Hostname: page-component-7479d7b7d-qs9v7 Total loading time: 0 Render date: 2024-07-12T12:59:43.819Z Has data issue: false hasContentIssue false

Fault reactivation and pseudotachylite generation in the semi-brittle and brittle regimes: examples from the Gavilgarh–Tan Shear Zone, central India

Published online by Cambridge University Press:  20 August 2008

A. CHATTOPADHYAY*
Affiliation:
Department of Geology, Delhi University, Delhi 110 007, India
L. KHASDEO
Affiliation:
Department of Geology, Delhi University, Delhi 110 007, India
R. E. HOLDSWORTH
Affiliation:
Reactivation Research Group, Department of Earth Sciences, Durham University, Durham DH1 3LE, UK
S. A. F. SMITH
Affiliation:
Reactivation Research Group, Department of Earth Sciences, Durham University, Durham DH1 3LE, UK
*
Author for correspondence: anupamchatto@gmail.com

Abstract

In the sheared and foliated granitoids of the Proterozoic Gavilgarh–Tan Shear Zone (GTSZ) in central India, two types of pseudotachylite (Pt-M and Pt-C) are recognized. Pt-M layers are interbanded with mylonite and ultramylonite, show strong internal plastic deformation and buckle folding concurrent with the host rocks, and appear to have formed within the greenschist facies (300–400 °C) in the brittle–plastic transitional (semi-brittle) regime. Pt-C layers show sharp contacts with the host rock, exhibit abundant coeval cataclasis, preserve no evidence of subsequent plastic deformation, and formed at shallower depths, at temperature < 300 °C. Sulphide droplets and embayment of quartz grain margins in the pseudotachylite (Pt-C) matrix indicates a melt origin. Ductile shear sense criteria in the host mylonites are consistently sinistral, while those associated with the deformed pseudotachylite (Pt-M) layers are dextral. It appears therefore that the host mylonite/ultramylonite foliation experienced reactivated slip movement in the ‘semi-brittle’ zone when pseudotachylite was generated and subsequently ductilely deformed. The brittle pseudotachylite (Pt-C) layers were generated later at a shallower level, and at a lower temperature. They are spatially associated with a set of foliation-parallel brittle shears with sinistral-sense displacements. The multiple episodes of frictional melt generation within the Gavilgarh–Tan Shear Zone illustrate that it has a complex history of multiple reactivations. It therefore represents an important new area for the study of seismic behaviour of the upper crust along pre-existing structures and may facilitate a better geological understanding of the present seismic activity in the central Indian Shield.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Acharyya, S. K. & Roy, A. 2000. Tectonothermal history of the Central Indian Tectonic Zone and reactivation of major faults and shear zones. Journal of the Geological Society of India 55, 239–56.Google Scholar
Allen, A. R. 1979. Mechanism of frictional fusion in fault zones. Journal of Structural Geology 1, 231–43.CrossRefGoogle Scholar
Allen, J. L. 2005. A multi-kilometer pseudotachylite system as an exhumed record of earthquake rupture geometry at hypocentral depths (Colorado, USA). Tectonophysics 402, 3754.CrossRefGoogle Scholar
Bandyopadhyay, B. K., Chattopadhyay, A., Khan, A. S. & Huin, A. K. 2001. Assembly of the Rodinia Supercontinent: Evidences from the Sakoli and Sausar Belts in central India (Abstract). In Rodinia, Gondwana and Asia (ISGRA, Japan) (eds Santosh, M., Biju-sekhar, S. & Shabeer, K. P.), pp. 569–70. Gondwana Research 4.Google Scholar
Di Toro, G., Goldsby, D. L. & Tullis, T. E. 2004. Friction falls towards zero in quartz rock as slip velocity approaches seismic rates. Nature 427, 436–9.CrossRefGoogle Scholar
Di Toro, G., Hirose, T., Nielsen, S., Pennacchioni, G. & Shimamoto, T. 2006. Natural and experimental evidence of melt lubrication of faults during earthquakes. Science 311, 647–9.CrossRefGoogle ScholarPubMed
Di Toro, G., Nielsen, S. & Pennacchioni, G. 2005. Earthquake rupture dynamics frozen in exhumed ancient faults. Nature 436, 1009–12.CrossRefGoogle ScholarPubMed
Di Toro, G., Pennacchioni, G. & Teza, G. 2005. Can pseudotachylites be used to infer earthquake source parameters? An example of limitation in the study of exhumed faults. Tectonophysics 402, 320.CrossRefGoogle Scholar
Ferré, E. C., Allen, J. L. & Lin, A. (eds) 2005. Pseudotachylites and seismogenic friction. Tectonophysics 402, 1168.CrossRefGoogle Scholar
Fitz Gerald, J. D. & Stunitz, H. 1993. Deformation of granitoids at low metamorphic grade. I: reactions and grain size reduction. Tectonophysics 221, 269–97.CrossRefGoogle Scholar
Francis, P. W. 1972. The pseudotachylite problem. Comments on Earth Sciences (Geophysics) 3, 3553.Google Scholar
Gammond, J. F. 1983. Displacement features associated with fault zones: a comparison between observed examples and experimental models. Journal of Structural Geology 5, 3345.CrossRefGoogle Scholar
Golani, P. R., Bandyopadhyay, B. K. & Gupta, A. 2001. Gavilgarh–Tan Shear: a prominent ductile shear zone in central India with multiple reactivation history. Geological Survey of India Special Publication 64, 265–72.Google Scholar
Grocott, J. 1981. Fracture geometry of pseudotachylite generation zones: a study of shear fractures formed during seismic events. Journal of Structural Geology 3, 169–78.CrossRefGoogle Scholar
Harris, L. B. 1993. Correlation of tectonothermal events between the Central Indian Tectonic Zone and the Albany mobile Belt of western Australia, In Gondwana 8: assembly, evolution and dispersal (eds Findley, R. N., Unrug, R., Banks, M. R. & Veerers, J. J.), pp. 165–80. Rotterdam: A. A. Balkema.Google Scholar
Hobbs, B. E., Ord, A. & Teyssier, C. 1986. Earthquakes in the ductile regime? Pure and Applied Geophysics 142, 309–36.CrossRefGoogle Scholar
Hirth, G. & Tullis, J. 1992. Dislocation creep regimes in quartz aggregate. Journal of Structural Geology 14, 145–59.CrossRefGoogle Scholar
Holdsworth, R. E. 2004. Weak faults, rotten cores. Science 303, 181–2.CrossRefGoogle ScholarPubMed
Holdsworth, R. E., Butler, C. A. & Roberts, A. M. 1997. The recognition of reactivation during continental deformation. Journal of the Geological Society, London 154, 73–8.CrossRefGoogle Scholar
Imber, J., Holdsworth, R. E. & Butler, C. A. 2001. A reappraisal of the Sibson-Scholz fault zone model: the nature of the frictional to viscous (‘brittle–ductile’) transition along a long-lived, crustal scale fault, Outer Hebrides, Scotland. Tectonics 20, 601–4.CrossRefGoogle Scholar
Katz, M. B. & Promoly, C. 1979. India and Madagasscar in Gondwanaland based on matching Precambrian lineaments. Nature 279, 312–15.CrossRefGoogle Scholar
Koch, N. & Masch, L. 1992. Formation of Alpine mylonites and pseudotachylites at the base of the Silvretta nappe, Eastern Alps. Tectonophysics 204, 289306.CrossRefGoogle Scholar
Legros, F., Cantagrel, J. M. & Devouerd, B. 2000. Pseudotachylyte (frictionalite) at the base of the Arequipa volcanic landslide deposit (Peru): implications for emplacement mechanism. Journal of Geology 180, 601–11.CrossRefGoogle Scholar
Lin, A., Maruyama, T., Aaron, S., Michibayashi, K., Camacho, A. & Kano, K. 2005. Propagation of seismic slip from brittle to ductile crust: evidence from pseudotachylite of the Woodroffe thrust, central Australia. Tectonophysics 402, 2135.CrossRefGoogle Scholar
Lin, A., Sun, Z. & Yang, Z. 2003. Multiple generations of pseudotachylyte in the brittle to ductile regimes, Qinling-Dabie Shan ultrahigh-pressure metamorphic complex, central China. Island Arc 12 (4), 423–35.CrossRefGoogle Scholar
Maddock, R. H. 1983. Melt origin of fault generated pseudotachylites as demonstrated by textures. Geology 11, 105–8.2.0.CO;2>CrossRefGoogle Scholar
Magloughlin, J. F. 1989. The nature and significance of pseudotachylite from the Nason terrane, North Cascade Mountains, Washington. Journal of Structural Geology 11, 907–17.CrossRefGoogle Scholar
Magloughlin, J. F. 1992. Microstructural and chemical changes associated with cataclasis and friction melting at shallow crustal levels, the cataclasite–pseudotachylite connection. Tectonophysics 204, 243–60.CrossRefGoogle Scholar
Magloughlin, J. F. & Spray, J. G. 1992. Frictional melting processes and products in geological materials, introduction and discussion. Tectonophysics 204, 197206.CrossRefGoogle Scholar
McKenzie, D. & Brune, J. N. 1972. Melting on fault planes during large earthquakes. Geophysical Journal of the Royal Astronomical Society 53, 311–18.Google Scholar
McNulty, B. A. 1995. Pseudotachylite generation in semi-brittle and brittle regimes, Bench Canyon shear zone, central Sierra Nevada. Journal of Structural Geology 17, 1507–21.CrossRefGoogle Scholar
Melosh, H. J. 2005. The mechanics of pseudotachylite formation in impact events. In Impact Tectonics (eds Koeberl, C. & Henkel, H.), pp. 5580. Impact Studies series 6. Springer-Verlag.CrossRefGoogle Scholar
Passchier, C. W. 1982. Pseudotachylite and the development of ultramylonite bands in the Saint Barthelemy Massif, French Pyrenees. Journal of Structural Geology 4, 6979.CrossRefGoogle Scholar
Philpotts, A. R. 1964. Origin of pseudotachylites. American Journal of Science 262, 1008–35.CrossRefGoogle Scholar
Radhakrishna, B. P. & Naqvi, S. M. 1986. Precambrian continental crust and its evolution. Journal of Geology 94, 145–66.CrossRefGoogle Scholar
Ramsay, J. G. & Huber, M. I. 1983. The techniques of modern structural geology, vol. 2: Folds and fractures. Academic Press, 700 pp.Google Scholar
Reimold, W. U. & Gibson, R. L. 2005. ‘Pseudotachylite’ in large impact structures. In Impact Tectonics (eds Koeberl, C. & Henkel, H.), pp. 153. Impact Studies series 6. Springer-Verlag.Google Scholar
Rogers, J. J. W. 1996. A history of continents in the past three billion years. Journal of Geology 104, 91107.CrossRefGoogle Scholar
Roy, A. & Prasad, M. H. 2001. Tectonomagmatic history of Tan Shear Zone and its environs, a preliminary study. Geological Survey of India Special Publication 64, 273–87.Google Scholar
Roy, A. & Prasad, M. H. 2003. Tectonothermal events in Central Indian Tectonic Zone (CITZ) and its implications in Rodinian crustal assembly. Journal of Asian Earth Science 22, 115–29.CrossRefGoogle Scholar
Scholz, C. H. 1988. The brittle-plastic transition and the depth of seismic faulting. Geologische Rundschau 77/1, 319–28.CrossRefGoogle Scholar
Shand, S. J. 1916. The pseudotachylite of Parijs (Orange Free State). Quarterly Journal of the Geological Society of London 72, 198221.CrossRefGoogle Scholar
Sherlock, S. C., Watts, L. M., Holdsworth, R. E. & Roberts, D. 2004. Dating fault reactivation by Ar/Ar laserprobe: an alternative view of apparently cogenetic mylonite–pseudotachylite assemblages. Journal of the Geological Society, London 161, 335–8.CrossRefGoogle Scholar
Shimamoto, T. 1989. The origin of S-C mylonites and a new fault zone model. Journal of Structural Geology 11, 5164.CrossRefGoogle Scholar
Sibson, R. H. 1975. Generation of pseudotachylite by ancient seismic faulting. Geophysical Journal of the Royal Astronomical Society 43, 775–94.CrossRefGoogle Scholar
Sibson, R. H. 1977. Fault rocks and fault mechanisms. Journal of the Geological Society, London 133, 191213.CrossRefGoogle Scholar
Sibson, R. H. 1980. Transient discontinuities in ductile shear zones. Journal of Structural Geology 2, 165–71.CrossRefGoogle Scholar
Spray, J. G. 1987. Artificial generation of pseudotachylite using friction welding apparatus, simulation of melting on a fault plane. Journal of Structural Geology 9, 4960.CrossRefGoogle Scholar
Spray, J. G. 1995. Pseudotachylite controversy: fact or friction? Geology 23 (12), 1119–22.2.3.CO;2>CrossRefGoogle Scholar
Stipp, M., Stünitz, H., Heilbronner, R. & Schmid, S. M. 2002. The eastern Tonale fault zone: a ‘natural laboratory’ for crystal plastic deformation of quartz over a temperature range from 250 to 700 °C. Journal of Structural Geology 24, 1861–84.CrossRefGoogle Scholar
Strehlau, J. 1986. A discussion of the depth extent of rupture in large continental earthquakes. In Earthquake Source Mechanics (eds Das, S., Boatwright, J. & Scholz, C.), pp. 131–46. AGU Geophysical Monograph no. 37. Washington, DC.Google Scholar
Swanson, M. T. 1992. Fault structure, wear mechanisms and rupture processes in pseudotachylite generation. Tectonophysics 204, 223–42.CrossRefGoogle Scholar
Tse, S. & Rice, J. 1986. Crustal earthquake instability in relation to the depth variation of frictional slip properties. Journal of Geophysical Research 91, 9452–72.CrossRefGoogle Scholar
Wenk, H. R. 1978. Are pseudotachylites products of fracture or fusion? Geology 6, 507–11.2.0.CO;2>CrossRefGoogle Scholar
Wenk, H. R. & Weiss, L. E. 1982. Al-rich calcic pyroxene in pseudotachylite, an indicator of high pressure and temperature. Tectonophysics 84, 329–41.CrossRefGoogle Scholar
White, J. C. 1996. Transient discontinuities revisited: pseudotachylite, plastic instability and the influence of low pore fluid pressure on deformation processes in the mid-crust. Journal of Structural Geology 18, 1471–86.CrossRefGoogle Scholar
Yoshida, M., Bindu, R. S., Kagami, H., Rajesham, T., Santosh, M. & Shirahata, H. 1996. Geochronological constrains of granulite terranes of South Indian and their implication for the Precambrian assembly of Gondwana. Journal of South East Asian Earth Science 14, 137–47.CrossRefGoogle Scholar
Zechmeister, M. S., Ferre, E. C., Cosca, M. A. & Geissman, J. W. 2007. Slow and fast deformation in the Dora Maira Massif, Italian Alps: Pseudotachylites and inferences on exhumation history. Journal of Structural Geology 29, 1114–30.CrossRefGoogle Scholar