Proskurowski Giora, Lilley Marvin D, Seewald Jeffery S, Früh-Green Gretchen L, Olson Eric J, Lupton John E, Sylva Sean P, Kelley Deborah S
School of Oceanography, University of Washington, Seattle, WA 98195, USA.
Science. 2008 Feb 1;319(5863):604-7. doi: 10.1126/science.1151194.
Low-molecular-weight hydrocarbons in natural hydrothermal fluids have been attributed to abiogenic production by Fischer-Tropsch type (FTT) reactions, although clear evidence for such a process has been elusive. Here, we present concentration, and stable and radiocarbon isotope, data from hydrocarbons dissolved in hydrogen-rich fluids venting at the ultramafic-hosted Lost City Hydrothermal Field. A distinct "inverse" trend in the stable carbon and hydrogen isotopic composition of C1 to C4 hydrocarbons is compatible with FTT genesis. Radiocarbon evidence rules out seawater bicarbonate as the carbon source for FTT reactions, suggesting that a mantle-derived inorganic carbon source is leached from the host rocks. Our findings illustrate that the abiotic synthesis of hydrocarbons in nature may occur in the presence of ultramafic rocks, water, and moderate amounts of heat.
天然热液流体中的低分子量碳氢化合物一直被认为是通过费托（Fischer-Tropsch type，FTT）反应进行非生物生成的，尽管尚未找到这一过程的确切证据。在此，我们展示了来自超镁铁质岩为主的失落之城热液区富含氢气流体中溶解碳氢化合物的浓度、稳定同位素和放射性碳同位素数据。C1至C4碳氢化合物稳定碳同位素和氢同位素组成呈现出明显的“反向”趋势，这与费托反应成因相符。放射性碳证据排除了海水中碳酸氢盐作为费托反应碳源的可能性，表明地幔来源的无机碳源是从寄主岩石中浸出的。我们的研究结果表明，自然界中碳氢化合物的非生物合成可能发生在存在超镁铁质岩、水和适量热量的环境中。
