West Turkana, Kenya 1.9-1.4 Ma Leaf Wax Hydrogen and Carbon Isotope Data Lupien, R.L.; Russell, J.M.; Feibel, C.; Beck, C.; Castañeda, I.S.; Deino, A.L.; Cohen, A.S. Lupien, R.L. Russell, J.M. Feibel, C. Beck, C. Castañeda, I.S. Deino, A.L. Cohen, A.S. earth science/paleoclimate/climate reconstructions|paleolimnology (age,null,null,million years ago,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (C3 plants,delta 13C,null,percent,null,climate reconstructions|paleolimnology,null,null,N,derived from a linear mixing model of the d13Cwax) earth science/paleoclimate/climate reconstructions|paleolimnology (delta 2H,precipitation,null,per mil,null,climate reconstructions|paleolimnology,null,null,N,derived following methods in Konecky et al. 2016) earth science/paleoclimate/paleolimnology (delta 13C,C28 n-alkanoic acid,null,per mil,null,paleolimnology,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (depth,null,null,meter,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/paleolimnology (delta 2H,C28 n-alkanoic acid,null,per mil,null,paleolimnology,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/paleolimnology earth science/paleoclimate/paleolimnology (West Turkana HSPDP-WTK13-1A>LATITUDE 4.1097>LONGITUDE 35.8718) Climate is thought to play a critical role in human evolution; however, this hypothesis is difficult to test due to a lack of long, high-quality paleoclimate records from key hominin fossil locales. To address this issue, we analyzed organic geochemical indicators of climate in a drill core from West Turkana, Kenya that spans ~1.9-1.4 Ma, an interval that includes several important hominin evolutionary transitions. We analyzed the hydrogen isotopic composition of terrestrial plant waxes (dDwax) to reconstruct orbital-timescale changes in regional hydrology and their relationship with global climate forcings and the hominin fossil record. Our data indicate little change in the long-term mean hydroclimate during this interval, in contrast to inferred changes in the level of Lake Turkana, suggesting that lake level may be responding dominantly to deltaic progradation or tectonically-driven changes in basin configuration as opposed to hydroclimate. Time-series spectral analyses of the isotopic data reveal strong precession-band (21 kyr) periodicity, indicating that regional hydroclimate was strongly affected by changes in insolation. We observe an interval of particularly high-amplitude hydrologic variation at ~1.7 Ma, which occurs during a time of high orbital eccentricity hence large changes in processionally-driven insolation amplitude. This interval overlaps with multiple hominin species turnovers, the appearance of new stone tool technology, and hominin dispersal out of Africa, supporting the notion that climate variability played an important role in hominin evolution. STUDY NOTES: Hydrogen and carbon isotopes of higher plant leaf waxes (dDwax and d13Cwax) from West Turkana, Kenya, covering ~1.9-1.4 Ma. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Lupien, R.L. Investigator : Russell, J.M. Investigator : Feibel, C. Investigator : Beck, C. Investigator : Castañeda, I.S. Investigator : Deino, A.L. Investigator : Cohen, A.S. 2018-03-23 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23690 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/wturkana2018iso.txt https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/wturkana2018iso.txt English https://www.ncdc.noaa.gov/paleo/study/23690 https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/wturkana2018iso.txt R.L. Lupien, J.M. Russell, C. Feibel, C. Beck, I. Castañeda, A. Deino, A.S. Cohen2018A leaf wax biomarker record of early Pleistocene hydroclimate from West Turkana, KenyaQuaternary Science Reviews186225-23510.1016/j.quascirev.2018.03.012https://www.sciencedirect.com/science/article/pii/S0277379117306169 START YEAR: 1867200 cal yr BP * END YEAR: 1378900 cal yr BP 35.8718 4.1097 35.8718 4.1097