Hydrogen partition coefficients between nominally anhydrous minerals and basaltic melts
Hydrogen partition coefficients between nominally anhydrous minerals and basaltic melts
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DOI：
10.1029/2004gl021341
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发表时间：
2004-10-30
影响因子：
5.2
通讯作者：
Hirschmann, MM
中科院分区：
文献类型：
--
作者：
Aubaud, C;Hauri, EH;Hirschmann, MM
在上地幔P-T条件（1 - 2gpa和1230 - 1380℃）下进行的13次水合熔融实验中，我们测量了名义上无水矿物（橄榄石、辉石）和玄武岩熔体之间的氢分配系数。所得液体有3.1 - 6.4 wt.% H2O，矿物/熔体平均分配系数如下：D-H(ol/melt) = 0.0017 +/- 0.0005 (n = 9), D-H(opx/melt) = 0.019 +/- 0.004 (n = 8), D-H(cpx/melt) = 0.023 +/- 0.005 （n = 2）。矿物/矿物分配系数D-H(ol/opx) = 0.11 +/- 0.01 (n = 4), D-H(ol/cpx) = 0.08 +/- 0.01 (n = 2), D-H(cpx/opx) = 1.4 +/- 0.3 （n = 1）。这些测量结果证实，在地幔熔融过程中，水的行为与Ce相似（D-H（橄榄岩/熔体）接近0.009）。对于地幔水浓度为50 - 200ppm的情况，融化的开始比干固体深5 - 20km，比以前的估计要小。
We have measured hydrogen partition coefficients between nominally anhydrous minerals ( olivine, pyroxenes) and basaltic melts in 13 hydrous melting experiments performed at upper mantle P-T conditions ( 1 - 2 GPa and 1230 - 1380 degreesC). Resulting liquids have 3.1 - 6.4 wt.% H2O and average mineral/melt partition coefficients as follows: D-H(ol/melt) = 0.0017 +/- 0.0005 ( n = 9), D-H(opx/melt) = 0.019 +/- 0.004 ( n = 8), and D-H(cpx/melt) = 0.023 +/- 0.005 (n = 2). Mineral/mineral partition coefficients are D-H(ol/opx) = 0.11 +/- 0.01 ( n = 4), D-H(ol/cpx) = 0.08 +/- 0.01 ( n = 2) and D-H(cpx/opx) = 1.4 +/- 0.3 ( n = 1). These measurements confirm that water behaves similarly to Ce during mantle melting (D-H(peridotite/melt) is similar to 0.009). For mantle water concentrations of 50 - 200 ppm, the onset of melting is 5 - 20 km deeper than the dry solidus, less than previous estimates.