Papers (Scientific Journals) by Orlando Cristiano da Silva
This work studies the Buracica Stage (Barremian, Early Cretaceous) in the Recôncavo Basin, Bahia ... more This work studies the Buracica Stage (Barremian, Early Cretaceous) in the Recôncavo Basin, Bahia State (N.E. Brazil), comprising the São Sebastião and Pojuca formations, from the analysis of 143 well logs and outcrop records. The Recôncavo Basin is a rift basin associated with the beginning of the South Atlantic Ocean. The basin started with very slow subsidence rates, leading to the formation of shallow lakes and the deposition of shales and sandstones, which compose the Brotas Group; later, subsidence accelerated and gave rise to the formation of a deep lake. Then the deep lake basin was filled throughout six depositional episodes making up the so-called Recôncavo tectonic sequence. Previous studies divided the last depositional event of Recôncavo Basin into seven fourth-order sequences concerning the Marker Bed "1" to the Marker Bed "F" stratigraphic interval. Sequence boundaries were marked by sharp flooding surfaces related to the transgression of lacustrine system due to rapid tectonic subsidence and generation of accommodation. In turn, the sequences are divided into three systems tracts: the lake lowstand systems tract, the transgressive systems tract and the lake highstand systems tract. The maximum flood surface of the sequences generally coincides with the stratigraphic marker "B" to "F". Depositional systems like braided-fluvial plus eolian dunes, meandering-fluvial, deltaic, or moving-lake and near-shore deposits were identified in this work. Isopach, isolith and sand percentage maps indicate depocentre and source area distribution like the previous Aratu Stage. The primary sources of the sediments are located in the west and north areas; only from the third sequence, an eastern source could be described conspicuously. The fourth-order cyclicity is controlled by lake level changes, related to climatic factors (Milankovitch cycles). The results from the studies of cyclicity confirm the proposed stratigraphic model. They indicate 43,000 years for each fourth-order sequence and 150,000 years for the third-order sequences, which provide an accumulation rate of 1200 mm per 1000 years for the studied interval.
Papers by Orlando Cristiano da Silva
Journal of Sedimentary Environments, 2020
This work studies the Buracica Stage (Barremian, Early Cretaceous) in the Recôncavo Basin, Bahia ... more This work studies the Buracica Stage (Barremian, Early Cretaceous) in the Recôncavo Basin, Bahia State (N.E. Brazil), comprising the São Sebastião and Pojuca formations, from the analysis of 143 well logs and outcrop records. The Recôncavo Basin is a rift basin associated with the beginning of the South Atlantic Ocean. The basin started with very slow subsidence rates, leading to the formation of shallow lakes and the deposition of shales and sandstones, which compose the Brotas Group; later, subsidence accelerated and gave rise to the formation of a deep lake. Then the deep lake basin was filled throughout six depositional episodes making up the so-called Recôncavo tectonic sequence. Previous studies divided the last depositional event of Recôncavo Basin into seven fourth-order sequences concerning the Marker Bed "1" to the Marker Bed "F" stratigraphic interval. Sequence boundaries were marked by sharp flooding surfaces related to the transgression of lacustrine system due to rapid tectonic subsidence and generation of accommodation. In turn, the sequences are divided into three systems tracts: the lake lowstand systems tract, the transgressive systems tract and the lake highstand systems tract. The maximum flood surface of the sequences generally coincides with the stratigraphic marker "B" to "F". Depositional systems like braided-fluvial plus eolian dunes, meandering-fluvial, deltaic, or moving-lake and near-shore deposits were identified in this work. Isopach, isolith and sand percentage maps indicate depocentre and source area distribution like the previous Aratu Stage. The primary sources of the sediments are located in the west and north areas; only from the third sequence, an eastern source could be described conspicuously. The fourth-order cyclicity is controlled by lake level changes, related to climatic factors (Milankovitch cycles). The results from the studies of cyclicity confirm the proposed stratigraphic model. They indicate 43,000 years for each fourth-order sequence and 150,000 years for the third-order sequences, which provide an accumulation rate of 1200 mm per 1000 years for the studied interval.
The territorial occupation from the Amazon region is characterized by isolated communities, which... more The territorial occupation from the Amazon region is characterized by isolated communities, which makes the conventional electric distribution economically and technically impracticable. To solve the electric problem of these communities, it is necessary for them to produce their own fuel in order to generate electric energy and promote the development. These are the premises which have guided the elaboration of the project PROVEGAM - "Implantation and test of a unit demonstration of vegetable oil energetic utilization" has a conventional diesel engine installation and performance testing objective, adapted to operate with palm oil "in natura" at the Vila Soledade community, Moju, Para, an isolated community that has approximately 700 inhabitants, in 120 houses, and it is located at one hundred and forty kilometers from downtown by car and 30 minutes more by boat. The electric energy of this community was previously generated by a conventional diesel engine, tech...
vi RESUMO SILVA, Orlando Cristiano da. Uma avaliação da produção de bioetanol no contexto da agri... more vi RESUMO SILVA, Orlando Cristiano da. Uma avaliação da produção de bioetanol no contexto da agricultura familiar a partir da experiência da cooperbio. 2012. 136 f. Tese (Doutorado)
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Papers (Scientific Journals) by Orlando Cristiano da Silva
Papers by Orlando Cristiano da Silva