层序地层学模拟研究进展及趋势

模拟层序地层学是层序地层学理论重要的研究手段之一,在国外该项技术较为成熟.层序地层计算机模拟软件采用的算法主要有扩散算法、流体流动算法、几何控制沉积算法、经验数值逼近算法、沉积物搬运的构造校正算法.目前,国外学者对以海平面升降、构造沉降和沉积物供应为主控因素的层序地层概念模拟的适用性提出了质疑,并对层序控制因素的多样性和不确定性进行了深入的研究.结合当前的研究进展,提出了层序控制因素的"多变量系统"观点,将层序的控制因素分为综合变量和独立变量,进一步指出如果假设综合变量为独立变量,则可以简化层序模拟,假设越多,模拟越简单,但模拟结果越粗略;要使模拟结果真实地反映实际地层特征,就要尽可能采用独立变量.

Progress and Developing Tendency of Sequence Stratigraphy Simulation

Sequence stratigraphic simulation is an important tool to the sequence stratigraphic analysis, and this technology is more mature internationally. The algorithms used by computer modeling softwares for sequence stratigraphic modeling can be divided into diffusion algorithm, fluid flow algorithm, geometry-controlled deposition algorithm, a priori numerical approximation algorithm, and tectonic modifications of sediment transport algorithms. At present, some oversea scholars are skeptical to the applicability of sequence stratigraphic conceptual models simply controlled by the eustasy, subsidence, and sediment supply, further investigation on the controlling factors of multivariates and uncertainties on sequence stratigraphy. On the basis of current study progresses, the authors put forward a multivariate system on the controlling factors of sequence stratigraphy, and divide the controlling factors into dependent variables and independent variables. Furthermore, if the dependent variables are premised as dependent variables, the sequence modeling can be simplified; it will be more simplified with more assumption, but the modeling outcome will be more imprecise. If the modeling outcome can capture the characteristics of the real-world strata, it is suggested to use the independent variables furthest.