胶东大邓格金多金属矿床成矿机制:来自黄铁矿Rb-Sr定年、原位硫同位素及微量元素的制约  

The metallogenic mechanism of the Dadengge gold polymetallic deposit in the Jiaodong Peninsula:Constraints from pyrite Rb-Sr dating,in situ S isotope and trace elements

作　　者：王美云 李杰 宋明春 张丽鹏 唐宗源 丁正江 WANG MeiYun;LI Jie;SONG MingChun;ZHANG LiPeng;TANG ZongYuan;DING ZhengJiang(Hebei Key Laboratory of Strategic Critical Mineral Resources,Shijiazhuang 050031,China;School of Water Resources and Environment,Hebei GEO University,Shijiazhuang 050031,China;College of Earth Sciences,Hebei GEO University,Shijiazhuang 050031,China;Center of Deep Sea Research,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Laboratory for Marine Geology,Laoshan Laboratory,Qingdao 266237,China;Shandong Provincial No.6 Exploration Institute of Geology and Mineral Resources,Weihai 264209,China)

机构地区：[1]河北省战略性关键矿产资源重点实验室,石家庄050031 [2]河北地质大学水资源与环境学院,石家庄050031 [3]河北地质大学地球科学学院,石家庄050031 [4]中国科学院海洋研究所深海研究中心,青岛266071 [5]崂山实验室海洋地质过程与环境功能实验室,青岛266237 [6]山东省地矿局第六地质大队,威海264209

出　　处：《岩石学报》2023年第5期1501-1515,共15页Acta Petrologica Sinica

基　　金：河北省自然科学基金项目(D2020403061);国家自然科学基金山东省联合基金项目(U2006201);国家自然科学基金项目(41973048)联合资助.

摘　　要：大邓格金多金属矿床是胶东半岛唯一的一个金、银、铅、锌、铜共生的多金属矿床。与胶东金矿床主要分布于华北克拉通东南缘的胶北地体不同,大邓格矿床处于苏鲁-大别造山带最东端的威海超高压变质带。准确限定大邓格矿床的成矿年龄和成矿物质来源对深入理解胶东晚中生代成矿作用及构造背景具有重要意义。本文选取大邓格金多金属矿床主成矿阶段矿石中的黄铁矿开展Rb-Sr同位素定年和原位硫同位素及微量元素分析,以此限定成矿时限、成矿物质来源和成矿机制。结果显示黄铁矿Rb-Sr同位素等时线年龄为109.8±1.7Ma(MSWD=1.4),与该区域的钼、铜等有色金属矿床成矿时代一致,略晚于胶东大规模金矿爆发的时代(~120Ma)。主成矿阶段的硫同位素在-1.20‰~6.65‰之间,平均值为5.31‰。黄铁矿中富集Cu、Pb、Zn、Co、Ni等亲硫元素和铁族元素,Co/Ni比值介于0.03~1.36之间。大邓格金多金属矿床在空间上产于伟德山岩体的崮庄岩石单元外围,且成岩、成矿时代一致,表明二者具有密切的成因联系。综合分析认为,胶东早白垩世成矿作用受控于与古太平洋板块俯冲、华北克拉通破坏有关的热隆-伸展构造环境,俯冲板块向东后撤造成了西早东晚的区域成矿时间差异。The Dadengge gold polymetallic deposit is located in the eastern part of the Jiaodong Peninsula,and is the only polymetallic deposit of gold,silver,lead,zinc and copper found in this area at present.Different from the famous Jiaodong gold concentration area,which is mainly located in the Jiaobei terrane on the southeastern margin of the North China Craton,the Dadengge deposit is located in the Weihai ultrahigh-pressure metamorphic belt at the easternmost end of the Sulu-Dabie orogenic belt.It is of great significance to accurately define the metallogenic age and source of ore-forming materials of the Dadengge deposit for further understanding the mineralization of different tectonic settings in the Mesozoic era in Jiaodong area.This paper selects pyrite in the main ore forming stage of the Dadengge gold polymetallic deposit to carry out Rb-Sr isotope dating and in-situ sulfur isotope and trace element analysis,so as to limit the regional metallogenic age,the source of metallogenic materials and the metallogenic mechanism.The results show that the Rb-Sr isotope isochron age of pyrite is 109.8±1.7Ma(MSWD=1.4),which is consistent with the metallogenic age of the molybdenum,copper and other non-ferrous metal deposits in this region,and slightly later than the age of the large-scale gold deposit explosion in Jiaodong(~120Ma).The sulfur isotope in the main mineralization stage is in the range of-1.20‰~6.65‰.Pyrite is rich in thiophile elements such as Cu,Pb,Zn,Co,Ni,and the Co/Ni ratio is 0.03~1.36.The Dadengge gold polymetallic deposit is spatially located in the periphery of the Guzhuang unit of the Weideshan rock mass,and it s diagenetic and metallogenic ages are consistent,indicating that they have close genetic relations.According to comprehensive analysis,the Early Cretaceous mineralization in Jiaodong was controlled by the thermal uplift-extension tectonic environment related to the subduction of the ancient Pacific plate and the destruction of the North China Craton,and the eastward retreat of the subducti

关 键 词：大邓格金多金属矿床 黄铁矿Rb-Sr测年 黄铁矿原位硫同位素 成矿机制 胶东半岛 

分 类 号：P597[天文地球—地球化学] P618.51[天文地球—地质学]