Part of the Faculty of Social Sciences at the University of Victoria, PACTAC is a pioneering, multidisciplinary research centre, and home to the electronic scholarly journal CTheory, CTheory Archive, and CTheory Multimedia.
Rocks: Rocks are a composed of one or more minerals. A rock can be made up of only one mineral or, as shown in the figure, a rock can be made up of a number of different minerals. So, rocks are composed of one or more minerals and minerals are composed of one or more elements. Previous Item: Why should we study rocks? Go Up: Learn About Rocks
As these pockets of magma cool slowly they become igneous rocks. Igneous rocks are also formed when volcanoes erupt. Igneous rocks are formed as the lava cools above ground. The upper 16 km of the Earthâs crust is composed of 95% igneous rock.Intrusive igneous rocks are formed from magma that cools and solidifies underground.These rocks are coarse grained.gneous rocks are formed as the lava cools above ground. The upper 16 km of the Earthâs crust is composed of 95% igneous rock. Intrusive igneous rocks are formed from magma that cools and solidifies underground. These rocks are coarse grained.