Marysvale Volcanic Field
Encyclopedia
The Marysvale volcanic field is located in southwestern Utah
, United States
.
One of the largest volcanic field
s in the western United States, the Marysvale straddles the Colorado Plateau
-Great Basin
transition zone. Most igneous rock
s belong to a middle Cenozoic
(~32 to 22 million years old) calc-alkaline sequence, although about 5% are related to an upper Cenozoic (23 million years to Holocene
) bimodal
(basalt
and rhyolite
) sequence. The Marysvale contains a variety of volcanic features, including stratovolcano
es, caldera
s, lava dome
s, and cinder cone
s.
The field is an example of intraplate volcanism; its earlier deposits are thought to be related to Farallon plate
subduction
, while the later bimodal assemblage (especially the basalts) have been linked to Basin and Range
extension.
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
One of the largest volcanic field
Volcanic field
A volcanic field is an area of the Earth's crust that is prone to localized volcanic activity. They usually contain 10 to 100 volcanoes, such as cinder cones and are usually in clusters. Lava flows may also occur...
s in the western United States, the Marysvale straddles the Colorado Plateau
Colorado Plateau
The Colorado Plateau, also called the Colorado Plateau Province, is a physiographic region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. The province covers an area of 337,000 km2 within western Colorado, northwestern New Mexico,...
-Great Basin
Great Basin section
The Great Basin section is a physiographic area which extends into the Colorado River watershed on the southeast , as well as into the watersheds of the Klamath River and Sacramento River...
transition zone. Most igneous rock
Igneous rock
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...
s belong to a middle Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
(~32 to 22 million years old) calc-alkaline sequence, although about 5% are related to an upper Cenozoic (23 million years to Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
) bimodal
Bimodal volcanism
Bimodal volcanism refers to the eruption of both mafic and felsic lavas from a single volcanic centre with little or no lavas of intermediate composition...
(basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
and rhyolite
Rhyolite
This page is about a volcanic rock. For the ghost town see Rhyolite, Nevada, and for the satellite system, see Rhyolite/Aquacade.Rhyolite is an igneous, volcanic rock, of felsic composition . It may have any texture from glassy to aphanitic to porphyritic...
) sequence. The Marysvale contains a variety of volcanic features, including stratovolcano
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...
es, caldera
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
s, lava dome
Lava dome
|250px|thumb|right|Image of the [[rhyolitic]] lava dome of [[Chaitén Volcano]] during its 2008–2009 eruption.In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano...
s, and cinder cone
Cinder cone
According to the , Cinder Cone is the proper name of 1 cinder cone in Canada and 7 cinder cones in the United States:In Canada: Cinder Cone In the United States:...
s.
The field is an example of intraplate volcanism; its earlier deposits are thought to be related to Farallon plate
Farallon Plate
The Farallon Plate was an ancient oceanic plate, which began subducting under the west coast of the North American Plate— then located in modern Utah— as Pangaea broke apart during the Jurassic Period...
subduction
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...
, while the later bimodal assemblage (especially the basalts) have been linked to Basin and Range
Basin and Range
The Basin and Range Province is a vast physiographic region defined by a unique topographic expression. Basin and Range topography is characterized by abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins...
extension.
Notable calderas
| Name | Size | Coordinates | Age |
| Monroe Peak Caldera | 20 x 16 km | 38.483333°N 112.058333°W | 23 Ma |
| Big John Caldera | 10 x 6 km | 38.318225°N 112.383333°W | 24 Ma |
| Mount Belknap Caldera | 17 x 13 km | 38.4475°N 112.5°W | 19 Ma |
See also
- Geology of the Bryce Canyon areaGeology of the Bryce Canyon areaThe exposed geology of the Bryce Canyon area in Utah shows a record of deposition that covers the last part of the Cretaceous Period and the first half of the Cenozoic era in that part of North America...
- Large volume volcanic eruptions in the Basin and Range ProvinceLarge volume volcanic eruptions in the Basin and Range ProvinceTh Large volume volcanic eruptions in the Basin and Range Province include Basin and Range eruptions in California, Idaho, Colorado, New Mexico, Texas, Arizona, Nevada, Wyoming, and Oregon, as well as those of the Long Valley Caldera geological province and the Yellowstone hotspot.-Volcanic...
- Tushar MountainsTushar MountainsThe Tushar Mountains are the third highest mountain range in Utah after the Uinta Mountains and the La Sal Range. Located in the Fishlake National Forest, Delano Peak, 12,174 ft NAVD 88, is the highest point in both Beaver and Piute counties and has a prominence of 4,689 ft...
, Delano PeakDelano PeakDelano Peak is the highest point in the Tushar Mountains of south-central Utah. The Tushars are the third-highest range in the state, after the Uinta Mountains and the La Sal Range, though Delano itself is surpassed in height by at least thirty-one other Utah peaks.Located in the Fishlake National...