河南泌阳条山富铁矿床交代成矿作用浅析  

Brief Analysis on Metasomatism of the Tiaoshan High-grade Iron Deposit in Biyang,Henan Province

作　　者：陈冲[1,2] 魏俊浩[2] 付乐兵[2] 田宁[2] 张道涵[2] 熊乐[2] 

机构地区：[1]湖南省地质调查院,湖南长沙410116 [2]中国地质大学资源学院,湖北武汉430074

出　　处：《西北地质》2014年第1期188-196,共9页Northwestern Geology

基　　金：河南省国土资源厅项目"河南省主要成矿区带深部找矿研究"(2010-61-3)

摘　　要：条山中型富铁矿床位于豫西南东秦岭二郎坪群内,为区内富铁矿床的典型代表。矿区主要构造形迹为轴向北西-南东的条山背斜,褶皱内层间滑脱面的张性空间控制了区内主要矿体的定位。矿区由两个矿带组成:A矿带位于背斜北东翼,以块状磁铁矿矿石为主,含少量浸染状矽卡岩型磁铁矿矿石;B矿带位于背斜轴部偏北东翼,以条带状磁铁矿矿石为主。矿体均自北西向南东斜列顺层分布,呈层状、似层状、透镜状与围岩同步褶曲、整合产出。从矿石组构特征来看,A矿带块状磁铁矿矿石镜下可见围岩的残留,而浸染状矽卡岩型矿石中可见后期磁铁矿交代早期石榴子石、绿帘石;B矿带条带状磁铁矿矿石中磁铁矿与围岩条带的接触界线呈港湾状、孤岛状,均表明条山富铁矿床以交代成矿作用为主。泥盆纪至早石炭世,二郎坪群弧后盆地的碰撞闭合过程导致区内存在一次较大规模的成矿作用,条山富铁矿床应为该期成矿作用的产物。The Tiaoshan medium-sized high-grade iron deposit is located in the Erlangping group of East Qinling, southwestern Henan province and is a typical representative of the high-grade iron deposits in the region. The main structural features of the Tiaoshan mining area is the Tiaoshan anticline of NW-SE trend, and the interlayer detachment surface tension space of the fold controls the positioning of main ore bodies. There are two ore belts in the mining area. A ore belt is located in the NE wing of the fold, mainly massive magnetite ore, containing a small amount of disseminated skarn-type ore; B ore belt is located in partial NE wing of the anticline＇s axis, mainly banded magnetite ore. Ore bodies are distributed in echelon bedding from NW to SE, as layered, stratiform, lenticular, synchronically fold and output with the surrounding rock. From the fabric characteristics of the ore, we can find residues of surrounding rock in massive magnetite ore, whereas, garnet and epidote of early metasomatism in post-magnetite are detected in disseminated skarn-type ore of A ore belt from microscope. It is also found that the contact boundaries of magnetite and banding rock shape like a harbor or isolated island in banded magnetite ore of B ore belt from microscope, showing that the formation of the Tiaoshan high-grade iron deposit is mainly of metasomatism. From Devonian to early Carboniferous, the collision closed process of back-arc basin in Erlangping group leads to the presence of a large-scale mineralization in the region, the Tiaoshan high-grade iron deposit should be the product of this period of mineralization.

关 键 词：矿石组构 交代成矿 二郎坪群 东秦岭 豫西南 

分 类 号：P618.31[天文地球—矿床学]