【作者】 焦中虎；

【导师】 刘少峰；

【作者基本信息】 中国地质大学(北京) ， 资源与环境遥感， 2012， 硕士

【副题名】以Aristarchus和南极-艾肯盆地为例

【摘要】 研究月表物质的可见光-近红外光谱特性是了解月球岩石矿物组成及结构的重要手段。根据矿物在可见光-近红外光谱中的吸收特征，我们可以反演月表的物质组成，识别关键性的元素和矿物，如FeO、TiO₂、斜长石、辉石等，并将这些数据应用于月球地质单元的成因和演化解释，取得很多重要的成果。首先，本文阐述了岩浆洋假设中对矿物形成和演化的内容，继而概述了经亿万年演化后月表主要的物质——月壤、玻璃物质和角砾岩。月球矿物的光谱特征是月球遥感应用的基础，本文分析了月球主要矿物（如斜长石、橄榄石、辉石等）的可见光-近红外光谱特征，特别是吸收峰的特征参数和形成原因。矿物光谱的影响因素包括矿物混合、太空风化效应、矿物颗粒效应等。其中，太空风化效应的去除是进行光谱分析和矿物信息提取的重要内容。其次，撞击坑能够暴露月壳深部物质，是研究新鲜月壤物质的重要窗口。Aristarchus地区具有复杂多样的地质背景，一直是月球地质研究的一个重点区域。最新可用的高分辨率和高光谱数据为Aristarchus的综合研究提供了新的可能。本文采用光谱分析方法、波段比值法、彩色合成法、主成分分析和非监督分类等方法，对Aristarchus地区的矿物和地质特征进行分析，并对分类后的地质单元进行描述。Aristarchus撞击坑中央峰具有很高的反射率，其光谱曲线没有明显的铁镁质矿物的吸收特征，表明它很可能来源于斜长岩的上月壳物质。撞击坑东南侧存在橄榄石富集区，与撞击熔融物相关。橄榄石可能来源于周围的风暴洋玄武岩经撞击作用重新熔融、分布、冷却结晶的产物。通过改进高斯模型（MGM）将橄榄石光谱分解为多个吸收波段的参数，并分析这些参数与矿物构成之间的关系，表明除具有橄榄石外，还可能含有高钙辉石或铬尖晶石等矿物。最后，本文分析了南极-艾肯（SPA）盆地Th元素的富集特征和形成机理。相比于雨海-风暴洋的Th主要来源于对其下覆KREEP物质的开掘，对SPA盆地的Th来源有各种不同的认识。本文通过对SPA盆地的地形、盆地构造、撞击坑分布、火山作用和地球化学特征的分析，以及对Th富集机理的探讨，认为SPA盆地内Th更可能来源于撞击作用对富Th下月壳物质的开掘；Th的弧形富集特征与盆地构造有很大相关性，并可能受到Apollo盆地形成的影响。更多还原

【Abstract】 Visible and near-infrared spectral properties of lunar material are an important means tounderstand the composition and structure of lunar rocks and minerals. According to mineralabsorption features in the visible and near-infrared spectroscopy, we can derive the lunarsurface material, identify key elements and minerals, such as FeO, TiO₂, plagioclase,pyroxene. And the data is used in the explanation of the causes and evolution of the lunargeologic units, which has achieved many significant results.First of all, this paper describes the content of the formation and evolution of minerals inthe magma ocean hypothesis. And then it summarizes major lunar material-the lunar soil,glass material and breccia, which has undergone hundreds of millions of years of evolution.The spectral characteristics of lunar minerals are the basis of the application of lunar remotesensing, the paper analyzes visible and near-infrared spectral features of the principal lunarminerals （such as plagioclase, olivine, pyroxene, etc.）, especially the characteristicparameters and causes of the absorption peak. Factors of mineral spectra include mineralmixed, effects of space weathering, effects of mineral particles and so on. Among them, theremoval of the effects of space weathering is an important part of the spectral analysis andmineral extraction.Furthermore, the impact crater is an important window for fresh lunar regolith material,which can expose the deep substance of the lunar crust. Aristarchus region has a complex anddiverse geological background, and has become one of the key areas of the lunar geologicalstudies. The latest available high-resolution and hyperspectral data provides new possibilitiesfor comprehensive study of Aristarchus. In this paper, the spectral analysis methods, theband ratio methods, color synthetic methods, principal component analysis and unsupervisedclassification methods are used for the analysis of the Aristarchus region’s minerals andgeological characteristics and the description of the classification of geological units.There is high reflectivity in the Aristarchus crater central peak, and its spectra lackobvious absorption characteristics of the mafic minerals. These all indicate that it probablyderived from the anorthositic material of the lunar crust. Olivine-rich regions exist in thesoutheast of Aristarchus crater, which have a close relation with impact melts. Olivine maybe the product of re-melting, distribution, cooling and crystallization of basalt which comefrom Oceanus Procellarum around because of impact effects. The spectra of olivine aredecomposed into more than one absorption band parameters by the modified Gaussian model（MGM）. The relationship between these parameters and mineral composition suggests that there may be high calcium pyroxene or chrome except olivine.Finally, this paper analyzes thorium enrichment characteristics and formationmechanism in the South Pole-Aitken basin （SPA）. It is generally believed that thorium inImbrium-Procellarum is derived from the KREEP layer underlying crust by Imbrium impact,but there are various explanations for the origin of thorium in SPA. Through the analysis ofthe geomorphology of SPA, basin structure, the distribution of craters, volcanism,geochemical characteristics, and the discussion of thorium enrichment mechanisms, thispaper argues that it is more likely that in SPA basin elevated thorium abundances stem fromthorium-rich lower crustal materials exposed by the SPA impact event and there is anintimate relation between curve pattern of thorium enrichment and basin structure with aprobable impact of Apollo basin formation.更多还原