PARKS AND PLATES: THE USE OF PLATE TECTONIC CONCEPTS TO TEACH A COURSE ON GEOLOGY OF NATIONAL PARKS

Introductory geology courses commonly employ a plate tectonic framework to help students understand Earth materials and processes. The same framework can be used to interpret the processes responsible for the development of the inspiring landscapes of our national parks, monuments, and seashores. Plate tectonics provides students the opportunity to appreciate the big things they see on Earth’s surface, to understand basic geologic processes, and to look for similarities and differences in the landscapes they see in different parks. For example, steep-sided composite volcanoes are found in parks in the Pacific Northwest and Alaska because they formed at subduction zones, while Hawaiian parks reveal broad shield volcanoes developed over an oceanic hotspot. The spectacular mountains, valleys, beaches, and rock formations in national parks, monuments, and seashores, commonly form at plate boundaries or hotspots. Students can see what happens where plates diverge by studying continental rift features in parks in the Basin and Range Province, as well as the passive continental margin morphology revealed in national seashores along the East Coast. Convergent plate boundary processes can be examined through accretionary-wedge and volcanic-arc features seen in subduction zone parks in the Pacific Northwest and Alaska; students can then be shown that parks in the Appalachian Mountains reveal a zone of continental collision that developed as plate convergence closed an ocean basin. The plate tectonic framework also allows for interpretation of park features in ancient settings, such as rock layers in Grand Canyon National Park deposited along a passive continental margin, and granite in the Sierra Nevada that formed during subduction.