Many Australian Proterozoic regions contain a complex but periodic history of sedimentation, magmatism, tectonism, metamorphism, fluid flow, and mineralisation. Time-space-event plots provide valuable insights into the geological history and processes recorded in these regions and assist in the identification of events associated with mineralisation within different areas. They also provide the basis for event correlations between regions, tectonic models and discussions regarding the evolution of the Australian Proterozoic. The Australian Proterozoic Events project is drawing together the data and understanding from Geoscience Australia?s current and recently completed Minerals Division regional projects to provide the most up-to-date tectonostratigraphic information for selected Australian Proterozoic regions, including the Mount Isa Inlier and McArthur Basin, Arunta and Tanami Inliers, and Gawler Craton.

No abstract available

2016 ESA Living Planet Symposium Abstract Submission - Mapping the Morphology of the Intertidal Zone using the time-series of Landsat data

The extended abstract describes the geophysical characteristics of the granite dominated geophysical map units of the Yilgarn Craton and the relationship between their deformation and gold mineralisation. Aeromagnetic data are not able to distinguish the five main granite geochemical groups. Gamma-ray spectromatric data provide some distinctin of the geochemical groups but their use is restricted to limited areas of outcrop. Faults host much gold but the majority of these structures are barren and spatial associations have been difficult to establish. Shear zones are irregularly distributed across the craton. Abundant intersecting shear zones, that transect both granite and greenstone, define a 200 km wide, north-trending corridor, with distinctive rhomboid to sigmoidal internal geometry. Greenstones in the corridor are extensively disrupded and strongly aligned with adjacent shear zones. This corridor correlates with the the region of highest gold endowment for the Yilgarn Craton and large deposits are spatially associated with bends and intersections of the shear zones. By contrast, shear zones are sparse in the Yalgoo Dome area in the north west of the Yilgarn Craton. The crustal architecture of this area is dominated by large ovoid bodies of granite. Adjacent greesntones are not regionally alligned, nor particularly disrupted internally, and gold endowment is low. These aparent contrasting structural styles and corresponding differences in gold endowment can be similarly applied to the Superior Province of Canada (Abatibi Belt, abundant intersecting shear zones, strongly aligned greenstone, and high gold endowment) and Australia's Pilbara Craton (few shear zones, oviod granite geometry dominant with little regional alignment of greenstone and low gold endowment).

No abstract available

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The purpose of this study was to constrain the processes of Paleoproterozoic crustmantle evolution by investigating the Lu-Hf, Sm-Nd and oxygen isotope systematics of igneous rocks of the Lamboo Province of the Halls Creek and King Leopold Orogens, in the Kimberley region of Western Australia. The specific objectives were to: 1. Ascertain the nature of the source rocks of the granites, and to test whether granite formation involved the reworking of ancient meta-igneous protoliths in an intra-plate environment or complex crust-mantle interaction processes typical of modern plate tectonic settings; 2. Use data from granite-hosted zircons to quantify the proportion of new crust formed during discrete magmatic events, and to link this with the longer-term record of crustal evolution preserved by detrital zircons, and 3. Constrain the tectonic setting of the Lamboo Province, and thus the geodynamic controls on global crustal growth in this key time period.

nThe Asia Pacific Reference Frame (APREF) main aim is to densify ITRF within this region. It helps to encourage CORS operators to follow IGS guidelines in terms of operation of the station and handling of metadata. We detail the contributing networks, and analysis solutions provided to APREF, and give details on our current combination strategy. We will provide results of the velocity field determined from the APREF solution as well as give details on how we will progress APREF in the future, with the imminent release of the next ITRF.

Accurate moment tensor solutions are crucial to developing a reliable seismic hazard assessment for Indonesia. Not only are these source parameters relied on for describing the style of faulting and earthquake recurrence in a particular region, they are also critical in developing the Ground Motion Prediction Equations that determine the level of hazard for a given level of earthquake activity. In the past, reliable earthquake source parameters for Indonesia have been problematic due to the sparseness of local observations. However, the dramatic improvement in network coverage following the 2004 Sumatra earthquake should result in a commensurate improvement in the accuracy of earthquake source parameters.

The preservation of marine black shales, especially during the Cretaceous, and their relationship to oceanic anoxic events (OAEs) has been extensively studies over the past three decades. However, molecular and isotopic geochemistry has revealed that there are many competing factors that lead to the presence of black shale in the fossil record. Each black shale `system? reflects the varying emphasis on the role of productivity vs preservation, autotrophy vs chemotrophy, and autochthonous (planktonic vs benthic vs bacterial) vs allochthonous (mainly terrestrial) inputs. It appears that each `system? represents a unique combination of the above processes. The Toolebuc Formations offers a natural laboratory where the relative contributions for individual processes can be addressed. Furthermore, the position of the anoxic/oxic boundary in relation to the sediment/water interface can be mapped with a high degree of confidence using a combination of organic and inorganic tracers. For example, increasing Ni/VO porphyrin and etio/DPEP ratios vary systematically with decreasing TOC contents as the boundary moves from within the water column to within the sediments, while Pr/Ph remains insensitive over the same transition. The importance of primary producers from the upper photic zone is best addressed using contents and carbon isotopes of metalloporphyrins, while sterane and isoprenoids are important markers for contributions from the lower photic zone. The role of the benthic community and recycled carbon is addressed using the carbon isotopes of individual compounds. When the anoxic/oxic and sediment/water interfaces coincide, specialised sulphur-oxidising bacteria flourish and represented by a diagnostic homologous series of mid-methylalkanes and even-number n-alkanes. Such a depositional model encompassing changing redox conditions is deemed to be a common thread in the deposition of many marine black shales and aspects of the Toolebuc `system? can be seen in the marine black shales of the Cenomanian-Turonian Greenhorn Formation, USA.