남극 맥스웰만의 큰띠조개에 대한 안정동위원소와 미량원소 성분을 이용한 과거 고해양변화 연구

Abstract

The gravity core was obtained from the slope of the South Scotia Sea, West Antarctica. Core sediments are mainly composed of laminated diatomaceous ooze and homogeneous silty clay. Stratigraphy is based on total organic carbon content and magnetic susceptibility with five radiocarbon dates. Oxygen, carbon and nitrogen isotopes of diatoms and diatom-bound organic matter are analyzed. The δ18O record show that the ~1.5‰ variations in Last Glacial to Holocene reflect the isotopic composition changes of surface seawater. It also shows that the transient depleted signals during deglaciation may imply the melt-water input. The δ13C values are depleted during Last Glacial relative to the Holocene, which indicate lower productivity during cold period. The anti-correlation patterns between δ15N and δ13C values during Last Glacial and Neoglacial periods may result from the restricted vertical mixing due to the sea ice extension.