摘要
福建紫金山Cu-Mo-Au-Ag多金属矿田是一个完整的斑岩-浅成低温热液矿床成矿体系。英安玢岩主要分布在紫金山Au-Cu矿床内火山机构及其附近,与高品位Au-Cu矿体空间上联系密切,是矿田内火山-侵入岩浆过程的一个重要环节。采自矿区的两个英安玢岩样品LA-ICP-MS锆石U-Pb定年结果分别为(105.0±0.7)Ma(MSWD=0.83)和(105.0±2.2)Ma(MSWD=1.70),其形成时代与区内Mo-Cu矿化的萝卜岭和四方岩体形成时代相近。三个岩体形成时代及地球化学特征的相似性表明它们应为同源岩浆演化的产物,它们均具有较高的锆石Ce4+/Ce3+值,即岩浆体系具有较高的氧逸度,与区内斑岩成矿体系巨量金属堆积的地质事实相一致。英安玢岩的精确定年表明,紫金山Cu-Au矿与萝卜岭Mo-Cu矿及四方岩体有关的Mo矿床为同一斑岩成矿体系的产物。
The dacite porphyry occurs in the volcanic caldera of Zijinshan ore field and closely associates with the Cu-Au mineralization. The LA-ICP-MS zircon U-Pb dating of two dacite porphyry samples yields weighted mean ages of （ 105.0 ± 0.7 ） Ma and （ 105.0 ± 2.2） Ma, respectively. These results suggest that the dacite porphyry was formed proximately contemporarily with the other two Mo and Cu mineralized granite porphyries, i. e. , the Sifang and Luoboling granite porphyries. The dacite and granite intrusives are characterized by high Ce^4＋/Ce^3＋ ratios, which indicates that the magmatic system was of oxidative and therefore consistent with the huge Cu-Mo-Au oreforming potential of the dacite and granite porphyries. Moreover, the similarities of age, geochemical characteristics and mineralization demonstrate that the Cu-Mo-Au mineralization in the Zijinshan ore field is most likely a unified porphyry ore-forming system.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2012年第2期284-292,共9页
Geotectonica et Metallogenia
基金
国土资源部深部矿产资源立体探测技术及实验研究(SinoProbe-03-01)
中国科学院重大项目(KZCX1-YW-15-3)
国家自然科学基金项目(41172080
41121002)资助
