The Fe-Mn carbonate breccias strata are in conformable contact with the roof and floor Jurassic volcanic complex in the Lengshuikeng Ag-Pb-Zn deposit of Jiangxi Province, with clear volcanic tuffaceous substance existent in interstitial materials. The REE distribution patterns are right- oblique, and the composition characteristics are similar to features of lower total rare earth content of normal lacustrine carbonate and positive Eu abnormal characteristics of pyroxenitic magmatic rocks. C, O isotopes show that the deformation occured in continental volcanic lakes, and continental sedimentary and magmatic rocks provided diagenetic material source. The zircon U- Pb age of the roof and floor volcanic complex is constrained around 155 Ma, and the Fe- Mn carbonate breccias underwent a diagenetic process of sedimentary-volcanic eruption of continental volcanic lakes, with the addition of the intrusion of pyroxenitic magmatic rocks.