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Earth’s Buried Treasures
The Economic Importance of
Minerals and Mineral Resources
The Economic Use of
Minerals
Minerals in Society
Economically
ImportantIndustrial Mineral
Important Non-metal
Minerals
Deposits
Sand and gravel
Clay minerals
Crushed rock
Salt
Silica sand
Phosphate
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Economically Important
Minerals Economically Important Minerals
Economically Important
Minerals
The Economic Use of
Mineral Tidbit:
Minerals
Did you ever wonder why “quartz” is used in watches?
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When a small electrical current
is applied to quartz it vibrates
at a very precise rate of
100,000 vibrations per second
Locating Mineral
How do Geologists Locate Mineral Deposits?
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18.12.a-b
3) Analyze the chemistry of rocks
1) Look for rocks altered by
fluids
4) Reconstruct the geologic history of area
2) Chemically altered rocks (events make, hide, or destroy deposit)
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How do Geologists Locate Mineral Deposits?
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Use geologic maps to identify
favorable rocks and structures
Above: Traditional geologic map
Left: 3-D geologic map
Locating Mineral
Locating Buried Mineral Deposits
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Conduct surveys
using geophysical
methods, including
magnetic surveys
Note where the
magnetic strength is
high over ore body
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Locating Mineral
How do Geologists Locate Mineral Deposits?
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A gravimeter is a specialized type of accelerometer designed for measuring the
local gravitational field of the Earth.
Commonly, gravimeters are used in
petroleum and mineral mining, as
well as for various types of
geophysical research,
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Geologists analyzing a geophysical map of region
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Locating Mineral
How do Geologists Locate Mineral Deposits?
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Airborne Geophysical Survey
Reflection seismology (or seismic reflection) is
a method of exploration geophysics that uses
the principles of seismology to estimate the
properties of the Earth's subsurface
from reflected seismic waves.
Locating Mineral
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Locating Mineral
How do Geologists Locate Mineral Deposits?
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Ground-penetrating radar (GPR) is
a geophysical method that uses radar
pulses to image the subsurface.
This nondestructive method uses
electromagnetic radiation in
the microwave band (UHF/VHF frequ
encies) of theradio spectrum, and
detects the reflected signals from
subsurface structures. GPR can be
used in a variety of media, including
rock, soil, ice, fresh water, pavements
and structures. It can detect objects,
changes in material, and voids and
cracks.
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Locating Mineral Deposits
Core sampling is the process of taking a solid core of
rock (usually about 50mm in diameter) out of the rock;
using a specialized circular drill bit; much like a hole
saw used on an electric drill. As the bit cuts through the
rock, the round core passes up through the drill, and
through the hollow drill rods, attached to the bit. The
entire core may be many feet long, broken into
handleable sections.
Core drilling is the only certain way of determining
the composition of the underground rocks; and is an
invaluable tool in mineral exploration and mine
development.
Mining companies often take cores, during both the
exploration and development stages of mining.
Government geological survey bodies also often
take core samples for general knowledge, and store
them in 'core libraries'; where they may be inspected
by geologists.
Locating Mineral
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Locating Mineral
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Locating Mineral
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CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) uses reflectance
spectroscopy to identify minerals on the martian surface.
Locating Mineral
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Afghanistan’s Buried Riches
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Under military cover, U.S. geologists have mapped Afghanistan’s deposits of critical
minerals. Rich reserves of rare-earth elements exist in the south, where Taliban control is
tightest.
If mining of important minerals can take off in the north, that success could create
enormous commercial and political momentum for opening the south. New estimates
indicate that rare earths could be triple the initial predictions.
Overcoming the country’s opium and Taliban strongholds with a mining bonanza could
change U.S. foreign policy and world stability.
Over the long term, Afghanistan’s geologists will have to take charge. The U.S. Geological
Survey is nearly done training them.
Conclusion
Earth’s Buried Treasures
The Economic Importance of
Minerals and Mineral Resources