摘要
鲁苏榴辉岩呈构造块体赋存于5种岩石类型中:(1)片麻岩;(2)石榴石橄榄岩;(3)大理岩;(4)石英岩;(5)阳起片岩.原岩属拉斑玄武质系列,并表现出由富MgO向富铁和富碱质演化,仅青岛榴辉岩属钙碱质;矿物化学研究表明,鲁苏榴辉岩属地幔成因和地壳成因.温度估算结果表明,鲁苏榴辉岩平衡温度为880～1100℃和600～700℃,前者代表变质高峰期温度,后者则代表退变质温度.据鲁苏榴辉岩中柯石英的普遍出现推断其变质高峰期压力为2.8GPa左右.根据鲁苏榴辉岩的同位素年龄确定它们形成于三叠纪早期华南陆块与华北陆块的碰撞俯冲作用.
The eclogites from Shandong and Jiangsu provinces occur as structure masses within 1) gneiss; 2) garnet peridotite; 3) marble; 4) quartzite; 5) actinolite schist. The primary rocks were tholeiite series showing evolution of enrichment from Mgo to FeO and Na_2O+K_2O. Only eclogite at Qingdao belongs to calci-alkalic series. Mineral chemistry indicates that the eclogites belong to mantle and crust genesis. Equilibrium estimated indicated the equilibrium temperature of 880-1100℃ and 600-700℃, the former for the peak of metamorphism, and the later for the retrometamorphism. According to the coesite widespreading in the eclogites it is infered that maximum pressure of meramorphism was about 3.0 GPa. According to the isotopic ages they were formed by the southern China plate collision and dive to the northern China plate at Triassic period.
出处
《地质找矿论丛》
CAS
CSCD
1992年第4期13-23,共11页
Contributions to Geology and Mineral Resources Research
基金
山东省地矿局科技基金
