Structure of the Earth discontinuity (a second order discontinuity). The uppermost mantle together with the crust constitutes the lithosphere. The crust-mantle boundary occurs as two physically different events. First, there is a discontinuity in the seismic velocity, which is most commonly known as the Mohorovičić discontinuity or Moho. The cause of the Moho is thought to be a change in rock composition from rocks containing plagioclase feldspar (above) to rocks that contain no feldspars (below). Second, in oceanic crust, there is a chemical discontinuity between ultramafic cumulates and tectonized harzburgites, which has been observed from deep parts of the oceanic crust that have been
For the Beauty of the Earth For the Beauty of the Earth "For the Beauty of the Earth" is a Christian hymn by Folliott S. Pierpoint (1835-1917). Pierpoint was 29 at the time he wrote this hymn; he was mesmerized by the beauty of the countryside that surrounded him. It first appeared in 1864 in a book of Eucharistic Hymns and Poems entitled "Lyra Eucharistica, Hymns and Verses on The Holy Communion, Ancient and Modern, with other Poems." It was written as a Eucharistic hymn - hence the title of "The Sacrifice of Praise", the refrain "Christ, our God, to Thee we raise, This, our sacrifice