楚科奇海盆M04柱晚更新世以来沉积古环境记录  

Paleoenvironmental record of core M04 in the Chukchi Sea Basin during Late Pleistocene

作　　者：章伟艳[1,2] 于晓果[1,2] 刘焱光[3] 金路[1,2] 叶黎明[1,2] 许冬[1,2] 边叶萍[1,2] 张德玉[3] 姚旭莹[2] 张富元[1,2] 

机构地区：[1]国家海洋局海底科学重点实验室,浙江杭州310012 [2]国家海洋局第二海洋研究所,浙江杭州310012 [3]国家海洋局第一海洋研究所,山东青岛266061

出　　处：《海洋学报》2015年第7期85-96,共12页

基　　金：南北极环境综合考察与评估专项--2014年度北极海域海洋地质考察(CHINARE2014-03-02);国家自然科学基金项目(41106050;41106048)

摘　　要：对"中国第五次北极科考"采自楚科奇海盆的M04柱进行粒度、冰筏碎屑、黏土矿物、岩心XRF扫描、沉积物颜色分析,初步建立了楚科奇海盆晚更新世MIS4期以来的沉积地层框架。MIS4期以来,楚科奇海盆M04柱沉积物粒度和黏土矿物组成具有明显的冰期/间冰期变化特征,冰期沉积物粒度分布以双峰态为主,由洋流搬运和海冰搬运沉积组分组成,伊利石含量高、高岭石含量低;间冰期沉积物具有三峰态粒度分布特征,由海冰搬运、洋流搬运和冰山搬运沉积组分组成,伊利石含量低、高岭石含量高。通过M04柱黏土矿物组合类型与北冰洋边缘海盆的表层沉积物黏土矿物组合类型对比表明,晚更新世以来楚科奇海盆沉积环境发生显著变化:温暖的间冰期受波弗特涡流驱动,波弗特海为研究区的物源输入提供了主要贡献;寒冷的冰期表层环流呈反向输运,细颗粒物源碎屑以东西伯利亚海的输入为主。A gravity core M04 was taken from the Chukchi Sea Basin during the fifth Chinese National Arctic Research Expedition in 2012.All samples were analyzed for grain size,ice-raft detritus,clay mineral,XRF scanning and sediment color features.The stratigraphic framework of core M04 since Marine Isotope Stage 4was established by synthesizing results of IRD,color cycles,clay proxies（kaolinite to illite and kaolinite to chlorite ratios）,AMS14 C ages,as done previously for other cores.It is clearly distinguished between sediments deposited during glacial and interglacial with the grain size and clay mineral composition of sediments.During glacial,the grain size distribution is bimodal components of the sediment through the current transport and sea ice transport process,with high content of illite and low content of kaolinite.In contrast,during interglacial,the grain size distribution is trimodal components of the sediment through the current transport and sea ice and iceberg transport process,with content of illite reducsing and content of kaolinite increasing.Clay-mineral association in core M04 and the adjacent marginal continental shelf areas are compared to identify source areas and transport pathways of terrigenous material in the Chukchi Sea Basin during the Late Pleistocene.Based on the above study,it is indicated that sedimentary environment has been significantly changed from the late Pleistocene.During the interglacial stage,terrestrial sources input into the study area from the Beaufort Sea driven by Beaufort Gyre,but during the glacial stage,fine particulate terrigenous input from the East Siberian Sea driven by the opposite direction circulation.

关 键 词：北极 楚科奇海盆 粒度 冰筏碎屑 黏土矿物 古环境 

分 类 号：P736.2[天文地球—海洋地质]