Application of the geoelectrochemical extraction method to the Xiyi Pb-Zn deposit in southwestern China

• Published in: Journal of geochemical exploration 2019-08, Vol.203, p.1-26
• Main Authors: Liu, Panfeng, Luo, Xianrong, Wen, Meilan, Anand, Ravi, Thorne, Robert, Zheng, Chaojie, Zhang, Jiali
• Format: Article
• Language: English
• Subjects: Feasibility; Geoelectrochemical extraction method; Prospect prediction; Xiyi Pb-Zn deposit; Yunnan Province
• ISSN: 0375-6742; 1879-1689
• DOI: 10.1016/j.gexplo.2019.03.005

This paper investigates Xiyi Pb-Zn deposit in Yunnan Province, China, which has little mineralized outcrop and rare supergene enrichment. The deposit is overlain by transported cover with a thickness of ~0.2–50 m. The geoelectrochemical extraction method (GEM) was tested over well-characterized areas of the deposit (sections A–B, C–D), and in an unexplored region (area E). GEM results are compared with soil geochemical methods (SGM) in areas of known mineralization and show that the geoelectrochemical anomalies (Pb, Zn, Ge, As, Au) exhibit a positive response to the deep concealed ore body, and that GEM can be more effective for finding the concealed Pb-Zn ore in the study area compared to SGM. A geoelectrochemical prospecting index was created for this deposit type and tested in an area without known mineralization (area E). The index shows that anomalies can be identified where the contrast value (CV) is >1 for Pb and Zn, and where there is the Y1 factor score (y1) >0 (for Pb-Zn-Ge-As-Mo-Bi). Correlation and factor analysis identify two comprehensive anomaly zones (CAZ) in area E with good prospecting potential, which can be used as the focus of the next exploration. The strong surface geoelectrochemical and soil geochemical anomalies above the fracture belt, with weak to moderate anomalies over thick transported cover above the fracture belt extension, suggest that dilatancy pumping is a dominant migration mechanism in the formation of anomalies in areas of shallow transported cover. •The geoelectrochemical extraction method (GEM) is feasible and more effective than soil geochemical method (SGM).•The anomalies of GEM can indicate the deep concealed mineralization or ore bodies.•The CV anomalies of Pb, Zn (CV