How Do Oceanic Plateaus Form? Clues From Drilling at Shatsky Rise

Oceanic plateaus are huge basaltic constructions whose eruptions may briefly outstrip even global mid‐ocean ridge magma production. Although they form great undersea mountains, their origins are poorly understood. A widely accepted explanation is that oceanic plateaus are built by massive eruptions from the head of nascent thermal mantle plumes that rise from deep in the mantle to the surface [e.g., Duncan and Richards, 1991]. An alternative is that plateaus erupt by decompression melting of fusible patches in the upper mantle at plate edges or zones of extension [Foulger, 2007].