Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages
High-grade gneisses from Mt. Riiser-Larsen, East Antarctica, have been dated by whole-rock-mineral Sm-Nd and SHRIMP zircon and monazite U-Pb to help define the thermal history of ultrahigh temperature (UHT) metamorphism in the Napier Complex. Both the monazite and youngest zircon yield a range of ap...
Published in: | The Journal of Geology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
University of Chicago Press
|
Subjects: | |
Online Access: | http://hdl.handle.net/1885/25884 https://doi.org/10.1086/498100 https://openresearch-repository.anu.edu.au/bitstream/1885/25884/5/Suzuki_2006_ISW_Thermal.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/25884/7/01_Suzuki_Thermal_history_of_UHT_2006.pdf.jpg |
id |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/25884 |
---|---|
record_format |
openpolar |
spelling |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/25884 2024-01-14T10:01:12+01:00 Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages Suzuki, Satoko Arima, Makato Williams, Ian Shiraishi, Kazuyuki Kagami, Hiroo http://hdl.handle.net/1885/25884 https://doi.org/10.1086/498100 https://openresearch-repository.anu.edu.au/bitstream/1885/25884/5/Suzuki_2006_ISW_Thermal.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/25884/7/01_Suzuki_Thermal_history_of_UHT_2006.pdf.jpg unknown University of Chicago Press 0022-1376 http://hdl.handle.net/1885/25884 doi:10.1086/498100 https://openresearch-repository.anu.edu.au/bitstream/1885/25884/5/Suzuki_2006_ISW_Thermal.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/25884/7/01_Suzuki_Thermal_history_of_UHT_2006.pdf.jpg Journal of Geology Keywords: gneiss ultrahigh temperature metamorphism Antarctica East Antarctica Journal article ftanucanberra https://doi.org/10.1086/498100 2023-12-15T09:38:34Z High-grade gneisses from Mt. Riiser-Larsen, East Antarctica, have been dated by whole-rock-mineral Sm-Nd and SHRIMP zircon and monazite U-Pb to help define the thermal history of ultrahigh temperature (UHT) metamorphism in the Napier Complex. Both the monazite and youngest zircon yield a range of apparent ages (∼2.51-2.47 Ga), consistent with crystallization during an extended period of metamorphism. Some zircon also preserves an isotopic record of earlier events, placing an upper limit of a few million years on the duration of peak metamorphic conditions. The similarity of the monazite and zircon U-Pb ages implies rapid initial postpeak, cooling to below the blocking temperature of these minerals (∼900°C). Consistently lower Sm-Nd whole-rock-mineral isochron ages (∼2.38 Ga) indicate that cooling slowed before the temperature reached ∼650°C. The history of the UHT metamorphism is interpreted to be (1) protracted high-temperature (≥800°C) conditions ∼2.51-2.47 Ga, (2) peak conditions (up to 1100°C) for at most a few million years, (3) rapid cooling (10°-60°C/m.yr.) immediately after peak metamorphism, and (4) very slow cooling (≤4°C/m.yr.) at midcrustal levels (∼30-km depth) to a steady state geotherm by 2.38 Ga. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Australian National University: ANU Digital Collections East Antarctica Riiser-Larsen ENVELOPE(50.667,50.667,-66.783,-66.783) Napier ENVELOPE(-58.440,-58.440,-62.167,-62.167) The Journal of Geology 114 1 65 84 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: gneiss ultrahigh temperature metamorphism Antarctica East Antarctica |
spellingShingle |
Keywords: gneiss ultrahigh temperature metamorphism Antarctica East Antarctica Suzuki, Satoko Arima, Makato Williams, Ian Shiraishi, Kazuyuki Kagami, Hiroo Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages |
topic_facet |
Keywords: gneiss ultrahigh temperature metamorphism Antarctica East Antarctica |
description |
High-grade gneisses from Mt. Riiser-Larsen, East Antarctica, have been dated by whole-rock-mineral Sm-Nd and SHRIMP zircon and monazite U-Pb to help define the thermal history of ultrahigh temperature (UHT) metamorphism in the Napier Complex. Both the monazite and youngest zircon yield a range of apparent ages (∼2.51-2.47 Ga), consistent with crystallization during an extended period of metamorphism. Some zircon also preserves an isotopic record of earlier events, placing an upper limit of a few million years on the duration of peak metamorphic conditions. The similarity of the monazite and zircon U-Pb ages implies rapid initial postpeak, cooling to below the blocking temperature of these minerals (∼900°C). Consistently lower Sm-Nd whole-rock-mineral isochron ages (∼2.38 Ga) indicate that cooling slowed before the temperature reached ∼650°C. The history of the UHT metamorphism is interpreted to be (1) protracted high-temperature (≥800°C) conditions ∼2.51-2.47 Ga, (2) peak conditions (up to 1100°C) for at most a few million years, (3) rapid cooling (10°-60°C/m.yr.) immediately after peak metamorphism, and (4) very slow cooling (≤4°C/m.yr.) at midcrustal levels (∼30-km depth) to a steady state geotherm by 2.38 Ga. |
format |
Article in Journal/Newspaper |
author |
Suzuki, Satoko Arima, Makato Williams, Ian Shiraishi, Kazuyuki Kagami, Hiroo |
author_facet |
Suzuki, Satoko Arima, Makato Williams, Ian Shiraishi, Kazuyuki Kagami, Hiroo |
author_sort |
Suzuki, Satoko |
title |
Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages |
title_short |
Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages |
title_full |
Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages |
title_fullStr |
Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages |
title_full_unstemmed |
Thermal history of UHT metamorphism in the Napier Complex, East Antarctica: insights from zircon, monazite and garnet ages |
title_sort |
thermal history of uht metamorphism in the napier complex, east antarctica: insights from zircon, monazite and garnet ages |
publisher |
University of Chicago Press |
url |
http://hdl.handle.net/1885/25884 https://doi.org/10.1086/498100 https://openresearch-repository.anu.edu.au/bitstream/1885/25884/5/Suzuki_2006_ISW_Thermal.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/25884/7/01_Suzuki_Thermal_history_of_UHT_2006.pdf.jpg |
long_lat |
ENVELOPE(50.667,50.667,-66.783,-66.783) ENVELOPE(-58.440,-58.440,-62.167,-62.167) |
geographic |
East Antarctica Riiser-Larsen Napier |
geographic_facet |
East Antarctica Riiser-Larsen Napier |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
Journal of Geology |
op_relation |
0022-1376 http://hdl.handle.net/1885/25884 doi:10.1086/498100 https://openresearch-repository.anu.edu.au/bitstream/1885/25884/5/Suzuki_2006_ISW_Thermal.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/25884/7/01_Suzuki_Thermal_history_of_UHT_2006.pdf.jpg |
op_doi |
https://doi.org/10.1086/498100 |
container_title |
The Journal of Geology |
container_volume |
114 |
container_issue |
1 |
container_start_page |
65 |
op_container_end_page |
84 |
_version_ |
1788067015636811776 |