Where | Cocos, Nazca & Caribbean Plates | Boundary plates | Mendocino Coast
Plate tectonics is the name applied by experts to the facts and theories associated with the 
movement of the crust of the earth.
The planet's crust is made up of volcanic, sedimentary and organic rocks as the great mass lies, floats or rests above the molten mantle of the earth in separate sections called "plates."
In this image the magma, or viscous material called lava rises from the mantle at a stylized mid-ocean ridge. The accumulating rock at either side of this rift builds up to push one side or plate of the Earth's surface away from the other side of the rift. Thus the two plates are moving apart or away from each other. The dark and light bands seen above refer to the age of the cooled magma, because as the magma cools its magnetic properties cause the alignment of particles in the cooling mass in relation to the earths magnetic poles. Periodically, as the magnetic poles of the Earth reverse, so the cooling magma's iron content aligns in opposite directions. This allows geologists to date the age of different ocean basins.
Where are the plates?
In this animation the different plates are delineated in relation to one another on the surface of the planet. It is as if the crust of the Earth is cracked into pieces like a ceramic dish plate dropped on a stone floor, except that the planetary fluid, or magma moves the broken pieces across the surface in three different ways. Pieces of the planetary crust either collide in upheavals, or collide and one slips beneath the other piece, or they catch and grind past each other along fault lines. One such fault system is in southern and coastal California, called the San Andreas fault.
This movement of the surface through a billion years explains to a large extent both far-flung rock formations with similar structural elements and the dispersal of animals and plants across the Earth's several continents. Thus, the existence of marsupials in Australia and New Zealand, or the speciation of birds in the Galapagos Islands that baffled Darwin and his associates, are well accounted for by the understanding today that the stage of evolution, or the surface of the earth--although it looks stable--is actually slowly moving at centimeters per year or inches per decade.
Where | Cocos, Nazca & Caribbean Plates | Boundary plates
The continents are merely the weathered surface of accumulated igneous, metamorphic and sedimentary rocks that have been pushed up by the movement of the Earth's fractured, and ceaselessly moving surface.
Where | Cocos, Nazca & Caribbean Plates | Boundary plates
Plate Boundaries account for earthquakes an accreting terrains that attach to continents because of the movement of one plate underneath another bordering plate.
Earth's surface is actually a shifting sort of mixture of rocks called a thin crust. The crust, by analogy, is like an outer skin that forms on cooling porridge or thick pea soup. Both the planet's rotation on its axis and the rising currents of hot magma ascending up from the mantle of the molten core move these blocks of terrain we call the land.
Where | Cocos, Nazca & Caribbean Plates | Boundary plates
