Chronology, petrochemistry of fine grained granite and their implication to Mo-Cu mineralization in Xichong Mo Deposit, Anhui Province, China

Xichong Mo deposit is located in Yuexi county of Anhui province, China, which is in the east part of Tongbai - Dabie metallogenic belt. A series of giant and large porphyry Mo deposits have been reported in this belt including Shapinggou, Qian'e'chong, Tangjiaping Yaochong and Xichong etc., as well as some Au, Pb-Zn deposits. The geology, geochronology and geochemistry of key porphyry Mo deposits in this belts have been reported by Yang (2009), Meng et al. (2012), Zhang et al. (2011), Zhang et al. (2012), Chen et al. (2013), Li et al. (2011), Huang et al. (2011), Gao et al. (2014) and Wang et al. (2014). Most of these researchs is for Shapinggou, Qian'e'chong, Tangjiaping and Yaochong, no much for Xichong deposit.

Based on field observation, petrographic, oremicroscopic, SEM/EDS, XRD results together with chronology and petrochemical results of fine grained granite (FGG), this paper discusses the alteration, minerlization and the genetic link between FGG and Mo- Cu mineralization in Xichong deposit. The results show that Yanshanian FGG formed at the starting of regional extentional and is closely related to Mo - Cu mineralization. The potassic-silification represents the early alteration and followed by sericite - quartz alteration, propylitization and argillation. The Mo-Cu mineralization is closely related to propylitization. Late stage Cu mineralization is related to argillation.