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...

high FeO, low potassium, and are usually composed of greater than 90% mafic minerals (dark colored, high magnesium and iron content). The Earth's mantle...

volcanics. The hangingwall to the deposit is broadly related to a more mafic sequence of volcanic rocks, either andesite (examples being Whim Creek &...

ultramafic-mafic intrusive complex consists of ultramafic peridotites and pyroxenites with associated chromitite layers toward the base with more mafic norites...

feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present. Anorthosites...

dark mafic minerals and generally light felsic minerals in an igneous rock. The color index of an igneous rock is the volume percentage of mafic minerals...

GAB-roh) is a phaneritic (coarse-grained and magnesium- and iron-rich), mafic intrusive igneous rock formed from the slow cooling magma into a holocrystalline...

relatively rich in elements that form feldspar and quartz. It is contrasted with mafic rocks, which are richer in magnesium and iron. Felsic refers to silicate...

consists largely of tonalitic and granodioritic gneisses and lesser amounts of mafic and ultramafic gneisses. It underlies and is largely concealed by thin,...

from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More...