【摘要】 研究福建深沪湾多种相的晚更新世沉积,包括有冲洪积相的含砾砂黏土、湖相黏土、潮间带生物沉积相即大片的古牡蛎滩及滨海相河口潮滩砂黏土和风成老红砂等,研究了它们的沉积学特征和形成古环境及其可能反映的复杂的构造形变.沉积相特征表明,深沪湾地壳经历了距今约60 000 a以来早期的可能下沉(距今约28 000 a开始海浸)—距今约25 000~15 000 a的与水动型海平面上升速率大致相同的抬升(生成晚更新世古牡蛎滩)—距今约15 000~11 000 a的可能与古强地震相关的快速抬升(古牡蛎滩脱离海面形成古牡蛎滩台地,深沪湾地区生成多个陆地凹陷)—距今约11 000~7 000 a的相对稳定(凹陷内生长古森林)—距今约7 000 a的古强地震快速下沉(形成潟湖、古森林沉溺)—相对稳定—微弱抬升(又一次成陆)—距今约2 400 a的又一次古强地震快速下沉(形成海底古森林及潮间带古牡蛎滩遗迹)—相对稳定(海岸堤形成)的地壳形变及环境变迁过程.更多还原

【Abstract】 There are several kinds of Late Pleistocene facies in the Shenhu Bay of Fujian Province,China,including alluvial gravel-bearing sandy clay,lacustrine clay,vast oyster reef,estuary and tidal sand and clay and socalled red sand,a kind of eolian deposits.The sedimentary features and the inferred paleoenvironmental changes are discussed.On the bases of the data,a tectonic movement pattern is proposed.It shows that the bay underwent a historical change from land to sea,sea to land,land to sea,sea to land and land to sea again.It has included the following stages since 60 000 a B.P.: subsidence(red alluvial gravel-bearing sandy clay was deposing)—lifting in the same place with the "eustatic" sea-level change(the paleooyster was growing and the oyster beach was formed)—a quick lifting related to a strong paleoearthquack(oyster beach platform and land depressions were formed) —Early Holocene relatively stable stage(the paleoforests were growing in the depressions)—sudden subsidence related to a strong paleoearthquack(the lagoons in the depressions were formed and the paleoforests were sunk in the lagoons)—relative stability—slightly lifting(the land was formed again) —sudden subsidence related to a strong paleoearthquack(the paleooyster beach came back in the sea bottom of the intertidal and undertidal zones,the paleoforests are sunk in the more deep sea bottom).更多还原