Silurian
Mostrando 1-6 de 6 artigos, teses e dissertações.
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1. Sedimentology and stratigraphy of Neoproterozoic-lower Paleozoic carbonate-siliciclastic succession of the southwesternmost Amazon Craton, state of Rondônia, Brazil
ABSTRACT: Facies and stratigraphic analysis were carried out in Neoproterozoic-Lower Paleozoic carbonate-siliciclastic deposits of Cacoal and Pimenta Bueno formations exposed on basement rocks and into the Pimenta Bueno Graben, northwestern portion of Parecis Basin, southwesternmost Amazon Craton. The redescription and redefinion of this succession confirmed
Braz. J. Geol.. Publicado em: 22/02/2018
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2. Vila Maria Formation (Silurian, Paraná Basin, Brazil): integrated radiometric and palynological age determinations
Fresh shale samples taken from a well-known outcrop section of the Silurian Vila Maria Formation, located on the northeastern margin of the Paraná Basin (Três Barras Farm, Goiás State, central-western Brazil), have been analysed for both palynological and radiometric age determinations. The rocks yielded a fairly diverse, age-definitive cryptospore assemb
Publicado em: 2011
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3. Tectônica e sedimentação na Bacia do Camaquã Central (RS): exemplos do Grupo Guaritas e do Grupo Santa Bárbara / Tectonics and sedimentation in Central Camaquã Basin: the Guaritas Group and the Santa Bárbara Group
The relationship between tectonics and sedimentation plays a primordial role in the understanding of sedimentary successions. On the other hand, the study of pre-Silurian fluvial deposits represents a challenge due to the lack of interaction between land plants and river systems which characterizes post-Silurian environments. The Camaquã Basin (Ediacaran to
Publicado em: 2010
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4. SeqÃÃncias siluro-devoniana e eocarbonÃfera da Bacia do ParnaÃba, Brasil, como anÃlogos para a explotaÃÃo de hidrocarbonetos
The present study was applied to understanding the similar hydrocarbon reservoirs on the Silurian, Devonian and Early Carboniferous sequences of the ParnaÃba Basin. The exposure investigated are located in the central area in the Piauà state. These outcrops are geologicaly inserted in the southeastern border of the ParnaÃba Basin. Three outcrops constitui
Publicado em: 2005
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5. A three-dimensionally preserved fossil polychaete worm from the Silurian of Herefordshire, England.
Polychaete body fossils are rare, and are almost invariably compressed and too poorly preserved for meaningful comparison with extant forms. We here describe Kenostrychus clementsi gen. et sp. nov. from the Silurian Herefordshire Konservat-Lagerstätte of England, in which three-dimensional external morphology is preserved with a fidelity unprecedented among
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6. Rapid recovery from the Late Ordovician mass extinction
Understanding the evolutionary role of mass extinctions requires detailed knowledge of postextinction recoveries. However, most models of recovery hinge on a direct reading of the fossil record, and several recent studies have suggested that the fossil record is especially incomplete for recovery intervals immediately after mass extinctions. Here, we analyze
National Academy of Sciences.