Element geochemistry of the Sishanling iron deposit in Liaoning Province and its geological implications

The Sishanling iron deposit is located in the northern margin of North China platform and geographically lies in Benfen area,Liaoning Province.The ores are composed of magnetite and hematite and controlled by Anben Formation of Achean Cigou Group,the sedimentary facies is of the oxide-silicate phase.Through the study of element geochemistry of the main minerals,ores and wall rocks,the authors have obtained some useful information: Metamorphic facies has reached low amphibolite facies,and the BIF can be classified as mafic volcanic-muddy sandstone-ferrosilicic sedimentary formation.The metamorphic volcanic rocks are characterized by oceanic tholeiite.The shale-normalized REE patterns of the ores display depletion of light REE relative to heavy REE,high ratios of Y/Ho and distinct positive anomalies of La,Y.Eu shows stronger positive anomalies in comparison with the other main BIFs in North China platform.The geochemical information of the BIF shows that the ore-forming elements came from the mixed solution of volcanic-hydrothermal solution and sea water,and that the hydrothermal solution was related to the mantle material.