摘要
The Xiaojiayingzi Mo(Fe)deposit is temporally and spatially associated with diorite,and the mineralization is hosted in skarn.Concentrations of platinum group elements(PGE)in various major ore minerals and host rocks of the Xiaojiayingzi deposit were analyzed by using the inductively coupled plasma mass spectrometry(ICP-MS).The results show that the total PGE values in various samples vary greatly between 0.46×10-9 to 216×10-9.PGE is rich in molybdenum and pyrite and poor in magnetite,garnet,diorite and dolomite,suggesting that PGE tends to be concentrated in sulfides.The primary mantle-normalized PGE patterns of various samples show marked negative Ir and Pt and positive Ru anomalies.The molybdenum shows marked fractionation of PGE and is similar to the pyrite.The fractionation patterns of PGE in magnetite and garnet are characterized by weak PGE anomalies,similar to things of diorite and dolomite,suggesting that the metal sources were closely related to the diorite and dolomite.An analysis of S isotope of sulfides from the Xiaojiayingzi deposit indicates that the δ34S values of most sulfides from the Xiaojiayingzi deposit show a peak of 3‰~5‰,similar to things of diorite.Based on geological characteristics,PGE and S isotope of the Xiaojiayingzi deposit,the authors hold that different ore-forming stages had different metallogenic materials.The metallogenic materials of the skarn mineralization stage were derived mainly from the diorite and dolomite.The metallogenic materials of the hydrothermal sulfide stage were derived not only from the diorite and dolomite but also from the mixed crust-mantle system.