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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Geological Society of London
2015
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/94240 2023-05-15T13:35:18+02:00 Basement chronology of the Antarctic Peninsula: recurrent magmatism and anatexis in the Palaeozoic Gondwana Margin Millar, Ian L Pankhurst, Robert J Fanning, Christopher 2015-12-13T23:39:55Z http://hdl.handle.net/1885/94240 unknown Geological Society of London 0016-7649 http://hdl.handle.net/1885/94240 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 2015 ftanucanberra 2015-12-28T23:39:56Z 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 Adie ENVELOPE(-62.333,-62.333,-66.417,-66.417) Adie Inlet ENVELOPE(-62.315,-62.315,-66.338,-66.338) Antarctic Antarctic Peninsula Palmer Land ENVELOPE(-65.000,-65.000,-71.500,-71.500) The Antarctic |
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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 |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/94240 |
long_lat |
ENVELOPE(-62.333,-62.333,-66.417,-66.417) ENVELOPE(-62.315,-62.315,-66.338,-66.338) ENVELOPE(-65.000,-65.000,-71.500,-71.500) |
geographic |
Adie Adie Inlet Antarctic Antarctic Peninsula Palmer Land The Antarctic |
geographic_facet |
Adie Adie Inlet Antarctic Antarctic Peninsula Palmer Land The Antarctic |
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 |
_version_ |
1766064015188951040 |