## 1 Introduction  
The Great Xing'an Range is in a region where two global tectonic mineralization domains, the Paleozoic Paleo-Asian Ocean Tectonic Mineralization Domain and the Mesozoic Paleo-Pacific Ocean Tectonic Mineralization Domain, are strongly superimposed. On the basis of the ancient basement tectonics and the Late Paleozoic corogenic belt, the Mesozoic volcanic-magmatic activities were intense, and the polymetallic metallogenetic belts of Cu-Sn-Mo-Pb-Zn-Ag were formed. As an important Pb-Zn-Ag polymetallic ore-concentrated area in China, the southern section of the Great Xing'an Range has more than 30 Ag-Pb-Zndeposits in the area, with a total Ag resource of more than 57,000 t, making it the largest silver-metallogenic province in China [1]. Important Ag-Pb-Zn hydrothermal deposits include the Shuangjianzishan, Bianjiadanyuan, Weilasituo, and Bairendaba deposits. With the deepening of theoretical research and geological work, a number of tin polymetallic deposits have been discovered in the district, such as the Huanggang, Maodeng, Baiyinnuoz, Baiyinchagan, Weilasituo, and Bianjiadayuan. These hydrothermal tin polymetallic mineralizations are closely related to vein Pb-Zn-Ag polymetallic mineralization, showing good prospects for finding tin polymetallic resources [2]. Overall, the Sn-Cu-Pb-Zn-Ag polymetallic system has a similar vertical zonation, with Sn-Cu-(W) mineralization developed at depth and associated with highly fractionated granite bodies, while Ag-Pb-Zn is close to the shallow surface and fracture-controlled [3]. The intrinsic genesis relationship between medium- and high-temperature tin mineralization and medium- and low-temperature Cu-Pb-Zn-Ag mineralization has long been debated. The debate centers on the spatial distance, and the age difference between the Pb-Zn-Ag mineralization and the rock mass makes it difficult to establish a genesis link between the mineralization and the rock mass [4], restricting the exploration of the mineral sources of Pb-Zn and Cu-Sn mineralization [5]. A previous study held that the Shuangjianzishan deposit is typically an epithermal Ag-Pb-Zn deposit that lacks a high-temperature mineralization stage [6; 7; 8; 9]. In recent years, some scholars found abundant Cu-Sn mineralization in the ore and drill holes of the Shuangjianzishan deposit and concluded that the Shuangjianzishan deposit has great potential for Cu-Sn mineralization [10; 11]. As the discovery of copper-tin mineralization in the Shuangjianzishan deposit is still recent, less work has been carried out on the metallogenic chronology and mineralogy of chalcopyrite and cassiterite. Chalcopyrite and cassiterite, as important ore minerals in the copper-tin mineralization stage, often contain a variety of trace elements [12; 13] and contain rich metallogenic information, which is an important indication of the formation process and genesis type of the deposit [14; 15]. At present, there are more studies on pyrite [16], sphalerite, and galena, but the trace element characteristics of chalcopyrite and cassiterite are seldom reported. In this paper, we carry out detailed mineralogical and LA-ICP-MS trace element studies on chalcopyrite and cassiterite from the Shuangjianzishan deposit to reveal the trace element characteristics of chalcopyrite and cassiterite and their relationship with the genesis of the deposit.