6:i4 MANGANESE DEPOSITS OK INDIA : DESCRIPTIVE. [PaRT IV : 
2. Bhimgad. 
In 1874:, Mr. R. B. Foote,i late of the Geological Survey of India, 
found, near the east gate of the fort, a considerable quantity of a dark 
blackish -brown powder 
'accumulated on the surface of the dolt>nute from which it had evidently been 
weathered out. The limestone, the face of which was greatly concealed by vege- 
tation, was here darker in colour tlian in the main mass of the mountain. The 
mode in which the black mineral occurred in the original rock was not clear. ..' 
An analysis by Mr. Tween of this ore, which is apparently a very 
impure wad, showed it to consist of : — 
Water and organic matter ...... 14-6 
Oxide of iron and a little alumina .... 22-0 
Binoxide of manganese . . . . . .20-0 
Insoluble 44 -S 
101-4 
\?hiie an analysis of the dolomite, also by Mr. Tween, showed : — 
Water and organic matter ...... 4-0 
Carbonate of lime . . . . . . . .56-4 
Carbonate of magnesia . . . . . .34-8 
Oxide of iron with a little alumina and manganese . . 3-G 
Insoluble 2-2 
101-0 
Judging from the second analysis, it seems as if this wad is a resi- 
dual crust ieft on the surface of the dolomite when the carbonates of 
calcium and magnesium are dissolved away by meteoric waters ; it is 
possible that the manganese was originally contained in the dolomite 
as the carbonate. The dolomite was included by Foote in his gneissic 
series. Tliis was, however, previous to the establishment by him in 
18882 of the Dharwar Series; and Mr. J. M. Maclaren, late of the 
Geological Survey, who visited this area in 1904-05, has added, under 
the name of the Castle Rock Band, 3 a fourth to the three main bands of 
Dharwar rocks already distinguished by Foote in this part of India. The 
dolomites of Bhimgad, and the limestones and schistose rocks of Tale- 
vadi and Ncrsa, are mapped by Maclaren as forming part of this band. 
1 sMem. Geol. Surv. hid., XII, pp. 56, 259, (1876). Bee. Oeol. Surv. Ind., VII, 
p. 125, (1873). 
2 Rec. Geol. Surv. Ind., XXI, p. 41, (1888). 
3 Ibid., XXXIV, p. 96, (1906). 
