Changes in detrital sediment supply to the central Yellow Sea since the last deglaciation
<p>The sediment supply to the central Yellow Sea since the last deglaciation was uncovered through clay mineralogy and geochemical analysis of core 11YS-PCL14 in the Central Yellow Sea Mud (CYSM). The core can be divided into four units based on the various proxies, such as grain size, clay mi...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-10-01
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| Series: | Ocean Science |
| Online Access: | https://os.copernicus.org/articles/16/1247/2020/os-16-1247-2020.pdf |
| Summary: | <p>The sediment supply to the central Yellow Sea since the
last deglaciation was uncovered through clay mineralogy and geochemical
analysis of core 11YS-PCL14 in the Central Yellow Sea Mud (CYSM). The core
can be divided into four units based on the various proxies, such as grain
size, clay mineralogy, geochemistry, and Sr and Nd isotopes: Unit 4 (700–520 cm; 15.5–14.8 ka), Unit 3 (520–310 cm; 14.8–12.8 ka), Unit 2 (310–130 cm;
12.8–8.8 ka), and Unit 1 (130–0 cm; <span class="inline-formula"><8.8</span> ka). Unit 2 is subdivided
into two subunits, Unit 2-2 (310–210 cm; 12.8–10.5 ka) and Unit 2-1 (210–130 cm; 10.5–8.8 ka), according to smectite content. Comparison of the clay
mineral compositions, rare earth elements, and <span class="inline-formula"><i>ε</i></span>Nd indicate
distinct provenance shifts in core 11YS-PCL14. Moreover, the integration of
clay mineralogical and geochemical indices show different origins according
to particle size. During the late last deglaciation (Units 3 and 4,
15.5–12.8 ka), Unit 4 sediments originated from all potential provenance
rivers, such as the Huanghe, Changjiang, and western Korean rivers, while the
source of coarse sediments changed to the Huanghe beginning with Unit 3.
Fine-grained sediment was still supplied from all rivers during the deposition
of Unit 3. Early Holocene (Unit 2) sediments were characterized by
oscillating grain size, clay minerals, and moderate <span class="inline-formula"><i>ε</i></span>Nd values.
In this period, the dominant fine-sediment provenance changed from the
Huanghe to the Changjiang, whereas coarse sediments most likely originated
from western Korean rivers. The Unit 1 CYSM sediments were sourced primarily
from the Changjiang, along with minor contributions from the western Korean
rivers. Possible transport mechanisms concerning such changes in the
sediment provenance include paleo-river pathways, tidal stress evolution,
and the development of the Yellow Sea Warm Current and coastal circulation
systems, depending on the sea level fluctuations.</p> |
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| ISSN: | 1812-0784 1812-0792 |