Paleo-pCO2 Database Piceance Creek Basin Eocene Nahcolite CO2 Data Jagniecki, E.A.; Lowenstein, T.K.; Jenkins, D.M.; Demicco, R.V. Jagniecki, E.A. Lowenstein, T.K. Jenkins, D.M. Demicco, R.V. earth science/paleoclimate/climate forcing (age,null,null,million years ago,null,climate forcing,null,null,N,null) earth science/paleoclimate/climate forcing (age,null,one standard deviation,million years ago,null,climate forcing,null,null,N,null) earth science/paleoclimate/climate forcing (carbon dioxide,bulk atmosphere,null,parts per million,null,climate forcing,null,null,N,based on nahcolite) earth science/paleoclimate/climate forcing (Shell 23x-2>LATITUDE 39.90546>LONGITUDE -108.36224) Estimates of the atmospheric concentration of CO2, [CO2]atm, for the "hothouse" climate of the early Eocene climatic optimum (EECO) vary for different proxies. Extensive beds of the mineral nahcolite (NaHCO3) in evaporite deposits of the Green River Formation, Piceance Creek Basin, Colorado, USA, previously established [CO2]atm for the EECO to be >1125 ppm by volume (ppm). Here, we present experimental data that revise the sodium carbonate mineral equilibria as a function of [CO2] and temperature. Co-precipitation of nahcolite and halite (NaCl) now establishes a well-constrained lower [CO2]atm limit of 680 ppm for the EECO. Paleotemperature estimates from leaf fossils and fluid inclusions in halite suggest an upper limit for [CO2]atm in the EECO from the nahcolite proxy of ~1260 ppm. These data support a causal connection between elevated [CO2]atm and early Eocene global warmth, but at significantly lower [CO2]atm than previously thought, which suggests that ancient climates on Earth may have been more sensitive to a doubling of [CO2]atm than is currently assumed. STUDY NOTES: Paleo-CO2 derived from Eocene nahcolite from a Piceance Creek Basin, Colorado sediment core (Green River Formation), contributed to the Paleo-pCO2 Database. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Jagniecki, E.A. Investigator : Lowenstein, T.K. Investigator : Jenkins, D.M. Investigator : Demicco, R.V. 2018-03-08 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23531 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/jagniecki2015nahcolite.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/jagniecki2015nahcolite.xlsx https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/jagniecki2015nahcolite.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/jagniecki2015nahcolite.xlsx English https://www.ncdc.noaa.gov/paleo/study/23531 https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/jagniecki2015nahcolite.txt https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/jagniecki2015nahcolite.xlsx Elliot A. Jagniecki, Tim K. Lowenstein, David M. Jenkins, Robert V. Demicco2015Eocene atmospheric CO2 from the nahcolite proxyGeology43121075-107810.1130/G36886.1https://pubs.geoscienceworld.org/gsa/geology/article-abstract/43/12/1075/131750/eocene-atmospheric-co2-from-the-nahcolite-proxy Tim K. Lowenstein, Robert V. Demicco2006Elevated Eocene Atmospheric CO2 and Its Subsequent DeclineScience3135795192810.1126/science.1129555 http://science.sciencemag.org/content/313/5795/1928 START YEAR: 51550000 cal yr BP * END YEAR: 49320000 cal yr BP -108.36224 39.90546 -108.36224 39.90546