Timescales for the development of methanogenesis and free gas layers in recently-deposited sediments of Arkona Basin (Baltic Sea)

[摘要] Arkona Basin (southwestern Baltic Sea) is a seasonally-hypoxic basincharacterized by the presence of free methane gas in its youngestorganic-rich muddy stratum. Through the use of reactive transport models,this study tracks the development of the methane geochemistry in Arkona Basinas this muddy sediment became deposited during the last 8 kyr. Four cores aremodeled each pertaining to a unique geochemical scenario according to theirrespective contemporary geochemical profiles. Ultimately the thickness of themuddy sediment and the flux of particulate organic carbon are crucial indetermining the advent of both methanogenesis and free methane gas, thetimescales over which methanogenesis takes over as a dominant reactionpathway for organic matter degradation, and the timescales required for freemethane gas to form.

[学科分类] 地球化学与岩石