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...
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2003
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n4_p583_Koukharsky http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p583_Koukharsky |
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paper:paper_00044822_v58_n4_p583_Koukharsky2023-06-08T14:25:42Z The Balbuena Formation, integrant of the Pampean magmatic arc in the Sierra de Ambargasta, Province of Santiago del Estero 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. 2003 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n4_p583_Koukharsky 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 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. |
| 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 |
| publishDate |
2003 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v58_n4_p583_Koukharsky http://hdl.handle.net/20.500.12110/paper_00044822_v58_n4_p583_Koukharsky |
| _version_ |
1768544298723180544 |