常德陨石雨物质成分和球粒结构的初步研究

MINERALOGY, PETROLOGY, AND CHEMICAL COMPOSITION OF THE CHANGDE METEORITE SHOWER

On Mareh 11,1977,the Changde stone meteorite shower fell near the town of Changde,Hunan Province(29°05'N,111°45'E).The total recovered mass vas 1.81kg in weight(900g,254g,220g,184g,50g,20g,11.8g,20g,20g,18.3g,and 113g)X-ray diffraction analyses and microseopic identification have indicated the presence of the following minerals:olivine(175,Fa),orthopyroxene(18% Fs),elinopyroxene,plagioclase,orthoclase,whitlockite,kamocite,taenite,troilite and chromite,Turbid glass has been found in chondrules.Shock effect has bee also observed in olivinc and pyroxene.Chemical analyses have given;SiO2 37.61,TiO2 0.086,Al2O3 2.18,Cr2O3 0.52,FeO 8.00,MnO 0.18,MgO22.87,CaO 1.92,Na2O 0.87,K2O 0.11,H2O^- 0.06,H2O^+0.06,P2O5 0.21,Fe°18.44,Ni 1.80,Co0.091,Cu0.014,Zn0.006,FeS5.59,C 0.16,total 100.78 Model analysis gives;olivine 26.86%,pyroxene 36.62%,plagioclase 9.06%,orthoclase 0.65%,whitlockite 0.46%,titanite 0.17%,kamocite and taenite 20.24%,troilite 5.59%,Chemieo-petrological stndies have shown that the meteorite bclongs to H-group chondrites,and petrologically to Type 5.Based upon the textures of the chondrules,a model of the evolution for the Changde chondrite is presented.

On March 11, 1977, the Changde stone meteorite shower fell near the town of Changde, Hunan Province (29°05' N, 111°45' B). The total recovered mass was 1.81 kg in weight (900 g, 254 g, 220 g, 184 g, 50 g, 20 g, 11.8 g, 20 g, 20 g, 18.3 g and 113 g). X-ray diffraction analyses and microscopic identification have indicated the presence of the following minerals: olivine (17% Fa), orthopyroxene (18% Fs), clinopyroxen'e, plagioclase, orthoclase, whitlockite, kamocite, taenite, troilite and chromite. Turbid glass has been found in chondrules. Shock effect has been also observed in olivine and pyroxene. Chemical analyses have given: SiO2 37.61, TiO2 0.086, A12O3 2.18, Cr2O3 0.52, FeO 8.00, MnO 0.18, MgO 22.87, CaO 1.92, Na2O 0.87, K2O 0.11, H2O- 0.06, H2O + 0.06, P2O5 0.21, Fe° 18.44, Ni 1.80, Co 0.091, Cu 0.014, Zn 0.006, FeS 5.59, C 0.16, total 100.78. Model analysis gives: olivine 26.86%, pyroxene 36.62%, plagioclase 9.06%, orthoclase 0.65%, whitlockite 0.46%, titanite 0.17%, kamocite and taenite 20.24%, troilite 5.59%. Chemico-petrological studies have shown that the meteorite belongs to H-group chondrites, and petrologically to Type 5. Based upon the textures of the chondrules, a model of the evolution for the Changde chondrite is presented.