Geology Edit History Talk0 10,969pages on this wiki Category page “A volcano is an opening in the crust of a planet, through which molten magma, ash, and gases can... Volcano Subcategories This category has the following 3 subcategories, out of 3 total. G [×] Gemstones (7 P) M [×] Metals (10 P) R [×] Rocks (4 P) Pages in category "Geology" This category contains only the following page. V Volcano Categories: Science Add category Cancel Save