Abstract:QiheYucheng area is located in the northwest of Shandong province. Based on systematic analysis of oreforming geological characteristics and oreforming regularity in this area, comparing with Hanxing type iron deposit and Laiwu type iron deposit, "Yucheng type" iron deposit has been put forward and metallogenic model has been preliminarily set up. Litun, Guodian and Dazhang rich iron deposits have been found in the area, the orecontrolling rock mass is mainly diorite, the surrounding rock strata are mainly CarboniferousPermian and a little Ordovician. The ore body is stratified, mainly granular structure and massive structure. Litun deposit is the most typical "Yucheng type" iron deposit in the area. Main occurrence location of the ore body is the interlayer structure of clastic rock outside the contact zone. Limestone and marlinization zone are missing in the main orebody occurrence area. Large amount of iron and less associated elements are significant characteristics of mineral enrichment. Early cretaceous, the crustmantle mixed magma intruded along the deep and large fault at the basin margin. Due to the shielding of the overlying strata, full contact metasomatism occurred between magmatic hydrothermal fluids and Ordovician carbonate rocks，transformed "Shanxi type" iron ore in the sedimentary strata, and "Shanxi type" iron deposit in the sedimentary strata may has been transformed. It has caused the magnetite to experience multiphase accumulation and enrichment.The magnetite deposits are enriched in the interlayer structures of the CarboniferousPermian period.
