基于Apollo15月壤和普通球粒与碳质球粒陨石模拟实验的太空风化特征产物成因分析  

Formation mechanisms of space weathering products:Apollo lunar soil and simulation experimental study by ordinary and carbonaceous chondrites

作　　者：邰凯瑞 郭壮 李阳[2,4,5] 刘燊[1] 张鹏飞[6] 赵斯哲 李琛 唐红 庞荣华[1] TAI Kairui;GUO Zhuang;LI Yang;LIU Shen;ZHANG Pengfei;ZHAO Sizhe;LI Chen;TANG Hong;PANG Ronghua(Department of Geology,Northrwest University,Xi'an,Shannxi 710069,China;Lunar and Planetary Sciences Research Center,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang,Guizhou 550081,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Center for Excellence in Comparative Planetology,Chinese Academy of Sciences,Hefei,Anhui 230026,China;Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geo physics,Chinese Academy of Sciences,Beijing 100029,China;State Key Laboratory of Lunar and Planetary Sciences,Macao University of Science and Technology,Macao 519020,China;College of Earth Sciences,Gruilin University of Technology,Guilin,Guangxi 541006,China;School of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming,Yunnan 650093,China)

机构地区：[1]西北大学地质学系,陕西西安710069 [2]中国科学院地球化学研究所月球与行星科学研究中心,贵州贵阳550081 [3]中国科学院大学地球与行星科学学院,北京100049 [4]中国科学院比较行星学卓越创新中心,安徽合肥230026 [5]中国科学院地质与地球物理研究所地球与行星物理重点实验室,北京100029 [6]澳门科技大学月球与行星科学国家重点实验室,澳门519020 [7]桂林理工大学地球科学学院,广西桂林541006 [8]昆明理工大学冶金与能源工程学院,云南昆明650093

出　　处：《地质学报》2021年第9期2857-2865,共9页Acta Geologica Sinica

基　　金：国家自然科学基金重点项目(编号41931077),面上项目(编号41673071);中国科学院青年创新促进会(编号2020395);中国科学院太空制造技术重点实验室开放基金(编号CAS-SMT-202001);中国科学院地球与行星物理重点实验室开放课题等资助成果;国家国防科技工业局民用航天技术预先研究课题(编号D020201)。

摘　　要：月球、小行星等无大气行星体具有独特的反射光谱太空风化改造特征,其成因主要被归结于纳米级—亚微米级不透明颗粒等太空风化特征产物。本研究结合Apollo返回月壤样品、普通球粒和碳质球粒陨石样品的模拟实验结果,综合分析了太空风化特征产物的来源和成因,并讨论了其可能的光谱效应。研究结果表明,np-Fe0(纳米级单质金属铁)是铁镁硅酸盐等矿物经过微陨石轰击引起的气化沉积作用和原位还原作用形成。np-FeNi(纳米级铁镍金属)的成因主要包括FeNi金属和陨硫铁的气化沉积与冲击分散成因。np-FeNiS(纳米级铁镍金属的硫化物)和sm-FeNiS(亚微米级铁镍金属的硫化物)主要形成于陨硫铁的冲击分散过程。上述不透明颗粒是形成月球与S型小行星紫外—近红外波段光谱反射率降低、特征吸收峰减弱和连续统红移等特征的主要原因。气泡结构主要形成于层状硅酸盐等矿物在微陨石轰击过程中的挥发分逃逸,推测是含水量较高的小行星(如Bennu)紫外-近红外波段光谱反射率增加和连续统蓝移等特征的主要成因。实验结果预期对月球与小行星返回样品分析以及反射光谱的太空风化改造特征的解释提供一定的参考。Space weathering products, such as nano-to submicron sized opaque particles, are the main reason for the unique reflectance spectra characteristics of weathered particles on airless planetary bodies(e.g., the Moon and asteroids). In this study, the source, formation mechanisms, and distribution of space weathering products were discussed on the basis of Apollo 15 soil samples and the irradiated results of ordinary chondrites and carbonaceous chondrites. Our experiments indicate that np-Fe0(nanophase iron particles) should be formed by the vapor deposition and in-situ reduction of iron-magnesium silicate and other minerals caused by the bombardment of micrometeorites. np-FeNi(nanophase FeNi particles) are formed by the vapor deposition and shock dispersion of FeNi and troilite. np-FeNiS(nanophase FeNiS particles) and sm-FeNiS(submicron FeNiS particles) are mainly formed by the impact dispersion of troilite. These opaque particles are the main reason for the change of spectral characteristics of the Moon and S-type asteroids in the ultraviolet-near infrared reflectance(UV-NIR) band, including reduced reflectance, weaker absorption bands, and the redshift of the continuum. The bubble structure can be attributed to the escape of volatiles in phyllosilicates during micrometeorite bombardment, which is speculated to be the main reason for the increased spectral reflectance and blueshift of the continuum in the UV-NIR band of asteroids with high water content(such as Bennu). The experimental results could provide a reference for the analysis of returned lunar samples, future asteroid samples, and the interpretation of space weathering characteristics of the reflectance spectrum.

关 键 词：月壤 小行星 太空风化 纳米级单质金属铁 反射光谱 

分 类 号：P184[天文地球—天文学]