Speleothems from Arctic Siberia: A unique terrestrial archive for past temperature and hydrological conditions in the late Miocene.

来自北极西伯利亚的洞穴化石：一个独特的陆地档案，记录了中新世晚期过去的温度和水文条件。

• 批准号: 391505347
• 负责人: Professor Dr. Sebastian Breitenbach
• 金额: --
• 依托单位: Institut für Geologie, Mineralogie und Geophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/391505347?language=en
• 关键词: Speleothems; Arctic; Siberia; unique; terrestrial

The onset of northern hemisphere glaciation, and build-up of Eurasian permafrost between the late Miocene (Tortonian-Messinian) and the Pleistocene is one of the most profound changes in the Cenozoic. The timing of extensive glaciation and freezing of the Arctic Ocean, and related changes in climatic conditions remain poorly understood. Speleothems (secondary cave carbonates) are highly valuable archives of continental environmental conditions and offer precise and accurate radiometric chronologies for a large array of palaeoclimate proxies.We identified diagenetically unaltered and datable sample material from central and Arctic Siberia and propose a multi-proxy study on U/Pb dated speleothems to gain detailed insights into the thermal and hydrological conditions between 10.3 Ma and 8 Ma. Fluid inclusion water, trapped in the carbonate, will be extracted to study the isotopic composition of original Miocene-age infiltration water. Additionally, lamination found in the speleothem samples offers information on seasonality changes during the Tortonian and Messinian times. We seek funding for the analysis of parallel fluid inclusion water isotopes, carbonate oxygen and carbon isotopes and element concentrations, to reconstruct regional environmental conditions, as well as moisture source and temperature dynamics, prior to the build-up of continuous permafrost. New samples will be added to determine the timing of the change from an ice-free to the permafrost-governed Siberia. This study will extend our knowledge of atmospheric circulation and associated changes in moisture budget and temperature under conditions of a seasonally ice-free Arctic Ocean.

北方冰川作用的开始，以及中新世晚期（托托尼亚-梅西尼亚）和更新世之间欧亚永久冻土的建立是新生代最深刻的变化之一。对北冰洋大面积冰川作用和冻结的时间以及气候条件的相关变化仍然知之甚少。洞穴沉积物（次生洞穴碳酸盐）是非常有价值的大陆环境条件的档案，并提供了一个大阵列的古气候proximate.We确定成岩不变的和可测年的样品材料从中央和北极西伯利亚和提出了一个多代理研究的U/Pb测年洞穴沉积物，以获得详细的了解10.3 Ma和8 Ma之间的热和水文条件的精确和准确的放射性年代。提取碳酸盐岩中的流体包裹体水，研究原始中新世入渗水的同位素组成。此外，在洞穴沉积物样品中发现的层压提供了托顿和梅西尼亚时期季节性变化的信息。我们寻求资金用于分析平行流体包裹体水同位素，碳酸盐氧和碳同位素和元素浓度，以重建区域环境条件，以及水分来源和温度动态，建立连续多年冻土之前。将增加新的样本，以确定从无冰到永久冻土统治的西伯利亚变化的时间。这项研究将扩大我们的知识，大气环流和相关的变化，在水分收支和温度的条件下，季节性无冰北冰洋。