Yucca Mountain is a mountain in

Nevada Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...

, near its border with

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

, approximately northwest of

Las Vegas Las Vegas (; Spanish for "The Meadows"), often known simply as Vegas, is the 25th-most populous city in the United States, the most populous city in the state of Nevada, and the county seat of Clark County. The city anchors the Las Vegas ...

. Located in the Great Basin, Yucca Mountain is east of the

Amargosa Desert The Amargosa Desert is located in Nye County in western Nevada, United States, along the California–Nevada border, comprising the northeastern portion of the geographic Amargosa Valley, north of the Ash Meadows National Wildlife Refuge. Th ...

, south of the

Nevada Test and Training Range The Nevada Test and Training Range (NTTR) is one of two military training areas at the Nellis Air Force Base Complex in Nevada and used by the United States Air Force Warfare Center at Nellis Air Force Base. The NTTR land area includes a "sim ...

and in the

Nevada National Security Site The Nevada National Security Site (N2S2 or NNSS), known as the Nevada Test Site (NTS) until 2010, is a United States Department of Energy (DOE) reservation located in southeastern Nye County, Nevada, about 65 miles (105 km) northwest of th ...

. It is the site of the

Yucca Mountain nuclear waste repository The Yucca Mountain Nuclear Waste Repository, as designated by the Nuclear Waste Policy Act amendments of 1987, is a proposed deep geological repository storage facility within Yucca Mountain for spent nuclear fuel and other high-level radio ...

, which is currently identified by Congressional law as the nation's spent nuclear waste storage facility. However, while licensure of the site through the Nuclear Regulatory Commission is ongoing, political maneuvering led to the site being de-funded in 2010. YuccaMountain6-7-2005

Geology

The formation that makes up Yucca Mountain was created by several large eruptions from a

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

volcano A volcano is a rupture in the Crust (geology), crust of a Planet#Planetary-mass objects, planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Ear ...

and is composed of alternating layers of

ignimbrite Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surro ...

(welded

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock ...

), non-welded tuff, and semi-welded tuff. The volcanic

units Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * Unit (album), ...

have been tilted along fault lines, thus forming the current ridge line called Yucca Mountain. In addition to these faults, Yucca Mountain is criss-crossed by fractures, many of which formed when the volcanic units cooled.

Volcanic history

A series of large explosive volcanic eruptions occurred to the north of Yucca Mountain millions of years ago, producing dense clouds of volcanic ash and rock fragments which melted or compressed together to create layers of rock called tuff, forming the mountains and hills of the region. The volcanic eruptions that produced Yucca Mountain ended about 12 million years ago. This explosive volcanism produced almost all (more than 99 percent) of the volcanic material in the Yucca Mountain region. Several million years ago, a different type of eruption began in the area. These eruptions were smaller and much less explosive. These small eruptions were marked by lava and cinders seeping and sputtering from cones or fissures. The last such small eruption occurred about 80,000 years ago. The remaining volcanic material (less than one percent) in the Yucca Mountain region is a result of these smaller eruptions. Yucca Mountain borders a region known as Crater Flat containing several small cones.

Cultural history

Yucca Mountain and surrounding lands were central in the lives of the

Western Shoshone Western Shoshone comprise several Shoshone tribes that are indigenous to the Great Basin and have lands identified in the Treaty of Ruby Valley 1863. They resided in Idaho, Nevada, California, and Utah. The tribes are very closely related cultur ...

and Southern Paiute peoples, who shared them for religious ceremonies, resource uses, and social events; Yucca Mountain continues to be considered sacred by the Shoshone people living today.

References

External links

* GNIS - Feature Detail Report for Yucca Mountain * * * * * * * * * {{Authority control Amargosa Desert Extinct volcanoes History of Nye County, Nevada Mountains of Nye County, Nevada Miocene volcanoes Mojave Desert Mountains of Nevada Mountains of the Great Basin Pleistocene volcanoes Pliocene volcanoes Religious places of the indigenous peoples of North America Volcanoes of Nevada Cinder cones of the United States North American 2000 m summits Calderas of Nevada