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
Igneous Rocks. Igneous Rocks are rocks that have crystallized from molten rock, or magma. Magma is generated in the subsurface where it may solidify to form a plutonic rock, such as granite. The magma may also rise to the surface and erupt out of a volcano or volcanic fissure to form a volcanic rock, such as basalt.Igneous rock composition. Magma has a range of composition that is dominated by the elements silicon and oxygen, or silica (SiO 2).agma is generated in the subsurface where it may solidify to form a plutonic rock, such as granite. The magma may also rise to the surface and erupt out of a volcano or volcanic fissure to form a volcanic rock, such as basalt.