Orbicular granite

Orbicular granite

Igneous Rock
Polished rock sample of orbicular granite from Mount Magnet, Western Australia.
Composition
Granitic

Outcrop of orbicular granite near Caldera, Chile.

Orbicular granite (also known as orbicular rock or orbiculite) is an uncommon plutonic rock type which is usually granitic in composition. These rocks have a unique appearance due to orbicules - concentrically layered, spheroidal structures, probably formed through nucleation around a grain in a cooling magma chamber. Almost one third of known orbicular rock occurrences are from Finland.^[1] The occurrences are usually very small.^[2]

Places with orbicular granites

• Caldera, Chile
• Kuru, Finland
• Mount Magnet, Western Australia
• Savitaipale, Finland
• Karamea, New Zealand^[3]
• Cape Geology in Granite Harbour, McMurdo Sound, Antarctica
• Taylor Valley in Antarctica
• Skurun, Jämtland, Sweden
• Concordia, South Africa

References

1. ^ Mineralogical Magazine; April 2006; v. 70; no. 2; p. 238-239: Book Review
2. ^ Kristallin.de: Orbicular rocks vs. Rapakivis
3. ^ http://www.teara.govt.nz/en/west-coast-places/1/5 Te Ara Encyclopedia of New Zealand

This article related to petrology is a stub. You can help Wikipedia by expanding it.v · Categories: Granitic rocks Petrology stubs Wikimedia Foundation. 2010. Игры ⚽ Нужно сделать НИР? Orbexilum stipulatum Caracanthidae Look at other dictionaries: Orbicular Granite — is an uncommon rock type found near Mount Magnet, in Western Australia. It is a granitic rock with orbicules concentrically layered, spheroidal structures, probably formed through nucleation around a grain in a cooling magma chamber …   Wikipedia Granite — For other uses, see Granite (disambiguation). Granite Igneous Rock Granite containing potassium feldspar, plagioclase feldspar, quartz, and biotite and/or amphibole Composi …   Wikipedia Granito orbicular — Orbiculita Granito orbicular cerca de Caldera, Chile.. General Tipo Ígnea Tamaño grano …   Wikipedia Español Caldera, Chile — Infobox Settlement official name = Caldera, Chile other name = native name = nickname = settlement type = motto = imagesize = 300px image caption = Port of Caldera flag size = image seal size = image shield = shield size = image blank emblem =… …   Wikipedia igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary …   Universalium Geology of Alderney — Although Alderney is only five kilometers long, it has a geological history spanning half of the life of the earth. Part of the Armorican massif, it has similarities in its rock to the neighbouring Normandy and Guernsey.Geological historyRelics… …   Wikipedia Diorite — classification on QAPF diagram Di …   Wikipedia Nepenthes kerrii — Lower pitchers of Nepenthes kerrii Scientific classification Kingdom: Plantae …   Wikipedia Quartz — This article is about the mineral. For other uses, see Quartz (disambiguation). Quartz Quartz crystal cluster from Tibet General Category …   Wikipedia Moss agate — pebble, 1 inch (25 mm) long. Montana mo …   Wikipedia 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”