Donghwan Kim , Hyunwoo Lee , Mi Jung Lee , Changkun Park , Andrea Luca Rizzo
{"title":"东北亚新生代板内岩浆活动的上地幔尺度富集：朝鲜半岛周围玄武岩的 He-Sr-Nd-Pb-O 同位素地球化学研究","authors":"Donghwan Kim , Hyunwoo Lee , Mi Jung Lee , Changkun Park , Andrea Luca Rizzo","doi":"10.1016/j.gr.2024.09.016","DOIUrl":null,"url":null,"abstract":"<div><div>The Earth’s mantle is considered to be geochemically heterogeneous, which is reflected by the diverse compositions of oceanic island basalts (OIB). The mantle enrichment resulting in this is primarily attributed to the influx of recycled crustal materials into the mantle through subduction. Additionally, the sub-continental lithospheric mantle (SCLM) complicates the elucidation of mantle heterogeneity. From this perspective, Northeast Asia, where the Pacific stagnant slab in the mantle transition zone and the SCLM distribution are presented, is the suitable site for examining the upper mantle scale enrichment. Here we report He-Sr-Nd-Pb-O isotope compositions of Cenozoic basalts found around the Korean Peninsula to illustrate the source lithology and components that caused mantle heterogeneity. Our measured helium isotope ratios ranging from 5.7 to 7.3 R<sub>a</sub> (<sup>3</sup>He/<sup>4</sup>He ratio of air, R<sub>a</sub> = 1.39 x 10<sup>-6</sup>) are mostly within the SCLM range (6.1 ± 0.9 R<sub>a</sub>) but lower than the mid-ocean ridge basalt range (MORB; 8 ± 1 R<sub>a</sub>). The Sr-Nd-Pb isotope compositions of the basalts generally display a mixture of depleted MORB mantle (DMM), enriched mantle 1 (EM1), and enriched mantle 2 (EM2) components. In addition, the basalts have δ<sup>18</sup>O<sub>olivine</sub> (vs. V-SMOW) values ranging from 4.7 to 5.7 ‰ that deviate from the DMM range (δ<sup>18</sup>O<sub>olivine</sub> = 5.1 ± 0.2 ‰). Our isotopic analysis results highlight the role of a pyroxenite source in the metasomatized SCLM in the genesis of basalts, and the low <sup>3</sup>He/<sup>4</sup>He ratios of the basalts indicates a significant contribution of SCLM. Moreover, the delaminated cratonic SCLM and asthenosphere-lithosphere interaction are scenarios for the low <sup>3</sup>He/<sup>4</sup>He ratios. Therefore, we propose that mixing of DMM (high <sup>3</sup>He/<sup>4</sup>He ratio; 7 to 9 R<sub>a</sub>) and the metasomatized SCLM (low <sup>3</sup>He/<sup>4</sup>He ratio; 5 to 7 R<sub>a</sub>) allowed enrichment within the upper mantle scale for the Cenozoic intraplate magmatism in Northeast Asia.</div></div>","PeriodicalId":12761,"journal":{"name":"Gondwana Research","volume":"137 ","pages":"Pages 349-364"},"PeriodicalIF":7.2000,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Upper mantle scale enrichment of Cenozoic intraplate magmatism in Northeast Asia: He-Sr-Nd-Pb-O isotope geochemistry of the basalts around the Korean peninsula\",\"authors\":\"Donghwan Kim , Hyunwoo Lee , Mi Jung Lee , Changkun Park , Andrea Luca Rizzo\",\"doi\":\"10.1016/j.gr.2024.09.016\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The Earth’s mantle is considered to be geochemically heterogeneous, which is reflected by the diverse compositions of oceanic island basalts (OIB). The mantle enrichment resulting in this is primarily attributed to the influx of recycled crustal materials into the mantle through subduction. Additionally, the sub-continental lithospheric mantle (SCLM) complicates the elucidation of mantle heterogeneity. From this perspective, Northeast Asia, where the Pacific stagnant slab in the mantle transition zone and the SCLM distribution are presented, is the suitable site for examining the upper mantle scale enrichment. Here we report He-Sr-Nd-Pb-O isotope compositions of Cenozoic basalts found around the Korean Peninsula to illustrate the source lithology and components that caused mantle heterogeneity. Our measured helium isotope ratios ranging from 5.7 to 7.3 R<sub>a</sub> (<sup>3</sup>He/<sup>4</sup>He ratio of air, R<sub>a</sub> = 1.39 x 10<sup>-6</sup>) are mostly within the SCLM range (6.1 ± 0.9 R<sub>a</sub>) but lower than the mid-ocean ridge basalt range (MORB; 8 ± 1 R<sub>a</sub>). The Sr-Nd-Pb isotope compositions of the basalts generally display a mixture of depleted MORB mantle (DMM), enriched mantle 1 (EM1), and enriched mantle 2 (EM2) components. In addition, the basalts have δ<sup>18</sup>O<sub>olivine</sub> (vs. V-SMOW) values ranging from 4.7 to 5.7 ‰ that deviate from the DMM range (δ<sup>18</sup>O<sub>olivine</sub> = 5.1 ± 0.2 ‰). Our isotopic analysis results highlight the role of a pyroxenite source in the metasomatized SCLM in the genesis of basalts, and the low <sup>3</sup>He/<sup>4</sup>He ratios of the basalts indicates a significant contribution of SCLM. Moreover, the delaminated cratonic SCLM and asthenosphere-lithosphere interaction are scenarios for the low <sup>3</sup>He/<sup>4</sup>He ratios. Therefore, we propose that mixing of DMM (high <sup>3</sup>He/<sup>4</sup>He ratio; 7 to 9 R<sub>a</sub>) and the metasomatized SCLM (low <sup>3</sup>He/<sup>4</sup>He ratio; 5 to 7 R<sub>a</sub>) allowed enrichment within the upper mantle scale for the Cenozoic intraplate magmatism in Northeast Asia.</div></div>\",\"PeriodicalId\":12761,\"journal\":{\"name\":\"Gondwana Research\",\"volume\":\"137 \",\"pages\":\"Pages 349-364\"},\"PeriodicalIF\":7.2000,\"publicationDate\":\"2024-10-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Gondwana Research\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1342937X24002879\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Gondwana Research","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1342937X24002879","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Upper mantle scale enrichment of Cenozoic intraplate magmatism in Northeast Asia: He-Sr-Nd-Pb-O isotope geochemistry of the basalts around the Korean peninsula
The Earth’s mantle is considered to be geochemically heterogeneous, which is reflected by the diverse compositions of oceanic island basalts (OIB). The mantle enrichment resulting in this is primarily attributed to the influx of recycled crustal materials into the mantle through subduction. Additionally, the sub-continental lithospheric mantle (SCLM) complicates the elucidation of mantle heterogeneity. From this perspective, Northeast Asia, where the Pacific stagnant slab in the mantle transition zone and the SCLM distribution are presented, is the suitable site for examining the upper mantle scale enrichment. Here we report He-Sr-Nd-Pb-O isotope compositions of Cenozoic basalts found around the Korean Peninsula to illustrate the source lithology and components that caused mantle heterogeneity. Our measured helium isotope ratios ranging from 5.7 to 7.3 Ra (3He/4He ratio of air, Ra = 1.39 x 10-6) are mostly within the SCLM range (6.1 ± 0.9 Ra) but lower than the mid-ocean ridge basalt range (MORB; 8 ± 1 Ra). The Sr-Nd-Pb isotope compositions of the basalts generally display a mixture of depleted MORB mantle (DMM), enriched mantle 1 (EM1), and enriched mantle 2 (EM2) components. In addition, the basalts have δ18Oolivine (vs. V-SMOW) values ranging from 4.7 to 5.7 ‰ that deviate from the DMM range (δ18Oolivine = 5.1 ± 0.2 ‰). Our isotopic analysis results highlight the role of a pyroxenite source in the metasomatized SCLM in the genesis of basalts, and the low 3He/4He ratios of the basalts indicates a significant contribution of SCLM. Moreover, the delaminated cratonic SCLM and asthenosphere-lithosphere interaction are scenarios for the low 3He/4He ratios. Therefore, we propose that mixing of DMM (high 3He/4He ratio; 7 to 9 Ra) and the metasomatized SCLM (low 3He/4He ratio; 5 to 7 Ra) allowed enrichment within the upper mantle scale for the Cenozoic intraplate magmatism in Northeast Asia.
期刊介绍：
Gondwana Research (GR) is an International Journal aimed to promote high quality research publications on all topics related to solid Earth, particularly with reference to the origin and evolution of continents, continental assemblies and their resources. GR is an "all earth science" journal with no restrictions on geological time, terrane or theme and covers a wide spectrum of topics in geosciences such as geology, geomorphology, palaeontology, structure, petrology, geochemistry, stable isotopes, geochronology, economic geology, exploration geology, engineering geology, geophysics, and environmental geology among other themes, and provides an appropriate forum to integrate studies from different disciplines and different terrains. In addition to regular articles and thematic issues, the journal invites high profile state-of-the-art reviews on thrust area topics for its column, ''GR FOCUS''. Focus articles include short biographies and photographs of the authors. Short articles (within ten printed pages) for rapid publication reporting important discoveries or innovative models of global interest will be considered under the category ''GR LETTERS''.
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