4 
Records of the. Geological Survey of India, 
there is a decided ghat or sudden descent into the wide valley of the Mohun, where the far 
stretching view over the low plains at once suggests a change in the nature of the rocks ; there, 
in fact, comes in a portion of the great central area of the rocks associated with the coal-bearing 
series of India, The road itself, excepting in one or two spots where the newer formations still 
exist, runs upon crystalline rocks, keeping to the north side of the Mohun valley; although west¬ 
wards from Burwah, the upper members of these newer formations had been noticed capping 
some of the hills of the upland area, in one case themselves capped by trap. 
These rocks extend from Pertabgurk to the Husdoo, through Bisrampur (60 miles), here 
and there varied by a tongue-like extension of the crystalline rocks, Jbnning prolongations in 
most cases of lulls lying to the eastward. Many of these hills by their outline show that the 
crystalline rocks extend lo their summit, while others form table-lands, on the scarped edges of 
which the white sandstone is conspicuous. These scarps admirably exhibit the very unequal 
surface of deposition on which the sandstones were formed. From the Hnsdoo and the plains 
of Belaspur, the main mass of the crystalline rocks, which greatly predominate, lies to the 
north-west, forming the hilly, region of Mahtin, while the numerous and almost detached areas 
of the secondary rocks (ihieily of the Talcheer series) are extensions from the eastwards, where 
the table-topped lulls of Odeypur appear to be formed altogether of the sandstones. With this 
extension ol that series of rocks is connected the small coal basin of Koorbah. On the 
Mahtin hills themselves a few remnants of the upper sandstones stand up like old fortresses 
on the highest summits. 
Over the area, lying between the Koorbah coal-basin and the plains of Belaspur, there is 
no continuous high ground. Isolated ridges, mostly of inconsiderable elevation and composed 
of the crystalline rocks, occur. 
In this region of the Mahanuddi, as also in that of the Godavery drainage basin, the only 
knowledge we had of the structure of the country was derived from the Revd. Mr. Hislop’s 
exertions; he had, however, confounded rocks belonging to two distinct series, between the 
deposition of which there had been an immense interval of time. The great plains of 
Chntteesghnr were colored as belonging to the same series as the eoal-field of Koorbah. In 
reality, however, the rocks belong to that very much older series to which the general name of 
Vindnyan has been given. These cover an area of more than 12,000 square miles, limestone 
being the prevalent rock. On the north, they abut against the crystalline rocks; on the west, 
they pass under the Deccan traps; to the south-west, they stretch to an. unknown (as yet) 
distance up the valley ol the Mahanuddi; to the south-east, they rest upon crystalline rocks ; 
and to the east, they are crushed up with, and upon, similar rocks in*a complicated manner. 
The more recent Talcheer rocks are filled with debris from these, but nowhere was the actual 
contact or superposition visible. 
The Talcheer rocks extend from the Odeypur district to very near Sumbulpur. The 
country towards Gangpur from Chaibassa is now being examined in detail, so that it need not 
be more specially alluded to here. At Chaibassa itself there is the junction of the newer 
submetamorphic with the gneissose rocks. There is also a grand exhibition of trappean 
intrusions, which, it is noteworthy, occur with vastly greater frequency in the granites than in 
the slates. 
This extended reconnoissance of Mr. Medlicott’s will prove of very great value when we 
are able to extend our detailed researches into this vast area. 
The Iloharo or Karunpoora coal-field was completed in the early part of the year by 
Mr. Hughes. This, as stated in my report for last year, is of considerable extent, covering an 
area of not less than five hundred square miles, but it is poor in coal, few of the seams 
promising well. Iron is largely smelted within this area, nearly 200 small native furnaces 
being still at work. Later in the season Mr. Hughes completed the examination of the South 
Karunpoora coal-field, also of considerable superficial area, and at the same time richer in coal. 
We have unfortunately been unable to obtain maps so as to enable us to continue and 
complete the examination ol the coal-field of Palamow, lying to the west of those just alluded 
to. We bad commenced this last year, and in fall hopes of being able to proceed steadily to 
the completion of its examination. It is highly important to obtain some trustworthy 
information regarding the prospects of good fuel being discovered there, especially in connection 
with the proposed execution of the Soane canals, As soon as maps are available, the geological 
examination of the field will not take long 
