攀枝花地区两类铁钛氧化物矿床对比研究  

The Comparative Study of Two Fe-Ti Oxide Deposit Types in the Panzhihua Area

作　　者：罗伟[1,2] 李佑国[1] 彭静[2] LUO Wei LI You-guo PENG Jing(College of Earth Sciences, Chengdu University of Technology, Chengdu 610059, China Geochemical Exploration Brigade of Sichuan Provincial Geology and Mineral Resources Bureau, Deyang 618000, China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]四川省地质矿产勘查开发局化探队,四川德阳618000

出　　处：《内蒙古师范大学学报（自然科学汉文版）》2017年第2期195-199,共5页Journal of Inner Mongolia Normal University(Natural Science Edition)

基　　金：基金项目:四川攀枝花式铁矿成矿地球动力学背景;过程;定量评价及岩浆成矿系统的复杂性研究(1212011220921)

摘　　要：攀枝花矿区存在贯入式和韵律式两种类型的铁矿床.相比韵律式铁矿,贯入式铁矿相对富TiO_2、Fe_2O_3(t)、MnO,贫SiO_2、Al_2O_3、CaO、Na_2O+K_2O和P_2O_5;两类铁矿石具相似的稀土和微量元素地球化学特征,稀土元素相对富集LREE,亏损HREE,具弱的正Eu异常.微量元素相对富集Ba、Ti、Nb、Ta,亏损Th、La、Ce、P;两种类型铁矿中磁铁矿和钛铁矿的主要氧化物含量变化不大,贯入式铁矿中磁铁矿具稍高的TiO_2、FeO和MgO值,钛铁矿相对富MgO、贫MnO、FeO和Fe_2O_3;贯入式铁矿中磁铁矿的δ57 Fe变化范围小,铁同位素组成较轻.研究结果表明,来自地幔的富铁、富挥发份的超临界流体贯入玄武质岩浆中,与玄武质岩浆相互作用、结晶沉淀形成了韵律式铁矿,后期贯入的富铁超临界流体沿先存侵入体、围岩的薄弱面侵位、沉淀形成了贯入式铁矿.There are two types of iron ore deposits in the Panzhihua area：rhythm type and penetration type.The rhythm type is mainly produced in the Middle Zone of Panzhihua instrusion in bedded or near bedded forms and dominated by poor ore.The penetration type is mainly produced in the Lower Zone of Panzhihua instrusion in lenticular or irregular polygonal forms and dominated by rich ore.Compared torhythm type,the penetration type are relatively rich in TiO_2、Fe_2O_3（t）、MnO,lean in SiO_2、Al_2O_3、CaO、Na_2O＋K_2Oand P_2O_5.The geochemical features of the rare earth elements and trace elements of the two iron ore types are similar.They both relatively enrich in LREE and deplete in HREE,and have weak positive Eu anomaly.They are relative enrichment of Ba,Ti,Nb,Ta,loss of Th,La,Ce,P for trace elements.The main oxide contents of magnetite and ilmenite in the two types iron ores have not changed much.The magnetite in the penetrating iron ore has a slightly higher value of TiO_2,FeO and MgO,ilmenite is relatively rich in MgO,MnO,FeO and Fe_2O_3.Theδ57Fe change range of the magnetite in the penetrating iron ore is small,and the iron isotope composition is lighter.The studies shown the formation of rhythm iron ore is due to the penetration of supercritical fluid dissolving numerous iron and volatile into the basalt magma,and injection with it,Crystallization and precipitation from it.The iron-rich supercritical fluids lately penetrated into the soft surface of the existing intrusive bodies and surrounding rocks,and formed penetrating iron deposit.

关 键 词：贯入式铁矿 韵律式铁矿 攀枝花岩体 峨眉山大火成岩省 

分 类 号：P611.11[天文地球—矿床学]