Adapted by Lyndsay R. Hauber & Joyce M. McBeth (2018) University of Saskatchewan from Deline B, Harris R & Tefend K. (2015) “Laboratory Manual for Introductory Geology”. First Edition. Chapter 10 “Sedimentary Rocks” by Bradley Deline, CC BY-SA 4.0.  View source. Last edited: 8 Jan 2020

4.1  INTRODUCTION

We are particularly interested in the history and events that occur on the surface of the Earth because it is easier to directly observe and test, and has direct relevance to our lives and history. Sedimentary rocks are the pages in which history is written, since they contain powerful environmental indicators, traces of life, and chemical signatures that can inform us about many subjects, from the occurrence of ancient catastrophes to the productivity of life.

The identification of sedimentary rocks is more than applying names, since each name is a loaded term that conveys information regarding its history, where it was formed, potentially when it was formed, and the processes that lead to its formation. Each sedimentary rock is a puzzle, and by identifying a set of rocks, how they are layered, the fossils within, and patterns in the rocks, a geologist can reconstruct an entire environment and ecosystem. Solving these puzzles is both an academic exercise to better understand the world around us and a tool for finding the resources that are important to our lives. In particular, fossil fuels and other natural resources are, or are contained within, sedimentary rocks such as coal, natural gas, petroleum, salt, and the materials that go into wallboard or in the making of cement. Therefore, a better understanding of sedimentary rocks and how and where they are formed directly influences your everyday life.

4.1.1  Learning Outcomes

After completing this chapter, you should be able to:

• Describe how erosion and weathering relate to the formation of sedimentary rocks
• Identify sedimentary rocks and their features
• Describe the formation and history of different types of sedimentary rocks

4.1.2  Key Terms

• Biochemical Sedimentary Rocks
• Chemical Sedimentary Rocks
• Chemical Weathering
• Clast
• Clastic Sedimentary Rocks
• Dissolution
• Erosion
• Hydrolysis
• Maturity
• Mechanical Weathering
• Oxidation
• Sorting