论铁氧化物铜金型(IOCG)矿床地球化学岩相学填图新技术研发

R&D on New Mapping Technology of Geochemical Lithofacies in Prediction and Exploration for Iron-Oxide Copper Gold Deposits(IOCG)

在铁质苦橄岩—铁质安山岩、钛铁辉长岩—钛铁质闪长岩和二长岩—二长斑岩岩体附近,同岩浆侵入期脆韧性剪切带中构造岩相和热液角砾岩相,它们是铁氧化物铜金型(IOCG)矿床含矿岩相学类型。总体垂向蚀变分带为:上部为粘土化—绢云母化—赤铁矿蚀变带,中部钾质蚀变相带(电气石—铁质)+热液角砾岩化相带,下部钠质蚀变相(铁质)—热液角砾岩化带。围绕二长斑岩—二长闪长岩舌状侵入体形成电气石蚀变岩相带,属于汽成热液蚀变中心。大型—超大型IOCG矿床具有多期蚀变相系叠加特征,不同成因的热液角砾岩化相带发育、异时同位多期蚀变岩相叠加和汽成热液蚀变相发育等是寻找大型—超大型IOCG矿床标志。

Tectonic lithofacies and breccia lithofacies of hydrothermal fluid were hosted in the syn-magmaticbrittle-ductile shear zone around Fe-rich picrite-Fe-rich andesite,Ti-Fe-rich gabbro-Ti-Fe-rich diorite,and monzonite-iverniteintrusive body.All of these lithofacies are supposed to be ore-hosted lithofacies for iron-oxide copper gold deposits（IOCG）.In general,vertical zonation of altered lithofacies are as follows： The top altered lithofacies is calyization-sericitization-hematitization zone,and the middle altered lithofacies is potassic alteration lithofacies with tourmalinization and Fe-rich alteration lithofacies ＋breccia lithofacies of hydrothermal fluid,while the low sodic alteration lithofacies with Fe-rich alteration lithofacies＋breccia lithofacies of hydrothermal fluid.However,tourmalinization lithofacies may be the center of pneumatolytic hydrothermal fluid around the tongue-shaped intrusion of ivernite and monzodiorite.Large-superlarge iron-oxide copper gold deposits（IOCG） are of multistage alteration lithofacies system superimposed by breccia lithofacies of hydrothermal fluid in different origins.Multistage of alteration lithofacies superimposed by heterochronousheterochemical potential lithofacies at the same place and excellent altered lithofacies of pneumatolytic hydrothermal fluid are exploration and predictionindicators for Large-superlarge iron-oxide copper gold deposits.