盆地的形成和充填过程模拟──以拉伸盆地为例

沉积盆地定量动力学模拟和分析是目前地学领域的一个研究热点。文中建立的拉伸盆地模拟系统可模拟拉伸盆地的沉降过程、估算盆地的拉伸量、分析盆地深部结构和热流背景；动态模拟盆地的充填过程及预测层序格架和沉积体系域的分布样式。沉降和热史模拟结合了二维的回剥法和简单或纯剪切的盆地形成模型。盆地充填模型综合考虑了盆地的构造沉降、均衡作用。沉积物供给。海（湖）平面变化等对盆地充填过程的控制作用。对莺、琼盆地模拟分析揭示了盆地的幕式拉伸过程和深部热演化；层序模拟提示了盆地沉降。海平面变化等对盆地充填演化的控制作用。

BASIN FORMATION AND FILLING SIMULATION:A CASE STUDY ON EXTENSIONAL BASINS

Nurnerical simulation of basin processes is the frontier of basin analysis. The integrated modelling system of sedimentary basins established in this paper can be used to (1 ) mimic the subsidence history and estimate the amount (β) of lithosphere stretching; (2) reconstructthe thermal history and (3) simulate the filling processes and predict the geometries of depositional sequences in extensional basins. The basin subsidence and thermal history are modelledby using a coup1e simple-shear/pure shear model and the backstripping technique. The forwardgeometric simulation of depositional apuence takes into account of tectonic subsidence, isostasy, sediment input and sea or lake level change. Study on Yinggehai and Qiongdongnan basinshas revealed the epiwhic subsidence history and thermal evolution of the basins. The forwardsimulation of rift lacustrine basins in East China shows that the tectonic inversion, block rotation and high-frequency fluctuation of lake level are the major factors controlling the formationof different orders of lacustrine sequences. It has been also shown that the balance between tectonic subsidence and sediment input is the key factor controlling the development of lacustrinesequence types.