Provenance and weathering of sediments in the deep basin of the northern South China Sea during the last 38 kyr
Provenance and weathering of sediments in the deep basin of the northern South China Sea during the last 38 kyr
复制标题
DOI：
10.1016/j.margeo.2021.106602
复制
发表时间：
2021-10
期刊：
影响因子：
2.9
通讯作者：
Fangjian Xu;Bangqi Hu;Jingtao Zhao;Xiting Liu;Kehui Xu;Z. Xiong;Feifei Wang;Xue Ding;Qing Li-Qin
中科院分区：
文献类型：
--
作者：
Fangjian Xu;Bangqi Hu;Jingtao Zhao;Xiting Liu;Kehui Xu;Z. Xiong;Feifei Wang;Xue Ding;Qing Li-Qin
深海沉积物是研究物源和邻近陆地相关化学和物理风化作用的理想记录器。对采自南海北方深盆的4 m长的CS 11孔岩芯进行了主量元素、微量元素（Fe、K、Al、Ti、V、Rb、Th、Cr）和稀土元素（REE）、粒度和AMS 14 C年龄的研究。CS 11柱样沉积物主要来自台湾岛西南部，除37 ~ 35 kyr BP受吕宋岛北方输入影响外，其余时间主要受向南的底流搬运。在过去的35 kyr，叠加化学风化指数（SCWI）与全球新仙女木（YD），Heinrich 1（H1），Heinrich 2（H2），Heinrich 3（H3）事件，表明全球气候控制的风化强度在该地区。然而，SCWI表现出最强的化学风化强度在低海平面在末次盛冰期（LGM）时，来自台湾的沉积物暴露在大陆架上，化学风化，并越来越多地输送到深盆的南海。影响南海北方深盆沉积物化学风化强度的主要因素在不同的地质时间尺度上存在差异，千年尺度上的气候变化和轨道尺度上的海平面变化是主要影响因素。
Deep-sea sediments are ideal recorders for studying the provenances and relevant chemical and physical weathering of adjacent lands. Major, trace (Fe, K, Al, Ti, V, Rb, Th, and Cr), and rare earth elements (REEs), grain size, and AMS14C ages were studied on a 4-m-long core CS11 collected from a deep basin in the northern South China Sea (SCS). Core CS11 sediments were mainly derived from southwestern Taiwan Island and transported by the southward bottom current during most of the study periods, except from 37 to 35 kyr BP, when northern Luzon inputs temporarily had influence. For the past 35 kyr, the stacked chemical weathering index (SCWI) correlated well with the worldwide Younger Dryas (YD), Heinrich 1 (H1), Heinrich 2 (H2), and Heinrich 3 (H3) events, indicating global climate control on weathering intensity in this area. However, the SCWI showed the strongest chemical weathering intensity during the low sea level at the Last Glacial Maximum (LGM) when Taiwan-derived sediments were subaerially exposed on the shelf, chemically weathered and increasingly transported to the deep basin of the SCS. The major factors influencing chemical weathering intensities for sediments in the deep basin of the northern SCS varied on different geological time scales, with climate changes on millennial scales and sea-level changes on orbital scales.