Deep electromagnetic sounding for mineral exploration: LOTEM Validation Study 2017

Although the exploitation of strategic important mineral deposits is currently feasible down to a depth of ~ 1000 m, the extension of ore deposits in Germany is poorly known. The BMBF funded DESMEX (Deep Electromagnetic Sounding for Mineral Exploration) project focuses on the development of an electromagnetic exploration system which can be used for the exploration of mineral resources for depths down to 1000 m. The main focus lies in the exploration of potential mineral deposits in Germany. Ore mineralization leads to an increase of electrical conductivity in the host rock. Therefore, innovative methods are developed, which are able to image zones of high conductivity with respect to the intended exploration depth and deliver insights in the geometry of the ore deposit. In order to obtain an high coverage as well as an high resolution, air borne and ground based methods are combined in a semi airborne controlled source EM (CSEM) concept. This concept was tested in an old antimony mining area in eastern Thuringia. In the framework of DESMEX, the University of Cologne carried out ground based (long offset) transient-electromagnetic (LOTEM) measurements. Within the LOTEM validation study, an independent resistivity model of the survey area was derived, which serves as reference model for the semi airborne concept and is integrated in a final mineral deposition model. This data publication (https://doi.org/10.5880/GIPP-MT.201716.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

尽管目前战略性重要矿床的开采可在约1000米深度范围内实施，但德国境内矿床的延伸范围仍知之甚少。由BMBF资助的DESMEX（Deep Electromagnetic Sounding for Mineral Exploration，矿产勘探深层电磁测深）项目聚焦于开发一种电磁勘探系统，可用于探测深度达1000米的矿产资源，其核心目标在于勘探德国境内的潜在矿床。矿石矿化作用会导致围岩电导率升高，因此项目开发了创新方法，能够针对目标勘探深度对高电导率区域进行成像，并揭示矿床的几何形态特征。为实现高覆盖度与高分辨率，项目将航空与地面方法相结合，形成半航空可控源电磁法（Controlled Source Electromagnetic，CSEM）技术方案。该技术方案已在图林根州东部的一处旧锑矿区进行了测试。在DESMEX项目框架内，科隆大学开展了地面（长偏移距）瞬变电磁法（Long Offset Transient Electromagnetic，LOTEM）测量。在LOTEM验证研究中，项目推导了测区的独立电阻率模型，该模型可作为半航空技术方案的参考模型，并被整合至最终的矿床沉积模型中。本数据出版物（https://doi.org/10.5880/GIPP-MT.201716.1）包含一份PDF格式的详细报告，内容涉及项目描述、实验装置、数据采集、所用仪器、记录配置及数据质量等信息。数据仓库的文件夹结构与内容详见Ritter等人（2019）的研究。时间序列数据以EMERALD格式（Ritter等人，2015）提供。