http://hdl.handle.net/11422/55 Tue, 21 Jul 2026 12:53:28 GMT 2026-07-21T12:53:28Z http://hdl.handle.net/11422/29445 Title: Análise de sismossequências na Seção Drifte da porção offshore da bacia de Barreirinhas, margem equatorial brasileira Author(s)/Inventor(s): Sampol, Juliana Ferreira Gomes Advisor: Borghi, Leonardo Abstract: Important discoveries made over recent years in the South American (Zaedyus discovery) and African (Jubilee Field) equatorial margins opened new perspectives in the exploration of the Brazilian equatorial margin, particularly for the Barreirinhas Basin. The objective of this study is a first seismic analysis approach for the Drift section of Barreirinhas Basin, in deep water areas, based on the identification, correlation and mapping of the seismic facies, horizons and sequences. The few stratigraphic data available together with the lack of stratigraphic interpretations in the studied area make this study challenging. Five 2D depth seismic lines (Pre-Stack Depth Migration) dip oriented and one strike oriented are located in an approximately 1100km2 area, in the offshore Barreirinhas Basin, were interpreted using Petrel (Schlumberger), and its applications. The analysis of seismic characters, impedance contrast, reflectors’ patterns, and sequence geometries showed nine seismic facies, and ten seismic horizons, which seven of them limit six seismic sequences. Geometries identified by isopach maps of the sequences reveals a stratigraphic pattern of aggradational (seismic sequence 1) to retrogradational (seismic sequences 2, and 3) to progradational (seismic sequences 4 and 5) and finally to retrogradational (seismic sequence 6) which can be associated to transgressive-regressive cycles which allowed attemptive correlation to depositional sequences in the onshore previously proposed by literature Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação Wed, 21 Oct 2015 00:00:00 GMT http://hdl.handle.net/11422/29445 2015-10-21T00:00:00Z http://hdl.handle.net/11422/29421 Title: Estruturas sedimentares microbianas em arenitos da Formação Sergi (Jurássico), Bacia do Recôncavo, Bahia, Brasil Author(s)/Inventor(s): Avalone, Maiana Cláudia Kreff Advisor: Borghi, Leonardo Abstract: The bosedimentology is a new area of knowledge in geosciences which studies the influence of microbial organisms in sedimentological processes. Within this new area, there are more traditional studies in carbonate rocks, but more recently, a new focus on the genesis of certain structures in sedimentary sandstones and shales that occur from the precambrian to recent has opened new possibilities for studying biosedimentogy in terrigenous sediments and rocks. This study aims to identify the microbial influence in the genesis of some sedimentary structures in eolian sandstones of Sergi Formation, Jurassic of Recôncavo basin. Several structures have been recognized in this formation, similar to those which has been identified in the literature as elephant skin, pinnacles, wrinkle marks, exfoliating sand laminae and domal buildups, and microscopic structures such as laminations with peculiar spatial arrangement of grains and heavy mineral concentration, all which are associated with microbial genesis. The correct diagnosis of these structures not only increases the descriptive capacity of sedimentary lithofacies for the Sergi Formation, as well as the paleoenvironmental interpretative ability of the formation, through the possibility of recognition of humid aeolian depositional systems (paleoenvironments of interdune / sand sheet), that had not yet been hypothesized in the literature of the basin Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação Wed, 20 Mar 2013 00:00:00 GMT http://hdl.handle.net/11422/29421 2013-03-20T00:00:00Z http://hdl.handle.net/11422/29298 Title: Meteorito Buritizal: classificação de meteorito condrítico brasileiro Author(s)/Inventor(s): Salaverry, Rogerio Nogueira Advisor: Mendes, Julio Cezar Abstract: On 1967 August 14th, the reporter Saulo Gomes, working at TV Tupi, went to a small city in the State of São Paulo called Buritizal to investigate reports of a meteorite fall and write a newspaper report. He actually recovered three fragments of the meteorite at a small farm. In 2014, he donated one of the fragments to the Museu Nacional of the Universidade Federal do Rio de Janeiro (MN/UFRJ). We named this meteorite Buritizal and studied its petrology, geochemistry, magnetic properties and cathodoluminescence with the intent to determine the petrologic classification of the meteorite. In this manner, the Buritizal meteorite is classified as an ordinary chondrite LL 3.2 breccia (as indicated by the lithis fragments it contains. The meteorites consists of ~ 2% of metallic Fe,Ni and many well-defined chondrules with ~ 0.8 mm in average diameter. An ultramafic ferromagnesian mineralogy is predominant in the meteorite, represented by olivine, orthopyroxene, clinopyroxene, Fe-Ni alloy, troilite and glass. The total iron content was calculated as 20.88 wt%. Furthermore, the meteorite was classified as weathering grade W1 and shock stage S3. Buritizal is the 25th observed meteorite fall recovered in Brazil, of 70 meteorites known from Brazil. Thus, the study of the Buritizal meteorite is very important and relevant to the Brazilian scientific community Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação Tue, 14 Jun 2016 00:00:00 GMT http://hdl.handle.net/11422/29298 2016-06-14T00:00:00Z http://hdl.handle.net/11422/29283 Title: Variação de rigidez normal no contato rocha e solo em função do grau de saturação Author(s)/Inventor(s): Castro, Aliane Silva de Advisor: Barroso, Emilio Velloso Abstract: Natural disasters are increasingly common phenomena and have struck increasingly areas or regions inhabited by man. Of the various processes causing natural disasters, mass movements, specifically the rockfall type is being increasingly studied. Different factors can cause the movement of the blocks on the slope, whose range and trajectory are difficult to predict, since their behavior is governed by the geometry, by the mechanical interactions of the blocks with geological materials at the surface and by the topography of the slope. In studies of the components involved in the rockfall process, the geomechanical properties of the soil, such as stiffness can be neglected. In order to fill this gap, in this work was studied the behavior of normal stiffness in contact between rock and soil, simulating the shock that occurs on the rockfall movement, and how the humidity may come to influence the behavior of this stiffness. For it was developed a shock experiment to obtain data that are intrinsically related to the normal stiffness. Mineralogical and geomechanic characterization were also carried out for the rock and the soil used in the experiment, for the determination of parameters to be used in the calculation of stiffness. Normal stiffness, tangential stiffness and stiffness ratio were determined at different humidities, in the contacts where occurred the impacts. The results showed that there is a range of humidity in the soil, where with increasing humidity, there is an increase in the normal and tangential stiffness in the soil. This kind of behavior occurred in very low humidity, in the range of 12% to 15%. After this interval of humidities, was verified gradual reduction of normal stiffness in the soil-rock contact in function of increase of soil humidity. The ratio between the normal and tangential stiffness is around 0.90, which is an acceptable value, since it is next to the values founded in the literature scant that there is on the subject. Publisher: Universidade Federal do Rio de Janeiro Type: Dissertação Wed, 29 Jun 2016 00:00:00 GMT http://hdl.handle.net/11422/29283 2016-06-29T00:00:00Z