Abstract:Xitonggou lead and zinc deposit in Zhen'an county of Shaanxi province has commonly been considered as a sedimentaryexhalative (SEDEX) type deposit, but the author thinks that the deposit may be an orogenic type deposit. The ore bodies in the deposit area cut across the strata and these strata belong to the Devonian Dafengou formation. Through study on hydrogen, oxygen, sulfur and lead isotope of this deposit, it is found that the source of the oreforming material is Devonian marine sedimentary strata in the southern margin. The mineralization may be divided into three stages. The early stage is quartz stage, the middle stage is sulfidequartz stage, and the late stage is quartzcarbonate stage. The forming time should be formed in late Triassic to Jurassic period. When the Yangtze plate collided with the North China plate, the collision had led to a series of intracontinental subduction or thrust events inside Qinling microplate, and produced a thermal anomaly. Thermal anomaly drives fluid circulation, extracts oreforming elements from strata, and transports them to space which is suitable for fluid accumulation and unloading of oreforming materials. Thus, oreforming materials have been concentrated.
