Structure of the Earth obducted onto the continental crust and preserved as ophiolite sequences. Many rocks now making up Earth's crust formed less than 100 million (1) years ago; however, the oldest known mineral grains are about 4.4 billion (4.4) years old, indicating that Earth has had a solid crust for at least 4.4 billion years. Earth's mantle extends to a depth of 2,890 km, making it the thickest layer of Earth. The mantle is divided into upper and lower mantle. The upper and lower mantle are separated by the transition zone. The lowest part of the mantle next to the core-mantle boundary is
The Theatre and its Double The Theatre and its Double The Theatre and Its Double ("Le Théâtre et son Double") is a collection of essays by French poet and playwright Antonin Artaud and published in 1938. Artaud intended his work as an attack on theatrical convention and the importance of language of drama, opposing the vitality of the viewer's sensual experience against theatre as a contrived literary form, and urgency of expression against complacency on the part of the audience. The collection's more famous pieces include "No More Masterpieces", an attack on what Artaud believed to be the elitism of an irrelevant, outdated literary/theatrical canon,