Why does felsic lava tend to form composite volcanoes?
Volcanic eruptions range from explosive to quiet depending on the viscosity of the magma & the amount of dissolved gases. Felsite volcanoes are the most viscous & the most explosives. The explosive products from a volcano are called pyroclastic rocks. Thus the most explosive volcano are those whose composition is felsitic.This viscous felsite may plug the vocano, causing the pressure to build within it. When the pressure becomes great, an explosive eruption will occur. That is how composite volcoanos are formed.
