【摘要】 测试了 37个南海中部北部、南部陆坡以及深海平原表层近代沉积物中的烃类气体的组成和 14个样品的甲烷碳同位素组成,北部陆坡区甲烷的归一化平均含量 94%,南部陆坡区 91%,深海平原 95%,重烃含量分布在 0 ~20%,总体平均为 9%,甲烷的碳同位素陆坡区为-30‰~-40‰,深海平原区在-24‰到-36‰之间。陆坡区烃类气体主要为热成因气,深海平原中的烃类气体可能由与火山活动有关的有机成因气以及通过断裂到达海洋表层沉积物的无机成因气组成。更多还原

【Abstract】 37samples of hydrocarbon gases in the recent sediment from South China Sea were analyzed for their geochemical composition and 14 samples were analyzed for isotopic composition of Methane. The relative average content of methane in the northern continental slope, southern continental slope and deep-sea plain is 95%, 91% and 94%, respectively. The content of heavy hydrocarbon gas is between 0 to 20%, average 9%. The isotopic composition of methane in continental slope area ranged form 30 to 40 and 24 to 36 in deep-sea plain area. Those data show that hydrocarbon gases in the recent sediment from continental slope area maybe come from thermal genetic gases and those from deep sea plain area may have two resources which either might be originated from biogenetic gases or from non-biogenetic gases via fault.更多还原