Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-20T00:24:58.165Z Has data issue: false hasContentIssue false

A late Quaternary paleotemperature record from Hanging Lake, northern Yukon Territory, eastern Beringia

Published online by Cambridge University Press:  20 January 2017

Joshua Kurek*
Affiliation:
Department of Biology, University of New Brunswick, PO Box 4400, Fredericton, NB, E3B 5A3 Canada
Les C. Cwynar
Affiliation:
Department of Biology, University of New Brunswick, PO Box 4400, Fredericton, NB, E3B 5A3 Canada
Jesse C. Vermaire
Affiliation:
Department of Biology, McGill University, Canada
*
Corresponding author.

E-mail addresses:[email protected] (J. Kurek), [email protected] (L.C. Cwynar), [email protected] (J.C. Vermaire).

Abstract

The late Quaternary paleoclimate of eastern Beringia has primarily been studied by drawing qualitative inferences from vegetation shifts. To quantitatively reconstruct summer temperatures, we analyzed lake sediments for fossil chironomids, and additionally we analyzed the sediments for fossil pollen and organic carbon content. A comparison with the δ18O record from Greenland indicates that the general climatic development of the region throughout the last glaciation–Holocene transition differed from that of the North Atlantic region. Between ∼ 17 and 15 ka, mean July air temperature was on average 5°C colder than modern, albeit a period of near-modern temperature at ∼ 16.5 ka. Total pollen accumulation rates ranged between ∼ 180 and 1200 grains cm− 2 yr− 1. At ∼ 15 ka, approximately coeval with the Bølling interstadial, temperatures again reached modern values. At ∼ 14 ka, nearly 1000 yr after warming began, Betula pollen percentages increased substantially and mark the transition to shrub-dominated pollen contributors. Chironomid-based inferences suggest no evidence of the Younger Dryas stade and only subtle evidence of an early Holocene thermal maximum, as temperatures from ∼ 15 ka to the late Holocene were relatively stable. The most recognizable climatic oscillation of the Holocene occurred from ∼ 4.5 to 2 ka.

Type
Research Article
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abbott, M.B., and Stafford, T.W. Radiocarbon geochemistry of modern and ancient Arctic lake systems, Baffin Island, Canada. Quaternary Research 45, (1996). 300311.CrossRefGoogle Scholar
Abbott, M.B., Finney, B.P., Edwards, M., and Kelts, K.R. Paleohydrology of Birch Lake, central Alaska: lake-level reconstructions using seismic reflection profiles and core transect approaches. Quaternary Research 23, (2000). 154166.CrossRefGoogle Scholar
Ager, T.A., and Brubaker, L.B. Quaternary palynology and vegetation history of Alaska. Bryant, V.M., and Holloway, R.G. Pollen Records of Late Quaternary North American Sediments. (1985). American Association of Stratigraphic Palynologists, Dallas, Texas. 353384.Google Scholar
Anderson, P.M., and Brubaker, L.B. Vegetation history of northcentral Alaska — a mapped summary of late-Quaternary pollen data. Quaternary Science Review 13, (1994). 7192.CrossRefGoogle Scholar
Anderson, P.M., Bartlein, P.J., Brubaker, L.B., Gajewski, K., and Ritchie, J.C. Vegetation–pollen–climate relationships for the Arcto–Boreal region of North America and Greenland. Journal of Biogeography 18, (1991). 565582.CrossRefGoogle Scholar
Anderson, L., Abbott, M.B., and Finney, B.P. Large and rapid Holocene moisture balance shifts in the Yukon Territory, Canada, based on lake-level reconstructions. The Holocene 15, (2005). 11721183.CrossRefGoogle Scholar
Anderson, L., Abbott, M.B., Finney, B.P., and Burns, S. Regional atmospheric circulation change in the North Pacific during the Holocene inferred from lacustrine carbonate oxygen isotopes, Yukon Territory, Canada. Quaternary Research 64, (2005). 2135.CrossRefGoogle Scholar
Barley, E.M., (2004). Palaeoclimate analysis of southwestern Yukon Territory using subfossil chironomid remains from Antifreeze Pond. MSc. thesis, Simon Fraser University, .Google Scholar
Barley, E.M., Walker, I.R., Kurek, J., Cwynar, L.C., Mathewes, R.W., Gajewski, K., and Finney, B. A northwest North America training set: distribution of freshwater midges in relation to air temperature and lake depth. Journal of Paleolimnology 36, (2006). 295314.CrossRefGoogle Scholar
Barnosky, C.W., Anderson, P.M., and Bartlein, P.J. The northwestern US during deglaciation: vegetational history and paleoclimatic implications. Ruddiman, W.F., Wright, H.E. Jr. North America and Adjacent Oceans during The Last Deglaciation, The Geology of North America. (1987). Geological Society of America, Boulder, Colorado. 289321.Google Scholar
Bartlein, P.J., Anderson, P.M., Edwards, M.E., and McDowell, P.F. A framework for interpreting paleoclimatic variations in eastern Beringia. Quaternary International. 10–12, (1991). 7383.CrossRefGoogle Scholar
Bennett, K.D. Determination of the number of zones in a biostratigraphical sequence. New Phytologist 132, (1996). 155170.CrossRefGoogle Scholar
Bennett, K.D., (2005). PSIMPOLL v 4.25.Google Scholar
Bennike, O., Brodersen, K.P., Jeppesen, E., and Walker, I.R. Aquatic invertebrates and high latitude paleolimnology. Pienitz, R.P., Douglas, M.S.V., and Smol, J.P. Long-term Environmental Change in Arctic and Antarctic Lakes. (2004). 159186. Springer, Dordrecht Google Scholar
Bigelow, N.H., and Edwards, M.E. A 14,000 yr paleoenvironmental record from Windmill Lake, central Alaska: lateglacial and Holocene vegetation in the Alaska Range. Quaternary Science Reviews 20, (2001). 203215.CrossRefGoogle Scholar
Bigelow, N.H., Brubaker, L.B., Edwards, M.E., Harrison, S.P., Prentice, I.C., Anderson, P.M., Andreev, A.A., Bartlein, P.J., Christensen, T.R., Cramer, W., Kaplan, J.O., Lozhkin, A.V., Matveyeva, N.V., Murray, D.F., Mcguire, A.D., Razzhivin, V.Y., Ritchie, J.C., Smith, B., Walker, D.A., Gajewski, K., Wolf, V., Holmqvist, B.H., Igarashi, Y., Kremenetskii, K., Paus, A., Pisaric, M.F.J., and Volkova, V.S. Climate change and Arctic ecosystems: 1. Vegetation changes north of 55 degrees N between the last glacial maximum, mid-Holocene, and present. Journal of Geophysical Research-Atmospheres 108, D19 (2003). Art. No. 8170 CrossRefGoogle Scholar
Birks, H.J.B., Line, J.M., Juggins, S., Stevenson, A.C., and ter Braak, C.J.F. Diatoms and pH reconstruction. Philosophical Transactions of The Royal Society of 640 London Series B-Biological Sciences 327, (1990). 263278.Google Scholar
Brubaker, L.B., Anderson, P.M., Edwards, M.E., and Lozhkin, A.V. Beringia as a glacial refugium for boreal trees and shrubs: new perspectives from mapped pollen data. Journal Biogeography 32, (2005). 833848.CrossRefGoogle Scholar
Bunbury, J., and Gajewski, K. Postglacial climates inferred from a lake at treeline, southwest Yukon Territory, Canada. Quaternary Science Reviews 28, (2009). 354369.CrossRefGoogle Scholar
Clarke, K.R., Gorley, R.N., (2001). PRIMER v 5.Google Scholar
Cwynar, L.C. A late-Quaternary vegetation history from Hanging Lake, northern Yukon. Ecological Monographs 52, (1982). 124.CrossRefGoogle Scholar
Cwynar, L.C., and Ritchie, J.C. Arctic steppe-tundra: a Yukon perspective. Science 208, (1980). 13751377.CrossRefGoogle ScholarPubMed
Cwynar, L.C., and Spear, R.W. Reversion of forest to tundra in the central Yukon. Ecology 72, (1991). 202212.CrossRefGoogle Scholar
Cwynar, L.C., and Spear, R.W. Paleovegetation and paleoclimatic changes in the Yukon at 6 ka yr BP. Geographie Physique Quaternaire 49, (1995). 2935.CrossRefGoogle Scholar
Cwynar, L.C., Burden, E., and McAndrews, J.H. An inexpensive sieving method for concentrating pollen and spores from fine-grained sediments. Canadian Journal Earth Sciences 16, (1979). 11151120.CrossRefGoogle Scholar
Davis, P.T. Holocene glacier fluctuations in the American Cordillera. Quaternary Science Reviews 7, (1988). 129158.CrossRefGoogle Scholar
Dean, W.E. Jr Determination of carbonate and organic matter in calcareous sediments and sedimentary rocks by loss on ignition: comparison with other methods. Journal of Sedimentary Petrololgy 44, (1974). 242248.Google Scholar
Denton, G.H., and Karlén, W. Holocene climatic variations: their pattern and possible cause. Quaternary Research 3, (1973). 155205.CrossRefGoogle Scholar
Dixon, E.J. Human colonization of the Americas: timing, technology, and process. Quaternary Science Reviews 20, (2001). 277299.CrossRefGoogle Scholar
Duk-Rodkin, A., Barendregt, R.W., Tarnocai, C., and Phillips, F.M. Late Tertiary to late Quaternary record in the Mackenzie Mountains, Northwest Territories, Canada: stratigraphy, paleomagnetism, and chlorine-361 . Canadian Journal Earth Sciences 33, (1996). 875895.CrossRefGoogle Scholar
Dyke, A.S., and Prest, V.K. Late Wisconsin and Holocene history of the Laurentide ice sheet. Geographie Physique et Quaternaire 41, (1987). 237263.CrossRefGoogle Scholar
Dyke, A.S., Moore, A., and Robertson, L. Deglaciation of North America. Geological Survey of Canada Open File 1574, (2003). Google Scholar
Edwards, M.E., Mock, C.J., Finney, B.P., Barber, V.A., and Bartlein, P.J. Potential analogues for paleoclimatic variations in eastern interior Alaska during the past 14,000 yr: atmospheric-circulation controls of regional temperature and moisture responses. Quaternary Science Reviews 20, (2001). 189202.CrossRefGoogle Scholar
Engstrom, D.R., Hansen, B.C.S., and Wright, H.E. A possible Younger Dryas record in southeastern Alaska. Science 250, (1990). 13831385.CrossRefGoogle ScholarPubMed
Faegri, K., Iversen, J., Kaland, P.E., and Krzywinski, K. Textbook of Pollen Analysis. 4th edition (1989). John Wiley and Sons Ltd., Toronto.Google Scholar
Fredskild, B. The genus Betula in Greenland–Holocene history, present distribution and synecology. Nordic Journal of Botany 11, (1991). 393412.CrossRefGoogle Scholar
Gavin, D.G., Oswald, W.W., Wahl, E.R., and Williams, J.W. A statistical approach to evaluating distance metrics and analog assignments for pollen records. Quaternary Research 60, (2003). 356367.CrossRefGoogle Scholar
Grootes, P.M., and Stuiver, M. Oxygen 18/16 variability in Greenland snow and ice with 10^3 to 10^5-year time resolution. Journal of Geophysical Research 102, (1997). 2645526470.CrossRefGoogle Scholar
Guthrie, R.D. Paleoecology of the large mammal community in interior Alaska during the late Pleistocene. American Midland Naturalist 79, (1968). 346363.CrossRefGoogle Scholar
Guthrie, R.D. Origin and causes of the mammoth steppe: a story of cloud cover, woolly mammal tooth pits, buckles, and inside-out Beringia. Quaternary Science Reviews 20, (2001). 549574.CrossRefGoogle Scholar
Guthrie, R.D. New carbon dates link climatic change with human colonization and Pleistocene extinctions. Nature 441, (2006). 207209.CrossRefGoogle ScholarPubMed
Heiri, O., and Lotter, A.F. Effect of low count sums on quantitative environmental reconstructions: an example using subfossil chironomids. Journal of Paleolimnology 26, (2001). 343350.CrossRefGoogle Scholar
Heiri, O., Lotter, A.F., and Lemcke, G. Loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results. Journal of Paleolimnology 25, (2001). 101110.CrossRefGoogle Scholar
Hill, M.O. Diversity and evenness: a unifying notation and its consequences. Ecology 54, (1973). 427432.CrossRefGoogle Scholar
Hopkins, D.M., Matthews, J.V., Schweger, C.E., and Young, S.B. Paleoecology of Beringia. (1982). Academic Press, New York.Google Scholar
Hu, F.S., Ito, E., Brubaker, L.B., and Anderson, P.M. Ostracode geochemical record of Holocene climatic change and implications for vegetational response in the northwestern Alaska Range. Quaternary Research 49, (1998). 8695.CrossRefGoogle Scholar
Hu, F.S., Lee, B.Y., Kaufman, D.S., Yoneji, S., Nelson, D.M., and Henne, P.D. Response of tundra ecosystem in southwestern Alaska to Younger-Dryas climatic oscillation. Global Change Biology 8, (2002). 11561163.CrossRefGoogle Scholar
Hu, F.S., Nelson, D.M., Clarke, G.H., Ruhland, K.M., Huang, Y., Kaufman, D.S., and Smol, J.P. Abrupt climatic events during the last glacial–interglacial transition in Alaska. Geophysical Research Letters 33, (2006). L18708 CrossRefGoogle Scholar
Jackson, D.A. Stopping rules in principal components analysis — a comparison of heuristic and statistical approaches. Ecology 74, (1993). 22042214.CrossRefGoogle Scholar
Jackson, S.T., and Williams, J.W. Modern analogs in Quaternary paleoecology: here today, gone yesterday, gone tomorrow?. Annual Review of Earth and Planetary Sciences 32, (2004). 495537.CrossRefGoogle Scholar
Juggins, S. C2 Version 1.4.. Software for Ecological and Palaeoecological Data Analysis and Visualization. (2003). University Of Newcastle, Google Scholar
Kaplan, J.O., Bigelow, N.H., Prentice, I.C., Harrison, S.P., Bartlein, P.J., Christensen, T.R., Cramer, W., Matveyeva, N.V., Mcguire, A.D., Murray, D.F., Razzhivin, V.Y., Smith, B., Walker, D.A., Anderson, P.M., Andreev, A.A., Brubaker, L.B., Edwards, M.E., and Lozhkin, A.V. Climate change and arctic ecosystems: 2. Modeling, Paleodata-model comparisons, and future projections. Journal of Geophysical Research-Atmospheres 108, D19 (2003). Art. No. 8171 CrossRefGoogle Scholar
Kaufman, D.S., Hu, F.S., Briner, J.P., Werner, A., Finney, B.P., and Gregory-Eaves, I. A ∼33,000 year record of environmental change from Arolik Lake, Ahklun Mountains, Alaska, USA. Journal of Paleolimnology 30, (2003). 343362.CrossRefGoogle Scholar
Kaufman, D.S., Ager, T.A., Anderson, N.J., Anderson, P.M., Andrews, J.T., Bartlein, P.J., Brubaker, L.B., Coats, L.L., Cwynar, L.C., Duvall, M.L., Dyke, A.S., Edwards, M.E., Eisner, W.R., Gajewski, K., Geirsdottir, A., Hu, F.S., Jennings, A.E., Kaplan, M.R., Kerwin, M.W., Lozhkin, A.V., MacDonald, G.M., Miller, G.H., Mock, C.J., Oswald, W.W., Otto-Bliesner, B.L., Porinchu, D.F., Ruhland, K., Smol, J.P., Steig, E.J., and Wolfe, B.B. Holocene thermal maximum in the western Arctic (0–180 degrees W). Quaternary Science Reviews 23, (2004). 529560.CrossRefGoogle Scholar
Kienast, S.S., and McKay, J.L. Sea surface temperatures in the subarctic northeast Pacific reflect millennial-scale climate oscillations during the last 16 kyrs. Geophysical Research Letters 28, (2001). 15631566.CrossRefGoogle Scholar
Kokorowski, H.D., Anderson, P.M., Mock, C.J., and Lozhkin, A.V. A re-evaluation and spatial analysis of evidence for a Younger Dryas climatic reversal in Beringia. Quaternary Science Reviews 28, (2008). 17101722.CrossRefGoogle Scholar
Kurek, J., Cwynar, L.C., Ager, T.A., Abbott, M.B., and Edwards, M.E. Late Quaternary paleoclimate of western Alaska inferred from fossil chironomids and its relation to vegetation histories. Quaternary Science Reviews 28, (2009). 799811.CrossRefGoogle Scholar
Larocque, I. How many chironomid head capsules are enough? A statistical approach to determine sample size for palaeoclimatic reconstructions. Palaeogeography, Palaeoclimatology, Palaeoecology 172, (2001). 133142.CrossRefGoogle Scholar
Laing, T.E., Ruhland, K.M., and Smol, J.P. Past environmental and climatic changes related to treeline shifts inferred from fossil diatoms from a lake near the Lena River Delta, Siberia. The Holocene 9, (1999). 547557.CrossRefGoogle Scholar
Laird, K.R., Fritz, S.C., and Cumming, B.F. A diatom-based reconstruction of drought intensity, duration, and frequency from Moon Lake, North Dakota: a sub-decadal record of the last 2300 years. Journal of Paleolimnology 19, (1998). 161179.CrossRefGoogle Scholar
Lotter, A.F., Walker, I.R., Brooks, S.J., and Hofmann, W. An intercontinental comparison of chironomid palaeotemperature inference models: Europe vs North America. Quaternary Science Reviews 18, (1999). 717735.CrossRefGoogle Scholar
Marshall, E. Pre-Clovis sites fight for acceptance. Science 291, (2001). 17301732.CrossRefGoogle ScholarPubMed
Mann, D.H., Peteet, D.M., Reanier, R.E., and Kunz, M.L. Responses of an Arctic landscape to lateglacial and early Holocene climatic changes: the importance of moisture. Quaternary Science Reviews 21, (2002). 9971021.CrossRefGoogle Scholar
Mathewes, R.W. Evidence for Younger Dryas-age cooling on the North Pacific coast of America. Quaternary Science Reviews 12, (1993). 321331.CrossRefGoogle Scholar
Matthews, J.V. East Beringia during late Wisconsin time: a review of the biotic evidence. Hopkins, D.M., Matthews, J.V., Schweger, C.E., and Young, S.B. Paleoecology of Beringia. (1982). Academic Press, New York. 127150.Google Scholar
McAndrews, J.H., Berti, A.A., and Norris, G. Key to the Quaternary Pollen and Spores of the Great Lakes region. (1978). Royal Ontario Museum Life Sciences Miscellaneous Publications. University of Toronto Press, Toronto, Canada.Google Scholar
Mikolajewicz, U., Crowley, T.J., Schiller, A., and Voss, R. Modeling teleconnections between the North Atlantic and North Pacific during the Younger Dryas. Nature 387, (1997). 384387.CrossRefGoogle Scholar
Murton, J.B., Frechen, M., and Maddy, D. Luminescence dating of mid- to Late Wisconsinan aeolian sand as a constraint on the last advance of the Laurentide Ice Sheet across the Tuktoyaktuk Coastlands, western Arctic Canada. Canadian Journal of Earth Sciences 44, (2007). 857869.CrossRefGoogle Scholar
New, M., Lister, D., Hulme, M., and Mankin, I. A high resolution data set of surface climate over global land areas. Clim. Res. 21, (2002). 125.CrossRefGoogle Scholar
Overpeck, J.T., Webb, T., and Prentice, I.C. Quantitative interpretation of fossil pollen spectra — dissimilarity coefficients and the method of modern analogs. Quaternary Research 23, (1985). 87108.CrossRefGoogle Scholar
Oliver, D.R., and Roussel, M.E. The Insects and Arachnids of Canada Part 11: The Genera of Larval Midges of Canada. Diptera: Chironomidae. (1983). Agriculture Canada Publication, 1746 Google Scholar
Pienitz, R., Smol, J.P., Last, W.M., Leavitt, P.R., and Cumming, B.F. Multi-proxy Holocene palaeoclimatic record from a saline lake in the Canadian Subarctic. The Holocene 10, (2000). 673686.CrossRefGoogle Scholar
Quinlan, R., and Smol, J.P. Setting minimum head capsule abundance and taxa deletion criteria in chironomid-based inference models. Journal of Paleolimnology 26, (2001). 327342.CrossRefGoogle Scholar
Rampton, V.N. Quaternary geology of the Yukon Coastal Plain. Geological Survey of Canada, Bulletin 317, (1982). Google Scholar
Rampton, V.N. Quaternary geology of the Tuktoyaktuk coastlands, Northwest Territories. Geological Survey of Canada, Memoir 423, (1988). Google Scholar
Reimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Bertrand, C.J.H., Blackwell, P.G., Buck, C.E., Burr, G.S., Cutler, K.B., Damon, P.E., Edwards, R.L., Fairbanks, R.G., Friedrich, M., Guilderson, T.P., Hogg, A.G., Hughen, K.A., Kromer, B., Mccormac, G., Manning, S., Ramsey, C.B., Reimer, R.W., Remmele, S., Southon, J.R., Stuiver, M., Talamo, S., Taylor, F.W., Van Der Plicht, J., and Weyhenmeyer, C.E. Intcal04 terrestrial radiocarbon age calibration, 0–26 cal kyr BP. Radiocarbon 46, (2004). 10291058.Google Scholar
Resson, H. The global response to Younger Dryas boundary conditions in an AGCM simulation. Climate Dynamics 13, (1997). 587599.Google Scholar
Ritchie, J.C., Cwynar, L.C., and Spear, R.W. Evidence from northwest Canada for an early Holocene Milankovitch thermal maximum. Nature 305, (1983). 126128.CrossRefGoogle Scholar
Sarnthein, M., Kiefer, T., Grootes, P.M., Elderfield, H., and Erlenkeuser, H. Warmings in the far northwestern Pacific promoted pre-Clovis immigration to America during Heinrich event 1. Geology 34, (2006). 141144.CrossRefGoogle Scholar
Schmittner, A., Saenko, O.A., and Weaver, A.J. Coupling of the hemispheres in observations and simulations of glacial climate change. Quaternary Science Reviews 22, (2003). 659671.CrossRefGoogle Scholar
Spear, R.W. The palynological record of late-Quaternary Arctic tree-line in northwestern Canada. Review of Palaeobotany and Palynology 79, (1993). 99111.CrossRefGoogle Scholar
Spooner, I.S., Barnes, S., Baltzer, K.B., Raeside, R., Osborn, G.D., and Mazzucchi, D. The impact of air mass circulation dynamics on late Holocene paleoclimate in northwestern North America. Quaternary International 108, (2003). 7783.CrossRefGoogle Scholar
Stuiver, M., and Reimer, P.J. Extended C-14 data-base and revised Calib 3.0 C-14 age calibration program. Radiocarbon 35, (1993). 215230.CrossRefGoogle Scholar
Szeicz, J.M., and MacDonald, G.M. Montane climate and vegetation dynamics in easternmost Beringia during the Late Quaternary. Quaternary Science Reviews 20, (2001). 247257.CrossRefGoogle Scholar
ter Braak, C.F.J., and Šmilauer, P. CANOCO Reference Manual and CANODRAW for Windows User's Guide: Software for Canonical Community Ordination (v 4.5). (2002). Microcomputer Power, Ithaca, NY.Google Scholar
Wahl, E.R. A general framework for determining cut-off values to select pollen analogs with dissimilarity metrics in the modern analog technique. Review of Palaeobotany and Palynology 128, (2004). 263280.CrossRefGoogle Scholar
Wahl, H.E., Fraser, D.B., Harvey, R.C., and Maxwell, J.B. Climate of the Yukon. Environment Canada, Atmospheric Environment Service, Climatological Studies, Number. (1987). 40 Google Scholar
Walker, I.R. Midges: Chironomidae and related Diptera. Smol, J.P., Birks, H.J.B., Last, W.M. Tracking Environmental Change Using Lake Sediments Vol 4, (2001). Zoological Indicators. Kluwer Academic Publishers, Dordrecht. 4366.CrossRefGoogle Scholar
Walker, I.R., (2007). The WWW field guide to fossil midges. http://www.paleolab.ca/wwwguide/.Google Scholar
Wiederholm, T. Chironomidae of the Holarctic region. Keys and diagnoses Part I. Larvae. Entomologica Scandinavica Supplement 19, (1983). 1457.Google Scholar
Zazula, G.D., Duk-Rodkin, A., Schweger, C.E., and Morlan, R.E. Late Pleistocene chronology of glacial Lake Old Crow and the north-west margin of the Laurentide Ice Sheet. Ehlers, J., and Gibbard, P.L. Quaternary Glaciations — Extent and Chronology, Part II. (2004). Elsevier, In. 347362.Google Scholar