동해 한국대지 심해 탄산염퇴적물의 산상

Title
동해 한국대지 심해 탄산염퇴적물의 산상
Alternative Title
The first occurrence of the Miocene shallow marine carbonate sediments of the deep-sea core (MO-PC1A), Korea Plateau, East Sea, Korea
Author(s)
우경식; 김진경; 석봉출; 현상민; 김정무; 윤석훈
KIOST Author(s)
Hyun, Sangmin(현상민)
Publication Year
2005-02-17
Abstract
East Sea is a semi-isolated marginal sea with an average depth of 1,350m (maximum depth of 3,700m), and comprises three basins such as the Japan, Yamato, and Ulleung Basins.The Korea Plateau is located north of the Ulleung Basin and is less than 1,000m deep.One piston core from the top of the Korea Plateau was obtained at the depth of 758.7m.The core is 587cm long, and is mostly composed of sandy mud and muddy sand with abundant foraminifers.The sediments also contain a few layers of tuffaceous sands and often include granule-sized volcanic fragments.Especially notable are the lowermost part of the core (431~587cm), which consists of carbonate sediments containing sand- to granule-sized bioclastic sands. Radiocarbon dating of some selected foraminifers (G. bulloides & N. pachyderma) shows 6,00235 BP and 45,2001700 BP at the core interval of 7~9cm and 83~85cm, respectively.In contrast, 87Sr/86Sr initial ratio of the lower carbonate sands ranges from 0.70881 to 0.70883 (at the core intervals of 506~507, 526~527, 542~543, 558~559, 571~572, and 586~587cm) and the data indicate the sediment age of 12.8~13.4 Ma (Middle Miocene). The lowermost part of the core (431~587cm), composed of calcareous bioclasts, can be divided into two units (431~490cm and 490~587cm) according to lithology and composition of the sediments. The sediments of the lower unit ranges from -1 to 1 in size with minor contribution of the sediments smaller than 2.This sediment is mostly composed of bioclasts of mollusks and barnacles along with planktonic and benthic foraminifers, bryozoans, echinoids, ostracodes and volcanic rock fragments. In this unit, mean grain size tend to decrease upwards, and this coincides with the abundance of the grains (>-1).The upper unit shows the overall fining-upward sequence.The upper part of the upper unit (431~490cm) is mostly composed of planktonic foraminifers, however the lower part of the upper unit contains more mollusks, benthic foraminifers, bryozoans, echi
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/31584
Bibliographic Citation
제1회 동아시아몬순진화 및 고기후변화 국제 심포지움, pp.45, 2005
Publisher
한국해양연구원
Type
Conference
Language
English
Publisher
한국해양연구원
Related Researcher
Research Interests

Marine environmentology,Marine environmentology,Organic chemistry,해양환경학,화학해양학,유기화학

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