Magma 50%, because eventually the melted rock mass becomes a crystal-and-melt mush that can then ascend "en masse" as a diapir, which may then cause further decompression melting. The degree of partial melting is critical for determining what type of magma is produced. The degree of partial melting required to form a melt can be estimated by considering the relative enrichment of incompatible elements versus compatible elements. Incompatible elements commonly include potassium, barium, caesium, and rubidium. Rock types produced by small degrees of partial melting in the Earth's mantle are typically alkaline (Ca, Na), potassic (K) and/or peralkaline (high aluminium to
Volcanism plate tectonic activity, but some earthquakes are generated as a result of volcanic activity (though that itself is ultimately driven by the same forces). These are formed where water interacts with volcanism. These include geysers, fumaroles, hotsprings and mudpots, they are often used as a source of geothermal energy. The amount of gas and ash emitted by volcanic eruptions has a significant effect on the Earth's climate. Large eruptions correlate well with some significant climate change events. When magma cools it solidifies and forms rocks. The type of rock formed depends on the chemical composition of the magma and how