The Guangrao meteorite,weighing 1.9kg,fell on June 21,1980 near Gnaugrao County,Shandong Provinee(37.1°N，118.4°E）.Mineralogical and chemical compositions of the meteorite from Guangrao County were determin...The Guangrao meteorite,weighing 1.9kg,fell on June 21,1980 near Gnaugrao County,Shandong Provinee(37.1°N，118.4°E）.Mineralogical and chemical compositions of the meteorite from Guangrao County were determined,indicating an olivine-hypersthene chondrite with perfect recrystallization structure.It is composed mainly of olivine(Fa24)and orthopyroxene(Fs 10),and minor amounts of plagioclase,kamacite,taenite,troilite,chromite,and a negligible amount of native copper.Textural features of the Guangrao meteorite show that there are only a few chondrules with distinct outlines,as identified in thin sections.Examined in polarized cross light,it was found that the meteorite is of high petrographic type,belonging to type 6-5 chondrites of Van Schmus and Wood(1967).The preliminary results of wet chemical analysis are given as follows:SiO2 39.81,MgO 25.09,FeO 15.78,Al2O3 2.08,CaO 1.93,Na2O 1.00,K2O 0.13,Cr2O3 0.52,MnO 0.27,TiO2 0.13,P2O5 0.26,Cu0.012,Fe 6.3,Ni1.55,Co0.055,FeS5.91,H2O^- 0.033,H2O^+ 0.016,total Fe22.38(%);the ratios of SiO2/MgO 1.59,Fe^0/Fe 0.28,Fe/Si 0.61.Si/Mg 1.06;Fe(mole %)24.In accordance with the bulk chemical composition,the Guangrao meteorite belongs to L-group chondrites,A preliminary hypothesis for L6-5 chondrite is suggested on the basis of the homogeneity and composition of silicate minerals and the apparent lack of chondrules with distinet outlines and reerytallized matrix.展开更多
文摘The Guangrao meteorite,weighing 1.9kg,fell on June 21,1980 near Gnaugrao County,Shandong Provinee(37.1°N，118.4°E）.Mineralogical and chemical compositions of the meteorite from Guangrao County were determined,indicating an olivine-hypersthene chondrite with perfect recrystallization structure.It is composed mainly of olivine(Fa24)and orthopyroxene(Fs 10),and minor amounts of plagioclase,kamacite,taenite,troilite,chromite,and a negligible amount of native copper.Textural features of the Guangrao meteorite show that there are only a few chondrules with distinct outlines,as identified in thin sections.Examined in polarized cross light,it was found that the meteorite is of high petrographic type,belonging to type 6-5 chondrites of Van Schmus and Wood(1967).The preliminary results of wet chemical analysis are given as follows:SiO2 39.81,MgO 25.09,FeO 15.78,Al2O3 2.08,CaO 1.93,Na2O 1.00,K2O 0.13,Cr2O3 0.52,MnO 0.27,TiO2 0.13,P2O5 0.26,Cu0.012,Fe 6.3,Ni1.55,Co0.055,FeS5.91,H2O^- 0.033,H2O^+ 0.016,total Fe22.38(%);the ratios of SiO2/MgO 1.59,Fe^0/Fe 0.28,Fe/Si 0.61.Si/Mg 1.06;Fe(mole %)24.In accordance with the bulk chemical composition,the Guangrao meteorite belongs to L-group chondrites,A preliminary hypothesis for L6-5 chondrite is suggested on the basis of the homogeneity and composition of silicate minerals and the apparent lack of chondrules with distinet outlines and reerytallized matrix.
