北淮阳带新元古代花岗质侵入体的特征及大地构造意义  

CHARACTERS AND TECTONIC SIGNIFICANCE OF THE NEOPROTEROZOIC DEFORMED GRANITIC PLUTONS OF BEIHUAIYANG AREA, ANHUI PROVINCE

作　　者：王果胜[1] 马文璞[1] 刘文灿[1] 程三友[1] 

机构地区：[1]中国地质大学,北京100083

出　　处：《成都理工大学学报（自然科学版）》2003年第1期25-29,共5页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家自然科学基金 ( 4990 2 0 1 7);地质行业科学技术发展基金 ( HY97983 3 )资助项目

摘　　要：近些年来 ,在北淮阳带地层研究方面的主要进展之一 ,是将以前建立的一些变质岩群解体成不同时代、不同性质的构造地层或岩石地层单位 ,并重新厘定了它们的含义和分布。最近从原卢镇关群、佛子岭群、梅山群中识别出了较多变形花岗质岩体 ,马文璞等运用单颗粒锆石 U- Pb法测得四个变形花岗岩的年龄为 74 4± 9Ma和 665± 3 9Ma,属新元古代。岩石化学和元素地球化学分析表明 ,这些变形花岗岩的 R1 变化主要范围为 1 93 4～ 2 768,Ga/Al值位于1 .72～ 3 .61范围内。在 Zr,Nb,Ce,Y - Ga/A l图解上 ,它们主要落入后造山 ( PA)型花岗岩区 ;在 R1 - Ga/Al图解上 ,也属于后造山 ( PA)型花岗岩。上述事实可能意味着 ,Rodinia泛大陆的汇聚发生在新元古代变形花岗岩侵入之前 。In recent years, many advances have been made in the investigation on the strata exposed in the Beihuaiyang area. One of them is that the former single metamorphic litho group is disintegrated into a few of tectono stratigraphic units and litho formations with different ages. The geologic characters and the distribution of these newly identified units have been become clearer. Recent field mapping and associate geochemical investigations have led to the identification of several deformed granitic plutons from the so called Luzhenguan Group, Foziling Group and Meishan Group as well. The U Pb dating on zircons from four of these deformed plutons gives an age ranging from 744±9 Ma to 665±39 Ma. The whole rock chemical analysis and geochemistry research on the deformed plutons indicate that the R 1 varies from 1934 to 2768, and Ga/Al varies from 1.72 to 3.61. The deformed plutons are plotted in the area of the post orogenic alkali granite (PA) in both Zr, Nb, Ce,Y Ga/Al diagram and R 1 Ga/Al diagram. These geochronological and geochemical results suggest that at least in the Beihuaiyang area, the convergence of Rodinia supercontinents occurred before Neoproterozoic and followed by an extensional tectonic event.

关 键 词：北淮阳带 新元古代 变形花岗质岩体 花岗质侵入体 大地构造意义 构造环境 安徽 岩石化学 

分 类 号：P588.121[天文地球—岩石学]