Rb-Sr dating and tracer study of quartz from the Jiangjiaya lead-zinc deposit in western Hunan

Abstract: The Jiangjiaya Pb-Zn deposit, located on the southeastern margin of the Yangtze craton and along the axis of the Hongyanxi anticline, is an important Pb-Zn deposit in the western Hunan-western Hubei metallogenic belt. The orebody exhibits stratabound and veined forms and is controlled by strata and faults, and the deposit occurs in the Ordovician (Early Paleozoic) Nanjingguan Formation. The ultra-low procedural blanks and Rb-Sr dating of quartz separates yielded an isochron age of (372±9.8) Ma, with n(87Sr)/ n(86Sr) equal to (0.709409±0.000058) for the deposit, which represents the main stage ore-forming age of the deposit. Geological setting indicates that the formation of the deposit was probably related to the late Devonian mass movement of basin fluids resulting from extensional and fault depression in South China. Initial Sr isotope ratios show that the ore materials of the deposit were derived from the host rocks, and the influence of continental crust was obvious in the ore-forming process.