Abstract: The processes of hydration of oceanic core rocks by ocean water containing a dissloved carbon dioxide are considered in the article. It is shown, that these processes lead to generation of abiogenous methane and hydrogen. The greater amount of methane is derivated during the process of serpentinization of ferruginous ultrabasite rocks at the expense of oxidizing divalent iron up to its tribalen state and restoring of carbon dioxide up to methane. Thus hydrogen is released owing to dissociations of ocean water on dibalent iron. The generation rate of methane in the oceanic core reaches 9 million t/year, and hydrogen 9.7 t/year. The considerable part of methane and hydrogen acidifies by bacteria, occupy ing hydrotherms, or is saved as gas hydrates in ocean sediments, but the essential part of these gases is allocated in the atmosphere.

Key words: oceanic crust, serpentinite, source bed, natural gas, hydrate