Understanding the role of chalcophile-siderophile elements in the petrogenesis of metabasalts of Kudremukh greenstone belt, western Dharwar Craton, India: A Platinum group elements geochemical perspective

AbstractAn oxide-silicate occurrence, containing >40 wt.% NiO whole rock and showing enrichment in the platinum-group elements and antimony, was investigated at high magnification. Many phases with grain sizes generally <100 μm were observed; electron microprobe analysis indicated that, although some of these are known minerals in Ni–Sb–As space (such as breithauptite and orcelite), most of them cluster around the following compositions: Ni3Sb, Ni3(Sb,As), Ni3As, Ni5(Sb,As)2, Ni7(Sb,As)3 and Ni11(Sb,As)8. Such phases have been observed in synthetic systems, but up to now not in nature. The data reported here therefore probably represent the compositions of new minerals.

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Hydrothermal Chromitites from the Oman Ophiolite: The Role of Water in Chromitite Genesis

Minerals ◽

10.3390/min10030217 ◽

2020 ◽

Vol 10 (3) ◽

pp. 217

Author(s):

Shoji Arai ◽

Makoto Miura ◽

Akihiro Tamura ◽

Norikatsu Akizawa ◽

Akira Ishikawa

Keyword(s):

High Temperature ◽

Mantle Wedge ◽

Platinum Group Elements ◽

Hydrothermal Fluids ◽

Oman Ophiolite ◽

Crustal Rocks ◽

The Matrix ◽

Platinum Group ◽

Podiform Chromitite

The role of water-rich solutions in the formation of chromitites has been the matter of controversy. We found small chromite concentrations (chromitites) in diopsidites, precipitated from high-temperature hydrothermal fluids, in the mantle to the crust of the Oman ophiolite. Here, we present petrologic characteristics of the hydrothermal chromitites to understand their genesis. In the chromitites, the chromite is associated with uvarovite in the crust and diopside + grossular in the mantle. They are discriminated from the magmatic podiform chromitite by dominance of the Ca-Al silicates in the matrix. The fluids responsible for chromite precipitation are possibly saline, being derived from the seawater circulated into the mantle through the crust. The saline fluids precipitate chromite to form chromite upon decompression and cooling, and transport platinum-group elements (especially Pt and Pd). The fluids obtain Ca and Al from the crustal rocks and Cr from the mantle rocks during circulation. Saline fluids are also supplied from the slab to the mantle wedge, and can metasomatically precipitate chromite and pyroxenes within peridotites. They re-distribute Cr and chromite in peridotites along with circulation of saline fluids in the mantle wedge.

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Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2015.01.020 ◽

2015 ◽

Vol 105 ◽

pp. 300-319 ◽

Cited By ~ 16

Author(s):

Abhishek Saha ◽

C. Manikyamba ◽

M. Santosh ◽

Sohini Ganguly ◽

Arubam C. Khelen ◽

...

Keyword(s):

Platinum Group Elements ◽

Dharwar Craton ◽

Mantle Melting ◽

Platinum Group ◽

Pge Geochemistry

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Noble metal mineralization in apatite titanomagnetite ores of the Suroyam massif (Middle Urals)

Georesursy ◽

10.18599/grs.2020.4.98-100 ◽

2020 ◽

Vol 22 (4) ◽

pp. 98-100

Author(s):

Dmitry E. Saveliev ◽

Ivan A. Blinov

Keyword(s):

Noble Metal ◽

Mineralogical Composition ◽

Platinum Group Elements ◽

Middle Urals ◽

Leading Role ◽

Mineral Phases ◽

Noble Metal Mineralization ◽

Platinum Group

The mineralogical composition of apatite-titanomagnetite clinopyroxenites of the Suroyam massif, characterized by stable elevated contents of platinum group elements with the leading role of palladium, has been studied. In association with accessory chalcopyrite, palladium and silver minerals have been identified – mertieite, merenskyite, hessite. It has been suggested that the presence of intrinsic mineral phases of palladium, represented by tellurides and arsenides-antimonides, allows us to consider the Suroyam massif as a promising deposit of complex Pd-P-Fe ores.

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