Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton
The geodynamic regime that governed the crustal evolution of Earth during the early Archean remains intensely debated. The North China Craton (NCC) preserves a geological history spanning 3.8–2.5 Ga, particularly in the Anshan area, making it an ideal natural laboratory for probing the formation and...
| Main Authors: | , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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Elsevier
2024
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| _version_ | 1826312815721316352 |
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| author | Xuan, Y Liu, J Liu, Z Palin, RM Xu, Z Li, G Dong, X Li, P Zhang, H |
| author_facet | Xuan, Y Liu, J Liu, Z Palin, RM Xu, Z Li, G Dong, X Li, P Zhang, H |
| author_sort | Xuan, Y |
| collection | OXFORD |
| description | The geodynamic regime that governed the crustal evolution of Earth during the early Archean remains intensely debated. The North China Craton (NCC) preserves a geological history spanning 3.8–2.5 Ga, particularly in the Anshan area, making it an ideal natural laboratory for probing the formation and evolution of the NCC and its associated geodynamic regime. Here, we document new geochronology, geochemistry, and zircon Hf-O isotope data from newly discovered Paleoarchean <i>meta</i>-mafic rocks in the Anshan area. Based on their whole-rock geochemistry, these unit can be divided into tholeiitic and komatiitic series. Of which, the komatiitic rocks are characteristic by high MgO contents (up to 20.6 wt%). Zircon U-Pb dating shows that all <i>meta</i>-mafic rocks formed contemporaneously, with crystallization ages of <i>ca</i>. 3.3 Ga. Most of the studied <i>meta</i>-mafic rocks display radiogenic zircon Hf isotopes, with T<sub>DM</sub><sup>1</sup> ages ranging from 3592 to 3346 Ma and ε<sub>Hf</sub>(<i>t</i>) values from −1.94 to + 3.49. They also exhibit mantle-like zircon δ<sup>18</sup>O values (+4.92 ‰ to + 5.98 ‰). These zircon Hf-O isotope data indicate that the protoliths of the <i>ca</i>. 3.3 Ga <i>meta</i>-mafic rocks originated from the partial melting of a depleted mantle without significant crustal contamination. Furthermore, the parental magmas of the komatiitic rocks and some of tholeiitic rocks were generated from 20 % and 5–10 % partial melting of spinel-lherzolite, respectively, whereas other tholeiitic rocks were the result of a low degree (1–5 %) of partial melting of spinel-garnet lherzolite. The <i>ca</i>. 3.3 Ga tholeiitic-komatiitic rocks were most likely formed in an intraplate rifting setting, associated with a mantle plume. |
| first_indexed | 2024-04-23T08:27:20Z |
| format | Journal article |
| id | oxford-uuid:f0cb63f7-cdb4-4e16-b972-07c8b36dee90 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-04-23T08:27:20Z |
| publishDate | 2024 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:f0cb63f7-cdb4-4e16-b972-07c8b36dee902024-04-22T13:02:25ZPetrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China CratonJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f0cb63f7-cdb4-4e16-b972-07c8b36dee90EnglishSymplectic ElementsElsevier2024Xuan, YLiu, JLiu, ZPalin, RMXu, ZLi, GDong, XLi, PZhang, HThe geodynamic regime that governed the crustal evolution of Earth during the early Archean remains intensely debated. The North China Craton (NCC) preserves a geological history spanning 3.8–2.5 Ga, particularly in the Anshan area, making it an ideal natural laboratory for probing the formation and evolution of the NCC and its associated geodynamic regime. Here, we document new geochronology, geochemistry, and zircon Hf-O isotope data from newly discovered Paleoarchean <i>meta</i>-mafic rocks in the Anshan area. Based on their whole-rock geochemistry, these unit can be divided into tholeiitic and komatiitic series. Of which, the komatiitic rocks are characteristic by high MgO contents (up to 20.6 wt%). Zircon U-Pb dating shows that all <i>meta</i>-mafic rocks formed contemporaneously, with crystallization ages of <i>ca</i>. 3.3 Ga. Most of the studied <i>meta</i>-mafic rocks display radiogenic zircon Hf isotopes, with T<sub>DM</sub><sup>1</sup> ages ranging from 3592 to 3346 Ma and ε<sub>Hf</sub>(<i>t</i>) values from −1.94 to + 3.49. They also exhibit mantle-like zircon δ<sup>18</sup>O values (+4.92 ‰ to + 5.98 ‰). These zircon Hf-O isotope data indicate that the protoliths of the <i>ca</i>. 3.3 Ga <i>meta</i>-mafic rocks originated from the partial melting of a depleted mantle without significant crustal contamination. Furthermore, the parental magmas of the komatiitic rocks and some of tholeiitic rocks were generated from 20 % and 5–10 % partial melting of spinel-lherzolite, respectively, whereas other tholeiitic rocks were the result of a low degree (1–5 %) of partial melting of spinel-garnet lherzolite. The <i>ca</i>. 3.3 Ga tholeiitic-komatiitic rocks were most likely formed in an intraplate rifting setting, associated with a mantle plume. |
| spellingShingle | Xuan, Y Liu, J Liu, Z Palin, RM Xu, Z Li, G Dong, X Li, P Zhang, H Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton |
| title | Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton |
| title_full | Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton |
| title_fullStr | Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton |
| title_full_unstemmed | Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton |
| title_short | Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton |
| title_sort | petrogenesis of newly identified mantle plume related ca 3 3 ga tholeiitic komatiitic rocks in the anshan area north china craton |
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