SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism

Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC), obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ag...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Hervé,Francisco, Calderón,Mauricio, Fanning,C. Mark, Kraus,Stefan, Pankhurst,Robert J
Lenguaje:	English
Publicado:	Servicio Nacional de Geología y Minería (SERNAGEOMIN) 2010
Materias:	Cambrian plutonism Permian metamorphism U-Pb SHRIMP ages Basement complex Magallanes Basin
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062010000200001
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:scielo:S0718-71062010000200001
record_format	dspace
spelling	oai:scielo:S0718-710620100002000012010-10-06SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphismHervé,FranciscoCalderón,MauricioFanning,C. MarkKraus,StefanPankhurst,Robert J Cambrian plutonism Permian metamorphism U-Pb SHRIMP ages Basement complex Magallanes Basin Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC), obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ages (523±7 Ma, 522±6 Ma and 538±6 Ma), interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inherited zircon grains in addition to two grains with ages of ca. 525 Ma, suggesting involvement of Grenvillian and Brasiliano material in the protolith of a Cambrian migmatite. A cordierite-sillimanite-garnet gneiss contains igneous zircons of Cambrian age and a population of U-rich metamorphic Permian zircons, indicating that a Permian high-grade metamorphic and anatectic (P=2-3 kbar, T=730-770°C) event affected the Cambrian igneous rocks or sedimentary rocks derived from them. Cambrian/Ediacaran plutonic rocks are known from the basement of NW Argentina, the Sierra de la Ventana, the Cape Fold Belt in South Africa, and the Ross Orogen in Antarctica. The Permian metamorphic event is coeval with the deformation and low-grade metamorphism of the sedimentary successions that overlie the basement in many of these areas. In Tierra del Fuego at least 8 to 12 km of cover rocks were removed following the high-grade Permian metamorphic episode and the unconformable deposition of the Tobífera Formation volcanic rocks in the Middle to Late Jurassic. This eroded cover could nave been an important source of detritus for the conglomeratic Permian and Triassic? Successions of neighboring regions in South America, Africa and Antarctica.info:eu-repo/semantics/openAccessServicio Nacional de Geología y Minería (SERNAGEOMIN)Andean geology v.37 n.2 20102010-07-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062010000200001en
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Cambrian plutonism Permian metamorphism U-Pb SHRIMP ages Basement complex Magallanes Basin
spellingShingle	Cambrian plutonism Permian metamorphism U-Pb SHRIMP ages Basement complex Magallanes Basin Hervé,Francisco Calderón,Mauricio Fanning,C. Mark Kraus,Stefan Pankhurst,Robert J SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism
description	Five new SHRTMP U-Pb zircon ages are reported for gneisses and foliated plutonic rocks belonging to the Tierra del Fuego igneous and metamorphic basement complex (TFIMC), obtained from the bottom of borehole cores through the Magallanes Basin. Three of the samples yielded weighted mean 206Pb/238U ages (523±7 Ma, 522±6 Ma and 538±6 Ma), interpreted as indicating Early Cambrian igneous crystallization of the host rocks. A migmatitic gneiss shows peaks at ca. 950-1,100 Ma and 560-650 Ma from inherited zircon grains in addition to two grains with ages of ca. 525 Ma, suggesting involvement of Grenvillian and Brasiliano material in the protolith of a Cambrian migmatite. A cordierite-sillimanite-garnet gneiss contains igneous zircons of Cambrian age and a population of U-rich metamorphic Permian zircons, indicating that a Permian high-grade metamorphic and anatectic (P=2-3 kbar, T=730-770°C) event affected the Cambrian igneous rocks or sedimentary rocks derived from them. Cambrian/Ediacaran plutonic rocks are known from the basement of NW Argentina, the Sierra de la Ventana, the Cape Fold Belt in South Africa, and the Ross Orogen in Antarctica. The Permian metamorphic event is coeval with the deformation and low-grade metamorphism of the sedimentary successions that overlie the basement in many of these areas. In Tierra del Fuego at least 8 to 12 km of cover rocks were removed following the high-grade Permian metamorphic episode and the unconformable deposition of the Tobífera Formation volcanic rocks in the Middle to Late Jurassic. This eroded cover could nave been an important source of detritus for the conglomeratic Permian and Triassic? Successions of neighboring regions in South America, Africa and Antarctica.
author	Hervé,Francisco Calderón,Mauricio Fanning,C. Mark Kraus,Stefan Pankhurst,Robert J
author_facet	Hervé,Francisco Calderón,Mauricio Fanning,C. Mark Kraus,Stefan Pankhurst,Robert J
author_sort	Hervé,Francisco
title	SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism
title_short	SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism
title_full	SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism
title_fullStr	SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism
title_full_unstemmed	SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism
title_sort	shrimp chronology of the magallanes basin basement, tierra del fuego: cambrian plutonism and permian high-grade metamorphism
publisher	Servicio Nacional de Geología y Minería (SERNAGEOMIN)
publishDate	2010
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-71062010000200001
work_keys_str_mv	AT hervefrancisco shrimpchronologyofthemagallanesbasinbasementtierradelfuegocambrianplutonismandpermianhighgrademetamorphism AT calderonmauricio shrimpchronologyofthemagallanesbasinbasementtierradelfuegocambrianplutonismandpermianhighgrademetamorphism AT fanningcmark shrimpchronologyofthemagallanesbasinbasementtierradelfuegocambrianplutonismandpermianhighgrademetamorphism AT krausstefan shrimpchronologyofthemagallanesbasinbasementtierradelfuegocambrianplutonismandpermianhighgrademetamorphism AT pankhurstrobertj shrimpchronologyofthemagallanesbasinbasementtierradelfuegocambrianplutonismandpermianhighgrademetamorphism
_version_	1714205827982688256

SHRIMP chronology of the Magallanes Basin basement, Tierra del Fuego: Cambrian plutonism and Permian high-grade metamorphism

Ejemplares similares