首钢秘鲁马尔科纳铁矿地质特征及找矿新发现  

Geological characteristics of Marcona Iron ore deposit in Peru and the new discovery in the deposit made by Shougang Geological Exploration Institute

作　　者：刘海彬 滕正双 杨艳忠[1] 王俊山[1] LIU Haibin;TENG Zhengshuang;YANG Yanzhong;WANG Junshan(Shougang Geological Exploration Institute,Beijing 100144,China)

机构地区：[1]首钢地质勘查院,北京100144

出　　处：《地质找矿论丛》2024年第2期265-274,共10页Contributions to Geology and Mineral Resources Research

摘　　要：首钢秘鲁马尔科纳铁矿位于安第斯山脉西南侧的秘鲁中南部沿海沙漠地带。目前探明或开采的多个铁矿体均呈层状、似层状,走向NE向或近EW向,倾向NW或N。单个矿体走向延伸达2000~2700 m,厚度100~300 m,倾向延伸200~1000 m,为超大型铁矿床。铁矿赋存于古生界马尔科纳组和中生界塞里托斯组中,不同地层的铁矿石结构构造、化学成分有所不同,其中马尔科纳组中的铁矿石品位较高,品质较好;塞里托斯组中的铁矿石品位较低。随着矿山不断开采,需要增加后备资源,优先寻找赋存于马尔科纳组中的高品位铁矿体。通过分析研究区内航磁异常和地磁异常数据,在矿区东部塞里托斯组与马尔科纳组交界处发现马尔科纳铁矿A-53磁异常区,该异常长约880 m,宽约400 m,面积约0.35 km~2,异常南端梯度大,北端梯度小,该异常极大值4400 nT。推测该异常深部的马尔科纳组中存在隐伏铁矿体。通过钻孔验证,在该磁异常区发现了分别赋存于塞里托斯组和马尔科纳组中的厚大隐伏铁矿体,铁矿石资源量约1.5亿吨,是首钢秘鲁马尔科纳铁矿近期找矿工作的一个新突破。Marcona is a super-large Fe deposit located in the southwest side of the Andes Mountains in the central southern coastal desert area of Peru.Fe ore bodies being proven and mined at present are layered,layeroid with NE,or nearly EW strike and N or N dip.Individual ore body is 2000~2700 m long,100~300 m thick extending 200~1000 m along dip.The Fe ore occurs in Paleozoic Marcona Formation and the Mesozoic Ceritos Formation and is varied in chemical composition and ore texture and structure.The ore in Marcona Formation is quality ore with high grade and that in Ceritos Formation low grade.With the continuous mining more quality ore reserves is required.Based on analysis of air and ground magnetic anomalies of the area magnetic anomaly A-53 is located at bounder of the Ceritos Formation and Marcona Formation in the eastern part of the mining area.It is about 880 m long,400 m wide covering an area of about 0.35 km~2 with large gradient at southern end and small gradient at northern end and maximum value of 4400 nT.Blind Fe ore body is predicted to depth of the anomaly in the Marcona Formation and drill holes hit big and thick Fe ore bodies in Marcona Formation and Ceritos Formation with estimated Fe resources 150,000,000 t.This is breakthrough made by Shougang Geological Exploration Institute.

关 键 词：马尔科纳铁矿 矿床地质特征 找矿新发现 秘鲁 

分 类 号：P613[天文地球—矿床学] P618.31[天文地球—地质学]