동해 남한국대지 퇴적물의 생물기원 성분 입도 분포의 특성과 고해양학적 의미

• Published in: Ocean and polar research Vol. 42; no. 3; pp. 249 - 261
• Main Authors: 장준호, 박장준, 김은정, 엄인권, Jang, Jun-Ho, Bahk, Jang-Jun, Kim, Eun-Jung, Um, In-Kwon
• Format: Journal Article
• Language: Korean
• Published: 한국해양과학기술원 01.09.2020
• Subjects: 해양학; East Sea; paleoceanography; grain composition; grain-size distribution; South Korea Plateau
• ISSN: 1598-141X; 2234-7313
• DOI: 10.4217/OPR.2020.42.3.249

This study details grain-size distributions (GSDs) of carbonate and biogenic opal fractions of the sediments retrieved from the South Korea Plateau in the East Sea and draws paleocanographic implications from them. The opal-fraction GSDs show fine modes of 10.3 ㎛ and coarse modes of 102.5 ㎛ on average. The fine-mode grains of opal fractions mainly consist of small diatoms and radiolarians including their broken frustules, while the coarse-mode grains are mostly comprised of large warm-water diatoms and radiolarians. Significant positive correlation between opal contents and abundances of the coarse-mode GSDs in the total GSDs suggests that the abundances of the coarse-mode GSDs were controlled by the increased surface productivity of warm-water diatoms during interglacial stages. The carbonate-fraction GSDs show fine modes of 2.4 ㎛ and coarse modes of 99.1 ㎛ on average. The fine-mode grains mainly consist of coccolithophores, while the coarse-mode grains are mostly comprised of intact or broken planktonic foraminifera. The abundances of coarse-mode and fine-mode GSDs were not correlated with carbonate contents, suggesting a complex control exerted by both the degree of carbonate dissolution and the productivity of coccolithophores on the carbonate-fraction GSDs.