Boninite

Boninite

La boninite est une roche mafique extrusive riche en magnésium et en silice. Son nom provient de l'arc volcanique de l'archipel d'Ogasawara, anciennement appelé les îles Bonin, où on en trouve un gisement.

La boninite est d'abord observée dans des volcans éteints très anciens, vieux d'au moins un million d'années. Puis, en 2009, une équipe de scientifiques observe une éruption du volcan sous-marin Mata Ouest, dans les Tonga, et se rend compte que le volcan produit de la lave contenant de la boninite, apportant ainsi la preuve que la roche se trouve toujours dans les laves des volcans actifs à l'époque contemporaine[1].

Notes et références

Bibliographie

  • (en) A. J. Crawford, Boninites, Londres, Unwin Hyman, 1989, (ISBN 0-0444-5003-6)
  • (en) P. F. Dobson, J. G. Blank, S. Maruyama, et J. G. Liou, « Petrology and geochemistry of boninite series volcanic rocks, Chichi-jima, Bonin Islands, Japan », International Geology Review n°48, 2006, p.  669–701 (LBNL #57671)
  • (en) P. F. Dobson, H. Skogby et G. R. Rossman, « Water in boninite glass and coexisting orthopyroxene: concentration and partitioning », Contrib. Mineral. Petrol. n°118, 1995, p. 414-419.
  • Portail des minéraux et roches Portail des minéraux et roches

Wikimedia Foundation. 2010.

Contenu soumis à la licence CC-BY-SA. Source : Article Boninite de Wikipédia en français (auteurs)

Игры ⚽ Поможем написать реферат

Regardez d'autres dictionnaires:

  • Boninite — is a mafic extrusive rock high in both magnesium and silica, formed in fore arc environments, typically during the early stages of subduction. The rock is named for its occurrence in the Izu Bonin arc south of Japan. It is characterized by… …   Wikipedia

  • Boninit — ist ein mafisches vulkanisches Gestein, das als primitiver Andesit angesehen wird. Es tritt als extrusives Gestein mit hohem Gehalt an Magnesium und Silizium in Forearc Becken auf, typischerweise in den Frühstadien von Subduktionsprozessen.… …   Deutsch Wikipedia

  • Isua greenstone belt — The Isua greenstone belt is an Archean greenstone belt in southwestern Greenland dated at 3.8 3.7 Ga and contains the oldest known, well preserved, metavolcanic (metamorphosed mafic volcanic), metasedimentary and sedimentary rocks on Earth. It… …   Wikipedia

  • Lava — flow redirects here. For the programming anti pattern, see Lava flow (programming). For other uses, see Lava (disambiguation) …   Wikipedia

  • Basalt — For the World War II raid, see Operation Basalt. For the cities, see Basalt, Colorado and Basalt, Idaho. Basalt Igneous Rock Composition …   Wikipedia

  • List of rock types — This page is intended as a list of all rock types. NOTOC A : Amphibolite: Andesite: Anorthosite : Anthracite: Aplite: Argillite: Arkose B : Banded iron formation: Basalt: Basanite: Blueschist: Boninite: Breccia C : Carbonatite: Cataclasite: Chalk …   Wikipedia

  • Bonin Islands — Ogasawara Islands * UNESCO World Heritage Site Country Japan Type Natural Criteria ix …   Wikipedia

  • Ultramafic rock — Ultramafic (also referred to as ultrabasic) rocks are igneous and meta igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are composed of usually greater than 90% mafic minerals (dark… …   Wikipedia

  • Komatiite — Komatiites are ultramafic mantle derived volcanic rocks. They have low SiO2, low K2O, low Al2O3, and high to extremely high MgO. They were named for their type locality along the Komati River in South Africa. True komatiites are very rare and… …   Wikipedia

  • Geology of Australia — Australia is a continent situated on the Indo Australian Plate.The geology of Australia includes virtually all known rock types and from all geological time periods spanning over 3.8 billion years of the Earth s history. ComponentsAustralia s… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”