Estudo dos sedimentos encontrados no interior de vasilhas de cerâmica do sítio ilha de Terra em Caxiuanã-PA

Abstract

In the Caxiuanã region 27 archaeological sites have so far been registered in IPHAN, which are located mainly on the shores of the Caxiuanã bay, rivers and streams. The sites are generally of the habitation type, and so far only one of the cemetery/habitation type has been found (site PA-GU-14:ilha de Terra). This site is located on the right bank of the Camuim borehole and is occupied by a community whose main activity is timber extraction, with permanent circulation of heavy vehicles (tractor and truck). For this reason, the Ilha de Terra site was the target of an archaeological rescue in late 1999, where pottery vessels were recovered. The present work aims to determine the mineralogy and the Ca, Mg, Zn, Mn and P content of the sediments inside these vessels, to compare them with each other and with the soils of the site and its adjacent area. To this end, a 50g aliquot of sediment was pulverized and passed through a 2 mm sieve. The samples were analyzed: Ca O, Mg O, P205, Mn and Zn (total aperture HF+HCIP04), determined by atomic absorption and colorimetry. The mineralogy was determined by X-ray diffraction. The results show that quartz and kaolinite are the predominant minerals in both the sediments inside the vessels and in the soil. As for the chemical elements, there was a great variation in the Ca, Mg and P contents from one vessel to another, and in all of them the contents are significantly higher than in the Terra Preta Arqueológica soil that composes this site. The Zn and Mn contents did not show variations among the vessels, being lower than the levels found in the Terra Preta Arqueológica soil from the site and equivalent to the soil from the adjacent area. The highest concentrations were found in the sediment of vessel S7, with Ca, 3800 mg/Kg, Mg, 2800 mg/Kg, and P205, 7700 mg/dm3. Among the elements studied, the lowest content was found in the sediment of vessel S2, with 300 mg/Kg for Ca and 1100 mg/kg for Mg. The lowest P205 content was detected in the sediment of vessel S3 (2700mg/dm3). The variation in the content of chemical elements from one container to another may suggest different ways of using them by prehistoric man. Thus, the vessels with high levels of Ca, Mg and P could have been used for In the Caxiuanã region 27 archaeological sites have so far been registered in IPHAN, which are located mainly on the shores of the Caxiuanã bay, rivers and streams. The sites are generally of the habitation type, and so far only one of the cemetery/habitation type has been found (site PA-GU-14:ilha de Terra). This site is located on the right bank of the Camuim borehole and is occupied by a community whose main activity is timber extraction, with permanent circulation of heavy vehicles (tractor and truck). For this reason, the Ilha de Terra site was the target of an archaeological rescue in late 1999, where pottery vessels were recovered. The present work aims to determine the mineralogy and the Ca, Mg, Zn, Mn and P content of the sediments inside these vessels, to compare them with each other and with the soils of the site and its adjacent area. To this end, a 50g aliquot of sediment was pulverized and passed through a 2 mm sieve. The samples were analyzed: Ca O, Mg O, P205, Mn and Zn (total aperture HF+HCIP04), determined by atomic absorption and colorimetry. The mineralogy was determined by X-ray diffraction. The results show that quartz and kaolinite are the predominant minerals in both the sediments inside the vessels and in the soil. As for the chemical elements, there was a great variation in the Ca, Mg and P contents from one vessel to another, and in all of them the contents are significantly higher than in the Terra Preta Arqueológica soil that composes this site. The Zn and Mn contents did not show variations among the vessels, being lower than the levels found in the Terra Preta Arqueológica soil from the site and equivalent to the soil from the adjacent area. The highest concentrations were found in the sediment of vessel S7, with Ca, 3800 mg/Kg, Mg, 2800 mg/Kg, and P205, 7700 mg/dm3. Among the elements studied, the lowest content was found in the sediment of vessel S2, with 300 mg/Kg for Ca and 1100 mg/kg for Mg. The lowest P205 content was detected in the sediment of vessel S3 (2700mg/dm3). The variation in the content of chemical elements from one container to another may suggest different ways of using them by prehistoric man. Thus, the vessels with high levels of Ca, Mg and P could have been used for burial, while others, with levels of these elements equivalent to the levels found in the soils, could have been used as an offering deposit for the dead.