Mercury in some arc crustal rocks and mantle peridotites and relevance to the moderately volatile element budget of the Earth
Mercury in some arc crustal rocks and mantle peridotites and relevance to the moderately volatile element budget of the Earth
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DOI：
10.1016/j.chemgeo.2014.12.029
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发表时间：
2015-03-09
期刊：
影响因子：
3.9
通讯作者：
Telmer, Kevin
中科院分区：
文献类型：
--
作者：
Canil, Dante;Crockford, Peter W.;Telmer, Kevin
我们测量了汞浓度的37个火成岩弧地壳部分和30个地幔橄榄岩蛇绿岩，造山带和捕虏体设置。汞在火成岩中的分布不均匀，并显示出“块金效应”，表明它集中在痕量相中，可能是硫化物。地壳样品中Hg的丰度为0.9 ~ 8 ppb，与S和Cu相关，但与其他指示分异的元素无关。我们数据的平均值为2.9 +/- 2.6汞，比以前的估计低10倍。地幔橄榄岩含有0.2-5 ppb的汞和汞与铝，铜，硫或烧失量（LOI）的相关性取决于样品类型。由于低温蚀变或地幔交代作用，蛇绿岩和造山带样品中汞的二次吸收是明显的。原始上地幔（PUM）含有0.4-0.6 ppb的汞的基础上，在新鲜捕虏体样品的贫化/富集趋势，证明保留原生Cu/S在侵位。在地幔熔融产生地壳的过程中，汞表现为一种温和的不相容元素（D-Hg残留物/熔体类似于0.1），与铜没有什么不同。对于310 ppb Hg的汞丰度，我们对地幔中Hg的估计要求该元素在块状硅酸盐地球中具有与Se、Te或S类似的贫化。(C)2015爱思唯尔B. V.保留所有权利。
We measured Hg concentrations in 37 igneous rocks from an arc crustal section and in 30 mantle peridotites from ophiolite, orogenic massif and xenolith settings. Mercury is heterogeneously distributed in the igneous rocks and shows a 'nugget effect', suggesting it is concentrated in a trace phase, likely sulfide. The abundance of Hg in the crustal samples varies from 0.9 to 8 ppb and correlates with S and Cu but no other element indicative of differentiation. The average of our data produces 2.9 +/- 2.6 Hg for the bulk crust, a factor of 10 lower than previous estimates. The mantle peridotites contained 0.2-5 ppb Hg and a correlation of Hg with Al, Cu, S or loss on ignition (LOI) depending on sample type. Secondary uptake of Hg due to low-temperature alteration or mantle metasomatism is evident in the ophiolite and orogenic massif samples, respectively. The primitive upper mantle (PUM) contains 0.4-0.6 ppb Hg based on the depletion/enrichment trends in the fresh xenolith samples that demonstrably retained primary Cu/S during emplacement. During mantle melting to produce the crust, Hg behaves as a mildly incompatible element (D-Hg residue/melt similar to 0.1), not unlike Cu. For a chondritic abundance of 310 ppb Hg, our estimate for Hg in the mantle requires this element has a similar depletion to Se, Te or S in the bulk silicate Earth. (C) 2015 Elsevier B.V. All rights reserved.