184 
Records of the Geological Survey of India. 
[vol. x. 
of Kalahandi quite a distinct group is met with. The}' consist principally of hornblendic 
rocks, being generally dioritic or syenitic; but there are also some crystalline felsites, in 
which there is no trace of hornblend. The few short traverses I was able to make across the 
outer ranges of this hilly region were not sufficient to enable me to define the limits of this 
group of rocks; and owing in a great measure to what I believe to be the origin of the rocks, 
the sections examined are of a nature very difficult to describe. In some few places, as in 
the Bodra-jor, these hornblendic rocks appear interbedded with schists and garnetiferous 
gneiss; but far more commonly the relations are of a most complicated and disturbed nature 
—one, in short, which can only be explained by regarding a portion of the rocks as intrusive. 
From the fact that these rocks occur sometimes interbedded with, while at others they 
envelop and surround, masses of gneiss, but more particularly from the fact that an 
obscure foliation structure is sometimes apparent both in the diorites and felsites, I am 
inclined to believe that these rocks are the product of original intrusive volcanic rocks, which 
have been affected by the general metamorphie action of the formation, and are not of plutonie 
derivation, as might be supposed from their more ordinary lithological characters. 
It is impossible to give all the details which I have recorded hero. It will bo sufficient 
at present to give the observations made on the longest traverse. The ascent to Moulpatna 
is effected by a ghat, about 1,235 feet high, in whieh there is a confused mass of tumbled 
rocks. What to call the principal form, it is not easy to say. It contains both quartz and 
felspar, and in places might he called a petrosilex, but it passes into a pegmatite, and is 
occasionally even syenitic. Towards the top of the ghat, dioritic rocks, with a spheroidal 
(cannon ball) structure, appear; and (dose to Moulpatna, gneisses also are seen striking across 
some of the valleys, and apparently running under peaks and ridges of the diorites. In the 
section of the ludravati there arc coarsely crystalline diorites and syenites, with no distinct 
sign of either bedding or foliation. Thence, eastward to the Baplaimali plateau, the rocks 
seen consist, for the most part, of the same rocks, boulders from which strew the surface in 
every direction. Gneissose rocks, however, occur also, and the plateau is formed of white 
ashy-looking beds, spotted with magnetic iron. They dip to east-south-east at angles of from 
60° to 80°, and are capped by a thickness of 300 feet of laterite. I have once before, in 
Manblmm, met somewhat similar rooks. In that instance the dioritic rocks, being well 
exposed, in plan, in a Hat country, often appeared to be interbedded with the ordinary 
metamorphie bods ; but frequently they would suddenly leave the steady strike and pass 
across from between one pair of beds to another, and occasionally also occurred as consider¬ 
able amorphous masses. 
Jaipur Area. —The crystalline rocks of this area belong to three different groups. 
On the tlic north-east there appears to be a continuation of the just-described Kalahandi rocks. 
In the central northern portions there are ordinary metamorphie rocks, which are characterised 
by including an unusual proportion of hornblendic gneisses. These are well seen in the 
Borigmna, Poragarb, and llaigarh groups of hills. On the north-west of Jaipur the rocks 
seem to belong to the group of granites and porphyries of Nowagarh, about to be described. 
Throughout the whole of the area the rocks are much concealed by laterite and alluvium, and 
it would be useless to enumerate details here. 
Bcstae Area. —It is almost certain that crystalline rocks occur in the southern parts of 
Bustar, and it is not improbable that they will also be found in the north; but as there 
are none in the portion of Bustar examined by me, we may pass on to the next area. 
Nowagarh Area. —Throughout Nowagarli I did not meet with a single completely 
satisfactory instance ol‘ a distinctly foliated or bedded metamorphie rock. Massive granites, 
syenites, and dioritic rocks have, with rare exceptions, alone been observed. It is a matter 
of some uncertainty whether these should be regarded as being of metamorphie or true igneous 
