Intraplate Magmatism

Intraplate magmatism is pervasive within both oceanic and continental crust. Expansive spatially and across geologic time, it is complex because of both its causative magmatic processes as well as its interplay with Earth’s mantle geodynamics and plate tectonic processes. The scale of intraplate magmatism ranges from large igneous provinces (LIPs) encompassing millions of cubic kilometers of igneous rock to small individual volcanoes. Similarly, compositions of intraplate igneous rock span the spectrum of extrusive compositions between highly mafic and highly silicic. However, intraplate volcanic rocks are dominantly basaltic and have compositions distinctly different from those found at “normal” mid-ocean ridges and in arc-trench systems. Herein we focus on intraplate magmatism in the oceans that cover 71 % of Earth’s surface. We examine intraplate magmatism both present and past in the oceans, which has occurred predominantly within oceanic crust. The geological record of oceanic crust flooring much of the world’s oceans extends back to ~200 million years ago, or slightly less than 5 %, of Earth history.