Aspectos neotectônicos e ecologia da paisagem em parte da área dos municípios do NE do estado do Pará (Tucurui, Baião, Breu Branco, Goianésia, Moju e Tailândia)

Abstract

This work inside investigated the aspects of the landscape and geologic and geomorphological evidences of the neotectonic context in the region that understands the Tucurui Cities until Thailand (Pará). In this region the incidence of neotectonics processes was responsible for the generation of structures, sedimentary sequences, standards of draining net (Basin of the Tocantins River) and relief System. For execution of this study had been used Landsat ETM+ images for the digital processing in platform ENVI 4,0, digital Models of rise supplied by the SRTM/NASA and images of radar SAR analysis of the relief, draining and recognition of the lineaments expressives, analogical bases elaboration of cartographic bases in environment ArcGIS 9.1. The Analysis of the relief, in the investigated area, allowed to identify as genetic groups: ) Group of Degradation - Constituted of System of Mountain ranges (Mountain range of the Trucará) with flattened topos of amplitude varying between 253 and 290 meters, System of Mounts with angular topos up to 180 meters and Colinoso System with 0 amplitude varying it enters m (base level) up to 120 meters, which constitute most of the paisagística expression; b) Group of Agradação - Englobando Aluvial Plain Systems and System of Fluvial Terraces. These systems are shown with geometrias whose joints if give through the installation of discontinuities, characterizing morfoestrutural compartimentação. The integration of the data, deriving of the analysis of the relief, as well as the characterization of the anomalies of draining and the discontinuities, allowed to the recognition of "landorfms" elementary schools tectonics associates the beams of guided lineaments the E-W, NW-SE, NE-SW and N-S. The joint enters beams of neotectonics imperfections gives way to define one extensional romboedro to south of the parallel 3030"S. The romboedral structure is defined by the arrangement between beams of guided discontinuities to NW-SE, with symmetrical trend and apparent transtensive nature and guided beams of discontinuities the E-W, to the center of the area, with probable dominant component "strike-slip". This geometry is cut by to complicate structures guided to NE-SW. Three main beams of guided discontinuities the N-S affect the inquiry area, and represent "landforms" elementary schools tectonics with extensional trend. These structures had been interpreted as decurrent of the reactivation of the Cinturão Araguaia. They are organized in an anti-symmetrical structure with dominant diving for East and in the height of the meridian 49038W they seem to have strong bond with the tracing of the Tocantins River and imposes fort has controlled to the quaternary deposits. The draining net adjusts it to these standards of structural tropia readily, which answer for the presence of anomalous feições as arcs and elbows, and for the installation of standards in treliça, with strong asymmetry, some partially interpreted as treliça of imperfection. Morfogênese of the area in appraise, in that it concerns to its tectônics aspects was admitted as tied to the performance of a binary guided dextral the E-W, fruit of the dynamics established for the current phase of drift of the American South Plate for West.