The Late Pleistocene Glacial And Sea Level History of Wrangel Island, Northeast Siberia

摘要：末次冰盛期北极冰盖的范围和结构是第四纪历史中重要的缺失部分之一。 北极冰川作用的范围和年代学在形成现代高纬度植物群和动物群的现代分布和组成方面发挥了重要作用。 没有一个冰盖比提议覆盖东西伯利亚海的冰盖更有争议。 一些冰川学家认为第四纪晚期存在着东西伯利亚海基冰盖（ESIS），并将其用于古气候模型中。 然而，冰川地质沿着拟议的冰盖的东部边缘只进行了表面上的调查。 弗兰格尔岛是这样一个调查的关键地区。 东西伯利亚海第四纪晚期条件的确认将有助于古气候模拟工作，并大大提高我们对俄罗斯北极东部和西部冰范围差异的理解。首席调查员将研究弗兰格尔岛的冰川历史，以提供第一个实地证据来验证以下假设：1）弗兰格尔岛在LGM或更早的时候被冰盖覆盖; 2）弗兰格尔岛未被发现，但位于ESIS的外围洼地;或3）弗兰格尔岛仍然没有冰川，除了有限的高山冰川。 这些假设将通过使用放射性碳，气相色谱氨基酸，10 Be，26 A1和36 C1宇宙成因同位素测年提供该地区的第一个放射性海平面和冰川年表进行测试。 通过孢粉学分析评估变化，将用于解释晚第四纪植被和推断气候。 这项研究应有助于显着的晚第四纪古环境研究在西伯利亚中部，西部和东北部不断增长的数据库。 这项研究将满足俄罗斯-美国北极大陆架环境倡议（RAISE）的目标，也将满足其他国际项目的需要，如欧亚北部第四纪环境（QUEEN）和环北极古环境（CAPE）。

AbstractOPP-9906702The extent and configuration of the Arctic ice sheet during the Last Glacial Maximum (LGM) is one of the critical missing pieces in Quaternary history. The extent and chronology of glaciation in the Arctic has played a significant role in shaping the modern distribution and composition of modern high latitude flora and fauna. No ice sheet has been more controversial than the one proposed to cover the East Siberian Sea. The presence of a marine-based East Siberian Ice Sheet (ESIS) during the late Quaternary has been suggested by some glaciologists and has been used in paleoclimate models. However, the glacial geology along the proposed ice sheet's eastern margin has only been superficially investigated. Wrangel Island is the key region for such an investigation. Confirmation of the late Quaternary conditions of the East Siberian Sea would aid paleoclimate modeling efforts and greatly improve our understanding of differences in ice extent between the eastern and western Russian Arctic.The Principal Investigators will study the glacial history of Wrangel Island to provide the first field evidence to test the following hypotheses: 1) Wrangel Island was covered by an ice sheet covered during the LGM or earlier; 2) Wrangel Island was uncovered, but lay in the peripheral depression of an ESIS; or 3) Wrangel Island remained unglaciated, except perhaps for limited alpine glaciation. These hypotheses will be tested by providing the first radiometric sea-level and glacial chronologies for this region by using radiocarbon, gas chromatography amino acid, 10Be, 26A1, and 36C1 cosmogenic isotope dating. Palynological analysis to assess variations will be used to interpret Late Quaternary vegetation and inferred climates. This research should contribute a significantly to a growing database of Late Quaternary paleoenvironmental studies in central, western and northeast Siberia. This research will fufill the Russian-American Initiative on Shelf-Land Environments in the Arctic (RAISE) goals and will also meet the needs of other international programs, such as Quaternary Environment of the Eurasian North (QUEEN)and Circum-Arctic Paleo-Environments (CAPE).