Temperature dependence of organic matter remineralization in deeply-buried marine sediments

摘要: Abstract Assuming that the temperature dependence of sediment organic matter remineralization can be described by Arrhenius equation, is highly refractory at seafloor temperatures (~ 2–3 °C) should become more reactive depths several hundred meters due to burial and heating natural geothermal gradient. Results obtained using a coupled non-linear reactive-transport model support this suggestion. For deeply-buried marine sediments (i.e., those found 100s below seafloor) results predict occurrence deep zone methanogenesis separated relatively thick region in which methane diffuses upwards oxidized downward diffusing sulfate. This depth zonation biogeochemical processes sharp contrast observed nearshore where sulfate reduction generally occur much closer vertical proximity. Model presented here also provide simple mechanistic explanation for linear pore water profiles are common many continental margin sediments. Linear gradients often taken as an indirect indicator gas hydrate although suggest does not necessarily always have case. Application hydrate-containing on Blake Ridge yields good agreement with data, microbial rate studies these situ and/or near stability may play important role supplying hydrates.