Permafrost history in Arctic Siberia - insights from the cryogenic weathering record at El'gygytgyn Crater, NE Siberia

北极西伯利亚的永久冻土历史 - 来自西伯利亚东北部埃尔吉吉金火山口的低温风化记录的见解

• 批准号: 36801406
• 负责人: Dr. Georg Schwamborn
• 金额: --
• 依托单位: Forschungsstelle Potsdam
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/36801406?language=en
• 关键词: Permafrost; history; Arctic; Siberia; insights

I propose to determine climate variations expressed in variations of permafrost conditions in Arctic Siberia. Particularly I am interested in establishing a sedimentological method that allows estimating the degree of cryogenic weathering and palaeo soil temperatures through geologic time. My studies explore a lake sediment record from Elgygytgyn Crater lake, Arctic Siberia, spanning the last 300.000 years and representing the longest terrestrial palaeoclimate and -environment archive for the Arctic at present, permafrost sediments from the catchment spanning the last 14.000 years, and a set of surface samples representing modern conditions. I will study the following mineralogical properties in lake, permafrost, and surface sediments, which are considered to mirror long term periglacial dynamics in NE Siberia: (1) The ratio of quartz to feldspar in selected grain size fractions will be used as an indicator reflecting the degree of frost weathering. (2) Image analysis of scanning electron micrographs of particles will be performed to provide a quantification of quartz grain morphology and surface features stemming from frost weathering. (3) Heavy minerals will be used as provenance indicators to define changes in source rock composition and cryogenic detritus. The results prepare a fundamental tool that allows determining the intensity of permafrost conditions through Quaternary glacial cycles and estimating palaeo soil temperatures in the North Siberian Arctic. This is a conceptual outcome of future cores from ICDP funded deep drillings.

我建议确定北极西伯利亚永久冻土条件变化所表达的气候变化。我特别感兴趣的是建立一种沉积学方法，可以通过地质时间来估计低温风化的程度和古土壤温度。我的研究探索了Elgygytgyn火山口湖的湖泊沉积物记录，北极西伯利亚，跨越过去30万年，代表了目前北极最长的陆地古气候和环境档案，来自集水区的永久冻土沉积物跨越过去14000年，以及一组代表现代条件的地表样本。我将研究湖泊、永久冻土和地表沉积物的以下矿物学性质，这些矿物学性质被认为反映了西伯利亚东北部冰周的长期动态：(1)选定粒度组分中石英与长石的比例将被用作反映霜风化程度的指标。(2)对颗粒的扫描电子显微照片进行图像分析，定量分析石英颗粒的形貌和霜冻风化的表面特征。(3)重矿物可作为物源指标，界定烃源岩组成和低温碎屑的变化。这些结果准备了一个基本的工具，可以通过第四纪冰川循环来确定永久冻土条件的强度，并估计北西伯利亚北极地区的古土壤温度。这是ICDP资助的深层钻探的未来岩心的概念结果。