The user can create, shape, and manipulate mud volcanoes, formations created by geo-exuded slurries (usually including water) and gases with temperatures ranging from near 100 °C (212 °F) to occasionally 2 °C (36 °F), they are not true (igneous) volcanoes as they produce no lava. About 86% of the gas released from these structures is methane, with much less carbon dioxide and nitrogen emitted. Ejected materials are often a slurry of fine solids suspended in liquids which may include water, which is frequently acidic or salty, and hydrocarbon fluids.