PART 1.] 
Annual Report for 1871. 
7 
In addition to this labour, Mr. Mallet undertook the duties of Curator, during the 
temporary absence of Mr. Tween, for three months’ privilege leave. 
Mr. Mallet has this season again taken up the examination of the Kota coal-field, ex¬ 
tending as it does both into Rewa and Chota Nagpore. 
At the commencement of the year (1871), as stated in the Report of 1870, Mr. Hughes 
was actively engaged in the investigation of the Wurdha river coal-fields. During the 
early portion of the season, his time was much occupied in meeting the district officers 
during their visits to the field, and in pointing out to them how much had been ascertained 
regarding the coal. These interruptions to his regular work most seriously interfered with 
his progress, and by necessitating frequent long and forced marches to and fro, without any 
sufficient convenience for such rapid moving, the cost of which is such as the limited allow¬ 
ances of the Geological Survey do not meet, they also resulted in his beiug laid up by an 
injury to one of his feet, which for some time entirely prevented his moving about at all. 
He remained, however, on the ground, and continued to give advice as to the borings. As 
soon as able, he resumed his work, but at the close of the season he was obliged to proceed 
home on medical certificate. 
Late in the season (May) he crossed into His Highness the Nizam’s territories, and 
pointed out to Mr. Whyte, who had been sent by the Nizam’s Government to put down trial 
borings in the country opposite Ballarpur, the structure of the rocks, and suitable places 
to work, for which aid Mr. Whyte expressed his obligation, and I am informed that the 
result has been the proving the existence there of more than fifty feet in thickness of coal. 
During the season, the various borings carried out on both sides of the river have en¬ 
tirely confirmed the conclusion already arrived at with respect to this field, and have 
established conclusively upon what a very irregular surface the irpper rocks have been depo¬ 
sited. The eastern boundary of these rocks was examined for a considerable distance, and 
they were found to be faulted against the gneiss, as far south as Sitarampett, or nearly to 
Moharli; here, however, the fault at the surface passes through the Kamthi rocks them¬ 
selves, bringing into contact different beds of the same series. South of Moharli again the 
gneiss and sandstone are in contact along the boundary fault. The occurrence also of a 
small inlier of the Talchlr rocks between Walwut and Sinaia adds a convincing fact to the 
other evidence as to the irregular thickness of the upper (Kamthi) series, and shows the 
necessity for actual trials before attempting to assert definitely the depth at which, or the 
points where, coal may he found. The general structure of the whole field, namely, a wide 
anticlinal, largely denuded at the top of the curve as pointed out (by Mr. W. Blanford,) on 
the first examination of the area, coupled with the many instances in which the Vindhyan 
rocks below the coal occur in isolated and detached patches either at the surface, or at small 
depths below it, places it beyond a question, that this central portion of the field is one in 
which the flooring of the older rocks comes very near to the surface, and so irregularly that 
the coal, where found, will only he in small and discontinuous basins. For any large and con¬ 
tinuous areas, we must go beyond this portion. To the west, the existence of the coal has 
been fully proved over a long line of country in East Berar. To the east there is no reason 
to assume its absence, hut its occurrence has not been proved as yet. 
Wurrora, where a coal-pit has been commenced, is unfortunately not, as stated, on the 
east scarp of l b.'-* anticlinal, but a considerable distance from it, although the coal extends over 
a sufficient area to yield a g*ood supply for some time. 
From a knowledge of these facts, and a general consideration of the lie of the ground, I was 
compelled during the year, on the question being referred to me, as to ‘ what action should he 
