Minerais pesados do furo de Sondagem FD – 1124, polo Vera Cruz, Paragominas

Abstract

The study of heavy minerals Hole Survey FD-1124, Polo Vera Cruz, Paragominas revealed a supermatura mineralogy, represented predominantly by zircon and tourmaline and subordinate, rutile, kyanite, staurolite, anatase and topaz. The meeting identified heavy mineral does not vary significantly towards the top of the profile, but the frequency in which they occur varies along the profile. This work demonstrated by petrographic analysis, ZTR indices and percentage zircon frequency, the borehole analyzed contains at least three stratigraphic units: I, II and III. Unit I, which occurs at the hole bottom, displays bedrock characteristics at the base harrowing for saprolite soil on top, which are represented by sandstones, shales and massive pink kaolinitic variegated mudstone. The top of this unit is marked by the percentage contents of ZTR and zircon remain relatively constant, causing a break in the top coinciding typological change of saprolite horizon (HS) for Bauxite Amorphous / Crystallized (BAC). Unit II, characterized by BAC and LF horizons, is marked by high ZTR values are close to 100%, the gibbsita the main mineral. Unit III is marked by relative increase ZTR rates and Zircon percentage toward the top, followed by decrease towards the base of the unit. The increase and decrease these ZTR and Zircon values, mark the abrupt passage of Bauxite Nodular (BN) and Capstone Argillaceous (CAP). Through the data obtained in this study we can suggest stratigraphic correlation with Ipixuna formations to the drive unit I. II was interpreted as a stratigraphic period in which no deposition, or the pellets were exposed to intense processes bauxitization occurred in that region, known in the texts of Koschoubey et al. (2005) as Lower Bauxite. The unit III is interpreted as widely known as sediment Belterra Clay.