Eutrophication and recovery of Lake Vesij�rvi (south Finland): Diatom frustules in varved sediments over a 30-year period

Hydrobiologia ◽  
1993 ◽  
Vol 269-270 (1) ◽  
pp. 415-426 ◽  
Author(s):  
Mikko Liukkonen ◽  
Timo Kairesalo ◽  
Juha Keto
Keyword(s):  
Varved Sediments

scholarly journals A long-term multi-proxy record of varved sediments highlights climate-induced mixing-regime shift in a large hard-water lake ~5000 years ago

2014 ◽  
Vol 73 (2) ◽  
Author(s):  
Walter Finsinger ◽  
Thierry Fonville ◽  
Emiliya Kirilova ◽  
Andrea Lami ◽  
Piero Guilizzoni ◽  
...  
Keyword(s):  
Regime Shift ◽  
Hard Water ◽  
Proxy Record ◽  
Varved Sediments ◽  
Water Lake ◽  
Mixing Regime

scholarly journals VARDA (VArved sediments DAtabase) – providing and connecting proxy data from annually laminated lake sediments

2020 ◽  
Author(s):  
Arne Ramisch ◽  
Alexander Brauser ◽  
Mario Dorn ◽  
Cecile Blanchet ◽  
Brian Brademann ◽  
...  
Keyword(s):  
High Resolution ◽  
Lake Sediments ◽  
Climate Models ◽  
Detailed Comparison ◽  
High Temporal Resolution ◽  
Proxy Data ◽  
Varved Sediments ◽  
Proxy Records ◽  
Data Compilation ◽  
Varved Lake Sediments

Abstract. Varved lake sediments provide long climatic records with high temporal resolution and low associated age uncertainty. Robust and detailed comparison of well-dated and annually laminated sediment records is crucial for reconstructing abrupt and regionally time-transgressive changes as well as validation of spatial and temporal trajectories of past climatic changes. The VARved sediments DAtabase (VARDA) presented here is the first data compilation for varve chronologies and associated palaeoclimatic proxy records. The current version 1.0 allows detailed comparison of published varve records from 95 lakes. VARDA is freely accessible and was created to assess outputs from climate models with high-resolution terrestrial palaeoclimatic proxies. VARDA additionally provides a technical environment that enables to explore the database of varved lake sediments using a connected data-model and can generate a state-of-the-art graphic representation of multi-site comparison. This allows to reassess existing chronologies and tephra events to synchronize and compare even distant varved lake records. Furthermore, the present version of VARDA permits to explore varve thickness data. In this paper, we report in detail on the data mining and compilation strategies for the identification of varved lakes and assimilation of high-resolution chronologies as well as the technical infrastructure of the database. Additional paleoclimate proxy data will be provided in forthcoming updates. The VARDA graph-database and user interface can be accessed online at https://varve.gfz-potsdam.de, all datasets of version 1.0 are available at http://doi.org/10.5880/GFZ.4.3.2019.003 (Ramisch et al., 2019).

Multiple Dating of a Freeze Core from Lake 227, an Experimentally Fertilized Lake with Varved Sediments

1994 ◽  
Vol 51 (10) ◽  
pp. 2274-2285 ◽  
Author(s):  
Brent Wolfe ◽  
Hedy J. Kling ◽  
Gregg J. Brunskill ◽  
Paul Wilkinson
Keyword(s):  
Algal Blooms ◽  
Seasonal Abundance ◽  
Sedimentation Rates ◽  
Experimental Lakes Area ◽  
Varved Sediments ◽  
Varve Chronology ◽  
Freeze Core ◽  
N Loading ◽  
Planktonic Community

A freeze core taken from Experimental Lakes Area Lake 227 in 1988 contained 321 rhythmically paired, dark and light laminations in the upper 60.7 cm. Tape peels revealed cyclic, seasonal abundance peaks in organic and inorganic remains, which suggested that the couplets are varves. However, comparison between varve chronology and 22 yr of experimental changes in phosphorus (P) and nitrogen (N) loading and their influence on the planktonic community confirmed that the most recent varve-year estimates were 5 or 6 yr too old; this was caused by irregular sedimentation and multiple algal blooms resulting from experimental fertilization since 1969, and indistinct laminations that hampered precise couplet identification and separation. Dated horizons determined from biostratigraphic markers were used to generate compatible profiles between 1-cm slices of Lake 227 137Cs flux and reference fallout records. Nutrient concentration profiles were less helpful, as increases in carbon, N, and, P were gradual and no distinct horizon was identified as a clear marker of eutrophication. Long-term assessment of the varve chronology using 210Pb was hindered by experimental additions of 226Ra to the lake in 1970, although similar sedimentation rates from varve years 1860–1934 suggested that the varve and the deep part of the 210Pb chronologies were comparable.

scholarly journals Late-Holocene ultra-distal cryptotephra discoveries in varved sediments of Lake Żabińskie, NE Poland

2020 ◽  
Vol 402 ◽  
pp. 106988 ◽  
Author(s):  
Małgorzata Kinder ◽  
Sabine Wulf ◽  
Oona Appelt ◽  
Mark Hardiman ◽  
Maurycy Żarczyński ◽  
...  
Keyword(s):  
Late Holocene ◽  
Varved Sediments ◽  
Ne Poland

Deglaciation history of Lake Ladoga (northwestern Russia) based on varved sediments

Boreas ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 330-348 ◽  
Author(s):  
Raphael Gromig ◽  
Bernd Wagner ◽  
Volker Wennrich ◽  
Grigory Fedorov ◽  
Larisa Savelieva ◽  
...  
Keyword(s):  
Lake Ladoga ◽  
Varved Sediments ◽  
History Of ◽  
Northwestern Russia

Taphonomic variations in Eocene fish-bearing varves at Horsefly, British Columbia, reveal 10 000 years of environmental change

2005 ◽  
Vol 42 (2) ◽  
pp. 137-149 ◽  
Author(s):  
Douglas G Barton ◽  
Mark VH Wilson
Keyword(s):  
British Columbia ◽  
Environmental Change ◽  
Morphological Changes ◽  
Short Term ◽  
Stratified Lake ◽  
Varved Sediments ◽  
Fish Morphology ◽  
Hypoxic Water ◽  
Lake Floor ◽  
Several Intervals

The Eocene Horsefly locality in British Columbia has yielded many fossil fishes, insects, and plants. Its varved sediments make it ideal for study of temporal changes in environment and fish morphology. Several intervals of diatomaceous varves indicate a deep, stratified lake setting. Earlier studies focused on morphological and taphonomic change during the 700-year H2 interval and morphological change during the 10 000-year H3 interval. The present study uses taphonomy as an index for environmental change during the ten millennia represented by H3, comparing taphonomic changes with the morphologic changes found earlier. The H3 interval records deposition in deep water, indicated by dominance of the fish genera Amyzon and Eohiodon. Quiet water conditions are indicated by minimal fin disarticulation. Hypoxia at the time of fish death is confirmed by open mouths of most fish specimens, while cool water on the lake floor prevented full flotation of fish carcasses. Water depth, temperature, and oxygenation fluctuated during H3 deposition. Periods of cooler, deeper, more hypoxic water are indicated by greater numbers and size of Amyzon specimens and by less disarticulation of skull and abdominal bones. Periods of warmer, shallower, more oxygenated waters are indicated by more disarticulation, less fin tetany, smaller fish specimens, and greater diversity of species. Correlations between the taphonomic changes and morphological changes in A. aggregatum are weak. Therefore, the morphological changes are not easily explained as ecophenotypic or short-term evolutionary responses to changes in physical lake conditions.

Orbital and solar forcing of shifts in Mid- to Late Holocene flood intensity from varved sediments of pre-alpine Lake Ammersee (southern Germany)

2013 ◽  
Vol 61 ◽  
pp. 96-110 ◽  
Author(s):  
Markus Czymzik ◽  
Achim Brauer ◽  
Peter Dulski ◽  
Birgit Plessen ◽  
Rudolf Naumann ◽  
...  
Keyword(s):  
Late Holocene ◽  
Alpine Lake ◽  
Solar Forcing ◽  
Southern Germany ◽  
Varved Sediments ◽  
Flood Intensity

Minor element variations during the past 1300 years in the varved sediments of Lake Xiaolongwan, north-eastern China

GFF ◽  
2013 ◽  
Vol 135 (3-4) ◽  
pp. 265-272 ◽  
Author(s):  
Guoqiang Chu ◽  
Qing Sun ◽  
Shengqiang Li ◽  
Yuan Lin ◽  
Xiaohua Wang ◽  
...  
Keyword(s):  
Eastern China ◽  
Minor Element ◽  
Varved Sediments ◽  
The Past ◽  
North Eastern
Sign in / Sign up

Export Citation Format

Share Document