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  2. Bimodal volcanism - Wikipedia

    en.wikipedia.org/wiki/Bimodal_volcanism

    Mechanism of formation. Bimodal volcanism is normally explained as a result of partial melting of the crust, creating granitic magmas, during the emplacement of large volumes of relatively hot basaltic magma from a mantle source. The two magma types then form separate magma chambers giving rise to periodic eruption of both types of lava. [7][8]

  3. Tholeiitic magma series - Wikipedia

    en.wikipedia.org/wiki/Tholeiitic_Magma_Series

    The tholeiitic magma series (/ ˌθoʊliˈaɪtɪk /) 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. Rock types of the tholeiitic ...

  4. Magma - Wikipedia

    en.wikipedia.org/wiki/Magma

    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 ...

  5. Basalt - Wikipedia

    en.wikipedia.org/wiki/Basalt

    Basalt (UK: / ˈbæsɔːlt, - əlt /; [1] US: / bəˈsɔːlt, ˈbeɪsɔːlt /) [2] 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. More than 90% of all volcanic rock on Earth is basalt.

  6. Rhyolite - Wikipedia

    en.wikipedia.org/wiki/Rhyolite

    Rhyolite (/ ˈraɪ.əlaɪt / RY-ə-lyte) [1][2][3][4] is the most silica -rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase.

  7. Granite - Wikipedia

    en.wikipedia.org/wiki/Granite

    In continental arc settings, granitic rocks are the most common plutonic rocks, and batholiths composed of these rock types extend the entire length of the arc. There are no indication of magma chambers where basaltic magmas differentiate into granites, or of cumulates produced by mafic crystals settling out of the magma. Other processes must ...

  8. Calc-alkaline magma series - Wikipedia

    en.wikipedia.org/wiki/Calc-alkaline_magma_series

    The calc-alkaline magma series is one of two main subdivisions of the subalkaline magma series, the other subalkaline magma series being the tholeiitic series. A magma series is a series of compositions that describes the evolution of a mafic magma, which is high in magnesium and iron and produces basalt or gabbro, as it fractionally crystallizes to become a felsic magma, which is low in ...

  9. Magmatism - Wikipedia

    en.wikipedia.org/wiki/Magmatism

    Magmatism. Geological map showing the Gangdese batholith, which is a product of magmatic activity about 100 million years ago. Magmatism is the emplacement of magma within and at the surface of the outer layers of a terrestrial planet, which solidifies as igneous rocks. It does so through magmatic activity or igneous activity, the production ...