华南晚三叠世前陆盆地的成因地层格架及演化历史

在详细研究盆地中各类沉积体系的沉积构成和演化过程的基础上,通过成因地层对比,建立了残留海湾—前陆盆地的成因地层格架。根据沉积体系的时空组合及其与相关等时性地层面的配置关系,划分出了3个构造沉积幕,每个构造沉积幕都是盆地基底荷载挠曲变形至弹性回跳过程的沉积响应。海平面升降变化和盆内软沉积物压实沉降虽然不能触发和主控盆地基底的构造挠曲旋回,但对各构造沉积幕的地层构型和持续时间有重要影响。盆地基底荷载挠曲变形与海平面升降或压实沉降过程以不同方式叠加,产生各种类型的构造沉积幕,与前陆盆地共生的还有后陆盆地和残留的弧后盆地。

Genetic Stratigraphic Framework and Evolutional History of Late Triassic Foreland Basins in South China

Based on researches on the depositional architecture and depositional processes of various deposi-tional systems, a genetic stratigraphic framework of remanent embayment-foreland basin is established by the aid of genetic stratigraphic comparison. Three tectono-depositional episodes may be recognized by means of the time-space association and the relationship to chronostratigraphic interface of the depositional systems, and each tectono-depositional episode responds to a coarse of the flexure under load and elastic spring of basin basement. Eustatic change of the sea leyel and subsidence due to compaction of the soft deposits may have a great influence upon stratigraphic pattern and continuous time of a tectono-depositional episode, although it can not create and control the tectonic flexure cycle of the basin basement. Superposition between the basin basement flexure under load and eustatic change of sea level or subsidence due to compaction with different way should produce various types of tectono-depositional episode. There are also some backland basins and relict back-are basins associated with foreland basins during the Late Triassic.