Chapter 14: Geology and Earth
Resources
14.1 Earth Processes Shape Our
Resources
• Earth is a dynamic planet
• Tectonic processes reshape continents and
cause earthquakes and volcanoes
The Solid Earth
Global Earthquakes
Global Volcanoes
The Earth’s Plates
The Plate Tectonics Model
Global Plate Motions
14.2 Rocks And Minerals
• The Rock Cycle Creates And Recycles Rocks
• Weathering And Erosion Wear Down Rocks
The Rock Cycle
14.3 Economic Geology And
Mineralogy
• Metals are essential to our economy
• What Do You Think? Should We Revise Mining
Laws?
– The Mining Law of 1872
• Nommetallic minerals include gravel, clay,
sand, and salts
Bingham Canyon Pit, Utah
Bingham Canyon
Everything in Mines is Big
Everything in Mines is Very Big
My Truck Can Eat Your Truck
Where Are They Now?
The Krupps
Taconite Pelletizer
Taconite Pellets
Taconite Pellets
Smelter, Sudbury, Ontario
“Superstack”,
Sudbury,
Ontario:
Once 1% of the
entire planet’s
sulfur emissions
– 40,000
tons/day
Slag Pouring, Sudbury, Ontario
14.4 Environmental Effects of Resource
Extraction
• Mining can have serious environmental
impacts
– Acid runoff
– Toxic metals
• Processing ores also has negative effects
– Sulfur Emissions
– Waste Disposal
Tailings, Bingham Canyon, Utah
Mercury Mine, California
Mine Runoff, Colorado
Climax Tailings Ponds, Colorado
Coal Tip, England
Aberfan Slide, Wales
14.5 Conserving Geological Resources
• Recycling saves energy as well as materials
– About 50% of Iron and Steel is Recycled
– Recycling Electronics
• New materials can replace mined resources
– New Methods of Mining Low-Grade Ores
– Synthesizing Minerals (Quartz, Diamonds)
– Alternatives (Plastics for Metals)
Recycling
Electronics
Three Emerging Resource Problems
• Lithium (Batteries)
– Evaporites (Bolivia): Far Easier to Extract
– Pegmatites (Lepidolite, Spodumene)
• Rare Earths (Electronics)
– Col-Tan and Congo Civil War
– Chinese Monopoly
– California mine to reopen
• Phosphorus (Fertilizer)
– Morocco, China, South Africa, Jordan, U.S. = 90%
14.6 Geological Hazards
• Earthquakes can be very destructive
– “Earthquakes Don’t Kill People, Buildings Kill
People”
• Volcanoes eject gas and ash, as well as lava
– Lava is the Least Dangerous Product of Volcanoes
• Landslides are examples of mass wasting
Products of Eruptions
Lava Flows
Pyroclastic Debris
• Bombs
• Lapilli
• Ash
Mudflows
Landslides
Gases
• Steam
• Carbon Dioxide
• H2S
• SO2
• HCl
• HF
Environmental Hazards of Volcanoes
Pollution
• SO2, HCl in Water
Lava Flows
Falling Ejecta
Ash Falls
• Building Collapse
• Crop Destruction
Mudflows
• Direct Damage
(Colombia, 1985)
• Floods (Several Types)
Blast (Mt. St. Helens, 1980)
Pyroclastic Flow (St. Pierre,
1902)
Gas (Lake Nyos, Cameroon,
1986)
Volcanic Explosivity Index
VEI Classification
Description
Plume
Ejecta
volume
Frequency
Example
0
non-explosive
< 100 m
< 104m³
daily
Mauna Loa
gentle
100-1000 m > 104 m³
daily
Stromboli
explosive
1-5 km
> 106 m³
weekly
Galeras 1993
1
2
Hawaiian
Hawaiian
Strombolian
Strombolian
Vulcanian
3
Vulcanian /Pelean
severe
3-15 km
> 107 m³
yearly
Lassen 1915
4
Pelean/Plinian
cataclysmic
10-25 km
> 0.1 km³
≥ 10 yrs
Soufrière Hills
1995
5
Plinian
paroxysmal
> 25 km
> 1 km³
≥ 50 yrs
St. Helens 1980
6
Plinian/Ultra-Plinian colossal
> 25 km
> 10 km³
≥ 100 yrs
Pinatubo 1991
7
Plinian/Ultra-Plinian super-colossal
> 25 km
> 100 km³
≥ 1000 yrs
Tambora 1815
8
Ultra-Plinian
> 25 km
> 1,000 km³ ≥ 10,000 yrs
mega-colossal
Toba (73,000
BP)
Major Hazards of Earthquakes
•
•
•
•
Building Collapse
Landslides
Fire
Tsunamis (Not Tidal Waves!)
Safest & Most Dangerous Buildings
•
•
•
•
•
•
Small, Wood-frame House - Safest
Steel-Frame
Reinforced Concrete
Unreinforced Masonry
Adobe - Most Dangerous
Loose Concrete Blocks (Haiti, 2010)
Not the Best Place to Build?
Construction, Turkey
Construction, Turkey
Construction, Turkey
Construction, Bosnia
Tile Roof, Costa Rica
Tile Roof, Costa Rica
Adobe Buttresses, Texas
Types of Mass Wasting
•
•
•
•
•
Creep
Slow Landslide
Slump
Earthflow, Mudflow, Debris Flow
Avalanche
Soil Creep
Slide Lake, Wyoming, 1925
Vaiont Slide, Italy, 1962
Rear of Dam
Yungay, Peru, May 31, 1970
Yungay, Peru, May 31, 1970
Lituya Bay, Alaska, July 9, 1958
Lituya Bay,
Before and
After
The Scour Line
The Highest Wave Ever Recorded
Dealing With Mass-Wasting
• Proper Land Use – Stay out of Danger
• Take warnings seriously
• Structural Control
– Retaining Structures
– Drainage
– Terraces
• Warning System
• Accept the Risk and Responsibility
• Abolish Insurance ?