Correct Response: B. The shape of Hawaiian shield volcanoes results from the mafic composition of the magma that generates low-viscosity magma flows during eruptions. This lava's viscosity is low so the lava generated is very fluid and flows easily over long distances before solidifying. The gas content (A) of magmas feeding Hawaiian-style eruptions is low and although it does affect viscosity, is not as important as the magma's silica content. Hawaiian lavas are mafic and their relatively high iron content
(C) is not a major factor in the lava's low viscosity. Lava with a felsic composition (D) is more viscous than mafic lava and is associated with more explosive stratovolcanoes and not Hawaiian-style shield volcanoes.
