Plane detection from monocular image sequences

AIRES, Kelson R. T. ; ARAÚJO, Hélder J. ; MEDEIROS, Adelardo A. D. . Plane Detection from Monocular Image Sequences. In: VISUALIZATION, IMAGING AND IMAGE PROCESSING, 2008, Palma de Mallorca, Spain. Proceedings..., Palma de Mallorca: VIIP, 2008

Dream characteristics in a Brazilian sample: an online survey focusing on lucid dreaming

During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional and lacking in rational judgment of their bizarreness. However, during lucid dreaming (LD), subjects know that they are dreaming, and may control oneiric content. Dreaming and LD features have been studied in North Americans, Europeans and Asians, but not among Brazilians, the largest population in Latin America. Here we investigated dreams and LD characteristics in a Brazilian sample (n=3,427; median age=25 years) through an online survey. The subjects reported recalling dreams at least once a week (76%), and that dreams typically depicted actions (93%), known people (92%), sounds/voices (78%), and colored images (76%). The oneiric content was associated with plans for the upcoming days (37%), memories of the previous day (13%), or unrelated to the dreamer (30%). Nightmares usually depicted anxiety/fear (65%), being stalked (48%), or other unpleasant sensations(47%). These data corroborate Freudian notion of day residue in dreams, and suggest that dreams and nightmares are simulations of life situations that are related to our psychobiological integrity. Regarding LD, we observed that 77% of the subjects experienced LD at least once in life (44% up to 10 episodes ever), and for 48% LD subjectively lasted less than 1 min. LD frequency correlated weakly with dream recall frequency (r =0.20,p< 0.01), and LD control was rare (29%). LD occurrence was facilitated when subjects did not need to wake up early (38%), a situation that increases rapid eye movement sleep (REMS) duration, or when subjects were under stress (30%), which increases REMS transitions into waking. These results indicate that LD is relatively ubiquitous but rare, unstable, difficult to control, and facilitated by increases in REMS duration and transitions to wake state. Together with LD incidence in USA, Europe and Asia, our data from Latin America strengthen the notion that LD is a general phenomenon of the human species.

Compressão de Imagens Usando a Função de Peano e a Transformada Wavelet 1D

In this work, spoke about the importance of image compression for the industry, it is known that processing and image storage is always a challenge in petrobrás to optimize the storage time and store a maximum number of images and data. We present an interactive system for processing and storing images in the wavelet domain and an interface for digital image processing. The proposal is based on the Peano function and wavelet transform in 1D. The storage system aims to optimize the computational space, both for storage and for transmission of images. Being necessary to the application of the Peano function to linearize the images and the 1D wavelet transform to decompose it. These applications allow you to extract relevant information for the storage of an image with a lower computational cost and with a very small margin of error when comparing the images, original and processed, ie, there is little loss of quality when applying the processing system presented . The results obtained from the information extracted from the images are displayed in a graphical interface. It is through the graphical user interface that the user uses the files to view and analyze the results of the programs directly on the computer screen without the worry of dealing with the source code. The graphical user interface, programs for image processing via Peano Function and Wavelet Transform 1D, were developed in Java language, allowing a direct exchange of information between them and the user

Teodora e Porcina: faces simbólicas da natureza em narrativas de mulheres sábias

This research looks at the collective imagination in which it keeps alive the issue of heroin wise. Two wise women appear in the narratives of popular history and the History of Donzela Theodora and History Imperatriz Porcina, collated by Luís da Câmara Cascudo in his Five Books of the People. The universality, mobility and circularity of these narratives are discussed by authors such as Bakhtin and Guinzburg. The research is developed from three key categories: Knowledge Magic as the knowledge of tradition (Almeida), sensitive knowledge (Levi-Strauss), thought mythical / magical / symbolic (Morin); Wise Women as carriers of this knowledge, which merge and overlap with the imagery of witches and healers; and Mythical Elements which corresponds to the archetypal images (Jung and Silveira), symbols and other images that relate to the magic universe, the magical beliefs and practices considered, ie belonging to the imaginary magic (Bethencourt). Porcina and Theodora are understood as bearers of knowledge of Métis (Detienne and Vernant), or the cunning intelligence, the manipulation of phármakon (Derrida), the healing potion, which may be the word or ointment of the herb. The route takes us to meet the great archetype of the Wise Woman as psychic power of the feminine, the anima. Narratives are medicinal balms (Estes) and is the clash between the anima and its embodiments by wise women, and animus, his opponents, which gives the transmutation of the psyche, a work comparable to that of alchemyThe Knowledge Magic, operating through the female, myth and nature can recover from its essential value to the emerging paradigm that suggests a more complete human science and a more plural

Natal como destino turístico : um estudo das imagens (re)veladas pela mídia, pelos turistas e suas implicações educacionais e culturais

This thesis is a result of a research on Natal/RN as a tourist destination. We understand that cities are chosen as tourist destinations beyond its cartographic localization, from other dimensions of meanings that, in its set, constitute images. These images are, probably, very different of the images constructed by native and resident populations, who possess relations of identity with the place. The knowledge of the meanings that others attribute to this city as tourist destination, bring us near to the symbolic bonds established by individuals or social groups on the act of their choices, as well as bring us near to the interaction process city-tourists where the expectations are confirmed or not. The images divulgated by the media also participate of the complex formation of the tourist image that is being constructed and available for the different public, in different social contexts. The tourism constitutes a symbolic asset of the modern society, being considered by the studious, as one of the most expressive phenomena of the modernity, for involving each year displacement and the interaction of thousand of people of different cultures in the entire world. All this people s mobilization points to practical social related to personal motivations, to the entailed desired to the idea to travel and to exceed borders. It is already consensus that tourism is a phenomenon of economic growth, generating jobs, income, professional, qualification, bringing improvements for the host cities. Since 1995, in Brazil, the tourism as a sector of the economy, passed to be considered one of the national priorities, and in this perspective, the national politics of the tourism invested in infrastructure of Brazilian cities with high tourist potential, objecting to increase the flows of Brazilian and foreign tourists. Owing to this fact, the country still invests in programs of tourist marketing, mainly divulging the images of the natural beauties of Brazil abroad. And for Brazilians, the campaigns appeal to rescue the feeling to be Brazilian, associating the idea to travel and know its country. Natal city possesses an excellent positioning in the tourist marketing, being predominantly divulgated in national and international level, for its naturalistic singularity, where the images of its natural enchantments as warm water beaches, white dunes, warm weather, constant breeze and an always blue sky are shown as the favorite scene on this city. From what was viewed above that the choice of a tourist destination articulates from a determined imaginary of a place, already constructed or in process of construction, we consider the knowledge of this imaginary a basic learning for the population of the city and especially, for educators, in the formation of professionals in this area and for tourism managers, elaborators of public politics. Based on this estimative, we developed this research that had as a general objective to identify the images that illustrate Natal city as a tourist destination - our objective of study, particularly the meanings and senses attributed by the tourist marketing (hotel s folders) and by the tourists that visited the city during this study. The discussions and reflections that had guided this research had been given from the theoretical link between imaginary and social representation, also considering some interfaces between the fields of communication and symbol. From the studied authors, Baczko (1985) clarifies that the study of social imaginary is directed for the mechanisms and structures of the social life, especially for the intervention accomplishes and efficient of the representations and symbols in the practical collectives, as well as in its direction and orientation . Following this same thought, Moscovici (1978) says that the social representation are produced in communicational and symbolic contexts, and these representations once that already constituted circulate socially as almost tangible entities. Based on this fundament and on the analyze of Barthes (1990), particularly in the approach given to the reading of photographic image, we could observe on hotel s folders that each page evidences senses and meanings of functionality of internal and external spaces, pointing to the way of leisure offered by the keepers of city which is the hotels. About, the leisure that they offer, it is directed to young public, giving meaning to the young myth of personalized leisure tourism on children, young and adults images. The image about security that hotels offer and the singular image of Natal city as a paradise place, provide an idealization of pleasure through the sun, dunes, and beaches and also due to the hospitability of the natives who are assigned as educated . For the tourist that participated on this research, Natal city is tied only by the imaginary of leisure and nature which constitute the emotional link of the relation media-city-tourist. And with such force and fullness of directions the city discloses without tensions and contradictions as a place protected by a mythical and sacred aura. The study also demonstrates us that the potiguar culture remains (almost) forgotten, due to the silenced in this imaginary. In this perspective, we highlight that this culture silence is very close related to the disvalue of education in its general meaning. We defend that the imaginary apprehended constitutes a new reading and a new looking and understanding the tourist reality that comes historically consolidating in this city. In this direction, we glimpse that this study and its future dismemberments can collaborate with the process of rescue the cultural values of the potiguar people, in the way that the meaning of tourist may be redefined, and the tourist image of the city can be also disclosed for its identities particularities of its culture

Uso de renderização volumétrica e realidade virtual para problemas de percolação na engenharia

In the recovering process of oil, rock heterogeneity has a huge impact on how fluids move in the field, defining how much oil can be recovered. In order to study this variability, percolation theory, which describes phenomena involving geometry and connectivity are the bases, is a very useful model. Result of percolation is tridimensional data and have no physical meaning until visualized in form of images or animations. Although a lot of powerful and sophisticated visualization tools have been developed, they focus on generation of planar 2D images. In order to interpret data as they would be in the real world, virtual reality techniques using stereo images could be used. In this work we propose an interactive and helpful tool, named ZSweepVR, based on virtual reality techniques that allows a better comprehension of volumetric data generated by simulation of dynamic percolation. The developed system has the ability to render images using two different techniques: surface rendering and volume rendering. Surface rendering is accomplished by OpenGL directives and volume rendering is accomplished by the Zsweep direct volume rendering engine. In the case of volumetric rendering, we implemented an algorithm to generate stereo images. We also propose enhancements in the original percolation algorithm in order to get a better performance. We applied our developed tools to a mature field database, obtaining satisfactory results. The use of stereoscopic and volumetric images brought valuable contributions for the interpretation and clustering formation analysis in percolation, what certainly could lead to better decisions about the exploration and recovery process in oil fields

A vária máscara de Joana : melancolia em perto do coração selvagem

Entitled Joana s several mask: the melancholy in Perto do coração selvagem, the work is divided in six parts: the first one consists of the elaboration of a theoretical sketch about the melancholy that it offers the presuppositions that orientate the work, it is a short introduction about the study of the melancholy, a report until our time, the against-depressive ones and the arrival of the melancholy in Brazil and their particularities; the second part raises the theme of the melancholy, deepening its conception until what is called creative melancholy spread by Walter Benjamin, it serves as anchor for Clarice s writing and as a potential force for the processes lived by the characters of this writer; the third part examines Clarice Lispector s method emphasizing important points of production related to the theme of the melancholy, her style is the psychological analysis; the last one parts (fourth, fifth and sixth parts) are divided in topics that illustrate the conflicts, in most of the time contradictory, of the protagonist Joana, as well as, her difficult interaction with the things and the people that surround her. The fragmentary writing, the being's essential searches, the proximity with the death, the multiplicity of voices of feminine, De profundis, surrealist images, the incessant search for the thing , trips, epiphany, the flaw in the language, the taste of the badly, everything starting from melancholy - transformation and creation tool. The work about melancholy (Freud, Benjamin, Kristeva), it s place of ambiguous and contradictory movements. It is a trip that leads to several corporal and psychological sensations of Joana, enigma-scenes to be deciphered and conflicting images that make you wake up for a critical vision of the modern society. Since the beginning, something pulses without stopping, an incessant memory and the search for something that is lost. We are before recyclings of the interior/exterior, pain/pleasure, visions, abyss, ecstasy in the future and an exit through the melancholic light

Cidade e identidade: discursividades imagético-espaciais e a construção da identidade espacial do Recife, Veneza Brasileira

This treatise analyzes the identitary setting called Veneza Brasileira (Brazilian Venice) which is subscribed to the discoursive materialization related to the imagetic setting (literary and mediatic) produced about the city of Recife. The main investigation of this research is to examine the way how the identitary setting called Veneza Brasileira has been constructed in the imagetic setting practices about the city of Recife in the nineteenth and twentieth centuries. This study is subscribed to the Applied Linguistics and considers the theoretical perspectives that come from the Cultural Studies which investigation basis is focused on authors such as: Hall (2006); Bauman (1999; 2001;2005); Silva (2000); and Castells (2000) related to the discussion over identity, as well as the discussion over Urban Studies presented in Santos (1997; 1999); Ferrara (1998); and Pesavento (2001). Moreover it is also based on the theoretical basis found in Foucault (2004; 2006; 2007). Furthermore theoretical-methodological approaches rely on the French Discourse Analysis (DA) found in Orlandi (2001); Gregolin (2007); and Courtine (2006). On being so, this treatise aims to: analyze the meaning effects over the production of the identitary setting, especially the so-called Veneza Brasileira, in the imagetic setting discoursive practices (Poems, Post Cards and Touristic Guides) which are produced over the urban setting of the city of Recife. This research is characterized by being qualitative and interpretative and the theoretical analytical approaches contributed to the reading of both poetic and iconic images presented in the excerpts of poems from the nineteenth century and early twentieth century in: Manuel Bandeira s poems, Carlos Pena Filho s poems, and João Cabral de Melo Neto s poems which were produced in the early and late twentieth century. Moreover, this study observed some photographic images in Post Cards and Touristic Guides related to the visiting of historical sites in Recife. One could conclude that the imagetic setting discourse about Recife produced different identitary effects over the so-called Veneza Brasileira along these three centuries: in the nineteenth century, the poetry constructed the utopia city along with the meaning effect of identitary unit; as for the twentieth century, one observed an oscillation between a utopia/heteroutopia city meaning effect of both united and fragmented identity, the latter one is prevalent. As for the twenty-first century, the media reconstructed over again the utopia city, and consequently, produced meaning effect of identitary unit. These same meaning effects of identity either corroborate or contradict to/with the concepts of the postmodernism over identity along these three centuries. In other words, considering the imagetic setting, this oscillation occurs in the proportion of one finds an (ex) inclusion of social agents that construct these same identities.

Machado de Assis em contos :Uma constelação de partituras

This work aims at encouraging the reading or rereading of tales such as Um homem célebre , Cantiga de esponsais , Terpsícore , Trio em lá menor , O machete , and Marcha fúnebre from the Brazilian writer Joaquim Maria Machado de Assis, hoping to find in them the manifestations of musicality, which is understood, from the viewpoint of contemporary musical theories, as dinamicity indications resulting from the melopaico (melodious verse) stimulus to the understanding of words and/or images, which are inserted in the writing static body from the literary procedures transferring to the text specific characteristics from other arts, such as music, poetry, performatic dance e theater. Such procedures, which are reflected in the writing as a product of Machado s close repertory, often favor, through the fiction, the delineation of the musical context from Rio de Janeiro in the 19th century, as well as the social implications that the transformations of the musical scene impose on the subjectivity constitution

Morfologia em alta resolução espacial de estrelas de tipo Mira e R Corenae Borealis

Mira and R Coronae Borealis (R CrB) variable stars are evolved objects surrounded by circumstellar envelopes (CSE) composed of the ejected stellar material. We present a detailed high-spatial resolution morfological study of the CSE of three stars: IRC+10216, the closest and more studied Carbon-Rich Mira; o Ceti, the prototype of the Mira class; and RY Sagitarii (RY Sgr), the brightest R CrB variable of the south hemisphere. JHKL near-infrared adaptive optics images of IRC+10216 with high dynamic range and Vband images with high angular resolution and high depth, collected with the VLT/NACO and VLT/FORS1 instruments, were analyzed. NACO images of o Ceti were also analyzed. Interferometric observations of RY Sgr collected with the VLTI/MIDI instrument allowed us to explore its CSE innermost regions (»20 40 mas). The CSE of IRC+10216 exhibit, in near-infrared, clumps with more complex relative displacements than proposed in previous studies. In V-band, the majority of the non-concentric shells, located in the outer CSE layers, seem to be composed of thinner elongated shells. In a global view, the morphological connection between the shells and the bipolar core of the nebulae, located in the outer layers, together with the clumps, located in the innermost regions, has a difficult interpretation. In the CSE of o Ceti, preliminar results would be indicating the presence of possible clumps. In the innermost regions (.110 UA) of the CSE of RY Sgr, two clouds were detected in different epochs, embedded in a variable gaussian envelope. Based on a rigorous verification, the first cloud was located at »100 R¤ (or »30 AU) from the centre, toward the east-north-east direction (modulo 180o) and the second one was almost at a perpendicular direction, having aproximately 2£ the distance of the first cloud. This study introduces new constraints to the mass-loss history of these kind of variables and to the morphology of their innermost CSE regions

Atividades comportamentais e comportamento alimentar de rã touro, Lithobates catesbeianus (Shaw, 1802), de pigmentação normal e albina em cativeiro

The behavior of bullfrogs reared in captivity must be well understood to support management practices that use efficient feeding regimes. In general, bullfrogs reared in captivity have normal pigmentation, but to develop an enhanced product, some studies have investigated the introduction of albino individuals in frog farms. The present study characterized the behavior of both pigmented and albino bullfrogs reared in captivity. In an initial experiment, 48 bullfrogs (70.5 ± 25.6 g) housed in small stalls were fed once a day at random times. Frogs were filmed and the images showed that both the pigmented and albino varieties behaved similarly: food intake was more frequent at dawn followed by light periods; moving and resting in dry areas may be associated to feeding events; frogs appeared to anticipate feeding time and to rest in the water more frequently in periods other than feeding time; daylight is the recommended period for feeding both pigmented and albino frogs. In a second experiment, 72 albino bullfrogs were fed at fixed times (10 a.m. or 4 p.m.) in small stalls. An initial weight of 23.8 ± 7.6 g was considered to evaluate frog performance, and after the animals reached 60.0 ± 20.0 g, they were filmed for behavior analyses. Food intake varied as a function of feeding time, and frogs were more likely to eat during the early hours of the day and immediately after receiving fresh food. Frogs fed only in the afternoon changed their behavior. Food supplied twice a day stimulated the albino frogs to eat at different times, but did not increase growth. Although fresh food stimulated feeding behavior, food intake was more frequent at dawn. Food supplied at this time of day should therefore be further investigated. The results did not indicate a more suitable feeding time (10 a.m. or 4 p.m.) for albino bullfrogs, or any advantage in using two feedings per day. The results provide xvi important information about bullfrogs in terms of food supply regime and activity preferences throughout the day. This novel information will contribute to future studies in this area

Aspectos epidemiológicos, cognitivo-comportamentais e neurofisiológicos do sonho lúcido

Lucid dreaming (LD) is a mental state in which the subject is aware of being dreaming while dreaming. The prevalence of LD among Europeans, North Americans and Asians is quite variable (between 26 and 92%) (Stepansky et al., 1998; Schredl & Erlacher, 2011; Yu, 2008); in Latin Americans it is yet to be investigated. Furthermore, the neural bases of LD remain controversial. Different studies have observed that LD presents power increases in the alpha frequency band (Tyson et al., 1984), in beta oscillations recorded from the parietal cortex (Holzinger et al., 2006) and in gamma rhythm recorded from the frontal cortex (Voss et al., 2009), in comparison with non-lucid dreaming. In this thesis we report epidemiological and neurophysiological investigations of LD. To investigate the epidemiology of LD (Study 1), we developed an online questionnaire about dreams that was answered by 3,427 volunteers. In this sample, 56% were women, 24% were men and 20% did not inform their gender (the median age was 25 years). A total of 76.5% of the subjects reported recalling dreams at least once a week, and about two-thirds of them reported dreaming always in the first person, i.e. when the dreamer observes the dream from within itself, not as another dream character. Dream reports typically depicted actions (93.3%), known people (92.9%), sounds/voices (78.5%), and colored images (76.3%). The oneiric content was related to plans for upcoming days (37.8%), and memories of the previous day (13.8%). Nightmares were characterized by general anxiety/fear (65.5%), feeling of being chased (48.5%), and non-painful unpleasant sensations (47.6%). With regard to LD, 77.2% of the subjects reported having experienced LD at least once in their lifetime (44.9% reported up to 10 episodes ever). LD frequency was weakly correlated with dream recall frequency (r = 0.20, p <0.001) and was higher in men (χ2=10.2, p=0.001). The control of LD was rare (29.7%) and inversely correlated with LD duration (r=-0.38, p <0.001), which is usually short: to 48.5% of the subjects, LD takes less than 1 minute. LD occurrence is mainly associated with having sleep without a fixed time to wake up (38.3%), which increases the chance of having REM sleep (REMS). LD is also associated with stress (30.1%), which increases REMS transitions into wakefulness. Overall, the data suggest that dreams and nightmares can be evolutionarily understood as a simulation of the common situations that happen in life, and that are related to our social, psychological and biological integrity. The results also indicate that LD is a relatively common experience (but not recurrent), often elusive and difficult to control, suggesting that LD is an incomplete stationary stage (or phase transition) between REMS and wake state. Moreover, despite the variability of LD prevalence among North Americans, Europeans and Asians, our data from Latin Americans strengthens the notion that LD is a general phenomenon of the human species. To further investigate the neural bases of LD (Study 2), we performed sleep recordings of 32 non-frequent lucid dreamers (sample 1) and 6 frequent lucid dreamers (sample 2). In sample 1, we applied two cognitive-behavioral techniques to induce LD: presleep LD suggestion (n=8) and light pulses applied during REMS (n=8); in a control group we made no attempt to influence dreaming (n=16). The results indicate that it is quite difficult but still possible to induce LD, since we could induce LD in a single subject, using the suggestion technique. EEG signals from this one subject exhibited alpha (7-14 Hz) bursts prior to LD. These bursts were brief (about 3s), without significant change in muscle tone, and independent of the presence of rapid eye movements. No such bursts were observed in the remaining 31 subjects. In addition, LD exhibited significantly higher occipital alpha and right temporo-parietal gamma (30-50 Hz) power, in comparison with non-lucid REMS. In sample 2, LD presented increased frontal high-gamma (50-100 Hz) power on average, in comparison with non-lucid REMS; however, this was not consistent across all subjects, being a clear phenomenon in just one subject. We also observed that four of these volunteers showed an increase in alpha rhythm power over the occipital region, immediately before or during LD. Altogether, our preliminary results suggest that LD presents neurophysiological characteristics that make it different from both waking and the typical REMS. To the extent that the right temporo-parietal and frontal regions are related to the formation of selfconsciousness and body internal image, we suggest that an increased activity in these regions during sleep may be the neurobiological mechanism underlying LD. The alpha rhythm bursts, as well as the alpha power increase over the occipital region, may represent micro-arousals, which facilitate the contact of the brain during sleep with the external environment, favoring the occurrence of LD. This also strengthens the notion that LD is an intermediary state between sleep and wakefulness

Compreendendo como as crianças significam o direito de brincar

This research aimed to understand how children mean the right to play. For that, assumes that the children composed a social category generational, with children experiencing their own skills, the result of the mediated relationship with the social and its transformative capacity. Adding to that, they are subject of duties with competence to means your own condition. After a long history of repression and an intense political struggle, the Doctrine of Integral Protection is inaugurated in Brazil and the Citizen (1889), which regulates the fundamental rights of all children and adolescents. Among these rights is the right to play. However, it is sufficient to provide by law, it is necessary to break with the diminishment of the play activity, still present in our society, watching it as a structuring activity of the subject and ensuring the enforcement of this right. Considering the child as the central focus of research, the research was conducted in a public school education. The subjects were six children of six years old, enrolled in 1st year of elementary school. The procedures employed for constituting the corpus of the research were: observation of children at school meetings and dialogue, monitoring of play resources such as drawings, cartoons and representative images of child rights. Also, the parents were interviewed with the goal to enlarge the understanding the context of the child. With the thematic content analysis, we raise two areas: play and children's rights. The results showed that children, however don‟t have a systematized knowledge about child rights , they understand that any elements are important for the children and your development, being the play the most recurrent, followed by education and family. The right to play configure as a necessity of the child, that even if she does not understand conceptually as a right, she feels the importance of living of the play activity

Evolução geodinâmica e condicionamento estrutural dos terrenos Piancó-Alto Brígida e Alto Pajeú, domínio da zona transversal, NE do Brasil

This thesis aims to advance in the geological knowledge of the region comprising the Piancó-Alto Brígida (TPAB) and Alto pajeú (TAP) terranes, in the Transversal Zone Domain (Borborema Province, NE Brazil), with the main objective of understanding the geodynamic evolution and the structural framework of these units. To reach this objective, and besides field work and interpretation of traditional aerial photographs, other tools were employed like of remote sensing products (Landsat 7 ETM+, aeroradiometrics, aeromagnetics and topographical images), lithogeochemical (whole rock) analyses and geochronological dating (U-Pb in zircon), besides integration with literature data. In the area, several precambrian geological units outcrop, represented in the TAP by the paleoproterozoic Serra Talhada and Afogados da Ingazeira complexes, Riacho Gravatá Complex (metavolcano-sedimentary sequence of Stenian-Tonian age) and Cariris Velhos orthogneisses (of Tonian age). The TPAB comprises the Santana do Garrote (lower unit) and Serra do Olho d'Água (upper unit) formations of the Cachoeirinha Group (Neoproterozoic III), besides the Piancó orthogneisses and Bom Jesus paragneisses; the latter correspond to an older (basement ?) block and a possible high grade equivalent of the Cachoeirinha Group (or Seridó Group ?), respectively. Several Brasiliano-age plutons occur in both terranes.The aeromagnetic data show the continuity, at depth, of the main shear zones mapped in the region. The Patos, Pernambuco, Boqueirão dos Cochos, Serra do Caboclo, Afogados da Ingazeira/Jabitacá and Congo-Cruzeiro do Nordeste shear zones reach depths greater than to 6-16 km. The aeromagnetic signature of other shear zones, like the Juru one, suggests that these structures correspond to shallower crustal features. The satellite images (Landsat 7 ETM+) and aerogamaspectrometric images discriminate different geological units, contributing to the mapping of the structural framework of the region. The Serra do Caboclo Shear Zone was characterized as the boundary/suture between the TPAB and TAP. This structure is an outstanding, pervasive feature that separates contrasting geological units, such as the Neoproterozoic III Cachoeirinha Group in the TPAB and the Riacho Gravatá Complex and the Cariris Velhos metaplutonics, of Stenian-Tonian age, in the TAP. Occupying different blocks, these units are not found in authoctonous relations, like unconformities and intrusive contacts. Concerning the Cariris Velhos (ca. 1,0 Ga old) event is recorded by radiometric ages of the Riacho Gravatá Complex metavolcanics and intrusive augen and orthogneisses, all of them displaying geochemical affinities of arc or collisional settings. A structural signature of this event was not recorded in the region, possibly due to its low grade/low strain style, obliterated by the overprinting of younger, higher grade/high strain Brasiliano-age fabrics.The first tectonic event (D1) observed in the Cariris Velhos lithotypes presents contractional kinematics with transport to the NW. Neoproterozoic III geochronologic dates, obtained in late-D1 granitoids, imply a Brasiliano age (ca. 610-600 Ma) for this deformation event. The second tectonic event (D2) characterized in the region corresponds to the Brasiliano transcurrent kinematics of the outstanding shear zones and associated granitoid plutons. The geochronological (U-Pb in zircon) data obtained during this thesis also confirms the occurrence of the Cariris Velhos magmatic suite in the TAP, as well as the Neoproterozoic III age to the Cachoeirinha Group in the TPAB. The TAP (Riacho Gravatá Complex, augen and orthogneisses) is interpreted as a continental arc possibly accreted to a microcontinent during the Cariris Velhos (Stenian-Tonian) event. Later on, this terrane collided with the TPAB at the beginning of the Brasiliano orogeny (D1 contractional deformation), and both domins were reworked by the transcurrent shear deformation of the D2 event

Reavaliação de critérios estruturais na hidrogeologia de terrenos cristalinos, com ênfase na neotectônica e sensoriamento remoto

Hydrogeological prospecting in Northeast Brazil and in other crystalline terrains has been developed on the basis of structural and regional geology concepts that date back to the 50-60 decades and, as such, demand a natural re-evaluation and update. In this kind of terrain, the percolation and accumulation of ground water are controlled by fractures and other types of discontinuities, such as foliations and geological contacts that, through weathering, impart porosity and permeability to the rocks, allowing water flow and storage. Several factors should be considered in the process of locating water wells, as discussed in the literature. Among these, the kind of structures, fracture geometry (including aperture and connectivity) and their geological and chronological context. It is important to correlate fracture systems with the regional neotectonic framework. Fractures at low angle (sub parallel) with the principal stress axis (s1) are those which tend to open (actually they work as tension joints) and, in principle, would present major hydric potential; in the opposite side, fractures at high angle to s1 would behave as closed by a compressional component. Fractures diagonal to the compression and tension axes correspond to shear fractures and, due to their connectivity with second fractures, are also important in terms of hydric potential. Uplift followed by terrain denudation leads to decompression and a general tendency to open (aided by weathering processes) fractures and other rock discontinuities, at different orientations. Low angle fractures, formed in this context, are equally important to increase connectivity, collection of water and recharge of the aquifer systems. In a general way, an opening component (neotectonic or by terrain decompression) and several models to increase fracture connectivity correlate with a greater hydric potential of these structures. Together with parallel research, this thesis addresses models of ground water occurrence in crystalline terrains, either improving well established concepts like the (Riacho-Fenda model), but also stressing other possibilities, like the role of alluvium and paleo-regoliths (the Calha Elúvio-Aluvionar model) and of strongly altered, permo-porous zones placed at variable depths below the present surface, flanking several types of discontinuities, especially interconnected fracture arrays (the Bolsões de Intemperismo model). Different methodological approaches are also discussed in order to improve success rates in the location of water wells in crystalline terrains. In this methodological review, a number of case studies were selected in the eastern domain of the State of Rio Grande do Norte, involving the localities of Santa Cruz, Santo Antônio, Serrinha, Nova Cruz, Montanhas, Lagoa de Pedras and Lagoa Salgada. Besides the neotectonic analysis of brittle structures, this Thesis addresses the validation of remote sensing as a tool for ground water prospecting. Several techniques were tested in order to detect and select areas with higher potential for ground water accumulation, using Landsat 5-TM and RADARSAT images, besides conventional aerial photos. A number of filters were tested to emphasize lineaments in the images, improving their discrimination, to identify areas with higher overburden humidity, which could reflect subsurface water accumulation, as well as alluvium and other sedimentary covers that might act as recharge zones. The work started with a regional analysis with the orbital images, followed by analysis of aerial photos, up to a detailed structural study of rock exposures in the terrain. This last step involved the analysis of outcrops surrounding wells (in a ray of approximately 10 to 100 m) with distinct productivities, including dry examples. At the level required for detail, it was not possible to accomplish a statistical approach using the available well data catalogs, which lack the desired specific information. The methodology worked out in this Thesis must undergo a testing phase through location of new water wells. An increase in the success rates as desired will led to a further consolidation step with wider divulgation of the methodology to private companies and governmental agencies involved in ground water prospecting in crystalline terrains