Mod+7.8+-+Kaytelyn+N

**// __Dynamic Earth__//**
Have you ever heard of plate tectonics? Do you know what they make up? If you don't, you should know that plate tectonics is the theory of plates in the lithosphere that describe the formation and movements of plates. This theory is commonly known as plate boundaries. There are three different types of boundries. They are:
 * //__Plate Tectonics__//**
 * Divergent
 * Subducton
 * Convergent

Divergent Boundries are boundaries that are between two lithosphere plates that seperate or move apart. Most of the diverant Boundaries in the world lie along the ocean floor and have rift valleys. A rift valley are deep in the center of a mid- ocean ridge. It is like a separation of water. There is only one process to a divergent boundary is sea- floor spreading. Characteristics that feature this is A current example (because plates are constantly moving) is the Mid-Atlantic Ridge or the East Pacific rise.
 * //__Divergent Boundaries__//**
 * mid-ocean ridges
 * rift valleys
 * earthquake activity along mid- ocean ridges
 * volcanic activity.



**//__Subduction Boundaries__//** Next, we are talking about subduction boundaries. When an oceanic plate comes out from another plate, the oceanic plate is "subducting" beneath the over-ridding plate. That is how the subduction boundary has been know as this. An example of subduction boundary is Mount Shasta. It is a volcano in California that formed near a subduction boundary. Another subduction boundary is the Indoneisian island of Krakatau has formed near a subduction boundary. Krakatau formed between two oceanic plate.



__//**Convergent Boundaries**//__ A convergent boundary is a boundary that is between two plates that move toward one another/ converge. Two classifications of this boundary is the subduction boundaries and collision boundaries.The process of this boundary is ocean-ocean subduction, ocean- continent subduction, or continent- continent collision. Characteristics of convergent boundaries are earthquake activity, volcantic activity, and deep-sea trenches. An example of ocean- ocean subduction are the islands of Indonesia. One example of continent- continent collision is in the Himalayas which are located in India. And an example of ocean- continent subduction is the western coast of South America.



__//**Plates**//__ Churning currents in molten rock from below (magma), propel along through the lithosphere.Plates can be minor or major. Some major plates are named after the continents within them, such as: Minor plates like Juan de Fuca plate is largely for most of the volcanoes that dot the Pacific Northwest of the United States of America.
 * North American
 * African
 * Antarctic



"Earth Science" By: Spaulding Edited by:McDougal //** Pgs. 176-180 1st collection
 * //__Citations__

"Nettrekker" www.nettrekker.com Web.11 Nov. 2009