摘要
开展海洋沉积物物源研究,可以更好地认识其搬运机理与区域及全球物质循环的过程。通过对南极宇航员海ANT36-C4-05岩芯沉积物的稀土元素及Sr-Nd同位素的测试分析开展了沉积物物源研究,结果显示ANT36-C4-05岩芯沉积物的稀土元素平均含量相对较高,轻、重稀土分馏明显,87Sr/86Sr平均值相对偏高,εNd(0)平均值明显偏负。沉积物的稀土元素及Sr-Nd同位素特征指示中全新世晚期以来,宇航员海沉积物主要来自于东南极普里兹湾周边陆地及恩德比地一带的高级变质岩,这些碎屑物质一方面在冰-海作用下进入宇航员海,其中南极沿岸流与南极陆坡流在其运输过程中发挥了重要作用;同时,其还可能依靠发源于南极内陆高原的下降风完成从源区到研究区的输送过程。物源端元混合模型的结果表明,岩芯沉积物绝大部分(大于70%)来自于普里兹湾地区的变质岩,来自恩德比地物质的贡献相对较少。两个源区对宇航员海沉积物的贡献存在明显差异,这与地区之间冰川、洋流及风力的差异有关:与恩德比地相比,中山站一带的冰川规模较大,运动速度较快,其对基岩的侵蚀与搬运能力更强;发源于普里兹湾底层的南极底层水可能在普里兹湾-宇航员海的物质输送过程中发挥了一定的作用;普里兹湾地区是南极下降风较为强盛的地区之一,它可以将更多的风化碎屑吹向下风向的宇航员海。这些因素综合导致了宇航员海ANT36-C4-05岩芯沉积物主要来自于普里兹湾的特征。
Carrying out researches on marine sediments’source can help to better understand the mechanism of ma-terial transport and the process of regional and global material circulation.A sediment provenance study has been conducted by analyzing the rare earth element and Sr-Nd isotopes of the ANT36-C4-05 core sediment in the Cosmo-naut Sea,Antarctic.The results show that the average content of rare earth element(REE)in the sediment is relat-ively high,with an obvious fractionation between light REE(LREE)and heavy REE(HREE);and the average 87Sr/86Sr value of the sediment is relatively high,while the averageεNd(0)value is significantly negative.The REE and Sr-Nd isotopic characteristics indicate that since the late Middle-Holocene,the sediment is mainly originated from high-grade metamorphic rocks in the vicinity of the Prydz Bay and Enderby Land,East Antarctic.These detrit-al materials are partly introduced into the Cosmonaut Sea under the ice-sea interaction,with the Antarctic Coastal Current and Antarctic Slope Current playing important roles in the transportation;simultaneously,it may also rely on katabatic winds originating from the Antarctic interior plateau to complete the transport process from source areas to the study area.The results of the provenance end member mixing model show that the sediment is mainly originated from metamorphic rocks in the Prydz Bay area(>70%),while the contribution from Enderby Land is rel-atively small.The significant difference in the contribution of two source areas is related to the differences in gla-ciers,ocean currents,and wind forces between two areas:compared to Enderby Land,the glacier in the Prydz Bay area is larger in scale and moves at a faster speed,with a stronger erosive and transport capacity for the bedrock;in the meanwhile,the Antarctic Bottom Water originating from the bottom of the Prydz Bay area may play an import-ant role during the westward transportation;and the Prydz Bay area is one of the stronger wind force regions of katabatic winds,which can contribute
作者
张泳聪
胡良明
孙曦
韩喜彬
龙飞江
武文栋
向波
王逸卓
葛倩
边叶萍
Zhang Yongcong;Hu Liangming;Sun Xi;Han Xibin;Long Feijiang;Wu Wendong;Xiang Bo;Wang Yizhuo;Ge Qian;Bian Yeping(Key Laboratory of Submarine Geosciences,Ministry of Natural Resources,Hangzhou 310012,China;Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China;School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
出处
《海洋学报》
CAS
CSCD
北大核心
2023年第5期14-26,共13页
基金
国家重点研发计划(2022YFC2905500)
自然资源部专项(IRASCC2020-2022)
中央级公益性科研院所基本科研业务费专项资金项目(SZ2102)
上海交通大学“深蓝计划”基金(SL2002)。
