Abstract:

Abstract: The Wulagen zinclead deposit occurring in the Kashi MesozoicCenozoic sedimentary sag, Xinjiang, is a newly explored deposit, with perspective of a superlarge scale. The ZnPb orebodies of tabular shape occur in the northern and southern flanks of the Wulagen syncline, which are in parallel with the stratum and hosted in the faded gray sandstoneconglomerate of the fifth Member of Lower Cretaceous Kezilesu Group(K1kz5) and the muddolostones of Paleocene Aertashi Formation(E1a). The ores are characterized mainly by massive structure, microdisseminated structure, veinlet structure, porphyritic structure, cemented texture, and metasomatic reaction edge texture. The sulfide δ34SVCDT of the Wulagen deposit varies from -27.9‰ to 14.6‰, which indicates that the gypsum, celestite and other sulfate in the adjacent stratum provided sulfur, and that the thermal decomposition of sulfurbearing organic matter may also be the source of the sulfur. Reduced sulfurs were mainly derived from the biogenic sulfate reduction and the thermochemical reduction of organic matter. The compositions of Pb isotopes of Wulagen deposit are homogenous (206Pb/204Pb=18.52818.663, 207Pb/204Pb=15.61115.669, 208Pb/204Pb=38.61638.839), which indicates that the oreforming materials came from the upper crust and orogenic erosion zone. Integrated analysis of geological characteristics and geochemistry of the Wulagen deposit and compared with the previous understanding of its genesis, we concluded that the Wulagen deposit is a basin fluidrelated sandstonetype zinclead deposit.

Key words: ore geology, S and Pbisotopic compositions, MesozoicCenozoic, sandstonetype of ZnPb ore deposit, Wulagen, Kashi, Xinjiang