monzonite

monzonitic /mon'zeuh nit"ik/, adj.
/mon"zeuh nuyt'/, n.
any of a group of granular igneous rocks having approximately equal amounts of orthoclase and plagioclase feldspar, intermediate in composition between syenite and diorite.
[1880-85; < G Monzonit, named after Monzoni, mountain in Tyrol; see -ITE1]

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Type of igneous rock that contains abundant and approximately equal amounts of plagioclase and potash feldspar, as well as other minerals.

The type region is Monzoni, Italy, in the Italian Tirol; similar rocks have been described from Montana, Norway, Sakhalin Island, and other localities. Monzonite is not rare, but it generally occurs in rather small, heterogeneous masses mixed with diorites, pyroxenites, or gabbros.

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      intrusive igneous rock that contains abundant and approximately equal amounts of plagioclase and potash feldspar; it also contains subordinate amounts of biotite and hornblende, and sometimes minor quantities of orthopyroxene. Quartz, nepheline, and olivine, which are occasionally present, produce quartz, nepheline, and olivene monzonites. In the type region of Monzoni, Italy, in the Italian Tirol, these minerals rarely occur as major constituents; moreover, in Monzoni the plagioclase is often calcium-rich (labradorite) and commonly shows prominent zoning. Rocks similar to those of the type area have been described from Norway (akerite), Montana (yogoite, shonkinite), Sakhalin Island off the Pacific coast of Russia, and other localities throughout the world. Monzonite is not a rare rock type, but it generally occurs in rather small, heterogeneous masses associated with (and perhaps gradational to) diorites, pyroxenites, or gabbros.

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Universalium. 2010.

Look at other dictionaries:

  • monzonite — ● monzonite nom féminin (de Monzoni, nom propre) Roche magmatique grenue contenant surtout des feldspaths (plagioclases et feldspaths potassiques), moins de 5 % de quartz, de la biotite et des amphiboles en quantité variable …   Encyclopédie Universelle

  • monzonite — [män′zə nīt΄] n. [Ger monzonit, after Mt. Monzoni (in Tyrol), where it occurs] a dark colored, intrusive igneous rock containing orthoclase and plagioclase in nearly equal quantities, a small amount of quartz, and some biotite …   English World dictionary

  • Monzonite — Photomicrograph of thin section of monzonite (in cross polarised light) …   Wikipedia

  • Monzonite — Monozonite (Larvikite) et une pièce pour donner l échelle Une monzonite est une roche magmatique plutonique à structure grenue composée d’orthose, de feldspath plagioclase, d’hornblende, d’augite et de biotite. La roche volcanique équivalente …   Wikipédia en Français

  • monzonite — noun Etymology: French, from Mt. Monzoni, Italy Date: 1895 a granular igneous rock composed of plagioclase and orthoclase in about equal quantities usually together with augite and biotite …   New Collegiate Dictionary

  • monzonite — noun An intrusive igneous rock composed mostly of plagioclase and orthoclase …   Wiktionary

  • monzonite — n. type of grainy igneous rock …   English contemporary dictionary

  • monzonite — [ mɒnzənʌɪt] noun Geology a granular igneous rock containing approximately equal amounts of orthoclase and plagioclase. Origin C19: named after Mount Monzoni in the Tyrol, Italy, + ite1 …   English new terms dictionary

  • monzonite — mon·zo·nite …   English syllables

  • monzonite — /ˈmɒnzənaɪt/ (say monzuhnuyt) noun any of a group of granular igneous rocks intermediate in composition between syenite and diorite. {German Monzonit, from Monzoni (name of mountain in Tyrol) + it ite1} –monzonitic /mɒnzəˈnɪtɪk/ (say monzuh… …   Australian English dictionary

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