Open Access Open Access  Restricted Access Subscription Access
Open Access Open Access Open Access  Restricted Access Restricted Access Subscription Access

Application of SEM-EBSD to Regional Scale Shear Zone Analysis: A Case Study of the Bhavani Shear Zone, South India


Affiliations
1 Department of Geology, University of Kerala, Kariavattom, Trivandrum - 695 581, India
2 Institute of Geophysics and Tectonics, School of Earth and Environment, The University of Leeds, Leeds LS2 9JT, United Kingdom
     

   Subscribe/Renew Journal


The Bhavani Shear Zone (BSZ), part of the Palghat-Cauvery shear system of southern India, comprises a number of subparallel shear zones ranging in width from a few centimetres to tens of metres. These shear zones are characterised by progressive mylonitisation and shear fabrics corresponding to increasing strain, as documented by grain size reduction, flattening, elongation and dimensional preferred orientation of constituent minerals (quartz, hornblende, biotite, plagioclase and orthoclase). However, SEM-EBSD measured crystal preferred orientations (CPO) of these minerals are more complex and indicate interchange of maximum (X) and intermediate (Y) tectonic axes during different phases of deformation, with the minimum axis (Z) remaining approximately constant. The tectonic evolution of the BSZ and the disposition of the surrounding Archaean and Pan-African granulites are interpreted therefore in terms of polyphase deformation involving both dip-slip and strike-slip movement events in a multiply reactivated setting. SEM-EBSD CPO analysis provides clearer indication of potentially conflicting movement directions that are otherwise poorly constrained by shear markers and shear sense indicators.

Keywords

SEM-EBSD, Progressive Strain, Reactivation, Bhavani Shear Zone, South India.
Subscription Login to verify subscription
User
Notifications
Font Size

  • ADAMS, B.L., WRIGHT, S.I. and KUNZE, K. (1993) Orientation imaging: the emergence of a new microscopy. Metallurgical Trans., v.24A, pp.819-831.
  • BARTLET, J.M., HARRIS, N.B.W., HAWKESWORTH, C.J. and SANTOSH, M. (1995) New isotope constraints on crustal evolution of southern India and Pan-African metamorphism. Mem. Geol. Soc. India, no.34, pp.391-397.
  • BARATOUX, L., SCHULMANN, K., ULRICH, S. and LEXA, O. (2005) Contrasting microstructures and deformation mechanisms in metagabbro mylonites contemporaneously deformed under different temperatures c.650 C and c.750 C). In: D. Gapais, J.P. Brun and P.R. Cobbold (Eds.), Deformation mechanism, rheology and tectonics: from minerals to the lithosphere. Geol. Soc. London, Spec. Publ., no.243, pp.97-125.
  • BECKINSALE, R.D., DRURY, S.A. and HOLT, R.W. (1980) 3360 m.y old gneisses from the south Indian craton. Nature, v.283, pp.469-470.
  • BERGER, A. and STUNITZ, H. (1996). Deformation mechanisms and reactions of hornblende: examples from the Bergell tonalite (Central Alps). Tectonophysics, v.257, pp.149-174.
  • BHADRA, B.K. (2001) Ductile shearing in Attur shear zone and its relation with Moyar shear zone, South India. Gondwana Res., v.3, pp.361-370.
  • Brodie, K.H. and Rutter, E.H. (1985) On the relationship between deformation and metamorphism with special reference to the behaviour of basic rocks. In:A.B. Thompson and D.C. Rubie (Eds.), Metamorphic reactions: Kinetics, textures and deformation. Springer-Verlag, New York, pp.138-179.
  • BUNGE, H.J. (1982) Texture Analysis in Materials Science. Butterworths, London, 599p.
  • BUTLER, R.W.H., HOLDSWORTH, R.E. and LLOYD, G.E. (1997) The role of basement reactivation in continental deformation. Journal of the Geological Society 154, 69-71.
  • CHETTY, T.R.K. (1996) Proterozoic shear zones in Southern Granulite Terrain. In:M. Santosh and M. Yoshida (Eds.), The Archaean and Proterozoic terrains in southern India within East Gondwana India. Gondwana Res. Group Mem., v.3, pp.77-89.
  • CRUZ., E.D., NAIR, P.K.R. and PRASANNAKUMAR, V. (2000) Palghat Gap-a dextral shear zone from the south Indian granulite terrain. Gondwana Res., v.3, pp.21-31.
  • DIAZ ASPIROZ, M., LLOYD, G.E. and FERNANDEZ, C. (2007) Development of lattice preferred orientation in clinoamphiboles deformed under low-pressure metamorphic conditions. A SEM/EBSD study of metabasites from the Aracena metamorphic belt (SW Spain). Jour. Struct. Geol., v.29, pp.629-645.
  • DOLLINGER, G. and BLACIC, J.D. (1975) Deformation mechanisms in experimentally and naturally deformed amphiboles. Earth Planet. Sci. Lett., v.26, pp.409-416.
  • DRURY, S.A. and HOLT, R.W. (1980) The tectonic framework of the south Indian craton: a reconnaissance involving Landsat imagery. Tectonophysics, v.65, pp.T1-T5.
  • DRURY, S.A., HARRIS, N.B.W., HOLT, R.W., REEVES-SMITH, G.J. and WIGHTMAN, R.T. (1984) Precambrian tectonics and crustal evolution in southern India. Jour. Geol., v.92, pp.3-20.
  • EGYDIO-SILVA, M., VAUCHEZ,A., BASCOU, J. and HIPPERTT, J. (2002) High-temperature deformation in the Neoproterozoic transpressional Ribeira belt, southeast Brazil. Tectonophysics, v.352, pp.203-224.
  • FOSSEN, H. and TIKOFF, B. 1993. The deformation matrix for simultaneous simple shearing, pure shearing and volume change, and its application to transpression-transtension tectonics. Jour. Struct. Geol., v.15, pp.413-422.
  • FOSSEN, H., TIKOFF, B. and TEYSSIER C. (1994) Strain modelling of transpressional and transtensional deformation. Norsk Geologisk Tidsskrift, v.74, pp.134-145.
  • FRIEND, C.R.L. and NUTMAN, A.P. (1992) Response of zircon UPb isotopes and whole rock geochemistry to CO2 fluid-induced granulite facies metamorphism, Kabbaldurga, Karnataka, South India. Contrib. Mineral. Petrol., v.111, pp.299-310.
  • GRADY, J.C. (1971) Deep main faults in South India. Jour. Geol. Soc. India, v.12, pp.56.
  • HARRIS, N.B.W., SANTOSH, M. and TAYLOR, P.N. (1994) Crustal evolution in South India - constraints from Nd isotopes. Jour. Geol., v.102, pp.139-150.
  • IMBER, J., HOLDSWORTH, R.E., BUTLER, C.A. and LLOYD, G.E. 1997. Fault-zone weakening processes along the reactivated Outer Hebrides Fault Zone, Scotland. Jour. Geol.Soc. Londona, no.154, pp.105-109.
  • IMON, R., OKUDAIRA, T. and KANAGAWA, K. (2004) Development of shape-and lattice-preferred orientations of amphibole grains during cataclastic deformation and subsequent deformation by dissolution-precipitation creep in amphibolites from the Ryoke metamorphic belt. SW Japan. Jour. Struct. Geol., v.26, pp.793-805.
  • JAIN, A.K., SINGH, S. and MANICKAVASAGAM, R.M. (2003) Intracontinental shear zones in the southern granulite terrain: their kinematics and evolution. Mem. Geol. Soc. India, no.50, pp.225-253.
  • JI, S.C. and MAINPRICE, D. (1988a) Sense of shear in high temperature movement zones from the fabric asymmetry of plagioclase feldspars. Jour. Struct. Geol., v.10, pp.73-81.
  • JI, S.C. and MAINPRICE, D. (1988b) Natural deformation fabrics of plagioclase - implications for slip systems and seismic anisotropy. Tectonophysics, v.147, pp.145-163.
  • JI, S.C. andMAINPRICE, D. (1989) Seismic anisotropy in the lower crust induced by the lattice preferred orientation of minerals. Seismol. Geol., v.11, pp.15-30.
  • JI, S.C. and MAINPRICE, D. (1990) Recrystallisation and fabric development in plagioclase. Jour. Geol., v.98, pp.65-79.
  • JI, S.C., SALISBURY, M.H. and HANMER, S. (1993) Petrofabric, Pwave anisotropy and seismic reflectivity of high grade tectonites. Tectonophysics, v.222, pp.195-226.
  • KATZ, M.B. (1978) Tectonic evolution of Archaean granulite facies belt Sri Lanka - South India. Jour. Geol. Soc. India, v.19, pp.185-205.
  • KIRBY, S.H. and KRONENBERG, A.K. (1987) Rheology of the lithosphere: selected topics. Reviews in Geophysics, v.25, pp.3177-3192.
  • KRUHL, J.H. (1987) Preferred lattice orientations of plagioclase from amphibolite and greenschist facies rocks near the Insubric Line (Western Alps). Tectonophysics, v.135, pp.233-242.
  • LAW, R.D. (1990) Crystallographic fabrics; a selective review of their applications to research in structural geology. In: R.J. Knipe and E.H. Rutter (Eds.), Deformation mechanisms, rheology and tectonics. Geol. Soc. London Spec. Publ., no.54, pp.335-352.
  • LIN, S., JIANG, D., WILLIAMS, P.F., DEWEY, J., HOLDSWORTH, R.E. and STRACHAN, R.A. (1999) Discussion on transpression and transtension zones. Jour. Geol. Soc. London, v.156, pp.1045-1050.
  • LLOYD, G.E. (1987) Atomic number and crystallographic contrast images with the SEM: a review of backscattered electron techniques. Mineral. Mag., v.51, pp.3-19.
  • LLOYD, G.E. (2000) Grain boundary contact effects during faulting of quartzite: an SEM/EBSD analysis. Jour. Struct. Geol., v.22, pp.1675-1693.
  • LLOYD, G.E. (2004) Microstructural evolution in a mylonitic quartz simple shear zone: the significant roles of dauphine twinning and misorientation. In: G.I. Alsop, R.E. Holdsworth, K. McCaffrey and M. Hand (Eds.), Transports and Flow Processes in Shear Zones. Geol. Soc. London, Spec. Publ., no.224, pp.39-61.
  • LLOYD, G.E. andKENDALL, J.M. (2005) Petrofabric derived seismic properties of a mylonitic quartz simple shear zone: implications for seismic reflection profiling. In: P.K.Harvey,T. Brewer, P.A. Pezard and V.A. Petrov (Eds.), Petrophysical Properties of Crystalline Rocks, Geol. Soc. London, Spec. Publ., no.240, pp.75-94.
  • MAINPRICE, D. (2003) World Wide Web Address: http:// www.isteem.univ-montp2.fr/TECTONOPHY/petrophysics/software/petrophysics_software.html.
  • MAINPRICE, D., LLOYD, G.E. and CASEY, M. (1993). Individual orientation measurements in quartz polycrystals - advantages and limitations for texture analysis and petrophysical property determination. Jour.f Struct. Geol. v.15, pp.1169-1187.
  • MEHL, L. and HIRTH, G. (2008) Plagioclase preferred orientation in layered mylonites: evaluation of flow laws for the lower crust. Jour. Geophys. Res., 113, B05202, doi:10.1029/ 2007JB005075.
  • MEISNER, B., DETERS, P., SRIKANTAPPA, C. and KOHLER, H. (2002) Geochronological evolution of the Moyar, Bhavani and Palghat shear zones of southern India: implications for east Gondwana correlations. Precambrian Res., v.114, pp.149-175.
  • MICHIBAYASHI, K. andMAINPRICE, D. (2004) The role of pre-existing mechanical anisotropy on shear zone development within oceanic mantle lithosphere: an example from the Oman ophiolite. Jour. Petrol., v.45, pp.405-414.
  • MUKHOPADHYAY, D., KUMAR, P.S., SRINIVASAN, R. and BHATTACHARYA, T. (2003) Nature of Palghat-Cauvery lineament in the region south of Namakkal, Tamil Nadu: implications for terrane assembly in south Indian granulite province. In: M. Ramakrishnan (Ed.), Tectonics of Southern Granulite Terrain, Kuppam-Palani Geotransect. Mem. Geol. Soc. India., no.50, pp.279-296.
  • NAHA, K. and SRINIVASAN, R. (1996) Nature of the Moyar and Bhavani shear zones, with a note on its implications on the tectonics of the southern Indian Precambrian shield. Proc. Indian Acad. Sci., v.105, pp.173-189.
  • NAIR, P.K.R., PRASANNAKUMAR, V. and THOMAS MATHAI. (1981) Structure of the western termination of the Bhavani lineament. Jour. Geol. Soc. India, v.22, pp.285-291.
  • NICOLAS, A. and POIRIER, J.P. (1976) Crystalline Plasticity and Solid-State Flow in Metamorphic Rocks. John Wiley and Sons, Ltd.
  • PASSCHIER, C.W., MYERS, J.S. and KRONER,A. (1990) Field Geology of High-Grade Gneiss terrains. Springer-Verlag, Heidelberg.
  • PASSCHIER, C.W. and TROUW, R.A.J. (2005) Microtectonics. Springer-Verlag, Berlin. 289p.
  • PRIOR, D.J. and WHEELER, J. (1999) Feldspar fabrics in a greenschist facies albite-rich mylonite from electron backscatter diffraction. Tectonophysics, v.303, pp.29-49.
  • PRIOR, D.J., BOYLE, A.P., BRENKER, F., CHEADLE, M.C., DAY, A., LOPEZ, G., POTTS, G.J., REDDY. S., SPIESS, R., TIMMS, N., TRIMBY, P.WHEELER, J. and ZETTERSTROM, L. (1999) The application of electron backscatter diffraction and orientation contrast imaging in the SEM to textural problems in rocks. Amer. Min., v.84, pp.1741-1759.
  • PRASANNAKUMAR, V. and LLOYD, G.E. (2007) Development of crystallographic lattice preferred orientation and seismic properties in Bhavani shear zone, southern India. Jour. Geol. Soc. India., v.70, pp.282-296.
  • PAULI, C., SCHMID, S. and HEILBRONNER, R. (1996) Fabric domains in quartz mylonites: localized three dimensional analysis of microstructure and texture Jour. Struct. Geol., v.18, pp.1183-1203.
  • RAITH, M., SRIKANTAPPA, C., BUHL, D. and KOEHLER, H. (1999) Niligiri enderbites, South India: nature and age constraints on protolith formation, high-grade metamorphism and cooling history. Precambrian Res., v.98, pp.129-150.
  • RAMAKRISHNAN, M. (2003) Craton-mobile belt relations in Southern Granulite Terrain. In: M. Ramakrishnan (Ed.), Tectonics of Southern Granulite Terrain, Kuppam-Palani Geotransect. Mem. Geol. Soc. India., no.50, pp.1-24.
  • RAMSAY, J.G. (1980) Shear zone geometry: a review. Jour. Struct. Geol., v.2, pp.83-100.
  • RANALLI, G. and MURPHY, D.C. (1987) Rheological stratification of the lithosphere. Tectonophysics, v.132, pp.281-295.
  • REYNARD, B., GILLET, P. and WILLIAM, C. (1989) Deformation mechanisms in naturally deformed glaucophanes - a TEM and HREM study. Europ. Jour. Min., v.1, pp.611-624.
  • ROONEY, T.P., RIECKER, R.E. and GAVASCI,A.T. (1975) Hornblende deformation features. Jour. Geol., v.3, pp.364-366.
  • RUTTER, E.H., BORIANI, A., BRODIE, K.H. and BURLINI, L. (1998) Special Issue: Structures and properties of high strain zones in rocks. Jour. Struct. Geol., v.20, pp.200.
  • SCHMID, S.M. and CASEY, M. (1986) Complete fabric analysis of some commonly observed quartz c axis patterns. In: H.C. Heard and B.E. Hobbs (Eds.), Mineral and rock deformation, Lab. Studies- the Patterson volume. Geophys. Mono., Am. Geophys. Union, v.36, pp.263-286.
  • SCHMIDT, N.H. and OLESEN. N.O. (1989) Computer-aided determination of crystal-lattice orientation from electron channelling patterns in the SEM. Can. Min., v.27, pp.15-22.
  • SCHWERDTNER, W.M. (1964) Preferred orientation of hornblende in a banded hornblende gneiss. Amer. Jour. Sci., v.262, pp.1212-1229.
  • SHELLEY, D. (1994) Spider texture and amphibole preferred orientation. Jour. Struct. Geol., v.16, pp.709-717.
  • SIEGESMOND, S., HELMING, K. and KRUSE, R. (1994) Complete texture analysis of a deformed amphibolite: comparison between neutron diffraction and U-stage data. Jour. Struct. Geol., v.16, pp.131-142.
  • SIMPSON, C. and DE PAOR, D.G. (1993) Strain and kinematic analysis in general shear zones. Jour. Struct. Geol., v.15, pp.1-20.
  • Skrotzki, W. (1990) Microstructure in hornblende of a mylonitic amphibolite. In: R.J. Knipe and E.H. Rutter (Eds.), Deformation mechanisms, rheology and tectonics, Geol. Soc. Spec. Publ., v.54, pp.321-325.
  • TATHAM, D.J., LLOYD, G.E., BUTLER, R.W.H. and CASEY, M. (2008) Amphibole and lower crustal seismic properties. Earth Planet. Sci. Lett., v.267, pp.118-128.
  • TEYSSIER, C. and TIKOFF, B. (1999) Fabric stability in oblique convergence and divergence. Jour. Struct. Geol., v.21, pp.969-974.
  • VAN DER PLUIJM, B.A., KLAUS MEZGER, K., COSCA, M.A. and ERIC J. ESSENE (1994). Determining the significance of highgrade shear zones by using temperature-time paths, with examples from the Grenville orogen. Geology, v.22, pp.743-746;
  • WHEELER, J. (1987) The determination of true shear sense from the deflection of passive markers in shear zones. Jour. Geol. Soc. London, v.144, pp. 73-77.
  • WILKS, K.R. and CARTER, N.L. (1990) Rheology of some continental lower crustal rocks. Tectonophysics, v.182, pp.57-77.

Abstract Views: 180

PDF Views: 0




  • Application of SEM-EBSD to Regional Scale Shear Zone Analysis: A Case Study of the Bhavani Shear Zone, South India

Abstract Views: 180  |  PDF Views: 0

Authors

V. Prasannakumar
Department of Geology, University of Kerala, Kariavattom, Trivandrum - 695 581, India
Geoffrey E. Lloyd
Institute of Geophysics and Tectonics, School of Earth and Environment, The University of Leeds, Leeds LS2 9JT, United Kingdom

Abstract


The Bhavani Shear Zone (BSZ), part of the Palghat-Cauvery shear system of southern India, comprises a number of subparallel shear zones ranging in width from a few centimetres to tens of metres. These shear zones are characterised by progressive mylonitisation and shear fabrics corresponding to increasing strain, as documented by grain size reduction, flattening, elongation and dimensional preferred orientation of constituent minerals (quartz, hornblende, biotite, plagioclase and orthoclase). However, SEM-EBSD measured crystal preferred orientations (CPO) of these minerals are more complex and indicate interchange of maximum (X) and intermediate (Y) tectonic axes during different phases of deformation, with the minimum axis (Z) remaining approximately constant. The tectonic evolution of the BSZ and the disposition of the surrounding Archaean and Pan-African granulites are interpreted therefore in terms of polyphase deformation involving both dip-slip and strike-slip movement events in a multiply reactivated setting. SEM-EBSD CPO analysis provides clearer indication of potentially conflicting movement directions that are otherwise poorly constrained by shear markers and shear sense indicators.

Keywords


SEM-EBSD, Progressive Strain, Reactivation, Bhavani Shear Zone, South India.

References