摘要
对湖北黄土岭麻粒岩中锆石同时进行了激光拉曼探针、阴极发光 (CL)观察和U ,Th及Pb Pb年龄ICPMS测定 ,发现麻粒岩中部分锆石发生的不是固态重结晶作用 ,而是部分熔蚀 /沉淀再结晶过程。结合CL图像结构特征和2 0 7Pb/ 2 0 6Pb年龄初步推断 ,麻粒岩相事件发生在 2 0亿年之后。结构、化学和同位素组成的测定表明 ,大别地区广泛存在的燕山期热事件使锆石发生不同程度的变质重结晶作用 ,使锆石晶格愈合。
Zircons from Huangtuling Northern Dabie were investigated by Raman microprobe(RMP) analysis and CL images. U,Th compositions and Pb\|Pb ages were measured by LAM\|ICP\|MS. Combining RMP and LAM\|ICP\|MS analysis, we found that some zircons have suffered dissolving/sedimentation and crystallizing. The granulite\|grade event occurred before 2 000 Ma. The zircons of Huangtuling may have undergone continuous thermal annealing of the radiation damage for a long time after closure of the U\|Pb isotope system, probably until about 130 Ma,they were completely reconstructed by the Yanshanian thermal event.
出处
《地学前缘》
EI
CAS
CSCD
2003年第2期313-317,共5页
Earth Science Frontiers
基金
国家自然科学基金项目 ( 4 9973 0 19
40 2 73 0 2 8)
