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Yeadong Kim - One of the best experts on this subject based on the ideXlab platform.
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late holocene cyclic glaciomarine sedimentation in a subpolar fjord of the south shetland islands antarctica and its paleoceanographic significance sedimentological geochemical and paleontological evidence
Geological Society of America Bulletin, 2010Co-Authors: Ho Il Yoon, Kyu-cheul Yoo, Yeadong Kim, Youngsuk Bak, Hyoun Soo Lim, Jae Il LeeAbstract:The glaciomarine sedimentary record of the fjord head (Collins Harbor) in Maxwell Bay, South Shetland Islands (West Antarctica), a large marine calving embayment, contains repeating couplets of organic-rich massive Diamicton and organic-poor stratified Diamicton. The massive Diamicton is characterized by high total organic carbon (TOC) content and carbon to nitrogen (C/N) ratios and was deposited in a cold climate regime by iceberg-rafted sedimentation from coastal fast ice in which algal plants, as well as gravels, were entrained. The stratified Diamicton is characterized by low TOC content and C/N ratios and was formed in a warmer climate regime when the flux of icebergs was suppressed, but turbid meltwater discharge continued to produce lamination. When the meltwater discharge decreased in cold climatic conditions, and resultant phytoplankton productivity was reduced due to the increased sea-ice coverage, ice rafting from shorefast sea ice might have played a major role in entraining benthic algae, as well as loads of sand and gravel, along the coastal area, resulting in an increased C/N ratio and gravel content in the massive Diamicton. Accelerator mass spectrometry (AMS) radiocarbon analyses conducted on well-preserved calcite shells were used to construct a chronology for the past 3000 years. Fluctuations in TOC are recorded (approximately four cycles over this time period), with the average duration of a cooling cycle being ∼500 years. These cycles may be correlative with the high-frequency (550 yr) variability in reduced Circumpolar Deep Water (CDW) on the West Antarctic Peninsula shelf, because a decrease in CDW may be related to reduced deep water production in the North Atlantic during colder periods, as demonstrated for glacial intervals throughout the Pleistocene.
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retracted advance of the outlet glaciers during regional warming as inferred from late holocene massive Diamicton in the king george island fjords the south shetland islands west antarctica
Quaternary Research, 2006Co-Authors: Kyu-cheul Yoo, Ho Il Yoon, Byong-kwon Park, Yeadong KimAbstract:This article has been retracted at the request of the Editor-in-Chief. Please see http://www.elsevier.com/locate/withdrawalpolicy.Reason: Following publication of this article, the Editor-in-Chief has realized that much of the included information had been previously published in the paper Yoon, H.I., Yoo, K.-C., Park, B.-K., Kim, Y., Khim, B.-K., and Kang, C.-Y., 2004. The origin of massive Diamicton in Marian and Potter coves, King George Island, West Antarctica. Geosciences Journal 8, 1–10. As a result, the later manuscript is being retracted; readers interested in this topic should refer to the earlier paper.
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The origin of massive Diamicton in Marian and Potter coves, King George Island, West Antarctica
Geosciences Journal, 2004Co-Authors: Ho Il Yoon, Kyu-cheul Yoo, Byong-kwon Park, Yeadong Kim, Boo-keun Khim, Cheon-yun KangAbstract:Marine sediment cores were obtained from in front of the tidewater glaciers in Marian and Potter coves in the South Shetland Islands in the austral summer of 1998–1999. Sedimentological and geochemical data from these cores document an advance of ice tongue for the deposition of clast-supported, massive Diamicton, interpreted as having been produced by ice rafting in front of glacier margin and/or releasing of clasts from basal debris zones in the sub-ice tongue setting. A C-14 chronology for a core indicates that glacial advance took place ca. 1450–1700 yrs B.P., coincident with warm, humid phase in the study area. During this period, the glacier margin was likely to advance and release Diamicton clasts, inferred from a reduction in the total organic carbon content, and an increase in sand and clasts within the Diamicton facies. The glacial advance probably caused enhanced ice-edge blooms near the core sites, resulting in increased abundance of sea-ice related diatoms i.e., Fragilariopsis curta and Fragilariopsis cylindrus in the Diamicton. The warm and humid conditions between 1450–1700 yrs B.P. might allow the intrusion of warm circumpolar deep water within the fjords, bringing about increased abundance of warm water form, i.e., Fragilariposis kerguelensis . On the other hands, this warming condition probably prohibited the intrusion of Weddell Ice shelf water from the fjord, as evidenced by lack of cold water form, Thalassiosira antarctica , in the Diamicton. Clearly, the response of the outlet glacier system along the periphery of the South Shetland Islands Ice Sheet during the late Holocene warm, humid period (1450–1700 yrs B.P.) was expansion. Thus the process of clast-supported massive Diamicton formation is likely to be applicable to a number of areas of the modern and Quaternary Antarctic Peninsula.
Hanna Lokrantz - One of the best experts on this subject based on the ideXlab platform.
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late quaternary stratigraphy glacial limits and paleoenvironments of the marresale area western yamal peninsula russia
Quaternary Research, 2002Co-Authors: Steven L Forman, Valery Gataullin, Olafur Ingolfsson, William F Manley, Hanna LokrantzAbstract:Stratigraphic records from coastal cliff sections near the Marresale Station on the Yamal Peninsula, Russia, yield new insight on ice-sheet dynamics and paleoenvironments for northern Eurasia. Field studies identify nine informal stratigraphic units from oldest to youngest (the Marresale formation, Labsuyakha sand, Kara Diamicton, Varjakha peat and silt, Oleny sand, Baidarata sand, Betula horizon, Nenets peat, and Chum sand) that show a single glaciation and a varied terrestrial environment during the late Pleistocene. The Kara Diamicton reflects regional glaciation and is associated with glaciotectonic deformation from the southwest of the underlying Labsuyakha sand and Marresale formation. Finite radiocarbon and luminescence ages of ca. 35,000 to 45,000 yr from Varjakha peat and silt that immediately overlies Kara Diamicton place the glaciation >40,000 yr ago. Eolian and fluvial deposition ensued with concomitant cryogenesis between ca. 35,000 and 12,000 cal yr B.P. associated with the Oleny and the Baidarata sands. There is no geomorphic or stratigraphic evidence of coverage or proximity of the Yamal Peninsula to a Late Weichselian ice sheet. The Nenets peat accumulated over the Baidarata sand during much of the past 10,000 yr, with local additions of the eolian Chum sand starting ca. 1000 yr ago. A prominent Betula horizon at the base of the Nenets peat contains rooted birch trees ca. 10,000 to 9000 cal yr old and indicates a >200-km shift northward of the treeline from the present limits, corresponding to a 2° to 4°C summer warming across northern Eurasia.
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late quaternary stratigraphy of western yamal peninsula russia new constraints on the configuration of the eurasian ice sheet
Geology, 1999Co-Authors: Steven L Forman, Valery Gataullin, Olafur Ingolfsson, William F Manley, Hanna LokrantzAbstract:Ice-sheet reconstructions for the last glacial maximum in northern Eurasia range from nearly complete coverage by a contiguous marine-based ice sheet to large unglaciated areas. Stratigraphic records from Yamal Peninsula, Russia, provide new insight on the eastern limit of the Eurasian ice sheet in the Kara Sea. Radiocarbon and infrared stimulated luminescence ages from coastal cliff sections date the emplacement of the Kara Diamicton as older than ca. 40 ka, reflecting regional glaciation. Ice-wedge growth, peat accumulation, and eolian and fluvial deposition characterized the past ~40 k.y. and do not support coverage of Yamal Peninsula by an ice sheet or proximity to a glacier margin. Thus, the late Weichselian Eurasian ice sheet was largely confined to Barents Sea and its global sea-level contribution is reduced to ~7 m of sea-level equivalent.
Kyu-cheul Yoo - One of the best experts on this subject based on the ideXlab platform.
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late holocene cyclic glaciomarine sedimentation in a subpolar fjord of the south shetland islands antarctica and its paleoceanographic significance sedimentological geochemical and paleontological evidence
Geological Society of America Bulletin, 2010Co-Authors: Ho Il Yoon, Kyu-cheul Yoo, Yeadong Kim, Youngsuk Bak, Hyoun Soo Lim, Jae Il LeeAbstract:The glaciomarine sedimentary record of the fjord head (Collins Harbor) in Maxwell Bay, South Shetland Islands (West Antarctica), a large marine calving embayment, contains repeating couplets of organic-rich massive Diamicton and organic-poor stratified Diamicton. The massive Diamicton is characterized by high total organic carbon (TOC) content and carbon to nitrogen (C/N) ratios and was deposited in a cold climate regime by iceberg-rafted sedimentation from coastal fast ice in which algal plants, as well as gravels, were entrained. The stratified Diamicton is characterized by low TOC content and C/N ratios and was formed in a warmer climate regime when the flux of icebergs was suppressed, but turbid meltwater discharge continued to produce lamination. When the meltwater discharge decreased in cold climatic conditions, and resultant phytoplankton productivity was reduced due to the increased sea-ice coverage, ice rafting from shorefast sea ice might have played a major role in entraining benthic algae, as well as loads of sand and gravel, along the coastal area, resulting in an increased C/N ratio and gravel content in the massive Diamicton. Accelerator mass spectrometry (AMS) radiocarbon analyses conducted on well-preserved calcite shells were used to construct a chronology for the past 3000 years. Fluctuations in TOC are recorded (approximately four cycles over this time period), with the average duration of a cooling cycle being ∼500 years. These cycles may be correlative with the high-frequency (550 yr) variability in reduced Circumpolar Deep Water (CDW) on the West Antarctic Peninsula shelf, because a decrease in CDW may be related to reduced deep water production in the North Atlantic during colder periods, as demonstrated for glacial intervals throughout the Pleistocene.
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retracted advance of the outlet glaciers during regional warming as inferred from late holocene massive Diamicton in the king george island fjords the south shetland islands west antarctica
Quaternary Research, 2006Co-Authors: Kyu-cheul Yoo, Ho Il Yoon, Byong-kwon Park, Yeadong KimAbstract:This article has been retracted at the request of the Editor-in-Chief. Please see http://www.elsevier.com/locate/withdrawalpolicy.Reason: Following publication of this article, the Editor-in-Chief has realized that much of the included information had been previously published in the paper Yoon, H.I., Yoo, K.-C., Park, B.-K., Kim, Y., Khim, B.-K., and Kang, C.-Y., 2004. The origin of massive Diamicton in Marian and Potter coves, King George Island, West Antarctica. Geosciences Journal 8, 1–10. As a result, the later manuscript is being retracted; readers interested in this topic should refer to the earlier paper.
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The origin of massive Diamicton in Marian and Potter coves, King George Island, West Antarctica
Geosciences Journal, 2004Co-Authors: Ho Il Yoon, Kyu-cheul Yoo, Byong-kwon Park, Yeadong Kim, Boo-keun Khim, Cheon-yun KangAbstract:Marine sediment cores were obtained from in front of the tidewater glaciers in Marian and Potter coves in the South Shetland Islands in the austral summer of 1998–1999. Sedimentological and geochemical data from these cores document an advance of ice tongue for the deposition of clast-supported, massive Diamicton, interpreted as having been produced by ice rafting in front of glacier margin and/or releasing of clasts from basal debris zones in the sub-ice tongue setting. A C-14 chronology for a core indicates that glacial advance took place ca. 1450–1700 yrs B.P., coincident with warm, humid phase in the study area. During this period, the glacier margin was likely to advance and release Diamicton clasts, inferred from a reduction in the total organic carbon content, and an increase in sand and clasts within the Diamicton facies. The glacial advance probably caused enhanced ice-edge blooms near the core sites, resulting in increased abundance of sea-ice related diatoms i.e., Fragilariopsis curta and Fragilariopsis cylindrus in the Diamicton. The warm and humid conditions between 1450–1700 yrs B.P. might allow the intrusion of warm circumpolar deep water within the fjords, bringing about increased abundance of warm water form, i.e., Fragilariposis kerguelensis . On the other hands, this warming condition probably prohibited the intrusion of Weddell Ice shelf water from the fjord, as evidenced by lack of cold water form, Thalassiosira antarctica , in the Diamicton. Clearly, the response of the outlet glacier system along the periphery of the South Shetland Islands Ice Sheet during the late Holocene warm, humid period (1450–1700 yrs B.P.) was expansion. Thus the process of clast-supported massive Diamicton formation is likely to be applicable to a number of areas of the modern and Quaternary Antarctic Peninsula.
Ho Il Yoon - One of the best experts on this subject based on the ideXlab platform.
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late holocene cyclic glaciomarine sedimentation in a subpolar fjord of the south shetland islands antarctica and its paleoceanographic significance sedimentological geochemical and paleontological evidence
Geological Society of America Bulletin, 2010Co-Authors: Ho Il Yoon, Kyu-cheul Yoo, Yeadong Kim, Youngsuk Bak, Hyoun Soo Lim, Jae Il LeeAbstract:The glaciomarine sedimentary record of the fjord head (Collins Harbor) in Maxwell Bay, South Shetland Islands (West Antarctica), a large marine calving embayment, contains repeating couplets of organic-rich massive Diamicton and organic-poor stratified Diamicton. The massive Diamicton is characterized by high total organic carbon (TOC) content and carbon to nitrogen (C/N) ratios and was deposited in a cold climate regime by iceberg-rafted sedimentation from coastal fast ice in which algal plants, as well as gravels, were entrained. The stratified Diamicton is characterized by low TOC content and C/N ratios and was formed in a warmer climate regime when the flux of icebergs was suppressed, but turbid meltwater discharge continued to produce lamination. When the meltwater discharge decreased in cold climatic conditions, and resultant phytoplankton productivity was reduced due to the increased sea-ice coverage, ice rafting from shorefast sea ice might have played a major role in entraining benthic algae, as well as loads of sand and gravel, along the coastal area, resulting in an increased C/N ratio and gravel content in the massive Diamicton. Accelerator mass spectrometry (AMS) radiocarbon analyses conducted on well-preserved calcite shells were used to construct a chronology for the past 3000 years. Fluctuations in TOC are recorded (approximately four cycles over this time period), with the average duration of a cooling cycle being ∼500 years. These cycles may be correlative with the high-frequency (550 yr) variability in reduced Circumpolar Deep Water (CDW) on the West Antarctic Peninsula shelf, because a decrease in CDW may be related to reduced deep water production in the North Atlantic during colder periods, as demonstrated for glacial intervals throughout the Pleistocene.
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retracted advance of the outlet glaciers during regional warming as inferred from late holocene massive Diamicton in the king george island fjords the south shetland islands west antarctica
Quaternary Research, 2006Co-Authors: Kyu-cheul Yoo, Ho Il Yoon, Byong-kwon Park, Yeadong KimAbstract:This article has been retracted at the request of the Editor-in-Chief. Please see http://www.elsevier.com/locate/withdrawalpolicy.Reason: Following publication of this article, the Editor-in-Chief has realized that much of the included information had been previously published in the paper Yoon, H.I., Yoo, K.-C., Park, B.-K., Kim, Y., Khim, B.-K., and Kang, C.-Y., 2004. The origin of massive Diamicton in Marian and Potter coves, King George Island, West Antarctica. Geosciences Journal 8, 1–10. As a result, the later manuscript is being retracted; readers interested in this topic should refer to the earlier paper.
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The origin of massive Diamicton in Marian and Potter coves, King George Island, West Antarctica
Geosciences Journal, 2004Co-Authors: Ho Il Yoon, Kyu-cheul Yoo, Byong-kwon Park, Yeadong Kim, Boo-keun Khim, Cheon-yun KangAbstract:Marine sediment cores were obtained from in front of the tidewater glaciers in Marian and Potter coves in the South Shetland Islands in the austral summer of 1998–1999. Sedimentological and geochemical data from these cores document an advance of ice tongue for the deposition of clast-supported, massive Diamicton, interpreted as having been produced by ice rafting in front of glacier margin and/or releasing of clasts from basal debris zones in the sub-ice tongue setting. A C-14 chronology for a core indicates that glacial advance took place ca. 1450–1700 yrs B.P., coincident with warm, humid phase in the study area. During this period, the glacier margin was likely to advance and release Diamicton clasts, inferred from a reduction in the total organic carbon content, and an increase in sand and clasts within the Diamicton facies. The glacial advance probably caused enhanced ice-edge blooms near the core sites, resulting in increased abundance of sea-ice related diatoms i.e., Fragilariopsis curta and Fragilariopsis cylindrus in the Diamicton. The warm and humid conditions between 1450–1700 yrs B.P. might allow the intrusion of warm circumpolar deep water within the fjords, bringing about increased abundance of warm water form, i.e., Fragilariposis kerguelensis . On the other hands, this warming condition probably prohibited the intrusion of Weddell Ice shelf water from the fjord, as evidenced by lack of cold water form, Thalassiosira antarctica , in the Diamicton. Clearly, the response of the outlet glacier system along the periphery of the South Shetland Islands Ice Sheet during the late Holocene warm, humid period (1450–1700 yrs B.P.) was expansion. Thus the process of clast-supported massive Diamicton formation is likely to be applicable to a number of areas of the modern and Quaternary Antarctic Peninsula.
Steven L Forman - One of the best experts on this subject based on the ideXlab platform.
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late quaternary stratigraphy glacial limits and paleoenvironments of the marresale area western yamal peninsula russia
Quaternary Research, 2002Co-Authors: Steven L Forman, Valery Gataullin, Olafur Ingolfsson, William F Manley, Hanna LokrantzAbstract:Stratigraphic records from coastal cliff sections near the Marresale Station on the Yamal Peninsula, Russia, yield new insight on ice-sheet dynamics and paleoenvironments for northern Eurasia. Field studies identify nine informal stratigraphic units from oldest to youngest (the Marresale formation, Labsuyakha sand, Kara Diamicton, Varjakha peat and silt, Oleny sand, Baidarata sand, Betula horizon, Nenets peat, and Chum sand) that show a single glaciation and a varied terrestrial environment during the late Pleistocene. The Kara Diamicton reflects regional glaciation and is associated with glaciotectonic deformation from the southwest of the underlying Labsuyakha sand and Marresale formation. Finite radiocarbon and luminescence ages of ca. 35,000 to 45,000 yr from Varjakha peat and silt that immediately overlies Kara Diamicton place the glaciation >40,000 yr ago. Eolian and fluvial deposition ensued with concomitant cryogenesis between ca. 35,000 and 12,000 cal yr B.P. associated with the Oleny and the Baidarata sands. There is no geomorphic or stratigraphic evidence of coverage or proximity of the Yamal Peninsula to a Late Weichselian ice sheet. The Nenets peat accumulated over the Baidarata sand during much of the past 10,000 yr, with local additions of the eolian Chum sand starting ca. 1000 yr ago. A prominent Betula horizon at the base of the Nenets peat contains rooted birch trees ca. 10,000 to 9000 cal yr old and indicates a >200-km shift northward of the treeline from the present limits, corresponding to a 2° to 4°C summer warming across northern Eurasia.
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late quaternary stratigraphy of western yamal peninsula russia new constraints on the configuration of the eurasian ice sheet
Geology, 1999Co-Authors: Steven L Forman, Valery Gataullin, Olafur Ingolfsson, William F Manley, Hanna LokrantzAbstract:Ice-sheet reconstructions for the last glacial maximum in northern Eurasia range from nearly complete coverage by a contiguous marine-based ice sheet to large unglaciated areas. Stratigraphic records from Yamal Peninsula, Russia, provide new insight on the eastern limit of the Eurasian ice sheet in the Kara Sea. Radiocarbon and infrared stimulated luminescence ages from coastal cliff sections date the emplacement of the Kara Diamicton as older than ca. 40 ka, reflecting regional glaciation. Ice-wedge growth, peat accumulation, and eolian and fluvial deposition characterized the past ~40 k.y. and do not support coverage of Yamal Peninsula by an ice sheet or proximity to a glacier margin. Thus, the late Weichselian Eurasian ice sheet was largely confined to Barents Sea and its global sea-level contribution is reduced to ~7 m of sea-level equivalent.