180 
Records of the Geological Survey of India. 
[vol. x. 
Jaipuk-Bustae Aeea. —Ou the Jaipur-Bustar plateau we find a group of limestones, 
shales and quartzite-sandstones of precisely similar character to those of the Chhattisgarh 
basin. It is not improbable that the two areas will be found to be continuous, but the inter¬ 
vening country has not yet been traversed. 
In Jaipur the rocks of this group, although they occupy a by no means inconsiderable area, 
are, for the most part, so much concealed by superficial deposits that it is quite impossible 
to give anything like a connected section of them. But a few detached points, marking the 
boundaries, have as yet been fixed; from these, however, it would seem that the limestones 
and shales occupy a truncated triangular area, which, commencing near the Naorungpur and 
Jaipur road, spreads westwards into Bustar. It would be useless with the imperfect data at 
present available to attempt a discussion in these pages either as to the sequence of the rocks 
or the nature of their boundaries; but from what I saw, I think it not improbable that both 
north and south boundaries may ultimately prove to bo faulted. Certainly I did not see 
at any of the points examined any clear case of superposition. At Korenga there are sandy 
quartzites with a dip of 35° to south-west, or away from the crystallines. They are of incon¬ 
siderable thickness, possibly the dip cariies them under some red calcareous sandy flags which 
are exposed near Jobra, but the interval between the outcrops is considerable. It is not 
improbable that the river beds which cross the boundary near Korenga may disclose the 
nature of the junction. 
To the south of Kotepad there is a fairly continuous section of impure grey limestones 
with red shales, exposed in the bed of the Joura River above its junction with the Ambabal. 
The limestones dip south 35°. The overlying shales are in places a good deal contorted, but 
south-east 40° [represents the principal direction. Lithologically, these rocks correspond 
closely with certain beds of the Chhattisgarh basin, as, for example, with some of those above 
described in the Mahanadi section at Padampur. 
In Bustar the rocks seen consisted chiefly of red flaggy nearly horizontal beds of sandy 
clays; these, at Karinji, are seen overlying quartzite sandstones of, apparently, no great 
thickness. These beds are in places calcareous, and occasionally impure red limestones occur. 
I was unable to visit the Chiterkot falls on the Indravati, but specimens brought thence 
included fragments of vitreous quartzite, and a black shale, like that found at the base of the 
Karial quartzites. 
The examination of the gorge below this fall may not improbably shed a considerable 
light upon the relations of the beds which constitute the plateau. 
From the neighbourhood of Chitapur, which is about sixteen miles to the south-west of 
J ugdalpur, I received a specimen of a limestone of very similar character to the very pure form 
already mentioned as occurring at Dongri near Padampur. It is an opaque greyish-white 
rock with a splintery fracture. A similar rock is found at Korokpur, sixteen miles to south-east 
of Jugdalpur. Lime is manufactured from this rock in preference to all the other varieties. 
Sakoli Beds. 
West of Gortalou on the Raipur and Nagpur road there is a section of trap-like 
rocks, the structural relation of which to other rocks in their vicinity is very obscure. 
Within the area occupied by them we find also ridges of (? pseudomorphic) quartz-rock 
apparently similar in character to some found in the adjoining metamorphic areas, where 
they are, in some instances at least, metalliferous, as will be mentioned further on. One 
of these ridges is found to the south of the Bagh-nadi bungalow, strike 10° west of 
north. Before it is reached, however, between the 94th and 95th milestones, there is[ a bed 
of quartzose pebble conglomerate which cannot at present be referred to any known forma¬ 
tion. The pebbles are mostly of white quartz and 2 to 3 inches in diameter. A similar 
