Remote sensing in mineral exploration: South American examples of benefits gained from recent advances in sensor and processing technologies

South America has presented significant challenges to mineral exploration, with
its highly diversified metallogenic environments, vast territory and general lack of
geologic mapping at appropriate scales. In this overall scenario, remote sensing has
played a key role in providing geologic information. From regional information on
geologic units and structures to ore vectoring (such as mineral mapping), various airborne
and spaceborne sensors have been used in mineral exploration activities in the
past three decades. They have been deployed in different regions of South America,
going from the arid lands of the Andean Cordillera and Patagonia, into the rainforests
of the Amazon.
This paper focuses on two successful case histories in South America that illustrate
the technological developments of remote sensing as an exploration tool and
their impacts on mineral exploration activities. The benefits of increasing the spectral
resolution are examined, as well as the introduction of new sensors operating in
some of the still underexploited portions of the electromagnetic spectrum and their
integration with geophysical data. These techniques comprise the use of Landsat and
ASTER to map hydrothermal alteration mineral associated with gold in Patagonia,
as well as SAR integrated with airborne geophysics for gold exploration in the
Brazilian Amazon.
Finally, some of the current and future technological trends are reviewed and
their impacts for mineral exploration activities in South America analyzed, including
the deployment of multi-hyperspectral sensors in airplanes and satellites.