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A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include basalt, diabase and gabbro. Mafic rocks often also contain calcium-rich varieties of plagioclase ...
This list of shield volcanoes includes active, dormant and extinct shield volcanoes. Shield volcanoes are one of the three types [ specify ] of volcanoes. They have a short cone shape, and have basaltic lava which means the lava has low viscosity (viscosity is a measure of the ability for a liquid to flow)
The calc-alkaline magma series is one of two main subdivisions of the subalkaline magma series, the other subalkaline magma series being the tholeiitic series. A magma series is a series of compositions that describes the evolution of a mafic magma, which is high in magnesium and iron and produces basalt or gabbro, as it fractionally crystallizes to become a felsic magma, which is low in ...
The pristine volcanic mineralogy of komatiites is composed of forsteritic olivine (Fo90 and upwards), calcic and often chromian pyroxene, anorthite (An85 and upwards) and chromite. A considerable population of komatiite examples show a cumulate texture and morphology.
Shield volcanoes are large, slow forming volcanoes [6] that erupt fluid basaltic magma that cools to form the extrusive rock basalt. Basalt is composed of minerals readily available in the planet's crust, including feldspars and pyroxenes. [2] Fissure volcanoes pour out low viscosity basaltic magma from fissure vents to form the extrusive rock ...
Examples of pyroclastic shields include Billy Mitchell volcano in Papua New Guinea and the Purico complex in Chile; [8] [9] an example of a felsic shield is the Ilgachuz Range in British Columbia, Canada. [10] Shield volcanoes are similar in origin to vast lava plateaus and flood basalts present in various parts of the
List of volcanoes in Europe; List of volcanoes in Armenia; List of volcanoes in France; List of volcanoes in Germany; List of volcanoes in Georgia (country) List of volcanoes in Greece; List of volcanoes in Iceland; List of volcanoes in Italy; List of volcanoes in the Netherlands; List of volcanoes in North Macedonia; List of volcanoes in Norway
Rhyodacite – Volcanic rock rich in silica and low in alkali metal oxides – A felsic volcanic rock which is intermediate between a rhyolite and a dacite; Rhyolite – Igneous, volcanic rock, of felsic (silica-rich) composition Comendite – Hard, peralkaline igneous rock, a type of light blue grey rhyolite