Impact of methane seeps on the local carbon‐isotope record: a case study from a Late Jurassic hemipelagic section
Impact of methane seeps on the local carbon‐isotope record: a case study from a Late Jurassic hemipelagic section
复制标题
DOI：
10.1111/j.1365-3121.2007.00744.x
复制
发表时间：
2007-08
期刊：
影响因子：
2.4
通讯作者：
Beat Louis-Schmid;Pauline Rais;Dmitry Logvinovich;S. Bernasconi;H. Weissert
中科院分区：
文献类型：
--
作者：
Beat Louis-Schmid;Pauline Rais;Dmitry Logvinovich;S. Bernasconi;H. Weissert
An Oxfordian (Late Jurassic) hemipelagic succession from Beauvoisin (SE France) contains a pronounced, short‐lived negative excursion in the bulk‐carbonate carbon‐isotope record, with an amplitude of 4‰. It was shown previously that the Beauvoisin paleoenvironment was impacted by hydrocarbon seepage. New isotopic data corroborate that methane was a significant constituent of these hydrocarbons. The negative excursion was caused by transient enhanced precipitation of 13C‐depleted carbonate, mediated by anaerobic oxidation of methane. Despite its local diagenetic origin, the Beauvoisin excursion is similar in shape and duration to globally recognized negative C‐isotope excursions that have been related to catastrophic, massive dissociation of methane hydrate. Shape and duration of negative excursions therefore cannot be used as an argument when determining their origin if they have not been shown to represent a global perturbation of the carbon cycle.
