large, rigid, block of the Earth's crust.

Plates, otherwise known as tectonic plates, are large, rigid slabs of the Earth's crust. The crust is divided into a number of these gigantic slabs, up to 100km thick, which float on the Earth's molten mantle. earthquake volcano

a large rigid, but mobile, block involved in plate techtonics; thickness ranges from 30 to 150 miles and includes both crust and a portion of the upper mantle.

One of the dozen or more segments of the lithosphere that ride as distinct units over the asthenosphere.

One of about twenty distinct pieces of the relatively rigid lithosphere.

A rigid, thin segment of the Earth's lithosphere, which may be assumed to move horizontally and adjoins other plates along zones of seismic activity called plate boundaries.

A section of the Earth's crust that may or may not have a portion that sits above water and is called a landmass. The individual plates 'float' on the surface of the many molten layers of rock that make up much of the interior of the planet. Convection currents in this molten rock cause a slow movement of the plates above. The plates are generally made up of a base layer of basalt with successive layers of sedimentary rock on the exposed surface.

Major section of the earth's crust, bounded by such features as mid-ocean ridges.

The Earth's crust and part of the underlying mantle are divided into several rigid plates which glide over the underlying, viscous mantle. The movement of the plates (plate tectonics) is due to convection currents in the mantle.

A broad segment of the lithosphere (including the rigid upper mantle, plus oceanic and continental crust) that floats on the underlying asthenosphere and moves independently of other plates.

(baseball) base consisting of a rubber slab where the batter stands; it must be touched by a base runner in order to score; "he ruled that the runner failed to touch home"

a rigid layer of the Earth's crust that is believed to drift slowly

a large piece of Earth's surface

a large, rigid slab of solid rock

a large section of the earth's crust

one of the sections of the earth's crust.

Plates are huge slabs into which the crust as well as the upper part of the mantle are divided.

piece of Earth's crust

One of the segments which make up the Earth's crust. The plates are continuously moving relative to each other.

Although it appears to be motionless and static, the Earth's crust is made up of a number of huge 'plates' called tectonic plates that move and shift. It is the movement of these plates that produces mountains and valleys and also causes volcanoes and earthquakes.

A piece of the Earth's lithosphere which is internally rigid and moves independently over the asthenosphere.

A slab of rigid lithosphere ( crust and uppermost mantle) that moves over the asthenosphere. more details...

see "lithosphere". PLATE TECTONICS - - the study of the tectonics of lithospheric plates. See "tecton-ics".

a large, relatively rigid segment of the Earth's lithosphere that moves in relation to other plates over the asthenosphere.

One of the huge sections which make up the Earth's crust. The plates are continuously moving.

1. One of about fifteen rigid sections of the Earth's surface; a section of the Earth's surface bordered by seismic activity (earthquakes and volcanoes). 2. Pieces of calcium carbonate forming the outer shell of some marine creatures, for example echinoids.

n. Rigid parts of the Earth's crust and part of the Earth's upper mantle that move and adjoin each other along zones of seismic activity. The theory that the crust and part of the mantle are divided into plates that interact with each other causing seismic and tecotnic activity is called plate tectonics.

a rigid piece of the Earth's lithosphere that moves horizontally and interacts with other plates along its boundaries.

The outer crust of the earth is composed of a number (about 20) of large rigid pieces of rock which are called plates. These plates move around relative to each other and sometimes collide. Friction between these plates causes mountain building, volcanoes and earthquakes. All of North America sits on one plate.

A large rigid slab of lithosphere, distinguished from neighbouring plates by frequent earthquake activity along its edges.

In the theory of plate tectonics, one of the sections of the earthâ€(tm)s lithosphere, constantly moving in relation to the other sections.