Browsing by Author "Pereira, Z."
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- New palynostratigraphic data of the Irati (Assistencia Member) and the Corumbatai formations, Parana Basin, Brazil, and correlation with other south American basinsPublication . Rocha, H., V; Mendes, M.; Pereira, Z.; Rodrigues, C.; Manuel Carvalho Fernandes, Paulo; Lopes, Gilda; Sant'Anna, L. G.; Tassinari, C. C. G.; Lemos de Sousa, M. J.This research presents the palynostratigraphy of organic-rich shales from the Irati and the Corumbatai formations, Parana Basin (PB), Southeastern Brazil, as part of an unconventional hydrocarbon source rock and CO2 reservoir assessment study. Thirty-four samples from the Corumbatai Formation and the Assistencia Member of the Irati Formation were collected in the states of Goias (northern border of the PB), Sao Paulo and Parana (eastern and southern border of the PB, respectively). The acquired data allowed to establish a comprehensive palynostratigraphic study across the basin where a total of 18 pollen genera (34 pollen species), seven spore genera, four microplankton genera (1 species), and Chlorophyceae algae species where identified. The palynostratigraphic analysis also reveals a clear dominance of bisaccate pollen grains such as Corisaccites alutas, Lueckisporites virkkiae, and Weylandites lucifer. The Lueckisporites virkkiae zone was identified in the upper part of the Irati Formation (Assistencia Member) and the lowermost part of the Corumbatai Formation, indicating a Kungurian to Roadian age for this part of the succession. Differences in the Guttulapollenites hannonicus and Tornopollenites toreutos biostratigraphic ranges, recovered in the Corumbatai Formation, suggest an earlier development of these species in the Parana Basin during the middle Permian. Therefore, to evaluate the differences in the first occurrences of key species within the Parana Basin, a close palynostratigraphic correlation between the main Guadalupian-Lopingian South American Gondwana basins is tentatively established.
- New palynostratigraphic data of the irati (Assistência Member) and the corumbataí formations, Paraná Basin, Brazil, and correlation with other south American basinsPublication . Rocha, H. V.; Mendes, M.; Pereira, Z.; Rodrigues, C.; Fernandes, Paulo; Lopes, Gilda; Sant’Anna, L. G.; Tassinari, C.C.G.; Lemos de Sousa, M.J.This research presents the palynostratigraphy of organic-rich shales from the Irati and the Corumbataí formations, Paraná Basin (PB), Southeastern Brazil, as part of an unconventional hydrocarbon source rock and CO2 reservoir assessment study. Thirty-four samples from the Corumbataí Formation and the Assistência Member of the Irati Formation were collected in the states of Goiás (northern border of the PB), São Paulo and Paraná (eastern and southern border of the PB, respectively). The acquired data allowed to establish a comprehensive palynostratigraphic study across the basin where a total of 18 pollen genera (34 pollen species), seven spore genera, four microplankton genera (1 species), and Chlorophyceae algae species where identified. The palynostratigraphic analysis also reveals a clear dominance of bisaccate pollen grains such as Corisaccites alutas, Lueckisporites virkkiae, and Weylandites lucifer. The Lueckisporites virkkiae zone was identified in the upper part of the Irati Formation (Assistência Member) and the lowermost part of the Corumbataí Formation, indicating a Kungurian to Roadian age for this part of the succession. Differences in the Guttulapollenites hannonicus and Tornopollenites toreutos biostratigraphic ranges, recovered in the Corumbataí Formation, suggest an earlier development of these species in the Paraná Basin during the middle Permian. Therefore, to evaluate the differences in the first occurrences of key species within the Paraná Basin, a close palynostratigraphic correlation between the main Guadalupian-Lopingian South American Gondwana basins is tentatively established.
- Palynology of Bonito and Barro Branco coal seams from Rio Bonito Formation (Lower Permian of Parana Basin) in the Criciuma coal region, southernmost BrazilPublication . Pereira, Z.; Mendes, M.; Souza, P. A.; Rodrigues, C.; Fernandes, Paulo; Ade, M.; Araujo, C.; Almeida, J. R. L.; Santos, E. M.; Rocha, H., V; Santos, V. E. S.; Araujo, B. P.; Garavaglia, L.; Lemos de Sousa, M. J.Seven coal seams were sampled from several mines and outcrops of the Rio Bonito Formation, Bonito and Barro Branco coal seams, in the coal mining region of Criciuma, Parana Basin, Santa Catarina State (Brazil), for a detailed palynostratigraphic study. The coal seams sampled yield abundant, diverse and moderately to well preserved palynological assemblages. A total of twenty-seven spore species, fourteen pollen species and four microplanktonic or clorophyceae algae and fungi species were identified. The palyno-assemblages recovered in the Bonito and Barro Branco coal seams are assigned to the Vittatina costabilis Interval Zone, Protohaploxypinus goraiensis Subzone of the Parana Basin, of Asselian? to Artinskian age (Lower Permian). The microflora assemblages identified in these coal seams are very similar in composition, presenting a dominance of arborescent and herbaceous lycophytes. The Barro Branco coal seam shows a relatively higher frequency of algae like composition than in the Bonito coal seam, suggesting a possible fluvial or lagoonal facies influence.
- Preliminary late Miocene palynomorph assemblages from the Quifangondo and Luanda formations, Onshore Kwanza Basin, AngolaPublication . Rodrigues, C. F.; Pereira, Z.; Mendes, M.; Nsungani, P. C.; Fernandes, P.; Lopes, Gilda; Duarte, L., V; Aboelkomsan, W.; Taylor, E.; Tyrrell, M.; Fernando, M. F.; Machado, VA Miocene succession exposed at the Cabo Ledo and Miradouro da Lua sections in the Onshore Kwanza Basin, Angola, was examined for palynology. Palynomorphs of preliminary late Miocene age identified are presented herein. The upper part of the Quifangondo Formation is dated as middle Tortonian in age based on the co-occurrence of the pollen grain Fenestrites spinosus and the dinoflagellate species Selenopemphix armageddonensis. The palynomorph signature indicates a middle neritic marine environment dominated by dinoflagellate cyst taxa. A late Miocene (late Tortonian to Messinian) age is also documented for the first time at the base of the Luanda Formation based on the co-occurrence of the pollen taxa Echitricolporites spinosus, Fenestrites spinosus, Fenestrites longispinosus, Monoporopollenites annulatus, and Retistephanocolpites gracilis. The palynomorph signature of this unit reflects an inner neritic marine (coastal/lagoon transitional) environment dominated by terrestrial palynomorphs and very rare dinoflagellate cyst taxa. The present research contributes data for improving the stratigraphical framework of the Quifangondo and Luanda formations, both of which are recognized as the main potential source rocks and reservoirs of the Post-Salt Paleogene/Neogene Petroleum System of the Kwanza Basin. This significant contribution provides important biostratigraphic and palaeoenvironmental data for defining the vital temporal horizons of these settings in a basin where petroleum exploration is of interest.
- Superimposed thermal histories in the southern limit of the Ossa Morena Zone - PortugalPublication . Fernandes, Paulo Manuel Carvalho; Lopes, Gilda; Machado, G.; Pereira, Z.; Rodrigues, B.The Mississippian volcano-sedimentary complex in the Toca da Moura - Cabrela areas represents remnants of intra-volcanic marine sedimentary basins, formed during the collision between the Ossa Morena Zone with the South Portuguese Zone. These rock units are unconformably overlain by the Pennsylvanian intramontane coal-bearing Santa Susana Basin. Vitrinite reflectance determinations from rocks of these two basins indicate two episodes of thermal maturation. During the first episode, the Toca da Moura - Cabrela volcano-sedimentary complexes attained high maturation levels, equivalent to anthracite coal rank (3.0-3.5% R-oran ), which pre-dates the middle Moscovian Santa Susana Basin. The Santa Susana Basin attained moderate maturation levels equivalent to bituminous coal rank (1.35-1.5% R-oran ) recording a second episode of thermal maturation. Here, peak thermal conditions did not overprint the first maturation episode. The observed effects of magmatic intrusion on the thermal maturity and the lack of any increase in vitrinite reflectance with depth through c. 400 m of section in borehole SDJ-1 indicate high geothermal gradients during the first maturation episode. A contemporaneous magmatic event associated with the c. 335-320 Ma Cuba-Alvito Gabbros/Diorites of the Beja Massif was the possible cause for the high geothermal gradients postulated for the first maturation episode. Burial under a post-upper Moscovian sedimentary cover was the most likely process to account for the maturation levels determined for the Santa Susana Basin and for the second episode of thermal maturation.
- The Late Permian in the Muarádzi Sub-basin, Moatize-Minjova Basin, Mozambique – multidisciplinary palaeoenvironmental characterizationPublication . Lopes, Gilda; Pereira, Z.; Fernandes, Paulo; Mendes, M.; Marques, J.; Jorge, R.C.G.S.A study involving lithofacies, palynofacies, and palynological analysis is presented for the Muarádzi Sub-basin. This sub-basin is part of the Moatize-Minjova Basin (MMB), a crucial Karoo aged coalfield in Mozambique previously situated in the southern-central part of Gondwana.