An assessment of the cultural practices behind the formation (or Not) of amazonian dark earths in marajo island archaeological sites

Abstract

For many decades, archaeologists working in Amazonia have looked for terra preta (black soil) areas in their search for ancient settlements. The typical Amazonian archaeological site is comprised of a combination of black soil, ceramic sherds and some distinct vegetation species, which William Balée calls cultural forests (Balée 1989). Sites are usually located in elevated terrains or riverine bluffs, pro tected from the annual floods when along the major rivers floodplains. Archaeologists also know that there is some correlation between soil color and density of ceramic sherds, both being a sensor for ancient demography patterns. Ever since Sombroek (1966) and Smith and Nigel (1980) reported the existence of the anthropogenic terra preta soils, and especially after several research projects carried out by soil scientists and archaeologists during the last 20 years, research on ADE (Amazonian Dark Earth) sites has drawn much scientific interest. Analysis of ADE samples have demonstrated that such soils present higher levels of chemi cal nutrients such as C (carbon), P (phosphorus), Ca (calcium), Mg (magnesium), Zn (zinc) and Mn (manganese) when compared to original, background soils, besides presenting superior pH, as well as higher amounts of organic material, which make them particularly fertile (Kern and Kampf 1989; Kern et al. 1999; McCann et al. 2000). Such elements were possibly added to the soils during degra dation of organic debris related to human occupation and discarding activities (Eidt 1985; Kern, et al. 1999; Woods and McCann 1999; McCann et al. 2000). © Springer Science + Business Media B.V. 2009.