Multi-stage pyrite and hydrothermal mineral assemblage of the Hatu gold district (west Junggar, Xinjiang, NW China): Implications for metallogenic evolution
Multi-stage pyrite and hydrothermal mineral assemblage of the Hatu gold district (west Junggar, Xinjiang, NW China): Implications for metallogenic evolution
复制标题
哈图金矿区（新疆西准噶尔）多期黄铁矿和热液矿物组合：对成矿演化的启示
DOI：
10.1016/j.oregeorev2015.02.021
复制
发表时间：
2015
影响因子：
3.3
通讯作者：
Zhu Yongfeng
中科院分区：
文献类型：
--
作者：
Wang Lei;Zhu Yongfeng
新疆西准噶尔哈图—抱北火山—沉积盆地的哈图、七ⅲ、七ⅴ型金矿床分别代表了哈图金矿带的近端、中端和远端。矿床矿体主要为含金石英脉和蚀变带浸染状硫化物矿物的寄主岩。本文对这些矿山中的6种黄铁矿进行了研究，以说明成矿过程。沉积黄铁矿主要产于含泥岩的沉积岩或蚀变的火山沉积岩中，包括树状黄铁矿和细粒黄铁矿。草莓状黄铁矿形成于沉积层的氧化还原变化过程中。热液黄铁矿包含Py1 ~ Py5 5个亚群。多孔的Py1在金矿化之前形成，并被Py2覆盖，Py2含有硫化物矿物和天然金的包裹体。较粗的Py3与毒砂和天然金共存，砷含量最高。金、锑也优先富集于砷的Py2和Py3中。贫au - as的Py4和Py5在矿后过程中形成。Py1、Py2和Py3中As和S的含量呈负相关，表明硫被砷取代。金在含石墨凝灰岩和含石墨凝灰岩中以相对还原的条件析出。铯、Rb、Sr、La、Ce、Au、As、Sb、Cu、Pb富集于蚀变寄主岩中。含金石英脉和浸染型硫化物矿体是由共生热液形成的，形成阶段不同。流体与岩石相互作用过程中o2的变化和砷黄铁矿的结晶是控制金沉淀的主要因素。
The Hatu, Qi-III, and Qi-V gold deposits in the Hatu–Baobei volcanic–sedimentary basin (west Junggar, Xinjiang) represent the proximal, middle, and distal parts of the Hatu gold district, respectively. Orebodies of these deposits mainly consist of Au-bearing quartz veins and altered host rocks with disseminated sulfide minerals. Six types of pyrite in these mines are studied here to illustrate ore-formation processes. Sedimentary pyrite, including framboidal and fine-grained pyrite, occurs in mudstone-bearing sedimentary rocks or altered volcanic–sedimentary rocks. Framboidal pyrite formed during redox changes in sedimentary layers. Hydrothermal pyrite contains five subgroups, from Py1 to Py5. Porous Py1 formed prior to gold mineralization, and is overgrown by Py2 that contains inclusions of sulfide minerals and native gold. Coarser Py3 coexists with arsenopyrite and native gold, and contains the greatest As concentrations. Gold and antimony are also preferentially concentrated in arsenian Py2 and Py3. The Au–As-deficient Py4 and Py5 formed during the post-ore process. There is a negative correlation between the As and S contents in Py1, Py2, and Py3, implying the substitution of sulfur by arsenic. Gold precipitated under relatively reducing condition in framboid- and graphite-bearing tuffaceous rocks. Cesium, Rb, Sr, La, Ce, Au, As, Sb, Cu, and Pb are concentrated in altered host rocks. The Au-bearing quartz veins and disseminated sulfide mineral orebodies were formed via a co-genetic hydrothermal fluid and formed during different stages. The variation offO2during fluid/rock interactions, and crystallization of arsenian pyrite were major factors that controlled gold precipitation.