Sedimentary
Mostrando 1-12 de 362 artigos, teses e dissertações.
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1. Indicator kriging applied to RMR geomechanical modelling in a Pb-Zn deposit case study
Abstract The opening of a mining enterprise requires knowledge of the geomechanical characteristics of the mineral deposit, which will be worked according to the use of parameters of stability and/or resistance of the material, as well as the discontinuities present in the rock. In this study, the Rock Mass Rating methodology was used to propose a geomechani
REM, Int. Eng. J.. Publicado em: 2021-06
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2. Radionuclídeos como marcadores de um novo tempo: o Antropoceno
On May 2019, the members of the Anthropocene Working Group completed a binding vote to affirm some of the key questions that have been agreed in 2016: the Anthropocene should be considered as a formal chronostratigraphic unit, defined by a Global Boundary Stratotype Section and Point (GSSP), using one of the stratigraphic signals around the mid-twentieth cen
Quím. Nova. Publicado em: 2020-04
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3. Sporepolinic morphology of fluvial terrace sediments in the Western Amazon
ABSTRACT Morphological descriptions were made for pollen grains and spores extracted from samples from three sedimentary sections - Chandless 1, Purus 10 and Purus 30 - from fluvial terraces on the Chandless and Purus rivers, Acre State, Brazil. Level CH1-12 at Chandless 1 was C14-dated to 4861 - 5050 cal yr BP, P10-3 of Purus 10 was dated through the OSL me
Acta Bot. Bras.. Publicado em: 2020-03
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4. Constraints from magnetotellurics on the geological structure across a seismic area associated with water wells in the Paraná basin, Brazil
ABSTRACT: The occurrence of earthquakes associated with the opening of groundwater wells is a very rare phenomenon. We present the results from a magnetotelluric profile of about 4 km-long that crosses a seismic zone near the town of Bebedouro, in the Northeastern part of the intra-cratonic Paraná basin, in Brazil. The seismic activity is thought to be caus
Braz. J. Geol.. Publicado em: 13/01/2020
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5. White sand vegetation in an Amazonian lowland under the perspective of a young geological history
Abstract: What controls the formation of patchy substrates of white sand vegetation in the Amazonian lowlands is still unclear. This research integrated the geological history and plant inventories of a white sand vegetation patch confined to one large fan-shaped sandy substrate of northern Amazonia, which is related to a megafan environment. We examined flo
An. Acad. Bras. Ciênc.. Publicado em: 02/12/2019
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6. Age and palaeoenvironments of the Manacapuru Formation, Presidente Figueiredo (AM) region, Lochkovian of the Amazonas Basin
Abstract The Manacapuru Formation, Amazonas Basin, outcrops on the margins of a highway in the region of Presidente Figueiredo, state of Amazonas. A systematic palynological and a lithofaciological analysis was carried out aiming to contribute to the paleoenvironmental understanding of the Manacapuru Formation and its respective age. The present work uses th
Braz. J. Geol.. Publicado em: 28/11/2019
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7. Sequence stratigraphy of fluvial to shallow-marine deposits: The case of the early Permian Rio Bonito Formation, Paraná Basin, southernmost Brazil
Abstract This study presents new sedimentology data and attempts to understand coastal processes, sedimentary dynamics and stratigraphic patterns of the Rio Bonito Formation (early Permian) in Paraná Basin, southern Brazil. The study was performed based on the description of five cores, located in a small-scale area - São Gabriel City - in Rio Grande do Su
Braz. J. Geol.. Publicado em: 25/11/2019
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8. Sporepolinic morphology of fluvial terrace sediments in the Western Amazon
ABSTRACT Morphological descriptions were made for pollen grains and spores extracted from samples from three sedimentary sections - Chandless 1, Purus 10 and Purus 30 - from fluvial terraces on the Chandless and Purus rivers, Acre State, Brazil. Level CH1-12 at Chandless 1 was C14-dated to 4861 - 5050 cal yr BP, P10-3 of Purus 10 was dated through the OSL me
Acta Bot. Bras.. Publicado em: 11/11/2019
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9. The sedimentary record of wet and dry eolian systems in the Cretaceous of Southeast Brazil: stratigraphic and paleogeographic significance
Abstract Sedimentologic and stratigraphic studies of paleo-deserts from the Brazilian Cretaceous are of great potential to understand the paleoclimate and paleogeography of Gondwana during its final rifting stage. Herein, we describe and discuss two depositional units characterized by two distinct eolian systems that are bounded by a long-lived unconformity.
Braz. J. Geol.. Publicado em: 11/11/2019
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10. Morphometry and longitudinal profile of the river cobras sub-basin in planning the location of underground dams
RESUMO Um estudo na sub-bacia hidrográfica do rio das Cobras foi realizado com o objetivo de avaliar as características morfométricas e o perfil longitudinal da bacia hidrográfica, como ferramenta de planejamento na locação de barragens subterrâneas. Os parâmetros morfométricos - coeficiente de compacidade, fator forma, densidade de drenagem e índi
Rev. Ciênc. Agron.. Publicado em: 04/11/2019
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11. Provenance of the Ediacaran Salinas Formation (Araçuaí Orogen, Brazil): Clues from lithochemical data and zircon U-Pb (SHRIMP) ages of volcanic clasts
Abstract Salinas Formation occurs in a large region of the Northern Araçuaí orogen, Southeastern Brazil. It includes turbiditic wackes (> 10% matrix) to arenites (< 10% matrix), pelites and clast-supported conglomerates, metamorphosed from the biotite zone of the greenschist facies to the sillimanite zone of the amphibolite facies. Salinas Formation lies u
Braz. J. Geol.. Publicado em: 01/07/2019
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12. Sedimentary and U-Pb detrital zircons provenance of the Paleoproterozoic Piracicaba and Sabará groups, Quadrilátero Ferrífero, Southern São Francisco craton, Brazil
Abstract The Quadrilátero Ferrífero is an important mineral province located in Southern São Francisco craton, SE Brazil. Its prominent feature is the Gandarela syncline that was formed as part of the regional deformation event in the southernmost part of the craton at ca. 2,000 Ma. The syncline exposes several economically important units of Rio das Velh
Braz. J. Geol.. Publicado em: 03/06/2019