Join geologist Kirt Kempter as he explores the geology of Western National Parks over the course of 2023, with an in-depth look at one or more locations every month. Each program’s content is enhanced by geologic maps, photos, and Google Earth flyovers to reinforce geologic concepts and interpretations.
Please Note: Individual sessions are available for purchase.
July 10 Yosemite, California
Many consider Yosemite to be the crown jewel of the National Park system. First protected in 1864 the park presents a stunning glaciated landscape, including classic U-shaped valleys, moraines, and hanging valleys with iconic waterfalls. Massive granite intrusions form the main rock in the park, mostly intruded during the Cretaceous Period and related to the subduction of the Farallon plate beneath the western margin of North America. Half Dome, El Capitan, and Sentinel Rock are superb monoliths of granite within the park. The Pleistocene glaciers, granitic rocks, and uplift of the Sierra Nevada Mountains are part of the fascinating geologic story of Central California.
August 7 Crater Lake, Oregon, and Lassen, California
Lassen Volcanic and Crater Lake National Parks represent spectacular volcanic features along the Cascade volcanic arc. Still active, these volcanoes are born from the ongoing subduction of the Juan de Fuca plate beneath the North American plate. A visceral eruption from ancient Mount Mazama approximately 7,700 years ago created a 5 by 6-mile wide caldera that today is filled with a pristine crater lake almost 0.6-miles deep. To the south, Lassen Volcanic Center has formed in the past million years, creating a landscape of volcanic domes, cinder cones, and lava flows.
September 11 Yellowstone, Wyoming
The Yellowstone Caldera, which formed during a massive volcanic eruption approximately 630,000 years ago, is the centerpiece of our nation’s first national park, founded in 1872. The volcanic story of Yellowstone, however, begins approximately 17 million years ago and will certainly continue long into the geologic future. Kempter leads an exploration of the geology of Yellowstone, including the rocks and hydrothermal features that make this national park unique in the world.