Links between magma- tectonic rate balances, plutonism, and volcanism

With Smith's (1979) model of ash flow magmatism as the point of departure, quantitative regimes of crustal magmatic evolution are outlined. The average extrusive regime of ash flow magmatism operates at a rate of about 0.001 km³/yr; progressively larger episodes of increasing repose times characterize the evolution of caldera-forming eruptions. Categorical examples of the principal types of igneous path are discussed relative to continental basalt, silicic ash flow, batholithic granite, and intrusive porphyry systems.-from Author