In the canonical view of lunar evolution,mare basalts are regarded as secondary partial melts of deep-seated lunar mantle formed as cumulates from a lunar magma ocean(LMO)during the early stage of lunar magmatism[1].M...In the canonical view of lunar evolution,mare basalts are regarded as secondary partial melts of deep-seated lunar mantle formed as cumulates from a lunar magma ocean(LMO)during the early stage of lunar magmatism[1].Mare basalts filled mainly near-side lunar basins and occupied approximately 17%of the lunar surface[2].Mare volcanism is a long-lived process(1.0 to 4.4 Ga)that primarily involved the emplacement of lunar basins during the era of large impact basin formation(3.5-3.8 Ga)[1].Some earlier pulses of volcanism(prior to 3.9 Ga)also existed on the moon but covered only a small area(2%)in the form of cryp-tomare basalts[3].Ancient lunar basalts are relatively enriched in Al,K,and rare earth elements(REEs).Representative rocks include high-Al,high-K,K-REE-P-rich rock(KREEP)and some cryp-tomare basalts[1],which were emplaced at the surface during a continuous episode contemporaneous with lunar crust formation[1].Younger patches of mare volcanism(as late as 1.0 Ga)have been recognized via remote sensing techniques[2].However,only the Chang’E 5(CE5)samples provided solid evidence for 2.0 Ga young volcanic activity[4,5].Mare volcanism on the lunar far side,while relatively sparse,follows a similar temporal distribution pat-tern[6].展开更多
Lunar breccias provide crucial insights into the lithological diversity,shock processing and evolution of the lunar crust.Here,we report a unique regolith breccia(CE5C0000YJYX070GP,hereafter CE5C)returned from the Cha...Lunar breccias provide crucial insights into the lithological diversity,shock processing and evolution of the lunar crust.Here,we report a unique regolith breccia(CE5C0000YJYX070GP,hereafter CE5C)returned from the Chang'E-5(CE-5)mission.CE5C is one of the largest CE-5 breccias with a wide variety of lithologies,dominated by basaltic and mineral fragments as well as impact-melted clasts(including mid-Ti glasses,high-Al glasses,and crystal-bearing impact melt clasts).A comprehensive study of petrology and mineralogy on several representative clasts was conducted by integrating Scanning Electron Microscopy(SEM),Tescan Integrated Mineral Analysis(TIMA),Electron Probe Microanalysis(EPMA)and Laser Ablation Inductively Coupled Plasma Mass Spectrometry(LA-ICP-MS)techniques.Evidence is sufficient that CE5C is a mixed mare-highland regolith breccia,with a high percentage of KREEPy material(>20 vol.%),which has not been previously reported in other CE-5 samples.The mid-Ti impact glasses are characterized by high FeO(24.0 wt.%)and intermediate TiO_(2)(5.5 wt.%)contents,while the high-Al impact glasses have a chemical composition compatible with KREEP.Integrated with the regional geological context of the CE-5 landing site,we propose that CE5C is likely derived from a mixed region between the P58/Em4 mare unit and its contiguous eastern highlands.Despite the difficulty in assessing the representativeness of CE5C,the substantial presence of KREEPy material may provide valuable clues to the provenance of exotic ejecta,including the identification of unrecognized source craters situated in the eastern periphery of the sampling unit.展开更多
基金supported by the National Key Research and Development Program of China(2021YFA0716100)the Science and Technology Development Fund,Macao SAR(002/2024/SKL)+1 种基金the National Natural Science Foundation of China(42202260)the Minor Planet Foundation of China.
文摘In the canonical view of lunar evolution,mare basalts are regarded as secondary partial melts of deep-seated lunar mantle formed as cumulates from a lunar magma ocean(LMO)during the early stage of lunar magmatism[1].Mare basalts filled mainly near-side lunar basins and occupied approximately 17%of the lunar surface[2].Mare volcanism is a long-lived process(1.0 to 4.4 Ga)that primarily involved the emplacement of lunar basins during the era of large impact basin formation(3.5-3.8 Ga)[1].Some earlier pulses of volcanism(prior to 3.9 Ga)also existed on the moon but covered only a small area(2%)in the form of cryp-tomare basalts[3].Ancient lunar basalts are relatively enriched in Al,K,and rare earth elements(REEs).Representative rocks include high-Al,high-K,K-REE-P-rich rock(KREEP)and some cryp-tomare basalts[1],which were emplaced at the surface during a continuous episode contemporaneous with lunar crust formation[1].Younger patches of mare volcanism(as late as 1.0 Ga)have been recognized via remote sensing techniques[2].However,only the Chang’E 5(CE5)samples provided solid evidence for 2.0 Ga young volcanic activity[4,5].Mare volcanism on the lunar far side,while relatively sparse,follows a similar temporal distribution pat-tern[6].
基金funded by the National Key Research and Development Program of China(Grant No.2021YFA0716100)the National Natural Science Foundation of China(Grant Nos.41973060,42173044,42241146 and 42273007)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB 41000000)the preresearch Project on Civil Aerospace Technologies(Grant Nos.D020202 and D020302)the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDBS-SSW-JSC007)。
文摘Lunar breccias provide crucial insights into the lithological diversity,shock processing and evolution of the lunar crust.Here,we report a unique regolith breccia(CE5C0000YJYX070GP,hereafter CE5C)returned from the Chang'E-5(CE-5)mission.CE5C is one of the largest CE-5 breccias with a wide variety of lithologies,dominated by basaltic and mineral fragments as well as impact-melted clasts(including mid-Ti glasses,high-Al glasses,and crystal-bearing impact melt clasts).A comprehensive study of petrology and mineralogy on several representative clasts was conducted by integrating Scanning Electron Microscopy(SEM),Tescan Integrated Mineral Analysis(TIMA),Electron Probe Microanalysis(EPMA)and Laser Ablation Inductively Coupled Plasma Mass Spectrometry(LA-ICP-MS)techniques.Evidence is sufficient that CE5C is a mixed mare-highland regolith breccia,with a high percentage of KREEPy material(>20 vol.%),which has not been previously reported in other CE-5 samples.The mid-Ti impact glasses are characterized by high FeO(24.0 wt.%)and intermediate TiO_(2)(5.5 wt.%)contents,while the high-Al impact glasses have a chemical composition compatible with KREEP.Integrated with the regional geological context of the CE-5 landing site,we propose that CE5C is likely derived from a mixed region between the P58/Em4 mare unit and its contiguous eastern highlands.Despite the difficulty in assessing the representativeness of CE5C,the substantial presence of KREEPy material may provide valuable clues to the provenance of exotic ejecta,including the identification of unrecognized source craters situated in the eastern periphery of the sampling unit.
