Collaborative Research: Developing an Improved Chronology of the Southern Margin of the Scandinavian Ice Sheet

合作研究：改进斯堪的纳维亚冰盖南缘年代学

• 批准号: 0000652
• 负责人: Edward Brook
• 金额: $ 7.43万
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-15 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0000652&HistoricalAwards=false
• 关键词: Collaborative; Research; Developing; Improved; Chronology

This is a collaborative project whose principal objective is to develop an improved chronology of the southern (terrestrial) margin of the Scandinavian Ice Sheet (SIS) during the last glaciation in order to compare the history of this margin with that of the western margin of the SIS, with other ice sheets, and with other records of climate change in order to further evaluate the relationship between ice-margin fluctuations and climate change. The project will construct a chronology by dating (1) key organic-bearing units by AMS radiocarbon and (2) erratic boulders on moraine surfaces using cosmogenic nuclides (10Be and 26Al). Prominent recessional moraines delimit five to six retreat phases following the late Weichselian maximum at about 18,000 yr B.P., clearly suggesting a strong millennial-scale signal (five to six moraine building events between 18,000 and 10,000 yr B.P). However, dating control constraining the age of retreat phases along the southern SIS margin is all but lacking. The project will investigate (i) the age of the nonglacial interval before advance of the southern SIS margin to its last glacial maximum position, (ii) the age that the southern margin reached its last glacial maximum, and (iii) the area(s) of recessional phases of the southern margin that are prominently recorded by recessional moraines. The project will focus on deposits and landforms of the SIS in Poland, Latvia, Estonia, Lithuania, Belarus, and Russia.

这是一个合作项目，其主要目标是制定一个改进的南方年表，（陆地）边缘的斯堪的纳维亚冰盖（SIS）在末次冰期，以比较历史的边缘与西边缘的SIS，与其他冰盖，并与其他气候变化记录相结合，以进一步评估冰缘波动与气候变化之间的关系。该项目将通过测定（1）AMS放射性碳的关键有机承载单元和（2）使用宇宙成因核素（10 Be和26 Al）冰碛表面上的不稳定巨石的年代来构建年表。在大约18,000年B. P.的Weichselian晚期最大值之后，突出的后退冰碛划分了5到6个后退阶段，这清楚地表明了一个强烈的千年尺度的信号（B.P在18，000年到10，000年之间发生了5到6次冰碛形成事件）。然而，年代控制约束的后退阶段的年龄沿着南部SIS边缘是所有，但缺乏。该项目将调查（一）南部SIS边缘推进到末次冰期最大值位置之前的非冰川间隔的年龄，（二）南部边缘达到末次冰期最大值的年龄，以及（三）南部边缘的退缩阶段的面积，这些退缩阶段被退缩冰碛显著记录。该项目将重点关注波兰、拉脱维亚、爱沙尼亚、立陶宛、白俄罗斯和俄罗斯的SIS矿床和地貌。