Chronological study of the pre-Permian basement rocks of southern Patagonia
Small outcrops of the basement of the Deseado Massif, consisting of weathered, altered granitoids and their metasedimentary host rocks, were dated by the U-Pb zircon method using thermal ionization mass spectrometry and ion microprobe (SHRIMP). The provenance ages of detrital zircon in the metasedim...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/86044 2023-05-15T13:35:18+02:00 Chronological study of the pre-Permian basement rocks of southern Patagonia Pankhurst, Robert J Rapela, Carlos W Loske, W Marquez, M Fanning, Christopher 2015-12-13T23:07:03Z http://hdl.handle.net/1885/86044 unknown Pergamon-Elsevier Ltd 0895-9811 http://hdl.handle.net/1885/86044 Journal of South American Earth Sciences Keywords: basement rock Gondwana ion microprobe mass spectrometry paleogeography tectonic reconstruction uranium-lead dating zircon South America Argentina Granites Southwest Gondwana U-Pb SHRIMP Journal article 2015 ftanucanberra 2015-12-28T23:38:59Z Small outcrops of the basement of the Deseado Massif, consisting of weathered, altered granitoids and their metasedimentary host rocks, were dated by the U-Pb zircon method using thermal ionization mass spectrometry and ion microprobe (SHRIMP). The provenance ages of detrital zircon in the metasediments are typical of material available in the adjacent regions of the Gondwana margin, with prominent components at 1000-1100 and 580±6 Ma, the latter probably approximating the age of sedimentation (latest Neoproterozoic). SHRIMP data for pre-Jurassic granodiorite from a borehole in the Magallanes basin in Tierra del Fuego give a Cambrian age of 521±4 Ma, which confirms published conventional U-Pb dating from the same borehole. SHRIMP ages of 476±4 and 472±5 Ma for granitic cobbles in a Permian conglomerate (La Golondrina Formation) are evidence of nearby Ordovician (Famatinian) intrusive activity. In situ granitoids indicate late Silurian to early Carboniferous ages (422±2, 395±3, and 346±4 Ma). All these events are recognised in the evolution of adjacent South America and the Antarctic Peninsula suggesting that these parts of the Gondwana margin were contiguous throughout their Cambrian to Jurassic history. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Tierra del Fuego Australian National University: ANU Digital Collections Antarctic Antarctic Peninsula Argentina Golondrina ENVELOPE(-60.800,-60.800,-62.467,-62.467) Magallanes ENVELOPE(-62.933,-62.933,-64.883,-64.883) Patagonia The Antarctic |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: basement rock Gondwana ion microprobe mass spectrometry paleogeography tectonic reconstruction uranium-lead dating zircon South America Argentina Granites Southwest Gondwana U-Pb SHRIMP |
spellingShingle |
Keywords: basement rock Gondwana ion microprobe mass spectrometry paleogeography tectonic reconstruction uranium-lead dating zircon South America Argentina Granites Southwest Gondwana U-Pb SHRIMP Pankhurst, Robert J Rapela, Carlos W Loske, W Marquez, M Fanning, Christopher Chronological study of the pre-Permian basement rocks of southern Patagonia |
topic_facet |
Keywords: basement rock Gondwana ion microprobe mass spectrometry paleogeography tectonic reconstruction uranium-lead dating zircon South America Argentina Granites Southwest Gondwana U-Pb SHRIMP |
description |
Small outcrops of the basement of the Deseado Massif, consisting of weathered, altered granitoids and their metasedimentary host rocks, were dated by the U-Pb zircon method using thermal ionization mass spectrometry and ion microprobe (SHRIMP). The provenance ages of detrital zircon in the metasediments are typical of material available in the adjacent regions of the Gondwana margin, with prominent components at 1000-1100 and 580±6 Ma, the latter probably approximating the age of sedimentation (latest Neoproterozoic). SHRIMP data for pre-Jurassic granodiorite from a borehole in the Magallanes basin in Tierra del Fuego give a Cambrian age of 521±4 Ma, which confirms published conventional U-Pb dating from the same borehole. SHRIMP ages of 476±4 and 472±5 Ma for granitic cobbles in a Permian conglomerate (La Golondrina Formation) are evidence of nearby Ordovician (Famatinian) intrusive activity. In situ granitoids indicate late Silurian to early Carboniferous ages (422±2, 395±3, and 346±4 Ma). All these events are recognised in the evolution of adjacent South America and the Antarctic Peninsula suggesting that these parts of the Gondwana margin were contiguous throughout their Cambrian to Jurassic history. |
format |
Article in Journal/Newspaper |
author |
Pankhurst, Robert J Rapela, Carlos W Loske, W Marquez, M Fanning, Christopher |
author_facet |
Pankhurst, Robert J Rapela, Carlos W Loske, W Marquez, M Fanning, Christopher |
author_sort |
Pankhurst, Robert J |
title |
Chronological study of the pre-Permian basement rocks of southern Patagonia |
title_short |
Chronological study of the pre-Permian basement rocks of southern Patagonia |
title_full |
Chronological study of the pre-Permian basement rocks of southern Patagonia |
title_fullStr |
Chronological study of the pre-Permian basement rocks of southern Patagonia |
title_full_unstemmed |
Chronological study of the pre-Permian basement rocks of southern Patagonia |
title_sort |
chronological study of the pre-permian basement rocks of southern patagonia |
publisher |
Pergamon-Elsevier Ltd |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/86044 |
long_lat |
ENVELOPE(-60.800,-60.800,-62.467,-62.467) ENVELOPE(-62.933,-62.933,-64.883,-64.883) |
geographic |
Antarctic Antarctic Peninsula Argentina Golondrina Magallanes Patagonia The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Argentina Golondrina Magallanes Patagonia The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Tierra del Fuego |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Tierra del Fuego |
op_source |
Journal of South American Earth Sciences |
op_relation |
0895-9811 http://hdl.handle.net/1885/86044 |
_version_ |
1766063980882690048 |