NRS-15666 | Gravity reports (GR)

Gravity reports provide analysis and interpretation of exploration data obtained through gravity surveys. The reports ascertain whether there are deposits such as coal, oil, or gas. Gravity readings are taken with a meter, such as a Worden Meter, from numerous points (stations) across the area being surveyed.The reports may include Bouguer anomaly maps; a location map of the survey area; geological and gravitational maps of the area; survey data, including measurement readouts and Bouguer gravity computations; maps showing measuring station location and elevation; structural cross-sections; correspondence; diagrams and description of previous survey work including seismic, aeromagnetic, and gravity results; description of how the data was processed and interpreted; conclusions and recommendations. The reports may also include a description of the current survey work including a list of personnel, equipment used, and the operational procedure followed. There may also be a summary of the area’s geology and a list of existing geophysical information. There may also be progress reports, survey notes, and applications for subsidies from the Commonwealth Government to conduct surveys under the terms of the Petroleum Search Subsidy Act 1959 - 1967. Some reports may contain a notice inserted into the reports to acknowledge a missing document.Gravity reports are part of the Geological Survey collection, a unique collection of unpublished reports on the results of exploration submitted to the then Department of Mineral Resources by companies and individuals as a consequence of exploration and mining licences being granted. The exploration reports are essential sources of information for explorers, and also add to the understanding of the State's geology, mineral, coal and petroleum resources. If the company is still engaged in mining activity or if mining licences are still active then reports may be confidential and unavailable.Due to the high access rates for the Geological Survey Reports, the then Department of Mineral Resources undertook a copying program making digitised copies available on the Geological Survey (DIGS). Interested parties can view published and unpublished exploration, mining and Departmental reports on-screen and these can be downloaded. The images have been slightly downgraded to minimise download times, however, higher quality images can be ordered from DIGS. Custody History The original reports comprising the Geological Survey collection were transferred from the Department of Mineral Resources to the State Records Authority between 1999 and 2001. A note concerning access to Gravity reportsThe original reports will not be issued to the public so those interested in accessing them should refer to the Geological Survey (DIGS) website where copies of non-confidential reports are available. The reports are indexed and can be searched by title, author, subject terms, tenement, location, map reference, report number, and report year. In addition to the reports being indexed, the various documents making up the report, such as contents page, text, maps, and photographs, are also indexed and therefore retrievable.