摘要
鲁南苏北榴辉岩按产状分为两类:一类是呈条带状、透镜状或肠状鳌合赋存于胶南混杂岩系中,另一类是呈透镜状赋存于石榴石橄榄岩中,以前者分布最为广泛,后者仅见于日照及东海地区。胶南混杂岩系中的榴辉岩由橄榄拉斑玄武岩深成变质作用形成,石榴石橄榄岩中的榴辉岩为地幔来源,它们共同经历了早期2.8 GPa,800℃的高温高压平衡结晶及后期600—700℃,1.1—1.3 GPa的退变质作用改造。Sm-Nd等时年龄为222±6Ma,^(143)Nd/^(144)Nd初始比值为0.511 36±3,推测本区榴辉岩形成于早三叠世华南陆块与华北陆块的碰撞事件。
The eclogites from the southern Shandong and the northern Jiangsu district can be divided into two types according to its occurrences,one is within the Jiaonan mingling rocks series as bands, lens or intestines, and the other is within garnet peridotite as lens. The former is widespread, the latter only occurs in Rizhao of Shandong province and Donghai of Jiangsu province. Study of perology and geochemistry indicated that the eclogites within the Jiaonan mingling rocks series formation by hypozonal metamorphism from olive tholeiite,and the eclogites within garnet peridotite genesis in mantle, both of them undergo 2. 8 GPa,800℃ of early stage high-temperature and high-pressure equlibrium crystalization and 600—700℃,l. 1—1. 3 GPa of retrometamorphism of later stage. The Sm-Nd isochron age is 222±6 Ma, ^(143)Nd/^(144)Nd primary ratio is 0. 511 36±3,It is inferred that the eclogites from this district were formed dy the collision event of the southern china plate with the northern China plate at the early Triassic Period.
出处
《矿物岩石》
CAS
CSCD
1992年第4期28-35,共8页
Mineralogy and Petrology
基金
山东省地质矿产局科技基金资助项目
关键词
榴辉岩
岩石学
地球化学
成因
eclogite
petrology
mineral chemistry
geochemistry
the Jiaonan mingling rocks series
Sm-Nd isochron age
