Antarctic
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Physical and biological characteristics of benthic communities on the George V Shelf have been analysed from underwater camera footage collecting during Aurora Australis voyages in 2007/08 and 2010/11. The 2007/08 data revealed a high degree of variability in the benthic communities across the shelf, with the benthic habitats strongly structured by physical processes. Iceberg scouring recurs over timescales of years to centuries along shallower parts of this shelf, creating communities in various stages of maturity and recolonisation. Upwelling of modified circumpolar deep water (MCDW) onto the outer shelf and cross-shelf flow of high salinity shelf water (HSSW) create spatial contrasts in nutrient and sediment supply, which are largely reflected in the distribution of deposit and filter feeding communities. Long term cycles in the advance and retreat of icesheets (over millennial scales) and subsequent focussing of sediments in troughs such as the Mertz Drift create patches of consolidated and soft sediments, which also provide distinct habitats for colonisation by different biota. These interacting physical processes of iceberg scouring, current regimes and depositional environments, in addition to water depth, are important factors in the structure of benthic communities across the George V Shelf. In February 2010, iceberg B09B collided with the Mertz Glacier Tongue, removing about 80% or 78km from the protruding tongue. This event provided a rare opportunity to access a region previously covered by the glacier tongue, as well as regions to the east where dense fast ice has built up over decades, restricting access. The 2010/11 voyage imaged 3 stations which were previously beneath the floating tongue, as well as 9 stations covered by multi-year and annual fast ice since the mid 1970s.
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The Rayner Complex of East Antarctica is exposed between 45??80?E in the Enderby Land through Princes Elizabeth Land sector of East Antarctica. It is known to correlate with parts of present day India and to have been deformed and metamorphosed at high grades in the earliest Neoproterozoic (990-900 Ma). The age and origin of the protolith rocks of the Rayner Complex however remains largely unknown, as does the tectonic setting in which these rocks formed. New age data collected from the northern Prince Charles Mountains (eastern Rayner Complex), demonstrate that the pre-orogenic rocks from this region consist of: (1) volcanogenic and terrigenous sediments deposited between 1400 Ma and 1020 Ma in a magmatically active basin characterised by limited input from cratonic sources and, (2) probable syn-sedimentary granitoids dated to 1150 Ma. Our data confirm the continuity of the Rayner Complex into Prydz Bay, a region that preserves a remarkably similar geologic history but which is often differentiated from the Rayner Complex on the basis of a higher grade early Cambrian (~520 Ma) overprint. On the basis of our data we further conclude that the Rayner Complex protoliths likely in formed in a back-arc system that existed along the margin of the pre-Gondwana Indian craton. Anticlockwise P-T paths and high-T, low-P metamorphism associated with the inversion of the Rayner back-arc (990-900 Ma) suggest this event resulted from the accretion of a number of independent microplates, rather than continent-continent collision.
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To study the seafloor morpholofy on the George V land shelf, East Antarctica, over 2000 kilometres of high-frequency echo-sounder data were collected between February and March 2000. The acoustic facies are explained in terms of glacial and oceanographic influences on the shelf since the Last Glacial Maximum.
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The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.
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The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.
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The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.
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The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.
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The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.
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The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.
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The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.