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

这是一个合作项目，其主要目标是编制上一次冰川期间斯堪的纳维亚冰盖(SIS)南缘(陆地)的改进年表，以便将这一边缘的历史与SIS西缘的历史、与其他冰盖以及其他气候变化记录进行比较，以便进一步评估冰缘波动与气候变化之间的关系。该项目将通过以下方法建立年表：(1)用AMS放射性碳测定关键有机单元的年龄；(2)用宇宙成因核素(10Be和26Al)测定冰雹表面上的不稳定巨石。显著的退缩冰雹划分了魏氏晚期最大值之后约18,000年的五到六个退缩阶段，清楚地表明了一个强烈的千禧年尺度的信号(18,000到10,000年间的五到六个冰雹建造事件)。然而，制约SIS南部边缘撤退阶段年龄的测年控制几乎是缺乏的。该项目将调查(I)SIS南缘向其最后一次冰川最大位置推进之前的非冰期间隔的年龄，(Ii)南缘达到其最后一次冰川最大位置之前的年龄，以及(Iii)由退缩冰雹显著记录的南缘衰退阶段的地区(S)。该项目将重点研究波兰、拉脱维亚、爱沙尼亚、立陶宛、白俄罗斯和俄罗斯的SIS的矿藏和地貌。

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.