Geochemistry of pyrite from stratabound massive sulfide deposits, Tongling region, China: implication for its genesis

Abstract Stratabound massive sulfide deposits are widely distributed along Middle-Lower Yangtze River metallogenic belt, in eastern China. There has much debate as to whether these deposits were associated with Late Mesozoic igneous or Carboniferous sedimentary exhalative (SEDEX). Three-type pyrites, i.e., colloform (Py1), fine-grained (Py2) and medium- to coarse-grained (Py3), from Xinqiao and Taoyuan stratabound massive sulfide deposits in Tongling region were investigated using electron probe microanalysis (EPMA), in-situ laser-ablation inductively-coupled plasma-mass spectrometry (LA-ICP-MS) and sulfur isotopic analysis. The analytic data indicate that the three-type pyrites have high S and As, and relatively consistent Au contents. The Au, Ag, Bi, Sb and Pb elements are mainly of lattice bound appearance in the Xinqiao and Taoyuan pyrites. Low Au (mainly   1), Se/Tl (mainly > 1) and δ34SCDT (4.0‰ to 5.9‰) values of the studied Xinqiao and Taoyuan pyrites imply a magmatic-hydrothermal origin. High Bi (>1 ppm) and Mo contents, and low Co/Ni ratios (