| 16 ka以来冲绳海槽中南部沉积物物源演化及其对古气候的响应 |
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| 引用本文： | 王玥铭,窦衍光,李军,徐景平,蔡峰,温珍河,赵京涛,陈晓辉.16 ka以来冲绳海槽中南部沉积物物源演化及其对古气候的响应[J].沉积学报,2018,36(6):1157-1168. |
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| 作者姓名： | 王玥铭 窦衍光 李军 徐景平 蔡峰 温珍河 赵京涛 陈晓辉 |
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| 作者单位： | 1.中国海洋大学海洋地球科学学院, 山东青岛 266100; |
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| 基金项目： | 国家自然科学基金项目（41776077，41476070，41530966）；国家重点基础研究发展计划（973计划）项目（2013CB429704） |
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| 摘 要： | 基于有孔虫AMS14C年龄年代框架，通过冲绳海槽中南部的OKT12孔沉积物黏土矿物的分析，探讨了16 ka以来冲绳海槽细颗粒沉积物的物源变化及其对源区气候的响应。研究结果显示，10 ka时黏土矿物组成发生明显变化，伊利石、绿泥石含量增加，高岭石、蒙皂石含量减少，指示物源由之前的长江和东海陆架源转变为台湾源。受到海平面上升影响，长江河口和冲绳海槽距离增加，夏季风增强，黑潮增强，既搬运台湾来源物质，又阻碍长江物质跨陆架输运，在这些因素综合作用下，长江物质减少、台湾物质增加。高岭石/（伊利石+绿泥石）和绿泥石/（伊利石+蒙皂石）比值在4 ka以来增加指示全新世晚期台湾源区侵蚀强度发生变化。4 ka前后物源判别显示，OKT12孔沉积物来源由台湾东北部河流变为台湾东南部河流，反映了该时期季风降雨导致源区台湾不同区域的侵蚀差异，可能与ITCZ南移、ENSO活动增强有关。
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| 关 键 词： | 冲绳海槽 黏土矿物 物源 全新世 古气候 |
| 收稿时间： | 2017-09-13 |
Sediment Provenance Change and Its Response to Paleochimate Change in the Middle Okinawa Trough since 16 ka |
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| Abstract: | Based on an AMS14C age framework, clay mineral analysis of Core OKT12 from the Middle Okinawa Tough was conducted to determine sediment provenance and its response to Holocene climate change. A remarkable change took place at 10 ka with an increase of illite and chlorite, and a decrease of kaolinite and smectite, indicating that sediment provenance changed from Changjiang and the ECS shelf to Taiwan after 10 ka. With a rise in sea level the distance between the Changjiang estuary and the Okinawa Trough increased. The Kuroshio Current was strengthened following the evolution of the East Asia summer monsoon since the LGM. The Kuroshio Current was able to transport sediment from Taiwan to OT and to obstruct the cross-helf transport of Changjiang sediment, resulting in an increase in Taiwan material and a decrease in Changjing material. Kaolinite/(illite+chloite) and chlorite/(illite+smectite) ratios have increased since 4 ka, indicating sediment provenance erosion change during the Holocene. By comparing the clay mineral compositions from the main rivers in Taiwan, it was determined that sediment provenance changed from northeastern to southeastern Taiwan Rivers since 4 ka. Holocene sediment provenance change was probably a result of erosion difference induced by a typhoon precipitation distribution discrepancy due to the southern shift of ITCZ and the strengthening of ENSO. |
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