Hostname: page-component-7479d7b7d-t6hkb Total loading time: 0 Render date: 2024-07-10T22:06:32.976Z Has data issue: false hasContentIssue false

Platinum-group element sulpharsenides and Pd bismuthotellurides in the metamorphosed Ni-Cu deposit at Las Aguilas (Province of San Luis, Argentina)

Published online by Cambridge University Press:  05 July 2018

Fernando Gervilla
Affiliation:
Instituto Andaluz de Ciencias de la Tierra and Departamento de Mineralogía y Petrología (Universidad de Granada-CSIC). Avda. Fuentenueva, s/n, 18002 Granada, Spain
Alejandro Sáncnez-Anguita
Affiliation:
APLITEG S.L. Colonia de San Sebastian, 6-6° 18007 Granada, Spain
Rogelio D. Acevedo
Affiliation:
Centro Austral de Investigaciones Científicas, CONICET, 9410 Ushuaia, Tierra del Fuego, Argentina
Purificación Fenoll Hach-Ali
Affiliation:
Instituto Andaluz de Ciencias de la Tierra and Departamento de Mineralogía y Petrologia (Universidad de Granada-CSIC). Avda. Fuentenueva, s/n, 18002 Granada, Spain
Andres Paniagua
Affiliation:
Departamento de Geología, Universidad de Oviedo, Arias de Velasco s/n, 33005 Oviedo, Spain

Abstract

The Las Aguilas Ni-Cu-PGE deposit is associated with a sequence of basic-ultrabasic rocks made up of dunite, harzurgite, norite and amphibolite. These igneous (partially metamorphosed) rocks, and their host granulites, gneisses and migmatites of probable Precambrian age, are highly folded. The sulphide ore, consisting of pyrrhotite, pentlandite and chalcopyrite, occurs in the cores of both antiform and synform structures, within dunite, harzburgite and mainly along shear zones in bronzitite, replacing small mylonitic subgrains. The platinum-group mineral assemblage is dominated by Pd bismuthotellurides (Pt-free merenskyite, palladian bismuthian melonite and michenerite), with minor sperrylite, and PGE-sulpharsenides. The latter often occur as single, zoned crystals frequently showing cores of irarsite; outside these are concentric zones of cobaltian hollingworthite, rhodian nickelian cobaltite and Fe-rich nickelian cobaltite.

Mineralogical, textural and chemical evidence indicate that the sperrylite and platinum-group element sulpharsenides were formed during a primary magmatic event associated with the fractionation of a basaltic melt, which was contaminated by the assimilation of metamorphic crustal rocks. PGE sulpharsenides crystallized from As-bearing, residual magmatic liquids that collected PGE and segregated after the crystallization of the monosulfide solid solution. During high-grade metamorphism, sulpharsenides were remobilized as solid crystals in the liquated sulfides suffering partial dissolution and fracturing. On the other hand, there is no evidence of a primary concentration of Pd-bismuthotelluride minerals, and their present spatial distribution is only the consequence of their formation under high- to medium-grade metamorphism, down to temperatures of below 500°C. Pd bismuthotellurides crystallize even in fractures of sulpharsenides, attached to the boundaries of highly dissolved sulpharsenide crystals, and intergrown with molybdenite.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

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

Arnold, R.G. (1962) Equilibrium relations between pyrrhotite and pyrite from 325° to 743 °. Econ. Geol., 57, 72-90.CrossRefGoogle Scholar
Bayliss, P. (1969) X-ray data, optical anisotropism, and thermal stability of cobaltite, gersdorffite, and ullmanite. Mineral. Mag., 37, 26-33.CrossRefGoogle Scholar
Buchanan, D.L. and Nolan, J. (1979) Solubility of sulphur and sulphide immiscibility in synthetic tholeiitic melts and their relevance to Bushveld-Complex rocks. Can. Mineral., 17, 483—94.Google Scholar
Cabri, L.J. (1981). The platinum-group minerals. In Platinum-Group Elements: Mineralogy, Geology, Recovery (Cabri, L. J., ed.) Can. Inst. Mining Metall. Spec., 23, 83150.Google Scholar
Cabri, L.J. (1992) The distribution of trace precious metals in minerals and mineral products. Mineral. Mag., 56, 289-308.CrossRefGoogle Scholar
Cabri, L.J. and Laflamme, J.H.G. (1976) The miner-alogy of the platinum-group elements from some copper-nickel deposits of the Sudbury area, Ontario. Econ. Geol., 71, 1159-95.CrossRefGoogle Scholar
Cook, N.J. and Wood, S.A. (1994) Platinum-group minerals in the Lac Sheen Cu-Ni-PGE prospect, Quebec. Can. Mineral., 32, 703-12.Google Scholar
Distler, V.V. and Laputina, I.L. (1979) Nickel and cobalt sulpharsenides containing platinum metals. Dokl. Acad. Nauk. SSSR, E.S.S., 24B, 718-21.Google Scholar
Edgar, A.D., Charbonneau, H.E. and McHardy, D.C. (1989) Pd-bismuthotelluride minerals at Rathbun Lake, Ontario: significance to post-magmatic evolution of PGE deposits. Neues Jahrb. Mineral., Mh., 461-75.Google Scholar
Fleet, M.E., Chryssoulis, S.L., Stone, W.E. and Weisener, C.G. (1993) Partitioning of platinum-group elements and Au in the Fe-Ni-Cu-S system: experiments on the fractional crystallization of sulphide melt. Contrib. Mineral. Petrol., 115, 36-44.CrossRefGoogle Scholar
Garuti, G. and Rinaldi, R. (1986) Mineralogy of Melonite-group and other tellurides from the Ivera-Verbano Basic Complex, Western Italian Alps. Econ. Geol., 81, 1213-7.CrossRefGoogle Scholar
Gervilla, F., Sabalúa, J.C., Carrillo, R., Fenoll Hach-Alí, P. and Acevedo, R.D. (1993) Mineralogy and mineral chemistry of the Las Aguilas Ni-Cu deposit (province of San Luis, Argenita). In Current Research in Geology Applied to Ore Deposits (Fenoll Hath-Alí, P., Torres-Ruiz, J. and Gervilla, F., eds.), Servicio de Publicaciones de la Universidad de Granada, 461—4.Google Scholar
Gervilla, F., Fenoll Hath-Alí, P., Acevedo, R.D., Carrillo, R. and Sabalfia, J.C. (1994) Minerales de Pd, Pt y Au del yacimiento de Ni-Cu de Las Aguilas (Provincia de San Luis). In II Jornadas de Mineralogía, Petrografía y Metalogénesis de Rocas Ultrab6sicas. Publicación del Instituto de Recursos Minerales. Universidad Nacional de La Plata. 3, 517-21.Google Scholar
Häkli, T.A., Häinninen, E., Vourelainen, Y. and Papunen, H. (1976) Platinum-group minerals in the Hitura Nickel Deposit, Finland. Econ. Geol., 71, 1206-13.CrossRefGoogle Scholar
Hoffman, E. and MacLean, W.H. (1976) Phase relations of michenerite and merenskyite in the Pd-Bi-Te system. Econ. Geol., 71, 1461-8.CrossRefGoogle Scholar
Klemm, D.D. (1965) Synthesen und Analysen in den Dreieckdiagrammen FeAsS-CoAsS-NiAsS un FeS2-CoS2-NiS2 . Neues Jahrb. Mineral., Abh., 103, 205-55.Google Scholar
McCallum, M.E., Loucks, R.R., Carlson, R.R., Cooley, E.F. and Doerge, T.A. (1976) Platinum metals associated with the hydrothermal copper ores of the New Rambler mine, Medicine Bow Mountains, Wyoming. Econ. Geol., 71, 1429-50.CrossRefGoogle Scholar
Makovicky, E., Karup-Moller, S., Makovicky, M. and Rose-Hansen, J. (1990) Experimental studies on the phase systems Fe-Ni-Pd-S and Fe-Pt-Pd-As-S applied to PGE deposits. Mineral. and Petrol., 42, 307-19.CrossRefGoogle Scholar
Makovicky, E., Rose-Hansen, J., Karup-Møller, S. and Makovicky, M. (1991) Factors governing concentration of platinum-group elements in layered complexes. Final Report. European Economic Communities Contract No. MAIM-OOO6-DK. (unpublished).Google Scholar
Makovicky, M., Makovicky, E. and Rose-Hansen, J. (1992) The phase system Pt-Fe-As-S at 850° and 470° Neues Jahrb. Mineral., Mh., 441-53.Google Scholar
Malvicini, L. and Brogioni, N. (1993) Petrología y génesis del yacimiento de sulfuros de Ni, Cu y platinoideos “Las Aguilas Este”, Provincia de San Luis. Revista de la Asociación Geológica Argentina., 48 (1), 320.Google Scholar
Marchetto, C.M.L. (1990) Platinum-group minerals in the O'Toole (Ni-Cu-Co) Deposit, Brazil. Econ. Geol., 85, 921-7.CrossRefGoogle Scholar
Mogessie, A., Stumpfl, E.F. and Wiblen, P.W. (1991) The role of fluids in the formation of platinum-goup minerals, Duluth Complex, Minnesota: mineralogic, textural and chemical evidences. Econ. Geol., 86, 1506-18.CrossRefGoogle Scholar
Mogessie, A., Hoinkes, G., Stumpfl, E.F., Bjerg, E. and Kostadinoff, J. (1995) Occurrence of platinum group minerals in the Las Aguilas ultramafic unit within a granulite facies basement, San Luis Province, central Argentina. In Mineral Deposit: from their Origin to their Environmental Impacts (Pašava, J., Kríbek, B. and Záik, K., eds), A.A. Balkema, Rotterdam. 897900.Google Scholar
Naldrett, A.J. (1981) Nickel sulphide deposits: classification, composition, and genesis. Econ. Geol., 75th armiv, vol., 628-85.Google Scholar
Naldrett, A.J., Brügmann, G.E. and Wilson, A.H. (1990) Models for the concentration of PGE in layered intrusions. Can. Mineral., 28, 389-408.Google Scholar
Olmenstetter, D., Watkinson, D.H. and Dahl, R. (1991) Zoned hollingworthite from the Two Duck Lake intrusion, Coldwell complex, Ontario. Amer. Mineral., 76, 1694-700.Google Scholar
Piispanen, R. and Tarkian, M. (1984) Cu-Ni-PGE mineralization at Rometölväs, Koillismaa Layered Igneous Complex, Finland. Mineral. Deposita., 19, 105-11.CrossRefGoogle Scholar
Rowell, W.F. and Edgar, A.D. (1986) Platinum-group element mineralization in a hydrothermal Cu-Ni sulphide occurence, Rathbun Lake, northeastern Ontario. Econ. Geol, 81, 1272-7.CrossRefGoogle Scholar
Sabalúa, J.C. (1986) Yacimiento Las Aguilas. Mineralization Ni-Cu-Co, Departamento Pringles, Provincia de San Luis, Repúiblica Argentina. Informe Final, Direccién General de Fabricaciones Militares, Mendoza. 32pp.Google Scholar
Scott, S.D. (1973) Experimental calibration of the sphalerite geobarometer. Econ. Geol., 68, 466—74.CrossRefGoogle Scholar
Skinner, B.J., Luce, F.D., Dill, J.A., Ellis, D.E., Hagan, H.A., Lewis, D.M., Odell, D.A., Sverjensky, D.A. and Williams, N. (1976) Phase relations in ternary portions of the system Pt-Pd-Fe-As-S. Econ. Geol., 71, 1469-75.CrossRefGoogle Scholar
Toulmin, P. and Barton, P.B.Jr. (1964) A thermo-dynamic study of pyrite and pyrrhotite. Geochim. Cosmochim. Acta, 28, 641-71.CrossRefGoogle Scholar
Watkinson, D.H. and Melling, D.R. (1992) Hydrothennal origin of platinum-group mineraliza-tion in low temperature copper sulphide-rich assemblages, Salt Chuck intrusion, Alaska. Econ. Geol., 87, 175-84.CrossRefGoogle Scholar