The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia
Previous work has shown that Devonian magmatism in the southern Andes occurred in two contemporaneous belts: one emplaced in the continental crust of the North Patagonian Massif and the other in an oceanic island arc terrane to the west, Chaitenia, which was later accreted to Patagonia. The country...
Published in: | Andean Geology |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Servicio Nacional de Geologia y Mineria
|
Subjects: | |
Online Access: | http://hdl.handle.net/1885/201847 https://doi.org/10.5027/andgeoV45n3-3117 https://openresearch-repository.anu.edu.au/bitstream/1885/201847/5/01_Herv%25C3%25A9_The_country_rocks_of_Devonian_2018.pdf.jpg |
id |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/201847 |
---|---|
record_format |
openpolar |
spelling |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/201847 2024-01-14T10:02:27+01:00 The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia Hervé, Francisco Calderón, Mauricio Fanning, Christopher Mark Pankhurst, Robert J Rapela, Carlos W Quezada, Paulo 17 pages application/pdf http://hdl.handle.net/1885/201847 https://doi.org/10.5027/andgeoV45n3-3117 https://openresearch-repository.anu.edu.au/bitstream/1885/201847/5/01_Herv%25C3%25A9_The_country_rocks_of_Devonian_2018.pdf.jpg en_AU eng Servicio Nacional de Geologia y Mineria 0718-7092 http://hdl.handle.net/1885/201847 doi:10.5027/andgeoV45n3-3117 https://openresearch-repository.anu.edu.au/bitstream/1885/201847/5/01_Herv%25C3%25A9_The_country_rocks_of_Devonian_2018.pdf.jpg © Servicio Nacional de Geología y Minería (SERNAGEOMIN) Andean Geology Devonian Metamorphic complexes U-Pb zircon ages North Patagonian Massif Chaitenia Journal article ftanucanberra https://doi.org/10.5027/andgeoV45n3-3117 2023-12-15T09:36:58Z Previous work has shown that Devonian magmatism in the southern Andes occurred in two contemporaneous belts: one emplaced in the continental crust of the North Patagonian Massif and the other in an oceanic island arc terrane to the west, Chaitenia, which was later accreted to Patagonia. The country rocks of the plutonic rocks consist of metasedimentary complexes which crop out sporadically in the Andes on both sides of the Argentina-Chile border, and additionally of pillow metabasalts for Chaitenia. Detrital zircon SHRIMP U-Pb age determinations in 13 samples of these rocks indicate maximum possible depositional ages from ca. 370 to 900 Ma, and the case is argued for mostly Devonian sedimentation as for the fossiliferous Buill slates. Ordovician, Cambrian-late Neoproterozoic and "Grenvilleage" provenance is seen throughout, except for the most westerly outcrops where Devonian detrital zircons predominate. Besides a difference in the Precambrian zircon grains, 76% versus 25% respectively, there is no systematic variation in provenance from the Patagonian foreland to Chaitenia, so that the island arc terrane must have been proximal to the continent: its deeper crust is not exposed but several outcrops of ultramafic rocks are known. Zircons with devonian metamorphic rims in rocks from the North Patagonian Massif have no counterpart in the low metamorphic grade Chilean rocks. These Paleozoic metasedimentary rocks were also intruded by Pennsylvanian and Jurassic granitoids. Chilean Fondecyt projects 1130227 and 1180457 financed this research. Some of the sampling and analysis in the North Patagonian Massif was carried out earlier with support from CONICET (Argentina) and British Antarctic Survey. Article in Journal/Newspaper Antarc* Antarctic British Antarctic Survey Australian National University: ANU Digital Collections Antarctic Patagonia Argentina Andean Geology 45 3 301 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
English |
topic |
Devonian Metamorphic complexes U-Pb zircon ages North Patagonian Massif Chaitenia |
spellingShingle |
Devonian Metamorphic complexes U-Pb zircon ages North Patagonian Massif Chaitenia Hervé, Francisco Calderón, Mauricio Fanning, Christopher Mark Pankhurst, Robert J Rapela, Carlos W Quezada, Paulo The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia |
topic_facet |
Devonian Metamorphic complexes U-Pb zircon ages North Patagonian Massif Chaitenia |
description |
Previous work has shown that Devonian magmatism in the southern Andes occurred in two contemporaneous belts: one emplaced in the continental crust of the North Patagonian Massif and the other in an oceanic island arc terrane to the west, Chaitenia, which was later accreted to Patagonia. The country rocks of the plutonic rocks consist of metasedimentary complexes which crop out sporadically in the Andes on both sides of the Argentina-Chile border, and additionally of pillow metabasalts for Chaitenia. Detrital zircon SHRIMP U-Pb age determinations in 13 samples of these rocks indicate maximum possible depositional ages from ca. 370 to 900 Ma, and the case is argued for mostly Devonian sedimentation as for the fossiliferous Buill slates. Ordovician, Cambrian-late Neoproterozoic and "Grenvilleage" provenance is seen throughout, except for the most westerly outcrops where Devonian detrital zircons predominate. Besides a difference in the Precambrian zircon grains, 76% versus 25% respectively, there is no systematic variation in provenance from the Patagonian foreland to Chaitenia, so that the island arc terrane must have been proximal to the continent: its deeper crust is not exposed but several outcrops of ultramafic rocks are known. Zircons with devonian metamorphic rims in rocks from the North Patagonian Massif have no counterpart in the low metamorphic grade Chilean rocks. These Paleozoic metasedimentary rocks were also intruded by Pennsylvanian and Jurassic granitoids. Chilean Fondecyt projects 1130227 and 1180457 financed this research. Some of the sampling and analysis in the North Patagonian Massif was carried out earlier with support from CONICET (Argentina) and British Antarctic Survey. |
format |
Article in Journal/Newspaper |
author |
Hervé, Francisco Calderón, Mauricio Fanning, Christopher Mark Pankhurst, Robert J Rapela, Carlos W Quezada, Paulo |
author_facet |
Hervé, Francisco Calderón, Mauricio Fanning, Christopher Mark Pankhurst, Robert J Rapela, Carlos W Quezada, Paulo |
author_sort |
Hervé, Francisco |
title |
The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia |
title_short |
The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia |
title_full |
The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia |
title_fullStr |
The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia |
title_full_unstemmed |
The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia |
title_sort |
country rocks of devonian magmatism in the north patagonian massif and chaitenia |
publisher |
Servicio Nacional de Geologia y Mineria |
url |
http://hdl.handle.net/1885/201847 https://doi.org/10.5027/andgeoV45n3-3117 https://openresearch-repository.anu.edu.au/bitstream/1885/201847/5/01_Herv%25C3%25A9_The_country_rocks_of_Devonian_2018.pdf.jpg |
geographic |
Antarctic Patagonia Argentina |
geographic_facet |
Antarctic Patagonia Argentina |
genre |
Antarc* Antarctic British Antarctic Survey |
genre_facet |
Antarc* Antarctic British Antarctic Survey |
op_source |
Andean Geology |
op_relation |
0718-7092 http://hdl.handle.net/1885/201847 doi:10.5027/andgeoV45n3-3117 https://openresearch-repository.anu.edu.au/bitstream/1885/201847/5/01_Herv%25C3%25A9_The_country_rocks_of_Devonian_2018.pdf.jpg |
op_rights |
© Servicio Nacional de Geología y Minería (SERNAGEOMIN) |
op_doi |
https://doi.org/10.5027/andgeoV45n3-3117 |
container_title |
Andean Geology |
container_volume |
45 |
container_issue |
3 |
container_start_page |
301 |
_version_ |
1788057473473576960 |