ItisanacceptedfactthatthemainsolidphasesupportforpotassiumintheSichuanBasinispolyhalite[K2MgCa2(SO4)4·2H2O]ratherthansylvineis(KCl)(GongDXetal.,2015).Themineraltypes,occurrencecharacteristicsandmetasomatismofthepolyhalitebearingore-bedwereidentifiedandtheoriginofthepolyhalitewasdiscussed.ThepolyhalitesampleswereobtainedfromthecoreofZ12,locatedinDalongVillage,Guang'anCityofcentralSichuan.Thesamplingdepthswere2974m(s-1),3023m(s-2)and3106m(s-3).Themicrobeamanalysisofback-scatteringimageswascarriedoutusingaShimadzuEPMA-1720Serieselectronprobemicro-analyzer,supplementedbyaquantitativespectrumanalysisthatdeterminedthemineraltypes.
