INTERRELATIONS BETWEEN THE TECTONOMORPHIC HISTORY OF THE ARCTIC AND ITS PAST ENVIRONMENTAL CHANGESPart I: Cenozoic tectonothermal evolution of North and Northeast Greenland

北极构造形态历史与其过去环境变化之间的相互关系第一部分：格陵兰岛北部和东北部新生代构造热演化

• 批准号: 412852745
• 负责人: Professor Dr. Frank Lisker
• 金额: --
• 依托单位: Fachgebiet Geodynamik der Polargebiete
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/412852745?language=en
• 关键词: INTERRELATIONS; BETWEEN; TECTONOMORPHIC; HISTORY; ARCTIC

The Wandel Hav Mobile Belt is situated at the northeastern corner of Greenland and was located in the central part of the Paleogene Eurekan orogen, formerly connecting the Canadian High Arctic in the West with the Barents Shelf in the East. We hypothesize that the Eurekan orogen has influenced the climatic evolution of the Arctic in that topography associated with Eurekan deformation may have formed the nucleus for assumed Eocene continental glaciation of Greenland. Continental glaciation of Greenland was postulated based on the occurrence of ice rafted debris in offshore sediments from ~44 Ma onwards. For this part of the study, we aim to test the basic prerequisite of our hypothesis - i.e., enhanced tectonic movements associated with enhanced erosion and thus presumably topography formation at the right time to initiate continental glaciation of Greenland at ~44 Ma - by applying thermochronological dating methods to onshore and offshore samples of North(-east) Greenland. In a companion proposal – for which this study will also provide reference material and data – we aim to investigate the provenance of offshore ice rafted debris, thus obtaining information on glaciated source areas and iceberg pathways during Eocene, Oligocene and Miocene times. After Eurekan deformation ceased, the tectonic regime of the Wandel Hav Mobile Belt changed to (trans-)tension, which eventually led to the separation of Greenland from the Eurasian continent and the opening of the Fram Strait. The Fram Strait forms the only deep water connection of the Arctic Ocean with other oceans, and thus its opening strongly impacted on the environmental and climatic evolution of the Arctic. Previous studies postulated widening of the Fram Strait during the mid Miocene and related this to regional uplift and heating, which may coincide with the change from seasonal to perennial sea ice cover in the Arctic Ocean. In the past, this mid Miocene thermotectonic event could not be dated precisely, thus inhibiting temporal correlations with environmental changes. Vitrinite reflectance data from the Wandel Hav region, however, suggest post Eurekan (mid Miocene?) heating of the coastal regions at temperatures sufficiently high to allow for direct dating by thermochronological analyses. Thus, the second major aim of this study is to decipher and date thermotectonic processes that influenced the Greenland side of the Fram Strait margin subsequent to Eurekan deformation.

Wandel HAV移动带位于格陵兰岛东北角，位于古代eurekan造山机的中部，以前是将西方的加拿大高北极与东部的Barents架子连接起来。我们假设尤里克造山基因影响北极的气候演化，因为与尤里克人变形相关的地形可能已经形成了假定的格陵兰岛始新世连续冰川的细胞核。基于约44 mA的近海沉积物中冰筏碎屑的发生，对格陵兰的大陆冰川化进行了假设。在这一研究的这一部分中，我们旨在测试我们的假设的基本先决条件 - 即增强了与增强的侵蚀相关的构造运动，因此在正确的时候可以在〜44 MA上启动格陵兰岛连续冰川化的形成，通过应用热力学约会方法，以对北部和北部（北（-east））进行热量系统学日期。在伴侣建议中（本研究还将提供参考材料和数据）中，我们旨在调查离岸冰筏碎片的出处，从而在始新世，渐新世和中新世时获得有关冰川源区域和冰山途径的信息。尤里克（Eurekan）变形停止后，Wandel HAV移动带的构造政权变为（Trans-）张力，这最终导致了格陵兰岛与欧亚大陆分离和弗拉姆海峡的开放。弗拉姆海峡构成了北极海与其他海洋的唯一深水连接，因此其开口对北极的环境和气候进化产生了强烈影响。先前的研究在中新世中期发布了框海峡的扩大，并将其与区域隆升和暖气有关，这可能与北极海中从季节性到多年生海冰覆盖的变化相吻合。过去，中新世的热电位事件无法准确日期，从而抑制了与环境变化的暂时相关性。然而，来自Wandel Hav地区的玻璃铁矿反射率数据表明，在尤里坎（中新世中期？）在温度上加热沿海地区的加热非常高，以允许通过热力学分析直接日期。这是这项研究的第二个主要目的是破译和日期热电位过程，影响尤里克（Eurekan）变形之后的格陵兰海峡边缘的格陵兰侧。