Intrusive Suite of Sonora Pass explained

The Intrusive Suite of Sonora Pass (also, the Sonora Pass Intrusive Suite) is one of several intrusive suites in Yosemite National Park. These also include

1. Fine Gold Intrusive Suite
2. Intrusive Suite of Buena Vista Crest
3. Intrusive Suite of Jack Main Canyon
4. Intrusive Suite of Merced Peak
5. Intrusive Suite of Yosemite Valley
6. Tuolumne Intrusive Suite

The Intrusive Suite of Sonora Pass is ~92-89 Ma, and is the northernmost of four large Late Cretaceous zoned intrusive suites in the central Sierra Nevada batholith.^[1]

Rock types

On a large scale, it is composed of Kinney Lakes granodiorite and the younger Topaz Lake granodiorite.^[2]

On a finer scale, the Intrusive Suite of Sonora Pass is made of light-gray, coarse-grained biotite granodiorite, plus granite with roughly equant, well-formed potassium feldspar phenocrysts composing about 2–10% of the rock. Quartz usually occurs in clots of 0.5cm (00.2inches). The mafic mineral content is about 10%.^[3]

External links

• A Masters thesis

Notes and References

1. Web site: Structure and Construction of the Cretaceous Sonora Pass Intrusive Suite, a large zoned intrusion of the Sierra Nevada Batholith, California . gsa.confex.com . May 2014 . 8 January 2019 . Leopold, Monika.
2. Web site: Structure, Construction, and Emplacement of the Late Cretaceous Sonora Pass Intrusive Suite: Central Sierra Nevada Batholith, California . Leopold . Monika B. . 2016.
3. Web site: Yosemite National Park: Geologic resources inventory report. Natural Resource Report NPS/NRSS/GRD/NRR . National Park Service, Fort Collins, Colorado . 2012 . 8 January 2019 . Graham, J..