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
Museum of Minerals in Siófok Museum of Minerals in Siófok Mineral Museum (Hungarian: Ásványmúzeum) is a museum in Siófok, Hungary. It was opened in 1986 in the centre of the city. It is a private museum, but the State also takes care of the collection. It includes more than 3000 pieces. It includes examples most notably from the Carpathian basin, and most of them are minerals and fossils. There are a lot of very rare minerals from the mining areas of Transylvania. There are some objects from distant regions of the world as well. The Kövecses Family has been collecting minerals for 4 generations. The