Magnetotelluric exploration of deep-seated gold deposits in the Qingchengzi orefield, Eastern Liaoning (China), using a SEP system

Abstract

The Liaodong Peninsula in northern China has undergone multi-stage magmatic and tectonic modifications, similar to those recorded by the Jiaodong gold province that is the largest gold-producing district in China, indicating that Liaodong Peninsula has great potential for new discoveries. However, no significant gold deposit has been discovered thus far at depths below 1.5 km, the typical depth of the gold-bearing system in the comparable Jiaodong gold province. This study focused on the Qingchengzi orefield on the northern Liaodong Peninsula. Qingchengzi recorded multiple post-magmatic hydrothermal gold-mineralizing events along the Jianshanzi fault zone, the main ore-controlling structure in the orefield. Given the potential for undiscovered, deep-seated gold mineralization along the Jianshanzi fault zone, we performed a magnetotelluric (MT) study designed to identify any deeper exploration targets. The surface electromagnetic prospecting (SEP) system, a portable instrument suitable for use in electromagnetically mountain environments, was employed for the purpose of acquiring the MT data. Shallow conductive anomalies identified in the vicinity of the Jianshanzi fault zone were tested by known drilling recorder. The survey not only helped to generate a detailed map of the deep geological architecture, but also allowed us to estimate the vertical extent of the known gold orebody to a depth of more than 2 km.