Geoarqueologia dos sítios pontão e Santa Helena na região de Silves-AM

Abstract

This article provide a Geoarchaeological contribution for the study of the settlement of the Pontão (AM-SL-06) and Santa Helena (AM-SL-07) archeological sites located in the Lower Urubu River, in the township of Silves, Amazonas. The objective is analyze the deposition system of the archaeological vestiges and characterizing the black earth of indian and ceramic artifacts related to these sites. The methodology process adopted is based on a morphological, mineralogical and chemical analysis of soil samples, sediments and ceramic traces. The soils of the region are classified as immature profiles, formed on Alter do Chao formation, the mineralogy is represented by quartz, kaolinite, hematite, gibbsite and goethite, the sediments come from alluvial deposits that constitute a clay-sandy material, mineralogically composed by 2: 1 clay, quartz and iron oxides. The black soil can reach 40 to 220 cm depth, with a sandy granulometry for Pontão site and a sandy-clay for Santa Helena site, consisting of quartz and kaolinite and high proportions of Ti, Zr, Ag and Mn. Ceramics artifacts are commonly associated as pre colonial period: Incisal Edge Tradition an the Saracá regional Tradition, being mineralogically constituted by quartz, kaolinite, smithite, illite, gibbsite, hematite, feldspar, phosphates, and presents additional seasonings to the blend of cauixi, cariape and ceramics shards, which are distinguished only by the proportion of this constituents for each of the studied sites. Based on the analyzes of ceramic data is possible to infer two places as being the material provider: the first, associated to the immature profiles is formed on the cretaceous deposits and the second, associated to the sediments is coming from the alluvial deposits present in the lakes of the region, which currently provides primary resources for the manufacture of tiles and bricks. For questioning about the origin of the resource areas and manufacturing of the artifacts from the studied sites, we can correlate that the ceramics were produced locally with the raw material available in the region.