Transition from continental break‐up to punctiform seafloor spreading: How fast, symmetric and magmatic

Abstract

[1] We present a comparison between numerical and analogue models focusing on the role of inherited lithospheric structures in influencing the process of continental break-up. Our results highlight that the presence of pre-existing anisotropies localizes strain and favors continental break-up and formation of a new ocean. For a fixed strain rate, the pre-rift lithosphere configuration influences rift duration, melt production and width and symmetry of the continental margin pair. Model results show a mainly two-phase tectonic history from continental extension to oceanization. In the first phase extension affects contemporaneously the whole rift structure, while in the second phase asthenosphere upwelling occurs into punctiform regularly-spaced spots sequentially propagating in an extension-orthogonal direction.

From continental rifting to seafloor spreading: Insight from 3D thermo-mechanical modeling

“…2, 3 and 5), and the area with more magma production ruptures earlier. This is consistent with the previous study by Corti et al (2003), which discussed that continental rifting occurs contemporaneously while break-up happens in a punctiform way.…”

Margin segmentation and volcano-tectonic architecture along the volcanic margin off Argentina/Uruguay, South Atlantic

“…Among other factors the pre-rift lithosphere configuration influences rift duration, melt production and width and symmetry of the continental margin pair (Van Wijk et al, 2001;Corti et al, 2003;Van Wijk et al, 2004). The most significant along-margin change in breakup magmatism and volcanism marks the transition between margin segments I and II along the Colorado transfer.…”

Seismic structure beneath the Gulf of California: a contribution from group velocity measurements

“…Numerical models of continental break-up (Corti et al 2003) demonstrate that this process is characterized by a first stage of extension affecting the entire rift length and a second stage in which asthenospheric upwelling occurs in regularly spaced well-confined regions propagating in an extension-orthogonal (along strike) direction. In particular, tholeiitic volcanism or MORB are associated with the Cerro Prieto volcanic field, the Guaymas Basin (Isla Tortuga and Isla Esteban, which are close to the Guaymas Basin) and the EPR.…”