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{{Short description|Geologic feature in Nevada, United States}}
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 [[tectonics|tectonic]] crustal block called a [[terrane]] and the [[North American Plate]]. The collision occurred during the Devonian Era, about 350 million years B.P. The collision is associated with what is sometimes referred to as the [[Antler Orogeny]].
[[File:Sedimentary-rock hosted gold deposits in Nevada.gif|thumb|350px|'''Carlin Trend''', shown with other alignments of sediment-hosted gold deposits in Nevada. Source: [[USGS]]. ]]
[[File:Newmont Gold Quarry mine.jpg|thumb|Newmont's Gold Quarry mine in 2009, on the Carlin Trend]]


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 [[tectonics|tectonic]] crustal block called a [[terrane]] and the [[North American Plate]]. The collision occurred during the [[Mississippian age|Mississippian]] Period, about 350 million years before present. The collision is associated with the [[Antler Orogeny]].<ref>{{cite web|url=http://jan.ucc.nau.edu/~rcb7/Text_WUS.html|title=Geologic History of Western US|first=Ron|last=Blakely|accessdate=2010-06-06|archive-date=2010-06-22|archive-url=https://web.archive.org/web/20100622013326/http://jan.ucc.nau.edu/~rcb7/Text_WUS.html|url-status=dead}}</ref>
The collision induced higher crustal temperatures and pressures which produced numerous hot springs along the suture zone. Several episodes of subsurface magmatism are known to have occurred subsequent to the collision, associated with tectonic forces affecting the entire [[Basin and Range]]. During each of these episodes, and particularly during the [[Eocene]] epoch, hot springs brought dissolved minerals toward the surface, precipitating them out along fissures. Among these minerals were [[gold]] and silver.


The collision induced higher crustal temperatures and pressures which produced numerous hot springs along the suture zone. Several episodes of subsurface magmatism are known to have occurred subsequent to the collision, associated with tectonic forces affecting the entire [[Basin and Range Province]]. During each of these episodes, and particularly during the [[Eocene]] epoch, hot springs brought dissolved minerals toward the surface, precipitating them out along fissures.<ref>{{cite journal|first1=Michael W.|last1=Ressel|first2=Christopher D.|last2=Henry|title=Igneous Geology of the Carlin Trend, Nevada: Development of the Eocene Plutonic Complex and Significance for Carlin-Type Gold Deposits|url=http://econgeol.geoscienceworld.org/cgi/content/abstract/101/2/347|journal=Economic Geology|date=March 2006|volume=101|issue=2|pages=347–383|doi=10.2113/gsecongeo.101.2.347|bibcode=2006EcGeo.101..347R }}</ref> Among these minerals were [[gold]] and silver.
The Carlin Gold trend is one of the world's richest gold mining districts. It is a belt of gold deposits, primarily in [[Paleozoic]] limy [[sediments]], that is about 5 miles wide and 40 miles long, extending in a north-northwest direction through the town of [[Carlin, Nevada]]. Gold was first discovered in the area in the 1870s, but there was very little production until 1909, and only about 22,000 ounces was produced through 1964. By 2002, mines in the Carlin Trend had produced over 50 million ounces of gold, worth around US$47 billion at 2009 prices. <ref>[http://www.nbmg.unr.edu/slides/jon.htm Remarks by Jonathan G. Price],

Director and State Geologist, Nevada Bureau of Mines and Geology, 2002. </ref>
The Carlin Gold trend is one of the world's richest gold mining districts. It is a belt of gold deposits, primarily in [[Paleozoic]] limy [[sediments]], that is about {{Convert|5|mi|km|abbr=on}} wide and {{Convert|40|mi|km|abbr=on}} long, extending in a north-northwest direction through the town of [[Carlin, Nevada]]. Gold was first discovered in the area in the 1870s, but there was little production until 1909, and only about 22,000 ounces was produced through 1964. By 2008, mines in the Carlin Trend had produced over 70 million ounces of gold, worth around $85 billion at 2010 prices.<ref>{{cite web|url=http://www.nbmg.unr.edu/_docs/Presentations/NWMAupdate09.pdf |title=Update on Production and Exploration Activity in Nevada - 2009 |publisher=Nevada Bureau of Mines and Geology |url-status=dead |archiveurl=https://web.archive.org/web/20120326095321/http://www.nbmg.unr.edu/_docs/Presentations/NWMAupdate09.pdf |archivedate=2012-03-26 }}</ref>


==See also==
==See also==
* [[Carlin–type gold deposit]]
* [[Gold mining in Nevada]]
* [[John Livermore]]
* [[John Livermore]]
*[[Ralph J. Roberts]]
* [[Ralph J. Roberts (geologist)|Ralph J. Roberts]]
*[[Gold mining in Nevada]]
mark is a bell


==References==
==References==
* ''Basin and Range'', by John McPhee, published 1981 by Farrar, Straus and Giroux, New York.
* ''Assembling California'', by John McPhee, published 1993 by Farrar, Straus and Giroux, New York.
*Michael W. Ressel and Christopher D. Henry, ''Igneous Geology of the Carlin Trend, Nevada: Development of the Eocene Plutonic Complex and Significance for Carlin-Type Gold Deposits'' [http://econgeol.geoscienceworld.org/cgi/content/abstract/101/2/347], [[Economic Geology]], March 2006; v. 101; no. 2
{{reflist}}
{{reflist}}


==Further reading==
[[Category:Geology of Nevada]]

[[Category:Terranes]]
*{{Cite book|last=McPhee |first= John |url=https://www.worldcat.org/oclc/7173053|title=Basin and range|date=1981|publisher=[[Farrar, Straus and Giroux]]|isbn=0-374-10914-1|location=New York|oclc=7173053}}
*{{Cite book|last=McPhee |first= John |url=https://www.worldcat.org/oclc/26809557|title=Assembling California|isbn=0-374-10645-2|edition=First |year=1993 |publisher =Farrar, Straus and Giroux |location=New York |oclc=26809557}}
*{{Cite web|title=Carlin trend exploration history: Discovery of the Carlin deposit|url=https://data.nbmg.unr.edu/public/freedownloads/sp/sp013.zip |first1= J. Alan | last1=Coope |year=1991 |publisher=Nevada Bureau of Mines and Geology Publications| series=Special Publication 13 |format=pdf|access-date=2021-01-19}}
*[https://web.archive.org/web/20100613144806/http://www.nbmg.unr.edu/dox/b111/history.pdf Newmont's reserve history on the Carlin Trend, 1965 - 2001] by Dean G. Heitt, Newmont Mining Corporation
*{{Cite book|last1=Teal|first1=Lewis|last2=Jackson|first2=Mac|date=1997-01-01|chapter=Geologic Overview of the Carlin Trend Gold Deposits and Descriptions of Recent Deep Discoveries
|url=https://pubs.geoscienceworld.org/books/book/1841/chapter/107706193/Geologic-Overview-of-the-Carlin-Trend-Gold|title=Carlin-Type Gold Deposits Field Conference |series=Society of Economic Geologists Guidebook Series
|volume=25|language=en|publisher=Society of Economic Geologists|isbn=9781934969816|doi=10.5382/GB.28}}

[[Category:Unconformities]]
[[Category:Carboniferous events]]
[[Category:Carboniferous geology of Nevada]]
[[Category:Gold mining in Nevada]]
[[Category:Gold mining in Nevada]]

Latest revision as of 23:36, 18 June 2024

Carlin Trend, shown with other alignments of sediment-hosted gold deposits in Nevada. Source: USGS.
Newmont's Gold Quarry mine in 2009, on the Carlin Trend

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 Mississippian Period, about 350 million years before present. The collision is associated with the Antler Orogeny.[1]

The collision induced higher crustal temperatures and pressures which produced numerous hot springs along the suture zone. Several episodes of subsurface magmatism are known to have occurred subsequent to the collision, associated with tectonic forces affecting the entire Basin and Range Province. During each of these episodes, and particularly during the Eocene epoch, hot springs brought dissolved minerals toward the surface, precipitating them out along fissures.[2] Among these minerals were gold and silver.

The Carlin Gold trend is one of the world's richest gold mining districts. It is a belt of gold deposits, primarily in Paleozoic limy sediments, that is about 5 mi (8.0 km) wide and 40 mi (64 km) long, extending in a north-northwest direction through the town of Carlin, Nevada. Gold was first discovered in the area in the 1870s, but there was little production until 1909, and only about 22,000 ounces was produced through 1964. By 2008, mines in the Carlin Trend had produced over 70 million ounces of gold, worth around $85 billion at 2010 prices.[3]

See also

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References

[edit]
  1. ^ Blakely, Ron. "Geologic History of Western US". Archived from the original on 2010-06-22. Retrieved 2010-06-06.
  2. ^ Ressel, Michael W.; Henry, Christopher D. (March 2006). "Igneous Geology of the Carlin Trend, Nevada: Development of the Eocene Plutonic Complex and Significance for Carlin-Type Gold Deposits". Economic Geology. 101 (2): 347–383. Bibcode:2006EcGeo.101..347R. doi:10.2113/gsecongeo.101.2.347.
  3. ^ "Update on Production and Exploration Activity in Nevada - 2009" (PDF). Nevada Bureau of Mines and Geology. Archived from the original (PDF) on 2012-03-26.

Further reading

[edit]