Modeling the interaction between lithospheric and surface processes in foreland basins

Abstract

This chapter reviews a number of key advances in quantitative understanding of foreland basins since the early 1990s, with a focus on the interplay between lithospheric flexure, erosion, and river transport. Flexure can be the result of topographic loading and slab-pull forces, though can also reflect other deep processes such as slab-detachment, lithospheric delamination, and buckling. We particularly address quantitative insights on (1) flexural modeling, elastic thickness estimations and interpretation in terms of the lithospheric rheological stratification; (2) detailed basin infill geometric/stratigraphic modeling; (3) the significance of forebulge uplift for basin evolution and hydrological drainage; (4) the mutual influence of tectonics, fluvial drainage, basin connectivity, and surface sediment redistribution; and (5) the roles of inherited lateral heterogeneity of the lithosphere, and temporal changes in tectonic regime during foreland basin evolution. Spatial and temporal variations in rheology exert a key control on (1) basin accommodation space, (2) the evolution of flexural foreland bulges, and (3) changes in basin connectivity through river captures. The main challenges for further understanding of the geodynamics of foreland basins are rooted in the interplay between the complex 3D dynamics of surface processes and the (un)coupled deformation of mantle and crust during orogenesis. Regarding this, it is important to differentiate intra-crustal decoupling and lateral flow of lower crust, from lithospheric mantle delamination. The coupling of numerical and analogue modeling shows that tectonic deformation, through its effects on drainage networks, has an impact on sediment spatial redistribution, which might ultimately be responsible for along-strike variations in tectonic style. During the continental stage of foreland basin development, the role of climate becomes particularly important in intramontane basins, where internal drainage can substantially prolong sediment trapping.