清镇顽辉石球粒陨石（EH3）不透明相的岩石、矿物学研究

^^PETROGRAPHICAL AND MINERALOGICAL STUDY OF OPAQUE MINERALS IN THE QINGZHEN ENSTATITE CHONDRITE (EH3)

通过对最新鲜、最原始的ＥＨ３型陨石──清镇陨石不透明矿物的岩石学、矿物学研究，揭示了不透明矿物化学组成与产状的成因关系，提出了星云冷凝、金属与星云气相组分的硫化反应、矿物出熔及矿物分解等四种形成机制。对不透明矿物的各种环带结构及闪锌矿、硫镁矿等矿物温度计的研究，揭示了该陨石在星云阶段和母体中的热历史。与Ｙａｍａｔｏ６９１（ＥＨ３）的对比表明，清镇陨石不透明矿物形成于更加还原的星云条件。

The petrographical and mineralogical studies on the opaque minerals of the Qingzhen meteorite, a highly unequilibrated and very fresh EH3 chondrite, reveal the relationship between their chemical composition and occurrence. Four types of formation mechanism for the opaque minerals were suggested. They are: (1)condensation, (2)sulfurization of metal, (3)exsolution, and(4) decomposition. Thermal history of the Qingzhen meteorite in solar nebula and in its parent body was also discussed based on various zonings of opaque minerals and the cosmothermometer of sphalerite and niningerite. The comparative study between the Qingzhen meteorite and the Yamato-691(EH3) meteorite indicates that the opaque minerals in the former was formed under more reducing condition in the nebula than the later.