Save guides, add subjects and pick up where you left off with your BBC account. Geology is the study of how the Earth is formed and the things that happen to the Earth. As part of this, geologists ...

The characteristics of the rocks that hold fossils can be as informative as the fossils themselves. There are three main types of rock: igneous rock, metamorphic rock, and sedimentary rock. Almost all ...

Pumice is an example of extrusive igneous rock. The word extrusive means that the magma was forced onto the earth's surface and cooled in a matter of hours. Granite is an example of intrusive ...