British Geological Survey - New Gold Exploration Techniques
British Geological Survey - New Gold Exploration Techniques
British Geological Survey - New Gold Exploration Techniques
Geological
Survey
Advanced
instruments
and
information
technology
Gus Gunn
Keyworth
50 m
Au
New exploration
techniques
Study of gold grains
An exciting new tool for gold exploration has been developed at the BGS in
recent years. This technique involves
the microchemical characterisation of
alluvial (river sediment) gold grains
using an electron microprobe. Alluvial
gold grains frequently show internal
chemical heterogeneity, and they also
contain minute inclusions of other
minerals. These features are usually
inherited from the bedrock source and
are preserved throughout the processes
of weathering and transport.
Examination of alluvial grains can thus
provide important information which
can be used to deduce the geological
and structural setting of the source from
which the gold was derived. Multiple
sources for alluvial gold can be recognised, and the most appropriate
pathfinder elements for use in exploration can be identified. This method
has attracted considerable interest from
mining companies worldwide and has
been applied to the study of alluvial
gold in various geological environments
in South America, southern Africa,
south-east Asia and Europe.
Ag
Microchemical maps showing the distribution of gold (Au), silver (Ag) and copper (Cu) in a single gold grain.
22
Cu
Advanced IT
The increased availability of geoscience
information in digital form and major
improvements in information technology have had a significant impact on
mineral exploration in the last decade.
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