## 6 Discussion
### Exploration for the Sanjiang Tethyan Orogenic Belt
The high \(\varepsilon\)Hf(t) anomaly region in the northern part of the Jinshajiang-Ailaoshan suture is between the Jinshajiang binding zone and the Nujiang binding zone. In between, the Jinshajiang basal-ultramafic zone, Baimaxueshan granite belt, Yulong alkaline granite belt, the Leiwuqi-Dongdashan granite zone, Nujiang-Bitu basic ultrabasic rock belt, Guoqingchaw granite belt, and Zaxize-Sanmiancun granite belt are developed from east to west [53]. The geochemical anomalies in this area are controlled by regional geological structure and magmatic rocks and are distributed in the NW-SE direction. From east to west, it can be clearly divided into four anomalous zones: Jinshajiang Au and Cu polymetallic anomalous zone; Yulong porphyry Cu and Mo anomalous zone; Lancangjiang W, Sn, Pb, Zn, Ag, Cu polymetallic anomalous zone; and Nujiang Au, Pb, Ag, W, Sn, Cu polymetallic anomalous zone [53]. The discovered and evaluated large and medium-sized porphyry Cu(-Mo-Au) deposits are all produced in the banded Yulong porphyry Cu and Mo anomaly, which is consistent with the high \(\varepsilon\)Hf(t) anomaly area. In addition, the distribution characteristics of the enrichment degree and dispersion of elements in the earth rocks and aqueous sediments of the eastern Tibetan region suggest that the eastern Tibetan earth has very good prospects for polymetallic mineralization such as Cu-Mo, Au, Pb, and Zn [53; 177], which is consistent with the region of high anomalous values of Hf in this paper. A high \(\varepsilon\)Hf(t) anomaly region is also seen in the south-central part of the Jinshajiang-Ailaoshan suture. This anomalous region is consistent with the distribution of the Himalayan alkali-rich porphyry belt in western Yunnan. The alkali-rich porphyry belt in western Yunnan can be divided from north to south into six alkali-rich porphyry groups: the Bengge-Taohua Group, the Yongsheng-Ninglang Group, the Machangqing-Beiya-Liuhe Group, the Yongping-Weishan Group, the Yaoan-Huaping Group, and the Jinping-Luchun Group (Figure 6) [178; 179]. The quartz diorite porphyry and quartz diorite porphyrites in the contact zone of the Jinsichang and Taohua areas (Figure 6) are commonly developed with strong silicification, hornification, yellow (brown) iron mineralization, and skarnization. Large-scale physical surveys in the Taohua-Jinsichang area also show the existence of concealed ore bodies and concealed rock bodies and the presence of chemical anomalies of Cu, Pb, Zn, Ag, Au, Sb, and other elements [50]. In the area of Ninglang-Yongsheng (Figure 6), 47 gold anomalies were traced by the chemical anomalies, which were distributed in the NE direction and coincided with the Cu anomalies. The Cu anomaly is accompanied by the main fracture in a band-like spreading, forming a concentration center with w (Cu) \(>\) 300 \(\times\) 10\({}^{-6}\) in the Bainiuchang and Luobodi areas, generally containing w (Au) of (5-7) \(\times\) 10\({}^{-9}\) and w (Ag) of (0.15-1.2) \(\times\) 10\({}^{-6}\)[53]. The Beiya and Heqing (Figure 6) areas are dominated by chemical anomalies of gold, with a large scale, high intensity, and obvious concentration center. Important gold anomalies include Songgui, Tanyao, Beiya, and Huadianba. In the Tiesuodongshan area of Yongren, Yunnan, the geochemical anomalies are mainly Cu, Pb, Au, Pb, Ag, and Mo, among which the copper anomalies mostly coincide with the Cu deposits in the area, and some of the gold-copper anomalies are located in the distribution area of porphyry bodies or their sides [53]. In the Weishan-Yongping area (Figure 6), regional chemical probes show Au, Sb, Hg, As, Cu, Co, Pb, Zn, Ag, and other elemental anomalies [180]. Au anomaly higher values are mainly located in Yongping Zhuopan, Yangbi Huanglianpu, Weishan Zijinshan, Weishan Lianhuashan, and Nanrun Gonglanghu areas [180]. The higher value of Cu anomalies is mainly concentrated in Yongpingchang Street, Shuixie, and Nanjian Gonglanghu areas,and the Co anomaly is basically similar to the Cu anomaly [180].