what does the oceanic lithosphere consist of and how thick is it
(For reasons discussed later in this chapter, new oceanic lithosphere at a mid-ocean ridge is much thinner.) Recall that the crustal part of continental lithosphere ranges from 25 to 70 km thick and consists largely of low-density felsic and intermediate rock. In contrast, the crustal part of oceanic lithosphere is only 7 to 10 km thick and consists largely of relatively high-density maï¬c rock (basalt and gabbro). The mantle part of both continental and oceanic lithosphere consists of very high-density ultramaï¬c rock (peridotite).