Avaliação dos desempenhos produtivo e reprodutivo de um rebanho bubalino no Estado do Ceará

Foram avaliados os desempenhos produtivo e reprodutivo de um rebanho bubalino, localizado no município de Paracuru, litoral oeste do Estado do Ceará. Os animais foram mantidos em sistema intensivo e submetidos a duas ordenhas diárias. Foram analisadas informações de 87 fêmeas da raça Murrah, entre os anos de 1984 e 1998. As análises estatísticas foram efetuadas por meio do procedimento GLM (SAS, 1990), usando um modelo linear misto. As médias observadas para produção total de leite, duração da lactação, produção de leite no pico de lactação, idade ao primeiro parto e intervalo de partos foram: 2130,80+535,60kg, 301,41+49,30dias, 9,78+1,95kg, 1132,69+166,99dias e 430,79+100,44dias, respectivamente. Alta porcentagem de parições das ocorreu no período chuvoso (79,3%) e apenas 20,7%, no período seco. A produção total de leite e a produção no pico de lactação foram influenciadas pelos efeitos do ano e ordem de parto. A duração da lactação foi influenciada pelos efeitos do ano e mês de parto. A idade ao primeiro parto foi influenciada pelo efeito do ano de nascimento da búfala. O intervalo de partos foi influenciado pelo mês do parto anterior, além dos efeitos do mês dentro do ano de parto e mês de nascimento da búfala.

Palavras da maldição: O Ceará de José Alcides Pinto entre símbolos e alegorias.

This work treats about the speeches that produced the crisis of symbols of Ceará, researching on matters and ways of expression of space between 1950s and 1970s. Therefore, we search discursive practices that since the end of nineteenth century built the identity of Ceará and in the middle of twentieth century produced the crisis of modes of seeing and telling the space in front of enunciations of the national modernization, especially with the emergence of politics by SUDENE to the Northeast, the progressive actions by Catholic Church, the defense of tradition by regional literature of union of Ceará Clã. The contradictions between the glorification and fear the modernization of Brazil produced on the space speeches that his identity would be fractured, that the old symbols of drought, cangaço, mysticism and colonels declined. Among analyzed speeches, we centered the analysis of Trilogia da Maldição formed of novels O Dragão, of 1964, Os Verdes Abutres da Colina and João Pinto de Maria: a biografia de um louco by José Alcides Pinto. In this novel, the enunciation of the crisis of symbologies about the space produced another aesthetic, the allegory, which, mixed with the mystical and melancholy, in search of ways to restore the language of the old themes Ceará, drop of Ceará the same stigma of anti-modern space, where the images of delay changed icons of a fractured identity in front of the modern streams, where the word was transformed in the dimension precarious and redeemer of the tradition, of old, of nature, of the plenitude of senses. In Jose Alcides, the colonel returns as the origin of the lost space, the drought is the revolt of God against the devil place, the apocalypse, the end imminent threat to the village, signs that fantastic, however, are in dialogue with the settings space and time in which they were produced

O teatro de Deus: a construção do espaço sagrado de juazeiro a partir de narrativas femininas (Ceará, 1889-1898)

In this work, we discuss the construction of Juazeiro in the state of Ceará -, as a sacred space from the analysis of the testimonies of nine religious women called beatas in an Episcopal process in the late nineteenth century. This process was initiated in 1891 to investigate the occurrence of an Eucharistic miracle with beata Maria Magdalena do Espírito Santo de Araújo. We show that the punitive strategies of the Diocese eventually caused a reordering of pilgrimages to Juazeiro which until 1894 worshipped the Precious Blood and that after the condemnation of the phenomena by the Holy See are rearranged around the figure of Father Cicero Romão Batista, under the pretext of worshipping the priest himself and also Nossa Senhora das Dores, currently the patron saint of the city of Juazeiro do Norte.

Patrimônio, Memória e Espaço: a construção da paisagem açucareira do Vale do Ceará-Mirim

This work aims to understand how the installation of sugar culture along the river Ceará-Mirim defined the spatial organization of the Valley, and thus setting the landscape. This space has begun to be defined only in the second half of the nineteenth century, when the sugarcane growth had atarted on land located on the banks of the river Ceará-Mirim. The passage of this period of great prosperity can be seen through the heritage material which is still presented in the region. Walking through the Valley, we found a considerable number of architectural buildings, many in ruins, linked to this historical moment. This perception, caused by these buildings, will take us on a trip to the past, back to a time characterized by great-houses, mills, sugarcane plantations, planters, slaves, etc. The references that lead us to consider the sugar mills located along the valley of Ceará Mirim as a patrimony, which carry an entire historical baggage, guide us to the first half of the twentieth century. During this period, the role of intellectuals from the Rio - Sao Paulo through the modernist movement will be decisive in the formation of a national identity. The heritage material identified along the valley of Ceará Mirim defined its current spatial organization, setting the landscape. But we must conceive this landscape into two ways: first, as a material representation of social practices carried out in this space, where social, cultural, economic and environmental aspects have interacted to their training; as well as a landscape that carries a whole historical baggage which was built throughout the twentieth century

Viagem-memória de Nilo Pereira: do Ceará Mirim ao Recife e do Recife ao Ceará Mirim

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

O (in)imaginável elefante mal-ajambrado: a questão de limites entre o Ceará e o Rio Grande do Norte e o exame da formação espacial e identitária norte-rio-grandense na Primeira República

This study s main goal is to analyze the way the limits between Ceará and Rio Grande do Norte states, the so called Grossos matter, has been associated to the norte-rio-grandense spacial and identity formation during the first republic period. Thus, a consistet number of sources: RN and CE old newspapers, as well as a república from Natal and Fortaleza and o mossoroense ; historical drafts from the historical and geographical institute associated and historical, gographical and anthropological institute of Ceará; the Ação Cível Originária de nº 6 from the supreme federal tribunal and many other cartographies. The documents haven t been hierarchized, neither accepted as proof effects, but understood as the base matter for this text composition by the deconstruction of the analyzed discusses. In order to do that the ablação or bricolagem method, without quotations marks or long quotations themselves, has been used. Along the three analyzed charpters: the two phases the litigious was found, since its beginning yet in the XVIII century until 1888 and its return within the republic proclamation, in the 1920 resolution; the development of the documental, historical and identity dispute between IHGA-CE and IHG-RN; and, at last, the political game existing between the Albuquerque Maranhão oligarchy , Manuel Pereira Reis and Rui Barbosa, explaining the intentions, silent and miths built along the time by these intellectual participations

Fungos gasteroides (Basidiomycota, Agaricomycetes) de três áreas de semiárido no Estado do Ceará, Brasil

Gasteroid fungi include several distinct lineages of basidiomycetes that were grouped by presenting some striking features in common like angiocarpic development and passive release of basidiospores. For a long period these fungi were accomodate in Gasteromycetes class. However, biochemistry and molecular studies showed the polyphyly of this group and curriently this class lies devoid of taxonomic value. These organisms influence the ecology of the various biomes, however, are poorly studied and knowledge of their diversity in neotropical ecosystems remains insufficient, despite studies that have been developed in recent years. The Brazilian semiarid region has many areas with an unexplored mycobiota. Ceará State has many areas of extreme biological importance and for this study three protected areas were chosen: Área de Proteção Ambiental da Serra da Ibiapaba, Parque Nacional de Ubajara and Área de Proteção Ambiental de Baturité. Therefore, the aim of this study was to inventory gasteroid fungi ocorring in these three areas in the semiarid region of Ceará. The expeditions, herborization and analysis of specimes were based in traditional methodology used to identify gasteroid fungi. Were identified 16 species belong to 5 families: Agaricaceae, Clathraceae, Geastraceae, Nidulariceae and Phallaceae. Morganella nuda Alfredo & Baseia is recorded for the second time in the world, Blumenavia angolensis (Welw. & Curr) Dring and Mutinus elegans (Mont.) E. Fisch. corresponds to a first record in the Brazilian Northeastern. Except for Abrachium floriforme (Baseia & Calonge) Baseia & T.S. Cabral and Geastrum lloydianum Rick, all remaining species are new records for Ceará, increasing the list of gasteroid fungi in the region of 3 for 17 species. Identified species were deposited in the collection of the Herbarium of Universidade Federal do Rio Grande do Norte. Although these areas have proved conducive to the study of gasteroid fungi, more efforts are still needed to increase knowledge of these fungi in the region

Análise da degradação ambiental das áreas de preservação permanente localizadas no estuário do rio Ceará-mirim/RN

The purpose of this paper is to identify and analyze the main environmental impacts taking place in the permanent preservation areas located in the Ceará-Mirim River estuary/RN and its surrounding areas. For that, the study was divided in two chapters, structured in the shape of a scientific paper. The first is a theoretical proposition on the occupation of the APPs in light of the discussion of the geographic space and the sustainability of the development, where a bibliographical review was made emphasizing the production of the geographic space, the sustainability of the development and the permanent preservation areas. In the second chapter, from a systemic approach, geoprocessing techniques and the adaptation of the Pressure-State- Response Indicators System were used, the latter being developed by the Organization for Economic Co-operation and Development OECD. Therefore, from the methodological approaches used, it's been observed that the use of permanent preservation areas for purposes other than those determined in the legislation and, mainly guided by capitalist interests, leads to the environmental degradation of these areas, fact which has been confirmed in the empiric study conducted in the second chapter, where it was possible to identify a series of environmental impacts such as: deforestation of mangrove and riparian vegetation for carciniculture implantation, the devastation of dune areas caused by the urban expansion in the coastal stretch and siltation of fluvial channel

Compreendendo a dança do Torém: visões de folclore, ritual e tradição entre os Tremembé do Ceará

Este artigo pretende discutir as mudanças históricas e culturais que têm afetado o torém, a dança específica mantida pelos Tremembé do estado do Ceará. Ainda que o torém tenha sido referido em registros históricos desde o século dezenove, ele tem sido objeto de apreciações e percepções diversas por muitos grupos sociais. Índios, pesquisadores, missionários e agentes do Estado têm tido diferentes posições, às vezes contraditórias, sobre a dança. Um de meus principais objetivos é entender como o torém tem sido progressivamente objetificado por idéias de folclore, etnicidade e política a partir dos contextos históricos específicos nos quais eles devem ser situados. Preocupações antropológicas sobre a experiência da etnicidade são relacionadas a elementos particulares da dança, especialmente os significados do vestuário, da música e da performance.

Entre índios tremembé e trabalhadores rurais: historicidade, mobilização política e identidades plurais no Ceará

As pesquisas antropológicas brasileiras podem tratar de forma frequentemente estanque e separada, por um lado, grupos camponeses e, por outro lado, grupos étnicos, quais sejam, ‘índios’, ‘quilombolas’, etc. Contextos e situações que indicam pluralidade identitária costumam ser simplificados em sua caracterização etnográfica e da dimensão multifacetada de relações e redes sociais. Assim, discuto aqui os processos de mobilização étnico-política e de demanda territorial, sem perder de vista os processos de ressignificação cultural e construção identitária que se engendram a partir de um campo semântico da etnicidade. Abordo, então, certas situações étnicas Tremembé (estado do Ceará) que desestabilizam, embaralham e colocam em risco representações antropológicas sobre o ‘camponês’, o ‘regional’ e o ‘indígena

Antropologia das mediações: um estudo sobre trocas, tensões e hierarquias em Coqueiros, Vale do Ceará Mirim

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Condicionamento estrutural das zonasa de cisalhamento da região de Forquilha, domínio Ceará Central: uma abordagem integrada de sensoriamento remoto e geologia estrutural

The studied region, named Forquilha and localized in northwestern Central Ceará domain (northern portion of Borborema Province), presents a lithostratigraphic framework constituted by paleoproterozoic metaplutonics, metasedimentary sequences and neoproterozoic granitoids. The metasedimentary rocks of Ceará group occupy most part of the area. This group is subdivided in two distinct units: Canindé and Independência. Canindé unit is represented basically by biotite paragneisses and muscovite paragneisses, with minor metabasic rocks (amphibolite lens). Independência sequence is composed by garnetiferous paragneisses, sillimanite-garnet-quartz-muscovite schists and quartz-muscovite schists, pure or muscovite quartzites and rare marbles. At least three ductile deformation events were recognized in both units of Ceará group, named D1, D2 and D3. The former one is interpreted as related to a low angle tangential tectonics which mass transport is southward. D2 event is marked by the development of close/isoclinal folds with a N-S oriented axis. Refolding patterns generated by F1 and F2 superposition are found in several places. The latest event (D3) corresponds to a transcurrent tectonics, which led to development of mega-folds and several shear zones, under a transpressional regime. The mapped shear zones are Humberto Monte (ZCHM), Poço Cercado (ZCPC) and Forquilha (ZCF). Digital image processing of enhanced Landsat 7-ETM+ satellite images, combined with field data, demonstrate that these penetrative structures are associated with positive and negative geomorphologic patterns, distributed in linear and curvilinear arrangements with tonal banding, corresponding to the ductile fabric and to crests. Diverse color composites were tested and RGB-531 and RGB-752 provided the best results for lineament analysis of the most prominent shear zones. Spatial filtering techniques (3x3 and 5x5 filters) were also used and the application of Prewitt filters generated the best products. The integrated analysis of morphological and textural aspects from filtered images, variation of tonalities related to the distribution of geologic units in color composites and the superposition over a digital elevation model, contributed to a characterization of the structural framework of the study area. Kinematic compatibility of ZCHM, ZCPC, ZCF shear zones, as well as Sobral-Pedro II (ZCSPII) shear zone, situated to the west of the study area, was one of the goal of this work. Two of these shear zones (ZCHM, ZCPC) display sinistral movements, while the others (ZCSPII, ZCF) exhibit dextral kinematics. 40Ar/39Ar ages obtained in this thesis for ZCSPII and ZCPC, associated with other 40Ar/39Ar data of adjacent areas, indicate that all these shear zones are related to Brasiliano orogeny. The trend of the structures, the opposite shear senses and the similar metamorphic conditions are fitted in a model based on the development of conjugate shear zones in an unconfined transpression area. A WNW-ESE bulk shortening direction is infered. The geometry and kinematic of the studied structures suggest that shortening was largely accommodated by lateral extrusion, with only minor amounts of vertical stretch

Evolução tectono-estrutural do Campo de Xaréu (Sub-bacia de Mundaú, Bacia do Ceará - NE do Brasil: abordagem multiescala e pluriferramental

The Xaréu Oil Field, located in the center-southern portion of the Mundaú Sub-Basin (eastern portion of the Ceará Basin), is characterized by a main Iramework of NW-trending and NE-dipping faults. The faults in the Xaréu Oil Field, among which the Xaréu Fautt stands out, are arranged according to an extensional-listriclan, rooted on a detachment surface corresponding to the Mundaú Fault, the border fautt of Mundaú Sub-Basin. During the tectonic-structural evolution of the Xaréu Oil Field and the Mundaú Sub-Basin, the Mundaú Fault played a crucial role on the control of the geometry of both compartments. The main carbonatic unit in the Xaréu Oil Field, named the Trairí Member(Paracuru Formation of Late Aptian to Early Albian age), contains the largest oil volume in the field, concentrated in structurally-controlled accumulations. The Trairí Member is composed by a variety of carbonatic rocks (massive, bedded or laminated calcilutites, ostracodites, calcarenites and carbonatic rudites, all of them presenting variable degrees of dolomitization). The carbonatic rocks are interbedded into thick packages of black shales and marls, besides local beds of siliciclastic conglomerates, sandstones, siltnes and argillites. From the spatial association and the genetic relationships between the carbonatic and siliciclastic units, it is possible to group them in three lithofacies associations (Marginal Plain, Ramp and Lacustrine Interior) that, together, were developed in a lacustrine system associated to a marginal sabkha. Structural studies based on drill coresthat sample the Trairí Member in the Xaréu Oil Field allowed to characterize two generations of meso- to microscale structures: the D1 group presents a typical hydroplastic character, being characterized by intra/interstratal to oblique-bedding shear zones. The hydroplastic character related to these structures allowed to infer their development at an early-lithilication stage of the Trairí Member, leading to infer an Early Cretaceous age to them. The second group of structures identified in the drill cores, nominated D2 and ascribed to a Neogene age, presents a strictly brttle character, being typilied by normal faults and slickenfibers of re-crystallized clayminerals, ali olthem displaying variable orientations. Although the present faults in the Xaréu Oil Field (and, consequently, in the Mundaú Sub-Basin) were classically relerred as struetures of essentially normal displacement, the kinematics analysis of the meso-to microscaie D1 struetures in the drill cores led to deline oblique displacements (normal with a clockwise strike-slip component) to these faults, indicating a main tectonic transport to ENE. These oblique movements would be responsible for the installation of a transtensive context in the Mundaú Sub-Basin, as part of the transcurrent to translormant opening of the Atlantic Equatorial Margin. The balancing of four struetural cross-sections ofthe Xaréu Oil Field indicates that the Mundaú Fault was responsible for more than 50% of the total stretching (ß factor) registered during the Early Aptian. At the initial stages of the "rifting", during Early Aptianuntil the Holocene, the Mundaú Sub-Basin (and consequently the Xaréu Oil Fleld) accumulated a total stretching between 1.21 and 1.23; in other words, the crust in this segment of the Atlantic Equatorial Margin was subjeeted to an elongation of about 20%. From estimates of oblique displacements related to the faults, it ws possible to construct diagrams that allow the determination of stretching factors related to these displacements. Using these diagrams and assuming the sense 01 dominant teetonictransport towards ENE, it was possible to calculate the real stretching lactors related to the oblique movement 0 of the faults in the Mundaú Sub-Basin. which reached actual values between 1.28 and 1.42. ln addnion to the tectonic-structural studies in the Xaréu Oil Field, the interpretation of remote sensing products, coupled wnh characterization of terrain analogues in seleeted areas along the northern Ceará State (continental margins of the Ceará and Potiguar basins), provided addnional data and constraints about the teetonic-structural evolution of the oil lield. The work at the analogue sites was particularly effective in the recognition and mapping, in semidetail scale, several generations of struetures originated under a brittle regime. Ali the obtained information (from the Xaréu Oil Field, the remote sensor data and the terrain analogues) were jointly interpreted, culminating with the proposnion of an evolutionary model lor this segment of the Atlantic Equatorial Margin; this model that can be applied to the whole Margin, as well. This segmentof the Atlantic Equatorial Margin was delormedin an early E-W (when considered lhe present-day position of the South American Plate) transcurrent to transform regime with dextral kinematics, started Irom, at least, the Early Aptian, which left its record in several outcrops along the continental margin of the Ceará State and specilically in the Xaréu off Field. The continuous operation of the regime, through the Albian and later periods, led to the definitive separation between the South American and African plates, with the formation of oceanic lithosphere between the two continental blocks, due to the emplacement off spreading centers. This process involved the subsequent transition of the transcurrent to a translorm dextral regime, creating lhe Equatorial Atlantic Oceano With the separation between the South American and African plates already completed and the increasing separation between lhe continental masses, other tecton ic mechanisms began to act during the Cenozoic (even though the Cretaceous tectonic regime lasted until the Neogene), like an E-W compressive stress líeld (related to the spreading olthe oceanic floor along lhe M id-Atlantic Ridge and to the compression of the Andean Chain) effective Irom the Late Cretaceous, and a state of general extension olthe horizontal surface (due to the thermal uplift ofthe central portion of Borborema Province), effective during the Neogene. The overlap of these mechanisms during the Cenozoic led to the imprint of a complex tectonic framework, which apparently influenced the migration and entrapment 01 hydrocarbon in the Ceará Basin

Litoestratigrafia e deformação cenzóica na região de Icapuí, Ceará, e implicações para a estruturação de campos de petróleo na borda ocidental da bacia Potiguar(NE do Brasil)

This thesis deals with the sedimentological/stratigraphic and structural evolution of the sedimentary rocks that occur in the NW continental border of the Potiguar Basin. These rocks are well exposed along coastal cliffs between the localities of Lagoa do Mato and Icapuí, Ceará State (NE Brazil). The sedimentological/stratigraphic study involved, at the outcrop scale, detailed facies descriptions, profile mapping of the vertical succession of different beds, and columnar sections displaying inferred lateral relationships. The approach was complemented by granulometric and petrographic analyses, including the characterization of heavy mineral assemblages. The data set allowed to recognize two kinds of lithological units, a carbonate one of very restricted occurrence at the base of the cliffs, and three younger, distinct siliciclastic units, that predominate along the cliffs, in vertical and lateral extent. The carbonate rocks were correlated to the late Cretaceous Jandaíra Formation, which is covered by the siliciclastic Barreiras Formation. The Barreiras Formation occurs in two distinct structural settings, the usual one with nondeformed, subhorizontal strata, or as tilted beds, affected by strong deformation. Two lithofacies were recognized, vertically arranged or in fault contacts. The lower facies is characterized by silty-argillaceous sandstones with low-angle cross bedding; the upper facies comprises medium to coarse grained sandstones, with conglomeratic layers. The Tibau Formation (medium to coarse-grained sandstones with argillite intercalations) occurs at the NW side of the studied area, laterally interlayered with the Barreiras Formation. Eolic sediments correlated to the Potengi Formation overly the former units, either displaying an angular unconformity, or simply an erosional contact (stratigraphic unconformity). Outstanding structural features, identified in the Barreiras Formation, led to characterize a neocenozoic stress field, which generated faults and folds and/or reactivated older structures in the subjacent late cretaceous (to paleogene, in the offshore basin) section. The structures recognized in the Barreiras Formation comprise two distinct assemblages, namely a main extensional deformation between the localities of Ponta Grossa and Redonda, and a contractional style (succeeded by oblique extensional structures) at Vila Nova. In the first case, the structural assemblage is dominated by N-S (N±20°Az) steep to gently-dipping extensional faults, displaying a domino-style or listric geometry with associated roll-over structures. This deformation pattern is explained by an E-W/WNW extension, contemporaneous with deposition of the upper facies of the Barreiras Formation, during the time interval Miocene to Pleistocene. Strong rotation of blocks and faults generated low-angle distensional faults and, locally, subvertical bedding, allowing to estimate very high strain states, with extension estimates varying between 40% up to 200%. Numerous detachment zones, parallel to bedding, help to acommodate this intense deformation. The detachment surfaces and a large number of faults display mesoscopic features analoguous to the ones of ductile shear zones, with development of S-C fabrics, shear bands, sigmoidal clasts and others, pointing to a hydroplastic deformation regime in these cases. Local occurrences of the Jandaíra limestone are controled by extensional faults that exhume the pre-Barreiras section, including an earlier event with N-S extension. Finally, WNWtrending extensional shear zones and faults are compatible with the Holocene stress field along the present continental margin. In the Vila Nova region, close to Icapuí, gentle normal folds with fold hinges shallowly pluging to SSW affect the lower facies of the Barreiras Formation, displaying an incipient dissolution cleavage associated with an extension lineation at high rake (a S>L fabric). Deposition of the upper facies siliciclastics is controlled by pull-apart graben structures, bordered by N-NE-trending sinistral-normal shear zones and faults, characterizing an structural inversion. Microstructures are compatible with tectonic deformation of the sedimentary pile, burried at shallow depths. The observed features point to high pore fluid pressures during deformation of the sediments, producing hydroplastic structures through mechanisms of granular flow. Such structures are overprinted by microfractures and microfaults (an essentially brittle regime), tracking the change to microfracturing and frictional shear mechanisms accompanying progressive dewatering and sediment lithification. Correlation of the structures observed at the surface with those present at depth was tested through geophysical data (Ground Penetrating Radar, seismics and a magnetic map). EW and NE-trending lineaments are observed in the magnetic map. The seismic sections display several examples of positive flower structures which affect the base of the cretaceous sediments; at higher stratigraphic levels, normal components/slips are compatible with the negative structural inversion characterized at the surface. Such correlations assisted in proposing a structural model compatible with the regional tectonic framework. The strong neogenepleistocene deformation is necessarily propagated in the subsurface, affecting the late cretaceous section (Açu and Jandaíra formations), wich host the hydrocarbon reservoirs in this portion of the Potiguar Basin. The proposed structural model is related to the dextral transcurrent/transform deformation along the Equatorial Margin, associated with transpressive terminations of E-W fault zones, or at their intersections with NE-trending lineaments, such as the Ponta Grossa-Fazenda Belém one (the LPGFB, itself controlled by a Brasiliano-age strike-slip shear zone). In a first step (and possibly during the late Cretaceous to Paleogene), this lineament was activated under a sinistral transpressional regime (antithetic to the main dextral deformation in the E-W zones), giving way to the folds in the lower facies of the Barreiras Formation, as well as the positive flower structures mapped through the seismic sections, at depth. This stage was succeeded (or was penecontemporaneous) by the extensional structures related to a (also sinistral) transtensional movement stage, associated to volcanism (Macau, Messejana) and thermal doming processes during the Neogene-Pleistocene time interval. This structural model has direct implications to hydrocarbon exploration and exploitation activities at this sector of the Potiguar Basin and its offshore continuation. The structure of the reservoirs at depth (Açu Formation sandstones of the post-rift section) may be controlled (or at least, strongly influenced) by the deformation geometry and kinematics characterized at the surface. In addition, the deformation event recognized in the Barreiras Formation has an age close to the one postulated for the oil maturation and migration in the basin, between the Oligocene to the Miocene. In this way, the described structural cenario represents a valid model to understand the conditions of hydrocarbon transport and acummulation through space openings, trap formation and destruction. This model is potentially applicable to the NW region of the Potiguar Basin and other sectors with a similar structural setting, along the brazilian Equatorial Atlantic Margin

Orientação de falhas presentes em testemunhos de sondagens do campo de Xaréu/bacia do Ceará

A research project is being developed by PPGG/UFRN and PETROBRAS in the Xaréu Oil Field located in Ceará Basin, Northeastern Brazil. The objective of the research is to characterize a fractured carbonate reservoir, the Trairi Limestone, in order to drill a borehole with two horizontal legs taking advantage of the natural fracture system to enhance the oil recovery. The present master thesis is part of this research and its contribution is to estimate fault orientation from unoriented cores, using the method proposed by Hesthammer & Henden (2000). In order to orient a fault cutting a bed observed in the core, the bed should be previously oriented. As additional constraint to orient the bed, we use regional bedding orientation obtained from structure maps of Trairi Limestone. Because the number of cores drilled from the Trairi Limestone was too small, we analyzed all cores from the field. As geologic constraint, we admit that all faults were formed as result of the South America and Africa separation, in the context of a regional dextral strike-slip fault formation. In this context, secondary faults are manly T and R faults according Riedel s classification. We analyzed 236.5 m of cores. The dip of bedding varies from 0o to 8o, being the most frequent value equal to 2o. We interpret this result as evidence that the deformation process was manly ruptil. 77 faults were identified in the cores. These faults strike manly to NW and NE with dips, in general, inside the interval 700 - 900. We suggest that the horizontal legs of the borehole should be oriented to NW and NE in order to improve the probability of intercepting open fractures and faults