PETROLOGY is defined as the study of rocks, and especially, the study of the geological processes that create igneous, sedimentary, and metamorphic rocks. The goal of this course is to introduce undergraduate students to the fundamental principles of modern petrology. Although sedimentary petrology will be discussed in this course, we will focus primarily on igneous and metamorphic petrology (you will learn much more about sedimentary petrology in Geol 536: Sedimentology and Lithostratigraphy!). Unlike sedimentary rocks, the formation of both igneous and metamorphic rocks is governed by geological processes that occur at relatively high temperature and pressure within the Earth. These processes cannot be directly observed. The origin of these rocks must be deciphered through indirect observations: their structure and texture, mineralogy, and chemical and isotopic compositions. Because of this, chemical equilibrium and thermodynamics are the “rules” that govern the igneous and metamorphic petrology “game”. Thus, you will need a firm background in chemistry, preferably at the college level, to be successful in this course. Physics and calculus will also be helpful, but are not required.