PART 4.] 
87 
Stuihr : Copper deposits of Singhbhdm. 
of clay-slate. At the junction of the sedimentaries and the granitics there occurs a strange 
quartzose formation, a true arkose, many feet thick and almost vertical; in which are found 
angular fragments of the different metamorphics, in a fine quartzose mass. Of minerals 
I obtained garnet, schorl, kyanitc, rhatizite, and chloritoid (of Kenngott); also a bine-black 
mineral of an elongated form, which Kenngott considered to be apatite united with a car¬ 
bonaceous substance. 
2. Greenstone dykes. —The irregularities that these ranges exhibit are due to the pre¬ 
sence of transverse dykes, especially of diorite. Simple inspection cannot determine whether 
the greenstone is amphibolic or pyroxenic—diorite or diobase; T incline to consider it diorite. 
Generally hard, it often becomes soft, changing to aphanite; at Paraum near Dlioba it is almost 
serpentinous, containing nearly 10 per cent, of water. Not far off are considerable runs of 
potstone, which this aphanite seems at all events to approach. In other places the greenstone 
passes into greenstone-schist, following the strike of the series. Although these dykes do not 
always come to the surface, they can he traced at intervals in long ridges recognisable from a 
distance as longitudinally extended lines of conical hills, generally double-topped. The 
strike of these diorite masses varies, generally north and south, or 15° on either side. 
Where such a north-south range crosses those of the older rocks all is confused; still a most 
picturesque conical hill always detaches itself from the mass. This very hornblendic diorite 
has a remarkable tendency to spheroidal structure, and appears on the summits split into 
vertical columns, like ruined castles. It is noteworthy that one often finds such clefts with 
quite fresh surfaces of fracture : this is the result of the sudden cooling by rain of the rocks 
when highly heated by the sun’s rays, as I determined by direct experiment. These diorite* 
are so rich in iron that they often disturb the magnetic needle, and weather into iron-sand. 
The diorite cones seldom form considerable elevations ; but this is not without exception, as at 
Bagmuri, 2,000 feet high. Where the diorites come in contact with the sedimentaries these 
are altogether metamorphosed; basalt-jasper occurs; the schists are calcined, and columnar 
divisions are frequent. These greenstones are not limited to the north and south dykes. 
Whether the introduction of the greenstones has had any connection with the appearance 
of the copper oi - e must for the present remain undetermined ; it would seem the more 
likely, inasmuch as the potstone and serpentine formation is certainly so connected. 
3. Granilics. —These diorites run into the granitic area to the south and west; where 
gneiss-granite and, less frequently, true granite form dome-shaped hills; these also here 
observe an east-west direction in long parallel ranges above the plain, Unversed by the north- 
south diorites—an arrangement that gives to the whole area a strange chessboard-like aspect. 
At the intersections of the two systems of ranges, the most picturesque cones occur; 
and remarkable development of mica appears in the granitic rock, so that the mica is applied 
to many ornamental purposes. 
4. Laterite. —In India many different formations are grouped under the name of 
laterite. There is the laterite of the plains formed of detrital matter into which the iron 
constituent came from without, probably from springs; such is the laterite of Midnapur. 
From these are to be distinguished that which owes its tbrmatiou to the decomposition in 
situ of ferriferous rocks; such is the only laterite known to me in our district, as on the 
summit of Mahadeo, derived from the ferriferous diorites. 
_ 5. Mineral prodnHs. —I have already mentioned the potstone that is worked into 
various utensils. I may here notice an ochreous schist that is used as a dye. Of ores there 
are—iron ore, sometimes as a vein, sometimes stratified; mostly pure magnetic iron (see 
Berg- und lluttenmiinnischen Zeituug for 18G3); seldom red haematite, and once only 
brown hsematite; then the rich copper oro, which was the object of my journey to India. 
6. Copper ore: its range. —This copper ore would be interesting if only on account 
of its unusual longitudinal extension—for 80 miles it' not, more. I have examined it more 
closely through a length of 05 miles, from Lopso hill in the west to as far as Badia in the 
east. I know nothing of its further distribution in the western forest-clad hills, but in 
its eastern range it goes far beyond Badia to Bairagurha, the most south-east point on my 
map; and so far as I examined the intermediate hills, traces of the ore were found everywhere; 
but in its longitudinal range, it appears most in the northern hills. 
7. A lode, or bedded. —The strike and dip so coincide witli thoso of tire containing 
strata that one is induced to consider the mineral deposit as stratified; against such a 
supposition there is the vein-like mode of deposit, the frequent cuirasses and slickensides, 
the occurrence of druses, and the broken outcrop. At all events the deposit is a filling of 
