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Soil, land care and environmental research

Exploring pedogenesis via nuclide-based soil production rates and OSL-based bioturbation rates

Marshall T. Wilkinson A B and Geoff S. Humphreys A

A Department of Physical Geography, Macquarie University, NSW 2109, Australia.

B Corresponding author. Email:

Australian Journal of Soil Research 43(6) 767-779
Submitted: 29 October 2004  Accepted: 4 May 2005   Published: 22 September 2005


New dating techniques are available for soil scientists to test fundamental pedogenic ideas. Recent developments in applications of terrestrial in situ cosmogenic nuclides (TCN) from bedrock and saprolite allow the derivation of soil production rates, at scales ranging from local (sub-hillslope) to catchment wide, generally averaged over timescales of 104–105 years. Where soil depths are relatively constant over time, soil production rates equal transport rates and are thus essential to establishing sustainable erosion rates. TCN also allow the form of the soil production function to be compared to theoretical models—a difficult task previously. Furthermore, parameterised soil production functions can now be incorporated into numerical surface process models to test landscape evolution ideas.

Bedrock and saprolite conversion to soil is demonstrably dependent on the overlying soil depth, and there is general agreement that weathering declines exponentially beyond maximum soil production, consistent with theory. Whether maximum soil production occurs under a finite or non-existent soil cover at particular sites remains unresolved. We suggest that, in general, soil production from saprolite declines exponentially with increasing depth, while production from bedrock follows a humped function.

Estimates of the role of flora, fauna and processes such as freeze–thaw that mix soil mantles to depth, have been limited prior to optically stimulated luminescence (OSL) dating techniques. Recently derived OSL mixing rates extend the magnitude of previous partial, short-term bioturbation rates. In fact, bioturbation appears to be the most active pedogenic process operating in many soils, with freeze–thaw environments a noted exception. Although bioturbation far outweighs soil production, it does not always lead to homogenisation as is often reported. We maintain that the above-ground component of bioturbation, i.e. mounding, may alone, or particularly when combined with particle sorting via rainwash processes, lead to horizonisation and texture contrast soils in those materials that can be sorted such as mixtures of sand and clay. Together, TCN- and OSL-based estimates of hillslope soil transport and bioturbation, suggest significant rates of downslope soil mantle movement coupled with rapid mixing, contrary to in situ soil development models.

Additional keywords: soil formation, soil mixing, horizonisation, geochronology.


We thank the following for helpful discussion in developing the ideas presented in this paper: the late Don Adamson, Peter Almond, Bob Anderson, John Chappell, Tony Dosetto, David Jon Furbish, Manny Gabet, Arjun Heimsath, Paul Hesse, Jon Olley, and Josh Roering. Brad Pillans and two anonymous referees also provided useful comments on a draft version of this manuscript. Karen Carthew and Kerrie Tomkins drafted the figures.


Ahnert F (1967) The role of the equilibrium concept in the interpretation of landforms of fluvial erosion and deposition. ‘L’evolution des versants’. (Ed. P Macar) pp. 23–41. (Universite de Liege: Liege)

Ahnert F (1970) A comparison of theoretical slope models with slopes in the field. Zeitschrift Fur Geomorphologie Supplementband 9, 88–101. open url image1

Ahnert F (1976) Brief description of a comprehensive three-dimensional process-response model of landform development. Zeitschrift Fur Geomorphologie Supplementband 25, 29–49. open url image1

Ahnert F (1988) Modelling landform change. ‘Modelling geomorphological systems’. (Ed. MG Anderson) pp. 375–400. (Wiley: Chichester, UK)

Aitken MJ (1994) Optical dating: a non-specialist review. Quaternary Geochronology 13, 503–508. open url image1

Aitken, MJ (1998). ‘An introduction to optical dating—the dating of Quaternary sediments by the use of photon-stimulated luminescence.’ (Oxford University Press: New York)

Anderson RS (2002) Modeling the tor-dotted crests, bedrock edges, and parabolic profiles of high alpine surfaces of the Wind River Range, Wyoming. Geomorphology 46, 35–58.
CrossRef | open url image1

Bateman MD, Frederick CD, Jaiswal MK, Singhvi AK (2003) Investigations into the potential effects of pedoturbation on luminescence dating. Quaternary Science Reviews 22, 1169–1176.
CrossRef | open url image1

Belton DX, Brown RW, Kohn BP, Fink D, Farley KA (2004) Quantitative resolution of the debate over antiquity of the central Australian landscape: implications for the tectonic and geomorphic stability of cratonic interiors. Earth and Planetary Science Letters 219, 21–34.
CrossRef | open url image1

Bierman P, Steig EJ (1996) Estimating rates of denudation using cosmogenic isotope abundances in sediment. Earth Surface Processes and Landforms 21, 125–139.
CrossRef | open url image1

Bierman PR (1994) Using in situ produced cosmogenic isotopes to estimate rates of landscape evolution: a review from the geomorphic perspective. Journal of Geophysical Research 99, 13885–13896.
CrossRef | open url image1

Bierman PR, Caffee MW (2002) Cosmogenic exposure and erosion history of Australian bedrock landforms. Geological Society of America Bulletin 114, 787–803.
CrossRef | open url image1

Birkeland, PW (1999). ‘Soils and geomorphology.’ (Oxford University Press: New York)

Bush DA, Feathers JK (2003) Application of OSL single-aliquot and single-grain dating to quartz from anthropogenic soil profiles in the SE United States. Quaternary Science Reviews 22, 1153–1159.
CrossRef | open url image1

Carson, MA ,  and  Kirkby, MJ (1972). ‘Hillslope form and process.’ (Cambridge University Press: Cambridge, UK)

Cox NJ (1980) On the relationship between bedrock lowering and regolith thickness. Earth Surface Processes 5, 271–274. open url image1

Darwin, C (1881). ‘The formation of vegetable mould through the action of worms, with observations on their habits.’ (John Murray: London)

Dietrich WE, Reiss R, Hsu M, Montgomery DR (1995) A process-based model for colluvial soil depth and shallow landsliding using digital elevation data. Hydrological Processes 9, 383–400. open url image1

Duller GAT (2004) Luminescence dating of Quaternary sediments: recent advances. Journal of Quaternary Science 19, 183–192.
CrossRef | open url image1

Dunne J, Elmore D, Muzikar P (1999) Scaling factors for the rates of production of cosmogenic nuclides for geometric shielding and attenuation at depth on sloped surfaces. Geomorphology 27, 3–11.
CrossRef | open url image1

Evans AC (1948) Studies on the relationships between earthworms and soil fertility. II: Some effects of earthworms on soil structure. Annals of Applied Biology 34, 307–330. open url image1

Furbish DJ, Fagherazzi S (2001) Stability of creeping soil and implications for hillslope evolution. Water Resources Research 37, 2607–2618.
CrossRef | open url image1

Gabet EJ, Reichman OJ, Seabloom EW (2003) The effects of bioturbation on soil processes and sediment transport. Annual Review of Earth and Planetary Sciences 31, 249–273.
CrossRef | open url image1

Gilbert, GK (1877). ‘Report on the geology of the Henry Mountains.’ (U.S. Geographical and Geological Survey of the Rocky Mountain Region: Washington, DC)

Gosse JC, Phillips FM (2001) Terrestrial in situ cosmogenic nuclides: theory and application. Quaternary Science Reviews 20, 1475–1560.
CrossRef | open url image1

Granger DE, Kirchner JW, Finkel R (1996) Spatially averaged long-term erosion rates measured from in situ-produced cosmogenic nuclides in alluvial sediment. Journal of Geology 104, 249–257. open url image1

Heimsath AM, Chappell J, Dietrich WE, Nishiizumi K, Finkel RC (2000) Soil production on a retreating escarpment in southeastern Australia. Geology 28, 787–790.
CrossRef | open url image1

Heimsath AM, Chappell J, Dietrich WE, Nishiizumi K, Finkel RC (2001a) Late Quaternary erosion in southeastern Australia: a field example using cosmogenic nuclides. Quaternary International 83–85, 169–185.
CrossRef | open url image1

Heimsath AM, Chappell J, Spooner NA, Questiaux DG (2002) Creeping soil. Geology 30, 111–114.
CrossRef | open url image1

Heimsath AM, Dietrich WE, Nishiizumi K, Finkel RC (1997) The soil production function and landscape equilibrium. Nature 388, 358–361.
CrossRef | open url image1

Heimsath AM, Dietrich WE, Nishiizumi K, Finkel RC (1999) Cosmogenic nuclides, topography, and the spatial variation of soil depth. Geomorphology 27, 151–172.
CrossRef | open url image1

Heimsath AM, Dietrich WE, Nishiizumi K, Finkel RC (2001b) Stochastic processes of soil production and transport: erosion rates, topographic variation and cosmogenic nuclides in the Oregon Coast Range. Earth Surface Processes and Landforms 26, 531–532.
CrossRef | open url image1

Humphreys GS (1994) Bioturbation, biofabrics and the biomantle: an example from the Sydney Basin. ‘Soil micromorphology: studies in management and genesis’. (Eds AJ Ringrose-Voase, GS Humphreys) pp. 421–436. (Elsevier: Amsterdam)

Humphreys GS, Field R (1998) Mixing, mounding and other aspects of bioturbation: implications for pedogenesis. Registered paper no. 18. ‘16th World Congress of Soil Science’. Montpellier, France.. (International Society of Soil Science)

Humphreys GS, Mitchell PB (1983) A preliminary assessment of the role of bioturbation and rainwash on sandstone hillslopes in the Sydney Basin. ‘Australian and New Zealand Geomorphology Group’. (Eds RW Young, GC Nanson) pp. 66–80. (Australian and New Zealand Geomorphology Group)

Jahn A (1968) Denudational balance of slopes. Geographia Polonica 13, 9–29. open url image1

Johnson DL (1990) Biomantle evolution and the redistribution of earth materials and artifacts. Soil Science 149, 84–102. open url image1

Johnson DL (2002) Darwin would be proud: bioturbation, dynamic denudation, and the power of theory in science. Geoarchaeology 17, 7–40.
CrossRef | open url image1

Johnson DL, Domier JEJ, Johnson DN (2005) Animating the biodynamics of soil thickness using process vector analysis: a dynamic denudation approach to soil formation. Geomorphology 67, 23–46.
CrossRef | open url image1

Kirchner JW, Finkel RC, Riebe CS, Granger DE, Clayton JL, King JG, Megahan WF (2001) Mountain erosion over 10 yr, 10 k.y., and 10 m.y. time scales. Geology 29, 591–594.
CrossRef | open url image1

Lal D (1991) Cosmic ray labeling of erosion surfaces: in situ nuclide production rates and erosion models. Earth and Planetary Science Letters 104, 424–439.
CrossRef | open url image1

Lal R (2004) Soil carbon sequestration impacts on global climate change and food security. Science 304, 1623–1627.
CrossRef | PubMed | open url image1

Lavelle P (1978) Les ver de terre de la savane de kamto (Côe d’Ivoire) peuplements, populations et fonctions dans l’ecosystem. In ‘Publication du Laboratore de Zoologie’. pp. 12. (Paris Ecole Normale Superiere: Paris)

Lee, KE ,  and  Wood, TG (1971). ‘Termites and soils.’ (Academic Press: London)

McBratney AB, Mendonca Santos ML, Minasny B (2003) On digital soil mapping. Geoderma 117, 3–52.
CrossRef | open url image1

McBratney AB, Odeh IOA, Bishop TFA, Dunbar MS, Shatar TM (2000) An overview of pedometric techniques for use in soil survey. Geoderma 97, 293–327.
CrossRef | open url image1

McKean JA, Dietrich WE, Finkel RC, Southon JR, Caffee MW (1993) Quantification of soil production and downslope creep rates from cosmogenic 10Be accumulations on a hillslope profile. Geology 21, 343–346.
CrossRef | open url image1

McNeill JR, Winiwarter V (2004) Breaking the sod: humankind, history and soil. Science 304, 1627–1629.
CrossRef | PubMed | open url image1

Monaghan MC, McKean J, Dietrich WE, Klein J (1992) 10Be chronometry of bedrock-to-soil conversion rates. Earth and Planetary Science Letters 111, 483–492.
CrossRef | open url image1

Murray AS, Olley JM (2002) Precision and accuracy in the optically stimulated luminescence dating of sedimentary quartz: a status review. Geochronometria 21, 1–16. open url image1

Murray AS, Roberts RG (1997) Determining the burial time of single grains of quartz using optically stimulated luminescence. Earth and Planetary Science Letters 152, 163–180.
CrossRef | open url image1

Nikiforoff CC (1949) Weathering and soil evolution. Soil Science 67, 219–230. open url image1

Nishiizumi K, Kohl CP, Arnold JR, Dorn R, Klein J, Fink K, Middleton R, Lal D (1993) Role of in situ cosmogenic nuclides 10Be and 26Al in the study of diverse geomorphic processes. Earth Surface Processes and Landforms 18, 407–425. open url image1

Nishiizumi K, Kohl CP, Arnold JR, Klein J, Fink D, Middleton R (1991) Cosmic ray produced 10Be and 26Al in Antarctic rocks: exposure and erosion history. Earth and Planetary Science Letters 104, 440–454.
CrossRef | open url image1

Paton, TR , Humphreys, GS ,  and  Mitchell, PB (1995). ‘Soils: a new global view.’ (UCL Press Limited: London)

Pillans B (1997) Soil development at snail’s pace: evidence from a 6 Ma soil chronosequence on basalt in north Queensland, Australia. Geoderma 80, 117–128.
CrossRef | open url image1

Pillans, B (1998). ‘Regolith dating methods—a guide to numerical dating techniques.’ (Cooperative Research Centre for Landscape Evolution and Mineral Exploration: Canberra)

Pillans B, Spooner N, Chappell J (2002) The dynamics of soils in north Queensland: rates of mixing by termites determined by single grain luminescence dating. In ‘Regolith and landscapes in eastern Australia’. (Ed. IC Roach) pp. 100–101. (Cooperative Research Centre for Landscape Evolution and Mineral Exploration: Canberra)

Prosser IP, Williams L (1998) The effect of wildfire on runoff and erosion in native Eucalyptus forest. Hydrological Processes 12, 251–265.
CrossRef | open url image1

Reneau SL, Dietrich WE (1990) Depositional history of hollows on steep hillslopes, coastal Oregon and Washington. National Geographic Research 6, 220–230. open url image1

Reneau SL, Dietrich WE, Rubin M, Donahue JD, Jull AJT (1989) Analysis of hillslope erosion rates using dated colluvial deposits. Journal of Geology 97, 45–63. open url image1

Roberts R, Bird M, Olley J, Galbraith R, Lawson E , et al. (1998) Optical and radiocarbon dating at Jinmium rock shelter in northern Australia. Nature 393, 358–362.
CrossRef | open url image1

Roberts RG, Galbraith RF, Olley JM, Yoshida H, Laslett GM (1999) Optical dating of single and multiple grains of quartz from Jinmium Rock Shelter, northern Australia. Part II: Results and implications. Archaeometry 41, 365–395. open url image1

Roberts RG, Galbraith RF, Yoshida H, Laslett GM, Olley JM (2000) Distinguishing dose populations in sediment mixtures: a test of single-grain optical dating procedures using mixtures of laboratory-dosed quartz. Radiation Measurements 32, 459–465.
CrossRef | open url image1

Roering JJ, Almond P, Tonkin P, McKean J (2002) Soil transport driven by biological processes over millennial times scales. Geology 30, 1115–1118.
CrossRef | open url image1

Satchell JE (1967) Lumbricidae. ‘Soil biology’. (Eds A Burges, F Raw) pp. 259–322. (Academic Press: London)

Small EE, Anderson RS, Hancock GS (1999) Estimates of the rate of regolith production using 10Be and 26Al from an alpine hillslope. Geomorphology 27, 131–150.
CrossRef | open url image1

Spencer JQ, Sanderson DCW, Deckers K, Sommerville AA (2003) Assessing mixed dose distributions in young sediments identifed using small aliquots and a simple two-step SAR procedure: the F-statistic as a diagnostic tool. Radiation Measurements 37, 425–431.
CrossRef | open url image1

Stace, HCT , Hubble, GD , Brewer, R , Northcote, KH , Sleeman, JR , Mulcahy, MJ ,  and  Hallsworth, EG (1968). ‘A handbook of Australian soils.’ (Rellim Technical Publications: Glenside, S. Aust.)

Stallard RF (1992) Tectonic processes, continental freeboard, and the rate-controlling step for continental denudation. ‘Global biogeochemical cycles’. (Ed. SS Butcher) (Academic Press: London)

Stone JO (2000) Air pressure and cosmogenic isotope production. Journal of Geophysical Research 105, 23,753–23,759.
CrossRef | open url image1

Vigier N, Bourdon B, Turner S, Allegre CJ (2001) Erosion timescales derived from U-decay series measurements in rivers. Earth and Planetary Science Letters 193, 549–563.
CrossRef | open url image1

Wilkinson MT, Humphreys GS, Chappell J, Fifield K, Smith B (2003) Estimates of soil production in the Blue Mountains, Australia, using cosmogenic 10Be. ‘Advances in regolith’. Canberra, ACT. (Ed. IC Roach) pp. 441–443. (Cooperative Research Centre for Landscape Evolution and Mineral Exploration: Canberra)

Wilkinson MT, Chappell J, Humphreys GS, Fifield K, Smith B, Hesse PP (2005) Soil production in heath and forest, Blue Mountains, Australia: influence of lithology and palaeoclimate. Earth Surface Processes and Landforms 30, 923–934.
CrossRef |
open url image1

Williams MAJ (1968) Termites and soil development near Brocks Creek, Northern Territory. Australian Journal of Science 31, 135–154. open url image1

Yoshida H, Roberts RG, Olley JM, Laslett GM, Galbraith RF (2000) Extending the age range of optical dating using single ‘supergrains’ of quartz. Radiation Measurements 32, 439–446.
CrossRef | open url image1

Young A, Saunders I (1986) Rates of surface processes and denudation. ‘Hillslope processes’. (Ed. AD Abrahams) pp. 3–27. (Allen and Unwin: Boston, MA)

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