90 
Records of the Geological Survey of India. 
[vol. x. 
Many of these bands of trap can be traced for several miles; this is particularly the case 
with those west and north-west of Raialo, and also in the Rimtumbour hills; but in other 
places, as near Tehla, they often die out very suddenly. Occurring on nearly the same geolo¬ 
gical horizon as these traps are some bands of hornblende rock, which are probably of meta- 
morphic origin. 
The position of the Arvali series in the scale of Indian formations is somewhat doubtful. 
Relations of Arvalis to other I have already stated that it rests unconformably upon the 
gneiss and the schists, and that outlying ridges and hills pro¬ 
bably belonging to the Vindhyan series rest upon it. The doubtful point then, is the 
relative position of the Gwalior and the Arvali series. 
The Gwalior series is most largely developed in the neighbourhood of Gwalior, where it 
rests unconformably upon the gneiss of Bundelkhand, and is covered, also unconformably, by 
the Vindhvans. The series there consists of a quartzite-sandstone at base, covered by 
many hundred feet of banded jasper, including several bands of limestone and contempora¬ 
neous trap. The rocks of the series are only slightly disturbed, seldom dipping at a higher 
angle than 5°, and are much less altered than the Arvali series in Rajputana. 
The only representative of the Gwalior series within our area is a long broken rido-e of 
banded jasper rocks dipping at an angle of between 60° and 80° to north-west near Ilindon. 
The ridge runs in a north-east to south-west direction parallel to, and at a varying distance of 
200 yards to two or three miles from, the north-west boundary of the main area of the 
Vindhyan series. The north-eastern extremity of this ridge extends to within three miles of 
the south-eastern end of the Byaua hills formed of the Arvali series. 
The only rocks seen in contact with the banded jasper of the Gwalior ridge at Hindon 
are some hills of quartzite saudstoue associated with some red and black slaty shales and 
irregular bands of limestone. The quartzite sandstone is in places highly altered; but in 
others it shows scarcely any traces of alteration. It is nearly vertical, and the strike is 
roughly parallel to that of the banded jasper. All the junctions ars concealed by debris ; but 
the quartzite appears to rest upon different beds of the jasper rock; thus at the northern end 
of the ridge the quartzites are on the southern side, hut further south they cross the rido-e and 
are on the north-west side of it. From the position of these hills of quartzite sandstone, 
and from their being generally less altered than the rocks of the Arvali series, it seems 
probable that they are outliers of the Vindhyan series. On the other hand, the black and red 
slaty shales and limestone are unknown in the lowest beds of the Vindhyans; but somewhat 
similar beds occur in the quartzites of the Arvalis. 
The only other evidence bearing upon this point is the presence of some jasper pebbles 
in the conglomerate beds of the Arvali series ; but although these resemble the Gwalior 
jaspers, they are not sufficiently characteristic to determine the point. The question is one 
of much geological interest; it would greatly complicate matters to have to make the Arvalis 
younger than the Gwaliors. 
The useful minerals found within our area are -copper pyrites, rutile, argentiferous 
Economic geology. galena, manganese nickel, iron. 
Several old copper workings exist, from which through a loug series of years a con¬ 
siderable amount of ore has been extracted, but at the present time they are almost entirely 
abandoned. The natives say that some of the richest deposits of ore had to be abandoned in 
consequence of the influx of water. In other cases, the richest mines fell together, burying a 
number of miners, and have not since been re-opened. 
