The role of edge-driven convection in the generation of volcanism – Part 1: A 2D systematic study

• Main Authors: A. Manjón-Cabeza Córdoba, M. D. Ballmer
• Format: Article
• Language: English
• Published: Copernicus Publications 2021-03-01
• Series: Solid Earth
• Online Access: https://se.copernicus.org/articles/12/613/2021/se-12-613-2021.pdf

<p>The origin of intraplate volcanism is not explained by plate tectonic theory, and several models have been put forward for explanation. One of these models involves edge-driven convection (EDC), in which cold and thick continental lithosphere is juxtaposed with warm and thin oceanic lithosphere to trigger convective instability. To test whether EDC can produce long-lived high-volume magmatism, we run numerical models of EDC for a wide range of mantle properties and edge (i.e., the oceanic–continental transition) geometries. We find that the most important parameters that govern EDC are the rheological parameters mantle viscosity <span class="inline-formula"><i>η</i>₀</span> and activation energy <span class="inline-formula"><i>E</i>_a</span>. However, even the maximum melting volumes predicted by our most extreme cases are insufficient to account for island-building volcanism on old seafloor, such as at the Canary Islands and Cabo Verde. Also, beneath old seafloor, localized EDC-related melting commonly transitions into widespread melting due to small-scale sublithospheric convection, inconsistent with the distribution of volcanism at these volcano chains. In turn, EDC is a good candidate to sustain the formation of small seamounts on young seafloor, as it is a highly transient phenomenon that occurs in all our models soon after initiation. In a companion paper, we investigate the implications of interaction of EDC with mantle plume activity <span class="cit" id="xref_paren.1">(<a href="#bib1.bibx53">Manjón-Cabeza Córdoba and Ballmer</a>, <a href="#bib1.bibx53">2021</a>)</span>.</p>