Thallium isotope systematics in volcanic rocks from St. Helena - Constraints on the origin of the HIMU reservoir
文献类型：期刊论文
| 作者 | Blusztajn, Jerzy1,2; Nielsen, Sune G.1,2; Marschall, Horst R.2,3; Shu, Yunchao1,4,5; Ostrander, Chadlin M.6; Hanyu, Takeshi7 |
| 刊名 | CHEMICAL GEOLOGY
 |
| 出版日期 | 2018-01-05 |
| 卷号 | 476页码:292-301 |
| 关键词 | Thallium isotopes St. Helena HIMU Oceanic crust |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2017.11.025 |
| 通讯作者 | Blusztajn, Jerzy(jblusztajn@whoi.edu) |
| 英文摘要 | It is generally accepted that subduction of the oceanic crust plays an important role in creation of mantle heterogeneity. HIMU (stands for high mu = ((238) U/Pb-204)) is a rare and probably not volumetrically large mantle component, which is sampled at St. Helena in the Atlantic and in the Cook-Austral Islands in the South Pacific. Previous studies that used radiogenic isotopes have specifically invoked subducted hydrothermally altered oceanic crust (AOC) as a significant component in the source of HIMU. However, because radiogenic isotopes are affected by both parent-daughter fractionation and time that cannot be independently determined, it is difficult to unambiguously use these tracers to determine the source material of the HIMU reservoir. Thallium isotopes can be used to identify the involvement of sediments rich in Mn oxides or AOC, because these two components exhibit high Tl concentrations and highly fractionated Tl isotope compositons, whereas the upper mantle is depleted in Tl and homogenous with respect to Tl isotopes. Here we report Tl isotope data for a suite of St. Helena lavas previously characterized to investigate if the HIMU mantle reservoir can be linked to AOC. Samples show large Tl isotopic variation, from epsilon Tl-205= -9.8 to epsilon Tl-205 = + 3.9 and do not correlate with Sr, Nd, Hf or Pb isotopes. Eight samples have epsilon Tl-205 lighter than the mantle value (epsilon T-205= - 2), with the lightest values similar to those observed for modern AOC. These features are consistent with the presence of different proportions of recycled oceanic crust in the source of St. Helena mantle source. Our results, therefore, support previous studies that inferred AOC as a significant component in the HIMU mantle reservoir and show that the Tl isotopic system can be used as a powerful tracer to detect contributions of AOC in the creation of mantle heterogeneities. |
| 资助项目 | NSF[EAR-1119373] ; NSF[1427310] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000418472000023 |
| 出版者 | ELSEVIER SCIENCE BV |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/157771]  |
| 专题 | 海洋研究所_海洋地质与环境重点实验室 |
| 通讯作者 | Blusztajn, Jerzy |
| 作者单位 | 1.Woods Hole Oceanog Inst, NIRVANA Labs, Woods Hole, MA 02543 USA 2.Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA 3.Goethe Univ Frankfurt, Inst Geowissensch, Altenhoferalle 1, D-60438 Frankfurt, Germany 4.Chinese Acad Sci, Inst Oceanol, Seafloor Hydrothermal Act Lab, Key Lab Marine Geol & Environm, Qingdao 266071, Shandong, Peoples R China 5.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 6.Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA 7.Japan Agcy Marine Earth Sci & Technol, Dept Solid Earth Geochem, Yokosuka, Kanagawa 2370061, Japan |
| 推荐引用方式 GB/T 7714 | Blusztajn, Jerzy,Nielsen, Sune G.,Marschall, Horst R.,et al. Thallium isotope systematics in volcanic rocks from St. Helena - Constraints on the origin of the HIMU reservoir[J]. CHEMICAL GEOLOGY,2018,476:292-301. |
| APA | Blusztajn, Jerzy,Nielsen, Sune G.,Marschall, Horst R.,Shu, Yunchao,Ostrander, Chadlin M.,&Hanyu, Takeshi.(2018).Thallium isotope systematics in volcanic rocks from St. Helena - Constraints on the origin of the HIMU reservoir.CHEMICAL GEOLOGY,476,292-301. |
| MLA | Blusztajn, Jerzy,et al."Thallium isotope systematics in volcanic rocks from St. Helena - Constraints on the origin of the HIMU reservoir".CHEMICAL GEOLOGY 476(2018):292-301. |
入库方式： OAI收割
来源：海洋研究所
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