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  • 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.

  • The Ranger deposit is one of Australia's largest known uranium resources, with current open pit mining of the No. 3 orebody and a total resource of 109,600 tonnes of U3O8 grading 0.08% at this orebody (ERA, January 2011). This unconformity-related deposit is hosted by Paleoproterozoic metasedimentary rocks of the Cahill Formation which is unconformably overlain by sandstones of the Kombolgie Formation. A maximum depositional age of ~1818 Ma is inferred for the sandstones, based on the presence of the Nabarlek Granite of this age in the basement beneath the Kombolgie Formation. Most mineralisation occurs within a largely stratabound shear and breccia zone and is associated with intense proximal chlorite and distal white mica alteration. The Kombolgie Formation is weakly deformed, faulted and weakly chloritised above the mineralisation.

  • This report describes the ornamental stones used in the ground floor foyer of the Geoscience Australia building. There are three ornamental stones used. The flooring tiles are basalt. The 'fault' line through this is a polished norite and the blade walls are covered by a Persian red Travertine. Investigations have established that the basalt and norite are from Australian quarries and the travertine is from an unknown source overseas possibly Italy.

  • 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.

  • 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.

  • Canning Basin Chart updated August 2013

  • 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.

  • This entails publishing a formal analysis which, under the International Codes of Zoological and Botanical Nomenclature, must be accompanied by illustrations of specimens. These illustrated specimens can then become the 'ype specimens'. The type specimen acts as a reference upon which the understanding of each species relies. So, if any subsequent research worker wants to compare their material with, or to assign their material to a known species, the concept of that species is dependent on the type specimens and the research worker must refer to those type specimens.