- Exploration geophysics
Exploration geophysics is the applied branch of
geophysicswhich uses surface methods to measure the physical properties of the subsurface Earth, in order to detect or infer the presence and position of concentrations of oreminerals and hydrocarbons.
Exploration geophysics is the practical application of physical methods (such as seismic, gravitational, magnetic, electrical and electromagnetic) to measure the physical properties of rocks, and in particular, to detect the measurable physical differences between rocks that contain ore deposits or hydrocarbons and those without.
Exploration geophysics can be used to directly detect the target style of mineralisation, via measuring its physical properties directly. For example one may measure the density contrasts between
iron oreand silicate wall rocks, or may measure the conductivitycontrast between conductive sulfide minerals and barren silicate minerals.
Exploration geophysics is also used to map the subsurface structure of a region, to elucidate the underlying structures, spatial distribution of rock units, and to detect structures such as faults, folds and intrusive rocks. This is an indirect method for assessing the likelihood of ore deposits or hydrocarbon accumulations.
Methods devised for finding mineral or hydrocarbon deposits can also be used in other areas such as monitoring environmental impact, imaging subsurface archaeological sites, ground water investigations, subsurface salinity mapping,
civil engineering site investigations and interplanetary imaging.
In addition to universities and technical institutes such as the
Colorado School of Mines, [http://www.eos.ubc.ca/research/themes/index.html University of British Columbia] , [http://www.geophysics.curtin.edu.au/website Curtin University] , professional societies such as the Society of Exploration Geophysicists (SEG) ( [http://www.seg.org seg.org] ) and the [http://www.cseg.ca CSEG] and [http://www.aseg.org.au/ ASEG] have the most recent updates of the sciences and technologies of exploration geophysics.
Exploration Geophysics careers are in such widely varying industries as oil & gas exploration,
mining, environmental studies, planetary physics and even archaeology.
The following techniques are used:
# Seismic methods, such as
reflection seismology, seismic refraction, [http://www.seismo.unr.edu/ftp/pub/louie/papers/disper/refr.html refraction microtremor (ReMi)] and seismic tomography.
electromagnetic(EM) ("see, e.g. [http://www.geonics.com Geonics instruments] ")
Radio frequencyelectromagnetic propagation (e.g., ground penetrating radar)
# Electrical techniques, including
Electrical resistivity tomographyand induced polarization
# Magnetic techniques, including
aeromagnetic surveys and magnetometers.
Gravityand Gravity Gradiometry
Kola Superdeep Borehole
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