东昆仑祁漫塔格地区牛苦头东矿床地质特征及找矿前景

Geological Characteristics and Prospecting Prospects of East Niukutou Deposit in Qimantage Area,East Kunlun

牛苦头东矿床位于柴达木盆地西南缘与祁漫塔格山北麓的交接带,大地构造位置处于秦祁昆造山系、东昆仑弧盆系,三级构造单元为北昆仑岩浆弧,属于东昆仑铁、铅、锌、铜、钴、金、钨、锡、石棉成矿带,成矿地质条件优越。区内第四系覆盖面积较大,地表未见直接的矿化线索。为对1∶50000高磁异常进行查证,首先采用1∶10000地面高精度磁法测量圈出磁异常13处;其次结合磁异常特征布设钻孔并进行井中三分量磁测,以初步查明异常源和盲矿体的地质特征。详细讨论了区域地质背景、矿床地质特征、矿石质量、矿石类型等,同时对矿床成因进行了分析,探讨了找矿方向。研究表明:矿体主要赋存于变砂岩和大理岩中,矿床成因类型为沉积变质型铁矿床,铁矿的磁性特征是有效的、主要的找矿信息,磁测成果中圈定的异常都是直观的、重要的找矿标志;通过对1∶10000磁异常的钻探工程验证,共发现铁矿体22条,划分矿带3个,初步估算出铁矿石量440.2万t;结合磁异常特征并综合分析已有钻孔资料,认为矿区西段规模较大的C1磁异常存在寻找深部矿体的潜力;已发现的矿体多为单孔控制,个别矿体为2个钻孔控制,充分利用钻孔三分量磁测井指示的旁侧异常施工钻孔,有望进一步扩大矿体规模,增加区内资源量;△T化极后上延100 m部分磁异常强度变小,而它们的形态基本未发生变化,说明异常源较深,施工深部钻孔验证这些异常,有进一步发现深部矿体的潜力。

East Niukutou Deposit is located in the junction zone between the southwestern margin of Qaidam Basin and the northern foot of Qimantag Mountains.Its geotectonic location is in the Qinqikun orogenic system and the eastern Kunlun arc basin system.The third-order tectonic unit is the northern Kunlun magmatic arc.It belongs to the East Kunlun iron,lead,zinc,copper,cobalt,gold,tungsten,tin and asbestos metallogenic belt with excellent metallogenic geological conditions.The Quaternary system covers a large area in the area,and there is no direct mineralization clue on the surface.In order to verify the 1∶50000 high magnetic anomalies,firstly,the 1∶10000 surface high-precision magnetic survey method is used to circle13 magnetic anomalies.Secondly,combined with the characteristics of magnetic anomalies,drilling holes are laid and threecomponent magnetic survey is carried out in wells to preliminarily identify the anomaly source and the geological characteristics of blind ore bodies.The regional geological background,geological characteristics,ore quality and ore type are discussed in detail.At the same time,the genesis of the deposit is analyzed and the prospecting direction is discussed.The research shows that the ore bodies mainly occur in metamorphic sandstone and marble,and the ore deposit is of sedimentary metamorphic type.The magnetic characteristics of iron ore are effective and main prospecting information.The anomalies delineated in the magnetic survey results are intuitive and important prospecting indicators.Through drilling engineering verification of 1∶10000 magnetic anomalies,it is found that all of the anomalies are direct and important prospecting indicators.There are 22 iron ore bodies and 3 ore belts,with a preliminary estimate of 4.402 million tons of iron ore.Most of the discovered ore bodies are controlled by single hole,while individual ore bodies are controlled by two boreholes.According to the discovered ore bodies and combined with the characteristics of magnetic anomalies,boreholes are constructed beside the borehole three-component magnetic logging,which is expected to expand the scale of ore bodies and further increase the reserves of ore body resources in the area.internal resources;the intensity of some magnetic anomalies extending up to 100 m after△T-polarization becomes smaller,but their morphology basically unchanged,ndicating that the anomaly source is deep,construction of deep boreholes to verify these anomalies,there is potential for further discovery of deep orebodies.