From Rio Tinto6 Nov 2015 19:22
"The evolution of a project from initial
testing to commissioning can take 10
to 20 years involving a series of study
stages to reach investment approval
and implementation. The exploration
process can be divided into five
stages. The number of opportunities
that progress to the next stage
decreases as we move through
the process. "
Area selection
– deciding where to explore
The Exploration team conducts
desktop evaluations of geological,
geochemical and geophysical data to
find areas that have the potential to
contain an orebody. Issues relating to
health, safety, the environment and
communities, or technical or political
risks, are identified at this stage. The
team often makes an initial visit to
the area.
Target identification
– determining whether
a deposit may exist
Mapping and surveying takes place
within a selected area. The team
determines whether a target exists
that represents the mineral deposit
they seek. Discussions take place
with local communities to obtain
temporary land access, and to assess
opportunities for local sourcing
and employment.
Target testing
– assessing the nature
of mineralisation
The team performs the first
sub-surface evaluation of the better
prospects through limited drilling
and trenching. They may start to
collect environmental and social
baseline data at this stage.
Resource delineation
– determining deposit size,
grade and metallurgy
If results from initial drilling are
encouraging, additional drilling
takes place to estimate the extent
of mineralisation. The team
works increasingly closely with
local stakeholders to analyse
environmental and community issues,
and starts baseline studies if these
have not previously begun.
Resource evaluation
– judging whether a
deposit will be economical
The team carries out more detailed
investigation of a deposit to decide
whether it will be economic to
develop. This involves more drilling,
metallurgical and engineering studies
and economic analysis. After this
stage, called an Order of Magnitude
Study, a deposit is handed over to
a product group evaluation team if
it has significant potential value to
Rio Tinto.
http://www.riotinto.com/documents/ReportsPublications/corpPub_Exploration.pdf