大兴安岭南段乌苏图如地区锡多金属矿地质特征及找矿潜力

Geological Characteristics and Prospecting Potential of Tin Polymetallic Deposit in the Wusuturu Area,Southern Da Hinggan Mountains

大兴安岭地区是我国重要的锡成矿带之一,乌苏图如地区位于大兴安岭南段,西伯利亚板块和华北板块之间的增生造山带上,属突泉—林西华力西、燕山期铁(锡)、铜、铅、锌、银、铌钽三级成矿带。为查明该区成矿规律及找矿潜力,通过综合开展1∶5万矿产地质调查、1∶5万水系沉积物测量、1∶5万高精度磁测及1∶1万地质草测、1∶2.5万土壤测量、1∶1万地化剖面测量、1∶1万激电中梯剖面测量、激电测深、槽探等工作,对区域成矿地质特征及成矿潜力进行了研究。结果表明:①区内以锡、铅、锌、铜、银等内生金属矿为主,新发现矿(化)点21处;②1∶5万水系沉积物测量圈出化探单元素异常438个,综合异常57个;③1∶5万高精度磁测圈定规模较大的磁异常34个,区内矿(化)点多处于正磁异常区与负磁异常区之间的梯度带上,是寻找多金属矿的有利部位;④矿床成因类型为热液型和接触交代型,主要成矿期为华力西成矿期和燕山成矿期,燕山期为锡多金属矿的主要成矿期;⑤区内矿产分布严格受控于地质构造、岩体以及地层,在横向分布上呈NE向带状展布,由北向南共5个矿带;⑥提交各类找矿靶区16处,其中以锡为主要矿种或伴生矿种的找矿靶区7个。

Da Hinggan Mountains area is one of the most important tin metallogenic belts in China,and the Wusuturu area is located in the south of the Da Hinggan Mountains,on the accretionary orogenic belt between the Siberian Plate and the North China Plate,belonging to the Tuquan-Linxi Hualixi period and Yanshan period iron(tin),copper,lead,zinc,silver,niobium-tantalum metallogenic belt.In order to find out the metallogenic regularity and prospecting potential of this area,by comprehensively carrying out 1∶50000 mineral geological survey,1∶50000 stream sediment survey,1∶50000 high-precision magnetic survey and 1∶25000 soil survey,1∶10000 geological grass survey,1∶10000 geochemical profile survey,1∶10000 IP mid-ladder profile survey,IP sounding,trenching and other working methods,the metallogenic geological characteristics and metallogenic potential are studied.The results show that:①The area is dominated by endogenous metal deposits such as tin,lead,zinc,copper and silver,and 21 new ore(mineralization)points have been discovered;②There are 438 geochemical single element anomalies and 57 comprehensive anomalies by 1∶50000 stream sediment survey;③34 large scale magnetic anomalies were delineated by 1∶50000 high-precision magnetic survey,and most of the mineralization points in the area were in the gradient belt between the positive and negative magnetic anomalies,which was a favorable location for searching for polymetallic ore;④The genetic types of the deposit are hydrothermal type and contact metasomatism type,the main mineralization periods are Hualixi mineralization period and Yanshan mineralization period,and Yanshan mineralization period is the main mineralization period of tin polymetallic deposit;⑤The distribution of mineral resources is strictly controlled by geological structure,rock mass and strata,and the horizontal distribution is distributed in a band to northeast,with a total of 5 ore belts from north to south;⑥16 prospecting targets of various types were submitted,including 7 prospecting targets with tin as the main mineral or associated mineral.