Iceberg-rafted tephra as a potential tool for the reconstruction of ice-sheet processes and ocean surface circulation in the glacial North Atlantic
Iceberg-rafted tephra as a potential tool for the reconstruction of ice-sheet processes and ocean surface circulation in the glacial North Atlantic
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DOI：
10.1144/sp398.8
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发表时间：
2014-02
期刊：
影响因子：
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通讯作者：
Marion Kuhs;W. Austin;P. Abbott;D. Hodell
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文献类型：
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作者：
Marion Kuhs;W. Austin;P. Abbott;D. Hodell
摘要对北大西洋加达漂流带U 1304站的海洋同位素第6阶段（MIS 6）冰筏火山碎屑沉积物的碎屑粒度分布和主要元素组成进行了研究。不均匀的成分，大的碎片尺寸和与冰筏碎片（IRD）的关联表明，这些晚期MIS 6矿床是通过冰山漂流从冰岛运到现场U 1304的。个别碎片的地球化学与地球化学的全新世火山系统从冰岛允许识别不同的潜在火山源区。这种详细的地球化学分析，结合冰岛冰盖（IIS）流动模型的末次盛冰期（LGM），表明IIS有崩解边缘的北部和南部在晚MIS 6和冰山可能已被运送到现场U 1304以下的表面海洋环流模式类似于那些盛行于LGM。我们表明，描述性的概念，冰岛玻璃在表征火山灰成分在北大西洋IRD可以显着改善，通过定量表征，这些数据有可能帮助限制表面海洋环流模型，同时也可能产生新的信息IIS在冰川早期。补充材料：统计测试、分析碎片的主要元素浓度、一级和二级标准品可在http://www.geolsoc.org.uk/SUP18716上获得
Abstract Ice-rafted tephra deposits, of Marine Isotope Stage 6 (MIS 6) age, from Site U 1304 on the Gardar Drift, North Atlantic were examined for their shard size distribution and major element composition. The heterogeneous composition, large shard sizes and association with ice-rafted debris (IRD) indicate that these late MIS 6 deposits were transported by iceberg-rafting from Iceland to Site U 1304. Comparison of individual shard geochemistry with the geochemistry of Holocene volcanic systems from Iceland allows the identification of different potential volcanic source regions. This detailed geochemical analysis, when combined with Icelandic Ice Sheet (IIS) flow models for the Last Glacial Maximum (LGM), suggests that the IIS had calving margins to both the north and south during the late MIS 6 and that icebergs could have been transported to the Site U 1304 by following surface ocean circulation patterns similar to those that prevailed during the LGM. We demonstrate that the descriptive concept of Icelandic glass in the characterization of tephra components within North Atlantic IRD can be significantly improved through quantitative characterization and that such data hold the potential to help constrain surface ocean circulation models, while also potentially yielding new information about the IIS during earlier glacial periods. Supplementary material: Statistical tests, major element concentrations of analysed shards, primary and secondary standards are available at http://www.geolsoc.org.uk/SUP18716