Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes

Petrographic and geochemical studies combined with U-Pb SHRIMP II analyses of zircons from three granitoid rocks in northwest Argentina reveal new data to enhance the understanding of the margin of western Gondwana. The I-type granite at Pomán (‘Granito Pomán’), with a typical continental arc geoche...

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Guardado en:
Detalles Bibliográficos
Publicado: 2018
Materias:
Cambrian
Granites
Northwest Argentina
SHRIMP II
Sierra Ambato
Volcanic arc
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02643707_v_n_p_Zimmermann
http://hdl.handle.net/20.500.12110/paper_02643707_v_n_p_Zimmermann
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_02643707_v_n_p_Zimmermann
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spelling paper:paper_02643707_v_n_p_Zimmermann2023-06-08T15:23:01Z Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes Cambrian Granites Northwest Argentina SHRIMP II Sierra Ambato Volcanic arc Petrographic and geochemical studies combined with U-Pb SHRIMP II analyses of zircons from three granitoid rocks in northwest Argentina reveal new data to enhance the understanding of the margin of western Gondwana. The I-type granite at Pomán (‘Granito Pomán’), with a typical continental arc geochemical signature, has been intruded into schists and gneisses of the regional basement during the Lower Cambrian (535 ± 5 Ma; MSDW = 0.024). This supports the existence of a volcanic arc of Lower Cambrian age evolving possibly contemporary to some successions of the Puncoviscana Complex. Two deformed and metamorphosed, granitoid bodies (Chacritas and San Ignacio-Los Pinos granitoids) derived from metamorphic (metasedimentary?) rocks, contain few euhedral Mesoproterozoic zircon crystals, which show no sign of reworking. Most of these euhedral zircons have rims of younger ages (Neoproterozoic to Permian) with Th/U ratios mostly lower than 0.001. Both, the S-type granite from Chacritas and the San Ignacio-Los Pinos granitoid from Balcozna and their protoliths, may represent the previously unidentified local source for the abundant late Mesoproterozoic detrital zircons reported in Neoproterozoic to Paleozoic sedimentary sequences of NW Argentina. This would imply Mesoproterozoic basement, alike the Arequipa Massif (in Peru and Bolivia) and the Western Sierras Pampeanas, in northwest Argentina. © 2018 Elsevier Ltd 2018 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02643707_v_n_p_Zimmermann http://hdl.handle.net/20.500.12110/paper_02643707_v_n_p_Zimmermann
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Cambrian
Granites
Northwest Argentina
SHRIMP II
Sierra Ambato
Volcanic arc
spellingShingle Cambrian
Granites
Northwest Argentina
SHRIMP II
Sierra Ambato
Volcanic arc
Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes
topic_facet Cambrian
Granites
Northwest Argentina
SHRIMP II
Sierra Ambato
Volcanic arc
description Petrographic and geochemical studies combined with U-Pb SHRIMP II analyses of zircons from three granitoid rocks in northwest Argentina reveal new data to enhance the understanding of the margin of western Gondwana. The I-type granite at Pomán (‘Granito Pomán’), with a typical continental arc geochemical signature, has been intruded into schists and gneisses of the regional basement during the Lower Cambrian (535 ± 5 Ma; MSDW = 0.024). This supports the existence of a volcanic arc of Lower Cambrian age evolving possibly contemporary to some successions of the Puncoviscana Complex. Two deformed and metamorphosed, granitoid bodies (Chacritas and San Ignacio-Los Pinos granitoids) derived from metamorphic (metasedimentary?) rocks, contain few euhedral Mesoproterozoic zircon crystals, which show no sign of reworking. Most of these euhedral zircons have rims of younger ages (Neoproterozoic to Permian) with Th/U ratios mostly lower than 0.001. Both, the S-type granite from Chacritas and the San Ignacio-Los Pinos granitoid from Balcozna and their protoliths, may represent the previously unidentified local source for the abundant late Mesoproterozoic detrital zircons reported in Neoproterozoic to Paleozoic sedimentary sequences of NW Argentina. This would imply Mesoproterozoic basement, alike the Arequipa Massif (in Peru and Bolivia) and the Western Sierras Pampeanas, in northwest Argentina. © 2018 Elsevier Ltd
title Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes
title_short Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes
title_full Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes
title_fullStr Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes
title_full_unstemmed Mesoproterozoic to Paleozoic U-Pb SHRIMP II ages of granitoid bodies in NW Argentina and their consequences for the interpretation of the geological evolution of the Central Andes
title_sort mesoproterozoic to paleozoic u-pb shrimp ii ages of granitoid bodies in nw argentina and their consequences for the interpretation of the geological evolution of the central andes
publishDate 2018
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02643707_v_n_p_Zimmermann
http://hdl.handle.net/20.500.12110/paper_02643707_v_n_p_Zimmermann
_version_ 1768544863374016512

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