New oceanic crust is formed at mid-ocean ridges ... Some can be nearly as old as the solar system itself, about 4.6 billion years. Continental crust is generally higher in silica, which makes ...

Continental and oceanic plates all fit together to form the outer crust of the planet. Eight major plates are named on the diagram below. Heat from the core makes magma in the mantle rise towards ...

Deep trenches appear at these boundaries, caused by the oceanic plate bending downward into the Earth. Deep below the Earth's surface, subduction causes partial melting of both the ocean crust and ...

The property presents the complete portrayal of the geological events that took place when the ancient continental margin of North America was modified by plate movement by emplacement of a large, ...