Members

Dizzy PortraitDr Richard "Dizzy" Gillespie

BSc(Hons) Physical Chemistry, University of Sydney 1969; PhD Physical Chemistry, University of Sydney 1976

Email:     dizheights@gmail.com
Phone:   +61 2 6677 9500

Dizzy Heights
Ripps Road
Stokers Siding NSW 2484

Position
  • Honorary Fellow

Professional Profile
  • Qualifications: BSc(Hons) Physical Chemistry, University of Sydney 1969; PhD Physical Chemistry, University of Sydney 1976
  • Regular reviewer for Radiocarbon; Palaeo 3; Quaternary Science Reviews; Science; American Antiquity.

Key Research Interests
  • Radiocarbon (14C) dating of specific molecules
  • Freshwater shell dating
  • Rock art dating
  • Lake sediment dating
  • Modern human colonisation of islands and continents
  • Timimg and cause(s) of Late Quaternary megafauna extinctions

Chemical decontamination methods for 14C dating

Since 1970, when I started building a liquid scintillation radiocarbon dating laboratory at Sydney University, my research has been mostly involved with the chemistry of samples destined for 14C and stable isotope analysis. From 1980, I ran the sample pretreatment and graphite production laboratory for the Accelerator Mass Spectrometry (AMS) dating facility in Oxford, and continued with research positions in AMS chemistry at the University of Arizona and the Australian National University. These appointments, and sporadic excursions since, have afforded diverse multi-disciplinary research opportunities with fieldwork in Africa, Europe, North America and Australia.

The application of  AMS to the 14C dating of sub-milligram samples has facilitated new avenues for superior chemistry, and better decontamination leads to better dates. This is particularly the case for specific molecule dating, such as the isolation of cellulose from wood or the separation of single amino acids from bone collagen, and stable isotope measurements also contribute to the establishment of sample integrity and purity. Such developments increase the reliability of 14C dates, which consequently improve and refine chronologies for human and other animal migrations, landscape evolution and climate change.

Representative publications
  • Rodríguez-Rey, M, Herrando-Pérez, S, Gillespie, R, Jacobs, Z, Saltré, F, Brook, BW, Prideaux, GJ, Roberts, RG, Cooper, A, Alroy, J, Miller, GH, Bird, MI, Johnson, CN, Beeton, N, Turney, CSM, Bradshaw, CJA. (2015) Criteria for assessing the quality of Middle Pleistocene to Holocene vertebrate fossil ages. Quaternary Geochronology 30, 69-79.
  • Bowler, J.M., Gillespie, R., Bolkjovac, K. & Johnson, H. 2012 Wind v Water: Glacial Maximum records from the Willandra Lakes. In S.G. Haberle and B. David (ed.), Peopled Landscapes: Archaeological and Biogeographic Approaches to Landscapes. Terra Australis 34: 271-296.
  • Gillespie, R., Fifield, L.K., Levchenko, V. & Wells, R. 2008. New 14C ages on cellulose from Diprotodon gut contents: explorations in oxidation chemistry and combustion. Radiocarbon 50: 75-81.
  • Stevenson, J., Gillespie, R., Hope, G., Jacobsen, G., Fallon, S. & Levchenko, V. 2010. The archaic and puzzling record of Lake Xere Wapo, New Caledonia. In S. Haberle, J. Stevenson & M. Prebble (ed.) Altered Ecologies: fire, climate and human influence on terrestrial landscapes. Terra Australis 32: 381-393.
  • Williams, M.A.J., Bishop, P.M., Dakin, F.M. & Gillespie, R. 1977. Late Quaternary lake levels in Southern Afar and the adjacent Ethiopian Rift. Nature 267: 690-693. 
  • Gillespie R., Fink, D., Petchey, F. & Jacobsen, G. 2009. Murray-Darling basin freshwater shells: riverine reservoir effect. Archaeology in Oceania 44: 107-111.

RG Eroding midden
Shell midden eroding from lunette at Lake Mungo, NSW (photo: Richard Gillespie)
Dizzy Ethiopia
Camp at Gadeb, Ethiopia, with excavations directed by Desmond Clark in 1975 (photo M. Williams).


Global human colonisation and megafauna extinctions

Radiocarbon dating has been the mainstay for estimating when modern humans arrived in new landscapes and when previously-resident large animals became extinct. However, directly dating the skeletal remains of humans and other animals by radiocarbon has frequently been compromised by small samples and inadequate decontamination chemistry. AMS measurement solves the sample size problem, while new chemistry for collagen, ultrafiltered gelatin and single amino acid separations address issues of specificity, reliability and accuracy.

Human and now-extinct megafauna bones preserve well in cold and temperate environments at high northern latitudes, but the semi-arid and arid environments of Australia are much less conducive to protein survival. Despite decades spent analysing ca. 150 extinct megafauna bones and teeth from mainland Australian sites, I have never found any collagen. Recently, my attention has shifted to Tasmania where extinct animal bones with well-preserved collagen have been discovered.

In addition to laboratory bone analyses, I compile lists of radiocarbon age estimates on modern human arrivals and megafauna extinctions for Australia, the Americas and oceanic islands. Calibrating the dates to make them calendar ages comparable with luminescence and other dating methods, and examining the intersections of these databases with coeval climate change leads to probable cause assignment for the extinctions.

Representative publications
  • Saltré, F, M Rodriguez-Rey, BW Brook, CN Johnson, CSM Turney, J Alroy, A Cooper, N Beeton, MI Bird, DA Fordham, R Gillespie, S Herrando-Pérez, Z Jacobs, GH Miller, D Nogués-Bravo, GJ Prideaux, RG Roberts, CJA Bradshaw. (2016) Climate change not to blame for late Quaternary megafauna extinctions in Australia. Nature Communications 7, DOI: 10.1038/ncomms10511
  • Johnson, CN, J Alroy, NJ Beeton, MI Bird, BW Brook, A Cooper, R Gillespie, S Herrando-Pérez, Z Jacobs, GH Miller, GJ Prideaux, RG Roberts, M Rodríguez-Rey, F Saltré, CSM Turney, CJA Bradshaw. (2016) What caused extinction of the Pleistocene megafauna of Sahul? Proceedings of the Royal Society B 283, 20152399. http://dx.doi.org/10.1098/rspb.2015.2399 
  • Gillespie, R.,Camens, A.B., Worthy, T.H., Rawlence, N.J., Reid, C., Bertuch, F., Levchenko, V. & Cooper, A. 2012. Man and megafauna in Tasmania: closing the gap. Quaternary Science Reviews 37: 38-47.
  • Gillespie, R., Brook, B.W. &  Baynes, A. 2006. Short overlap of people and megafauna in Pleistocene Australia. Alcheringa Special Issue 1: 163-185.
  • Gillespie, R. 2008. Updating Martin’s global extinction model. Quaternary Science Reviews 27: 2522-2529.
  • Bada, J.L., Gillespie, R., Gowlett, J.A.J. & Hedges, R.E.M. 1984. Accelerator mass spectrometric based radiocarbon ages of amino acid extracts from several Palaeoindian skeletons from California. Nature 312: 442-444.

Dizzy radiocarbon graph                      
Radiocarbon results on extinct megafauna bone collagen and on charcoal from archaeological sites in Tasmania (Gillespie et al., 2012).

      Richard Gillespie 2       Richard Gillespie 3

Left: Excavation of megafauna site on Kangaroo Island, South Australia, directed by Rod Wells in 2004 (photo: Dizzy). Right: Mammoth molar from the Clovis type site, Blackwater Draw Locality 1, New Mexico (photo: Richard Gillespie).


Research Projects

My research involves collaboration with scientists in radiocarbon and other dating methods, archaeologists, geologists, palynologists and palaeoecologists.


Current projects

Potential Honours or PhD topic
  • Australian megafauna: isotopes in single amino acids from bone collagen

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Last reviewed: 21 June, 2016