scholarly journals Late Glacial and early Holocene development of an oxbow lake in Central Europe (Poland) based on plant macrofossil and geochemical data

The Holocene ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 178-189 ◽  
Author(s):  
Mariusz Gałka ◽  
Agnieszka Lewandowska ◽  
Przemysław Niedzielski ◽  
Thomas G Sim ◽  
Graeme T Swindles ◽  
...  
Keyword(s):  
Water Level ◽  
Cold Water ◽  
Late Glacial ◽  
Early Holocene ◽  
Oxbow Lake ◽  
Geochemical Data ◽  
Ceratophyllum Demersum ◽  
Plant Macrofossil ◽  
Glacial Origin ◽  
The North

Sediments from an oxbow lake located in the Prosna River valley (Poland) were analysed to investigate the developmental history of the wetland ecosystem and any response to abrupt climatic changes. High resolution plant macrofossil analysis and radiocarbon dating were undertaken on two cores, with lower resolution geochemical analysis conducted on one of these cores. We provide evidence of a palaeolake with a late Glacial origin (older than 12,500 years). Abundant fossil presence of macrophytes (e.g. multiple Potamogeton species) in the studied palaeomeander may indicate that the north–south orientation of the Prosna valley made it an important route for the spreading of aquatic plants during the late Glacial. Chara sp., Batrachium sp. and Potamogeton spp. were the pioneer plants that colonised cold water with a high Ca2+ content. Early Holocene warming trigged a decrease in water level at the oxbow lake and facilitated the expansion of thermophilous water plants, for example, Ceratophyllum demersum, Typha sp. and Lemna trisulca, which usually occur in shallow water. A decreasing water level resulted in the gradual isolation of the study site from the influence of groundwater, leading to acidification of the habitat and the development of a Sphagnum population, with S. contortum and S. teres as dominant species. The presence of S. contortum (the oldest occurrence in the European lowlands) and S. teres during the early Holocene may indicate that river valleys and the peatlands that developed in this region acted as an important habitats (and possibly refugia) for some minerotrophic Sphagnum species.

scholarly journals A major hydrobiological change in Dasht-e Arjan Wetland (southwestern Iran) during the late glacial – early Holocene transition revealed by subfossil chironomids

2019 ◽  
Vol 56 (8) ◽  
pp. 848-856
Author(s):  
Cyril Aubert ◽  
Morteza Djamali ◽  
Matthew Jones ◽  
Hamid Lahijani ◽  
Nick Marriner ◽  
...  
Keyword(s):  
Lake Level ◽  
Regional Scale ◽  
Younger Dryas ◽  
Late Glacial ◽  
Early Holocene ◽  
Geochemical Data ◽  
The Holocene ◽  
Chironomus Plumosus ◽  
Subfossil Chironomids ◽  
Southwestern Iran

The late glacial – early Holocene transition is a key period in the earth’s history. However, although this transition is well studied in Europe, it is not well constrained in the Middle East and palaeohydrological records with robust chronologies remain scarce from this region. Here we present an interesting hydrobiological record showing a major environmental change occurring in the Dasht-e Arjan Wetland (southwestern Iran, near to Persepolis) during the late glacial – early Holocene transition (ca. 11 650 years cal BP). We use subfossil chironomids (Insecta: Diptera) as a proxy for hydrological changes and to reconstruct lake-level fluctuations. The Arjan wetland was a deep lake during the Younger Dryas marked by a dominance of Chironomus plumosus/anthracinus-type, taxa adapted to anoxic conditions of deep waters. At the beginning of the Holocene, a drastic decrease (more than 80% to less than 10%) of Chironomus plumosus/anthracinus-type, combined with diversification of littoral taxa such as Polypedilum nubeculosum-type, Dicrotendipes nervosus-type, and Glyptotendipes pallens-type, suggests a lake-level decrease and a more vegetalized aquatic environment. We compare and contrast the chironomid record of Arjan with a similar record from northwestern Iran. The palaeoclimatic significance of the record, at a local and regional scale, is subsequently discussed. The increase in Northern Hemisphere temperatures, inferred by geochemical data from NGRIP, at the beginning of the Holocene best explains the change from the Younger Dryas highstand to early Holocene lowstand conditions in the Dasht-e Arjan wetland. However, a contribution of the meltwater inflow from small local glaciers in the catchment basin is not excluded.

Lost in dating – Problems with the absolute chronologies and sedimentation rates of Late Glacial and Early Holocene oxbow lake deposits in Central Europe

2017 ◽  
Vol 41 ◽  
pp. 187-201 ◽  
Author(s):  
Piotr Kołaczek ◽  
Mariusz Gałka ◽  
Karina Apolinarska ◽  
Piotr Gębica ◽  
Sławomir Superson ◽  
...  
Keyword(s):  
Central Europe ◽  
Late Glacial ◽  
Early Holocene ◽  
Oxbow Lake ◽  
Sedimentation Rates ◽  
The Absolute ◽  
Lake Deposits

Early Holocene hydrology and environments of the Ner River (Poland)

2016 ◽  
Vol 85 (2) ◽  
pp. 187-203 ◽  
Author(s):  
Piotr Kittel ◽  
Mateusz Płociennik ◽  
Ryszard K. Borόwka ◽  
Daniel Okupny ◽  
Dominik Pawłowski ◽  
...  
Keyword(s):  
Climate Changes ◽  
Late Glacial ◽  
Reference Points ◽  
Early Holocene ◽  
Oxbow Lake ◽  
Pollen Data ◽  
Overbank Sediments ◽  
Winter Temperatures ◽  
Organic Deposits ◽  
Boreal Period

The Ner River valley (central Poland) underwent substantial transformation during the Weichselian–Holocene transition as a result of fluvial processes and climate changes, resulting in the establishment of its present shape in the Holocene. A multiproxy study based on organic deposits from a palaeochannel fill (Lutomiersk–Koziówki) shows that after the channel was cut off during the late glacial termination, it became a shallow oxbow, fed by local springs. In the Boreal period, the oxbow lake was also fed by precipitation and became a telmatic environment overgrown by rush and swamp vegetation. Finally, it was covered by overbank deposits. The first flooding phase (9900–9600 cal. BP) was followed by the accumulation of overbank sediments (after 9500 cal. BP) and flooding increased after ca. 9300–9000 cal. BP. Pollen data provide information on the regional vegetation context for local and regional changes. In the Atlantic period, an increase in both summer and winter temperatures is inferred from the pollen data, corresponding to an expansion of thermophilous deciduous forests. While in general, flooding phases of the Early Holocene are poorly recognised in Eastern Europe, the Lutomiersk–Koziówki site may be considered as one of the reference points for this phenomenon in the region.

Exploration of submerged Mesolithic landscapes around the Brown Bank, southern North Sea

2020 ◽  
Author(s):  
Merle Muru ◽  
Rachel Harding ◽  
Simon Fitch ◽  
Tine Missiaen ◽  
Vince Gaffney
Keyword(s):  
North Sea ◽  
Late Glacial ◽  
Early Holocene ◽  
Ex Situ ◽  
Commercial Fishing ◽  
Peat Layer ◽  
Dry Land ◽  
Archaeological Material ◽  
Southern North Sea ◽  
The North

<p>During the late glacial and early Holocene, vast areas of dry land stretched from the British Isles to continental Europe over what is now the southern part of the North Sea. Whilst it is known that this landscape was inhabited, little is known about the cultures that lived there and the surrounding environment. This study focuses on the Brown Bank area, between the UK and Dutch coasts, with its significant 25 km long and 10-15 m high ridge on the seabed which has provided many Mesolithic ex-situ finds. However, all of these finds have been recovered serendipitously due to commercial fishing and dredging, and thus the landscape and sedimentary context of these archaeological finds is unclear.<br>The goal of this study is to map the terrestrial features in the Brown Bank area and reconstruct the palaeolandscape and its inundation to determine the potential locations from which this archaeological material derives, and potentially locate Mesolithic settlement sites. The project uses high-resolution parametric echosounder surveys in a dense survey network to record the area and facilitate later targeted dredging and vibro-core sampling.<br>The seismic surveys revealed a pre-marine inundation landscape with fluvial channels eroded into post glacial sediments. A peat layer was located on the top of the banks of the channels where it continues laterally hundreds of metres. Radiocarbon dating of the top part of the peat layer, just below the transgressive deposits gave ages around 10.2-9.9 cal ka BP. Palaeogeographic reconstructions based on the mapped terrestrial features and the available relative sea level change data suggest that the final inundation of the area happened c. 1000 years later. Where dredging was carried out in areas of interest, primarily where the early Holocene surface outcropped onto the seabed, a large number of blocks of peat with pieces of wood and other macrofossils were recovered, suggesting a good potential for preservation of possible archaeological material and possible locations of origin for the serendipitous finds made by fishermen.<br>We conclude that this study provides new insights into the palaeogeography and the timing of the inundation of the Brown Bank area and gives the landscape context to the potential Mesolithic habitation of this part of the southern North Sea.</p>

Postglacial evolution of a small lake in the South Baltic coastal zone based on geochemical, pollen and subfossil Cladocera analysis

2018 ◽  
Vol 47 (4) ◽  
pp. 384-397 ◽  
Author(s):  
Monika Niska ◽  
Joanna Gadziszewska ◽  
Jerzy Jonczak ◽  
Wacław Florek ◽  
Bogusława Kruczkowska
Keyword(s):  
Water Level ◽  
Late Glacial ◽  
Water Level Fluctuations ◽  
Geochemical Data ◽  
Peat Bogs ◽  
Subfossil Cladocera ◽  
Sedimentary Records ◽  
Pollen Content ◽  
Mire Ecosystem ◽  
Climate Fluctuation

Abstract The paper presents sedimentary records acquired as part of the research on the coastal cliff located between 221.3 and 221.4 km of the Slovincian (Słowinskie) Coast near Debina. Palynological and subfossil Cladocera analysis of sediments combined with geochemical data proves the existence of varying environmental conditions that occurred depending on the climate fluctuation. The Debina reservoir was formed in the Late Glacial period. Mud and gyttja were deposited in an initially cold proglacial lake. Species of Cladocera identified in this period indicate a deeper oligotrophic reservoir. The end of the Late Glacial cooling inhibited the development of fauna in the reservoir. Climate change at the beginning of the Holocene improved the habitat conditions in the Debina paleolake, which is reflected in the growth of zooplankton biodiversity and enrichment of the aquatic pollen content. We distinguished three phases that illustrate the evolution of the studied aquatic-mire ecosystem. In the following periods, the trophic level in the reservoir increased and significant water-level fluctuations led to periodic transformations of reservoirs into peat bogs. Gradually, the water-level lowering and the intensification of eolian processes led to terrestrialization of the paleolake.

A high-resolution late-glacial and early Holocene diatom record from Baffin Island, eastern Canadian Arctic

1996 ◽  
Vol 33 (6) ◽  
pp. 928-937 ◽  
Author(s):  
Alexander P. Wolfe
Keyword(s):  
North Atlantic ◽  
North Atlantic Ocean ◽  
Sediment Accumulation ◽  
Late Glacial ◽  
Early Holocene ◽  
Baffin Island ◽  
Diatom Analysis ◽  
The North ◽  
Holocene Climatic Optimum ◽  
Water Ph

An interval of late-glacial to early Holocene sedimentation, spanning the period 12.9–8.4 ka BP (14C dated by accelerator mass spectrometry), is contained within 15 cm of gyttja in a core from a small lake on southwestern Cumberland Peninsula, Baffin Island. This sediment was subsampled in continuous 2.5 mm increments for diatom analysis. Extremely low sediment accumulation rates (~1.8 cm ka−1) are characteristic of the initial phase of organic sedimentation, but they increase rapidly (to 14.2 cm ka−1) after 9 ka BP. The first 0.5 cm of gyttja contained an acidophilous diatom flora resembling that of underlying mineral sediments. Thereafter, and throughout the late glacial and earliest Holocene, diatom floras were dominated by alkaliphilous and circumneutral species of Fragilaria. Around 9 ka BP, shifts to acidophilous floras dominated by Brachysira brebissonii, and, later, Eunotia rhomboidea and Frustulia rhomboides vars. saxonica and crassinervia, suggest a period of natural lake acidification. High diatom production accompanied the lowered lake-water pH, which reflects, respectively, the paleolimnological response to an early Holocene climatic optimum, and progressive depletion of lake alkalinity sources. There is no evidence of diatom or sediment responses attributable to the Younger Dryas oscillation, implying that deglacial reorganizations of the North Atlantic Ocean did not necessarily affect paleoclimatic conditions in the southern Cumberland Sound region.

New insights on sources contributing dust to the loess record of the western edge of the Pampean Plain during the transition from the late MIS 2 to the early Holocene

The Holocene ◽  
2019 ◽  
Vol 30 (4) ◽  
pp. 537-545 ◽  
Author(s):  
Gabriela Torre ◽  
Diego M Gaiero ◽  
Nicolás Juan Cosentino ◽  
Renata Coppo ◽  
André Oliveira-Sawakuchi
Keyword(s):  
Source Area ◽  
Climatic Conditions ◽  
Early Holocene ◽  
Future Climate Change ◽  
Geochemical Data ◽  
Climate Change Scenarios ◽  
Dust Source ◽  
The North ◽  
Dust Sources ◽  
Pampean Plain

High-resolution studies of palaeorecords located closer to the dust source areas of South America are relevant for increasing the knowledge on past climatic conditions in the Southern Hemisphere. In this sense, the Pampean loess archives can offer explicit records of dust source, transport, and deposition in the region, providing new insights which may be used to better understand the role of dust in future climate change scenarios. In this work, we studied a loess sequence located at the westernmost Pampean Plain. The studied sequence covers a span of time from the late Marine Isotope Stage (MIS 2) period up to the early Holocene. Loess samples from this record have two grain-size populations, indicating more than one dust source area. The dominance of a coarse-silt subpopulation during the transition from the late MIS 2 to the early Holocene suggests that proximal dust sources were dominant at that time. Two of the most proximal dust sources were analyzed as probable contributors to the Lozada site: sediments derived from the Eastern Pampean Ranges and sediments derived from the shorelines of the Mar Chiquita Lake. The geochemical data suggest that neither area was a significant dust source to the eastern Pampean Plain during the studied interval. Instead, our geochemical data suggest a dominant supply from a southern and relatively closer area, linked to the foothills of the Andes, and the increased activation during the early Holocene of a more distant source to the north in the Puna region, which contributed finer loess.

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