Geodynamic Setting and Metallogenic Model of Lithium Deposits in China

ABSTRACT

The anomalous enrichment and mineralisation of lithium are jointly controlled by geodynamic processes and tectono–magmatic responses. Based on three metallogenic belts, namely, the Songpan–Ganze–West Kunlun (SGWK), the Himalaya and South China, this work systematically examines the divergent lithium mineralisation patterns under different geological settings. The SGWK metallogenic belt extends for approximately 2800 km. Its deep driving force is the terrane collision and amalgamation following the closure of the Paleo–Tethys Ocean, accompanied by crustal thickening and anatexis, which induced partial melting and melt–fluid extraction of lithium–rich flysch sequences, resulting in the formation of giant spodumene‐type accumulations. The Himalaya metallogenic belt, extending about 1500 km in an east–west direction, is controlled by the extensional detachment structures of the South Tibetan Detachment System (STDS). Driven by tectonic stress, deep crustal melts underwent plastic flow and vertical differentiation, and lithium was further enriched during migration, reflecting the unique contribution of melt dynamic differentiation to mineralisation under a post–collisional extensional regime. The South China metallogenic province formed in an intracontinental extensional setting. The lithospheric thinning, localised delamination and deep heat input associated with the evolution of the Paleo–Pacific tectonic domain promoted voluminous granitic magmatism. Prolonged fractional crystallisation favoured the enrichment of elements such as W and Sn, whereas large–scale lithium mineralisation was controlled not only by magmatic differentiation but also significantly constrained by the initial Li endowment of the source region. The above comparison shows that lithium mineralisation results from the combined effects of geodynamic settings (collision–amalgamation, extensional detachment and delamination–thermal perturbation) and the Li endowment of the source region, which result in different magmatic–hydrothermal evolution paths and mineralisation style.