Geometry of flexural uplift by continental rifting in Corinth, Greece

David Fernández‐blanco (1) , Gino Gelder (1, 2) , Robin Lacassin (1) , Rolando Armijo (1)

1 IPGP - Institut de Physique du Globe de Paris
2 ISTerre - Institut des Sciences de la Terre

Understanding early rifting of continental lithosphere requires accurate descriptions of up-bended rift margins and footwalls that ought to correlate in space and time with the elastic flexural uplift that produces them. Here we characterize the geometry of elastic flexural uplift by continental rifting at its spatiotemporal scale in nature (tens of kilometers; 10 4-10 6 years) using geomorphic evidence along the uplifting margin of the Corinth Rift, Greece. Our geomorphic analyses of space-borne topography novelly outline the coherent elastic flexure of continental lithosphere along and across the rift margin and throughout faulting (~10 6 years), as defined by the distribution of footwall uplift south of the active bounding fault. Topography and river drainages outline an elastic flexure signal that increases exponentially toward the bounding fault across the footwall for >50 km and changes in amplitude along the footwall following a parabola that decays from the rift center and has a >60-km wavelength that correlates with rift length. This continental lithosphere up-bend correlates with the scale of the rift, and appears maximum in the center of the rift, where drainage reversal of large catchments suggests rapid slip rates at the bounding fault. This is consistent with the growth of a new, rift-scale, high-angle normal fault. The coherency of elastic flexure in space and time implies highly localized strain in the rift-bounding fault and suggests that the fault transects continental lithosphere with long-term strength. The unparalleled record of flexural uplift and highly localized strain in the landscape of Corinth suggest these processes are intrinsic to early continental rifting elsewhere.

Domaines: Tectonique; Géomorphologie

David Fernández‐blanco, Gino Gelder, Robin Lacassin, Rolando Armijo. Geometry of flexural uplift by continental rifting in Corinth, Greece. Tectonics, 2019, ⟨10.1029/2019TC005685⟩. ⟨insu-02362436⟩