El Capitan Granite
El Capitan Granite is a type of granite, in a large area near El Capitan, in Yosemite National Park, California, United States. The granite forms part of the Tuolumne [Intrusive Suite], one of the four major intrusive suites within the Sierra Nevada.
El Capitan granite is mostly unjointed.
Composition
The granite has abundant quartz, plagioclase, crystals of orthoclase, and both feldspars — orthoclase and plagioclase — are white. Hornblende is rare, compared to other Yosemite granites. Most black minerals are biotite.Location
It is found west of Half Dome Granodiorite, both north and south, to a western limit near Cookie [Cliffs (Yosemite National Park)|Cookie Cliffs].All of Turtleback Dome, El Capitan, The Three Brothers, and Cathedral Rocks are made of El Capitan Granite as is Elephant [Rock (Yosemite Valley)|Elephant Rock].
El Capitan Granite makes up most of the granite found in the west half of the Yosemite Valley area.