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36422 record(s)
 
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From 1 - 10 / 36422
  • A multicomponent seismic survey using an IVI MiniVib as a source was carried out to assist in mapping of fracture porosity in shear zones in areas of dryland salinity for the School of Biological, Earth and Environmental Sciences (UNSW). The survey obtained a set of three dimensional, three component data at two sites near Spicers Creek, some 45km east of Dubbo. The acquisition was undertaken by Australian National Seismic Imaging Resource (ANSIR) from the 5th to the 12th April 2003 with the assistance of staff from UNSW. The objectives of this seismic survey are: 1. Develop quantitative measure of azimuthal anisotropy of P- and S-waves using refracted head wave amplitudes. 2. Determine the relative effects of lithological fabric and fracture porosity on P- and S-wave anisotropy factors. 3. Determine quantitative relationships between azimuthal anisotropy and fracture porosity. 4. Measure the horizontal and vertical variability of the fracture porosity in the fracture zones which control the discharge of saline groundwater and the occurrence of dryland salinity at the three experimental sites in the Spicers Creek Catchment. 5. Develop cost-effect field techniques for 3D - 3C (three dimensional - three component) shallow seismic refraction surveys for geotechnical, environmental and groundwater applications. Raw data for this survey are available on request from clientservices@ga.gov.au

  • This dataset contains the limit and extent of Northern Australia as defined by the Northern Australia Infrastructure Facility Act 2016 (https://www.legislation.gov.au/Details/C2021C00228) and Northern Australia Infrastructure Facility Amendment (Extension and Other Measures) Act 2021 (https://www.aph.gov.au/Parliamentary_Business/Bills_Legislation/bd/bd2021a/21bd062).

  • This service represents the National Digital Elevation Model (DEM) 1 Second Percentage Slope product, derived from the National DEM SRTM 1 Second. Slope measures the inclination of the land surface from the horizontal. Percent slope represents this inclination as the ratio of change in height to distance.

  • The Marine Survey Multibeam Bathymetry Web Map Service contains the highest-resolution multibeam bathymetry grids available for download on Geoscience Australia's website. These bathymetry grids were collected over numerous multibeam survey programs conducted in Australian mainland and Antarctic waters by both Geoscience Australia and our collaborators. Layers are grouped by survey or region and where available include both the Geoscience Australia and vessel survey identification numbers that contributed to the bathymetry grids. Bathymetry grids have been rendered over a rainbow colour-ramp with minimum and maximum depth values unique for each survey. These values are specified in each survey's layer description. The resolution of each bathymetry grid is also specified in each survey's layer description

  • Small angle neutron scattering (SANS) and ultra-small angle neutron scattering (USANS) are used to directly detect the processes of hydrocarbon generation in the 10 nm to 10 μm size pores in carbonate and siliciclastic rocks which contain no land-plant material suitable for conventional maturity determination by vitrinite reflectance. The method takes advantage of the pore-size-specific variation of neutron scattering contrast between the solid rock matrix and pore-space content with depth, which is caused by thermal maturation of organic matter through the oil and gas generation windows. SANS and USANS measurements were performed on bedding plane-orientated core slices, extracted from a series of 10 to 12 depth intervals for three wells, CKAD0001, MacIntyre 1 and Baldwin 1 in the southern Georgina Basin, central Australia. The depth intervals, intersecting the organic-rich basal ‘hot’ shales of the middle Cambrian Arthur Creek Formation, were selected based on Rock-Eval pyrolysis data. SANS and USANS results indicate that oil generation has occurred in the past in nano-sized pores in rocks that are now at depths of around 538.4 m in CKAD0001 and 799.3 m in MacIntyre 1. Furthermore, in the CKAD0001 well, the oil-wet pores extend into the larger pore-size range (at least up to 10 μm) due to the efficient expulsion of oil. At around 880 m in Baldwin 1, the influence of pyrobitumen reverts pore space from gas wet to oil wet. These hydrocarbons have remained in situ since the Devonian when the Neoproterozoic to Paleozoic section was exhumed in the Alice Springs Orogeny and subsequently eroded, preserving only remnants of the once extensive basin sediments.

  • <p>Summary <p>Spring point locations compiled for the Nulla Basalt Province <p>A compilation of spring locations as identified through various methods, including existing Queensland Springs Database, topographic mapping, fieldwork visits, landholder citizen scientist mapping, and inspection for neighbouring similar features in Google Earth. This compilation has had locations adjusted through inspecting visible imagery and elevation data to identify the likely positions of springs at higher resolution.

  • The Tasmante bathymetry survey, GA-0125 was acquired by Geoscience Australia onboard the IFREMER N/O L'Atalante from the 12th of February to the 28th of March 1994 using a Simrad EM12 Dual sonar system. The objectives of the west Tasmanian swath-mapping cruise (Tasmante) are to: determine the structure of the continental margin off west Tasmania, on the South Tasman Rise, and on the adjacent abyssal plain; examine the relationships between lithospheric extension in continental crust, the orientation of the seafloor spreading phases, and the formation of the transform margin along west Tasmania and the South Tasman Rise; map sedimentary patterns and processes to build an understanding of Neogene changes in sedimentation and their relationship to tectonic and climatic. This dataset contains a 100m resolution 32-bit geotiff of the Tasmante survey, produced from the processed EM12D bathymetry data of the survey area using the CARIS HIPS and SIPS software. This dataset is published with the permission of the CEO, Geoscience Australia. Not to be used for navigational purposes.

  • The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This radiometric thorium grid has a cell size of 0.001 degrees (approximately 110m) and shows thorium element concentration of the Urapunga, NT, 1994 survey. The data used to produce this grid was acquired in 1994 by the NT Government, and consisted of 68000 line-kilometres of data at 500m line spacing and 100m terrain clearance.

  • Legacy product - no abstract available