The formation of passive margins has been intensively studied on the Iberian-Newfoundland margins for over two decades leading to complex models for the formation of conjugate nonvolcanic rifted margins. The main area of debate is focussed on deciphering the nature of the so-called transitional zone between unambiguous continental and oceanic crust. The transitional zone often displays characteristics of both continental and oceanic crust. The Great Australian Bight and Wilkes Land margins are type-examples of conjugate nonrifted volcanic margins, but much less well studied than the Iberian-Newfoundland margins. Research along the Southeast Indian Ocean margins has been propelled by Australia's submission to the United Nations Convention of the Law of the Sea, yet the study of the margins has been limited to research on particular regions on either the Australian or Antarctic margins. No consistent stratigraphy has been derived that would allow a unified study of this margin pair. This thesis uses seismic and potential field data to provide a consistent interpretation across the two margins in terms of sedimentary sequences and crustal structure for the first time. The interpretation of both margins provides insight into the nature and formation of the transitional zone. A new sequence stratigraphy for the Wilkes Land margin has been developed to correlate with the interpretation of Totterdell et al. (2000) along the Great Australian Bight margin. Combined with the crustal structure classification of Leitchenkov et al. (2007) a revised model for the breakup and formation of the transitional zone was developed. The formation of the transitional zone is interpreted to be the result of extension of the two plates and the successive breakup of continental crust and mantle followed by the emplacement of oceanic mantle, initially without the formation of oceanic crust. The presence of the Moho within the seismic data shows that the transitional zone is underlain by mantle rocks. Continental mantle is interpreted to be exhumed to form prominent basement highs on both margins. Seaward of these highs, the change in basement architecture and the presence of magnetic anomaly 34 (83Ma) is interpreted to correlate with the juxtaposition of continental mantle and the emplacement of oceanic mantle. This is consistent with well subsidence data from Totterdell et al. (2000) which shows a change in the rate of subsidence at this time. The location of the Transitional Zone-Ocean Boundary (TZOB) and Transitional Zone- Continent Boundary (TZCB) are repositioned as a result of this study. The TZOB is located further landward of previous interpretations by Sayers et al. (2001) and Colwell et al. (2005). The interpretation of the transitional zone being underlain by mantle rocks renders the term Continent-Ocean Boundary (COB) invalid as, continental crust is not found immediately next to oceanic crust.

This includes collection of core from sonic drilling and soil and water samples from boreholes and surface water. The Core is stored in plastic in core trays (4 x 1m). The water samples are disposed of once analysed.

The Corporate Administrative Records Collection of Geoscience Australia (GA) is a bi fold collection; consisting of electronic/digital documents and records in physical paper format. The digital collection consists of electronic information, which may be "born digital" (created using computer technology) or converted into digital form from their original format (e.g. scans of paper documents). These records are created by all GA employees and are evidence of business conducted by GA and its predecessors. The location of these digital records is in TRIM (electronic document management system). This product treats documents and records in the same way, so that end users perform the same task on all items that are stored in the system, irrespective of whether the item is a document or is to be declared as a record. The digital records can be captured in any format; e.g. excel document, word document, pdf document, emails, etc. When a user saves a document for the first time in TRIM they are prompted for metadata, which is then used to create the record.

No abstract available

WorldInfo provides world-wide digital maps where the entire world coverage is in a single table and can be viewed in one Mapper.

No abstract available

This disc contains scanned PDF copies of uranium-related reports held by Geoscience Australia from the archives of the former Australian Atomic Energy Commission. These reports date from the early 1970s to early 1980s. The reports are a mix of exploration reports, geological and geographical maps, proposals, feasibility studies, estimations, reserve information, drill hole data and drill cross section files.

No abstract available

This study tested and assessed several methods for identifying and describing physical and chemical characteristics of nearshore sediments in East Antarctica. The study emphasised non-destructive techniques that can be used with small volumes of sample. There were three key aims: 1. Provide information about analytical techniques that are non-destructive and can be used on small-volume samples, 2. Apply these techniques to a set of samples where sufficient material is available and compare the results with the outcomes of traditional geochemical techniques, and, 3. Gain additional information on sedimentary processes in the nearshore environment in East Antarctica. Sediment samples from the Antarctic region are especially difficult to collect because of large logistical requirements and are thus highly valuable. Sediment traps are an example of samples with typically small volumes. Such samples provide valuable information about the nature and quantity of marine sediment in the water column and are highly sought after by researchers. By testing characterisation methods on larger samples, this scoping study provides recommendations for analysing small-volume samples, using non-destructive techniques and techniques that can provide additional information to traditional analysis. In this study, laser Raman spectroscopy and infrared spectroscopy were used to provide qualitative mineralogy for calcite, aragonite, and biogenic silica. Microtextural analysis of quartz grains was undertaken with a scanning electron microscope to provide information on the physical transport processes that the sediment has undergone. With this technique we were also able to identify chemical weathering features. Raman spectroscopy is a relatively rapid technique and has simple sample preparation requirements. The technique can target individual grains but can also measure bulk mineralogy. It is a promising technique for distinguishing mineral polymorphs but scope for quantification is limited for multi-component mixtures compared to traditional mineralogical methods like x-ray diffraction (XRD). Infrared spectroscopy is also quick and sample preparation is minimal. The technique requires more sample than will probably be recovered from sediment traps or sediment cores, at least 15 grams. For samples with large proportions of terrigenous sediment, distinguishing biogenic minerals is difficult because of low concentrations. Acquisition of more reference spectra for minerals of interest in marine substrates (particularly biogenic minerals) would be useful for comparing with sample spectra. Microtextural analysis provides detailed information about potential transport processes but sample preparation and analysis is time-consuming when compared to geochemical analysis. The technique is also somewhat destructive as quartz grains need to be cleaned and mounted. We recommend that an absolute minimum of 20 quartz grains is required for microtextural analysis. Microtextural analysis of sediments from near Davis Station suggests reworking of sediments in a subaqueous environment and minimal aeolian transport. There is also evidence of secondary silica precipitation and minor dissolution of quartz grains.

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