TY - JOUR
T1 - A multiproxy analysis of sedimentary organic carbon in the Changjiang Estuary and adjacent shelf
AU - Yao, Peng
AU - Yu, Zhigang
AU - Bianchi, Thomas S.
AU - Guo, Zhigang
AU - Zhao, Meixun
AU - Knappy, Chris S.
AU - Keely, Brendan J.
AU - Zhao, Bin
AU - Zhang, Tingting
AU - Pan, Huihui
AU - Wang, Jinpeng
AU - Li, Dong
PY - 2015/7
Y1 - 2015/7
N2 - Surface sediments from the Changjiang Estuary and adjacent shelf were analyzed using a variety of bulk and molecular techniques, including grain size composition, sediment surface area (SSA), elemental composition (C, N), stable carbon isotopic composition (δ13C), n-alkanes, lignin phenols, and glycerol dialkyl glycerol tetraether lipids to obtain a more comprehensive understanding of the sources and fate of sedimentary organic carbon (SOC) in this dynamic region. Bulk N/C ratios of 0.09 to 0.15, δ13C of -24.4‰ to -21.1‰, branched/isoprenoid tetraether index of 0 to 0.74, n-alkane content of 0.02 to 0.37mgg-1 organic carbon (OC), and lignin content (Λ8) of 0.10 to 1.46mg/100mg OC and other related molecular indices in these samples indicate a mixed source of marine, soil, and terrestrial plant-derived OC in the study area. A three-end-member mixing model using principal component analysis (PCA) factors as source markers and based on Monte Carlo (MC) simulation was constructed to estimate the relative contributions of OC from different sources. Compared with traditional mixing models, commonly based on a few variables, this newly developed PCA-MC model supported bulk and biomarker data and yielded a higher-resolution OC inputs to different subregions of this system. In particular, the results showed that the average contributions of marine, soil, and terrestrial OC in the study area were 35.3%, 47.0%, and 17.6%, and the highest contribution from each OC source was mainly observed in the shelf, inner estuary, and coastal region, respectively.
AB - Surface sediments from the Changjiang Estuary and adjacent shelf were analyzed using a variety of bulk and molecular techniques, including grain size composition, sediment surface area (SSA), elemental composition (C, N), stable carbon isotopic composition (δ13C), n-alkanes, lignin phenols, and glycerol dialkyl glycerol tetraether lipids to obtain a more comprehensive understanding of the sources and fate of sedimentary organic carbon (SOC) in this dynamic region. Bulk N/C ratios of 0.09 to 0.15, δ13C of -24.4‰ to -21.1‰, branched/isoprenoid tetraether index of 0 to 0.74, n-alkane content of 0.02 to 0.37mgg-1 organic carbon (OC), and lignin content (Λ8) of 0.10 to 1.46mg/100mg OC and other related molecular indices in these samples indicate a mixed source of marine, soil, and terrestrial plant-derived OC in the study area. A three-end-member mixing model using principal component analysis (PCA) factors as source markers and based on Monte Carlo (MC) simulation was constructed to estimate the relative contributions of OC from different sources. Compared with traditional mixing models, commonly based on a few variables, this newly developed PCA-MC model supported bulk and biomarker data and yielded a higher-resolution OC inputs to different subregions of this system. In particular, the results showed that the average contributions of marine, soil, and terrestrial OC in the study area were 35.3%, 47.0%, and 17.6%, and the highest contribution from each OC source was mainly observed in the shelf, inner estuary, and coastal region, respectively.
KW - Changjiang Estuary
KW - Chemical biomarkers
KW - Mixing model
KW - Monte Carlo simulation
KW - Principal component analysis
KW - Sedimentary organic carbon
UR - http://www.scopus.com/inward/record.url?scp=84937785172&partnerID=8YFLogxK
U2 - 10.1002/2014JG002831
DO - 10.1002/2014JG002831
M3 - Article
SN - 2169-8953
VL - 120
SP - 1407
EP - 1429
JO - Journal of Geophysical Research: Biogeosciences
JF - Journal of Geophysical Research: Biogeosciences
IS - 7
ER -