rock
 |
Credit: U.S. Geological Survey
|
A naturally occurring mixture of minerals, mineral matter, or organic materials. Three main types occur: sedimentary rocks, formed by weathering and mechanical sorting on the Earth's surface; metamorphic rocks, which are rocks that have been transformed by the effects of high temperature and pressure; and igneous rocks, derived from magma (for example, volcanic rocks ).
Related category
• GEOLOGY AND PLANETARY SCIENCE
Source: U.S. Geological Survey
Also on this site:
Encyclopedia of Alternative Energy & Sustainable Living
Encyclopedia of History
Transport Concepts & Designs (partner site)
BACK TO TOP
|
