宋鹤桐 白银增 于志宏 刘幸

【摘 要】辽宁省朝阳县老道沟铁矿区位于华北地台北缘宁城断凹东部，凌源—北票断裂北西侧之康家湾—松太沟背斜，太古宙变质基性、超基性—中酸性火山岩—沉积岩系作为本区的基底，矿体主要赋存于建平群小塔子沟组斜长角闪片麻岩中，多呈薄层状产出，与地层产状一致，具有鞍山式磁铁矿典型特征。矿体与磁异常吻合度较高，论文通过对已知矿体及磁异常对比研究，归纳找矿标志，总结找矿方向，为下一步勘查奠定基础。

【Abstract】The Laodaogou iron mine in Chaoyang county of Liaoning province is located in the eastern part of Ningcheng fault depression in Taibei border of North China， and the upper bend of Kangjiawan-Songtai in the west of Lingyuan-Beipiao fault. Archean metamorphic and ultrabasic property， intermediate-felsic volcanic rocks and sedimentary rock system are the basement of this area. The ore bodies mainly exist in the plagioclase gneiss of groove group of Xiaotazigou of Jianping group. It is mostly thin bedded and consistent with the occurrence of strata， and has typical characteristics of Anshan magnetite. The correlation between ore body and magnetic anomaly is high. Through the comparison of the known ore bodies and magnetic anomalies， the ore prospecting marks are summed up and the prospecting direction is summarized， which lays the foundation for the further exploration.

【關键词】鞍山式磁铁矿；地质特征；找矿标志

【Keywords】 Anshan magnetite； geological characteristics； prospecting indicator

【中图分类号】P612.31 【文献标志码】A 【文章编号】1673-1069（2018）06-0177-02

1 区域地质背景

老道沟铁矿区地处华北地台北缘宁城断凹东部，凌源—北票断裂北西侧[1]。太古宙变质基性、超基性—中酸性火山岩—沉积岩系作为本区的基底，断陷盆地中断续沉积了古生界至新生界沉积岩系，构成沉积盖层（图1）。

区域地层以新太古界建平群变质建造为主、其次为中上元古界长城系、中生界侏罗系、白垩系以及第四系。该区处于青龙—锦西、承德—北票两大壳断裂所挟持的区域内，它们对区内构造的发育起着控制作用。区域构造经受多期次地壳运动和构造活动的叠加，形成了一系列北东向的压扭性断裂构造及北西向的张性断裂系统。

2 矿区地质

2.1矿区地质概况

矿区内出露地层较单一，大面积出露为新太古界建平群小塔子沟组，仅在沟谷地段出露小面积新生界第四系。区内构造较简单，小塔子沟组总体呈单斜产出，区内断裂不发育。……