Aspects of Late Weichselian deglaciation in South Norway: timing of deglaciation, ice sheet geometry, and climate variations inferred from surface exposure ages of Late Pleistocene and Holocene landforms

IF 0.8 4区社会学 Q3 GEOGRAPHY

Erdkunde Pub Date : 2019-12-31 DOI:10.3112/erdkunde.2019.04.03

P. Marr, S. Winkler, J. Löffler

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引用次数: 2

Abstract

The investigation of periglacial and related landforms in South Norway is of great interest for exploring the timing of deglaciation and to assess their geomorphological connectivity to palaeoclimatic changes during the Late Pleistocene and the Holocene. The ice margins of the Scandinavian Ice Sheet during the Last Glacial Maximum (LGM) are reasonably well established. Palaeo-ice thickness can, however, only be estimated by modelling and remains uncertain over large parts of Norway due to sparse field based evidence. Because of the significant influence of the former horizontal and vertical ice-sheet extent on sea-level rise, atmospheric and oceanic circulation patterns, erosive properties of glaciers and ice sheets, englacial thermal boundaries, and deglaciation dynamics, it is crucial to improve the understanding of the topographic properties of the LGM ice sheet. Despite recent progress, there is a lack of terrestrial evidence in the form of numerical age data from South Norway. In this study two high-mountain regions and their surroundings in west (Dalsnibba, 1476 m a.s.l.) and east (Blåhø, 1617 m a.s.l.) South Norway were studied to reconstruct palaeoclimatic conditions and deglaciation patterns. Terrestrial cosmogenic nuclide (10Be) and Schmidt-hammer exposure-age dating (SHD) have been utilized to determine the surface exposure age of glacially transported boulders as well as of boulder-dominated glacial, periglacial, and paraglacial landforms and bedrock outcrops. By developing calibration curves at both study sites for the first time it was possible to obtain landform-age estimates from Schmidt hammer R-(rebound) values. In addition, the formation and stabilization of those landforms and the formative processes have provided indications about the Late Pleistocene and Holocene climate variability and its connectivity to landform development.

查看原文本刊更多论文

南挪威晚期魏奇塞勒冰川消融的各个方面:从晚更新世和全新世地貌的地表暴露年龄推断出的冰川消融时间、冰盖几何形状和气候变化

对挪威南部冰缘地貌和相关地貌的调查对于探索冰川消融的时间以及评估其地貌与晚更新世和全新世古气候变化的联系具有重要意义。斯堪的纳维亚冰盖在最后一次冰川盛期（LGM）的冰缘已经得到了合理的确定。然而，古冰厚度只能通过建模来估计，由于缺乏实地证据，挪威大部分地区的古冰厚度仍不确定。由于以前的水平和垂直冰盖范围对海平面上升、大气和海洋环流模式、冰川和冰盖的侵蚀特性、英界面热边界和冰川消融动力学有着重要影响，因此提高对LGM冰盖地形特性的理解至关重要。尽管最近取得了进展，但缺乏来自南挪威的数字年龄数据形式的陆地证据。在本研究中，研究了挪威南部西部（Dalsnibba，1476 m a.s.l.）和东部（Blåhø，1617 m a.s.l.）的两个高山区及其周围环境，以重建古气候条件和冰川消融模式。陆地宇宙成因核素（10Be）和Schmidt-hammer暴露年龄定年（SHD）已被用于确定冰川搬运巨石以及以巨石为主的冰川、冰缘和副冰川地貌和基岩露头的表面暴露年龄。通过首次在两个研究地点绘制校准曲线，可以从Schmidt-hammer R-（回弹）值中获得地貌年龄估计值。此外，这些地貌的形成和稳定以及形成过程为晚更新世和全新世的气候变化及其与地貌发展的联系提供了指示。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Erdkunde 地学-自然地理

CiteScore

2.00

自引率

7.10%

发文量

审稿时长

>12 weeks

期刊介绍： Since foundation by Carl Troll in 1947, ''ERDKUNDE – Archive for Scientific Geography'' has established as a successful international journal of geography. ERDKUNDE publishes scientific articles covering the whole range of physical and human geography. The journal offers state of the art reports on recent trends and developments in specific fields of geography and comprehensive and critical reviews of new geographical publications. All manuscripts are subject to a peer-review procedure prior to publication. High quality cartography and regular large sized supplements are prominent features of ERDKUNDE, as well as standard coloured figures.