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Presentation Type

Presentation

Full Name of Faculty Mentor

Zhixiong Shen, Marine Science

Major

Marine Science

Presentation Abstract

Coarseness of floodplain sediment is indicative of extreme paleoflood, but not their causes. Diatoms, abundant in fluvial deposits, may reveal the causes of extreme flooding due to their sensitivity to environment changes, but their correlation to extreme flooding has not been established. This study aims testing whether diatom assemblages in fluvial deposits is sensitive to extreme river flooding. Deposits from a sediment core taken from an oxbow lake of the Waccamaw River were identified as flooding or non-flooding based on grain-size analysis. Diatoms were subsequently extracted and purified from the sediments using a method modified from Morley et al. (2004) and counted. The diatom assemblage is dominated by the genus Aulacoseria in flood deposits, but Eunotia and Pinnularia in non-flood deposits. The assemblages in flood and non-flood deposits are different according to the Bray-Curtis Similarity test, suggesting that diatom assemblage may be used as a paleoflood indicator.

Location

Virtual Session Room 1

Start Date

21-4-2021 2:50 PM

End Date

21-4-2021 3:10 PM

Disciplines

Oceanography

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Apr 21st, 2:50 PM Apr 21st, 3:10 PM

Diatom Assemblage Used as an Indicator of Extreme Inland Flooding

Virtual Session Room 1

Coarseness of floodplain sediment is indicative of extreme paleoflood, but not their causes. Diatoms, abundant in fluvial deposits, may reveal the causes of extreme flooding due to their sensitivity to environment changes, but their correlation to extreme flooding has not been established. This study aims testing whether diatom assemblages in fluvial deposits is sensitive to extreme river flooding. Deposits from a sediment core taken from an oxbow lake of the Waccamaw River were identified as flooding or non-flooding based on grain-size analysis. Diatoms were subsequently extracted and purified from the sediments using a method modified from Morley et al. (2004) and counted. The diatom assemblage is dominated by the genus Aulacoseria in flood deposits, but Eunotia and Pinnularia in non-flood deposits. The assemblages in flood and non-flood deposits are different according to the Bray-Curtis Similarity test, suggesting that diatom assemblage may be used as a paleoflood indicator.