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 and The Theater of Cruelty, where Artaud expressed the importance of recovering "the notion of a kind of unique language half-way between gesture and thought". The collection is still read, and strongly influenced the directing philosophies of such renowned figures as Peter Brook and The Living Theatre. 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