Abstract:Xiongcun coppergold deposit is located in the middle of the southern margin ofthe Gangdise orogenic belt. Its southern margin is near to the Yarlung Zangbo suture zone (IYS) and Xigaze forearc basin, and the north is Xietongmen Eocene biotite granodiorite batholith. Based on the comprehensive microscopical identification and the analytical contents of major elements and trace elements (including REE) from the Xiongcun sandstones, the tectonic settings and provenance were studied. The result of study indicates that the content of SiO2 varies from 53.27% to 66.13% (average 58.27%) and is similar to that (66.1%) of Paleozoic greywackes. The high content of Al2O3 varies from 14.53% to 24.04% (average 20.12%), this may suggest that there are some feldspar in sandstones and with strong clayization. Combined with the microscopic characteristics, the Xiongcun sandstone may belong to feldspathic lithic sandstone. The special major element assemblages Fe2O3+MgO(7.3%~17.6%),TiO2(0.68%~1.25%) and Al2O3/SiO2 (0.22%~0.45%) of the Xiongcun sandstones are similar to those of Oceanic Island Arc. It can be seen from the spider diagram that the Xiongcun sandstones are depleted in HFSE elements such as Ta, Nb, P, Ti and HREE, and enriched with LILE elements such as K, Rb, U and REE. The chondrite standard curve of REEs has rightward trend which reveals an enrichment of LREEs and an indifference of HREEs. The contents of standard trace elements Th (2.5×10-6), Zr (114×10-6), Hf (3.6×10-6), Ce (27.95×10-6), Ti (0.54×10-6) and the ratios of trace elements Th/U (2.9), Zr/Th (46), La/Sc (0.72), Th/Sc (0.11) show that the genesis of the Xiongcun sandstones is Oceanic Island Arc. The discriminatory diagrams of LaThSc, ThScZr/10 and ThCoZr/10 were the same result. There are weak negative Ce anomalies and positive Eu anomalies in the PAASnormalized rare element plots, which show the same conclusion with these from major elements and trace elements, indicating that the sandstones are influenced by both seawater and the fluids from deep. Diagrams of Co/ThLa/Sc and La/ThHf show that the provenance of Xiongcun sandstones is mixed with intermediate acidic felsic volcanic rocks and andesitic volcanic rocks. Combined with the detrital zircon ages of the sandstones (studied by other researcher), it is considered that the detrital zircon ages are not early in Late Triassic, and the provenance is of island arc volcanics features.