First results from the Lateglacial and Early
Holocene fill of Lac Retournemer (Vosges, France):
another INTIMATE Example
Wim Z. Hoek
1, Arjan van Eijk
1, Stan Schouten
1, Stefan Engels
2, Christine Lane
3, Nathalie van der Putten
4, Didier Roche
4,5, and summer school participants
1
Department of Physical Geography, Faculty of Geosciences, Utrecht University, the Netherlands
2
Department of Geography, Birkbeck University of London, United Kingdom
3
Department of Geography, University of Cambridge, United Kingdom
4
Department of Earth Sciences, VU University Amsterdam, The Netherlands
5
Laboratoire des Sciences du Climat et de l’Environnement, Gif sur Yvette, France
One of the current activities of the INTIMATE Network is the organization of bi-annual Research Training Schools for Early Career Scientists. During these INTIMATE Example Summer Schools, a mix of fieldwork, lectures and lab-based activities are executed focusing on a central theme/specific site. After successful training schools in Germany
(2013), Rumania (2014) and Poland (2016), the fourth INTIMATE Example Research Training School centered around the coring of Lac Retournemer, France in July 2018.
Lac Retournemer is located in the Vosges mountains (eastern France) at 776m above sea level in the head-waters of the Vologne Valley and is currently an 11m deep lake behind a glacial threshold of
igneous rock. This area is one of the wettest areas in France with high precipitation values and might therefore be a good site to record Icelandic tephras. Previous investigations in 1970-80 show that at least 15m of partially laminated sediments are present in this basin with also a possible occurrence of Laacher See Tephra.
11.4 ka
-44 -42 -40 -38 -36 ‰
INTIMATE event stratigraphy after Rasmussen et al. (2014) showing cold and warm phases in the NGRIP icecore
The Loss on Ignition profile on a depth scale shows lower organic values during the siliciclastic Younger Dryas interval. Within the Lateglacial Interstadial (GI-1) and Early Holocene multiple fluctuations occur which compares to the oscillations in the INTIMATE event stratigraphy for this time period. Preliminary palynological results support the Lateglacial and Early Holocene age of the sequence with open vegetation phases in zone 1 & 3 and a birch-pine forest in zone 2, with zone 4 resembling the Holocene.
The differences in response with other proxies such as chironomids, geochemistry etc. are currently under investigation. The occurrence of Laacher See Tephra (2856 cm) and Icelandic tephras in the core will add to the existing tephra lattice for the Lateglacial and Early Holocene in Central and NW Europe.
We obtained a 18m sediment record from the deepest part of the lake before we reached the basal
glaciolacustrine sediments at 29 m below water level. The first results from the basal two meters of the
sequence show a clear Lateglacial and Early Holocene laminated sediment record with Laacher See Tephra and a possible occurrence of Vedde Ash in the more siliciclastic Younger Dryas (GS-1) sediments.
Supported by:
Geomorphological map (Salomé, 1968)
Disturbed
2740 2750 2760 2770 2780 2790 2800 2810 2820 2830 2840 2850 2860 2870 2880 2890 2900 2910 2920 2930 2940
Lamina ted
0 5 10 15 20 25%
Lac Retournemer pollen diagram with selected taxa and organic content of the basal 2m
Loss on Ignition
2740 2750 2760 2770 2780 2790 2800 2810 2820 2830 2840 2850 2860 2870
2880 2890
2900
2910 20 40 60 80 100 20 20 40 20 40 20 40 60 20 20 20 20 20
82 217 112 88 158 116 129 89 164
50 192 244 69 126 112 40 64 172 68 63 117 80 23 155 96 171 252119 171 66 113339 288291 316272 290 287 286 277275 273253 126 195
20 40 20 50 100 150 20 40 60 80 100
Zone
4
3
2
1
trees & shrubs upland herbs local taxa
analysis W.Z. Hoek & MSc course students 2019
LST
