Hostname: page-component-77c89778f8-n9wrp Total loading time: 0 Render date: 2024-07-18T15:47:27.188Z Has data issue: false hasContentIssue false
  • English
  • Français

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

Published online by Cambridge University Press:  05 July 2018

S. Arai ,
H. M. Prichard ,
I. Matsumoto  and
P. C. Fisher
S. Arai
Affiliation:
Department of Earth Sciences, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
H. M. Prichard
Affiliation:
Department of Earth Sciences, Cardiff University, P.O. Box 914, Cardiff, CF1 3YE, UK
I. Matsumoto
Affiliation:
Dowa Engineering Co., 5-10-5 Shimbashi, Minato-ku, Tokyo 105-0044, Japan
P. C. Fisher
Affiliation:
Department of Earth Sciences, Cardiff University, P.O. Box 914, Cardiff, CF1 3YE, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

Pd-rich PGM (platinum-group minerals) have been found in sulphide-bearing dunites and harzburgites from the Inazumi-yama ultramafic complex in southwestern Japan. In the dunite, potarite (PdHg0.85–0.88) is the most abundant PGM but other associated PGM include stibiopalladinite (Pd5Sb2) and rare sperrylite (PtAs2) and Pd-rich alloys. A Pd telluride has been found in the harzburgite. The PGM are enclosed usually by pentlandite-heazlewoodite composite grains and, rarely, by altered chrome-spinel. These minerals are characteristic of an ultramafic assemblage but they are accompanied by ubiquitous galena and minor sphalerite not usually associated with these ultramafic assemblages. The ultramafic part of this complex has been thermally metamorphosed (olivine-talc zone) within the contact aureole of an adjacent granite. The PGM, sulphides and altered spinel are all intergrown with antigorite and/or chlorite, indicating a metamorphic overprint on the primary igneous mineralogy. The Pd/Pt ratios of 9 suggest a process of hydrothermal concentration for the Pd and it is proposed that the Pd has been remobilized and reconcentrated by hydrothermal solutions derived from the granitic magma which reacted with the Pd concentrated in the primary magmatic sulphides. Mercury may have been leached from surrounding sediments by the hydrothermal solutions. It is possible that potarite and the other PGM formed at temperatures of up to 650°C and are likely to be found in other thermally metamorphosed ultramafic rocks showing a depleted character (spinel Cr/[Cr+Al]>0.7), common in orogenic belts.

Keywords

potaritestibiopalladinitemetamorphosed dunitethermal metamorphismSangun zoneJapan
Type
Research Article
Information
Mineralogical Magazine , Volume 63 , Issue 3 , June 1999 , pp. 369 - 377
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arai, S. (1975) Contact metamorphosed dunite-harzburgite complex in the Chugoku district, western Japan. Contrib. Mineral. Petrol., 52, 1–16.CrossRefGoogle Scholar
Arai, S. (1980) Dunite-harzburgite-chromitite complexes as refractory residue in the Sangun-Yamaguchi zone, western Japan. J. Petrol., 21, 141–65.CrossRefGoogle Scholar
Arai, S. and Matsukage, K. (1996) Petrology of the gabbro-troctolite-peridotite complex from Hess Deep, equatorial Pacific: implications for mantle-melt interaction within the oceanic lithosphere. Proc. ODP, Sci. Results, 147, 135–55.Google Scholar
Arai, S. and Yurimoto, H. (1994) Podiform chromitite of the Tari-Misaka ultramafic complex, Southwestern Japan, as mantle-melt interaction products. Econ. Geol., 89, 1279–88.CrossRefGoogle Scholar
Berman, R.G., Engi, M., Greenwood, H.J. and Brown, T.H. (1986) Derivation of internally consistent thermodynamic data by the technique of mathematical programming: a review with application to the system MgO-SiO2-H2O. J. Petrol., 27, 1331–64.CrossRefGoogle Scholar
Cabri, L.J. and Laflamme, J.H.G. (1976) The mineralogy of the platinum-group elements from some copper-nickel deposits of the Sudbury area, Ontario. Econ. Geol., 71, 1159–96.CrossRefGoogle Scholar
Dick, H.J.B. and Bullen, T. (1984) Chromian spinel as a petrogenetic indicator in abyssal and alpine-type peridotites and spatially associated lavas. Contrib. Mineral. Petrol., 86, 54–76.CrossRefGoogle Scholar
Frost, B.R. (1975) Contact metamorphism of serpentinite, chloritic blackwall and rodingite at Paddy-Go-Easy Pass, Central Cascades, Washington. J. Petrol., 16, 272–313.CrossRefGoogle Scholar
Grange, F.K. (1996) PGM occurrence in secondary deposits, with emphasis on methods of recovery and observations for temperature climate exploration. M.Sc. thesis, Univ. Wales Cardiff.Google Scholar
Jedwab, J. (1992) Platinum-group minerals in ultrabasic rocks and nickeliferous veins from Zabargad Island (Egypt). Compt. Rendu. Acad. Sci., Paris, 314, Sér. II, 157–63.Google Scholar
Kim, W.-S. and Chao, G. Y. (1996) Phase relations in the system Pd-Pt-Sb. Neues Jahrb. Mineral. Mh., 351–64.Google Scholar
Kinloch, E.D. (1982) Regional trends in the platinum-group mineralogy of the critical zone of the Bushveld Complex, South Africa. Econ. Geol., 77, 1328–47.CrossRefGoogle Scholar
Krupp, R. (1988) Physicochemical aspects of mercury metallogenesis. Chem. Geol., 69, 345–56.CrossRefGoogle Scholar
Kucha, H. (1982) Platinum-group metals in the Zechstein copper deposits, Poland. Econ. Geol., 77, 1578–91.CrossRefGoogle Scholar
Lord, R.A., Prichard, H.M. and Neary, C.R. (1994) Magmatic PGE concentrations and hydrothermal upgrading in the Shetland ophiolite complex. Trans. Inst. Min. Metal., B103, 87–162.Google Scholar
Matsumoto, I., Arai, S., Muraoka, H. and Yamauchi, H. (1995) Petrological characteristics of the dunite-harzburgite-chromitite complexes of the Sangun zone, Southwest Japan. J. Mineral. Petrol. Econ. Geol., 90, 13–26.(in Japanese with English abstract).CrossRefGoogle Scholar
Matsumoto, I., Arai, S. and Yamauchi, H. (1997) High-Al podiform chromitites in dunite-harzburgite complexes of the Sangun zone, central Chugoku district, Southwest Japan. J. Asian Earth Sci., 15, 295–302.CrossRefGoogle Scholar
McCallum, M.E., Louks, R.R., Carlson, R.R., Cooley, E.F. and Doerge, T.A. (1976) Platinum metals associated with hydrothermal copper ores of the New Rambler mine, Nedicine Boe Mountains, Wyoming. Econ. Geol., 71, 1429–50.CrossRefGoogle Scholar
McDonough, W.F. and Sun, S-S. (1995) The composition of the Earth. Chem. Geol., 120, 223–53.CrossRefGoogle Scholar
McLaren, C.H. and De Villiers, J.P.R. (1982) The Platinum-group chemistry and mineralogy of the UG-2 chromitite layer of the Bushveld Complex. Econ. Geol., 77, 1348–66.CrossRefGoogle Scholar
Miyashiro, A. (1973) Metamorphism and Metamorphic Belts. George Allen and Unwin, London, 492 pp.CrossRefGoogle Scholar
Mountain, B.W. and Wood, S.A. (1988 a) Chemical controls on the solubility, transport, and deposition of platinum and palladium in hydrothermal solutions: a thermodynamic approach. Econ. Geol., 83, 492–510.CrossRefGoogle Scholar
Mountain, B.W. and Wood, S.A. (1988 b) Solubility and transport of platinum-group elements in hydrothermal solutions: thermodynamic and physical chemical constraints. In Geo-Platinum 87, (Prichard, H.M., Potts, P.J., Bowles, J.F.W. and Cribbs, S.J., eds.). Elsevier, London, 57–82.CrossRefGoogle Scholar
Naldrett, A.J. (1989) Magmatic Sulfide Deposits. Clarendon Press/Oxford Univ. Press, New York, 186 pp.Google Scholar
Naldrett, A.J. and Cabri, L.J. (1976) Ultramafic and related mafic rocks: their classification and genesis with special reference to the concentration of nickel sulfides and platinum-group elements. Econ. Geol., 71, 1131–58.CrossRefGoogle Scholar
Neary, C.R. and Prichard, H.M. (1985) Molybdenum mineralisation on Unst, Shetland Isles. Scott. J. Geol., 21, 197–204.CrossRefGoogle Scholar
Niu, Y. and Hékinian, R. (1997) Spreading-rate dependence of the extent of mantle melting beneath ocean ridges. Nature, 385, 326–329.CrossRefGoogle Scholar
Ohnenstetter, M., Karaj, N., Neziraj, N., Johan, Z. and Cina, A. (1991) Le potentiel platinifère des ophiolites: minéralisations en éléments du groupe du platine (PGE) dans les massifs de Tropoja et Bulquiza, Albanie. Compt. Rendu. Acad. Sci., Paris, 313, Sér. II, 201–8.Google Scholar
Peabody, C.E. and Einaudi, M.T. (1992) Origin of petroleum and mercury in the Culver-Baer cinnabar deposit, Mayacmas district, California. Econ. Geol., 87, 1078–103.CrossRefGoogle Scholar
Pedersen, R.B., Johannesen, G.M. and Boyd, R. (1993) Stratiform PGE mineralisations in the ultramafic cumulates of the Leka ophiolite complex, central Norway. Econ. Geol., 88, 782–803.CrossRefGoogle Scholar
Prichard, H.M. and Lord, R.A. (1993) An overview of the PGE concentrations in the Shetland ophiolite complex. In Magmatic Processes and Plate Tectonics, (Prichard, H.M., Alabaster, T., Harris, N.B.W. and Neary, C.R., eds.). Geol. Soc. Special Pub., No. 76, 273–94.Google Scholar
Prichard, H.M. and Lord, R.A. (1994) Evidence for the mobility of PGE in the secondary environment in the Shetland ophiolite complex. Trans. Inst. Min. Metal., 103B, 79–86.Google Scholar
Prichard, H.M. and Tarkian, M. (1988) Platinum and palladium minerals from two PGE-rich localities in the Shetland ophiolite complex. Canad. Mineral., 26, 979–90.Google Scholar
Prichard, H.M., Ixer, R.A., Lord, R.A., Maynard, J. and Williams, N. (1994) Assemblages of platinum-group minerals and sulfides in silicates lithologies and chromite-rich rocks within the Shetland ophiolite. Canad. Mineral., 32, 271–94.Google Scholar
Prichard, H.M., Lord, R.A. and Neary, C.R. (1996 a) A model to explain the occurrence of platinum- and palladium-rich ophiolitic complexes. J. Geol. Soc., London, 153, 323–8.CrossRefGoogle Scholar
Prichard, H. M., Puchalt, H., Eckhardt, J-D. and Fisher, P. C. (1996 b) Platinum-group element concentrations in mafic and ultramafic lithologies drilled from the Hess Deep. Proc. ODP, Scientific Results, 147, 77–90.Google Scholar
Rankama, K. and Sahama, Th. G. (1950) Geochemistry. Univ. Chicago Press, Chicago, 912 pp.Google Scholar
Wagner, P.A. (1929) The Platinum Deposits and Mines of South Africa. Republished 1973 by C. Struik (Pty) Ltd., Cape Town, R.S.A., 338 pp.Google Scholar