Isotopic evidence for volatile replenishment of the Moon during the Late Accretion  

作　　者：Yanhao Lin Wim van Westrenen 

机构地区：[1]Department of Earth Sciences, Vrije Universiteit Amsterdam

出　　处：《National Science Review》2019年第6期1247-1254,共8页国家科学评论（英文版）

基　　金：supported financially through Netherlands Organisation for Scientific Research(NWO)Vici and User Support Programme Space Research grants to W.v.W.(865.13.006 and GO/14–23,respectively);the Key Research Program of the Chinese Academy of Sciences(XDPB11);the National Natural Science Foundation of China(U1530402)

摘　　要：The traditional view of a dry,volatile-poor Moon has been challenged by the identification of water and other volatiles in lunar samples,but the volatile budget delivery time(s),source(s)and temporal evolution remain poorly constrained.Here we show that hydrogen and chlorine isotopic ratios in lunar apatite changed significantly during the Late Accretion(LA,4.1-3.8 billion years ago).During this period,deuterium/hydrogen ratios in the Moon changed from initial carbonaceous-chondrite-like values to values consistent with an influx of ordinary-chondrite-like material and pre-LA elevatedδ^37C1 values drop towards lower chondrite-like values.Inferred pre-LA lunar interior water contents are significantly lower than pristine values suggesting degassing,followed by an increase during the LA.These trends are consistent with dynamic models of solar-system evolution,suggesting that the Moon’s(and Earth’s)initial volatiles were replenished〜0.5 Ga after their formation,with their final budgets reflecting a mixture of sources and delivery times.The traditional view of a dry, volatile-poor Moon has been challenged by the identification of water and other volatiles in lunar samples, but the volatile budget delivery time（s）, source（s） and temporal evolution remain poorly constrained. Here we show that hydrogen and chlorine isotopic ratios in lunar apatite changed significantly during the Late Accretion（LA, 4.1–3.8 billion years ago）. During this period,deuterium/hydrogen ratios in the Moon changed from initial carbonaceous-chondrite-like values to values consistent with an influx of ordinary-chondrite-like material and pre-LA elevated δ37 Cl values drop towards lower chondrite-like values. Inferred pre-LA lunar interior water contents are significantly lower than pristine values suggesting degassing, followed by an increase during the LA. These trends are consistent with dynamic models of solar-system evolution, suggesting that the Moon’s（and Earth’s） initial volatiles were replenished ～0.5 Ga after their formation, with their final budgets reflecting a mixture of sources and delivery times.

关 键 词：BUDGET VOLATILE INTERIOR 

分 类 号：P184[天文地球—天文学]