The Australian Geological Survey Organisation (formerly the Bureau of Mineral Resources,
Geology and Geophysics) flew an airborne geophysical survey of 45 500 line km over a large part
of the Ballarat 1:250 000 Map Sheet area during March and April, 1992.
This survey, which formed part of the National Geoscience Mapping Accord, was flown along eastwest
flight lines 400m apart at an altitude of 100m above ground level. An area in the south-west of
the survey area was infilled with additional lines to reduce the line separation to 200m. The NSW
Department of Mineral Resources funded the additional flying.
The total magnetic intensity and gamma-ray spectrometric data which were collected during the
survey, have been processed and are available for purchase, in both digital (position located data
and grids) and map form, from the Australian Geological Survey Organisation.