Tectonic Plate Boundaries

Types of Boundaries Convergent Divergent Transform

Convergent Two tectonic plates collide Three types: Oceanic-Oceanic Continental-Continental Oceanic-Continental

Oceanic-Oceanic Two oceanic plates collide The denser one subducts beneath the other Subduction zone Volcanoes can form The denser plate melts and becomes magma Magma can be forced up through vents

Oceanic-Continental An oceanic and a continental plate collide The denser oceanic plate subducts beneath the less dense continental plate Subduction zone Volcanoes can form The denser plate melts and becomes magma Magma can be forced up through vents

Continental-Continental Two continental plates collide The plate are of equal densities They buckle and thicken, pushing the crust upward Mountains form

Divergent Two tectonic plates move away from one another

Divergent Seafloor spreading occurs at divergent boundaries Volcanoes can form at divergent boundaries Plates move apart and expose a vent Magma slowly rises to the surface Magma cools and hardens into new oceanic lithosphere

Transform Two tectonic plates slide past each other horizontally

Transform Earthquakes typically occur at transform boundaries Stress builds up and is eventually released, causing a violent shift The movement from this shift is an earthquake

Volcanoes at Hot Spots A hot spot is a place beneath the earth where very hot magma exists. When a plate moves over a hot spot in the mantle, a vent can be exposed Fountains of magma punch through the crust

Summary Three types of boundaries Convergent Divergent Transform Oceanic-oceanic Oceanic-Continental Continental-Continental Divergent Transform

Summary Volcanoes form at: Convergent Boundaries Divergent Boundaries Oceanic-oceanic Oceanic-continental Divergent Boundaries Hot Spots

Summary Seafloor spreading occurs at Earthquakes typically occur at Divergent boundaries Earthquakes typically occur at Transform boundaries