Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

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Fabric Transpositions in Granite Plutons - An Insight from Non-Scaled Analogue Modelling


Affiliations
1 Geophysical Institute, Czech Academy of Sciences, Bocni II/1401, 14131 Praha 4, Czech Republic
2 Institute of Petrology and Structural Geology, Charles University, Prague, Czech Republic
     

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Investigations on a set of experimental models of highly viscous intrusions were carried out in order to study the internal strain pattern during vertical ascent and emplacement of granite intrusions. The strain pattern was determined by means of anisotropy of magnetic susceptibility (AMS) resulting from the orientation of magnetite particles in a liquid plaster medium. The modelled intrusions show distinct fabrics reflecting the flow of a rheologically complex, non- Newtonian material. During the vertical growth of the intrusion, constrictional vertical fabrics are transposed into flattening fabrics, and along with the development of low-intensity fabric domains are passively transported upwards. Vertical growth takes place along subvertical thrust shear zones that satisfactorily explain the discordant magmatic fabrics in granites along intrusion sides. The resulting complex fabric patterns suggest that the vertical movement of material in ascending intrusions is accommodated by various flow mechanisms operating simultaneously.

Keywords

Analogue Modelling, AMS, Magmatic Fabrics, Granite Intrusions, Rheology.
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  • ARCHANJO, C., TRINDADE, R., BOUCHEZ, J. L. and ERNESTO, M. (2002) Granite fabrics and regional-scale strain partitioning in the Serido belt (Borborema Province, NE Brazil). Tectonics, v.21, pp.1-13.

  • ARCHANJO, C., HOLLANDA, M.H., RODRIGUES, S., NEVES, B. and ARMSTRONG, R. (2008) Fabrics of pre-and syntectonic granite plutons and chronology of shear zones in the Eastern Borborema Province, NE Brazil. Jour. Struct. Geol., v.30(3), pp.310-326.

  • BAGDASSAROV, N. and PINKERTON, H. (2004) Transient phenomena in vesicular lava flows based on laboratory experiments with analogue materials. Jour.Volcanol. Geoth. Res., v.132, pp.115-136.

  • BENN, K., HAM, N.M., PIGNOTTA, G.S. and BLEEKER, W. (1998) Emplacement and deformation of granites during transpression: magnetic fabrics of the Archean Sparrow pluton, Slave Province, Canada. Jour. Struct. Geol., v.20, pp.1247-1259.

  • BENN, K., PATERSON, S.R., LUND, S.P., PIGNOTTA, G.S. and KRUSE, S. (2001) Magmatic Fabrics in Batholiths as Markers of Regional Strains and Plate Kinematics: Example of the Cretaceous Mt. Stuart Batholith. Phys. Earth Planet. In: Part A: Solid Earth and Geodesy (A), v.26, pp.343-354.

  • BONINI, M., SOKOUTIS, D., MULUGETA, G., BOCCALETTI, M., CORTI, G., INNOCENTI, F., MANETTI, P. and MAZZARINI, F. (2001) Dynamics of magma emplacement in centrifuge models of continental extension with implications for flank volcanism. Tectonics, v.20, pp.1053-1065.

  • BOUCHEZ, J.L. (1997) Granite is never isotropic: an introduction to AMS studies of granitic rocks. In: J.L. Bouchez, D.W.H. Hutton and W.E. Stephens (Eds.), Granite: From Segregation of Melt to Emplacement Fabrics, Kluwer Acad. Publ., Dordrecht, The Netherlands, pp.95-112.

  • BOUCHEZ, J.L., GLEIZES, G., DJOUADI, T. and ROCHETTE, P. (1990) Microstructure and magnetic susceptibility applied to emplacement kinematics of granites: the example of the Foix pluton (French Pyrenees). Tectonophysics, v.184, pp.157-171.

  • BOUILLIN, J.P., BOUCHEZ, J.L. and LESPINASSE, P. (1993) Granite emplacement in an extensional setting - an AMS study of the magmatic structures of Monte-Capanne (Elba, Italy). Earth Planet. Sci. Lett., v.118, pp.263-279.

  • BUISSON, C. and MERLE, O. (2002) Experiments on internal strain in lava dome cross sections. Bull. Volcanol., v.64, pp.363-371.

  • CASTRO,A. (1987) On granitoid emplacement and related structures - a review. Geol. Rundsch., v.76, pp.101-124.

  • COLLINS, W.J. and SAWYER, E.W. (1996) Pervasive granitoid magma transfer through the lower-middle crust during non-coaxial compressional deformation. Jour. Metam. Geol., v.14, pp.565-579.

  • DIETL, C. and KOYI, H. A. (2002) Emplacement of nested diapirs: Results of centrifuge modelling. Jour. Virtual Explorer, v.6, pp.81-88.

  • DIETL, C. and KOYI, H.A. (2008) Formation of tabular plutons - results and implications of centrifuge modelling. Jour. Geosciences, v.53, pp.253-261.

  • DUNLOP, D. J. (2002) Theory and application of the Day plot (Mrs/ M-s versus H-cr/H-c) 2. Application to data for rocks, sediments, and soils. Jour. Geophys. Res., v.107, B3.

  • ESMAEILY, D., BOUCHEZ, J.L. and SIQUEIRA, R. (2007) Magnetic fabrics and microstructures of the Jurassic Shah-Kuh granite pluton (Lut Block, Eastern Iran) and geodynamic inference. Tectonophysics, v.439, pp.149-170.

  • FERNANDEZ, A. and LAPORTE, D. (1991) Significance of low symmetry fabrics in magmatic rocks. Jour. Struct. Geol., v.13, pp.337-347.

  • GROUT, F. F. (1945) Scale models of structures related to batholiths. Am. Jour. Sci., v.243A, pp.260-284.

  • HROUDA, F. (1994) A Technique for the Measurement of Thermal-Changes of Magnetic-Susceptibility of Weakly Magnetic Rocks by the Cs-2 Apparatus and Kly-2 Kappabridge. Geophys. Jour. Int., v.118, pp.604-612.

  • HROUDA, F., JELINEK, V. and HRUEKOVA, L. (1990) A package of programs for statistical evaluation of magnetic data using IBM PC computers. AGU 1990 fall meeting. Eos, Trans., Amer. Geophys. Union, v.71, pp.1289.

  • JELINEK, V. (1978) Statistical processing of anisotropy of magnetic susceptibility measured on groups of specimens. Stud. Geophys. Geod., v.22, pp.50-62.

  • JELINEK, V. (1981) Characterization of magnetic fabric of rocks. Tectonophysics, v.79, pp.63-67.

  • JELINEK, V. and POKORNY, J. (1997) Some new concepts in technology of transformer bridges for measuring susceptibility anisotropy of rocks. Phys. Chem. Earth, v.22, pp.179-181.

  • KRATINOVA, Z., ZAVADA, P., HROUDA, F. and SCHULMANN, K. (2006) Non-scaled analogue modelling of AMS development during viscous flow: A simulation on diapir-like structures. Tectonophysics, v.418, pp.51-61.

  • KRATINOVA, Z., SCHULMANN, K., EDEL, J. B., JEUEK, J. and SCHALTEGGER, U. (2007) Model of successive granite sheet emplacement in transtensional setting: Integrated microstructural and anisotropy of magnetic susceptibility study. Tectonics, v.26, TC6003, doi:10.1029/2006TC002035.

  • LEITCH, A.M. and WEINBERG, R.F. (2002) Modelling granite migration by mesoscale pervasive flow. Earth Planet. Sci. Lett., v.200, pp.131-146.

  • LEXA, O., STIPSKA, P., SCHULMANN, K., BARATOUX, L. and KRONER, A. (2005) Contrasting textural record of two distinct metamorphic events of similar P-T conditions and different durations. Jour. Metam. Geol., v.23, pp.649-666.

  • MAJUMDER, S. and MAMTANI, M. A. (2009) Magnetic fabric in the Malanjkhand Granite (Central India)-Implications for regional tectonics and Proterozoic Suturing of the Indian shield. Phys. Earth Planet. Inter., v.172, pp.310-323.

  • NAGATA, T. (1961) Rock Magnetism, Maruzen, Tokyo. PARRY, M., STIPSKS, P., SCHULMANN, K., HROUDA, F., JEUEK, J. and KRONER, A. (1997) Tonalite sill emplacement at an oblique plate boundary: northeastern margin of the Bohemian Massif. Tectonophysics, v.280, pp.61-81.

  • PATERSON, S.R., FOWLER, T.K., SCHMIDT, K.L., YOSHINOBU, A.S., YUAN, E.S. and MILLER, R.B. (1998) Interpreting magmatic fabric patterns in plutons. Lithos, v.44, pp.53-82.

  • PATERSON, S.R. and VERNON, R.H. (1995) Bursting the bubble of ballooning plutons: A return to nested diapirs emplaced by multiple processes. GSA Bulletin, v.107, pp.1356-1380.

  • PETFORD, N. (1996) Dykes and diapirs? T. Roy. Soc. Edin-Earth, v.87, pp.105-114.

  • PITCHER,W.S. (1979) Nature, ascent and emplacement of granitic magmas. Jour. Geol. Soc. London, v.136, pp.627-662. RAMBERG, H. (1981) Gravity, deformation and the Earth’s crust. Academic Press, New York.

  • RAMSAY, J.G. (1989) Emplacement kinematics of a granite diapir; the Chindamora Batholith, Zimbabwe. Jour. Struct. Geol., v.11, pp.191-209.

  • RAPOSO, M. I. B., CARMO, M. and GASTAL, P. (2009) Emplacement mechanism of the main granite pluton of the Lavras do Sul intrusive complex, South Brazil, determined by magnetic anisotropies. Tectonophysics, v.466, pp.18-31.

  • ROMAN-BERDIEL, T. (1999) Geometry of granite emplacement in the upper crust: contributions of analogue modelling. Geol. Soc. London Spec. Publ., v.168, pp.77-94.

  • ROCHETTE, P., AUBOURG, C. and PERRIN, M. (1999) Is this magnetic fabric normal? A review and case studies in volcanic formations. Tectonophysics, v.307, pp.219-234.

  • SIMAKIN, A. and TALBOT, C. (2001) Tectonic pumping of pervasive granitic melts. Tectonophysics, v.332, pp.387-402.

  • SCHULMANN, K., JEUEK, J. and VENERA, Z. (1997) Perpendicular linear fabrics in granite: markers of combined simple shear and pure shear flows? In: J.L. Bouchez, D.W.H. Hutton and W.E. Stephens (Eds.), Granite: From Segregation of Melt to Emplacement Fabrics, Kluwer Acad. Publ., Dordrecht, The Netherlands, pp.159-76.

  • SCHWERDTNER, W.M. and TROENG, B. (1978) Strain distributon within arcuate diapiric ridges of silicon putty. Tectonophysics, v.50, pp.13-28.

  • TARLING, D.H. and HROUDA, F. (1993) The Magnetic Anisotropy of Rocks. Chapman and Hall, London, 232p.

  • VERNON, R.H., JOHNSON, S.E. and MELIS, E.A. (2004) Emplacement-related microstructures in the margin of a deformed pluton: the San Jose tonalite, Baja California, Mexico. Jour. Struct. Geol, v.26, pp.1867-1884.

  • VERNON, R.H. and PATERSON, S.R. (2008) How late are K-feldspar megacrysts in granites? Lithos, v.104, pp.327-336.

  • WEINBERG, R.F. (1999) Mesoscale pervasive melt migration alternative to dyking. Lithos, v.46, pp.393-410.

  • WEINBERG, R.F. and PODLADCHIKOV, Y. (1994) Diapiric ascent of magmas through power law crust and mantle. Jour. Geophys. Res., v.99(B5), pp.9543-9559.

  • ZAVADA, P., KRATINOVA, Z., KUSBACH,V. and SCHULMANN, K. (2008) Internal fabric development in complex lava domes. Tectonophysics, v.466, pp.101-113.

  • ZAK, J., SCHULMANN, K. and HROUDA, F. (2005) Multiple magmatic fabrics in the Sazava pluton (Bohemian Massif, Czech Republic): a result of superposition of wrench-dominated regional transpression on final emplacement. Jour. Struct. Geol., v.27, pp.805-22.

  • ZAK, J., VERNER, K. and TYCOVA, P. (2008) Multiple magmatic fabrics in plutons: an overlooked tool for exploring interactions between magmatic processes and regional deformation? Geol. Mag., v.145, pp.537-551.


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  • Fabric Transpositions in Granite Plutons - An Insight from Non-Scaled Analogue Modelling

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Authors

Zuzana Kratinova
Geophysical Institute, Czech Academy of Sciences, Bocni II/1401, 14131 Praha 4, Czech Republic
Matej Machek
Geophysical Institute, Czech Academy of Sciences, Bocni II/1401, 14131 Praha 4, Czech Republic
Vladimir Kusbach
Institute of Petrology and Structural Geology, Charles University, Prague, Czech Republic

Abstract


Investigations on a set of experimental models of highly viscous intrusions were carried out in order to study the internal strain pattern during vertical ascent and emplacement of granite intrusions. The strain pattern was determined by means of anisotropy of magnetic susceptibility (AMS) resulting from the orientation of magnetite particles in a liquid plaster medium. The modelled intrusions show distinct fabrics reflecting the flow of a rheologically complex, non- Newtonian material. During the vertical growth of the intrusion, constrictional vertical fabrics are transposed into flattening fabrics, and along with the development of low-intensity fabric domains are passively transported upwards. Vertical growth takes place along subvertical thrust shear zones that satisfactorily explain the discordant magmatic fabrics in granites along intrusion sides. The resulting complex fabric patterns suggest that the vertical movement of material in ascending intrusions is accommodated by various flow mechanisms operating simultaneously.

Keywords


Analogue Modelling, AMS, Magmatic Fabrics, Granite Intrusions, Rheology.

References