Contrasting Geomorphic and Stratigraphic Responses to Normal Fault Development During Single and Multi-Phase Rifting

Sofia Pechlivanidou,Robert L Gawthorpe,Emma Finch,Christos Pennos,Guillaume Duclaux,Anneleen H Geurts

doi:10.3389/feart.2021.748276

Abstract

Understanding the impact of tectonics on surface processes and the resultant stratigraphic evolution in multi-phase rifts is challenging, as patterns of erosion and deposition related to older phases of extension are overprinted by the subsequent extensional phases. In this study, we use a one-way coupled numerical modelling approach between a tectonic and a surface processes model to investigate topographic evolution, erosion and basin stratigraphy during single and multi-phase rifting. We compare the results from the single and the multi-phase rift experiments for a 5 Myr period during which they experience equal amounts of extension, but with the multi-phase experiment experiencing fault topography inherited from a previous phase of extension. Our results demonstrate a very dynamic evolution of the drainage network that occurs in response to fault growth and linkage and to depocentre overfilling and overspilling. We observe profound differences between topographic and depocenter development during single and multi-phase rifting with implications for sedimentary facies architecture. Our quantitative approach, enables us to better understand the impact of changing extension direction on the distribution of sediment source areas and the syn-rift stratigraphic development through time and space.

Highlights

Unravelling the long-term interactions between surface processes and tectonics is key to understanding basin evolution; yet it remains challenging, especially for rift basins that are characterized by complex multiple phases of extensional histories
We evaluate and compare landscape evolution and basin stratigraphy between single-phase rifts and multi-phase rifts that form in response to two phases of extension, with an angle between the two extension directions of 60° (Figure 1A), similar to what observed in several natural rifts such as in the Mygdonia Rift, Greece (Figure 1B)
The motivation of this study is to investigate the differences in topographic evolution, erosion and basin stratigraphy between single and multi-phase rifting, following a numerical modelling approach

Summary

Introduction

Unravelling the long-term interactions between surface processes and tectonics is key to understanding basin evolution; yet it remains challenging, especially for rift basins that are characterized by complex multiple phases of extensional histories. Resolving surface processes evolution in time and space and their response to fault network growth during multi-phase rifting remains unclear. In the active Mygdonia Rift in northern Greece (Figure 1B) understanding the interplay between tectonics and surface processes is ambiguous since patterns of erosiondeposition related to the older NE-SW extensional phase (Psilovikos, 1977; Dinter and Royden, 1993) are overprinted by the subsequent N-S extensional phase (Chatzipetros and Pavlides, 1998)

Methods

Results

Discussion

Conclusion