Abstract
Mount St. Helens has been a prolific source of tephra-fall deposits for about 40 000 years. These tephra deposits (1) record numerous explosive eruptions, (2) form important regional time-stratigraphic marker beds, and (3) record repeated changes in composition within and between eruptive periods.
Recognized tephra strata record more than 100 explosive eruptive events at Mount St. Helens; those tephra strata are classified as beds, layers, and sets. Tephra sets, each of which consists of a group of beds and layers, define in part the nine eruptive periods recognized at the volcano. Individual tephra sets are distinguished from stratigraphically adjacent sets by differences in composition or by evidence of clapsed time.
Several tephra units from Mount St. Helens form important marker beds at distances of hundreds of kilometers downwind from the volcano. Cummingtonite phenocrysts, which are known in ejecta from only Mount St. Helens in the Pacific Northwest, characterize some marker beds and readily identify their source.
The tephra sequence also records eruption of the mafic andesites that mark the appearance of the modern Mount St. Helens and numerous changes in composition among dacite, basalt, and andesite since that time.
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Borchardt GA, Norgren JA, Harward ME (1973) Correlation of ash layers in peat bogs of eastern Oregon. Geol Soc Am Bull 84: 3101–3108
Carithers W (1946) Pumice and pumicite occurrences of Washington. Wash Div Mines Geol Rep Invest 15: 1–78
Carrara PE, Wilcox RE, Richmond GM (1984) Deglaciation and revegetation in the Glacier National Park region, Montana. Geol Soc Am Abst Programs 16: 217
Carrara PE, Wilcox RE, Short SK (1986) Deglaciation of the mountainous region of northwestern Montana east of the Continental Divide. Arc Alp Res (in press)
Crandell DR (1980) Recent eruptive history of Mt. Hood, Oregon, and potential hazards from future eruptions: US Geol Surv Bull 1492: 1–81
Crandell DR, Hoblitt RP (1986) Lateral blasts at Mt. St. Helens and hazards zonation. Bull Volvanol 48: 26–36
Crandell DR, Mullineaux DR (1978) Potential hazards from future eruptions of Mt. St. Helens volcano, Washington: US Geol Surv Bull 1383-C: 1–26
Crandell DR, Mullineaux DR, Miller RD, Rubin M (1962) Pyroclastic deposits of Recent age at Mount Rainier, Washington. In: Short papers in geology, hydrology, and topography. US Geol Surv Prof Paper 450-D: D64–68
Crandell DR, Mullineaux DR, Rubin M (1975) Mt. St. Helens volcano; recent and future behavior. Science 187: 438–441
Crandell DR, Mullineaux DR, Rubin M, Spiker E, Kelley ML (1981) Radiocarbon dates from volcanic deposits at Mt. St. Helens, Washington. US Geol Surv Open-File Rep 81-844: 1–15
Davis JO (1978) Quaternary tephrochronology of the Lake Lahontan area, Nevada and California, Nevada University. Nevada Archeol Surv Res Paper 7, Reno: 29
Dudas, MJ, Harward ME, Schmitt RA (1973) Identification of dacitic tephra by activation analysis of their primary mineral phenocrysts. Quat Res 3: 307–315
Hammatt HH, Foley LL, Leonhardy FC (1976) Late Quaternary stratigraphy in the lower Snake River canyon — toward a chronology of slack-water sediments. Geol Soc Am Abst with Programs 8. 3: 379
Harris SE (1976) Fire and ice, the Cascade volcanoes, Seattle, Craftsman & Met Press, the Mountaineers, and Pacific Search Books, pp. 1–316
Hopson CA (1971) Eruptive sequence at Mount St. Helens, Washington. Geol Soc Am Absts with Programs 3, 2: 138
Hyde JH (1975) Upper Pleistocene pyroclastic-flow deposits and lahars south of Mt. St. Helens volcano, Washington. US Geol Surv Bull 1383-B: 1–20
Lawrence DB (1939) Continuing research on the flora of Mt. St. Helens; a progress report. Mazama 21. 12: 49–54
Lawrence DB (1954) Diagrammatic history of the northeast slope of Mt. St. Helens. Mazama 36. 13: 41–44
Lemke RW, Mudge MR, Wilcox RE, Powers HA (1975) Geologic setting of the Glacier Peak and Mazama ash-bed markers in west-central Montana. US Geol Surv Bull 1395-H: 1–31
Mack CB (1980) Postglacial tephrochronology of the Indian Heaven area, south Cascade Range, Washington. Wash State Univ, MS. Thesis, pp 1–75
Mehringer PJ, Sheppard JC, Foit FF (1984) The age of Glacier Peak tephra in west-central Montana. Quat Res 21: 36–41
Moody UL (1977) Correlation of flood deposits containing Mt. St. Helens set S ashes and the stratigraphic position of Mt. St. Helens set J and Glacier Peak ashes, central Washington. Geol Soc Am Absts with Programs 9. 7: 1098–1099
Mullineaux DR (1964) Extensive Recent pumice lapilli and ash layers from Mt. St. Helens volcano, southern Washington (abst). Geol Soc Am Spec Paper 76, 1963, p 285
Mullineaux DR (1974) Pumice and other pyroclastic deposits in Mount Rainier National Park, Washington. US Geol Surv Bull 1326: 1–83
Mullineaux DR (1977) Volcanic hazards - extent and severity of potential tephra hazard interpreted from layer Yn from Mt. St. Helens, Wash. (abst). Geol Soc Am Abst with Programs 9. 7: 1105
Mullineaux DR, Crandell DR (1981) The eruptive history of Mt. St. Helens. In: Lipman PW, Mullineaux DR, (eds). The 1980 eruptions of Mt. St. Helens, Washington. US Geol Surv Prof Pap 1250: 3–15
Mullineaux DR, Hyde JH, Rubin M (1972) Preliminary assessment of upper Pleistocene and Holocene pumiceous tephra from Mt. St. Helens, southern Washington. Geol Soc Am Abst with Programs 4. 3: 204–205
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Mullineaux, D.R. Summary of pre-1980 tephra-fall deposits erupted from Mount St. Helens, Washington State, USA. Bull Volcanol 48, 17–26 (1986). https://doi.org/10.1007/BF01073510
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DOI: https://doi.org/10.1007/BF01073510
