Widespread (>100 km) Tephra from a Deep-Sea (>3000 mbsl) Eruption at the Cape Verde Archipelago, Central-East Atlantic Ocean

Abstract:

Sediment gravity cores recovered during the RV METEOR cruise M80/3 in 2010 around the northwestern end of the Cape Verde Archipelago contain three widespread hyaloclastic tephra layers. One of these layers occurs in two sediment cores 40 km apart. The blocky shapes of the vesicle-poor/-free glass-shards clearly indicate their origin from a subaqueous eruption. There are three potential sources in the northwestern Cape Verdean Seamount Province: (1) the Nola Seamount, (2) the Sodade Seamount and (3) the Charles Darwin Volcanic Field. Using geochemical fingerprinting the hyaloclastic glass-shards could be unambiguously correlated to the Charles Darwin Volcanic Field. This is a deep-sea volcanic field consisting of at least 14 eruption centers all at >2,850 m below sea level, located about 100 km east of the core locations. Previous studies have documented widespread tephra distributions from relatively shallow (< 500 mbsl) submarine explosive eruptions, but here we record such a widespread tephra from a deep-sea (probably >3000 mbsl) eruption. We discuss the mechanisms of formation and far transport of the hyaloclastic particles.