Late Glacial and Early Holocene Climatic Changes Based on a Multiproxy Lacustrine Sediment Record from Northeast Siberia

• Main Authors: Kokorowski, H D, Anderson, P M, Sletten, R S, Lozhkin, A V, Brown, T A
• Language: unknown
• Published: 2021
• Subjects: 58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES; CARBON; CLIMATIC CHANGE; MAGNETIC SUSCEPTIBILITY; NITROGEN; PLANTS; POLLEN; RESOLUTION; SAMPLING; SEDIMENTS; SHRUBS; SIBERIA; SILICA; TREES; TUNDRA; Elikchan; Tundra; Siberia
• Online Access: http://www.osti.gov/servlets/purl/965078; https://www.osti.gov/biblio/965078; https://doi.org/10.1657/1523-0430%2807-036%29%5BKOKOROWSKI%5D2.0.CO%3B2; https://doi.org/10.1657/1523-0430(07-036)[KOKOROWSKI]2.0.CO;2

Palynological (species assemblage, pollen accumulation rate), geochemical (carbon to nitrogen ratios, organic carbon and biogenic silica content), and sedimentological (particle size, magnetic susceptibility) data combined with improved chronology and greater sampling resolution from a new core from Elikchan 4 Lake provide a stronger basis for defining paleoenvironmental changes than was previously possible. Persistence of herb-dominated tundra, slow expansion of Betula and Alnus shrubs, and low percentages of organic carbon and biogenic silica suggest that the Late-Glacial transition (ca. 16,000-11,000 cal. yr BP) was a period of gradual rather than abrupt vegetation and climatic change. Consistency of all Late-Glacial data indicates no Younger Dryas climatic oscillation. A dramatic peak in pollen accumulation rates (ca. 11,000-9800 cal. yr BP) suggests a possible summer temperature optimum, but finer grain-sizes, low magnetic susceptibility, and greater organic carbon and biogenic silica, while showing significant warming at ca. 11,000 cal. yr BP, offer no evidence of a Holocene thermal maximum. When compared to trends in other paleo-records, the new Elikchan data underscore the apparent spatial complexity of climatic responses in Northeast Siberia to global forcings between ca. 16,000-9000 cal. yr BP.