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Jan Mangerud - One of the best experts on this subject based on the ideXlab platform.
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the bolling age blomvag beds western norway implications for the Older Dryas glacial re advance and the age of the deglaciation
Boreas, 2017Co-Authors: Jan Mangerud, John Inge Svendsen, Jason P. Briner, Tomasz GoslarAbstract:Blomvag, on the western coast of Norway north of Bergen, is a classical site in Norwegian Quaternary science. Foreshore marine sediments, named the Blomvag Beds and now dated to the Bolling-Allerod from 14.8 to 13.3 cal. ka BP, contain the richest Lateglacial bone fauna in Norway, numerous mollusc shells, driftwood, and flint that some archaeologists consider as the oldest traces of humans in Norway. The main theme of this paper is that the Blomvag Beds are overlain by a compact diamicton, named the Ulvoy Diamicton, which was interpreted previously as a basal till deposited during a glacial re-advance into the ocean during the Older Dryas (c. 14 cal. ka BP). Sediment sections of the Blomvag Beds and the Ulvoy Diamicton were exposed in ditches in a cemetery that was constructed in 1941–42 and have subsequently not been accessible. A number of radiocarbon and cosmogenic 10Be exposure ages demonstrate that the diamicton is not likely to be a till because minimum deglaciation ages (14.8–14.5 cal. ka BP) from the vicinity pre-date the Ulvoy Diamicton. We now consider that sea ice and icebergs formed the Ulvoy Diamicton during the Younger Dryas. The Scandinavian Ice Sheet margin was located on the outermost coastal islands between at least c. 18.5 and 14.8 cal. ka BP; however, no ice-marginal deposits have been found offshore from this long period. The Older Dryas ice margin in this area was located slightly inside the Younger Dryas margin, whereas farther south it was located slightly beyond the Younger Dryas margin.
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A 10Be chronology of south-western Scandinavian Ice Sheet history during the Lateglacial period
2016Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:ABSTRACT: We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bølling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.00.6 ka; n 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.40.4 ka; n 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 0.9 ka (n5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 0.3 ka (n 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middl
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a 10be chronology of south western scandinavian ice sheet history during the lateglacial period
Journal of Quaternary Science, 2014Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bolling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.0 ± 0.6 ka; n = 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.4 ± 0.4 ka; n = 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 ± 0.9 ka (n = 5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 ± 0.3 ka (n = 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middle and late part of the Younger Dryas.
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quaternary stratigraphy of norden a proposal for terminology and classification
Boreas, 2008Co-Authors: Jan Mangerud, Svend Th Andersen, Bjorn E Berglund, Joakim J DonnerAbstract:Principles and terminology for classification of the Quaternary are discussed, including lithostratigraphy, biostratigraphy. morphostratigraphy, climatostratigraphy and chronostratigraphy. The main conclusion is a proposal for a common chronostratigraphical classification of the Quaternary in Norden (and partly continental NW Europe). The Quaternary is subdivided into the Pleistocene and the Holocene Series. The Pleistocene is further subdivided into several provisional stages (Weichselian, Eemian, etc.), based on the sequence of glacials/interglacials. but with the boundaries preferably defined by stratotypes. The Late Weichselian and the Flandrian (Holocene) are subdivided into chronozoncs (Bolling, Older Dryas, Allerod, Younger Dryas, Preboreal, Boreal, Atlantic, Subboreal, Subatlantic) with the boundaries dcfined in conventional radiocarbon years.
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the retreat of the barents sea ice sheet on the western svalbard margin
Boreas, 2008Co-Authors: John Inge Svendsen, Anders Elverhmi, Jan MangerudAbstract:The deglaciation of the continental shelf to the west of Spitsbergen and the main fjord, Isfjorden. is discussed based on sub-bottom seismic records and scdirncnt cores. The sea lloor on the shelf to the west of Isfjorden is underlain by less than 2 m of glaciomarine sediments over a firm diamicton interpreted as till. In central Isfjordcn up to 10 m of deglaciation sediments were recorded, whereas in cores from the innermost tributary, Billefjorden, less than a meter of ice proximal sediments was recognized between the till and the ‘normal’ Holocene marine sediments. We conclude that the Barents Sea Ice Sheet terminated along the shelf break during the Late Weichselian glacial maximum. Radiocarbon dates from thc glaciomarine sediments above the till indicate a stepwise deglaciation. Apparently the ice front rctrcatcd from the outermost shelf around 14. 8 ka A dramatic increase in the flux of line-grained glaciomarine sediments around 13 ka is assumed to reflect increased melting and/or current activity due to a climatic warming. This second stage of deglaciation was intcrruptcd by a glacial readvance culminating on the mid-shelf area shortly after 12.4 ka. The glacial readvance, which is correlated with a simultaneous readvance of the Fennoscundian ice sheet along the western coast of Norway, is attributed to the so-called ‘Older Dryas’ cooling event in the North Atlantic region. Following this glacial readvance the outer part of Isljorden became rapidly deglaciated around 12.3 ka. During the Younger Dryas the inner fjord branches were occupied by large outlet glaciers and possibly the ice liont terminated far out in the main fjord. The remnants of the Harcnts Sea Ice Shcet melted quickly away as a response to the Holocene warming around 10 ka.
John Inge Svendsen - One of the best experts on this subject based on the ideXlab platform.
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the bolling age blomvag beds western norway implications for the Older Dryas glacial re advance and the age of the deglaciation
Boreas, 2017Co-Authors: Jan Mangerud, John Inge Svendsen, Jason P. Briner, Tomasz GoslarAbstract:Blomvag, on the western coast of Norway north of Bergen, is a classical site in Norwegian Quaternary science. Foreshore marine sediments, named the Blomvag Beds and now dated to the Bolling-Allerod from 14.8 to 13.3 cal. ka BP, contain the richest Lateglacial bone fauna in Norway, numerous mollusc shells, driftwood, and flint that some archaeologists consider as the oldest traces of humans in Norway. The main theme of this paper is that the Blomvag Beds are overlain by a compact diamicton, named the Ulvoy Diamicton, which was interpreted previously as a basal till deposited during a glacial re-advance into the ocean during the Older Dryas (c. 14 cal. ka BP). Sediment sections of the Blomvag Beds and the Ulvoy Diamicton were exposed in ditches in a cemetery that was constructed in 1941–42 and have subsequently not been accessible. A number of radiocarbon and cosmogenic 10Be exposure ages demonstrate that the diamicton is not likely to be a till because minimum deglaciation ages (14.8–14.5 cal. ka BP) from the vicinity pre-date the Ulvoy Diamicton. We now consider that sea ice and icebergs formed the Ulvoy Diamicton during the Younger Dryas. The Scandinavian Ice Sheet margin was located on the outermost coastal islands between at least c. 18.5 and 14.8 cal. ka BP; however, no ice-marginal deposits have been found offshore from this long period. The Older Dryas ice margin in this area was located slightly inside the Younger Dryas margin, whereas farther south it was located slightly beyond the Younger Dryas margin.
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A 10Be chronology of south-western Scandinavian Ice Sheet history during the Lateglacial period
2016Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:ABSTRACT: We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bølling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.00.6 ka; n 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.40.4 ka; n 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 0.9 ka (n5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 0.3 ka (n 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middl
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a 10be chronology of south western scandinavian ice sheet history during the lateglacial period
Journal of Quaternary Science, 2014Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bolling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.0 ± 0.6 ka; n = 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.4 ± 0.4 ka; n = 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 ± 0.9 ka (n = 5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 ± 0.3 ka (n = 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middle and late part of the Younger Dryas.
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the retreat of the barents sea ice sheet on the western svalbard margin
Boreas, 2008Co-Authors: John Inge Svendsen, Anders Elverhmi, Jan MangerudAbstract:The deglaciation of the continental shelf to the west of Spitsbergen and the main fjord, Isfjorden. is discussed based on sub-bottom seismic records and scdirncnt cores. The sea lloor on the shelf to the west of Isfjorden is underlain by less than 2 m of glaciomarine sediments over a firm diamicton interpreted as till. In central Isfjordcn up to 10 m of deglaciation sediments were recorded, whereas in cores from the innermost tributary, Billefjorden, less than a meter of ice proximal sediments was recognized between the till and the ‘normal’ Holocene marine sediments. We conclude that the Barents Sea Ice Sheet terminated along the shelf break during the Late Weichselian glacial maximum. Radiocarbon dates from thc glaciomarine sediments above the till indicate a stepwise deglaciation. Apparently the ice front rctrcatcd from the outermost shelf around 14. 8 ka A dramatic increase in the flux of line-grained glaciomarine sediments around 13 ka is assumed to reflect increased melting and/or current activity due to a climatic warming. This second stage of deglaciation was intcrruptcd by a glacial readvance culminating on the mid-shelf area shortly after 12.4 ka. The glacial readvance, which is correlated with a simultaneous readvance of the Fennoscundian ice sheet along the western coast of Norway, is attributed to the so-called ‘Older Dryas’ cooling event in the North Atlantic region. Following this glacial readvance the outer part of Isljorden became rapidly deglaciated around 12.3 ka. During the Younger Dryas the inner fjord branches were occupied by large outlet glaciers and possibly the ice liont terminated far out in the main fjord. The remnants of the Harcnts Sea Ice Shcet melted quickly away as a response to the Holocene warming around 10 ka.
Jason P. Briner - One of the best experts on this subject based on the ideXlab platform.
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the bolling age blomvag beds western norway implications for the Older Dryas glacial re advance and the age of the deglaciation
Boreas, 2017Co-Authors: Jan Mangerud, John Inge Svendsen, Jason P. Briner, Tomasz GoslarAbstract:Blomvag, on the western coast of Norway north of Bergen, is a classical site in Norwegian Quaternary science. Foreshore marine sediments, named the Blomvag Beds and now dated to the Bolling-Allerod from 14.8 to 13.3 cal. ka BP, contain the richest Lateglacial bone fauna in Norway, numerous mollusc shells, driftwood, and flint that some archaeologists consider as the oldest traces of humans in Norway. The main theme of this paper is that the Blomvag Beds are overlain by a compact diamicton, named the Ulvoy Diamicton, which was interpreted previously as a basal till deposited during a glacial re-advance into the ocean during the Older Dryas (c. 14 cal. ka BP). Sediment sections of the Blomvag Beds and the Ulvoy Diamicton were exposed in ditches in a cemetery that was constructed in 1941–42 and have subsequently not been accessible. A number of radiocarbon and cosmogenic 10Be exposure ages demonstrate that the diamicton is not likely to be a till because minimum deglaciation ages (14.8–14.5 cal. ka BP) from the vicinity pre-date the Ulvoy Diamicton. We now consider that sea ice and icebergs formed the Ulvoy Diamicton during the Younger Dryas. The Scandinavian Ice Sheet margin was located on the outermost coastal islands between at least c. 18.5 and 14.8 cal. ka BP; however, no ice-marginal deposits have been found offshore from this long period. The Older Dryas ice margin in this area was located slightly inside the Younger Dryas margin, whereas farther south it was located slightly beyond the Younger Dryas margin.
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A 10Be chronology of south-western Scandinavian Ice Sheet history during the Lateglacial period
2016Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:ABSTRACT: We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bølling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.00.6 ka; n 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.40.4 ka; n 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 0.9 ka (n5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 0.3 ka (n 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middl
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a 10be chronology of south western scandinavian ice sheet history during the lateglacial period
Journal of Quaternary Science, 2014Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bolling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.0 ± 0.6 ka; n = 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.4 ± 0.4 ka; n = 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 ± 0.9 ka (n = 5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 ± 0.3 ka (n = 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middle and late part of the Younger Dryas.
Nicolás E. Young - One of the best experts on this subject based on the ideXlab platform.
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A 10Be chronology of south-western Scandinavian Ice Sheet history during the Lateglacial period
2016Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:ABSTRACT: We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bølling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.00.6 ka; n 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.40.4 ka; n 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 0.9 ka (n5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 0.3 ka (n 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middl
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a 10be chronology of south western scandinavian ice sheet history during the lateglacial period
Journal of Quaternary Science, 2014Co-Authors: Jason P. Briner, Jan Mangerud, Øystein S. Lohne, John Inge Svendsen, Nicolás E. YoungAbstract:We present 34 new cosmogenic 10Be exposure ages that constrain the Lateglacial (Bolling–Preboreal) history of the Scandinavian Ice Sheet in the Lysefjorden region, south-western Norway. We find that the classical Lysefjorden moraines, earlier thought to be entirely of Younger Dryas age, encompass three adjacent moraines attributed to at least two ice sheet advances of distinctly different ages. The 10Be age of the outermost moraine (14.0 ± 0.6 ka; n = 4) suggests that the first advance is of Older Dryas age. The innermost moraine is at least 2000 years younger and was deposited near the end of the Younger Dryas (11.4 ± 0.4 ka; n = 7). After abandonment of the innermost Lysefjorden Moraine, the ice front receded quickly towards the head of the fjord, where recession was interrupted by an advance that deposited the Trollgaren Moraine at 11.3 ± 0.9 ka (n = 5). 10Be ages from the inboard side of the Trollgaren Moraine suggest final retreat by 10.7 ± 0.3 ka (n = 7). The late culmination of the Younger Dryas advance contrasts with other sectors of the Scandinavian Ice Sheet where the margin appears to have culminated earlier during the Younger Dryas stadial, followed by retreat during the middle and late part of the Younger Dryas.
Guy Seret - One of the best experts on this subject based on the ideXlab platform.
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Palynological analyses in the laminated sediment of Lake Holzmaar (Eifel, Germany): duration of Lateglacial and Preboreal biozones
2015Co-Authors: Suzanne Alice, G. Leroy, Bernd Zolitschka, Guy SeretAbstract:The laminated sediment of Lake Holzmaar (Germany) has provided a continuous varve chronology for the last 3500 varve years (vy) and beyond that a floating varve chronology back to more than 22500 vy BP. This chronology in calendar years, in combination with palynology, enables us to determine the timing and the magnitude of Lateglacial and Early Holocene environmental changes on land (from 13838 to 10930 vy BP). The palynological diagram has a mean time resolution of 27 vy between samples. This paper establishes for the first time the biozonation for Lake Holzmaar below the Laacher See Tephra. Fifteen pollen subzones grouped in four biozones are defined by cluster analysis. After a period disturbed by microturbidites, only a part of the Bølling is present. Three cold periods have been evidenced by pollen analyses: the Older Dryas (96-vy-long), the Younger Dryas (654-vy-long) and the Rammelbeek phase (237-vy-long). The Allerød (883-vy-long) is bipartite with a first Betula-dominated period followed by a Pinus-dominated one. The Younger Dryas is also bipartite, with first a decrease of winter temperatures along with a change to a more continental climate. It is followed by a drier phase with a second decrease in temperatures, probably this time also affect-ing summer temperatures. The Preboreal is 702-yr-long. The duration of most phases corresponds to published records, except for that of the Younger Dryas. Cluster and rate-of-change analyses indicate a sharp change in the terrestrial vegetation assemblages that may be caused by a sedimentary hiatus of erosive origin during thi
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palynological analyses in the laminated sediment of lake holzmaar eifel germany duration of lateglacial and preboreal biozones
Boreas, 2000Co-Authors: Suzanne A G Leroy, Bernd Zolitschka, Jorg F W Negendank, Guy SeretAbstract:The laminated sediment of Lake Holzmaar (Germany) has provided a continuous varve chronology for the last 3500 varve years (vy) and beyond that a floating varve chronology back to more than 22500 vy BP. This chronology in calendar years, in combination with palynology, enables us to determine the timing. and the magnitude of Lateglacial and Early Holocene environmental changes on land (from 13838 to 10930 vy BP). The palynological diagram has a mean time resolution of 27 vy between samples. This paper establishes for the first time the biozonation for Lake Holzmaar below the Leacher see Tephra. Fifteen pollen subzones grouped in four biozones are defined by cluster analysis. After a period disturbed by microturbidites, only a parr of the Belling is present. Three cold periods have been evidenced by pollen analyses: the Older Dryas (96-vy-long), the Younger Dryas (654-vy-long) and the Rammelbeek phase (237-vy-long). The Allerod (883-vy-long) is bipartite with a first Betula-dominated period followed by a Pinus-dominated one. The Younger Dryas is also bipartite, with first a decrease of winter temperatures along with a change to a more continental climate. It is followed by a drier phase with a second decrease in temperatures. probably this time also affecting summer temperatures. The Preboreal is 702-yr-long. The duration of most phases corresponds to published records, except for that of the Younger Dryas. Cluster and rare-of-change analyses indicate a sharp change in the terrestrial vegetation assemblages that may be caused by a sedimentary hiatus of erosive origin during this cold and dry period. As a result the chronology of Holzmaar has to be revised most likely below the middle of the Younger Dryas. Comparison with the varve record of Meerfelder Maar, a neighbour maar lake, suggests adding 320 vy below 12025 vy.
