Magma-poor continent-ocean transition zones of the southern North Atlantic: a wide-angle seismic synthesis of a new frontier

Magma-poor rifted margins, and their corresponding potential zones of exhumed serpentinized mantle, represent a unique class of tectonic boundaries with enormous promise for advancing the energy transition, such as with hydrogen production and carbon sequestration and in the search for critical minerals. In this study, a synthesis of the results from seismic refraction and wide-angle reflection (RWAR) profiling and resulting velocity models across the continent-ocean transitions of the southern North Atlantic Ocean is presented. The models are assessed and compared to understand characteristic basement types and upper mantle behaviour across the region and between conjugate margin pairs and to calibrate how their continent-ocean transition zones (COTZs) are defined. Ultimately, this work highlights the variable nature of continent-ocean transition zones, even within the magma-poor rifted margin end-member case, and points to avenues for future research to fill the knowledge gaps that will accelerate the energy transition.