Table of Contents
What class does basalt belong to?
extrusive igneous
basalt, extrusive igneous (volcanic) rock that is low in silica content, dark in colour, and comparatively rich in iron and magnesium. Some basalts are quite glassy (tachylytes), and many are very fine-grained and compact.
Where are basalt type rocks found?
It is found all over Earth, but especially under the oceans and in other areas where Earth’s crust is thin. It formed in the Isle Royale-Keweenaw region because of the Midcontinent Rift. Most of Earth’s surface is basalt lava, but basalt makes up only a small fraction of continents.
What type of rock is basalt and granite?
igneous rocks
Basalt and granite actually have quite a bit in common. Both are igneous rocks, which means that they cooled from a magma (the earth gets very hot just below the surface, and there is lots of liquid rock available). Both are made up of minerals from the silicate group, so both have large amounts of silicon and oxygen.
Is Basalt The most common igneous rock?
Basalt is a mafic extrusive rock, is the most widespread of all igneous rocks, and comprises more than 90% of all volcanic rocks.
How basalt rock is formed?
Basalts are formed by the rapid cooling of basaltic lava, equivalent to gabbro-norite magma, from interior of the crust and exposed at or very close to the surface of Earth. These basalt flows are quite thick and extensive, in which gas cavities are almost absent.
What type of rock is basalt igneous sedimentary or metamorphic?
What is Basalt? 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 in small intrusive bodies, such as an igneous dike or a thin sill. It has a composition similar to gabbro.
Is phyllite a sedimentary rock?
phyllite, fine-grained metamorphic rock formed by the reconstitution of fine-grained, parent sedimentary rocks, such as mudstones or shales.
What type of rock is basalt?
Basalt ( US: /bəˈsɔːlt, ˈbeɪsɒlt/, UK: /ˈbæsɔːlt, ˈbæsəlt/) is a mafic extrusive igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or very near the surface of a terrestrial planet or a moon. More than 90% of all volcanic rock on Earth is basalt.
What are the characteristics of basalt?
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 in small intrusive bodies, such as an igneous dike or a thin sill.
What minerals are in basalt?
Basalt is not a mineral, because is can not be expressed in a definite chemical equation, nor does it have a definite crystal structure. Basalt is a hard, black volcanic rock with less than about 52 weight percent silica (SiO2). Common minerals in basalt include olivine, pyroxene, and plagioclase.
Where is basalt formed?
Most of Earth’s basalt is produced at divergent plate boundaries on the mid-ocean ridge system (see map). Here convection currents deliver hot rock from deep in the mantle. This hot rock melts as the divergent boundary pulls apart, and the molten rock erupts onto the sea floor.