Time-domain IP 3D inversion and ore-prospecting prediction of volcanic rock coverage area in the northern Nanjing-Wuhu area: A case study of the Wuzhuang work area

The Nanjing-Wuhu area is one of the most favorable iron-copper polymetallic areas in the Middle and Lower Yangtze metallogenic belt. High extent of exploration in this area has led to discovery of several iron and copper polymetallic deposits. However, prospecting progress has been slow in recent years. Therefore, how to make prospecting breakthrough in the Nanjing-Wuhu volcanic rock covered area has thus become a research focus and hot spot. Previous researchers employed only one-dimensional and two-dimensional time domain inversion technique to process data and interpret anomalies. Three-dimensional inversion technique has not been put into practice due to its high hardware requirements. Based on regional geological data of the work area, as well as parameter measurement and statistical analysis of physical properties of typical formations and rock specimen, time domain induced polarization(TDIP)measurement in the Wuzhuang working area was conducted using a T30 electromagnetic transmitter and an EM-R06 multi-functional electromagnetic receiver, and three-dimensional inversion of field data was performed with EM3DSPI software. Three dimensional inversion results indicate that the rock masses in the work area intruded into the volcanic rock formation of Dawangshan Formation as stocks and dykes, characterized by dominant NE-trending faults interspersed by minor NW-trending faults. Combined with mining information in surrounding areas and existing drilling data, it can be considered that Wangjiachang at the Wuzhuang work area should be favorable area for mineralization and worthy of further deployment.