Lithium mineralization in plateau brines and orogen pegmatites: A lithium cycling perspective

Continental brines and Li -enriched pegmatites are two primary lithium resources nowadays, with the former concentrated from streams derived from the weathering of subaerial crust or springs derived from the crust -fluid interaction in high temperature, and the latter highly fractionated from the crustal sediment derived melts as Li -enriched hard rocks. Continental crust serves as the source rocks in both weathering scenarios. Exploring how Li -enriched continental crust grows and weathers is vital for a fundamental understanding of how lithium mineralizes in continental brines and pegmatites. From a perspective of elemental cycling in subduction zones, we first review lithium geochemical behaviors in both endogenous and exogenous geological processes. We further discuss the primary factors for lithium enrichment in arc magmas and the significance of Li -enriched arcs to the lithium mineralization of continental brines in plateau and pegmatites in orogen. Three conclusions are reached here: (1) Subduction contributes limited lithium input to arc magma; (2) Arc magma with thicker crust has higher lithium contents; (3) Cycling of Li -enriched arc rocks in orogen shall be a crucial step in the lithium mineralization in continental brine and pegmatite.