DOI: 10.1016/j.epsl.2021.116759
论文题名: Controls on the abundance, provenance and age of organic carbon buried in continental margin sediments
作者: Ausín B. ; Bruni E. ; Haghipour N. ; Welte C. ; Bernasconi S.M. ; Eglinton T.I.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 558 语种: 英语
中文关键词: continental margins
; grain size
; hydrodynamic sorting
; organic carbon
; radiocarbon age
英文关键词: Deposition
; Grain size and shape
; Hydrodynamics
; Screening
; Sedimentology
; Sediments
; Silt
; Biological productivity
; Depositional environment
; Hydrodynamic characteristics
; Hydrodynamic particles
; Hydrodynamic process
; Preservation of organic matters
; Sedimentary sequence
; Stable isotopic compositions
; Organic carbon
; continental margin
; depositional environment
; grain size
; hydrodynamics
; isotopic composition
; marine sediment
; organic carbon
; organic matter
; provenance
; radiocarbon dating
; sediment chemistry
; sedimentary sequence
; stable isotope
; structural control
英文摘要: Continental margins play a fundamental role in the carbon cycle as primary oceanic locations of organic carbon (OC) burial. However, gaps remain in our understanding of factors controlling the distribution and preservation of organic matter (OM) in these heterogeneous and dynamic systems. In particular, the impact of hydrodynamic processes on the age, abundance, and stable isotopic composition of sedimentary OC is poorly constrained. Here, we characterize the OC present in bulk and grain-size sediment fractions from seven continental margin settings. Our results reveal that hydrodynamic particle sorting processes exert a ubiquitous influence on the radiocarbon age of OC. Both, hydrodynamic characteristics of mineral particles and the nature of their interactions with OM influence sedimentary OC content, whereas no significant influence of either effect is manifested in corresponding δ13C values. Since OC preferentially resides within the fine silt fraction (2-8 μm), and this fraction accounts for a substantial fraction of the bulk sediment mass, translocation and subsequent re-deposition of distant fine silt has the greatest potential to distort local OC signatures relative to those associated with clay or coarse silt fractions. We suggest that the magnitude of differences in 14C-age and OC content among grain-size fractions, determined by the interplay of hydrodynamic sorting and other site-specific processes, allow three different categories of depositional environment to be defined: initial, stable, and mature. Each domain is characterized by different degrees of vertical and lateral OC supply that reflect influences of local biological productivity and carbon export from overlying surface waters and physical forcing that drive hydrodynamic processes. This generic framework may serve as a guide to refine assessment of OC burial and to constrain the magnitude of potential aliasing among co-eval proxy signals in continental margin sedimentary sequences. © 2021 The Author(s) Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165401
Appears in Collections: 气候变化与战略
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作者单位: Geological Institute, ETH Zurich, Switzerland; Geology Department, Salamanca University, Salamanca, Spain; Laboratory of Ion Beam Physics, ETH Zurich, Switzerland
Recommended Citation:
Ausín B.,Bruni E.,Haghipour N.,et al. Controls on the abundance, provenance and age of organic carbon buried in continental margin sediments[J]. Earth and Planetary Science Letters,2021-01-01,558