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  • Submerged relict reef systems and modern coral communities discovered around the Balls Pyramid shelf are presented as new evidence of extensive carbonate production at the boundary of reef-forming seas. Balls Pyramid is the southernmost island in a chain of island-reefs in the southwest Pacific Ocean, 24 km south of the southernmost known coral reef in the Pacific Ocean at Lord Howe Island. This paper explores the detailed geomorphic structure of the shelf through the production of a high resolution bathymetric model from multibeam echosounder data and depth estimates from satellite imagery. Key seafloor features identified include a large, mid shelf reef dominating the shelf landscape in 20 - 60 m water depth, mid shelf basins and channels, and shelf margin terrace sequences in 50 - 100 m depth. Sub-bottom profiles, backscatter, drill core and vibro-core data are used to investigate the seafloor composition. Drill cores extracted from the submerged reef surface confirm coral, coralline algae and cemented sands composition, and vibro-core material extracted from unconsolidated areas demonstrate substantial accumulation of carbonates shed from the reef surface. Underwater video imagery reveals abundant modern mesophotic reef communities, including hard corals, colonising the relict reef surface. This paper reveals prolific past reef growth and abundant modern coral growth on what was previously considered to be a planated volcanic shelf outside of reef-forming seas, thus extending understanding of reef evolution at, and beyond, the limits of growth.

  • The coverage of this dataset is over the PortStephens region . The C3 LAS data set contains point data in LAS 1.2 format sourced from a LiDAR ( Light Detection and Ranging ) from an ALS50 ( Airborne Laser Scanner ) sensor . The processed data has been manually edited to achieve LPI classification level 3 whereby the ground class contains minimal non-ground points such as vegetation , water , bridges , temporary features , jetties etc . Purpose: To provide fit-for-purpose elevation data for use in applications related to coastal vulnerability assessment, natural resource management ( especially water and forests) , transportation and urban planning . Additional lineage information: This data has an accuracy of 0.3m ( 95 CI ) vertical and 0.8m ( 95 CI ) horizontal with a minimum point density of one laser pulse per square metre . For more information on the datas accuracy, refer to the lineage provided in the data history .

  • The coverage of this dataset is over the CoffsHarbour region . The C3 LAS data set contains point data in LAS 1.2 format sourced from a LiDAR ( Light Detection and Ranging ) from an ALS50 ( Airborne Laser Scanner ) sensor . The processed data has been manually edited to achieve LPI classification level 3 whereby the ground class contains minimal non-ground points such as vegetation , water , bridges , temporary features , jetties etc . Purpose: To provide fit-for-purpose elevation data for use in applications related to coastal vulnerability assessment, natural resource management ( especially water and forests) , transportation and urban planning . Additional lineage information: This data has an accuracy of 0.3m ( 95 CI ) vertical and 0.8m ( 95 CI ) horizontal with a minimum point density of one laser pulse per square metre . For more information on the datas accuracy, refer to the lineage provided in the data history .

  • The data covers an area of approximately 4000 sq km in the Namoi Valley, located around Narrabri, NSW. The LiDAR was captured by RPS Spatial in September and October 2013 with a point density of two points per square metre. The specified accuracies; 30cm vertical and 80cm horizontal, were achieved and verified through a rigorous network of check points and base stations. A set of seamless products were produced including hydro-flattened bare earth DEMs, DSMs, Canopy Height Models (CHM) and Foliage Cover Models (FCM). The outputs of the project are compliant with National ICSM LiDAR Product Specifications and the NEDF.

  • The coverage of this dataset is over the WestNarranLake region . The C3 LAS data set contains point data in LAS 1.2 format sourced from a LiDAR ( Light Detection and Ranging ) from an ALS50 ( Airborne Laser Scanner ) sensor . The processed data has been manually edited to achieve LPI classification level 3 whereby the ground class contains minimal non-ground points such as vegetation, water , bridges , temporary features , jetties etc . Purpose: To provide fit-for-purpose elevation data for use in applications related to coastal vulnerability assessment, natural resource management ( especially water and forests) , transportation and urban planning . Additional lineage information: This data has an accuracy of 0.3m ( 95 CI ) vertical and 0.8m ( 95 CI ) horizontal with a minimum point density of one laser pulse per square metre . For more information on the datas accuracy, refer to the lineage provided in the data history .

  • Offshore seismic surveys have long been considered to be disruptive to fisheries, and recent claims have been made that marine seismic operations cause scallop declines in southeastern Australia. Despite the importance of this issue to both fisheries and petroleum industries, few studies target commercially important species in realistic exposure scenarios. One of the main challenges in underwater sound impact studies is the meaningful translation of laboratory results to the field, largely due to variations due to underwater sound properties and experimental set-ups. In the current study, we use in situ experiments to investigate whether field populations of the commercial (Pectens fumatus ) and doughboy scallops (Mimachlamys asperrima) are negatively affected by a seismic survey undertaken in the Gippsland Basin in April 2015 (30 80 m depth). Both theoretical and field-based noise propagation models were developed to quantify noise exposure of the animals at the seabed and to establish whether sound monitoring markedly improves model outputs. Images of the seafloor at were acquired using an Automated Underwater Vehicle (AUV) to evaluate the novel use of AUVs in scallop stock assessment. Samples were collected before and after the seismic survey using a commercial scallop dredge, and a range of metrics are currently being quantified. In this presentation, we describe preliminary results and critically review our current understanding of low-frequency sound impact on marine molluscs.

  • Analysis of the distribution patterns of Pb isotope data from mineralised samples using the plumbotectonic model of Carr et al. (1995), which invokes mixing between crustal and mantle reservoirs, indicates systematic spatial patterns that reflect major metallogenic and tectonic boundaries in the Lachlan and Delamerian orogens in New South Wales and Victoria. This distribution pattern accurately maps the boundary between the Central and Eastern Lachlan. The Central Lachlan is characterised by Pb isotope characteristics with a strong crustal signature, whereas the Eastern Lachlan is characterised by variable crustal and mantle signatures. The Macquarie Arc is dominated by Pb with a mantle signature: known porphyry Cu-Au and high sulphidation epithermal Au-Cu deposits in the arc are associated with a zone characterised by the strongest mantle signatures. In contrast, granite-related Sn deposits in the Central Lachlan are characterised by the strongest crustal signatures. The Pb isotope patterns are broadly similar to Nd isotope model age patterns derived from felsic magmatic rocks, although a lower density of Nd isotope analyses makes direct comparison problematic. The two reservoirs identified by Carr et al. (1995) do not appear to be isotopically linked: the crustal source was not formed via extraction from the mantle source. Rather, the two reservoirs must have formed separately. The mantle reservoir may have been sourced from a subducting proto-Pacific plate, whereas the crustal reservoir is most likely to be extended Australian crust. The data allow the possibility that the proto-Pacific mantle source was isotopically linked to the western Tasmanian crustal source. Comparison of Pb isotope data from the Girilambone district (e.g., Tritton and Avoca Tank deposits) with those from the Cobar district in north central New South Wales indicates a less radiogenic signature, and probably older age, for deposits in the Girilambone district. Hence, a syngenetic volcanic-associated massive sulphide origin for these deposits is preferred over a syn-tectonic origin. The data are also consistent with formation of the Girilambone district in a back-arc basin inboard from the earliest phase of the Macquarie Arc.

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    Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This NSW Coonabarabran first vertical derivative magnetic grid geodetic is a first vertical derivative of the Total Magnetic Intensity grid for the Coonabarabran Airborne Magnetic Radiometric and DEM Survey, NSW, 2017. This grid has a cell size of 0.00045 degrees (approximately 47m). The grid has units of nanoTesla per km (or nT/km). The data used to produce the TMI grid was acquired in 2017 by the NSW Government, and consisted of 50961 line-kilometres of data at 250m line spacing and 60m terrain clearance. A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid.

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    Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This magnetic grid has a cell size of 0.00045 degrees (approximately 47m).The data are in nanoTesla (or nT). The data used to produce this grid was acquired in 2017 by the NSW Government, and consisted of 50961 line-kilometres of data at 250m line spacing and 60m terrain clearance. The data has had a variable reduction to the pole applied to centre the magnetic anomaly over the magnetised body. The VRTP processing followed a differential reduction to pole calculation up to 5th order polynomial. Magnetic inclination and declination were derived from the IGRF-11 geomagnetic reference model using a data representative date and elevation representative of the survey.

  • Sandy clays deposited during the waning phase of Oligocene-Middle Miocene transgression of the Murray Basin conformablyoverlie the shallow to marginal marine Geera Clay and grade laterally into fluvio-Iacustrine sediments of the Middle and Upper Renmark Group. These sandy clays (informally named "Geera Clay equivalent") and the Geera Clay preserve marine dinoflagellates that became extinct by middle to late Middle Miocene time. If the subsequent regression was due to a global drop in relative sealevel, then we propose that the unconformity developed across the Geera Clay and that the lateral equivalents during the Late Miocene (Mologa weathering surface) correlates with either the 13.8 Ma or (preferred) 10.5 Ma sequence boundary of Haq and others (1987). Three pollen species of potential biostratigraphic value in the Murray Basin are illustrated and discussed. One new species is described: Tetrapollis campbellbrownii.