中全新世以来南黄海岩心记录的沉积环境演变对东亚季风的响应  

ENVIRONMENTAL CHANGES SINCE MID HOLOCENE REVEALED BY CORE Z1 IN THE SOUTH YELLOW SEA AND THEIR RESPONSE TO EAST ASIAN MONSOON

作　　者：皮仲 李铁刚[1,3,4] 南青云[1] 

机构地区：[1]中国科学院海洋研究所,青岛266071 [2]中国科学院大学,北京100049 [3]海洋沉积与环境地质国家海洋局重点实验室,国家海洋局第一海洋研究所,青岛266061 [4]青岛海洋科学与技术国家实验室海洋地质过程与环境功能实验室,青岛266061

出　　处：《海洋地质前沿》2016年第7期1-10,共10页Marine Geology Frontiers

基　　金：国家自然科学基金(41576054,41230959);中国科学院战略先导专项(XDA11030104)

摘　　要：对南黄海中部泥质沉积区中心位置的Z1钻孔进行了AMSMC年龄、粒度和TOC／TN分析，综合指标结果揭示了中晚全新世以来南黄海区域的沉积环境演化。自6094aBP以来，沉积速率、平均粒径和TOC／TN整体趋势的减少指示，研究区陆源物质输入的减少与东亚冬／夏季风的减弱有关。根据粒度参数和TOC／TN变化将研究区沉积环境演化分成3个阶段：①6．1～5．4kaBP时沉积物粒度最粗，TOC／TN值较高，这与该阶段东亚冬季风的强盛且稳定和黄海暖流的形成初期较弱有关；②5．4～3．9kaBP时沉积物粒度减小但波动幅度较大，TOC／TN值呈减小趋势，此阶段东亚冬季风减弱但波动剧烈；③3．9～0kaBP时沉积物粒度较细且相对稳定，TOC／TN增加直至趋于稳定，该阶段冬季风减至最弱且趋于稳定。另外岩心记录的6．0、5．3、4．6、4．0和3．4kaBP沉积物粒度明显较粗、TOC／TN值较大与东亚冬季风增强、海区温度较低有关；6．1～5．7kaBP的高速沉积与冬季风强盛有关；2．8～1．9kaBP的高速沉积则与黄海沿岸流和黄海暖流共同作用形成的南黄海中部气旋式冷涡的加强稳固有关。High-resolution multi-proxies records, including AMS 14C ages, grain size and TOC/TN for a gravity core Z1 from the South Yellow Sea were collected in this program. The variation in grain size is closely related to the resuspension and coastal currents droved by the East Asian Winter Monsoon （EAWM）. And the organic geochemistry proxy TOC/TN could be used to indicate the input of terrig- enous materials and/or the intensity of ocean primary productivity. Our results reveal the evolution history of the sedimentary environment in the area of muddy deposits in the South Yellow Sea since Mid Holocene, which could be divided into three stages. （1）A relatively high-energy and stable sedimentary environment with low ocean productivity from 6.1 to 5.4 ka BP corresponding to the strong and stable EAWM; （2）A weakening and variable hydrodynamic condition at 5.4-3.9 ka BP associated with fluctuating and weakening EAWM; （3）A low-energy and stable sedimentary environment with high ocean productivity since 3.9 ka BP related to the weakened and stable EAWM. Correlation between regional records and global climate variations reveals that, the grain size was coarser at 6.0 ka BP, 5.3 ka BP, 4.6 ka BP, 4.0 ka BP and 3.4 ka BP corresponding well in time to the strengthening of EAWM. However, The high deposition rate during 6.1-5.7 ka BP is related to the EAWM and during 2.8-1.9 ka BP, owing to the strengthening of YSWC, the stabilization of cyclone cold water mass of Yellow Sea might increase the depositional process.

关 键 词：沉积环境 东亚季风 黄海暖流 粒度 

分 类 号：P736.21[天文地球—海洋地质]