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
The Cyborg from Earth In the end, Jeff finds that he is not a coward and everyone else knows that as well. The engines used by Vanguard Mining's spacecraft are Diabelli Omnivores. This particular brand of engine is used repeatedly throughout Sheffield's books, across many different fictional settings. The Cyborg from Earth The Cyborg from Earth is a 1998 science fiction novel by Charles Sheffield. It is the fourth in a series of unrelated stories, published by Tor Books in their Jupiter line. The novel starts in a future dystopian Earth where the upper class lives a life of privilege, while most others live