嫦娥二号γ谱数据反演月表Fe元素分布  

The distribution of lunar iron revealed by Chang'E-2 gamma ray spectrometer

作　　者：陈剑[1] 凌宗成[1,2] 李勃[1] 孙灵芝[1] 张江[1] 刘建忠[3] 

机构地区：[1]山东大学空间科学研究院山东省光学天文与日地空间环境重点实验室,威海264209 [2]中国科学院月球与深空探测重点实验室,北京100012 [3]中国科学院地球化学研究所,贵阳550002

出　　处：《中国科学：物理学、力学、天文学》2016年第2期53-60,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:U1231103;41473065;41373068;41490634);山东省自然科学基金(编号:JQ201511;ZR2015DQ001);中国科学院重点部署项目(编号:KGZD-EW-603);中国科学院月球与深空探测重点实验室开放基金;山东大学(威海)青年学者未来计划资助

摘　　要：Fe作为重要的成岩元素之一,其月表含量和分布特征对于认识月球岩石成因和岩浆演化具有重要指示意义.本文由嫦娥二号γ谱仪2C级数据出发,经过谱线筛选、宇宙线校正、能谱累积与本底处理后提取Fe峰计数率.我们借助月球勘探者号的热中子数据进行中子校正,之后结合月球样品、陨石与嫦娥三号的就位探测数据标定Fe元素丰度.嫦娥二号γ谱仪全月Fe分布图中月海玄武岩区域与Fe元素富集区域吻合,其中风暴洋和雨海中部为Fe含量高值区域(Fe O>23 wt.%),南极艾肯盆地内也出现Fe的相对富集,而月陆区域Fe含量较低(Fe O<8 wt.%).与月球勘探者号g谱仪的探测结果相比,嫦娥二号γ谱仪解算的Fe元素丰度(Fe O)平均偏低0.7 wt.%.As one of the important rock-forming elements, lunar global iron abundance and distribution are essential for the understanding of petrogenisis and crustal evolution of the Moon. In this paper, we derive lunar iron map from Chang＇E-2 Gamma Ray Spectrometer （CE2GRS） data. Beginning from level 2C scientific data, a series of processing procedures （data selection, galactic cosmic ray correction, spectral accumulation and background estimation, etc.） are conducted to extract iron peak count rates. Neutron correction is achieved with the help of thermal neutron density data acquired by Lunar Prospector Neutron Spectrometer. We map the absolute abundance of iron （FeO） in terms of ground truths mostly from Apollo and Luna soils and regolith breccias, FeO-poor feldspathic lunar meteorites and young FeO-rich mare basalt detected in-situ by Chang＇E-3 Paticle Induced X-ray Spectrometer （PIXS）. The global iron map indicates that majority of iron-rich regions match well with mare basalt deposits. Especially, Oceanus Procellarum and central Mare Imbrium dominate the high values （FeO 〉 23 wt.%） of iron abundance and the richest FeO （30.2 wt.%） region locates in the young mare basaltic unit south of Aristarchus crater. South Pole Aitken basin is relatively enriched in iron （maximum of 12.7 wt.%） compared to the highlands poor of iron （FeO 〈 8 wt.%）. When coordinated with the iron map derived by Lunar Prospector Gamma Ray Spectrometer （LPGRS）, iron map determined by CE2GRS reveals slightly lower abundances （average difference of 0.7 wt.%） than the result of LPGRS at global level.

关 键 词：嫦娥二号 Γ射线 Fe元素分布图 月海玄武岩 

分 类 号：P184.5[天文地球—天文学]