Preserved Nd-Hf-Os isotope variability in replacive channels from the Lanzo ophiolite: Traces of incomplete melt aggregation in the shallow mantle
文献类型：期刊论文
| 作者 | Sanfilippo, A.5,6; Liu, C. Z.1; Salters, V.2; Mosconi, A.3; Zanetti, A.; Tribuzio, R.4,5,6 |
| 刊名 | CHEMICAL GEOLOGY
 |
| 出版日期 | 2023-12-20 |
| 卷号 | 641页码:12 |
| 关键词 | Re - Os isotopes Replacive mantle dunites Alpine Ophiolites Melt-rock reaction Mantle melting |
| ISSN号 | 0009-2541 |
| DOI | 10.1016/j.chemgeo.2023.121779 |
| 英文摘要 | Long-lived radiogenic isotopes of abyssal peridotites, residues of MORB extraction, show that the asthenosphere is intrinsically heterogeneous, which is inherited from ancient melting events and crustal recycling during Earth's history. Yet, Mid Ocean Ridge Basalts (MORB) have a rather uniform average composition, suggesting that the variability of their mantle source is concealed during their ascent. Here we document that mantle heterogeneity is exceptionally well preserved in high permeability mantle conduits from the Lanzo South mantle massif, Western Italian Alps. Nd-Hf-Os isotopes of decametre-scale replacive bodies provide evidence for the existence of two generations of mantle channels. The first generation consists of dunites concordant to the main foliation of host peridotites. The replacive dunites include clinopyroxene with MORB-like incompatible element signature and initial (160 Ma) sigma Nd and sigma Hf ranging from +4 to +7 and from +10 to +15, respectively. The second generation, made up of pyroxene-poor harzburgites discordant to the main foliation, is geochemically depleted in incompatible elements and its clinopyroxene displays highly radiogenic Hf isotopes (initial sigma Hf up to +202). The mantle channel heterogeneity is confirmed by Re-Os isotopes and platinum-groups elements. The MORB-type dunites have high Pt, Pd and, locally, Re, and have 187Os/188Os ratios similar to the host peridotite (0.122-0.128). On the other hand, the depleted bodies have lower Pt, Pd and Re, and 187Os/188Os ratios ranging from those of host peridotites (0.124) to highly unradiogenic values (0.118) in the most refractory sample. The preserved heterogeneity in trace elements, PGE, and Nd-Hf-Os isotopes highlights infiltration of melts from a highly heterogeneous mantle, still partially preserved within these mantle bodies. If applied to present-day Mid Ocean Ridges, our model indicates that the isotopic variability of melts migrating through replacive mantle conduits is by far larger than magmas erupted on the seafloor, which implies that diverse mantle components are mainly delivered and homogenised above the crust-mantle boundary. |
| WOS关键词 | HIGHLY SIDEROPHILE ELEMENT ; OCEANIC LITHOSPHERE CONSTRAINTS ; PLATINUM-GROUP ELEMENTS ; ABYSSAL PERIDOTITES ; RIDGE BASALT ; HETEROGENEOUS MANTLE ; MIGRATION PROCESSES ; UPWELLING MANTLE ; DEPLETED MANTLE ; WESTERN ALPS |
| 资助项目 | National Science Foun-dation[2015C5LN35] ; National Science Foun-dation[.2017KX5ZX8] ; State of Florida[DMR-1157490] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:001096802900001 |
| 出版者 | ELSEVIER |
| 资助机构 | National Science Foun-dation ; National Science Foun-dation ; State of Florida ; State of Florida ; National Science Foun-dation ; National Science Foun-dation ; State of Florida ; State of Florida ; National Science Foun-dation ; National Science Foun-dation ; State of Florida ; State of Florida ; National Science Foun-dation ; National Science Foun-dation ; State of Florida ; State of Florida |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/110659]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 通讯作者 | Sanfilippo, A. |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing, Peoples R China 2.Florida State Univ, Dept Earth Ocean & Atmospher Sci & Natl High Magne, Tallahassee, FL USA 3.Univ Milan, Dept Earth Sci A Desio, Via Botticelli 23, I-21133 Milan, Italy 4.Ist Nazl Oceanog & Geofis Sperimentale, Borgo Grotta Gigante 42-C, I-34010 Trieste, Italy 5.Univ Pavia, Dipartimento Sci Terra & Ambiente, via Ferrata 1, Pavia, Italy 6.CNR, Ist Geosci & Georisorse, Via Ferrata 1, Pavia, Italy |
| 推荐引用方式 GB/T 7714 | Sanfilippo, A.,Liu, C. Z.,Salters, V.,et al. Preserved Nd-Hf-Os isotope variability in replacive channels from the Lanzo ophiolite: Traces of incomplete melt aggregation in the shallow mantle[J]. CHEMICAL GEOLOGY,2023,641:12. |
| APA | Sanfilippo, A.,Liu, C. Z.,Salters, V.,Mosconi, A.,Zanetti, A.,&Tribuzio, R..(2023).Preserved Nd-Hf-Os isotope variability in replacive channels from the Lanzo ophiolite: Traces of incomplete melt aggregation in the shallow mantle.CHEMICAL GEOLOGY,641,12. |
| MLA | Sanfilippo, A.,et al."Preserved Nd-Hf-Os isotope variability in replacive channels from the Lanzo ophiolite: Traces of incomplete melt aggregation in the shallow mantle".CHEMICAL GEOLOGY 641(2023):12. |
入库方式： OAI收割
来源：地质与地球物理研究所
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