Subduction invasion of the Atlantic

Subduction initiation in Atlantic-type oceans is a fundamental process in the evolution of oceanic basins, described by the Wilson cycle. However, it is widely known that subduction zones are not easy to initiate and require a combination of factors, including forcing from nearby active subduction zones. There are currently three subduction systems in the Atlantic: the Lesser Antilles, Scotia and Gibraltar arcs. In recent years, these subduction systems have been studied using a combination of methods, including advanced numerical models that have yielded new insights into the dynamics of subduction initiation. Both the Scotia and Lesser Antilles arcs seem to be cases of subduction transfer from the Pacific into the Atlantic, while the Gibraltar Arc may constitute a case of a direct invasion of a Mediterranean slab. Here, we will briefly review the main characteristics of these arcs and present recent geodynamic models of their evolution. Models show that, while these arcs share some commonalities, they are also fundamentally different. These results suggest that despite subduction initiation being a non-trivial process, it is an unescapable outcome of the Earth’s oceans evolution.

 

This work is supported by FCT, I.P./MCTES through national funds (PIDDAC): LA/P/0068/2020 - https://doi.org/10.54499/LA/P/0068/2020, UID/50019/2025, https://doi.org/10.54499/UID/PRR/50019/2025, UID/PRR2/50019/2025