Biogenic and abiogenic sedimentation in the northern East China Sea in response to sea-level change during the Late Pleistocene
Biogenic and abiogenic sedimentation in the northern East China Sea in response to sea-level change during the Late Pleistocene
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DOI：
10.1016/j.gloplacha.2006.01.013
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发表时间：
2006-08
影响因子：
3.9
通讯作者：
H. Kawahata;M. Nohara;K. Aoki;K. Minoshima;L. Gupta
中科院分区：
文献类型：
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作者：
H. Kawahata;M. Nohara;K. Aoki;K. Minoshima;L. Gupta
为了了解陆地和海洋环境的波动响应海平面的变化，在过去的42 ky，我们调查了沉积的生物和非生物成分的核心MD 982195，收集从北方东海（ECS），在世界上最大的边缘海之一。氨基酸（AAs）是海洋有机质（OM）中的主要含氮化合物，可以被保护在生物源物质中并在分解过程中存活。总氨基酸与有机碳（OC）呈高度正相关（r=0.91; p<0.05），与总氮（TN）相关性较低（r=0.76; p<0.05）。因此，总的AAs和OC含量应反映初级生产力（PP）超过总氮在核心MD 982195。PP在42-15 ka期间基本稳定，在15-14 ka期间增加，并保持稳定，直到7 ka。从5 ka到现在，PP增加。高沉积速率区的高分辨率古环境重建是IECMS程序的主要目标，其主要原因是成岩物质的丰富供应。成岩物质与非树栖花粉（NAP）丰度的正相关性表明，成岩物质和NAP主要是从沿海低地在冰期期间的海平面大幅度下降所造成的。海洋表面温度和盐度的大的千年尺度波动并不总是对应于OC和成岩物质的沉积脉冲。生物和非生物成分的沉积作用更多地受到海平面变化的影响，海平面变化控制着海岸线和河口的位置以及裸露大陆架上陆地环境的存在。日本海对海平面变化也很敏感，因为它与其他海洋盆地相连的浅底。
In order to understand fluctuations in terrestrial and marine environments in response to sea-level change during the last 42 ky, we investigated sedimentation of biogenic and abiogenic components in core MD982195, collected from the northern East China Sea (ECS), one of the largest marginal seas in the world. Amino acids (AAs), major nitrogen compounds in marine organic matter (OM), can be protected inside biogenic material and survive the decomposition process. The total AAs were highly correlated with organic carbon (OC) (r=0.91; p<0.05) but less with total nitrogen (TN) (r=0.76; p<0.05). Therefore, total AAs and OC contents should reflect primary production (PP) more than TN in core MD982195. PP was approximately constant during 42–15 ka, increased in 15–14 ka was kept constant until 7 ka. Then PP increased from 5 ka to the present. IMAGES program is generally interested in high-resolutional reconstruction of paleo-environments in the area with high sedimentation rate, which is mainly due to abundant supply of lithogenic matter. The positive correlation of lithogenic matter with nonarboreal pollens (NAP) abundance suggests that lithogenic matter and NAP were mainly transported from the coastal lowlands created by the large drop in sea level during the glacial period. Large, millennial-scale fluctuations in sea-surface temperature and salinity did not always correspond to sedimentation pulses of OC and lithogenic matter. Sedimentation of biogenic and abiogenic components was more affected by sea-level change, which controls the positions of the coastline and river mouths and the presence of terrestrial environments on the exposed continental shelf. The Japan Sea is also sensitive to sea-level change because of the shallow sills connecting it to other ocean basins.