Tracing Sediment Erosion in the Yangtze River Subaqueous Delta Using Magnetic Methods

Can Ge, Weiguo Zhang, Chenyin Dong, Feng Wang, Huan Feng, Jianguo Qu, Lizhong Yu

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)

Abstract

We assessed the usefulness of magnetic properties for tracing sediment erosion in a deltaic environment. Surface and core sediments from the Yangtze River subaqueous delta were subjected to magnetic, granulometric, geochemical, and radionuclide analyses. Based on magnetic properties and particle size, the surface sediments can be divided into three groups. Groups I and II have a similar particle size distribution and geochemical composition, but the former has higher values of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM). We interpret Group I as consisting of modern sediments, while Group II represents previously buried sediments that have undergone significant reductive diagenesis and that have been subsequently exposed by erosion. Group III has coarser particle size, which reflects the mixing of delta sediments with Pleistocene relict sands. Two cores from the areas occupied by Groups I and II have significantly different magnetic profiles. Core A3-4 (Group II) records a partial loss of magnetic mineral concentration due to diagenesis and has much lower χ, SIRM, and S −300 values than core A6-2 (Group I). Radionuclide dating reveals that core A3-4 sediments are older. We conclude that core A3-4 location has undergone erosion, which is consistent with recent bathymetric survey results. We propose that the ratio of SIRM/Fe can be potentially used to trace mobilized old sediment in this environment. Our study demonstrates that magnetic properties provide a robust approach for studying sediment dynamics in this type of environment. In addition, our findings provide insights into the nature of biogeochemical processes associated with deltaic erosion.

Original languageEnglish
Pages (from-to)2064-2078
Number of pages15
JournalJournal of Geophysical Research: Earth Surface
Volume122
Issue number11
DOIs
StatePublished - 1 Nov 2017

Fingerprint

magnetic method
Yangtze River
tracing
rivers
erosion
Erosion
Sediments
sediments
Rivers
river
magnetic properties
sediment
remanent magnetization
magnetic property
Magnetization
Magnetic properties
particle size
saturation
methodology
radionuclides

Keywords

  • Yangtze subaqueous delta
  • diagenesis
  • erosion
  • magnetic properties

Cite this

Ge, Can ; Zhang, Weiguo ; Dong, Chenyin ; Wang, Feng ; Feng, Huan ; Qu, Jianguo ; Yu, Lizhong. / Tracing Sediment Erosion in the Yangtze River Subaqueous Delta Using Magnetic Methods. In: Journal of Geophysical Research: Earth Surface. 2017 ; Vol. 122, No. 11. pp. 2064-2078.
@article{de70102e401f4aca8afe3e1c94c0c7a4,
title = "Tracing Sediment Erosion in the Yangtze River Subaqueous Delta Using Magnetic Methods",
abstract = "We assessed the usefulness of magnetic properties for tracing sediment erosion in a deltaic environment. Surface and core sediments from the Yangtze River subaqueous delta were subjected to magnetic, granulometric, geochemical, and radionuclide analyses. Based on magnetic properties and particle size, the surface sediments can be divided into three groups. Groups I and II have a similar particle size distribution and geochemical composition, but the former has higher values of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM). We interpret Group I as consisting of modern sediments, while Group II represents previously buried sediments that have undergone significant reductive diagenesis and that have been subsequently exposed by erosion. Group III has coarser particle size, which reflects the mixing of delta sediments with Pleistocene relict sands. Two cores from the areas occupied by Groups I and II have significantly different magnetic profiles. Core A3-4 (Group II) records a partial loss of magnetic mineral concentration due to diagenesis and has much lower χ, SIRM, and S −300 values than core A6-2 (Group I). Radionuclide dating reveals that core A3-4 sediments are older. We conclude that core A3-4 location has undergone erosion, which is consistent with recent bathymetric survey results. We propose that the ratio of SIRM/Fe can be potentially used to trace mobilized old sediment in this environment. Our study demonstrates that magnetic properties provide a robust approach for studying sediment dynamics in this type of environment. In addition, our findings provide insights into the nature of biogeochemical processes associated with deltaic erosion.",
keywords = "Yangtze subaqueous delta, diagenesis, erosion, magnetic properties",
author = "Can Ge and Weiguo Zhang and Chenyin Dong and Feng Wang and Huan Feng and Jianguo Qu and Lizhong Yu",
year = "2017",
month = "11",
day = "1",
doi = "10.1002/2017JF004403",
language = "English",
volume = "122",
pages = "2064--2078",
journal = "Journal of Geophysical Research: Earth Surface",
issn = "2169-9003",
publisher = "Wiley-Blackwell",
number = "11",

}

Tracing Sediment Erosion in the Yangtze River Subaqueous Delta Using Magnetic Methods. / Ge, Can; Zhang, Weiguo; Dong, Chenyin; Wang, Feng; Feng, Huan; Qu, Jianguo; Yu, Lizhong.

In: Journal of Geophysical Research: Earth Surface, Vol. 122, No. 11, 01.11.2017, p. 2064-2078.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Tracing Sediment Erosion in the Yangtze River Subaqueous Delta Using Magnetic Methods

AU - Ge, Can

AU - Zhang, Weiguo

AU - Dong, Chenyin

AU - Wang, Feng

AU - Feng, Huan

AU - Qu, Jianguo

AU - Yu, Lizhong

PY - 2017/11/1

Y1 - 2017/11/1

N2 - We assessed the usefulness of magnetic properties for tracing sediment erosion in a deltaic environment. Surface and core sediments from the Yangtze River subaqueous delta were subjected to magnetic, granulometric, geochemical, and radionuclide analyses. Based on magnetic properties and particle size, the surface sediments can be divided into three groups. Groups I and II have a similar particle size distribution and geochemical composition, but the former has higher values of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM). We interpret Group I as consisting of modern sediments, while Group II represents previously buried sediments that have undergone significant reductive diagenesis and that have been subsequently exposed by erosion. Group III has coarser particle size, which reflects the mixing of delta sediments with Pleistocene relict sands. Two cores from the areas occupied by Groups I and II have significantly different magnetic profiles. Core A3-4 (Group II) records a partial loss of magnetic mineral concentration due to diagenesis and has much lower χ, SIRM, and S −300 values than core A6-2 (Group I). Radionuclide dating reveals that core A3-4 sediments are older. We conclude that core A3-4 location has undergone erosion, which is consistent with recent bathymetric survey results. We propose that the ratio of SIRM/Fe can be potentially used to trace mobilized old sediment in this environment. Our study demonstrates that magnetic properties provide a robust approach for studying sediment dynamics in this type of environment. In addition, our findings provide insights into the nature of biogeochemical processes associated with deltaic erosion.

AB - We assessed the usefulness of magnetic properties for tracing sediment erosion in a deltaic environment. Surface and core sediments from the Yangtze River subaqueous delta were subjected to magnetic, granulometric, geochemical, and radionuclide analyses. Based on magnetic properties and particle size, the surface sediments can be divided into three groups. Groups I and II have a similar particle size distribution and geochemical composition, but the former has higher values of magnetic susceptibility (χ) and saturation isothermal remanent magnetization (SIRM). We interpret Group I as consisting of modern sediments, while Group II represents previously buried sediments that have undergone significant reductive diagenesis and that have been subsequently exposed by erosion. Group III has coarser particle size, which reflects the mixing of delta sediments with Pleistocene relict sands. Two cores from the areas occupied by Groups I and II have significantly different magnetic profiles. Core A3-4 (Group II) records a partial loss of magnetic mineral concentration due to diagenesis and has much lower χ, SIRM, and S −300 values than core A6-2 (Group I). Radionuclide dating reveals that core A3-4 sediments are older. We conclude that core A3-4 location has undergone erosion, which is consistent with recent bathymetric survey results. We propose that the ratio of SIRM/Fe can be potentially used to trace mobilized old sediment in this environment. Our study demonstrates that magnetic properties provide a robust approach for studying sediment dynamics in this type of environment. In addition, our findings provide insights into the nature of biogeochemical processes associated with deltaic erosion.

KW - Yangtze subaqueous delta

KW - diagenesis

KW - erosion

KW - magnetic properties

UR - http://www.scopus.com/inward/record.url?scp=85038034920&partnerID=8YFLogxK

U2 - 10.1002/2017JF004403

DO - 10.1002/2017JF004403

M3 - Article

VL - 122

SP - 2064

EP - 2078

JO - Journal of Geophysical Research: Earth Surface

JF - Journal of Geophysical Research: Earth Surface

SN - 2169-9003

IS - 11

ER -