Mineralogy of the Lunar surface provides important clues for understanding the composition and evo- lution of the primordial crust in the Earth-Moon system. The primary rock forming minerals on the Moon such as pyroxe...Mineralogy of the Lunar surface provides important clues for understanding the composition and evo- lution of the primordial crust in the Earth-Moon system. The primary rock forming minerals on the Moon such as pyroxene, olivine and plagioclase are potential tools to evaluate the Lunar Magma Ocean （LMO） hypothesis. Here we use the data from Moon Mineralogy Mapper （M3） onboard the Chandrayaan- 1 project of India, which provides Visible/Near Infra Red （NIR） spectral data （hyperspectral data） of the Lunar surface to gain insights on the surface mineralogy. Band shaping and spectral profiling methods are used for identifying minerals in five sites： the Moscoviense basin, Orientale basin, Apollo basin, Wegener crater-highland, and Hertzsprung basin. The common presence of plagioclase in these sites is in conformity with the anorthositic composition of the Lunar crust. Pyroxenes, olivine and Fe-Mg-spinel from the sample sites indicate the presence of gabbroic and basaltic components. The compositional difference in pyroxenes suggests magmatic differentiation on the Lunar surface. Olivine contains OH/H20 band, indicating hydrous phase in the primordial magmas.展开更多
The Tengchong volcano field(TVF),situated at the southeastern margin of the Tibetan Plateau,holds crucial information regarding Cenozoic volcanic activities and geotectonic evolution of the SE Tibet.To provide new con...The Tengchong volcano field(TVF),situated at the southeastern margin of the Tibetan Plateau,holds crucial information regarding Cenozoic volcanic activities and geotectonic evolution of the SE Tibet.To provide new constraints on petrogenesis and evolution of the Tengchong volcanism,here we conducted copper(Cu)elemental and isotopic analyses on a suite of samples that document the evolution from basalts to andesites in the TVF.The basalts are Cu-depleted(29.7-36.9 ppm)and have higherδ65Cu val-ues(0.19‰-0.40‰,mean=0.31‰±0.05‰;n=11)than those of mid-ocean ridge basalts(MORBs,~0.09‰)and the mantle(~0.06‰)as well as the majority of island arc lavas.Along with the low Cu/Zr ratios,these characteristics are interpreted to reflect the fractionation of isotopically light sulfides in the S-saturated systems during magma ascent,rather than source heterogeneity induced by recycled materials and redox reactions.Compared with the basalts,the andesites have slightly lower Cu contents(14.4-29.4 ppm)and lighter Cu isotopic compositions(mean=-0.14‰±0.06‰;n=13).These differences cannot be attributed to progressive sulfide fractionation of basaltic magmas but require the assimilation of lower crustal materials with lowδ65Cu values during evolution of the andesitic magmas.Our results collectively suggest that Cu isotopes can provide valuable insights into magma origin and evolution.展开更多
文摘Mineralogy of the Lunar surface provides important clues for understanding the composition and evo- lution of the primordial crust in the Earth-Moon system. The primary rock forming minerals on the Moon such as pyroxene, olivine and plagioclase are potential tools to evaluate the Lunar Magma Ocean （LMO） hypothesis. Here we use the data from Moon Mineralogy Mapper （M3） onboard the Chandrayaan- 1 project of India, which provides Visible/Near Infra Red （NIR） spectral data （hyperspectral data） of the Lunar surface to gain insights on the surface mineralogy. Band shaping and spectral profiling methods are used for identifying minerals in five sites： the Moscoviense basin, Orientale basin, Apollo basin, Wegener crater-highland, and Hertzsprung basin. The common presence of plagioclase in these sites is in conformity with the anorthositic composition of the Lunar crust. Pyroxenes, olivine and Fe-Mg-spinel from the sample sites indicate the presence of gabbroic and basaltic components. The compositional difference in pyroxenes suggests magmatic differentiation on the Lunar surface. Olivine contains OH/H20 band, indicating hydrous phase in the primordial magmas.
基金supported by the National Natural Science Foundation of China(grant 42121002)the National Key R&D Program of China(2019YFA0708400).
文摘The Tengchong volcano field(TVF),situated at the southeastern margin of the Tibetan Plateau,holds crucial information regarding Cenozoic volcanic activities and geotectonic evolution of the SE Tibet.To provide new constraints on petrogenesis and evolution of the Tengchong volcanism,here we conducted copper(Cu)elemental and isotopic analyses on a suite of samples that document the evolution from basalts to andesites in the TVF.The basalts are Cu-depleted(29.7-36.9 ppm)and have higherδ65Cu val-ues(0.19‰-0.40‰,mean=0.31‰±0.05‰;n=11)than those of mid-ocean ridge basalts(MORBs,~0.09‰)and the mantle(~0.06‰)as well as the majority of island arc lavas.Along with the low Cu/Zr ratios,these characteristics are interpreted to reflect the fractionation of isotopically light sulfides in the S-saturated systems during magma ascent,rather than source heterogeneity induced by recycled materials and redox reactions.Compared with the basalts,the andesites have slightly lower Cu contents(14.4-29.4 ppm)and lighter Cu isotopic compositions(mean=-0.14‰±0.06‰;n=13).These differences cannot be attributed to progressive sulfide fractionation of basaltic magmas but require the assimilation of lower crustal materials with lowδ65Cu values during evolution of the andesitic magmas.Our results collectively suggest that Cu isotopes can provide valuable insights into magma origin and evolution.
