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The Effects of Fire on Archaeological Soils and Sediments: Temperature and Colour Relationships

  • M.G. Canti and N. Linford (a1)

Abstract

Although fire is a fundamental building block of interpretation, details of its effect on archaeological substrates are still poorly understood. The key questions, from an interpretative point of view, are the level of heating produced in the soil underneath different fires and the degree of reddening preserved in the final stratigraphy. This paper explores these questions by examination of previous studies and through a series of instrumented experimental fires. We conclude that, although there is some variation, temperatures beneath most surface-built fires remain below 500° C and reddening of the soil happens only rarely. These two generalisations are, however, linked in a complex way which is not fully clarified. Some sediments redden dramatically at temperatures commonly found under the experimental fires and in the literature on soil heating, while others fail to redden even at significantly higher temperatures. These ‘anomalies’ could relate to either organic matter content or chemical variations affecting the progress of the iron oxide transformations that lead to soil reddening.

Bien que le feu soit un pilier fondamental de l'interprétation archéologique, on ne saisit encore qu'insuffisamment les détails de son effet sur les sous-couches archéologiques. Les questions clés, du point de vue de l'interprétation, sont le degré de chaleur atteint par le sol sous divers feux et le degré de rougeoiement préservé dans la statigraphie finale. Cette étude explore ces questions en examinant les études précédentes et à la lueur d'une série d'incendies expérimentaux mesurés. Nous en concluons que, bien qu'il y ait certaines variations, la température sous la plupart des incendies allumés en surface ne dépasse pas les 500°C et il est rare que le sol rougisse. Ces deux généralisations sont toutefois liées d'une manière complexe qui n'a pas été totalement clarifiée. Certains sédiments rougissent dramatiquement à des températures qu'on trouve couramment sous des feux expérimentaux et dans la littérature sur l'échauffement des sols, tandis que d'autres ne présentent aucun signe de rougoiement même à des températures nettement plus élevées. Il se pourrait que ces ‘anomalies’ soient liées soit au contenu de la matière organique, soit à des modifications chimiques qui affectent le processus de transformation de l'oxide de fer responsable de la coloration rouge du sol.

Obwohl Feuer ein fundamentaler Baustein der Interpretation ist, versteht man die Details seiner Auswirkung auf die archäologischen Substrate immer noch unzureichend. Mit einer interpretativen Perspektive betreffen die Kernfragen zum einen die Höhe der Hitze, die im Boden unter den verschiedenen Feuern produziert wird, zum anderen den Grad der Rötung, die sich in der Stratigraphie zeigt. Der Artikel untersucht diese Fragen durch eine Analyse früherer Studien und durch eine Reihe instrumentalisierter, experimentieller Feuer. Wir fassen zusammen, daß obwohl es einige Variationen gibt, Temperaturen unter den meisten oberflächlichen Feuern unter 500° C bleibt, und die Rötung des Bodens nur selten eintritt. Diese zwei Verallgemeinerungen sind jedoch in einer komplexen Weise miteinander verbunden, die noch nicht vollkommen geklärt ist. Einige Sedimente röten sich sehr stark bei einer Temperatur, die normalerweise unter experimentiellen Feuern und in der Literatur zu Bodenerhitzung zu finden ist, während andere sogar bei bedeutend höheren Temperaturen nicht röten. Diese „Anomalitäten‟ könnten entweder von organischem Inhalt der Materie oder von chemikalischen Variationen herrühren, die den Fortschritt der Eisenoxidierung beeinflussen, die schließlich zur Bodenrötung führt.

Aunque el fuego es un bloque de construcción fundamental en la interpretación, se conocen aún muy pobremente los detalles de su efecto en los substratos arqueológicos. Las preguntas clave desde el punto de vista interpretativo, son el nivel de calor producido en el suelo bajo distintos tipos de fuegos y el grado de enrojecimiento preservado en la estratigrafía final. Este trabajo explora estas preguntas a través del examen de estudios previos y a través de una serie de fuegos experimentales controlados. Concluimos que, aunque hay algo de variación, las temperaturas bajo la mayoría de los fuegos prendidos en la superficie se mantiene bajo los 500°C y que el enrojecimiento del suelo ocurre sólo raramente. Estas dos generalizaciones están, sin embargo, complejamente unidas de modo que no ha sido del todo clarificado. Algunos sedimentos enrojecen dramaticamente a las temperaturas normalmente alcanzadas bajo fuegos experimentales y en la literatura sobre calentamiento de suelos, mientras que otros no enrojecen siquiera a temperaturas significativamente superiores. Estas “anomalias” pueden estar relacionadas bien con el contenido de materia orgánica o con variaciones químicas que afectan el proceso de transformación del óxido de hierro que conduce al enrojecimiento de los suelos.

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Barbetti, M., Taborin, Y., Schmider, B. & Flude, K. 1980. Archaeomagnetic results from late Pleistocene hearths at Etiolles and Marsannay, France. Archaeometry 22, 2546
Beadle, N.C.W. 1940. Soil temperatures during forest fires and their effect in the survival of vegetation. Journal of Ecology 28, 180–92
Bellomo, R.V. 1990. Methods for Documenting Unequivocal Evidence for Humanly-controlled Fire at early Pleistocene Archaeological Sites in East Africa: the Role of Actualistic Studies. PhD thesis. University of Wisconsin-Milwaukee.
Bellomo, R.V. 1993. A methodological approach for identifying archaeological evidence of fire resulting from human activity. Journal of Archaeological Science 5, 525–53
Bellomo, R.V. & Harris, J.W.K. 1990. Preliminary reports of actualistic studies of fire within Virunga National Park, Zaire: towards an understanding of archaeological occurrences. In Boaz, N.T. (ed.), Evolution of Environments and Hominidae in the African Western Rift Valley, 317–38. Martinsville, VA: Virginia Museum of Natural History, Memoir 1
Bennett, J.L. 1999. Thermal alteration of burned bone. Journal of Archaeological Science 26, 18
Bentley, J.R. & Fenner, R.L. 1958. Soil temperatures during burning related to postfire seedbeds on woodland range. Journal of Forestry 56, 737–44
Bradstock, R.A. & Auld, T.D. 1995. Soil temperatures during experimental bushfires in relation to fire intensity: consequence for legume germination and fire management in south-eastern Australia. Journal of Applied Ecology 32, 7684
Brain, C.K. & Sillen, A. 1988. Evidence from the Swartkrans cave for the earliest use of fire. Nature 336, 464–6
Campbell, G.S., Jungbauer, J.D., Bidlake, W.R. & Hungerford, R.D. 1994. Predicting the effect of temperature on soil thermal conductivity. Soil Science 158, 307–13
Campbell, G.S., Jungbauer, J.D., Bristow, K.L. & Hungerford, R.D. 1995. Soil temperature and water content beneath a surface fire. Soil Science 159, 363–74
Clark, J.D. & Harris, J.W.K. 1985. Fire and its roles in early hominid lifeways. African Archaeological Review 3, 327
Cornell, R.M. & Schwertmann, U. 1996. The Iron Oxides. Weinheim: VCH
Cromer, R.N. & Vines, R.G. 1966. Soil temperatures under a burning windrow. Australian Forest Research 2, 29
Debano, L.F., Dunn, P.H. & Conrad, C.E. 1977. Fire's Effect on Physical and Chemical Properties of Chaparral Soils. United States Department of Agriculture Forest Service General Technical Report WO-3, 6574
DeBano, L.F. 1991. The Effect of Fire on Soil Properties. United States Department of Agriculture Forest Service General Technical Report INT-280, 151–6
Eisely, L.C. 1954. Man the fire maker. Scientific American 191, 52–7
Fitzpatrick, R.W. 1988. Iron compounds as indicators of pedogenetic process; examples from the southern hemisphere. In Stucki, J.W.Goodman, B.A &, U. Schwertmann (eds), Iron in Soils and Clay Minerals, 351–96. Dordrecht: Reidel; Nato ASI Series 217
Floyd, A.G. 1966. Effect of fire upon weed seeds in the wet sclerophyll forests of northern N.S.W. Australian Journal of Botany 14, 243
Frandsen, W.H. & Ryan, K.C. 1986. Soil moisture reduces belowground heat flux and soil temperatures under a burning fuel pile. Canadian Journal of Forest Research 16, 244–8
Gowlett, J.A.J., Harris, J.W.K., Walton, D. & Wood, B.A. 1981. Early archaeological sites, hominid remains and traces of fire from Chesowanja, Kenya. Nature 294, 125–9
Heyward, F. 1938. Soil temperatures during forest fires in the longleaf pine region. Journal of Forestry 36, 478–91
Humphreys, F.R. & Craig, F.H. 1981. Effects of fire on soil chemical, structural and hydrological properties. In Gill, A.M.Groves, R.H. & Noble, I.R. (eds), Fire and the Australian Biota, 177200. Canberra: Australian Academy of Science
Humphreys, F.R. & Lambert, M.J. 1965. Soil temperature profiles under slash and log fires of various intensities. Australian Forest Research 1, 23–9
James, S.R. 1989. Hominid use of fire in the Lower and Middle Pleistocene: a review of the evidence. Current Anthropology 30, 126
Loon, A.P. van 1969. Investigations into the effects of prescribed burning on young even-aged blackbutt. Forestry Commission New South Wales Research Note 23, 649
Marel, H.W. van der. 1951. Gamma ferric oxide in sediments. Journal of Sedimentary Petrology 21, 1221
Marshall, A. 1998. Visualising burnt areas: patterns of magnetic susceptibility at Guiting Power 1 round barrow (Glos., UK). Archaeological Prospection 5, 59177
McKinley, J. 1997. Bronze Age ‘barrows’ and funerary rites and rituals of cremation. Proceedings of the Prehistoric Society 63, 129–45
Mellars, P. 1976. Fire ecology, animal populations and man: a study of some ecological relationships in prehistory. Proceedings of the Prehistoric Society 42, 1545
Miller, R.B., Stout, J.D. & Lee, K.E. 1955. Biological and chemical changes following scrub burning on a New Zealand hill soil. New Zealand Journal of Science and Technology 37, 290313
Norton, B.E. & McGarity, J.W. 1966. The effect of burning of native pasture on soil temperature in northern New South Wales. Journal of the British Grassland Society 20, 101–5
Oakley, K.P. 1955. Fire as a Palaeolithic tool and weapon. Proceedings of the Prehistoric Society 21, 3648
Roberts, W.B. 1965. Soil temperatures under a pile of burning logs. Australian Forest Research 1, 21–5
Schwertmann, U. & Fechter, H. 1984. The influence of aluminium on iron oxides XI. Aluminium-substituted maghemite in soils and its formation. Soil Science Society of America Journal 48, 1462–3
Schwertmann, U. 1993. Relations between iron oxides, soil colour and soil formation. In Bigham, J.M. & Ciolcosz, E.J. (eds), Soil Colour, 5169. Madison: Soil Science Society of America Special Publication 31
Scotter, D.R. 1970. Soil temperatures under grass fires, Australian Journal of Soil Research, 8, 273–9
Simmons, I.G., Dimbleby, G.W & Grigson, C. 1981. The Mesolithic. In Simmons, I.G. & Tooley, M.J. (eds), The environment in British Prehistory, 82124. London: Duckworth
Tothill, J.C. & Shaw, N.H. 1968. Temperatures under fires in bunch spear grass pastures in south-east Queensland. Journal Australian Institute of Agricultural Science 34, 94–7
Uggla, E. 1957. Soil and air temperature during burning of clear-felled areas and the effect of fire on vegetation and humus. Norrlands Skogsvdrdsforbunds Tidskrift 4, 443500
Ulery, A.L. & Graham, R.C. 1993. Forest fire effects on soil colour and texture. Soil Science Society of America Journal 57, 135–40
Vines, R.G. 1968. Heat transfer through bark and the resistance of trees to fire. Australian Journal of Botany 16, 499514
Weiner, S., Xu, Q., Goldberg, P., Liu, J. & Bar-Yosef, O. 1998. Evidence for the use of fire at Zhoukoudian, China. Science 281, 251–3
Wells, C.G., Campbell, R.E., DeBano, L.F., Lewis, C.E., Fredriksen, R.L., Franklin, E.C., Froelich, R.C. & Dunn, P.H. 1979. The effects of fire on soil; a state-of-knowledge review. National fire effects workshop, Denver, Colorado, April 10–14, 1978. United States Forest Service General Technical Report WO-7
Wendorf, M. 1982. The fire areas of Santa Rosa Island: an interpretation. North American Archaeologist 3, 173–80
Whittaker, E. 1961. Temperatures in heath fires. Journal of Ecology 49, 709–15
Wright, H.A. & Bailey, A.W. 1982. Temperature and heat effects. In Wright, H.A. & Bailey, A.W., Fire and Ecology: United States and Southern Canada, 823. New York: J. Wiley & Sons

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