The Moon’s KREEP component—rich in potassium(K),rare earth elements(REE),and phosphorus(P)—is considered a critical heat source sustaining prolonged volcanic activity.However,Chang’e mission samples reveal a lack ...The Moon’s KREEP component—rich in potassium(K),rare earth elements(REE),and phosphorus(P)—is considered a critical heat source sustaining prolonged volcanic activity.However,Chang’e mission samples reveal a lack of KREEP signatures in the sources of mare basalt erupted∼2.8 and 2.0 billion years ago,raising questions about its contribution to late-stage volcanism.Here,we present geochemical and geochronological analyses of the lunar basaltic meteorite NWA 16286,which crystallized 2201±13 million years ago,representing the youngest known lunar meteorite.Its mantle source shows a high^(238)U/^(204)Pb ratio(∼2000)and a lowεNd(t)value(–4.3),indicating strong KREEP enrichment and extending the duration of KREEP-related magmatism by∼800 million years.Compiled isotopic data from lunar basalts reveal three volcanic episodes,each characterized by progressively increasing 238U/204Pb and decreasingεNd,suggesting episodic mantle convection.We propose that episodic sluggish mantle overturn or plume-driven upwelling triggered initial decompression melting,followed by increasing incorporation of KREEP components into basalt sources during each episode of younger mare volcanism.展开更多
基金supported by the National Natural Science Foundation of China(42225301,42241105,and 42403008)the Strategy Priority Research Program(Category B)of the Chinese Academy of Sciences(XDB0710000)the Key Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS-202401).
文摘The Moon’s KREEP component—rich in potassium(K),rare earth elements(REE),and phosphorus(P)—is considered a critical heat source sustaining prolonged volcanic activity.However,Chang’e mission samples reveal a lack of KREEP signatures in the sources of mare basalt erupted∼2.8 and 2.0 billion years ago,raising questions about its contribution to late-stage volcanism.Here,we present geochemical and geochronological analyses of the lunar basaltic meteorite NWA 16286,which crystallized 2201±13 million years ago,representing the youngest known lunar meteorite.Its mantle source shows a high^(238)U/^(204)Pb ratio(∼2000)and a lowεNd(t)value(–4.3),indicating strong KREEP enrichment and extending the duration of KREEP-related magmatism by∼800 million years.Compiled isotopic data from lunar basalts reveal three volcanic episodes,each characterized by progressively increasing 238U/204Pb and decreasingεNd,suggesting episodic mantle convection.We propose that episodic sluggish mantle overturn or plume-driven upwelling triggered initial decompression melting,followed by increasing incorporation of KREEP components into basalt sources during each episode of younger mare volcanism.
