The term lava was first used by Francesco Serao when writing about Vesuvius’ magma eruption from 14 May to 4 June 1737. Serao described a striped lava flow resembling a stream of water and mud after heavy rains. .
“Lava” is molten rock that comes out of a volcano during an eruption. When it erupts from a volcano, it is liquid at a temperature of about 700°C to 1,200°C (1,300°F to 2,200°F). Although lava is quite viscous, about 100,000 times taller than water, it can flow over long distances before freezing into rock, due to its thixotropic and shear thinning properties.
Lava flow is the flow of lava, produced during a smooth eruption. When it stops flowing, the lava solidifies to form an erupting igneous rock.
The composition of the lava will determine its properties rather than the temperature at which it erupts.
In general, the composition of the lava will determine its properties more than the temperature when it erupts. Magma rocks formed from lava can be classified into three groups based on chemical composition: felsic, intermediate, and mafic
Felsic lavas such as ryolite and dacite specifically form from lava spines, lava domes or “coulees” (which are short, thick lava) and are associated with debris deposits. Most felsic lava flows are very viscous, and especially flake when they erupt, producing clumps of clumps.
Intermediate lava or andesite is low in aluminum and silica and often high in magnesium and iron. Intermediate lava forms arches of andesite and lava mass , often forming the steps of mixed volcanoes such as those in the Andes.
Mafic lava or basalt lava is characterized by high iron and magnesium content, and eruption temperatures are often above 950°C. Basalt magma is high in iron and magnesium and relatively low in aluminum and silica, which reduces the degree of polymerization in the molten state.
Ultramafic lavas such as komatiite have a high magnesium magma content forming boninites with extremely high eruption temperatures. Komatiite contains more than 18% magnesium oxide, and has an eruption temperature of about 1,600°C.