Core material obtained from three boreholes was studied from the Ruunaa area, Finnish northern Ka... more Core material obtained from three boreholes was studied from the Ruunaa area, Finnish northern Karelia, in order to reveal the Late Pleistocene environmental history of eastern Finland. Conventional litho‐ and biostratigraphical methods were used and suitable sediment samples were dated using quartz optically stimulated luminescence. The results indicate that two till units were deposited by two separate Weichselian ice advances into the area. The first advance took place prior to 52 kyr ago, most likely during the early Middle Weichselian, while the second is thought to have taken place during the Late Weichselian after 25 kyr ago. The sediment succession at Ruunaa therefore indicates a Middle Weichselian ice‐free period around 50–25 kyr ago in the eastern part of Fennoscandia.
Middle Pleistocene Glaciations. In Lapland and western Finland there are sites where till or glac... more Middle Pleistocene Glaciations. In Lapland and western Finland there are sites where till or glaciofluvial deposits underlie Eemian organic sediments. Many of them are correlative to the Saalian glaciation. At Naakenavaara a Holsteinian peat is underlain by the Elsterian till unit. These sites provide the basis for the general Quaternary stratigraphy of Finland.Late Pleistocene Glaciations. After the Eemian Stage interglacial
The most complete terrestrial sequence of Anglian (Elsterian) glacial sediments in western Europe... more The most complete terrestrial sequence of Anglian (Elsterian) glacial sediments in western Europe was investigated in northeast Norfolk, England in order to reconstruct the evolution of the contemporary palaeoenvironments. Lithostratigraphically the glacial sediments in the northeast Norfolk coastal cliffs can be divided into the Northn Sea Drift and Lowestoft Till Formations. Three of the diamicton members of the North Sea Drift Formation (Happisburgh, Walcott and Cromer Diamictons) were deposited as lodgement and/or subglacial deformation till by grounded ice, but one, the Mundesley Diamicton, is waterlain and was deposited in an extensive glacial lake. Sands and fine sediments interbedded between the diamictons represent deltaic sands and glaciolacustrine sediments derived not solely from the melting ice in the north but also from extra‐marginal rivers in the south. The Lowestoft Till Formation is not well preserved in the cliffs but includes lodgement till (Marly Drift till) and, most probably, associated meltwater deposits. Extensive glaciotectonism in the northern part of the area is shown to relate to oscillating ice that deposited the Cromer Diamicton and also partially to the ice sheet that deposited the Marly Drift till. It is suggested that during the Anglian Stage the present day northeast Norfolk coast was situated on the northwestern margin of an extensive glaciolacustrine basin. This basin was dammed by the Scandinavian ice sheet in the north and northeast. Because the grounding line of this ice sheet oscillated in space and time, part of the North Sea Drift diamictons were deposited directly by this ice. However, during ice retreat phases glaciolacustrine deposition comprised waterlain diamicton, sands and fines. When the Scandinavian ice sheet was situated in northernmost Norfolk, the British ice sheet (responsible for depositing the Marly Drift facies) entered the area from the west. This ice sheet partially deformed the North Sea Drift Formation sediments in the northern part of the area but not in the south, where the British ice sheet apparently terminated in water. The interplay of these two ice sheets on the northern and western margins of the glacial lake is thought to be the major determining factor for the accumulation of thick glacial deposits in this area during the Anglian glaciation.
Abstract An important question in climate science is how ice sheets will respond to a climate war... more Abstract An important question in climate science is how ice sheets will respond to a climate warmer than present. Because our understanding of how these changes will occur remains limited, reconstructing the deglaciation of former ice sheets allows for a better understanding of how past ice sheets responded to a climate warmer than present along with understanding their contribution to sea-level rise. We will present new cosmogenic 10Be ages from erratic boulders along three transects spanning southern to northern Sweden ...
We determined in situ cosmogenic 10Be ages for nine boulders sampled on the SalpausselkaI (Ss I) ... more We determined in situ cosmogenic 10Be ages for nine boulders sampled on the SalpausselkaI (Ss I) Moraine. Previous dating of this moraine indicated that it formed during the Younger Dryas Stadial along the southern margin of the Scandinavian Ice Sheet in southern Finland. Our new exposure ages range from 10.971.0 to 13.571.2 10Be ka, with an error-weighted mean age of12.4
Core material obtained from three boreholes was studied from the Ruunaa area, Finnish northern Ka... more Core material obtained from three boreholes was studied from the Ruunaa area, Finnish northern Karelia, in order to reveal the Late Pleistocene environmental history of eastern Finland. Conventional litho‐ and biostratigraphical methods were used and suitable sediment samples were dated using quartz optically stimulated luminescence. The results indicate that two till units were deposited by two separate Weichselian ice advances into the area. The first advance took place prior to 52 kyr ago, most likely during the early Middle Weichselian, while the second is thought to have taken place during the Late Weichselian after 25 kyr ago. The sediment succession at Ruunaa therefore indicates a Middle Weichselian ice‐free period around 50–25 kyr ago in the eastern part of Fennoscandia.
Middle Pleistocene Glaciations. In Lapland and western Finland there are sites where till or glac... more Middle Pleistocene Glaciations. In Lapland and western Finland there are sites where till or glaciofluvial deposits underlie Eemian organic sediments. Many of them are correlative to the Saalian glaciation. At Naakenavaara a Holsteinian peat is underlain by the Elsterian till unit. These sites provide the basis for the general Quaternary stratigraphy of Finland.Late Pleistocene Glaciations. After the Eemian Stage interglacial
The most complete terrestrial sequence of Anglian (Elsterian) glacial sediments in western Europe... more The most complete terrestrial sequence of Anglian (Elsterian) glacial sediments in western Europe was investigated in northeast Norfolk, England in order to reconstruct the evolution of the contemporary palaeoenvironments. Lithostratigraphically the glacial sediments in the northeast Norfolk coastal cliffs can be divided into the Northn Sea Drift and Lowestoft Till Formations. Three of the diamicton members of the North Sea Drift Formation (Happisburgh, Walcott and Cromer Diamictons) were deposited as lodgement and/or subglacial deformation till by grounded ice, but one, the Mundesley Diamicton, is waterlain and was deposited in an extensive glacial lake. Sands and fine sediments interbedded between the diamictons represent deltaic sands and glaciolacustrine sediments derived not solely from the melting ice in the north but also from extra‐marginal rivers in the south. The Lowestoft Till Formation is not well preserved in the cliffs but includes lodgement till (Marly Drift till) and, most probably, associated meltwater deposits. Extensive glaciotectonism in the northern part of the area is shown to relate to oscillating ice that deposited the Cromer Diamicton and also partially to the ice sheet that deposited the Marly Drift till. It is suggested that during the Anglian Stage the present day northeast Norfolk coast was situated on the northwestern margin of an extensive glaciolacustrine basin. This basin was dammed by the Scandinavian ice sheet in the north and northeast. Because the grounding line of this ice sheet oscillated in space and time, part of the North Sea Drift diamictons were deposited directly by this ice. However, during ice retreat phases glaciolacustrine deposition comprised waterlain diamicton, sands and fines. When the Scandinavian ice sheet was situated in northernmost Norfolk, the British ice sheet (responsible for depositing the Marly Drift facies) entered the area from the west. This ice sheet partially deformed the North Sea Drift Formation sediments in the northern part of the area but not in the south, where the British ice sheet apparently terminated in water. The interplay of these two ice sheets on the northern and western margins of the glacial lake is thought to be the major determining factor for the accumulation of thick glacial deposits in this area during the Anglian glaciation.
Abstract An important question in climate science is how ice sheets will respond to a climate war... more Abstract An important question in climate science is how ice sheets will respond to a climate warmer than present. Because our understanding of how these changes will occur remains limited, reconstructing the deglaciation of former ice sheets allows for a better understanding of how past ice sheets responded to a climate warmer than present along with understanding their contribution to sea-level rise. We will present new cosmogenic 10Be ages from erratic boulders along three transects spanning southern to northern Sweden ...
We determined in situ cosmogenic 10Be ages for nine boulders sampled on the SalpausselkaI (Ss I) ... more We determined in situ cosmogenic 10Be ages for nine boulders sampled on the SalpausselkaI (Ss I) Moraine. Previous dating of this moraine indicated that it formed during the Younger Dryas Stadial along the southern margin of the Scandinavian Ice Sheet in southern Finland. Our new exposure ages range from 10.971.0 to 13.571.2 10Be ka, with an error-weighted mean age of12.4
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