Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin
A revised pre-Jurassic chronology is presented for the Antarctic Peninsula on the basis of new U-Pb zircon dating, using both conventional (11 samples) and SHRIMP microprobe data (10 samples). The age range for plutonism and high-grade metamorphism is from 435 ±8 Ma (Silurian) to c. 206 Ma (approxim...
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/94240 2024-01-14T09:59:33+01:00 Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin Millar, Ian L Pankhurst, Robert J Fanning, Christopher http://hdl.handle.net/1885/94240 https://doi.org/10.1144/0016-764901-020 https://openresearch-repository.anu.edu.au/bitstream/1885/94240/5/MigratedxPub23776_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94240/7/01_Millar_Basement_chronology_of_the_2002.pdf.jpg unknown Geological Society of London 0016-7649 http://hdl.handle.net/1885/94240 doi:10.1144/0016-764901-020 https://openresearch-repository.anu.edu.au/bitstream/1885/94240/5/MigratedxPub23776_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94240/7/01_Millar_Basement_chronology_of_the_2002.pdf.jpg Journal of the Geological Society Keywords: anatexis basement rock chronology magmatism tectonic evolution Triassic uranium series dating Antarctica Antarctic Peninsula Basement Traissic U-Pb Journal article ftanucanberra https://doi.org/10.1144/0016-764901-020 2023-12-15T09:37:58Z A revised pre-Jurassic chronology is presented for the Antarctic Peninsula on the basis of new U-Pb zircon dating, using both conventional (11 samples) and SHRIMP microprobe data (10 samples). The age range for plutonism and high-grade metamorphism is from 435 ±8 Ma (Silurian) to c. 206 Ma (approximately the Triassic-Jurassic boundary), with peaks of activity in Devonian, Carboniferous, Permian and mid-Triassic times, although some are represented by rocks with limited outcrops. The new data confirm the importance of Mid- and latest Triassic magmatic events, previously identified using Rb-Sr geochronology. The Adie Inlet gneiss, previously thought to be Neoproterozoic, is recognized as a Permian migmatite derived from paragneiss with a provenance dominated by Cambrian granitoids. Granite gneiss from NW Palmer Land, previously dated as Cambrian, is shown to be Triassic. Detrital zircons in metasedimentary rocks, and inherited zircons in granitoids, are dominated by Mesoproterozoic to Cambrian components, with sparse Palaeoproterozoic to Archaean grains, suggesting sources within Gondwana. At times these sources were nearby, as shown by an Archaean cobble-sized granite clast from a Permo-Triassic conglomerate; another clast in the same conglomerate, previously thought to be Devonian in age, has an Ordovician crystallization age. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Palmer Land Australian National University: ANU Digital Collections Antarctic The Antarctic Antarctic Peninsula Palmer Land ENVELOPE(-65.000,-65.000,-71.500,-71.500) Adie ENVELOPE(-62.333,-62.333,-66.417,-66.417) Adie Inlet ENVELOPE(-62.315,-62.315,-66.338,-66.338) Journal of the Geological Society 159 2 145 157 |
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Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: anatexis basement rock chronology magmatism tectonic evolution Triassic uranium series dating Antarctica Antarctic Peninsula Basement Traissic U-Pb |
spellingShingle |
Keywords: anatexis basement rock chronology magmatism tectonic evolution Triassic uranium series dating Antarctica Antarctic Peninsula Basement Traissic U-Pb Millar, Ian L Pankhurst, Robert J Fanning, Christopher Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin |
topic_facet |
Keywords: anatexis basement rock chronology magmatism tectonic evolution Triassic uranium series dating Antarctica Antarctic Peninsula Basement Traissic U-Pb |
description |
A revised pre-Jurassic chronology is presented for the Antarctic Peninsula on the basis of new U-Pb zircon dating, using both conventional (11 samples) and SHRIMP microprobe data (10 samples). The age range for plutonism and high-grade metamorphism is from 435 ±8 Ma (Silurian) to c. 206 Ma (approximately the Triassic-Jurassic boundary), with peaks of activity in Devonian, Carboniferous, Permian and mid-Triassic times, although some are represented by rocks with limited outcrops. The new data confirm the importance of Mid- and latest Triassic magmatic events, previously identified using Rb-Sr geochronology. The Adie Inlet gneiss, previously thought to be Neoproterozoic, is recognized as a Permian migmatite derived from paragneiss with a provenance dominated by Cambrian granitoids. Granite gneiss from NW Palmer Land, previously dated as Cambrian, is shown to be Triassic. Detrital zircons in metasedimentary rocks, and inherited zircons in granitoids, are dominated by Mesoproterozoic to Cambrian components, with sparse Palaeoproterozoic to Archaean grains, suggesting sources within Gondwana. At times these sources were nearby, as shown by an Archaean cobble-sized granite clast from a Permo-Triassic conglomerate; another clast in the same conglomerate, previously thought to be Devonian in age, has an Ordovician crystallization age. |
format |
Article in Journal/Newspaper |
author |
Millar, Ian L Pankhurst, Robert J Fanning, Christopher |
author_facet |
Millar, Ian L Pankhurst, Robert J Fanning, Christopher |
author_sort |
Millar, Ian L |
title |
Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin |
title_short |
Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin |
title_full |
Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin |
title_fullStr |
Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin |
title_full_unstemmed |
Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin |
title_sort |
basement chronology of the antarctic peninsula: recurrent magmatism and anatexis in the palaeozoic gondwana margin |
publisher |
Geological Society of London |
url |
http://hdl.handle.net/1885/94240 https://doi.org/10.1144/0016-764901-020 https://openresearch-repository.anu.edu.au/bitstream/1885/94240/5/MigratedxPub23776_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94240/7/01_Millar_Basement_chronology_of_the_2002.pdf.jpg |
long_lat |
ENVELOPE(-65.000,-65.000,-71.500,-71.500) ENVELOPE(-62.333,-62.333,-66.417,-66.417) ENVELOPE(-62.315,-62.315,-66.338,-66.338) |
geographic |
Antarctic The Antarctic Antarctic Peninsula Palmer Land Adie Adie Inlet |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Palmer Land Adie Adie Inlet |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Palmer Land |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Palmer Land |
op_source |
Journal of the Geological Society |
op_relation |
0016-7649 http://hdl.handle.net/1885/94240 doi:10.1144/0016-764901-020 https://openresearch-repository.anu.edu.au/bitstream/1885/94240/5/MigratedxPub23776_RSD_2002.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/94240/7/01_Millar_Basement_chronology_of_the_2002.pdf.jpg |
op_doi |
https://doi.org/10.1144/0016-764901-020 |
container_title |
Journal of the Geological Society |
container_volume |
159 |
container_issue |
2 |
container_start_page |
145 |
op_container_end_page |
157 |
_version_ |
1788059657801039872 |