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Fluid inclusion evidence for the development of Zn–Pb–Cu–F skarn mineralization in SW Sardinia, Italy

Published online by Cambridge University Press:  05 July 2018

M. Boni ,
A. H. Rankin  and
M. Salvadori
M. Boni
Affiliation:
Dipartimento di Scienze della Terra, Universitá di Napoli, Largo S. Marcellino, 10 80138 Naples, Italy
A. H. Rankin
Affiliation:
Department of Geology, Royal School of Mines, Imperial College of Science, Technology and Medicine, London SW7 2BP, U.K.
M. Salvadori
Affiliation:
Department of Geology, Royal School of Mines, Imperial College of Science, Technology and Medicine, London SW7 2BP, U.K.
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Abstract

New microthermometric data are presented for fluid inclusions in epidote, garnet, hedenbergite, armenite, quartz, fluorite, calcite and baryte associated with skarn-related base metal mineralization in the Iglesiente and Sulcis mining districts of SW Sardinia. Based on a comparison of these data with published results for vein and palaeokarst mineralization a ‘two fluid’ model is proposed for the mineralization in the area. An early fluid, responsible for skarn-associated sulphide mineralization, developed above 350–400°C with a salinity generally less than about 10 eq. wt.% NaCl, and on cooling was also responsible for some of the vein and palaeokarst mineralization. The origin of this fluid is, at this stage, speculative (meteoric/magmatic?). A separate fluid regime, characterized by lower temperatures and much higher salinities (Th < 140°C and >20 eq. wt. % NaCl) was mainly responsible for the bulk of the Permo-Triassic vein and palaeokarst mineralization, and some late-stage skarn mineralization. This low-temperature, saline (basinal or evaporitic?) brine appears to have mixed with more dilute groundwaters during this stage of mineralization. The existence of two (or more) mineralizing fluids with different characteristics at the end of Hercynian tectonic/magmatic events appears to be widespread throughout the whole of Europe.

Keywords

fluid inclusionsskarn mineralizationtwo-fluid modelSardiniaItaly
Type
Ore environments—base-metal mineralization
Information
Mineralogical Magazine , Volume 54 , Issue 375 , June 1990 , pp. 279 - 287
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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References

Aponte, F., Balassone, G., Boni, M., Costamagna, L. and Di Maio, G. (1988) Variscan skarn ores in SW Sardinia: their relationships with Cambro-Ordoviclan stratabound deposits. Rend. Soc. ltal. Min. Petr. 43, 445-62.Google Scholar
Balassone, G., Boni, M., Di Maio, G. and Franco, E. (1989) Armenite in South-West Sardinia: first recorded occurrence in Italy. Neues Jahrb. Mineral., Mh., 49-58.Google Scholar
Behr, H. J., Horn, E. E., Frentzel-Beyme, K. and Reutel, C. (1987) Fluid inclusion characteristics of the Variscan and post-Variscan mineralizing fluids in the Federal Republic of Germany. Chem. Geol. 61, 273-85.CrossRefGoogle Scholar
Boni, M. (1985) Les gisements de type Mississippi Valley du Sud Ouest de la Sardaigne (Italie): une synthèse. Chron. Rech. Min., 479, 7-34.Google Scholar
Boni, M. (1986) The Permo—Triassic vein and paleokarst ores in south-west Sardinia: contribution of fluid inclusion studies to their genesis and paleoenvironment. Mineral. Deposita, 21, 53-62.CrossRefGoogle Scholar
Boni, M. and Amstutz, G. C. (1982) The Permo-Triassic paleokarst ores of South-West Sardinia (Iglesiente-Sulcis). An attempt at a reconstruction of paleokarst conditions. In Ore Genesis, the State of the Art (Amstutz, G. C., eds.) Springer, Berlin, 73–82.CrossRefGoogle Scholar
Boni, M. and lannace, A. (in press) Epigenetic dolomitization and mineralization in SW Sardinia. Documents du BRGM. Google Scholar
Cortecci, G., Fontes, J. C., Maiorani, A., Perna, G., Pintus, E. and Turi, B. (1989) Oxygen, sulfur and strontium isotope and fluid inclusion studies of barite deposits from the Iglesiente-Sulcis mining districts, South-Western Sardinia, Italy. Mineral. Deposita, 24, 34-42.CrossRefGoogle Scholar
Crawford, M. L. (1981) In Fluid Inclusions—Applications to Petrology (Hollister, L. S. and Crawford, M. L., eds.) Mineral. Soc. Canada Short Course Handb. 6, 75–100.Google Scholar
Del Moro, A., Di Simplicio, P., Ghezzo, C., Guasparri, G., Pellizzer, R., Ricci, C. A., Rita, F. and Sabatini, G. (1975) II metamorfismo eil magmatismo paleozoico nella Sardegna. Rend. Soc. Ital. Min. Petr. 30, 97-1068.Google Scholar
De Vivo, B., Maiorani, A., Perna, G. and Turi, B. (1987) Fluid inclusion and stable isotope studies of calcite, quartz and barite from karstic caves in the Masua mine, Southwestern Sardinia, Italy. Chem. Erde, 46, 25-73.Google Scholar
Giamello, M., Protano, G., Riccobono, F. and Sabatini, G. (1989) Fluid evolution in the Funtana Raminosa hydrothermal field, Central Sardinia, Italy. Abstract, Ecrofi X, London, April 1989, p. 36.Google Scholar
Hall, D. L., Sterner, S. M. and Bodnar, R. J. (1988) Freezing point depression of NaCl-KCl-H2O solutions. Econ. Geol. 83, 197-202.CrossRefGoogle Scholar
Hein, U. F., Luders, V. and Dulski, P. (1989) The fluorite-vein mineralization of the Southern Alps, Italy: combined application of fluid inclusions and REE distribution. Abstract, Ecrofi X, London, April 1989, p. 47.Google Scholar
Kerrick, D. M. (1977) The genesis of zoned skarn in the Sierra Nevada, California. J. Petrol. 18, 144-81.CrossRefGoogle Scholar
Mullis, J. (1987) Fluideinschluss-Untersuchungen in den Nagra-Bohrungen der Nordschweiz. Ecl. Geol. Helv. 80, 553-68.Google Scholar
Mullis, J. and Stalder, H. A. (1987) Salt-poor and salt-rich fluid inclusions in quartz from two boreholes in northern Switzerland. Chem. Geol. 61, 263-72.CrossRefGoogle Scholar
Potter, R. W. III (1977) Pressure corrections for fluid inclusion homogenization temperatures based on the volumetric properties of the system NaCl-H2O. U.S.G.S. J. Res. 5, 603-7.Google Scholar
Rankin, A. H. and Criddle, A. J. (1985) Mineralising fluids and metastable low-temperature inclusion brines at Llanharry iron deposit, South Wales. Trans. Inst. Min. Metall. B. 94, 126-32.Google Scholar
Roedder, E. (1984) Fluid Inclusions. Mineral. Soc. Amer. Revs. in Mineralogy, 12, 644 pp.Google Scholar
Shepherd, T. J., Rankin, A. H. and Alderton, D. H. M. (1985) A practical guide to fluid inclusion studies. Blakie and Sons, Glasgow, 235 pp.Google Scholar