Geology, geochemistry, and geophysics of the Moon: Status of current understanding
Geology, geochemistry, and geophysics of the Moon: Status of current understanding
复制标题
DOI：
10.1016/j.pss.2012.08.019
复制
发表时间：
2012-12-01
影响因子：
2.4
通讯作者：
Oberst, J.
中科院分区：
文献类型：
--
作者：
Jaumann, R.;Hiesinger, H.;Oberst, J.
月球是了解地球和太阳系行星过程的关键，并且已经见证了太阳系历史超过4.5 Ga。在早期望远镜观测的基础上，我们对月球的认识被阿波罗和其他太空任务提供的丰富信息所改变。这些都证明了月球对于理解推动行星形成和演化的基本过程的价值。月球被认为是一个惰性天体，其地质主要限于撞击和火山活动，以及相关的构造，成分相对简单。与地球不同的是，由于没有板块构造，因此保留了明确的增生和地质演化记录。然而，最近的月球任务表明，这种传统的月球表面视图肯定是过于简单化的。例如，虽然长期以来一直怀疑冰可能保存在月球两极的冷阱中，但最近的结果也表明在极地地区之外形成和保留了OH-和H2O。这些挥发物可能是由于月球表面的水合作用而形成的，包括太阳风质子与微陨石撞击月球土壤颗粒时产生的富氧岩石表面相互作用而产生的H2O和OH。此外，根据月球勘探者的伽马射线数据，月球地壳和下地幔被划分为不同的板块，具有独特的地球化学，地球物理和地质特征。在Procellarum KREEP地体中，月球近侧半球的产热元素集中，显然导致近侧的火山活动比远侧更活跃。最近对玄武岩的测年表明，月球火山活动活跃了近3 Ga，从大约3.9-4.0 Ga开始，大约在1.2 Ga结束。最近对地震数据的重新处理支持地幔底部存在部分熔融层，并显示不仅存在330公里的液体核，而且还存在一个小的固体内核。今天，月球没有像地球那样的发电机产生的磁场。然而，月壳的剩余磁化强度和一些月球样本的古地磁记录表明，磁化强度可能是由早期月球核心发电机引起的内在磁场获得的。总而言之，月球是一个复杂的行星天体，还有很多东西有待探索和发现，特别是关于月球的起源，地月系统的历史，以及过去4.5 Ga在太阳系内部运行的过程。因此，重返月球是进一步探索和了解我们的行星邻居的关键下一块垫脚石。(C)2012爱思唯尔有限公司保留所有权利。
The Moon is key to understanding both Earth and our Solar System in terms of planetary processes and has been a witness of the Solar System history for more than 4.5 Ga. Building on earlier telescopic observations, our knowledge about the Moon was transformed by the wealth of information provided by Apollo and other space missions. These demonstrated the value of the Moon for understanding the fundamental processes that drive planetary formation and evolution. The Moon was understood as an inert body with its geology mainly restricted to impact and volcanism with associated tectonics, and a relative simple composition. Unlike Earth, an absence of plate tectonics has preserved a well-defined accretion and geological evolution record. However recent missions to the Moon show that this traditional view of the lunar surface is certainly an over simplification. For example, although it has long been suspected that ice might be preserved in cold traps at the lunar poles, recent results also indicate the formation and retention of OH- and H2O outside of polar regions. These volatiles are likely to be formed as a result of hydration processes operating at the lunar surface including the production of H2O and OH by solar wind protons interacting with oxygen-rich rock surfaces produced during micrometeorite impact on lunar soil particles. Moreover, on the basis of Lunar Prospector gamma-ray data, the lunar crust and underlying mantle has been found to be divided into distinct terranes that possess unique geochemical, geophysical, and geological characteristics. The concentration of heat producing elements on the nearside hemisphere of the Moon in the Procellarum KREEP Terrane has apparently led to the nearside being more volcanically active than the farside. Recent dating of basalts has shown that lunar volcanism was active for almost 3 Ga, starting at about 3.9-4.0 Ga and ceasing at similar to 1.2 Ga. A recent re-processing of the seismic data supports the presence of a partially molten layer at the base of the mantle and shows not only the presence of a 330 km liquid core, but also a small solid inner core. Today, the Moon does not have a dynamo-generated magnetic field like that of the Earth. However, remnant magnetization of the lunar crust and the paleomagnetic record of some lunar samples suggest that magnetization was acquired, possibly from an intrinsic magnetic field caused by an early lunar core dynamo. In summary, the Moon is a complex differentiated planetary object and much remains to be explored and discovered, especially regarding the origin of the Moon, the history of the Earth-Moon system, and processes that have operated in the inner Solar System over the last 4.5 Ga. Returning to the Moon is therefore the critical next stepping-stone to further exploration and understanding of our planetary neighborhood. (C) 2012 Elsevier Ltd. All rights reserved.