Fig. 5From: Geochemical characteristics and origin of the formation water of the Saline Lake Basin: a case study of the Quaternary Qigequan Formation in the Sanhu Depression, Qaidam BasinRelationship between salinity and r(Na+)/r(Cl−) of formation water in the Qigequan Formation in the Sanhu Depression. The CaCl2-type formation water of the Qigequan Formation in the Tainan-Sebei area is mainly type IV and type VBack to article page