Platform: The Great Courses
Taught by Professor James F. P. Cotter of the University of Minnesota, Morris, this course teaches you the fundamentals of field geology. You learn the basics of rocks, minerals, and landforms, and how to apply this knowledge to read an outcrop, find and prepare fossils, assess soil and groundwater, prospect for gems and ore, and much more.Reading rock samples like the pages of a book, Professor Cotter recounts the stories they tell of change across vast stretches of time. He presents three key concepts that will open your mind to the fun and fascination of practical geology. Then he focuses on the idea of deep time, noting that humans have been around for only an infinitesimal fraction of Earth's 4.6-billion-year geologic drama.
Geomorphology is the study of landscapes and their individual landforms. Learn the five major influences on landscape formation. Use this background to tour the United States, which is a remarkable laboratory of geomorphology with features such as the Appalachian and Rocky Mountains, the Grand Canyon and Channeled Scablands, and more.
Go outside and find an outcropa roadcut, cliff face, or other site where rocks are exposed. These are ideal places for practicing field geology. Professor Cotter gives tips on safety, maps, tools, and techniques. A notebook and record-keeping are essential. Amateur geologists can make important discoveries, so field geology is your chance to advance knowledge while enjoying the outdoors.
Rivers are the key to understanding why many landscapes look the way they do. Study how rivers form, how they sculpt the land, how water and sediment move in a river, and how rivers change course over time. Rivers also create habitats for plants and animals, both of which influence the landscape. Finally, signs of vanished rivers tell the story of geologic events in the deep past.
Visit the beach with a geologist's eyes and see how the interaction of waves, ocean currents, and winds lead to the ebb and flow of sediments and blending of landforms. Consider the four types of waves and what they reveal about the ocean floor just offshore. Also, zero in on individual grains of sand, identifying their minerals and tracing their origin. Reflect on why beaches are sandy at all.
Sedimentary rocks make up a substantial majority of rocks at Earth's surface. In this episode, focus on clastic rocks, which are composed of broken fragments of pre-existing rocks. The fragments can vary in size from clay particles to silt, sand, gravel, and larger pieces. Learn how these rocks form and the rich stories they tell about the past.
Steppes and deserts make up almost a third of Earth's land surface and are an ideal place to practice geology due to the distinctive landforms, often unobstructed by vegetation. Explore alluvial fans, washes, playa lakes, dunes, and other features typical of arid regions. Also ask why steppes and deserts are so dry. What combination of surface, ocean, and atmospheric conditions produce them?
Investigate glaciers, which now cover about 10 percent of Earth's land area; 25,000 years ago, they covered 30 percent. Learn how to spot evidence of past glaciationfrom sculpted valleys in Yosemite National Park, to the cliffs at Vicksburg, Mississippi (which formed far from glaciers), to Minnesota's 10,000 lakes. Dig into the physics of glaciers: how they develop and the forces they exert.
Check out limestone, one of nature's most amazing rocks, with medical, economic, and sightseeing benefits. Not to mention, limestone provides insight into environments eons ago. Examine its chemistry and the ways it forms. Survey different kinds of limestone, including types that preserve detailed fossils. Finally, look at sinkholes and caves, which occur in limestone karst topography.
Starting with the concept of strataparallel layers of sedimentary rock lying one atop the otherlearn how to look at a cliff face and read the strata like an epic adventure. The story can encompass hundreds of millions of years, involving advancing and retreating glaciers, falling and rising seas, the ebb and flow of life, and much else. Work up to the paragon of stratigraphy, the Grand Canyon.
Fossils are an exciting component of field geology. The term covers not only preserved ancient life-forms, but also evidence of their activity, such as footprints. Look at different ways nature has of preserving fossilsby encasing in amber, freezing, pickling, chemical alteration, and other natural processes. Ask what life-forms are likely to be fossilized and in what environments.
Having learned about sediments, sedimentary environments, and how fossils are preserved, you are ready to go fossil hunting! Professor Cotter prepares you with background on rules and regulations, strategies for finding the best sites, and how to photograph and collect specimens. He closes with a quiz, challenging you to predict the types of fossils associated with different geologic formations.