crust
 |
Image credit: US Geological Service
|
The solid surface layer of a planet or moon. Earth’s crust, which forms
the upper part of the lithosphere, makes
up about 0.6 percent of Earth's volume and 0.4 percent of its mass. It varies
greatly in thickness. Under the oceans, the crust (mainly composed of basalt)
ranges between 5 and 11 km (3 and 6.8 miles). Under the continents, the
crust (made mostly of granite) ranges between
19 and 64 km (12 and 40 miles) thick. As in the case of other planetary
bodies in the inner Solar System, it consists of lighter rocks that rose
to the surface when molten, leaving denser materials to form the mantle
and core. Large solid bodies in the outer
Solar System typically have crusts made of water-ice.
Related
category
• GEOLOGY
AND PLANETARY SCIENCE
Also on this site:
Encyclopedia
of Alternative Energy & Sustainable Living
Encyclopedia
of History
BACK TO TOP
|
