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Radiocarbon and cation-radio ages for rock varnish on Tioga and Tahoe marainal boulders of Pine Creek, eastern Sierra Nevada, California, and their paleoclimatic implications

Quaternary Research

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, , , , and
DOI: 10.1016/0033-5894(87)90031-7

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Abstract

Accelerator mass spectrometry 14C analyses of organic matter extracted from rock varnishes on morainal boulders yield limiting minimum ages for three crests of the Tioga glaciation. At Pine Creek in the eastern Sierra Nevada, varnish started to form on boulders of the outermost Tioga moraine before 19,000 yr B.P., and varnish originated on the innermost Tioga moraine before 13,200 yr B.P. Comparisons with lake-level, paleohydrological, paleoecological, colluvial, and rock varnish micromorphological data indicate that central-eastern California and western Nevada experienced a moisture-effective period during the late Pleistocene but after the Tioga maximum, and perhaps as Tioga glaciers receded from the mouth of Pine Creek canyon. Varnishes on Tahoeage morainal boulders at Pine Creek have cation-ratio ages of about 143,000-156,000 yr B.P., suggesting that the Tahoe glaciation should not be correlated with oxygen-isotope stage 4 in the early Wisconsin, but rather with stage 6. Varnishes on morainal boulders of an older glaciation at Pine Creek are dated by cation ratio at about 182,000-187,000 yr B.P. ?? 1987.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Radiocarbon and cation-radio ages for rock varnish on Tioga and Tahoe marainal boulders of Pine Creek, eastern Sierra Nevada, California, and their paleoclimatic implications
Series title:
Quaternary Research
DOI:
10.1016/0033-5894(87)90031-7
Volume
28
Issue:
1
Year Published:
1987
Language:
English
Publisher:
Elsevier
Publisher location:
Amsterdam, Netherlands
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Quaternary Research
First page:
36
Last page:
49
Number of Pages:
14