gorman crags antarctica mt jacqueline antarctica greenland zodiac

DR GEOFF NICHOLS
Honorary Associate, Macquarie University, GEMOC, Dept of Earth Sciences, Sydney NSW 2109 Email mE

RESEARCH SUMMARY
My research interests are directed at understanding lower crustal processes. My approach combines field-based mapping of high-grade rocks in Antarctica and Greenland, with high-pressure piston-cylinder experiments aimed at quantifying mineral and vapour partitioning as well as the melting behaviour of rocks. The experimental melting studies of pelagic sediments, and basanite, are directed at understanding magma genesis in subduction regimes. The integration of structural and petrologic data is one of my emphases, and recently I have combined this approach with age constraints provided by isotopic ion-probe dating.

Grt-Spl, Grt-Crd, Crd-Spl THERMOBAROMETRY

garnet insitu

CURRENT RESEARCH COLLABORATIONS

  • developing new analytical ICPMS laser ablation techniques in the piston-cylinder study of trace-element partitioning behaviour between hydrous fluids and mantle melts (with Assoc. Prof. T. Green, GEMOC Macquarie Uni).
  • radiogenic isotope dating of east Antarctic granulite-grade mylonites (with Dr A. Fahey, NIST Washington, USA)
  • applying ICPMS laser ablation in-situ measurement of trace-element geochemistry of garnets to model the pressure-temperature evolution of Greenland rocks (with Dr N. Pearson, GEMOC Macquarie Uni)
  • presenting geochemical evidence for magma differentiation in carbonatitic and picritic rocks, east Antarctica (with Drs G. Yaxley and V. Kamenetsky, RSES Canberra & Uni Tasmania)
  • understanding the pressure-temperature-time evolution of west Greenland granulite-amphibolite crustal rocks (with Dr L. Kreigsman, Uni NSW and the Danish Lithosphere Centre, Copenhagen)
  • deciphering the pressure-temperature crustal evolution of Himalayan rocks across the Main Central Thrust, (with Drs S. Johnson and N. Pearson, GEMOC Macquarie Uni)

    UNDERGRADUATE TEACHING
    Currently I am involved with teaching units in first, second and third year, including:

  • Materials of the Earth (GEOS115),
  • Introduction to field geology (GEOS224),
  • Geological structures (GEOS255),
  • Igneous and metamorphic petrology (GEOS395), &
  • Field geology and mapping (GEOS307).

    RECENT PUBLICATIONS

  • van Gool, J. A. M., Kriegsman, L. M., Marker, M. & Nichols, G. T. 1999.
    Thrust stacking in the inner Nordre Stromfjord area, West Greenland: significance for the tectonic evolution of the Palaeoproterozoic Nagssugtoqidian orogen. Precambrian Research 93:71-85.

  • Nichols, G. T. & Wiebe, R. A., 1998.
    Desilication veins in the Cadillac Mountain granite (Maine, USA): a record of reversals in the SiO2 solubility of H2O-rich vapour released during subsolidus cooling. Journal of Metamorphic Geology 16:795-808.

  • Nichols, G. T., Wyllie, P. J. & Stern, C. R., 1996.
    Experimental melting of pelagic sediment, constraints relevant to subduction.
    in Subduction Top to Bottom, G. E. Bebout, D. Scholl, S. Kirby, J. P. Platt (eds), AGU Monograph, 96:293-298.

  • Nichols, G. T., 1995.
    The role of mylonites in the uplift of an oblique lower crustal section, East Antarctica. Journal of Metamorphic Geology, 13:223-238.

  • Nichols, G. T., Wyllie, P. J. & Stern, C. R., 1994.
    Subduction zone melting of pelagic sediments constrained by melting experiments. Nature, 371:785-788.

  • Nichols, G. T., Berry, R. F. & Green, D. H., 1992.
    Internally consistent gahnitic spinel-cordierite-garnet equilibria in the FMASHZn system: geothermobarometry and applications.Contributions to Mineralogy and Petrology, 111:362-377.

  • Nichols, G. T. & Berry, R. F., 1991.
    A decompressional P-T path, Reinbolt Hills, East Antarctica. Journal of Metamorphic Geology, 9:257-266.

    SELECTED ABSTRACTS

  • Nichols, G. T. & Pearson, N. J., 1996.
    Trace element zonation in granulite-facies garnet porphyroblasts, Ikertoq, Nagssugtoqidian Orogen, west Greenland. Proceedings of the 2nd DLC Workshop on Nagssugtoqidian geology, 39-41.

  • Nichols, G. T. & Fahey, A., 1996.
    Preliminary monazite ages of second generation mylonites, Prince Charles Mountains, East Antarctica. Geological Society of Australia, Abstracts No. 41, p 316, 13th AGC, Canberra.

  • Nichols, G. T., Green, T. H., Pearson, N. & Sharma, A.,1996.
    A new analytical technique for measuring element partitioning between experimental vapour and melt. Geological Society of Australia, Abstracts No. 41, p 317, 13th AGC, Canberra.

  • Kriegsman, L., Nichols, G.T., Van Gool, J. & Marker, M., 1996.
    P-T-D evolution of a transpressional orogen: a structural and petrological traverse through the Nagssugtoqidian Orogen, Western Greenland. Meeting of the German Mineralogical Society, Kiel, Germany, 9-12 Sept. European Journal of Mineralogy, Beiheft 8:164.

  • Kriegsman, L. & Nichols, G.T., 1996.
    Low-P partial melting in the Nordre Isortoq area: Petrology of spinel-bearing, partially melted pelites. Proceedings of the 2nd DLC Workshop on Nagssugtoqidian geology, 42-45.

    GEMOC Geology
    School of Earth Sciences Page Macquarie University
    html: R Firkin 11th march 1997 update Jan 99