Proglacial lake sediments – a basis for uninterrupted chronicles of the Holocene glacier variations

• Published in: Ice and Snow
• Main Authors: M. Alexandrin Y., М. Александрин Ю.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2015
• Subjects: Holocene climate;lake sediments;paleoclimatic reconstructions;paleolimnology;reconstructions of glacier variations; Климат голоцена;озёрные осадки;палеоклиматические реконструкции;палеолимнология;реконструкции оледенения; Ela; Arctic; Arctic and Alpine Research
• Online Access: https://ice-snow.igras.ru/jour/article/view/14; https://doi.org/10.15356/2076-6734-2015-1-89-102

The article covers the origin of paleolimnological method in glaciology, concerns the theoretical background of the approach, and focuses on the principal methods of analysis of the lake sediments and creating the sedimentary age-depth models. Lake sediments can provide a basis for creating uninterrupted reconstructions of the Holocene glacier variations with high resolution. The fundament of paleolimnological method is based on the differences between glacial and non-glacial components of the bottom sediments of proglacial lakes. The glacial signal in the lake sediments was originally distinguished by measuring the organic content of the sediment (normally with loss-on-ignition) and the magnetic properties of the sediment. Subsequent methods of analysis could yield more precision and normally include geochemical composition (with the use of high-resolution scanning x-ray fluorescence analysis), use of biogenic indicators (such as pollen and diatoms contained in the sediment) and more. Obtaining the most accurate age of the sediment is a crucial question in subsequent application of the sediment parameters for reconstruction of glacier variability. The article covers various methods of dating the lake sediment – radiocarbon, Cs- and Pb-isotope dating, varve counting. Techniques of creating age-depth models are taken into account. A state-of-the-art application of sedimentary properties in paleoglaciology yields a reconstruction of a former equilibrium line altitude – ELA. The article focuses on the basis of the ELA reconstruction approach. Successful examples of reconstructions of glacier variations based on the lake sediments can be found throughout the majority of the glaciated regions of the planet. The article states the most prominent of them and gives an update on the current progress in paleolimnological research in the Caucasus Mountains. Применение палеолимнологических методов в гляциологии даёт возможность делать непрерывные реконструкции высоты границы питания ледников, что невозможно никакими ...