## 6 Result
### Geochemical Characteristics of Trace Elements in Cassiterite  
Cassiterite is one of the main tin-bearing minerals in the Shuangjianzishan deposit. Containing 78.6% tin, cassiterite is the most common tin mineral and the most important ore mineral of tin. Its chemical component is SnO\({}_{2}\), which is a rutile tetragonal crystal system oxide mineral. The results of cassiterite trace elements (see Table S2, Figure 6) show that the trace element contents of the two cassiterite samples extracted from the tunnel and the drill, respectively, are similar, generally enriched in Fe, Co, Ni, Cd, In, Sb, and W; relatively enriched in Mn, Zn, and Pb; with a small amount of Cu, Ga, Ge, Sr, Nb, and Ba; and poor in Cr, As, Rb, Mo, Cs, Hf, Ta, Tl, and Bi. Some element contents are even below the detection limit, and the elemental content of tunnel samples is generally higher than that of drill holes. The specific characteristics are as follows:  
1. Rich in Fe, Cd, Ni, In, Co, and W. Fe content ranged between 1272.46 \(\times\) 10\({}^{-6}\) and 36,766.47 \(\times\) 10\({}^{-6}\), average 7405.76 \(\times\) 10\({}^{-6}\). Cd content ranged between 28,522.69 \(\times\) 10\({}^{-6}\) and 31,034.52 \(\times\) 10\({}^{-6}\), average 29,820.29 \(\times\) 10\({}^{-6}\). Ni content ranged between 6944.71 \(\times\) 10\({}^{-6}\) and 7731.47 \(\times\) 10\({}^{-6}\), average 7337.13 \(\times\) 10\({}^{-6}\). In content ranged between 2475.65 \(\times\) 10\({}^{-6}\) and 2536.9 \(\times\) 10\({}^{-6}\), average 2651.89 \(\times\) 10\({}^{-6}\). Co content ranged between 1153.17 \(\times\) 10\({}^{-6}\) and 1274.97 \(\times\) 10\({}^{-6}\), average 1205.67 \(\times\) 10\({}^{-6}\). W content ranged between 0 \(\times\) 10\({}^{-6}\) and 9952.13 \(\times\) 10\({}^{-6}\), average 1193.93 \(\times\) 10\({}^{-6}\). Figure 5: Boxand-whisker plots for different generations of chalcopyrite in situ trace elements from the Shuangjianzishan ore area. * Less rich in Mn, Zn, Pb, and Sb. Sb content ranged between 0 \(\times\) 10\({}^{-6}\) and 802.1 \(\times\) 10\({}^{-6}\), average 73.89 \(\times\) 10\({}^{-6}\). Mn content ranged between 0 \(\times\) 10\({}^{-6}\) and 185.46 \(\times\) 10\({}^{-6}\), average 18.42 \(\times\) 10\({}^{-6}\). Pb content ranged between 0 \(\times\) 10\({}^{-6}\) and 225.18 \(\times\) 10\({}^{-6}\), average 9.08 \(\times\) 10\({}^{-6}\). Zn content ranged between 0 \(\times\) 10\({}^{-6}\) and 117.03 \(\times\) 10\({}^{-6}\), average 7.43 \(\times\) 10\({}^{-6}\). * Contains small amounts of Cu, Ga, Ge, Sr, Nb, Ba, and As. Cu content ranged between 0 \(\times\) 10\({}^{-6}\) and 2.49 \(\times\) 10\({}^{-6}\), average 0.2 \(\times\) 10\({}^{-6}\). Ga content ranged between 0 \(\times\) 10\({}^{-6}\) and 36.61 \(\times\) 10\({}^{-6}\), average 7.08 \(\times\) 10\({}^{-6}\). Ge content ranged between 0 \(\times\) 10\({}^{-6}\) and 3.59 \(\times\) 10\({}^{-6}\), average 0.56 \(\times\) 10\({}^{-6}\). Sr content ranged between 0 \(\times\) 10\({}^{-6}\) and 28.83 \(\times\) 10\({}^{-6}\), average 2.18 \(\times\) 10\({}^{-6}\). Nb content ranged between 0 \(\times\) 10\({}^{-6}\) and 5.64 \(\times\) 10\({}^{-6}\), average 1.02 \(\times\) 10\({}^{-6}\). Ba content ranged between 0 \(\times\) 10\({}^{-6}\) and 17.25 \(\times\) 10\({}^{-6}\), average 1.01 \(\times\) 10\({}^{-6}\). As content ranged between 0 \(\times\) 10\({}^{-6}\) and 51.73 \(\times\) 10\({}^{-6}\), average 4.46 \(\times\) 10\({}^{-6}\). * Poor in Cr, Rb, Mo, Cs, Hf, Ta, Tl, and Bi. The contents of Cr, Rb and Cs in all cassiterite samples were lower than the detection limit, and the contents were very low. Mo content ranged between 0 \(\times\) 10\({}^{-6}\) and 2.89 \(\times\) 10\({}^{-6}\), average 0.31 \(\times\) 10\({}^{-6}\). Hf content ranged between 0 \(\times\) 10\({}^{-6}\) and 2.22 \(\times\) 10\({}^{-6}\), average 0.21 \(\times\) 10\({}^{-6}\). Ta content ranged between 0 \(\times\) 10\({}^{-6}\) and 0.11 \(\times\) 10\({}^{-6}\), average 0.02 \(\times\) 10\({}^{-6}\).