COLLABORATIVE RESEARCH: Forward and Inverse Modeling of TwoCretaceous Foreland Basins

最近开发的一个定量模型根据变形历史和海平面变化预测了前陆盆地和被动边缘盆地的地层和几何形状。该模型结合了广泛接受的岩石圈力学描述和一种新的方法，即通过扩散模拟沉积物的表面迁移。新方法的稳健性将通过将科尔维尔盆地和西部内海两个前陆盆地的预测地层与地质数据进行比较来测试。将在已知时间间隔内测量沉积物通量和沉积剖面，并通过二维反剥离程序计算岩石圈负荷。然后将负荷历史和泥沙通量输入到盆地演化的正演模型中。该项目是由康奈尔大学、拉蒙特-多尔蒂地质天文台和科罗拉多大学的科学家合作完成的。这些结果将解决前陆盆地形成过程中岩石圈是否显著松弛、盆地远端逆冲作用对沉降的构造效应以及海平面变化对地层层序的贡献。这些发现将对构造学和沉积学产生重要影响。

A recently developed quantitative model predicts the stratigraphy and geometry of foreland basins and passive margin basins in response to deformation history and sea-level change. The model combines a largely-accepted mechanical description of the lithosphere with a new approach, that of simulation of the surface transport of sediments by diffusion. The robustness of the new approach will be tested by comparing the predicted stratigraphies of two foreland basins, the colville basin and the Western Interior Seaway, to the geological data. Sediment fluxes and depositional profiles will be measured over known time intervals and the lithospheric loads calculated by two-dimensional back-stripping procedures. The load histories and sediment fluxes will then be input to the forward model of basin evolution. The project is a collaboration of scientists from Cornell University, Lamont-Doherty Geological Observatory, and the University of Colorado. The results will resolve whether or not the lithosphere relaxes significantly during foreland basin formation, the tectonic effects of thrusting on subsidence in the distal parts of basins, and the contribution of eustatic sea-level change to stratigraphic sequences. These findings will have important consequences for tectonics and sedimentology.