Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean
Schirmacher Oasis, central Dronning Maud Land, East Antarctica, a dispersed fragment of the 660-610 Ma East African Orogen (EAO), exposes platformal-facies high-grade metasedimentary rocks. Here we constrain the depositional age of these sedimentary rocks to test models relating to timing of the clo...
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ftnipr:oai:nipr.repo.nii.ac.jp:00015459 2023-05-15T13:49:00+02:00 Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean 2018-12 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=15459 http://id.nii.ac.jp/1291/00015364/ en eng https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=15459 http://id.nii.ac.jp/1291/00015364/ Polar Science, 18, 39-47(2018-12) 18739652 https://doi.org/10.1016/j.polar.2018.07.004 Schirmacher Oasis Metasedimentary rocks Depositional ages Mozambique Ocean East African Orogen Correlation Journal Article 2018 ftnipr https://doi.org/10.1016/j.polar.2018.07.004 2022-12-03T19:43:10Z Schirmacher Oasis, central Dronning Maud Land, East Antarctica, a dispersed fragment of the 660-610 Ma East African Orogen (EAO), exposes platformal-facies high-grade metasedimentary rocks. Here we constrain the depositional age of these sedimentary rocks to test models relating to timing of the closure of the Mozambique Ocean, the southern segment of the EAO, since Tonian time. Zircon, a proxy for detritus, was dated by LA-MC-ICPMS (206Pb/238U ages) that includes both magmatic and (older) metamorphic populations, in addition to those formed during the granulite-facies metamorphic events (660-600 Ma and 580-555 Ma) having an age range between 1240 and 500 Ma. In conjunction with field evidence, their depositional time is constrained to the Neoproterozoic (Tonian to early Cryogenian, i.e. 1000 >Tdep >800 Ma and 930 >Tdep>800 Ma) with their provenance likely dominated by metamorphic (orogenic) over magmatic rocks.These metacarbonate and psammitic rocks are correlated with similar rocks from the Montepuetz Complex, Northeastern Mozambique, metacarbonate rocks from the Sør Rondane Mountains and with the Linta Group, Vohibory Domain, Southeastern Madagascar. The coeval deposition of platformal sedimentary protoliths, interpreted as occurrence of multiple Mozambique Oceanic strands, were incorporated into the continental arc crust during collision between the Congo and Azania cratonic blocks forming the EAO. Article in Journal/Newspaper Antarc* Antarctica Dronning Maud Land East Antarctica Polar Science Polar Science National Institute of Polar Research Repository, Japan East Antarctica Dronning Maud Land Sør-Rondane ENVELOPE(25.000,25.000,-72.000,-72.000) Sør Rondane Mountains ENVELOPE(25.000,25.000,-72.000,-72.000) Polar Science 18 39 47 |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
Schirmacher Oasis Metasedimentary rocks Depositional ages Mozambique Ocean East African Orogen Correlation |
spellingShingle |
Schirmacher Oasis Metasedimentary rocks Depositional ages Mozambique Ocean East African Orogen Correlation Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean |
topic_facet |
Schirmacher Oasis Metasedimentary rocks Depositional ages Mozambique Ocean East African Orogen Correlation |
description |
Schirmacher Oasis, central Dronning Maud Land, East Antarctica, a dispersed fragment of the 660-610 Ma East African Orogen (EAO), exposes platformal-facies high-grade metasedimentary rocks. Here we constrain the depositional age of these sedimentary rocks to test models relating to timing of the closure of the Mozambique Ocean, the southern segment of the EAO, since Tonian time. Zircon, a proxy for detritus, was dated by LA-MC-ICPMS (206Pb/238U ages) that includes both magmatic and (older) metamorphic populations, in addition to those formed during the granulite-facies metamorphic events (660-600 Ma and 580-555 Ma) having an age range between 1240 and 500 Ma. In conjunction with field evidence, their depositional time is constrained to the Neoproterozoic (Tonian to early Cryogenian, i.e. 1000 >Tdep >800 Ma and 930 >Tdep>800 Ma) with their provenance likely dominated by metamorphic (orogenic) over magmatic rocks.These metacarbonate and psammitic rocks are correlated with similar rocks from the Montepuetz Complex, Northeastern Mozambique, metacarbonate rocks from the Sør Rondane Mountains and with the Linta Group, Vohibory Domain, Southeastern Madagascar. The coeval deposition of platformal sedimentary protoliths, interpreted as occurrence of multiple Mozambique Oceanic strands, were incorporated into the continental arc crust during collision between the Congo and Azania cratonic blocks forming the EAO. |
format |
Article in Journal/Newspaper |
title |
Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean |
title_short |
Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean |
title_full |
Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean |
title_fullStr |
Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean |
title_full_unstemmed |
Zircon U-Pb age constraints for Tonian-early Cryogenian deposition of metasedimentary rocks from the Schirmacher Oasis, East Antarctica: Implications for correlations across the Mozambique Ocean |
title_sort |
zircon u-pb age constraints for tonian-early cryogenian deposition of metasedimentary rocks from the schirmacher oasis, east antarctica: implications for correlations across the mozambique ocean |
publishDate |
2018 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=15459 http://id.nii.ac.jp/1291/00015364/ |
long_lat |
ENVELOPE(25.000,25.000,-72.000,-72.000) ENVELOPE(25.000,25.000,-72.000,-72.000) |
geographic |
East Antarctica Dronning Maud Land Sør-Rondane Sør Rondane Mountains |
geographic_facet |
East Antarctica Dronning Maud Land Sør-Rondane Sør Rondane Mountains |
genre |
Antarc* Antarctica Dronning Maud Land East Antarctica Polar Science Polar Science |
genre_facet |
Antarc* Antarctica Dronning Maud Land East Antarctica Polar Science Polar Science |
op_source |
https://doi.org/10.1016/j.polar.2018.07.004 |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=15459 http://id.nii.ac.jp/1291/00015364/ Polar Science, 18, 39-47(2018-12) 18739652 |
op_doi |
https://doi.org/10.1016/j.polar.2018.07.004 |
container_title |
Polar Science |
container_volume |
18 |
container_start_page |
39 |
op_container_end_page |
47 |
_version_ |
1766250382309195776 |