实验测定Re在硅酸盐熔体中的溶解度  

Experimental determination of the solubility of rhenium in silicate melts

作　　者：孙晶晶 李元[1,3] 张明东[4] 刘志伟 SUN Jingjing;LI Yuan;ZHANG Mingdong;LIU Zhiwei(State Key Laboratory of Deep Earth Processes and Resources,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China;University of Chinese Academy of Sciences,Beijing 100049,China;CAS Center for Excellence in Deep Earth Science,Guangzhou 510640,Guangdong,China;School of Earth Sciences,Yunnan University,Kunming 650500,Yunnan,China)

机构地区：[1]中国科学院广州地球化学研究所,深地过程与战略矿产资源全国重点实验室,广东广州510640 [2]中国科学院大学,北京100049 [3]中国科学院深地科学卓越创新中心,广东广州510640 [4]云南大学地球科学学院,云南昆明650500

出　　处：《地球化学》2025年第2期308-316,共9页Geochimica

基　　金：国家自然科学基金项目(41673028)资助。

摘　　要：通过使用活塞圆筒装置进行高温高压实验,探究还原条件下Re在含S硅酸盐熔体中的溶解度。并使用激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)测量实验产物玻璃中的Re溶解度,利用激光信号谱图排除“nuggets”(金属中细小的粒状包裹体)对Re溶解度的干扰。结果表明,温度为1400℃,压力为1.5 GPa时,当硅酸盐熔体中S含量从172μg/g增加至1332μg/g时,Re溶解度为3.2~5.4 ng/g。因此,在高度还原条件下,硅酸盐熔体中的S含量对Re溶解度基本没有影响。本研究还利用溶解度数据估算Re在金属和硅酸盐熔体之间的分配系数(D_(Re)^(met/sil))约为7×10^(8),证实了Re具有非常强的亲铁性。与现今上地幔的Re丰度相比,利用D_(Re)^(met/sil)计算的地球早期核幔平衡后,地幔岩中Re的理论含量亏损程度达7个数量级,富Re球粒陨石物质的加入能更合理地解释现今地幔中相对高的Re丰度,这一解释便是“后增薄层(late veneer)”模型最简单的描述。To further understand the geochemical properties of Re,we investigated the effect of S on Re solubility in silicate melts.We experimentally investigated the solubility of Re in S-bearing silicate melts under reduced conditions at 1400℃ and 1.5 GPa using a piston cylinder.All experiments in this study were conducted under metal-saturated conditions.Laser Ablation Inductively Coupled Plasma Mass Spectrometry(LA-ICP-MS)was employed to measure the solubility of Re in silicate glasses.The interference of“nuggets”(i.e.,fine granular inclusion in metal)on the solubility of Re was excluded by the laser signal spectrogram.The results show that the solubility of Re ranges from 3.2 to 5.4 ng/g when the concentration of S in silicate melts ranges from 172μg/g to 1332μg/g.Therefore,S in silicate melts has little effect on Re solubility under reduced conditions.Based on our solubility data,we estimated the partition coefficient of Re between the metal and the silicate melt(D_(Re)^(met/sil))and the calculated D_(Re)^(met/sil) is about 7×10^(8),which is consistent with previous studies.This suggests that Re has a strong affinity to iron.We also calculated the Re content in the mantle after the core-mantle equilibrium in the early Earth,and the calculated Re was 7 orders of magnitude depleted compared with the Re abundance in the present upper mantle.To reasonably explain the excess Re abundance in the present mantle,it is necessary to add Re-rich chondritic materials after the core-mantle differentiation.This is the simplest description of the“late veneer”model.

关 键 词：S含量 Re溶解度 金属硅酸盐分配系数 核幔分异 

分 类 号：P599[天文地球—地球化学]