Caracterização paleoambiental a partir dos componentes orgânicos particulados em depósitos bioturbados do Bloco Central da Jazida Carbonífera do Iruí (Cachoeira do Sul, RS)

Abstract

The integrated analysis of sedimentology and paleoichnology of the Rio Bonito Formation and the lower part of Palermo Formation (Paraná Basin) in Cachoeira do Sul

region (Rio Grande do Sul State, south Brazil) revealed that the Rio Bonito Formation are characterized at the base by tide-dominated fluvio-estuarine deposits, changing upward to

wave-dominated estuarine deposits, which are overlapped by the shallow marine deposits of the Palermo Formation. With the aim of refine such interpretations, a high-resolution

paleopalynologic analysis of the bioturbed deposits is conducted in this study. Thus, 26 samples were selected from the cores IC-07-RS, IC-44-RS, IC-03-RS and IC-12-RS, from the central area of the Iruí Quarry (Cachoeira do Sul). Only mudstones and siltstones samples were used for the paleopalynologic analysis, in order to homogenize possible disparities in the organic assemblage due to the grain-size. Paleopalynomorph and palynofacies samples were prepared following the traditional methods for Pa