CONTINENTAL DRIFT AND BASIN DEVELOPMENT IN SOUTH EASTERN AUSTRALIA

The Gippsland, Bass and Otway Basins in southeastern Australia are filled with sediments ranging in age from earliest Cretaceous to Recent. These basins were formed from the processes and forces which fragmented the Pacific margin of Gondwanaland. Their sedimentary histories and tectonic styles locate and date the movement of those continental masses now detached.An Early Cretaceous rift valley extended from the Otway Basin through the Gippsland Basin and on to Lord Howe Rise, (a part of eastern Australia at that time). A transform fault separated Tasmania and Antarctica resulting in the continuing detachment of Antarctica.During the Late Cretaceous, Australia drifted from Antarctica sufficiently to allow the Southern Indian Ocean to invade the Otway Basin and the build-out of river deltas. The Otway continental crust was further stretched, resulting in normal faulting and block rotation. Crustal tension continued in the Gippsland Basin and opened the Bass Basin. Fluvial sediments were deposited in both basins. The Tasman Basin was opened.During the Early Tertiary, crustal tension continued to shape the Bass and Gippsland Basins, where thick, fluvial sediments were deposited. The first marine indicators in Gippsland are Paleocene in age and, during the Eocene, two large submarine valleys were cut and filled and a regional unconformity was developed. Early Tertiary marine elastics prograded into the Southern Indian Ocean.Mid-Tertiary marine shales, marls and limestones formed the continental margin of the Otway Basin and gently filled the Bass Basin. In the Gippsland Basin the same -aged sediments unconformably truncated and sealed Early Tertiary sandstones and contructed the continental slope into the Tasman Sea, while a right lateral shear formed the producing structures.

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Tectonic evolution of the Pacific margin of Antarctica 2. Structure of Late Cretaceous-early Tertiary plate boundaries in the Bellingshausen Sea from seismic reflection and gravity data

Journal of Geophysical Research Atmospheres ◽

10.1029/2002jb001897 ◽

2002 ◽

Vol 107 (B12) ◽

pp. EPM 6-1-EPM 6-20 ◽

Cited By ~ 19

Author(s):

Alex P. Cunningham ◽

Robert D. Larter ◽

Peter F. Barker ◽

Karsten Gohl ◽

Frank O. Nitsche

Keyword(s):

Late Cretaceous ◽

Tectonic Evolution ◽

Seismic Reflection ◽

Gravity Data ◽

Plate Boundaries ◽

Early Tertiary ◽

The Pacific ◽

Bellingshausen Sea ◽

Pacific Margin

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MAPPING THE PLATE TECTONIC RECONSTRUCTION OF SOUTHERN AND SOUTHEASTERN AUSTRALIA AND IMPLICATIONS FOR PETROLEUM SYSTEMS

The APPEA Journal ◽

10.1071/aj00001 ◽

2001 ◽

Vol 41 (1) ◽

pp. 15 ◽

Cited By ~ 82

Author(s):

M.S. Norvick ◽

M.A. Smith

Keyword(s):

Second Phase ◽

Continental Margins ◽

Ocean Crust ◽

Petroleum Systems ◽

Southeastern Australia ◽

Structural Style ◽

Oceanic Spreading ◽

Tasman Sea ◽

Eastern Australia ◽

Thermal Subsidence

Southern Australian breakup history is divisible into three phases. The first phase began with Callovian (c.159–165 Ma) rifting in the western Bight Basin. During the Tithonian (c.142–146 Ma), rifting extended eastwards into the Duntroon, Otway and Gippsland Basins. By the Valanginian (c.130–135 Ma), ocean crust formed between India and western Australia. Structural style in the western Bight changed to thermal subsidence. However, fluvio-lacustrine rift sedimentation continued in Duntroon, Otway and Gippsland until the Barremian (c.115–123 Ma) when these basins also changed to thermal subsidence. The diachronous progression of basin fill types produces a progressive shift in ages of potential source, seal and reservoir intervals along the margin.The second phase began during the Cenomanian (c.92–97.5 Ma) with uplift in eastern Australia, stress reorganisation and divergence of basin development. The Otway, Sorell and Great South Basins formed in a transtensional regime. These tectonics resulted in trap generation through faulting, inversion and wrenching. During the Santonian, oceanic spreading began in the southern Tasman Sea (c.85 Ma). Slow extension caused thinning of continental crust in the Bight and Otway Basins and subsidence into deeper water. Ocean crust formed south of the Bight Basin in the Early Campanian (c.83 Ma) and also started extending up the eastern Australian coast.The third stage in development was caused by Eocene changes to fast spreading in the Southern Ocean (c.44 Ma), final separation of Australia and Antarctica, and cessation of Tasman Sea spreading. These events caused collapse of continental margins and widespread marine transgression. The resultant loading, maturation and marine seal deposition are critical to petroleum prospectivity in the Gippsland Basin.

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An Aerial Survey of 3 Game Species of Waterfowl (Family Anatidae) Populations in Eastern Australia

Wildlife Research ◽

10.1071/wr9860213 ◽

1986 ◽

Vol 13 (2) ◽

pp. 213 ◽

Cited By ~ 17

Author(s):

LW Braithwaite ◽

M Maher ◽

SV Briggs ◽

BS Parker

Keyword(s):

Surface Waters ◽

New South ◽

New South Wales ◽

Aerial Survey ◽

Game Species ◽

South Wales ◽

Black Duck ◽

The Pacific ◽

Eastern Australia ◽

Central Eastern

Populations of waterfowl of three game species, the Pacific black duck Anus superciliosa, grey teal A. gibberifrons, and maned duck Chenonetta jubata, were assessed by aerial survey in October 1983 within a survey region of 2 697 000 km2 of eastern Australia. The numbers of each species were assessed on all surface waters of over 1 ha, and on a sample of smaller surface waters within 10 survey bands each 30 km wide and spaced at intervals of 2� latitude from 20�30' to 38�30'S. The area within the survey bands was 324 120 km2, which gave a sampling intensity of 12.0% of the land surface area. The area of features shown as wetlands or water impoundments within the survey bands on 1 : 2 500 000 topographic maps was 19 200 km2 or 11.2% of the total area of these features in the survey region. The area of surface waters surveyed was assessed at 465 300 ha. Assessments of populations of each species were tallied for wetlands by grid cells of 6 min of 1� longitude along the survey bands (258-309 km2 depending on latitude). Distributions were then mapped, with log*10 indices of populations in each cell. Distributions of the black duck and grey teal showed a pattern of intense aggregation in limited numbers of cells, that of the maned duck was more evenly distributed. The major concentrations of the Pacific black duck were recorded in northern New South Wales and the south-eastern, western, central eastern and central coastal regions of Queensland; those of the grey teal were in south-western, western and northern New South Wales and central-eastern Queensland; the maned duck was broadly distributed over inland New South Wales with the exception of the far west, inland southern Queensland, and central northern Victoria.

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Towards community-driven paleogeographic reconstructions: integrating open-access paleogeographic and paleobiology data with plate tectonics

Biogeosciences ◽

10.5194/bg-10-1529-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 1529-1541 ◽

Cited By ~ 42

Author(s):

N. Wright ◽

S. Zahirovic ◽

R. D. Müller ◽

M. Seton

Keyword(s):

Ocean Circulation ◽

Plate Tectonics ◽

Numerical Models ◽

Plate Motion ◽

Temporal Data Mining ◽

Dynamic Topography ◽

Southeastern Australia ◽

Eastern Australia ◽

Spatio Temporal ◽

Fossil Data

Abstract. A variety of paleogeographic reconstructions have been published, with applications ranging from paleoclimate, ocean circulation and faunal radiation models to resource exploration; yet their uncertainties remain difficult to assess as they are generally presented as low-resolution static maps. We present a methodology for ground-truthing the digital Palaeogeographic Atlas of Australia by linking the GPlates plate reconstruction tool to the global Paleobiology Database and a Phanerozoic plate motion model. We develop a spatio-temporal data mining workflow to validate the Phanerozoic Palaeogeographic Atlas of Australia with paleoenvironments derived from fossil data. While there is general agreement between fossil data and the paleogeographic model, the methodology highlights key inconsistencies. The Early Devonian paleogeographic model of southeastern Australia insufficiently describes the Emsian inundation that may be refined using biofacies distributions. Additionally, the paleogeographic model and fossil data can be used to strengthen numerical models, such as the dynamic topography and the associated inundation of eastern Australia during the Cretaceous. Although paleobiology data provide constraints only for paleoenvironments with high preservation potential of organisms, our approach enables the use of additional proxy data to generate improved paleogeographic reconstructions.

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Aplysiid species from Eastern Australia with notes on the Pacific Ocean Aplysiomorpha (Gastropoda, Opisthobranchia)

The Transactions of the Zoological Society of London ◽

10.1111/j.1096-3642.1977.tb00373.x ◽

2010 ◽

Vol 34 (1) ◽

pp. 87-147 ◽

Cited By ~ 14

Author(s):

Alan Bebbington

Keyword(s):

Pacific Ocean ◽

The Pacific ◽

Eastern Australia ◽

The Pacific Ocean

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Cold seeps and benthic habitat on the Pacific margin of Canada

Continental Shelf Research ◽

10.1016/j.csr.2010.02.013 ◽

2011 ◽

Vol 31 (2) ◽

pp. S85-S92 ◽

Cited By ~ 15

Author(s):

J. Vaughn Barrie ◽

Sarah Cook ◽

Kim W. Conway

Keyword(s):

Benthic Habitat ◽

Cold Seeps ◽

The Pacific ◽

Pacific Margin

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Response of the Snowy River Estuary to two environmental flows

Proceedings of the Royal Society of Victoria ◽

10.1071/rs15016 ◽

2015 ◽

Vol 127 (2) ◽

pp. 28

Author(s):

Errol J. McLean ◽

Jon B. Hinwood

Keyword(s):

Fresh Water ◽

Peak Flow ◽

Environmental Flows ◽

River Estuary ◽

Environmental Flow ◽

River Channel ◽

Salinity Gradients ◽

Tasman Sea ◽

Eastern Australia ◽

Major River

The Snowy River is a major river in south-eastern Australia, discharging to the Tasman Sea via a barrier estuary, with its entrance constricted by marine sands. Since the construction of the Snowy Mountains Scheme, river flows have not been sufficient to maintain the river channel. A program of environmental flow releases (EFR) is returning water to the river to restore the fluvial reaches and is now trialling flow regimes that may also benefit the estuarine reaches. This paper documents the response of the estuarine segments of the Snowy River to two EFRs; the release in 2010 was designed to scour the upper reaches of the Snowy River while the larger 2011 release was intended to extend the scouring downstream. For each release, the effects on the entrance morphology, tides and salinity through the flow peak and recovery are described. Each EFR caused minor increases in depth and very minor longshore movement of the entrance channel, although each EFR had been preceded by a larger fresh flow that would have scoured the channels. The small increase in fresh water inflow in the 2010 EFR pushed salinity contours seawards and steepened vertical salinity gradients. The larger inflow in the 2011 EFR purged the upper estuary of saltwater. After the peak flow, salinity recovery was rapid in the principal estuarine channels but took weeks where poorly connected wetlands could store fresh flood waters. Critical flows for scouring the entrance and purging salinity are estimated.

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Mid Pleistocene arid shift in southern Australia, dated by magnetostratigraphy

Soil Research ◽

10.1071/sr99089 ◽

2001 ◽

Vol 39 (1) ◽

pp. 89 ◽

Cited By ~ 24

Author(s):

Brad Pillans ◽

Robert Bourman

Keyword(s):

Marked Change ◽

Source Area ◽

Pronounced Change ◽

Sea Levels ◽

Leeuwin Current ◽

Polarity Transition ◽

Tasman Sea ◽

Eastern Australia ◽

Regional Climates ◽

Regional Rainfall

In coastal sections at Hallett Cove and Sellicks Beach, south of Adelaide, and at Redbanks section on Kangaroo Island, the Brunhes/Matuyama polarity transition (780 ka) is identified in the strongly oxide-mottled Ochre Cove Formation. At all 3 sections, the Ochre Cove Formation is overlain by a calcareous grey-green aeolian clay, called Ngaltinga Clay, which in turn is overlain by calcareous sediments of the Taringa and Christies Beach Formations. The marked change from an oxide-dominated weathering regime to a carbonate-dominated weathering regime, estimated to have occurred at about 500–600 ka, is interpreted as a major arid shift in regional climates. Similar arid shifts are known from Lake Bungunnia in the Murray Basin and Lake Lefroy in southern Western Australia, where changes from lacustrine clays to evaporites and dune sediments are estimated to have occurred between 400 and 700 ka, and about 500 ka, respectively. An increase in aeolian dust accession in south-eastern Australia, consistent with increased aridity in the interior source area, occurred after 780 ka, and was probably coeval with increased dust input to Tasman Sea sediments since 350 ka. Between 600 and 900 ka, oxygen isotope fluctuations in deep-sea cores showed a pronounced change in frequency, from a 40 ka (obliquity dominated) to a 100 ka (eccentricity dominated) pattern. At the same time, glacial-interglacial amplitudes increased, with a marked enrichment of glacial d18O values consistent with larger continental based ice-sheets. Colder global temperatures, and lower sea levels during glacials, may have played a part in the mid Pleistocene arid shift recorded in southern Australia. Associated variations in the strength of the warm Leeuwin Current may also have affected regional rainfall patterns in southern Australia.

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