In the Amazon there are soils called Terra Preta Arqueológica (TPA) or Terra Preta do Índio (Indian Black Earth), with dark colors, fragments of archeological materials (remains of pottery, lithic artifacts), resulting from the intense occupation of prehistoric man in these areas. These soils present high levels of Ca, Mg, Zn, Mn and C, as a consequence of the accumulation of unconsumed organic matter. The objective of this work is to verify whether the palm trees contributed to the increase of Zn, Mn, P and Ca contents in the TPA, since they were widely used by prehistoric man, either in the construction of their dwellings or in the making of straw baskets, besides serving as a source of subsistence. In the Amazon about 250 species have been identified, among these, 14 were collected in duplicate in the region of Caxiuanã-Pa. The first ones were packed and pressed between newspapers, and sent to the Botany Department (DBO/MPEG), to be classified. The results obtained from the specimens that were chemically analyzed showed P2O5 contents ranging from 0.41 to 7.11 % in the leaves. Considering that the P2O5 contents in the TPA soils of the Caxiuanã region reach average values around 0.137 %, then, we can suggest that the palm trees are also responsible for the high content in these soils.
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