Mineral Magnetic Characterization of High‐Latitude Sediments From Lake Levinson‐Lessing, Siberia
Mineral Magnetic Characterization of High‐Latitude Sediments From Lake Levinson‐Lessing, Siberia
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DOI：
10.1029/2021gl093026
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发表时间：
2021-05
影响因子：
5.2
通讯作者：
S. Scheidt;R. Egli;M. Lenz;C. Rolf;K. Fabian;M. Melles
中科院分区：
文献类型：
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作者：
S. Scheidt;R. Egli;M. Lenz;C. Rolf;K. Fabian;M. Melles
位于西伯利亚中部北部的莱文森-莱辛湖是一个沉积档案，其特征是连续的、广泛持续的高速沉积(0.7mka−1 for>；32ka)。这项研究首次提供了利用46米长的Co1401岩芯进行古地磁分析的湖泊沉积物适宜性的证据。尽管最低的8米受到了干扰，但Co1401的较高38米为在内核的切线柱体内进行特殊的高分辨率古地磁记录提供了先决条件。磁化率、磁滞剩余磁化强度、等温剩余磁化强度和磁滞参数的高分辨率分析表明，矿物磁性基本均匀。一阶反转曲线表明，磁性载体主要为拟单磁区状态的磁铁矿粒子，其次为单磁区粒子，其来源可能为趋磁细菌。在6.7m以上，块体磁性矿物学比下部略硬，形成初始云母岩。然而，主要的剩磁载体仍然是碎屑成因。
Levinson‐Lessing Lake in northern Central Siberia is a sedimentary archive characterized by continuous, widely constant sedimentation at high rates (0.7 m ka−1 for >32 ka). This study provides the first evidence of the suitability of the lake′s sediments for paleomagnetic analyses using the 46‐m‐long core Co1401. Although the lowermost 8 m are disturbed, the upper 38 m of Co1401 provide the preconditions for an exceptional, high‐resolution paleomagnetic record located within the tangent cylinder of the inner core. High‐resolution analyses of magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization, and hysteresis parameters show largely uniform mineral magnetic properties. First‐order reversal curves indicate magnetite particles in pseudo‐single domain state are the main remanence carrier, supplemented by single‐domain particles, originating likely from magnetotactic bacteria. Above 6.7 m, the bulk magnetic mineralogy is slightly harder than below and initial greigite formation occurs. However, the main remanence carriers are still of detrital origin.