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Fission-Track Age (400,000 yr) of the Rockland Tephra, Based on Inclusion of Zirco Grains Lacking Fossil Fission Tracks

Published online by Cambridge University Press:  20 January 2017

C.E. Meyer
Affiliation:
U.S. Geological Survey, Menlo Park, California 94025
A.M. Sarna-Wojcicki
Affiliation:
U.S. Geological Survey, Menlo Park, California 94025
J.W. Hillhouse
Affiliation:
U.S. Geological Survey, Menlo Park, California 94025
M.J. Woodward
Affiliation:
Stanford University, Stanford, California 94305
J.L. Slate
Affiliation:
University of Colorado, Boulder, Colorado 80225
D.H. Sorg
Affiliation:
U.S. Geological Survey, Menlo Park, California 94025

Abstract

A zircon fission-track age of about 400,000 yr B.P. has been determined for the Rockland tephra, a widespread pyroclastic layer in northern California and western Nevada. New ages of zircon separates from both proximal and distal exposures of this layer range from 370,000 to 460,000 yr; ages of the best material provide a narrower range, from 370,000 yr for unwelded ash-flow tuff to 420,000 yr for distal air-fall ash that appears to be uncontaminated by clastic detritus or xenocrysts. Detrital or xenocrystic grains in the ash-flow tuff may have been annealed during emplacement and cooling of the tuff. Detrital and xenocrystic zircons are identified on the basis of their physical characteristics and distinctly older ages. Independent stratigraphic and magnetostratigraphic data constrain the age of the Rockland tephra between 300,000 and 600,000 yr, a range that is compatible with the fission-track age. Zircon grains containing no spontaneous (fossil) tracks are regarded as part of the normal population of comagmatic grains because maximum ages calculated for these grains form a population that mimics the distribution of ages of individual zircon grains that contain fossil tracks; modal ages of both groups fall between 250,000 and 500,000 yr. Induced fission tracks from grains that lack fossil tracks are included in the age calculations, resulting in significantly younger and more coherent dates than would result if these tracks had been omitted, especially those of the finer-grained distal samples.

Type
Research Article
Copyright
University of Washington

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References

Adam, D.P. Sarna-Wojcicki, A.M. Rieck, H.J. Bradbury, J.P. Dean, W.E. Forester, R.M. Tulelake, California: The last 3 million years Palaeogeography, Palaeoclimatology, Palaeoecology 72 1989 89 103 CrossRefGoogle Scholar
Coe, R.S. Plaeo-intensities of the Earth's magnetic field determined from Tertiary and Quaternary Rocks Journal of Geophysical Research 72 No. 12 1967 3247 3262 Google Scholar
Davis, J.O. Quaternary Tephrochronology of the Lake Lahontan Area, Nevada and California Nevada Archeological Survey Research Paper No. 7 1978 Nevada University Reno Google Scholar
Gilbert, N.J. Chronology of Post-Tuscan Volcanism in the Manton Area, California 1969 University of California Berkeley Unpublished M.Sc. dissertation Google Scholar
Glenn, W. Pliocene and lower Pleistocene of the western part of the San Francisco Peninsula University of California Publications in the Geological Sciences 36 No. 2 1959 147 198 Google Scholar
Gleadow, A.J.W. Fission track age of the KBS Tuff and associated hominid remains in northern Kenya Nature 284 1980 225 230 CrossRefGoogle Scholar
Gleadow, A.J.W. Hurford, A.J. Quaife, R.D. Fission track dating of zircon: Improved etching techniques Earth and Planetary Science Letters 33 1976 273 276 Google Scholar
Hall, N.T. Petrology of the Type Merced Group, San Francisco Peninsula, California M.Sc. dissertation 1965 University of California Berkeley Google Scholar
Herd, D.G. Naeser, C.W. Radiometric evidence for pre-Wisconsin glaciation in the northern Andes Geology 2 1974 603 604 Google Scholar
Hillhouse, J.W. Late Tertiary and Quaternary Geology of the Tecopa Basin, Southeastern California U.S. Geological Survey Miscellaneous Investigations Map I-1728 1987 scale 1:48,000 Google Scholar
Hurford, A.J. Hammerschmidt, K. 40Ar/39Ar and K/Ar dating of the Bishop and Fish Canyon tuffs: Calibration ages for fission-track dating standards Chemical Geology (Isotopic Geoscience Section) 58 1985 23 32 Google Scholar
Izett, G.A. Naeser, C.W. Age of the Bishop Tuff of eastern California as determined by the fission track method Geology 4 1976 587 590 Google Scholar
Izett, G.A. Wilcox, R.E. Map Showing Localities and Inferred Distributions of the Huckleberry Ridge, Mesa Falls, and Lava Creek Ash Beds (Pearlette Family Ash Beds) of Pliocene and Pleistocene Age in the Western United States and Canada U.S. Geological Survey Miscellaneous Investigations Map I-135 1982 scale 1:4,000,000 Google Scholar
Lawson, A.C. Description of the San Francisco District U.S. Geological Survey Atlas, Folio 193 1914 Google Scholar
Mankinen, E.A. Dalrymple, G.B. Revised geomagnetic polarity time scale for the interval 0–5 m.y. B.P. Journal of Geophysical Research 84 No. B2 1979 615 626 Google Scholar
Meyer, C.E. Woodward, M.J. Sarna-Wojcicki, A.M. Naeser, C.W. Zircon Fission-Track Age of 0.45 Million Years on Ash in the Type Section of the Merced Formation, West-Central California U.S. Geological Survey Open-File Report 80-1071 1980 Google Scholar
Naeser, C.W. Fission Track Dating U.S. Geological Survey Open-File Report 76-190 1976 (revised 1978) CrossRefGoogle Scholar
Naeser, C.W. Briggs, N.D. Obradovich, J.D. Izett, G.A. Geochronology of Quaternary tephra deposits Self, S. Sparks, R.S.J. Tephra Studies 1981 D. Reidel Dortrecht 13 47 Google Scholar
Naeser, C.W. Johnson, N.M. McKee, V.E. A Practical Method of Estimating Standard Error of Age in the Fission-Track Method U.S. Geological Survey Open-File Report 78-701 1978 303 304 Google Scholar
Naeser, C.W. Zimmerman, R.A. Cebula, G.T. Fission-track dating of apatite and zircon: An interlaboratory comparison Nuclear Tracks 5 1981 65 72 CrossRefGoogle Scholar
Ogle, B.A. Geology of the Eel River Area, Humboldt Co., California Division of Mines Bulletin 164 1953 California Department of Natural Resources Google Scholar
Sarna-Wojcicki, A.M. Hall, N.T. Bowman, H.R. Naeser, C.W. Russell, P.C. Correlation and age of a widespread Pleistocene ash bed in northern California and western Nevada Geological Society of America, Abstracts with Program, Annual Meeting 9 1977 1155 No. 7 Google Scholar
Sarna-Wojcicki, A.M. Meyer, C.E. Bowman, H.R. Hall, N.T. Russell, P.C. Woodward, M.J. Slate, J.L. Correlation of the Rockland ash bed, a 400,000-year-old stratigraphic marker in northern California and western Nevada, and implications for middle Pleistocene paleogeography of central California Quaternary Research 23 1985 236 257 Google Scholar
Sarna-Wojcicki, A.M. Meyer, C.E. Nakata, J.K. Scott, W.E. Hill, B.E. Slate, J.L. Russell, P.C. Age and correlation of mid-Quaternary ash beds and tuffs in the vicinity of Bend, Oregon Scott, W. Guidebook for Field Trip to the Mount Bachelor-South Sister-Bend Area, Central Oregon High Cascades U.S. Geological Survey Open-File Report 89-645 1989 55 62 and others Google Scholar
Sarna-Wojcicki, A.M. Morrison, S.D. Meyer, C.E. Hillhouse, J.W. Correlation of upper Cenozoic tephra layers between sediments of the western United States and eastern Pacific Ocean and comparison with biostratigraphic and magnetostratigraphic age data Geological Society of American Bulletin 98 1987 207 223 Google Scholar
Wilson, T.A. The Geology near Mineral, California M.Sc. dissertation 1961 University of California Berkeley Google Scholar