The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero

A set of dikes in the Eastern Sierras Pampeanas (29°25′ - 29°35′S y 63°43′ - 64°00′W) trending from 90° to 120° azimuths and with thickness less than 10 m wide are assigned to the Balbuena Formation. These dikes are basaltic, andesitic to dacitic in composition representing basic to intermediate mem...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Koukharsky, M., de Brodtkorb, M.K., Kay, S.M., Munizaga, F.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p583_Koukharsky
Aporte de:
id todo:paper_00044822_v58_n4_p583_Koukharsky
record_format dspace
spelling todo:paper_00044822_v58_n4_p583_Koukharsky2023-10-03T13:57:51Z The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero Koukharsky, M. de Brodtkorb, M.K. Kay, S.M. Munizaga, F. Andesitic and dacitic dikes Balbuena Formation Cambrian Eastern Sierras Pampeanas Santiago del Estero Cambrian dike magma chemistry subduction zone Argentina Sierras Pampeanas South America Western Hemisphere World A set of dikes in the Eastern Sierras Pampeanas (29°25′ - 29°35′S y 63°43′ - 64°00′W) trending from 90° to 120° azimuths and with thickness less than 10 m wide are assigned to the Balbuena Formation. These dikes are basaltic, andesitic to dacitic in composition representing basic to intermediate members of the calc-alkaline magmas that gave rise to the rhyodacitic Oncán Porphyries. The fine porphyritic rocks of the Balbuena Formation have an intense alteration of the mafic minerals and groundmass that indicates an important deuteric event. Minimum ages for the dikes come from the observation that they are intrusive into the Upper to Middle Cambrian granitoids of the Ojo de Agua and Ambargasta Formations that are related to the rhyodacitic Oncán Porphyry. Major and trace element analyses presented here and isotopic ages support the hypothesis that these dikes along with similar age plutonic and volcanic rocks in the region formed in a subduction setting. In detail, their chemistry supports an arc-retroarc setting on continental crust. The magmatism of Balbuena Formation represents the last important Pampean age igneous event in this region. © 2003 Asociación Geológica Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p583_Koukharsky
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Andesitic and dacitic dikes
Balbuena Formation
Cambrian
Eastern Sierras Pampeanas
Santiago del Estero
Cambrian
dike
magma chemistry
subduction zone
Argentina
Sierras Pampeanas
South America
Western Hemisphere
World
spellingShingle Andesitic and dacitic dikes
Balbuena Formation
Cambrian
Eastern Sierras Pampeanas
Santiago del Estero
Cambrian
dike
magma chemistry
subduction zone
Argentina
Sierras Pampeanas
South America
Western Hemisphere
World
Koukharsky, M.
de Brodtkorb, M.K.
Kay, S.M.
Munizaga, F.
The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero
topic_facet Andesitic and dacitic dikes
Balbuena Formation
Cambrian
Eastern Sierras Pampeanas
Santiago del Estero
Cambrian
dike
magma chemistry
subduction zone
Argentina
Sierras Pampeanas
South America
Western Hemisphere
World
description A set of dikes in the Eastern Sierras Pampeanas (29°25′ - 29°35′S y 63°43′ - 64°00′W) trending from 90° to 120° azimuths and with thickness less than 10 m wide are assigned to the Balbuena Formation. These dikes are basaltic, andesitic to dacitic in composition representing basic to intermediate members of the calc-alkaline magmas that gave rise to the rhyodacitic Oncán Porphyries. The fine porphyritic rocks of the Balbuena Formation have an intense alteration of the mafic minerals and groundmass that indicates an important deuteric event. Minimum ages for the dikes come from the observation that they are intrusive into the Upper to Middle Cambrian granitoids of the Ojo de Agua and Ambargasta Formations that are related to the rhyodacitic Oncán Porphyry. Major and trace element analyses presented here and isotopic ages support the hypothesis that these dikes along with similar age plutonic and volcanic rocks in the region formed in a subduction setting. In detail, their chemistry supports an arc-retroarc setting on continental crust. The magmatism of Balbuena Formation represents the last important Pampean age igneous event in this region. © 2003 Asociación Geológica Argentina.
format JOUR
author Koukharsky, M.
de Brodtkorb, M.K.
Kay, S.M.
Munizaga, F.
author_facet Koukharsky, M.
de Brodtkorb, M.K.
Kay, S.M.
Munizaga, F.
author_sort Koukharsky, M.
title The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero
title_short The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero
title_full The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero
title_fullStr The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero
title_full_unstemmed The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero
title_sort balbuena formation, integrant of the pampean magmatic arc in the sierra de ambargasta, province of santiago del estero
url http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p583_Koukharsky
work_keys_str_mv AT koukharskym thebalbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
AT debrodtkorbmk thebalbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
AT kaysm thebalbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
AT munizagaf thebalbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
AT koukharskym balbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
AT debrodtkorbmk balbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
AT kaysm balbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
AT munizagaf balbuenaformationintegrantofthepampeanmagmaticarcinthesierradeambargastaprovinceofsantiagodelestero
_version_ 1807316821162852352