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Chronology of sediment deposition in Upper Klamath Lake, Oregon

Journal of Paleolimnology

By:
, , , , ,
DOI: 10.1023/B:JOPL.0000019234.05899.ea

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Abstract

A combination of tephrochronology and 14C, 210Pb, and 137Cs measurements provides a robust chronology for sedimentation in Upper Klamath Lake during the last 45 000 years. Mixing of surficial sediments and possible mobility of the radio-isotopes limit the usefulness of the 137Cs and 210Pb data, but 210Pb profiles provide reasonable average sediment accumulation rates for the last 100-150 years. Radiocarbon ages near the top of the core are somewhat erratic and are too old, probably as a result of detrital organic carbon, which may have become a more common component in recent times as surrounding marshes were drained. Below the tops of the cores, radiocarbon ages in the center of the basin appear to be about 400 years too old, while those on the margin appear to be accurate, based on comparisons with tephra layers of known age. Taken together, the data can be combined into reasonable age models for each site. Sediments have accumulated at site K1, near the center of the basin, about 2 times faster than at site CM2, on the margin of the lake. The rates are about 0.10 and 0.05 cm/yr, respectively. The chronological data also indicate that accumulation rates were slower during the early to middle Holocene than during the late Holocene, consistent with increasing wetness in the late Holocene.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Chronology of sediment deposition in Upper Klamath Lake, Oregon
Series title:
Journal of Paleolimnology
DOI:
10.1023/B:JOPL.0000019234.05899.ea
Volume
31
Issue:
2
Year Published:
2004
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Paleolimnology
First page:
139
Last page:
149
Number of Pages:
11