PART 1.] 
Animal report for 1869 . 
5 
This limitation of original deposition has long been the view held by Mr. Hughes (and by 
myself) with reference to the Bengal fields which he had examined, and Mr. Medlicott now 
shows how he considers it applicable to those in the west also. 
There appear to me, however, wider and larger views of this variation in mineral character, 
and in succession of beds, as well as in limitation of area occupied, which must be wox'ked out 
in greater detail before any definite conclusions be possible. They may, however, be indicated. 
All these successive beds, (possibly with the exception of the Talchir s) representing an enor¬ 
mous lapse of time, agree in one respect, that they seem to be purely fresh water (fluviatile 
or fluvio-lacustriue) or estuarine deposits. This tact alone involves the consideration of defi¬ 
nite limits within which the rivers or lakes by which, or in which, they were formed were 
confined at the time of their deposition. This again would seem unavoidably to bring with 
it a very large amount of variation in each basin of deposition quite consistently with a 
general resemblance or agreement in the succession. It seems difficult, if not almost impos¬ 
sible, to suppose that coincidently with any great changes of surface level, &c., which may 
have atf'ected the whole country, there were not also variations in each more limited area, or 
drainage basin of the then existing dry land. Thus it seems to me, we are naturally led, 
a priori, to look for a general persistence of type coincidently with a wide limit of variation 
in detail. And this, I believe, will go far to account for much of the variation we do find. The 
present distribution of these coal-fields in India, modified, as it undoubtedly has been, by the 
great destruction and denudation to which not only the coal-bearing, but all subjacent rocks 
have been subjected, appears to me to point also to this limitation to defined areas. Thus the 
Ranigunj, the Jherria, the Bokaro, the Ramghur, and the Ivarunpura fields all 
belong to the drainage basin of the Damoodah river. Itkuri (Eetcoora), and the 
Kurhurbari fields are in the basin of the Barakar, the largest affluent of the Damoodah, 
from which in the upper part of its course it is separated by the lofty ranges of Par a snath 
and the wide plateau of Hazaribagh. The Kasta deposits and the limited field near 
Dubrajpur and the Deogur fields are in the valley of the Adjai, and limited to it, 
while the valley of the More, further to the north, has its small field near to Soory. (In a 
wider view, all these rivers may be considered to have formed one general estuary at an 
early period). The Talchir field, near Kattak, the detached areas of Talchir sandstones in 
the Sumbulpur country, and the Belaspur field, are limited to the Mahanuddy basin; 
the Palamow, the Singrowli, and South Rewah coals are all strictly confined to the 
Sone basin;—the Chanda field and the continuation of this field in detached areas down 
the Godavery valley, considerably below Dumagudiam, all are strictly confined to the basin 
of the Godavery and its affluents, while similarly the coal-fields of the Nerbudda valley are 
all limited to the drainage basin of that river. 
In other words, it seems to me that there is very strong evidence to lead to the 
conviction (announced by me at the meeting of the British Association in December 1867, 
when speaking generally of the Geology of India), that the great drainage basins of this 
country were on the large scale marked out, and existed (as drainage-basins) at the enormously 
distant period which marked the commencement of the deposition of the great plant-bearing 
series to which I have referred. 
In this point of view, local variations in the lithological type, and local variations in 
the thickness of the groups, and even their occurrence or non-occurrence, are only necessary 
consequences of the mode and limits of formation. And this will, I think, go far to account 
for these variations. 
Mr. Medlicott has arrived at somewhat similar conclusions bearing on the limits 
of deposition of these beds as applied to some of the basins. 
At the commencement of the present season, Mr. Medlicott proceeded to the 
Nerbudda valley, to work out more closely than had before been practicable the coal-bearing 
rocks in that area. When first visited, now more than twelve years since, no maps whatever 
existed of the Nurs in gpur and Ho shun gab ad districts, and it was necessary, in order 
to obtain any record, to carry out a general topographical sketch or survey concurrently 
with the geological examination. Within the last few months we obtained the finished 
revenue survey maps of these districts (Hoshungabad and Nursingpur), and I have at 
once taken advantage of them to ascertain with greater accuracy than was originally possible 
the distribution and contents of the coal-measure rocks there. The approaching completion 
