Yosemite's Granite Cooled Three Miles Underground

El Capitan and Half Dome are made of granite that cooled from magma about three miles underground, beneath a chain of volcanoes that no longer exists, more than 80 million years ago. Today they stand thousands of feet above Yosemite Valley, and the park records roughly one rockfall a week. How does rock that cooled three miles underground end up standing three thousand feet in the air? In this documentary: the scale of El Capitan, Half Dome and Yosemite Falls; the Farallon Plate, the ancient volcanoes and the 35 plutons of the Sierra Nevada batholith; how erosion stripped the volcanoes away and the granite began to peel (exfoliation); the uplift of the Sierra and the Merced River's V-shaped canyon; the glaciers that carved the U and left hanging valleys and waterfalls; Josiah Whitney, John Muir and Francois Matthes; Deep Time, a climb up El Capitan through 100 million years; Lake Yosemite and the buried basin beneath the meadows; and the science of Yosemite's rockfalls, from Happy Isles in 1996 to the heat that pries the walls apart. Sources include N. King Huber, The Geologic Story of Yosemite National Park (USGS Bulletin 1595), F. E. Matthes, Geologic History of the Yosemite Valley (USGS Professional Paper 160), the National Park Service, Stock et al. 2013 (USGS Data Series 746), Wieczorek et al. 2000 (GSA Bulletin), and Collins & Stock 2016 (Nature Geoscience).