The oceanic crust is the outermost layer of the Earth’s lithosphere that underlies the ocean basins. It is composed primarily of basalt, gabbro, and other mafic rocks, and is thinner but denser than continental crust. The study of oceanic crust is essential for understanding plate tectonics, seafloor spreading, and the geodynamic processes of the Earth’s mantle.
Reference: White, R. S., & McKenzie, D. (1989). “Magmatism at Rift Zones: The Generation of Volcanic Continental Margins and Flood Basalts.” Journal of Geophysical Research, 94(B6), 7685-7729.