« PreviousContinue »
All these have been exhaustively dealt with by Sir L. L. Fermor n his memoir on the Manganese-Ore Deposit of India.1
The Kajlidongri deposit is situated five miles to the W.N.W. of Meghnagar (22° 54′ 74° 32') station : of the B.B. and C.I. Railway. It forms a low ridge rising to nearly 70 feet above the ground level, running with a strike of N. 30°W. for a distance of about 1,000 yards. Psilomelane, pyrolusite and braunite form the main bulk of the ore-body.
The Rambhapur deposit lies immediately to the north-west of Rambhapur town (22° 55′ : 74° 29′) and forms a low mound running N. 30° W. for nearly 250 yards along the line of strike of the Kajlidongri deposit, with which it is probably genetically connected. Pyrolusite, psilomelane and braunite are the main oreminerals of this deposit. Kajlidongri and Rambhapur are no longer worked.
Manganese ores at Amlamal (23° 0′: 74° 25') occur in a steeply folded fine-grained reddish quartzite and appear to be very limited in extent.
At Nagankheri-Mandli (22° 45' 74° 39′) manganese minerals are included in siliceous boulders occurring as a mound approximately 20 feet high, 30 feet wide and 100 feet long. The occurrence is very limited in extent.
Low grade ore-bodies interlaminated with quartz have been recorded near Pitol. (22° 47' 74° 28'). : The occurrence forms a low mound about 140 yards long.
A new occurrence is near Mandli (22° 57′ : 74° The ore is associated with vein-quartz and grey calcite. Massive psiloinelane forms the bulk of the ore. Crystalline aggregates of braunite, hollandite with rhodonite, and piedmontite also abound. The ore body is irregular in its occurrence and no data for the estimation of the amount accessible for exploitation are available.
Sir L. L. Fermor examined the manganese occurrences of Shivrajpur in 1905. The ores are irregularly distributed in the Aravalli slates and quartzites and are probably replacement products. The ores consist of pyrolusite, The quality of the ore is rather variable
psilomelane and braunite.
1 Mem. Geol. Surv. Ind., XXXVII, Pt. 4, pp. 651, 679, 687-9, (1909).
owing to the residual patches of the original quartzite and slate that have escaped replacement.
A new occurrence of manganese ore has been noted in the Aravalli schists of the Panch Mahals district. This lies about three miles north of the Anas railway station of the B. B. and C. I. Railway. The ore consists of pyrolusite, psilomelane and wad. These occur as local bands and lenticles along with quartzite interbanding in the country-rock.
Manganese-ore deposits of considerable economic importance occur near Pani (22° 27' 73° 47') in Chhota Udepur State in the midst of the Aravalli phyllite and quartzites. The ore body is mainly pyrolusite and appears to be the result of replacement of the quartzite by oxides of manganese. Occurrences of particularly rich ores have occasionally been found to contain as much as 95 per cent of pyrolusite. Mr. G. V. Hobson examined the occurrences in 19241.
The manganese ore deposits near the village Jothvad (22° 24': 73° 44′) in Narukot State were examined by Sir L. L. Fermor in 1905.2 These occur about half a mile north of the village, in a small hill striking north and south for about half a mile and rising about 150 feet above the general level of the surrounding plains. The hill is composed of an inlier of intensely folded Aravalli gneisses surrounded and traversed by porphyritic biotite-granite. Rich in variety of very interesting manganese minerals as this occurrence is, it has been found to be of but little economic importance.
The pegmatite dykes in the granite of the area often contain muscovite in considerable amount. The mica is stainless but the flakes are generally small in size.
1 Mem. Geol. Surv. Ind., XXXVII, Pt. 4, p. 646, (1909). 2 Rec. Geol. Surv. Ind., LIX, Pt. 3, pp. 352-354, (1926).