Modelling of drainage dynamics influence on sediment routing system in a fold‐and‐thrust belt

Abstract

Drainage networks link erosional landscapes and sedimentary basins in a source‐to‐sink system, controlling the spatial and temporal distribution of sediment flux at the outlets. Variations of accumulation rates in a sedimentary basin have been classically interpreted as changes in erosion rates driven by tectonics and/or climate. We studied the interactions between deformation, rainfall rate and the intrinsic dynamics of drainage basins in an experimental fold‐and‐thrust belt subjected to erosion and sedimentation under constant rainfall and shortening rates. The emergence of thrust sheets at the front of a prism may divert antecedent transverse channels (perpendicular to the structural grain) leading to the formation of longitudinal reaches, later uplifted and incorporated in the prism by the ongoing deformation. In the experiments, transverse incisions appear in the external slopes of the emerging thrust sheets. Headward erosion in these transverse channels results in divide migration and capture of the uplifted longitudinal channels located in the inner parts of the prism, leading to drainage network reorganization and modification of the sediment routing system. We show that the rate of drainage reorganization increases with the rainfall rate. It also increases in a nonlinear way with the rate of uplift. We explain this behaviour by an exponent > 1 on the slope variable in the framework of the stream power erosion model. Our results confirm the view that early longitudinal‐dominated networks are progressively replaced by transverse‐dominated rivers during mountain building. We show that drainage network dynamics modulate the distribution of sedimentary fluxes at the outlets of experimental wedges. We propose that under constant shortening and rainfall rates the drainage network reorganization can also modulate the composition and the spatial distribution of clastic fluxes in foreland basins.

Erosional response of granular material in landscape models

“…R. Reitano et al: Erosional response of granular material in landscape models bounding a double-verging orogenic wedge (Braun and Yamato, 2010); the coupling between climate, erosion and tectonics (e.g., Batt and Braun, 1999;Beaumont et al, 1992Beaumont et al, , 2001Beaumont et al, , 2004Jamieson et al, 2004;Ueda et al, 2015;Whipple and Meade, 2004); the interaction between surface processes and multilayer folding systems (Collignon et al, 2014); the role of orographically enhanced precipitation in a double-verging 2-D model (Willett, 1999;Willett et al, 1993); the control exerted by tectonic strain (Castelltort et al, 2012;Duvall and Tucker, 2015;Goren et al, 2015); and interaction with tectonics in three dimensions (Ueda et al, 2015). Nevertheless, the computational capacities necessary to realistically simulate geologic features coupled with erosion using complex rheologies and/or three-dimensional settings still place strong limitations on numerical runs.…”

Review of River patterns reveal landscape evolution at the edge of subduction, Marlborough Fault System, New Zealand

“…Earth Surface Processes and Landforms, 43(15), 3152-3163. http://doi.org/10.1002/esp.4477 Chapter 3.1 "Drainage anomalies, or unusual patterns in river planform, can indicate recent river captures and reorganization of drainage networks, often in response to active tectonics (e.g. Bishop, 1995;Brookfield, 1998;Hallet and Molnar, 2001;Burrato et al, 2003;Clark et al, 2004;Delcaillau et al, 2006;Willett et al, 2014)". Since you cite Bishop 1995 here, who actually provides an in-depth examination of this issue, I would emphasise that the "can" is very important: indeed in the next sentence you explain "We mapped drainage anomalies across the study site and found abundant evidence of fluvial disruption within both domains.…”

“…Basin Research,8,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] The rest of the chapters describes and quantifies to some extent drainage in the study area and examine the relation between drainage and the tectonic pattern. I regret a lack of use of recently utilised chi-maps (see papers by Willett's group for instance: Willett, S. D., McCoy, S. W., Perron, J. T., Goren, L., Chen, C. Y. (2014).…”

“…Tectonics, 31(4), n/a-n/a. http://doi.org/10.1029/2011TC003015 Fox, M., Goren, L., May, D. A., Willett, S. D. (2014). Inversion of fluvial channels for paleorock uplift rates in Taiwan.…”

Erosional response of granular material in landscape models

“…bounding a double-verging orogenic wedge (Braun and Yamato, 2010); the coupling between climate, erosion and tectonics (e.g., Batt and Braun, 1999;Beaumont et al, 1992Beaumont et al, , 2001Beaumont et al, , 2004Jamieson et al, 2004;Ueda et al, 2015;Whipple and Meade, 2004); the interaction between surface processes and multilayer folding systems (Collignon et al, 2014); the role of orographically enhanced precipitation in a double-verging 2-D model (Willett, 1999;Willett et al, 1993); the control exerted by tectonic strain (Castelltort et al, 2012;Duvall and Tucker, 2015;Goren et al, 2015); and interaction with tectonics in three dimensions (Ueda et al, 2015). Nevertheless, the computational capacities necessary to realistically simulate geologic features coupled with erosion using complex rheologies and/or three-dimensional settings still place strong limitations on numerical runs.…”