ZHU Feng, LI Wen-bo*, HU Chuan-sheng

(Key Laboratory of Orogenic Belt and Crustal Evolution, Peking University, Beijing 100871, China)

Abstract: Yindonggou Ag–Au deposit is an important large-size silver deposit in South Qinling mountains, central China. Quartz vein type ore bodies are hosted by the metamorphosed volcanic rocks of Wudang Group and controlled by shear zones. According to field observation and laboratory studies, silver-bearing assemblages are electrum, native silver, argentite and jalpaite in sequence, with a trend from silver mineralization to a copper one, indicating a transition from oxidization to reduction of ore-forming fluid environment. The 40Ar/39Ar plateau age of muscovite intergrowth with Ag–Au minerals is 231.0 ± 2.0 Ma (MSWD = 0.96), and inverse isochron age is 229.5 ± 1.4 Ma (MSWD = 0.73). These ages are consistent with the 40Ar/39Ar ages of phengite in the shear zones of the mining area, implying that the metallogenesisis related to the regional shear deformation.

Keywords: Yindonggou; Ag-Au deposit; geological characteristics; geochronology

E-mail: liwenbo@pku.edu.cn

ACTA MINERALOGICA SINICA Vol. 37, No. 4, 2017, Page 386-394