Integrated geophysical exploration of favorable potassium salt mineralization on the northeastern margin of Qaidam Basin, China

Abstract Potash is one of the three most important fertilizers in agriculture. It has obvious yield-increasing effects on most crops and provides the foundation for food. China is the world's largest consumer of potash fertilizer, and the third largest importer. Potash mines are an urgently needed strategic mineral resource for food security; therefore, the identification of domestic resources is important for the increased storage and guaranteed supply of potash. The Qaidam Basin, Qinghai Province, is the focus of potash extraction in China. Brine-type potash resources are abundant and found in saline lakes. This study aimed to identify new potash resources on the northeastern margin of Qaidam Basin using integrated geophysical methods. Audio magnetotelluric (AMT) and shallow seismic exploration were used to determine the shallow geological structures and tectonic characteristics of the study area. The data revealed the characteristics of brine reservoirs and delineated favorable areas for potash mineralization. Brine storage modes in the study area can be divided into a horizontal-layer mode, controlled by stratum distribution, and steep-dip mode, determined by fault development. The results of this study provide a geophysical basis for exploration block selection, well deployment, and potash resource evaluation.