Tectono-geochemistry and deep prospecting prediction in the Lekai lead-zinc deposit, Northwestern Guizhou Province, China

This paper is the result of mineral exploration engineering.

Objective The Lekai lead-zinc deposit, located in the Pb-Zn deposit concentration of northwestern Guizhou, is one of the small-scale lead-zinc deposits newly discovered in recent years. Different from most lead-zinc deposits in the Pb-Zn deposit concentration of northwestern Guizhou, the Lekai lead-zinc deposit is controlled strictly by NE trending fault-fold structure, which is similar to most lead-zinc deposits in the Pb-Zn deposit concentration of northeastern Yunnan. The current research provided significant implications for the deep exploration in the Lekai lead-zinc deposit and the Sichuan–Yunnan–Guizhou Triangle area (SYGT).

Methods This study applied a large deal of detailed structural analysis on mechanical properties for faults and folds in the mining area and tectono-geochemistry method.

Results The results showed that duo-type and λ-type are the main ore-controlling structural styles in this area. Moreover, three tectonic associations have been divided, which are correspond to four tectonic systems, namely Hercynian to Mid Indosinian, Late Indosinian to Early Yanshanian, Mid-Late Yanshanian, and Himalayan epochs. The trace elements concentrations of tectonites represented three element associations of principal factors, including frontal halo elements (Sb-As-Hg) in low temperature ore-forming stage, mineralization-halo elements (Zn-Pb-Cd) in medium-low temperature ore-forming stage, and tail-halo elements (In-Sn-Ni-Cu) in medium temperature ore-forming stage.

Conclusions In four tectonic systems, ore-forming tectonic system corresponded with Late Indosinian to Early Yanshanian. According to anomaly features and their distribution regularities, the possible migration direction of ore-forming fluid is from southwest to northeast, and six target prospecting areas have been put forward in the depth of mining.