Abstract:It is predicted that salt should form in early Mesozoic in the Qiangtang Basin. However, no salt were discovered in the Jurassic and Triassic marine strata in the Qiangtang Basin in last decades. Drilling of wells in the Shenglihe Depression reveals salt as thick as hundreds meters in the Middle Jurassic Xiali Formation, and halite resource is estimated based on present data in the Shenglihe area of northern Qiangtang Basin. Methods: Field studies, drilling of wells, two- dimensional seismic profiling and element content analyses of core samples.Results: Marine evaporite formed in the Upper Jurassic Suowa Formation, the Middle Jurassic Xiali and Buqu Formations, the Lower Jurassic Quemoco Formation and the Upper Triassic Bagong Formation, respectively. Thick salt layers are discovered in middle—lower section of the Middle Jurassic Xiali Formation in the Shenglihe Depression, northern Qiangtang Basin. Total thickness of the salt is 351 m, and amount of salt layers is 32 with thickness of separate layer of salt range from 2 m to 50 m. Color of the salt changes from violet red, light red and pink to white and grey, and the salt layers are interbedded with gypsum, marl, mudstone and limestone in the Middle Jurassic Xiali Formation. Major component of the salt is sodium chloride (NaCl), containing Na 17%~38%, Cl 20%~50%, Mg 1.0%~1.9% and Ca 0.4%~5.1%. Salt as thick as 300~350 m, 200~300 m, 100~200 m and 50~100m cover area of 46 km2, 55 km2, 117 km2 and 218 km2, respectively, in the Qingshuihu foreland basin, central Shenglihe Depression. It is revealed that halite resource of 100 billion tonne exists in the Shenglihe Depression, and some salt layers contain potash with K 0.5%~1.7%,which indicates potential for exploration of moraine potash in the Qiangtang Basin.