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,
Civilization and Its Discontents Civilization and Its Discontents Civilization and Its Discontents is a book by Sigmund Freud, the founder of psychoanalysis. It was written in 1929 and first published in German in 1930 as "Das Unbehagen in der Kultur" ("The Uneasiness in Civilization"). Exploring what Freud sees as the important clash between the desire for individuality and the expectations of society, the book is considered one of Freud's most important and widely read works, and one of the most influential and studied books in the field of modern psychology. Freud enumerates what he sees as the fundamental tensions between civilization and the individual.