measures is precisely 
like that of the Kiimthi and Hengir rocks to the similar coal-measures of the 
Godavari and Maluinadi .regions, while in the eastern part of the field it overlies 
beds (Panchets), -vvhicli in turn overlie those (Raniganj) that hawe been corre¬ 
lated wdth the Kamthis. 
The gneissic barrier between the Aurunga and Karunpura fields being 
much higher relatively to the former than to the latter, Mr. Ball considers that the 
separation is due to disturbance, by a sinking of the Aurunga basin; so that they 
may still be virtually considered as belonging to the same original area, and the 
similarity of the sections be attributed to some peculiar conditions of that ground. 
In the Son region, shortly to the west of Palamow, the upper sandstone 
scries becomes enormously expanded; and if, as seems probable, this rock in 
Palamow repi-esents the base of that expanded series, which, again, in its 
southern extension is likely to bo identified with the Kamthi bcd.s of Hengir, 
then the top sandstone of the Damuda region cannot properly be classed as 
upper Gondwana (Mahadeva), or identified with the Dubrajpiir group of the 
Riijmahal region; nor could the Kdmthis then be properly correlated with the 
Raniganj group, unless a ccriain correspondence of the fossil floras at distant 
localities is to set aside local superposition in the Damuda region, represented 
elsewRere by the most cleai-ly and most widely marked stratigraphical change in 
the whole Gondwana series. 
