New records from old tephra from Northern Germany.

Dörfler, Walter and van den Bogaard, Christel (2011) New records from old tephra from Northern Germany. [Poster] In: 18. INQUA-Congress, Quaternary Sciences – The View From The Mountains. , 21.07.-27.07.2011, Bern, Switzerland .

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Abstract

Tephra layers detected in a laminated lake sediment in Northern Germany provide a good chance for high resolution studies of the deposition process and for independent dating. Lake Belau, a 28,3 m deep lake in the young morain area of Schleswig-Holstein has an overall Holocene record of 29 m. Most of the upper 23 m is well laminated und stratified. By a total of 92 marker horizons a consistent record is created out of nine parallel cores. Unfortunately the record is not continuing to the top and by this the chronology is shifting. A number of 14C-dates provide a good chronology and give new datings for the detected tephra layers,
Particles from Hekla 3 shows the highest input values. The first distinct traces of tephra particles were detected in the summer and autumn layer of varve no. 6294 with a density of 0.96 particles/mg. The highest values occured in the next layer, representing the winter and spring deposits of warve no. 6295, with a density of 4.83 particles /mg. Just a few glass shards were found in the deposits above these layers with a maximum density of 0.14 particles/mg indicating just little redeposition or erosion of soil material with tephra particles. Hekla 4 ( sample H4-7) shows much lower values with a distinct increase from one sample to another but a longer reverberation. Values increase from 0.01 to 0.30 particles/mg in varve no. 5016 to 5017. Both layers, the winter/spring and the summer/autumn layer, have high values that decrease slowly in the next two years. According to this there is more redeposition of surface material or the eruption is built up by a series of single eruptions.
A third layer, Lairg B (Lairg 6), shows a fast increase up to values of 0.37 particles/mg in the winter layer of warve no. 2570 and just low values of 0.04 particles/mg in the following years.
The poster will present further results from the pollen studies on the dating and duration of Neolithic settlement phases, the AMS dating of terrestrial material and the chemical composition of the particles.

Document Type: Conference or Workshop Item (Poster)
Keywords: Paleoceanography; Geology
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-P-OZ Paleo-Oceanography
Kiel University
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Date Deposited: 12 Jan 2012 10:49
Last Modified: 23 Feb 2012 06:18
URI: http://oceanrep.geomar.de/id/eprint/13377

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