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A Younger Dryas Icecap in the Equatorial Andes

Published online by Cambridge University Press:  20 January 2017

Chalmers M. Clapperton
Affiliation:
Department of Geography, University of Aberdeen, Aberdeen, AB24 3UF, Scotland, United Kingdom
Minard Hall
Affiliation:
Instituto Geofisico, Escuela Politecnica Nacional, Apartado, 2759, Quito, Ecuador
Patricia Mothes
Affiliation:
Instituto Geofisico, Escuela Politecnica Nacional, Apartado, 2759, Quito, Ecuador
Malcolm J. Hole
Affiliation:
Department of Geology & Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UF, Scotland, United Kingdom
John W. Still
Affiliation:
Department of Geology & Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UF, Scotland, United Kingdom
Karin F. Helmens
Affiliation:
Arctic Centre, University of Lapland, P.O. Box 122, 96101, Rovaniemi, Finland
Peter Kuhry
Affiliation:
Arctic Centre, University of Lapland, P.O. Box 122, 96101, Rovaniemi, Finland
Alastair M.D. Gemmell
Affiliation:
Department of Geography, University of Aberdeen, Aberdeen, AB24 3UF, Scotland, United Kingdom

Abstract

Morphologic and stratigraphic evidence shows that a late-glacial ice cap existed on part of the Eastern Cordillera of Ecuador (Lat. 0° 20′ S) on ground with a mean elevation of 4200 m where none exists now. An outlet glacier from an ca. 800 km2ice cap terminated at 3850 m altitude in the Papallacta valley on the eastern side of the plateau. Radiocarbon dates show that moraines formed by this advance were ice-free by 13,20014C yr B.P. Tephras and the age of organic deposits at the plateau edge indicate ice-free conditions before 11,80014C yr B.P. This interval was followed by the expansion of an ca. 140 km2ice cap that discharged glaciers into adjacent valleys where terminal moraines were built at 3950 m altitude. AMS and conventional radiocarbon dates from macrofossils, peat, and gyttja above and below till of the readvance indicate that the ice cap formed between ca. 11,000 and 10,00014C yr B.P. and was thus coeval with the European Younger Dryas event. The ice cap developed in response to a surface temperature cooling of at least 3°C in the tropical Andes, a finding that is consistent with a coupled equatorial/high latitude North Atlantic climate system operating at the late-glacial/Holocene transition. These results are further evidence that Younger Dryas cooling may have been a global event.

Type
Research Article
Copyright
University of Washington

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References

Alley, R. B. Bond, G. Chappelaz, J. Clapperton, C. M. Del Genio, A. Keigwin, L.andPeteet, D. H.(1993a). Global Younger Dryas? Eos 74, 587589.Google Scholar
Alley, R. B. Meese, D. A. Shuman, C. A. Gow, A. J. Taylor, K. C Grootes, P. M. White, J. C Ram, M. Waddington, E. D. Mayewski, P. A.andZielinski, G. A.(1993b). Abrupt increase in Greenland snow accumulation at the end of the Younger Dryas event. Nature 362, 527529.CrossRefGoogle Scholar
Ashworth, A. C.andMarkgraf, V.(1989). Climate of the Chilean Channels between 11–10,000 yr B.P. based on fossil beetles and pollen analysis. Revista Chilena de Historia Natural 62, 6174.Google Scholar
Bard, E. Arnold, M. Maurice, P. Duprat, J. Moyes, J.andDuplessy, J.-C.(1987). Retreat velocity of the North Atlantic polar front during the last deglaciation determined by 14C accelerator mass spectrometry. Nature 328, 791794.CrossRefGoogle Scholar
Bond, G. C.andLotti, R.(1995). Iceberg discharges into the North Atlantic on millenial timescales during the last glaciation. Science 267, 10051010.Google Scholar
Bond, G. C, Broecker, W. S. Johsen, S. McManus, J. Labeyrie, L. Jouzel, J.andBonani, G.(1993). Correlations between climate records from North Atlantic sediments and Greenland ice. Nature 365 143147.Google Scholar
Broecker, W. S.(1994). Massive iceberg discharges as triggers for global climate change. Nature 372, 421424.Google Scholar
Broecker, W. S.andDenton, G. H.(1990). The role of ocean-atmosphere reorganisations in glacial cycles. Quaternary Science Reviews 9, 305341.CrossRefGoogle Scholar
Clapperton, C. M.(1983). The glaciation of the Andes. Quaternary Science Reviews!,83155.CrossRefGoogle Scholar
Clapperton, C. M.(1987). Glacial geomorphology, Quaternary glacial sequence and palaeoclimatic inferences in the Ecuadorian Andes. In “International Geomorphology Part II” ( Gardiner, V.Ed.), pp. 843870.Google Scholar
Clapperton, C. M.(1993a). “Quaternary Geology and Geomorphology of South America.” Elsevier Science, Amsterdam.Google Scholar
Clapperton, C. M.(1993b). Glacier readvances in the Andes at 12 500–10 000 yr BP; implications for mechanism of Late-glacial climatic change. Journal of Quaternary Science 8, 197215.CrossRefGoogle Scholar
Clapperton, C. M. Clayton, J. D. Benn, D. I.andMarden, C. J.(in press). Late Quaternary glacier advances and palaeolake highstands in the Bolivian altiplano. Quaternary International.Google Scholar
Clark, D. H.andGillespie, A. R.(in press). Timing and significance of Late-glacial and Holocene glaciation in the Sierra Nevada, California. Quaternary International.Google Scholar
Cleef, A. M.(1980). Vegetaci"n del p"ramos eotropical y sus lazos australo-ant"rcticos. Colombia Geogr"fica 7, 749.Google Scholar
Cleef, A. M.(1981). The vegetation of the paramos of the Colombian Cordillera Oriental. Dissertationes Botanicae 61 J. Cramer, Vaduz.Google Scholar
Dansgaard, W. Johnsen, S. J. Clausen, H. B. Dahl-Jensen, D. S. Gun-destrup, N. Hammer, C. U. Hvidberg, C. S. Steffensen, J. R. Sveins-bjornsdottir, A. E. Jouzel, J.andBond, G.(1993). Evidence for general instability of past climate from a 250-kyr ice-core record. Nature 364, 218220.Google Scholar
Deer, W. A. Howie, R. A.andZussman, J.(1992). “An Introduction to the Rock Forming Minerals.” Appendix 3 p. 683. Longman, London.Google Scholar
Denton, G. H.andHendy, C.(1994). Younger Dryas age advance of Franz Josef glacier in the Southern Alps of New Zealand. Science 264, 14341437.CrossRefGoogle Scholar
Droop, G. T. R.(1987). A general equation for estimating Fe3+ concentrations in ferromagnesian silicates and oxides from microprobe analyses using stoichiometric criteria. Mineralogical Magazine 51, 431435.Google Scholar
Grabant, R. A. J.(1980). Pollen rain in relation to arboreal vegetation in the Colombian Cordillera Oriental. Review of Palaeobotany and Palynol-ogy 29, 65147.Google Scholar
Grabant, R. A. J.(1985). “Pollen rain in relation to vegetation in the Colombian Cordillera Oriental.” Unpublished PhD dissertation, University of Amsterdam.Google Scholar
Hall, M. L.(1977). “El Volcanismo en El Ecuador.” Instituto Panameri-cana de Geograf"a e Historia, Quito.Google Scholar
Hall, M. L.andBeate, B.(1991). El vocanismo Plio-Cuaternario en los Andes del Ecuador. Estudios de Geografia 4, 538.Google Scholar
Hall, M.andMothes, P. A.(1994). Tefrostratigrafia holocenica de los volcanes principales del valle interandino, Ecuador. Estudios de Geograf"a 6, 4767.Google Scholar
Hansen, B. C. S.(1995). A review of Lateglacial Pollen Records from Ecuador and Peru with Reference to the Younger Dryas Event. Quaternary Science Reviews 14, 853866.Google Scholar
Hansen, B. C. S.andRodbell, D. T.(1995). A Late-glacial/Holocene pollen record from the eastern Andes of northern Peru. Quaternary Research 44, 216227.Google Scholar
Hastenrath, S.(1981). “The Glaciation of the Ecuadorian Andes.” Bal-kema, Rotterdam.Google Scholar
Helmens, K. F.andKuhry, P.(1986). Middle and late Quaternary vegeta-tional and climatic history of the Paramo de Agua Blanca (Eastern Cordillera, Colombia). Palaeogeography, Palaeoclimatology, Palaeoecology 56, 291335.Google Scholar
Helmens, K. F.andKuhry, P.(1995). Glacier fluctuations and vegetation change associated with Late Quaternary climatic oscillations in the Andes. In “Quaternary of South America and Antarctic Peninsula” ( Rabassa, J.and Salemme, M.Eds.), Vol. 9, pp. 117140. Balkema, Rotterdam.Google Scholar
Heine, J. T.(1993). A reevaluation of the evidence for a Younger Dryas climatic reversal in the tropical Andes. Quaternary Science Reviews 12, 769779.Google Scholar
Heine, K.(1995). Late Quaternary glacier advances in the Ecuadorian Andes: a preliminary report. In “Quaternary of South America and Antarctic Peninsula” ( cRabassa, J.and Salemme, M.Eds.), Vol. 9, pp. 122. Balkema, Rotterdam.Google Scholar
Heusser, C. J.(1984). Late-glacial-Holocene climate of the Lake District of Chile. Quaternary Research 22, 7790.Google Scholar
Hooghiemstra, H.(1983). Pollen morphology of the Plantago species of the Colombian Andes and its application to fossil material. Revista de la Academia Colombiana de Ciencias Exactas, F"sicas y Naturales 15, 4166.Google Scholar
Hughen, K. A. Overpeck, J. T. Petersen, L. C.andTrumbore, S.(1996). Rapid climate changes in the tropical Atlantic region during the last deglaciation. Nature 380, 5154.Google Scholar
Islebe, G. A. Hooghiemstra, H.andvan der Borg, K.(1995). A cooling event during the Younger Dryas Chron in Costa Rica. Palaeogeography, Palaeoclimatology, Palaeoecology 117, 7380.Google Scholar
Johnsen, J. J. Clausen, H. B. Dansgaard, W. Fuhrer, K. Gundestrup, N. Hammer, C. U. Iversen, P. Jouzel, J. Stauffer, B.andSteffensen, J. P.(1992). Irregular glacial interstadials in a new Greenland ice core. Nature 359, 311313.Google Scholar
Keigwin, L.(1995). The North Pacific through the millenia. Nature 377, 485486.Google Scholar
Kennett, J. P.andIngram, B. L.(1995). A 20,000-year record of ocean circulation and climate change from the Santa Barbara basin. Nature 377, 510514.Google Scholar
Kotilainen, A. T.andShackleton, N. J.(1995). Rapid climate variability in the North Pacific Ocean during the past 95,000 years. Nature 377, 323326.Google Scholar
Kuhry, P. Hooghiemstra, H. van Geel, B.andvan der Hammen, T.(1994). The El Abra Stadial in the Eastern Cordillera of Colombia (South America). Quaternary Science Reviews 12, 333344.CrossRefGoogle Scholar
Leake, B. E.(1978). Nomenclature of amphiboles. MineralogicalMagazine 42, 533565.Google Scholar
Ledru, M. P.(1993). Late Quaternary environmental and climatic changes in central Brazil. Quaternary Research 39, 9098.CrossRefGoogle Scholar
Linsley, B. K.(1996). Oxygen-isotope record of sea level and climate variations in the Sulu Sea over the past 150,000 years. Nature 380, 234237.Google Scholar
Marden, C. J.andClapperton, C. M.(1995). Fluctuations of the South Patagonian Ice-field during the last glaciation and the Holocene. Journal of Quaternary Science 10, 197210.Google Scholar
Markgraf, V.(1991). Younger Dryas in southern South America? Boreas 20, 6369.Google Scholar
Markgraf, V.(1993). Younger Dryas in southernmost South America"an update. Quaternary Science Reviews 12, 351355.Google Scholar
McGlone, M. S.(1995). Lateglacial Landscape and Vegetation Change and the Younger Dryas Oscillation in New Zealand. Quaternary Science Reviews 14, 867882.Google Scholar
Melief, A.M.(1984). Comparison of vegetation and pollen rain on the Buritaca-La Cumbre transect. In “Studies on Tropical Andean Ecosystems” (van der Hammen, T.and Ruiz, P. M.Eds.), Vol. 2, pp. 547559. J. Cramer, Vaduz.Google Scholar
Melief, A. B. M.(1985). “Late Quaternary palaeoecology of the Parque Nacional Natural de los Nevados (Cordillera Central), and Sumapaz (Cordillera Oriental) areas, Colombia.” Unpublished Ph.D. dissertation, University of Amsterdam.Google Scholar
Mercer, J. H.(1969). The Allerod oscillation: a European climatic anomaly? Arctic and Alpine Research 1, 85104.Google Scholar
Osborn, G.andGerloff, L. (in press). Latest Pleistocene and Early Holocene fluctuations of glaciers in the Canadian and Northern American Rockies. Quaternary International.Google Scholar
Peteet, D. H.(1995). Global Younger Dryas? Quaternary International 28, 93104.Google Scholar
Sauer, W.(1965). “Geolog"a del Ecuador.” Editorial de Ministerio de Education, Quito.Google Scholar
Stacker, T. F.andWright, D. G.(in press). Rapid changes in ocean circulation and atmospheric carbon. Palaeoceanography.Google Scholar
Stuiver, M.andReimer, P. J.(1993). Extended 14C data base and revised CALIB 3.0 14C age calibration program. Radiocarbon 35, 215230.Google Scholar
Thompson, L. G. Mosley-Thompson, E. Davis, M. E. Lin,, P-N. Henderson, K. A. Cole-Dai, J. Bolzan, J. F.andLiu,, K-b.(1995). Late Glacial Stage and Holocene tropical ice core records from Huascaran, Peru. Science 269, 4650.Google Scholar
Van der Hammen, T. Weiner, J. H.andVan Dommelen, H.(1973). Palyno-logical record of the upheaval of the Northern Andes: a study of the Pliocene and lower Quaternary of the Colombian Eastern Cordillera and the early evolution of its High-Andean biota. Review of Palaeobotany and Palynology 1b, 1122.Google Scholar
Van der Hammen, T. Barelds, J. de Jong, H.andde Veer, A. A.(1981). Glacial sequence and environmental history in the Sierra Nevada del Cocuy (Colombia). Palaeogeography, Palaeoclimatology, Palaeoecology 32, 247340.Google Scholar
Van der Hammen, T.andHooghiemstra, H.(1995). The El Abra Stadial, a Younger Dryas equivalent in Colombia. Quaternary Science Reviews 14, 841852.Google Scholar
Van Geel, B.andVan der Hammen, T.(1973). Upper Quaternary vegeta-tional and climatic sequence of the Fuquene area (Eastern Cordillera, Colombia). Palaeogeography, Palaeoclimatology, Palaeoecology 14, 992.CrossRefGoogle Scholar
Zbinden, H. Andree, M. Oeschger, H. Ammann, B. Lotter, A. Bonani, G.andWolfli, W.(1989). Atmospheric radiocarbon at the end of the last glacial: An estimate based on AMS radiocarbon dates on terrestrial macrofossils from lake sediments. Radiocarbon 31, 795804.Google Scholar