Reverse Weathering in Salt Lakes on the Qinghai-Xizang Plateau and Its Implications for Key Element Cycling

Reverse weathering in salt lake environments, also known as reverse chemical weathering, refers to the process by which authigenic clay minerals or carbonates form within the lake.This mechanism plays a crucial role in regulating the geochemical cycling of key elements in these environments.The Qinghai-Xizang Plateau(QTP) represents a globally significant salt lake region, functioning as a major carbon sink for inland ecosystems, and is rich in essential mineral resources such as lithium, potassium, rubidium, and cesium.Salt lakes in the QTP exhibit diverse water chemistry types, including carbonate, sulfate, and chloride, with each type influencing the types and formation mechanisms of salts and clay minerals differently.This paper reviews recent advances in the study of reverse weathering in salt lake environments and examines how reverse weathering processes in QTP salt lakes affect the geochemical cycling of key elements.The formation of authigenic clay minerals (e.g., illite) in these lakes is a primary mechanism for the consumption of critical elements such as lithium, potassium, rubidium in the brines.In contrast, the formation of carbonates has a relatively minor impact on the consumption of these elements unless it involves the formation of critical metal-containing minerals such as zabuyelite.Both authigenic clay minerals and carbonates significantly influence the inorganic carbon cycles of the lakes.Quantifying the extent of reverse weathering, elucidating the limiting factors, and assessing the impact of key element depletion are pivotal issues in studying salt lake mineral resources.The rapid advancement of nontraditional stable isotope techniques offers new opportunities for reverse weathering research.Salt lakes in the QTP serve as natural laboratories for reverse weathering studies, providing insights into critical metal element formation and carbon cycling processes and contributing to the theoretical development of reverse weathering.