δ¹⁸O composition of ice wedges from Ayon Island and paleotemperature reconstructions of the Northern Chukotka

• Main Authors: Vasil'chuk, Yurij K, Vasil'chuk, Alla Constantinovna
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Ayon Island; Chaun-Chukotka; deuterium; heavy oxygen; Holocene; ice wedge; Late Pleistocene; Stable isotope; Arctic; Kolyma; Chaun; Ayon; Chukotka; kolyma river; Permafrost and Periglacial Processes
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.915112; https://doi.org/10.1594/PANGAEA.915112

Syngenetic ice wedges have been investigated on Ayon Island. Their isotope composition and the geochemical characteristics of both ice wedges and enclosing sediments have been obtained; four ice-wedge stages have been distinguished. Paleo temperature reconstructions for Ayon Island and adjacent territories of northern Chukotka have been obtained based of these results. Almost identical trends in the distribution of ice-wedge isotope characteristics in the Arctic islands and in the lower reaches of the Kolyma River were observed, as well as differences in the magnitude of isotope oscillations during the transition from the Late Pleistocene to the Holocene compared to ice wedges of the Lower Kolyma region. The sediments have been dated by the radiocarbon (14C) method (Kotov and Ryabchun, 1986). Winter mean (twint.mean) and January (tJ) air temperature values were calculated using equation: tJ = 1.5 δ18Opiw (±3 °C), twint.mean = δ18Opiw (±2 °C). by the technique of Yu. Vasil'chuk (1989, 199). Mean annual ground temperatures were calculated using reconstructions of mean summer temperature by the technique of A. Vasil'chuk [2007] and of mean winter temperature by the technique of Yu. Vasil'chuk (1989). Analysis of major ion chemistry of ice - titration methods (titrimetric methods) are based on determining the quantity of a reagent of known concentration that is required to react completely with the analyte. Isotopic analyses were performed at the Institute of Water Problems, RAS and at the Institute of Geology, the city of Tallinn. Oxygen isotope measurements of ice wedge were carried out in the isotope laboratory of the Institute of Geology of Estonia (Prof. R. Vaikmae) using a Finnigan Delta-E mass spectrometer. Analytical precision was ±0.4‰ and in the isotope laboratory of the Institute of Water Problems RAS (Dr. A.Yesikov) using a Finnigan MAT 250 mass spectrometer. Analytical precision was ±0.6‰.