Antler orogeny
Encyclopedia
The Antler orogeny is a mountain-building episode that is named for Antler Peak, at Battle Mountain, Nevada
. The orogeny
extensively deformed Paleozoic
rocks of the Great Basin
in Nevada
and western Utah
during Late Devonian and Early Mississippian time. In the late Devonian, the Antler volcanic island arc
terrane
collided with what was then the west coast of North America in the vicinity of today's border between Utah and Nevada. The collision zone is today signified by the geological alignment called the Carlin Unconformity
(or Carlin Trend), an area enriched in various ores including gold. It is also represented by the Roberts Mountains Thrust. It is broadly contemporary with the Acadian orogeny
of eastern North America.
The Antler orogeny was first defined by the American geologist Ralph J. Roberts
. It was, however, originally described in terms of the old geology of geosyncline
s, before the acceptance of what is now known as plate tectonics
including the concept of terrane
s.
Battle Mountain, Nevada
Battle Mountain is an unincorporated community and census-designated place in Lander County, Nevada, United States. The population was 2,871 at the 2000 census. Though it has no legal status as a municipality, it still functions as the county seat of Lander County...
. The orogeny
Orogeny
Orogeny refers to forces and events leading to a severe structural deformation of the Earth's crust due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts...
extensively deformed Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
rocks of the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...
in Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
and western Utah
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...
during Late Devonian and Early Mississippian time. In the late Devonian, the Antler volcanic island arc
Island arc
An island arc is a type of archipelago composed of a chain of volcanoes which alignment is arc-shaped, and which are situated parallel and close to a boundary between two converging tectonic plates....
terrane
Terrane
A terrane in geology is short-hand term for a tectonostratigraphic terrane, which is a fragment of crustal material formed on, or broken off from, one tectonic plate and accreted or "sutured" to crust lying on another plate...
collided with what was then the west coast of North America in the vicinity of today's border between Utah and Nevada. The collision zone is today signified by the geological alignment called the Carlin Unconformity
Carlin Unconformity
The Carlin Unconformity or Carlin Trend is a geologic feature in northeastern Nevada which represents a period of erosion or non-deposition likely associated with a collision between a tectonic crustal block called a terrane and the North American Plate. The collision occurred during the...
(or Carlin Trend), an area enriched in various ores including gold. It is also represented by the Roberts Mountains Thrust. It is broadly contemporary with the Acadian orogeny
Acadian orogeny
The Taconic, Acadian and Alleghenian orogenies are the three tectonic phases responsible for the formation of the present Appalachian Mountains. The Acadian orogeny is a middle Paleozoic mountain building episode dating back 325-400 million years which should not be regarded as a single event but...
of eastern North America.
The Antler orogeny was first defined by the American geologist Ralph J. Roberts
Ralph J. Roberts (geologist)
Ralph J. Roberts was an American geologist and research scientist with the USGS. He is credited with the discovery of the Carlin and Battle Mountain Gold Belts, which make up the richest gold-mining region in Nevada as well as the United States....
. It was, however, originally described in terms of the old geology of geosyncline
Geosyncline
In geology, geosyncline is a term still occasionally used for a subsiding linear trough that was caused by the accumulation of sedimentary rock strata deposited in a basin and subsequently compressed, deformed, and uplifted into a mountain range, with attendant volcanism and plutonism...
s, before the acceptance of what is now known as plate tectonics
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
including the concept of terrane
Terrane
A terrane in geology is short-hand term for a tectonostratigraphic terrane, which is a fragment of crustal material formed on, or broken off from, one tectonic plate and accreted or "sutured" to crust lying on another plate...
s.