Abstract
Mineralogical studies demonstrate that the Hercynian polymetallic antimony-rich deposit of Bournac can be described by four stages of ore deposition and one of partial ore remobilization. Fluid inclusion data permit calculation of the composition and temperature of the fluids associated with each stage of hydrothermal mineralization and concomitant wall-rock alteration. Stages I and II (Fe-As and Zn) are represented by moderate-salinity H2O-CO2-(NaCl) inclusions which correlate closely with early carbonate deposition. Stage III fluids which are responsible for the deposition of Pb-Sb ores are characterized by low-salinity H2O-(NaCl) inclusions. During the final stage of mineralization (IV), corresponding to the main phase of stibnite deposition, abundant aqueous inclusions confirm the continued involvement of low-salinity fluids and the intense development of potassic clays and secondary silica in the wall rocks. Homogenization temperatures suggest that the whole cycle of mineralization took place during a gradual decrease in fluid temperature of 380°–140°C. Stibnite deposition is restricted to the interval of 230°–140°C thus confirming an essentially epithermal environment. Stage V (partial remobilization) is distinguished by the presence of high-salinity CaCl2-rich inclusions which are tentatively related to Triassic barite mineralization in the region and therefore postdate the Bournac antimony ores. Homogenization temperatures for this stage range 140°–60°C.
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Aubague, M., Orgeval, J. J., Soulie, M.: Les gîtes minéraux de la terminaison méridionale du Massif Central et de sa bordure languedocienne. Bull. B.R.G.M. (2), II, 3 (1977)
Balitsky, V. S., Mozgova, N. N., Ozerova, N. A., Komova, N. N.: Concentrations of natural antimony and stibnite formations and their interrelations in antimony deposits from experimental data and results of inclusions investigations. 25th Intern. Geol. Cong. Abs. Sydney (1976)
Boyer, C.: Volcanismes acides paléozoïques dans le massif armoricains. Thèse d'Etat, Paris (1974)
Bozzo, A. T., Chen, H. S., Kass, J. R., Barduhn, A. J.: The properties of the hydrates of chlorine and carbon dioxide. 4th Intern. Symposium on fresh water from the sea, A. Delyannis and E. Delyannis, eds., vol. 3, 437–451 (1973)
Bril, H.: Fluid inclusion study in the W, Au, As, Sb and Pb-Zn district of Brioude-Massiac (Massif Central Français). Tschermaks Min. Petr. Mitt. 30, 1–16 (1982)
Bruchon, I., Munoz, M., Tollon, F.: Mineralogical signature of regional polymetallic anomalies in the Brassac-Lacaune area (Tarn, France). Terra Cognita, vol. 5, 2–3, 297 (1985)
Burruss, R.: Cohs inclusions. In: Hollister, L. S., Crawford M. L.: “Fluids inclusions: applications to petrology”, Calgary, Mineralog. Ass. Canad. pp. 39–74 (1981)
Collins, P. L. F.: Gas-hydrates in CO2-bearing fluid inclusions and the use of freezing data for estimation of salinity. Econ. Geol. 74, 1435–1444 (1979)
Crawford, M. L.: Phase equilibria in aqueous fluid inclusions. In: Hollister, L. A., Crawford, M. L. “Fluid inclusions: applications to petrology”, Calgary, Mineralog. Ass. Canad. pp. 75–100 (1981)
Crouzet, J., Tollon, F.: Le gisement stratiforme et filonien de Salsigne (Aude): Au, As, (AG, Bi, Cu). 26ème Cong. Géol. Int., Paris, Gisements Français fasc. E8, 54 p. (1980)
Donnot, M., Guerange, B.: Le synclinorium cambrien de Brusque. Implications stratigraphiques et structurales dans les monts de l'est de Lacaune (Tarn, Aveyron, Hérault). Versant Nord de la Montagne Noire. Bull. B.R.G.M. (2), I, 4, (1978)
Foglierini, F., Beziat, P., Tollon, F., Chabod, J. C.: Le gisement filonien de Noailhac Saint-Salvy (Tarn) Zn (Ag, Ge, Pb, Cd). 26ème Cong. Géol. Int., Paris, gisements français, fasc. E6, 42 p. (1980)
Fouquet, Y.: Les districts antimonifères de Quimper et du Cap Sizun (Finistère). Leur place dans la métallogénie de l'antimoine dans le Massif Armoricain (France). Thèse Doct. 3ème cycle. Univ. de Clermont-Ferrand 227 p. (1980)
Geffroy, J.: Metallogenie de l'antimoine dans les aires hercyniennes francaises. Bull. Assoc. Anc. El. Lab. Geol. Appl. Paris, 1 Gasc., 28–35 (1955)
Hamet, J.: Etude systématique par la méthode 87Rb-87Sr des processus orogéniques. Examples de la Montagne Noire. Thèse d'Etat Paris (1975)
Heyen, G., Bamboz, C., Dubessy, J.: Simulation des équilibres de phases dans le système CO2-CH4 en dessous de 50°C et de 100 bars. Application aux inclusions fluides. C.R. Acad. Sc. Paris, t.294, série II, 203–206 (1982)
Kay, A., Strong, D. F.: Geologic and fluid controls on As-Sb-Au mineralization in the Moretons Harbour Area, Newfoundland. Econ. Geol. 78, 1590–1604 (1983)
Konnerup-Madsen, J.: Fluid inclusions in quartz from deep-seated granitic intrusions, south Norway, Lithos 12, 13–23 (1979)
Konnerup-Madsen, J.: Compositions of fluid inclusions in granites and quartz syenites from the Gardar continental rift province (South Greenland). Bull. Mineral. 107:327–340 (1984)
Krestschmar, U., Scott, S. D.: Phase relations involving arsenopyrite in the system Fe-As-S and their application. Can. Mineral. 14:364–386 (1976)
Linke, W. F.: Solubilities of inorganic and metal organic compounds (4th ed.) 2, Am. Chem. Soc., 1914 p. (1965)
Manucharyants, B. O., Naumov, V. B., Jhodakovski, J. I. L.: Physicochemical conditions of formation of hydrothermal deposits of antimony and mercury. Geochem. Intern. 7:911–923 (1970)
Marcoux, E., Serment, R., Allon, A.: Les gîtes d'antimoine de Vendée (Massif armoricain, France): Historique des recherches et synthèse métallogénique. Chron. Rech. Min. no 476:3–30 (1984)
Marcoux, E., Bril, H.: Héritage et sources des métaux d'après la géochimie isotopique du plomb. Example des minéralisations filoniennes (Sb, Pb, Ba, F) de Haut-Allier (Massif Central Français). Minéral. Deposita 20:1–9 (1985)
Marcoux, E., Picot, P., Moëlo, Y. — Evolution paragéntique des minéralisations sulfurées aurifères du district de Pontieux-Labessette (Puy-de-Dôme). Apport des études isotopiques du plomb. Bull. Minéral. 108:103–119 (1985)
Moëlo, Y.: Contribution à l'étude des conditions naturelles de formation des sulfures complexes d'antimoine et plomb (sulfosels de Pb/Sb). Signification métallogénique. Thèse Doct. d'Etat, Université Paris VI, Ed., B.R.G.M., Orléans, 624 p. (1982)
Munoz, M.: Les minéralisations antimonifères du champ filonien de Bournac (Hérault). Thèse 3ème cycle, Université Paul Sabatier, Toulouse (1981)
Munoz, M., Moëlo, Y. — Etude paragénétique de la minéralisation suflurée complexe (Sb-Pb-Zn...) de Bournac (Hérault, France). Bull. Minéral. 105:625–632 (1982)
Otkhemezuri, Z. V., Dolidze, I. D. — On the chemical composition of fluid inclusions in ore-forming minerals of antimony-mercury-arsenic deposits. I.M.A. 12th general meeting, Orléans, abs., p. 137 (1980)
Perichaud, I. I.: Les gisements metallifères du district à antimoine de Brionde-Massiac (Massif Central Francais). Bull. BRGM 2:1–55 (1971)
Potter, R. W., Clynne, M. A., Brown, D. L. — Freezing-point depression of aqueous sodium chloride solutions. Econ. Geol. 73:284–285 (1978)
Ramboz, C.: Problèmes posés par la détermination de la composition des fluides carboniques complexes à l'aide des techniques microthermométriques. C.R. Acad. Sci. sér. D, 290:499–502 (1980)
Robinson, B. W., Farrand, M. G.: Sulfur isotopes and the origin of stibnite mineralization in New England, Australia. Mineral. Deposita 17:161–174 (1982)
Rouchy, J. M.: Etude géologique et métallogénique de la haute vallées de l'Orb (34). Relations socle-couverture. Problèmes des silicifications et des minéralisations barytiques. Thèse 3ème cycle, Faculté des Sciences de Paris (1973)
Routhier, P.: Les gisements metallifères. Masson, Paris, 1282 p. (1963)
Scratch, R. B., Watson, G. P., Kerrich, R., Hutchinson, R. W.: Fracture-controlled antimony-quartz mineralization, Lake George deposit, New Brunswick: mineralogy geochemistry, alteration, and hydrothermal regimes. Econ. Geol. 79:1159–1186 (1984)
Shepherd, T. J.: Temperature programmable heating-freezing stage for microthermometric analysis of fluid inclusions. Econ. Geol. 76:1244–1247 (1981)
Swanenberg, H. E. C.: Phase equilibria in carbonic systems, and their application to freezing studies of fluid inclusions. Contr. Mineral. Petrol. 68:303–306 (1979)
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Munoz, M., Shepherd, T.J. Fluid inclusion study of the bournac polymetallic (Sb-As-Pb-Zn-Fe-Cu...) vein deposit (montagne noire, France). Mineral. Deposita 22, 11–17 (1987). https://doi.org/10.1007/BF00204237
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DOI: https://doi.org/10.1007/BF00204237