TY - JOUR
T1 - Unprecedented last-glacial mass accumulation rates determined by luminescence dating of loess from western Nebraska
AU - Roberts, H. M.
AU - Muhs, Daniel R.
AU - Wintle, Ann G.
AU - Duller, Geoff A. T.
AU - Bettis III, E. Arthur
N1 - Roberts, H. M., Muhs, D. R., Wintle, A. G., Duller, G. A. T., & Bettis III, E. A. (2003). Unprecedented last-glacial mass accumulation rates determined by luminescence dating of loess from western Nebraska. Quaternary Research, 59(3), 411-419.
RAE2008
PY - 2003/5
Y1 - 2003/5
N2 - A high-resolution chronology for Peoria (last glacial period) Loess from three sites in Nebraska, midcontinental North America, is determined by applying optically stimulated luminescence (OSL) dating to 35–50 μm quartz. At Bignell Hill, Nebraska, an OSL age of 25,000 yr near the contact of Peoria Loess with the underlying Gilman Canyon Formation shows that dust accumulation occurred early during the last glacial maximum (LGM), whereas at Devil’s Den and Eustis, Nebraska, basal OSL ages are significantly younger (18,000 and 21,000 yr, respectively). At all three localities, dust accumulation ended at some time after 14,000 yr ago. Mass accumulation rates (MARs) for western Nebraska, calculated using the OSL ages, are extremely high from 18,000 to 14,000 yr—much higher than those calculated for any other pre-Holocene location worldwide. These unprecedented MARs coincide with the timing of a mismatch between paleoenvironmental evidence from central North America, and the paleoclimate simulations from atmospheric global circulation models (AGCMs). We infer that the high atmospheric dust loading implied by these MARs may have played an important role, through radiative forcing, in maintaining a colder-than-present climate over central North America for several thousand years after summer insolation exceeded present-day values.
AB - A high-resolution chronology for Peoria (last glacial period) Loess from three sites in Nebraska, midcontinental North America, is determined by applying optically stimulated luminescence (OSL) dating to 35–50 μm quartz. At Bignell Hill, Nebraska, an OSL age of 25,000 yr near the contact of Peoria Loess with the underlying Gilman Canyon Formation shows that dust accumulation occurred early during the last glacial maximum (LGM), whereas at Devil’s Den and Eustis, Nebraska, basal OSL ages are significantly younger (18,000 and 21,000 yr, respectively). At all three localities, dust accumulation ended at some time after 14,000 yr ago. Mass accumulation rates (MARs) for western Nebraska, calculated using the OSL ages, are extremely high from 18,000 to 14,000 yr—much higher than those calculated for any other pre-Holocene location worldwide. These unprecedented MARs coincide with the timing of a mismatch between paleoenvironmental evidence from central North America, and the paleoclimate simulations from atmospheric global circulation models (AGCMs). We infer that the high atmospheric dust loading implied by these MARs may have played an important role, through radiative forcing, in maintaining a colder-than-present climate over central North America for several thousand years after summer insolation exceeded present-day values.
KW - Climate forcing
KW - Coarse-silt-sized grains
KW - Dust flux
KW - Mass accumulation rate (MAR)
KW - OSL
KW - Optically stimulated luminescence dating
KW - Peoria Loess
KW - Quartz
UR - http://www.scopus.com/inward/record.url?scp=0038375425&partnerID=8YFLogxK
U2 - 10.1016/S0033-5894(03)00040-1
DO - 10.1016/S0033-5894(03)00040-1
M3 - Article
SN - 0033-5894
VL - 59
SP - 411
EP - 419
JO - Quaternary Research
JF - Quaternary Research
IS - 3
ER -