胶西北玲珑、焦家金矿田锆石(U-Th)/He年龄及其对成矿后剥露程度的指示  

Zircon(U-Th)/He Age and Its Implication for Post-Mineralization Exhumation Degree of Linglong and Jiaojia Goldfields,Northwest Jiaodong,China

作　　者：孙华山[1] 韩静波[2] 申玉科[3] 刘浏 冷双良 许冲[6] 杨巧梅[1] 葛风建 欧阳淑冰 邓旭[1] 

机构地区：[1]中国地质大学资源学院,湖北武汉430074 [2]河北省地质矿产勘查开发局秦皇岛矿产水文工程地质大队,河北秦皇岛066000 [3]中国地质科学院地质力学研究所,北京100081 [4]广东省有色地质勘查院,广东广州510080 [5]湖北省地质调查院,湖北武汉430034 [6]河南省地质矿产勘查开发局第二地质勘查院,河南许昌461000

出　　处：《地球科学（中国地质大学学报）》2016年第4期644-654,共11页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目(No.41172087);中央高校基本科研业务费专项资金项目(No.CUG090102)

摘　　要：玲珑和焦家矿田是胶西北地区最负盛名的两个金矿田.目前有关这两个矿田成矿研究的成果已十分丰富,但是,成矿后隆升剥蚀程度的研究尚属空白.为此,利用最近兴起的低温热年代学技术,对两个矿田成矿后剥露程度进行了尝试研究.结果表明,玲珑矿田锆石（U-Th）/He年龄主要为80~100Ma,焦家矿田锆石（U-Th）/He年龄主要为90~105Ma.这些年龄与前人运用其他方法获得的成岩成矿年龄不同,其不是本区岩浆-热液成矿事件的年龄,而是成矿后花岗岩隆升剥蚀的热年龄.基于锆石（U-Th）/He年龄制约,估算本区成矿后隆升剥蚀速率大致与全球造山型金矿剥露速率相当（大约60m/Ma）.玲珑矿田总体比焦家矿田成矿后多剥露了600~900m,焦家矿田深部找矿潜力应比玲珑矿田大.The Linglong and Jiaojia goldfields are the two most famous goldfields in the Northwest Jiaodong with voluminous publication focused on gold mineralization.Whereas it is still a barren land as far to pay attention to the post-mineralization exhumation.Utilizing the latest low-temperature thermochronological technique,this work carries out a tentative research on the exhumation degree in the two goldfields.The results show that the zircon（U-Th）/He ages in Linglong goldfield vary predominantly between 80 and 100Ma,while they are of significant concentration between 90 and 105Ma in Jiaojia goldfield.Theseages yielded in this work are different from those of the previous obtained by other methods,they are not the geochronological ages in respond to magmatic-hydrothermal mineralization events,instead they must have recorded the thermochronological ages of the post-mineralization exhumation of the granitoid rocks.Based on the constrain of the zircon（U-Th）/He ages,it can be concluded that the degree of exhumation in this area is roughly in agreement with that from the statistics of the global orogenic gold deposits,about 60m/Ma.The amount of post-mineralization exhumation in the Linglong goldfield is overall ca.600-900 m more than that in the Jiaojia goldfield,so the prospecting potential at deep part is larger in the Jiaojia goldfield than that in the Linglong goldfield.

关 键 词：锆石(U-Th)/He 剥露程度 胶西北金矿集中区 矿产 矿床学 

分 类 号：P62[天文地球—地质矿产勘探]