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C-O-H-N fluid inclusions associated with gold-stibnite mineralization in low-grade metamorphic rocks, Mari Rosa mine, Caceres, Spain

Published online by Cambridge University Press:  05 July 2018

L. Ortega ,
E. Vindel  and
C. Beny
L. Ortega
Affiliation:
Dpto. Cristalografía y Mineralogía, Universidad Complutense, 28040 Madrid, Spain
C. Beny
Affiliation:
GIS-BRGM CNRS, 45071 Orleáns Cedex-2, France
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Abstract

The Mari Rosa mine lies within a low-grade Precambrian alternating series of black shales and metagreywackes in the Spanish Hercynian massif. There are two generations of mineralized veins: V2, gold-(stibnite)-bearing quartz veins, parallel to the main cleavage, and V3, stibnite-bearing quartz veins which postdate the main deformation event.

Four main types of inclusions have been identified. Type I, II and IV are aqueous-carbonaceous inclusions, with variable degrees of filling, while type III are non-aqueous and typically single-phase at room temperature. Except for type I (absent in V3), similar inclusions have been observed in both V2 and V3 veins. Gas compositions are always characterised by CH4-N2-CO2 assemblages, ranging from CO2-rich mixtures in the earliest inclusions (type I), to N2-rich mixtures in the latest inclusions (type IV).

Gold precipitation in V2 veins can be related to type I inclusions at T > 380°C (TH = 300–380°C). A subsequent drop in XCO2 and cooling are recorded in type II and III inclusions, interpreted to be the result of unmixing of a previously homogeneous fluid derived from type I. This boiling would provoke the precipitation of stibnite at 300°C and 1 kbar. The type IV inclusions, which are the richest in H2O, represent a late fluid circulation at lower temperatures (TH = 190–280°C).

Keywords

fluid inclusionsgoldstibniteCaceresSpain
Type
Fluid Inclusion Studies
Information
Mineralogical Magazine , Volume 55 , Issue 379 , June 1991 , pp. 235 - 247
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1991

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References

Bottrell, S. H., Shepherd, T. J., Yardley, B. W. D., and Dubessy, J. (1988) A fluid inclusion model for the genesis of the ores of the Dolgellau Gold Belt, North Wales. J. Geol. Soc. London, 145, 139-45.CrossRefGoogle Scholar
Bozzo, A. T., Chen, H. S., Kass, J. R., and Barduhn, A. J. (1975) The properties of the hydrates of chlorine and carbon dioxide. Desalination, 16, 303-20.CrossRefGoogle Scholar
Burrus, R. C. (1981) Analysis of phase equilibria in C-O-H-N-S fluid inclusions. Mineral. Assoc. Canada Short Course Handbook, 6, 39–74.Google Scholar
Chen, H. S. (1972) The thermodynamics and composition of carbon dioxide hydrate. Unpub. M.Sc. thesis. Syracuse Univ., 67 pp.Google Scholar
Collins, P. L. F. (1979) Gas hydrates in CO2-bearing fluid inclusions and the use of freezing data for estimation of salinity. Econ. Geol., 74, 1435-44.CrossRefGoogle Scholar
Darimont, A., Burke, T., and Touret, J. (1988) Nitrogen-rich metamorphic fluids in devonian meta-sediments from Bastogne, Belgium. Bull. Min., 111, 321-30.Google Scholar
Dhamelincourt, P., Bcny, J. M., Dubessy, J., and Poty, B. (1979) Analyse d'inclusions fluides a la microsonde MOLE a effect Raman. Ibid., 107, 600-10.Google Scholar
Dubessy, J. (1984) Simulation des équilibres chimiques dans le système C-O-H. Conséquences mctodo-logiques pour les inclusions fluides. Ibid., 107, 155-68.Google Scholar
Dubessy, J. and Ramboz, C. (1986) The history of organic nitrogen from early diagenesis to amphibolite facies: mineralogical, chemical, mechanical and isotopic implications. 5th Int. Symp. Water-Rock Interaction. Reykjavik, Iceland, August 8-17. Extended Abstracts, 170–4.Google Scholar
Dubessy, J., Poty, B., and Ramboz, C. (1989) Advances in C-O-H-N-S fluid geochemistry based on micro-Raman spectrometric analysis of fluid inclusions. Ear. J. Mineral., 1, 517-34.CrossRefGoogle Scholar
Duit, W., Jansen, J. B. H., Van Breenen, A., and Bos, A. (1986) Ammonium micas in pelitic rocks as exemplified by Dôme de l'Agout (France). Am. J. Sci., 286, 702-32.CrossRefGoogle Scholar
Gumiel, P. (1983) Metalogenia de los yacimientos de Sb de la Penínusla Ibérica. Tecniterrae, 2, 6–120.Google Scholar
Gumiel, P. and Arribas, A. (1987) Antimony deposits in the Iberian Peninsula. Econ. Geol., 82, 1453-63.CrossRefGoogle Scholar
Gumiel, P. and Saavedra, J. (1976) Geologiía y metalogenia del yacimiento de estibina-scheelita de San Antonio, Alburquerque (Badajoz). Studia Geol., 10, 61–93.Google Scholar
Hand, J. H., Katz, D. L., and Verma, V. K. (1974) Review of gas hydrates with implication for ocean sediments. In Natural Gases in Marine Sediments (I. Kaplan, ed.). Plenum Press, 179-94.CrossRefGoogle Scholar
Hanor, J. S. (1980) Dissolved methane in sedimentary brines: Potential effect on the PVT properties of fluid inclusions. Econ. Geol., 75, 603-17.CrossRefGoogle Scholar
Hollister, L. S. and Burrus, R. C. (1976) Phase equilibria in fluid inclusions from the Khtada Lake metamorphic complex. Geochim. Cosmochim. Acta, 40, 163-75.CrossRefGoogle Scholar
Holloway, J. R. (1981) Compositions and volumes of supercritical fluids in the earth's crust. Min. Assoc. Canada Short Courses Handbook, 6, 13–38.Google Scholar
Honma, H. and Itihara, Y. (1981) Distribution of ammonia in minerals of metamorphic and granitic rocks. Geochim. Cosmochim. Acta, 45, 983–8.CrossRefGoogle Scholar
Japas, M. L. and Franck, E. U. (1985) High-pressure phase equilibria and PVTdata of the water-nitrogen system to 673 K and 250 MPa. Ber. Bunsenges. Phys. Chem., 89, 793–800.CrossRefGoogle Scholar
Kerkhof, A. M. van den (1988a) Phase transition and molar volumes of CO2-CH4-N2 inclusions. Bull. Min., 111, 257-66.CrossRefGoogle Scholar
Kerkhof, A. M. van den (19886) The system CO2-CH4-N2 in fluid inclusions: theoretical modelling and geological applications. Ph.D. Thesis. Free University Press, Amsterdam, 206 pp.Google Scholar
Kreulen, R. and Schuiling, R. D. (1982) N2-CH4-CO2 fluids during formation of the Dôme de l'Agout, France. Geochim. Cosmochim Acta, 46, 193–203.CrossRefGoogle Scholar
Leroy, J. (1979) Contribution a l'etalonnage de la pression interne des inclusions fluides lors de leur décrepitation. Bull. Mineral, 102, 584-93.Google Scholar
Martôn Herrero, D. and Bascones, L. (1979) Memoria explicativa de la Hoja 674, Sever-Santiago de Alcántara (MAGNA). Inst. Geol. Minero España, 25 pp.Google Scholar
Parrish, W. R. and Prausnitz, J. M. (1972) Dissociation pressures of gas hydrates formed by gas mixtures. Ind. Eng. Chem. Process. Des. Develop, 11, 26–35.CrossRefGoogle Scholar
Pichavant, M., Ramboz, C., and Weibrod, A. (1982) Fluid immiscibility in natural processes: use and misuse of fluid-inclusion data. I. Phase equilibria analysis. A theoretical and geometrical approach. Chem. Geol., 37, 1–27.CrossRefGoogle Scholar
Poty, B., Leroy, J., and Jachimowicz, L. (1976) Un nouvel appareil pour la mesure des temperatures sous le microscope: l'instalation de microthermometrie Chaixmeca. Bull. Soc. Fr. Mineral. Cristallogr., 99, 182–6.Google Scholar
Quesada, C., Florido, P., Gumiel, P., and Osborne, J. (1987) Memoria Explicativa del Mapa Geologico y Minero de Extremadura. Junta de Extremadura, 126 pp.Google Scholar
Ramboz, C., Pichavant, M., and Weisbrod, A. (1982) Fluid immiscibility in natural processes: use and misuse of fluid inclusion data. II. Interpretation of fluid inclusion data in terms of immiscibility. Chem. Geol., 37, 29–48.CrossRefGoogle Scholar
Ramboz, C., Schnapper, D., and Dubessy, J. (1985) The P-V-T-X-fO2 evolution of H2O-CO2-CH4-bearing fluid in a wolframite vein: Reconstruction from fluid inclusion studies. Geochim. Cosmochim. Acta, 49, 205-19.CrossRefGoogle Scholar
Roedder, E. (1976) Fluid inclusion evidence on the genesis of ores in sedimentary and volcanic rocks. Handbook of stratabound and stratiform ore deposits, 4 (K. H. Wolf, ed.), Elsevier Sc. Pub. Co. Amsterdam.Google Scholar
Roedder, E. (1984) Fluid inclusions. Reviews in Mineralogy, 12, 644 pp. Mineral. Soc. Am.Google Scholar
Seitz, J. C., Pasteris, J. D., and Wopenka, B. (1987) Characterization of CO2-CH4-H2 fluid inclusions by microthermometry and laser Raman microprobe spectroscopy: Inferences from clathrate and fluid equilibria. Geochim. Cosmochim. Acta, 51, 1651-64.CrossRefGoogle Scholar
Stone, H. W. (1943) Solubility of water in liquid carbon dioxide. Indus. Eng. Chem., 35, 1284–6.CrossRefGoogle Scholar
Swanenberg, H. E. C. (1979) Phase equilibria in carbonic systems and their application to freezing studies of fluid inclusions. Contrib. Mineral. Petrol., 68, 303–6.CrossRefGoogle Scholar
Swanenberg, H. E. C. (1980) Fluid inclusions in high-grade metamorphic rocks from S.W. Norway. Geologica Utraiectina, 25, (Univ. Utretch), 146 pp.Google Scholar
Touray, J. C, Beny, C., Dubessy, J., and Guilhaumou, N. (1985) Microcharacterization of fluid inclusions in minerals by Raman microprobe. Scanning Electron microscopy, 1, 103-18.Google Scholar
Touret, J. (1987) Fluid inclusions and pressure-temperature estimates in deep-seated rocks. Chemical Transport in Metasomatic Processes (H. C. Helgeson, ed.), D. Riedel Publ. Co., 91–121.CrossRefGoogle Scholar
Unruh, C. H. and Katz, D. L. (1949) Gas hydrates of carbon dioxide-methane mixtures. Petrol. Trans. AIME, 186, 83.Google Scholar
Welch, H. (1973) Die systeme xenon-wasser und methan-wasser bei hohen drucken und temperaturen.Ph.D. thesis. Institute for Physical Chemistry, Karlsruhe.Google Scholar