虹湾地区橄榄石的光谱特征及其镁数(Fo#)分析

研究橄榄石的分布和成分，对于估测如月球类的火成岩行星体的地质演化有重要的意义。以嫦娥系列卫星探测区域虹湾地区为例，基于M3高光谱数据采用波谱特征拟合方法调查橄榄石物质的分布情况。虹湾地区橄榄石主要分布在北部坑壁和侏罗山脉山脚，且周围伴生辉石及少量斜长石。所处地层单元为撞击产生的溅射物和弹射物，地质年龄较老。以月球橄榄石样品镁数为因变量，经改进高斯模型(MGM)拟合得到的月球橄榄石样品光谱吸收中心参数为自变量，利用多元线性回归的统计方法建立月球橄榄石物质的镁数(Fo#)反演模型。在此基础上，通过MGM模型提取虹湾18个橄榄石富集点光谱的吸收中心参数，利用镁数反演模型反演虹湾橄榄石的镁数。反演结果表明，虹湾橄榄石物质的镁数较高，均值为Fo~80.84，而富镁橄榄石指示了深源特性，因此虹湾地区的橄榄石绝大多数来自于月幔。

Spectral Feature and Mg Number (Fo#) Analysis of Olivine in Sinus I ri di um

The research on the distribution and component of olivine is one of great significance to evaluate the geologic evolution of igneous planetary bodies such as the Moon .In this paper ,the Sinus Iidium ,as the survey region ,was explored by Chang’s serial satellite .Here we present an olivine survey of the Sinus Iridium by using Spectral Feature Fitting (SFF) method based on the M3 data .The exposures of olivine were located in the northern crater wall and at the foot of Montes Jura ,which were associ‐ated with plagioclase and little anorthosite .The stratigraphic units of the located formation were the interior crater slopes and debris ejected from the impact‐formed Iridium crater ,and the geological age was relatively older .The Mg number of the lunar olivine samples was dependent variables ,and the band center of the lunar olivine spectrums were independent ,which derived from the fitting analysis using Modified Gaussian Model (MGM ) .The quantitative inversion models of Mg number (Fo# ) of the lunar olivine is established with multiple linear regression analysis .On this basis ,the Mg number of the olivine rich point in the Sinus Iridium are calculated with quantitative inversion models of Mg number (Fo#) .The result shows that ,the Fo# of ol‐ivine in the Sinus Iridium are relatively high .The mean value of Fo# is Fo~80.84 .As mantle olivine would be expected to be quite Mg‐rich ,it is suggested that at the vast majority of the olivine detected in the Sinus Iridium come from upper mantle of the Moon .