白云鄂博REE-Nb-Fe矿床地质与航磁、航放特征及其对找矿工作的启示  

A comprehensive comparative study of geological characteristics as well as aeromagnetic and aeroradiometric features of the Bayan Obo REE-Nb-Fe depoits and their implications for prospecting work

作　　者：王继春[1,2] 宋崇宇 王志利[2] 周路路[2] 张占飞[2] 胡巧娥[2] 

机构地区：[1]中国地质大学(北京),北京100083 [2]内蒙古自治区地质调查院,内蒙古呼和浩特010020 [3]中化地质矿山总局化工地质调查总院,北京100120

出　　处：《中国地质》2016年第2期594-606,共13页Geology in China

基　　金：中国地质调查局天津地质调查中心优选项目(1212011220468);内蒙古勘查资金项目(08-2-HK01)联合资助~~

摘　　要：通过对白云鄂博REE-Nb-Fe矿床的航磁及航放成果的分析,结合矿床地质特征进行综合对比研究,发现该矿床具有独特且典型的航磁、航放特征,航磁异常特征显示矿区为强度较高的近东西向条带状正负伴生磁异常特征,是具有较强磁性的矿体与弱磁性围岩反映;航磁ΔTmax为5000 n T以上,航磁ΔTmin为-2000 n T,有30余条测线上具有明显正负磁异常发育,呈现多期次异常叠加特征,属于不同期次、不同强度磁性体的反映,说明该矿床经历过多期次构造热事件的叠加、改造活动。该矿床向下延深的规模随深度的变化有逐渐缩小的趋势,当航磁ΔT等值线向上延拓3000 m时,依然表现为较明显的正磁异常特征,这说明该矿床在深部依然存在较明显的矿化现象。另外白云鄂博矿区航放特征具有醒目的总计数率、钾、铀、钍高值晕,它们总体上呈近东西向带状展布。矿区处于航放总计数率高值区,一般为3000-15381 cps,局部为团块状,高值区范围大于矿区范围;钾含量为2.0%-2.8%的偏高值,矿床及附近局部为2.8%-12%的高值;钍含量为26×10^-6-223×10^-6。钍高值晕范围较赋矿的加里东中期第二次侵入的碳酸岩出露的范围要大;铀含量一般为大于1.6×10^-6的偏高值,矿床及附近局部为2.8×10^-6-9.1×10^-6的高值。经综合分析,充分证明该区的航磁、航放特征与矿床信息对应性较强。在今后寻找类似矿床的过程中,可以将航磁正负伴生磁异常信息作为寻找铁多金属矿的有利信息,将放射性核素钾、钍、铀等高值信息做为寻找稀土矿有利信息,对找矿工作具有十分重要的指导意义。Through analyzing the aeromagnetic and aeroradiometric results obtained in the Bayan Obo REE- Nb- Fe deposit in combination with the comprehensive comparative study of its geological characteristics, the authors found that the Bayan Obo REENb- Fe ore deposit has unique and typical aeromagnetic and aeroradiometric characteristics. The aeromagnetic anomaly characteristics show that the ore deposit is characterized by a high- intensity banded and nearly EW positive magnetic anomaly associated with a parallel positive anomaly, which is the reflection of the contact between strong magnetic orebodies and poor magnetic wall rocks. The aeromagnetic ΔTmaxvalue is over 5000 n T, and the ΔTminvalue is about-2000 n T. There are over 30 survey lines which indicate obvious positive- negative magnetic anomaly development and show that the superimposed anomaly characteristics are the reflection of magnetic rocks of varying ages and intensities. It indicates that the ore deposit has experienced superposition and transformation activities of tectonic thermal events of varying ages. The scale of ore deposit decreases gradually with the increasing depth of downward extension, but it still shows obvious positive magnetic characteristics while aeromagnetic ΔT contour exhibits upward continuation to 3000 m, which indicates that the ore deposit has obvious mineralization in the depth. In addition, the aeroradiometric characteristics of the Bayan Obo ore deposit show marked high value halos of total counting rate and potassium and uranium and thorium elements, and they all show nearly EW banded distribution. The mining area is located in the high value zone, with values between 3000 and 15381 cps and partially in lumpy form, and the range of the high value zone exceeds the range of the mining area. The potassium content is high with values between 2.0% and 2.8%, and partially even reaching 2.8%-12% in the ore deposit and adjacent areas. The thorium values are in the range of 26×10^-6-223×10^-6, and the range of thorium high value zo

关 键 词：白云鄂博REE-Nb-Fe矿床 航磁特征 航放特征 综合对比 内蒙古 

分 类 号：P631[天文地球—地质矿产勘探] P618.2[天文地球—地质学]