1887
ASEG2006 - 18th Geophysical Conference
  • ISSN: 2202-0586
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Abstract

IC and b spacing values of white micas in slates from the Tabberabbera Zone have been used to assess the P and T conditions of metamorphism. IC values range from 0.19 to 0.34, with upper anchizone conditions (T = 250–300° C) over much of the zone, and a belt of epizone rocks (T > 300° C) along the eastern edge of the zone. Average b spacing is 9.023 ± 0.006 ¬, with no discernible trends across the zone. This value is typical of medium-P metamorphic belts, with a geothermal gradient of about 30° C/km. For a temperature of 300° C, this equates to a pressure of ~0.3 GPa, and a depth of about 10 km, the same as migmatites of the Omeo Zone, adjacent to the east. The medium-P metamorphism is difficult to fit to an accretionary prism origin for the zone, unless an active spreading ridge was subducted under it.

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2006-12-01
2026-01-22

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References

  1. Fergusson, C.L. 1987. Early Palaeozoic back-arc deformation in the Lachlan Fold Belt, southeastern Australia: implications for terrane translation in eastern Gondwanaland. In Leitch, E.C. and Scheibner, E. eds, Terrane Accretion and Orogenic Belts, American Geophysical Union Geodynamics Series 19, 39-56.
  2. Fergusson, C.L. and Fanning, C. M. 2002. Late Ordovician stratigraphy, zircon provenance and tectonics, Lachlan Fold Belt, southeastern Australia. Australian Journal of Earth Sciences 49, 423-436.
  3. Fergusson, C.L., Fanning, C.M., Phillips, D. and Ackerman, B.R. 2005. Structure, detrital zircon U-Pb ages and 40Ar/39Ar geochronology of the Early Palaeozoic Girilambone Group, central New South Wales: subduction, contraction and extension associated with the Benambran Orogeny. Australian Journal of Earth Sciences 52, 137-159.
  4. Foster, D.A., Gray, D.R. and Bucher, M. 1999. Chronology of deformation within the turbidite-dominated Lachlan Orogen: implications for the tectonic evolution of eastern Australia and Gondwana. Tectonics 18, 542-485.
  5. Glen, R.A. 2005. The Tasmanides of eastern Australia. In Vaughan, A.P.M., Leat, P.T. and Pankhurst, R.J. (eds) Terrane Processes at the Margins of Gondwana. Geological Society, London, Special Publications, 246, 23-96.
  6. Guidotti, C.V. & Sassi, F.P. 1986. Classification and correlation of metamorphic facies series by means of muscovite b0 data from low-grade metapelites. Neues Jarhbuch fur Mineralogie Abhandlungen 153, 363-380.
  7. Kisch H. J., 1991. Illite crystallinity: recommendations on sample preparation, X-ray diffraction settings and inter-laboratory samples. J. Metamorph. Geol. 9, 665-670.
  8. Kubler, B. 1968. Evaluation quantitive de metamorphisme par la crystallinité de l’illite. Centre de Recherche de Pau, Societé National des Pétroles d’Aquitaine, Bulletin 2, 385-397.
  9. Morand, V.J. 1990. Low-pressure regional metamorphism in the Omeo Metamorphic Complex, northeastern Victoria, Australia. Journal of Metamorphic Geology 8, 1-12.
  10. Morand, V.J. and Gray, D.R. 1991. Major fault zones related to the Omeo Metamorphi Complex, northeastern Victoria. Australian Journal of Earth Sciences 38, 203-221.
  11. Morand, V.J., Simons, B.A., Taylor, D.H., Cayley, R.A., Maher, S., Wohlt, K.E. and Radaojkovic, A.M. 2005. Bogong 1:100 000 map area geological report. Geological Survey of Victoria Report 125.
  12. Osozawa, S., Takeuchi, H. and Koitabashi, T. 2004. Formation of the Yakuno ophiolite; accretionary subduction under medium-pressure-type metamorphic conditions. Tectonophysics 393, 197-219.
  13. Sassi, F.and Scolari, A. 1974. The b0 value of the potassium white micas as a barometric indicator in low grade metamorphism of pelitic schists. Contributions to Mineralogy and Petrology 45, 143-152.
  14. Soesoo, A., Bons, P.D., Gray, D.R. and Foster, D.A. 1998. Divergent double subduction: tectonic and petrologie consequences. Geology 25, 755-758.
  15. Spaggiari, C.V., Gray, D.R. and Foster, D.A. 2002. Blueschist metamorphism during accretion in the Lachlan Orogen, southeastern Australia. Journal of Metamorphic Geology 20, 711-726.
  16. Spaggiari, C.V., Gray, D.R., Foster, D.A. and McKnight, S. 2003. Evolution of the boundary between the western and central Lachlan Orogen: implications for Tasmanide tectonics. Australian Journal of Earth Sciences 50, 725-749.
  17. VandenBerg, A.H.M., Willman, C.E., Maher, S., Simons, B.A., Cayley, R.A., Taylor, D.H., Morand, V.J., Moore, D.H. and Radojkovic, A.M. 2000. The Tasman Fold Belt System in Victoria. Geological Survey of Victoria Special Publication.
  18. VandenBerg, A.H.M., Willman, C.E., Morand, V.J., McHaffie I.W., Simons, B.A., Quinn, C. and Westcott, A.L. 2004. Buffalo 1:100 000 map area geological report, Geological Survey of Victoria Report 124.
  19. Watson, J.M. and Gray, D.R. 2001. Character, extent and significance of broken formation for the Tabberabbera Zone, central Lachlan Orogen. Australian Journal of Earth Sciences 48, 943-954.
  20. Xu, G., Will, T.M. and Powell, R. 1994. A calculated petrogentic grid for the system K2O–FeO–MgO–Al2O3–SiO2–H2O, with particular reference to contact metamorphosed pelites. Journal of Metamorphic Geology 12, 99-119.
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  • Article Type: Research Article
Keyword(s): Benambran Orogeny; illite crystallinity; Lachlan Fold Belt; metamorphism; Tabberabbera Zone

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