Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications
The Ross Orogenic Belt is in the Antarctica Transantarctic Mountains. North Victoria Land Granite Harbour Intrusive complex (GHI) records the tectonic-magmatism evolution of Ross orogeny. Extensively developed post-collisional granites around this margin of early Paleozoic magmatism can provide insi...
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2023
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ftdoajarticles:oai:doaj.org/article:9ab92fbbaee54301ba48e2263b8fabf1 2023-05-15T13:59:55+02:00 Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications Peng Gao Limei Tang Ling Chen 2023-01-01T00:00:00Z https://doi.org/10.3389/feart.2022.966085 https://doaj.org/article/9ab92fbbaee54301ba48e2263b8fabf1 EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/feart.2022.966085/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2022.966085 https://doaj.org/article/9ab92fbbaee54301ba48e2263b8fabf1 Frontiers in Earth Science, Vol 10 (2023) U-Pb geochronology geochemistry Rose orogeny syenite Inexpressible island Science Q article 2023 ftdoajarticles https://doi.org/10.3389/feart.2022.966085 2023-01-15T01:26:04Z The Ross Orogenic Belt is in the Antarctica Transantarctic Mountains. North Victoria Land Granite Harbour Intrusive complex (GHI) records the tectonic-magmatism evolution of Ross orogeny. Extensively developed post-collisional granites around this margin of early Paleozoic magmatism can provide insights into the growth of continental crust through accretionary orogenesis. We provide geochemical and geochronological data from syenites from Terra Nova Bay, north Victoria Land in order to constrain its tectonic evolution and setting. The syenite belongs to the potassium-alkaline, calc-alkaline series and is characterized by high concentrations of rare Earth elements and large ion lithophile elements (LILE), and low content in high field strength elements (Nb, Ta, P, Ti). The petrographic and geochemical signatures show a possible island-arc granite affinity. LA-ICP-MS zircon U-Pb dating results suggest that the Inexpressible Island syenite was emplaced at ca. 471.8 ± 1.8 Ma and 477.3 ± 1.7 Ma, respectively. Zircon εHf(t) values range from −7.4 to −9.1; average −8.2 and whole-rock εNd (t) values range from −8.5 to −10.3, indicating that formed by the partial melting of the lithospheric mantle enriched with subduction slab fluids and subcontinental lithosphere. Whereas, the syenite has a strong positive Eu anomaly and a positive Sr anomaly, suggesting that plagioclase cumulate crystallization occurred in the magma source area. Furthermore, through integration with previous studies, we suggest that syenite is a result of the melting zone of an older previously subduction enriched layer of the subcontinental lithospheric mantle (SCLM). To enable syenite emplacement we suggest a tectonic-magmatic model that invokes alternating phases of extension and contraction in the overriding plate. Finally, we report the youngest age of (post-orogenic) magmatism occurred during extension in the overriding plate ca. 478–471 Ma. Article in Journal/Newspaper Antarc* Antarctica Inexpressible Island Victoria Land Directory of Open Access Journals: DOAJ Articles Granite Harbour ENVELOPE(162.733,162.733,-76.883,-76.883) Inexpressible Island ENVELOPE(163.650,163.650,-74.900,-74.900) Terra Nova Bay Transantarctic Mountains Victoria Land Frontiers in Earth Science 10 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
U-Pb geochronology geochemistry Rose orogeny syenite Inexpressible island Science Q |
spellingShingle |
U-Pb geochronology geochemistry Rose orogeny syenite Inexpressible island Science Q Peng Gao Limei Tang Ling Chen Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications |
topic_facet |
U-Pb geochronology geochemistry Rose orogeny syenite Inexpressible island Science Q |
description |
The Ross Orogenic Belt is in the Antarctica Transantarctic Mountains. North Victoria Land Granite Harbour Intrusive complex (GHI) records the tectonic-magmatism evolution of Ross orogeny. Extensively developed post-collisional granites around this margin of early Paleozoic magmatism can provide insights into the growth of continental crust through accretionary orogenesis. We provide geochemical and geochronological data from syenites from Terra Nova Bay, north Victoria Land in order to constrain its tectonic evolution and setting. The syenite belongs to the potassium-alkaline, calc-alkaline series and is characterized by high concentrations of rare Earth elements and large ion lithophile elements (LILE), and low content in high field strength elements (Nb, Ta, P, Ti). The petrographic and geochemical signatures show a possible island-arc granite affinity. LA-ICP-MS zircon U-Pb dating results suggest that the Inexpressible Island syenite was emplaced at ca. 471.8 ± 1.8 Ma and 477.3 ± 1.7 Ma, respectively. Zircon εHf(t) values range from −7.4 to −9.1; average −8.2 and whole-rock εNd (t) values range from −8.5 to −10.3, indicating that formed by the partial melting of the lithospheric mantle enriched with subduction slab fluids and subcontinental lithosphere. Whereas, the syenite has a strong positive Eu anomaly and a positive Sr anomaly, suggesting that plagioclase cumulate crystallization occurred in the magma source area. Furthermore, through integration with previous studies, we suggest that syenite is a result of the melting zone of an older previously subduction enriched layer of the subcontinental lithospheric mantle (SCLM). To enable syenite emplacement we suggest a tectonic-magmatic model that invokes alternating phases of extension and contraction in the overriding plate. Finally, we report the youngest age of (post-orogenic) magmatism occurred during extension in the overriding plate ca. 478–471 Ma. |
format |
Article in Journal/Newspaper |
author |
Peng Gao Limei Tang Ling Chen |
author_facet |
Peng Gao Limei Tang Ling Chen |
author_sort |
Peng Gao |
title |
Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications |
title_short |
Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications |
title_full |
Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications |
title_fullStr |
Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications |
title_full_unstemmed |
Geochemistry and zircon U–Pb ages of early Ordovician syenites from the Inexpressible Island, Antarctica and tectonic implications |
title_sort |
geochemistry and zircon u–pb ages of early ordovician syenites from the inexpressible island, antarctica and tectonic implications |
publisher |
Frontiers Media S.A. |
publishDate |
2023 |
url |
https://doi.org/10.3389/feart.2022.966085 https://doaj.org/article/9ab92fbbaee54301ba48e2263b8fabf1 |
long_lat |
ENVELOPE(162.733,162.733,-76.883,-76.883) ENVELOPE(163.650,163.650,-74.900,-74.900) |
geographic |
Granite Harbour Inexpressible Island Terra Nova Bay Transantarctic Mountains Victoria Land |
geographic_facet |
Granite Harbour Inexpressible Island Terra Nova Bay Transantarctic Mountains Victoria Land |
genre |
Antarc* Antarctica Inexpressible Island Victoria Land |
genre_facet |
Antarc* Antarctica Inexpressible Island Victoria Land |
op_source |
Frontiers in Earth Science, Vol 10 (2023) |
op_relation |
https://www.frontiersin.org/articles/10.3389/feart.2022.966085/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2022.966085 https://doaj.org/article/9ab92fbbaee54301ba48e2263b8fabf1 |
op_doi |
https://doi.org/10.3389/feart.2022.966085 |
container_title |
Frontiers in Earth Science |
container_volume |
10 |
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1766268846897889280 |