Mod+2+-+Marley+B

__Convergent Boundries__

 * 1) When plates under landmasses collide, the crust forms into mountain ranges.
 * 2) India and Asia collided 55 million years ago, slowly forming the Himalayas. It forms more and more each day, so Mount Everest gets taller everyday.
 * 3) Convergent Boundries also happen when plates in the water crash into each other.
 * 4) As the plates lift up, it can also form mountain ranges.
 * 5) When plates melt, it can cause underwater volcanoes, forming islands like Japan
 * 6) There are two types of collison orogenies. They are continent-island arc, and continent-continent.
 * 7) Both put together is an ocean basin. When it goes down a subduction zone, it's called a remanant ocean basin.
 * 8) Trenches are formed when a plate dives underneath another.
 * 9) On an island, heat causes to form a volcano.

[[image:himalaya1.jpg width="250" height="162"]] [[image:japan3[1].gif width="171" height="194"]] __Divergant Boundries__

 * 1) Magma from deep inside the mantle comes up towards the surface and pushes the plates apart.
 * 2) This process re-news the ocean floor and widens basins.
 * 3) One mid-ocean ridge connects the world's oceans. This makes the the ridge the longest mountain range in the world.
 * 4) Giant troughs are formed like the Great Rift Valley in Africa. Plates are tugged apart in this trough.
 * 5) If plates continue to diverge, Eastern Africa will split into a new continent. Then a mid-ocean ridge would come between the two continents.
 * 6) Sometimes the uppermantle has been to flexible to create enough friction to pull the tetonic plates apart.

__Mid-Atlantic Ridge__

 * 1) This is an underwater mountain range that starts 207 miles below the North Pole to the Atlantic Ocean just below South Africa.
 * 2) The Mid-Atlantic Ridge is caused by seafloor spreading. Seafloor spreading is volcanic activity that happens in the ocean's crust.