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

摘要 该奖项支持一个研究白令海峡周边地区晚更新世冰川地质的项目。 通过对近三年来在楚科奇半岛采集的化石资料的野外工作和室内分析表明，俄罗斯东北部晚新生代地层格架需要进行重大修订。 这项工作使人们对海岸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者基于生物地层学和海拔高度对间断间冰期海洋序列的相关性。 要为白令海峡两岸的白令半岛部分地区制定统一的地层系统，就需要俄罗斯东北部的更新世地层学更牢固地建立在现代冰川沉积学、等厚线和真厚线概念的基础上，并以更好的地质年代学加以保证。 了解俄罗斯北极地区冰川冰范围对于建立古气候建模的准确边界条件非常重要。 同样，了解该地区间冰期海洋条件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。 根据过去的实地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碛和其他冰川沉积物的完整清单，该项目将修订该地区的晚新生代地层，并为美国和俄罗斯研究人员提供一个机会，通过联合研究关键的地层剖面和冰碛序列，比较和交流野外方法和实验室技术，白令海峡两岸。 将特别注意古气候和古海洋学意义的相似性和对比的更新世记录。 矿床的对比和地质年代学将以各种现代技术为基础，包括软体动物氨基酸地质年代学、软沉积物古地磁学、宇宙成因同位素表面暴露年代测定和冰碛物定量地貌学，沿着传统的生物地层学。 这一项目的结果将是重要的发展在这个地区的古环境条件的全貌。 除了这里所描述的科学工作之外，这项美俄合作项目还有附带的好处。 由于我们共同边界的共同地球和文化历史，活跃在白令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。 拟议由国家公园管理局和俄罗斯同行在白令海峡地区开发一个共同管理的白令遗产公园，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，因此有必要在野外共同解决问题。 一个重要的好处将是有机会让我们的俄罗斯同事了解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.