Ultramafic tuff is extremely rare. It has a characteristic abundance of olivine or serpentine and a scarcity or absence of feldspar and quartz. Rare occurrences may include unusual surface …

Ultramafic igneous rocks are a distinct class characterized by their extremely low silica content (less than 45%) and high magnesium content (typically >18% MgO). They are dark in color …

Ultramafic rocks are a vast family of rocks consisting predominantly of mafic minerals (olivine, pyroxene, and amphibole) with very limited contents of felsic minerals (generally calcium …

Ultramafic rocks are defined as igneous rocks that have a color index greater than 90 and contain less than 45 wt% silica (SiO2) in their bulk chemical composition, often consisting …

Ultramafic (or ultrabasic) rocks are dark-colored igneous and meta-igneous rocks that are rich in minerals containing magnesium and iron ("mafic" minerals) and have a relatively low content …

Dec 12, 2023 · Ultramafic rocks are igneous or metamorphosized igneous rocks that are very low in silica (usually less than 45 wt.%) and with more than 18% magnesium oxide. These rocks …

Ultramafic metamorphic rocks result from the metamorphism of mantle rocks and some oceanic crust and contain dominantly magnesium, silicon, and carbon dioxide, with smaller amounts of …