Legacy product - no abstract available

Legacy product - no abstract available

Abstracts for Workshop organised jointly by the Australian Geological Survey Organisation, CSIRO Division of Exploration and Mining, and the Research School of Earth Sciences ANU. Workshop held on May 3rd and 4th at AGSO.

The Australian Geological Survey Organisation (AGSO) flew an airborne geophysical survey of 49 397 line km covering the Julia Creek 1:250 000 map Sheet area in the northwestern Queensland. The survey formed part of the National Geoscience Mapping Accord and was flown along east-west flight lines, 400 metres apart at an altitude of 80 metres above ground level. The survey was flown from 24 April to 6 June 1999. The total magnetic intensity, gamma-ray spectrometric and digital elevation model data collected during the survey, have been processed and are available for purchase. These data are sold as digital point located data, grids and hardcopy maps by the Australian Geological Survey Organisation. Colour and greyscale pixel image maps are also available.

This record represents a summary of the specifications of most surveys held in the National Airborne Geophysic Database (updated from 1998 when the third edition of this record was released).

In the various methods of geophysical prospecting, sensitive instruments are used on or near the surface of the earth to measure effects which arise from differences between the physical properties of rocks, ores and minerals. The analysis and interpretation of these measurements permit conclusions to be drawn concerning the sub-surface geology and the presence or absence of orebodies, coal seams, and the like, or of structures likely to be favourable to the occurrence of oil, etc. The principal physical properties of rocks which are useful in geophysical prospecting are density, elasticity, electrical conductivity, radio-conductivity and magnetic susceptibility. Aeromagnetic survey methods, their present use, and results of such surveys, are discussed in this report.

During July and August 1951, officers of the Geophysical Section of the Bureau of Mineral resources carried out an aeromagnetic survey of the East Gippsland area of Victoria, using the Bureau's D.C.3 aircraft VH-BUR. An F24 type aerial camera was used for taking vertical photographs for the purpose of plotting flight paths of the aircraft along the flight lines. The magnetic equipment consisted of a modified magnetic airborne Detector unit type AN/ASQ-1. The aircraft was flown at an altitude of one thousand feet above terrain, along parallel flight lines running in a north-south direction one mile apart. This report comprises notes on the survey. A provisional map showing contour lines of total magnetic intensity and magnetic anomalies is attached.

The purpose of the investigation was to determine the degree of uniformity of the earth's magnetic field over the existing and the alternate compass swinging sites for ground swinging of aircraft. Field work was carried out on 30/1/51 and 5/2/51. Instruments used were the Vertical Force Variometer and the Wingfield Compass. The report gives an account of the field work and the results of the survey.

Legacy product - no abstract available

Legacy product - no abstract available