Mountains & Plate Boundaries

Types of Mountains The three most common mountain types are: Folded Faulted Volcanoes

Folding in a section of the Folded Mountains Most common type of mountain Forms at a convergent boundary when two plates with continental crust collide Folding in a section of the Rocky Mountains Himalayas

Faulted (or Fault Block) Mountains Occurs when there is vertical movement along fault lines Uplift – when a section of land moves up Downdropping – when a section of land drops down Tilt – when a section of land rises and tilts

Faulted Mountain Images Uplift Downdropping Sierra Nevada Mountains, CA

Volcanoes Volcanoes are made of layers of lava Volcanoes can occur at convergent subduction zones, divergent boundaries, and hot spots Mount Orsono, Chile

Types of Plate Boundaries There are three types of plate boundaries: Divergent (plates move apart) Convergent (plates move toward each other) Transform (plates slide by each other)

Divergent Boundary Ocean Ridge Rift Valley Convection Currents

Divergent Boundary Divergent boundaries occur mostly along spreading centers where the magma rises forming new crust. Spreading zones on continents create parallel mountains and valleys as the crust pulls apart https://youtu.be/uSKzdbEVsI8

Convergent Boundaries Convergent boundaries occur in three arrangements: continental-continental crust continental-ocean crust ocean-ocean crust

Convergent (continent-continent) Folded Mountain Two thick continental plates collide and buckle into high mountains Ex: Himalaya Mountain Range https://youtu.be/MaHfGc-S5Dc Convection Currents

Convergent (ocean-continent) Ocean plate dives beneath a continental plate. Volcanic mountain chain forms inland Japan, Sumatra https://youtu.be/Wt_jJUnTFhg Volcano Trench Convection Currents

Convergent (ocean- ocean) Ocean plate dives beneath another ocean plate; volcanic island chain forms above the zone Ex: The Marianas https://youtu.be/SOmZODVotKk

Transform Boundary Fault AKA Transform Fault is a type of fault whose relative motion is predominantly horizontal While most transform faults are hidden in the deep oceans where they form a series of short zigzags accommodating seafloor spreading Fault

Hot Spot Volcano Super Hot Magma volcanic regions thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle https://youtu.be/AhSaE0omw9o Super Hot Magma