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
Miller Range (MIL) 05035 and LaPaz Icefield (LAP) 02224 are unbrecciated lunar basalt meteorites. In this report, we studied their petrography and mineralogy and made in situ uranogenic Pb/Pb dating of Zr-rich mineral...Miller Range (MIL) 05035 and LaPaz Icefield (LAP) 02224 are unbrecciated lunar basalt meteorites. In this report, we studied their petrography and mineralogy and made in situ uranogenic Pb/Pb dating of Zr-rich minerals. Petrography and mineralogy of these two lunar meteorites are consistent with previous investigations. The zirconolite Pb/Pb age of MIL 05035 is 3851±8 Ma (2σ), in excellent agreement with previous reports. This age suggests that MIL 05035 could be paired with Asuka 881757, a low-Ti mare basalt meteorite. The magmatic event related to MIL 05035 was probably due to the late heavy impact bom- bardment on the moon around 3.9 Ga. One baddeleyite grain in LAP 02224 shows a large variation of Pb/Pb age, from 3109±29 to 3547±21 Ma (2σ), much older than the whole-rock age of the same meteorite (~3.02±0.03 Ga). The other baddeleyite grain in LAP 02224 has an age of 3005±17 Ma (2σ). The result indicates that the minimum crystallization age of LAP 02224 is ~3.55 Ga and the younger ages could reflect late thermal disturbance on U-Pb system.展开更多
In December 2020, Chang’E-5(CE-5), China’s first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain,...In December 2020, Chang’E-5(CE-5), China’s first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain, a great distance from those of Apollo and Luna missions. These young mare basalts bear critical scientific significance as they could shed light on the nature of the lunar interior(composition and structure) as well as the recent volcanism on the Moon. In this article, we investigated a CE-5 basalt sample(CE5 C0000 YJYX065) using a combination of state-of-art techniques, including high resolution X-ray tomographic microscopy(HR-XTM), energy dispersive X-ray spectroscopy(EDS)-based scanning electron microscope(SEM), and electron probe microanalysis(EPMA) to reveal its 3 D petrology and minerology.Our results show that this sample has a fine-to medium-grained subophitic texture, with sparse olivine phenocrysts setting in the groundmass of pyroxene, plagioclase, ilmenite and trace amounts of other phases. It has an extremely high ilmenite modal abundance(17.8 vol%) and contains a significant amount(0.5 vol%) of Ca-phosphate grains. The mineral chemistry is in excellent agreement with that of Apollo and Luna high-Ti basalts. The major phase pyroxenes also display strong chemical zoning with compositions following the trends observed in Apollo high-Ti basalts. Based on current data, we came to the conclusion that CE5 C0000 YJYX065 is a high-Ti mare basalt with a rare earth element(REE) enriched signature. This provides a rigid ground-truth for the geological context at the CE-5 landing site and clarifies the ambiguity inferred from remote sensing surveys.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supported by State Key Laboratory of Lithospheric Evolution at the Institute of Geology and Geophysics, Chinese Academy of Sciences, National Natural Science Foundation of China (Grants Nos. 40703015, 40773046)Minor Planet Foundation of China
文摘Miller Range (MIL) 05035 and LaPaz Icefield (LAP) 02224 are unbrecciated lunar basalt meteorites. In this report, we studied their petrography and mineralogy and made in situ uranogenic Pb/Pb dating of Zr-rich minerals. Petrography and mineralogy of these two lunar meteorites are consistent with previous investigations. The zirconolite Pb/Pb age of MIL 05035 is 3851±8 Ma (2σ), in excellent agreement with previous reports. This age suggests that MIL 05035 could be paired with Asuka 881757, a low-Ti mare basalt meteorite. The magmatic event related to MIL 05035 was probably due to the late heavy impact bom- bardment on the moon around 3.9 Ga. One baddeleyite grain in LAP 02224 shows a large variation of Pb/Pb age, from 3109±29 to 3547±21 Ma (2σ), much older than the whole-rock age of the same meteorite (~3.02±0.03 Ga). The other baddeleyite grain in LAP 02224 has an age of 3005±17 Ma (2σ). The result indicates that the minimum crystallization age of LAP 02224 is ~3.55 Ga and the younger ages could reflect late thermal disturbance on U-Pb system.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB 41000000)the Civil Aerospace Pre-research Projects (D020202 and D020302)+2 种基金the National Natural Science Foundation of China (41773059, 41873076, 41803051, 41973060, 42073060, and 42173044)the National Key Research and Development Program of China (2021YFA0716100)the Minor Planet Foundation of China
文摘In December 2020, Chang’E-5(CE-5), China’s first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain, a great distance from those of Apollo and Luna missions. These young mare basalts bear critical scientific significance as they could shed light on the nature of the lunar interior(composition and structure) as well as the recent volcanism on the Moon. In this article, we investigated a CE-5 basalt sample(CE5 C0000 YJYX065) using a combination of state-of-art techniques, including high resolution X-ray tomographic microscopy(HR-XTM), energy dispersive X-ray spectroscopy(EDS)-based scanning electron microscope(SEM), and electron probe microanalysis(EPMA) to reveal its 3 D petrology and minerology.Our results show that this sample has a fine-to medium-grained subophitic texture, with sparse olivine phenocrysts setting in the groundmass of pyroxene, plagioclase, ilmenite and trace amounts of other phases. It has an extremely high ilmenite modal abundance(17.8 vol%) and contains a significant amount(0.5 vol%) of Ca-phosphate grains. The mineral chemistry is in excellent agreement with that of Apollo and Luna high-Ti basalts. The major phase pyroxenes also display strong chemical zoning with compositions following the trends observed in Apollo high-Ti basalts. Based on current data, we came to the conclusion that CE5 C0000 YJYX065 is a high-Ti mare basalt with a rare earth element(REE) enriched signature. This provides a rigid ground-truth for the geological context at the CE-5 landing site and clarifies the ambiguity inferred from remote sensing surveys.
