Using the CSAMT method to predict deep mineralisation of copper and molybdenum: a case study of the Zhongxingtun area in Inner Mongolia, China

ABSTRACT

The Zhongxingtun area in Inner Mongolia, China, hosts an important copper polymetallic ore field. Surface copper and molybdenum–copper orebodies have been found, without deep drilling. A new round of prospecting is focused on finding deep orebodies. To identify these copper and molybdenum orebodies and the deep structure, the controlled-source audio frequency magnetotelluric (CSAMT) method was implemented in the Zhongxingtun area with a V8 multi-function electrical prospecting system using the continuous profile method with a network density of 100 m × 20 m in the western region and 50 m × 20 m in the east. These measurement densities are different from that used in most other areas, and a dense network is mainly utilised due to the need for mineral exploration. The borehole positions were determined by a comprehensive analysis of the two-dimensional imaging from the collected data, the geological features of the study area, and the physical characteristics of the bedrock. The drilling proved that molybdenum orebodies exist in the deeper regions where the mineralisation is characterised by the predominance of molybdenum followed by copper. The results show that through the analysis of the apparent resistivity obtained by the CSAMT method in the Zhongxingtun area, drilling hole positions are determined, and a deep mineralised body is discovered, showing that the CSAMT method is effective. This method is expected to be widely used in prospecting for copper polymetallic ore deposits.

KEYWORDS:

• Electrical geophysics
• geology
• mineral exploration
• resistivity methods

Acknowledgements

This research was supported by funds from the Chinese Ministry of Science and Technology (2016YFC0600103) and the project of “Comprehensive integration and service of mineral geology and its metallogenic regularity in China” from the China Geological Survey (grant number DD20160346). The authors are also appreciative of Professor Zhongren Sun and Qun Zhu for their constructive comments and suggestions, which significantly improved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by funds from the Chinese Ministry of Science and Technology (2016YFC0600103) and the project of “Comprehensive integration and service of mineral geology and its metallogenic regularity in China” from the China Geological Survey (grant number DD20160346).