What is the classification of pegmatite?
Pegmatites are classified as LCT and are subdivided into 4 unique groups to the Pegmatite belt. Structural analysis shows an exclusive post-orogenic timing of pegmatite emplacement. Sn, Ta and Nb element enrichment was due to pegmatite fractionation and not contamination as previously thought.
What are granitic pegmatites?
Pegmatites are unusually coarse-grained crystalline igneous rocks, usually of granitic composition and characterized by interlocking crystals several centimeters up to tens of meters in length.
Why are pegmatites important to society?
Economic importance Pegmatites are important because they often contain rare earth minerals and gemstones, such as aquamarine, tourmaline, topaz, fluorite, apatite and corundum, often along with tin, rare earth, and tungsten minerals, among others.
What is the meaning of Phaneritic?
[ făn′ə-rĭt′ĭk ] Of or relating to an igneous rock in which the crystals are so coarse that individual minerals can be distinguished with the naked eye.
What is the significance of peridotite?
Peridotites are economically important rocks because they often contain chromite – the only ore of chromium; they can be source rocks for diamonds; and, they have the potential to be used as a material for sequestering carbon dioxide. Much of Earth’s mantle is believed to be composed of peridotite.
What is in a peridotite?
peridotite, a coarse-grained, dark-coloured, heavy, intrusive igneous rock that contains at least 10 percent olivine, other iron- and magnesia-rich minerals (generally pyroxenes), and not more than 10 percent feldspar.
Is there a classifi cation of granitic pegmatites?
The classifi cation of granitic pegmatites was frequently attempted during the past century, with variable degrees of success and applicability. Internal structure, paragenetic relationships, bulk chemical composition, petrogenetic aspects, nature of parent medium, and geochemical features were applied.
Is there a petrogenic class for pegmatites?
ites, and to granites in general ( e.g., London 1995). pegmatites of the rare-element and miarolitic classes. 1976). However, petrological, petrochemical and available. Consequently, the petrogenetic classi fi cation
What are the different classes of pegma Tites?
The fi rst concept deals with geological location, leading to division of granitic pegma- tites into fi ve classes (abyssal, muscovite, muscovite – rare-element, rare-element, and miarolitic), most of which are subdivided into subclasses with fundamentally different geochemical (and in part geological) characteristics.
What are the characteristics of pegmatites?
These pegmatites feature aplitic to minor to accessory K-feldspar, spodumene or lepidolite. strongly layered. The localities quoted in T able 5, and type that were described in reasonable detail. So far, ( Č ern´ y 1992).