福建政和夏山铅锌矿成矿时代研究及讨论  

Research and discussion on the metallogenic epochs of the Xiashan Pb-Zn deposit in Zhenghe County, Fujian Province

作　　者：隰弯弯[1] 陈世忠[1] 朱筱婷[1] XIWanwan;CHEN Shizhong;ZHU Xiaoting(Nanjing Center,China Geological Survey,Nanjing 210016,Jiangsu,China)

机构地区：[1]中国地质调查局南京地质调查中心,江苏南京210016

出　　处：《中国地质》2020年第2期440-449,共10页Geology in China

基　　金：中国地质调查局项目(12120114002601)资助。

摘　　要：福建政和夏山铅锌矿是福建省于20世纪50年代发现的大型铅锌矿,其成因类型长期存在分歧。前人多将其归为沉积-改造型铅锌矿床,即矿层在新元古代由含矿热水沉积形成,燕山期岩浆侵入仅对其进行了改造和富集;但也有部分学者认为夏山铅锌矿是受燕山期铜盆庵正长花岗岩侵入作用影响所形成的矽卡岩型铅锌矿床。本文通过对夏山铅锌矿矿区精细的地质调查表明,夏山铅锌矿体的分布及形态与矿区内花岗斑岩密切相关,铜盆庵岩体对夏山铅锌矿的影响表现在后期的叠加、富集作用。为精确厘定夏山铅锌矿成岩成矿时代,文章对夏山铅锌矿矿区内与成矿相关的花岗斑岩进行了精确的锆石La-ICP-MS U-Pb定年工作。测试结果表明矿区花岗斑岩的侵入时代为(173.0±1.7)Ma,要早于铜盆庵岩体(155~150 Ma),而夏山铅锌矿则形成于(173±1.7)Ma(燕山早期)。这一成矿时代与赣东北地区主要的铜、银、铅锌多金属矿的成矿时代较为一致,表明武夷山地区对华南中生代第一期爆发式成矿作用亦有积极响应,具有早燕山期铜、银、铅锌多金属矿的成矿潜力。而结合前人研究成果,将武夷成矿带北段成矿期次划分为173 Ma和90~125 Ma两个重要的成矿期次,这一研究结果对武夷山成矿带进一步开展隐伏、叠加矿床的找矿工作及成矿规律研究具有重要意义。The Xiashan Pb-Zn deposit is a large-sized Pb-Zn deposit discovered in Fujian Province in the 1950 s. Although most researchers have classified this deposit as a sedimentary-reworked Pb-Zn deposit, some geologists still believe that it is a skarn type deposit formed by the intrusion of the Tongpenan pluton(syenite granite) in Yanshanian period. Based on geological survey, the authors hold that the distribution and morphology of orebodies are closely related to granite porphyry. Ore-related granite porphyry samples from the Xiashan Pb-Zn deposit were dated by zircon La-ICP-MS U-Pb chronology, which yielded an age of 173±1.7 Ma. This result confirms that the Xiashan Pb-Zn deposit involved a skarn mineralization process of Early Yanshanian period which was earlier than the intrusion of the Tongpenan pluton(155-150 Ma). In addition, the age of 173 ± 1.7 Ma is consistent with the metallogenic epoch of Cu, Ag, Pb and Zn polymetallic deposits in northeastern Jiangxi Province, suggesting that the Wuyi Mountain metallogenic belt in Fujian Province had a positive response to the first large metallogeny of the Early Yanshanian period in southern China, and has the potential in the search for Cu, Ag, Pb and Zn polymetallic deposits. According to the results obtained by the authors and previous studies, two important metallogenic periods(173 Ma and 90-125 Ma) of Yanshanian period can be recognized in the Wuyi Mountain metallogenic belt, especially in the north region. These results are of great significance for discovering and studying the concealed and superimposed deposits in the Wuyi Mountain metallogenic belt.

关 键 词：夏山铅锌矿 矽卡岩型矿床 铜盆庵岩体 矿产勘查工程 武夷山 福建政和 

分 类 号：P536[天文地球—古生物学与地层学] P597.3[天文地球—地质学]