plate tectonics(redirected from Plate boundaries)
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1. (used with a sing. verb) A theory that explains the global distribution of geological phenomena such as seismicity, volcanism, continental drift, and mountain building in terms of the formation, destruction, movement, and interaction of the earth's lithospheric plates.
2. (used with a sing. or pl. verb) The dynamics of plate movement.
(Geological Science) (functioning as singular) geology the study of the structure of the earth's crust and mantle with reference to the theory that the earth's lithosphere is divided into large rigid blocks (plates) that are floating on semifluid rock and are thus able to interact with each other at their boundaries, and to the associated theories of continental drift and seafloor spreading
a geologic theory that describes the earth's crust as divided into a number of rigid plates, movement of which accounts for such phenomena as continental drift and the distribution of earthquakes.
Did You Know? Have you ever noticed that the Earth's continents seem to fit together like pieces of a puzzle? This observation is what led the German meteorologist Alfred Wegener to propose the theory of continental drift in 1915. Since rocks and fossils were found to match up in parts of different continents, it seemed that they must have once been joined, but no one could explain how such large landmasses could move so far apart. This problem was not solved until the 1960s, when the theory of plate tectonics was proposed. According to this theory, the continents move apart by riding piggyback on plates—huge slabs of the Earth's lithosphere—that are much larger than the continents themselves. The plates move like parts of a conveyor belt powered by huge convection currents of molten rock that many geologists believe is heated by the decay of radioactive elements deep within the Earth. Although they only move a few inches per year, over hundreds of millions of years the continents are carried thousands of miles. Along their boundaries, the plates crumple, scrape, or pull apart from one another, giving rise to volcanoes and earthquakes and creating and destroying rock on the ever-changing surface of the planet.
The study of how lithospheric plates move around.
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|Noun||1.||plate tectonics - the branch of geology studying the folding and faulting of the earth's crust|
geomorphology, morphology - the branch of geology that studies the characteristics and configuration and evolution of rocks and land forms