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Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers

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Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers. / Hernández-Sánchez, Maria T.; LaRowe, Douglas E.; Deng, Feifei; Homoky, William B.; Browning, Thomas J.; Martin, Patrick; Mills, Rachel A.; Pancost, Richard D.

In: Organic Geochemistry, Vol. 76, 01.11.2014, p. 220-234.

Research output: Contribution to journalArticle

Harvard

Hernández-Sánchez, MT, LaRowe, DE, Deng, F, Homoky, WB, Browning, TJ, Martin, P, Mills, RA & Pancost, RD 2014, 'Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers', Organic Geochemistry, vol. 76, pp. 220-234. https://doi.org/10.1016/j.orggeochem.2014.08.006

APA

Hernández-Sánchez, M. T., LaRowe, D. E., Deng, F., Homoky, W. B., Browning, T. J., Martin, P., ... Pancost, R. D. (2014). Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers. Organic Geochemistry, 76, 220-234. https://doi.org/10.1016/j.orggeochem.2014.08.006

Vancouver

Hernández-Sánchez MT, LaRowe DE, Deng F, Homoky WB, Browning TJ, Martin P et al. Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers. Organic Geochemistry. 2014 Nov 1;76:220-234. https://doi.org/10.1016/j.orggeochem.2014.08.006

Author

Hernández-Sánchez, Maria T. ; LaRowe, Douglas E. ; Deng, Feifei ; Homoky, William B. ; Browning, Thomas J. ; Martin, Patrick ; Mills, Rachel A. ; Pancost, Richard D. / Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers. In: Organic Geochemistry. 2014 ; Vol. 76. pp. 220-234.

Bibtex

@article{0ae202ce351b4559b46baec4fa562517,
title = "Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers",
abstract = "Sedimentary biomarker distributions can record ocean productivity and community structure, but their interpretation must consider alteration during organic matter (OM) export and burial. Large changes in the water column redox state are known to impact on the preservation of biomarkers, but more subtle variation in sediment redox conditions, characteristic of major modern ocean basins, have been less thoroughly investigated. Here we evaluate changes in biomarker distributions during sinking and burial across a nearshore to offshore transect in the southwestern Cape Basin (South East Atlantic), which includes a range of sedimentary environments. Biomarker concentrations and distributions in suspended particulate matter from the upper water column were determined and compared with underlying sedimentary biomarker accumulation rates and distributions. Biomarker distributions were similar in surface and subsurface waters, indicating that the OM signature is exported from the ocean mixed layer with minimal alteration. We show that, while export production (100m) is similar along this transect, 230Thxs-corrected biomarker accumulation rate varies by over an order of magnitude in sediments and is directly associated with sedimentary redox conditions, ranging from oxic to nitrogenous-ferruginous. Biomarker distributions were dominated by sterols in surface water, and by alkenones in underlying sediments, which we propose to be primarily the result of selective preservation. Notably, the difference in sediment O2 penetration depth was associated with relative biomarker preservation. Subtle variation in sedimentary redox conditions has a dramatic impact on the distribution of preserved biomarkers. We discuss mechanisms for preferential degradation of specific biomarkers within this setting.",
keywords = "Atlantic Ocean, Biomarker preservation, Paleoproductivity proxies",
author = "Hern{\'a}ndez-S{\'a}nchez, {Maria T.} and LaRowe, {Douglas E.} and Feifei Deng and Homoky, {William B.} and Browning, {Thomas J.} and Patrick Martin and Mills, {Rachel A.} and Pancost, {Richard D.}",
year = "2014",
month = "11",
day = "1",
doi = "10.1016/j.orggeochem.2014.08.006",
language = "English",
volume = "76",
pages = "220--234",
journal = "Organic Geochemistry",
issn = "0146-6380",
publisher = "Elsevier",

}

RIS - suitable for import to EndNote

TY - JOUR

T1 - Further insights into how sediment redox status controls the preservation and composition of sedimentary biomarkers

AU - Hernández-Sánchez, Maria T.

AU - LaRowe, Douglas E.

AU - Deng, Feifei

AU - Homoky, William B.

AU - Browning, Thomas J.

AU - Martin, Patrick

AU - Mills, Rachel A.

AU - Pancost, Richard D.

PY - 2014/11/1

Y1 - 2014/11/1

N2 - Sedimentary biomarker distributions can record ocean productivity and community structure, but their interpretation must consider alteration during organic matter (OM) export and burial. Large changes in the water column redox state are known to impact on the preservation of biomarkers, but more subtle variation in sediment redox conditions, characteristic of major modern ocean basins, have been less thoroughly investigated. Here we evaluate changes in biomarker distributions during sinking and burial across a nearshore to offshore transect in the southwestern Cape Basin (South East Atlantic), which includes a range of sedimentary environments. Biomarker concentrations and distributions in suspended particulate matter from the upper water column were determined and compared with underlying sedimentary biomarker accumulation rates and distributions. Biomarker distributions were similar in surface and subsurface waters, indicating that the OM signature is exported from the ocean mixed layer with minimal alteration. We show that, while export production (100m) is similar along this transect, 230Thxs-corrected biomarker accumulation rate varies by over an order of magnitude in sediments and is directly associated with sedimentary redox conditions, ranging from oxic to nitrogenous-ferruginous. Biomarker distributions were dominated by sterols in surface water, and by alkenones in underlying sediments, which we propose to be primarily the result of selective preservation. Notably, the difference in sediment O2 penetration depth was associated with relative biomarker preservation. Subtle variation in sedimentary redox conditions has a dramatic impact on the distribution of preserved biomarkers. We discuss mechanisms for preferential degradation of specific biomarkers within this setting.

AB - Sedimentary biomarker distributions can record ocean productivity and community structure, but their interpretation must consider alteration during organic matter (OM) export and burial. Large changes in the water column redox state are known to impact on the preservation of biomarkers, but more subtle variation in sediment redox conditions, characteristic of major modern ocean basins, have been less thoroughly investigated. Here we evaluate changes in biomarker distributions during sinking and burial across a nearshore to offshore transect in the southwestern Cape Basin (South East Atlantic), which includes a range of sedimentary environments. Biomarker concentrations and distributions in suspended particulate matter from the upper water column were determined and compared with underlying sedimentary biomarker accumulation rates and distributions. Biomarker distributions were similar in surface and subsurface waters, indicating that the OM signature is exported from the ocean mixed layer with minimal alteration. We show that, while export production (100m) is similar along this transect, 230Thxs-corrected biomarker accumulation rate varies by over an order of magnitude in sediments and is directly associated with sedimentary redox conditions, ranging from oxic to nitrogenous-ferruginous. Biomarker distributions were dominated by sterols in surface water, and by alkenones in underlying sediments, which we propose to be primarily the result of selective preservation. Notably, the difference in sediment O2 penetration depth was associated with relative biomarker preservation. Subtle variation in sedimentary redox conditions has a dramatic impact on the distribution of preserved biomarkers. We discuss mechanisms for preferential degradation of specific biomarkers within this setting.

KW - Atlantic Ocean

KW - Biomarker preservation

KW - Paleoproductivity proxies

UR - http://www.scopus.com/inward/record.url?scp=84907465109&partnerID=8YFLogxK

U2 - 10.1016/j.orggeochem.2014.08.006

DO - 10.1016/j.orggeochem.2014.08.006

M3 - Article

VL - 76

SP - 220

EP - 234

JO - Organic Geochemistry

JF - Organic Geochemistry

SN - 0146-6380

ER -