黑龙江高岗山斑岩型钼矿床成岩成矿时代及其地质意义  

Geochronology of Intrusive Rocks and Associated Ores of the Gaogangshan Porphyry Molybdenum Deposit in Heilongjiang Province

作　　者：章永梅[1,2] 顾雪祥[1,2] 刘瑞萍[1] 高海军[1] 苏宇 郑硌[1] 顾枫华 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [3]黑龙江省有色金属地质勘查研究总院,哈尔滨150040

出　　处：《矿物岩石地球化学通报》2014年第5期624-635,共12页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：中国地质调查局地质调查工作项目(1212011120686);国家自然科学基金青年基金项目(41302064);高等学校博士学科点专项科研基金新教师类资助课题(20130022120016);中央高校基本科研业务费专项资金(2-9-2013-010)

摘　　要：高岗山钼矿床是小兴安岭—张广才岭成矿带上首次发现的早三叠世斑岩型钼矿床,对其进行详细的年代学研究,对于研究区域构造演化和拓展找矿方向具有重要意义。为确定高岗山钼矿床的成岩成矿时代,本文开展了同位素年代学的研究。本次用LA-ICP-MS U-Pb方法对矿区内的片麻状花岗闪长岩和与成矿有关的花岗斑岩中的锆石进行了测试,获得其年龄分别为459.8±2.7Ma和259.9±2.0Ma,说明片麻状花岗闪长岩是中奥陶世时洋壳向松嫩"张广才岭地块俯冲形成的,花岗斑岩是晚二叠世时"佳蒙地块"与华北板块北缘东段碰撞形成的。对矿石中的辉钼矿的Re-Os同位素分析,获得其加权平均年龄为250.2±1.4Ma,等时线年龄为247±6Ma,这与成矿岩体的侵位年龄基本一致。The Gaogangshan deposit is the first discovered Early Triassic porphyry molybdenum deposit in the Xiaoxing＇anling-Zhangguangcailing metallogenic belt.Studies on the timing of the intrusive rocks and mineralization provide a significant implication in better understanding of regional tectonic evolution and ore prospecting.LA-ICP-MS U-Pb dating of zircon in gneissic granodiorite gave a weighted average age of 459.8 ± 2.7 Ma,indicating its emplacement in the Middle Ordovician during the westward subduction of the ocean crust under the Songnen-Zhangguangcailing microplate.Dating of zircon in granitic porphyry yielded a weighted average age of 259.9 ± 2.0 Ma,corresponding to the Late Permian collision between Jiamusi-Mongolia block and the eastern segment of the northern margin of the North China Plate.Re-Os dating of molybdenum ore gave an isochron age of 250.2±1.4 Ma and a weighted average age of 247±6 Ma,consistent with the emplacing age of granitic porphyry.

关 键 词：U-PB年龄 RE-OS年龄 斑岩型钼矿床 高岗山 黑龙江省 

分 类 号：P618.65[天文地球—矿床学]