dunite उदाहरण वाक्य
उदाहरण वाक्य
- If partial melting of the harzburgite continues, all of the pyroxene may be extracted from it to form magma, leaving behind the pyroxene-poor peridotite called dunite.
- The mantle parts of the lithosphere are made of harzburgite and dunite ( both peridotites ), with about 50 to 80 % of the minerals now transformed into serpentinite.
- It is considered equally plausible that such large dunite-peridotite bodies represent lave channels or sills through which, perhaps, great volumes of lava flowed en route to the surface.
- Adams'work showed that only two minerals, dunite and eclogite, could possible make up the discontinuity, and further exploration showed that dunite was a better fit than eclogite.
- Adams'work showed that only two minerals, dunite and eclogite, could possible make up the discontinuity, and further exploration showed that dunite was a better fit than eclogite.
- Nearly the entire area is underlain by dunite, a variety of peridotite consisting of dark green olivine and minor chromite, which has been partly or entirely serpentinized to antigorite magnesite-magnetite.
- However, serpentinite synthesis and spinel cracking reactions require hydrothermal alteration of pristine peridotite-dunite, which is a finite process intrinsically related to metamorphism, and further, requires significant addition of water.
- One proposed reaction is that of the olivine-rich rock dunite, or its hydrated equivalent serpentinite with carbon dioxide to form the carbonate mineral magnesite, plus silica and iron oxide ( magnetite ).
- Dunite was named by the German geologist, Ferdinand von Hochstetter in 1859 after Dun Mountain near oxidizes the iron in olivine in temperate climates ( weathering in tropical climates creates a deep red soil ).
- In all cases these rocks are pyrometamorphic ( that is, metamorphosed in the presence of molten rock ) and represent either fertile mantle ( lherzolite ) or partially depleted mantle ( harzburgite, dunite ).