摘要
根据精细岩相分析,在滇东南泥盆纪台地及台地边缘沉积区识别出9个三级层序,而在深水盆地沉积区仅能识别出3个三级层序。结合海平面波动及构造作用分析,认为在台地或台地边缘沉积区,能划分出的层序在盆地中难以一一对应的原因是:掀斜拉伸作用导致下沉一侧的沉降速度总大于海平面的下降及沉积速率,而保持盆地深水沉积体系的沉积特点或海侵沉积特点,或是以饥饿性盆地性质出现,以致形成的沉积层序相对较少。三级及三级以上(高频沉积层序)沉积层序的形成主要受区域构造作用影响,因构造活动强度的差异而难以进行大区域对比,同一层序界面在不同地区表现出不同的性质。
Based on the careful sedimentary facies analysis of Devonian in SE Yunnan, there are 9 third-order sequences in the platform and platform margin areas, whereas only 3 second-order ones in the deep basin. According to the analysis of sea l evel fluctuation and tectonic movement, we think the origin of this difference i s the tilt tensioning which causes the sinking velocity of depression side to be always larger than the velocity of sea levels falling and sedimentation so th at the sedimentary sequence is fewer. The third-order and higher (high-frequen cy) sequence are mainly controlled by the tectonism. Because the intensity of te ctonism is different, they cant be correlated regionally. And the same sequenc e boundary in different region shows different features.
出处
《云南地质》
2003年第2期131-141,共11页
Yunnan Geology
