晚更新世以来南极罗斯海陆坡沉积物岩芯常量元素地球化学特征及其古环境意义  

Geochemical characteristics and paleoenvironmental implications of major elements in sediments from the continental slope of the Ross Sea, Antarctica since late Pleistocene

作　　者：李国刚 李云海 布如源 季有俊 李薏新 赵晓 李超 段琳娜 LI Guogang;LI Yunhai;BU Ruyuan;JI Youjun;LI Yixin;ZHAO Xiao;LI Chao;DUAN Linna(Beihai Offshore Engineering Survey Institute,North China Sea Administration,Ministry of Natural Resources,Qingdao 266061,China;Third Institute of Oceanography,Ministry of Natural Resources,Xiamen 361005,China;Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China)

机构地区：[1]自然资源部北海局北海海洋工程勘察研究院,青岛266061 [2]自然资源部第三海洋研究所,厦门361005 [3]自然资源部第二海洋研究所,杭州310012

出　　处：《海洋地质与第四纪地质》2022年第4期1-11,共11页Marine Geology & Quaternary Geology

基　　金：南极重点海域对气候变化的响应和影响项目(IRASCC2020-2022-01-03-02,IRASCC 2020-2022-01-02-03);极地考察业务化与科研项目(2021-Z002)。

摘　　要：基于中国第32次南极科学考察在罗斯海外陆坡扇区获取的ANT32-RA05C岩芯,开展常量元素地球化学研究,探讨地球化学特征及其古环境意义。结果表明,ANT32-RA05C岩芯以分选差的混合冰海沉积物为主,含有大量的冰筏碎屑(平均29.76%),并含有一定量生物硅(平均4.81%)。化学元素定量测试表明,沉积物常量元素配分模式为SiO_(2)>Al_(2)O_(3)>Fe_(2)O_(3)>Na_(2)O>K_(2)O>MgO>CaO>TiO_(2)>P_(2)O_(5)>MnO,其中含量最高的常量元素为Si,主要来源于陆源碎屑(石英)和硅质生物沉积(生物硅)。对比XRF元素连续扫描与定量测试结果发现,Si、Ca等相关性较高,可用作高分辨率环境研究。结合环境指标研究发现,晚更新世MIS 7末期以来,常量元素含量变化与南极气候具有良好的对应关系,主要反映了气候对物源和环境的控制,气候转暖通常对应于冰山和初级生产力输入增强,气候转冷对应于冰山和初级生产力输入受限。该岩芯对重建罗斯海古气候演变,深化对罗斯海古环境认识有重要意义。Based on the ANT32-RA05C sediment core obtained from the Ross Sea continental slope sector during the 32nd Chinese National Antarctic Research Expedition,major-element geochemistry,the geochemical characteristics,and their paleoenvironmental implications were analyzed.Results show that the ANT32-RA05C core is dominated by poorly-sorted compound glacial-marine sediment,containing a large amount of ice-rafted debris(average 29.76%)and a certain amount of biogenic silica(average 4.81%).Quantitative analysis of elements shows that the distribution pattern of major elements in core follows SiO_(2)>Al_(2)O_(3)>Fe_(2)O_(3)>Na_(2)O>K_(2)O>MgO>CaO>TiO_(2)>P_(2)O_(5)>MnO.Clearly,the most abundant major element is Si,coming mainly from terrigenous debris(quartz)and siliceous biogenic deposit(biogenic silica).Data of Si and Ca XRF element scanning show good correlation with quantitative analysis results thus could be used for high-resolution environmental research.Combining with environmental indicators,we found that the changes in element content have a good relationship with the Antarctic climate since the end of MIS 7 of late Pleistocene,reflecting mainly the control of climate on provenance and environment.A warming climate usually causes enhanced iceberg inputs and primary productivity,and vice versa in a cooling climate.This study provides a valuable information to reconstruct the paleoclimate and understand the climate evolution of the Ross Sea in the Antarctic region.

关 键 词：地球化学 环境演变 冰筏碎屑 生物硅 南极罗斯海 

分 类 号：P736.4[天文地球—海洋地质]