Sérgio Bergamaschi

SILURIAN AND LOWER DEVONIAN CHITINOZOAN BIOSTRATIGRAPHY OF THE PARANÁ BASIN IN BRAZIL AND PARAGUAY

Abstract The taxonomy and distribution of Chitinozoa from Silurian (Llandovery) and Lower Devonian strata are reported from the Parana Basin in southern Brazil and eastern Paraguay. The pre‐Carboniferous sequences of the Parana Basin in this area are present in three sub‐basins viz., the Alto Garcas (north) and Apucarana (south) sub‐basins in Brazil, and the “East Paraguay Sub‐basin”; in east Paraguay. There is more similarity in the lithology between the Alto Garcas and “East Paraguay”; sub‐basins, than between the former and the Apucarana sub‐basin. Llandoverian and Lochkovian to Pragian beds are present in all sub‐basins. So far, no Emsian beds have been found in outcrops from the north‐northwest margin of the Alto Garcas Sub‐basin, and no early Emsian beds in the outcrops on the northeast margin. Furthermore, Emsian beds could not be identified from the “East Paraguay Sub‐basin”; in the present study. The Early Devonian sequence is more complete in the Apucarana Sub‐basin. It seems that the Apucarana ...

An Early Devonian flora, including Cooksonia from the Paraná Basin (Brazil)

We report here the presence of an extensive flora from an early Lochkovian (Lower Devonian: ∼406 million years) locality in the Parana Basin (Brazil). The exceptional macrofossil assemblage includes several hundred specimens of a new Cooksonia species, and representatives of 10 other taxa, 5 of which at least are new. This plant assemblage illustrates the amplitude of the Siluro-Devonian land plant primary radiation. During the Lochkovian, the Parana Basin was positioned in southern Gondwana, within the southern polar circle. The occurrence of this rich plant assemblage substantiates the hypotheses of a Warm Mode and of an ice-free southern pole during the earliest Devonian. Some taxa exhibit characters interpreted as potentially related to cold hardiness: embedding of the sporangium within the axis, abundance of emergences, dense branching, and protection of the apical meristem.

MIDDLE AND UPPER DEVONIAN CHITINOZOAN BIOSTRATIGRAPHY OF THE PARANÁ BASIN IN BRAZIL AND PARAGUAY

Abstract Chitinozoans from Middle and Upper Devonian strata have been investigated from the Parana Basin in southern Brazil and eastern Paraguay. These sequences are present in the Alto Garcas (north) and Apucarana (south) sub‐basins in Brazil, and the “East Paraguay Sub‐basin”; in eastern Paraguay. Marine communication between the sub‐basins was established during the early Givetian. Of the 49 chitinozoan species encountered, 28 species are retained in open nomenclature, and Ancyrochitina simplex is newly described. A chitinozoan biozonation, with five zones, is proposed for the investigated interval. The zones are from oldest to youngest: concurrent range zone of Alpenachitina eisenacki and Spinachitina biconstricta (late Eifelian?‐early Givetian); the interval range zone of Ancyrochitina taouratinensis (latest early‐middle Givetian); concurrent range zone of Fungochitina pilosa and Ancyrochitina langei (late Givetian); concurrent range zone of Hoegisphaera glabra and Ramochitina derbyi (early Frasnian)...

Biochemical Composition and Foraminiferal Content of Sediments for Determining Bottom Sector Environments in Guanabara Bay (Rio de Janeiro, Brazil)

ABSTRACT Clemente, I.M.M.M.; da Silva, F.S.; Laut, L.L.M.; Frontalini, F.; da Costa, V.L.; da Conceição Rodrigues, M.A.; Pereira, E.; Bergamaschi, S.; Filho, J.G.M., and Martins, M.V.A., 2015. Biochemical composition and foraminiferal content of sediments for determining bottom sector environments in Guanabara Bay (Rio de Janeiro, Brazil). Three cities in Brazil—Rio de Janeiro, Niterói, and São Gonçalo—with an estimated total population of 11 million people, are located in the surroundings of Guanabara Bay (RJ-Brazil), making it a highly contaminated coastal system. Because of its importance, Guanabara Bay has been one of the most studied coastal environments in Brazil. Despite that, this study represents the first investigation, to our knowledge, to couple benthic foraminifera with the quantity and quality of organic matter in the area. The spatial distribution of water salinity and the surface sediment reduction potential, grain size, total organic carbon, sulfur, bacterial organic carbon, biopolymers such as carbohydrates, proteins, lipids, bacterial enzyme esterase, and total foraminiferal assemblages were studied at 30 stations in Guanabara Bay. Based on these data, six bottom environments—industrial, marginal urban, marginal urban/industrial mixing, eutrophic, transitional, and outer— were identified and described.

REGIONAL OUTCROPS WITH DIDACTIC INTEREST AND SEDIMENTARY FACIES ASSOCIATION OF THE ITARARÉ GROUP AT SÃO PAULO (BRAZIL)

The main objective of this work is to locate and identify the outcrops considered iconic and valuable as references, not only from the point of view of Cultural or Didactic Tourism, but also in paleoenvironmental reconstruction studies, based on the lithologies that comprise the Itarare Group, in the State of Sao Paulo, Brazil. This work also intends to relate these sites to outcrops of sedimentary facies, in an area located at south of Itu and Porto Feliz, and north of Sorocaba. The Itarare Group lies within the Parana Basin (Paleozoic), and is composed by sedimentary sequences associated with the record of the Permo-Carboniferous glaciation event that occurred in the Gondwana supercontinent. This work is based on observations of outcrops in a macro- and mesoscopic scale, considering the characterization of external and internal aspects of the layer, the stratigraphic sequence in the outcrop, and the continuity of the layers within the mapped area. The study area has outcrops where the evidences of glaciomarine deposits predominate. Sedimentary sequences deposited in a subaquatic low-energy environment, as well as episodic deposits, in which relatively more energetic phases alternated with low hydrodynamic conditions are well-developed in the study area. There are also fluvio-deltaic environmental occurrences related to sea level oscillations linked with glacier advances and receding. doi: 10.12957/jse.2016.21964