论文部分内容阅读
1984年10月25日15时,在黑龙江省肇东县境内坠落了两颗陨石,一颗落地后即碎成多块,另一颗形貌保持完整,重约14公斤。陨石基体部分呈灰色,表面有厚约1毫米的黑色熔壳。经研究,陨石的化学成分,主要化学参数,稀土元素,主要矿物成分和结构特征等与吉林陨石和普通H型球粒陨石大体相同,但局部特征也有某些变化。在陨石中见有26种矿物,主要硅酸盐矿物为贯橄榄石和古铜辉石;主要金属矿物为铁纹石、镍纹石和陨硫铁等。陨石具有典型而复杂的球粒结构,如全晶球粒、玻晶球粒、隐晶球粒和玻璃球粒等。球粒轮廓清晰,大小不等,最大者达5毫米,一般0.2至1毫米。球粒含量约占44％。陨石具显著的热变质(重结晶,脱歧化、金属扩散等)和冲击形变(晶体碎裂、弯曲、玻状消光等)现象。稳定同位素分析,δO~(18)值为+6.3(?);δS~(34)值为+0.31(?)。氧、硫同位素没有分馏现象。陨石稳定同位素成分与月岩和地球玄武岩大体相同,表明它们同来源于太阳系的星云物质。陨石中不相容矿物(如橄榄石与石英)的共生,复杂的原生、次生结构特征,以及矿物形成顺序的复杂性和矛盾性,反映了陨石的形成与演化历经了复杂而特殊的物理化学环境,是多种复杂因素长期作用的结果。
At 15:00 on October 25, 1984, two meteorites fell in Zhaodong County, Heilongjiang Province. After one piece fell to the ground, it was crushed into pieces. The other piece remained intact and weighed about 14 kg. Meteorite part of the base is gray, the surface has a thickness of about 1 mm black shell. The research shows that the chemical composition, major chemical parameters, rare earth elements, major mineral components and structural features of meteorites are similar to those of Jilin meteorites and ordinary H type chondrites, but some changes have also been observed in local features. There are 26 kinds of minerals in the meteorite, the main silicate minerals for the peridot and the ancient copper pyroxene; the main metal minerals are iron stone, nickel stone and meteorite pyrite and so on. Meteorites have typical and complex spherulitic structures, such as all-crystal spherulites, glass spherulites, cryptocrystalline spherulites and glass spherulites. Pellets outline clear, ranging in size, the largest of up to 5 mm, generally 0.2 to 1 mm. Pellets accounted for about 44%. Meteorites with significant thermal deterioration (recrystallization, disproportionation, metal diffusion, etc.) and impact deformation (crystal fragmentation, bending, glassy extinction, etc.) phenomenon. For stable isotope analysis, δO ~ (18) was +6.3 (?); ΔS ~ (34) was +0.31 (?). Oxygen, sulfur isotopes without fractionation phenomenon. The stable isotope composition of meteorites is roughly the same as that of lunar rocks and earth basalts, indicating that they are related to the nebular material derived from the solar system. The symbiosis of incompatible minerals (such as olivine and quartz) in meteorites, the complex primary and secondary structural features, and the complexity and contradiction of the mineral formation sequence reflect the formation and evolution of meteorites through complex and special physics The chemical environment is the result of the long-term effects of many complex factors.