Dynamic topography and sediment routing systems

Software Used:

  • Badlands 1.0

Dynamic topography due to mantle flow contributes to shaping Earth’s evolving landscapes by affecting sediment routing, which has rarely been explored in source-to-sink contexts. Here, we design a generic model to investigate the impact of dynamic topography on both landscape evolution and stratigraphic formations. We find that (1) Dynamic topography affects all the segments of a source-to-sink system. It induces significant reorganizations of river networks and drives complex erosion and sediment routing responses in the source region; (2) The migrating dynamic topography results in variations in sediment supply, depending on the relative directions between dynamic topography propagation and sediment transport; (3) Variations in sediment supply driven by the migrating dynamic topography contribute to the formation of diachronous unconformities along continental margins.

Model Setup:

Model setup of a generic case showing a wave of positive dynamic topography migrating under a fixed circular continent. The circular continent is 700 km in diameter with a spatial resolution of 1 km. Its initial landscape of the continent consists of a central plateau (source area) surrounded by an alluvial plain (transfer zone) and a continental margin (sink area). A sinusoidal wave of positive dynamic topography with a wavelength of 1000 km and amplitude of 300 m propagating to the west at 5 cm/yr is considered.


Variables Parameter value
Non Marine Erodibility K_e 2.e-7
Rainfall P [m/a] 1.0
(Rainfall * Area) exponent m m 0.5
Slope exponent n n 1.0
Slope Minimum for Flood-plain Deposition slp_cr 0.001
Non-Marine % Max Deposition perc_dep 0.5
Land sed. Transport by River criver 10
Land sed. Transport by Wind caerial 0.001
Lake/Sea sed. Transport by Currents cmarine 0.005
No. Time Steps To Distribute Marine Deposits diffnb 5
Marine % Max Deposition diffprop 0.4


(a) Sediment supply histories and erosion of stratigraphic layers, stratal stacking patterns represented by (b) depositional environments, (c) interpreted systems tracts, and (d) Wheeler diagrams reconstructed on the eastern margin. (e-h) Same for the western margin. Paleo-depth is assumed to be a proxy for depositional environments, including alluvial plain (>0 m), shoreface (or delta front, 0-30 m), distal offshore (or prodelta, 30-100 m), upper slope (100-300 m), middle slope (300-500m) and abyss (>500 m). Key stratigraphic surfaces and their timing are indicated in c, d, g and h. Systems tracts are interpreted for Case 3 with abbreviations: A - aggradation, P - progradation, R - retrogradation, D - degradation, HST - highstand systems tract, TST - transgressive systems tract, LST - lowstand systems tract, FSST - falling-stage systems tract, MTS - maximum transgressive surface, MFS - maximum flooding surface, TS – transgressive surface, MRS - maximum regressive surface, SB - sequence boundary.


Submitted to Geophysics Research Letter