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  • A symposium was held at the University of Wales, Swansea in July 2007 to honour the career and achievements of Professor Michael Collins. The symposium was organised by Michael's former postgraduate students as a tribute to his contributions over the past 30 years as a scientist, teacher, mentor and friend. About 30 of the 50+ Ph.D. and M.Sc. students that Michael has supervised over the years were fortunate to attend the symposium, which offered the opportunity for all of us to learn about the many different subjects and projects that Michael supervised and to renew our friendships with the Collins family, as well as the extended, academic Collins 'family'.

  • Two sediment cores collected from beneath the Amery Ice Shelf, East Antarctica describe the physical sedimentation patterns beneath an existing major embayed ice shelf. Core AM01b was collected from a site of basal freezing, contrasting with core AM02, collected from a site of basal melting. Both cores comprise Holocene siliceous muddy ooze (SMO), however, AM01b also recovered interbedded siliciclastic mud, sand and gravel with inclined bedding in its lower 27 cm. This interval indicates an episode of variable but strong current activity before SMO sedimentation became dominant. 14C ages corrected for old surface ages are consistent with previous dating of marine sediments in Prydz Bay. However, the basal age of AM01b of 28250 ± 230 14C yr bp probably results from greater contamination by recycled organic matter. Lithology, 14C surface ages, absolute diatom abundance, and the diatom assemblage are used as indicators of sediment transport pathways beneath the ice shelf. The transport pathways suggested from these indicators do not correspond to previous models of the basal melt/freeze pattern. This indicates that the overturning baroclinic circulation beneath the Amery Ice Shelf (near-bed inflow-surface outflow) is a more important influence on basal melt/freeze and sediment distributions than the barotropic circulation that produces inflow in the east and outflow in the west of the ice front. Localized topographic (ice draft and bed elevation) variations are likely to play a dominant role in the resulting sub-ice shelf melt and sediment distribution.

  • Advanced burial and thermal geo-history modelling was carried out using Fobos Pro modelling software for the first time in Australia without relying on default or inferred values (such as heat flow or geothermal gradient). Our methodology is a substantial extension to the conventional approach.

  • During the Quaternary, the Mac. Robertson shelf of East Antarctica was deeply eroded by glaciers and currents exposing the underlying basement, resulting in a scalped shelf.

  • Legacy product - no abstract available

  • During 2009-10 Geoscience Australia completed a petroleum prospectivity study in the offshore northern Perth Basin, 200 km northwest of Perth. In some parts of this basin acoustic basement is deep and not resolved in the reflection seismic data. Improvements to the magnetic ship-track database and magnetic anomaly grid produced during the study allowed for assessment of depth to magnetic sources, and estimation of sediment thickness, and provided new insight into basement trends. 2.5D models along several transects, and analysis using spectral methods indicate penetration of the lower sediments by high-susceptibility bodies is necessary to approximate the observed magnetic anomaly. The reflection seismic evidence for these bodies is not obvious, though in some cases they may be associated with interpreted faults. Where the modelled bodies penetrate the sediments, they are mostly below or within the Permian section, except in the west of the study area where sediments thin over oceanic crust. On the northern-most profiles a large positive magnetic anomaly (the Batavia Ridge) is modelled by massive bodies whose tops are 5-10 km below sea floor. On these and other profiles to the south other dyke-like bodies rarely penetrate to shallower than 5 km below the sea floor.

  • The Bland Basin is the broad alluviated palaeovalley of Bland Creek, a tributary of the Lachlan River in the central part of New South Wales, Australia, within the drainage basin of the Murray-Darling River System. It covers about 4000 km2 and contains up to 120 m of terrestrial sediments, interpreted as being deposited by alluvial, colluvial, lacustrine/paludal, and aeolian processes. It is undated, but is likely to be coeval with the downstream contiguous fill of the Lachlan River palaeovalley, dated elsewhere by palynology as Miocene to Recent. The southwestern part of the basin has been studied in detail using airborne geophysics (electromagnetics, magnetics, and gamma ray spectrometry) and drilling. The small erosional catchment area of the modern Basin surface has resulted in a paucity of sediment available for deposition in the Basin, but drainage base level has been driven by the rate of sedimentation of the Lachlan palaeovalley downstream of the Basin. Therefore, most of the sediment derived from the catchment has been trapped in the Basin rather than being transported downstream and into the Lachlan palaeovalley, and at times large lakes and/or swamps have formed in the central part of the Basin. The sediments in the southwest of the Basin are dominated by clay and silt, with local sand and gravel, mostly in basal gravelly sand and a sandier interval in the middle part of the sequence. Quartz silt derived from aeolian dust is a major component of the upper part of the sedimentary sequence. Geophysical responses of the sediment include high conductivity due to saline groundwater, low gamma response dominated by thorium decay emissions due to the leached nature of the sediment, and short wavelength-low amplitude magnetic anomalies resulting from local concentrations of detrital maghemite-rich gravel formed during weathering in the catchment area. Other broad valleys draining to the Lachlan River may contain similar mud-dominated Neogene basins.