The polygenetic Kahouanne Seamounts in the northern Lesser Antilles island arc: Evidence for large-scale volcanic island subsidence.

Abstract

Remotely operated vehicle (ROV) explorations of the Kahouanne seamounts, located 25 km SE of Montserrat in the northern Lesser Antilles island arc, have discovered the occurrence of honeycomb-scalloped erosional features on volcanic and limestone outcrops at depths of up to 600 meters below sea level (mbsl). These features, combined with the flat-topped morphology of the seamounts, the occurrence of shallow-water carbonates (rhodoliths, benthic foraminifera), and the presence of oxidized, highlyvesicular volcanic fragments, suggest that the seamounts were once subaerial islands and have subsequently subsided to their present depth.