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Vesicular texture is a volcanic rock texture characterized by a rock being pitted with many cavities (known as vesicles) at its surface and inside. [1] This texture is common in aphanitic, or glassy, igneous rocks that have come to the surface of the Earth, a process known as extrusion. As magma rises to the surface the pressure on it decreases ...
The individual crystals in an aphanitic igneous rock are not distinguishable to the naked eye. Examples of aphanitic igneous rock include basalt, andesite, and rhyolite. Glassy or vitreous textures occur during some volcanic eruptions when the lava is quenched so rapidly that crystallization cannot occur. The result is a natural amorphous glass ...
In geology, texture or rock microstructure [1] refers to the relationship between the materials of which a rock is composed. [2] The broadest textural classes are crystalline (in which the components are intergrown and interlocking crystals), fragmental (in which there is an accumulation of fragments by some physical process), aphanitic (in which crystals are not visible to the unaided eye ...
Basalt (UK: / ˈ b æ s ɒ l t,-ɔː l t,-əl t /; [1] [2] US: / b ə ˈ s ɔː l t, ˈ b eɪ s ɔː l t /) [3] is an aphanitic (fine-grained) extrusive igneous rock formed 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.
Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock formed by ejection from a volcano as a molten blob and cooled in the air to form discrete grains called clasts. [ 1 ] [ 2 ] It is typically dark in color (brown, black or purplish-red), and basaltic or andesitic in composition.
Shield volcanoes are large, slow forming volcanoes [6] that erupt fluid basaltic magma that cools to form the extrusive rock basalt. Basalt is composed of minerals readily available in the planet's crust, including feldspars and pyroxenes. [2] Fissure volcanoes pour out low viscosity basaltic magma from fissure vents to form the extrusive rock ...
In an encore “20/20” airing Dec. 27 at 9 p.m. ET, the show, which originally aired in 2023, tells the story of Julie Jensen, the mother of two who was found dead in her bed in 1998.
This glass is formed naturally by the rapid cooling of molten basalt. It is a type of mafic igneous rock that is decomposable by acids and readily fusible. [citation needed] The color is a black or dark-brown, and it has a greasy-looking, resinous luster. It is very brittle and occurs in dikes, veins, and intrusive masses.