This paper is the result of geological survey engineering.

Objective The Yarkand Basin is a secondary basin in the southwest of the Tarim Basin. The Late Cretaceous–Paleogene Proto–Para–Tethys multi-stage subencroach-regressive cycle provides the basin with abundant sources of salt-forming and potassium-forming materials, and multiple sets of evaporite strata are developed in the basin. Although many studies have been made on evaporative rock formation, sedimentary environment and potassium-forming conditions in Yarkand Basin, the summary of potassium-forming information is not systematic enough.

Methods This study conducted systematic sampling and geochemical analysis of surface solid salt rock and salt frost in the Yarkand Basin, focusing on potassium content and other geochemical characteristic coefficients, and combined with previous research results for comprehensive analysis.

Results The K⁺ content and the characteristic coefficients of Br×10³/Cl, K×10³/Cl and Mg/Ca indicate that Karatale is the abnormal points of potassium in the northern region of the Yarkand Basin, and Urukchati is the most potential area for potassium formation, which is the latest abnormal area for finding potassium. The southern region and the Shaman region are potassium anomalies.

Conclusions Based on the comprehensive and comparative analysis with the previous researches on surface salt rock geochemistry, the information of remote sensing interpretation, gravity anomaly, drilling geochemistry and saline spring in Shachai Basin is investigated. It is predicted that the Urukchati–Wb1–Karatal area is the most favorable area for potassium formation, and the Upa and Shaman areas are the spots for potassium anomaly. This research provides important clues and directions for the exploration of potassium salts in the Tarim Basin.