基于磁异常信息的鄂东北四方山地区沉积变质型锰矿找矿预测  

Prospecting of sedimentary-metamorphic type manganese deposits in the Sifangshan area,northeastern Hubei Province:Insight from magnetic anomaly information

作　　者：王川 石文杰[1] 朱建东 徐江嬿 陈松 李艳军[1] Wang Chuan;Shi Wenjie;Zhu Jiandong;Xu Jiangyan;Chen Song;Li Yanjun(School of Earth Resources,China University of Geosciences(Wuhan),Wuhan 430074,China;Key Laboratory of Resources and Eco-environment Geology of Hubei,Hubei Geology Bureau,Wuhan 430022,China;The Sixth Geological Team of Hubei Geological Bureau,Xiaogan Hubei 432000,China;Geological Exploration Fund Management Center of Hubei Province,Wuhan 430071,China)

机构地区：[1]中国地质大学(武汉)资源学院,武汉430074 [2]资源与生态环境地质湖北省重点实验室(湖北省地质局),武汉430022 [3]湖北省地质局第六地质大队,湖北孝感432000 [4]湖北省地质勘查基金管理中心,武汉430071

出　　处：《地质科技通报》2022年第4期184-196,共13页Bulletin of Geological Science and Technology

基　　金：湖北省地质勘查基金项目(〔2020〕7号);中国地质大学(武汉)中央高校基本科研业务费“地学长江计划”核心项目群资助项目(CUGCJ1817)。

摘　　要：为系统开展鄂东北地区锰矿找矿预测,以四方山地区典型沉积变质型锰矿床为重点解剖对象,结合高精度磁法测量异常信息,查明磁异常与锰矿床(体)的空间对应关系。四方山地区锰矿床主要以层状或似层状赋存于新元古代红安岩群黄麦岭岩组(Pt_(3) h)中,含锰岩系为一套含火山物质、泥质、粉砂质碎屑沉积岩夹碳酸盐岩,属于陆源碎屑-碳酸盐岩系。含锰岩系因含少量磁铁矿等铁氧化物而多与1∶5万磁法测量中高强度磁异常套合,但也有部分位于正负磁异常梯度带上。1∶5万磁法总梯度模量中锰矿化富集地段往往与中-低值区(尤其是线性梯度带)对应。基于矿床地质特征、磁法测量资料的二次开发及野外调查成果,在四方山地区圈定了四个找矿靶区。其中四方山矿区北侧找矿靶区Ⅰ经TC160揭露一层锰矿体,厚度2.53 m,Mn平均品位为14.63%;四方山矿区内找矿靶区Ⅱ北段经探槽TC140揭露两层锰矿体,第一层厚1.63 m,Mn平均品位达24.57%;第二层厚0.98 m,Mn品位为16.73%;南段经探槽TC114揭露一层锰矿体,厚度1.32 m,Mn平均品位为17.60%。团山沟矿区东南部找矿靶区Ⅳ经地质路线调查也发现了锰矿化体,显示具有良好的找矿前景。In order to systematically study the prospecting of manganese deposits in northeastern Hubei Province,this study focuses on the typical sedimentary-metamorphic manganese deposits in the Sifangshan area.Based on the anomaly information from a high-precision magnetic survey,the spatial coupling relationship between magnetic anomalies and the manganese deposits.Manganese deposits in the Sifangshan area are predominantly layered and quasi-layered within the Huangmailing Formation(Pt_(3) h)of the Neoproterozoic Hong′an Group.The manganese-bearing sedimentary rocks consist of typical terrigenous clastic-carbonate rocks,including volcanic rocks and argillaceous rocks with silty carbonates.Most manganese-bearing rocks corresponding with medium and high-intensity magnetic anomalies measured by the 1∶50000 magnetic survey,because they contain a small amount of iron oxides such as magnetite.However,some are also located in the gradient zone of positive and negative magnetic anomaly gradient belts.In the total gradient modulus of 1∶50000 magnetic survey,the enrichment areas of manganese mineralization correspond to the middle-low values(in particular of the linear gradient zone).Based on the geological characteristics of the Mn deposits,geophysical information,and field investigation results,four ore prospecting targets have been delineated in the Sifangshan area.Target I is located in the northern Sifangshan district.As revealed by exploratory trench TC160,one manganese orebody with a thickness of 2.53 m and an average grade of 14.63%Mn is found in this belt.In targetⅡin the Sifangshan district,two manganese orebodies have been revealed the through the exploration trench TC140,one with a thickness of 1.63 m and an average grade of 24.57%Mn,and the other having a thickness of 0.98 m and a grade of 16.73%Mn.One manganese orebody was revealed through the exploration trench TC114 in predicted beltⅡ,with a thickness of 1.32 m and an average grade of 17.60%Mn.Manganese mineralization has also been identified in target�

关 键 词：高精度磁法测量 总梯度模 沉积-变质型锰矿 找矿预测 鄂东北 

分 类 号：P618.32[天文地球—矿床学]