Geology: Plate Tectonics and Rock Cycle

Plate Tectonics

• The theory that the Earth's lithosphere is broken into large plates that move relative to each other
• These plates float on the more fluid asthenosphere below
• Plate movement is responsible for geological phenomena such as earthquakes, volcanoes, and the creation of mountain ranges

Rock Cycle

• The process by which rocks are formed, transformed, and destroyed
• The three main types of rocks:
  1. Igneous: formed from the cooling and solidification of magma or lava
  2. Sedimentary: formed from the accumulation and compression of sediments
  3. Metamorphic: formed from the alteration of existing rocks under high pressure and temperature

Geological Time Scale

• A system of categorizing time periods in the Earth's history
• Divided into eons, eras, periods, and epochs
• Key events in the geological time scale include:
  • Formation of the Earth (~4.5 billion years ago)
  • Origin of life (~3.5 billion years ago)
  • Development of complex life forms (~1 billion years ago)
  • Present day (Holocene epoch)

Earth's Structure

• Crust: the outermost solid layer of the Earth, ranging in thickness from 5-70 km
• Mantle: the thick layer of hot, viscous rock beneath the crust, divided into the upper and lower mantle
• Core: the central, iron-rich part of the Earth, divided into the solid inner core and liquid outer core

Geological Processes

• Weathering: the breakdown of rocks into sediments through exposure to wind, water, and ice
• Erosion: the transportation of sediments away from their source
• Deposition: the accumulation of sediments in a new location
• Plate boundary processes: including subduction, collision, and rifting

Plate Tectonics

• The Earth's lithosphere is broken into large plates that move relative to each other, causing geological phenomena like earthquakes, volcanoes, and mountain range creation
• These plates float on the more fluid asthenosphere below

Rock Cycle

• The process involves the formation, transformation, and destruction of rocks
• Igneous rocks form from the cooling and solidification of magma or lava
• Sedimentary rocks form from the accumulation and compression of sediments
• Metamorphic rocks form from the alteration of existing rocks under high pressure and temperature

Geological Time Scale

• A system of categorizing time periods in the Earth's history, divided into eons, eras, periods, and epochs
• Key events include the formation of the Earth (~4.5 billion years ago), origin of life (~3.5 billion years ago), and development of complex life forms (~1 billion years ago)

Earth's Structure

• The crust is the outermost solid layer, ranging in thickness from 5-70 km
• The mantle is the thick layer of hot, viscous rock beneath the crust, divided into the upper and lower mantle
• The core is the central, iron-rich part, divided into the solid inner core and liquid outer core

Geological Processes

• Weathering is the breakdown of rocks into sediments through exposure to wind, water, and ice
• Erosion is the transportation of sediments away from their source
• Deposition is the accumulation of sediments in a new location
• Plate boundary processes include subduction, collision, and rifting