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1.1: What is Petrology?

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    Learning Objectives

    Students will be able to:

    • Describe the three main branches of petrology.
    • List key aspects of petrology.
    Prior Knowledge and Skills



    Petrology (from the Ancient Greek: πέτρος, romanized: pétros, lit. ‘rock’ and λόγος, lógos) is the branch of geology that studies rocks and the conditions under which they form.

    The field of petrology is traditionally split into three subcategories: igneous, metamorphic, and sedimentary petrology. Click on the pull-down menu below to explore the definitions of these sub-fields:

    Guided Inquiry Figure \(\PageIndex{1}\) Petrology Sub-fields

    At the university level, igneous and metamorphic petrology are traditionally (but not always) taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams (Teaching Mineralogy and Petrology). Sedimentary petrology is more commonly taught as a stand-alone class or together with stratigraphy because stratigraphy deals with the processes that form sedimentary rocks. Introduction to Petrology covers igneous and metamorphic petrology for this reason.

    However, it is increasingly common for mineralogy and petrology (sometimes igneous, metamorphic, and sedimentary) to be combined into a semester- or year-long Earth Materials course. The modular structure of this online book is designed so that students and instructors can use the modules relevant to the course at their college or university.

    Guided Inquiry Question \(\PageIndex{1}\)

    Key Aspects of Petrology

    Click on the pull-down menu below to explore some of the ways scientists study igneous and metamorphic rocks:

    Guided Inquiry Question Figure \(\PageIndex{2}\)


    Introduction to Petrology by Elizabeth Johnson, Juhong Christie Liu, and Mark Peale is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

    This chapter contains material from “Petrology” by Wikipedia which is licensed under CC BY-SA 4.0.

    Teaching Igneous and Metamorphic Petrology (ret. 7/1/2019)

    Table of Contents

    This page titled 1.1: What is Petrology? is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Elizabeth Johnson and Juhong Christie Liu (Virtual Library of Virginia) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.