Plate Tectonics Theory and Processes

Plate Tectonics

• Theory: The Earth's lithosphere is broken into large plates that move relative to each other, creating and destroying landforms.
• Types of Plate Boundaries:
  • Divergent: Plates move apart, new crust forms (e.g., mid-ocean ridges)
  • Convergent: Plates collide, crust is destroyed (e.g., subduction zones)
  • Transform: Plates slide past each other horizontally (e.g., fault lines)
• Plate Tectonics Processes:
  • Continental drift: continents move across the Earth's surface
  • Seafloor spreading: new oceanic crust is created at mid-ocean ridges
  • Hotspots: volcanic regions where magma rises to the surface

Rock Cycle

• The Rock Cycle: The continuous process by which rocks are formed, transformed, and destroyed
• Rock Types:
  • Igneous: formed from magma or lava
  • Sedimentary: formed from compressed sediments
  • Metamorphic: formed when existing rocks are altered by heat and pressure
• Rock Cycle Processes:
  • Weathering: rocks break down into sediments
  • Lithification: sediments are compressed into sedimentary rocks
  • Metamorphism: rocks are transformed under heat and pressure
  • Magmatic differentiation: magma cools and crystallizes to form igneous rocks

Weathering and Erosion

• Weathering: The breakdown of rocks into sediments through chemical, physical, or biological processes
  • Types of Weathering:
    • Mechanical weathering: physical breakdown of rocks
    • Chemical weathering: chemical reactions that alter rocks
  • Factors Affecting Weathering:
    • Temperature
    • Moisture
    • Oxygen
• Erosion: The transportation of sediments away from their source
  • Agents of Erosion:
    • Water
    • Wind
    • Ice
  • Types of Erosion:
    • Running water
    • Glacial erosion
    • Coastal erosion

Earth's Interior

• Earth's Internal Structure:
  • Crust: outermost solid layer
  • Mantle: thick, hot, viscous layer
  • Outer Core: liquid iron-nickel alloy
  • Inner Core: solid, iron-nickel alloy
• Heat and Energy:
  • Geothermal energy: heat from the Earth's interior
  • Radioactive decay: heat generated by radioactive elements
• Earth's Internal Processes:
  • Convection currents: slow circulation of the mantle
  • Plate tectonics: movement of the Earth's lithosphere

Plate Tectonics

• The Earth's lithosphere is broken into large plates that move relative to each other, creating and destroying landforms.
• There are three types of plate boundaries: divergent, convergent, and transform.
• Divergent boundaries: plates move apart, new crust forms, e.g., mid-ocean ridges.
• Convergent boundaries: plates collide, crust is destroyed, e.g., subduction zones.
• Transform boundaries: plates slide past each other horizontally, e.g., fault lines.
• Continental drift: continents move across the Earth's surface.
• Seafloor spreading: new oceanic crust is created at mid-ocean ridges.
• Hotspots: volcanic regions where magma rises to the surface.

Rock Cycle

• The rock cycle is the continuous process by which rocks are formed, transformed, and destroyed.
• There are three main types of rocks: igneous, sedimentary, and metamorphic.
• Igneous rocks: formed from magma or lava.
• Sedimentary rocks: formed from compressed sediments.
• Metamorphic rocks: formed when existing rocks are altered by heat and pressure.
• Weathering: rocks break down into sediments.
• Lithification: sediments are compressed into sedimentary rocks.
• Metamorphism: rocks are transformed under heat and pressure.
• Magmatic differentiation: magma cools and crystallizes to form igneous rocks.

Weathering and Erosion

• Weathering: the breakdown of rocks into sediments through chemical, physical, or biological processes.
• Mechanical weathering: physical breakdown of rocks.
• Chemical weathering: chemical reactions that alter rocks.
• Factors affecting weathering: temperature, moisture, oxygen.
• Erosion: the transportation of sediments away from their source.
• Agents of erosion: water, wind, ice.
• Types of erosion: running water, glacial erosion, coastal erosion.

Earth's Interior

• The Earth's internal structure consists of: crust, mantle, outer core, inner core.
• Crust: outermost solid layer.
• Mantle: thick, hot, viscous layer.
• Outer core: liquid iron-nickel alloy.
• Inner core: solid, iron-nickel alloy.
• Geothermal energy: heat from the Earth's interior.
• Radioactive decay: heat generated by radioactive elements.
• Convection currents: slow circulation of the mantle.
• Plate tectonics: movement of the Earth's lithosphere.