Search results
Results from the WOW.Com Content Network
The resultant molten rock rose through the Earth's crust over the span of 100 Ma, forming several plutons, or a chain of volcanoes if the magma reached the surface. Most of the granitic rocks formed between 105 and 85 Ma, during the Cretaceous, with pluton formation ending around about 70 Ma.
The volcanoes seem to share a common feeder dyke. This dyke may be connected to deep-seated extensional processes [38] along a transform fault that links the San Andreas Fault to the Gulf of California. [9] The source of heat for the volcanoes and geothermal field is unclear: both deep mafic and shallow felsic sources have been proposed. [33]
Chaos Crags is the youngest group of lava domes in Lassen Volcanic National Park, California. They formed as six dacite domes 1,100-1,000 years ago, one dome collapsing during an explosive eruption about 70 years later. The eruptions at the Chaos Crags mark one of just three instances of Holocene activity within the Lassen volcanic center.
Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava, and have low temperatures to keep the felsic minerals molten. Felsic rocks are usually light in color and have specific ...
Mammoth Mountain is a lava dome complex partially located within the town of Mammoth Lakes, California, in the Inyo National Forest of Madera and Mono Counties. [3] It is home to a large ski area primarily on the Mono County side. Mammoth Mountain was formed in a series of eruptions that ended 57,000 years ago.
Cinder Cone is a cinder cone volcano in Lassen Volcanic National Park within the United States. It is located about 10 mi (16 km) northeast of Lassen Peak and provides an excellent view of Brokeoff Mountain, Lassen Peak, and Chaos Crags. The cone was built to a height of 750 ft (230 m) above the surrounding area and spread ash over 30 sq mi (78 ...
A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive (sills, dikes) and extrusive (lava flows, tephra deposits), arising when magma travels through the crust towards the surface. The formation of LIPs is variously attributed to mantle plumes or to processes associated with divergent plate ...
A batholith (from Ancient Greek bathos 'depth' and lithos 'rock') is a large mass of intrusive igneous rock (also called plutonic rock), larger than 100 km 2 (40 sq mi) in area, [1] that forms from cooled magma deep in the Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, such as granite, quartz ...