Brachinite is a group of primitive achondrites that enables investigating the evolution of asteroids not fully diff erentiated in the early stage of the solar system.Kumtag 061 is a new meteorite sample collected on O...Brachinite is a group of primitive achondrites that enables investigating the evolution of asteroids not fully diff erentiated in the early stage of the solar system.Kumtag 061 is a new meteorite sample collected on October 27,2019,in Kumtag Desert,Xinjiang Province,China.The oxygen isotope composition(δ^(18)O=5.086‰,δ^(17)O=2.396‰,Δ’^(17)O=-0.298‰)and petrologic and mineralogic analysis suggest Kumtag 061 is a heavy-impacted brachinite(S4-S5).The geochemical composition suggests Kumtag 061 represents a partial melting residue of the brachinite parent body.Based on the noble gas composition,the cosmic ray exposure age of Kumtag 061 is 60.9±9.0 Ma.Combined with the gas retention ages,they indicate a(series of)thermal events on the parent body of brachinites before Kumtag 061 was ejected into space.展开更多
基金supported by the Project of Highlevel Innovative Talents of Guizhou Province(GCC[2022]017-1)the National Natural Science Foundation of China(grant no.42173046)。
文摘Brachinite is a group of primitive achondrites that enables investigating the evolution of asteroids not fully diff erentiated in the early stage of the solar system.Kumtag 061 is a new meteorite sample collected on October 27,2019,in Kumtag Desert,Xinjiang Province,China.The oxygen isotope composition(δ^(18)O=5.086‰,δ^(17)O=2.396‰,Δ’^(17)O=-0.298‰)and petrologic and mineralogic analysis suggest Kumtag 061 is a heavy-impacted brachinite(S4-S5).The geochemical composition suggests Kumtag 061 represents a partial melting residue of the brachinite parent body.Based on the noble gas composition,the cosmic ray exposure age of Kumtag 061 is 60.9±9.0 Ma.Combined with the gas retention ages,they indicate a(series of)thermal events on the parent body of brachinites before Kumtag 061 was ejected into space.
