Plate Boundaries PDF

Ms. Janelle Alexes Y. Alido  A plate boundary where two plates move towards each other. Boundaries between two plates that are colliding  Oceanic-Continental Oceanic-Oceanic Continental-Continental  A continental plate colliding with another continental plate. Have Collision...

Ms. Janelle Alexes Y. Alido  A plate boundary where two plates move towards each other. Boundaries between two plates that are colliding  Oceanic-Continental Oceanic-Oceanic Continental-Continental  A continental plate colliding with another continental plate. Have Collision Zones: o A place where folded and thrust faulted mountains form.  Oceanic plate colliding with a less dense continental plate Subduction Zone: The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.  Oceanic plate colliding with another oceanic plate The less dense plate slides under the more dense plate creating a subduction zone called a TRENCH  A plate boundary where two plates move away from each other. Magma rises and creates new crust or seafloor. Causes: mid-ocean ridges, rift valleys, new crust , volcanoes The hot lava rose from the ocean floor to the surface and cooled off to become a new crust and fill the rift valleys. New crust was created through a constant activity of these volcanoes. Iceland contains about 130 volcanoes and there is usually an eruption every decade or half-decade.  A continental rift valley is a region where the continental lithosphere is weakening and stretching apart. East African rift valley is an example of a continental rift valley.  When two tectonic plates slide past each other horizontally May cause Earthquakes when the rock snaps from the pressure.  A famous fault at a Transform Boundary is the San Andreas Fault in California.  Dip-slip Strike-slip Oblique slip  Dip - the angle that describes the steepness of the fault surface. This angle is measured from Earth's surface, or a plane parallel to Earth's surface. Slip – the movement  Fault movement occurs when the hanging wall moved predominantly up or down relative to the footwall. If the motion was down, the fault is called a normal fault, if the movement was up, the fault is called a reverse fault.  Hanging wall – above the fault plane Footwall – below the fault plane  Thrust fault – a type of reverse fault where the angle of the dip is 45° or less.  When the hanging wall moves horizontally, it's a strike-slip  Combination of strike slip and dip slip. Ms. Janelle Alexes Y. Alido