Professor Brad Pillans
Emeritus Professor
BSc(Hons), PhD (ANU)
email brad.pillans@anu.edu.au
call +61 2 61259644

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About

Lecturer in Geology, Victoria University of Wellington, New Zealand (1982-1993); Fellow/Senior Fellow, Research School of Pacific and Asian Studies, ANU (1994-1997); Senior Fellow, Research School of Earth Sciences, ANU (1998-2006); Professor, Research School of Earth Sciences, ANU (2006-present); President, Geological Society of Australia (2010-2012); President, Australian & New Zealand Geomorphology Group (2008-2011); Director, National Rock Garden (2010-present); Member, International Commission on Stratigraphy (2003-present); President, INQUA Stratigraphy & Chronology Commission (2003-2011); Member, Editorial Board of Quaternary Science Reviews (1996-2013); Honorary Fellow, Royal Society of New Zealand (2007); Honorary Life Fellow, International Union for Quaternary Research (2015); Distinguished Geomorphologist Medal, Australian & New Zealand Geomorphology Group (2019)

Affiliations

  Groups

Research interests

  • Quaternary stratigraphy
  • Geomorphology
  • Regolith geology
  • Paleoclimatology
  • Sea level change
  • Geochronology

Regolith-landform evolution in Australia

1. Where did all the quartz come from?

Many Cenozoic gravel deposits in SE Australia are dominated by quartz clasts (>95% quartz; Fig. 1), whereas modern stream gravels are polymict (various lithologies with ~10-15% quartz; Fig. 2). Two scenarios might explain the overwhelming dominance of quartz in older gravels: firstly, sediment supply may have been quartz dominated either through deep weathering of source rocks or breakage and loss of weaker (non-quartz) clasts during transport, or, secondly, polymict gravels may have been weathered after deposition to leave residual quartz clasts. The research is aimed at evaluating which scenario is most likely.

Figure 1. Quartz dominated Cenozoic gravels

Figure 2. Polymict modern bedload gravels

2. The age and origin of zebra rock and print stone in Western Australia

Two unusual, decorative rocks, known as zebra rock and print stone occur near Kununurra and Mt Tom Price in Western Australia. Both rocks are characterised by distinctive red banding caused by hematite pigmentation, within variably silicified siltstone (Figs. 3 and 4). A paleomagnetic study of the print stone (Abrajevitch, Pillans & Roberts. 2014. Geophysical Journal International v.199, 658-672) allows the age(s) of pigmentation to be determined. By comparison with the Australian apparent polar wander path, magnetic remanence directions in a uniformly distributed pigment yield a Miocene age (15-25 Ma), while there are two age options for the distinctive ‘newsprint’ pigmentation – Mesoproterozoic (~1.5 Ga) or middle Carboniferous (~320-310 Ma). A paleomagnetic study of the zebra rock is underway.

Figure 3. Zebra rock, Mt Tom Price, WA

Figure 4. Print stone, Mt Tom Price, WA

Projects

Location

Jaeger 8, Room 3.07

Publications

  • Westgate, J.A., Pillans, B.J., Alloway, B.V., Pearce, N.J.G., Simmonds, P. (2021). New fission-track ages of Australasian tektites define two age groups: discriminating between formation and reset ages. Quaternary Geochronology, 66, 101113. 
  • Macphail, M., Pillans, B., Hope, G. & Clark, D. (2020). Extirpations and extinctions: a plant microfossil-based history of the demise of rainforest and wet sclerophyll communities in the Lake George basin, Southern Tablelands of NSW, south-east Australia. Australian Journal of Botany, 68, pp. 208-228. 
  • Abrajevitch, A., Pillans, B., Roberts, A.P. & Kodama, K. (2018). Magnetic properties and paleomagnetism of Zebra Rock, Western Australia: chemical remanence acquisition in hematite pigment and Ediacaran field behavior. Geochemistry, Geophysics, Geosystems, 19, pp. 732-748. 
  • Johnson, M.O., Mudd, S.M., Pillans, B., Spooner, N.A., Fifield, L.K., Kirkby, M.J. & Gloor, M. (2014). Quantifying the rate and depth dependence of bioturbation based on optically stimulated luminescence (OSL) dates and meteoric 10Be. Earth Surface Processes & Landforms, 39,  pp. 1188-1196.
  • Pillans, B. & Fifield, L.K. (2013). Erosion rates and weathering history of rock surfaces associated with Aboriginal rock art engravings (petroglyphs) on Burrup Peninsula, Western Australia, from cosmogenic nuclide measurements. Quaternary Science Reviews, 69, pp. 98-106.
  • Pillans, B. & Gibbard, P. (2012). The Quaternary Period. In: Gradstein, F., Ogg, J., Schmitz, M. & Ogg, G. (Eds). (2012). The Geological Time Scale 2012. Elsevier, Amsterdam, pp. 979-1010.
  • Bishop, P. & Pillans, B. (Eds). (2010). Australian Landscapes. Geological Society of London Special Publication 346, 328 pp.
  • Smith, M.L, Pillans, B.J. & McQueen, K.G. (2009). Palaeomagnetic evidence for periods of intense oxidative weathering, McKinnons mine, Cobar, NSW. Australian Journal of Earth Sciences, 56, pp. 201-212.
  • Pillans, B. (2008). Regolith through time. In: Scott, K.M. & Pain, C.F. (Eds.). Regolith Science. CSIRO Publishing, Collingwood, pp. 7-29.
  • Pillans, B. (2007). Pre-Quaternary landscape inheritance in Australia. Journal of Quaternary Science, 22, pp. 439-447.
  • Pillans, B., Alloway, B.V., Naish, T. R., Westgate, J.A., Abbott, S.T. & Palmer, A. (2005). Silicic tephras in Pleistocene shallow marine sediments of Wanganui Basin, New Zealand. Journal of the Royal Society of New Zealand, 35, pp. 43-90.
  • Pillans, B., Williams, M., Cameron, D., Patnaik, R., Hogarth, J., Sahni, A., Sharma, J.C., Williams, F. & Bernor, R.L. (2005). Revised correlation of the Haritalyangar magnetostratigraphy, Indian Siwaliks: implications for the age of the Miocene hominids Indopithecus and Sivapithecus, with a note on a new hominid tooth. Journal of Human Evolution, 48, pp. 507-515.
  • Pillans, B. & Naish, T. (2004). Defining the Quaternary. Quaternary Science Reviews, 23, pp. 2271-2282.