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
Do Not Ask What Good We Do the 2010 election. A majority of those he spoke with and listened to were Republicans, especially among the 87 new legislators. The title of the book, "Do Not Ask What Good We Do", is taken from a sentence in a letter from Fisher Ames to Thomas Dwight, dated May 30, 1796: "Do not ask what good we do : that is not a fair question, in these days of faction." The prologue to the book details how, on the night of Obama's inauguration, a group of around 15 Republican Representatives and Senators met in the Caucus Room, a "high-end D.C.