摘要
以分布于攀枝花大田地区侵入于混合岩中的辉绿岩脉和花岗质岩脉为研究对象,采集不同方向的辉绿岩脉和花岗质岩脉进行LA-ICP-MS锆石U-Pb定年,探讨它们形成地质背景、时代及其意义。研究结果表明:(1)不同方向辉绿岩脉的年龄集中在770～780 Ma之间,花岗质岩脉的年龄集中在760～770 Ma之间;(2)在时空上,辉绿岩脉和花岗岩脉具有双峰式岩浆活动的特点,应是Rodinia大陆裂解过程中岩浆上侵的产物;(3)岩脉的形成时代限制了研究区混合岩的形成下限,即大田地区的混合岩的形成时代早于780 Ma;(4)大田地区辉绿岩脉/花岗质岩脉与构造蚀变带中的花岗质及长英质脉体的形成时代一致,结合大田地区505铀矿的形成时代和产出的空间位置,认为攀枝花大田地区铀矿的形成与导致辉绿岩脉和花岗质岩脉形成的岩浆活动有着密切的关系,提供了热源和流体来源。研究成果为该区铀矿成矿规律的探究及找矿具有重要的意义。
Samples of diabase and granitic dikes in different directions which intruded into migmatite in Datian area,Panzhihua were collected for LA-ICP-MS zircon U-Pb dating so as to discussed their geological background,formation age and significance.The results shewed that:(1)the ages of diabase dikes in different directions are between 770 Ma and 780 Ma,and granitic dikes are between 760 Ma and 770 Ma;(2)diabase dikes and granite dikes have the characteristics of bimodal magmatic activity in time and space,which should be the product of magma invasion during the cracking process of Rodinia continent;(3)the formation age of dikes constricted the formation time of migmatization in the study area,the migmatite was formed before 780 Ma;(4)The age of diabase dikes/granite dikes is consistent with that of granite and felsic dikes in the structural alteration zone.Based on the above feature and the formation time and spatial location of 505 uranium deposit in Datian area,it is believed that the formation of uranium deposits was closely related to the magmatic activity resulted from diabase and granitic dike in Panzhihua Datian,which may provide heat and fluid sources to the uranium mineralization.
作者
柏勇
徐争启
秦琪瑞
张成江
陈友良
BAI Yong;XU Zhengqi;QIN Qirui;ZHANG Chengjiang;CHEN Youliang(College of Geoscience of Chengdu University of Technology,Chengdu,Sichuan 610059,China;Key Laboratory of Earth Exploration and Information Technology,Ministry of Education,Chengdu Sichuan 610059,China;Key Laboratory of Geoscience and Nuclear Technology,Sichuan Province,Chengdu Sichuan 610059,China)
出处
《铀矿地质》
CAS
CSCD
2019年第2期80-87,128,共9页
Uranium Geology
基金
国家自然科学基金项目"康滇地轴粗粒晶质铀矿标型特征及形成机理(编号:41872079)"
中国铀业公司科研项目"康滇地轴新元古代铀成矿特征对比研究(编号:201807)"资助
关键词
辉绿岩脉
花岗质岩脉
年代学
铀矿
大田
diabase dikes
granitic dikes
geochronology
uranium deposits
Datian
