The Earth is an ever-changing system consisting of many components and interactions between those components. Unlike the physical and chemical processes governing short-term, smaller, and simpler systems (which often can be worked out by direct experiment), the Earth itself is too large, too important, and changes too slowly to be “experimented upon” in a direct fashion. If we want to find out more about how the Earth works, we must turn to natural experiments that have already been performed for us in Earth history. The process of doing this is in a sense the inverse of experimental science: instead of doing an experiment and seeing the outcome, we look at the “outcome” of the experiment and try to infer the causes. This inverse problem in historical geosciences is very similar to the inverse problem a detective faces when trying to determine what happened at a crime scene: examine the evidence, then work backwards to the crime itself. Geologists are detectives, trying to work out what happened to produce the Earth as we know it today. In this class, you will first train to be a detective by learning (or in some cases reviewing) some of the basic geologic, chemical, physical, and biological processes that govern how the Earth works. We will then use that knowledge to make inferences about Earth history that are grounded in evidence from rocks, chemistry, geophysics, and fossils. Along the way, you’ll learn how to identify basic groups of fossils, how to interpret geologic age and isotopic data, how to relate one group of rocks in one location to another group of rocks at a different location, and how to piece all this information together into a coherent picture of Earth system evolution. Rocks are the Earth’s memory. Like most of our memories, Earth’s memory is often faded, and sometimes altered. And there are certainly many events that the Earth has forgotten. Geologists have worked out a lot of Earth’s history from the record that has already been explored. But there is still a lot to do! You won’t learn everything about Earth history in this course. Like most of your courses, you’ll only be scratching the surface. But I hope that what you learn from this course will give you a greater appreciation for what we know and what we don’t, how the Earth works, and how and why it has evolved through time.
Cope, Tim, "GEOS 210 Historical Geology (or, Evolution of the Earth) Cope Spring 2023" (2023). Course Syllabi. 203, Scholarly and Creative Work from DePauw University.