Late Pleistocene Glaciations of the Snag-Klutlan Area, Yukon Territory

Abstract

Two late Pleistocene limits of glaciation were delineated in the Snag-Klutlan area. Radiocarbon dates, surficial characteristics of its drift, and the palynology of overlying sediments imply the older glaciation (Mirror Creek) is early Wisconsin in age; the younger glaciation (Macauley) is late Wisconsin in age and culminated c. 13,700 B.P. The stratigraphy of depositswithin the Macauley glacial limit implies that deglaciation between the two glaciations was minimal.R ~S U M É . Glaciations finî-pléistocènes dans la région de Snag-KIutlan, Territoire du Yukon. On a retracé dans la région de Snag-Klutlan deux limites fini-pléistodnes de glaciation. Les datations au radiocarbone, les caractéristiques superficielles de sa moraine et la palynologie des sédiments de recouvrement impliquent que la plus ancienne glaciation (Mirror Creek) est d'âge wisconsinien ancien; la glaciation plus récente (Macauley) est d'âge hi-wisconsinien et a culminé vers 13,700 A.P. La stratigraphie des dépôts englobés par la limite glaciaire de Macauley laisse supposer que la déglaciation interglaciaire a été minime. PESIOME. lIo3tlwnneümnoqeuoeoe onetleutenuee pa&ne Cnaa -K d y m a u (K)xox).

Investigating the glacial history of the northern sector of the Cordilleran Ice Sheet with cosmogenic 10Be concentrations in quartz

“…Radiocarbon ages from wood and fossils underlying McConnell till indicate that the McConnell glaciation began after 29,600±300 14 C yr BP (Matthews et al, 1990), but glaciers did not advance into major valleys before 26,350±280 14 C yr BP (Jackson and Harington, 1991), and a fully developed CIS did not exist until after 23,900±1140 14 C yr BP (Lowdon and Blake, 1981). Published radiocarbon ages indicate that the St. Elias lobe of the CIS was in retreat by 13,660±180 14 C yr BP (Rampton, 1971) and the Selwyn lobe by 12,590±120 14 C yr BP (Ward, 1989) (Fig. 2).…”

Plant and Insect Fossils from the Mayo Indian Village Section (Central Yukon): New Data on Middle Wisconsinan Environments and Glaciation

“…Spruce woodland vegetation existed in the northern Yukon Bell Basin between 34-40 ka BP (Hughes et ai, in preparation) and in the Bonnet Plume Basin between 37 and 34 ka BP (Hughes et al, 1981, Hughes et al, in preparation (Denton and Stuiver, 1967), the Snag-Klutlan area of western Yukon (Rampton, 1971a(Rampton, , 1971b and Liard Plain in southeastern Yukon (Klassen, 1987) (Fig. 6).…”

The Cordilleran Ice Sheet: One Hundred and Fifty Years of Exploration and Discovery

“…Since 1950, two generations of Quaternary scientists have modified existing schemes and established new stratigraphies in many other areas (Table I). Denton and Stuiver, 1967;Rampton, 1971Klassen, 1978, 1987Rutter, 1976, 1977Mathews, 1978Clague, 1987, 1988Fulton and Smith, 1978Clague, 1975Armstrong et ai, 1965Armstrong, 1981, 1984Willis, 1898, Armstrong etal., 1965, Easterbrook, 1969, 1986Fyles, 1963Howes, 1981a, 1981bDawson and McConnell, 1895Alley, 1973;Alley and Harris, 1974;Stalker andHarrison, 1977 Rutter, 1972;Jackson, 1980Boydell, 1978Roed, 1975 Géographie physique et Quaternaire, 45(3), 1991 A major contribution of this stratigraphie and sedimentological work has been the documentation of a lengthy interstadial period in the Canadian Cordillera during the Middle Wisconsinan. Nonglacial deposits of Middle Wisconsinan age are more extensive and better dated in the southern Cordillera than anywhere else in Canada (Fulton, 1968(Fulton, ,1971Westgate and Fulton, 1975;Armstrong and Clague, 1977;Alley, 1979;Alley et al, 1986;Clague et al, 1990).…”