白令海北部陆坡23ka以来古生产力变化及其对海冰扩张的响应  

Paleoproductivity changes in the northern Bering Slope over the last 23 ka and the response to the sea-ice evolution

作　　者：宋腾飞 王宏雷 陈漪馨 李朝新[1] 朱爱美[1] 白亚之[1] 石学法[1,3] Gorbarenko Sergei Bosin Aleksandr 刘焱光 Song Tengfei;Wang Honglei;Chen Yixin;Li Chaoxin;Zhu Aimei;Bai Yazhi;Shi Xuefa;Gorbarenko Sergei;Bosin Aleksandr;Liu Yanguang(Key Laboratory of Marine Sedimentology and Environment Geotogy, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China;No. 7 Geological Bridgade, Shandong Provincial Bureau of Geology ＆ Mineral Resources, Linyi 276000, China;Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology , Qingdao 266061 , China;V.I. Il＇ichev Pacific Oceanological Institute, Far East Branch of Russian Academy of Science, Vladivostok 690041 ,Russia)

机构地区：[1]国家海洋局第一海洋研究所国家海洋局海洋沉积与环境地质重点实验室,山东青岛266061 [2]山东省地质矿产勘查开发局第七地质队,山东临沂276000 [3]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,山东青岛266061 [4]V.I. Il'ichev Pacific Oceanological Institute,Far East Branch of Russian Academy of Science

出　　处：《海洋学报》2018年第5期90-106,共17页

基　　金：南北极环境综合调查与评估专项(CHINARE2017-03-02);国家自然科学基金(41476054;41106166)

摘　　要：本文基于白令海北部陆坡ARC6-B11岩心的沉积物粒度、颜色反射率、有机碳/氮含量和高分辨率化学元素XRF扫描数据,结合底栖和浮游有孔虫AMS14C测年资料,重建了研究区23ka以来至中全新世的沉积记录,重点研究了海冰的扩张变化对生产力和沉积物输入的影响。研究结果显示,末次盛冰期白令海北部陆坡受到海冰南向扩张的影响而生产力较低,沉积物中砂粒级和冰筏碎屑(IRD)含量较高。HS 1时期由于受到常年冰的覆盖,沉积物中砂粒级和IRD含量存在低值,沉积物中较高的总有机碳(TOC)含量受陆源有机质的影响较大,异常的TOC含量峰值主要受到低海平面和海冰形成过程产生的富氧水团控制下的高浓度细粒物质携带的陆源有机质的快速沉积作用的影响,难以作为反映白令海古生产力的替代指标。B/A暖期和全新世生产力较高,在B/A暖期存在Ca/Ti峰值现象,Ca/Ti峰值现象的产生与碳酸盐补偿深度增加有关,水体通风条件的改变可能起到一定的作用,也不能忽视颗石藻对其产生的潜在影响。The gravity core ARC6-B11 recovered from the northern Bering Slope was analyzed to reconstruct the sedimentary record and paleoproductivity changes from 23 ka BP to the Middle Holocene.Based on geochemical,high-resolution core logging and AMS14 C data the variation of sediment input and productivity of the study area and it＇s response to the sea-ice evolution were discussed.Our results demonstrate that,on account of the southern extended sea-ice,the paleoproductivity is low during the Last Glacial Maximum,while the sand and ice rafting debris（IRD）contents of the sediments are high.But the sand and IRD contents decreased sharply during Heinrich Stadial1（HS 1）cold period because of the perennial sea-ice cover.The total organic carbon（TOC）content peaks during HS 1 could not be used as the paleoproductivity indicator due to the influence of the terrigenous organic matter.The abnormal peak value of the TOC content may relates to the redisposition of the shelf clay matter suspended by the oxygen enriched water mass influenced by the sea level change and sea-ice formation.The paleoproductivity is high during Blling/Allerd（B/A）and Holocene warm period,there are also Ca Peak Event and sedimentary laminae.The occurrence of Ca Peak Event in the B/A warming period is directly influenced by the deepening of carbonate compensation depth,but the alteration of ventilation and the coccolith bloom may play a certain role on it.

关 键 词：白令海北部陆坡 冰筏碎屑 古生产力 海冰扩张 

分 类 号：P736.22[天文地球—海洋地质]