Lake Tiefer See varve microfacies, bulk geochemistry, µ-XRF, vegetation openness and Cladocera record
Cobertura |
LATITUDE: 53.583300 * LONGITUDE: 12.516700 |
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Data(s) |
30/06/2016
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Resumo |
The Holocene sediment record of Lake Tiefer See exhibits striking alternations between well-varved and non-varved intervals. Here we present a high resolution multi-proxy record for the past ~6000 years and discuss possible causes for the observed sediment variability. This approach comprises of microfacies, geochemical and microfossil analyses as well as of a multiple dating concept including varve counting, tephrochronology and radiocarbon dating. Four periods of predominantly well-varved sediment were identified at 6000-3950 cal. a BP, 3100-2850 cal. a BP, 2100-750 cal. a BP and AD 1924-present. Except of sub-recent varve formation, these periods are considered to reflect reduced lake circulation and consequently, stronger anoxic bottom water conditions. In contrast, intercalated intervals of poor varve preservation or even extensively mixed non-varved sediments indicate strengthened lake circulation. Sub-recent varve formation since AD 1924 is, in addition to natural forcing, influenced by enhanced lake productivity due to modern anthropogenic eutrophication. The general increase in periods of intensified lake circulation in Lake Tiefer See since ~4000 cal. a BP presumably is caused by gradual changes in Northern Hemisphere orbital forcing, leading to cooler and windier conditions in Central Europe. Superimposed decadal to centennial scale variability of the lake circulation regime likely is the result of additional human-induced changes of the catchment vegetation. The coincidence of major non-varved periods at Lake Tiefer See and intervals of bioturbated sediments in the Baltic Sea implies a broader regional significance of our findings. |
Formato |
application/zip, 6 datasets |
Identificador |
https://doi.pangaea.de/10.1594/PANGAEA.862117 doi:10.1594/PANGAEA.862117 |
Idioma(s) |
en |
Publicador |
PANGAEA |
Direitos |
CC-BY: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted |
Fonte |
Supplement to: Dräger, Nadine; Theuerkauf, Martin; Szeroczynska, Krystyna; Wulf, Sabine; Tjallingii, Rik; Plessen, Birgit; Kienel, Ulrike; Brauer, Achim (2016): Varve microfacies and varve preservation record of climate change and human impact for the last 6000 years at Lake Tiefer See (NE Germany). The Holocene, online first, doi:10.1177/0959683616660173 |
Palavras-Chave | #Age; AGE; Age, comment; Age, maximum/old; Age, minimum/young; Age, uncertainty; Age max; Age min; Age model; Age unc; B. coregoni; B. longirostris; B. longispina; Bosmina (Eubosmina) coregoni; Bosmina (Eubosmina) longispina; Bosmina longirostris; C/N; cal. ka BP; Carbon, inorganic, total; Carbon, organic, total; Carbon/Nitrogen ratio; Cladocera; Cladocera, benthic; Cladocera benth; Comm; COMPCORE; Composite Core; composite depth; composite depth, sediment gap 1 between 9.5667 and 9.5649 m, gap 2 between 7.6989 and 7.6975 m; Core; Depth; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Depth bot; Depth top; Label; ln(Ca/Mn); ln(Ti/Si); ln-Calcium/Manganese ratio; ln-Titanium/Silicon ratio; mean; Mecklenburg-West Pomerania, Germany; Reconstructed; Sample code/label; Sedimentation rate per year; Sedim rate; TIC; Tiefer-See; TOC; Varve quality index; Varve type; Varve types; Vegetation open; Vegetation openness; very long mucro; VQI |
Tipo |
Dataset |