Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula
The LeMay Group accretionary complex of Alexander Island (Antarctic Peninsula) comprises a 4 km thick succession of variably deformed turbidites associated with thrust slices of ocean floor basalts. The depositional age and provenance of the succession is uncertain with estimates ranging from Carbon...
Main Authors: | , , , , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
AMER GEOPHYSICAL UNION
2023
|
Subjects: | |
Online Access: | https://discovery.ucl.ac.uk/id/eprint/10171241/1/Tectonics%20-%202023%20-%20Riley%20-%20Evolution%20of%20an%20Accretionary%20Complex%20LeMay%20Group%20and%20Terrane%20Translation%20in%20the%20Antarctic.pdf https://discovery.ucl.ac.uk/id/eprint/10171241/ |
id |
ftucl:oai:eprints.ucl.ac.uk.OAI2:10171241 |
---|---|
record_format |
openpolar |
spelling |
ftucl:oai:eprints.ucl.ac.uk.OAI2:10171241 2023-12-24T10:07:54+01:00 Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula Riley, Teal RR Millar, Ian LL Carter, Andrew Flowerdew, Michael JJ Burton-Johnson, Alex Bastias, Joaquin Storey, Craig DD Castillo, Paula Chew, David Whitehouse, Martin JJ 2023-02-01 text https://discovery.ucl.ac.uk/id/eprint/10171241/1/Tectonics%20-%202023%20-%20Riley%20-%20Evolution%20of%20an%20Accretionary%20Complex%20LeMay%20Group%20and%20Terrane%20Translation%20in%20the%20Antarctic.pdf https://discovery.ucl.ac.uk/id/eprint/10171241/ eng eng AMER GEOPHYSICAL UNION https://discovery.ucl.ac.uk/id/eprint/10171241/1/Tectonics%20-%202023%20-%20Riley%20-%20Evolution%20of%20an%20Accretionary%20Complex%20LeMay%20Group%20and%20Terrane%20Translation%20in%20the%20Antarctic.pdf https://discovery.ucl.ac.uk/id/eprint/10171241/ open Tectonics , 42 (2) , Article e2022TC007578. (2023) Science & Technology Physical Sciences Geochemistry & Geophysics Gondwana detrital zircon U-Pb geochronology Lu-Hf isotopes U-PB AGES NATURAL REFERENCE MATERIAL CENTRAL ALEXANDER ISLAND WEST ANTARCTICA LU-HF SOUTHWESTERN GONDWANA ISOTOPE SYSTEMATICS ELLSWORTH MOUNTAINS DETRITAL ZIRCONS TRACE-ELEMENT Article 2023 ftucl 2023-11-27T13:07:36Z The LeMay Group accretionary complex of Alexander Island (Antarctic Peninsula) comprises a 4 km thick succession of variably deformed turbidites associated with thrust slices of ocean floor basalts. The depositional age and provenance of the succession is uncertain with estimates ranging from Carboniferous to Cretaceous. The accretion history is also poorly established and whether the LeMay Group developed allochthonously and accreted during an episode of Cretaceous terrane translation. We have examined the geochronology and geochemistry of 22 samples from across the entire accretionary complex to determine its depositional, provenance and accretion history. The accretionary complex has been subdivided into four separate groups based on detrital zircon U-Pb age and Lu-Hf provenance analysis. Groups 1 and 2 are interpreted to be a continuation of the extensive Permian accretionary complexes of West Gondwana and have a depositional age of c. 255 Ma, with volcaniclastic input from the extensive silicic volcanism of the Choiyoi Province. Accretion of the LeMay Group to the continental margin developed during the mid-Triassic, potentially related to the Peninsula Orogeny and an episode of flat-slab subduction of the proto-Pacific plate. Group 3 is only identified from an island to the west of Alexander Island and has a mid-Cretaceous depositional age and provenance akin to offshore sequences from Thurston Island. A para-autochthonous origin is suggested, with mid-Cretaceous accretion associated with the melange belts of central Alexander Island. Group 4 is also a distinct unit with an Early Jurassic depositional age and a source more closely related to the Antarctic Peninsula. Article in Journal/Newspaper Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Thurston Island West Antarctica University College London: UCL Discovery Antarctic The Antarctic Antarctic Peninsula West Antarctica Pacific Alexander Island ENVELOPE(-69.895,-69.895,-71.287,-71.287) Ellsworth Mountains ENVELOPE(-85.000,-85.000,-78.750,-78.750) Thurston ENVELOPE(-97.500,-97.500,-71.833,-71.833) Thurston Island ENVELOPE(-99.000,-99.000,-72.167,-72.167) |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
English |
topic |
Science & Technology Physical Sciences Geochemistry & Geophysics Gondwana detrital zircon U-Pb geochronology Lu-Hf isotopes U-PB AGES NATURAL REFERENCE MATERIAL CENTRAL ALEXANDER ISLAND WEST ANTARCTICA LU-HF SOUTHWESTERN GONDWANA ISOTOPE SYSTEMATICS ELLSWORTH MOUNTAINS DETRITAL ZIRCONS TRACE-ELEMENT |
spellingShingle |
Science & Technology Physical Sciences Geochemistry & Geophysics Gondwana detrital zircon U-Pb geochronology Lu-Hf isotopes U-PB AGES NATURAL REFERENCE MATERIAL CENTRAL ALEXANDER ISLAND WEST ANTARCTICA LU-HF SOUTHWESTERN GONDWANA ISOTOPE SYSTEMATICS ELLSWORTH MOUNTAINS DETRITAL ZIRCONS TRACE-ELEMENT Riley, Teal RR Millar, Ian LL Carter, Andrew Flowerdew, Michael JJ Burton-Johnson, Alex Bastias, Joaquin Storey, Craig DD Castillo, Paula Chew, David Whitehouse, Martin JJ Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula |
topic_facet |
Science & Technology Physical Sciences Geochemistry & Geophysics Gondwana detrital zircon U-Pb geochronology Lu-Hf isotopes U-PB AGES NATURAL REFERENCE MATERIAL CENTRAL ALEXANDER ISLAND WEST ANTARCTICA LU-HF SOUTHWESTERN GONDWANA ISOTOPE SYSTEMATICS ELLSWORTH MOUNTAINS DETRITAL ZIRCONS TRACE-ELEMENT |
description |
The LeMay Group accretionary complex of Alexander Island (Antarctic Peninsula) comprises a 4 km thick succession of variably deformed turbidites associated with thrust slices of ocean floor basalts. The depositional age and provenance of the succession is uncertain with estimates ranging from Carboniferous to Cretaceous. The accretion history is also poorly established and whether the LeMay Group developed allochthonously and accreted during an episode of Cretaceous terrane translation. We have examined the geochronology and geochemistry of 22 samples from across the entire accretionary complex to determine its depositional, provenance and accretion history. The accretionary complex has been subdivided into four separate groups based on detrital zircon U-Pb age and Lu-Hf provenance analysis. Groups 1 and 2 are interpreted to be a continuation of the extensive Permian accretionary complexes of West Gondwana and have a depositional age of c. 255 Ma, with volcaniclastic input from the extensive silicic volcanism of the Choiyoi Province. Accretion of the LeMay Group to the continental margin developed during the mid-Triassic, potentially related to the Peninsula Orogeny and an episode of flat-slab subduction of the proto-Pacific plate. Group 3 is only identified from an island to the west of Alexander Island and has a mid-Cretaceous depositional age and provenance akin to offshore sequences from Thurston Island. A para-autochthonous origin is suggested, with mid-Cretaceous accretion associated with the melange belts of central Alexander Island. Group 4 is also a distinct unit with an Early Jurassic depositional age and a source more closely related to the Antarctic Peninsula. |
format |
Article in Journal/Newspaper |
author |
Riley, Teal RR Millar, Ian LL Carter, Andrew Flowerdew, Michael JJ Burton-Johnson, Alex Bastias, Joaquin Storey, Craig DD Castillo, Paula Chew, David Whitehouse, Martin JJ |
author_facet |
Riley, Teal RR Millar, Ian LL Carter, Andrew Flowerdew, Michael JJ Burton-Johnson, Alex Bastias, Joaquin Storey, Craig DD Castillo, Paula Chew, David Whitehouse, Martin JJ |
author_sort |
Riley, Teal RR |
title |
Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula |
title_short |
Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula |
title_full |
Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula |
title_fullStr |
Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula |
title_full_unstemmed |
Evolution of an Accretionary Complex (LeMay Group) and Terrane Translation in the Antarctic Peninsula |
title_sort |
evolution of an accretionary complex (lemay group) and terrane translation in the antarctic peninsula |
publisher |
AMER GEOPHYSICAL UNION |
publishDate |
2023 |
url |
https://discovery.ucl.ac.uk/id/eprint/10171241/1/Tectonics%20-%202023%20-%20Riley%20-%20Evolution%20of%20an%20Accretionary%20Complex%20LeMay%20Group%20and%20Terrane%20Translation%20in%20the%20Antarctic.pdf https://discovery.ucl.ac.uk/id/eprint/10171241/ |
long_lat |
ENVELOPE(-69.895,-69.895,-71.287,-71.287) ENVELOPE(-85.000,-85.000,-78.750,-78.750) ENVELOPE(-97.500,-97.500,-71.833,-71.833) ENVELOPE(-99.000,-99.000,-72.167,-72.167) |
geographic |
Antarctic The Antarctic Antarctic Peninsula West Antarctica Pacific Alexander Island Ellsworth Mountains Thurston Thurston Island |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula West Antarctica Pacific Alexander Island Ellsworth Mountains Thurston Thurston Island |
genre |
Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Thurston Island West Antarctica |
genre_facet |
Alexander Island Antarc* Antarctic Antarctic Peninsula Antarctica Thurston Island West Antarctica |
op_source |
Tectonics , 42 (2) , Article e2022TC007578. (2023) |
op_relation |
https://discovery.ucl.ac.uk/id/eprint/10171241/1/Tectonics%20-%202023%20-%20Riley%20-%20Evolution%20of%20an%20Accretionary%20Complex%20LeMay%20Group%20and%20Terrane%20Translation%20in%20the%20Antarctic.pdf https://discovery.ucl.ac.uk/id/eprint/10171241/ |
op_rights |
open |
_version_ |
1786165078204088320 |