Zinc isotope evidence for sulfate-rich fluid transfer across subduction zones.
Zinc isotope evidence for sulfate-rich fluid transfer across subduction zones.
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DOI：
10.1038/ncomms13794
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发表时间：
2016-12-16
影响因子：
16.6
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中科院分区：
文献类型：
--
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俯冲带调节着地球地幔的化学演化。板块中的水和挥发性元素作为流体释放到地幔楔中，这一过程被广泛认为是导致次弧地幔氧化的原因。然而，这些流体的化学成分和形态，这是至关重要的经济重要的元素的流动性，仍然没有受到很好的约束。硫具有作为氧化剂和运输介质的潜力。在这里，我们使用锌稳定同位素（δ 66 Zn）在俯冲阿尔卑斯蛇纹岩破译板片流体的化学性质。结果表明，δ 66 Zn随变质程度的增加而逐渐降低，这与硫含量的降低有关。由于现有的理论工作预测Zn-SO 42 −络合物优先结合重δ 66 Zn，我们的结果为氧化的、富含硫酸盐的板状蛇纹岩衍生流体释放到地幔楔提供了强有力的证据。 在俯冲过程中，流体被释放到地幔楔中，但这些流体的确切成分尚不清楚。脑桥等人通过分析蛇纹岩中的锌同位素提供了证据，证明在俯冲过程中，氧化的富含硫酸盐的流体被释放到地幔楔中。
Subduction zones modulate the chemical evolution of the Earth's mantle. Water and volatile elements in the slab are released as fluids into the mantle wedge and this process is widely considered to result in the oxidation of the sub-arc mantle. However, the chemical composition and speciation of these fluids, which is critical for the mobility of economically important elements, remain poorly constrained. Sulfur has the potential to act both as oxidizing agent and transport medium. Here we use zinc stable isotopes (δ66Zn) in subducted Alpine serpentinites to decipher the chemical properties of slab-derived fluids. We show that the progressive decrease in δ66Zn with metamorphic grade is correlated with a decrease in sulfur content. As existing theoretical work predicts that Zn-SO42− complexes preferentially incorporate heavy δ66Zn, our results provide strong evidence for the release of oxidized, sulfate-rich, slab serpentinite-derived fluids to the mantle wedge. During subduction, fluids are released into the mantle wedge, but the exact compositions of these fluids are unclear. Pons et al. by analysing zinc isotopes from serpentinite provide evidence that oxidized, sulphate rich fluids are released to the mantle wedge during subduction.
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影响因子：
5
作者：
Delacour, Adelie;Frueh-Green, Gretchen L.;Bernasconi, Stefano M.
通讯作者：
Bernasconi, Stefano M.
影响因子：
18.3
作者：
Ague, Jay J.;Nicolescu, Stefan
通讯作者：
Nicolescu, Stefan
影响因子：
5
作者：
Alt, JC;Shanks, WC
通讯作者：
Shanks, WC
影响因子：
3.9
作者：
Debret, Baptiste;Andreani, Muriel;Lafay, Romain
通讯作者：
Lafay, Romain
影响因子：
3.4
作者：
Debret, B.;Nicollet, C.;Godard, M.
通讯作者：
Godard, M.