Geology, Earth Resources, and Climate Change Overview

Crust

Outermost layer, least dense, brittle.

Oceanic Crust

Thinner, denser, recycled under 200 million years.

Continental Crust

Thicker, less dense, up to 3.8 billion years.

Outer Core

Hot, slowly moving liquid, generates magnetic field.

Inner Core

Solid state of iron and nickel under pressure.

Mantle

Hot, pliable rock layer, increases in density.

Asthenosphere

Upper mantle part, less rigid, allows movement.

Tectonic Plates

Sections of crust floating on mantle.

Divergent Boundary

Plates move apart, creates new oceanic crust.

Convergent Boundary

Plates move together, destroys oceanic crust.

Transform Fault Boundary

Plates slide past, no crust created or destroyed.

Subduction

Denser oceanic plate descends into mantle.

Trenches

Formed at converging plate boundaries.

Volcanic Arcs

Created at converging plate boundaries from magma.

Orogeny

Mountain formation at converging plate boundaries.

Precambrian Era

4.6 billion - 545 million years ago.

Great Oxygenation Event

2.4 billion years ago, atmosphere became oxygen-rich.

Paleozoic Era

545 - 245 million years ago, explosion of life.

Cambrian Period

Begins Paleozoic, abundant fossil record starts.

Mesozoic Era

Age of Dinosaurs, 245 - 65 million years ago.

Mass Extinction

Largest extinction at end of Permian period.

Converging Plate Boundaries

Denser plates subduct, lighter plates remain.

Earth Processes

Natural occurrences shaping Earth's structure and resources.

Plateosaurus

Oldest dinosaur fossil, 243 million years old.

Meteor extinction theory

Meteor impact caused dinosaur extinction 66 million years ago.

Cenozoic Era

Current geological era, began 65 million years ago.

Australopithecus afarensis

Early hominid species appeared 3.2 million years ago.

Homo sapiens

Modern humans appeared 315,000 years ago.

Igneous Rocks

Formed from magma cooling at surface or underground.

Extrusive igneous rocks

Form from lava, cool quickly, microscopic grains.

Basalt

Fine-grained rock formed from quickly cooled lava.

Intrusive igneous rocks

Form from magma underground, larger mineral grains.

Granite

Slowly cooled rock with visible mineral grains.

Metamorphic Rocks

Formed under pressure and heat from existing rocks.

Foliated metamorphic rocks

Mineral grains align under directional pressure.

Gneiss

Foliated rock formed from granite.

Non-foliated metamorphic rocks

Mineral grains not aligned due to omnidirectional pressure.

Marble

Non-foliated rock formed from limestone.

Sedimentary Rocks

Formed on Earth's surface from weathering and erosion.

Clastic rocks

Formed from lithified smaller rocks.

Conglomerates

Large rocks lithified together.

Organic rocks

Formed from deposition of plant or animal materials.

Coal

Organic rock formed from plant matter deposition.

Chemical rocks

Formed from minerals precipitating out of solution.

Halite

Rock salt formed from evaporated seawater.

Mechanical weathering

Physical break-up of rocks without chemical change.

Chemical weathering

Alters specific components, weakens rock structure.

Oxidation

Oxygen reacts with minerals, causing rusting.

Hydrolysis

Water dissolves minerals in rocks.

Carbonation

Acidic water breaks down limestone into carbon dioxide.

Sedimentation

Deposition of transported rock particles in new locations.

Peat

Organic matter that forms coal over time.

Coal Formation

Burial of peat under pressure and heat.

Energy Density

Amount of energy produced per unit mass.

Lignite Coal

Lowest grade coal, requires 60 million years burial.

Sub-bituminous Coal

Requires 250 million years burial for formation.

Bituminous Coal

Requires 300 million years burial for formation.

Anthracite Coal

Highest grade coal, requires 350 million years burial.

Carbon Dioxide Release

Anthracite releases most CO2 per BTU.

Mesozoic Era

Period when most oil reserves formed.

Kerogen

Organic matter in oil shale that generates oil.

Anoxic Environment

Lack of oxygen preventing decomposition of organic matter.

Oil Formation Temperature

Oil forms at 90°C to 160°C; above forms gas.

Confining Layer

Structure holding oil in place, resembles upside-down bowl.

Rare Earth Elements

China dominates market; U.S. has stricter laws.

Mountain Pass Mine

California mine closed due to competition and costs.

Recycling Benefits

Reduces demand for new ore and environmental impact.

Substitution

Using alternatives to reduce resource demand.

Open-Pit Mining

Surface mining method for various minerals and ores.

Toxic Lake

Water-filled open pits can become hazardous to wildlife.

Berkeley Pit Incident

Thousands of birds died from contaminated mine water.

Strip Mining

Removes vegetation and soil to access coal seams.

Spoil Banks

Debris piles from mining that can erode and contaminate.

Reclamation Measures

Efforts to restore land after mining activities.

Mountaintop Removal

Explosives remove mountains to access coal seams.

Buried Streams

900 km of streams buried in West Virginia.

Clean Water Act

EPA halted major mountaintop removal in 2011.

Underground Mining Risks

Includes tunnel collapses, explosions, and contamination.

Centralia Mine Fire

Burning since 1962, costing $40 million to control.

Coal Mine Fires in China

Some have burned for 400 years.

Ore Processing Pollution

Can be more polluting than mining itself.

Smelting

Heating ore to extract metals, causes air pollution.

Sulfur Dioxide (SO2)

Released from sulfide ores, contributes to acid rain.

Acid Rain

Forms from sulfuric acid, harms vegetation and aquatic life.

Heap Leach Extraction

Uses cyanide to dissolve gold from crushed ore.

Freshwater Usage

Rinsing ores consumes large amounts of water.

Contaminated Wastewater

Contains arsenic, heavy metals, and mercury.

Mine Site Reclamation Costs

Estimated $70 billion cleanup cost for U.S. abandoned mines.

Bonding Money Requirement

1977 law requires funds for site cleanup before mining.

Meridian Gold Beartrack Mine

$220 million gold extracted, only $2 million bonded.

Gold King Mine Incident

Toxic sludge leaked, killing aquatic life in Animas River.

General Mining Law of 1872

Allowed mining land sales at $2.50 to $5 per acre.

Land Use Abuse

Purchased land can be used for non-mining purposes.

Royalty Payments

Mining companies pay no royalties on federal land.

Potential Royalty Revenue

8% royalties could generate $320 million annually.

Current Bonding Issues

Existing bonds for cleanup are insufficient.

Environmental Regulations Debate

Should mining laws be revised for better protections?

Bonds for site cleanup

Higher bonds could save $320 million annually.

Meteor impact

Caused Mesozoic extinction through atmospheric soot.

Volcanic eruptions

Permian extinction caused by gases and cooling.