摘要
招平断裂是胶东地区重要的金矿控矿断裂,附近已查明大、中、小型金矿床多处,控制的金资源量近2000 t。地质资料显示,招平断裂主要发育于栖霞序列片麻岩与玲珑序列花岗岩接触带附近的破碎蚀变带。近年来,随着勘查深度的不断增加,发现断裂深部产状与浅部不同,其空间赋存规律有待进一步研究和验证。为此,在区内典型的大尹格庄和焦格庄矿床深部开展可控源音频大地电磁测量,利用反演电阻率参数建立表征断裂带深部侧伏规律的三维物性结构模型。模型显示电阻率变化梯级带对应的招平断裂带,呈舒缓波状向下延深,推断其深度超过2500 m,且深部变缓并向北东侧伏。结合断裂控矿特征和先验地质信息,在断裂产状变化部位预测了2处深部找矿靶区,并得到钻孔证实。本文提出的招平断裂侧伏规律的地球物理证据,提高了对断裂带的认识,对断裂带深部找矿预测及工作部署具有一定的指导意义;同时,本次工作证明利用CSAMT方法探测断裂带深部金矿控矿构造是可行的。
Zhaoping fault in Jiaodong area is an important gold ore controlling fault.Many large,medium and small gold deposits have been identified nearby,and the controlled gold resources are nearly 2000 t.The existing geological data show that Zhaoping fault is mainly developed in the fracture alteration zone near the contact zone between Qixia sequence granite and Linglong sequence granite.In recent years,with the increasing exploration depth,it is found that the occurrence of the deep part of the fault is different from that of the shallow part,and its spatial occurrence law needs to be further studied and verified.Therefore,the controllable source audio frequency magnetotelluric survey is carried out in the deep part of the typical Dayingezhuang and Jiaogezhuang deposits,and a three-dimensional physical property structural model was established to characterize the deep lateral subduction law of the fault zone by inversion resistivity parameters.The model shows that the Zhaoping fault zone correspond-ing to the gradient zone of resistivity changes extends downward in a gentle wave shape.It is inferred that its depth is more than 2500 m,and the depth slows down and lies to the northeast.Combined with the ore control characteristics of the fault and a priori geological information,two deep prospecting targets are predicted at the change of fault occurrence,which are confirmed by drilling.On one hand,the geophysical evidence of the lateral lodging law of Zhaoping fault proposed in this paper improves the understanding of the fault zone,and has a cer-tain guiding significance for the deep prospecting prediction and work deployment of the fault zone.On the other hand,this work verifies that it is feasible to use the CSAMT method to detect the deep gold ore-controlling struc-ture in the fault zone.
作者
刘振
杜利明
梅贞华
韩进国
胡创业
LIU Zhen;DU Liming;MEI Zhenhua;Han Jinguo;HU Chuangye(Geological Exploration Insititute of Shandong Zhengyuan,Jinan 250101,China;Comprehensive Geophysical Technology Engineering Laboratory for Deep Exploration of Shandong Geophysical Society,Jinan 250101,China;Institute of Advanced Studies,China University of Geosciences,Wuhan 430074,China)
出处
《桂林理工大学学报》
CAS
北大核心
2023年第3期397-405,共9页
Journal of Guilin University of Technology
基金
山东省重大科技创新工程项目(2018CXGC1602)
中国地质调查局地质调查项目(1212011220694)。
作者简介
刘振(1967—),男,高级工程师,研究方向:矿产勘查,942220536@qq.com;通讯作者:杜利明,高级工程师,duliming@foxmail.com。
