Karharbari Group.—This
group of beds, which consists of conglomerates, sandstones, and coal,
was long considered, in consequence of the strong litho-logical
resemblance which its members bore to the Barakar rocks, to belong to
that group. Recent pataontological investigations, by Dr. Feistmantel,
are considered to be of sufficient weight to cause it to be classed in
closer proximity to the Talchir group, a number of species of plants
having been found common to both ; but the physical relations between
the Karharbari beds and those of the Talchir group seem to be identical
with those existing between the Barakars and the latter, and there is
not any sign in the lithological characters, or in the conditions of
deposit thence deducible common to the Talchir and Karharbari groups.
Attempts to point lithological distinctions as existing between the
Karharbari and Barakar beds appear to me to be somewhat strained, and
not very successful. The differences are simply such variations as
might have been determined by local conditions of deposit. I believe,
therefore, that the fossil evidence merely proves a survival of certain
species, and cannot be taken to counterbalance the geological evidence
as to a marked separation between the deposition of the Talchir and
succeeding groups.
The
Karharbari rocks were named after the coal field bearing that title;
they have also been identified at Mopani. Their thickness is 500 feet.
Barakar Group.—This
group of rocks, from which, as I have said, I believe the Karharbari
beds cannot be separated, consists of sandstones, grits, pebble
conglomerates, conglomerates with angular fragments, carbonaceous and
other shales, and coal. Except in some of the eastern fields of the
Damuda valley series, this group includes all the valuable coal of
Peninsular India.
