Abstract
Gold-bearing quartz veins fill late-Alpine brittle structures in Pennine nappes of Austria (in the Tauern window) and in northern Italy. The veins formed in the latter stages of uplift of the Alps. Fluid inclusions in veins sampled from Böckstein, Austria, and Valle Anzasca, Italy have a wide variety of compositions, ranging from aqueous brine (about 5 wt% NaCl equiv.) to about 50 mol% CO2. At room temperature, the inclusions range with increasing CO2 content from two-phase aqueous, through three-phase in which the CO2 homogenizes to vapour, to three-phase with CO2 homogenizing to liquid. This wide range of inclusion compositions is interpreted as evidence for fluid immiscibility, with most inclusions being accidental mixtures of the two end-member immiscible fluids. The homogenization temperatures of the aqueous inclusions, 200–280°C, gives the best estimate of temperature of formation of the veins. Vein formation fluid pressure at Böckstein and Valle Anzasca was about 1 kbar, and Böckstein veins formed at lower pressure than Valle Anzasca veins. Fluid immiscibility may have contributed to deposition of gold at both Valle Anzasca and Böckstein, and possibly many other uplift-related Alpine gold localities.
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References
Bodnar, R.J., Reynolds, T.J., Kuehn, C.A. (1985) Fluid inclusion systematics in epithermal systems. Rev. Econ. Geol. 2:73–98
Böhlke, J.K., Kistler, R.W. (1986) Rb-Sr, K-Ar, and stable isotope evidence for ages and sources of fluid components of gold-bearing quartz veins in the northern Sierra Nevada foothills metamorphic belt, California. Econ. Geol. 81:296–322
Bowers, T.S., Helgeson, H.C. (1983) Calculation of the thermodynamic and geochemical consequences of nonideal mixing in the system H2O-CO2-NaCl on the phase relations in geologic systems: metamorphic equilibria at high temperatures and pressures. Am. Mineral. 68:1059–1075
Brown, K.L. (1989) Kinetics of gold precipitation from experimental hydrothermal sulfide solutions. In: Keays, R., Ramsay, T., Groves, D. (eds) The Geology of Gold Deposits. Econ. Geol. Monogr. 6:320–327
Burrows, D.R., Wood, P.C., Spooner, E.T.C. (1986) Carbon isotope evidence for a magmatic origin for Archean gold-quartz vein ore deposits. Nature 321:851–854
Cliff, R.A., Norris, R.J., Oxburgh, E.R., Wright, R.C. (1971) Structural, metamorphic and geochronological studies in the Reisseck and southern Ankogel Groups, the Eastern Alps. Jahrb. Geol. B.-A. 114:121–272
Cox, S.F., Etheridge, M.A., Wall, V.J. (1986) The role of fluids in syntectonic mass transport, and localization of metamorphic vein-type ore deposits. Ore Geol. Rev. 2:65–86
Craw, D. (1986) Shallow-level penetration of metamorphic fluids in a high uplift rate mountain belt, Southern Alps, New Zealand. J. Metam. Geol. 6:1–16
Craw, D., Koons, P.O. (1989) Tectonically induced hydrothermal activity and gold mineralization adjacent to major fault zones. In: Keays, R., Ramsay, R., Groves, D. (eds) The Geology of Gold Deposits. Econ. Geol. Monogr. 6:463–470
Curti, E. (1987) Lead and oxygen isotope evidence for the origin of the Monte Rosa gold lode deposits (western Alps, Italy): a comparison with Archean lode gold deposits. Econ. Geol. 82:2115–2140
Damm, B., Simon, W. (1966) Das Tauerngold. In Zur Mineralogie und Geologie des Landes Salzburg und der Tauern. Sonderh. Z. Aufschluß 15:98–119
Diamond, L.W. (1990) Fluid inclusion evidence for P-V-T-X evolution of hydrothermal solutions in late-Alpine quartz veins at Brusson, Val d'Ayas, northwest Italian Alps. Am. J. Sci. 290:912–958
Droop, G.T.R. (1985) Alpine metamorphism in the south-east Tauern Window, Austria: 1. P-T variations in space and time. J. Metam. Geol. 3:371–402
Günther, M.A. (1990) Flüssigkeitseinschlüsse und geologisches Umfeld zentralafrikanischer Sn-, W- und Au-Lagerstätten (Rwanda und Burundi). Braunschweig Geol-Paläont, Diss. 11, 148 p
Hedenquist, J.W., Henley, R.W. (1985) The importance of CO2 on freezing point measurements of fluid inclusions: evidence from active geothermal systems and implications for epithermal ore deposition. Econ. Geol. 80:1379–1406
Henley, R.W. (1984) Metals in hydrothermal fluids. Rev. Econ. Geol. 1:115–128
Holzer, H.F. (1986) Austria. In: Dunning, F.W., Evans, A.M. (eds) Mineral Deposits of Europe, Volume 3: Central Europe. Inst. Min. Metall., pp. 15–40
Kerrich, R. (1986) Fluid infiltration into fault zones: chemical, isotopic and mechanical effects. Pure Appl. Geophys. 124:225–268
Kerrich, R., Fyfe, W.S. (1981) The gold-carbonate association: the source of CO2, and CO2 fixation reactions in Archean lode deposits. Chem. Geol. 33:265–294
Lattanzi, P.F. (1990) The nature of the fluids associated with the Monte Rosa gold district, NW Alps, Italy. Mineral. Deposita 25:S86-S89
Lattanzi, P.F., Curti, E., Bastogi, M. (1989) Fluid inclusion studies on the gold deposits of the upper Anzasca Valley, northwestern Alps, Italy. Econ. Geol. 84:1382–1397
Laubscher, H. (1988) Material balance in Alpine orogeny. Geol. Soc. Am. Bull. 100:1313–1328
McKeag, S.A., Craw, D., Norris, R.J. (1989) Origin and deposition of a graphite schist-hosted metamorphogenic Au-W deposit, Macraes, East Otago, New Zealand, Mineral. Deposita 24:124–131
Naden, J., Shepherd, T.J. (1989) Role of methane and carbon dioxide in gold deposition. Nature 342:793–795
Nesbitt, B.E., Muehlenbachs, K. (1989) Geology, geochemistry and genesis of mesothermal lode gold deposits of the Canadian Cordillera: evidence for ore formation from evolved meteoric water. In: Keays, R., Ramsay, R., Groves, D. (eds). The Geology of Gold Deposits. Econ. Geol. Monogr. 6:553–563
Paar, W. (1992) New data on the mineralogies of structurally controlled Au-Ag mineralization of the Hohe Tauern region. Austria. Mineral. Petrol. (in press)
Paterson, C.J. (1986) Controls on gold and tungsten mineralization in metamorphic-hydrothermal systems, Otago, New Zealand. Geol. Assoc. Can. Spec. Paper 32:25–39
Roedder, E. (1984) Fluid Inclusions. Rev. Mineralogy 12, 644 p
Roedder, E., Bodnar, R.J. (1980) Geologic pressure determinations from fluid inclusion studies. Ann. Rev. Earth Planet. Sci. 8:263–301
Schulz, O. (1983) Recent results and critical considerations of the Eastern Alpine metallogenesis. In: Schneider, H.J. (ed) Mineral deposits of the Alps and of the Alpine epoch in Europe. Springer-Verlag, Berlin, p. 19–27
Sharp, Z.D., Essene, E.J., Kelly, W.C. (1985) A re-examination of the arsenopyrite geothermometer, pressure considerations, and implications to natural assemblages. Can. Mineral. 23:517–534
Sibson, R.H., Robert, F., Poulsen, K.H. (1988) High angle reverse faults, fluid pressure cycling, and mesothermal gold-quartz deposits. Geology 16:551–555
Seward, T.M. (1973) Thiocomplexes of gold and the transport of gold in hydrothermal ore solutions. Geochim. Cosmochim. Acta 37:379–399
Seward, T.M. (1989) The hydrothermal chemistry of gold and its implications for ore formation: boiling and conductive cooling as examples. In: Keays, R., Ramsay, R., Groves, D. (eds). The Geology of Gold Deposits. Econ. Geol. Monogr. 6:398–404
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Craw, D., Teagle, D.A.H. & Belocky, R. Fluid immiscibility in late-Alpine gold-bearing veins, Eastern and Northwestern European Alps. Mineral. Deposita 28, 28–36 (1993). https://doi.org/10.1007/BF00199007
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DOI: https://doi.org/10.1007/BF00199007