Records of ike Geological Stare// of India. 
[VOL. It. 
42 
latter ease the inner vallies are so deeply eroded that it is often difficult to get a sight of 
the softer rocks contiguous with the hard quartzite. The Rajgir group is the most 
removed from the main crystalline area ; the rocks are less altered than elsewhere ; and 
it presents the best chance of discovering the normal order of succession of the strata. 
It cannot, however, he said that the strata here are less disturbed than elsewhere ; although, 
on the whole, the strike of the ridges and of the rocks is very constant to norttneast by east, 
the state of contortion could not well be aggravated short of presenting a great brecciated 
agglomeration. 'There are some sections in which there Seem to be several hundred feet 
of quartzite in regular succession. At some points also the line slaty schists present a very 
wide outcrop without any admixture of quartzite. Except very locally at the contact of 
the two there is no appearance of interstratiliention. It will presently be seen how essential 
it is to the geology of this whole region to ascertain the true order of succession of these 
two bands of strata. Some of my colleagues have considered the quartzite to be the bottom 
group; the supposition would alleviate some of our difficulties, and there are no doubt 
cases in which the schist now overlies the quartzite; but a close examination of the ground 
does not permit me to adopt this view; I consider that there is here but one great band 
of quartzite normally underlaid by a considerable thickness of argillaceous strata. There is 
only one spot at which these Rajgir rocks are seen in contact with others : along the whole 
south-east face of the range (at least at the several points at which I crossed it) nothing is 
seen immediately external to the quartzites; at about a mile from the base on this side there is 
one small outcrop of massive granitoid gneiss. On the north-west side the schists are very 
generally exposed; and at about the middle they form a wide fringe of low hills, on the 
outer margin of which, near (Thunsura, there is one good contact-section of the schists with 
a strong mass of granite. The relation is unmistakably one of intrusion ; there are small 
protrusions and ramifying offshoots from the granite into the sedimentary rocks, and enclosing 
angular fragments of them. Tins general effect on the schists is very noteworthy: there is 
little of what is usually considered as hypogene metamorphism ; the line of contact is 
sharply defined, and the schists tend rather to assume a homogeneous, trappoid aspect, 
than a foliated, quartzose, granitic one; the granite of the intrusions has lost much of its 
quartz. Elsewhere to the west, atSapineri. Eutturkati near Gya, and Muhair, and in 
other isolated outcrops, these re-actions are exhibited on a much larger scale ; idols and utensils 
are extensively wrought from the soft serpent lupus rock of the converted schists ; and some of 
the granite dykes yield a fine kaolin, the only considerable use made of which is to adulterate 
lime. 
To the south-east of the Rajgir bills the Bheowa range stands on the border of 
the crystalline area ; and further south, across the narrow valley of the Sukri, rises the fine 
hill-mass of Mahabnr, well in among the crystallines, and overlooking all the high land 
to the south. One cannot resist identifying the great quartzites of these ranges with those 
of Rajgir; and at. Mahabur we again find a thick underlying series of fine schists. There 
are, however, considerable changes to be taken into account: all the rocks are more metamor- 
phic than those of Rajgir; the quartzites are frequently full of small innate mica; and the 
schists are fine mica-schists, garnetiferous. and often with much globular felspar, but 
still the very kind of me.tamorphic rock that one might expect from the slaty' schists of 
Rajgir; and they are very markedly distinct from any variety commonly associated with 
the gneiss. Round the base of Mahabur I did not succeed in finding a section showing 
eveu au approximate contact with the surrounding rocks; but on the north flank of 
the Bheowa ridge there is a fair example of what the general relation of the two series 
in this region may be. At the north end of the Hurkur pass there are several line domes 
of granite ; they are excellent instances of a form of rock that is of frequent occurrence 
all over the gneiss area; a more or less faint foliation is generally traceable in it, and 
it never shows any attempt to throw out dykes ; it would seetu nevertheless highly probable 
that it is in some manner intrusive; the partial foliation (as Mr. Sarope has maintained) 
being due to traction in the viscid mass. The case before us is about the best evidence that 
could now be given in favor of such intrusion : one of these domes occurs close up to the 
ridge of quartzite, and the t wo rocks show distinct re-actions at the contact; the granite 
has lost its usual coarse porphyritie texture; the quartzite is more than usually charged 
with mica, and has a steep underlie from the granite; at the lower levels traces of the 
schists were observed. If the supposition that forces itself so strongly upon our judgment 
be correct, that these several hill-masses are remains of a once continuous formation of 
argillaceous, succeeded by quartzose, deposits, there could be no doubt left of the truly 
