那西郭勒沉积变质型铁-石墨矿床成矿特征及找矿方法组合

那西郭勒铁-石墨矿床位于伯喀里克-香日德印支期金、铅、锌(铜、稀有、稀土)成矿带(Ⅲ12)的西端。铁、石墨矿体主要赋存于金水口岩群地层中的条带状磁铁石英岩、石英片岩、斜长角闪片岩、斜长角闪岩和大理岩中。矿体产出受地层岩性控制,成矿经历了热水喷流沉积期、变质作用期和构造-岩浆变形-改造期三个阶段,矿区地磁异常明显,并具带状分布特征,同时分布有规模较大的激电异常,槽探揭露和钻探验证表明,激电异常与石墨矿带具有一定的对应性,铁、石墨矿体表现为明显的低阻高极化特征。在矿床发现及勘查过程中,磁法测量、激电测量发挥了重要作用。通过归纳总结得出东昆仑地区沉积变质型铁-石墨矿床有效的勘查方法组合为:①通过成矿地质背景及找矿模型的研究,确定找矿远景区;②开展1∶50 000高精度磁测圈定磁异常并划分成矿有利地段;③进行1∶10 000地面高精度磁测和激电剖面测量工作,进一步缩小靶区;④进一步开展1∶2 000磁电剖面测量,详细了解异常特征,进行磁异常的2.5D反演解释;⑤利用钻探进行验证,确定矿体或矿床。该方法组合经济有效并能够提高找矿成功率。

Metallogenic characteristics and ore-prospecting method combination of Naxi sedimentary metamorphic iron-graphite deposit

The naxi iron-graphite deposit is located at the western end of the Berkalik-Xiangri indosinian gold,lead,zinc ( copper,rare,rare earth ) metallogenic belt (Ⅲ 12 ).Iron and graphite ore bodies are mainly distributed in gold Shuikou rock groupbanded magnet Shi Ying rock,Shi Ying schist,plagioclase amphibole,plagioclase amphibole and marble.Ore body output is controlled by formation lithology.Mineralization has experienced three stages:hot water jet deposition stage,metamorphism stage and tectonic-magmatic deformation-transformation stage.In the process of ore deposit discovery and exploration,the geological and magnetic anomalies in the mining area are obvious and have the characteristics of banded distribution,and large-scale.Excitation anomalies are distributed at the same time.The exploration and drilling verification show that the excitation anomalies have certain correspondence with the graphite ore belt.The iron and graphite ore bodies show obvious characteristics of low resistance and high polarization.In the process of ore deposit discovery and exploration,magnetic measurement and excitation measurement play an important role.The sedimentary metamorphic iron - graphite deposit and geophysical characteristics are analyzed in this study.An effective method to obtain ore - finding breakthrough is used.We concluded that the effective exploration method combination for sedimentary metamorphic iron-graphite deposit in plateau desert area is :the first one is get through study the metallogenic geological setting and prospecting model,identify key point for mining area;the second is to carry out the 1:50000 high-precision magnetic survey and gravity measurement,delineate the magnetic anomaly and forecast contact zone of rock mass and the stratum,then delineating favorable district of metallogenic;the third is carry out the 1:10000 high-precision magnetic survey to the ground,further narrowing the target area;the forth is further carry out 1:2000 magnetoelectric profile survey,detailed understanding the characteristics of anomaly,proceeding 2.5D inversion interpretation of magnetic anomaly;and the fifth is using drilling verification,determine the ore bodies or deposits.The method combination is economical and effective,furthmore improve the success rate of prospecting.