Research On Geological Characteristics And Genesis Of The Luoyang Fe Multi-metal Deposit,Fujian Province

Luoyang iron deposit of Fujian Province is dominated by iron,associated with kinds of useful elements such as Mo,S and Zn etc.What's more,some integrated minerals such as coal,limestone and kaolinite are inclueded.The Luoyang iron deposit,located on the margin of Late-Paleozoic Minxi basin,is part of Minxi Maykang-type polymetallic iron deposits.This thesis is based on the formers' conclusion and analysis,combined with field observation and interior research,from a series of aspects such as mineralogy,fluid inclusions,mineralization chronology,in order to find the mineralization principle of this kind of ore deposit,to analyze the genesis and finally to establish a mineralization model.Luoyang iron poly-metallic deposit is located on the southeastern margin of Minxi South depression.The basement of this depression is a Caledonian syncline fold belt,is composed of Devonian syncline deposition,rich in Fe,Pb,Zn,CU,Au,and S.Minxi South depression is characterized by the occurrence of Paleozoic-Mesozoic formations,especially,the Upper Paleozoic-Mid-Lower Triassic strata are widely distributed.In the long period tectonic activities,the Southwestern area of Fujian province is undergoing complicated tectonic deformation and multi-phase magmatic and volcanic activities,which afforded a good source of materials and tectonic condition.The formations in this ore deposit is well developed and fold belt is also well-developed.In addition,mineralization is closely related to lower Carboniferous Lindi Formation,upper Carboniferous Chuanshan Formation and lower Permian Xixia Formation.Fold belt and fault belt afforded migration pathways and enough Vacancy for ore deposit.The Yanshanian granite Intrusion provided metallogenic hydrothermal and resource.Granites in the deposit belong to strong differentiation granites,with high SiO2 and Na2O+K2O.REE distributed patterns showing as slight-right deviation ' Seagull-type' curves,show characteristics of LREE enrichment,HREE depletion and Eu negative anomaly.The metallogenic fluids of Luoyang iron deposit belongs to mid-low temperature,low salinity fluids,the depth of mineralization is very shallow(0.39km-1.82km,0.75km in average).Through the testing of molybdenite and other smaples,it shows that the mineralization age of molybdenite is 133.0±1.9Ma-134.0±4.2Ma,and the age of granite and Granite porphyry is about 131Ma.The age of Magnetite and molybdenite is very near.The main mineralization of this ore deposit is 133.0±1.9Ma?134.0±4.2Ma.In conclusion,Luoyang iron deposit belongs to stratabound skarn-type deposit formed by a mid-low temperature hydrothermal metasomatism in Early Cretaceous.