定量模拟层序叠加模式对断陷盆地非均一构造沉降活动的响应

利用SEDPAK二维层序模拟软件，通过考虑控制层序沉积过程的不同参数，探讨层序叠加模式对断陷盆地非均一性构造沉降活动的响应。结果表明，在非均一构造沉降活动作用下，盆地两侧同期层序显示出同步和非同步的叠加模式。同步叠加模式即盆地两侧同期层序同为退积或进积特征，非同步叠加模式即盆地两侧层序叠加模式相反（一侧退积，另一侧则进积）。同期层序非同步叠加模式的形成机理是盆地一侧可容纳空间的增量（△A）小于沉积物供应（△S）（△A＜△S），而另一侧盆地一侧可容纳空间的增量大于或等于沉积物供应（△A≥△S）。此外，二者可以控制非同步叠加模式的持续时间。同期层序非同步叠加模式的识别，对陆相层序地层研究提出新的认识，尤其是对我国东部新生代断陷盆地的层序研究，具有一定的参考价值。

Discussion on the Response of Sequence Stacking Patterns to Asymmetrical Tectonic Subsidence Depending on the Sequence Quantitative Simulation

On the Basis of stratigraphic modelling using the SEDPAK computer program, the response of sequence stacking patterns to asymmetrical tectonic subsidence within a rift basin was simulated by considering the various parameters controlling the deposition of a sequence. The simulation results indicate that isochronous sequence stratigraphy within a rift basin may exhibit both synchronous and non synchronous stacking patterns at different part of the basin. Synchronous stacking patterns refer to that at any part of the basin the same transgression, retrogression and aggression occurs concurrently. Non synchronous stacking patterns refer to that within the same basin some part may exhibit the exact opposite stacking patterns as other parts concomitantly.  〓〓The development of non synchronous stacking patterns were found to be caused by the combination of both accommodation space increment（ΔA）more than sediment supply increment（ΔS）（ΔA＜ΔS）in one side of basin and accommodation space increment（ΔA）less than or equal to sediment supply increment （ΔS）（ΔA≥ΔS）in other sides of basin. Meanwhile, duration of non synchronous stacking patterns was controlled by the interplay of accommodation space increment（ΔA）and sediment supply increment（ΔS）.Recognition of non synchronous stacking patterns of isochronous sequence stratigraphy provides a new insight into continental sequence stratigraphy, and might be widely applicable for the Cenozoic basins in the eastern China. 