Mineral exploration is a challenging enterprise that takes geologists to remote
regions throughout the world and requires a variety of scientific and technical
skills. Exploration geologists need exceptional perseverance, for they may
examine dozens and dozens of mineral deposits without finding one ore body
that is rich enough to support mining. On a worldwide scale, however,
geologists find a few new orebodies each year.
The exploration process begins with a geologist examining satellite images,
geologic maps, and reports to identify areas favorable for mineral deposits.
Once these areas are defined, the geologist conducts field examinations to
create more detailed maps and rock descriptions. Geologists commonly augment their field examinations with geochemical and geophysical exploration
techniques that help them identify specific mineral deposits. Geochemical
techniques are used to analyze samples of rocks, soils, water, vegetation, or
stream sediments which may contain elements that are important clues to
possible nearby metal deposits. Geophysical techniques, such as magnetic
surveys, can help characterize rocks beneath the surface. Very detailed studies
are done to determine if a mineral deposit contains an orebody. The geologist
carries out these studies by making detailed maps of the surface geology and
combining these with detailed characterizations of rocks extracted from the
mineral deposit. Drilling into a mineral deposit commonly recovers cores or
chips of the subsurface rocks that geologists then examine and analyze
chemically. Verifying the subsurface character and form of an orebody
requires extensive drilling.
In general, the exploration process — from initial office compilation to
extensive drilling — is expensive and time-consuming. It may take years of
work and millions of dollars of expense to reach a development decision for a
specific mineral deposit. In most cases, this work and expense will be incurred
only to determine that an orebody is not present. In that case, the disturbed
sites will be reclaimed and the exploration process starts over and the search
for another favorable area begins. Perseverance and insightful geologic
analysis are the keys to success — eventually they can lead to the excitement
of an orebody discovery, the ultimate reward for an exploration geologist.
Discovery of an orebody is the first step toward making the metals available.