Mineral Magnetic Characterization of High‐Latitude Sediments From Lake Levinson‐Lessing, Siberia

• Published in: Geophysical research letters Vol. 48; no. 10
• Main Authors: Scheidt, Stephanie, Egli, Ramon, Lenz, Matthias, Rolf, Christian, Fabian, Karl, Melles, Martin
• Format: Journal Article
• Language: English
• Published: 28.05.2021
• Subjects: lacustrine sediments; late quaternary; magnetic mineralogy; mineral magnetic characterization; sediment core; Siberia
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2021GL093026

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. Plain Language Summary 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). Because lakes with such long‐term constant properties are extremely rare throughout the Arctic Circle, the 46‐m‐long sediment core Co1401 recovered in 2017 provides an exceptional archive for climate and environmental changes of the past, but also for recordings of the evolution of the Earth’s magnetic field (EMF) in this region. This study tested the suitability of Co1401 for paleomagnetic analyses using hundreds of samples and various analytical approaches. Although the lowermost 8 m are shown to be disturbed, the upper 38 m of Co1401 provide an unusual homogeneous mineral‐magnetic composition and properties. In the uppermost 6.7 m, the magnetic mineralogy is slightly different with greigite as additional component. The presence of this mineral can be a problem in paleomagnetic studies, as it overprints the primary information recorded in the archive. In this case, the formation is only initial and thus not an issue. Overall, Co1401 provide ideal preconditions for a paleomagnetic archive. Thus, an upcoming paleomagnetic‐based chronology will unlock this archive for future studies on paleoclimate, paleoenvironment, and the evolution of the EMF. Key Points Core Co1401 from Lake Levinson‐Lessing is with a length of 46 m, an exceptional lacustrine sediment record in the Russian Arctic Core Co1401 provides sediments with unusual homogenic magnetic mineralogy and mineral magnetic properties Lake Levinson‐Lessing is expected to become a key record of paleomagnetic research on the Eurasian tangent cylinder