TYPES OF IGNEOUS ROCKS
They are formed from crystallization and solidification of molten magma. They may be deposited onto the earth’s surface or with in the earth’s crust i.e. extrusive or intrusive rocks respectively. The main process for the formation of igneous rocks is volcanicity. This is due to the radioactivity and connectivity with in the earth’s mantle. Lines of weakness or fault lines are created in the earth’s crust through which magma is either extruded or intruded. Igneous rocks are usually described as fire formed rocks, igneous rocks are characterized by being hard, don’t contain fossils and they are crystalline in nature. As magma is pushed from deep in the earth’s interior, it cools in different parts of the earth’s crust thus forming different types of rocks. They include Volcanic rocks or extrusive rocks Hypabyssal or intermediate rocks Plutonic or abyssal or deep seated rocks. Volcanic or extrusive rocks. These are igneous rocks formed on top of the earth’s surface. They are formed...