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Last Glacial loess in Europe: luminescence database and chronology of deposition
Earth System Science Data ( IF 11.4 ) Pub Date : 2023-05-31 , DOI: 10.5194/essd-2023-105
Mathieu Bosq, Sebastian Kreutzer, Pascal Bertran, Philippe Lanos, Philippe Dufresne, Christoph Schmidt

Abstract. During the last glacial period, the climate shift to cold conditions associated with changes in atmospheric circulation and vegetation cover resulted in the development of large aeolian systems in Europe. On a regional scale, many factors may have influenced dust dynamics, such as the latitudinal difference between the various aeolian systems and the variability of the sources of wind-transported particles. Therefore, the assumption that the timing of aeolian deposition is strictly synchronous in Europe does not seem to be the most plausible hypothesis and needs to be evaluated. To test this assumption, the chronology of loess deposition in different European regions was investigated by studying 93 luminescence-dated loess-palaeosol sequences with their data recalculated and compiled in a single CSV file: the ChronoLoess database. Our study shows that the two major aeolian systems, the Northern European Loess Belt (NELB) on the one hand and the systems associated with the rivers draining the Alpine Ice Sheet on the other hand, developed asynchronously. The significant deposition started at about 32 ka for the NELB vs 40 ka for the perialpine loess and peaked about two millennia later for the former (21.8 ka vs 23.9 ka, respectively). This shift resulted mainly from the time lag between the maxima of the Alpine and Fennoscandian ice sheets, which acted as the primary sources of fine-grained particles through glacial abrasion. The major geomorphic changes that resulted from the development and decay of the Fennoscandian and British-Irish ice sheets also played an important role. Particularly, ice sheet coalescence during the LGM diverted meltwater fluxes through the Manche River and provided vast amounts of glacial particles available for deflation in the western NELB. The period during which the maximum Mass Accumulation Rate was reached for each loess-palaeosol sequence is relatively homogeneous in the NELB and ranges from 30 ka to 19 ka, whereas it is more scattered in the perialpine systems (>60 ka to 14 ka). This probably resulted from a combination of factors, including the asynchrony of maximum valley glacier advances and local geomorphic factors.

中文翻译:

欧洲末次冰川黄土:发光数据库和沉积年表

摘要。在最后一个冰河时期,气候向寒冷条件转变,与大气环流和植被覆盖的变化相关,导致欧洲大型风成系统的发展。在区域范围内,许多因素可能会影响尘埃动力学,例如各种风成系统之间的纬度差异以及风输送颗粒来源的可变性。因此,欧洲风成沉积时间严格同步的假设似乎不是最合理的假设,需要进行评估。为了检验这一假设,通过研究 93 个发光年代的黄土-古土壤序列,研究了不同欧洲地区黄土沉积的年代学,并将其数据重新计算并编译在一个 CSV 文件中:ChronoLoess 数据库。我们的研究表明,两个主要的风成系统,一方面是北欧黄土带 (NELB),另一方面是与排干阿尔卑斯冰原的河流相关的系统,是不同步发展的。NELB 的显着沉积开始于约 32 ka,而 perialpine 黄土为 40 ka,前者在约两千年后达到顶峰(分别为 21.8 ka 和 23.9 ka)。这种转变主要是由于阿尔卑斯山冰盖和芬诺斯坎迪亚冰盖的最大值之间的时间滞后,这是通过冰川磨蚀产生细粒颗粒的主要来源。Fennoscandian 和 British-Irish 冰盖的发展和衰退导致的主要地貌变化也发挥了重要作用。特别,LGM 期间的冰盖合并转移了通过曼彻河的融水通量,并提供了大量可用于 NELB 西部通缩的冰川颗粒。每个黄土-古土壤序列达到最大质量积累率的时期在 NELB 中相对均匀,范围从 30 ka 到 19 ka,而在高山周系统中则更分散(>60 ka 到 14 ka)。这可能是多种因素共同作用的结果,包括最大山谷冰川推进的不同步和当地地貌因素。而它更分散在阿尔卑斯山周围系统(>60 ka 到 14 ka)。这可能是多种因素共同作用的结果,包括最大山谷冰川推进的不同步和当地地貌因素。而它更分散在阿尔卑斯山周围系统(>60 ka 到 14 ka)。这可能是多种因素共同作用的结果,包括最大山谷冰川推进的不同步和当地地貌因素。
更新日期:2023-05-31
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