Two PhD projects available on the earliest life on Earth

 

Two PhD projects to work on the earliest life on Earth and the setting for the Origin of Life

Where: Australian Centre for Astrobiology, University of New South Wales Sydney, Australia

Supervisor: Prof. Martin Van Kranendonk

 

Two PhD projects are available to be filled at the Australian Centre for Astrobiology, under the supervision of ACA director Prof. Martin Van Kranendonk, and internationally recognised expert on the early Earth and on early life. Both projects are funded by an Australian Research Council Discovery Project awarded to Van Kranendonk “A terrestrial hot spring setting for the origin of life? Darwin’s Warm Little Pond revisited”.

The ARC project aims to test the proposal that a terrestrial hot spring field could have been the setting for the origin of life, in preference over the currently favoured site at deep sea vents (see Van Kranendonk et al., 2017: Scientific American, August 2017, p. 28-35). This will be achieved through a world-first, integrated, and multi-disciplinary study of the rocks, fluids, and molecules that together make up ancient to modern hot spring systems, and experiments on prebiotic organic chemistry using early Earth materials. The project is run in collaboration with leading research scientists from The University of Western Australia (A/Prof Marco Fiorentini; metallogeny, hydrothermal fluids, alteration geochemistry), The University of Auckland (Prof. Kathy Campbell; hotspring facies, fluids, architecture, biosignatures), and the University of California at Santa Cruz (Prof. David Deamer; prebiotic organic geochemistry, hot springs; wet-dry cycling, experiments).

PhD1: This project will investigate the nature of the hydrothermal alteration that underlies the ancient hot spring setting represented by the 3.48 billion-year-old Dresser Formation in the North Pole Dome area of the Pilbara Craton, northwestern Australia. This site has recently been discovered to contain deposits from ancient terrestrial hot springs that contain a range of biosignatures (Djokic et al., 2017: Nature Communications 8:15263). The surficial hot springs were fed by a dense swarm of large black chert+/-barite hydrothermal veins that have altered the footwall to classic epithermal mineral assemblages. Significantly, we have also discovered that this area contains all of the most important elements required for prebiotic chemistry, including concentrations of Boron, Zn, Mn, etc.

This project will investigate the 4-dimensional history of the Dresser hydrothermal fluid system and how it was responsible for concentrating the elements required for prebiotic chemistry. Fieldwork will involve mapping the alteration assemblages and collecting samples for geochemical analyses that will enable the generation of element mobilisation maps that show show the transfer and concentration of elements. Analyses will also include O, and Li and B isotopes of fresh and hydrothermally altered basaltic rocks to determine the amount of chemical alteration and/or surficial weathering. The different alteration assemblages will then be used as substrates in organic geochemistry experiments to be conducted in the Deamer lab, aimed at better understanding the influence of mineralogy and real-world Archean materials on generating complexity in hot spring systems and the formation of prebiotic organic molecules. (Supervisors Van Kranendonk and Fiorentini).

PhD2: This project will focus on the active hot springs in the Rotorua district of New Zealand (north Island). Specifically, we are interested in the fluid chemistries, energetics, and biological components of zones of mixing between hot spring pools that have different chemistry, pH, Eh, etc. The aim here is to better understand the potential of mixing zones for promoting increased complexity as applies to the origin of life. This project will involve fieldwork in New Zealand, including mapping of hot spring systems, and sample collection of fluids, substrates, and microbial diversity of different parts of the system, particularly mixing zones. (Supervisors Van Kranendonk and Campbell).