华北地区铁矿资源成矿规律初探

Preliminary Study on the iron resources and the metallogenic regularity in North China

华北地区地处古亚洲、特提斯和环太平洋三大构造体系交汇部位,地质演化历史悠久,岩浆活动频繁,成矿地质条件优越,铁矿资源丰富。已查明铁矿床1085处,主要分布在河北省、河南省、山东省、山西省、内蒙古中西部和北京市,构成了冀东、包头、莱芜、五台-岚县、许昌-舞阳、邯邢等多处重要的国家级铁矿资源基地。矿床类型有受变质型(沉积变质型)、岩浆型、接触交代型(矽卡岩型)、海相火山岩型、陆相火山岩型、岩浆热液(狭义)型、化学沉积型、机械沉积型和中低温热液型,以受变质型、接触交代型、岩浆型、海相火山岩型为主。华北地区铁矿形成时代从太古代至中生代,其中贫铁矿以太古代、元古代为主,富铁矿以中生代为主。华北地区铁矿床划分出与变质作用、岩浆作用、沉积作用和不明流体作用有关的成矿系列11个,并初步建立了铁矿床成矿谱系。经综合评价,在华北地区划分出76个重要铁矿找矿远景区,显示了良好的铁矿资源潜力。尤其在莱芜-禹城、邯郸-邢台、安阳-林州、古交-临汾-平顺地区圈定出的接触交代型富铁矿成矿带,将成为下一步华北地区富铁矿找矿的最佳部署区带。

North China is located at the intersection of the three major tectonic systems of Paleoasian,Tethys and circum Pacific.It has a long history of geological evolution,frequent magmatic activities,superior metallogenic geological conditions and rich mineral resources.1085 iron deposits have been discovered in Hebei,Henan,Shandong,Shanxi Province,midwestern Inner Mongolia,Beijing and Tianjin,forming Jidong,Baotou,Laiwu,Wutai-Lanxian,Xuchang-Wuyang,Handan-Xingtai and other important state-level iron ore resource bases.There are nine types of iron deposits,i.e.,metamorphic type(sedimentary metamorphism type),magmatic type,contact metasomatism type(skarn type),marine volcanic type,continental volcanic type,magmatic hydrothermal type,chemical sedimentary type,mechanical sedimentary type and meso-low temperature hydrothermal type.The main types are metamorphic type,marine volcanic type,magmatic type and contact metasomatism type.The formation age of iron deposits in north China is from Archean to Mesozoic,in which the lean iron deposits are mainly Archaean and Proterozoic,and the rich iron deposits are mainly Mesozoic.The iron deposits in north China are divided into 11 metallogenic series related to Metamorphism,magmatism,sedimentation and unidentified fluid processes.Based on the classification of metallogenic series,the metallogenic spectrum of iron deposits is established.On the basis of the evaluation of mineral resources potential,76 important iron prospecting areas can be divided in North China,which shows good prospecting potential.Especially,the contact metasomatic rich iron ore belt delineated in Laiwu-Yucheng,Handan-Xingtai,Anyang-Linzhou and Gujiao-Pingshun area will be the best area for rich iron ore prospecting in north China.