The theory of plate tectonics states that the Earth's surface, the upper mantle and crust, was once made up of enormous rock plates that broke into smaller pieces approximately 300 million years ago. These smaller, broke... More »

According to About.com, plate tectonics is the scientific theory that attempts to explain the movement of the Earth's lithosphere, which has formed the landscape features seen across the globe. It provides geology with a... More »

Plate tectonics theory, formerly known as the theory of continental drift, is well supported in geology, geography and biology. It has the power to explain many phenomena, such as volcanoes and earthquakes. The theory pr... More »

The theory of plate tectonics, formerly known as continental drift, is a working model that describes the movement of the continents and sea floor across the surface of the Earth. The theory explains many anomalous facts... More »

The Earth's crust recycles itself through subduction of crustal material into the mantle and upwelling of magma from the mantle. These processes are described by plate tectonics, a commonly accepted theory that explains ... More »

Crustal plates are large sections of the outer layer of the Earth's surface that move along convection currents in the mantle. There are 10 major plates on the surface, and the tectonic forces behind their movement creat... More »

Constructive plate boundaries are divergent zones where the Earth forms new crust through the cooling of lava. The Internet Geography website states that most of these boundaries occur under the ocean. More »