Plate Boundaries and Landforms

Seafloor Spreading

• Seafloor spreading is the process of creating new oceanic crust from molten material.
• This process occurs at mid-ocean ridges where magma rises from the Earth's mantle and cools, forming new crust.
• The further away from the mid-ocean ridge, the older the oceanic crust.

Location of Young Oceanic Crust

• Younger oceanic crust is typically located near mid-ocean ridges.
• This is because the process of seafloor spreading constantly creates new crust at these locations.

Oceanic-Continental Convergence

• When oceanic and continental crust collide, the denser oceanic crust subducts beneath the continental crust.
• This process results in the formation of volcanoes, earthquakes, and mountain ranges along the coastlines.

Transform Plate Boundary

• A transform plate boundary is formed when two tectonic plates slide past each other horizontally.
• These boundaries are characterized by frequent earthquakes and lack of volcanic activity.

Slab Pull

• Slab pull refers to the force of gravity pulling the denser oceanic plate down into the mantle at a subduction zone.
• Transform plate boundaries are least likely to exhibit slab pull because there is no subduction occurring.

Divergent Plate Boundary

• The primary characteristic of divergent plate boundaries is the creation of new crust.
• This occurs as magma rises from the mantle and cools, forming new crust.

Oceanic Oceanic Convergence

• During oceanic-oceanic convergence, the denser oceanic plate subducts beneath the less dense plate.
• This process results in the formation of volcanic island arcs and deep trenches.

Transform Boundary

• A transform boundary is characterized by two plates sliding horizontally past one another.
• There is no creation or destruction of crust at this boundary.

Continental-Continental Convergence

• When two continental crusts collide, they are too buoyant to subduct.
• This results in the formation of mountain ranges through folding and uplift.

Divergent Boundary

• Mid-ocean ridges are the most common geological feature formed at a divergent boundary.
• These ridges represent the zone where new oceanic crust is created.

Oceanic-Oceanic Convergence

• During oceanic-oceanic convergence, the denser plate subducts beneath the less dense plate.
• This process causes the denser plate to melt, producing magma that rises and erupts to form volcanic island arcs.

Convergent Boundary Movements

• Convergent boundaries are characterized by the collision of tectonic plates.
• The denser plate subducts beneath the less dense plate, resulting in volcanic activity, earthquakes, and mountain formation.

Oceanic Crust Formation

• Divergent boundaries are responsible for the creation of new oceanic crust.
• This occurs through the process of seafloor spreading, where magma rises from the mantle and cools, forming new crust.