GEOLOGY

Detailed explanation-1: -The two most important properties of lava are its viscosity, and the amount of gases dissolved in the liquid rock. Let’s look at each of these separately. Viscosity is a term that describes the fluidity or “runniness” of the lava. Some lavas are very “runny, ” not quite like water, but more like warm honey or hot wax.

Detailed explanation-2: -Pahoehoe (Pa-Hoy-Hoy) lava flows are very hot, thin and runny. When it cools is has a smooth to ropey texture because of the low silica content which makes it cool quickly.

Detailed explanation-3: -If a magma has low viscosity (it is runny), gas can escape easily, so when the magma erupts at the surface it forms lava flows. These eruptions are (relatively!) gentle, effusive eruptions. If a magma rises very slowly within the conduit.

Detailed explanation-4: -So, mafic lavas are hot, low in silica and volatiles, and have relatively low viscosity. They flow easily outward from the vent (where it comes out of the ground), and may travel great distances before completely solidifying. Felsic lavas are not as hot, high in silica and volatiles, and have a high viscosity.