| What is Geophysics in Mineral Exploration? Geophysics
uses the various physical properties of the earth and its constituent rocks and minerals
to develop an understanding or interpretation of the earth's geology. When applied to
mineral exploration, properties such as magnetism, conductivity, radioactivity and density
can all be measured in different ways in the search for specific parameters that are
associated with particular styles of mineralisation.
Geophysical methods all rely heavily on a combination of physics maths, electronics and
computing and for a long time were considered to be beyond the comprehension of the
everyday exploration geologist. However, with the advent of powerful PCs and smart
software, geophysicists are now able to reduce the data to a form that can be presented in
image-maps or sections that are easily related to geology.
There are many different geophysical techniques available to the explorationist and
they can be summarised as either passive or active. Most techniques can be applied either
on the ground or from an airborne platform. In general, airborne surveys are lower in
resolution and are applied regionally whereas the ground surveys are higher resolution,
higher cost and applied to specific exploration targets. However, in the case of airborne
magnetics, recent advances in the accuracy of 3-dimensional position fixing and the
ability to fly low and slow, have enabled cost-effective low-level, high resolution
surveys to be more than competitive with ground surveys at a prospect scale.
Examples of work AGARSS has been involved in
See also:
Mudge, S., 1996; Geophysics for Geologists and Engineers - An Introduction. In:-
Ho, S.E. & Ammann, W.J., "Geophysics for Geologists and Engineers"
Australian Inst. For Geoscientists Bulletin 19, pp1-6. |
