The region of Caxiuanã land is located in the municipalities and Melgaço Portel (Pará State) in the Eastern Amazon, between the island and Marajó the Xingu River. In order to investigate the relationships and similarities between the soils of Dark Earth Archaeological (TPA), Yellow Oxisols (LA) and bottom sediments of the Bay of Caxiuanã (SFBC), we used the morphological and mineralogical study of the mineral heavy. The results are presented and discussed as the object of this monograph. After separation and counting of heavy minerals was found that both the soil of TPA as the LA showed the same heavy minerals: zircon, kyanite, tourmaline, andalusite, staurolite, hornblende, rutile, and anatase and titanite. The opaque minerals identified with the help of SEM were: ilmenite and hematite. Differences occur in terms of percentage on which, in turn, result only from factors related to processes dissolved after the formation of the soil and not the source. Sediments of bottom of the Bay of Caxiuanã preented the following minerals: kyanite, epidote, tourmaline, zircon, andalusite, staurolite, and titanite rutile, monazite, but also in less extension, muscovite, sillimanite and hornblende. Under the SEM were identified the main opaque minerals: hematite and ilmenite. Soils and bottom sediments display the same mineral assemblage, being epidote found only in the bottom sediments. Possibly is epidote an unstable mineral against the soil formation. These mineral assemblages suggest that the primary sources of the bottom sediments of the Caxiuanã bay were mainly of metamorphosed pelitic rocks, and secondarily acid to intermediate igneous rocks, which constitute the Amazon Craton, and not alone the Caxiuanã surroundings soils
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