Chapter 14: Geology and EarthResources

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 MudflowsLandslides

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 IndexVEI Classification Description Plume Ejecta

volume Frequency Example

0 Hawaiian non-explosive < 100 m < 104m³ daily Mauna Loa

1 HawaiianStrombolian gentle 100-1000 m > 104 m³ daily Stromboli

2 StrombolianVulcanian explosive 1-5 km > 106 m³ weekly Galeras 1993

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 mega-colossal > 25 km > 1,000 km³ ≥ 10,000 yrs 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 ?