1.2. Geological background of the South China Block
The SCB is composed of the Cathaysia and Yangtze Blocks, which are assembled along the Jiujiang-Shitai fault (He et al., 2013). The SCB was formed by collision of the Yangtze and Cathaysia subblocks at approximately 0.8–1 Ga along the Jiangnan orogen or the Jiujiang-Shitai fault, which shaped its fundamental tectonic architecture (Yao et al., 2011; He et al., 2013) (Fig. 1a, blue rectangular region; Fig. 1c). Following this event, the SCB further docked with the NCC to the north along the Qinling–Tongbai–Hong’an–Dabie–Sulu orogenic belt, to the west along the Longmenshan fault and to the southwest along the Ailaoshan-Song Ma orogen with the Indochina Block in the Triassic (Zheng et al., 2013).
The SCB basement is dominantly composed of Paleoproterozoic, Mesoproterozoic and early Neoproterozoic rocks (Zhao and Zheng, 2009) that were involved in and overprinted by at least three tectonic events, namely, the Caledonian in the early Palaeozoic, Indosinian in the Triassic and Yanshanian during the Jurassic-Cretaceous (e.g., Charvet, 2013), which might have led to the inhomogeneous rejuvenation of ancient crustal and lithospheric structures (e.g., Li et al., 2012). Concurrently, the SCB retains the imprints of several metallogenic and tectonothermal events that correspond to global supercontinental cycles and tectonic activity and is one of the major polymetallic provinces in the world.