Andesitic Rocks

Rocks with a composition between basaltic and granitic are rocks said to have an andesitic or intermediate composition. Andesitic is a term that came from the common volcanic rock andesite. Andesitic rocks are mainly composed of dark and light colored materials. Most materials in andesitic rocks are amphibole and plagioclase feldspar. Andesitic rocks are commonly related to volcanic eruptions on the margins of continents.