The Xinjiang sellekchem basin is a secondary fault basin, which is distributed across the west of the Qiantangjiang-Xinjiang taphrogenic trough [48, 49]. In the north segment of QHJB, there are two deep faults running in ENE direction, which are Qianshan-Pingxiang fault and Northeast Jiangxi-Qianshan-Pingxiang fault. In addition, the Dongxiang ore district is distributed in the northeast of Northeast Jiangxi fault and is located in the northwest of Qianshan-Pingxiang fault. Figure 3Geological map of QHJB (a) and Dongxiang area (b) ((a) after [36]; (b) after [48, 58]).The regional geology is simple relatively in the Dongxiang ore district. There are strata in three periods in the Dongxiang ore deposit, Fuzhou city, Jiangxi province, and South China (Figure 3(b)).

The rocks in the late Cretaceous strata include purple sandstone and conglomerate. The Carboniferous strata are mainly composed of clastic rock with interlayered volcanic clastic. In the Proterozoic strata, there are pelitic, limestone, and microsandstones. The metamorphism is relatively slight, and these rocks only partially metamorphosed into phyllite. The magmatism is weak with dykes of granite porphyry, granodiorite porphyry, and rhyolite. The strata generally form a monocline, which changes slightly with an approximate occurrence of 145��35��. Numerous fractures are distributed in the Dongxiang mining area, and their outcrops are on strikes of NE-ENE, SN, and NW directions. Additionally, the fractures along the NE-ENE strike represent a stripping fault, which are manifested as the main ore controlling fractures.

The Neopaleozoic siliceous rocks are collected from the mining area of Dongxiang area in the north segment of Qinzhou-Hangzhou joint belt. In the Xinjiang basin, there are several VMS-type polymetallic ore deposits including Dongxiang ore deposit, Yongping ore deposit, and Lehua ore deposit, and they exhibit intergrowth with siliceous rocks (Figure 3(b)). The siliceous rocks have outcropping conformably to the strata, which are either sill-like or conformable. The strata of siliceous rocks, with a thickness of up to 20 meters, are located in Carboniferous strata, which are located below the land surface about 100 meters to 150 meters. These siliceous rocks are often accompanied by carboniferous marine volcanic rock systems and massive sulphide-rich ore strata.

In this paper, the siliceous rocks were collected from the mining area of Dongxiang copper-polymetallic ore Brefeldin_A deposit, Fuzhou city, Jiangxi province, South China, which is located in the north segment of Qinzhou-Hangzhou joint belt.2.3. Petrological CharacteristicsIn the Dongxiang copper mining area, the sulfide ore (Figure 4(a)) and siliceous rocks (Figure 4(b)) were collected from the mine below the land surface. The ore were composed of volcanic breccia and metal sulphide minerals (Figure 4(a)), and the volcanic breccias were cemented by the metal sulphide minerals (e.g.