Trace element partitioning between mica- and amphibole-bearing garnet lherzolite and hydrous basanitic melt: 1. Experimental results and the investigation of controls on partitioning behaviour
Trace element partitioning between mica- and amphibole-bearing garnet lherzolite and hydrous basanitic melt: 1. Experimental results and the investigation of controls on partitioning behaviour
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DOI：
10.1007/s00410-006-0085-4
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发表时间：
2006-07-01
影响因子：
3.5
通讯作者：
Green, Trevor
中科院分区：
文献类型：
--
作者：
Adam, John;Green, Trevor
35种微量元素（Li、Be、B、Sc、Cu、Zn、Ga、Ge、As、Rb、Nb、Mo、Ag、Cd、In、Sn、Sb、Cs、Ba、La、Ce、Nd、Sm、Tb、Ho、Tm、Lu、Hf、Ta、W、Tl、Pb、Bi、Th和U），（澳大利亚），分析了LAM ICP-MS。一些卤素（F，Cl和I）也进行了分析，通过电子显微探针。分析用于确定矿物/熔体分配系数的云母，角闪石，石榴石，单斜辉石，斜方辉石和橄榄石的条件接近多饱和度的碧玄岩液相线与石榴石二辉橄榄岩（约2.6 GPa和1,200摄氏度与7.5重量%的添加水）。还研究了从1.0 GPa和1，025 ℃到3.5 GPa和1，190 ℃的更宽范围的条件，其中添加了5-10重量%的H2O。的范围和全面性的数据允许他们被用于两个目的，其中包括以下内容：调查的一些控制分配系数的影响;和汇编的一套分配系数，直接相关的弓山碧玄岩浆的形成部分熔融地幔橄榄岩。考虑到单斜辉石，矿物相，其中获得的数据最多，系统的压力和温度之间的相关性，矿物成分，阳离子半径和价态，和Δ G（库仑）（库仑势能取代不匹配的价态的阳离子到晶体学网站）。δ G（库仑）对于不同的晶体学位置是明显不同的，包括单斜辉石中的M2和M1位置。这些差异可以建模为单个M1和M2中心群体内最佳效价变化（表示为1 σ标准差）的函数。
Thirty five minor and trace elements (Li, Be, B, Sc, Cu, Zn, Ga, Ge, As, Rb, Nb, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ce, Nd, Sm, Tb, Ho, Tm, Lu, Hf, Ta, W, Tl, Pb, Bi, Th and U) in experimentally produced near-liquidus phases, from a primitive nelpheline basanite from Bow Hill in Tasmania (Australia), were analysed by LAM ICP-MS. A number of halogens (F, Cl and I) were also analysed by electron microprobe. The analyses were used to determine mineral/melt partition coefficients for mica, amphibole, garnet, clinopyroxene, orthopyroxene and olivine for conditions close to multiple saturation of the basanite liquidus with garnet lherzolite (approximately 2.6 GPa and 1,200 degrees C with 7.5 wt% of added H2O). A broader range of conditions was also investigated from 1.0 GPa and 1,025 degrees C to 3.5 GPa and 1,190 degrees C with 5-10 wt% of added H2O. The scope and comprehensiveness of the data allow them to be used for two purposes, these include the following: an investigation of some of the controlling influences on partition coefficients; and the compilation of a set partition coefficients that are directly relevant to the formation of the Bow Hill basanite magma by partial melting of mantle peridotite. Considering clinopyroxene, the mineral phase for which the most data were obtained, systematic correlations were found between pressure and temperature, mineral composition, cation radius and valence, and Delta G(coulb) (the coulombic potential energy produced by substituting a cation of mismatched valence into a crystallographic site). Delta G(coulb) is distinctly different for different crystallographic sites, including the M2 and M1 sites in clinopyroxene. These differences can be modelled as a function of variations in optimum valence (expressed as 1 sigma standard deviations) within individual M1 and M2 site populations.