Mantle dynamics and ore deposits

A. Cruden, M. Fiorentini, S. Barnes, A. Bunger, C. Jackson: Supported by ARC DP (commencing 2019)

Summary:  This project aims to investigate where, how and why narrow finger-like conduits form in lithosphere-scale magma plumbing systems by a novel integration of field surveys, three dimensional reflection seismic data, laboratory experiments and rock fracture mechanics. The project expects to generate new knowledge on the formation and location of highly valuable ore deposits of nickel, copper, cobalt and platinum group elements, which are preferentially trapped in poorly understood finger-like magma conduits.

Unveiling the fine structure of the Australian continent using ocean waves

Y. Yang, J.C. Afonso, N. Rawling, M. Ritzwoller, F. Niu: Supported by ARC DP (commencing 2019)

Summary:  This project aims to develop new methods to better image lithospheric and uppermantle structures by using noise from ubiquitous ocean waves, and then use these methods to illuminate fine-scale lithospheric-asthenospheric structures in Australia, from the surface to the upper mantle. Imaging the Earth’s structure using seismic tomography is one of the most fundamental tasks of geoscience. Conventional earthquake-based seismic tomography has difficulties in deciphering fine-scale lithospheric structures. The images from this project will provide a better understanding of the nature of intraplate earthquakes and volcanoes, and improve the assessment of intraplate seismic and volcanic hazards in Australia.

A terrestrial hot spring setting for the origin of life? Darwin’s Warm Little Pond revisited

M. Van Kranendonk, M. Fiorentini, K.A. Campbell, D. Deamer: Supported by ARC DP (commenced 2018)

Summary:  This Project aims to test the proposal that a terrestrial hot spring field could have been the setting for the origin of life, in preference to the currently favoured site at deep sea vents. This will be achieved by: 1) detailed characterisation of the only known, truly ancient, inhabited terrestrial hot spring analogue in the geological record – the 3.5 billion-year-old Dresser Formation, Western Australia; 2) comparison of this ancient analogue with active hot spring fields in New Zealand; and 3) experimental research on prebiotic organic chemistry using Dresser materials and active hot spring fluid chemistries. Results will be used to develop a terrestrial origin of life setting and assist in the search for life on Mars.

Engineering planetary habitability: Earth’s critical first billion years

A. Nutman, V. Bennett, M. Van Kranendonk: Supported by ARC DP (commenced 2017)

Summary: This project aims to establish the critical physical-chemical factors in the early surface environment and tectonic regime that supported early life and continuing habitability. Life was established on Earth within the first billion years of its 4.56-billion-year history. This project’s integrated geological and geochemical study will investigate this period’s rare sedimentary and volcanic record, including the oldest fossiliferous sequences discovered recently, to show how the early Earth’s chemistry supported life and evolution. The project expects to enhance understanding of why life prospers on some habitable zone planets but not on others.

Mechanisms of proxy uptake in biominerals

D. Jacob, S. Eggins, R. Wirth: Supported by ARC DP ( commenced 2016 )

Summary:  This project plans to combine nano-analytical and aquaculture methods to develop new models that improve the reliability of paleoclimate reconstructions. The compositions of shells and skeletal materials of marine invertebrates are essential archives for quantifying temperatures and environmental conditions before modern climate records began. However, their reliability relies on understanding their formation. Emerging knowledge from material sciences indicates that these biocarbonates form via transient precursors rather than direct precipitation from seawater, profoundly affecting their interpretation. This project plans to transfer this new understanding to the earth sciences using nanoscale analytical methods including in vitro geochemical partitioning experiments. This would enable realistic models for geochemical proxy behaviour to be developed, significantly improving paleoclimate interpretations and assessments of ocean acidification effects on marine calcifiers.

The roles of carbon, water and nitrogen in the development of plate tectonics as drivers of mantle evolution

S. Foley: Supported by ARC Laureate Fellowship (commencing 2019)

Summary:  This project aims to understand the roles of carbon, water and nitrogen in the development of plate tectonics as drivers of mantle evolution. Through improved understanding of the impact of melting on the deep earth cycles of carbon, water and nitrogen, this project intends to better understand how key elements are enriched towards economically viable concentrations. This project will generate knowledge of long-term benefit for decision-making in the minerals exploration industry and key government agencies. The project will establish a new generation of Australian scientists with a deep interdisciplinary understanding of earth sciences and pave the way for eventual unification of plate tectonics with climate systems.

How the Earth works- toward building a new tectonic paradigm

Z.X. Li: Supported by ARC Laureate Fellowship (commenced 2015)

Summary:  This fellowship project aims to build on the latest technological and conceptual advances to establish the patterns of Earth evolution and use this information to examine a ground-breaking geodynamic hypothesis which links cyclic plate aggregation and dispersion to deep Earth processes. Half a century after the inception of plate tectonics theory, we are still unsure how the Earth ’engine’ works, particularly the forces that drive plate tectonics. The project involves extensive national and international collaboration to potentially create a paradigm shift in our understanding of global tectonics and hopes to contribute to an understanding of the formation and distribution of Earth resources to provide a conceptual framework for their exploration.

>Measuring mantle hydrogen to map ore fluids and model plate tectonics

K. Selway: Supported by ARC Future Fellowship (commenced 2016)

Summary:  The goal of this project is to use magnetotellurics to measure mantle hydrogen contents to aid in the discovery of new mineral deposits. Hydrogen controls the strength of Earth’s mantle and is a vital component of the systems that form giant ore deposits. However, mantle hydrogen content is unconstrained. Ore-forming fluids hydrate the mantle pathways on which they travel. The first aim of this project is to image these fluid pathways to improve mineral exploration techniques. Plate tectonic models assume that the lithospheric mantle is dehydrated but existing data from magnetotellurics and mantle rocks show high hydrogen contents. The second aim of this project is to create a map of the hydrogen content of the plates, which may lead to new models for continental evolution and mantle dynamics.

Earth’s origin and evolution: a sulfurous approach

O. Alard: Supported by ARC Future Fellowship (commenced 2015)

Summary:  This project aims to shed new light on global element cycles in the deep Earth and how they connect to the evolution of the exospheres - one of the hottest topics in geosciences. It also aims to produce key knowledge on the extraction and transport of elements from the deep Earth to the surface, which may provide valuable information for resource exploration. Using novel integrated elemental and isotopic approaches, this program aims to track the origin and fate of sulfur, selenium and tellurium during accretion and subsequent redistribution in fluids to Earth’s surface. This new knowledge is critical to understanding how these and other elements of strategic and economic importance, such as the Platinum Group Elements, are extracted from the deep Earth and transported to the surface.

The Western Australia ThermoChronology Hub

M. Danisik, N. Evans, B. McInnes, C. Kirkland, Z.X. Li, M. Fiorentini, M. Wingate: Supported by ARC LIEF (commenced 2019)

Summary:  This project aims to facilitate novel geochronological research in diverse areas of Earth and planetary science by providing a world-first triple-dating instrument facility. Combining three independent radiometric dating methods, the facility will undertake research to advance our understanding of the origin and evolution of the Earth and other planets and provide tools to enhance exploration for Earth’s resources. Expected outcomes include the formation of a strong collaborative facility for academic, government and industry research and a further strengthening of Australia’s position as an international research and education leader in the field of geochronology. It will lead to an improved understanding of the evolution of Earth’s surface, and the formation and distribution of mineral and petroleum resources.

A novel ToF-SIMS facility for organic and inorganic analyses in WA

K. Grice, W. Rickard, G. Benedix, S.-P. Jiang, S. Reddy, M. Kilburn, P. Clode, D. Peyrot, D. Wacey, P. Lavery, P. Masque, R. Trengove, F. Xia, A. Deditius, G. Maker: Supported by ARC LIEF (commenced 2019)

Summary:  Time-of-flight secondary ion mass spectrometry is a surface sensitive analytical technique that provides detailed elemental, isotopic and molecular information on surfaces, interfaces and thin layers with detection limits reaching in the parts-per-billion-range. The proposed facility is a next generation time-of-flight secondary ion mass spectrometer that allows parallel detection of organic and inorganic species in a given sample. Most importantly it will provide structural information of organic molecules intimately associated with minerals, meteorites, fossils, petroleum source-rocks to biochemical samples bolstering Western Australia’s Earth and planetary sciences, energy, materials sciences, life science and metabolomics research.

Cutting-edge electron probe microanalysis driving Western Australia’s resource geosciences

D. Sampson, S. Barnes, M. Fiorentini, I. Fitzsimons, S. Johnson, A. Kemp, M. Kilburn, M. Martyniuk, A. Putnis, S. Reddy, R. Smithies, Y. Uvarova: Supported by ARC LIEF (commenced 2018)

Summary:  The overwhelming demand for electron probe microanalysis from outstanding research groups in Western Australia requires renewal of over-subscribed, aging facilities to drive innovation and alleviate bottlenecks in advanced geosciences multi-capability workflows. A new generation electron microprobe, with advances in trace element mapping and cathodoluminescence analysis, will enable superior characterisation of a wide range of materials. The electron probe will drive underpinning geoscience, resources science and economic geology, as well as support a broad range of disciplines and diverse fields, such as nanotechnology, microelectronics and aquatic sciences.

Determining the extent and nature of the oldest crust in Antarctica

S. Wilde, A. Nemchin, M. Whitehouse, S. Harley, M. Kusiak, D. Dunkley: Supported by Australian Antarctic Science Grant (commenced 2019)

Summary:  A large inventory of samples, collected by past Australian expeditions to Antarctica, reside with Geoscience Australia and provide a unique treasure-trove of information that can now be tapped, following major advances in knowledge and instrumentation over the past three decades. Selected samples collected from the Napier Complex in Enderby and Kemp Lands, on the western frontier of the Australian Antarctic Territory, have already provided exciting new insights into the timing and complexity of geological processes acting during the earliest stages of Earth’s history. In order to further advance our understanding of this globally significant area, and to add value to a vital academic resource, this project aims to determine the extent of this most ancient terrain and to unravel the complex geological events that affected the area since its formation almost four billion years ago.

Magnetotelluric analysis for Greenland and Postglacial Isostatic Evolution (MAGPIE)

C.P. Conrad, K. Selway, C. Gaina, R. Karlsson, K. Nisancioglu, B. Steinberger, L. Tarasov: Supported by Norwegian Research Council FRINATEK (commenced 2019)

Summary:  With this project we seek to develop new constraints on rock viscosity beneath Greenland by collecting geophysical data on the ice sheet. The magnetotelluric (MT) data image the Earth’s electrical conductivity, which is sensitive to the temperature and water content of mantle rocks. Because these factors also control mantle viscosity, we can use MT data to map viscosity variations beneath Greenland. These data are also sensitive to subglacial melt, which will enable us to detect extra heat added beneath Greenland by the Iceland Plume. We will develop a new numerical modelling technique for GIA that can accommodate large viscosity variations. The code will be useful to study GIA problems worldwide, but we will use it to predict GIA uplift patterns associated with the viscosity variations beneath Greenland. We will then use these much-improved GIA models to produce more accurate estimates for modern-day ice loss in Greenland.

Using geochemical and microstructural XFM mapping to identify proximal, medial and distal vectors around magma transfer zones

N. Daczko, J. Munnikhuis: Supported by ANSTO – Australian Synchrotron Beamline Program (commenced 2019)

Summary:  The Earth is composed of a layered crust overlying a relatively homogeneous mantle. This layered nature necessitates material (in the form of melts) to be transferred from the mantle to the crust. However, the types of melt migration pathways remain unclear. We aim to assess changing the degree of chemical interaction of melt pathways from a transect near a mass transfer zone from the crust-mantle transition zone using the Maia-384 detector. This study will allow for better identification of other more cryptic mass transfer zones from surrounding rocks on the km scale.

Constraining the palaeodepth evolution of the South Tasman Rise and determining its role in development of the Antarctic Circumpolar Current (ACC)

S. Loehr, J. Wittaker, N. Daczko, P. Hall: Supported by ANZIC IODP Legacy Analytical Funding (AILAF) (commenced 2019)

Summary:  This project aims to determine the palaeodepth evolution of the South Tasman Rise, a tectonically-thinned and submerged continental block formerly part of the Tasmanian Land Bridge which connected Australia and Antarctica until the Eocene. This will provide important constraints on the opening of the Tasmanian oceanic gateway to deep water circulation, hypothesised to be a primary control on the Eocene-Oligocene climate transition, arguably the most profound climatic re-organisation of the Cenozoic. A multiproxy sediment geochemistry approach developed and validated by the authors during recent work on the East Tasman Plateau will be employed to 1) determine the palaeodepth evolution of the South Tasman Rise during the Eocene and 2) to identify the timing of initial submergence of the continental blocks in this critical region of Eocene tectonics.

Melt-present deformation within the dynamic oceanic crust: Recognition and rheological consequences

N. Daczko, R. Gardener, S. Piazolo: Supported by ANZIC IODP Legacy Analytical Funding (AILAF) (commenced 2019)

Summary:  Once the oceanic crust is formed, it is commonly assumed to remain rigid with only very limited chemical and rheological (i.e. flow property) changes other than ocean floor metamorphism occurring close to the interface with sea water. However, studies of deformed gabbroic portions of oceanic crust show that it is not “passive” but actively deforms, leading to important changes in its chemistry and rheology. These changes influence the long-term behaviour of the oceanic crust with consequences for our understanding of its flow properties, resource development and location of melt generation. Based on our pilot examination of a legacy thin section from ODP leg 176, core 735B (section 148R2, depth 952.7 mbsf), we postulate that melt migration in oceanic crust is in fact an important process that not only changes the chemistry but also substantially changes the rheology of the oceanic crust; hence this process is important in the evolution of the oceanic crust and oceanic plates in general.

3D Earth

J.C. Afonso, J. Ebbing: Supported by European Space Agency and MQ University (commenced 2017)

Summary:  The goal of this project is to establish a global 3D reference model of the crust and upper mantle based on the analysis of satellite gravity and (electro-)magnetic data in combination with seismological models and analyse the feedback between processes in Earth’s deep mantle and the lithosphere. Selected case examples will provide the possibility to test these approaches on a global and regional scale. This will result in a framework for consistent models that will be used to link the crust and upper mantle to the dynamic mantle.

Australian membership of the International Ocean Discovery Program

R. Arculus, D. Cohen, S. Gallagher, P. Vasconcelos, C. Elders, J. Foden, M. Coffin, O. Nebel, H. McGregor, M. Clennell, C. Sloss, A. Heap, A. Webster, A. Kemp, S. George: Supported by ARC LIEF (commenced 2016)

Summary:  This project is for an Australian membership of the International Ocean Discovery Program. The Program will recover drill cores, situate observatories, and conduct down-hole experiments in all the world’s oceans from lowest to highest latitudes to address fundamental questions about Earth’s history and processes within four high-priority scientific themes: climate and ocean change - reading the past and informing the future; biosphere frontiers - deep life, biodiversity, and environmental forcing of ecosystems; Earth connections - deep processes and their impact on Earth’s surface environment; Earth in motion - processes and hazards on a human time scale.

CWAS: China-Western Australia Seismic Survey

L. Zhao, H. Yuan GSWA: Supported by the Institute of Geology and Geophysics, Chinese Academy of Sciences (commenced 2016)

Summary:  Western Australia is an ideal natural laboratory for understanding the evolution of the Australian craton. To better understanding how and where the cratonic nuclei merged in the Precambrian requires high-resolution probing of the crustal and mantle structure beneath Western Australia. IGGCAS, CCFS and GWSA will install a 900-km-long dense (station spacing of 10 to 15 km) seismic profile across the Western Australia from the Port Hedland to the southwestern border of Kimberly Craton, in order to:

- image the crustal structure of the north edge of Pilbara craton, the Canning basin and south edge of Kimberly craton with a high-resolution, and address the following issues: 1) deep geometry of the craton boundaries, 2) deep geometry of craton collisional belt; 3) differences of crustal structures between two cratons

- image the mantle structure of the north edge of Pilbara craton, the Canning basin and south edge of Kimberly craton and address the following questions: 1) geometry of the convergence beneath the craton boundaries, 2) characteristic difference of the upper mantle of the two cratons.