The Zhesang gold deposit is a Carlin-type gold deposit located in the “Golden Triangle” structural belt of Yunnan-Guizhou-Guangxi. Pyrite and arsenopyrite are important gold-bearing minerals of the deposit. In order to understand the typomorphic characteristics of pyrite and arsenopyrite and the enrichment mechanism of gold, morphological and structural features of these sulphides and the occurrence state of gold were investigated by using reflected light microscope and electron probes (EPMA). The results show that pyrites are characterized mainly by medium-fine broken pentagonal-dodecahedron crystal forms. Most of the arsenopyrites display needle and columnar crystal forms. Compositionally, pyrite is depleted in both Fe and S, whereas arsenopyrite is As-depleted but S-enriched. The (Co)/(Ni) of pyrite is between 1.731 and 3.215 (i.e., within the range of ratio of the hydrothermal pyrite, which is between 1 and 5). The crystal forms and compositional features of pyrite and arsenopyrite indicate that the Zhesang gold deposit is typical of medium-low temperature hydrothermal origin. The positive correlation between As and Au and the Au/As (mol%) ratio are lower than the solubility limit of Au in arsenic pyrite. Combined with previous studies, our data suggest that gold is likely to exist in the form of Au complex. Arsenic pyrite and arsenopyrite condensed Au in unsaturated ore-forming hydrothermal fluids relative to Au through surface voids and/or defects and the As content, forming a Zhesang Carlin-type gold deposit. Based on the age data of the Mesozoic polymetallic deposits in South China, it can be concluded that the age of the Zhesang gold deposit (215.3 ± 1.9 Ma), is consistent with the age of the main body of the Mesozoic polymetallic deposits (230–200 Ma) in South China Plate and the age of the granites (230–200 Ma) related to tungsten-tin mineralization in the Cathaysian Block. Therefore, we believe that the Zhesang gold deposit is the product of the subduction regime of the Paleo-Tethys Ocean in the Middle-Late Triassic.

中文翻译：

---

扬子地块西南缘古特提斯俯冲及相关成矿作用——来自哲桑卡林型金矿床的证据

哲桑金矿床是位于云贵桂“金三角”构造带上的卡林型金矿床。黄铁矿和毒砂是该矿床重要的含金矿物。为了了解黄铁矿和毒砂的标型特征以及金的富集机制，利用反射光显微镜和电子探针（EPMA）对这些硫化物的形态结构特征和金的赋存状态进行了研究。结果表明，黄铁矿的晶型主要为中细破碎的五方十二面体。大多数毒砂呈针状和柱状晶体形态。从成分上看，黄铁矿贫铁和硫，而毒砂贫砷但富硫。黄铁矿的(Co)/(Ni)在1.731至3.215之间(即在热液黄铁矿的比值范围内，其在1至5之间)。黄铁矿和毒砂的晶型和成分特征表明，哲桑金矿床是典型的中低温热液成因。 As和Au之间的正相关性以及Au/As(mol%)比值低于Au在砷黄铁矿中的溶解度极限。结合之前的研究，我们的数据表明金很可能以Au络合物的形式存在。砷黄铁矿和毒砂通过表面空隙和/或缺陷以及As含量将不饱和成矿热液中的Au相对于Au凝结，形成哲桑卡林型金矿床。根据华南中生代多金属矿床年龄资料，可以得出，哲桑金矿床年龄（215.3±1.9 Ma）与中生代多金属矿床主体年龄（230～华南板块的200 Ma)和华夏地块钨锡矿化相关花岗岩的年龄(230~200 Ma).因此，我们认为哲桑金矿是中晚三叠世古特提斯洋俯冲运动的产物。