Search results
Results from the WOW.Com Content Network
Peridotite, a type of ultramafic rock. Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are usually composed of greater than 90% mafic minerals (dark colored, high magnesium and iron content).
A quarry of listwanite in the region of Aosta Valley, in Italy A quarry of listwanite in the region of Aosta Valley, in Italy. Listwanite (also sometimes spelled listvenite, listvanite, or listwaenite) is a rock type that forms when the groundmass of ultramafic rocks, most commonly mantle peridotites, is partially altered to carbonate minerals and cut by ubiquitous carbonate veins containing ...
Lherzolite – an ultramafic and ultrabasic rock that is composed of olivine and pyroxene – An ultramafic rock, essentially a peridotite Monzodiorite – igneous rock Pages displaying wikidata descriptions as a fallback An intrusive igneous rock intermediate in composition between diorite and monzonite
Komatiite / k oʊ ˈ m ɑː t i ˌ aɪ t / is a type of ultramafic mantle-derived volcanic rock defined as having crystallised from a lava of at least 18 wt% magnesium oxide (MgO). [1] It is classified as a 'picritic rock'.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more
The width of the intrusions vary from 3 to 12 km (7.5 mi). The Great Dyke is unusual in that most ultramafic layered intrusions display near horizontal sill or sheet forms. The well-layered lower units of ultramafic rocks comprising the Great Dyke are locally overlain by erosional remnants of gabbroic rock. These mark the centres of the four ...
They consist of peridotites, ultramafic rocks of the mantle and to a lesser extent gabbroic rocks from the Earth's crust. Each detachment fault has three notable features: a breakaway zone where the fault began, an exposed fault surface that rides over the dome, and a termination, which is usually marked by a valley and adjacent ridge.
Dun Mountain was given its name because of the dun colour of the underlying ultramafic rocks. This color results from surface weathering that oxidizes the iron in olivine in temperate climates (weathering in tropical climates creates a deep red soil). The dunite from Dun Mountain is part of the ultramafic section of the Dun Mountain Ophiolite Belt.