We have recently been funded to expand our research in the following field:

“Oxygenating the Earth: using innovative techniques to resolve the timing of the origin of oxygen-producing photosynthesis in cyanobacteria”.

It is almost universally accepted that the oxygenation of the previously anaerobic Earth was driven by the oxygenic photosynthesis of cyanobacteria. But there are inconsistencies of hundreds of millions of years in the various lines of evidence for the timing of the oxygenation process.

We aim to reduce these inconsistencies by focusing on the record preserved in the Fortescue Group of West Australia, a remarkably well-preserved set of rocks reliably dated as lying in the disputed time range of the rise to prominence of cyanobacteria. At the same time we will use genomics to estimate the time of origin of cyanobacteria.

We will fund several PhD students in this program, with two positions being available immediately. You will be part of a team of five internationally respected scientists (Malcolm Walter, Brett Neilan, Simon George, Roger Summons and Bill Schopf) and two other PhD students, as well as your other colleagues in the Australian Centre for Astrobiology. Overseas applicants should note that the applicable doctoral programs are research-only, with no obligatory coursework. The available projects are:

1. Sedimentology and morphological palaeobiology of the Fortescue Group

PhD project available at the University of New South Wales, Sydney
Supervisor: Prof. Malcolm Walter, University of New South Wales, Sydney.
Co-supervisor:     Prof. Bill Schopf, UCLA

Your PhD project will involve detailed sedimentological studies in the field across the whole of the northern Hamersley Basin to refine palaeoenvironmental interpretations and to collect a highly targeted new set of samples. You will use the latest microscopic techniques to study the stromatolites and microfossils of the Fortescue Group to assess their biological affinities.

As well as the excellent facilities at UNSW you will work in the Schopf laboratory at UCLA using newly proven techniques. Confocal laser scanning microscopy (CLSM) and Raman imagery techniques recently introduced to Precambrian paleobiology can provide definitive data about the three-dimensional morphology, chemistry, and preservational history of ancient rock-embedded organic-walled fossils and the mineral matrix in which they are enclosed.  The techniques are complementary: three-dimensional CLSM images are derived from laser-induced fluorescence of the material analyzed (for the kerogen in rocks, its interlinked polycyclic aromatic hydrocarbons), whereas 2D-and 3D-Raman images provide direct analyses of the molecular-structural composition and geochemical maturity of such kerogen.  Both techniques are rock penetrating (to ~150 mm), non-destructive, and confocal. Both yield submicron spatial resolution (for CLSM <0.2 mm; for Raman, ~0.7 mm).  And the two techniques can be used in sequence to analyze the same individual specimen, providing mutually reinforcing data in three dimensions and at high spatial resolution. 

In the research proposed here, CLSM and Raman imagery will be used together to spatially correlate the cellular morphology and molecular-structural composition of detected microscopic fossils and to identify, document, and establish the biological origin of wispy microbe-like relict (palimpsest) fabrics we have already discovered in cherty carbonate Fortescue stromatolites.
A scholarship paying A$20,427 (2009 figures) will be available from January 2010 for 3.5 years.

For further information about this project, please contact:
Prof. Malcolm Walter, UNSW: malcolm.walter@unsw.edu.au 
Telephone: +61-2-9385-3761

2. Demonstrating the syngeneity and interpreting the palaeobiology of hydrocarbon biomarkers in the Fortescue Group (2.7 Ga)

Demonstrating the syngeneity and interpreting the palaeobiology of hydrocarbon biomarkers in the Fortescue Group (2.7 Ga)

PhD project available at Macquarie University, Sydney
Supervisor: A/Prof. Simon George, Macquarie University
Co-supervisors:    Prof. Roger Summons, MIT, USA
                           Prof. Malcolm Walter, University of NSW, Sydney

Your PhD project will apply new and innovative organic geochemical techniques to the study of the Fortescue Group to critically assess the evidence for the presence of cyanobacteria at 2.7-2.8 Ga.

A suite of Fortescue Group rocks, mainly from cores, will be analysed using solvent extraction, fluid inclusion geochemistry and novel pyrolysis methods so as to provide a dataset of molecular geochemical parameters related to the Precambrian organic matter, and especially to the question of presence/absence of cyanobacteria.

All techniques used will concentrate on the key issue of proving syngeneity of detected biomarkers. This organic geochemical study will be carried out in close conjunction with the microscopy and Raman imagery techniques and the broader sedimentological study, thus establishing direct links and associations amongst these datasets.

You will gain experience in several organic geochemical techniques, especially to those pertaining to the exciting, topical and controversial techniques for obtaining biomarker evidence from Archaean rocks. You will undertake fieldwork in NW Australia (Pilbara) in order to obtain outcrop material to supplement core material. Macquarie University in Sydney has a new and well-equipped organic geochemistry laboratory. In addition, some analyses will also be carried out at other labs in Australia (e.g. CSIRO) and in the USA (e.g. MIT).

A scholarship paying A$20,427 (2009 figures) will be available from January 2010 for 3.5 years; the scholarship also covers fees for overseas applicants.

For further information about this project, please contact:
A/Prof. Simon George, Macquarie University:  

Simon.George@mq.edu.au          Telephone: +61-2-9850-4424
or Prof. Malcolm Walter, UNSW: malcolm.walter@unsw.edu.au
Telephone: +61-2-9385-3761