Plate tectonics

Cards (30)

  • Convection currents in the mantle drive the movement of tectonic plates.
  • The mantle is made of solid rock.
  • The three main types of plate boundaries are convergent boundaries, divergent boundaries, and transform boundaries.
  • The features of a divergent plate boundary include mid-ocean ridges, rift valleys, and volcanic activity.
  • The features of a convergent plate boundary include subduction zones, volcanic arcs, and mountain ranges.
  • Transform plate boundaries are characterized by the horizontal sliding of two lithospheric plates past each other, resulting in earthquakes and the absence of volcanic activity.
  • Characteristics of a convergent plate boundary include the collision or subduction of tectonic plates, the formation of mountains or trenches, and the potential for volcanic activity and earthquakes.
  • At a transform plate boundary, two tectonic plates slide past each other horizontally, causing earthquakes.
  • At a convergent plate boundary, two tectonic plates collide and can either form mountains or cause one plate to be subducted beneath the other.
  • At a divergent plate boundary, two tectonic plates move away from each other, creating a gap where magma rises to form new crust.
  • Subduction in plate tectonics is the process where one lithospheric plate sinks beneath another into the Earth's mantle.
  • The two types of crust on Earth are continental and oceanic.
  • The three main layers of the Earth are the crust, mantle, and core.
  • Some evidence for continental drift are:
    continental fit
    similarity of rocks and mountain ranges
    fossil evidence
  • Alfred Wegener proposed the Continental Drift hypothesis in 1912.
  • The pangea consists of:
    Laurasia (Northern land mass)
    Gondwana (Southern land mass)
  • Features of the seafloor includes:
    • Continental margin
    • Abyssal plain
    • mid-oceanic ridges
    • Ocean trenches
  • Convection: the hot fluid goes up, cold fluid goes down.
  • Paleomagnetism is the remnant magnetism in ancient rocks.
  • Seafloor spreading was proposed by Harry Hess in 1962.
  • Seafloor spreading theory suggested that seafloor separates at oceanic ridges and provided the “how” to Wegener’s hypothesis.
  • Oceanic crust at the spreading ridges are younger than oceanic crusts farther from ridges.
  • Unifying Theory
    • Patterns of the continents
    • Patterns of seafloor ages
    • Patterns of seafloor depth
    • Patterns of magnetism
    • Patterns of volcanoes
    • Patterns of earthquakes
  • Examples of convergent (oceanic-oceanic) boundaries can be seen in Japan and the Philippines.
  • An example of oceanic-continental convergent is the Andes.
  • An example of continental-continental is the Eurasia-India plate/Himalayan mountains.
  • What moves the plates?
    Convective heat system and gravity-driven plate motion
  • What are some sources of heat?
    Radioactive decay, accretion, and differentation
  • What is ”slab-pull”?
    Pulling the plate behind a subduction cold slab of lithosphere
  • What is “ridge-push”?
    Gravity pushes oceanic lithosphere away from higher spreading sites and towards subduction.