An aphanitic (fine-grained) igneous rock is classified as basalt when its QAPF fraction is composed of less than 10% feldspathoid and less than 20% quartz, and plagioclase makes up …

Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form …

Apr 10, 2018 · Basalt is the most abundant volcanic rock on Earth, covering more than 90% of the ocean floor and large continental regions shaped by ancient lava flows. It forms when mafic …

Dec 20, 2025 · Basalt, extrusive igneous (volcanic) rock that is low in silica content, dark in color, and comparatively rich in iron and magnesium. Basalts may be broadly classified on a …

Basalt is defined as a fine-grained, dark-colored igneous rock composed mainly of plagioclase and pyroxene minerals, with or without olivine. It is formed from the rapid cooling of basaltic …

Aug 17, 2023 · Basalt is a common and widely used, fine-grained, dark-colored mafic volcanic rock. It has mainly calcic plagioclase feldspar and augite.

Dec 14, 2012 · Basalt is a very common dark-colored volcanic rock composed of calcic plagioclase (usually labradorite), clinopyroxene (augite) and iron ore (titaniferous magnetite). …

1 day ago · basalt (countable and uncountable, plural basalts) (mineralogy) A hard mafic igneous rock of varied mineral content; volcanic in origin, which makes up much of the Earth's oceanic …

The meaning of BASALT is a dark gray to black dense to fine-grained igneous rock that consists of basic plagioclase, augite, and usually magnetite.

Basalt is the most common composition of lava rocks that cool from magma, liquid rock that rises from the deep Earth at volcanoes. Today basalt is forming at many active rifts, including …