Earth's Mineral Resources: Formation, Plate Tectonics, and Rock Cycle

Mineral Resources

Almost all of the mineral resources on Earth accumulated when the planet formed 4.6 billion years ago.

Geologic Processes

Earth's geologic processes form and break down rocks and minerals, drive volcanic eruptions and earthquakes, determine the distribution of scarce mineral resources, and create the soil in which plants grow.

Geologic Time Scale

Earth's history is measured using the geologic time scale.

Formation of Earth

Earth formed roughly 4.6 billion years ago from cosmic dust in the solar system.

Early Earth

The early Earth was a hot, molten sphere.

Elemental Composition

The elemental composition of Earth has stabilized since the bombardment phase of planet formation has largely ceased.

Vertical Zonation

The planet is characterized by distinct vertical zonation due to the settling of elements according to their mass.

Core

The innermost zone of Earth's interior, composed mostly of iron and nickel, includes a liquid outer layer and a solid inner layer.

Silicon Dioxide

Silicon dioxide is the primary component of sand and glass and is readily available worldwide on beaches and in shallow marine and glacial deposits.

Diamonds

Diamonds are formed from carbon that has been subjected to intense pressure and are found in relatively few isolated locations.

Economic and Political Conflicts

The uneven geographic distribution of minerals has driven many economic and political conflicts throughout human history.

Cosmic Dust

Earth formed from cosmic dust in the solar system.

Asteroids

Asteroids occasionally strike Earth today, but the bombardment phase of planet formation has largely ceased.

Concentric Layers

If we could slice into Earth, we would see concentric layers composed of various materials.

Geological Processes

Geological processes continue to affect the distribution of Earth's mineral resources.

Scarce Mineral Resources

The distribution of scarce mineral resources is influenced by Earth's geologic processes.

First Humans

The Quaternary period marks the time of the first humans.

Mass Extinction

The Cretaceous period is known for the largest mass extinction.

Pangaea

The supercontinent Pangaea existed during the Jurassic period.

First Dinosaurs

The Triassic period is known for the first dinosaurs, birds, and mammals.

First Land Plants

The Ordovician period is marked by the appearance of the first land plants.

First Vertebrates

The Cambrian period is known for the first vertebrates.

Oxygen in Atmosphere

The Archean eon is characterized by the buildup of oxygen in the atmosphere.

Oldest Evidence of Life

The Archean eon also contains the oldest evidence of life.

Age of Bombardment

The age of bombardment refers to the period when debris from the formation of the Sun bombarded Earth.

Mantle

The layer of Earth above the core, containing molten rock, or magma.

Magma

Molten rock.

Asthenosphere

The layer of Earth located in the outer part of the mantle, composed of semi-molten rock.

Lithosphere

The outermost layer of Earth, including the mantle and crust.

Crust

In geology, the chemically distinct outermost layer of the lithosphere.

Thickness of Lithosphere

Approximately 100 km (60 miles) thick.

Convection Cells

Processes in which the mantle circulates, much like the atmosphere.

Hot Spots

Places where molten material from the mantle reaches the lithosphere.

Finite Mineral Resources

Earth contains only a finite supply of mineral resources, which cannot be extracted indefinitely.

Radioactive Decay

The process by which isotopes of elements such as potassium, uranium, and thorium release heat.

Fossil Evidence

Fossils of the freshwater reptile Mesosaurus have been found in South America and Africa.

Identical Rock Formations

Rock formations that are found on both sides of the Atlantic Ocean, indicating that current landmasses were once joined.

Upper Mantle

The solid upper portion of the mantle that is part of the lithosphere.

Brittle Outermost Layer

The lithosphere, which is the brittle outer layer of the planet.

Chemical Elements for Life

The crust and overlying soil provide most of the chemical elements that make up life.

Energy for Resource Extraction

Once easily obtained mineral resources are mined, more energy is required to extract remaining resources.

Surface Dynamics of Earth

Hot spots are an important component of the surface dynamics of Earth.

Concentric Layers of Earth

Earth is composed of concentric layers, including the core, mantle, and crust.

Supercontinent

A single large continent that may have existed in the past.

Plate Tectonics

The theory that the lithosphere of Earth is divided into plates, most of which are in constant motion.

Tectonic Cycle

The sum of the processes that build up and break down the lithosphere.

Subduction

The process of one crustal plate passing under another.

Oceanic Plates

Plates that lie primarily beneath the oceans and have a dense crust rich in iron.

Continental Plates

Plates that lie beneath landmasses and generally contain more silicon dioxide.

Mantle Convection

The process driven by heat from Earth's core that creates convection cells in the mantle.

Seafloor Spreading

The process where rising magma forms new oceanic crust on the seafloor at the boundaries between oceanic plates.

Plate Movement

The slow drift of continents on tectonic plates over the surface of Earth.

Geographic Barriers

Obstacles formed or removed due to plate movement, affecting species evolution.

Eurasian Plate

One of Earth's major tectonic plates.

Indian Plate

One of Earth's major tectonic plates.

North American Plate

One of Earth's major tectonic plates.

Pacific Plate

One of Earth's major tectonic plates.

Nazca Plate

One of Earth's major tectonic plates.

South American Plate

One of Earth's major tectonic plates.

Antarctic Plate

One of Earth's major tectonic plates.

Caribbean Plate

One of Earth's major tectonic plates.

Philippine Plate

One of Earth's major tectonic plates.

Cocos Plate

One of Earth's major tectonic plates.

Fiji Plate

One of Earth's major tectonic plates.

Indo-Australian Plate

One of Earth's major tectonic plates.

Collision Zone

A type of plate boundary where two plates collide.

Spreading Zone

A type of plate boundary where new lithosphere is added.

Subduction Zone

A type of plate boundary where older lithosphere is recycled into the mantle.

Continental crust

The thick part of the Earth's crust that forms the continents.

Oceanic crust

The thin part of the Earth's crust that underlies the oceans.

Lower portion of lithosphere

The rigid outer layer of the Earth, consisting of the crust and upper mantle.

Volcano

A vent in Earth's surface that emits ash, gases, or molten lava.

Rising magma

Magma that moves upward from the mantle to the Earth's surface.

Convection

The process by which heat is transferred through the movement of fluids, causing tectonic plate movement.

Divergent plate boundary

An area beneath the ocean where tectonic plates move away from each other.

Convergent plate boundary

An area where plates move toward one another and collide.

Transform fault boundary

A type of fault where two tectonic plates slide past each other horizontally.

Geologic hot spot

A location where magma from the mantle rises to the surface, creating volcanic activity.

Hawaiian Islands

An example of a series of volcanic islands formed by a hot spot as the Pacific Plate moved over it.

Earthquakes

Sudden shaking of the ground caused by the movement of tectonic plates.

Volcanic eruptions

The release of ash, gases, and molten lava from a volcano.

Magma reservoir

An underground pool of molten rock beneath the Earth's surface.

Chemical composition

The specific arrangement and types of elements that make up a substance.

Natural source of atmospheric carbon dioxide

Volcanoes, which emit carbon dioxide during eruptions.

Convergent plate boundaries

Boundaries form where plates move toward one another and collide.

Divergent plate boundaries

Boundaries where plates move apart.

Transform fault boundaries

An area where tectonic plates move sideways past each other.

Fault

A fracture in rock caused by movement in Earth's crust.

Seismic activity

The frequency and intensity of earthquakes experienced over time.

Fault zone

A large expanse of rock where a fault has occurred.

Mid-continental mountain range

Formed when two continental plates meet and both plate margins may be lifted.

Himalayas

A mountain range formed from the collision of two continental plates.

Rate of plate movement

Most plates and continents move at about 36 mm, or 1.4 inches, per year.

Plate Movement Calculation

To calculate the time it takes for plates to move, use the formula: time = distance ÷ rate.

Distance traveled for Los Angeles to San Francisco

The distance is 630 km (or 630,000,000 mm).

Net distance moved for Los Angeles

The plate under Los Angeles is moving northward at about 36 mm per year.

Time for Los Angeles to be adjacent to San Francisco

It will take 17,500,000 years.

Brittle upper lithosphere

Where fault zones form as two plates meet or slide past one another.

Fractured and deformed rock

Occurs in large expanses of rock where movement has occurred due to immense pressures from plate movement.

Earthquake frequency

Measured over time as part of seismic activity.