Plate Boundaries Quiz

Plate Boundaries

• Tectonic plates are large pieces of crust and rigid upper mantle, fitting together to cover Earth's surface.
• Plates move in different directions and at varying speeds relative to each other.
• Interactions at plate boundaries generate geological features and processes.

Convergent Boundaries

• Convergent boundaries involve two plates moving towards each other.
• When two plates collide, the denser plate subducts (dives beneath) the less dense plate.
• Subduction zones lead to the formation of trenches and volcanic arcs.

Types of Convergent Boundaries

Oceanic-Oceanic

• A subduction zone forms when one oceanic plate, denser due to cooling, descends below another.
• This process creates an ocean trench and a volcanic island arc parallel to the trench.

Oceanic-Continental

• When a denser oceanic plate converges with a continental plate, the oceanic plate subducts.
• This interaction results in a trench and a volcanic mountain range.

Continental-Continental

• Collisions between continental plates occur after an oceanic plate has converged with a continental plate.
• This results in a vast mountain range like the Himalayas.

Divergent Boundaries

• Divergent boundaries are where plates move apart.
• On continents, the separation of continental crust forms a rift valley.
• New crust is created by magma rising at these boundaries.

Transform Boundaries

• Transform boundaries involve plates sliding horizontally past each other.
• These boundaries are often marked by long faults and shallow earthquakes.

Causes of Plate Movement

• Convection currents in the mantle are a primary driver for plate movement.
• Heated material rises, cools, and sinks, creating circular motion.
• This movement transfers heat energy from Earth's interior to the exterior and moves the crust.

Ridge Push and Slab Pull

• Ridge push is the force generated by the elevated ridge pushing oceanic plate towards subduction zones.
• Slab pull happens when the weight of dense subducting plate pulls the trailing slab.