1831 .] 
Journey from Calcutta to Ghaztpur. 
135 
gudhy, we see the same kind of strata exposed in a rivulet ; but though the base is 
the same, it here contains a number of pebbles of quartz, sienite, sienitic and por- 
phyritic granite, mica slate, and perhaps flinty slate, mostly rounded, but some angu- 
lar. Near the 270th milestone, the crystalline rock again protrudes above the soil. 
From the direction of the stream, we might believe that this bed is only the termi- 
nation of a formation which is expanded in the lower ground, in the line of Baghel- 
pur. The notice of coal at Palamh might also lead us to conjecture its connec- 
tion with that quarter. 
The crystalline rock as mentioned, was a compound of hornblende and felspar, 
rather what we should describe as sienite than greenstone ; but 7 or 8 miles farther 
on, we come to rugged ridges, similar to what we passed before reaching Katcam- 
sandy, and the rock is again principally hornblende. With this we sometimes see 
masses of a white felspathic rock, in a state of decomposition, which sometimes con- 
tains mica or hornblende, and occasionally a large grained granite ; but these are 
partial appearances, and probably only masses that have been lifted by the trap. 
After crossing these ridges, we come by a rapid descent upon the alluvial plains of 
the Ganges. One or two detached masses of rock appear in the distance to the 
north, probably they are sienite; the main formation still appears in the distance, to 
the south. Between the 300th and 312th milestone, I observed two outliers from 
this, near the road, both principally felspathic, with mica and hornblende. 
The above observations are the only data which I have had to form the accom- 
panying section. The features of the country are probably familiar to many, and 
those who have studied the change of granitic and sienitic rocks, where they pass 
much into each other, can only know the difficulty of drawing any distinctions be- 
tween them, even where the rock is uncovered, the vegetation scanty, and the cli- 
mate favourable to exertion. How much more so is it likely to be, where on these 
points we find a lamentable difference ? 
Yet notwithstanding these difficulties, and the equivocal nature of the rock in 
many places, it sometimes takes a decided character ; as for instance, at the two 
Ghats I have described to the west of Hazaribagh. In the two points I have 
noticed to the east of this place, viz. near Amchatar, and on the eastern bank of the 
Damuda, it is less iharked ; but as I see there is a Tutki Ghat between Rakin- 
jah and Hazaribagh, it may perhaps be found there. 
The gradual passage of this hornblende rock or transition greenstone through 
sienite to granite, and the manner in which the layers of it lie between those of 
gneiss, lead us to conjecture that the two rocks have remained long in contact in a 
state of complete fusion. On such a supposition sienite and sienitic granite may be 
only portions of one or both rocks, the nature of which has been partially changed. 
Thus mica, with about 15 per cent, of quartz, and nearly the whole of its iron de- 
ducted, would differ little in chemical composition from felspar ; the same mica 
again, with the addition of some lime and oxide of iron, would have a similar com- 
position to hornblende. 
The manner in which the trap has burst out on each side the ridge, and its par- 
tial appearances of stratification, which shew that it has pushed between the strata 
rather than cut through them, are indicative of intense and long continued pressure. 
The inclination of these beds or dykes (for they most likely partake of the nature 
of both) to a common axis, renders it probable, that they are connected beneath ; 
aQ d, if this be allowed, we can hardly refuse the inference that they have been the 
principal cause which has upheaved the intermediate mass of granite and 
gneiss. 
