鲁西地区接触交代( 矽卡岩)型铁矿成矿机制——以济南地区为例  

A case study on mineralization mechanism of contact metasomatic skarn-type iron deposit in Jinan,western Shandong area

作　　者：刘书锋 侯建华[2] 刘鑫冉 孙思涵 Liu Shufeng;Hou Jianhua;Liu Xinran;Sun Sihan(Shandong First Institute of Geology and Mineral Exploration,Jinan 250100,Shandong,China;Shandong Geological Survey Institute,Jinan 250013,Shandong,China;No.2 Middle School of Jinan,Shandong Province,Jinan 250100,Shandong,China)

机构地区：[1]山东省第一地质矿产勘查院,山东济南250100 [2]山东省地质调查院,山东济南250013 [3]山东省济南第二中学,山东济南250100

出　　处：《地质学刊》2021年第2期122-137,共16页Journal of Geology

基　　金：中国地质调查局国土资源大调查之基础调查类项目“山东1∶25万淄博市幅区调修测”(10101137001);“山东省矿产资源潜力评价”(1212010813014);“华北重要经济区带资源与环境地质背景调查及数据更新”项目之子项目(200113000026)。

摘　　要：鲁西地区接触交代(矽卡岩)型铁矿主要分布在沂沭断裂带西侧鲁中隆起区济南、莱芜、金岭、潘店等地。济南地区铁矿资源丰富,亦是鲁西四大接触交代型铁矿成矿区之一。铁矿床形成于中生代燕山晚期中偏基性侵入杂岩与奥陶纪马家沟群碳酸盐岩的接触带上。济南地区杂岩体受齐广断裂控制,铁矿体在空间上严格受接触带的控制。通过岩石学、岩石化学、地球化学等分析,结合精细锆石LIMS U-Pb测年,发现济南地区中生代侵入杂岩形成时代约为130 Ma,属早白垩世燕山晚期,岩石类型具有同源岩浆演化特征;岩浆活动过程中有早期壳源物质参与,原始母岩浆来源于上地幔与下地壳,是在源区与早期拆沉的下地壳物质混合熔融所形成的产物。鲁西地区中生代燕山晚期侵入杂岩体源岩及围岩为铁矿提供铁质及矿化剂并提供热动力条件,各类构造为矿液运移提供通道及容(储)矿空间,接触交代变质为成矿提供动力条件,从而在该地区形成接触交代(矽卡岩)型铁矿。The contact metasomatic(skarn)type iron ore deposits in the west of Shandong are mainly distributed in Jinan,Laiwu,Jinling,Pandian and other places in the Luzhong uplift area on the west side of Yishu fault zone.Jinan is rich in iron ore resources and is one of the 4 contact metasomatic iron ore forming areas in the west of Shandong Province.The iron deposit was formed in the contact zone between the basicly medium intrusive complex in the late Yanshanian of Mesozoic and the Ordovician Majiagou Group carbonate rocks.The complex in Jinan area is controlled by Qiguang fault,and the iron ore body is strictly controlled by the contact zone in space.Based on petrology,petrochemistry,geochemistry and fine zircon LIMS U-Pb dating,the Mesozoic intrusive complex in Jinan area was formed at around 130 Ma,falling into Early Cretaceous and late Yanshanian,and the rock type is characterized by homologous magmatic evolution.The primary magma originated from the upper mantle and the lower crust and was formed by the mixing and melting of the source area and the early decomposed lower crust materials.The source rock and surrounding rock of the late Yanshanian intrusive complex in the west of Shandong provide iron and mineralization agent and thermal dynamic conditions for iron ore,all kinds of structures provide channels for ore fluid migration and ore storage space,and contact metasomatism provides dynamic conditions for mineralization,thus forming iron ore of contact metasomatism in the study area.

关 键 词：成矿 铁矿 矽卡岩 鲁西地区 

分 类 号：P588.31+2[天文地球—岩石学] P618.31[天文地球—地质学]