Geology and Mineral Resources
(Non-renewable)
Chapter 14
Geology
Study of the dynamic processes taking place on
the earth’s surface and in its interior
Three major concentric zones
Core

Innermost zone, extremely hot, solid inner part
surrounded by liquid/molten semisolid
Mantle

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Lithosphere - the outermost layer of the mantle and
consists of solid rock
Asthenosphere – a zone of partly melted rock that flows
Crust

Outermost and thinnest zone
Convection cells
The interior of the earth is composed of
convection cells that move large volumes of rock
and heat in loops within the mantle
These flows of energy and heated material
caused the lithosphere to break up into the
tectonic plates which move slowly on top of the
aesthenosphere
Theory of Plate Tectonics
Prior to 1900s scientists believed that Earth’s major
features (oceans & continents) were fixed in place
1912 Alfred Wegener proposed a revolutionary hypothesis
that the world’s continents had once been joined in a single
landmass called “Pangea”
Evidence to support his theory
Identical rock formations on both sides of the Atlantic
Fossil evidence
Theory of Plate Tectonics
Earth’s lithosphere is divided into plates, most of which are in
constant motion
Tectonic cycle is the sum of the processes that build up and
break down the lithosphere
Tectonic plates (2 types Oceanic & Continental)
Plate Boundaries
Convergent - collide

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Mountains
Volcanoes
Oceanic trenches
Divergent - pull apart

Oceanic ridges
Transform – slide past each other

Earthquakes
plate tectonics
plate boundary rap
Plate Boundaries
Volcanoes, Arcs, and Hotspots
85% of volcanoes occur along plate boundaries
Hot spots form when plumes of molten material from the
mantle reach the lithosphere
When plate boundaries move across a hot spot, a chain
of volcanoes form, as exemplified by the Hawaiian
Islands. As the plate continues to move, a chain of extinct
and active volcanoes are developed.
Volcanic Arcs – subduction of one plate under another
Oceanic – (2 oceanic plates, one subducts the other creating
an oceanic trench)
Continental - an oceanic plate is subducted under a land plate
creating a mountain range
Ring of Fire
Volcanoes, Earthquakes, Tsunamis
Mount Saint Helens Eruption 1980
Mt. Saint Helens Landslide
Northridge Earthquake 1994 photos and data
Tsunami Japan 2011
Rocks and Minerals
Mineral: an element or inorganic compound that
occurs naturally in the earth’s crust as a
crystalline solid (regular repeating 3 dimensional
arrangement of the atoms within)
Gold, mercury, sodium chloride, silicon dioxide
Rock: A solid combination of one or more
minerals found in the earth’s crust
Three major types of rock
Sedimentary rock
Igneous rock
Metamorphic rock
Sedimentary Rock
Made of sediments consisting of dead plant and
animal remains and tiny particles of weathered
and eroded rock
Sandstone, shale, limestone, dolomite, coal
Many fossils are found in this type of rock
Formed by pressure
Igneous Rock
Forms below the earth’s surface when magma
rises from the mantle and then cools and
hardens
Make up the greatest percentage of the earth’s
crust
Frequently contains valuable metal deposits
Granite
Lava Rock
Metamorphic Rock
Preexisting rock is subjected to high temperatures
or pressure causing the transformation of rocks by
reshaping their internal crystalline structure
Slate
Marble
Weathering, Erosion, Rock Cycle
Weathering
Physical, chemical, or biological processes that
break down rocks into smaller particles that help
build soil

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Physical – wind, water, temperature changes
Chemical – acidic water (acid rain or naturally acidified)
Biological – lichens, roots, burrowing animals
Erosion
Material is dissolved, loosened, or worn away from
one part of the earth’s surface and deposited
elsewhere

Rivers, streams, rain, wind, glaciers, burrowing animals
Rock Cycle
Rock moves from one physical state or location to
another.
Igneous, sedimentary, and metamorphic rocks are
continually formed, modified, transported, and
destroyed
Rock formation deep in the earth’s crust, then uplifted
Weathering and erosion
Particles are then transformed into another type of rock
Rock Cycle Animation
Mineral Resources – Nonrenewable
A naturally high concentration elements or
compounds in the earth’s crust that can easily
and affordably be extracted and processed into
raw materials and then useful products
Considered nonrenewable b/c they take so long
to form
2 types
Metallic minerals (gold, silver, platinum, aluminum
Nonmetallic minerals (sand/SiO2, limestone/CaCO3)
Know some uses for these:
Al, Fe, Mn, Co, Cr, Cu, Au, Phosphate salts
Mineral Ore
Rock that contains a high enough concentrations
of a specific mineral, making extraction
economically feasible
High grade – higher concentration
Low grade – lower concentration
Reserves
The identified resources from which we can extract
the mineral profitably at current prices (does not
include possible undiscovered resources)
Approximate Supplies of Metal Reserves
Metal
Global Reserves Remaining
(in years)
US Reserves Remaining
(in years)
Iron
120
40
Aluminum
330
0
Copper
65
40
Lead
20
40
Zinc
30
25
Gold
30
20
Nickel
75
0
Cobalt
50
0
Manganese
70
0
Chromium
75
0
Types of Mining
Subsurface mining
Minerals located deep beneath the surface of the earth
are removed through tunnels and shafts

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Slope and shaft
Room and pillar/stope and pillar
Surface Mining
Deposits are located close to the surface and the
overburden (soil or rock above the deposit) is removed
to access minerals
After minerals are extracted, waste materials called
spoils or tailings are dumped into holding ponds,
heaped into giant piles, or returned to the original hole
Subsurface Mining
Stope &Pillar/Room & Pillar
Slope and Shaft
Surface Mining
Open pit – creation of a large pit in the groups that is
visible from the earths surface but extends both
vertically and horizontally (Copper)
Strip mining – remove strips of soil and rock
Contour strip mining – remove strips of soil in rock using
the natural contour of the landscape
Mountaintop removal – remove entire top of mountain
using explosives
Placer mining – process of using water to separate river
sediments into precious metals and waste (gold,
diamonds, tantallum)
Open Pit Copper Mine
Contour Strip Mining
Mountaintop Removal
Placer Mining
Mineral Extraction and Processing
Environmental impacts include:
Soil displacement and
erosion
Solid waste
Greenhouse gases
Human health hazards
Acid mine drainage
Dropping water tables
Extraction & processing
requires large amounts of:
Energy
Water
Impacts from mining, processing and use
Human Health Impacts
Release of cyanide and mercury into the
environment
Acid mine drainage
Mining is a hazardous occupation
Black lung disease
Elemental Composition of the
Earth’s Crust
Distribution of Minerals and Reserves
Minerals are not distributed evenly throughout the
earth’s land areas
US, Canada, Russia, S. Africa, & Australia supply
most of the world’s nonrenewable minerals
Consumption differs greatly b/w LDCs and MDCs
China
Stockpiling 17 rare earth metals such as Tb, Ds
needed for advanced technology industry
United States
Has stockpiles of Cr, Ti, Sn, Mn, Cr, Pt, and Co, b/c
total of 20 elements must be imported, but reserves are
dwindling
Depletion Time
The amount of time it takes to use up 80% of the
reserves of a mineral at a given rate of use
Determined by two factors
Actual/potential supply
Rate of consumption
3 Scenarios
No recycling or reuse
Recycling, reuse, better technology
Recycle, reuse, better technologies, new discoveries
Economics of Mining
Mining becomes economically less feasible due
to three factors:
Increasing cost of mining due to quality of ore
Shortages of water due to water table disturbances
Environmental impacts
New forms of mining or alternatives
Biomining
Ocean mining
Find Substitutes for minerals
Mining Legislation
Mining Law of 1872 (General Mining Law)
Regulates the mining of silver, copper, and gold as well as
fuels
Companies can recover ores and fuels from federal lands
Designed to encourage westward expansion, little to no
environmental protections
Surface Mining Control and Reclamation Act of 1977
Regulates surface mining of coal and the surface effects
of subsurface coal mining
Land must be disturbed as little as possible during the
mining process
Treaties
Antarctic Treaty 1961
Limits activities to peaceful scientific endeavors
Environmental Protection Protocol to the Antarctic
Treaty/Madrid Protocol 1990
A moratorium on mineral exploration for a minimum of
50 years
Designated Antarctica as a “natural reserve dedicated
to peace and society”
U.N. Convention on the Law of the Sea (UNCLOS)
1994
The constitution of the ocean, binding for international
waters, protects the resources of the ocean (Mn)