Pleistocene Glacial Ice Cover and Interglacial Paleoclimatic History in the NE Russian Arctic - Comparisons with Alaska

该奖项支持一个研究白令海峡沿岸地区晚更新世冰川地质的项目。过去三年在楚科特卡半岛采集的野外工作和实验室分析表明，俄罗斯东北部晚新生代地层格架需要重大修改。这项工作使人们对沿海地层学中记录的冰川事件的数量产生了怀疑，并破坏了俄罗斯工作人员根据生物地层学和海拔高度对间冰期间断海洋序列进行的对比。为了制定白令海峡两岸贝林贾部分的统一地层方案，俄罗斯东北部的更新世地层必须更加牢固地建立在现代冰川沉积学、均衡和均衡概念的基础上，并有更好的地质年代学保障。了解俄罗斯北极的冰川范围对于为古气候模拟建立准确的边界条件很重要。同样，了解该区域间冰期海洋状况对于了解水团分布和热量输送的变化以及了解白令海峡在全球海洋环流模型中的作用也很重要。基于过去的野外工作和使用欧洲航天局合成孔径雷达图像对俄罗斯东北部冰雹和其他冰川成因沉积物的完整清查，该项目将修订该地区的晚新生代地层，并通过联合研究白令海峡两岸的关键地层剖面和冰川序列，为美国和俄罗斯研究人员提供一个比较和交流野外方法和实验室技术的机会。将特别注意更新世记录中相似和对比的古气候和古海洋学意义。矿床的对比和地质年代学将基于各种现代技术，包括软体动物的氨基酸年代学、软沉积物的古地磁、宇宙成因的同位素表面暴露测年和冰雹的定量地貌学，以及传统的生物地层学。该项目的结果将对全面了解该地区的古环境状况具有重要意义。除了这里描述的科学工作之外，这个美俄合作项目还有其他好处。由于我们共同的地球和文化历史，活跃在贝林贾地区的美国和俄罗斯第四纪研究人员之间的合作和联合实地工作是有益的。由国家公园管理局和俄罗斯对口单位在白令海峡地区共同管理的柏林遗产公园的拟议发展突出了这一共同遗产。由于各国在沉积学和地层学术语和概念上存在差异，有必要在实地共同解决问题。一个重要的好处将是有机会让我们的俄罗斯同事接触到他们国家目前没有的地质年代学技术。

Abstract This award supports a project to study the late Pleistoceneglacial geology of the regions bordering the Bering Strait. Field work and laboratory analyses of fossil materials collected on Chukotka Peninsula over the last three years indicates that the late Cenozoic stratigraphic framework for NE Russia is in need of significant revision. This work casts doubt on the number of glacial events recorded in the coastal stratigraphy and undermines the correlation by Russian workers of disjunct interglacial marine sequences that has been based on biostratigraphy and elevation above sea level. The development of a unified stratigraphic scheme for those parts of Beringia on both sides of the Bering Strait requires that the Pleistocene stratigraphy of NE Russia be more firmly based upon modern concepts of glacial sedimentology, isostasy, and eustasy and secured with better geochronology. Knowledge of glacial ice extent in the Russian Arctic is important for establishing accurate boundary conditions for paleoclimatic modeling. Likewise, knowledge of interglacial marine conditions in the region is important for understanding changes in the distribution of watermasses and heat transport as well as understanding the role of the Bering Strait in global ocean circulation models. Based upon past field work and a complete inventory of moraines and other glaciogenic deposits using European Space Agency synthetic-aperture-radar images across NE Russia, this project will revise the Late Cenozoic stratigraphy of the region and provide an opportunity for both US and Russian researchers to compare and exchange field methods and laboratory techniques via joint study of crucial stratigraphic sections and moraine sequences on both sides of the Bering Strait. Special attention will be given to the paleoclimatic and paleoceanographic significance of similarities and contrasts in the Pleistocene records. The correlation and geochronology of the deposits will be based upon a variety of modern techniques, including amino acid geochronology of mollusks, soft sediment paleomagnetism, cosmogenic isotope surface exposure dating and quantitative geomorphology of moraines, along with traditional biostratigraphy. The results of this project will be important to developing a complete picture of paleoenvironmental conditions in this region. Beyond the scientific work described here there are ancillary benefits to this US-Russian cooperative venture. Collaboration and joint field work between U.S. and Russian Quaternary researchers active in areas of Beringia is beneficial due to the shared earth and cultural history of our common border. The proposed development in the Bering Strait region of a jointly managed Beringian Heritage Park by the National Park Service and Russian counterparts highlights this shared legacy. Shared problem-solving in the field is necessary due to national differences in sedimentologic and stratigraphic terminology and concepts. An important benefit will be the opportunity to expose our Russian colleagues to geochronological techniques not presently available in their country.