Records of the Geological Survey of India. 
[vol. III. 
<u 
doubts tliat were entertained regarding the Door valley. To the south of the Pachmari 
range, including a large portion of the plain of the Tawa, the rooks, although belonging to 
the Damuda series, arc certainly higher than the true coal-bearing group of this part of 
India; they are throughout more or less carbonaceous, and contain the Damuda fossil 
plants; and there is therefore always a chance of coal occurring in them, as will be fully 
tested by the detailed survey; but every distinct indication of coal at present known 
throughout the entire region (with the exception of a poor Mahadeva coal to be noticed 
presently) is referrible to a thin band at the base of these rocks, immediately overlying the 
'i’alchir group, and outcropping near the margin of the basin, as indicated on the sketch-map. 
This restriction of the apparently large area of the coal-bearing rocks brings into greater 
importance the limited fields that are known, and suggests the close search for similar 
small outcrops of the measures along the edge of the basin. 
The Mohpani field. —The wide separation, by intervening barren (coal-less) rocks, of 
I ho several localities where coal appears at the surface within the large area hitherto generally 
referred to in this connection as the Narbadd coal-basin necessitates the recognition of 
as many distinct eoal-iiolds. Of these, the Mohpani field is at present by far the most 
important, on account of its accessible position, and because the value of the seams has been 
proved by actual mining. It is situated at the south edge of the Narbada plains, twelve miles from 
the Great Indian Peninsula Railway at Garrarwarra, and is traversed by the Sitariva river, 
in which the eutire section is exposed, in a length of about a mile and a half. On the south 
I ho measures are buried beneath lofty hills of younger rocks ; and on the east, from the sharp 
bend of the river, the field is rapidly cut off by an overlap of those same strata. To the 
west the extent of the field is very obscure and doubtful: for seven miles from the Sitariva 
the ground is very much covered, the talus from the ridge to the south of the measures being 
continent with the superficial deposits of the plains, so that only a few small and uncertain 
outcrops can ho seen. A little further west, however, in the Dharajhor, a complete section is 
obtained np to the metamorphic rocks at tlio edge of the basin; and the coal-measures are 
there altogether covered and overlapped, the whole ground being occupied by the younger 
rocks. Thus the possible limits of the field as appearing at the surface arc very restricted; 
and we have no certain knowledge of it beyond the much smaller area bordering the Sitariva. 
A description of this locality will bo the best guide to the experimental investigation of the 
rest and of the possible extension of the field by working the measures through overlying 
formations. The accompanying map, copied from the new Revenue Survey sheets, is not on a 
sufficiently large scale to express on it the detail that would be desirable for such a purpose; 
but it will at least make the case intelligible: the little map on the one inch to the mile 
scale shows all that is visible of the coal-measures in this field ; the larger map shows the 
area over which the measures may outcrop; beyond that area they must be sought through 
other rocks. 
Actual observations very limited. —Although it is now several years since mining was 
commenced by thS Narbada Company, very little lias been done to explore the field ; all the 
workings are on one spot close to the outcrop in the river. Two or three borings were made in 
the immediate neighbourhood, hut without cutting the coal, as will be accounted for presently. 
The Sitariva Company have been too busy opening their pits, close upon the northern out¬ 
crop in the river, to have had time for further explorations. Thus, for a description of the 
field and its extent there is little more data than that available from the natural outcrops. 
The extent of this information and of the field as at present known may be judged from the 
statement that one square mile would very nearly include all the localities where coal is visi¬ 
ble ; and fully one-halt of that square mile is occupied by rocks below the coal-measures. It 
may indeed be confidently expected that the coal exists and can be followed over a much 
larger area; but it needs no more at present to show how impossible it would be to arrive at 
a, correct estimate of the extent or value of the field until further trials have been made. 
Formations : —There are three formations to he considered: the Mahadeva series, the 
Barakar group (or the coal-measures), and the Talcbir group ; besides trap-rock, metamor¬ 
phic rocks, and the superficial clays and gravels, or ‘ wash-drift’: — 
Mahadeva Series. —The Mahadeva scries is of great thickness, and comprises a large 
variety of rooks; but as here exposed, at and near the contact with the coal-measures, it 
maintains very constant characters, being formed of massive coarso conglomerates, sandy or 
■ irtliy, and generally more or less rusty; with those are freely but. capriciously associated 
beds of deep red clay sometimes mottled and calcareous, or even with nodular layers of lime¬ 
stone. Courses of rusty sandstone are comparatively rare here. These rocks form the base 
of the lofty ridge of Nimugarh, as well as the smaller hills bounding the field on the east; 
