(1. 中南大学 地球科学与信息物理学院,长沙 410083;
2. 中南大学 有色金属成矿预测教育部重点实验室,长沙 410083;
3. 长沙五维地科勘察技术有限责任公司,长沙 410205;4. 重庆市地质勘查局 川东南地质大队,重庆 400038)
摘 要: 由于深埋富集铁矿矿体的埋深超过500 m,直接运用音频大地电磁法(AMT法)圈定深埋富集铁矿矿体异常的纵向分辨率难以实现,为此,根据矿床成因、成矿环境以及矿体赋存空间特征等地质因素,建立地质模型,在地质模型的基础上构建地电模型;在地电模型的基础上,应用AMT法达到间接找矿的目的。綦江式铁矿和宁乡式铁矿的勘查实践结果表明,应用AMT法能够确定找矿标志、含矿层次和赋矿构造等,从而间接实现探测深埋富集铁矿床。
关键字: 綦江式铁矿;宁乡式铁矿;AMT法;地电模型
audio-frequency magnetotelluric method
(1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China;
3. Changsha 5D Geo-survey and Technical Co., Ltd., Changsha 410205, China;
4. Geological Team of Southeastern Sichuan, Chongqing Bureau of Geological Exploration and Exploitation of
Mineral Resources, Chongqing 400038, China)
Abstract:When the enrichment iron ore is buried more than 500 m, it is difficult to achieve the longitudinal resolution of iron ore abnormalities by using audio-frequency magnetotelluric (AMT) method directly. For this reason, based on the geological factors of the ore genesis, metallogenic environment, ore controlling space, and so on, the geological model was made and then the electrical model was set up, which was used to achieve the aim of indirect ore prospection by AMT method. The prospecting tests results in Qijiang-type iron deposit and Ningxiang-type iron deposit prove that the AMT method can deterimine prespecting mark, ore-bearing strata, ore-bearing structure and so on. So, indirectly detect deep-buried rich iron ore.
Key words: Qijiang-type iron deposit; Ningxiang-type iron deposit; AMT method; geoelectric model