Abstract:The Nanwopu uranium deposit is located in the northeastern section of the Guyuan—Hongshanzi uranium metallogenic belt. Dacite,which belongs to Elitu Formation,is the direct surrounding rock of the Nanwopu uranium deposit.The aim of this paper is to investigate the petrogenesis and tectonic significance of this rock suite. Methods: Detailed geological survey,SHRIMP zircon U-Pb dating and whole-rock major and trace elements were carried out on the Nanwopu dacite in this paper.Results: The SHRIMP zircon U-Pb dating of the Nanwopu dacite is 268.1±2.5 Ma,it can be ascertained that the dacites are the products of Early Permian magmatic activities. The whole-rock geochemical analyses show that the Nanwopu dacite lie in middle K calc-alkaline fields,the Aluminium saturation index show the metalumininous and weak peraluminous features, integrated with enrichments of LREE and LILE (Rb,Ba,Th,K),depletions of Nb,Ta,P and Ti and Eu negative anomaly,belongs to I-type granites, suggesting plate subduction-related geochemical affinities.Conclusions:Combined with the regional studies,the above geochemical signatures indicate that the Nanwopu dacite was formed in the volcanic arc tectonic environment on the active continental margin of the Hercynian tectonic stage (north margin of North China Craton). This is inconsistent with the tectonic environment drew from the other Mesozoic uranium deposits related to volcanic rocks in eastern China.The Lower Permian Erlitu Formation is favorable for the occurrence of uranium mineralization in eastern China.