Crust (geology) enriched compared to the underlying mantle. Although the continental crust comprises only about 0.6 weight percent of the silicate on Earth, it contains 20% to 70% of the incompatible elements. All the other constituents except water occur only in very small quantities and total less than 1%. Estimates of average density for the upper crust range between 2.69 and 2.74 g/cm and for lower crust between 3.0 and 3.25 g/cm. Earth formed approximately 4.6 billion years ago from a disk of dust and gas orbiting the newly formed Sun. It formed via accretion, where planetesimals and other smaller rocky bodies
Do Not Ask What Good We Do Do Not Ask What Good We Do Do Not Ask What Good We Do: Inside the U.S. House of Representatives is a 2012 book by the author Robert Draper and published by Free Press. It details the activities of Republicans and Democrats in the United States House of Representatives and the Senate during the first term of Barack Obama's presidency. The book was republished under the title When the Tea Party Came to Town. In order to research the activities and politics within the House of Representatives, Draper "embedded with new and senior House members" that had been elected in