No abstract available

Recent centuries provide no precedent for the 2004 Indian Ocean tsunami, either on the coasts it devastated or within its source area. The tsunami claimed nearly all of its victims on shores that had gone 200 years or more without a tsunami disaster. The associated earthquake of magnitude 9.2 defied a Sumatra-Andaman catalogue that contains no nineteenth-century or twentieth-century earthquake larger than magnitude 7.9. The tsunami and the earthquake together resulted from a fault rupture 1,500 km long that expended centuries -worth of plate convergence. Here, using sedimentary evidence for tsunamis, we identify probable precedents for the 2004 tsunami at a grassy beach-ridge plain 125 km north of Phuket. The 2004 tsunami, running 2 km across this plain, coated the ridges and intervening swales with a sheet of sand commonly 5-20 cm thick. The peaty soils of two marshy swales preserve the remains of several earlier sand sheets less than 2,800 years old. If responsible for the youngest of these pre-2004 sand sheets, the most recent full-size predecessor to the 2004 tsunami occurred about 550-700 years ago.

2004 updated version of Helby, Morgan & Partridge (1987)

The geological evolution of Australia is closely linked to supercontinent cycles that have characterised the tectonic evolution of Earth, with most geological and metallogenic events relating to the assembly and breakup of Vaalbara, Kenorland, Nuna, Rodinia and Pangea-Gondwana. Australia largely grew from west to east, with two major Archean cratons, the Yilgarn and Pilbara Cratons, forming the oldest part of the continent in the West Australian Element. The centre consists mostly of the largely Paleo-to Mesoproterozoic North and South Australian Elements, whereas the east is dominated by the Phanerozoic-Mesozoic Tasman Element. The West, North and South Australian Elements initially assembled during the Paleoproterozoic amalgamation of Nuna, and the Tasman Element formed as a Paleozoic accretionary margin during the assembly of Gondwana-Pangea. Australia's present position as a relatively stable continent resulted from the break-up of Gondwana. Australia is moving northward toward southeast Asia, probably during the earliest stages of the assembly of the next supercontinent, Amasia. Australia's resources, both mineral and energy, are linked to its tectonic evolution and the supercontinent cycle. Clusters of resources, both in space and time, are associated with Australia's tectonic history and the Earth's supercontinent cycles. Australia's most important gold province is the product of the assembly of Kenorland, whereas its major zinc-lead-silver deposits and iron-oxide-copper-gold deposits formed as Nuna broke up. The diverse metallogeny of the Tasman Element is a product of Pangea-Gondwana assembly and most of Australia's hydrocarbon resources are a consequence of the break-up of this supercontinent.

The Nolans Bore deposit, located in the Aileron Province of south-central Northern Territory, is an emerging Australian rare earth development. It consists of steeply northwest dipping apatite veins hosted by ~1806 Ma granite gneiss. A preliminary ~1240 Ma U-Pb age for apatite may correspond to a major global period of alkalic magmatism between 1300 and 1130 Ma, including emplacement of the Bayan Obo deposit in China. Low ?Nd and 87Sr/86Sr in the mineralisation is reminiscent of modern EM-1 ocean island basalts and may indicate a link to carbonatitic magmatism. Oxygen isotope thermometry indicates a mineralisation temperature of 410°C, with '18Ofluid of ~8.0'. Fertilisation of the mantle to produce the EM-1 source may relate to subduction associated with convergence along the southern margin of the North Australian Craton.

This report presents new geochronological results for five uranium deposits in Australia, detailing the timing of uranium mineralisation in relation to regional geological events. The purpose of the study is to better constrain ore genetic and exploration models for these uranium mineral systems, and ultimately to improve understanding of the uranium resource potential of the Australian continent. The work was carried out under the auspices of the Onshore Energy Security Program. Each of the five uranium deposits represents a different style of mineralisation within three broad families of uranium mineral systems: magmatic-related, basin-related, and metamorphic-related. The results contribute to the current paucity of age data for uranium deposits in Australia, and for most of the deposits the new dates are the first reported direct ages for mineralisation or associated alteration.

Optically stimulated luminescence (OSL) dating of sand sheets provides a chronology of the largest tsunamis in western Thailand over the late Holocene. Four sand sheets deposited by pre-2004 tsunamis were dated by luminescence to 380 ± 50, 990 ± 130, 1410 ± 190 and 2100 ± 260 years ago (at 1-sigma precision). These compare with previous radiocarbon ages of detrital bark high in buried soils (Jankaew et al., 2008), which suggest that the most recent large-scale predecessor to the 2004 tsunami occurred soon after 550-700 cal BP, and that at least three such tsunamis occurred over the past 3000 years. Concordant OSL ages from successive beach ridges (1600 ± 210 to 2560 ± 350 years ago) and tidal flat deposits (2890 ± 390 years ago) provides a set of limiting maximum ages for sand sheet deposition which, when combined with the sand sheet ages, provide a robust average for tsunami recurrence. The ages imply that between 350 to 700 years separates successive tsunamis on the Andaman coast of Thailand with an average tsunami recurrence interval of 550 years. These results show OSL can provide independent estimates of tsunami recurrence for hazard analysis, particularly in areas where suitable material for radiocarbon dating is unavailable.

As part of Geoscience Australia's 2002-2004 work program, the Petroleum and Marine Division initiated a collaborative study of the Otway Basin (Figure 1) with Primary Industries and Resources SA (PIRSA) and the Department of Primary Industries (DPI), Victoria. The aim of the project was to enhance the petroleum prospectivity of the basin through an improved understanding of depositional systems, integrated petroleum systems analysis and enhanced access to basic datasets critical to the exploration industry. Major project work components included seismic- and well-interpretation to construct a new regional chronostratigraphic framework for the basin (Figure 2), geochemistry and geohistory modelling to document regional petroleum systems elements (Boreham et al ., 2004), and biostratigraphy to refine age-control, biozonations and correlations within the basin (Krassay et al ., 2004). Biostratigraphic work for the Otway Basin Project involved a major program of new sampling, processing and palynological analysis combined with a thorough review of existing biostratigraphic reports and data. Collection, processing and preparation of new samples were conducted in-house by Geoscience Australia staff. New palynological analyses were carried out by Morgan Palaeo Associates on a commercial contract basis. This Record (CD-ROM) contains consultants palynological reports (Microsoft Word) and digital data files as originally submitted (wmf and dex formats) and as updated and standardised (csv format) for over 200 new samples collected from 14 selected Otway Basin wells (Table 1). This Record also contains revised palynological data files (csv format) for 18 Otway Basin wells (Table 2). Revision and updating of palynological data from existing reports and new consultants reports involved initial quality-assurance and quality-control of the data followed by updating of synonyms and systematics to comply with a standardised taxonomy. Revised data files contained in this Record adhere to a standardised taxonomy in current use at Geoscience Australia. Revised data files are presented in a csv format (Excel spreadsheets).

Canning Basin Chart updated August 2013

This record contains zircon U-Pb geochronological data obtained between July 2001 and May 2003 on diamond drillcore from the Olympic Domain, Gawler Craton, South Australia. The data were collected as part of the Gawler Craton Project; a collaboration between Geoscience Australia (GA) and the Division of Mineral and Energy, Primary Industry and Resources, South Australia (PIRSA). The project aims to provide an improved geological and metallogenic framework for the Gawler Craton, with initial emphasis on the Olympic Domain. The term Olympic Domain (formerly 'Olympic Subdomain'; Daly et al. 1998) refers to the eastern extension of the Gawler Craton, concealed beneath Mesoproterozoic, Neoproterozoic and Cambrian sedimentary rocks of the Stuart Shelf. It also encompasses outcrop and subcrop of the Gawler Craton further south in the Moonta-Wallaroo region of the Yorke Peninsula. The sedimentary cover sequence of the Stuart Shelf is between about 300 and 1000 m thick, and the only knowledge of the underlying crystalline basement comprising the Olympic Domain is derived from exploratory drillholes. The long distances between drillholes impede inter-hole correlations. Thus U-Pb isotope dating of rocks intersected by (diamond) drillcore plays a key role in regional stratigraphic studies, establishing an absolute basis for temporal correlations across the Olympic Domain. This record describes the samples analysed and the analytical results obtained, and provides a brief discussion of their geochronological interpretation. The broader geological implications of the data will be published elsewhere.