AndreaBozzo/ceres-open-data-index huggingface dataset:
Australia's Maritime Jurisdiction in the Timor Sea 2019

Map showing Australia's Maritime Jurisdiction in the Timor Sea. Updated in December 2019 from "Australia's Maritime Jurisdiction in the Timor Sea" (GeoCat 81849 (2014), GeoCat 68796) to reflect the 2018 Australia - Timor-Leste Maritime Boundaries Treaty.

One of the 27 constituent maps of the "Australia's Maritime Jurisdiction Map Series" (GeoCat 71789).Depicting Australia's continental shelf as proclaimed in the "Seas and Submerged Lands (Limits of Continental Shelf) Proclamation 2012" established under the "Seas and Submerged Lands Act 1973".

Background bathymetric image is derived from a combination of the 2009 9 arc second bathymetric and topographic grid by GA and a grid by Smith and Sandwell, 1997. Background land imagery derived from Blue Marble, NASA's Earth Observatory.

This map is indicative only of the location of the territorial sea baselines and the outer limits of Australia's maritime zones, and should NOT be used as a definitive source of information.  Some limits may be subject to change.

Tags: Administrative Boundaries, Administrative Boundary, Earth Sciences, Published_External, Thematic Map, bathymetry, marine, marine jurisdiction
Organization: Geoscience Australia Data
On the Use of Abiotic Surrogates to Describe Marine Benthic Biodiversity

A growing need to manage marine biodiversity at local, regional and global scales cannot be met by applying the limited existing biological data sets.  Abiotic surrogacy is increasingly valuable in filling the gaps in our knowledge of biodiversity hotspots, habitats needed by endangered or commercially valuable species and systems or processes important to the sustained provision of ecosystem services.

This review examines the utility of abiotic surrogates across spatial scales with particular regard to how abiotic variables are tied to processes which affect biodiversity and how easily those variables can be measured at scales relevant to resource management decisions.

Tags: AU-EEZ, Article, CERF, Earth Sciences, External Publication, Published_External, abiotic surrogates, marine, marine biodiversity
Organization: Geoscience Australia Data
Shedding light on the seafloor

In 2007-08 scientists from Australia, Japan and France set out to survey the marine life and habitats in the region adjacent to Terre Adelie and George V Land in East Antarctica (Australian Antarctic Magazine 14: 2-13, 2008). The Collaborative East Antarctic Marine Census (CEAMARC) - part of Australia's contribution to the International Polar Year - aimed to understand the processes that have lead to the evolution and survival of marine life existing in the region today, so that scientists can predict how these organisms may respond to future climate-related changes in their environment. Scientists involved in the census are now finalising the collation and analysis of data and the following pages (13-18) provide an insight into some of the results. The team aims to publish its findings as a series of papers in a special volume of a scientific journal in late 2010.

Tags: AQ, Antarctic data, Article, Earth Sciences, External Publication, Published_External, abiotic surrogates, marine
Organization: Geoscience Australia Data
The Variability in Formation Water Composition and its Implications for CO2 Storage Conditions

Regional geological properties of sedimentary basins play a significant role in determining the safety of CO2 storage. Four major trapping mechanism have been identified: Structural and stratigraphic trapping is the containment of supercritical CO2 by low permeability / low porosity rocks and is the dominant mechanism during injection and initial storage phase. Residual or capillary trapping is the retention of supercritical CO2 in the pore space between grains and tends to be most relevant on a
scale of tens to thousands of years. Solubility trapping is the uptake of CO2 into the formation water, which is considered to be the most important trapping mechanism over hundreds to millions of years (1).
Mineral trapping leads to the permanent immobilization of carbon through the precipitation of carbonate minerals.

This study assesses the conditions for solubility trapping in major Australian sedimentary basins. The total dissolved solid (TDS) concentration of the formation water has been compiled from over
900 wells as it, along with pressure and temperature, is a key variable controlling CO2 solubility and the associated change in fluid density. Fluid density is a critical factor in driving fluid advection which determines the rate of solubility trapping and downward migration in the formation. This process is vital in reducing the amount of highly mobile supercritical CO2 at the top of the formation and storing it as dissolved CO2 in deeper parts of the formation.

Tags: Earth Sciences, GA Publication, Poster/Image, Published_External, carbon dioxide, marine
Organization: Geoscience Australia Data
Calcareous nannofossil biostratigraphy: an assessment of foraminiferal and sedimentation events in the Eocene of the Otway Basin, southeastern Australia

From a study of middle to late Eocene calcareous nannofossil assemblages in four sections in the Otway Basin of southeastern Australia, a sequence of biostratigraphic events has been deduced, spanning the interval from the lowest appearance of Cyclicargolithus reticulatus (middle Eocene) to the disappearance of Discoaster saipanensis (latest Eocene). The sequence is compared with its coumerpart in New Zealand, and is placed against the planktic foraminiferal P. zones of the tropics. The previously determined foraminiferal biostratigraphy of the sections studied has been compared with the nannofossil biostratigraphy, and, as a result, the local highest appearance of the foraminiferid Acarinina primitiva is now placed in zone P. l3 of the tropics , and not P.12 or P.14, as previously. The disappearance up the section of the foraminiferid Acarinina collactea is found to be locally inconsistent with other evidence. During the middle Eocene, marine ingressions, represented by isolated nannofossil assemblages, occurred in the Gambier Embayment of the western Otway Basin, but did not reach the Browns Creek area, eastern Otway Basin, attesting to the diachroneity of Eocene marine sedimentation in the basin . The diachroneity is also indicated by transgressive rock units in the Gambier Embayment. The ingressions seem to coincide with a major change in the sea-floor spreading rate south of Australia. During the latest middle to early late Eocene, a major transgression began synchronously in widely separated areas across the basin. The upper Eocene section in the Gambier Embayment represents condensed sedimentation and ends in a sharp disconformity, indicated by the simultaneous disappearance of Cyclicargolithus reticulatus and Discoaster saipanensis. At Browns Creek, that part of the section between the highest appearances of C. reticulatus and D. saipanensis is thick, suggesting relatively rapid rates of sedimentation. However, in the expanded part of the section at Browns Creek and also at Castle Cove, there is evidence that extreme shoal conditions existed as a result of imbalance between sedimentation and subsidence. During the middle and late Eocene, conditions along the Australian southern margin were generally temperate, with surface-water temperature decreasing eastward, and the depositional environment was essentially shallow marine - nearshore or shelf.

Tags: Earth Sciences, GA Publication, Journal, Published_External, SA, TAS, VIC
Organization: Geoscience Australia Data
Otway Basin hydrogeological inventory

This Otway 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 Otway Basin is an elongated sedimentary basin located on the south-east continental margin of Australia. Covering approximately 150,000 square kilometres and stretching about 500 km from South Australia's Cape Jaffa to Victoria's Port Phillip Bay and Tasmania's north-west, most of the basin is offshore, with a smaller portion onshore.

Geological studies of the Otway Basin have primarily focused on its hydrocarbon prospectivity, examining thick Cretaceous aged rocks both onshore and offshore. However, the shallower onshore sedimentary units are more relevant from a groundwater perspective.

The basin's formation began with rifting between the Australian and Antarctic plates during the Late Jurassic, leading to regional subsidence and the development of the elongated sedimentary basin. Following the Cretaceous plate breakup, a passive margin basin formed, which subsequently underwent basin inversion, reverse faulting, and folding, interspersed with extensional periods and normal faulting. This complex evolution, combined with sea level variations and volcanic activity, resulted in numerous sedimentary cycles.

The sedimentary succession in the basin comprises non-marine sediments and volcanic rocks from the Jurassic and early Cretaceous, with a period of tectonic compression interrupting sedimentation during the mid-Cretaceous. The late Cretaceous and Cenozoic sedimentary and volcanic rocks form the primary groundwater-bearing aquifers of the basin, with various sedimentary environments developing in the Neogene and Quaternary. The basin's structural geology is intricate, with numerous basement highs, sub-basins, troughs, and embayments. Fault systems are prevalent, separating tectonic blocks and potentially influencing groundwater flow, offering conduits for inter-aquifer connectivity.

Overall, the Otway Basin's geological history has shaped its hydrocarbon potential and groundwater resources, making it an essential area for ongoing research and exploration in Australia's geological landscape.

Tags: Basin Analysis, EARTH SCIENCES, ECOLOGY, ENVIRONMENTAL SCIENCES, Environmental Management, Exploring for the Future, GEOLOGY, Groundwater, Hydrogeology, Land Use and Environmental Planning, National Groundwater Sytems, National Hydrogeological Inventory, PHYSICAL GEOGRAPHY AND ENVIRONMENTAL GEOSCIENCE, Published_External, Sedimentology, Stratigraphy (incl. Biostratigraphy and Sequence Stratigraphy)
Organization: Geoscience Australia Data
Cruise Preview Report Prydz Bay and Mac.Robertson Shelf, Antarctica January-March 1993

The Natural Variability and Past Environmental change Sub-program of the Co-operative Research Centre for Antarctic and Southern Ocean Environments aims to use the records contained in ice and sediments to understand past environmental change to calibrate climatic models. The marine geoscience program for Voyage 7 consists of a sea bed sampling program designed to

. Elucidate sedimentation processes on the Antarctic shelf and slope.

. Provide sediment cores from the Antarctic shelf and slope for the study ofQuaternary environmental change.

Sampling is proposed for Prydz Bay and the adjoining Mac. Robertson Shelf. Prydz Bay is an important site for studying the past behaviour of the Lambert Glacier-Amery Ice Shelf system which is the largest ice stream draining the East Antarctic Ice Sheet. The adjacent but contrasting Mac. Robertson Shelf may not have experienced the same style of glaciation during the Quatemary and has accumulated biogenic sediments in places. Bathymetry and 3.5kHz echo sounder data from Prydz Bay reveal features formed by erosion and deposition beneath the Amery Ice Shelf. The extent of post-glaciation iceberg gouging can also be inferred. On the Mac. Robertson Shelf, sediment accumulations suitable for coring can also be interpreted from the 3.5 kHz records. Fifteen gravity cores at sites selected to help interpret the Late Quaternary history of Prydz Bay and the Mac. Robertson Shelf will be collected on Voyage 7 of the 1992/93 Antarctic Division shipping season, on the R.V. Aurora Australis. An additional core from BANZARE Bank, the southern-most extension of the Kerguelen Plateau will be collected for palaeotemperature studies at the Co-operative Research Centre for Antarctic and Southern Ocean Environments. Grab samples will also be collected to elucidate modem sediment types in Prydz Bay and the Mac. Robertson Shelf.

Tags: AQ, Earth Sciences, GA Publication, Published_External, Record, marine, marine survey
Organization: Geoscience Australia Data
Sequence stratigraphy: a review of fundamental concepts and their application to petroleum exploration and development in Australia

Sequence stratigraphic concepts and techniques provide a powerful tool to analyse and predict stratal architecture and facies patterns within sedimentary basins.  The concepts are based on an analysis of cyclic sedimentation patterns in terms of changes in sediment accommodation and sediment supply.  Sediment accommodation, the potential space available for sediments to accumulate, is controlled by the combined effects of eustasy and tectonic subsidence or uplift.  Sequence stratigraphy involves the analysis of these sediment accommodation cycles within a time-stratigraphic framework, and subdivides sedimentary successions on the basis of key surfaces (unconformities, flooding surfaces) into a systematic and predictable distribution of depositional units or system tracts.  The distribution of petroleum systems and key petroleum play elements (e.g., sand-shale ratio, reservoir type and connectivity, organic-rich shales and coals, marine shale seals etc,) can also be shown to be largely controlled by changes in sediment accommodation and sediment supply, Thus, sequence stratigraphic techniques provide a powerful tool to analyse petroleum systems and to predict the distribution of potential reservoirs, sources and seals for hydrocarbon accumulations.  The basic principles of sequence stratigraphy are independent of time and scale, such that large-scale sequences can be successively divided into progressively smaller scale or higher order sequences.  This notion of sequence hierarchy has important implications for hydrocarbon exploration, since the relative degree of development or dominance of depositional systems tracts (and their constituent play elements) is determined by the position of a particular sequence within a lower order sequence.  These lower order sequences thereby determine source-prone or reservoir-prone fairways.  Sequence stratigraphic concepts are now routinely applied to hydrocarbon exploration in Australia, including: the prediction of regional hydrocarbon systems, the search for specific depositional systems and reservoir-seal plays, and the hig h-resolution analysis of reservoirs for field development purposes, A review of recent applications to regional and specific hydrocarbon systems in the onshore Canning and offshore Carnarvon Basins highlights the potential of these techniques to influence future exploration strategy and mitigate exploration risk in Australias onshore and offshore basins.

Tags: Earth Sciences, GA Publication, Journal, Published_External
Organization: Geoscience Australia Data
Lithology and diagenesis of the carbonate foundations of modern reefs in the southern Great Barrier Reef

In the southern Great Barrier Reef a relativel y thin (&lt; 20 m) Holocene reef has developed on a foundation comprising a succession of older reefs. This reef foundation extends to a depth of up to 420 m in the subsurface and ranges from late Pleistocene to middle Miocene in age. The boundary between the Holocene and late Pleistocene reef is marked by a prominent solution unconformity that shows development of soils, calcrete, and extensive leaching in the underlying limestone. This has resulted from relative lowering of sea level during the period from the last interglacial to the post-glacial transgression. Late Pleistocene reef lithologies within individual drill holes are similar to their overlying Holocene counterparts, and there seems to have been a duplication of environments during both growth periods. However, Halimeda limestones, which are a prominent framework infill in the Pleistocene reef are not as abundant in the Holocene reef.  Petrographic analysis of the late Pleistocene reef limestones shows that they have been subjected to near-surface subaerial diagenesis in both the vadose and phreatic freshwater zones. The effects of subaerial diagenesis increase progressively with depth below the solution unconformity, initially within the vadose zone and, ultimately, into the underlying phreatic zone. In the vadose zone, aragonite skeletons (e.g. corals. Halimeda) show two distinct processes of transformation to calcite: (1) total leaching and subsequent infill by sparry calcite cement: and (2) neomorphic replacement of aragonite by calcite, by a process of thin-film transformation. Variations in vadose and phreatic environments suggest that a more permanent freshwater lens was established around reef perimeters than beneath lagoons during the period of subaerial exposure.

Tags: Earth Sciences, GA Publication, Journal, Published_External, QLD, marine
Organization: Geoscience Australia Data
World Bathymetry Base Map MapServer

World Bathymetry Base Map tile cache. The service includes world bathymetry data, and ocean, country, population and natural features. The information was derived from various sources, including Natural Earth and National Geophysical Data Center (NGDC) ETOPO2 Global 2 Elevations from the September 2001 data. The service contains layer scale dependencies.

Tags: MapServer, Natural Earth, Published_External, bathymetry, boundaries, marine, political, topography, web service, world
Organization: Geoscience Australia Data
Carpentaria Basin hydrogeological inventory

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.

Tags: Basin Analysis, EARTH SCIENCES, ECOLOGY, ENVIRONMENTAL SCIENCES, Environmental Management, Exploring for the Future, GEOLOGY, Groundwater, Hydrogeology, Land Use and Environmental Planning, National Groundwater Sytems, National Hydrogeological Inventory, PHYSICAL GEOGRAPHY AND ENVIRONMENTAL GEOSCIENCE, Published_External, Sedimentology, Stratigraphy (incl. Biostratigraphy and Sequence Stratigraphy)
Organization: Geoscience Australia Data
Understanding Australia's High Purity Silica Potential, A Global Mineral Systems Review

High-purity silica (HPS) is an integral component in technology such as semiconductors and solar photovoltaic cells. It is sourced from a limited number of locations around the world, with only one operational mine in Australia producing metallurgical grade silica (&gt;98% SiO2). Globally, HPS is found in a wide range of geological settings, with known deposits being relatively sparse. This presents a challenge for future exploration efforts, as the conditions that produce HPS are not well understood.

The report discusses various components of silica mineral systems and their prospectivity for HPS using the mineral systems framework. This framework defines the criteria necessary to produce silica. Five components are evaluated: 1) the sources of metals, fluids and ligands, 2) energy sources and fluid flow drivers, 3) fluid-flow pathways and architecture, 4) ore depositional gradients/traps and 5) preservation. The main criteria identified for these components include (1) pegmatites, granites, cherts and turbidites as potential silica sources; (2) granites, partial melting, convergent margins and the fluid pressure gradients triggered by resulting metamorphism as potential energy sources; (3) deep marine basins, shear zones/highly fractured or faulted crust, and competency contrasts as fluid-flow pathways and architecture; (4) deformation partitioning, contact aureoles and occurrences of known mineral associations as evidence of ore depositional gradients; and (5) source outcrop occurs at or near-surface to demonstrate preservation through uplift and erosion preferentially preserving the quartz-rich lithologies in economically viable conditions. In reviewing the components of HPS mineral systems, this report has identified key criteria that are present across a range of silica mineral systems. Greenschist to amphibolite metamorphic facies, and the presence of granitic plutons, appear to be a favourable criterion across a range of HPS targets.

In defining the criteria that govern the formation and emplacement of HPS, this report aims to equip mineral explorers with the mineral systems knowledge needed to motivate and de-risk exploration for HPS in Australia. This information is compiled to act as a foundation for future mineral potential assessments, with the goal of helping to identify new HPS targets in Australia. Integrating the various silica mineral systems into a single framework will create a tool for mineral explorers to effectively identify, discover and define HPS targets, leading to the diversification of silicon supply chains in Australia. This work is undertaken as part of the Australian Critical Minerals Research and Development Hub.

Tags: Australian Critical Minerals Research and Development Hub, Geology, Geoscience Australia, High Purity Quartz, High Purity Silica, Mineral Systems, Resource geoscience, critical minerals, silicon
Organization: Geoscience Australia Data