Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina

Rb-Sr and Sm-Nd whole-rock data for granitoids and orthogneisses from the western part of the Sierras Septentrionales of the southern Buenos Aires province yield an errorchron of 2009±71 Ma (initial 87Sr/86Sr=0.7041, MSWD=69) and an isochron of 2140±88 Ma (initial 143Nd/ 144Nd=0.50977), respectively...

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Autores principales: Pankhurst, R.J., Ramos, A., Linares, E.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_08959811_v16_n1_p5_Pankhurst
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spelling todo:paper_08959811_v16_n1_p5_Pankhurst2023-10-03T15:42:34Z Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina Pankhurst, R.J. Ramos, A. Linares, E. Continental crust formation Geochronology Neodymium isotopes Proterozoic Transamazonian orogeny continental crust geochronology Gondwana Proterozoic samarium-neodymium dating uranium-lead dating Argentina Buenos Aires Province Tandilia Rb-Sr and Sm-Nd whole-rock data for granitoids and orthogneisses from the western part of the Sierras Septentrionales of the southern Buenos Aires province yield an errorchron of 2009±71 Ma (initial 87Sr/86Sr=0.7041, MSWD=69) and an isochron of 2140±88 Ma (initial 143Nd/ 144Nd=0.50977), respectively. As in previous investigations, the Rb-Sr data are clearly disturbed, but the Sm-Nd isochron may record the age of emplacement of igneous precursors. These results reaffirm that this region is the southern extension of the crystalline basement of the Río de la Plata craton. The Sm-Nd age, though not very precise, is slightly older than previously demonstrated but consistent with most recent U-Pb studies of the craton exposed in Uruguay and Brazil. Crust-derived Sm-Nd model ages averaging 2620±80 Ma indicate that, though the principal rock-forming events were Paleoproterozoic, a Late Archaean prehistory is possible. However, the data place strict constraints on the nature and intensity of post-2000 Ma activity in this area, which seems to be confined to tholeiitic dyke emplacement and hydrothermal reactivation. © 2003 Elsevier Science Ltd. All rights reserved. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08959811_v16_n1_p5_Pankhurst
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Continental crust formation
Geochronology
Neodymium isotopes
Proterozoic
Transamazonian orogeny
continental crust
geochronology
Gondwana
Proterozoic
samarium-neodymium dating
uranium-lead dating
Argentina
Buenos Aires Province
Tandilia
spellingShingle Continental crust formation
Geochronology
Neodymium isotopes
Proterozoic
Transamazonian orogeny
continental crust
geochronology
Gondwana
Proterozoic
samarium-neodymium dating
uranium-lead dating
Argentina
Buenos Aires Province
Tandilia
Pankhurst, R.J.
Ramos, A.
Linares, E.
Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina
topic_facet Continental crust formation
Geochronology
Neodymium isotopes
Proterozoic
Transamazonian orogeny
continental crust
geochronology
Gondwana
Proterozoic
samarium-neodymium dating
uranium-lead dating
Argentina
Buenos Aires Province
Tandilia
description Rb-Sr and Sm-Nd whole-rock data for granitoids and orthogneisses from the western part of the Sierras Septentrionales of the southern Buenos Aires province yield an errorchron of 2009±71 Ma (initial 87Sr/86Sr=0.7041, MSWD=69) and an isochron of 2140±88 Ma (initial 143Nd/ 144Nd=0.50977), respectively. As in previous investigations, the Rb-Sr data are clearly disturbed, but the Sm-Nd isochron may record the age of emplacement of igneous precursors. These results reaffirm that this region is the southern extension of the crystalline basement of the Río de la Plata craton. The Sm-Nd age, though not very precise, is slightly older than previously demonstrated but consistent with most recent U-Pb studies of the craton exposed in Uruguay and Brazil. Crust-derived Sm-Nd model ages averaging 2620±80 Ma indicate that, though the principal rock-forming events were Paleoproterozoic, a Late Archaean prehistory is possible. However, the data place strict constraints on the nature and intensity of post-2000 Ma activity in this area, which seems to be confined to tholeiitic dyke emplacement and hydrothermal reactivation. © 2003 Elsevier Science Ltd. All rights reserved.
format JOUR
author Pankhurst, R.J.
Ramos, A.
Linares, E.
author_facet Pankhurst, R.J.
Ramos, A.
Linares, E.
author_sort Pankhurst, R.J.
title Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina
title_short Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina
title_full Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina
title_fullStr Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina
title_full_unstemmed Antiquity of the Río de la Plata craton in Tandilia, southern Buenos Aires province, Argentina
title_sort antiquity of the río de la plata craton in tandilia, southern buenos aires province, argentina
url http://hdl.handle.net/20.500.12110/paper_08959811_v16_n1_p5_Pankhurst
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