The formation and evolution of the oceanic lithosphere is the dominant process in the chemical differentiation and physical evolution of our planet. Plate tectonic processes completely repave the ocean basins every 100–200 million years. Lithosphere formation encompasses the transfer and transformation of material and energy from Earth's mantle to the crust and from the crust to the ocean and atmosphere. Independent of sunlight, the evolving ocean crust supports life in unique seafloor and subseafloor habitats that may resemble Earth's earliest ecosystems. From its formation until its return to the mantle by subduction, the evolving oceanic lithosphere interacts with seawater, sequesters water and other materials, and ultimately recycles them back into the mantle.