Potarite (Pd-Hg) in Thermally Metamorphosed Dunite from the Inazumi-Yama Ultramafic Complex, Southwestern Japan: An Implication for the Behaviour of Mercury in PGE Mineralization in Peridotite

AbstractThis paper reports the occurrence of Tsumoite (a bismuth telluride) in the Heti Cu-Ni-PGM prospect, Gondpipri mafic-ultramafic complex, Central India. The Gondpipri complex consists of several tectonically dismembered gabbronorite-gabbro-anorthositic gabbro — olivine gabbro -websterite disposed in ∼10 km long tonalite-trondhjemitegranodiorite (TTG) and charnockite-enderbite suite of rocks. The mineralization occurs in the sulphide zone hosted by gabbro variants. The host rocks have been deformed and metamorphosed to granulite grade and subjected to various degrees of hydrothermal alteration. The mineralization comprises chalcopyrite, pentlandite, pyrrhotite, cubanite, millerite, and pyrite. In addition to these, occur (1) tsumoite (2) PGM in the form of moncheite, merenskyite, Pd-mellonite, and Pt-Pd-Te-Bi-Fe-S alloy.The present study indicates that the mineralization occurs in two stages related to: (i) magmatic and (ii) hydrothermal remobilization and transport of Cu-rich sulphides, tsumoite and PGM, and their re-deposition in hydrosilicate alteration zones. It is possible that the mineralization at Heti formed at different stages of bismuth activity under variable fS2, T, and fTe2 conditions due to change in total concentration of Te and S and /or cooling. Since the role of S is limited, Te and cooling are important factor influencing mineralogy and composition of tsumoite and associated mineralization. Mineralization occurs in two different modes of occurrences. The early mineralisation occur as blebs, specks and dissemination of sulphides, viz. pyrrhotite, chalcopyrite, pentlandite and minor pyrite ± PGM, whereas later mineralisation occur as stringers, minor veins of sulphides viz. pyrite, millerite, cubanite, sijenite, tsumoite and ± PGM.Mineral assemblages and textural relationships at Heti has indicated precipitation of tsumoite and associated PGM along fractures and secondary silicates, which confirms their hydrothermal origin.

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Genesis of PGE mineralization in the Wengeqi mafic–ultramafic complex, Guyang County, Inner Mongolia, China

Mineralium Deposita ◽

10.1007/s00126-011-0351-x ◽

2011 ◽

Vol 47 (1-2) ◽

pp. 197-207 ◽

Cited By ~ 8

Author(s):

Shangguo Su ◽

C. Michael Lesher

Keyword(s):

Inner Mongolia ◽

Pge Mineralization ◽

Ultramafic Complex

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Alaskan-type nature and PGE mineralization of the Wuxing mafic–ultramafic complex in eastern part of the Central Asian Orogenic belt

Ore Geology Reviews ◽

10.1016/j.oregeorev.2020.103566 ◽

2020 ◽

Vol 123 ◽

pp. 103566

Author(s):

Meng-Meng Cui ◽

Ben-Xun Su ◽

Jing Wang ◽

Kai-Yun Chen ◽

Patrick Asamoah Sakyi ◽

...

Keyword(s):

Orogenic Belt ◽

Central Asian Orogenic Belt ◽

Central Asian ◽

Pge Mineralization ◽

Ultramafic Complex

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PETROLOGICAL AND GEOCHEMICAL CHARACTERIZATION OF THE SAN JUAN DE OTATES ULTRAMAFIC COMPLEX, LEÓN, GUANAJUATO: TECTONIC IMPLICATIONS

10.1130/abs/2020am-356140 ◽

2020 ◽

Author(s):

Nathalia Pineda rodriguez ◽

◽

Vanessa Colás ◽

José María González-Jiménez ◽

...

Keyword(s):

San Juan ◽

Geochemical Characterization ◽

Tectonic Implications ◽

Ultramafic Complex

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Mineral ages and zircon Hf isotopic composition of the Andong ultramafic complex: implications for the evolution of Mesozoic subduction system and subcontinental lithospheric mantle beneath SE Korea

Geological Magazine ◽

10.1017/s0016756813000757 ◽

2013 ◽

Vol 151 (5) ◽

pp. 765-776 ◽

Cited By ~ 5

Author(s):

GI YOUNG JEONG ◽

CHANG-SIK CHEONG ◽

KEEWOOK YI ◽

JEONGMIN KIM ◽

NAMHOON KIM ◽

...

Keyword(s):

Lithospheric Mantle ◽

Tectonic Setting ◽

Eastern China ◽

Mantle Xenoliths ◽

Late Triassic ◽

Magmatic Differentiation ◽

Suprasubduction Zone ◽

Ultramafic Complex ◽

Yeongnam Massif ◽

Subduction System

AbstractThe Phanerozoic subduction system of the Korean peninsula is considered to have been activated by at least Middle Permian time. The geochemically arc-like Andong ultramafic complex (AUC) occurring along the border between the Precambrian Yeongnam massif and the Cretaceous Gyeongsang back-arc basin provides a rare opportunity for direct study of the pre-Cretaceous mantle wedge lying above the subduction zone. The tightly constrained SHRIMP U–Pb age of zircons extracted from orthopyroxenite specimens (222.1±1.0 Ma) is indistinguishable from the Ar/Ar age of coexisting phlogopite (220±6 Ma). These ages represent the timing of suprasubduction zone magmatism likely in response to the sinking of cold and dense oceanic lithosphere and the resultant extensional strain regime in a nascent arc environment. The nearly coeval occurrence of a syenite-gabbro-monzonite suite in the SW Yeongnam massif also suggests an extensional tectonic setting along the continental margin side during Late Triassic time. The relatively enriched ɛHf range of dated zircons (+6.2 to −0.6 at 222 Ma) is in contrast to previously reported primitive Sr–Nd–Hf isotopic features of Cenozoic mantle xenoliths from Korea and eastern China. This enrichment is not ascribed to contamination by the hypothetical Palaeozoic crust beneath SE Korea, but is instead attributable to metasomatism of the lithospheric mantle during the earlier subduction of the palaeo-Pacific plate. Most AUC zircons show a restricted core-to-rim spread of ɛHf values, but some grains testify to the operation of open-system processes during magmatic differentiation.

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