GEOLOGY

Detailed explanation-1: -Both the temperature and mineral content of magma affect how easily it flows. The viscosity (thickness) of the magma that erupts from a volcano affects the shape of the volcano. Volcanoes with steep slopes tend to form from very viscous magma, while flatter volcanoes form from magma that flows easily.

Detailed explanation-2: -Viscosity of Magmas Viscosity is the resistance to flow (opposite of fluidity). Viscosity depends on primarily on the composition of the magma, and temperature. Higher SiO2 (silica) content magmas have higher viscosity than lower SiO2 content magmas (viscosity increases with increasing SiO2 concentration in the magma).

Detailed explanation-3: -Rhyolitic magma contains the most silica. Other types of magma have less silica in them. Basaltic magma has only 45 to 55 percent silica, and andesitic magma has about 55 to 65 percent. Rhyolitic magma also has a lower temperature than the other magma but higher viscosity and gas content.

Detailed explanation-4: -Felsic lavas are not as hot, high in silica and volatiles, and have a high viscosity. They are thick and gooey and resist flowing.

Detailed explanation-5: -Magma that has a higher viscosity and silica content produces rocks that are called rhyolite and andesite.