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标题：Provenance discrimination of the last glacial sediments from the northeastern South China Sea and its paleoenvironmental indications
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作者：Fang Liu ; Chupeng Yang ; Xiaohong Chang 等
期刊名称：Terrestrial Atmospheric and Oceanic Sciences
印刷版ISSN：1017-0839
出版年度：2018
卷号：29
期号：2
页码：131-148
DOI：10.3319/TAO.2017.07.31.01
出版社：Chinese Geoscience Union
摘要：A total of 849 core samples collected from two drilling core STD235 and ZSQD289 in the northeastern South China Sea were analyzed for elemental composition including total organic carbon (TOC), total nitrogen (TN), stable carbon and nitrogen isotopic composition (δ 13 C, δ 15 N), and clay mineral composition. Based on clay mineral assemblages and organic geochemistry characteristics, it is supposed that the terrestrial source for sediments at STD235 and ZSQD289 is mainly from southwestern Taiwan. Moreover, the sedimentary organic matter of site ZSQD289 was probably directly inputted from southwestern Taiwan submarine canyon, while the sedimentary organic matter of core STD235 was probably transported by deep water current. The chronology suggested that it covered the record since ~19.7 and 34.6 ka BP in site STD235 and ZSQD289 respectively. Before the Last Glacial Maximum (LGM), high TOC/TN ratios with low δ 13 C and δ 15 N values might indicate that terrestrial organic input and nitrogen fixation was enhanced. During the LGM, gradually increased TOC, TN, δ 13 C, and δ 15 N values might result from the enhanced burial of organic carbon and higher marine primary production constrained by the strong winter monsoon. TOC/TN ratios and δ 13 C values generally present a decreased trend from LGM to Holocene (18 - 11 cal ka BP), strongly correlated to the terrestrial organic input and marine primary production reduced during this period. Since Holocene, the terrestrial organic input to both sites further reduced and maintained a low level, in according with a high sea level and a gradual intensified summer monsoon.
关键词：Northeastern South China Sea; Sediment source; The last glacial period; Paleoenvironment;