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  • We present a new geological map of Warrumbungle Volcano created from volcanic facies field mapping, new geophysical, geochemical, and geochronological data as well as data from previous studies. Field mapping and petrography defined 19 volcanic and 2 mixed volcanic-sedimentary facies. Facies identification and distribution in conjunction with geochemical analyses indicate an early shield-forming phase of predominantly mafic and intermediate lavas and pyroclastic deposits, and minor felsic lavas deposited on an irregularly eroded basement of Surat and Gunnedah basin rocks. The shield was subsequently intruded by felsic intermediate to felsic magmas that formed dykes and other intrusions including possible cryptodomes, and also erupted as lava domes and block-and-ash-flow deposits. A radial dyke swarm cross-cuts most units, although is concentrated within basement sandstone surrounding the central area of the volcano, suggesting late inflation accompanied by dyke emplacement. Geochemistry indicates differentiation of a single although repeatedly recharged alkaline magmatic suite. Fractionation of olivine, Ti-magnetite and clinopyroxene occurred in mafic magmas, and after reaching 62 wt% SiO2 crystallisation of apatite and alkali feldspar took place. A new U-Pb zircon SHRIMP magmatic crystallisation age of 16.25 +/- 0.12 Ma on a felsic block-and-ash flow deposit is in agreement with the recalculated 40Ar/39Ar isochron dates of previous workers. Based on our mapping and the use of volcanic facies to define mappable units, we recommend the previous Warrumbungle Volcanics be elevated from formation to group status and renamed the Warrumbungle Volcanic Complex.

  • part-page item on matters related to the Australian Stratigraphy Commission and the Australian Stratigraphic Units Database. This column explains international connections and reviews several recent relevant articles.

  • Discusses requirements of a stratigraphic unit definition and why geoscientists should write more of them, where to research background information, where to get advice, and what standards apply.

  • This Officer Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Officer Basin is one of Australia's largest intra-cratonic sedimentary basins, spanning approximately 525,000 square kilometres. It contains a thick sedimentary sequence, ranging up to 10,000 m in depth, composed of rocks from the Neoproterozoic to Late Devonian periods. The basin features diverse depositional environments, including marine and non-marine siliclastic and carbonate units, evaporites, and minor volcanic deposits. The Neoproterozoic succession exhibits a range of depositional settings, including pro-delta to shelf, fluvial to shallow marine, lagoonal, glacial, and aeolian systems. The Cambrian to Ordovician sequence reveals evidence of fluvial, shallow marine, aeolian, sabkha to playa, and lacustrine settings. Volcanic rocks occur sporadically within the sequence, like the Cambrian Table Hill Volcanics in WA and the Neoproterozoic Cadlareena Volcanics in SA. The Officer Basin is considered a remnant of the larger Centralian Superbasin that formed during the Neoproterozoic, covering a vast region in central Australia. The Centralian Superbasin formed as a sag basin during the Tonian, accumulating fluvial, marine, and evaporitic sediments, followed by Neoproterozoic glacial deposits. The long-lasting Petermann Orogeny affected the earlier depositional systems, with extensive uplift along the northern margin of the basin leading to deposition of widespread fluvial and marine siliciclastic and carbonate sediments spanning the terminal Proterozoic to Late Cambrian. The Delamerian Orogeny renewed deposition and reactivated existing structures, and promoted extensive basaltic volcanism in the central and western regions of the basin. Later events are a poorly understood stage, though probably involved continued deposition until the Alice Springs Orogeny uplifted the region, terminating sedimentation in the Late Ordovician or Silurian. A suspected Late Devonian extensional event provided space for fluvial siliciclastic sediment deposition in the north-east. Today, the Officer Basin features four distinct structural zones: a marginal overthrust zone along the northern margin, a zone with rupturing by salt diapirs across the main depositional centre, a central thrusted zone, and a broad gently dipping shelf zone that shallows to the south.

  • This Carpentaria Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Carpentaria Basin is a vast intra-cratonic sedimentary basin situated on and offshore in north-eastern Australia, covering around 550,000 square kilometres across Queensland and the Northern Territory. It comprises predominantly sandstone-rich rock units deposited during sea level highs from the Late Jurassic to Mid Cretaceous. The basin overlies a heterogeneous Proterozoic basement and is separated from contemporaneous sedimentary structures by basement highs and inliers. Four main depocentres within the larger Carpentaria Basin form four major sub-basins: the Western Gulf Sub-basin, Staaten Sub-basin, Weipa Sub-basin, and Boomara Sub-basin. While the basin is extensive and continuous in Queensland, it becomes more heterogeneous and discontinuous in the Northern Territory. Remnants of the basin's stratigraphy, referred to as the Dunmarra Basin, are found along the Northern Territory coast and inland. The depositional history commenced during the Jurassic with down warping near Cape York Peninsula, resulting in the Helby beds and Albany Pass beds' concurrent deposition. The basin experienced marine transgressions during the Cretaceous, with the Gilbert River Formation widespread and the Wallumbilla Formation occurring during sea level highs. The Carpentaria Basin's strata are relatively undeformed and unmetamorphosed. The Northern Territory sequence displays slightly different stratigraphy, limited to the height of the Aptian marine transgression above the Georgina Basin. The Walker River Formation and Yirrkala Formation represent key units in this area, outcropping as tablelands and mesas largely unaffected by tectonism.

  • This Perth Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Perth Basin is a complex geological region extending along Australia's southwest margin for about 1,300 km. It comprises sub-basins, troughs, terraces, and shelves, hosting sedimentary rocks with coal, oil, gas, and significant groundwater resources. Off the coast of Western Australia, it reaches depths of up to 4,500 m, while its onshore part extends up to 90 km inland. The basin is bounded by the Yilgarn Craton to the east, and the Carnarvon and Bremer basins to the north and south. The basin's history involves two main rifting phases in the Permian and Late Jurassic to Early Cretaceous, creating 15 sub-basins with varying sedimentary thickness due to compartmentalization and fault reactivation. The sedimentary succession mainly comprises fluviatile Permian to Early Cretaceous rocks over Archean and Proterozoic basement blocks. Differences exist between northern and southern sequences, with the south being continental and the north featuring marine deposits. During the Permian, faulting and clastic sedimentation dominated, with marine transgressions in the north and continental rocks in the south. The Triassic saw a similar pattern, with the southern succession being continental and the northern succession showing marine deposits. The Kockatea Shale became a primary hydrocarbon source. The Jurassic period witnessed marine incursions in the central basin, while the Late Jurassic experienced sea level regression and deposition of the Yarragadee Formation. The Cretaceous saw the formation of the Early Cretaceous Parmelia Group due to heavy tectonic activity. The southern basin had a marine transgression leading to the Warnbro Group's deposition with valuable groundwater resources. Post-Cretaceous, Cenozoic deposits covered the basin with varying thicknesses. Overall, the Perth Basin's geological history reveals a diverse sedimentary record with economic and resource significance.

  • One page article discussing aspects of Australian stratigraphy; this article discusses new unit definitions, ne regional publications and changes to the membership of the Australian Stratigraphy Commission.

  • Geological maps are one of the most important datasets used in resource exploration and management. Despite increasing demand for subsurface resources such as minerals, groundwater and energy, maps of the inferred subsurface geology of Australia and other continents have been limited to small regions or jurisdictions. Here, we present the first seamless semi-continental chronostratigraphic solid geology dataset of the North Australian Craton. This dataset comprises five time slices of stratigraphic units: Cenozoic, Mesozoic, Paleozoic, Neoproterozoic and pre-Neoproterozoic. Interpretation of covered units is based on available data: surface geology and solid geology maps, magnetic intensity and gravity images, drilling logs, reflection seismic profiles and airborne electromagnetic soundings. In total, 2008 units have been mapped, all linked to the Australian Stratigraphic Units Database. So far, these maps have led to a refinement of sedimentary basin and tectonic province outlines, lessened the risks of mineral exploration through Australia’s extensive superficial cover, disclosed geological units known to host resources elsewhere, and highlighted undercover regions with poor geological constraints. <b>Citation:</b> Stewart, A.J., Liu, S.F., Bonnardot, M.-A., Highet, L.M., Woods, M., Brown, C., Czarnota, K. and Connors, K., 2020. Seamless chronostratigraphic solid geology of the North Australian Craton. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

  • Discussion of the uses made of the Australian Stratigraphic units database (ASUD), the sources of data to update it, and issues with maintaining quality. The importance of correct and consistent terminology, and the value of good reviews and editing are highlighted with examples.

  • This Gunnedah Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Gunnedah Basin is an intracratonic, sedimentary basin in northern NSW. It forms the middle section of the greater Sydney-Gunnedah-Bowen Basin system and mainly consists of Permian and Triassic sedimentary rocks resting on Late Carboniferous to Early Permian volcanics. The Gunnedah Basin is overlain by the Surat Basin and the younger alluvial sediments associated with modern and ancient river systems. The Gunnedah Basin is not considered a single well-connected aquifer, rather a series of porous rock aquifers separated by several non-porous or poorly conductive layers. The Lachlan Fold Belt forms what is thought to be an effective basement although little information is known of its hydrogeological properties. All units of the Gunnedah Basin are of low permeability and significantly lower hydraulic conductivity than the overlying alluvial aquifers. Most of the groundwater resources in the area are extracted from either the overlying Surat Basin or younger alluvial aquifers. There is relatively little groundwater sourced from the aquifers of the Gunnedah Basin, except in areas where the overlying aquifers do not occur. The most viable groundwater source in the Gunnedah Basin are the more porous aquifers of the Triassic sequence.