月球某些资源的开发利用前景

21世纪月球探测的主要趋势是建立月球基地，开发利用月球的矿产资源，能源和特殊环境，为人类社会的可持续发展发挥长期而有效的支撑作用，通过对月海玄武岩中的钛铁矿，克里普岩中的U，Th,REE和月壤中的拟－3在月面的含量与分布的系统分析，月海玄武碉中蕴藏有极丰富的钛铁矿，TiO2总资源量超过70万亿t，钛铁矿还是月球基地生产水和火箭燃料的主要原料；克里普岩是未来月球探测与研究的热点之一，其蕴藏有巨量的铀，钍，钾，磷和稀土元素资源；月壤长期受到太阳风的辐射，使其蕴藏有极其丰富的氢，氦，氧，氮等气体资源，其中氦－3的资源量大于100万t，它是一种可供人类社会长期使用的，安全，清洁，高效，廉价的核聚变发电燃料，其含量与月壤的化学成分，矿物组分，颗粒大小等有密切的关系。     

月海玄武岩与月球演化

月海玄武岩主要产于月球近边的盆地中,覆盖面积为月球表面的l％,其形成年龄多在39～31亿年之间,是各类月岩中最年轻的。与地球玄武岩相似,月海玄武岩由斜长石、辉石和橄榄石组成,但它们比地球玄武岩具有更低的Mg#、A1：0,、K和Na含量．高的FeO含量（大于16％）和变化范围大的TiO2含量（小于l％到大于13％）。根据TiO2含量的变化,月海玄武岩分成高Ti（〉6％）,低Ti（1．5％〈TiO：〈6％）以及极低Ti（〈1．5％）三类。所有月海玄武岩都具有Eu负异常,并亏损挥发性元素和亲铁元素。月海玄武岩的同位素特征指示其至少为三个组分混合的产物：（1）高：238U／204Pb、高87Sr／86Sr和负εNd组分,可能是岩浆海分异的残余岩浆即KREEP;（2）低：238U／204Pb、低87Sr／86sr和正εNd组分,来源于原始月幔,其熔融产物为低Ⅱ玄武岩;（3）中等87Sr／86Sr和εNd组分,位于月幔的顶部,经历了岩浆海（洋）过程中形成的堆晶物质的再熔融,还可能受到了陨击事件的影响,其熔融产物是高Ti玄武岩。月海玄武岩的元素和同位素地球化学性质支持岩浆海的假说,其源区的形成与岩浆海的分异密切相关,并经历了三个阶段：（a）岩浆海阶段,通过岩浆海的结晶分异形成顶部为斜长岩月壳,中间为高Ⅱ、富钛铁矿层,底部为巨厚的硅酸盐低Ti层的三层壳幔结构;（b）富钛铁矿堆晶岩（携带少量残余熔体）因密度大而下沉至下部的硅酸盐月幔（400km以下）;（C）月幔中这些不同源区的岩石发生减压熔融。早期由较浅的低熔点组分熔融形成低K高Ti玄武岩,之后形成来源较深的高Ti玄武岩和低Ti玄武岩。     

Lunar geochemistry as told by lunar meteorites

About 36 lunar meteorites have been found in cold and hot deserts since the first one was found in 1979 in Antarctica. All are random samples ejected from unknown locations on the Moon by meteoroid impacts. Lithologically and compositionally there are three extreme types: (1) brecciated anorthosites with high Al₂O₃ (26–31%), low FeO (3–6%), and low incompatible elements (e.g., <1 μg/g Th), (2) basalts and brecciated basalts with high FeO (18–22%), moderately low Al₂O₃ (8–10%) and incompatible elements (0.4–2.1 μg/g Th), and (3) an impact-melt breccia of noritic composition (16% Al₂O₃, 11% FeO) with very high concentrations of incompatible elements (33 μg/g Th), a lithology that is identified as KREEP on the basis of its similarity to Apollo samples of that designation. Several meteorites are polymict breccias of intermediate composition because they contain both anorthosite and basalt. Despite the large range in compositions, a variety of compositional parameters together distinguish lunar meteorites from terrestrial materials. Compositional and petrographic data for lunar meteorites, when combined with mineralogical and compositional data obtained from orbiting spacecraft in the 1990s, suggest that Apollo samples identified with the magnesian (Mg-rich) suite of nonmare rocks (norite, troctolite, dunite, alkali anorthosite, and KREEP) are all products of a small, geochemically anomalous (noritic, high Th) region of crust known as the Procellarum KREEP Terrane and are not, as generally assumed, indigenous to the vast expanse of typical feldspathic crust known as the Feldspathic Highlands Terrane. Magnesian-suite rocks such as those of the Apollo collection do not occur as clasts in the feldspathic lunar meteorites. The misconception is a consequence of four historical factors: (1) the Moon has long been viewed as simply bimodal in geology, mare or highlands, (2) one of the last, large basin-forming bolides impacted in the Procellarum KREEP Terrane, dispersing Th-rich material, (3) although it was not known at the time, the Apollo missions all landed in or near the anomalous Procellarum KREEP Terrane and collected many Th-rich samples formed therein, and (4) the Apollo samples were interpreted and models for lunar crust formation developed without recognition of the anomaly because global data provided by orbiting missions and lunar meteorites were obtained only years later.     

CE-1伽马能谱测量中4种月球岩石的能谱特征分析

从CE-1 γ能谱测量获得的数据出发,对原始数据进行处理,将原始谱线按每5°×5°网格内平均而获得月表上的γ能谱数据。选取了12条不同位置分别代表玄武岩、斜长岩、富镁岩和KREEP岩的能谱曲线进行分析,发现同一岩性的谱线具有相似性。通过对每种岩性选择的一条谱线进行分析可知,不同的岩性能谱曲线有一定的差别,表现为不同岩性在元素特征能谱峰的变化不同,玄武岩的能谱曲线特征峰主要的元素为Th、K、Si、Ca、C、Fe和Ti;斜长岩的能谱曲线特征峰主要元素为U、Ca、C、Mg、Al和Mn。KREEP岩的能谱曲线特征峰主要为K、Th、U、Si、Ca和Fe,而低C和Al;富镁岩能谱曲线表现为低U、Si、Ca和Cl而高K、Mg、Th和Fe含量特征。文中给出了能较好区分不同岩性的元素特征峰能量,可为月表γ能谱的定量分析奠定基础。     

行星矿产及行星资源地质学初论

了解并利用行星矿产资源、可持续永久开发太空成为行星科学与深空探测的一项重要研究任务。而行星矿产资源的开发利用,需要运用行星科学与地质学特别是矿床学的基础理论,利用行星观测、探测及开发技术方法,研究行星矿产资源形成演化规律,查明行星矿产资源的类型、特征、储量和分布规律;进行行星矿产资源的地质调查、岩石-矿石成分、结构与性能、元素赋存状态、开发利用条件评价与预测,为行星矿产资源开发与太空的可持续永久开发建设提供基础理论与关键技术方法。因此,行星矿产资源学是研究行星矿产资源的品种、类型与分布规律、行星矿产资源成因演化与比较行星成矿学、行星矿产资源勘查评价技术与开采利用工程学的交叉学科。笔者从行星资源地质学的视角,从地球与月球的层圈结构、演化历史、岩石组成与表生环境,研判月球可能产出的矿产资源类型。认为与月海玄武岩、月幔(柱)和陨石撞击成因的层状岩体与镁铁-超镁铁质小岩体有关的铬铁矿-铜镍钴硫化物-铂族元素-钒钛磁铁矿-金刚石矿产,KREEP岩以及月幔柱熔融上覆岩石圈所产生碱性岩相伴的铌-钽-铍-铀等稀有-稀土矿产,具有形成条件与产出可能,从而拓展可能的矿产类型、品种,从更宽广的视角研究月球矿产并规划月球基地建设资源供给。火星上由于水(以及可能存在的板块构造)的存在,除岩浆矿床之外,火星可能具备发育与化学风化沉积、次生富集作用以及变质作用有关矿产的形成条件,具有形成金属与非金属资源的禀赋,可与地球矿产相媲美。未来行星资源地质学应加强地质学、行星化学、行星地质学、行星物理学、矿业工程、冶金工程和材料学的交叉融合及理论应用,发展行星地质勘探方法与智能机器人工程技术,发展高/低温、高/低压、高辐照、低/微重力环境条件下样品采集、加工、多尺度测试分析理论与方法,培养行星资源地质资源与开发工程学科人才。     

月球表面多种金属元素的分布特征初探

美国的"克莱门汀"(Clementine)和"月球探测者"(Lunar Prospector)号月球探测器,分别于1994和1998年完成了对月球形貌、水冰以及月球重力和磁场等物理参数的高精度、高分辨率探测。月球探测者号还利用伽马射线仪探测了月表层中铁、钛、铀、钍和钾等元素含量分布,这为进一步研究月球的空间与表面环境,月球的地形、地貌、地层与地质构造,月表土壤与岩石的分布、成分与成因,月球物理场特征,月球的内部结构、演化与成因提供了大量的科学数据和证据。根据"克莱门汀"和"月球探测者"号测得的数据,对月球表面金属钛、铁、镁、铀、钍、钾的分布进行分析,初步研究了这些金属元素分布与月球地貌的关系,计算各金属元素之间空间分布的相关系数,分析蕴藏这些金属资源地区的岩性及各种元素可能的来源。由此推测30亿年前月球内部逐渐固化,大量小行星对月表岩石频繁的撞击导致金属元素分布不均衡,使金属元素在月球高原地带普遍含量低于月海,同时也形成了现在我们看到的遍布月表的环形山。     

http://dx.doi.org/10.1016/j.gsf.2016.08.003

The primordial crust on the Earth formed from the crystallization of the surface magma ocean during the Hadean. However, geological surveys have found no evidence of rocks dating back to more than 4 Ga on the Earth's surface, suggesting the Hadean crust was lost due to some processes. We investigated the subduction of one of the possible candidates for the primordial crust, anorthosite and KREEP crust similar to the Moon, which is also considered to have formed from the crystallization of the magma ocean. Similar to the present Earth, the subduction of primordial crust by subduction erosion is expected to be an effective way of eliminating primordial crust from the surface. In this study, the subduction rate of the primordial crust via subduction channels is evaluated by numerical simulations. The subduction channels are located between the subducting slab and the mantle wedge and are comprised of primordial crust materials supplied mainly by subduction erosion. We have found that primordial anorthosite and KREEP crust of up to ～50 km thick at the Earth's surface was able to be conveyed to the deep mantle within 0.1-2 Gy by that mechanism.     

KREEP Rocks

KREEP rocks with high contents of K, REE and P were first recognized in Apollo-12 samples, and it was confirmed later that there were KREEP rock fragments in all of the Apollo samples, particularly in Apollo-12 and -14 samples. The KREEP rocks distributed on the lunar surface are the very important objects of study on the evolution of the moon, as well as to evaluate the utilization prospect of REE in KREEP rocks. Based on previous studies and lunar exploration data, the authors analyzed the chemical and mineral characteristics of KREEP rocks, the abundance of Th on the lunar surface materials, the correlation between Th and REE of KREEP rocks in abundance, studied the distribution regions of KREEP rocks on the lunar surface, and further evaluated the utilization prospect of REE in KREEP rocks.     

月球表面天然放射性元素Th的分布特征及月球化学的原始不均一性

月球KREEP岩石形成于壳幔的分界层中,天然放射性元素Th是指示KREEP岩分布的主要元素之一。在月球正面,Th元素含量高的区域主要分布在西部的月海区,包括雨海和风暴洋及其附近地区,而在月球背面Th含量高的地区为雨海对峙区以及南极爱特肯地区。高地的Th含量相对较低。现代月球表面Th的分布特征与3.85Ga年前的雨海事件有重要的关系,且在月球正面还发现了椭圆形的高Th含量区域,是月球上特殊的地球化学省,与月球初期的化学成分分布的不均一性有关。     

月球陨石: 月球的物质组成及其演化历史的见证

月球陨石是遭受小行星物质撞击溅飞出来的月球岩石样品,是研究月球物质成分和演化历史的重要对象。自1979年发现和确认了第一块月球陨石（ALHA 81005）之后,至今已收集到136块月球陨石样品。虽然Apollo计划和Luna计划回收了382kg月球样品,但由于飞船登陆采样位置有限,月球陨石对了解月球的物质组成和成因演化提供了重要补充。除了少量具有结晶结构的岩石类型以外,大部分月球陨石为碎屑岩,这些碎屑岩主要有三类：高地斜长角砾岩、月海玄武质角砾岩、和高地斜长质-月海玄武质混合角砾岩。根据岩性分析,尤其是岩屑,月球陨石中存在斜长岩、玄武岩、辉长岩、橄长岩、苏长岩、KREEP岩。在月球陨石中逐渐发现了不少克里普岩组分,其中SaU169中VHK的富KREEP成分可能代表了月球中的原始富KREEP岩浆源,这为探索月球中KREEP成因提供重要信息。据研究,现已发现了6对溅射成对月球陨石,同时,发现了9个可能的月球陨石来源区域。后成合晶现象的发现对月球表面冲击变质作用研究具有重要的意义。此外,月球陨石同位素年龄和稀有气体成分研究不但获得了月球岩石结晶和月壳形成过程,同时获得了月球表面的冲击变质历史。