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North-western Canada and eastern Alaska are recognised as having one of the oldest known continental glacial records (Late Pliocene) preserved in stratigraphical sections. These include the individual and complex records of Cordilleran, montane and continental glaciations. Regional scale glaciations (Cordilleran and continental) started in northwestern Canada and east-central Alaska between 2.9 and 2.6 million years ago. Overall, two Cordilleran glaciations and two plateau ice caps (Horton Ice Cap) developed in Late Pliocene (Gauss and Matuyama Chron). During the Early Pleistocene, three Cordilleran glaciations occurred, while one to five continental glaciations (Keewatin Ice Sheet and Horton Ice Cap) are inferred...
This paper presents paleoecological analyses of 48 fossil arctic ground squirrel (Spermophilus parryii) middens (nests and caches) recovered from ice-rich loess sediments in the Klondike region of west-central Yukon Territory. AMS radiocarbon dates and stratigraphic association of middens with Dawson tephra (∼25 300 14C yr BP), indicate these paleoecological data reflect the onset of glacial conditions of early Marine Isotope Stage (MIS) 2 and terminal MIS 3 (∼24 000–29 450 14C yr BP). Plant macrofossils include at least 60 plant taxa, including diverse graminoids (Poa, Elymus trachycaulus, Kobresia myosuroides), steppe forbs (Penstemon gormanii, Anemone patens var. multifida, Plantago cf. canescens), tundra forbs...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene
This paper presents paleoecological analyses of 48 fossil arctic ground squirrel (Spermophilus parryii) middens (nests and caches) recovered from ice-rich loess sediments in the Klondike region of west-central Yukon Territory. AMS radiocarbon dates and stratigraphic association of middens with Dawson tephra (∼25 300 14C yr BP), indicate these paleoecological data reflect the onset of glacial conditions of early Marine Isotope Stage (MIS) 2 and terminal MIS 3 (∼24 000–29 450 14C yr BP). Plant macrofossils include at least 60 plant taxa, including diverse graminoids (Poa, Elymus trachycaulus, Kobresia myosuroides), steppe forbs (Penstemon gormanii, Anemone patens var. multifida, Plantago cf. canescens), tundra forbs...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene
The late Pleistocene Dawson tephra was deposited by one of the largest Quaternary eruptions in northwestern North America. Its distribution is known sparsely from sites near the source area in southwestern Alaska and central Yukon Territory, where more than 20 occurrences are documented in the Klondike region. Dawson tephra erupted about 25 , 300 14 C yr BP , near the onset of the last glaciation, and provides a stratigraphic marker across Eastern Beringia. We report radiocarbon ages, paleobotanical data, and cryostratigraphic observations from a new Dawson tephra locale at Goldbottom Creek, in the Klondike region of Yukon Territory, which collectively indicate that the eruption occurred in the late winter or early...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene
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Paleoecological research at Goldbottom Creek in the Klondike region of Yukon Territory (NW Canada) documents an in situ riparian grassy meadow that was buried during the winter or early spring by Dawson tephra, near the onset of Marine Isotope Stage (MIS) 2, ca. 25,300 14C years BP. Analyses of vascular plant macrofossils, bryophytes, pollen, insects and paleosols from the riparian meadow contrast with evidence for well-drained, upland steppe–tundra habitats obtained from fossil arctic ground squirrel middens within the same valley. The mesic valley bottom vegetation consisted of grasses (Deschampsia caespitosa, Alopecurus), sedges (Carex), horsetail (Equisetum cf. palustre), diverse bryophytes and few forbs. Upland...
Paleoecological research at Goldbottom Creek in the Klondike region of Yukon Territory (NW Canada) documents an in situ riparian grassy meadow that was buried during the winter or early spring by Dawson tephra, near the onset of Marine Isotope Stage (MIS) 2, ca. 25,300 14C years BP. Analyses of vascular plant macrofossils, bryophytes, pollen, insects and paleosols from the riparian meadow contrast with evidence for well-drained, upland steppe–tundra habitats obtained from fossil arctic ground squirrel middens within the same valley. The mesic valley bottom vegetation consisted of grasses (Deschampsia caespitosa, Alopecurus), sedges (Carex), horsetail (Equisetum cf. palustre), diverse bryophytes and few forbs. Upland...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene
This paper presents paleoecological analyses of 48 fossil arctic ground squirrel (Spermophilus parryii) middens (nests and caches) recovered from ice-rich loess sediments in the Klondike region of west-central Yukon Territory. AMS radiocarbon dates and stratigraphic association of middens with Dawson tephra (∼25 300 14C yr BP), indicate these paleoecological data reflect the onset of glacial conditions of early Marine Isotope Stage (MIS) 2 and terminal MIS 3 (∼24 000–29 450 14C yr BP). Plant macrofossils include at least 60 plant taxa, including diverse graminoids (Poa, Elymus trachycaulus, Kobresia myosuroides), steppe forbs (Penstemon gormanii, Anemone patens var. multifida, Plantago cf. canescens), tundra forbs...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene
Floodplain stratigraphy is used as a new method for reconstructing ice jam flood histories of northern rivers. The method, based on reconstruction of the sedimentary record of vertically-accreting floodplains, relies on stratigraphic logging and interpretation of floodplain sediments, which result from successive ice jam floods, and radiocarbon dating of inter-flood organic material for chronology. In a case study along a reach of the Yukon River that straddles the Yukon-Alaska border, the method is used to develop a record of ice jam flooding for the last 2000 years. Detailed chronostratigraphic logs from three sites along the Yukon River indicates that the long-term recurrence interval varies depending on location,...
Categories: Publication; Types: Citation; Tags: B3-Hydrological Datasets
The late Pleistocene Dawson tephra was deposited by one of the largest Quaternary eruptions in northwestern North America. Its distribution is known sparsely from sites near the source area in southwestern Alaska and central Yukon Territory, where more than 20 occurrences are documented in the Klondike region. Dawson tephra erupted about 25 , 300 14 C yr BP , near the onset of the last glaciation, and provides a stratigraphic marker across Eastern Beringia. We report radiocarbon ages, paleobotanical data, and cryostratigraphic observations from a new Dawson tephra locale at Goldbottom Creek, in the Klondike region of Yukon Territory, which collectively indicate that the eruption occurred in the late winter or early...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene
The late Pleistocene Dawson tephra was deposited by one of the largest Quaternary eruptions in northwestern North America. Its distribution is known sparsely from sites near the source area in southwestern Alaska and central Yukon Territory, where more than 20 occurrences are documented in the Klondike region. Dawson tephra erupted about 25 , 300 14 C yr BP , near the onset of the last glaciation, and provides a stratigraphic marker across Eastern Beringia. We report radiocarbon ages, paleobotanical data, and cryostratigraphic observations from a new Dawson tephra locale at Goldbottom Creek, in the Klondike region of Yukon Territory, which collectively indicate that the eruption occurred in the late winter or early...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene
The late Pleistocene Dawson tephra was deposited by one of the largest Quaternary eruptions in northwestern North America. Its distribution is known sparsely from sites near the source area in southwestern Alaska and central Yukon Territory, where more than 20 occurrences are documented in the Klondike region. Dawson tephra erupted about 25 , 300 14 C yr BP , near the onset of the last glaciation, and provides a stratigraphic marker across Eastern Beringia. We report radiocarbon ages, paleobotanical data, and cryostratigraphic observations from a new Dawson tephra locale at Goldbottom Creek, in the Klondike region of Yukon Territory, which collectively indicate that the eruption occurred in the late winter or early...
Categories: Publication; Types: Citation; Tags: Paleo and Holocene


map background search result map search result map Identification of last interglacial deposits in eastern Beringia; a cautionary note from the Palisades, interior Alaska Vegetation buried under Dawson tephra (25,300 14C years BP) and locally diverse late Pleistocene paleoenvironments of Goldbottom Creek, Yukon, Canada Middle to Late Pleistocene ice extents, tephrochronology and paleoenvironments of the White River area, southwest Yukon Vegetation buried under Dawson tephra (25,300 14C years BP) and locally diverse late Pleistocene paleoenvironments of Goldbottom Creek, Yukon, Canada Identification of last interglacial deposits in eastern Beringia; a cautionary note from the Palisades, interior Alaska Middle to Late Pleistocene ice extents, tephrochronology and paleoenvironments of the White River area, southwest Yukon