地幔硫化物的物理化学性质及其地质意义  

Physical and chemical properties of mantle sulfide and its geological implications

作　　者：张舟 ZHANG Zhou(School of Earth Sciences,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学地球科学学院,杭州310027

出　　处：《岩石学报》2023年第1期83-92,共10页Acta Petrologica Sinica

基　　金：中央高校基本科研业务费专项资金(226-2022-00176)资助.

摘　　要：地幔硫化物是地球亲硫、亲铁元素的重要载体,与硅酸盐矿物有很大的物理性质上差别,它在高温高压条件下的物理化学性质是认识地幔物质组成及其不均一性的重要内容。此外,早期地球、火星、水星和月球幔部来源的硫化物对认识行星演化具有重要意义。地幔硫化物的存在条件、赋存方式以及元素分配系数受到硫化物和硅酸盐体系的化学平衡控制;硫化物在流体介质和固体介质中的迁移可以分别用斯托克斯方程和表面张力模型进行解释。基于目前的天然样品和实验研究结果,本文提出了地幔硫化物物理化学性质研究中尚存在的问题,并作展望:高温高压实验制约分配系数适用的元素含量远高于天然样品,导致亨利定律并不一定适用,要求开展元素含量更低的实验并进行测试;现有的线性或自然对数的经验方程不能准确描述硫化物-硅酸盐体系,机器学习可能揭示其错综复杂的热力学关系;硫化物熔体在深部地幔硅酸盐矿物表面的分布尚不清楚,对极端条件下的静水压力实验提出了需求。Mantle sulfides are important carriers of siderophile and chalcophile elements,with distinct differences from silicates in terms of physical properties.Its physicochemical properties under high-temperature and high-pressure conditions are crucial to understanding mantle components and heterogeneity.In addition,sulfide has great implications for the understanding of planetary evolution,including the early Earth,Mars,Mercury,and the Moon.Mantle sulfide is controlled by sulfide-silicate equilibrium on sulfide precipitation,chemical species,and elemental partitioning coefficients.Mantle sulfide mobility in fluid media and solid media can be explained by Stokes equation and surface tension models.Based on the current progress on natural samples and experimental results,this paper points out the problems in the research on sulfide physics and chemistry:the high-temperature and high-pressure experiments on partitioning coefficients used much higher elemental contents than that of natural samples while Henry s law might not apply,requiring more experiments with low elemental contents;the empirical equations in linear or natural log form cannot accurately quantify sulfide-silicate system,with machine learning likely to reveal the complex thermodynamic relations;the distribution of sulfide melt on the mantle silicate surface is not clear,demanding more hydrostatic experiments at extreme conditions.

关 键 词：硫化物 高温高压实验 亲硫元素 亲铁元素 分配系数 地幔 早期地球 火星 月球 水星 

分 类 号：P589[天文地球—岩石学] P591[天文地球—地质学] P599