Is Basalt Intrusive And Extrusive?

Basalt is a mafic extrusive rock, is the most widespread of all igneous rocks, and comprises more than 90% of all volcanic rocks. Because of its relatively low silica content, basalt lava has a comparatively low viscosity, and forms thin flows that can travel long distances.

Is Basalt an extrusive rock?

Basalts are common aphanitic igneous extrusive (volcanic) rocks. Basalts are composed of minute grains of plagioclase feldspar (generally labradorite), pyroxene, olivine, biotite, hornblende and <20% quartz.

Is basalt an 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.

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 basalt a sedimentary rock?

Basalt is not a sedimentary rock. It is actually an igneous rock formed from cooled, melted rocks.

Is basalt a metamorphic rock?

Intense heat or great pressure transforms basalt into its metamorphic rock equivalents. … Basalts are important rocks within metamorphic regions because they can provide vital information on the conditions of metamorphism that have affected the region.

What rock is intrusive?

intrusive rock, also called plutonic rock, igneous rock formed from magma forced into older rocks at depths within the Earth’s crust, which then slowly solidifies below the Earth’s surface, though it may later be exposed by erosion. Igneous intrusions form a variety of rock types.

What is intrusive and extrusive?

The two main categories of igneous rocks are extrusive and intrusive. Extrusive rocks are formed on the surface of the Earth from lava, which is magma that has emerged from underground. Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet.

Is basalt coarse or fine-grained?

Basalt is a fine-grained mafic igneous rock. It is commonly vesicular and aphanitic.

What is the intrusive equivalent of basalt?

Diabase Dykes (intrusive relationships)

Diabase is a dark-coloured intrusive rock, found as dykes or sills, composed of mainly feldspar, pyroxene +/- olivine. It is the intrusive equivalent of basalt and the shallow intrusive equivalent of gabbro.

Is Obsidian intrusive or extrusive?

Obsidian is an “extrusive” rock, which means it is made from magma that erupted out of a volcano. If it was an igneous rock that formed from magma underground and did not erupt, it would have been called an “intrusive” rock.

Which of the following is extrusive?

The correct answer is Basalt. ​Basalt is a dark-colored, fine-grained, igneous rock. Basalt is an extrusive igneous rock formed by the rapid cooling of lava.

What is an example of intrusive igneous rock?

Intrusive igneous rocks are rocks that crystallize below the earth’s surface resulting in large crystals as the cooling takes place slowly. Diorite, granite, pegmatite are examples of intrusive igneous rocks.

Is basalt foliated or Nonfoliated?

This rock is usually non-foliated and sometimes you might find foliated pieces of it. The mineral chlorite gives it a green color. Metabasalt is metamorphosed basalt! It is sometimes called greenstone, or greenschist if it is foliated.

What type of rock is a basalt?

Basalt is a hard, black volcanic rock. Basalt is the most common rock type in the Earth’s crust. Depending on how it is erupted, basalt can be hard and massive (Figure 1) or crumbly and full of bubbles (Figure 2).

Is basalt metallic or nonmetallic?

Not metallic. Formation Environment: Low grade metamorphism of clays and micas (mudstones and basalts). Description: Nonmetallic luster.

Is andesite intrusive or extrusive?

Igneous Rock Types and Textures. Porphyritic texture — andesite: This is an extrusive igneous rock. The magma from which it formed cooled slowly for a while deep below the surface (forming the large crystals), then finished cooling very quickly when it was ejected at the surface, forming the fine-grained groundmass.

How can basalt become a sedimentary rock?

Weathering (breaking down rock) and erosion (transporting rock material) at or near the earth’s surface breaks down rocks into small and smaller pieces. These smaller pieces of rock (such as sand, silt, or mud) can be deposited as sediments that, after hardening, or lithifying, become sedimentary rocks.

Is quartzite intrusive or extrusive?

Metamorphism must occur below the surface since it occurs as the result of a rock “adjusting” to heat and pressure. For this reason there is no “intrusive/extrusive” distinction required. Some examples of metamorphic rocks are meta-quartzite, gneiss, and schist.

Is olivine intrusive or extrusive?

Mafic igneous rocks (olivine, pyroxene, and the plagioclase feldspars) include basalt (extrusive) and gabbro (intrusive), while felsic igneous rocks (quartz, amphibole, mica, and the orthoclase feldspars) include granite (intrusive) and rhyolite (extrusive).

How are extrusive and intrusive rocks formed Class 7?

Extrusive rocks are formed by the molten lava which comes out of volcanoes, reaches the earth’s surface and cools down rapidly to become a solid piece of rock. For example, basalt. When the molten magma cools down deep inside the earth’s crust, the solid rocks so formed are called intrusive rocks.

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