Magnetic susceptibility of eastern Mediterranean marine sediments as a proxy for Saharan dust supply?
Magnetic susceptibility of eastern Mediterranean marine sediments as a proxy for Saharan dust supply?
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DOI：
10.1016/j.margeo.2008.06.003
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发表时间：
2008-09-03
期刊：
影响因子：
2.9
通讯作者：
Rohling, Eelco J.
中科院分区：
文献类型：
--
作者：
Larrasoana, Juan C.;Roberts, Andrew P.;Rohling, Eelco J.
对环撒哈拉海洋沉积物磁化率变化的解释表明，与撒哈拉沙尘供应有密切关系，该解释假定沙尘在各种其他来源和过程的潜在贡献中占主导地位。为了评估撒哈拉沙尘供应的重要性与其他潜在来源的磁化率的变化，我们编译磁化率数据从东地中海上新世更新世序列在大洋钻探计划（ODP）网站964，966，967和969，与其他古气候和古海洋学代理数据相同的时间间隔进行比较。我们的研究结果表明，磁化率的变化与撒哈拉沙漠灰尘的供应，通过某些部分的研究间隔，但似乎主要是由悬浮物从欧亚河流和尼罗河的排放控制。火山灰层和腐泥附近地层的沉积和成岩过程也会影响磁化率值。我们的结论是，磁化率记录只能用作东地中海沉积物中撒哈拉尘埃供应的替代品，并且可能也用于其他撒哈拉周边海洋沉积物中，当进一步的分析证明这是唯一的（或主要的）来源时。磁化率变化。(C)2008 Elsevier B.V.保留所有权利。
Interpretations of magnetic susceptibility variations in circum-Saharan marine sediments have suggested a close relationship with Saharan dust supply, which assumes that dust dominates over the potential contributions from a variety of other sources and processes. To evaluate the importance of Saharan dust supply versus that of other potential sources of variability in magnetic susceptibility, we compile magnetic susceptibility data from eastern Mediterranean Plio-Pleistocene sequences at Ocean Drilling Program (ODP) sites 964, 966, 967 and 969, for comparison with other paleoclimatic and paleoceanographic proxy data for the same intervals. Our results demonstrate that magnetic susceptibility variations are linked to the supply of Saharan dust through some parts of the studied intervals, but seem to be predominantly controlled by the discharge of suspended matter from Eurasian rivers and the Nile. Depositional and diagenetic processes in the stratigraphic vicinity of ash layers and sapropels also affect magnetic susceptibility values. We conclude that magnetic susceptibility records can only be used as a proxy for Saharan dust supply in eastern Mediterranean sediments, and likely also in other peri-Saharan marine sediments, when this has been demonstrated by further analyses to be the only (or predominant) Source of magnetic susceptibility variability. (C) 2008 Elsevier B.V. All rights reserved.