Radiocarbon ages and age models for the past 30,000 years in Bear Lake, Utah and Idaho Colman, S.M.; Rosenbaum, J.G.; Kaufman, D.S.; Dean, W.E.; McGeehin, J.P. Colman, S.M. Rosenbaum, J.G. Kaufman, D.S. Dean, W.E. McGeehin, J.P. earth science/paleoclimate/paleolimnology (depth,null,null,centimeter,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,one standard deviation,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (age,null,null,calendar year before present,null,paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (Bear Lake Utah/Idaho>LATITUDE 42>LONGITUDE -111.3333) Radiocarbon analyses of pollen, ostracodes, and total organic carbon (TOC) provide a reliable chronology for the sediments deposited in Bear Lake over the past 30,000 years. The differences in apparent age between TOC, pollen, and carbonate fractions are consistent and in accord with the origins of these fractions. Comparisons among different fractions indicate that pollen sample ages are the most reliable, at least for the past 15,000 years. The post-glacial radiocarbon data also agree with agesindependently estimated from aspartic acid racemization in ostracodes. Ages in the red, siliclastic unit, inferred to be of last glacial age, appear to be several thousand years too old, probably because of a high proportion of reworked, refractory organic carbon in the pollen samples.Age-depth models for five piston cores and the Bear Lake drill core (BL00-1)were constructed by using two methods: quadratic equations and smooth cubic-spline fits. The two types of age models differ only in detail for individual cores, and each approach has its own advantages. Specific lithological horizons were dated in several cores and correlated among them, producing robust average ages for these horizons. The age of the correlated horizons in the red, siliclastic unit can be estimated from the age model for BL00-1, which is controlled by ages above and below the red, siliclasticunit. These ages were then transferred to the correlative horizons in the shorter piston cores, providing control for the sections of the age models in those cores in the red, siliclastic unit. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Colman, S.M. Investigator : Rosenbaum, J.G. Investigator : Kaufman, D.S. Investigator : Dean, W.E. Investigator : McGeehin, J.P. 2009-01-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/8648 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/utah/bearlake/bearlake2009age-models.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/utah/bearlake/bearlake2009age-models.xls https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/utah/bearlake/bearlake2009age-models.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/utah/bearlake/bearlake2009age-models.xls English https://www.ncdc.noaa.gov/paleo/study/8648 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/utah/bearlake/bearlake2009age-models.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/northamerica/usa/utah/bearlake/bearlake2009age-models.xls Colman, S.M., Rosenbaum, J.G., Kaufman, D.S., Dean, W.E., McGeehin, J.P. 2009. Radiocarbon ages and age models for the past 30,000 years in Bear Lake, Utah and Idaho. Geological Society of America Special Paper, 450, 133-144. START YEAR: 29187 cal yr BP * END YEAR: 4 cal yr BP -111.3333 42 -111.3333 42