This grid is derived from gravity observations stored in the Australian National Gravity Database (ANGD) as at February 2016 as well as data from the 2013 New South Wales Riverina gravity survey. Out of the approximately 1.8 million gravity observations 1,371,998 gravity stations in the ANGD together with 19,558 stations from the Riverina survey were used to generate this image. The grid shows isostatic residual gravity anomalies over onshore continental Australia. The data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. The isostatic corrections were based on the assumption that topographic loads are compensated at depth by crustal roots following the Airy-Heiskanen isostatic principle. A crustal density of 2670 kg/m3 was used for the isostatic correction, with an assumed density contrast between the crust and mantle of 400 kg/m3. An initial average depth to Moho at sea level of 37 km was used in the calculation. The isostatic corrections were then applied to the Complete Bouguer Gravity Anomaly Grid of Onshore Australia 2016 to produce the Isostatic Residual Gravity Anomaly Grid of Onshore Australia 2016.

This web service delivers metadata for onshore active and passive seismic surveys conducted across the Australian continent by Geoscience Australia and its collaborative partners. For active seismic this metadata includes survey header data, line location and positional information, and the energy source type and parameters used to acquire the seismic line data. For passive seismic this metadata includes information about station name and location, start and end dates, operators and instruments. The metadata are maintained in Geoscience Australia's onshore active seismic and passive seismic database, which is being added to as new surveys are undertaken. Links to datasets, reports and other publications for the seismic surveys are provided in the metadata.

An earlier report (Record 1950/041) has described the geophysical survey carried out early in 1950 on the Renison Bell tin field. The present report deals with the work of a second field season which commenced in November 1950 and continued until June 1951. The methods used were again the magnetic and self-potential. The 1950 survey was extended to the south and east by continuing along the Renison Bell Hill base-line a further 1000 feet south and reading stations on both sides of this base-line along traverses extending from the main quartz-porphyry dyke to the headwaters of the Montana Creek. In addition, some of the traverses were extended over the saddle between Dreadnought and Stebbins Hills as far as the Boulder tramway. The report gives an account of the survey work and its results, and provides recommendations for future testing. The geological features of the area covered by the present geophysical survey are briefly described.

The Chilcot copper mine is situated 15 miles south-south-west from Orange, from which it may be reached by reasonably good road. It was examined during 1942 by Dr. N.H. Fisher, Chief Geologist, Mineral Resources Survey, who recommended that a geophysical survey be made to search for additional ore shoots along the lode channel (1942/020). The geophysical survey was made during the three weeks ending 19th December. Operations were commenced over the area north-east of the mine, extending a distance of 550 feet from the mine, thus covering the part favoured by Dr. Fisher for extension of the lode channel. Later the survey was extended a similar distance to the south-west and the north-eastern part was extended a further 150 feet. Methods used comprised geomagnetic, spontaneous, polarisation, electro-magnetic and potential ratio. Traverses were placed at 50 feet intervals and observations by the various methods were made at intervals of 25 feet and, in some parts, at closer intervals. The results of this survey are discussed herein.

The Wallaroo-Moonta copper field offers a challenge to modern geological and geophysical ore-finding methods. After the production of some 338,066 tons of copper valued at over 20 million pounds, large scale mining ceased in 1923. In spite of the present urgent need for copper, investigators have agreed that no good purpose can be served by re-opening the old mines and that any further substantial production from the field depends upon the discovery of new ore-bodies. Since the ore-bearing rocks are almost completely covered by superficial deposits, it is not unreasonable to suppose that there are still undiscovered ore-bodies in the field. Nevertheless some 30,000 feet of diamond drilling have been carried out in the past and the results, generally speaking, have been very poor. This is not surprising, perhaps, when the local nature of ore occurrences and the vast extent of barren country rock is contemplated. It appears that there is a clear task for geological and geophysical methods to select sites where diamond drilling will have the maximum chance of intersecting ore. The masking of the surface geology immediately suggests the application of geophysical methods and in 1929 some work was carried out at Moonta by the Imperial Geophysical experimental Survey. After a limited amount of work this Survey was forced to the conclusion that the field presented greater difficulties to electrical prospecting, owing principally to the screening effect of the saline overburden. Since 1929, however, geophysical technique has progressed considerably, and more is known concerning the physical conditions of the field. In view of the possible prize at stake it was therefore decided early this year to re-open and carry out further geophysical surveys. The work was carried out in close co-operation with the South Australian Mines Department, which had previously made extensive investigations of the structural geology, and had recommended the use of the geophysical methods.

It was recently suggested by Mr. N. White, Superintendent of Minerals Production, N.S.W., that a geophysical survey be made of the Commonwealth Deep Lead near Glen Innes as part of a campaign to prospect for stanniferous wash beneath the basalt cover. In company with Mr. N. White and Mr. E. Dow, an inspection was made of the area on the 7th and 8th October, in order to determine in the first place whether the problem offers scope for geophysical methods. A geophysical survey, if carried out, would commence in the vicinity of what is known as the Commonwealth Mine and the inspection was made primarily of that area. At present there is no activity at the Commonwealth Mine, which is actually the site where some alluvial deposits were first dredged for tinstone in 1909 by the Commonwealth Tin Dredging Company, N.L., on PML 25, Ph. Wellington, Co. Gough.