Characteristics and origin of a new type of polyhalite potassium ore in the Lower Triassic Jialingjiang Formation, Puguang area, northeastern Sichuan Basin, SW China

Abstract A new type of polyhalite potassium ore (NTPPO) was found in the Lower Triassic Jialingjiang Formation, NE Sichuan Basin, SW China. It is water soluble, therefore can be exploited using water-solution method, and great potential economic value research significance. Based on cores, thin sections, energy spectrum SEM analyses, its microfeatures, macrofeatures origin are discussed, a genetic model established to provide scientific basis for future evaluation, prediction exploration Basin. proposed that NTPPO caused by storm activities: (1) broke original sedimentary polyhalite–gypsum beds, whose fragments were transported into salt basin with high content K + Mg 2+ ; (2) basin, continued formed from gypsum metasomatism K- Mg-rich brine; (3) during diagenesis, under temperature pressure, K–Mg-rich brine halite replace anhydrite (or gypsum) form polyhalite.