Abstract
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.
Original language | English |
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Pages (from-to) | 7663-7672 |
Number of pages | 10 |
Journal | Geophysical Research Letters |
Volume | 42 |
Issue number | 18 |
Early online date | 27 Aug 2015 |
DOIs | |
Publication status | Published - 28 Sept 2015 |
Keywords
- abyssal hill
- abyssal mountain
- benthos
- carbon
- amino acid
- fluid dynamics