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Absolute Pollen Diagram of Redrock Lake, Boulder County, Colorado

Published online by Cambridge University Press:  20 January 2017

Louis J. Maher Jr.
Louis J. Maher Jr.*
Affiliation:
Department of Geology and Geophysics, University of Wisconsin, Madison, Wisconsin 53706
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Abstract

Redrock Lake is situated at 3,095 m in the subalpine zone on the east flank of the Front Range, Boulder County, Colorado. The lake lies on Pinedale moraine, and it contains 170 cm of organic sediments that overlie 10 cm of silty clay. The oldest of seven 14C dates from the organic sediment is 9,490 ± 150 yr B.P., a minimum estimate of the time since Middle Pinedale ice receded from the lake basin.

A percentage pollen diagram and an absolute pollen diagram providing pollen deposition rates in grains/cm2/14C yr are compared and contrasted. Possible measurement errors are considered in detail, and for the first time confidence limits are assigned to all pollen data. A means of converting 14C years to calendar years is presented, and its effect on the diagram's deposition rates is discussed.

The silty clay contains a peculiar Artemisia-dominated pollen assemblage with very low pollen influx rates, which suggests the lake was receiving large volumes of glacial meltwater during its early history. The overlying organic sediments are characterized by pollen deposition rates of 4,000–6,000 grains/cm2/yr. With fluctuations, deposition rates of Pinus and total anemophilous pollen increase upward in the core; this evidence for a general upward shift in the region's vegetation zones during Postglacial time is supported by pollen trends from modern surface samples.

Type
Original Articles
Information
Quaternary Research , Volume 2 , Issue 4 , December 1972 , pp. 531 - 553
Copyright
Academic Press, Inc.

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References

Adam, D.P. 1967 Late-Pleistocene and Recent palynology in the central Sierra Nevada, California Cushing, E.J. Wright, H.E. Jr. Quaternary Paleoecology Yale Press New Haven 275 301 Google Scholar
Benninghoff, W.S. 1962 Calculation of pollen and spore density in sediments by addition of exotic pollen in known quantities (abstract) Pollen et Spores 2 332 333 Google Scholar
Bent, A.M. Wright, H.E. Jr. 1963 Pollen analyses of surface materials and lake sediments from the Chuska Mountains, New Mexico Geological Society of America Bulletin 74 491 500 CrossRefGoogle Scholar
Craig, A.J. 1972 Pollen influx to laminated sediments: a pollen diagram from northeastern Minnesota Ecology 53 46 57 CrossRefGoogle Scholar
Davis, M.B. 1965 A method for determination of absolute pollen frequency Kummel, B. Raup, D. Handbook of Paleontological Techniques Freeman San Francisco 675 686 Google Scholar
Davis, M.B. 1969 Climatic changes in southern Connecticut recorded by pollen deposition at Rogers Lake Ecology 50 409 422 CrossRefGoogle Scholar
Davis, M.B. Deevey, E.S. Jr. 1964 Pollen accumulation rates: estimates from Late-Glacial sediment of Rogers Lake Science 145 1293 1295 Google Scholar
Faegri, K. Iversen, J. 2d ed. 1964 Textbook of Pollen Analysis Hafner New York Google Scholar
Kirkland, D.W. 1967 Method of calculating absolute spore and pollen frequency Oklahoma Geology Notes 27 98 100 Google Scholar
Madole, R.F. 1969 Pinedale and Bull Lake Glaciation in upper St. Vrain drainage basin, Boulder County, Colarado Arctic and Alpine Research 2 279 287 CrossRefGoogle Scholar
Maher, L.J. Jr. 1963 Pollen analyses of surface materials from the southern San Juan Mountains, Colorado Geological Society of America Bulletin 74 1485 1504 CrossRefGoogle Scholar
Maher, L.J. Jr. 1964 Ephedra pollen in sediments of the Great Lakes Region Ecology 45 391 395 Google Scholar
Maher, L.J. Jr. 1972 Nomograms for computing 0.95 confidence limits of pollen data Review of Palaeobotany and Palynology 13 85 93 Google Scholar
Marr, J.W. 1961 Ecosystems of the east slope of the Front Range in Colorado University of Colorado Studies: Series in Biology 2 134 Google Scholar
Martin, P.S. 1963 The Last 10,000 Years: A Fossil Pollen Record of the American Southwest University of Arizona Press Tucson Google Scholar
Matthews, J. 1969 The assessment of a method for the determination of absolute pollen frequencies New Phytologist 68 161 166 Google Scholar
Mosimann, J.E. 1965 Statistical methods for the pollen analyst Kummel, B. Raup, D. Handbook of Paleontological Techniques Freeman San Francisco 636 673 Google Scholar
Ogden, J.G. III 1967 Radiocarbon determinations of sedimentation rates from hard and soft-water lakes in northeastern North America Cushing, E.J. Wright, H.E. Jr. Quaternary Paleoecology Yale Press New Haven 175 183 Google Scholar
Pennak, R.W. 1963 Ecological and radiocarbon correlations in some Colorado mountain lake and bog deposits Ecology 44 1 15 CrossRefGoogle Scholar
Pennington, W. Bonny, A.P. 1970 Absolute pollen diagram from the British Late-Glacial Nature (London) 226 871 873 Google Scholar
Stuiver, M. 1971 Evidence for the variation of atmospheric C14 content in the Late Quaternary Turekian, K.K. The Late Cenozoic Glacial Ages Yale Press New Haven 57 70 Google Scholar
Suess, H.E. 1971 Climatic changes and the atmospheric radiocarbon level Palaeogeography, Palaeoclimatology, Palaeoecology 10 199 202 CrossRefGoogle Scholar
Waddington, J.C.B. 1969 A stratigraphic record of the pollen influx to a lake in the Big Woods of Minnesota Geological Society of America Special Paper 123 263 282 Google Scholar
Walkley, A. 1947 A critical examination of a rapid method for determining organic carbon in soils: effect of variations in digestion conditions and of inorganic soil constituents Soil Science 63 251 264 CrossRefGoogle Scholar
Wendland, W.M. Donley, D.L. 1971 Radiocarbon-calendar age relationship Earth and Planetary Science Letters 11 135 139 CrossRefGoogle Scholar
Wright, H.E. Jr. 1967 A square-rod piston sampler for lake sediments Journal of Sedimentary Petrology 37 975 976 Google Scholar
Wright, H.E. Jr. 1971 Late Quaternary vegetational history of North America Turekian, K.K. The Late Cenozoic Glacial Ages Yale Press New Haven 425 464 Google Scholar