前言我国东部沿海地区早第三纪碎屑岩盆地非常发育。早第三纪地层中矿产十分丰富,是寻找石油、天然气、蒸发岩(盐岩、钾盐、石膏、天然碱)、硫、铜和铀等矿产的主要目的层。长期以来,人们总是把它看作是单纯的陆相沉积。近年在一些沉积盆地中,多处发现海相或半咸水相动物群,对上述看法有所冲击;但一般仍然认为海侵是短暂的,分布是有限的,或者认为早第三纪地层虽与海水有过某种联系,但主要还是陆相地层。对地层岩相的不同认识,必然对该地层的古地理、古沉积环境、成矿背 Introduction The early Tertiary clastic basins in the eastern coastal areas of China developed very well. Early Triassic strata are rich in minerals and are the primary targets for mineral deposits such as oil, gas, evaporites (salt, potash, gypsum, trona), sulfur, copper and uranium. For a long time, people always think of it as pure continental deposition. In recent years, some marine sedimentary basins or brackish aquatic fauna have been found in some sedimentary basins, which have had an impact on the above observations. However, transgressions are still generally considered to be ephemeral in nature and have limited distribution. There is some connection with seawater, but mainly continental terrains. Different understanding of stratigraphic lithofacies inevitably affects the palaeogeography, ancient sedimentary environment, metallogenic back