CAJ | 학술논문

盘古山钨矿是一个历史悠久、闻名国内外的大型矿床,为了厘定其岩浆活动及成矿作用时代,进而认识成岩与成矿关系、岩体内带与外带矿化关系及成岩成矿动力学背景,本研究采用LA-ICP-MS锆石U-Pb和ICP-MS辉钼矿Re-Os分析法分别对南岭2000 m科学钻探(SP-NLSD-2)所揭露的隐伏花岗岩体及其内带矿化石英脉进行了年龄测定。结果表明,隐伏花岗岩体形成于(161.7±1.6) Ma,内带矿化石英脉年龄为(155.3±2.8) Ma,均形成于中-晚侏罗世。盘古山钨矿床花岗岩浆活动与成矿作用的时代在误差范围内基本一致,矿化发育于岩体内外接触带,在空间上关系密切,并表现出花岗岩体→长石石英脉→石英脉的渐变演化关系,结合前人研究成果表明,矿化石英脉是花岗岩浆分异演化晚期的产物。岩体内带石英脉与外带石英脉的形成年龄吻合较好,形成于同一成矿作用。盘古山钨矿床及其隐伏花岗岩体均形成于165~150 Ma华南岩石圈伸展-岩体侵位-大规模成矿的动力学环境。
반고산오광시일개역사유구、문명국내외적대형광상,위료전정기암장활동급성광작용시대,진이인식성암여성광관계、암체내대여외대광화관계급성암성광동역학배경,본연구채용LA-ICP-MS고석U-Pb화ICP-MS휘목광Re-Os분석법분별대남령2000 m과학찬탐(SP-NLSD-2)소게로적은복화강암체급기내대광화석영맥진행료년령측정。결과표명,은복화강암체형성우(161.7±1.6) Ma,내대광화석영맥년령위(155.3±2.8) Ma,균형성우중-만주라세。반고산오광상화강암장활동여성광작용적시대재오차범위내기본일치,광화발육우암체내외접촉대,재공간상관계밀절,병표현출화강암체→장석석영맥→석영맥적점변연화관계,결합전인연구성과표명,광화석영맥시화강암장분이연화만기적산물。암체내대석영맥여외대석영맥적형성년령문합교호,형성우동일성광작용。반고산오광상급기은복화강암체균형성우165~150 Ma화남암석권신전-암체침위-대규모성광적동역학배경。
The Pangushan tungsten deposit is a well-known old and large ore deposit which has attracted many researchers and exploration geologists both in China and abroad. In order to determine the ages of magmatism and mineralization in the deposit and thus to gain insights into the relationship between magmatic process and tungsten mineralization, the association of endocontact mineralization with exocontact mineralization as well as their geodynamic setting, the authors conducted LA-ICP-MS zircon U-Pb and ICP-MS molybdenite Re-Os isotopic measurement of Pangushan concealed granite and its endocontact-mineralized quartz veins discovered by 2000 m Nanling Scientific Drilling (SP-NLSD-2). The results indicate that the weighted average ages of zircon 206Pb/238U ages for Pangushan granite and of molybdenite Re-Os isotopic model ages for the quartz veins are (161.7±1.6) Ma and (155.3±2.8) Ma, respectively, both subordinate to Mid-late Jurassic. The determinations, together with previous data, suggest that the mineralized quartz veins were produced by terminal magma evolution, which is supported by the fact that the ages of mineralization and magmatism were basically in accordance, the mineralization all occurred spatially at the inner- and outer-contacts of the granite, and the gradient relationship of granite→feldspar quartz vein→quartz vein was detected in the deposit. Endocontact and exocontact ore-bearing quartz veins were both produced by the same mineralization. Geodynamically, the Pangushan tungsten deposit is one of many important tungsten-polymetallic deposits formed from 165 Ma to 150 Ma associated with large-scale lithospheric extension in South China.