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.

part-page article on stratigraphic issues

One page article discussing aspects of Australian stratigraphy; this article discusses practical Australian solutions to igneous nomenclature and the indexing of relevant Antarctic units

This report was compiled and written to summarise the four-year Palaeovalley Groundwater Project which was led by Geoscience Australia from 2008 to 2012. This project was funded by the National Water Commission's Raising National Water Standards Program, and was supported through collaboration with jurisdictional governments in Western Australia, South Australia and the Northern Territory. The summary report was published under the National Water Commission's 'Waterlines' series. This document is supported by related publications such as the palaeovalley groundwater literature review, the WASANT Palaeovalley Map and associated datasets, and four stand-alone GA Records that outline the detailed work undertaken at several palaeovalley demonstration sites in WA, SA and the NT. Palaeovalley aquifers are relied upon in outback Australia by many groundwater users and help underpin the economic, social and environmental fabric of this vast region. ‘Water for Australia’s arid zone – Identifying and assessing Australia’s palaeovalley groundwater resources’ (the Palaeovalley Groundwater Project) investigated palaeovalleys across arid and semi-arid parts of Western Australia (WA), South Australia (SA) and the Northern Territory (NT). The project aimed to (a) generate new information about palaeovalley aquifers, (b) improve our understanding of palaeovalley groundwater resources, and (c) evaluate methods available to identify and assess these systems.

To test existing geological interpretations and the regional stratigraphic relationships of the Carrara Sub-basin with adjacent resource-rich provinces, the deep stratigraphic drill hole NDI Carrara 1 was located on the western flanks of the Carrara Sub-basin, on the seismic line 17GA-SN1. The recovery of high quality near-continuous core from the Carrara Sub-basin, in concert with the spectrum of baseline analytical work being conducted by Geoscience Australia through the EFTF program, as well as other work by government and university researchers is greatly improving our understanding of this new basin. While recently published geochemistry baseline datasets have provided valuable insight into the Carrara Sub-basin, the age of the sedimentary rocks intersected by NDI Carrara 1 and their chronostratigraphic relationships with adjacent resource rich regions has remained an outstanding question. In this contribution, we present new sensitive high-resolution ion microprobe (SHRIMP) geochronology results from NDI Carrara 1 and establish regional stratigraphic correlations to better understand the energy and base-metal resource potential of this exciting frontier basin in northern Australia.

This Daly 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 Daly Basin is a geological formation consisting of Cambrian to Ordovician carbonate and siliciclastic rocks, formed approximately 541 million to 470 million years ago. The basin stretches about 170 km in length and 30 km in width, shaped as a northwest elongated synform with gentle dips of less than 1 degree, likely due to prolonged sedimentary deposition in the shallow seas of the Centralian Superbasin, possibly along basin-scale faults. The primary groundwater reservoir within the Daly Basin is found in the Cambrian Daly River Group. This group comprises three units: the Tindall Limestone, Jinduckin Formation, and Oolloo Dolostone. The Tindall Limestone, which lies at the base, consists of grey, mottled limestone with some maroon-green siltstone or dark grey mudstone. The transition from the Tindall Limestone to the overlying Jinduckin Formation is marked by a shift from limestone to more siliciclastic rocks, indicating a change from open-shelf marine to peri-tidal environments. The Jinduckin Formation, situated above the Tindall Limestone, is composed of maroon-green dolomitic-siliciclastic siltstone with interbeds of dolomitic sandstone-siltstone, as well as dolostone and dolomitic quartz sandstone lenses. It gradually transitions into the carbonate-rich Oolloo Dolostone, with the highest finely laminated dolomitic sandstone-siltstone interbeds at the top of the Jinduckin Formation. The Oolloo Dolostone, the uppermost unit of the Daly River Group, comprises two members: the well-bedded lower Briggs Member, consisting of fine- to medium-grained crystalline dolostone and dolomitic quartz sandstone, and the massive upper King Member. Overlying the Daly River Group is the Ordovician Florina Formation, consisting of three carbonate intervals separated by two fine-grained, glauconite-bearing quartz sandstone units. The Florina Formation and the Daly River Group are covered unconformably by Cretaceous claystone and sandstone of the Carpentaria Basin, which extends over a significant portion of the Daly Basin.

Geoscience Australia has undertaken a regional seismic mapping study that extends into the frontier deep-water region of the offshore Otway Basin. This work builds on seismic mapping and petroleum systems modelling published in the 2021 Otway Basin Regional Study. Seismic interpretation spans over 18 000 line-km of new and reprocessed data collected in the 2020 Otway Basin seismic program and over 40 000 line-km of legacy 2D seismic data. Fault mapping has resulted in refinement and reinterpretation of regional structural elements, particularly in the deep-water areas. Structure surfaces and isochron maps highlight Shipwreck (Turonian–Santonian) and Sherbrook (Campanian–Maastrichtian) supersequence depocentres across the deep-water part of the basin. These observations will inform the characterisation of petroleum systems within the Upper Cretaceous succession, especially in the underexplored deep-water region. Presented at the 2022 Australian Petroleum Production & Exploration Association (APPEA)

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.

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 South Nicholson 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. This South Nicholson 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 South Nicholson Basin is a Mesoproterozoic sedimentary basin spanning Queensland and the Northern Territory and is bordered by neighbouring provinces and basins. The basin unconformably overlies the Lawn Hill Platform of the Mount Isa Province to the east, is bound by the Warramunga and Davenport provinces to the south-west, the Murphy Province to the north and the McArthur Basin to the north-west. It extends southwards under younger cover sequences. Rock units in the basin are correlated with the Roper Group in the McArthur Basin, forming the 'Roper Superbasin.' The underlying Mount Isa Province contains potential shale gas resources. The basin mainly consists of sandstone- and siltstone-bearing units, including the South Nicholson Group, with a prevailing east to east-northeast structural grain. Mild deformation includes shallowly plunging fold axes and numerous faults along a north-west to south-east shortening direction. Major geological events affecting the South Nicholson Basin region include the formation of the Murphy Province's metamorphic and igneous rocks around 1850 million years ago (Ma). The Mount Isa Province experienced deposition in the Leichhardt Superbasin (1800 to 1750 Ma) and Calvert Superbasin (1725 to 1690 Ma). The Isa Superbasin, with extensional growth faulting in the Carrara Sub-basin (~1640 Ma), deposited sediments from approximately 1670 to 1590 Ma. Subsequently, the South Nicholson Group was deposited around 1500 to 1430 Ma, followed by the Georgina Basin's sedimentation. The basin shows potential for sandstone-type uranium, base metals, iron ore, and petroleum resources, while unconventional shale and tight gas resources remain largely unexplored. The Constance Sandstone holds promise as a petroleum reservoir, and the Mullera Formation and Crow Formation serve as potential seals.