From 1 - 10 / 44
  • This Record presents 40Ar/39Ar chronologic results acquired in support of collaborative regional geoscientific investigations and mapping programs conducted by Geoscience Australia (GA) and the Northern Territory Geological Survey (NTGS). Argon isotopic data and interpretations from hornblende, muscovite, and biotite from seven samples collected from the Aileron Province in ALCOOTA , HUCKITTA, HALE RIVER, and ILLOGWA CREEK in the Northern Territory are presented herein. The results complement pre-existing geochronological constraints from U–Pb zircon and monazite analyses of the same or related samples, and provide new constraints on the thermal and deformation history of the Aileron Province. Three samples (2003082017, 2003082021, 2003083040) were taken from ALCOOTA in the northeastern portion of the Aileron Province. Biotite in sample 2003082017 from the ca 1.81 Ga Crooked Hole Granite records cooling below 320–280°C at 441 ± 5 Ma. Biotite in sample 2003082021 from the ca 1.73 Ga Jamaica Granite records cooling below 320–280°C at or after 414 ± 2 Ma. Muscovite in sample 2003083040 from the Delny Metamorphics, which were deposited after ca 1.82 Ga and preserve evidence for metamorphism at ca 1.72 Ga and 1.69 Ga, records cooling below 430–390°C at 399 ± 2 Ma. The fabrics preserved in the samples from the Crooked Hole Granite and Delny Metamorphics are interpreted to have formed due to dynamic metamorphism related to movement on the Waite River Shear Zone, an extension of the Delny Shear Zone, during the Palaeoproterozoic. Portions of the northeastern Aileron Province are unconformably overlain by the Neoproterozoic–Cambrian Georgina Basin, indicating these samples were likely at or near the surface by the Neoproterozoic. Together, these data indicate that rocks of the Aileron Province in ALCOOTA were subjected to heating above ~400°C during the Palaeozoic. Two samples (2003087859K, 2003087862F) of exoskarn from an indeterminate unit were taken from drillhole MDDH4 in the Molyhil tungsten–molybdenum deposit in central HUCKITTA. The rocks hosting the Molyhil tungsten–molybdenum deposit are interpreted as ca 1.79 Ga Deep Bore Metamorphics and ca 1.80 Ga Yam Gneiss. They experienced long-lived metamorphism during the Palaeoproterozoic, with supersolidus metamorphism observed until at least ca 1.72 Ga. Hornblende from sample 2003087859K indicates cooling below 520–480°C by 1702 ± 5 Ma and may closely approximate timing of skarn-related mineralisation at the Molyhil deposit; hornblende from sample 2003087862F records a phase of fluid flow at the Molyhil deposit at 1660 ± 4 Ma. The Salthole Gneiss has a granitic protolith that was emplaced at ca 1.79 Ga, and experienced alteration at ca 1.77 Ga. Muscovite from sample 2010080001 of Salthole Gneiss from the Illogwa Shear Zone in ILLOGWA CREEK records cooling of the sample below ~430–390°C at 327 ± 2 Ma. This may reflect the timing of movement of, or fluid flux along, the Illogwa Shear Zone. An unnamed quartzite in the Casey Inlier in HALE RIVER has a zircon U–Pb maximum depositional age of ca 1.24 Ga. Muscovite from sample HA05IRS071 of this unnamed quartzite yields an age of 1072 ± 8 Ma, which likely approximates, or closely post-dates, the timing of deformation in this sample; it provides the first direct evidence for a Mesoproterozoic episode of deformation in this part of the Aileron Province.

  • This Record presents new U–Pb geochronological data, obtained via Sensitive High Resolution Ion Micro Probe (SHRIMP), from 43 samples of predominantly igneous rocks collected from the East Riverina region of the central Lachlan Orogen, New South Wales. The results presented herein correspond to the reporting period July 2016–June 2020. This work is part of an ongoing Geochronology Project, conducted by the Geological Survey of New South Wales (GSNSW) and Geoscience Australia (GA) under a National Collaborative Framework agreement, to better understand the geological evolution and mineral prospectivity of the central Lachlan Orogen in southern NSW (Bodorkos et al., 2013; 2015; 2016, 2018; Waltenberg et al., 2019).

  • The Exploring for the Future program is an initiative by the Australian Government dedicated to boosting investment in resource exploration in Australia. The initial phase of this program led by Geoscience Australia focussed on northern Australia to gather new data and information about the potential mineral, energy and groundwater resources concealed beneath the surface. The northern Lawn Hill Platform is an intracratonic poly-phased history region of Paleoproterozoic to Mesoproterozic age consisting of mixed carbonates, siliciclastics and volcanics. It is considered a frontier basin with very little petroleum exploration to date, but with renewed interest in shale and tight gas, that may present new exploration opportunities. An understanding of the geochemistry of the sedimentary units, including the organic richness, hydrocarbon-generating potential and thermal maturity, is therefore an important characteristic needed to understand the resource potential of the region. As part of this program, Rock-Eval pyrolysis analyses were undertaken by Geoscience Australia on selected rock samples from 2 wells of the northern Lawn Hill Platform.

  • Geoscience Australia currently uses two commercial petroleum system modelling software packages, PetroMod https://www.software.slb.com/products/petromod and Zetaware http://www.zetaware.com, to undertake burial and thermal history modelling on wells in Australian sedimentary basins. From the integration of geological (age-based sedimentary packages, uplift and erosional events), petrophysical (porosity, permeability, and thermal conductivity) and thermal (downhole temperature, heat flow, vitrinite reflectance, and Tmax) input data, to name the most significant, a best-fit model of the time-temperature history is generated. Since the transformation of sedimentary organic matter (kerogen) into petroleum (oil and gas) is a chemical reaction, it is governed by chemical kinetics i.e. time and temperature (in the geological setting pressure is of secondary importance). Thus, the use of chemical kinetics associated with a formation-specific, immature potential source rock (where available) from the basin of interest is considered a better practical approach rather than relying on software kinetic defaults, which are generally based on the chemical kinetics determined experimentally on Northern Hemisphere organic matter types. As part of the Australian source rock and fluids atlas project being undertaken by the Energy Systems Group’s Exploring for the Future (EFTF) program, compositional kinetics (1-, 2-, 4- and 14-component (phase) kinetics) were undertaken by GeoS4, Germany. The phase kinetics approach is outlined in Appendix 1. This report provides the compositional kinetics for potential source rocks from the Ordovician Goldwyer (Dapingian–Darriwilian) Formation and the Bongabinni (Sandbian) Formation, Carribuddy Group, Canning Basin, Western Australia.

  • The Exploring for the Future program is an initiative by the Australian Government dedicated to boosting investment in resource exploration in Northern Australia. The Paleo- to Mesoproterozoic sedimentary and volcanic sequences of the Mount Isa–McArthur Basin region of Northern Territory and Queensland are host to a range of world class mineral deposits (Hutton et al., 2012) and include the basin-hosted base metal deposits of the North Australian Zinc Belt, the world’s richest belt of zinc deposits (Huston et al., 2006; Large et al., 2005). The region demonstrably has potential for additional world class mineral systems (Hutton et al. 2012), as well as potential to host shale gas plays (Gorton & Troup, 2018). An improved understanding of the chemistry of the host sedimentary units, including associated volcanic and intrusive rocks (potential metal source rocks) within these regions is therefore an important requisite to further understand the resource potential of the region. To assist in this we have undertaken a multi-year campaign (2016-2019) of regional geochemical sampling of geological units in the southeastern McArthur Basin, it’s continuation into the Tomkinson Province, and the Lawn Hill Platform regions of Northern Territory and northwest Queensland. Chief aims of the project were to characterise, as much as possible, the inorganic geochemistry of units of the Paleoproterozoic Tawallah, McArthur, Fickling and McNamara Groups and the Mesoproterozoic Roper and South Nicholson groups, with most emphasis on the Tawallah, McNamara and Fickling Groups. Minimal attention was paid to units of the McArthur Group which have been extensively previously sampled. The project also involved exploratory geochemical characterisation of sedimentary and igneous rocks from Paleoproterozoic and Mesoproterozoic rocks of the Tomkinson Province (Tomkinson, Namerinni and Renner groups) in Northern Territory. Minimal regional geochemical data exists for these rocks which are considered time equivalents of the Tawallah, McArthur, Nathan and Roper groups. The approach followed was based on targeting as many units as possible from drill core held within the core repository facilities of the Northern Territory and Queensland Geological surveys. Sampling strategy for individual units was based on targeting all lithological variability with particular emphasis on units not previously extensively sampled. Units were sampled at moderate to high resolution, with sampling density ranging from one sample per ~10 m intervals in organic rich intervals or lithological variable units, up to one sample per 20 to 50 m intervals in lithologically-monotonous units or in units recently sampled recently by GA or others. This data release contains the results of elemental analyses (XRF, ICP-MS), ferrous iron oxide content (FeO) and Loss-on-ignition (LOI) on 805 samples selected from 42 drill cores housed in the Geological Survey of Northern Territory’s Darwin and Alice Springs core repositories and in the Geological Survey of Queensland’s Brisbane and Mount Isa core repositories. Drillholes sampled include the Amoco holes DDH 83-1, DDH 83-2, DDH 83-3, DDH 83-4, and DDH 83-5, as well as 14MCDDH001, 14MCDDH002, 87CIIDH1, 87CIIDH2, Bradley 1, Broughton 1, DD81CY1, DD91RC18, DD91DC1, DD91HC1, DD95GC001, GCD-1, GCD-2A, GSQ Lawn Hill 3, GSQ Lawn Hill 4, GSQ Westmoreland 2, MWSD05, ND1, ND2, 12BC001, and Willieray (1DD, 3DD, 8DD), Hunter (1DD, 2DD, 3DD) and HSD001, HSD002 holes from the Tomkinson Province. The data also include a small number of non-basin samples (from drill holes AAI POTALLAH CREEK 1, ADRIA DOWNS 1, Bradley 1, GSQ Normanton 1, GSQ Rutland Plains 1, MULDDH001 and MURD013), collected at the same time, largely for isotopic studies. The resultant geochemical data was largely generated at the Inorganic Geochemistry Laboratory at Geoscience Australia (509 of the 805 analyses), with two batches (296 samples) analysed by Bureau Veritas in Perth. Eighteen samples analysed at GA were also reanalysed at Bureau Veritas for QA/QC purposes. All data was collected as part of the Exploring for the Future program. The report also includes a statistical treatment of the geochemical data looking at laboratory performance, based on certified reference material (CRMs) and sample duplicates, and interlaboratory agreement, based on samples analysed at both laboratories. Results show accuracies were within acceptable tolerances (±2 SD) for the majority of major and trace elements analysed at both laboratories. Notable exceptions included significant negative bias for Fe2O3 and positive bias for Na2O at Geoscience Australia. The results also showed that Mo (and As and Be) measurements were a consistent problem at GA, and Zn a consistent problem at BV. Precision (reproducibility) for major elements at both laboratories was very good, generally between 1 to 5%. Precisions for trace elements, varied from generally 5% or better at Geoscience Australia, and mostly between 5 and 10% for Bureau Veritas. Importantly, agreement between laboratories was good, with the majority of elements falling within ±5% agreement, and a few within 5-10% (Th, Tb, Sr, Zn, Ta, and Cr). Major exceptions to this included Na2O, K2O, Rb, Ba and Cs, as well as P2O5 and SO3, as well as those trace elements commonly present in low concentrations (e.g., Cu, As, Be, Mo, Sb, Ge, Bi). The mismatch between the alkalis is notable and of concern, with differences (based on median values) of 17% and 22% for K2O and Ba (higher at Bureau Veritas) and 32% and 300% for Ba and Na2O (higher at Geoscience Australia). The geochemical data presented here have formed the basis for ongoing studies into aspects of basin-hosted mineral systems in the McArthur–Mount Isa region, including insights into sources of metals for such deposits and delineating alteration haloes around those deposits (Champion et al., 2020a, b).

  • As part of the Onshore Energy Systems Group’s program, organic maturation levels were determined using polar compounds from potential source rocks from the Georgina and Canning basins. The Early Paleozoic organic matter is devoid of the vitrinite maceral so unsuitable of the measurement of the industry-standard vitrinite reflectance (Ro%) measurement.

  • As part of the Onshore Energy Systems Group’s program, late gas (methane) and compositional kinetics (1-, 2-, 4- and 14-component (phase) kinetics) were undertaken by GeoS4, Germany. The phase kinetics approach is outlined in Appendix 1. This report provides the data required to access the shale gas potential of source rocks from the Georgina Basin, Australia.

  • Geoscience Australia, CSIRO, and the Australian Space Agency collaboratively developed a 2-page A4 flyer to promote education and careers in space to students and teachers. The flyer showcases Australia's unique capability in the space sector, far beyond astronomers and astronauts. It also lists QR codes of several Australian educational resources on a diversity of space topics for preschoolers through to university students. It is designed to be shared virtually or in person with stakeholders interested in promoting space science literacy and careers.

  • Australian Resource and Energy Infrastructure map is a national view of Australia's mineral resources and energy infrastructure, Base scale of 1:5,000,000.

  • NDI Carrara 1 is a deep stratigraphic drill hole (~1751m) completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI) in collaboration with Geoscience Australia and the Northern Territory Geological Survey. It is the first test of the Carrara Sub-basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys (L210 in 2017 and L212 in 2019) recently acquired as part of the Exploring for the Future program. The drill hole intersected approximately 1100 m of Proterozoic sedimentary rocks uncomformably overlain by 630 m of Cambrian Georgina Basin carbonates. This report presents inorganic geochemical analyses undertaken by Geoscience Australia on selected rock samples, collected at roughly 4 m intervals.