摘要
月球晚期重轰击(Late Heavy Bombardment,LHB)假说认为在约39亿年前月球曾发生过一次短暂但剧烈的撞击高峰,形成了月球表面的主要大型盆地。它曾被认为是月球乃至太阳系类地天体演化的基本理论之一,其主要依据是在Apollo和Luna任务返回的月球样品中很少有早于40亿年的撞击熔岩。然而LHB假说自从提出以来就遭受质疑,近年更是被大多数行星科学家所摒弃,研究人员提出了多种理论解释返回样品中早期撞击熔岩缺失的原因。因为该假说经过了多年的发展,已经在动力学等领域出现了相匹配的理论,从而在一些科学家脑海中形成了根深蒂固的观念。本文首先介绍了该假说的起源与发展以及有关的质疑,然后利用我国嫦娥六号样品的外来苏长岩的定年结果等作为控制点,构建了撞击坑年代函数,在此基础上推导的撞击率函数进一步颠覆了LHB假说,指出月球以及内太阳系在形成之后撞击频率快速下降,在39亿年前左右并不存在撞击高峰。
The Late Heavy Bombardment(LHB)hypothesis proposed that around 3.9 billion years ago,the Moon experienced a brief but intense spike in impact activity,which formed major large basins on the lunar surface.The LHB hypothesis has been once considered as a foundational theory for the evolution of the Moon and other terrestrial bodies in the solar system,and it was primarily supported by the apparent scarcity of impact lavas whose ages are older than 4.0 billion years in the lunar samples returned by the Apollo and Luna missions.However,the LHB hypothesis has been questioned since its inception and,in recent years,has been largely rejected by most planetary scientists.Various kinds of theories have been proposed by researchers to explain the lack of early-stage impact lavas in the samples returned by the Apollo and Luna missions.As this hypothesis has undergone years of development,corresponding theories had emerged in fields such as dynamics,thus,some deeply rooted concepts were persistent in the minds of some scientists.In this paper,we firstly introduced the origin and development of the LHB hypothesis and its related questionings.Then we have constructed the chronological function of the impact crater on the Moon by utilizing the dating results of exotic norite clasts returned by the China′s Chang’e-6 mission as chronological anchors.Based on this,the derived impact frequency function further challenges the LHB hypothesis,indicating that the impact frequencies on the Moon and the inner solar system were declined rapidly after their formation,and there was no pronounced impact spike around 3.9 billion years ago.
作者
岳宗玉
芶盛
Gregory Michael
YUE Zongyu;GOU Sheng;Gregory Michael(Key Laboratory of Planetary Science and Frontier Technology,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Center for Lunar and Planetary Sciences,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang Guizhou 550081,China)
出处
《矿物学报》
北大核心
2025年第6期1047-1058,共12页
Acta Mineralogica Sinica
基金
中国科学院地质与地球物理研究所重点部署项目(嫦娥六号专项)(批准号:IGGCAS-202401)。
关键词
月球
撞击坑
晚期重轰击
年代函数
Moon
impact crater
late heavy bombardment
chronological function
