NSW
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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.
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Warrumbungle/Nandewar Ranges Volcano Gravity (P198202) contains a total of 107 point data values acquired at a spacing of 3500 metres. The data is located in NSW and were acquired in 1982, under project No. 198202 for None.
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Isogal Gravity Strengthening (P198090) contains a total of 46 point data values acquired at a spacing of None metres. The data is located in ACT, NSW, NT, QLD, SA, TAS, VIC, WA and were acquired in 1980, under project No. 198090 for Bureau of Mineral Resources (BMR).
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Gap Filling Gravity Putty (P198101) contains a total of 10 point data values acquired at a spacing between 500 and 6000 metres. The data is located in NSW and were acquired in 1981, under project No. 198101 for None.
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Pasminco Cobar Data (P198025) contains a total of 178 point data values acquired at a spacing of 500 metres. The data is located in NSW and were acquired in 1980, under project No. 198025 for Pasminco Ltd.
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Lake Cowal detailed Gravity - Forbes (P198033) contains a total of 767 point data values acquired at a spacing between 900 and 1000 metres. The data is located in NSW and were acquired in 1980, under project No. 198033 for Geopeko.
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Goonumbla detailed gravity - Narromine (P198034) contains a total of 748 point data values acquired at a spacing between 500 and 600 metres. The data is located in NSW and were acquired in 1980, under project No. 198034 for Geopeko.
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Soviet Absolute Gravity (P197999) contains a total of 1 point data values acquired at a spacing between 2000 and 2100 metres. The data is located in ACT, NSW, NT, QLD, SA, TAS, VIC, WA and were acquired in 1979, under project No. 197999 for None.
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Gravity data measures small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 Lachlan Fold Belt Gravity Traverses (P198001) contains a total of 761 point data values acquired at a spacing of 500 metres. The data is located in NSW and were acquired in 1980, under project No. 198001 for Bureau of Mineral Resources (BMR).
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Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected 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 South East Lachlan Gravity (CSCBA 1VD grid) is the first vertical derivative of the complete spherical cap Bouguer anomaly grid for the South East Lachlan Gravity Survey along Seismic Lines, P201930, Vic, NSW, 2019. This gravity survey was acquired under the project No. 201930 for the geological survey of NSW, VIC. The grid has a cell size of 0.0005 degrees (approximately 50m). A Fast Fourier Transform (FFT) process was applied to the original grid to calculate the first vertical derivative grid. A total of 3542 gravity stations at a spacing between 200m and 400m were acquired to produce this grid.