钙长辉长无球粒陨石NWA 11592的岩石矿物学特征及富铁橄榄石脉成因研究  

The petrological and mineralogical characteristics of Eucrite NWA 11592 and the study on the genesis of the Fe⁃rich olivine veins

作　　者：黄丽霖 温日强 缪秉魁[2] 陈国柱[2] 许胜才[1] HUANG Li-lin;WEN Ri-qiang;MIAO Bing-kui;CHEN Guo-zhu;XU Sheng-cai(Hezhou University,Hezhou 542800,China;Institute of Meteorites and Planetary Materials Research,Key Laboratory of Planetary Geological Evolution at Universities of Guangxi Province,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]贺州学院,广西贺州542800 [2]桂林理工大学陨石与行星物质研究中心,行星地质演化广西高校重点实验室,广西桂林541004

出　　处：《岩石矿物学杂志》2022年第4期746-758,共13页Acta Petrologica et Mineralogica

基　　金：广西科技基地和人才专项(桂科AD22035157);广西自然科学基金(2018GXNSFBA281129);贺州学院博士科研启动基金(HZUBS202102)。

摘　　要：灶神星是太阳系最大的硅酸盐质小行星,它的岩石样品(HED族陨石)是目前太阳系最古老的岩浆岩之一,很有可能记录了类地行星最早期地质流体活动的重要信息。本次工作首次在一块非角砾岩平衡型的Eucrite NWA 11592中发现了较粗长的富铁橄榄石脉。通过对NWA 11592陨石进行详细的岩相学和地球化学特征研究,将NWA 11592陨石划为玄武质非角砾岩型Eucrite,冲击变质程度至少为S4,热变质程度为6型。NWA 11592中富铁橄榄石脉最有可能为含H_(2)O流体沿裂隙的沉淀产物,反应系统应是开放且较为氧化的(f_(O2)达IW+0.9),且应发生在灶神星浅层地壳>4 km的埋藏深度。含H_(2)O流体渗透作用除更多地发生在灶神星表面或近地表外,还有可能发生在灶神星内部的浅层地壳中。Vesta is the largest silicate asteroid in the solar system,and its rock samples(HED meteorites)are among the oldest magmatic rocks in the solar system,possibly recording important information about the earliest geological fluid activities of terrestrial planets.For the first time in this work,a thicker and longer Fe⁃rich olivine vein was found in a piece of unbreccia equilibrium Eucrite NWA 11592.Through detailed research of petrographic and geochemical characteristics of the NWA 11592 meteorite,NWA 11592 is classified as basaltic unbreccia Eucrite,with an impact metamorphism degree of at least S4 and a thermal metamorphism degree of type 6.The Fe⁃rich olivine veins in NWA 11592 is most likely to be the precipitation products of H_(2)O⁃bearing fluids along the fractures.The reaction system should be open and relatively oxidized(f_(O2) up to IW+0.9),and it should occur at a burial depth of>4 km in the shallow crust of Vesta.The infiltration of H_(2)O⁃bearing fluids not only occurs more on the surface or near the surface of Vesta,but may also occur in the shallow crust of Vesta's interior.

关 键 词：非角砾岩平衡型Eucrite 富铁橄榄石脉 岩石矿物学 流体作用 

分 类 号：P185.83[天文地球—天文学] P588.124