# North Horn Formation, Utah Paleocene-Eocene Thermal Maximum Clumped Isotopes #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # Online_Resource: http://www.hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:16035 # # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/vandevelde2013/axhandle2013.txt # # Archive: Other Collections #--------------------------------------- # Contribution_Date # Date: 2014-01-23 #--------------------------------------- # Title # Study_Name: North Horn Formation, Utah Paleocene-Eocene Thermal Maximum Clumped Isotopes # #--------------------------------------- # Investigators # Investigators: VanDeVelde, J.; Bowen, G.; Passey, B.; Bowen, B. #--------------------------------------- # Description_and_Notes # Description: Clumped isotope study of pedogenic carbonates from North Horn Fm. paleosols #--------------------------------------- # Publication # Authors: Justin H. VanDeVelde, Gabriel J. Bowen, Benjamin H. Passey, Brenda B. Bowen # Published_Date_or_Year: 2013-05-15 # Published_Title: Climatic and diagenetic signals in the stable isotope geochemistry of dolomitic paleosols spanning the Paleocene-Eocene boundary # Journal_Name: Geochimica et Cosmochimica Acta # Volume: 109 # Issue: # Pages: 254-267 # Report Number: # DOI: 10.1016/j.gca.2013.02.005 # Online_Resource: http://www.sciencedirect.com/science/article/pii/S0016703713000823 # Abstract: The precipitation of primary dolomite in soil is rare and controversial, and its occurrence indicates highly unusual geochemical and climatic conditions. We utilize isotopic and petrographic techniques, including clumped isotope thermometry, to evaluate diagenetic alteration and preservation of primary climatic signal in dolomitic paleosol nodules from a section spanning the Paleocene-Eocene boundary in central Utah. Isotopic measurements differentiate samples into groups that may be interpreted in terms of alteration; however moderate burial depths and extreme warmth during the interval of soil formation make it difficult to reach definitive conclusions from isotope values alone. With the addition of petrographic analysis, including cathodoluminescence and scanning electron microscopy, we are able to identify textural differences between samples suggesting differing amounts of recrystallization. We conclude that while some nodules have experienced significant diagenetic alteration the original nodule mineralogy is dolomite, and the majority of sampled nodules retain a primary paleoclimate signal. Early Paleogene temperatures recorded at this site are considerably warmer than those suggested for the continental interior from alternate proxies, a result that may be partially the result of the clumped isotope temperatures recording warm season soil temperatures, rather than mean annual air temperature. Soil water isotopic composition is suggestive of heightened aridity, particularly through the Paleocene-Eocene Thermal Maximum (PETM). #--------------------------------------- # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: OCE-0902882, EAR-0628302 #--------------------------------------- # Site Information # Site_Name: Axhandle Canyon # Northernmost_Latitude: 39.4113 # Southernmost_Latitude: 39.41054 # Easternmost_Longitude: -111.69887 # Westernmost_Longitude: -111.701 # Elevation: 1980 #--------------------------------------- # Data_Collection # Collection_Name: Axhandle-NorthHorn # First_Year: 57000000 # Last_Year: 55000000 # Time_Unit: Cal. Year BP # Core_Length: 150 m # Notes: #--------------------------------------- # Chronology: # #--------------------------------------- # Variables ## notes-SampleID Notes-Sample identifier, , , , , , , ,C ## Level Section meter level, , ,meters, , ,above base of stratigraphic section, ,N ## d13CmicrVPDB carbon isotope ratio,pedogenic micrite,0.1,per mil VPDB, , , ,analytical technique: isotope ratio mass spectrometry,N ## d18OmicrVPDB oxygen isotope ratio,pedogenic micrite,0.1,per mil VPDB, , , ,analytical technique: isotope ratio mass spectrometry,N ## Cap47g clumped isotope ratio, Gosh scale,pedogenic micrite,0.01,per mil, , ,relative to Gosh et al., 2006 reference scale; see primary reference for details,analytical technique: isotope ratio mass spectrometry,N ## Cap47eq clumped isotope ratio, equilibrium scale,pedogenic micrite,0.01,per mil, , ,relative to equilibrium carbon dioxide reference scale; see primary reference for details,analytical technique: isotope ratio mass spectrometry,N ## micrite% percent micrite,pedogenic carbonate nodule, ,percent, , , ,thin section point count,N ## spar% percent spar,pedogenic carbonate nodule, ,percent, , , ,thin section point count,N ## sic% percent siliciclastic,pedogenic carbonate nodule, ,percent, , , ,thin section point count,N ## carb_min wavelenth of carbonate absorption feature minimum,pedogenic carbonate nodule, ,nanometers, , , ,analytical technique: reflectance spectroscopy,N ## cal/dol calcite to dolomite ratio,pedogenic carbonate nodule, , , , ,semiquantitative determination,analytical technique: x-ray diffraction,N ## Mg/Ca-micr magnesium to calcium ratio,pedogenic micrite,0.06, , , ,average 1 standard deviation reported for replicate SEM-EDX measurements on each sample,analytical technique: scanning electron microscopy,N # Data # Missing Value: -999 ## notes-SampleID Level d13CmicrVPDB d18OmicrVPDB Cap47g Cap47eq micrite% spar% sic% carb_min cal/dol Mg/Ca-micr ## NH060107 26 -6.6 -10.3 0.591 0.636 70 5.6 24.4 2330 -999 -999 ## NH060110 46 -5.5 -7.2 0.61 0.66 95 0 5 2322 0 0.91 ## NH060112 52 -4.8 -8.5 0.558 0.604 60 10 30 2334 -999 -999 ## NH060113 61 -5 -7.6 0.579 0.624 90 0 10 2326 0 0.84 ## NH060114 72.5 -4.8 -8.2 0.623 0.674 91.3 0 8.7 2325 0 0.84 ## NH060119 94 -6.3 -9.8 0.556 0.601 55 20 25 2336 0.96 0.72 ## NH060120 98.5 -8.6 -8.7 0.55 0.595 78.2 7.4 14.4 2336 0.5 0.82 ## NH060122 106.5 -9.4 -5.8 0.58 0.627 75.4 6.6 18 2322 -999 0.83 ## NH060124 117 -6.7 -8 0.575 0.623 77 14.2 8.8 2330 -999 0.54 ## NH060128 138.5 -7.7 -9.7 0.579 0.626 81.3 15 3.7 2336 0.51 0.28 ## NH060130 155 -6.5 -10 0.58 0.63 80 5 15 2336 0.61 0.14