Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-10T12:40:43.437Z Has data issue: false hasContentIssue false

Coupled substitutions in PGE-enriched cobaltite: new evidence from the Rio Jacaré layered complex, Bahia state, Brazil

Published online by Cambridge University Press:  02 January 2018

Andrei Y. Barkov*
Affiliation:
Research laboratory of industrial and ore mineralogy, Cherepovets State University, 5 Lunacharsky Avenue, 162600 Cherepovets, Russia
Yana Fedortchouk
Affiliation:
Department of Earth Sciences, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada
Robert A. Campbell
Affiliation:
Lake Shore Gold Corp., P.O. Box 1067, Timmins, Ontario P4N 2G0, Canada
Tapio A.A. Halkoaho
Affiliation:
Geological Survey of Finland, “Bedrock and Raw materials”, Eastern Finland Office, 5 Neulaniementie Street, P.O. Box 1237, FIN-70211 Kuopio, Finland
*

Abstract

Microcrystals of platinum-group element (PGE)-bearing cobaltite occur in the Gulcari A deposit of vanadiferous titanomagnetite in the lower zone of the Rio Jacaré mafic-ultramafic layered intrusion, Brazil. Aggregates of cobaltite and sperrylite are cluster-like and developed generally along the boundary of Fe-Ti oxide grains with deuteric silicates. Our observations of cryptic zoning, compositional variability and interelement correlations are based on 37 analytical points (wavelength-dispersion spectrometry mode) of cobaltite, and indicate that Ir and Rh behave uniformly with Ni and antipathetically with Co which, in turn, correlates directly with S content. Iridium, Rh and Ni apparently substitute for Co in the As-enriched grain core, and the substitution mechanism invokes solid solution with a cattierite-type molecule: (Ni + Ir + Rh) + (AsS) = Co + (S2). The PGE-bearing cobaltite probably crystallized as a primary phase at 500 to 300°C, from microvolumes of a late fluid phase. The observed enrichment in S and decrease in the As:S ratio at the cobaltite grain margins is a reflection of the increase in sulfur fugacity (fS2) with decrease in temperature of crystallization.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2015

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

Barkov, A.Y and Fleet, M.E. (2004) An unusual association of hydrothermal platinum-group minerals from the Imandra layered complex, Kola Peninsula, Northwestern Russia. The Canadian Mineralogist, 42, 455467.CrossRefGoogle Scholar
Barkov, A.Y, Alapieti, T, Laajoki, K. and Peura, R. (1996) Osmian hollingworthite and rhodian cobaltite-gersdorffite from the Lukkulaisvaara layered intrusion, Russian Karelia. Mineralogical Magazine, 60, 973978.CrossRefGoogle Scholar
Barkov, A.Y, Thibault, Y, Laajoki, K.V.O., Melezhik, V A. and Nilsson, L.P. (1999) Zoning and substitutions in Co-Ni-(Fe)-PGE sulfarsenides from the Mount General'skaya layered intrusion, Arctic Russia. The Canadian Mineralogist, 37, 127142.Google Scholar
Barkov, A.Y, Fleet, M.E., Martin, R.F. and Alapieti, T.T. (2004) Zoned sulfides and sulfarsenides of the platinum-group elements from the Penikat layered complex, Finland. The Canadian Mineralogist, 42, 515537.CrossRefGoogle Scholar
Beziat, D., Monchoux, P. and Tollon, F. (1996) Cobaltite-gersdorffite solid solution as a primary magmatic phase in spessartite, Lacaune area, Montagne Noire, France. The Canadian Mineralogist, 34, 503512.Google Scholar
Blanchard, M., Alfredsson, M., Brodholt, L, Wright, K andCatlow, R. (2007) Arsenic incorporation into FeS2 pyrite and its influence on dissolution: a DFT study. Geochemica et Cosmochimica Ada, 71, 624630.CrossRefGoogle Scholar
Cabri, L.J. (1992) The distribution of trace precious metals in minerals and mineral products. Mineralogical Magazine, 56, 289308.CrossRefGoogle Scholar
Cabri, LJ. (editor) (2002) The Geology, Geochemistry, Mineralogy, Mineral Beneficiation of the Platinum-Group Elements. Canadian Institute of Mining, Metallurgy and Petroleum, Special Volume 54. Canadian Institute of Mining, Quebec, Canada, pp. 852.Google Scholar
Campbell, R.A. (2012) Platinum Group Element (PGE) Mineralization Associated with Fe-Ti-VDeposit, Rio Jacare Intrusion, Bahia State, Brazil. Unpublished B.Sc. (Honours) thesis, Dalhousie University, Canada.Google Scholar
Dare, S.A.S., Barnes, S.-L, Prichard, H.M. and Fisher, PC. (2010) The timing and formation of platinum-group minerals from the Creighton Ni-Cu-platinum-group element sulfide deposit, Sudbury, Canada: early crystallization of PGE-rich sulfarsenides. Economic Geology, 105, 10711096.CrossRefGoogle Scholar
Distler, YY and Laputina, I.P (1979) Sulfarsenides of nickel and cobalt containing platinum elements. Doklady Akademii Nauk SSSR, 248, 718721 [in Russian].Google Scholar
Fanlo, I., Subias, I., Gervilla, F., Paniagua, A. and Garcia, B. (2004) The composition of Co-Ni-Fe sulfarsenides, diarsenides and triarsenides from the San Juan de Plan deposit, central pyrenees, Spain. The Canadian Mineralogist, 42, 12211240.CrossRefGoogle Scholar
Fleet, M.E. and Burns, PC. (1990) Structure and twinning of cobaltite. The Canadian Mineralogist, 28, 719723.Google Scholar
Genkin, A.D., Zhuravlev, N.N., Troneva, N.Y and Murav'yova, I.Y (1966) Irarsite, anew sulpharsenide of indium, rhodium, ruthenium and platinum. Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva, 95, 700-712 [in Russian].Google Scholar
Gervilla, F., Anguita, A.S., Acevedo, R.D., Hach-Ali, PF. and Paniagua, A. (1997) Platinum-group element sulpharsenides and Pd bismuthotellurides in the metamorphosed Ni-Cu deposit at Las Aguilas (province of San Luis, Argentina). Mineralogical Magazine, 61, 861877.CrossRefGoogle Scholar
Loffe, PA., Tsemekhman, L.S., Parshukova, L.N. and Bobkovskii, A.G. (1985) The chemical state of iron atoms in FeS2, FeAsS, and FeAs2. Russian Journal of Inorganic Chemistry, 30, 1566-1568 [in Russian].Google Scholar
Hem, S. (2006) Solid solutions in the Fe-Co-Ni-As-S system. Chemical Geology, 225, 291303.CrossRefGoogle Scholar
Hem, S.R. and Makovicky, E. (2004) The system Fe-Co-Ni-As-S. I. Phase relations in the (Fe,Co,Ni)As0 5Si 5section at 650° and 500°C. The Canadian Mineralogist, 42, 4362.CrossRefGoogle Scholar
Klemm, D.D. (1965): Synthesen and Analysen in den Dreiecks-diagrammen FeAsS-CoAsS-NiAsS und FeS2-CoS2-NiS2. Neues Jahrbuch fur Mineralogie, Abhandlungen, 103, 205255.Google Scholar
Makovicky, E. (2006) Crystal structures of sulfides and other chalcogenides. Pp. 7125 in: Sulflde Mineralogy and Geochemistry (D.I Vaughan, editor). Reviews in Mineralogy & Geochemistry, 61. Mineralogical Society of America, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Makovicky, E., Karup-Moller, S., Makovicky, M. and Rose-Hansen, I (1990) Experimental studies on the phase systems Fe-Ni-Pd-S and Fe-Pt-Pd-As-S applied to PGE deposits. Contributions to Mineralogy and Petrology, 42, 307319.CrossRefGoogle Scholar
Nimis, P., Dalla Costa, L. and Guastoni, A. (2014) Cobaltite-rich mineralization in the iron skarn deposit of Traversella (Western Alps, Italy). Mineralogical Magazine, 78, 1127.CrossRefGoogle Scholar
Pratt, J.L. and Bayliss, P. (1979) Crystal-structure refinement of cattierite. Zeitschrift fur Kristallographie, 150, 163167.CrossRefGoogle Scholar
Prichard, H.M., Fisher, PC, McDonald, I., Knight, R.D., Sharp, D.R. and Williams, IP. (2013) The distribution of PGE and the role of arsenic as a collector of PGE in the Spotted Quoll nickel ore deposit in the Forrestania greenstone belt, Western Australia. Economic Geology, 108, 19031921.CrossRefGoogle Scholar
Sa, J.H.S., Barnes, S-I, Prichard, H.M. and Fisher, PC. (2005) The distribution of base metals and platinum-group elements in magnetitite and its host rocks in the Rio Jacare intrusion, Northeastern Brazil. Economic Geology, 100, 333348.Google Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Ada Crystallographica, 751767.CrossRefGoogle Scholar
Song, X.-Y, Zhou, M.-F. and Cao, Z.-M. (2004) Genetic relationships between base-metal sulfides and platinum-group minerals in the Yangliuping Ni—Cu—(PGE) sulfide deposit, southwestern China. The Canadian Mineralogist, 42, 469–83.CrossRefGoogle Scholar
Szentpeteri, K, Watkinson, D.H., Molnar, F. and Jones, PC. (2002) Platinum-group elements-Co-Ni-Fe sulfarsenides and mineral paragenesis in Cu-Ni-platinum-group element deposits, Copper Cliff North area, Sudbury, Canada. Economic Geology, 97, 14591470.Google Scholar
Teixeira, J.B.G., da Silva, M.G., Misi, A., Cruz, S.C.P and Sa, J.H.S. (2010) Geotectonic setting and metallogeny of the northern Sao Francisco craton, Bahia, Brazil. Journal of South American Earth Sciences, 30, 7183.CrossRefGoogle Scholar
Tikhomirova, VI. and Chichagov, A.V (2000) Hydrothermal synthesis and crystallography of aurostibite (AuSb2), sperrylite (PtAs2) and geversite (PtSb2). DokladyAkademiiNauk, 373(3) 382384 [in Russian].Google Scholar
Tossell, J.A., Vaughan, DJ. and Burdett, IK. (1981) Pyrite, marcasite, and arsenopyrite type minerals; crystal chemical and structural principles. Physics and Chemistry of Minerals, 7, 177184.CrossRefGoogle Scholar
Wood, B.I and Strens, R.G. (1979) Diffuse reflectance spectra and optical properties of some sulphides and related minerals. Mineralogical Magazine, 43, 509518.CrossRefGoogle Scholar