A New Finding of Subsurface Potential Rhodochrosite Deposit from the Eastern Ghats, India: Unearthing Novel Prospective Areas for Future Exploration

ABSTRACT The Precambrian polydeformed Eastern Ghats granulite terrain holds a large number of small-sized Mn oxide deposits of low to medium grade with high iron, phosphorus, and silica contents. The primary ore minerals are considered to be syngenetic and syntectonic with the metasedimentary country rocks such as khondalite, quartzite and calc-silicate rock. Braunite, bixbyite, jacobsite, and manganite represent the primary minerals, whereas the secondary minerals are romanechite, cryptomelane, pyrolusite, and goethite. This paper presents a new find of a subsurface potential zone of massive Mn-carbonate (rhodochrosite) bands from Uchhabapalli-Thakurpalli and Dandapani area, Eastern Ghats Mobile Belt (EGMB), Balangir District, Odisha, for the first of its kind in India, which holds a large concealed manganese carbonate deposit of economic significance associated with manganese oxide. The presence of rhodochrosite has been confirmed through petrographic, XRD, SEM and Raman spectroscopic studies. The concealed rhodochrosite (Mn carbonate) bands have been established through exploration (UNFC G-2 stage), with cumulative thickness of rhodochrosite bands intersected by the drill holes varying from 1.0 to 24 m, with an average thickness of 8 m, occurring between 15 and 88 m vertical depth from the surface. The analytical results in wt.% show Mn (20-29.13), P (0.10-1.16), Fe (7.54-21.32) and Si (4.51-35.59). A total of more than 1.45 Mt of indicated resource of Mn carbonate has been estimated with an average grade of 18.30 wt.% Mn, and the rhodochrosite bands have been delineated over a cumulative strike length of 1450 m by the cross-section method. The findings significantly contribute to the understanding of manganese mineralisation in the Eastern Ghats granulite terrain and underscore the economic potential of the region. This discovery opens up new avenues for exploration and exploitation of manganese resources, potentially offering substantial economic benefits.