Lithosphere for silicate rocks, and formula_4 is the age of the given part of the lithosphere. The age is often equal to L/V, where L is the distance from the spreading centre of mid-oceanic ridge, and V is velocity of the lithospheric plate. Oceanic lithosphere is less dense than asthenosphere for a few tens of millions of years but after this becomes increasingly denser than asthenosphere. This is because the chemically differentiated oceanic crust is lighter than asthenosphere, but thermal contraction of the mantle lithosphere makes it more dense than the asthenosphere. The gravitational instability of mature oceanic lithosphere has the
What Is the What What Is the What What Is the What: The Autobiography of Valentino Achak Deng is a 2006 novel written by Dave Eggers. It is based on the life of Valentino Achak Deng, a Sudanese child refugee who immigrated to the United States under the Lost Boys of Sudan program. It was a finalist for the National Book Award. As a boy, Achak is separated from his family during the Second Sudanese Civil War when the Arab militia, referred to as "murahaleen" (which is Arabic for the deported), wipes out his Dinka village, Marial Bai. During the assault, he loses sight