Oceanic crust Oceanic crust Oceanic crust is the uppermost layer of the oceanic portion of a tectonic plate. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic cumulates. The crust overlies the solidified and uppermost layer of the mantle. The crust and the solid mantle layer together constitute oceanic lithosphere. Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and magnesium. It is thinner than continental crust, or sial, generally less than 10 kilometers thick; however it is denser,
Evacuate Earth propose that colonists will eat insects and algae, which are easily replenished and space efficient. The ark ship launches and quickly speeds away, a few days later the neutron star is close enough that its tidal force begins to deform the Earth's core and the crust, which causes massive earthquakes and volcanism. Next, the gravity from the neutron star tears away the surface, causing the crust to shatter and the hot interior of Earth to spill out into the vacuum of space, destroying the Earth, but only the colonists on the ark can witness this event, as the rest of