Compléter Science Version en ligne Find the correct word for each blank par Paul Benitez 1 tectonic mantle earthquakes volcanoes tectonic plates tectonics species oceanic Contintental asthenosphere Tectonic plates are large of rock that make up the foundation of the Earth's crust and the shape of the continents . The tectonic plates comprise the bottom of the crust and the top of the Earth's . There are ten major plates on Earth and many more minor ones . They float on a plastic - like part of the Earth's mantle called the . The plates are most famously known for being the source of . The plates are about 100 km ( 60 miles ) in thickness , with continental plates tending to be thicker than ones . The composure of the two types of plate is also quite different . Oceanic plates consist of thicker basaltic rocks , compressed by the pressure of kilometers of water . plates have a lower average density , containing granitic rocks with a heavy composition of aluminum and silica . The mantle underneath the plates is constantly recirculating , causing the plates to float around slowly in a process called tectonic drift . This process was described well by the theory of plate , which solved several scientific dilemmas about the distribution of when it was introduced . When plates push up against each other , they create mountain ranges and . Mt . Everest was created in this way .
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