This study examined the vertical distribution of conservative elements (Al, Fe, Li, and Cs) and trace metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) in sediment cores collected from the tidal flats of Yubudo in the Geum River estuary. Two sediment cores were obtained from different depositional environments: an estuary-proximal mudflat (Core A) and an offshore-influenced sandflat (Core B). These cores were subsampled at 2 cm intervals for ICP-MS analysis. The conservative elements displayed consistently higher concentrations in the finer-grained Core A, reflecting natural enrichment associated with silt and clay-dominated sediments. All seven trace metals were found to be below the Threshold Effect Level (TEL), indicating a low potential for ecological risk in both cores. The higher concentrations of trace metals observed in Core A were interpreted as natural enrichment due to the greater proportion of fine-grained, estuary-derived sediments rather than anthropogenic accumulation. These findings provide a geochemical baseline for understanding natural variability in the Yubudo tidal-flat system and offer crucial information for the future conservation and management of the tidal flats in the Geum River Estuary.

Abstract
1. 서 론
2. 재료 및 방법
    2.1. 조사 지역 및 조사 시기
    2.2. 주상코어 시료 채취 및 원소 분석
    2.3. 중금속 평가 기준 및 보존성 원소 활용
3. 결과 및 고찰
    3.1. 보존성 원소 (Al, Fe, Li, Cs)의 연직분포와정점 간 농도 차이
    3.2. 중금속 농도의 연직분포와 해양환경기준(TEL·PEL) 비교
    3.3. 금강하굿둑 건설 이후 유부도 갯벌의지화학적 변화
적 요
CRediT authorship contribution statement
Declaration of Competing Interest
사 사
REFERENCES

• 김지영(국립생태원 복원생태연구실 생태신기술팀) | Ji Yeong Kim (Ecological Technology Research Team, Division of Restoration Ecology Research, National Institute of Ecology, Seocheon 33657, Republic of Korea)
• 옥기영(국립생태원 복원생태연구실 생태신기술팀) | Giyoung Ock (Ecological Technology Research Team, Division of Restoration Ecology Research, National Institute of Ecology, Seocheon 33657, Republic of Korea) Corresponding author