Legacy product - no abstract available

The data set provides outlines for the maximum extent of Australian geological provinces and their components, including sedimentary, igneous and metallogenic provinces, both onshore and offshore. These data were compiled as part of Geoscience Australia's integrated digital information system to provide improved accessibility and knowledge relating to the petroleum and minerals geology and prospectivity, and to provide a national stratigraphic and tectonic framework for Australia. The current dataset is not complete for Australia, and covers only offshore sedimentary provinces and a selection of sedimentary, igneous and metallogenic provinces in onshore Australia.

Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

No abstract available

The Harts Range Metamorphic Complex (HRMC) in the eastern Arunta Province is part of the exhumed core of the intracratonic Alice Springs Orogen. SHRIMP U-Pb dating of intrusive rocks and metamorphism in the HRMC has constrained the timing and character of tectonism, showing that mutliphase deformation under high grade metamorphic conditions spanned at least 50 m.y. The age of a syn-tectonic pegmatite dyke in the northern HRMC records ductile shearing on E-W trending shear zones during or just after the ~380 Ma Pertnjara Movement, possibly related to extension after the main contractional phase. The age of a second syn- to late-deformational pegmatite dyke in the eastern Harts Range suggests that a SW-vergent fold and thrust system in the eastern HRMC formed during the ~360 Ma Brewer Movement. This deformation coincided with the intrusion of small granitic bodies in the northern HRMC, and the formation of rare metamorphic zircon in metasedimentary rocks during a period of crustal thickening. Metamorphic monazite and zircon reflect high-grade metamorphism during the ~330 Ma Mount Eclipse Movement, which coincided with the formation of a flat-lying, kyanite grade foliation in basement rocks of the HRMC. This foliation and later large-scale doming might reflect extensional collapse of the Alice Springs Orogen towards the end of the orogenic cycle. 40Ar-39Ar cooling ages indicate that much of the HRMC was exhumed at that time. Localisation of ASO tectonism in the eastern Arunta Province appears to be a result of thermal weakening associated with the ~480-460 Ma Larapinta Event, which partitioned plate boundary stresses into central Australia.

Legacy product - no abstract available

The timing and duration of metamorphic events is commonly constrained by radiometric dating using the U-Pb or 40Ar-39Ar dating methods, or a combination of both. Each dating method can be applied to a different range of minerals, and a combination of the two methods can provide more complete timing constraints than either method on its own. Comparison of radiometric ages from different isotopic systems introduces the problem of systematic uncertainties arising from uncertainty in parameters such as decay constants and the age of method-specific reference materials. Over the past decade it has been increasingly recognized that the laboratory-based determinations of the 40K decay constants, on which the 40Ar-39Ar method is based, are relatively imprecise and that the values recommended by Steiger and Jager (1977) result in a systematic offset of 40Ar-39Ar ages relative to U-Pb-derived ages by up to ~1%. This problem has been addressed by several studies over the past decade, with the most recent study (Renne et al., 2010; 2011) providing refined estimates for the 40K decay constants, and very significant improvements in precision. Paleozoic and Paleoproterozoic examples will be presented which illustrate the improvements in the accuracy and precision of 40Ar-39Ar ages calculated using the revised decay constants, and discuss the implications for studies that use a combination of U-Pb and 40Ar-39Ar data to constrain the timing and duration of metamorphic, deformation, and mineralisation events. An Excel spreadsheet is available on request that allows recalculation of 40Ar-39Ar ages and uncertainties using the revised parameters of Renne et al. (2010; 2011), provided certain minimum information has been reported with the published ages.

The GIS is based on the "Mount Isa Inlier and Environs" 1:500 000 scale map (published in 1987), which was digitised and verified against geochemical and mineral deposit point data. A series of interpretative geological and geochemical coverages were derived from these map data and point datasets such as ROCKCHEM, OZCHRON, and MINERAL DEPOSITS. Geophysical byte images provide broad regional views showing the concealed extent of the province.