Abstract:Objectives: The Shangxu gold deposit in the Shuanghu County, Xizang(Tibet), is located in the central segment of the Bangong Lake — Nujiang River suture. The deposit is controlled by EWtrending faults, and is hosted in melange of the Middle—Lower Jurassic Mugagangri Group. In this study we focus on the sources of oreforming materials in the Shangxu orogenic gold deposit, was beneficial for the study of genesis for the ore deposit, and provide new constraints for understanding the dynamic background of orogenic gold metallization in the Bangong Lake — Nujiang River suture.Methods: n this study, the Carbon isotopes of the CO2 inclusions in orestage quartz, and the sulfur and lead isotopes of sulfides are analyzed for discuss the sources of oreforming materials in the Shangxu orogenic gold deposit.Results:The δ13CCO2(VPDB) values of fluid inclusions range from -178‰ to -231‰, with a mean of -213%, which is similar to that of the sedimentary or metamorphic rocks. This indicate that the oreforming fluids of the Shangxu gold deposit may originated from the Mugagangri Group. Meanwhile, a few magmatic zircons, which yield the same UPb age with the Xiabie Co – Mogagangri San granite, are detected in auriferous quartz veins, suggesting that the magmatic hydrothermal fluids may have been involved during the oreforming process. The δ34SVCDT values of sulfides vary from -45‰ to 46‰, with a mean of -16‰, which is characteristic of a deep sulfur source, The Pb isotopic compositions of the sulfides(n(206Pb)/ n(204Pb)=18350~18690, n(207Pb)/n(204Pb)=15632~15700, n(208Pb)/n(204Pb)=38570~38980) are similar to those of the Xiabie Co – Mogagangri San granite(n(206Pb)/n(204Pb)=18558~19169, n(207Pb )/ n(204Pb)=15616~15651, n(208 Pb)/n(204Pb)=38838~39154) and slightly drifting to the Jurassic Mugagangri Group (n(206Pb)/n(204Pb)=18630~18970, n(207Pb )/ n(204Pb)=15619~15673, n(208 Pb)/n(204Pb)=38887~39260), implying that Pb in the Shangxu gold deposit may have been sourced from the magmatic activity in Early Cretaceous, with minor contribution from the Mugagangri Group.Conclusions: According to the above discussions, we suggest that the oreforming materials of the Shangxu gold deposit were mainly derived from deep crustal — mantle magmatism, and were carried by deepseated fluids to the shallow crust. The Mugagangri Group also contributed part of the oreforming materials, which were brought by the metamorphic hydrothermal fluids.