Plate Tectonics Theory PDF

 PLATE TECTONICS THEORY Objective: Describe the different hypothesis explaining the plate tectonics Earth’s outermost layer, the lithosphere consists of number of rigid but slowly moving plates. The plates are about 100km thick, consisting of the crust and uppermost mantle. They float on th...

 PLATE TECTONICS THEORY Objective: Describe the different hypothesis explaining the plate tectonics Earth’s outermost layer, the lithosphere consists of number of rigid but slowly moving plates. The plates are about 100km thick, consisting of the crust and uppermost mantle. They float on the molten magma of the mantle and carry continents or oceans, or both. Oceanic plates, made mostly of basalt, are denser and heavier. Continental plates are lighter and are mostly granite. In some parts of crust, plates are moving away from each other, in other parts, plates collide against each other. There are plates that are sliding past each other. Corresponding and respective to each type of movement, there are divergent plate boundaries, convergent plate boundaries and transform plate boundaries. Plate movements build up the crust. The study of the formation and movements as well as the building and destruction of the crust is called PLATE TECTONICS( tekton, Greek for builder) plate activity builds up the crust. What is a plate in science? massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate Major Plate African Plate Antarctic Plate Eurasian Plate Indo- Australian Plate North American Plate Pacific Plate South American Plate Minor Plates Arabian Plate Caribbean Plate Cocos Plate Juan de Fuca Plate Indian Plate Nazca Plate Philippine Sea Plate Scotia Plate A convergent boundary (also known as a destructive boundary) is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other, a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, called the Wadati–Benioff zone. These collisions happen on scales of millions to tens of millions of years and can lead to volcanism, earthquakes, orogenesis, destruction of lithosphere, and deformation. Convergent boundaries occur between oceanic-oceanic lithosphere, oceanic-continental lithosphere, and continental-continental lithosphere. The geologic features related to convergent boundaries vary depending on crust types A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge is an example of divergent plate boundaries A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust. The Mid-Atlantic Ridge is an example of divergent plate boundaries A transform boundary causes a fault between two plates of the lithosphere, which will slide past one another. This motion does not create or destroy crust and will cause earthquakes, but no volcanoes. A transform boundary occurs when two tectonic plates move past one another