Metallogenic Model and Prospecting Progress of the Qiandongshan–Dongtangzi Large Pb-Zn Deposit, Fengtai Orefield, West Qinling Orogeny

The Qiandongshan–Dongtangzi large Pb-Zn deposit is located in the Fengxian–Taibai (abbr. Fengtai) polymetallic orefield. ore bodies primarily occur within and around contact surface between limestone of Gudaoling Formation phyllite Xinghongpu Formation, which are clearly controlled by anticline specific lithohorizon. Magmatic rocks well developed mining area, consisting mainly granitoid plutons mafic–felsic dikes. Previous metallogenic geochronology studies have yielded a narrow range ages 226 211 Ma, overlapped extensive magmatism during Late Triassic period this region. ω(Co)/ω(Ni) ratio pyrite lead–zinc ranges from 4.44 to 15.57 (avg. 8.56), implying that its genesis probably related volcanic magmatic-hydrothermal fluids. δD δ18O values (ranging −94.2‰ −82‰, 18.89‰ 20.72‰, respectively,) ore-bearing quartz indicate fluids were perhaps derived magmatic source. δ34S ore-related sulfides display relatively 4.29‰ 9.63‰ less than 10‰, resembling those origin deposits. Pb isotopic composition (with 206Pb/204Pb ratios 18.06 18.14, 207Pb/204Pb 15.61 15.71, 208Pb/204Pb 38.15 38.50) similar Xiba granite pluton, suggesting they share same contents W, Mo, As, Sb, Hg, Bi, Cd, other elements associated with high ores, Sn, Co, Ni also enriched sphalerite. trace rare earth maybe propose as well. As result information, may be classified hydrothermal stratabound type, Si/Ca area being ore-forming structural plane. Thus, mineralization model has been proposed based on comparative analysis geological geochemical properties Fengtai It considered secondary anticlines both wings composite favorable sites for deposition. Accordingly, plane major ore-controlling factors prospecting targets. verification project was first set up north wing anticline, thick found all boreholes, accumulating successful experience deep exploration deposits