Methane clathrates can form from biogenic methane, thermogenic methane, or a mix of the two. Hydrocarbons, material containing sulfur, carbon dioxide, carbon monoxide, methane and ammonia were present. Natural seeps of methane and carbon dioxide occur. These include oxygen, nitrogen, carbon dioxide, hydrogen and methane. Coal mining releases methane, a potent greenhouse gas. It also has an important role in eliminating some greenhouse gases like methane and ozone. Carbon monoxide is a nutrient for methanogenic archaea, which reduce it to methane using hydrogen. Gas pipelines distribute large amounts of natural gas, of which methane is the principal component. The Arctic region is one of the many natural sources of the greenhouse gas methane. It is also often used in conjunction with steam reforming of methane and other hydrocarbons. Detectors are also available that warn of carbon monoxide and/or explosive gas (methane, propane, etc.). Other major mineral reserves include those of coal, coalbed methane, manganese and dolomite. The Rocky Mountains contain several sedimentary basins that are rich in coalbed methane. These processes begin with the reaction of water and natural gas (mainly methane). In 1886 Karol Olszewski liquefied methane, the primary constituent of natural gas.