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Phosphate Fractionation of Soils at Agroal, Portugal

Published online by Cambridge University Press:  20 January 2017

Katina T. Lillios*
Affiliation:
Department of Anthropology, Brandeis University, Waltham, MA 02254

Abstract

Eidt (1973, 1977, 1984a) suggested that the analysis of soil phosphate fractions (I-III) could be used to identify land-use areas on archaeological sites as well as serve as a relative-dating technique. He noted that the total inorganic phosphate value (I + II + III) reflects the type and intensity of land-use practice, and he hypothesized that the ratio of Fraction II/I correlates with the time elapsed since soil enrichment. A test of these propositions was carried out in conjunction with the excavations at the settlement of Agroal (Portugal), which was occupied during the Bronze Age (2000-1000 B.C.) and Middle Ages (A.D. 1300-1640). Samples were taken from all archaeological levels of the site as well from soils with known land-use histories in the area of Agroal. Results of this study support Eidt"s two principal hypotheses. First, there was a strong correspondence in the control soils between total phosphate values and the nature of land-use activities. Second, the ratio of Fraction II/I in the archaeological samples did, in fact, correlate with the relative age of the associated artifacts. A model of the site"s land-use history, based on the total inorganic phosphate and the Fraction II/I values, suggests a significant alteration and degradation of the soil landscape during the Bronze Age, as a consequence of agriculture, herding, and refuse disposal, followed by less-intensive use during the Middle Ages.

Resumen

Resumen

Eidt (1973, 1977, 1984a) ha sugerido que el análisis de las fracciones de fosfato en el suelo (I-III) podría ser utilizado como técnica para identificar áreas de uso en sitios arqueológicos y también como técnica de datación relativa. Este autor observó que el valor total de fosfatos inorgánicos (I + II + III) refleja el tipo e intensidad de uso de la tierra y propuso, a título hipotético, que la proportión Fractión II/I se encuentra correlacionada con el tiempo transcurrido desde el enriquecimiento del suelo. Se llevó a cabo una prueba de estas proposiciones durante las excavaciones en el sitio de Agroal (Portugal), un asentamiento que fue ocupado durante la Edad de Bronce (2000-1000 A.C.) y la Edad Media (1300-1640 D.C.). Se tomaron muestras de todos los niveles arqueológicos del sitio, así como de suelos en el área de Agroal, donde la historia de uso de la tierra es conocida. Los resultados de este estudio apoyan las dos hipótesis principales de Eidt. Primero, se observó una estrecha correspondencia en los suelos de control entre los valores globales de fosfato y la naturaleza de las actividades de uso de la tierra. Segundo, la proporción Fracción II/I en las muestras arqueológicas está correlacionada con la edad relativa de los artefactos asociados. Un modelo de la historia de uso de la tierra en el sitio basado en el contenido de fosfato inorgánico y en los valores de la proporción Fracción II/I indica una significativa alteratión y degradatión del suelo durante la Edad de Bronce, como consecuencia de la agricultura, el pastoreo y la deposición de residuos, y un uso menos intensivo durante la Edad Media.

Type
Reports
Copyright
Copyright © Society for American Archaeology 1992 

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References

Reference Cited

Bethell, P., and Mate, I. 1989 The Use of Soil Phosphate Analysis in Archaeology: A Critique. In Scientific Analysis in Archaeology and Its Interpretation, edited by Henderson, J., pp. 1-29. Monograph No. 19. Oxford University Committee for Archaeology, Oxford. Archaeological Research Tools No. 5. Institute of Archaeology, University of California, Los Angeles.Google Scholar
Camara Municipal de Tomar 1968 Anais do municipio de Tomar, vol. IV (1581-1700). Tomar, Portugal.Google Scholar
Cavanagh, W. G., Hirst, S., and Litton, C. D. 1988 Soil Phosphate, Site Boundaries, and Change Point Analysis. Journal of Field Archaeology 15: 67-83.Google Scholar
Comissao Nacional do Ambiente 1978 Carta dos solos. Scale 1: 1, 000, 000. Lisbon.Google Scholar
Comissao Nacional do Ambiente 1982 Carta litoldgica. Scale 1: 1, 000, 000. Lisbon.Google Scholar
Cornwall, I. W. 1958 Soils for the Archaeologist. Phoenix House, London.Google Scholar
Cruz, A. R., and Oosterbeek, L. M. 1985 A Gruta do Cadaval: Elementos para a pre-historia do vale do Nabao. Suplemento ao Boletim Cultural e Informativo da Camara Municipal de Tomar 1: 61-76. Tomar, PortugalGoogle Scholar
da Costa, Padre A. C. 1868-1869 Corografia portugueza e descripcam topografica dofamoso reyno de Portugal. 3 vols. Gouvea, Braga, Portugal.Google Scholar
Eidt, R. C. 1973 A Rapid Chemical Test for Archaeological Site Surveying. American Antiquity 38: 206-210.Google Scholar
Eidt, R. C. 1977 Detection and Examination of Anthrosols by Phosphate Analysis. Science 197: 1327-1333.Google Scholar
Eidt, R. C. 1984a Advances in Abandoned Settlement Analysis: Application to Prehistoric Anthrosols in Colombia, South America. Center for Latin America, University of Wisconsin-Milwaukee. Milwaukee.Google Scholar
Eidt, R. C. 1984b Theoretical and Practical Considerations in the Analysis of Anthrosols. In Archaeological Geology, edited by Rapp, G., Jr., Gilford, G., and Gilford, J. A., pp. 155-190. Yale University Press, New Haven.Google Scholar
Eidt, R. C, and Woods, W. 1974 Abandoned Settlement Analysis: Theory and Practice. Field Test Associates, Sherwood, Wisconsin.Google Scholar
Lillios, K. T. 1989a Preliminary Results from the 1988 Excavation at Agroal. Old World Archaeology Newsletter 13(1): 13-20.Google Scholar
Lillios, K. T. 1989b Results from the Second Season of Excavations at Agroal. Old World Archaeology Newsletter 13(3): 20-27.Google Scholar
Lillios, K. T. 1991 Competition to Fission: The Copper to Bronze Age Transition in the Lowlands of West Central Portugal (3000-1000 B. C.). Unpublished Ph. D. dissertation, Department of Anthropology, Yale University, New Haven.Google Scholar
Lines Escardo, A. 1970 The Climate of the Iberian Peninsula. In Climates of Northern and Western Europe, edited by Wallen, C. C., pp. 195-239. Elsevier, New York.Google Scholar
Lippi, R. D. 1988 Paleotopography and Phosphate Analysis of a Buried Jungle Site in Ecuador. Journal of Field Archaeology 15: 85-97.Google Scholar
Oosterbeek, L. M. 1987 “Gruta do Cadaval” e “Gruta dos Ossos. ” Informacao Arqueologica 8: 79-81. Lisbon.Google Scholar
Parreira, R. 1971-1975 O povoado da Idade do Bronze do Outeiro do Circo (Beringel/Beja). Arquivo de Beja 28-32: 31-34. Beja, Portugal.Google Scholar
Steventon, R. L., and J. E., Kutzbach 1990 University of Wisconsin Radiocarbon Dates. Radiocarbon 32: 209-228.Google Scholar
Wilde, S. A., Corey, R. B., Iyer, J. G., and Voigt, G. K. 1979 Soil and Plant Analysis for Tree Culture. 5th rev. ed. Mohan Primlani, New Delhi.Google Scholar
Zilhao, J. 1987 A Gruta do Caldeirao (Pedreira, Tomar): Balanco de sete afios de escava§6es arqueologicas (1979—1985). Algar 1: 29-38. Lisbon.Google Scholar
Zilhao, J. 1988 Nouvelles datations absolues pour la prehistoire ancienne du Portugal. Bulletin de la Societe Prehistorique Francaise 85: 247-250.Google Scholar