Experimentally determined partitioning of high field strength- and selected transition elements between spinel and basaltic melt
Experimentally determined partitioning of high field strength- and selected transition elements between spinel and basaltic melt
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DOI：
10.1016/0009-2541(94)90128-7
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发表时间：
1994-11
期刊：
影响因子：
3.9
通讯作者：
I. Horn;S. Foley;S. Jackson;G. Jenner
中科院分区：
文献类型：
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作者：
I. Horn;S. Foley;S. Jackson;G. Jenner
用激光烧蚀电感耦合等离子体质谱和/或电子探针，在1大气压下用碱性橄榄岩玄武岩测定了Ta、Nb、Hf、Zr、Sc、V、Ga、Zn和Co等元素在尖晶石和熔体之间的分配系数。高场强元素(HFSE)的DspLq是均匀的(DspLqNb=0.08，DspLqTa=0.06，DspLqHf=0.05，DspLqZr=0.06)，排除了在部分熔化或分离结晶过程中高场强元素内部分馏的可能性。DspLq V的结果延续了DspLq V随fO2的增加而减小的近似线性趋势，从先前研究的IW时的DspLq V=68到fO2=AIR时的DspLq V=0.09。D sp Lq Sc也依赖于f O2(0.24-0.56随f O2增加)，而D sp Lq Ga在3.2是恒定的。富铬尖晶石和富磁铁矿尖晶石之间的贫钛固溶体系列在Co、Zn和Sc从空气到Fmq−1的对数O2范围内的分配行为与组成有关。锌和钴表现出偏离亨利定律的行为。DspLq的近似值为4.5，与天然橄榄岩中观察到的分配值很好地吻合，但在较低温度下要大得多。钴的分配与温度呈强烈的负相关，且受fO2效应的影响较大。
Partition coefficients for the elements Ta, Nb, Hf, Zr, Sc, V, Ga, Zn and Co have been determined by laser ablation ICP-MS and/or electron microprobe between spinel and melt using an alkali olivine basalt at 1 atm. The D sp lq for high field strength elements (HFSE) are uniform (D sp lq Nb= 0.08, D sp lq Ta= 0.06, D sp lq Hf= 0.05, D sp lq Zr= 0.06), negating the possibility of intra-HFSE fractionation during partial melting or fractional crystallization processes. Results for D sp lq V continue an approximately linear trend of decreasing D sp lq V with increasing f O2 from D sp lq V= 68 at IW from previous studies to values of D sp lq V= 0.09 at f O2= air. D sp lq Sc is also f O2 dependent (0.24–0.56 with increasing f O2), whereas D sp lq Ga is constant at 3.2. A compositional dependence of partitioning behaviour was found for the Ti-poor solid-solution series between chromite-and magnetite-rich spinels in the log f O2 range from air to FMQ− 1 for Co, Zn and Sc. Zn and Co showed deviation from Henry's law behaviour. An approximate value for D sp lq Zn of 4.5 agrees well with the observed partitioning in natural peridotites, but is much larger at lower temperatures. Cobalt partitioning shows a strong negative correlation with temperature and is complicated by f O2 effects.