赣南珠兰埠岩体锆石U-Pb年代学研究及其含矿性评价  

U-Pb Dating of Zircons and Ore-bearing Potential of Zhulanbu Intrusions in the Southern Jiangxi Province

作　　者：曾乐[1] 陈郑辉[2] 孙丰月[1] 王家欢[3] 孙颖超[4] 陈振宇[2] 

机构地区：[1]吉林大学地球科学学院,吉林长春130026 [2]国土资源部成矿作用与资源评价重点实验室,中国地质科学院矿产资源研究所,北京100037 [3]长江大学地球环境与水资源学院,湖北荆州434023 [4]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《岩矿测试》2016年第2期199-207,共9页Rock and Mineral Analysis

基　　金：十二五科技支撑课题“赣南崇义-于都矿集区深部资源勘查技术集成与示范”(2011BAB04B07);深部探测与实验研究专项的“南岭于都-赣县矿集区立体探测技术与深部成矿示范研究”(201311165)课题;中国地质大调查项目“南岭地区岩浆岩成矿专属性研究”(1212011120989)

摘　　要：珠兰埠岩体是南岭地区大面积出露的岩体之一,也是缺少精确年龄数据的复杂岩体之一,在以往工作中被认为是燕山期早期岩体,此后相关研究较少,由于时代和方法的限制未见确切的同位素年龄数据发表。本文采用LA-(MC)-ICPMS锆石U-Pb法对珠兰埠复式岩体的粗粒斑状黑云母花岗岩、中细粒含斑黑云母花岗岩进行同位素年代学研究,探讨其成矿可能性。获得粗粒斑状黑云母花岗岩、中细粒含斑黑云母花岗岩等时线年龄分别为228.7±2.0 Ma和231.0±1.2 Ma,表明珠兰埠复式花岗岩体主体形成于印支期,而不是前人认为的燕山早期,由此修正了岩体成岩时代,同时结合珠兰埠岩体的地球化学特征与印支期花岗岩的成矿特点,较好印证了目前在该岩体及其周边,并未发现钨矿床的现象。本研究成果为赣南地区花岗岩研究提供了新的实例。Zhulanbu granite is located in the Nanling district with a large exposed area, but its formation age is still unknown. It was previously considered to have formed at the Yanshanian, but no precise isotopic age was reported, as a result of the limitation of time and method. LA-（MC）-ICPMS was used to determine the ages of zircons from coarse grained prophyritic bioxite granite and medium-fine grained prophyritic biotite granite, which were used to discuss the ore potential, and is reported here. These two types of rocks have ages of 228.7 ± 2.0 Ma and 231.0± 1.2 Ma, indicating Zhulanbu composite granite was formed in Indosinian. Combined with the geochemistry of Zhulanbu composite granite and ore-forming characteristic of Indosinian granite, these ages explain the phenomenon that tungsten deposits are not found within the granite and its surroundings. This study provides a new example for the study of granite in southern Jiangxi.

关 键 词：南岭花岗岩 珠兰埠岩体 LA-(MC)-ICPMS锆石U-Pb定年 印支期 

分 类 号：P588.121[天文地球—岩石学] O657.63[天文地球—地质学]