The low-grade Canal de las Montañas Shear Zone and its role in the tectonic emplacement of the Sarmiento Ophiolitic Complex and Late Cretaceous Patagonian Andes orogeny, Chile

M. Calderón, J. C. Fosdick, C. Warren, H. J. Massonne, C. M. Fanning, L. Fadel Cury, J. Schwanethal, P. E. Fonseca, G. Galaz, D. Gaytán, F. Hervé

Resultado de la investigación: Article

24 Citas (Scopus)

Resumen

The Canal de las Montañas Shear Zone (CMSZ), southern Patagonian Andes (51-52°S), is a low-grade mylonite belt generated from felsic ignimbritic, pelitic and basaltic protoliths of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The different types of rock fabrics across the CMSZ are thought to be associated with relatively intermediate and high strain conditions, characterized by the development of a narrow western belt of S-CD́-type mylonites and phyllonites interpreted as the metamorphic sole thrust of the Sarmiento Ophiolitic Complex. Highly strained rocks of the CMSZ display a reverse, continent-ward tectonic transport, with a minor dextral component of shearing. Transitional pumpellyite-actinolite and upper greenschist facies metamorphic conditions at ca. 5-6kbar and 230-260°C indicate that the primary shearing event occurred in a subduction zone setting. In-situ 40Ar/ 39Ar laserprobe chronology yielded ages of ca. 85Ma on syntectonic phengite which are interpreted as representing cooling synchronous with mica crystallization during the main compressive deformational event. The 78-81Ma U-Pb zircon crystallization ages of cross-cutting plutonic and hypabyssal rocks and 40Ar/ 39Ar amphibole age of ca.79Ma from lamprophyric dikes within the fold-thrust belt constrain an upper age limit of the ophiolite tectonic emplacement deformation.

Idioma originalEnglish
Páginas (desde-hasta)165-185
Número de páginas21
PublicaciónTectonophysics
Volumen524-525
DOI
EstadoPublished - 20 feb 2012

Huella dactilar

canals
Chile
orogeny
canal
shear zone
tectonics
grade
emplacement
rocks
shear
Cretaceous
shearing
thrust
crystallization
chronology
amphiboles
rock intrusions
hypabyssal rock
continents
mica

ASJC Scopus subject areas

  • Geophysics
  • Earth-Surface Processes

Citar esto

Calderón, M. ; Fosdick, J. C. ; Warren, C. ; Massonne, H. J. ; Fanning, C. M. ; Cury, L. Fadel ; Schwanethal, J. ; Fonseca, P. E. ; Galaz, G. ; Gaytán, D. ; Hervé, F. / The low-grade Canal de las Montañas Shear Zone and its role in the tectonic emplacement of the Sarmiento Ophiolitic Complex and Late Cretaceous Patagonian Andes orogeny, Chile. En: Tectonophysics. 2012 ; Vol. 524-525. pp. 165-185.
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title = "The low-grade Canal de las Monta{\~n}as Shear Zone and its role in the tectonic emplacement of the Sarmiento Ophiolitic Complex and Late Cretaceous Patagonian Andes orogeny, Chile",
abstract = "The Canal de las Monta{\~n}as Shear Zone (CMSZ), southern Patagonian Andes (51-52°S), is a low-grade mylonite belt generated from felsic ignimbritic, pelitic and basaltic protoliths of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The different types of rock fabrics across the CMSZ are thought to be associated with relatively intermediate and high strain conditions, characterized by the development of a narrow western belt of S-CD́-type mylonites and phyllonites interpreted as the metamorphic sole thrust of the Sarmiento Ophiolitic Complex. Highly strained rocks of the CMSZ display a reverse, continent-ward tectonic transport, with a minor dextral component of shearing. Transitional pumpellyite-actinolite and upper greenschist facies metamorphic conditions at ca. 5-6kbar and 230-260°C indicate that the primary shearing event occurred in a subduction zone setting. In-situ 40Ar/ 39Ar laserprobe chronology yielded ages of ca. 85Ma on syntectonic phengite which are interpreted as representing cooling synchronous with mica crystallization during the main compressive deformational event. The 78-81Ma U-Pb zircon crystallization ages of cross-cutting plutonic and hypabyssal rocks and 40Ar/ 39Ar amphibole age of ca.79Ma from lamprophyric dikes within the fold-thrust belt constrain an upper age limit of the ophiolite tectonic emplacement deformation.",
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The low-grade Canal de las Montañas Shear Zone and its role in the tectonic emplacement of the Sarmiento Ophiolitic Complex and Late Cretaceous Patagonian Andes orogeny, Chile. / Calderón, M.; Fosdick, J. C.; Warren, C.; Massonne, H. J.; Fanning, C. M.; Cury, L. Fadel; Schwanethal, J.; Fonseca, P. E.; Galaz, G.; Gaytán, D.; Hervé, F.

En: Tectonophysics, Vol. 524-525, 20.02.2012, p. 165-185.

Resultado de la investigación: Article

TY - JOUR

T1 - The low-grade Canal de las Montañas Shear Zone and its role in the tectonic emplacement of the Sarmiento Ophiolitic Complex and Late Cretaceous Patagonian Andes orogeny, Chile

AU - Calderón, M.

AU - Fosdick, J. C.

AU - Warren, C.

AU - Massonne, H. J.

AU - Fanning, C. M.

AU - Cury, L. Fadel

AU - Schwanethal, J.

AU - Fonseca, P. E.

AU - Galaz, G.

AU - Gaytán, D.

AU - Hervé, F.

PY - 2012/2/20

Y1 - 2012/2/20

N2 - The Canal de las Montañas Shear Zone (CMSZ), southern Patagonian Andes (51-52°S), is a low-grade mylonite belt generated from felsic ignimbritic, pelitic and basaltic protoliths of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The different types of rock fabrics across the CMSZ are thought to be associated with relatively intermediate and high strain conditions, characterized by the development of a narrow western belt of S-CD́-type mylonites and phyllonites interpreted as the metamorphic sole thrust of the Sarmiento Ophiolitic Complex. Highly strained rocks of the CMSZ display a reverse, continent-ward tectonic transport, with a minor dextral component of shearing. Transitional pumpellyite-actinolite and upper greenschist facies metamorphic conditions at ca. 5-6kbar and 230-260°C indicate that the primary shearing event occurred in a subduction zone setting. In-situ 40Ar/ 39Ar laserprobe chronology yielded ages of ca. 85Ma on syntectonic phengite which are interpreted as representing cooling synchronous with mica crystallization during the main compressive deformational event. The 78-81Ma U-Pb zircon crystallization ages of cross-cutting plutonic and hypabyssal rocks and 40Ar/ 39Ar amphibole age of ca.79Ma from lamprophyric dikes within the fold-thrust belt constrain an upper age limit of the ophiolite tectonic emplacement deformation.

AB - The Canal de las Montañas Shear Zone (CMSZ), southern Patagonian Andes (51-52°S), is a low-grade mylonite belt generated from felsic ignimbritic, pelitic and basaltic protoliths of the Late Jurassic-Early Cretaceous Rocas Verdes basin. The different types of rock fabrics across the CMSZ are thought to be associated with relatively intermediate and high strain conditions, characterized by the development of a narrow western belt of S-CD́-type mylonites and phyllonites interpreted as the metamorphic sole thrust of the Sarmiento Ophiolitic Complex. Highly strained rocks of the CMSZ display a reverse, continent-ward tectonic transport, with a minor dextral component of shearing. Transitional pumpellyite-actinolite and upper greenschist facies metamorphic conditions at ca. 5-6kbar and 230-260°C indicate that the primary shearing event occurred in a subduction zone setting. In-situ 40Ar/ 39Ar laserprobe chronology yielded ages of ca. 85Ma on syntectonic phengite which are interpreted as representing cooling synchronous with mica crystallization during the main compressive deformational event. The 78-81Ma U-Pb zircon crystallization ages of cross-cutting plutonic and hypabyssal rocks and 40Ar/ 39Ar amphibole age of ca.79Ma from lamprophyric dikes within the fold-thrust belt constrain an upper age limit of the ophiolite tectonic emplacement deformation.

KW - Geochronology

KW - Geothermobarometry

KW - Metamorphic sole

KW - Patagonian Andes

KW - Rocas Verdes basin

KW - Sarmiento Ophiolitic Complex

UR - http://www.scopus.com/inward/record.url?scp=84856707640&partnerID=8YFLogxK

U2 - 10.1016/j.tecto.2011.12.034

DO - 10.1016/j.tecto.2011.12.034

M3 - Article

AN - SCOPUS:84856707640

VL - 524-525

SP - 165

EP - 185

JO - Tectonophysics

JF - Tectonophysics

SN - 0040-1951

ER -