• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Doctoral Thesis
DOI
https://doi.org/10.11606/T.44.2018.tde-26042018-092735
Document
Author
Full name
Luana Pereira Costa de Morais Soares
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2017
Supervisor
Committee
Fairchild, Thomas Rich (President)
Carmo, Dermeval Aparecido do
Freitas, Bernardo Tavares
Simões, Marcello Guimarães
Warren, Lucas Verissimo
Title in Portuguese
Sistemática e tafonomia de microfósseis vasiformes neoproterozoicos do Brasil e seu significado paleoecológico e filogenético.
Keywords in Portuguese
Faixa Paraguai
Microfósseis em forma de vaso
Neoproterozoico
Abstract in Portuguese
Esta pesquisa investigou microfósseis neoproterozoicos em forma de vaso ("vase-shaped microfossils - VSMs") da Formação Urucum (Grupo Jacadigo) e Formação Bocaina (Grupo Corumbá), ambas inseridas na Faixa Paraguai Sul, Brasil. Estes microfósseis foram comparados a outras ocorrências neoproterozoicas no mundo. O objetivo foi contribuir com o conhecimento de aspectos paleobiológicos, evolutivos e bioestratigráficos relacionados ao aparecimento de eucariontes unicelulares tecados em ecossistemas anteriores ao surgimento dos metazoários. Os VSMs podem ser atribuídos a quitinozoários, tintinídeos e foraminíferos, porém, características diagnósticas importantes apontam o grupo Amoebozoa como afinidade biológica mais próxima. A variedade morfológica e composicional observada em VSMs neoproterozoicos, inclusive nos exemplares brasileiros, documenta a mais antiga diversificação da vida unicelular eucariótica, presumivelmente heterotrófica, preservada no registro geológico. As diferentes fácies sedimentares contendo VSMs fornecem informações valiosas sobre fatores ambientais que podem ter sido importantes na diversificação bem como no seu possível desaparecimento entre o Neoproterozoico e o Mesozoico. Além disso, a ampla distribuição e variedade desses microfósseis sugerem uma possível aplicação bioestratigráfica. Microscopia petrográfica (MP) e Eletrônica de Varredura (MEV), Espectrometria de Energia Dispersiva de Raios X (EDS), Microscopia Confocal (MC), Espectroscopia Raman (ER), Catodoluminescência (CL) além de técnicas geoquímicas e geocronológicas foram aplicadas para caracterizar a composição e morfologia dos microfósseis, bem como para a rocha encaixante, visando inferir a natureza e paleoecologia dos organismos responsáveis pelas produção das tecas e o ambiente em que viveram, se diversificaram e desapareceram.
Title in English
not available
Keywords in English
Neoproterozoic
Paraguay Fold Belt
Vase-shaped microfossils
Abstract in English
This research investigated vase-shaped microfossils (VSMs) from the Urucum Formation (Jacadigo Group) and Bocaina Formation (Corumbá Group), both inserted in the Southern Paraguay Fold Belt, Brazil. These microfossils were compared to other neoproterozoic occurrences in the world. The aim was to contribute to the knowledge of paleobiological, evolutionary and biostratigraphic aspects related to the appearance of unicellular eukaryotes in the ecosystems that preceed the appearance of metazoans. VSMs can be attributed to quitinozoan, tintinids and foraminifera, but important diagnostic features point to the Amoebozoa group as the closest biological affinity. The morphological and compositional variety observed in neoproterozoic VSMs, including Brazilian specimens, documents the earliest diversification of eukaryotic unicellular life, presumably heterotrophic, preserved in the geological record. The different sedimentary facies containing VSMs provide valuable information about environmental factors that may have been important in the diversification as well as their possible disappearance between the Neoproterozoic to the Mesozoic. In addition, the wide distribution and variety of these microfossils suggest a possible biostratigraphic application. Petrography, Scanning electron microscopy, Confocal microscopy, Energy-dispersive X-ray spectroscopy, Raman spectroscopy, Cathodoluminescense, besides geochemical and geochronological techniques, were applied to characterize the composition and morphology of the microfossils, as well as for the host rock, in order to infer the nature and paleoecology of the organisms responsible for the production of the test and the environment in which they lived, diversified and probably disappeared
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
Release Date
2020-04-25
Publishing Date
2018-04-27
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
CeTI-SC/STI
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2021. All rights reserved.