ENVS 1060 Lecture Notes - Lecture 5: Magma Chamber, Mantle Wedge, Shield Volcano
Document Summary
Classify the most common igneous rocks based on their colour: describe the general characteristics of the two main parent texture and mineralogy. (ans). Look at notes: describe the main textures of igneous rocks and know how each texture is produced. (ans). The texture of igneous rocks is determined by the rate of cooling of magma. magmas, what rocks they produce and how they can be modified as they rise toward the surface. (ans). Basaltic magma: this magma is associated with shield volcanoes and predominates with oceanic crust. This magma has a very low viscosity therefore it flows much more readily. As this magma rises to the surface it is typically iron and magnesium rich. As the temperature begins to cool more and more iron and magnesium is removed and replaced with olivine first and then pyroxene and amphiboles. At the lower temperatures only quartz can be formed.