Yosemite Valley is a glacial valley in Yosemite National Park in the western Sierra Nevada mountains of Central California, United States. The valley is about 7.5 mi (12.1 km) long and 3,000–3,500 ft (910–1,070 m) deep, surrounded by high granite summits such as Half Dome and El Capitan, and densely forested with pines. The valley is drained by the Merced River, and a multitude of streams and waterfalls flow into it, including Tenaya, Illilouette, Yosemite and Bridalveil Creeks. Yosemite Falls is the highest waterfall in North America and is a big attraction, especially in the spring, when the water flow is at its peak. The valley is renowned for its natural environment and is regarded as the centerpiece of Yosemite National Park.
The exposed geology of the Yosemite area includes primarily granitic rocks with some older metamorphic rock. The first rocks were laid down in Precambrian times, when the area around Yosemite National Park was on the edge of a very young North American continent. The sediment that formed the area first settled in the waters of a shallow sea, and compressive forces from a subduction zone in the mid-Paleozoic fused the seabed rocks and sediments, appending them to the continent. Heat generated from the subduction created island arcs of volcanoes that were also thrust into the area of the park. In time, the igneous and sedimentary rocks of the area were later heavily metamorphosed.
Cathedral Peak is part of the Cathedral Range, a mountain range in the south-central portion of Yosemite National Park in eastern Mariposa and Tuolumne Counties. The range is an offshoot of the Sierra Nevada. The peak which lends its name to the range derives its name from its cathedral-shaped peak, which was formed by glacial activity: the peak remained uneroded above the glaciers in the Pleistocene.
Aplite is an intrusive igneous rock that has a granitic composition. Aplites are fine-grained to aphanitic and may consist of only quartz and feldspar or the term may refer to any leucocratic (pale-coloured) minor intrusion of that grain size. They are associated with the later stages of many larger intermediate to felsic intrusions.
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form intrusions, such as batholiths, dikes, sills, laccoliths, and volcanic necks.
Granodiorite is a coarse-grained (phaneritic) intrusive igneous rock similar to granite, but containing more plagioclase feldspar than orthoclase feldspar.
The Sierra Nevada Batholith is a large batholith that is approximately 400 miles long and 60-80 miles wide which forms the core of the Sierra Nevada mountain range in California, exposed at the surface as granite.
Yosemite National Park is located in the central Sierra Nevada of California. Three wilderness areas are adjacent to Yosemite: the Ansel Adams Wilderness to the southeast, the Hoover Wilderness to the northeast, and the Emigrant Wilderness to the north.
The Cathedral Peak Granodiorite (CPG) was named after its type locality, Cathedral Peak in Yosemite National Park, California. The granodiorite forms part of the Tuolumne Intrusive Suite, one of the four major intrusive suites within the Sierra Nevada. It has been assigned radiometric ages between 88 and 87 million years and therefore reached its cooling stage in the Coniacian.
Half Dome Granodiorite is granodiorite found in a region on and near Half Dome, in Yosemite National Park, California, United States. The granodiorite forms part of the Tuolumne Intrusive Suite, one of the four major intrusive suites within the Sierra Nevada.
Exfoliating granite is a granite undergoing exfoliation, or onion skin weathering (desquamation). The external delaminated layers of granite are gradually produced by the cyclic variations of temperature at the surface of the rock in a process also called spalling. Frost and ice expansion in the joints during the winter accelerate the alteration process while the most unstable loosen external layers are removed by gravity assisted by runoff water.
Kuna Crest Granodiorite, is found, in Yosemite National Park, United States. The granodiorite forms part of the Tuolumne Intrusive Suite, one of the four major intrusive suites within the Sierra Nevada. Of the Tuolumne Intrusive Suite, it is the oldest and darkest rock.
Sentinel granodiorite is a type of granodiorite found in Yosemite National Park. It is a poorly understood western "outlier" of the ~93-85-Ma Tuolumne Intrusive Suite of the Sierra Nevada batholith. It is only slightly older than the undated Yosemite Creek Granodiorite and the Kuna Crest Granodiorite.
The Tuolumne Intrusive Suite is the youngest and most extensive of the intrusive suites of Yosemite National Park, and also comprises about 1/3 of the park's area. The Suite includes Half Dome Granodiorite, Cathedral Peak Granite, and Kuna Crest Granodiorite.
The Intrusive Suite of Buena Vista Crest is an intrusive suite which extends 30 kilometres (19 mi) southward, from Yosemite Valley to Yosemite National Park's southeastern boundary, into plutons of the Sierra Nevada Batholith, which are slightly older. These intrusive suites also include
- Fine Gold Intrusive Suite
- Intrusive Suite of Jack Main Canyon
- Intrusive Suite of Merced Peak
- Intrusive Suite of Sonora Pass
- Intrusive Suite of Yosemite Valley
- Tuolumne Intrusive Suite
The Intrusive Suite of Yosemite Valley is one of several intrusive suites in Yosemite National Park. These also include
- Fine Gold Intrusive Suite
- Intrusive Suite of Buena Vista Crest
- Intrusive Suite of Jack Main Canyon
- Intrusive Suite of Merced Peak
- Intrusive Suite of Sonora Pass
- Tuolumne Intrusive Suite
- Johnson Granite Porphyry
The Intrusive Suite of Sonora Pass is one of several intrusive suites in Yosemite National Park. These also include
- Fine Gold Intrusive Suite
- Intrusive Suite of Buena Vista Crest
- Intrusive Suite of Jack Main Canyon
- Intrusive Suite of Merced Peak
- Intrusive Suite of Yosemite Valley
- Tuolumne Intrusive Suite
The Intrusive Suite of Merced Peak is one of several intrusive suites in Yosemite National Park. These also include:
- Fine Gold Intrusive Suite
- Intrusive Suite of Buena Vista Crest
- Intrusive Suite of Jack Main Canyon
- Intrusive Suite of Sonora Pass
- Intrusive Suite of Yosemite Valley
- Johnson Granite Porphyry
- Tuolumne Intrusive Suite
Johnson Granite Porphyry is found in Tuolumne Meadows, Yosemite National Park.
