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The tendency of felsic lava to be cooler than mafic lava increases the viscosity difference. The silicon ion is small and highly charged, and so it has a strong tendency to coordinate with four oxygen ions, which form a tetrahedral arrangement around the much smaller silicon ion. This is called a silica tetrahedron. In a magma that is low in ...
Magmatic water. Magmatic water, also known as juvenile water, is an aqueous phase in equilibrium with minerals that have been dissolved by magma deep within the Earth's crust and is released to the atmosphere during a volcanic eruption. It plays a key role in assessing the crystallization of igneous rocks, particularly silicates, as well as the ...
In geology, igneous differentiation, or magmatic differentiation, is an umbrella term for the various processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption. The sequence of (usually increasingly silicic) magmas produced by igneous differentiation is known as a magma series.
Intermediate composition magma, such as andesite, tends to form cinder cones of intermingled ash, tuff and lava, and may have a viscosity similar to thick, cold molasses or even rubber when erupted. Felsic magma, such as rhyolite, is usually erupted at low temperature and is up to 10,000 times as viscous as basalt. Volcanoes with rhyolitic ...
Volatiles in a magma with a high viscosity, generally felsic with a higher silica (SiO 2) content, tend to produce eruptions that are explosive eruption. Volatiles in a magma with a low viscosity, generally mafic with a lower silica content, tend to vent as effusive eruption and can give rise to a lava fountain.
Hawaiian eruption. A Hawaiian eruption is a type of volcanic eruption where lava flows from the vent in a relatively gentle, low level eruption; it is so named because it is characteristic of Hawaiian volcanoes. Typically they are effusive eruptions, with basaltic magmas of low viscosity, low content of gases, and high temperature at the vent.
Strike-slip faults have a direct effect on magmatism. They can either induce magmatism, act as a conduit to magmatism and magmatic flow, or block magmatic flow. [3][4] In contrast, magmatism can also directly impact on strike-slip faults by determining fault formation, propagation and slip. [5] Both magma and strike-slip faults coexist and ...
Depending on the viscosity of the magma, the bubbles may start to rise through the magma and coalesce, or they remain relatively fixed in place until they begin to connect and form a continuously connected network. In the former case, the bubbles may rise through the magma and accumulate at a vertical surface, e.g. the 'roof' of a magma chamber.