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  • Over the last fifteen years, Geoscience Australia, through its Onshore Energy Security Program, in conjunction with Primary Industries and Resources South Australia (PIRSA), the Geological Survey of New South Wales (Industry & Investment NSW), the Australian Geodynamics Cooperative Research Centre, and the Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC), has acquired several deep seismic reflection profiles, which, when combined, form an east-west transect about 870 km long in southeastern Australia. The seismic data vary from low-fold, dynamite-source to higher-fold, vibroseis-source data. The combined seismic profiles, from the western Eyre Peninsula to the Darling Basin, provide a near complete cross-section of the crust across the Gawler Craton, Adelaide Rift System, Curnamona Province, Koonenberry Belt and Darling Basin. The entire region is dominated by east-dipping faults, some of which originated as basin-bounding extensional faults, but most appear also to have a thrust sense of movement overprinting the extension. In the Gawler Craton, an inferred shallow, thin-skinned thrust belt occurs to the west of an inferred thick-skinned thrust belt. The boundary between the two thrust belts, the Kalinjala Mylonite Zone, was active at least during the Kimban Orogeny, with possible extensional movement at that time. The thrust movement possibly occurred during the ~1600 Ma Olarian Orogeny.

  • Summary of forward gravity and flexure modelling of the New Caledonia Trough to highlight temporal variations in lithospheric rigidity during its evolution.

  • As part of initiatives by the Australian and Queensland Governments to support energy security and mineral exploration, a deep seismic reflection and magnetotelluric survey was conducted in 2007 to establish the architecture and geodynamic framework of north Queensland. With additional support from AuScope, nearly 1400 km of seismic data were acquired along four lines, extending from near Cloncurry in the west to almost the Queensland coast.

  • Beginning in the Archean, the continent of Australia evolved to its present configuration through the accretion and assembly of several smaller continental blocks and terranes at its edges. Australia grew usually by convergent plate margin processes, such as arc-continent collision, continent-continent collision or through accretionary processes at subduction zones. The accretion of several island arcs to the Australian continent, through arc-continent collisions, played an important role in this process, and the geodynamic implications of some Archean and Proterozoic island arcs recognised in Australia will be discussed here.

  • This set is composed of a selection of geoscience booklets, paper models and an image set - Climate Change booklet - Time and Life Booklet - Volcanoes booklet - Earthquakes booklet - Australian Earthquakes image set - Plate Tectonics booklet - Plate tectonics 3D paper model set Suitable for secondary Year levels 7-12

  • The Archean Yilgarn Craton of Western Australia, is not only one of the largest extant fragments of Archean crust in the world, but is also one of the most richly-mineralised regions in the world. Understanding the evolution of the craton is important, therefore, for constraining Archean geodynamics, and the influence of such on Archean mineral systems. The Yilgarn Craton is dominated by felsic intrusive rocks - over 70% of the rock types. As such these rocks hold a significant part of the key to understanding the four-dimensional evolution of the craton, providing constraints on the nature and timing of crustal growth, the role of the mantle, and also the timing of important switches in crustal growth geodynamics. The granites also provide constraints on the nature and age of the crustal domains within the craton. Importantly, this crustal pre-history appears to have exerted a significant, but poorly understood, spatial control on the distribution of mineral systems, such as gold, komatiite-associated nickel sulphide and volcanic-hosted massive sulphide (VHMS) base metal systems

  • Intrusive and extrusive, predominantly felsic, magmatism of Carboniferous to Permian age occurs throughout the north Queensland region (Figure kennedy), and comprises the most widespread and voluminous magmatic event in the region. The great bulk of the exposed KIA is concentrated in the Townsville-Cairns-Cooktown-Georgetown-Charters Towers-Burdekin Falls regions (Figure Kennedy)-within the early-mid-Palaeozoic Hodgkinson and Broken River Provinces, the Etheridge Province and associated Proterozoic provinces, and in the northern part of the Thomson Orogen including the Greenvale, Charters Towers, and Barnard Provinces, and the northern Drummond Basin. The boundary between the northern Drummond Basin and Connors (nNEO) Subprovince is taken to be the Millaroo Fault Zone (MFZ). Geophysical data (and limited geochronology) show that Carboniferous-Permian granites also form a westerly trending belt-the Townsville-Mornington Island Belt (TMIB; originally Townsville-Mornington Island Igneous Belt), which extends under cover from north of Mount Surprise, at least as far as Mornington Island in the Gulf of Carpentaria, transecting regional trends (Wellman, 1992, 1995; Wellman et al., 1994). There is also recent geochronological evidence for KIA magmatism in the environs of the Millungera Basin (Neumann & Kositcin, 2011). Outcrop is discontinuous in the belt extending northwards from Cairns up Cape York Peninsula, to the islands of Torres Strait (and beyond) but geophysical evidence implies there is more extensive magmatism under cover.

  • Aspects of the tectonic event history of Palaeo- to Mesoproterozoic Australia are recorded by metasedimentary basins in the Mt Isa, Etheridge, and Coen Provinces in northern Australia and in the Curnamona Province of southern Australia. Based on similarities in depositional ages and stratigrapy, these basins are interpreted to have been deposited in a tectonically-linked basin system. However, in deformed and metamorphosed basins, field correlations are difficult, making independent data, such as Nd isotope data and detrital zircon U-Pb geochronology essential to discriminate tectonic setting and sediment provenance.

  • The tectono-stratigraphic development of the southwestern corner of Australia is illustrated in a plate reconstructed setting with a series of palaeogeographic maps based on a newly compiled structural elements map and chronostratigraphic section for the Perth Basin. The area is complicated by at least two periods of extensional faulting, one in the Late Carboniferous Early Permian and a second in the Late Jurassic Early Cretaceous, separated by sag basin development in the Late Permian to Middle Jurassic. Depositional centres migrated through time and appear to have suffered oblique extension, with the most structuring associated with the Late Jurassic Early Cretaceous rifting episode. In addition, extensive volcanism leading up to breakup at about 132.5 Ma in the Valanginian has obscured the continent-ocean transition. The resulting basin structure comprises separate NS to NNW/SSE oriented rifted sub-basins, which were rotated and shifted westwards through time. Barremian/Albian oceanic crust then grew in a northwesterly direction in the Perth Abyssal Plain and was followed after ~100 Ma by fast spreading in a NNW direction in the NE Indian Ocean. Strata deposited during the Barremian to Recent sag phase of the Perth Basin are relatively thin and unstructured. Known or inferred source rocks in this complex basin include gas and minor oil-prone coals in the Lower Permian (Irwin River Formation), Upper Permian (Sue Group), Lower Jurassic (Cattamarra Coal Measures) and Upper Jurassic (Yarragadee Formation). Marine shales, which developed anoxia at flooding surfaces in the Lower Permian (Carynginia Formation, Holmwood Shale) and basal Triassic (Kockatea Shale) became oil-prone source rocks. In addition, there is the possibility of a further speculative oil-prone source in the Bajocian (Cadda Formation) in deep water areas.

  • This report documents a study into the Late Jurassic to Recent breakup and drift history of southern Australia, Antarctica and New Zealand , and the relationship between these tectonic events and the stratigraphy and drainage history of these areas. The study was conducted between March 1999 and August 2000. Many of the goals have been achieved, but the plate reconstructions still need to be put into a proper geo-referenced kinematic framework. The purpose behind the study was to lay the framework for understanding the palaeogeography, lithofacies, tectonics and geomorphology of these areas in a reconstructed palinspastic setting; something that had not been accomplished before. The methodology has been to first of all compile structural elements maps for the southern Australian and conjugate Antarctic margins. An updated ocean age map was also prepared as a basis for a first-pass reconstruction. Then the stratigraphy was summarised for three representative cross sections in the Great Australian Bight, Otway and Gippsland Basins, and these were displayed as detailed chronostratigraphic sections in order to demonstrate the stratigraphic responses to the breakup history. One of the vital predictive conclusions was to try and understand the structure and stratigraphy under the lower continental margins; the prime tools for this part of the study were deep-penetration seismic lines shot by AGSO under the Law of the Sea and Continental Margins programs. Finally, a set of 18 plate reconstruction maps were compiled for the period from the Oxfordian to the Present Day, with elements of the tectonics and stratigraphy plotted on them. Because of time constraints and the inability to work the appropriate plate kinematic software, the reconstructions presented here were prepared with scissors and tape from the ocean age map and hence must be regarded as indicative cartoons of the plate positions. This situation is obviously not ideal but is considered justified by the need to understand the geological relationships between the various terrains before going to a rigorous kinematic reconstruction. AGSO supported this study as a Collaborative Research Project, providing both data and support with expenses. In addition, this work has been shown at various stages to a large number of people, all of whom helped by making comments and suggestions, and their contributions are gratefully acknowledged. Some of those involved were:- Kevin Hill (La Trobe University) Nick Hoffman (La Trobe University) Mark Smith (Petroleum Consultant) Alan Partridge (La Trobe University) Heike Struckmeyer (AGSO) Jennie Totterdell (AGSO) Howard Stagg (AGSO) Jacques Sayers (AGSO) Russell Korsch (AGSO) Colin Pain (AGSO) Paul O'Sullivan (Syracuse University, NY) Meredith Orr (Monash University) Mike Hall (Monash University) Steve Gallagher (Melbourne University) Guy Holdgate (Melbourne University) Barry Kohn (Melbourne University) Dietmar Muller (U. Sydney) Mike Gurnis (Caltech) Chris Adams (NZIGNS) Tom Bernecker (VDNRE) Andrew Constantine (VDNRE) David Moore (VDNRE) Ross Cayley (Geol. Survey Victoria) Cliff Ollier (ANU) Graham Taylor (University of Canberra)