河南省永城市大王庄铁矿矿床特征及成矿规律

Characteristics and metallogenic regularity of Dawangzhuang iron deposit in Yongcheng,Henan Province

大王庄铁矿床为华北克拉通南缘永城—淮北矽卡岩型铁(铜金)矿集区最近取得重要勘查进展的中型铁矿床,累计探明资源储量1445.29万t,但迄今尚无对该矿床的任何研究报导。以河南省地质勘查基金项目成果为依托,对大王庄矿床的成矿规律和地质特征作一初步总结,研究认为,大王庄铁矿床产生于中奥陶统碳酸盐岩和燕山期花岗岩的外接触带,属于邯邢式矽卡岩型铁矿床。永城复式背斜控制了该区矿体的分布,背斜轴部是成矿的主要场所,层间薄弱带、裂隙等构造为含矿流体的汇聚提供了赋矿空间。磁铁矿石和围岩之间存在着较大的磁性差异,对于被新生界沉积物(平均厚140余米)全覆盖的大王庄铁矿区,可利用地磁异常作为主要的找矿手段。

Dawangzhuang iron deposit is located in the Cu-Au ore concentrated field of Yongcheng-Huaibei skarn type in the southen margin of North China craton.It is a middle scale iron deposit with the total proven resources/reserves of 14.4529 million tons as an important achievement in the current exploration,but there is no research report for the deposit until now.Base on the research result of project supported by Henan Geological Explortation Foundation,the paper has proposed of a preliminary summary of the geological characteristics and metallogenic regularity of Dawangzhuang deposit.The research result indicates that Dawangzhuang iron deposit occur in the outer contact zone of Yanshan granite and Middle Ordovician limestone.It is belonged to Hanxing skarn type iron deposit.The iron ore body distribution is controlled by Yongcheng anticlinorium,and the anticline axis is the main mineralization place,the structures of fracture and interlayered weak belt offer the ore-hosted space for the ore-bearing fluid.Because there are great differences of magnetic property between magnetite ore and wallrock,geomagnetic anomaly can be used as main exploration method in prospecting in Dawangzhuang iron mining area where is covered through by thick Cenozoic sediments of an average thickness up to 140 m.