Collaborative Research: Late Quaternary Glaciations of Northern Novaya Zemlya, Russia

合作研究：俄罗斯新地岛北部的晚第四纪冰川作用

• 批准号: 9529293
• 负责人: Steven Forman
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-15 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9529293&HistoricalAwards=false
• 关键词: Collaborative; Research; Late; Quaternary; Glaciations

The extent and timing of Pleistocene ice sheets over northern Eurasia remain unresolved. The views range from full coverage of the Barents and Kara Seas by a marine-based ice sheet to land-based ice-cap systems on adjacent archipelagos. The heart of the divergence on the nature of last glaciation in northern Eurasian is uncertainty on ice sheet thickness over Novaya Zemlya and extension into Siberia. In collaboration with the Murmansk Institute of Marine Biology we propose to initiate basic glacial-geologic, stratigraphic and geochronologic studies to provide new field data to independently evaluate the limits and timing of Weichselian glacial and deglacial events on Novaya Zemlya, Russia. Field research will focus on three field areas on northern Novaya Zemlya, where ice-free forelands contain abundant raised marine and glacial features. We plan to use the following approaches to decipher the record of Quaternary glaciations on Novaya Zemlya: 1) High resolution (10-m pixels) SPOT satellite imagery will be used to evaluate large scale sea-level, glacial erosional and depositional features (moraines) that may not readily be discernible in the field. 2) Documentation of the timing and rate of the glacial-isostatic response by radiocarbon dating of subfossils included in raised beaches of known elevation. 3) A study of the stratigraphy and sedimentology of superimposed Quaternary sediments in cliff sections. Particular attention will be given to the recognition of glacial damicts and unconformities, and the collection of micro-and macro-fauna for paleoenvironmental assessment and chronologice control. Provenance studies of clasts from glacial diamicts and fabric analysis should provide new information on glacial source area. 4) Age control for the latest glacial/sea level events will be derived from conventional and AMS radiocarbon dating of included marine subfossil and driftage. The number and timing of older events will be constrained by amino acid epimerization analyses of mollusks using L-isoleucine/D-alloisoleucine ratios and higher resolution D/L aspartic acid ratios. Numeric age will be determined by luminescence geochronometry on the fine-grained fraction (4-11(m) from raised sublittoral sediments. 5) Integration of field data with isostatic and glaciological modeling to provide insight into glacier thickness, position of ice divides, domes and streams and response to sea level rise. Results from this study are important for evaluating if ice sheets on northern continental shelves responded synchronously, if the Barents, Kara and Norwegian Seas deglaciated prior to 14 ka ago, and the effect of Eurasian ice sheets on North Atlantic thermohaline circulation. This field-based research will provide new data on Weichselian glacier geometry in the Russian Arctic, where little currently exists, which is a critical boundary condition for evolving global climate models.

更新世冰盖覆盖欧亚北方的范围和时间仍然没有解决。 这些景观范围从海洋冰盖完全覆盖的巴伦支海和喀拉海到邻近群岛的陆基冰盖系统。 欧亚北方末次冰期性质分歧的核心是新地岛冰盖厚度和向西伯利亚延伸的不确定性。 与摩尔曼斯克海洋生物研究所合作，我们建议启动基础的冰川地质，地层和地质年代学研究，提供新的现场数据，独立评估的限制和时间Weichselian冰川和冰消事件的新地岛，俄罗斯。 实地研究将集中在新属地北方的三个实地区域，那里的无冰前地含有丰富的海洋和冰川地貌。 我们计划使用以下方法来破译新地岛第四纪冰川的记录：1）高分辨率（10米像素）的SPOT卫星图像将被用来评估大规模的海平面，冰川侵蚀和沉积特征（冰碛），可能不容易辨别的领域。 2)通过对已知海拔的上升海滩中的亚化石进行放射性碳年代测定，记录冰川均衡反应的时间和速率。 3)崖剖面中第四纪叠加沉积物的地层学和沉积学研究。 将特别注意识别冰川碎屑和不整合面，收集微型和大型动物群，用于古环境评估和年代学控制。 冰川碎屑物源研究和组构分析可为冰川源区提供新的信息。 4)最新的冰川/海平面事件的年龄控制将来自常规和AMS放射性碳测年的海洋亚化石和漂流物。 使用L-异亮氨酸/D-别异亮氨酸比率和更高分辨率D/L天冬氨酸比率对软体动物进行氨基酸差向异构化分析，将限制较早事件的数量和时间。 数字年龄将通过发光地质年代测定法对来自上升的滨海沉积物的细粒部分（4-11（m））进行测定。 5)将实地数据与均衡和冰川学建模相结合，以深入了解冰川厚度、冰裂、冰丘和冰流的位置以及对海平面上升的响应。 这项研究的结果是重要的评估，如果冰盖北方大陆架同步响应，如果巴伦支海，喀拉海和挪威海冰消之前14 ka前，和欧亚冰盖对北大西洋温盐环流的影响。 这项基于实地的研究将提供俄罗斯北极地区Weichselian冰川几何形状的新数据，目前几乎不存在，这是不断发展的全球气候模型的关键边界条件。