Yosemite’s Half Dome stands, majestic, over a granite dominated terrain in the Yosemite Valley area; one of the most beautiful landscapes in northern America, and arguably, the world – it is also an Earth scientist’ playground.
Stamped into the west slope of the Sierra Nevada range, the Yosemite Valley is a collection of lush forests, deep valleys, meandering rivers and streams, all punctuated by huge domes and cliffs of ancient volcanic origin.
Come and explore this part of the world and you’ll not miss Half Dome. Standing at the head of the valley, the quartz monzonite (a coarse grained orthoclase and plagioclase feldspar dominated rock) structure rises a little short of 2700 m above sea level.
Despite standing proud in the present landscape, it was once a magma chamber, buried deep below a volcano. Over a long period of time, the molten magma cooled and crystalised to form the coarse granite rock we see today. Erosion and exposure did the rest, eventually exhuming the dome and cutting deep valleys into the surrounding landscapes.
For more information on the geology of the Yosemite Valley and Half Dome, please refer to these United States Geological Survey (USGS) resources:
The Geological Story of Yosemite Valley
How did Half Dome, acquire its unique shape?
Bedrock Geology of the Yosemite Valley Area
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