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
What We Do in Secret What We Do in Secret What We Do In Secret is an American Christian hardcore band from Memphis, Tennessee. They have toured with bands such as War of Ages, Phinehas, Silent Planet, Sleepwave, We Came As Romans, '68, For Today and Norma Jean. They have released two EPs. What We Do In Secret was formed in Memphis in March 2012 by Josh Adams, Drew Nance, Devin Harris and Nathan Moody. They recorded their first EP, "New Eyes", and released it on August 31, 2013. Moody left the band after this and was replaced by Clay Crenshaw and Austin Barnes. The