Gênese de cobertura superficial em perfil representativo da superfície geomorfológica de Chapecó – Planalto das Araucárias

Abstract

The present research aims to recognize the genesis of the surface of the geomorphological surface VIII - Araucaria Plateau, environment subtropical humid climate. For achieve this objective, field and laboratory surveys were performed. In the field were identified the macromorphological properties, such as: color, structure, consistency and texture, as well as granulometric analysis and chemical - macronutrients, sulfuric attack, chemical analytical analysis of the ten main oxides by FRX, mineralogy by XRD, total iron content, free and amorphous. The cover studied located at the apex of gently convex hill presented 9.05 meters of extension being identified the horizons: Ap, Bw1, Bw2, BC, CB, C1, C2. The physical, macronutrient and sulfuric indicate that it is a Bruno Dystrophic Latosol that develops from allochthonous material. The values of free Fe, amorphous Fe and total Fe indicate coverage with advanced stage of weathering, representing characteristics of lateritic development. The Fed / Fet and (Fed - Feo) / Fet ratios corroborate for interpretation of whether they are allochthonous materials at the top of the hedge analyzed. The values of analytical chemistry indicate the geochemical more intense hydrolysis in depth. The presence of 2: 1 filosilicates - EHE and HEV, in amounts relatively greater than the minerals of the 1: 1 group and with higher crystallinity in the Bw2, BC and CB horizons indicates that this material was climatic regime with very marked periods of dryness, different from the current one. The materials analyzed along the coverage profile representative of the geomorphological surface of Chapecó indicate genesis allochthon for the solum sector and autochthonous for the alterite, confirming the performance of the sculpture processes related to Dynamic Etchplanation for the Araucárias Plateau.