Genetic Mineralogy And Genesis Of Beiminghe Skarn Iron Deposit In Handan, Hebei Province

Beiminghe iron deposit, located in Handan, Hebei Province, is one of the typicalHan-Xing type iron deposits. Based upon the genetic mineralogy of magnetite and thedeposit genesis, the paper tries to establish metallogenic model and obtain someconclusions as follow:The metallogenic rock is diorite, which belongs to calc-alkaline–alkaline rocktype. The U-Pb age of zircon in metallogenic rock of Beiminghe iron deposit is136Ma. Through chronological study of Beiminghe iron deposit, the40Ar-39Ar age ofphlogopite that coexisted with magnetite and dioposite shows that the mainmetallogenic stage occurred around137Ma. Therefore, dating of diagenesis andmetallogeny is around136to137Ma.It draws several conclusions according to the genetic mineralogy research ofmagnetite from Beiminghe iron deposit. Magnetite of Beiminghe iron deposit ismainly xenomorphic crystal, with low content of mantle element such as Ti, Ni and V.It belongs to low titanium magnetite and its thermal conductivity is N type. Accordingto the thermoelectricity, it demonstrates that the mineralization temperature is650to750℃, with mixed forming characteristics of thermal fluid-skarn-sedimentationmetamorphism.The results of both hydrogen and oxygen isotopes from skarn minerals as well asmagnetit and sulfur, lead helium and argon isotopes from pyrite show that theore-forming fluid originally came from the mixed crust-mantle magma fluid. As itascended, there is also atmosphere water added into the metallogenic process. Therare-earth element of rocks and ores as well as the sulfur, lead helium and argonistopes from pyrite reveal that the mellogenic materials are originated from the crustwith a little mantle material. The percentage of mantle materials reaches to0.98～2.21%by calculating.It figures out the metallogenic model of Beiminghe iron deposit by studying thegeological conditions and genesis.