Abstract:Hydrothermal alteration is a prevalent signature in hydrothermal deposits, which plays a critical role in controlling element mobility and enrichment and thus provides vital constraints on understanding deposits’ genesis. The samples from the Zoujiashan uranium deposit are divided into fresh and altered porphyroclastic lava, of which the altered samples can be divided into albitization, potassium feldspathization and illitization respectively. Through the study of Whole-rock geochemical and element migration during the alteration, several important points with were reached: (1) the fresh volcanic rocks belong to high K calc-alkaline to shoshonitic series and are lightly to strongly peraluminous; (2) The content’s change of the trace elements such as Th, Zr and Hf are consistent with those of uranium, and HREE are related to uranium enrichment closely; (3) Si, Mn, Mg, K, Ca, P, Rb and U were extensively mobile during albitization, the average △C/C0 values of U is 69.56; (4) Mn, Mg, Ca, Na, P, U, Th and HREE have high activity during potassium feldspathization, the average △C/C0 values of U is 18.53; (5) Si, Al, Mn, Na, K, P, U and most rare earth elements were highly mobile during illitization with the average △C/C0 values of U is 159.70. The results indicate that the acid-alteration dominated by illitization is necessary for the forming of rich uranium ores.