Pichilemu Fault
{{Infobox fault
| name = Pichilemu Fault
| other_name = Falla de Pichilemu
| namedfor = Pichilemu
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| pushpin_map = Chile
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| country = Chile
| region = Libertador General Bernardo O'Higgins
| state = Cardenal Caro
| cities = Pichilemu
| coordinates = {{coord|34|23|30|S|72|00|00|W|region:CL|display=inline,title}}
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| length = {{convert|40|km|mi|abbr=on}}
| width = {{convert|20|km|mi|abbr=on}}
| depth = {{convert|15|km|mi|abbr=on}}
| strike = 010
| dip = East
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| displacement =
| plate = South American
| status = Active
| earthquakes = 2010 Pichilemu (Mw 6.9 & 7.0)
| type = Reverse
| movement =
| rockunit = Pichilemu metamorphic complex, Neogene sediments
| age = Late Paleozoic-recent
| orogeny = Andean
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The Pichilemu Fault ({{langx|es|Falla de Pichilemu}}),{{Cite web
|url= http://radiopolar.com/noticia_45169.html
|title= LAS CINCO FALLAS GEOLÓGICAS MÁS IMPORTANTES QUE CHILE DEBE TENER EN CUENTA
|publisher=Radio Polar
|location=Punta Arenas, Chile
|date=April 20, 2011
|language=es
|access-date=April 23, 2011
}} also referred to as the Pichilemu-Vichuquén Fault (Falla de Pichilemu-Vichuquén),{{Cite web
|url= http://www.scielo.cl/pdf/andgeol/v36n1/art03.pdf
|title=Structural overprint of a late Paleozoic accretionary system in north-central Chile (34°-35°S) during post-accretional deformation
|publisher=Andean Geology
|author1=Arne P. Willner |author2=Peter P. Richter |author3=Uwe Ring |access-date=November 10, 2010
|date=January 2009
}} is a Chilean geological fault, located in Libertador General Bernardo O'Higgins Region, some kilometers away from Pichilemu, at a depth of {{convert|15|km|mi}}.{{cite news|url=http://latercera.com/contenido/680_261687_9.shtml|title=Pichilemu tiene falla geológica que genera oleada de réplicas en esa zona|last=Fernández|first=O.|date=May 22, 2010|publisher=La Tercera|language=es|access-date=October 30, 2010|location=Santiago, Chile|url-status=dead|archive-url=https://web.archive.org/web/20120303085454/http://latercera.com/contenido/680_261687_9.shtml|archive-date=March 3, 2012}} The fault is {{convert|40|km|mi}} long and {{convert|20|km|mi}} wide.
Activity
The fault became reactivated after the February 27, 2010, Chile earthquake, and gave rise to the 2010 Pichilemu earthquake on March 11.{{cite news|url=http://spanish.china.org.cn/international/txt/2010-05/23/content_20099573.htm|title=Sismos en Chile se deben a falla geológica en Pichilemu|author=杜璐 (Dulu)|date=May 23, 2010|work=China Internet Information Center|language=es|access-date=October 30, 2010|location=China}} At first, it was not known if it was formed during the February earthquake, or if it was just reactivated;{{cite news|url=http://radio.uchile.cl/noticias/72407/|title=Sismólogos advierten sobre la activación de fallas después del terremoto|last=Correa|first=Paula|work=Radio Universidad de Chile|publisher=Universidad de Chile|language=es|access-date=October 30, 2010|location=Santiago, Chile}} however, according to University of Chile geologist José Cembrano, "[it] corresponds to a long-live fault (in a million years time) whose activity had not been detected before." Ancient activity of the fault has been theorized to have occurred in the Late Paleozoic and Late Mesozoic. The reverse fault has a north-northeast to south-southwest strike and dips to the east.{{cite journal |last1=Farías |first1=M. |last2=Comte |first2=S. |last3=Roecker |first3=D. |last4=Carrizo |first4=D. |last5=Pardo |first5=M. |year=2011 |title=Crustal extensional faulting triggered by the 2010Chilean earthquake: The Pichilemu Seismic Sequence |journal=Tectonics |volume=30 |issue=6010 |pages=1–11 |doi=10.1029/2011TC002888 |bibcode=2011Tecto..30.6010F |hdl=10533/132113 |s2cid=130357954 |hdl-access=free }}{{cite thesis |last=Muñoz Linford |first=Pamela Karina |year=2015 |title=Caracterización sísmica del Antearco Marino en la zona epicentral del mega-terremoto del Maule 2010 |url=http://repositorio.uchile.cl/bitstream/handle/2250/137787/Caracterizacion-sismica-del-antearco-marino-en-la-zona-epicentral-del-mega-terremoto.pdf?sequence=1 |type=MSc. thesis |publisher=Universidad de Chile |pages=1–71 |language=es |access-date=2018-06-03}}
"This is a new record that we have found, and it explains why Pichilemu is experiencing so many tremors," the director of the Seismological Service of the University of Chile, Sergio Barrientos told La Tercera on May 22, 2010. "It is not a crack nor an opening. It's a landslide," Barrientos added.{{cite news|url=http://www.eltipografo.cl/actualidad/noticia/9299/falla-geologica-seria-la-causante-de-la-oleada-de-replicas-en-pichilemu/|title=Falla geológica sería la causante de la oleada de réplicas en Pichilemu|last=Leiva|first=Erika|date=May 22, 2010|work=El Tipógrafo|language=es|access-date=October 30, 2010|location=Rancagua, Chile}}
The Pichilemu Fault, along with the San Ramón Fault, was as of 2011 being studied by geologists of the University of Chile.
References
{{Portal|Geology|Chile|Earth sciences}}
{{reflist}}
{{Geology of Chile|state=collapsed}}
{{Tectonics of South America}}
Category:Seismic faults of Chile
Category:Geology of O'Higgins Region
Category:Geology of the Chilean Coast Range
Category:Coasts of O'Higgins Region
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{{O'Higgins-geo-stub}}