102 
R'ecords of the Geological Survey of India. [vol. vm. 
The Raigarh and Hingir Coal-field, by V. Ball, m. a., f. g. s., Geological Survey 
of India. 
(Second notice.) 
Intkoduction. 
The following account refers to the south-eastern extension of a very considerable 
tract of coal-measure and associated sedimentary rocks which is situated in the south-west 
frontier districts of Bengal, and some of the north-eastern districts of the Central Provinces. 
The limits and consequently the contained area of this tract are at present imperfectly known, 
hut not improbably the latter exceeds 5,000 square miles. To the whole the name south¬ 
west frontier coal-field might he given ; hut for convenience in the description of certain 
portions which admit of separate treatment, such names as Bisrampnr and Raigarh—Hin- 
gir have been employed in previous accounts. 
The name Raigarh—Hingir was first adopted in 1871 as being less likely to mislead 
than the old name Gangpur,* no portion of the field being in Gangpur proper. The exten¬ 
sion of the coal-field, as ascertained during the past season, has not rendered any further 
change of name desirable, the States of Raigarh and Hingir being sufficiently centrically 
situated in the now known area to furnish a suitable local name; hut the fact that the area 
so indicated is not an isolated coal-field should not he lost sight of. To the west, through 
Udipur, the coal-measures or their associated rocks spread continuously to Ivorba in Bilaspur, 
while to the north, through Sirguja, the connection is unbroken up to Rewa and the borders 
of Mirzapur. 
The Talchir coal-field,f" though quite detached, is only a few miles distant from the most 
eastern points of our field, and may not improbably have been at one time connected with it. 
The area occupied by that portion of the coal-field to he described in the following pages 
has a very irregular outline. SaVe for two narrow prolongations which extend to the east of 
the Ebe, it may be said roughly to commence in the angle enclosed between the Ebe and 
Mahauadi rivers a few miles to the north-west of Sambalpur. Thence it spreads in a north¬ 
westerly direction, the southern and south-western limit being defined by a well marked and 
in part faulted boundary. On the north-east, for about twenty miles, the boundary has only 
been partially examined, but sufficient is known of it to show that it is of an unusually com¬ 
plicated and obscure character. Originally it is not improbable that, the extension of the Bara- 
kars was limited by the tolerably regular cliff of a low plateau of metamorphic rocks; but at 
the present time a considerable thickness of a newer series of rocks laps over this boundary 
and forms the hilly and difficult country of northern Raigarh and Hingir, thus concealing the 
edges of the Barakar rocks. 
The reasons for supposing the Barakars not to have extended much further north 
are, that in a line with the bounding, uncovered metamorphics of the north-eastern corner of 
the field, exposures of the same rocks are found at intervals, as we proceed westwards, paving 
the deep-cut valleys between the ranges of upper sandstones. 
How far these upper sandstones stretch northwards through Serapgarh is not known. 
It is possible that they conceal some small detached basins of Barakars. Thus far for twenty 
miles ol the northern and north-eastern boundary, but for thirty miles further, until Rahkob 
on the Maud in Udipur is reached, no northern limiting metamorphic rocks have been met 
with as yet. 
* Records No. 4,1871, p. 101. All previous notices of the field will be found mentioned in that paper, 
t Described m Mem. G. S, I., vol. I, 
