- Research Taps into Hydrocarbon Exploration of Volcanic Passive Margin Basins
- Research Sheds Light on South Australian Uranium Deposits.
- Geological Data Offers Insight into Arabian Nubian Shield.
- U-Pb zircon, zircon Hf and whole rock Sm-Nd isotopic constraints on the evolution of Paleoproterozoic rocks in the northern Gawler Craton.
- Cooling and Exhumation history of the northeastern Gawler Craton, South Australia.
- Genesis and preservation of a U-rich Palaeozoic epithermal system with a surface expression (Northern Flinders Ranges, South Australia): radiogenic heat driving regional hydrothermal circulation over geological timescales.
- Minor elements in bornite and associated Cu-sulfides: a LA-ICPMS study.
- Gold Biomineralisation Insights Offer Implications for Exploration and Extraction.
- Thermal weakening localizes intraplate deformation along the southern Australian continental margin
- 'Passive' continental margins - not so passive after all?
Global hydrocarbon exploration is increasingly focussed on passive margin basins. However exploration of continental margins poses major risks due to the significant geological uncertainties from sparse data coverage and their poorly understood formation and evolution.
An important geological risk associated with exploration in almost all passive margins is the presence of volcanic rocks. Volcanic activity is a key outcome of lithospheric stretching processes and thus all extensional sedimentary basins located along passive margins witness some degree of intrusive and extrusive activity during their life spans.
A project involving University of Adelaide researchers* used mineralogy and geochemistry of ore materials and sediments to gain understanding of the geological formation of the Beverley uranium deposit.
The research team used a range of techniques including the determination of heavy mineral provenance, thereby identifying the critical role of the emergence of the Mt Painter basement block due to tectonic uplift in the late Miocene time, as a critical source of uranium.
They found Beverley mineralisation is mostly composed of coffinite with minor uraninite and associated native copper, pyrite, marcasite, carnotite, sphalerite, barite and chalcopyrite. The presence of native lead necessitates highly reducing sulphur-poor microenvironments while using the groundwater composition and observed mineralogy, the conditions during mineralisation are estimated as pH 6.3 to 8.4.
However the upper part of the mineralisation at Beverley has a different mineralogy which records acidic oxidising conditions (carnotite, no coffinite, alunite, kaolinite, goethite and gypsum) with prevailing conditions of pH 3.9 and 4.5. U-Pb dating of coffinite and carnotite suggest that the U mineralisation is Pliocene (6.7-3.4 Ma).
* Wulser P, Brugger J, Foden J, Pfeifer H, 2011, ‘The Sandstone-Hosted Beverley Uranium Deposit, Lake Frome Basin, South Australia: Mineralogy, Geochemistry and a Time-Constrained Model for Its Genesis', Economic Geology, v 106, pp835-867.
Researchers from University of Adelaide, Saudi Geological Survey and Curtin University of Technology # offer new insights into the amalgamation of Gondwana across the northern East African Orogen (a belt in the Earth's crust involved in mountain formation). The findings have implications for the minerals and petroleum industry.
# Cox, G.M. Lewis, C. J; Collins, A. S; Halverson, G. P; Jourdan, F; Foden J; Nettle D; Kattan F (2011) Ediacaran terrane accretion within the Arabian-Nubian Shield, International Association for Gondwana Research, doi:10.1016/j.gr.2011.02.011
U-Pb zircon, zircon Hf and whole rock Sm-Nd isotopic constraints on the evolution of Paleoproterozoic rocks in the northern Gawler Craton.
Magmatic protoliths to orthogneisses in the northern Gawler Craton have ages of 1780-1750 Ma. Geochronology, isotopic data and geochemistry suggest that these orthogneisses can be considered as suitable sources to Paleoproterozoic basin sequences of the Gawler Craton and Curnamona Province.
Howard, K.E.; Hand, M.; Barovich, K.M.; Payne J.L.; Cutts, K.; Belousova, E. Australian Journal of Earth Sciences v. 58, p. 615-638.
This paper presents recent pressure-temperature and geochronological analysis of granulite facies metasediments in the poorly-exposed Mount Woods Inlier of the northeastern Gawler Craton, South Australia.
Forbes, C.J., Giles, D., Jourdan, F., Sato, K., Omori, S., Bunch, M. Precambrian Research
Genesis and preservation of a U-rich Palaeozoic epithermal system with a surface expression (Northern Flinders Ranges, South Australia): radiogenic heat driving regional hydrothermal circulation over geological timescales.
The authors have demonstrated that a radiogenic heat source have driven hydrothermal circulation over hundreds of millions of years, from the Permian to the present.
Brugger, J.; Wulser, P.A.; Foden, J. Astrobiology v. 11, p. 499-508.
This is the first detailed study of the distribution of trace elements in two common copper sulphide minerals, demonstrating systematic partitioning of, for example, Ag and Bi, during equilibration.
Cook, N.; Ciobanu, C.; Danyushevsky, L; Gilbert, S. Geochimica et Cosmochimica Acta v. 75, pp. 6473-6496.
Research team includes: Dr Frank Reith, Dr Barbara Etschmann, Professor Allan Pring and Professor Joel Brugger
The role of micro-organisms as the main drivers of metal mobility and mineral formation under Earth surface conditions is now widely accepted. However, it is commonly believed the formation of secondary gold (Au) in surface environments is attributed to abiotic processes, which are mediated by non-living chemical and physical factors in the environment.
Research by a group of expertsincluding IMER researchers Dr Frank Reith and Professor Joel Brugger, has found direct evidence that bacteria are actively involved in the biogeochemical cycling of rare and precious metals. The research has opened the way for the development of bioexploration and bioprocessing tools which could revolutionise the exploration for gold, improve gold extraction and assist hydrometallurgical processes.
New data was used to construct the most detailed map yet of the surface heat flow field of the southern Australian margin. New data was used to construct the most detailed map yet of the surface heat flow field of the southern Australian margin.
Holford, S.P.; Richard R. Hillis, R.R; Hand, M.; Sandiford, M.
'Passive' continental margins, such as that which that bounds the southern part of the Australian continent, are the scars that are left behind on the Earth's surface following the very intense tectonic activity that occurs when continents break apart to form new oceanic basins. The global hydrocarbon industry is increasingly focussing its attention on exploring passive margins in the search for new oil and gas resources, and thus understanding the processes involved in their formation are of paramount importance.
Stoker, M.S; Holford, S.P.; Hillis, R.R; Green, P.F.; Duddy, I.R. (2010) Cenozoic post-rift sedimentation off northwest Britain: Recording the detritus of episodic uplift on a passive continental margin. Geology, 38, 595-598.