洋壳蛇纹岩——生烃源

The Serpentinite in Oceanic Crust-Source Rock

介绍了用含有溶解二氧化碳的海水对大洋岩心进行水解的过程。结果表明,此水解过程可导致生成非生物成因的甲烷和氢。在含铁超基性岩的蛇纹岩化作用过程中,通过二价铁氧化为三价铁、二氧化碳还原,可以生成大量的甲烷。同时,海水经二价铁的分解,释放出氢。大洋岩石中甲烷的生成速度可达9×106t/a,氢的生成速度达9.7×106t/a.其中,大量的甲烷和氢因细菌的作用而发生酸化,除一部分气体散布到大气中之外,其余以热液或天然气水合物形式在大洋中储(沉)积下来。

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,occupying hydrotherms,or is saved as gas hydrates in ocean sediments,but the essential part of these gases is allocated in the atmosphere.