Records of the Geological Survey of India. 
[vol. x. 
G(5 
which the dyke was doubtless thrust. Although the section in the river bank is quite clean, 
the thick covering of laterite on the hill and from thence inland renders it impossible to 
trace the limits of the trap and examine its relations with the sandstones in that direction. 
These latter, however, appear to sweep round the Sideshar hill to the east with unbroken 
bedding; further south, however, both shales and basalt are again met with, as will presently 
be noticed. 
The trap on the river face extends for about 150 or 160 yards in a north-east, south-west 
direction, but this is probably oblique to the strike, and certainly so if the trap seen further 
south is continuous with it. It is a dense, heavy, greenish-black rock abounding in an earthy 
magnesian mineral, which in the exposed portion has been washed out and left hollows. 
On the southern side of the trap occur the shales above mentioned ; of these the lower 
portion is black and carbonaceous, but not in the smallest degree coaly; towards the top they 
become purplish and red, and include one or two distinct runs of ironstone. Unfortunately 
they do not shew any determinable remains of plants, a few charred fragments of vegetable 
matter being alone discernible. In general appearance, beyond the fact that they are car¬ 
bonaceous, these shales do not present any resemblance to those of the coal-measures, while 
they are of much the same character as certain well-known beds in the iutertrappeans of the 
Rajmehal hills. The hopes of coal occurring in this vicinity, which have from time to time 
beeu excited hy the appearance of these beds, are not, I venture to say, justified by the facts. 
The appearance of these beds at the surface, in this locality, being probably altogether due 
to the elevatory action of the trap, and the fact that they have not been elsewhere observed 
in any part of the area, prevent any decided opinion being formed as to their extent. Judging, 
however, from the sections in the Rajmehal hills, it is not improbable that they may originally 
have had a very limited area of deposit. 
The point at which they appear further south is situated about 500 yards to the east of 
the village of Mondali. Here, together with the trap, they have contributed to the formation 
of the soil, and are seen in certain shallow wells and excavations, but nowhere crop out at the 
surface. 
Close to Mondali there is an unusually hard and dense felspathic quartzite. In the 
river section, at intervals up to Bajipur, there are outcrops of sandstone of normal character. 
In the vicinity of the bund in the direction of the river, certain black clays situated in the 
bank at about the hot-weather water-level, and which had been pointed out to me as being 
possibly indicative of coal, proved on examination to be of a peaty character and of the same 
ago as the alluvial clays with which, indeed, they may be seen to be interbedded. Between 
this and Dompara the beds exposed in the river are fiat, ferruginous sandstones, rarely accom¬ 
panied by red clays. In the hills to the south of the road there are sandstones and con¬ 
glomerates similar to those seon in the ranges north of the river. 
Towards Talbust, a hill of metamorphic rocks occurs in close proximity to the sandstones, 
but no junctions were observed. The boundary is still probably natural, as the sandstones 
shew no signs of disturbance. Between Talbust and Huldia the rocks seen are massive beds 
of coarse sandstones and conglomerates, which are in places abruptly scarped. 
Between Huldia and Maindasal, at the foot of the Tuskai hills, the boundary is com¬ 
pletely hidden by laterite, under which the sandstones disappear. Springs are very abundant 
at the foot of the hills. 
