Physical
Geology
Mineral and Mining
Resources
Ore Minerals
 Minerals
that are
valuable and
economical to extract
are known as ore
minerals


Minerals that have no
commercial value are
called gangue minerals
Several separation
techniques are used to
separate ore or gangue
minerals
Ore Minerals
 Ore
minerals are further refined to extract
the valuable elements
 For mining to be profitable, the price of
the final product must be greater than the
costs of extraction and refining.
Mineral Resources and Their
Uses
 Some minerals are of
major economic and
industrial importance



Some metals can be
pressed into various shapes
or stretched very thinly
without breaking
Others are good
conductors of heat and
electricity
Some are prized for their
durability and resistance to
corrosion.
Mineral Resources and Their
Uses
 Often
two or more
metals are combined
to form alloys
 Alloys are important
because they
combine the most
desirable properties of
the metals used to
make them
Mineral Resources and Their
Uses
 Some
nonmetallic minerals are called
gemstones and are prized purely for their
beauty, rarity, or durability
 Important gemstones include:


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
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Diamond
Ruby
Sapphire
Emerald
Aquamarine
Topaz
Tourmaline
Mineral Exploration
 The
first step in finding an ore deposit is
exploring rock for mineralization


Planes can identify patterns in gravity,
magnetism, or radioactivity
Data and aerial photographs can be used
to create geologic maps of the surface
Mineral Exploration
 Samples
grade

are analyzed to determine ore
If the ore grade is high enough and the
deposit extensive enough, the cost to open
a mine may be warranted
Types of Mining
 Subsurface
Mining
 Surface Mining
 Placer Mining
Subsurface Mining
 Ore
deposits that are
usually found 50 m or
more beneath Earth’s
surface are mined via
subsurface mining

The most common
method is room-andpillar mining used to
mine coal and salt
Subsurface Mining
 Between
the rooms,
pillars of coal are left
standing to support
the roof
 When the mining of
rooms is completed,
the pillars are then
removed, beginning
with pillars at the
farthest point in the
mine.
Surface Mining

Surface mining methods
are used when ore deposits
are located close to Earth’s
surface

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
Open-pit mining is a
method that is often used
to mine large quantities of
near-surface ore
Coal and metals like
copper are mined using
open-pit method
Ore is mined downward,
layer by layer
Placer Mining
 When
rock weathers,
minerals within the rock
are released
 These minerals are
concentrated by wind
and water into surface
deposits called placer
deposits
 The most important
place deposits are
stream places
Undersea Mining
 The
ocean floor contains significant
mineral resources, which include
diamonds, precious metal such as gold
and silver, mineral ores, and sand and
gravel


Since the late 1950s, several attempts have
been made to mine the ocean
Land-based companies can mine mineral
more cheaply is a main reason undersea
mining is unsuccessful.
Mining Reclamation
 Mines
on land in the
United States are
regulated by federal
and states laws
 Reclamation

The process of
returning land to its
original or better
condition after
mining is completed
is called
reclamation
Mining Reclamation


The Surface Mining Control and
Reclamation Act of 1977 created a
program for the regulation of surface coal
mining on public and private land
The act set standards that would minimize
the surface effects of coal mining on the
environment.