In Australia’s semi-arid and arid interior, groundwater resources provide water supply security for agriculture and community consumptive use and are critical for underpinning economic development. . The Southern Stuart Corridor Project in central Australia, is an inter-disciplinary study which aims to better characterise regional groundwater systems and identify the location, quantity and quality of new groundwater resources. The main aims of the project are(1) to de-risk investment in development of a potential agricultural precinct in the Western Davenport Basin, and expansion of horticulture in Ti-Tree Basin, (2) to identify future water supplies for Alice Springs and Tennant Creek, and (3) for regional water supplies for mineral resource development.The project is funded by Geoscience Australia (GA) as part of the Exploring for the Future (EFTF) Programme. The project integrates airborne electromagnetic (AEM), ground geophysics (ground magnetic resonance (GMR) and borehole geophysics (Induction, gamma and nuclear Magnetic Resonance (NMR)) with drilling and pump testing; hydrochemistry and geochronology; and geomorphic, geological, hydrogeological and structural mapping and modelling. Advancements in temporal remote sensing technologies for surface hydrology, vegetation and landscape mapping are also used to facilitate the identification of recharge and discharge zones and groundwater-dependent vegetation.This paper reports on initial AEM inversion results for the Alice Springs, Ti-Tree Basin, Western Davenport and Tennant Creek areas and the use of a machine learning approach for rapid geological and hydrogeological interpretation of the AEM data. These machine learning approaches have the potential to significantly reduce interpretation time and facilitate the rapid delivery of project results.
A large portion of the western offshore Victorian portion of the Otway Basin appears to have originally been underlain by an extensive horizontal basic magnetic sheet emplaced during the initial stages of basin formation. Subsequent basin extension along transfer faults trending at 210 degrees has fractured this sheet, and evidence of the transfer fault fracture system is given by the present day outlines of the magnetic anomalies arising from the fragments of the sheet. The transfer fault system is further indicated by linear magnetic anomalies within the sedimentary section due to magnetic material accumulated in the fault planes. Gravity and seismic data support the transfer fault model which can be used to explain features of the depositional history and structural development of the area.
The presence of Neogene fault systems can have a significant impact on hydraulic connectivity of aquifers, juxtaposing otherwise disconnected aquifers, enhancing recharge and/or discharge or acting as barriers to flow and consequently compartmentalising groundwater resources. Previously, regional airborne electromagnetics (AEM) transects allied with groundwater investigations have pointed to the potential for localised compartmentalisation of the Daly River Basin groundwater systems. However, existing data is sparse, and equivocal.In this context, the main aim of the Daly River Basin Project is to determine if compartmentalisation of the aquifers is a significant factor and thus should be explicitly considered in groundwater modelling and water allocation planning. The objectives of the project main goals of the project are to: (1) map Neogene faults through the use of airborne electromagnetic (AEM) and morphotectonic mapping, and (2) assess the permeability and transmissivity of mapped fault zones and their role in potential groundwater system compartmentalisation. Data acquisition includes 3325 line-kilometres of new AEM and airborne magnetics, ground (ground magnetic resonance (GMR)), and borehole geophysics, drilling, groundwater sampling and hydrochemical analysis, geomorphic and morphotectonics mapping. Hydrogeophysical, geomorphic and hydrogeological data will also be used to better understand groundwater-surface water connectivity and the potential for managed aquifer recharge schemes to replenish extracted groundwater resources. The outcomes of this project will inform decisions on water allocations and underpin effective and efficient groundwater use. This paper specifically reports on the ability of AEM and morphotectonics mapping to identify Neogene fault systems in the Daly River Basin.
Other| June 01, 2004 Sequence Biostratigraphy of Prograding Clinoforms, Northern Carnarvon Basin, Western Australia: A Proxy for Variations in Oligocene to Pliocene Global Sea Level? GRAHAM D. MOSS; GRAHAM D. MOSS 1The University of Texas at Austin, Jackson School of Geosciences, Institute for Geophysics, Austin, TX 78759-8500, moss_cathro@hotmail.com Search for other works by this author on: GSW Google Scholar DONNA L. CATHRO; DONNA L. CATHRO 2The University of Texas at Austin, Jackson School of Geosciences, Institute for Geophysics and Department of Geological Sciences, Austin, TX 78759-8500 *Current Address: Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia. Search for other works by this author on: GSW Google Scholar JAMES A. AUSTIN, JR. JAMES A. AUSTIN, JR. 3The University of Texas at Austin, Jackson School of Geosciences, Institute for Geophysics, Austin, TX 78759-8500 Search for other works by this author on: GSW Google Scholar PALAIOS (2004) 19 (3): 206–226. https://doi.org/10.1669/0883-1351(2004)019<0206:SBOPCN>2.0.CO;2 Article history accepted: 20 Jan 2004 first online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation GRAHAM D. MOSS, DONNA L. CATHRO, JAMES A. AUSTIN; Sequence Biostratigraphy of Prograding Clinoforms, Northern Carnarvon Basin, Western Australia: A Proxy for Variations in Oligocene to Pliocene Global Sea Level?. PALAIOS 2004;; 19 (3): 206–226. doi: https://doi.org/10.1669/0883-1351(2004)019<0206:SBOPCN>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyPALAIOS Search Advanced Search Abstract Sequence biostratigraphic analyses from five industry wells in the Northern Carnarvon Basin (NCB), Western Australia, are tied to seismic stratigraphic interpretations from a set of 3D and 2D seismic data. Distribution patterns of ∼286 benthic and 73 planktonic foraminiferal taxa in sidewall cores and ditch cuttings from Eocene to Pliocene intervals are documented and supplemented with observations of other fossil groups (e.g., fragments of ostracodes, bryozoans, corals, and mollusks) and lithological components such as calcite cement and quartz sand.Preservation of foraminiferal assemblages is extremely variable in latest Eocene to Pliocene stratigraphy, depending upon the location of wells and the interval investigated. Nonetheless, consistent, detectable faunal signals correlate between wells and with prominent seismic horizons and sequences. The late Oligocene to middle Miocene is characterized by deeper-water benthic assemblages dominated by infaunal taxa and a high planktonic abundance. Stratigraphic events in the middle Miocene, including turnover in benthic foraminifera, are interpreted to record a regional flooding event (equivalent to cycle Tejas B (TB) 2.3) at the beginning of the mid-Miocene climatic optimum (∼16–14.5 Ma). Following this event, seismically defined geomorphic features include karstification on the shelf and incision on the clinoform front.All wells show a major transition to shallow-water, warm conditions on the shelf in the middle and late Miocene, with benthic assemblages dominated by larger foraminifera. This transition appears higher in more-basinward wells and appears to be a result of progradation. Geomorphic features in the late middle Miocene (∼12 Ma) identified from 3D seismic analyses show an intensification of earlier gully formation, resulting in the development of submarine canyons. Detailed analyses of faunal patterns also provide evidence of higher-frequency sea-level fluctuations (0.5–3 Ma), not detected in the seismic stratigraphic patterns. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
The WestraliaSPAN 2D regional program extends across all basins of Australia’s North West Shelf (Carnarvon/Roebuck/Browse/Bonaparte basins) and Arafura regions. The survey is designed with long offset and record length (18 sec) acquisition parameters to image the important deep crustal and sub crustal architecture and depositional systems across this complex margin. The regional program provides unique, state-of-the-art depth imaging of deep-basement rift structures of the Westralian Superbasin, as well as the lower crust and Moho. The survey has multiple transects which cross the transition from continental to oceanic crust, that provide insight into the distribution of volcanics and a possible hyper-extended rift margin. An integrated geological and geophysical interpretation encompasses available well, seismic and potential field data. Gravity models were developed to aid in depth conversion and the structural interpretation of the deep crust and Moho. A comprehensive model of basin formation provides the context for regional correlation of tectonostratigraphic packages throughout these linked basin systems, highlighting pre-Jurassic rift basins and their structural controls. While the North West Shelf, Browse and Bonaparte basins are proven and established hydrocarbon provinces, a future step-change in exploration concepts involves an integrated, margin-scale understanding of these basin systems and their potential resources. Collectively, the new dataset and interpretation will aid explorers in understanding the nature and distribution of key petroleum systems elements (reservoir/source/seal) and processes (heatflow, timing of source maturity, expulsion, migration and entrapment).
The Early Permian to Middle Triassic Bowen and Gunnedah Basins in eastern Australia developed in response to a series of interplate and intraplate tectonic events that occurred to the east of the basin system. The initial event was extensional and stretched the continental crust to form part of the major Early Permian East Australian Rift System that occurred at least from far-north Queensland to southern New South Wales. The most important of the rift-related features, in a commercial sense, are a series of half-grabens that form the Denison Trough, now the site of several producing gasfields. The eastern part of the rift system commenced at about 305 Ma and was volcanic dominated. In contrast, the half-grabens in, and to the west of, the Bowen Basin were non-volcanic, and appear to have initiated significantly later, at about 285 Ma. These half-grabens are essentially north–south in length with an extension direction of approximately east-northeast. Mechanical extension appears to have ceased at about 280 Ma, when subsidence became driven by thermal relaxation of the lithosphere. The extension occurred in a backarc setting, in response to far-field stresses that propagated from the west-dipping subduction system at the convergent plate margin of East Gondwanaland that was located to the east of the East Australian Rift System.
Neogene fault systems are increasingly recognised as an important control on hydraulic connectivity in some of Australia’s energy rich basins. However, accurate delineation of these faults systems is challenging and expensive. In this context, the main objective of the Exploring for the Future (EFTF) Surat-Galilee Basin (Phase 1) Project is to test novel methods for more cost-effective mapping of Neogene fault systems in the Coal Seam Gas (CSG) basins of eastern Australia. Methods assessed in this project include morphotectonic mapping using temporal remote sensing data and high-resolution terrain mapping techniques, airborne electromagnetics (AEM), and the use of earthquake databases to inform active tectonic and geomechanical analysis.The project is funded by Geoscience Australia (GA) as part of its EFTF Programme, and is focussed on exemplar areas in the Surat and Galilee Basins where Neogene fault activity has been interpreted on high-resolution 2D and 3D seismic reflection surveys. This paper reports on the use of airborne electromagnetics (AEM) for detecting near-surface (<50-150m) Neogene faults in both basins. Approximately 4,500 line km of AEM data were acquired in a number of smaller acquisition blocks where Neogene faults had previously been identified. The AEM inversion results are compared with interpretation of seismic reflection data, morphotectonic mapping, and other hydrogeological and tectonic/geomechanical data. The utility of AEM to map the broader hydrogeological system in these basins, including groundwater-surface water connectivity (springs and rivers), is also assessed.
ABSTRACT The Late Ordovician‐Early Silurian Mallowa Salt of the Carribuddy Group, Canning Basin, north‐west Australia, is the largest halite deposit known in Australia, attaining thicknesses of 800 m or more within an area of approximately 200 000 km 2 . Study of 675 m of drill core from BHP‐Utah Minerals’ Brooke No. 1 well in the Willara Sub‐basin indicates that the Mallowa Salt accumulated within a saltern (dominantly subaqueous evaporite water body) that was subject to recurrent freshening, desiccation and exposure. Textures and bromine signatures imply a shallow water to ephemeral hypersaline environment typified by increasing salinity and shallowing into evaporitic mudflat conditions toward the top of halite‐mudstone cycles (Type 2) and the less common dolomite/anhydrite‐halite‐mudstone cycles (Type 1). The borate mineral priceite occurs in the capping mudstones of some cycles, reinforcing the idea of an increasing continental influence toward the top of mudstone‐capped halite cycles. The rock salt in both Type 1 and Type 2 cycles typically comprises a mosaic of large, randomly orientated, interlocking halite crystals that formed during early diagenesis. It only partially preserves a primary sedimentary fabric of vertically elongate crystals, some with remnant aligned chevrons. Intraformational hiati, halite karst tubes and solution pits attest to episodic dissolution. Stacked Type 2 cycles dominate; occasional major recharges of less saline, perhaps marine, waters in the same area produced Type I cycles. The envisaged saltern conditions were comparable in many ways to those prevailing during the deposition of halite cycles of the Permian Salado Formation in New Mexico and the Permian San Andres Formation of the Palo Duro Basin area in Texas. However, in the Canning Basin the cycles are characterized by a much lower proportion of anhydrite, implying perhaps a greater degree of continental restriction to the basin. The moderately high level of bromine in the Mallowa Salt (156·5 ± 43·5 ppm Br for primary halite, 146·1 ± 54·7 ppm Br for secondary halite) accords with evolved continental brines, although highly evaporative minerals such as polyhalite and magnesite are absent. The bromine levels suggest little or no dissolution/reprecipitation of primary halite and yet, paradoxically, there is little preservation of the primary depositional fabric. The preservation of early halite cements and replacement textures supports the idea of an early shutdown of brine flow paths, probably at burial depths of no more than a few metres, and the resultant preservation of primary bromine values in the secondary halite.
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