China has the largest tungsten reserves in the world, with approximately 10.3 million tons of WO₃ ^[1][2][1,2], and most of the W deposits are mainly clustered in south China (Figure 1), which accounts for about 80% of the country’s total and around 50% of the world’s total ^{[3][4][5][6][7][8]}[3,4,5,6,7,8]. The formation of W deposits in south China is mainly related to the Mesozoic (concentrated in 160~150 Ma) magmatic activity ^[9][10][9,10], and most of the W deposits in south China are concentrated in the Nanling metallogenic belt (NLMB). Traditionally, most W-related granites are considered as S-type granites, derived from the reworking of ancient meta-sedimentary rocks [11], and it is thus assumed that tungsten mineralization occurred without the addition of mantle material, but recent studies suggest that these granites may be mainly I-type granites ^[12][13][12,13]. The reason for the controversy is that the granites associated with tungsten mineralization are mainly high-differentiated granites, which makes it difficult to classify the genetic types and evaluate the influence of mantle on tungsten mineralization.

Due to the distinct ³He/⁴He ratios of the crust (~0.05–0.01 Ra, where Ra is the atmospheric ³He/⁴He ratio, 1.39 × 10⁻⁶) and upper mantle (6–9 Ra), and different ⁴⁰Ar/³⁶Ar ratio of the atmosphere (295.5) versus the crust or mantle, the He-Ar isotopic compositions of fluid inclusion in minerals have been widely used in the studies of contribution of mantle-derived components and the relationship between crust–mantle interactions and mineralization ^{[17][18][19][20][21]}[17,18,19,20,21]. Recently, a growing number of studies have used the method of He-Ar isotopes to prove that mantle-derived components were involved in the genesis of some W deposits (such as the Gerês W deposit [22] and Panasqueira W deposit [20] in Portugal, Dae Hwa W deposit in South Korea [23], and Xihuashan [24], Yaogangxian [18], Shizhuyuan [25], Piaotang [26], Taoxikeng [27], Yaoling-Meiziwo [28], and other W deposits in south China).

The Xingluokeng W-Mo polymetallic deposit is one of the superlarge W deposits in China and the largest W deposit in the Wuyi metallogenic belt (WYMB), which is historically a Cu-dominated polymetallic belt ^[10][29][10,29]. Many researchers have studied the petrographic geochemical characteristics ^[30][31][32][30,31,32], deposit geochemical characteristics ^[33][34][33,34], and geochronology ^[2][35][2,35]. However, whether mantle components are involved in the genesis of the deposit is poorly studied understood.

2. Geological Background

The south China block is composed of the Yangtze block to the northwest and the Cathaysia block to the southeast, separated by the Qin-Hang belt [36]. Around 900 Ma ago, the paleo South China Ocean gradually closed, resulting in the collision of Yangtze and Cathaysian blocks on both sides of the ocean basin, forming an arc-shaped orogenic belt with a width of more than 100 km and an extension of about 1500 km at the junction, i.e., Qin-Hang belt ^[37][38][37,38]. The geological background of south China is complex, with strong tectonic movements ^[39][40][39,40] and a wide distribution of granites of different ages and types, which are known for large-scale magmatic activities and mineralization events in the Mesozoic, forming huge deposits of W, Sn, U, and REE ^{[7][41][42][43][44][45]}[7,41,42,43,44,45]. The WYMB is located in the northeast of the Cathaysian block and distributed in the NNE direction (Figure 1), bounded on the north by the Shaoxing-Jiangshan-Pingxiang fault and adjacent to the Qinhang metallogenic belt on the southeast edge of the Yangtze block, on the west by the Yingtan–Anyuan fault, near the NLMB, and on the east by the Lishui-Zhenghe-Dapu fault to the southeast coastal metallogenic belt ^[46][47][46,47]. The WYMB has experienced major geological events such as the formation and cracking of the Cathaysian block, the collision and splicing of the Cathaysian block and the Yangtze block, the collision between the north China block and south China block, and the subduction of the Pacific plate to the Eurasian continental margin, among which the Yanshanian tectonic magmatic activity is the strongest ^[48][49][48,49], and forming a large number of Cu, Au, Ag, Pb, and Zn deposits ^{[50][51][52][53]}[50,51,52,53], such as the Zijinshan Cu–Au deposit and the Lengshuikeng Ag–Pb–Zn deposit, as well as some large W deposits, such as the Shangfang W deposit and Xingluokeng W-Mo deposit. The strata in WYMB include the upper Archean to Quaternary, in which the pre-Devonian is the basement rock series, the Devonian Middle Triassic is the caprock rock series dominated by marine sedimentation, and the Meso Cenozoic is the continental clastic and volcanic rock series. The fault is mainly NNE-trending, followed by NW-trending, and partly NEE-trending. The study area is located in the western part of the NEE-trending Nanping-Ninghua fault zone (Figure 1). In addition to the Xingluokeng deposit, there are also tungsten deposits and mineralized sites in the zone, such as Beikeng and Guomuyang (Figure 2).