45029
2016
2016
eng
279
297
19
147
article
Elsevier
Oxford
1
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Holocene ice-wedge polygon development in northern Yukon permafrost peatlands (Canada)
Ice-wedge polygon (IWP) peatlands in the Arctic and Subarctic are extremely vulnerable to climatic and environmental change. We present the results of a multidisciplinary paleoenvironmental study on IWPs in the northern Yukon, Canada. High-resolution laboratory analyses were carried out on a permafrost core and the overlying seasonally thawed (active) layer, from an IWP located in a drained lake basin on Herschel Island. In relation to 14 Accelerator Mass Spectrometry (AMS) radiocarbon dates spanning the last 5000 years, we report sedimentary data including grain size distribution and biogeochemical parameters (organic carbon, nitrogen, C/N ratio, delta C-13), stable water isotopes (delta O-18, delta D), as well as fossil pollen, plant macrofossil and diatom assemblages. Three sediment units (SUS) correspond to the main stages of deposition (1) in a thermokarst lake (SW : 4950 to 3950 cal yrs BP), (2) during transition from lacustrine to palustrine conditions after lake drainage (SU2: 3950 to 3120 cal yrs BP), and (3) in palustrine conditions of the IWP field that developed after drainage (SU3: 3120 cal yrs BP to 2012 CE). The lacustrine phase (pre 3950 cal yrs BP) is characterized by planktonic-benthic and pioneer diatom species indicating circumneutral waters, and very few plant macrofossils. The pollen record has captured a regional signal of relatively stable vegetation composition and climate for the lacustrine stage of the record until 3950 cal yrs BP. Palustrine conditions with benthic and acidophilic diatom species characterize the peaty shallow-water environments of the low-centered IWP. The transition from lacustrine to palustrine conditions was accompanied by acidification and rapid revegetation of the lake bottom within about 100 years. Since the palustrine phase we consider the pollen record as a local vegetation proxy dominated by the plant communities growing in the IWP. Ice-wedge cracking in water-saturated sediments started immediately after lake drainage at about 3950 cal yrs BP and led to the formation of an IWP mire. Permafrost aggradation through downward closed-system freezing of the lake talik is indicated by the stable water isotope record. The originally submerged IWP center underwent gradual drying during the past 2000 years. This study highlights the sensitivity of permafrost landscapes to climate and environmental change throughout the Holocene. (C) 2016 Elsevier Ltd. All rights reserved.
Quaternary science reviews : the international multidisciplinary research and review journal
10.1016/j.quascirev.2016.02.008
0277-3791
wos2016:2019
2nd International Conference of the Palaeo-Arctic-Spatial-and-Temporal-Gateways-Network (PAST Gateways)
2014
WOS:000382409500018
Trieste, ITALY
Fritz, M (reprint author), Helmholtz Ctr Polar & Marine Res, Alfred Wegener Inst, Dept Periglacial Res, Telegrafenberg A43, D-14473 Potsdam, Germany., michael.fritz@awi.de; juliane.wolter@awi.de; nrudaya@gmail.com; opalagushkina@mail.ru; larisa.nazarova@uni-potsdam.de; jaroslay.obu@awi.de; janet.rethemeyer@uni-koeln.de; hugues.lantuit@awi.de; sebastian.wetterich@awi.de
importub
2020-03-22T15:07:02+00:00
filename=package.tar
3c34745bac99d5da01baf318f176b7bb
Michael Fritz
Juliane Wolter
Natalia Rudaya
Olga Palagushkina
Larisa B. Nazarova
Jaroslav Obu
Janet Rethemeyer
Hugues Lantuit
Sebastian Wetterich
eng
uncontrolled
Permafrost peatlands
eng
uncontrolled
Arctic
eng
uncontrolled
Thermokarst
eng
uncontrolled
Talik
eng
uncontrolled
Ice-wedge polygon
eng
uncontrolled
Pollen
eng
uncontrolled
Diatoms
eng
uncontrolled
Plant macrofossils
eng
uncontrolled
Stable water isotopes
eng
uncontrolled
Deuterium excess
Institut für Geowissenschaften
Referiert
Institut für Erd- und Umweltwissenschaften
Import
39624
2016
eng
176
doctoralthesis
1
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Mid- to Late Holocene environmental dynamics on the Yukon Coastal Plain and Herschel Island (Canada) - envidence from polygonal peatlands and lake sediment
online registration
Dissertation, Universität Potsdam, 2016
Keine öffentliche Lizenz: Unter Urheberrechtsschutz
Juliane Wolter
Fossilien, Paläontologie
Institut für Geowissenschaften
Institut für Erd- und Umweltwissenschaften
Universität Potsdam
Universität Potsdam