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移动的带位于格陵兰岛东北角，位于古近纪尤里卡造山带的中部，以前连接西部的加拿大高北极和东部的巴伦支大陆架。我们假设，尤里卡造山带的气候演变的影响，与尤里卡变形的地形可能形成了假定的格陵兰始新世大陆冰川的核北极。格陵兰大陆冰川作用是基于~44 Ma以来近海沉积物中冰筏碎片的出现而提出的。对于这部分研究，我们的目标是测试我们假设的基本前提-即，增强的构造运动与增强的侵蚀，从而推测地形形成在正确的时间开始大陆冰川的格陵兰岛在~44 Ma -通过应用热年代学测年方法的陆上和近海样品的北（东）格陵兰岛。在一个配套的建议-本研究也将提供参考材料和数据-我们的目标是调查海上冰筏碎片的来源，从而获得信息的冰川源区和冰山路径在始新世，渐新世和中新世的时间。尤里卡变形停止后，万德尔哈夫移动的带的构造体制转变为（跨）张，最终导致格陵兰岛与欧亚大陆分离，弗拉姆海峡开放。弗拉姆海峡是北冰洋与其他海洋唯一的深水通道，其开放对北极的环境和气候演变产生了重大影响。先前的研究假设在中新世中期弗拉姆海峡的扩大，并将其与区域抬升和加热有关，这可能与北冰洋海冰覆盖从季节性到常年性的变化相吻合。在过去，这一中新世中期的热构造事件不能被精确地定年，从而抑制了与环境变化的时间相关性。然而，从Wandel Hav地区的镜质组反射率数据表明，后尤里卡（中新世中期？）沿海地区的温度升高到足以通过热年代学分析直接测定年代。因此，本研究的第二个主要目的是破译和日期的热构造过程，影响格陵兰一侧的弗拉姆海峡边缘后，尤里卡变形。