Skip to main content
Log in

Assessment of Pedogenic Gibbsite as a Paleo-PCO2 Proxy Using a Modern Ultisol

  • Published:
Clays and Clay Minerals

Abstract

The stable carbon isotope composition of CO2 occluded in the gibbsite structure is proposed as a potential atmospheric paleo-PCO2 proxy. Analysis of pedogenic gibbsite from a modern Ultisol in the Piedmont of Georgia, USA, was conducted to test the basis for this concept and to help constrain the parameters used to describe physical and biological processes affecting such factors as the respiration rate of CO2. Co-variation of the δ13C and δ18O values with depth along a gradient parallel to the mixing line between the atmosphere and the soil organic material implies that diffusion is the process that determines the stable isotope composition of soil CO2. In the upper 40 cm, the measured δ13C values are not consistent with the expected diffusive depth profile assumed in paleo-PCO2 models. The isotope signature is reset downward in the depth profile with a concentration of the most atmosphere-like δ13C and δ18O values occurring at the top of the Bt horizon by some as-yet-unknown process. Bioturbation, recrystallization, and physical translocation are potential explanations for this observation. Regardless of the process at work, the net effect is an apparent two-component mixing curve between the top of the Bt horizon and deep within the saprolite. In cases where the A horizon is eroded but the Bt horizon is preserved it is possible that δ13C values of gibbsite-occluded CO2 can serve as a proxy for atmospheric paleo-PCO2. Careful textural study of all paleosols is therefore essential to match stable carbon isotope signatures with the horizons preserved. Understanding of modern dynamics and preservation of these isotopic signatures may also be important for those that employ other carbonate proxies.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
$34.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Explore related subjects

Discover the latest articles, news and stories from top researchers in related subjects.

References

  • Austin, J.C. (2011) Soil CO2 efflux simulations using Monte Carlo method and implications for recording paleo-atmospheric PCO2 in pedogenic gibbsite. Palaeogeography Palaeoclimatology Palaeoecology, 305, 280–285.

    Article  Google Scholar 

  • Bacon, A.R., Richter, D.D., Bierman, P., and Rood, D.H. (2012) Coupling meteoric 10Be with pedogenic losses of 9Be to improve soil residence time estimates on an ancient North American interfluve. Geology, 40, 847–850.

    Article  Google Scholar 

  • Berner, R.A. and Kothavala, Z. (2001) GEOCARB III: A revised model of atmospheric CO2 over Phanerozoic time. American Journal of Science, 301, 182–204.

    Article  Google Scholar 

  • Bowen, G.J. and Beerling, D.J. (2004) An integrated model for soil organic carbon and CO2: Implications for paleosol carbonate pCO2 paleobarometry. Global Biogeochemical Cycles, 18, GB1026 1021–1012.

    Article  Google Scholar 

  • Breecker, D.O., Sharp, Z.D., and McFadden, L.D. (2009) Seasonal bias in the formation and stable isotopic compostition of pedogenic carbonate in modern soils from central New Mexico, USA. Geological Society of America Bulletin, 121, 630–640.

    Article  Google Scholar 

  • Cerling, T.E. (1984) The stable isotopic composition of modern soil carbonate and its relationship to climate. Earth and Planetary Science Letters, 71, 229–240.

    Article  Google Scholar 

  • Cerling, T.E. (1991) Carbon dioxide in the atmosphere: evidence from Cenozoic and Mesozoic Paleosols. American Journal of Science, 291, 377–400.

    Article  Google Scholar 

  • Cerling, T.E., Quade, J., and Bowman, J.R. (1989) Carbon isotopes in soils and palaeosols as ecology and palaeoecology indicators. Nature, 341, 138–139.

    Article  Google Scholar 

  • Chen, Q., Zhu, R., and Xu, H. (2013) Stable isotopes of carbon dioxide in the marine atmosphere along a hemispheric course from China to Antartica. Atmospheric Environment, 80, 342–346.

    Article  Google Scholar 

  • Cuntz, M., Ciais, P., Hoffmann, G., and Knorr, W. (2003) A comprehensive global three-dimensional model of δ18O in atmospheric CO2: 1. Validation of surface processes. Journal of Geophysical Research, 108, 4528, doi: 10.1029/2002JD003153.

    Google Scholar 

  • Farrimond, P., Eglinton, G., and Brassell, S.C. (1986) Alkenones in Cretaceous black shales, Blake-Bahama Basin, western North Atlantic. Organic Geochemistry, 10, 897–903.

    Article  Google Scholar 

  • Francey, R.J., Allison, C.E., Etheridge, D.M., Trudinger, C.M., Enting, I.G., Leuenberger, M., Langerfelds, R.L., Michel, E., and Steele, L.P. (1999) A 1000-year high precision record of δ13C in atmospheric CO2. Tellus, 51B, 170–193.

    Article  Google Scholar 

  • Freeman, K.H. and Hayes, J.M. (1992) Fractionation of carbon isotopes by phytoplankton and estimates of ancient CO2 levels. Global Biogeochemical Cycles, 6, 185–198.

    Article  Google Scholar 

  • Hesterberg, R. and Siegenthaler, U. (1991) Production and stable isotopic composition of CO2 in a soil near Bern, Switzerland. Tellus, 43B, 197–205.

    Article  Google Scholar 

  • Hsieh, J.C.C., Savin, S.M., Kelly, E.F., and Chadwick, O.A. (1998) Measurement of soil-water δ18O values by direct equilibration with CO2. Geoderma, 82, 255–268.

    Article  Google Scholar 

  • Kump, L.R. and Arthur, M.A. (1999) Interpreting carbonisotope excursions: carbonates and organic matter. Chemical Geology, 161, 181–198.

    Article  Google Scholar 

  • Kurschner, W.M., Van Der Burgh, J., Visscher, H., and Dilcher, D.L. (1996) Oak leaves as biosensors of late Neogene and early Pleistocene paleoatmospheric CO2 concentrations. Marine Micropaleontology, 27, 299–312.

    Article  Google Scholar 

  • Marlowe, I.T., Brassell, S.C., Eglinton, G., and Green, J.C. (1990) Long-chain alkenones and alkyl alkenoates and the fossil coccolith record of marine sediments. Chemical Geology, 88, 349–375.

    Article  Google Scholar 

  • Miller, J.B., Yakir, D., White, J.W.C., and Tans, P.P. (1999) Measurement of 18O/16O in the soil-atmosphere CO2 flux. Global Biogeochemical Cycles, 13, 761–774.

    Article  Google Scholar 

  • Pagani, M., Freeman, K.H., and Arthur, M.A. (1999) Late Miocene atmospheric CO2 concentrations and the expansion of C4 grasses. Science, 285, 876–879.

    Article  Google Scholar 

  • Robertson, S.M. (1968) Soil Survey of Clarke and Oconee Counties, Georgia. Department of Agriculture, U.S.A.

    Google Scholar 

  • Royer, D.L., Berner, R.A., and Beerling, D.J. (2001) Phanerozoic atmospheric CO2 change: evaluating geochemical and paleobiological approaches. Earth Science Reviews, 54, 349–392.

    Article  Google Scholar 

  • Schroeder, P.A. and Melear, N.D. (1999) Stable carbon isotope signatures preserved in authigenic gibbsite from a forested granitic-regolith: Panola Mountain, Georgia, USA. Geoderma, 91, 261–279.

    Article  Google Scholar 

  • Schroeder, P.A., Melear, N.D., Bierman, P., Kashgarian, M., and Caffee, M.W. (2001) Apparent gibbsite growth ages for regolith in the Georgia Piedmont. Geochimica et Cosmochimica Acta, 65, 381–386.

    Article  Google Scholar 

  • Schroeder, P.A., Austin, J.C., and Dowd, J.F. (2006) Estimating long-term soil respiration rates from carbon isotopes occluded in gibbsite. Geochimica et Cosmochimica Acta, 70, 5692–5697.

    Article  Google Scholar 

  • Stern, L., Baisden, W.T., and Amundson, R. (1999) Processes controlling the oxygen isotope ratio of soil CO2: Analytic and numerical modeling. Geochimica et Cosmochimica Acta, 63, 799–814.

    Article  Google Scholar 

  • Su, C.M. and Suarez, D.L. (1997) In situ infrared speciation of absorbed carbonate on aluminum and iron oxide. Clays and Clay Minerals, 45, 814–825.

    Article  Google Scholar 

  • Tabor, N.J. and Yapp, C.J. (2005) Incremental vacuum dehydration-decarbonation experiments on a natural gibbsite (α-Al(OH)3): CO2 abundance and δ13C values. Geochimica et Cosmochimica Acta, 69, 519–527.

    Article  Google Scholar 

  • Van Der Burgh, J., Visscher, H., Dilcher, D.L., and Kurschner, W.M. (1993) Paleoatmospheric signatures in Neogene fossil leaves. Science, 260, 1788–1790.

    Article  Google Scholar 

  • Welp, L.R., Keeling, R.F., Meijer, H.A.J., Bollenbacher, A.F., Piper, S.C., Yoshimura, K., Francey, R.J., Allison, C.E., and Wahlen, M. (2011) Interannual variability in the oxygen isotopes of atmospheric CO2 driven by El Nino. Nature, 477, 579–582.

    Article  Google Scholar 

  • Woodward, F.I. and Bazzaz, F.A. (1988) The responses of stomatal density to CO2 partial pressure. Journal of Experimental Botany, 39, 1771–1781.

    Article  Google Scholar 

  • Yapp, C.J. (1997) An assessment of isotopic equilibrium in goethites from a bog iron deposit in a lateritic regolith. Chemical Geology, 135, 159–171.

    Article  Google Scholar 

  • Yapp, C.J. (2003) A model for 18O/16O variations in CO evolved from goethite during the solid-state α-FeOOH to α-Fe2O3 phase transition. Geochimica et Cosmochimica Acta, 67, 1991–2004.

    Article  Google Scholar 

  • Yapp, C.J. and Poths, H. (1986) Carbon in natural goethites. Geochimica et Cosmochimica Acta, 50, 1213–1220.

    Article  Google Scholar 

  • Yapp, C.J. and Poths, H. (1990) Infrared spectral evidence for a minor Fe(III) carbonate bearing component in natural goethite. Clays and Clay Minerals, 38, 442–444.

    Article  Google Scholar 

  • Yapp, C.J. and Poths, H. (1992) Ancient atmospheric CO2 pressures inferred from natural goethites. Nature, 355, 342–344.

    Article  Google Scholar 

  • Yapp, C.J. and Poths, H. (1996) Carbon isotopes in continental weathering environments and variations in ancient atmospheric CO2 pressure. Earth and Planetary Science Letters, 137, 71–82.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Jason C. Austin.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Austin, J.C., Schroeder, P.A. Assessment of Pedogenic Gibbsite as a Paleo-PCO2 Proxy Using a Modern Ultisol. Clays Clay Miner. 62, 253–266 (2014). https://doi.org/10.1346/CCMN.2014.0620402

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1346/CCMN.2014.0620402

Key Words

Navigation