Geodynamic modelling of salt-bearing rifted margins: from minibasin- to margin-scale salt tectonics across different margin types

<p>The largest and majority of salt basins form along rifted continental margins during the latest stages of rifting and prior to continental breakup. We use 2D thermo-mechanical finite-element modelling of lithospheric extension to investigate the interplay between rifted margin architecture, late syn-rift salt deposition, and post-rift salt tectonics across different types of continental margins. We evaluate the: 1) interplay between syn-rift extension, salt deposition and post-rift salt tectonics, 2) influence of salt basin architecture on salt flow, 3) distribution of salt-related structural domains, and 4) contrasting salt tectonic styles for different margin types. Narrow margins form partially-isolated salt sub-basins with prominent base-salt relief, limited translation but significant diapirism and minibasin development. Wide margins form wide salt basins with subtle base-salt relief, pronounced seaward salt expulsion and overburden translation, which result in updip extension with development of post-rift normal faults and rollovers, mid-margin translation and downdip diapir shortening. All margins develop a distal salt nappe that varies in width and complexity. The contrasting styles of diapirism and minibasin geometries as well as basin-scale salt deformation between different margin types are controlled by margin width, base-salt relief, salt thickness and the relative rate of progradation. The results are comparable to several examples of salt-bearing rifted margins worldwide, from minibasin- to margin-scale, and improve our understanding of their dynamics and structural variability.</p>