Advertisement

Swiss Journal of Geosciences

, Volume 111, Issue 1–2, pp 317–340 | Cite as

Bristen granite: a highly differentiated, fluorite-bearing A-type granite from the Aar massif, Central Alps, Switzerland

  • Kurt Bucher
  • Ulrike Seelig
Article

Abstract

Bristen granite is a body of fine-grained leucogranite occurring in the Gotthard rail base tunnel in the Central Alps. During construction of the tunnel, Bristen granite (Brgr) has been drilled along a 600 m long section. The aplite-granite belongs to the suite of Variscan granitoid intrusions of the Aar massif and contains a variety of accessory minerals typical of highly differentiated granites. Rock forming fluorite, partly enriched in yttrium (Y) and rare earth elements (REE), is intergrown with the late Y- and REE-bearing carbonate mineral synchysite. The granite contains a variety of Ti- and Y-REE-niobates, thorite, and zircon. Compared with the calc-alkaline central Aar granite (cAgr), Bristen granite is strongly depleted in Ti, P, Mg, Sr, and Ba and shows a remarkable enrichment in incompatible elements such as Rb, Th, U, Nb, Y, HREE and F. Bristen granite is the most evolved granitoid rock of the Aar massif. The composition of Brgr is typical of post-collisional reduced (ferroan) A-type granites. The Brgr melt formed in the lower crust and crystallized from a highly differentiated melt at the cotectic point in the quartz-feldspar system close to 100 MPa and 700 °C. The Brgr intruded as a small isolated stock pre-Variscan gneisses with sharply discordant contacts. The primary igneous host of Nb, Ta, Y, U, Th and REE is biotite in addition to minor amounts of allanite, and zircon. The presence of Y-REE-fluorite, synchysite, parisite and Y- and Ti-niobates and other REE-minerals can be related to reaction of igneous biotite and primary fluorite with hydrothermal fluids. The reaction is associated with alpine metamorphism, because Y-bearing fluorite and synchysite have been reported from Alpine fissures. The transformation of primary biotite to chlorite and muscovite released the heavy metal oxides under lower greenschist facies conditions that formed the Alpine diagnostic mineral stilpnomelane at about 300 °C.

Keywords

Bristen granite Aar massif Fluorite Synchysite REE niobates 

Notes

Acknowledgements

We would like to thank AlpTransit Gotthard AG for providing access to the tunnel. The generous support by the tunnel geologists Beat Frei and Thomas Breitenmoser providing rock and water samples is gratefully acknowledged. We are grateful to Peter Amacher for contributing data on the Alpine fissure minerals from the tunnel to the present study. Special thanks go to all technicians of the Mineralogy and Geochemistry laboratories of the University of Freiburg. Peter Hayoz from Swisstopo, Wabern, supported this study by providing fresh core samples of the granites. We gratefully acknowledge the constructive reviews by Christian Gisler and an anonymous reviewer and the efficient editorial handling by Edwin Gnos.

References

  1. Abrecht, J., & Schaltegger, U. (1988). Aplitic intrusions in the Central Aar massif basement: geology, petrography and Rb/Sr data. Eclogae Geologicae Helvetiae, 81, 227–239.Google Scholar
  2. Amacher, P., & Schüppach, T. (2011). NEAT-Mineralien, Kristall-Schätze tief im Berg (p. 233). Amsteg: Verlag GEO-Uri.Google Scholar
  3. Anderson, I. C., Frost, C. D., & Frost, B. R. (2003). Petrogenesis of the Red Mountain pluton, Laramie anorthosite complex, Wyoming: implications for the origin of A-type granite. Precambrian Research, 124, 243–267.CrossRefGoogle Scholar
  4. Armbruster, T., Kohler, T., Meisel, T., Nägler, T. F., Götzinger, M. A., & Stalder, H. A. (1996). The zeolite, fluorite, quartz assemblage of the fissure at Gibelsbach, Fiesch (Valais, Switzerland): crystal chemistry, REE patterns, and genetic speculations. Schweizerische Mineralogische und Petrographische Mitteilungen, 76, 131–146.Google Scholar
  5. Bartoli, O., Acosta-Vigil, A., Ferrero, S., & Cesare, B. (2016). Granitoid magmas preserved as melt inclusions in high-grade metamorphic rocks. American Mineralogist, 101, 1543–1559.CrossRefGoogle Scholar
  6. Berger, A., Mercolli, I., Herwegh, M., & Gnos, E. (2017). Geological Map of the Aar Massif (p. 129). Geological Special Map: Tavetsch and Gotthard Nappes.Google Scholar
  7. Blundy, J., & Cashman, K. (2001). Ascent-driven crystallisation of dacite magmas at Mount St Helens, 1980–1986. Contrib. Mineral. Petrol., 140, 631–650.CrossRefGoogle Scholar
  8. Breitschmid, A. (1982). Diagenese und schwache Metamorphose in den sedimentaren Abfolgen der Zentralschweizer Alpen. Eclogae Geologicae Helvetiae, 75, 331–380.Google Scholar
  9. Brown, G. C., Thorpe, R. S., & Webb, P. C. (1984). The geochemical characteristics of granitoids in contrasting arcs and comments on magma sources. Journal of the Geological Society, 141, 413–426.CrossRefGoogle Scholar
  10. Bucher, K., & Frost, B. R. (2006). Fluid transfer in high-grade metamorphic terrains intruded by anorogenic granites: the Thor Range, Antarctica. Journal of Petrology, 47, 567–593.CrossRefGoogle Scholar
  11. Charoy, B., & Raimbault, L. (1994). Zr-, Th-, and REE-rich biotite differentiates in the A-type granite pluton of Suzhou (Eastern China): the key role of fluorine. Journal of Petrology, 35, 919–962.CrossRefGoogle Scholar
  12. Conte, A. M., Cuccuru, St, D’Antonio, M., Naitza, St, Oggiano, G., Secchi, F., et al. (2017). The post-collisional late Variscan ferroan granites of southern Sardinia (Italy): Inferences for inhomogeneity of lower crust. Lithos, 294–295, 263–282.CrossRefGoogle Scholar
  13. Dall’Agnol, R., & Oliveira, D. C. (2007). Oxydized, magnetite-series, rapakivi-type granites of Carajas, Brazil: implications for classification and petrogenesis of A-type granites. Lithos, 93, 215–233.CrossRefGoogle Scholar
  14. De la Roche, H., Leterrier, J., Grandclaude, P., & Marchal, M. (1980). A classification of volcanic and plutonic rocks using R1R2-diagram and major-element analyses— its relationships with current nomenclature. Chemical Geology, 29, 183–210.CrossRefGoogle Scholar
  15. Dolejs, D., & Baker, D. R. (2004). Thermodynamic analysis of analysis of the system Na2O-K2O-CaO-Al2O3-SiO2-H2O-F2O-1: stability of fluorine-bearing minerals in felsic igneous suites. Contributions to Mineralogy and Petrology, 146, 762–778.CrossRefGoogle Scholar
  16. Duran, C. J., Seydoux-Guillaume, A.-M., Bingen, B., Gou, S., de Parseval, P., Ingrin, J., et al. (2016). Fluid-mediated alteration of (Y, REE, U, Th)–(Nb, Ta, Ti) oxide minerals in granitic pegmatite from the Evje-Iveland district, southern Norway. Mineralogy and Petrology, 110, 581–599.CrossRefGoogle Scholar
  17. El Bouseily, A. M., & El Sokkary, A. A. (1975). The relation between Rb, Ba and Sr in granitic rocks. Chemical Geology, 16, 207–219.CrossRefGoogle Scholar
  18. Finger, F., & Steyrer, H. P. (1990). I-Type granitoids as indicators of a late Paleozoic convergent ocean continent margin along the southern flank of the central European Variscan orogen. Geology, 18, 1207–1210.CrossRefGoogle Scholar
  19. Förster, H.-J. (2001). Synchysite-(Y)—synchysite-(Ce) solid solutions from Markersbach, Erzgebirge, Germany: REE and Th mobility during high-T alteration of highly fractionated aluminous A-type granites. Mineralogy and Petrology, 72, 259–280.CrossRefGoogle Scholar
  20. Förster, H.-J., Tischendorf, G., Turnbull, R. B., & Gottesmann, B. (1999). Late-collisional granite magmatism in the Variscan Erzgebirge, Germany. Journal of Petrology, 40, 1613–1645.CrossRefGoogle Scholar
  21. Frey, M. (1987). The reaction-isograd kaolinite + quartz = pyrophyllite + H2O, Helvetic Alps, Switzerland. Schweizer Mineralogische und Petrographische Mitteilungen, 67, 1–11.Google Scholar
  22. Frey, M., Bucher, K., Frank, E., & Mullis, J. (1980). Alpine metamorphism along the Geotraverse Basel-Chiasso— a review. Eclogae Geologicae Helveticae, 73, 527–546.Google Scholar
  23. Geyer, M., Nitsch, E., Simon, Th, Geyer, O. F., & Gwinner, M. P. (2011). Geologie von Baden-Württemberg (5th ed., p. 627). Stuttgart: Schweizerbart.Google Scholar
  24. Gieré, R., & Sorensen, S. S. (2004). Allanite and other REE-rich epidote-group minerals. Reviews in Mineralogy and Geochemistry, 56, 431–493.  https://doi.org/10.2138/gsrmg.56.1.431 CrossRefGoogle Scholar
  25. Gopeshwor Singh, L., & Vallinayagam, G. (2012). Petrological and geochemical constraints in the origin and associated mineralization of A-type granite suite of the Dhiran Area, Northwestern Peninsular India. Geosciences, 2, 66–80.Google Scholar
  26. Grapes, R., Bucher, K., & Hoskin, P. W. O. (2005). Monazite-epidote reaction in amphibolite grade blackwall rocks. European Journal of Mineralogy, 17, 553–566.CrossRefGoogle Scholar
  27. Guntli, P., Keller, F., Lucchini, R. and Rust, S. (2016). Gotthard-Basistunnel: geologie, geotechnik, hydrogeologie—zusammenfasender Schlussbericht. Berichte der Landesgeologie Nr.7 pp.180. Bundesamt für Landestopografie (swisstopo), Wabern, Switzerland.Google Scholar
  28. Hanson, S. L., Simmons, W. B., Webber, K. L., & Falster, W. U. (1992). Rare-earth-element mineralogy of granitic pegmatites in the Trout Creek Pass district, Chaffee county, Colorado. Canadian Mineralogist, 30, 673–686.Google Scholar
  29. Harris, N. B. W., Pearce, J. A., & Tindle, A. G. (1986). Geochemical characteristics 497 of collision-zone magmatism. In M. P. Coward & A. C. Ries (Eds.), Collision tectonics (Vol. 19, pp. 67–81). London: Geological Society Special Publication.Google Scholar
  30. Hollocher, K. (2007). Calculation of a CIPW norm from a bulk chemical analysis. Geology Department, Union College, Schenectady, NY, 12308, USA. http://www.union.edu/PUBLIC/GEODEPT/COURSES/petrology/norms.htm. Accessed 15 Mar 2016.
  31. Hollocher, K., Robinson, P., Seaman, K., & Walsh, W. (2016). Ordovician-Early Silurian intrusive rocks in the northwest part of the Upper Allochthon, Mid-Norway: Plutons of an Iapetan Volcanic Arc Complex. American Journal of Science, 316, 925–980.CrossRefGoogle Scholar
  32. Hu, Q., Yu, K., Liu, W., Hu, Z., & Zong, K. (2017). The 131–134 Ma A-type granites from northern Zhejiang Province, South China: implications for partial melting of the Neoproterozoic lower crust. Lithos, 294–295, 39–52.CrossRefGoogle Scholar
  33. Huang, Ch., Zhao, Z., Li, G., Zhua, D., Liua, D., & Shi, Q. (2017). Leucogranites in Lhozag, southern Tibet: implications for the tectonic evolution of the eastern Himalaya. Lithos, 294–295, 246–262.CrossRefGoogle Scholar
  34. Hügi, T. (1956). Vergleichende petrologische und geochemische Untersuchungen an Graniten des Aarmassivs. In: Beiträge zur Geologischen Karte der Schweiz (vol. N.F., 94, p. 86). Bern: Kümmerly and Frey AG, Geographischer Verlag.Google Scholar
  35. Irber, W. (1999). The lanthanide tetrad effect and its correlation with K/Rb, Eu/Eu*, Sr/Eu, Y/Ho, and Zr/Hf of evolving peraluminous granite suites. Geochimica et Cosmochimica Acta, 63, 489–508.CrossRefGoogle Scholar
  36. Izett, G. A. (1981). Volcanic ash beds: recorders of Upper Cenozoic silicic pyroclastic volcanism in the western United States. Journal of Geophysical Research, 86, 10200–10222.CrossRefGoogle Scholar
  37. Jahn, B.-M., Wu, F., Capdevilla, R., Martineau, F., Zhao, Z., & Wang, Y. (2001). Highly evolved juvenile granites with tetrad REE patterns: the Woduhe and Baerzhe granites from the the Great Xing’an Moubtains in NE China. Lithos, 59, 171–198.CrossRefGoogle Scholar
  38. Johannes, W., & Holtz, F. (1996). Petrogenesis and experimental petrology of granitic rocks (p. 335). Heidelberg: Springer.Google Scholar
  39. Keppie, J. D. (1994). Pre-Mesozoic geology in France and related areas (p. 536). Berlin Heidelberg: Springer.Google Scholar
  40. Labhart, T. P. (1977). Aarmassiv und Gotthardmassiv. In M. P. Gwinner (Ed.), Sammlung Geologischer Führer (Vol. 63, p. 173). Berlin, Stuttgart: Gebrüder Borntraeger.Google Scholar
  41. Labhart, T. P. (2005). Geologie der Schweiz (p. 211). Bern: Ott Verlag.Google Scholar
  42. Leake, B. E. (1974). The crystallization history and mechanism of emplacement of the western part of the Galway Granite, Connemara, Western Ireland. Mineralogical Magazine, 39, 498–512.CrossRefGoogle Scholar
  43. Maniar, P. D., & Piccoli, P. M. (1989). Tectonic discrimination of granitoids. Geological Society of America Bulletin, 101, 635–643.CrossRefGoogle Scholar
  44. McCann, T., Mader, H. M., & Coles, S. G. (2008). The Geology of Central Europe, vol 1 Precambrian and Palaeozoic (p. 784). London: The Geological Society of London.Google Scholar
  45. McDonough, W. F., & Sun, S. S. (1995). The composition of the Earth. Chemical Geology, 120, 223–253.CrossRefGoogle Scholar
  46. Mercolli, I., & Oberhänsli, R. (1988). Variscan tectonic evolution in the Central Alps: a working hypothesis. Schweizerische Mineralogische und Petrographische Mitteilungen, 68, 491–500.Google Scholar
  47. Möller, P., Stober, I., & Dulski, P. (1997). Seltenerdelement-, Yttrium-Gehalte und Bleiisotope in Thermal- und Mineralwässern des Schwarzwaldes.-. Grundwasser, 3(2), 118–132.CrossRefGoogle Scholar
  48. Monecke, T., Kempe, U., Monecke, J., Sala, M., & Wolf, D. (2002). Tetrad effect in rare earth element distribution patterns: a method of quantification with application to rock and mineral samples from granite-related rare metal deposits. Geochimica et Cosmochimica Acta, 66, 1185–1196.CrossRefGoogle Scholar
  49. Oberhänsli, R., Schenker, F., & Mercolli, I. (1988). Indications of Variscan nappe tectonics in the Aar Massif. Schweizerische Mineralogische und Petrographische Mitteilungen, 68, 509–520.Google Scholar
  50. Parsons, I., Thompson, P., Lee, M. R., & Cayzer, N. (2005). Alkali feldspar microtextures as provenance indicators in siliciclastic rocks and their role in feldspar dissolution during transport and diagenesis. Journal of Sedimentary Research, 75, 921–942.CrossRefGoogle Scholar
  51. Pearce, J. A., Harris, N. B. W., & Tindle, A. G. (1984). Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25, 956–983.CrossRefGoogle Scholar
  52. Pfiffner, O. A. (2014). Geology of the Alps (2nd edn., 368 pp.). Chichester: Wiley Blackwell.Google Scholar
  53. Pflugshaupt, P. (1927). Beiträge zur Petrographie des östlichen Aarmassifs—Petrographisch geologische Untersuchungen im Gebiete des Bristenstockes. Schweizerische Mineralogische und Petrographische Mitteilungen, 7, 321–378.Google Scholar
  54. Pouchou, J. L., & Pichoir, F. (1984). “PAP” (φ-ρ-z) correction procedure for improved quantitative microanalysis. In J. T. Armstrong (Ed.), Microbeam Analysis (pp. 104–106). California: San Francisco Press.Google Scholar
  55. Schaltegger, U. (1990). The Central Aar Granite: highly differentiated calc-alkaline magmatism in the Aar Massif (Central Alps, Switzerland). European Journal of Mineralogy, 2, 245–259.CrossRefGoogle Scholar
  56. Schaltegger, U. (1993). The evolution of the polymetamorphic basement in the Central Alps unravelled by precise U-Pb zircon dating. Contributions to Mineralogy and Petrology, 113, 466–478.CrossRefGoogle Scholar
  57. Schaltegger, U. (1994). Unravelling the pre-Mesozoic history of the Aar and Gotthard massifs (Central Alps) by isotopic dating—a review. Schweizerische Mineralogische und Petrographische Mitteilungen, 74, 41–51.Google Scholar
  58. Schaltegger, U., & Corfu, F. (1992). The age and source of late Hercynian magmatism in the central Alps: evidence from precise U-Pb ages and initial Hf isotopes. Contributions to Mineralogy and Petrology, 111, 329–344.CrossRefGoogle Scholar
  59. Schaltegger, U., & Corfu, F. (1995). Late Variscan “Basin and Range” magmatism and tectonics in the Central Alps: evidence from U-Pb geochronology. Geodinamica Acta, 8, 82–98.CrossRefGoogle Scholar
  60. Schaltegger, U., Gnos, E., Küpfer, T., & Labhart, T. P. (1991). Geochemistry and tectonic significance of Late Hercynian potassic and ultrapotassic magmatism in the Aar massif (Central Alps). Schweizerische Mineralogische und Petrographische Mitteilungen, 71, 391–403.Google Scholar
  61. Schenker, F., & Abrecht, J. (1987). Prä-aargranitische Anatexis, variszische Kontaktmetamorphose und alpidische Regionalmetamorphose im Oberhasli (zentrales Aarmassiv, Schweiz). Schweizerische Mineralogische und Petrographische Mitteilungen, 67, 13–26.Google Scholar
  62. Seelig, U., & Bucher, K. (2010). Halogens in water from the crystalline basement of the Gotthard rail base tunnel (Central Alps). Geochimica Cosmochimica Acta, 74, 2581–2595.CrossRefGoogle Scholar
  63. Smith, D. R., Noblett, J., Wobus, R. A., Unruh, D., Dougalss, J., Beane, R., et al. (1999). Petrolgoy and geochemistry of late-stage intrusions of the A-type, mid-Proterozoic Pikes Peak batholith (Central Colorado, USA): implications for petrogenetic models. Precambrian Research, 98, 271–305.CrossRefGoogle Scholar
  64. Stalder, H. A. (1964). Petrographische und mineralogische Untersuchungen im Grimselgebiet. Schweizerische Mineralogische und Petrographische Mitteilungen, 44, 187–398.Google Scholar
  65. Stalder, H. A., Wagner, A., Graeser, S., & Stuker, P. (1998). Mineralienlexikon der Schweiz (p. 608). Wepf: Basel.Google Scholar
  66. Uher, P., Ondrejka, M., Bačík, P., Broska, I., & Konečný, P. (2015). Britholite, monazite, REE carbonates, and calcite: products of hydrothermal alteration of allanite and apatite in A-type granite from Stupné, Western Carpathians, Slovakia. Lithos, 236–237, 212–225.CrossRefGoogle Scholar
  67. Vilalva, F. C. J., & Vlach, S. R. F. (2014). Geology, petrography and geochemistry of the A-type granites from the Morro Redondo Complex (PR-SC), southern Brazil, Graciosa Province. Annals of the Brazilian Academy of Sciences, 86, 85–116.CrossRefGoogle Scholar
  68. Von Raumer, J., Abrecht, J., Bussy, F., Lombardo, B., Menot, R.-P., & Schaltegger, U. (1999). The Palaeozoic metamorphic evolution of the Alpine External Massifs. Schweizerische Mineralogische und Petrographische Mitteilungen, 79, 5–22.Google Scholar
  69. Wang, R.-C., Wang, D.-Z., Zhao, G.-T., Lu, J.-J., Chen, X.-M., & Xu, S.-J. (2001). Accessory mineral record of magma-fluid interaction in the Laoshan I- and A-type granitic complex, Eastern China. Physics and Chemistry of the Earth (A), 26(9–10), 835–849.CrossRefGoogle Scholar
  70. Wanner, Ch., Bucher, K., Pogge von Strandmann, P. A. E., Waber, N. H., & Pettke, T. (2017). On the use of Li isotopes as a proxy for water-rock interaction in fractured crystalline rocks: a case study from the Gotthard rail base tunnel. Geochimica Cosmochimica Acta, 198, 396–418.CrossRefGoogle Scholar
  71. Weisenberger, T., & Bucher, K. (2010). Zeolites in fissures of granites and gneisses of the Central Alps. Journal of Metamorphic Geology, 28, 825–847.CrossRefGoogle Scholar
  72. Whalen, J. B., Currie, K. L., & Chappell, B. W. (1987). A-type granites: geochemical characteristics, discrimination and petrogenesis. Contributions to Mineralogy and Petrology, 95, 407–419.CrossRefGoogle Scholar
  73. Whitney, D. L., & Evans, B. W. (2010). Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187.CrossRefGoogle Scholar

Copyright information

© Swiss Geological Society 2018

Authors and Affiliations

  1. 1.Institute of Mineralogy and PetrologyUniversity of FreiburgFreiburgGermany
  2. 2.Projektträger Jülich (ptj)Forschungszentrum Jülich GmbHBerlinGermany

Personalised recommendations