What is true of lithospheric plates? A. They are constantly moving

B. They don't move for centuries at a time

C. There are fewer and fewer of them

D. Earthquakes cause them to move

A. They are constantly moving. I think.

Explanation:

Each lithospheric plate is composed of a layer of oceanic crust or continental crust superficial to an outer layer of the mantle. Containing both crust and the upper region of the mantle, lithospheric plates are generally considered to be approximately 60 mi (100 km) thick. Earth's tectonic plates may have taken as long as 1 billion years to form, researchers report today in Nature. The plates — interlocking slabs of crust that float on Earth's viscous upper mantle — were created by a process similar to the subduction seen today when one plate dives below another, the report says. A tectonic plate (also called lithospheric plate) is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere. Plate size can vary greatly, from a few hundred to thousands of kilometers across; the Pacific and Antarctic Plates are among the largest.

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