Litofácies e relações estratigráficas da formação Aquidauana no nordeste da Bacia do Paraná - São Sebastião do Paraíso (MG)

The Aquidauana Formation is characterized by sandstones of variable granulation, mudstones and diamectites abundant in clay, typical colors like brick red (vermelho tijolo) of glacial, fluvial and lacustrine origin. It’s chronostratigraphic equivalent to the Itarará group from the Neo Carboniferous age, that under the exploratory view, such units represent important intervals in the basin, occurring together with them minerals as well as energy resources as petroleum, underground water and coal – what requires a great paleogeography and stratigraphy knowledge for its exploration. By gathering information from the columnar sections of the area, it was possible to characterize the sedimentary facies, the stacking pattern as well as the association. It was also made an attempt of stratigraphic correlation, which showed great difficulties since glacial environments present a great lateral discontinuity of the facies besides the complex relationship process of formation. As a result, it was obtained 8 sedimentary facies, the lateral and vertical relations and genesis process. It is proposed that the sedimentary environment in the study area is the fluvio glacial, characterized by alluvial systems formed by defrosted water which transport the sediments that are deposited in plains in front of the glacier (distal outwash). Petrographic thin section analysis showed that the transportation process was ineffective. The grains present punctual to lobular contacts, characterizing good porosity and permeability to the rock, varying these qualities according to more or less existence of matrix. The presence of Iron Oxide deposited between the recrystallization border and feldspathic mineral indicates that this rock has possibly presented a primary rubefaction, intensified by alkaline fluid percolation

Análises tectono-estratigráfica e faciológico-diagenética da coquina-reservatório Lagoa Feia, Campo de Linguado, Bacia de Campos

A tectono-stratigraphic study of bivalve coquina-reservoir of Linguado Field allowed to identify two trends of permoporosity development. The delineation of these depositional-diagenetic traps were made through structural and stratigrafic cross-sections and maps. It resulted in the identification of shelf-ramp systems (tilted to SSE), it tickens from 60 to 70 meters and ends against an antithetic fault. The main coquina is bounded by fine siliciclastic units, white clay (low Gamma Ray values) or shale (high Gamma Ray values) lithologies, influencing diagenesis of basal or top coquina limestones (cimented, non-porous). Also in the middle of coquina-reservoir the “clayer” material is also associated with cemented carbonates, with also compartimentalize the reservoir into two subzones. The coquina porosity of the subzones is taken from density-neutron logs, while induction log estimates permeabilities and fluid saturations. It’s noticed the porosity development into pairs, good one followed by a regular/poor one and vice versa. These pairs form verticals succession, pair cycles where porosity improves or decreases upwards. These two scales of pore heterogeneity impose strong layering to the reservoir, and influences fluid saturations, oil-water contacts and porosity cut-offs. In a cross-section with density and induction logs, it can be observed the porosity variation along the shelf-ramp coquina (between 3LI_0004_RJS e 3RJS_0157C_RJ), the porosity is better developed in a downdip direction in the case of the two shelf wells, and also be the three ramp wells. The southern west downdip, 3RJS_0157C_RJ well, has best porosity pairs-cycles; however, its lowest structural conditions favour water saturation. Therefore it is fundamental for reservoir fluid evaluation a cross-plot analysis of RHOB-NPHI and Induction logs

Quimioestratigrafia do vulcanismo ácido mesozóico da província magmática do Paraná: porção SE do estado de Santa Catarina

The Mesozoic acid volcanism of the Paraná-Etendeka Province can be considered as one of the biggest events of its kind in the Earth's surface, and its study have attracted special interest in characterizing the end of magmatism that preceded the rupture process and the formation of continental Africa and South America Although significant, the acid volcanism featuring Members Chapecó Palmas and Serra Geral Formation represents only 2.5% of the total generated by the magmatic rocks and perhaps therefore the existing literature on these rocks is well less significant than that on the basalts. However, there are still aspects still unclear about the origin and evolution of these rocks in relation to the associated basalts. Thus, two profiles were selected, called RA and TA, which be a systematic collection of samples from the base where the Botucatu Formation sandstones occur at the top, where they observe Palmas acid rock type. These samples should be analyzed for major, minor and trace elements and treated in specific diagrams to define the vertical variation lithochemistry and their possible relationships with the associated basalts

Análise estrutural e microtectônica da inflexão do jordino e depósitos de ouro associados no greenstone belt de Pilar de Goiás

The study area is included in the geological context of the Goias Median Massif, a region where there are associations of Archean granite-gneiss complex (Block Moquém) and a Paleoproterozoic metavolcano-sedimentary sequence ( Pilar greenstone belt ). At the south of area, the greenstone sequence is partially overlain by Neopreoterozoic metasediments of the Araxá Group. The lithostratigraphic units of the Pilar greenstone belt define a shift from about N30W direction (north of the deposit) to N60 and 70W in the region south of the Jordino deposit, where are truncated by the Araxá Group rocks. Mineralogical associations described in this paper allow to indicate that the regional metamorphism that affected the rocks of the greenstone belt and Araxá Group, in the mapped area, reached the upper greenschist facies (garnet zone). Data obtained during mapping and by microtectonics analysis allow to indicate the existence of at least four deformational events that acted on the rocks of the Guarinos greenstone belt and Araxá Group, represented by the phases called Dn-1, Dn, Dn + 1 and Dn+2. It was observed that the pattern of sulphide porfitoblasts in mineralized levels is similar to garnet, biotite and muscovite porfiroblasts (tardi to post Dn) that marks the metamorphic peak of the area

Modelagem estratigráfica do intervalo cenomaniano-turoniano, formações Açu e Jandaíra, na borda sudoeste da Bacia Potiguar

Pós-graduação em Geociências e Meio Ambiente - IGCE

Análise estratigráfica em depósitos lacustres maastrichtianos da Formação Yacoraite (Bacia de Salta - Argentina): definição e rastreabilidade de sequências de alta resolução

Pós-graduação em Geologia Regional - IGCE

Análise paleopalinológica do Albiano (Cretáceo inferior) da Bacia de Campos, com ênfase no estudo de dinoflagelados

Pós-graduação em Geociências e Meio Ambiente - IGCE

Evolução tectônica e estratigráfica das bacias da margem continental do Uruguai

Pós-graduação em Geociências e Meio Ambiente - IGCE

Sistemas petrolíferos especulativos da bacia de Pelotas (offshore do Uruguai)

Pós-graduação em Geociências e Meio Ambiente - IGCE

Pyritic cone-in-cone concretions / Bertram G. Woodland --.

v.33:no.7(1975)

Pseudo-organic structures from the Precambrian Bass limestone in Arizona / [by] Matthew H. Nitecki --

v.23:no.1(1971)

Geochronology, stratigraphy, and typology / John Andrew Wilson --.

v.33:no.11(1975)

The stratigraphy of the Devonian Holland Quarry shale of Ohio / J. Ernest Carman --

v.14:no.1(1960)

Stratigraphy of the unsaturated zone and uppermost part of the Snake River Plain aquifer at Test Area North, Idaho National Engineering Laboratory, Idaho /

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