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The Age of Glacier Peak Tephra in West-Central Montana

Published online by Cambridge University Press:  20 January 2017

Peter J. Mehringer Jr.
Affiliation:
Department of Anthropology and Geology, Washington State University, Pullman, Washington 99164
John C. Sheppard
Affiliation:
Department of Chemical Engineering and Anthropology, Washington State University, Pullman, Washington 99164
Franklin F. Foit Jr.
Affiliation:
Department of Geology, Washington State University, Pullman, Washington 99164

Abstract

At Sheep Mountain Bog, near Missoula, Montana, a late-glacial tephra, that probably fell in late summer, is preserved as an 8-mm-thick graded bed overlain by another 8 mm of redeposited ash mixed with lake deposits. Sediment surrounding the ash was 14C dated to about 11,200 yr B.P. Electron-microprobe analyses of the volcanic glass and hornblende phenocrysts from this ash layer indicate that they are similar in major-element chemistry to those of Glacier Peak layer G previously considered to be about 12,000 yr old or older.

Type
Research Article
Copyright
University of Washington

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References

Blinman, E., Mehringer, P.J. Jr., Sheppard, J.C. (1979). Pollen influx and the deposition of Mazama and Glacier Peak tephra Sheets, P.D., Grayson, D.K., Volcanic Activity and Human Ecology Academic Press New York 393425 Google Scholar
Borchardt, G.A., Aruscavage, P.J., Millard, H.T. Jr., (1972). Correlation of the Bishop ash, a Pleistocene marker bed, using instrumental neutron activation analysis Journal of Sedimentary Petrology 42, 301306 Google Scholar
Chatters, R.M. (1968). Washington State University natural radiocarbon measurements, I Radiocarbon 10, 479498 CrossRefGoogle Scholar
Fryxell, R. (1965). Mazama and Glacier Peak volcanic ash layers: Relative ages Science 147, 12881290 Google Scholar
Lemke, R.W., Mudge, M.R., Wilcox, R.E., Powers, H.A. (1975). Geologic setting of the Glacier Peak and Mazama ash-bed markers in west-central Montana U.S. Geological Survey Bulletin 1395-H, Google Scholar
Mack, R.N., Rutter, N.W., Valastro, S. (1983). Holocene vegetational history of the Kootenai River Valley, Montana Quaternary Research 20, 177193 CrossRefGoogle Scholar
Mehringer, P.J. Jr., Arno, S.E., Petersen, K.L. (1977a). Postglacial history of Lost Trail Pass Bog, Bitterroot Mountains, Montana Arctic and Alpine Research 9, 345368 CrossRefGoogle Scholar
Mehringer, P.J. Jr., Blinman, E., Petersen, K.L. (1977b). Pollen influx and volcanic ash Science 198, 257261 CrossRefGoogle ScholarPubMed
Porter, S.C. (1978). Glacier Peak tephra in the North Cascade Range, Washington: Stratigraphy, distribution, and relationship to late-glacial events Quaternary Research 10, 3041 Google Scholar
Sarna-Wojcicki, A.M., Waitt, R.B. Jr., Woodward, M.J., Shipley, S., Rivera, J. (1981). Premagmatic ash erupted from March 27 through May 14, 1980—Extent, mass, volume, and composition Lipman, P.W., Mullineaux, D.R., The 1980 Eruptions of Mount St. Helens, Washington. U.S. Geological Survey Professional Paper 1250. 569575 Google Scholar
Smith, H.W., Okazaki, R., Knowles, C.R. (1977). Electron microprobe data for tephra attributed to Glacier Peak, Washington Quaternary Research 7, 197206 CrossRefGoogle Scholar
Waitt, R.B. Jr., Yount, J.C., Davis, P.T. (1982). Regional significance of an early Holocene moraine in Enchantment Lakes Basin, North Cascade Range, Washington Quaternary Research 17, 191210 Google Scholar
Westgate, J.A., Evans, M.E. (1978). Compositional variability of Glacier Peak tephra and its stratigraphic significance Canadian Journal of Earth Sciences 15, 15541567 CrossRefGoogle Scholar
Westgate, J.A., Gorton, M.P. (1980). Correlation techniques in tephra studies Self, S., Sparks, R.S.J., Tephra Studies D. Reidel Publ Boston 7394 Google Scholar
Westgate, J.A., Smith, D.G.W., Tomlinson, M. (1970). Late Quaternary tephra layers in south-western Canada Smith, R.A., Smith, J.W., Early Man and Environments in Northwest North America Students Press, University of Calgary 1334 Google Scholar