胶东地区蓬莱群沉积岩碎屑锆石年龄和物源  

Detritai Zircon Ages and Sources of Sedimentary Rocks in Penglai Formation, Eastern Shandong

作　　者：李向辉[1,2] 陈福坤[1] 李秋立[1] 郭敬辉[1] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]中国科学院研究生院地球科学院,北京100039

出　　处：《地球学报》2005年第B09期123-124,共2页Acta Geoscientica Sinica

基　　金：本文由973项目“大陆深俯冲作用”（编号：G1999075502）和国家教育部留学回国人员科研启动基金资助.

摘　　要：分布于鲁东胶北地区蓬莱群为一套浅变质沉积岩，角度不整合覆盖在太古宙胶东群、元古宙粉子山群上。关于蓬莱群的沉积时代尚存较大的争议，认为是震旦纪或古生代沉积形成的。蓬莱群和五莲杂岩、北淮阳变质岩带都是位于大别-苏鲁超高压变质造山带北部的重要岩石构造单元。本文报道蓬莱群沉积岩碎屑锆石年龄和铪同位素分析资料，并探讨其可能的物质来源。This paper reports ^207Pb/^206Pb ages and Hf isotopic composition of detrital zircons from sedimentary rocks of Penglai Formarion exposed in the northern part of the Sulu orogenic belt. Ages of fifty zircon grains obtained by the evaporation method mostly range from ca. 1 000 Ma to 1 800 Ma, clustering around 1 200 Ma and 1 600 Ma. Model ages of Hf isotopes range from about 1 300 Ma to 3 200 Ma, clustering around 1 700 Ma. The data of zircon ages and Hf isotopic composition imply that the sedimentary rocks were derived from sources of South China affinitv and probably deoosited between 1 000 Ma and 800 Ma.

关 键 词：碎屑锆石年龄 HF同位素组成 测定 蓬莱群 苏鲁 变质沉积岩 锆石年龄 胶东地区 碎屑 物源 

分 类 号：P588.2[天文地球—岩石学] P588.121[天文地球—地质学]