【摘要】 <正> 沿海平原和陆架浅海,都是第四纪洋面升降引起海岸线迁移的范围。近年来的大量钻孔资料表明:我国东部沿海凡有平原发育的地方,都曾经遭受第四纪海侵。在大平原区,海相沉积分布范围可以从现代海岸向内陆延伸近百公里,甚至沿河谷上溯数百公里处还有间冰期时海水内泛的踪迹。因此,海侵地层的研究应当是沿海平原第四纪研究中的更多还原

【Abstract】 As revealed by mieropaleontological analyses of the onshore and offshore drilling cores, the Quaternary Period Witnessed four marine transgressions in East China, namely:Ammonia transgression （Q₄, occurring during the last 10,000 years）,Pseudorotalia transgression （Q₃², 39,000—24,000B.P.）,Asterorotalia transgression （Q₃¹, 100,000—70,000 B.P.）,Spirillina transgression （Q₂, ca 300,000B. P.）The Middle Pleistocene transgression （i.e. Spirillina transgression） is eharacterised by its limited areal distribution （fig. 3c） and low degree of mariness. The next two （Asterorotalia and Pseudorotalia） transgressions took place in Late Pleistocene and are distinguished by tbeir wider areal distribution and sea-water invasions along river valleys （fig. 3b）. The warm water foraminifers and molluscs, such as Asterorotalia, Pseudorotalia and Oliviella, occur in strata formed by these two transgressions from the Yellow Sea and the Bohai Gulf regions, suggesting a temperature warmer then than now. The postglacial Ammonia transgression exceeded in extent the previous ones resulting in a wider distribution of the Holocene marine deposits along coastline （fig. 3a）. Besides the four transgressions mentioned above microfaunal evidences were found for an another marine transgressive-regressive sequence of uncertain age, belonging probably to the beginning of Pleistocene or the end of Pliocene.The micropaleontological approach is adopted in the present study, but paleomagnetic and radiocarbon dating, playnology and lithology are involved in discussion of the ages of transgressions. In addition to the time and scope of transgressions, here are considered factors of paleoenvironments such as water temperature, depth and salinity, as well as faunal changes Moreover, the trends of neotectonie movements are discussed basing on the burial depth of the transgression strata.更多还原