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An abyssal hill fractionates organic and inorganic matter in deep‐sea surface sediments
Author(s) -
Turnewitsch Robert,
Lahajnar Niko,
Haeckel Matthias,
Christiansen Bernd
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl065658
Subject(s) - abyssal plain , abyssal zone , organic matter , biogeochemical cycle , sediment , geology , context (archaeology) , total organic carbon , deep sea , biogeochemistry , oceanography , sediment trap , sedimentary organic matter , calcite , benthic zone , earth science , environmental science , geochemistry , environmental chemistry , geomorphology , ecology , chemistry , paleontology , biology
Current estimates suggest that more than 60% of the global seafloor are covered by millions of abyssal hills and mountains. These features introduce spatial fluid‐dynamic “granularity” whose influence on deep‐ocean sediment biogeochemistry is unknown. Here we compare biogeochemical surface‐sediment properties from a fluid‐dynamically well‐characterized abyssal hill and upstream plain: (1) In hill sediments, organic‐carbon and ‐nitrogen contents are only about half as high as on the plain while proteinaceous material displays less degradation; (2) on the hill, more coarse‐grained sediments (reducing particle surface area) and very variable calcite contents (influencing particle surface charge) are proposed to reduce the extent, and influence compound‐specificity, of sorptive organic‐matter preservation. Further studies are needed to estimate the representativeness of the results in a global context. Given millions of abyssal hills and mountains, their integrative influence on formation and composition of deep‐sea sediments warrants more attention.