Forward modelling was undertaken to test the architecture of the Southern Carnarvon deep seismic reflection survey (11GA-SC1) interpretation against gravity data. The seismic data extends to ~60 km depth and images the crust-mantle boundary (Mohorovi-i- discontinuity) allowing it to be incorporated in the forward modelling. Using average density values for the upper mantle, granulite to amphibolite facies mid to lower crustal rocks, and upper crustal felsic and sedimentary rocks, a model was generated which explains the observed gravity anomalies and is consistent with the seismic interpretation. This work highlighted areas where the seismically inferred models were inconsistent with the gravity data and the importance of understanding regional trends, such as those generated by the crust-mantle boundary. The modelling undertaken in this study reflects the most up to date understanding of the regional geology in this area.

Descriptive posters

Four posters describing work being undertaken in Antarctica: VULNERABLE MARINE ECOSYSTEMS IN ANTARCTICA SEABED MAPPING IN ANTARCTICA DEFINING ABSOLUTE GRAVITY AN ANTARCTIC GEODESY

To follow

The Georgina Basin is a Neoproterozoic to Lower Devonian sedimentary basin covering 325 000 km2 of western Queensland and the Northern Territory. It is a northwest-southeast-trending extensional basin, with conventional and unconventional hydrocarbon exploration targets in the southern depocentres within the middle Cambrian Arthur Creek Formation (AC Fm). Recent biostratigraphic work using agnostid trilobites [1] has determined that the prospective `hot shale (so called due to high gamma-ray log values) at the base of the AC Fm in the Dulcie Syncline is older (Templetonian) than the `hot shale in the Toko Syncline, which is of Floran age. To complicate the stratigraphy further, the Thorntonia Limestone (Th Lst) in the Undilla Sub-basin is also Templetonian in age, the same age as the AC Fm in the Dulcie Syncline and younger than the Th Lst in the Dulcie Syncline (Ordian). In this study molecular analyses of the AC Fm and the Th Lst from the CKAD0001 well were undertaken in order to distinguish between the two formations and assist with future correlations.

Poster prepared for International Association of Hydrogeologists Congress 2013 In this study, AEM mapping validated by drilling has enabled the lateral extents and thickness of the Pliocene aquifers to be identified. The Pliocene in this area dominantly comprises the fluvial Calivil Formation, with the shallow marine Loxton-Parilla Sands restricted to the southernmost part of the area. Post-depositional warping, tilting and discrete offsets associated with neotoectonics are also recognised. Facies analysis indicates the Calivil was deposited in deep braided streams across a dissected sedimentary landscape. Overall, the sequence is fining-upwards, with evidence for progradation over the Loxton-Parilla. Channel fill materials comprise gravels and sands, and local fine-grained units represent abandoned channels and local floodplain sediments. Integration of textural and hydraulic testing data has revealed there are five hydraulic classes within the Calivil,. At a local scale (10s to 100s of metres), there is considerable lithological heterogeneity, however at a regional scale (kms), sands and gravels are widely distributed with particularly good aquifers developed in palaeochannels and at the confluence of palaeo-river systems. Aquifer testing has revealed Calivil to be an excellent aquifer, with high storage capacity, and locally very high transmissivities (up to 50 l/s). Integration of the AEM data with borehole geophysical data (gamma, induction and NMR) and textural and pore fluid data has enabled maps of aquifer properties including groundwater salinity, porosity, storage and hydraulic conductivity to be derived. Overall, the multi-disciplinary approach adopted has enabled rapid delineation of new groundwater resources, and facilitated assessment of the Pliocene aquifers for managed aquifer recharge.

Fun facts about Antarctica in an Open Day display poster.

Joining Geoscience Australia's Graduate Program is an exciting opportunity to learn about the diverse earth science disciplines work for the nation's leading government geoscience research and information agency. Posters and Flyers.

Poster linked to accepted WABS abstract: GeoCat #74808 West Australian Basins Symposium (WABS), Perth, 18-21 August 2013

Back wall poster display in the library celebrating Library and Information Week 2014