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Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka

Published online by Cambridge University Press:  17 April 2019

Martin Margold Open the ORCID record for Martin Margold [Opens in a new window] ,
John C. Gosse ,
Alan J. Hidy ,
Robin J. Woywitka ,
Joseph M. Young  and
Duane Froese
Martin Margold*
Affiliation:
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada Department of Physical Geography and Geoecology, Charles University in Prague, Faculty of Science, 128 43 Praha 2, Czech Republic
John C. Gosse
Affiliation:
Department of Earth Sciences, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
Alan J. Hidy
Affiliation:
Centre for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
Robin J. Woywitka
Affiliation:
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
Joseph M. Young
Affiliation:
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
Duane Froese
Affiliation:
Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
*
*Corresponding author at: e-mail address: martin.margold@natur.cuni.cz (M. Margold).
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Abstract

The Foothills Erratics Train consists of large quartzite blocks of Rocky Mountains origin deposited on the eastern slopes of the Rocky Mountain Foothills in Alberta between ~53.5°N and 49°N. The blocks were deposited in their present locations when the western margin of the Laurentide Ice Sheet (LIS) detached from the local ice masses of the Rocky Mountains, which initiated the opening of the southern end of the ice-free corridor between the Cordilleran Ice Sheet and the LIS. We use 10Be exposure dating to constrain the beginning of this decoupling. Based on a group of 12 samples well-clustered in time, we date the detachment of the western LIS margin from the Rocky Mountain front to ~14.9 ± 0.9 ka. This is ~1000 years later than previously assumed, but a lack of a latitudinal trend in the ages over a distance of ~500 km is consistent with the rapid opening of a long wedge of unglaciated terrain portrayed in existing ice-retreat reconstructions. A later separation of the western LIS margin from the mountain front implies higher ice margin–retreat rates in order to meet the Younger Dryas ice margin position near the boundary of the Canadian Shield ~2000 years later.

Keywords

Laurentide Ice SheetCordilleran Ice SheetRocky Mountains10Be exposure datingdeglaciation
Type
Research Article
Information
Quaternary Research , Volume 92 , Issue 2 , September 2019 , pp. 469 - 482
Creative Commons
This is a work of the U.S. Government and is not subject to copyright protection in the United States
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Copyright © University of Washington. Published by Cambridge University Press, 2019

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References

REFERENCES

Antevs, E., 1935. The spread of aboriginal man to North America. Geographical Review 25, 302–309.10.2307/209605Google Scholar
Atkinson, N., Utting, D.J., Pawley, S.M., 2014a. Glacial Landforms of Alberta. AER/AGS Map 604. Alberta Energy Regulator, Edmonton.Google Scholar
Atkinson, N., Utting, D.J., Pawley, S.M., 2014b. Landform signature of the Laurentide and Cordilleran ice sheets across Alberta during the last glaciation. Canadian Journal of Earth Sciences 51, 1067–1083.10.1139/cjes-2014-0112Google Scholar
Balco, G., Stone, J.O., Lifton, N.A., Dunai, T.J., 2008. A complete and easily accessible means of calculating surface exposure ages or erosion rates from 10Be and 26Al measurements. Quaternary Geochronology 3, 174–195.10.1016/j.quageo.2007.12.001Google Scholar
Beierle, B., Smith, D.G., 1998. Severe drought in the early Holocene (10,000–6800 BP) interpreted from lake sediment cores, southwestern Alberta, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 140, 75–83.10.1016/S0031-0182(98)00044-3Google Scholar
Bobrowsky, P., Rutter, N., 1992. The quaternary geologic history of the Canadian Rocky Mountains. Géographie physique et Quaternaire 46, 5–50.10.7202/032887arGoogle Scholar
Borchers, B., Marrero, S., Balco, G., Caffee, M., Goehring, B., Lifton, N., Nishiizumi, K., Phillips, F., Schaefer, J., Stone, J., 2016. Geological calibration of spallation production rates in the CRONUS-Earth project. Quaternary Geochronology 31, 188–198.10.1016/j.quageo.2015.01.009Google Scholar
Braje, T.J., Dillehay, T.D., Erlandson, J.M., Klein, R.G., Rick, T.C., 2017. Finding the first Americans. Science 358, 592–594.10.1126/science.aao5473Google Scholar
Brink, J., 1981. Rock art sites in Alberta: retrospect and prospect. In: Moore, T.A. (Ed.), Alberta Archaeology: Prospect and Retrospect. Archaeological Society of Alberta, Lethbridge, pp. 69–82.Google Scholar
Bronk Ramsey, C., 2009. Bayesian analysis of radiocarbon dates. Radiocarbon 51, 337–360.10.1017/S0033822200033865Google Scholar
Burns, J.A., 1996. Vertebrate paleontology and the alleged ice-free corridor: the meat of the matter. Quaternary International 32, 107–112.10.1016/1040-6182(95)00057-7Google Scholar
Burns, J.A., 2010. Mammalian faunal dynamics in late Pleistocene Alberta, Canada. Quaternary International 217, 37–42.10.1016/j.quaint.2009.08.003Google Scholar
Catto, N., Liverman, D.G.E., Bobrowsky, P.T., Rutter, N., 1996. Laurentide, Cordilleran, and montane glaciation in the western Peace River—Grande Prairie region, Alberta and British Columbia, Canada. Quaternary International 32, 21–32.10.1016/1040-6182(95)00061-5Google Scholar
Clayton, L., Moran, S.R., Bluemle, J.P., 1980. Explanatory Text to Accompany the Geologic Map of North Dakota. North Dakota Geological Survey Report of Investigation 69, 93 pp.Google Scholar
Darvill, C.M., Menounos, B., Goehring, B.M., Lian, O.B., Caffee, M.W., 2018. Retreat of the western Cordilleran Ice Sheet margin during the last deglaciation. Geophysical Research Letters 45, 9710–9720.10.1029/2018GL079419Google Scholar
Delunel, R., Bourles, D.L., van der Beek, P.A., Schlunegger, F., Leya, I., Masarik, J., Paquet, E., 2014. Snow shielding factors for cosmogenic nuclide dating inferred from long-term neutron detector monitoring. Quaternary Geochronology 24, 16–26.10.1016/j.quageo.2014.07.003Google Scholar
Dunai, T.J., Stuart, F.M., Pik, R., Burnard, P., Gayer, E., 2007. Production of 3He in crustal rocks by cosmogenic thermal neutrons. Earth and Planetary Science Letters 258, 228–236.10.1016/j.epsl.2007.03.031Google Scholar
Dunning, S.A., Rosser, N.J., McColl, S.T., Reznichenko, N.V., 2015. Rapid sequestration of rock avalanche deposits within glaciers. Nature Communications 6, 7964.10.1038/ncomms8964Google Scholar
Duxbury, J., Bierman, P.R., Portenga, E.W., Pavich, M.J., Southworth, S., Freeman, S.P., 2015. Erosion rates in and around Shenandoah National Park, Virginia, determined using analysis of cosmogenic 10Be. American Journal of Science 315, 46–76.10.2475/01.2015.02Google Scholar
Dyke, A.S., 2004. An outline of North American deglaciation with emphasis on central and northern Canada. In: Ehlers, J., Gibbard, P.L. (Eds.), Quaternary Glaciations—Extent and Chronology. Part II. Elsevier, Amsterdam, pp. 373–424.10.1016/S1571-0866(04)80209-4Google Scholar
Dyke, A.S., Andrews, J.T., Clark, P.U., England, J.H., Miller, G.H., Shaw, J., Veillette, J.J., 2002. The Laurentide and Innuitian ice sheets during the Last Glacial Maximum. Quaternary Science Reviews 21, 9–31.10.1016/S0277-3791(01)00095-6Google Scholar
Dyke, A.S., Moore, A., Robertson, L., 2003. Deglaciation of North America. Geological Survey of Canada, Ottawa.10.4095/214399Google Scholar
Dyke, A.S., Prest, V.K., 1987. Late Wisconsinan and Holocene history of the Laurentide ice sheet. Géographie physique et Quaternaire 41, 237–263.10.7202/032681arGoogle Scholar
Evans, D.J.A., 2000. Quaternary geology and geomorphology of the Dinosaur Provincial Park area and surrounding plains, Alberta, Canada: the identification of former glacial lobes, drainage diversions and meltwater flood tracks. Quaternary Science Reviews 19, 931–958.10.1016/S0277-3791(99)00029-3Google Scholar
Goebel, T., Waters, M.R., O'Rourke, D.H., 2008. The late Pleistocene dispersal of modern humans in the Americas. Science 319, 1497–1502.10.1126/science.1153569Google Scholar
Harrison, J.E., 1976. Dated organic material below Mazama (?) tephra: Elk Valley, British Columbia. In: Blackadar, R.G., Griffin, P.J., Dumych, H., Irish, W.J.W. (Eds.), Report of Activities. Part C. Geological Survey of Canada, Ottawa, pp. 169–170.Google Scholar
Haynes, G., 2002. The Early Settlement of North America: The Clovis Era. Cambridge University Press, Cambridge.Google Scholar
Hebda, R.J., Burns, J.A., Geertsema, M., Jull, A.J.T., 2008. AMS-dated late Pleistocene taiga vole (Rodentia: Microtus xanthognathus) from northeast British Columbia, Canada: a cautionary lesson in chronology. Canadian Journal of Earth Sciences 45, 611–618.10.1139/E07-064Google Scholar
Heintzman, P.D., Froese, D., Ives, J.W., Soares, A.E.R., Zazula, G.D., Letts, B., Andrews, T.D., et al. , 2016. Bison phylogeography constrains dispersal and viability of the Ice Free Corridor in western Canada. Proceedings of the National Academy of Sciences USA 113, 8057–8063.10.1073/pnas.1601077113Google Scholar
Heyman, J., Stroeven, A.P., Harbor, J.M., Caffee, M.W., 2011. Too young or too old: evaluating cosmogenic exposure dating based on an analysis of compiled boulder exposure ages. Earth and Planetary Science Letters 302, 71–80.10.1016/j.epsl.2010.11.040Google Scholar
Hickman, M., Schweger, C.E., 1996. The Late Quaternary palaeoenvironmental history of a presently deep freshwater lake in east-central Alberta, Canada and palaeoclimate implications. Palaeogeography, Palaeoclimatology, Palaeoecology 123, 161–178.10.1016/0031-0182(95)00089-5Google Scholar
Ives, J.W., Froese, D., Supernant, K., Yanicki, G., 2014. Vectors, vestiges and Valhallas: rethinking the corridor. In: Graf, K.E., Ketron, C.V., Waters, M.R. (Eds.), Paleoamerican Odyssey. Texas A&M University Press, College Station, pp. 149–169.Google Scholar
Jackson, L.E., 2017. The Foothills Erratics Train region. In: Slaymaker, O. (Ed.), Landscapes and Landforms of Western Canada. Springer International Publishing, Cham, pp. 157–165.10.1007/978-3-319-44595-3_11Google Scholar
Jackson, L.E., Andriashek, L.D., Phillips, F.M., 2011. Limits of successive middle and late Pleistocene continental ice sheets, Interior Plains of southern and central Alberta and adjacent areas. In: Ehlers, J., Gibbard, P.L., Hughes, P.D. (Eds.), Quaternary Glaciations—Extent and Chronology: A Closer Look. Elsevier, Amsterdam, pp. 575–589.10.1016/B978-0-444-53447-7.00045-3Google Scholar
Jackson, L.E., Phillips, F.M., Little, E.C., 1999. Cosmogenic 36Cl dating of the maximum limit of the Laurentide Ice Sheet in southwestern Alberta. Canadian Journal of Earth Sciences 36, 1347–1356.10.1139/e99-038Google Scholar
Jackson, L.E., Phillips, F.M., Shimamura, K., Little, E.C., 1997. Cosmogenic 36Cl dating of the Foothills erratics train, Alberta, Canada. Geology 25, 195–198.10.1130/0091-7613(1997)025<0195:CCDOTF>2.3.CO;22.3.CO;2>Google Scholar
Jackson, L.E. Jr., Leboe, E.R., Little, E.C., Holme, P.J., Hicock, S.R., Shimamura, K., Nelson, F.E.N., 2008. Quaternary Stratigraphy and Geology of the Rocky Mountain Foothills, Southwestern Alberta. Geological Survey of Canada Bulletin 583. Natural Resources Canada, Ottawa.10.4095/224301Google Scholar
Johnston, W., 1933. Quaternary geology of North America in relation to the migration of man. In: Jenness, D. (Ed.), The American Aborigines. University of Toronto Press, Toronto, pp. 11–45.Google Scholar
Kohl, C., Nishiizumi, K., 1992. Chemical isolation of quartz for measurement of in situ-produced cosmogenic nuclides. Geochimica et Cosmochimica Acta 6, 3583–3587.10.1016/0016-7037(92)90401-4Google Scholar
Lal, D., 1991. Cosmic ray labeling of erosion surfaces: in situ nuclide production rates and erosion models. Earth and Planetary Science Letters 104, 424–439.10.1016/0012-821X(91)90220-CGoogle Scholar
Lambeck, K., Purcell, A., Zhao, S., 2017. The North American late Wisconsin ice sheet and mantle viscosity from glacial rebound analyses. Quaternary Science Reviews 158, 172–210.10.1016/j.quascirev.2016.11.033Google Scholar
Mandryk, C.A.S., Josenhans, H., Fedje, D.W., Mathewes, R.W., 2001. Late Quaternary paleoenvironments of Northwestern North America: implications for inland versus coastal migration routes. Quaternary Science Reviews 20, 301–314.10.1016/S0277-3791(00)00115-3Google Scholar
Margold, M., Jansson, K.N., Kleman, J., Stroeven, A.P., Clague, J.J., 2013. Retreat pattern of the Cordilleran Ice Sheet in central British Columbia at the end of the last glaciation reconstructed from glacial meltwater landforms. Boreas 42, 830–847.Google Scholar
Margold, M., Stokes, C.R., Clark, C.D., 2015. Ice streams in the Laurentide Ice Sheet: identification, characteristics and comparison to modern ice sheets. Earth-Science Reviews 143, 117–146.Google Scholar
Margold, M., Stokes, C.R., Clark, C.D., 2018. Reconciling records of ice streaming and ice margin retreat to produce a palaeogeographic reconstruction of the deglaciation of the Laurentide Ice Sheet. Quaternary Science Reviews 189, 1–30.10.1016/j.quascirev.2018.03.013Google Scholar
Margold, M., Stroeven, A.P., Clague, J.J., Heyman, J., 2014. Timing of terminal Pleistocene deglaciation at high elevations in southern and central British Columbia constrained by 10Be exposure dating. Quaternary Science Reviews 99, 193–202.Google Scholar
McCallum, K.J., Wittenberg, J., 1968. University of Saskatchewan Radiocarbon Dates V. Radiocarbon, 10, 365–378.10.1017/S0033822200010961Google Scholar
Menounos, B., Goehring, B.M., Osborn, G., Margold, M., Ward, B., Bond, J., Clarke, G.K.C., et al. , 2017. Cordilleran Ice Sheet mass loss preceded climate reversals near the Pleistocene termination. Science 358, 781–784.Google Scholar
Mott, R.J., 1973. Palynological Studies in Central Saskatchewan: Pollen Stratigraphy from Lake Sediment Sequences. Geological Survey of Canada, Ottawa.Google Scholar
Mountjoy, E.W., 1958. Jasper Area Alberta, a source of the Foothills Erratics Train. Bulletin of Canadian Petroleum Geology 6, 218–226.Google Scholar
Munyikwa, K., Feathers, J.K., Rittenour, T.M., Shrimpton, H.K., 2011. Constraining the late Wisconsinan retreat of the Laurentide ice sheet from western Canada using luminescence ages from postglacial aeolian dunes. Quaternary Geochronology 6, 407–422.10.1016/j.quageo.2011.03.010Google Scholar
Munyikwa, K., Rittenour, T.M., Feathers, J.K., 2017. Temporal constraints for the late Wisconsinan deglaciation of western Canada using eolian dune luminescence chronologies from Alberta. Palaeogeography, Palaeoclimatology, Palaeoecology 470, 147–165.Google Scholar
Newton, B., 1991. Bow Corridor Project: Summary of the 1988–1989 Research. In: Magne, M. (Ed.), Archaeology in Alberta, 1988 and 1989, pp. 113–125. Archaeological Survey, Provincial Museum of Alberta, Occasional Paper No. 33. Alberta Culture and Multiculturalism, Edmonton, Alberta.Google Scholar
Nishiizumi, K., Imamura, M., Caffee, M.W., Southon, J.R., Finkel, R.C., McAninch, J., 2007. Absolute calibration of 10Be AMS standards. Nuclear Instruments and Methods in Physics Research B 259, 403–413.10.1016/j.nimb.2007.01.297Google Scholar
Pedersen, M.W., Ruter, A., Schweger, C., Friebe, H., Staff, R.A., Kjeldsen, K.K., Mendoza, M.L., et al. , 2016. Postglacial viability and colonization in North America's ice-free corridor. Nature 537, 45–49.10.1038/nature19085Google Scholar
Peltier, W.R., 2004. Global glacial isostasy and the surface of the ice-age Earth: the ICE-5 G (VM2) model and GRACE. Annual Review of Earth and Planetary Sciences 32, 111–149.Google Scholar
Peltier, W.R., Argus, D.F., Drummond, R., 2015. Space geodesy constrains ice age terminal deglaciation: the global ICE-6G_C (VM5a) model. Journal of Geophysical Research: Solid Earth 120, 2014JB011176.Google Scholar
Phillips, F.M., Argento, D.C., Balco, G., Caffee, M.W., Clem, J., Dunai, T.J., Finkel, R., et al. , 2016a. The CRONUS-Earth project: a synthesis. Quaternary Geochronology 31, 119–154.10.1016/j.quageo.2015.09.006Google Scholar
Phillips, F.M., Argento, D.C., Bourlès, D.L., Caffee, M.W., Dunai, T.J., Goehring, B., Gosse, J.C., et al. , 2016b. Where now? Reflections on future directions for cosmogenic nuclide research from the CRONUS projects. Quaternary Geochronology 31, 155–159.Google Scholar
Porter, S.C., Swanson, T.W., 1998. Radiocarbon age constraints on rates of advance and retreat of the Puget Lobe of the Cordilleran Ice Sheet during the last glaciation. Quaternary Research 50, 205–213.10.1006/qres.1998.2004Google Scholar
Potter, B.A., Baichtal, J.F., Beaudoin, A.B., Fehren-Schmitz, L., Haynes, C.V., Holliday, V.T., Holmes, C.E., Ives, J.W., et al. , 2018a. Current evidence allows multiple models for the peopling of the Americas. Science Advances 4, eaat5473.Google Scholar
Potter, B.A., Beaudoin, A.B., Haynes, C.V., Holliday, V.T., Holmes, C.E., Ives, J.W., Kelly, R., et al. , 2018b. Arrival routes of first Americans uncertain. Science 359, 1224–1225.Google Scholar
Potter, B.A., Reuther, J.D., Holliday, V.T., Holmes, C.E., Miller, D.S., Schmuck, N., 2017. Early colonization of Beringia and Northern North America: chronology, routes, and adaptive strategies. Quaternary International 444, 36–55.10.1016/j.quaint.2017.02.034Google Scholar
Praetorius, S.K., Mix, A.C., 2014. Synchronization of North Pacific and Greenland climates preceded abrupt deglacial warming. Science 345, 444–448.Google Scholar
Rains, R.B., Shaw, J., Sjogren, D.B., Munro-Stasiuk, M.J., Robert Skoye, K., Young, R.R., Thompson, R.T., 2002. Subglacial tunnel channels, Porcupine Hills, southwest Alberta, Canada. Quaternary International 90, 57–65.Google Scholar
Rasmussen, S.O., Bigler, M., Blockley, S.P., Blunier, T., Buchardt, S.L., Clausen, H.B., Cvijanovic, I., et al. , 2014. A stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy. Quaternary Science Reviews 106, 14–28.10.1016/j.quascirev.2014.09.007Google Scholar
Reimer, P.J., Bard, E., Bayliss, A., Beck, J.W., Blackwell, P.G., Ramsey, C.B., Buck, C.E., et al. , 2013. IntCal13 and Marine13 radiocarbon age calibration curves 0–50,000 years cal BP. Radiocarbon 55, 1869–1887.Google Scholar
Roed, M.A., Mountjoy, E.W., Rutter, N.W., 1967. The Athabasca Valley erratics train and ice movement across the Continental Divide. Canadian Journal of Earth Sciences 4, 625–632.Google Scholar
Ross, M., Campbell, J.E., Parent, M., Adams, R.S., 2009. Palaeo-ice streams and the subglacial landscape mosaic of the North American mid-continental prairies. Boreas 38, 421–439.Google Scholar
Seguinot, J., Rogozhina, I., Stroeven, A.P., Margold, M., Kleman, J., 2016. Numerical simulations of the Cordilleran ice sheet through the last glacial cycle. Cryosphere 10, 639–664.10.5194/tc-10-639-2016Google Scholar
Shapiro, B., Drummond, A.J., Rambaut, A., Wilson, M.C., Matheus, P.E., Sher, A.V., Pybus, O.G., et al. , 2004. Rise and fall of the Beringian Steppe bison. Science 306, 1561–1565.Google Scholar
Stalker, A.M., 1956. The Erratics Train Foothills of Alberta. Geological Survey of Canada, Ottawa.10.4095/101536Google Scholar
Stone, J.O., 2000. Air pressure and cosmogenic isotope production. Journal of Geophysical Research: Solid Earth 105, 23753–23759.Google Scholar
Stroeven, A.P., Fabel, D., Margold, M., Clague, J.J., Xu, S., 2014. Investigating absolute chronologies of glacial advances in the NW sector of the Cordilleran Ice Sheet with terrestrial in situ cosmogenic nuclides. Quaternary Science Reviews 92, 429–443.Google Scholar
Stumpf, A.J., Broster, B.E., Levson, V.M., 2000. Multiphase flow of the late Wisconsinan Cordilleran ice sheet in western Canada. Geological Society of America Bulletin 112, 1850–1863.Google Scholar
Tarasov, L., Dyke, A.S., Neal, R.M., Peltier, W.R., 2012. A data-calibrated distribution of deglacial chronologies for the North American ice complex from glaciological modeling. Earth and Planetary Science Letters 315, 30–40.10.1016/j.epsl.2011.09.010Google Scholar
Ullman, D.J., Carlson, A.E., Hostetler, S.W., Clark, P.U., Cuzzone, J., Milne, G.A., Winsor, K., Caffee, M., 2016. Final Laurentide ice-sheet deglaciation and Holocene climate-sea level change. Quaternary Science Reviews 152, 49–59.Google Scholar
White, J.M., Mathewes, R.W., Mathews, W.H., 1979. Radiocarbon dates from Boone Lake and their relation to the ‘ice-free corridor’ in the Peace River District of Alberta, Canada. Canadian Journal of Earth Sciences 16, 1870–1874.Google Scholar
White, J.M., Mathewes, R.W., Mathews, W.H., 1985. Late Pleistocene chronology and environment of the ‘ice-free corridor’ of northwestern Alberta. Quaternary Research 24, 173–186.10.1016/0033-5894(85)90004-3Google Scholar
Wolfe, S., Huntley, D., Ollerhead, J., 2004. Relict late Wisconsinan dune fields of the northern Great Plains, Canada. Géographie physique et Quaternaire 58, 323–336.Google Scholar
Young, R.R., Burns, J.A., Smith, D.G., Arnold, L.D., Rains, R.B., 1994. A single, late Wisconsin, Laurentide glaciation, Edmonton area and southwestern Alberta. Geology 22, 683–686.10.1130/0091-7613(1994)022<0683:ASLWLG>2.3.CO;22.3.CO;2>Google Scholar
Zweck, C., Zreda, M., Desilets, D., 2013. Snow shielding factors for cosmogenic nuclide dating inferred from Monte Carlo neutron transport simulations. Earth and Planetary Science Letters 379, 64–71.Google Scholar
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