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Andesite (/ ˈ æ n d ə z aɪ t /) [1] is a volcanic rock of intermediate composition.In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite.
For example, andesitic magmatism is associated with the formation of island arcs at convergent plate boundaries while basaltic magmatism is found at mid-ocean ridges during sea-floor spreading at divergent plate boundaries. On Earth, magma forms by partial melting of silicate rocks either in the mantle, continental or oceanic crust. Evidence ...
The andesite line is the most significant regional geologic distinction in the Pacific Ocean basin. It separates the mafic basaltic volcanic rocks of the Central Pacific Basin from the partially submerged continental areas of more felsic andesitic volcanic rock on its margins.
Magma exists in three main forms that vary in composition. [3] When magma crystallizes within the crust, it forms an extrusive igneous rock. Dependent on the composition of the magma, it may form either rhyolite, andesite, or basalt. [3] Volatiles, particularly water and carbon dioxide, significantly impact the behavior of each form of magma ...
The tholeiitic magma series (/ ˌ θ oʊ l eɪ ˈ ɪ t ɪ k /) is one of two main magma series in subalkaline igneous rocks, the other being the calc-alkaline series. A magma series is a chemically distinct range of magma compositions that describes the evolution of a mafic magma into a more evolved, silica rich end member.
Magma that cools slowly within a magma chamber usually ends up forming bodies of plutonic rocks such as gabbro, diorite and granite, depending upon the composition of the magma. Alternatively, if the magma is erupted it forms volcanic rocks such as basalt , andesite and rhyolite (the extrusive equivalents of gabbro, diorite and granite ...
The composition of the soil found on Vikram’s landing site is consistent with an ancient magma ocean, the authors conclude. When analyzing the soil, the researchers found a relatively uniform ...
Scoria. Scoria or cinder 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.