Crust (geology) only planet in our Solar System with plate tectonics. The crust is a thin shell on the outside of the Earth, accounting for less than 1% of Earth's volume. It is the top component of lithosphere: a division of Earth's layers that includes the crust and the upper part of the mantle. The lithosphere is broken into tectonic plates that move, allowing heat to escape from the interior of the Earth into space. The crust lies on top of the mantle, a configuration that is stable because the upper mantle is made of peridotite and so is significantly denser than
Continental crust episodes of increased production through geologic time. Continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called "sial" because its bulk composition is richer in silicates and aluminium minerals and has a lower density compared to the oceanic crust, called "sima" which is richer in magnesium silicate minerals and is denser. Changes in seismic wave velocities have shown that at a certain depth (the Conrad discontinuity), there is a reasonably sharp contrast between the