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As the Moon formed, the outer part of it is thought to have been molten, a “lunar magma ocean.” Plagioclase feldspar crystallized in large amounts from this magma ocean and floated toward the surface. The upper part of the crust probably averages about 88% plagioclase (near the lower limit of 90% defined for anorthosite): the lower part of the crust may contain a higher percentage of ferromagnesian minerals such as the pyroxenes and olivine, but even that lower part probably averages about 78% plagioclase. The underlying mantle is denser and olivine-rich.
The thickness of the crust ranges between about 20 and 120 km.
The boundary between the crust and mantle is conventionally placed at the Mohorovi? discontinuity, a boundary defined by a contrast in seismic velocity.
The crust occupies less than 1% of Earth's volume. The oceanic crust of the sheet is different from its continental crust.
Filme Dievo sūnus Persėjus (Samas Worthingtonas) vyksta į Žemę, kur turi susikauti su požeminės karalystės valdovu (vaid. Most of this plagioclase-rich crust formed shortly after formation of the moon, between about 4.5 and 4.3 billion years ago.Perhaps 10% or less of the crust consists of igneous rock added after the formation of the initial plagioclase-rich material.The primordial crust was very thin and was probably recycled by much more vigorous plate tectonics and destroyed by significant asteroid impacts, which were much more common in the early stages of the solar system.Earth has probably always had some form of basaltic crust, but the age of the oldest oceanic crust today is only about 200 million years.