First 10Be dates of late holocene moraines of the Kashkatash and Irik glaciers, Northern Caucasus

• Main Authors: O. Solomina N., V. Jomelli, I. Bushueva S., О. Соломина Н., В. Джомелли, И. Бушуева С.
• Other Authors: We are grateful to our French colleagues of the Aix-Marseille University, CNRS, for the introduction of this method in the Caucasus. The ASTER AMS national facility (CEREGE, Aixen Provence) is supported by the INSU/CNRS, the ANR through the “Projets thematiques d’excel lence” program for the “Equipements d’excellence” ASTER-CEREGE action and IRD. We thank our colleagues Dr. Ekaterina Dolgova, Dr. Vladimir Mikhalenko, and Dr. Vladimir Matskovsky continuous efforts in sampling, processing the samples in the lab. and statistical analyses. The field works were supported by the framework (No 0148-2019-0004) of the State Assignment of Institute of Geography, Russian Academy of Sciences. The Megagrant project (agreement No 075-15-2021-599, 8.06.2021) of the Ministry of Highest Education of Russia “Natural and Anthropogenic Environmental Changes Inferred From Multi-Proxy Paleorecords. In Russia” supported the analyses of the data and writing of this paper., Мы благодарим наших французских коллег из Университета Экс-Марсель, Марсель, Франция за внедрение метода космогенных изотопов на Кавказе. Мы благодарны нашим коллегам Екатерине Долговой, Владимиру Михаленко и Владимиру Мацковскому за их усилия по отбору, подготовке и анализу образцов в лаборатории. Они также принимали участие в полевых работах и любезно предоставили данные по дендрохронологическому датированию и статистическому анализу. Полевые работы выполнены в рамках темы государственного задания Института географии No 0148-2019-0004. Анализ данных и написание статьи проведены в рамках Мегагранта № 075-15-2021-599 от 08.06.2021 г.
• Format: Article in Journal/Newspaper
• Language: English
• Published: IGRAS 2023
• Subjects: Late Holocene;glacier fluctuations;moraines;CRE dates;tree rings;lichenometry; поздний поздний голоцен;колебания ледников;морены;космогенные изотопы;дендрохронология;лихенометрия; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/1244; https://doi.org/10.31857/S2076673423030110

We present 11 10Be ages of the moraines of the Irik and Kashkatash glaciers that allowed identifying and dating several Late Holocene glacier advances for the first time, including a prominent advance exceeding the Little Ice Age (LIA) maximum that occurred at 1.6–1.7 ka at еру Irik Glacier. The advance is dated by the three very close 10Be ages of a moraine (1.57 ± 0.23 ka, 1.63 ± 0.23, and 1.68 ± 0.24 ka) located in the vicinity of the moraines of the Little Ice Age (LIA) maximum advance. The advance that occurred at 1.6–1.7 ka might be a possible analogue of the “Historical” stage described earlier in the Caucasus in literature basing at geomorphic evidence, speculations, and analogues with other mountain regions, but not dated. Another possibility is a potential correlation of this advance with the Late Antique Little Ice Age cooling in 536 to ~660 CE. The age of Irik Glacier advance is close to the humid period identified in the Garabashi (Baksan, Elbrus valley) lake sediments at 1500–1700 years BP. The magnitude of the identified glacier advances over the past two millennia was similar. Between the advance of 1.6–1.7 ka and the position of the glacier in 2022 CE the elevation of the Irik Glacier front increased by 520 m from 2490 to 3010 m asl. Four 10Be dates (0.7 + 0.11, 0.72 + 0.11, 0.77 + 0.11 and 0.82 + 0.18 ka) of the lateral moraine of the Kashkatash Glacier constrain the advance of the first stage of the LIA. The advance of the 13th century is also dated by 10Be at the DonguzOrun and Chalaati glaciers located at the Northern and Southern slopes of the Caucasus, respectively. The corresponding cooling in ca 1250–1400 CE is identified in the sedimentary paleoclimatic proxies of Lake Karakel (Teberda valley). A later advance at the Kashkatash Glacier is constrained by only one 10Be date (0.53 ± 0.13 ka) and needs further confirmation. Till deposited between the 1490s and 1640s at the Greater Azau Glacier is close to the date of this advance of the Kashkatash Glacier. A cooling at that time is recorded ...