Corpo e fronteira: o diário de Samuel Fritz e a conquista do espaço amazônico

Considering that the Jesuitical tradition which Father Samuel Fritz belonged, has a clear political and institutional dimension that reveals itself in the missionary initiative placed since the Trento Council, his journal is a experience story as missionary at Maynás region during the period from 1686 until 1725. In his narrative, a series of data related to the conquer of Amazonia, conflicts among the Iberic Kingdoms and french, dutches and british, transformation of culture and space close the period of the Madrid Deal. I´ll explore the men and space relationship, in this case, the missionary in his special practice, therefore an effective and geometrical politic for border control was only applied at 1750 with reformist governments and that Amazônia was, until now, an object of autonomous initiatives, not being until now a priority focused state politics action like the ones in the central regions (silver mines) and that the missionary action of Samuel Fritz represented ant that moment represented the most important border advance to the Spanish Kingdom, coinciding with the end of the borders previously set in Madrid and Santo Idelfonso, I´ll put the question of how and with which politics the experience of Fritz in Maynás could represent an advance about Amazônia space. Then I´ll approach the problem about three aspects that are chapters: The first one was focused to the Iberic Kingdoms atlantic politics and the internal geopolitical relationships they created as the centre and the border emerging a new order; in the second chapter I studied the special transformation cause by the encounter and conflicts between the Indian and European order generating a new organization; in the third chapter I´ll examined the political border of the state and the emergency of the missionary body as an institution, with the tradition and missionary action as support, or not, to the exploration of the east border of Spanish America influencing the delimitation process of the border between Portugal and Spain

Os Centros de Especialidades Odontológicas como suporte da atenção básica: uma avaliação na perspectiva da integralidade

The public dental services in Brazil were limited, practically, to the basic care, so that the specialized services acted, up to 2002, no more than 3,5% of the total of clinical procedures. That lower offer reveals the difficulty of continuity of the attention, that is, the comprehensiveness in the assistance, particulary, the reference and counter-reference system. Brasil Sorridente search to supply those needs when proposing Speciality Dental's Centers(CEOs Centros de Especialidades Odontológicas, Brazil) to compose the services of average complexity. In 2005, Ministry of Health enabled the three CEOs of Natal, located in the North II, East and West Sanitary Districts. This investigation evaluated the implantation of these CEOs, as support of the family health care teams, in the perspective of organization of the services in assistencial nets in Natal/RN. It was a study of evaluation, with qualitative approach and some quantitative data as contribution. Dentists, users and managers were interviewed to identify and to understand their perceptions, relationships and experiences in the daily of the services. The conceptual base that orientated the investigation was the principle of comprehensiveness, in its operational sense of the hierarchization in health attention levels. The collection of data was done with documental research, direct observation and semi-structured interview. The analysis was accomplished by triangulation of the extracted content from the used techniques and sources of interviewed groups depositions, looking for theoretical-conceptual support in specific bibliography. The results pointed aspects that go away from the comprehensiveness like: low resolution of problems in the basic net; little valorization of the space in the health units; traditional models of access to health services, insufficient offer for some specialties, compromising the reference and counter-reference system; practices centered in procedures in the CEO; bureaucratic directions from basic care to the specialized service; disintegrated and disjointed system among levels of attention; disrespect to the municipal protocol. On the other hand, there is an approach of compreensiveness in situations like: increase of the access and covering in the Family Health Strategy (ESF Estratégia Saúde da Família, Brazil); larger approach between professional and user; tendency to the quantitative and qualitative growth of specialized actions; punctual initiatives of relationships among levels; existence of protocol to guide professionals

Levantamento exploratório da composição e frações proteicas do leite bovino em propriedades leiteras

The direct relationship with the processing, industrial yield and price of milk, the importance of the centesimal composition of milk and their protein fractions has increased for both the dairy industry and for the producers, so it is important to identify the possible causes on variation of these components. The aim of this study was to evaluate the effect of the seasons, order of calving and lactation phase on milk composition and protein fractions in dairy farms in the Agreste and Leste meso-regions, of Rio Grande do Norte State (RN). Milk samples were taken in seven milk farms directly from the bulk tanks except for one farm where samples were taken from higher milking cows producers and heifers. The experiment was done in seven properties with milk samples taken directly from the bulk tanks and in one property were collected from higher production cows and heifers. Composition analyses were carried out for both experiments and sensorial trial was performed for the second experiment only. The data results were submitted to analysis of variance (ANOVA) and Tukey test performed for 5% significance level. In the first experiment was observed response of the seasons, dry and rainy season; while in the second, the effect of the order of calving and lactation phase had influence on milk composition and protein fractions. There was significant response (p < 0.05) for season effects but due to farms. The rainy season had higher averages in the protein, lactose, total solids and nonfat dry extract. Multiparous cows had higher CCS, NUL and PCAS milk contents; while, first calving heifers showed higher average for the sensory attribute, color of milk. The final third of lactation was responsible for the elevation of the levels of almost all milk components and their protein fractions

Estratégias de cuidado integral à saúde: os CAPS no processo de implementação do apoio matricial em Natal/RN

This study aims to analyzing the implementation of the Matrix Support proposal with professionals of Substitutive Services in Mental Health in the city of Natal/RN. The Matrix Support (MS) is an institutional arrangement which has been recently adopted by the Health Ministry, as an administrative strategy, for the construction of a wide care net in Mental Health, deviating the logic of indiscriminate follow-through changed by one of co-responsibility. In addition to this, its goal is to promote a major resolution as regards health assistance. Integral attention, as it is intended by the unique health system, may be reached by means of knowledge and practices interchange, establishing an interdisciplinary work logic, through an interconnected net of health services. For the accomplishment of this study, individual interviews of semi-structured character were used as instrument, with the coordinators and technical staff of the CAPs. The data collection was done in the following services: CAPS II ( East and West) and CAPS ad ( North and East), in the city of Natal/RN. The results point out that the CAPs to initiate of the discussion the process in the implementation of the MS aiming, to promote the reorganization and redefinition of the flow in the net, thus not acting in a fragmented way. Nevertheless, there is no effective articulation concerning the basic attention services, there is a major focus of the attention in mental health on the specialized services, little insertion in the territory and in the everyday life of the community

Ajuda mútua nos CAPS: o papel dos serviços no empoderamento dos usuários

The research objective is explore practices to mutual help between CAPS users from the east and west regions of the city of Natal, RN, in Brazil. In the mental health field, we observe the care from substitutive services is based on technical knowledge where the person of the mental health professional is predominant. The Brazilian psychiatry reform invests in equipments and mental health care protocols, but it is necessary to invest more vigorously in new strategies and actors capable of obtaining resources to achieve this goal, such as the users. If one cornerstone of the psychiatric reform consists of changing the type of relationship established with the person with mental disorders, why this relationship, nowadays, is still dominated by technique and unevenness, where on one side we have a person who knows something and who needs take care of someone, and on other side we have another who knows nothing and thus needs to be cared for? Starting from this problematization of the traditional methods of health/mental health care, an attempt was made to investigate in what ways the mutual help practices between people with mental disorders can realize potential avenues not yet explored within the scope of psychiatric reform. The objective of this research was to map possible mutual help practices among the users, and the technical understanding of such practices. For that, we took part in the daily activities of the CAPS, mapping the experiences of mutual help among users. In addition, we accompanied the users in external activities (such as return home, trips, etc), and we had roundtables with the professionals. The research was guided by theoretical methodological references of the institutional analysis. The results pointed to a lack of behaviors of mutual help or support among users, something that can probably be explained by the service work dynamics, as well as the relationship between technicians and users, which has a tendency to create hurdles for meetings among users, as well as being non-conducive to theirempowerment

Acessibilidade aos espaços urbanos :uma dimensão psicológica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Custo para implantação de Astronium fraxinifolium schott em área degradada utilizando-se adubos verdes e lodo de esgoto

A utilização de recursos naturais e a necessidade de recuperação de áreas degradadas têm assumido importância global, sendo que a estimativa de custos garante a viabilidade econômica, para implantação de projetos de conservação ou recuperação. Foram estimados os custos para implantação de um hectare da espécie arbórea Gonçalo-Alves (Astonium fraxinifolium Schott), com adubação verde, em Latossolo Vermelho degradado, como se segue: Gonçalo-Alves + Feijão-de-porco; Gonçalo-Alves + crotalária; Gonçalo-Alves + fórmula NPK (04-14-08); e Gonçalo-Alves + braquiária + lodo. A estimativa do custo de implantação de Gonçalo-Alves, para a região leste do Estado do Mato Grosso do Sul, variou entre R$ 2.829,13 e R$ 3.872,21. O tratamento com braquiária + lodo de esgoto foi o mais econômico, considerando-se um período de cinco anos, além dos benefícios ambientais relacionados ao descarte viável deste resíduo, por estações de tratamento de esgoto.

A juventude de Mãe Luíza e o seu lugar social no cenário urbano

It discusses the social place occupied by the youth of outlying areas in the urban social imaginary. Having the stigma issue as an axle, it presents the essential categories to its understanding, such as (in)visibility, violence and exclusion, pointing out this quarrel in a social- anthropologychal approach. The research was carried through with teenagers of the age band from 15 to 24 years old, living in Mãe Luiza neighborhood, a popular quarter of Natal s east zone, that has close to 16.000 inhabitants. Quantitative methods had been used, through questionnaires application to 364 teenagers; and qualitative methods through the accomplishment of 5 focal groups with the adolescents. The results point a strong youth concern regarding the quarter daily violence; and the weaved image in the urban social imaginary of the neighborhood As dangerous", "violent". It is also possible to perceive the social groups diversity, in general, related with churches and cultural activities, which are important catalysers of the envolvement process of the youth with the quarter

Estudo teórico-bioclimático da potencialidade de desenvolvimento do Aedes aegypti no estado do Rio Grande do Norte

In the current climate of global public health there is the emergence of urban dengue, a disease regarded as acute infectious fever. The disease annually, has affected millions of people worldwide, mostly in the range of the intertropical globe. The disease's main vector in urban areas, the Aedes aegypti mosquito. Recent studies indicate that the distribution of the insect vector of dengue in the geographical area is directly tied to the behavior of environmental restrictions that area, especially among those, the air temperature and relative humidity. From that context, the work aims to estimate and spatializing, monthly, for each municipality in the state of Rio Grande do Norte, the potential of biophysical conditions conducive to the development of Aedes aegypti. Yet, made use of the following methodology: collection of epidemiological data and climatological, Normal climatological, descriptive statistics (measures of central tendency and scatter), uniform distribution, estimation geostatistics and sufer program, version 8.0. The results flagged for a behavior very heterogeneous, both in space and in time, in the case of the potential of biophysical conditions conducive to the development of Aedes aegypti in the state of Rio Grande do Norte. Still, he noted that there is a tendency for lifting the potential of development for the entire state, from the month of January, ending in the month of April mainly in central and western portions of the state. By contrast, there is the permanence of increased potential for development in the eastern portion of the state. The latter record maximum potential in the month of July, resulting probability of greater than 70% have been favorable conditions for the development of Aedes aegypti in that area. In the period between the months of August to December, it is small potential for development of Aedes aegypti in all parts of the state

Potencialidade à degradação na microbacia Riacho Passagem/RN

A degradação dos recursos naturais é talvez o principal problema da região do semiárido brasileiro, e essa degradação é principalmente resultante das perdas de solo, decorrente do processo erosivo. Na busca de melhor conhecer esta problemática vem sendo empregado o processo de modelagem ambiental, cujo objetivo é identificar e propor soluções para a degradação dos solos. Nesse sentido, o trabalho aplica o modelo da Equação Universal de Perda de Solos (EUPS), desenvolvido nos Estados Unidos ao longo da década de 1950, agregado as ferramentas de geoprocessamento, informações de sensoriamento remoto e Sistemas de Informações Geográficas (SIGs). A área de estudo é a Microbacia Riacho Passagem localizada na região oeste do Estado do Rio Grande do Norte, a microbacia tem uma área de 221,7Km² e esta inserida no semiárido, região Nordeste do Brasil. A metodologia utilizada consiste: em agrupar as variáveis da EUPS no ambiente SIG utilizando imagens de satélite, levantamentos bibliográficos e trabalhos de campo. Para determinação das extensões das vertentes foi empregado o Modelo RAMPA, e para adequar a EUPS as condições da área de estudo, foram realizados ajuste através de modelos estatísticos, aperfeiçoando o trabalho e os resultados gerados pelo modelo. Ao fim do processo foi desenvolvida uma pseudo linguagem no aplicativo Linguagem Espacial para Geoprocessamento Algébrico (LEGAL) disponível no software SPRING versão 5.1.2 servindo de suporte para o processamento das informações contidas no banco de dados, base da EUPS. Os resultados demonstram que inicialmente é necessário delimitar com precisão o período seco e chuvoso, informação fundamental para a EUPS, uma vez que o trabalho busca identificar a perda de solo por erosão hídrica. O modelo RAMPA apresentou-se satisfatório e com elevado potencial de aplicação na determinação dos comprimentos de vertentes utilizando imagens de radar. Quanto ao comportamento das extensões de vertentes, na microbacia, o mesmo apresentou uma pequena variação na porção leste, maiores vertentes, área próxima a desembocadura. Após a aplicação do modelo o valor máximo de perda de solo foi 88 ton/ha.ano com núcleos localizados no NEOSSOLOS LITÓLICOS e o mínimo 0,01 ton/ha.ano localizado no domínio dos LATOSSOLOS e NEOSSOLOS FLÚVICOS. A erosão provoca diminuição do perfil de solo, principalmente nos NEOSSOLOS LITÓLICOS, resultando em alteração no balanço hídrico e conseqüentemente aumento da temperatura do solo, podendo desencadear a desertificação. Os resultados e a metodologia do presente trabalho poderão ser aplicados na busca pelo desenvolvimento sustentável, na região do semiárido brasileiro, auxiliando na compreensão do binômio uso do solo e capacidade de suporte do meio natural.

Influencia do turismo sobre a atividade pesqueira do município de Tibal do Sul-RN

A área da pesquisa localiza-se no município de Tibau do Sul, situado na costa leste do Estado do Rio Grande do Norte, a 80 km ao Sul da capital Natal. O turismo, a pesca esportiva e instalação de empreendimentos vêm aumentando nessa área litorânea, disputando espaços com pescadores artesanais. A dissertação teve como objetivo identificar e analisar os conflitos socioeconômicos e ambientais entre a atividade pesqueira e a atividade turística no Município de Tibau do Sul, para subsidiar órgãos governamentais e entidades ligadas ao setor pesqueiro, com futuras políticas de incentivo e desenvolvimento sustentável local. O presente trabalho está dividido em introdução e dois capítulos. A introdução apresenta proposta e justificativa da pesquisa, com fundamentação teórica, em seguida são apresentados os procedimentos metodológicos. O primeiro capítulo apresenta a caracterização da pesca artesanal e o perfil socioeconômico dos pescadores de Tibau do Sul, identificando os conflitos entre a atividade pesqueira e o turismo. Para alcançar esse propósito, foram realizados levantamentos qualitativos e quantitativos, através da efetivação de 100 entrevistas com questionários semiestruturados, os quais foram aplicados a quatro comunidades pesqueiras. Os resultados constataram a real situação da pesca artesanal local e foram identificados vários conflitos, dentre eles: a falta de investimento no setor, baixo desenvolvimento tecnológico e de infraestrutura, além da ocupação desordenada em área de desembarque da produção. Todos esses fatores têm contribuído para o declínio da atividade pesqueira nesse município. O segundo capítulo apresenta uma análise territorial a partir da elaboração do mapa de ocupação do solo utilizando a metodologia de geoprocessamento. Constatou-se que a ocupação desordenada ocorreu principalmente depois da chegada dos turistas em Tibau do Sul e está concentrada principalmente na praia de Pipa, observou-se também que os empreendimentos construídos na área de estudo interferem no acesso público as praias e área de desembarque da produção dos pescadores. Espera-se que este estudo contribua para elaboração do plano de manejo nas comunidades pesqueiras e possa subsidiar os gestores na implementação de políticas públicas voltadas para o desenvolvimento sustentável local

Percepção de riscos ambientais de populações vulneráveis a inundações e deslizamentos de dunas em Natal-RN

In urban, flooding and landslides are among the troubles that most bring human and material loss. Therefore, this study objected to perform an analysis on the risk perception on the population living in social environmental vulnerable places in order to understand what is the way this population realize the risks they are exposed to and what are the outbrave strategies the develop. The first analyzed area was Complexo Passo da Pátria for the flooding risk problematic and then the Cidade Nova neighborhood threatened by the dunes slides. The areas locate, respectively, in the West and East zones of Natal-RN. Using an interview screenplay adapted from risk perception researches from different brazilian cities, it was collected primarily data on the variables: perception, evaluation and choice, safety threshold, adjustment, decision and participation. Due to the studied areas characteristics the qualitative approach adjusted itself to the difficulties for accessing the areas. The studied places characterize for its insecure situation like selling/using drugs, robbery and murder among others. Due to this situation the interviewed individuals were the ones that could be found more accessibly and available in the moment and the interviews were made in the community leader presence of each area. Through the discourse of the respondents analysis it was able to conclude that the interviewed population is exposed to a high vulnerability grade and risks. However it was identified substantial differences between the perception and risks of Complexo Passo da Pátria and bairro Cidade Nova, because in the first area the intervied ones can recognize the high risk they are exposed to in a more emphatic way to the interviewed ones for the Cidade Nova neighborhood. Furthermore, there is a heavy dissatisfaction for the population of the two places about the city hall positions relating to the present problems in the studied areas. It was also identified the strategy development of acquaintanceship with the risk in the research places beyond a feeling of belonging and affection between the dwellers and the places, yet it was more evident for Complexo Passo da Pátria. Though this analysis it was possible to understand and perceptions and the behavior of the individuals or social groups facing the risks as acceptance and rejection of determined risks beyond adaptation measures of living together with the persistence presence of risks. Therefore, qualitative nature researches emphasizing the perception approach are in the fundamental importance in the studies about risks making it possible to offer aids to the urban planning and management in the implement of effective preventive measures and compatible with the population aims

Protozoários de vida livre em dois trechos da bacia hidrográfica do rio pirangi (RN): relações com a educação em ciências e preservação

The vast hidric wealth of Brazil gets its watersheds more susceptible to impacts that compromise the water quality, affecting the ecosystem stability of aquatic environments. The decrease in the quality of water resources also results in a decrease of its multiple uses, especially in tourist areas of the coast, where the continuous flow of people to these sites increases even further the probability of inappropriate behavior of both tourists and local residents. Studies regarding the microbiological communities are still scarce, especially on the free-living protozoa that play unique roles in the food chain of aquatic ecosystems. Due to the large role played by this group of microorganisms in aquatic environments, the present study aimed at identifying the genus and species of free-living protozoa present in two sections of the Pium River, east coast of Rio Grande do Norte, making an association between the its occurrence and trophic conditions of the environment in which they are, also checking the bioindicator capacity of these organisms in water quality. It also aimed to conduct a survey with students to identify the main difficulties regarding the knowledge of free-living protozoa and hydric transmission diseases in two public schools near the river studied in the Pium district, county of Parnamirim. The survey was analyzed by means of questionnaires at both schools. Students identified several activities developed Pium river, highlighting its multifunctionality and importance to the region. A total of 76 taxa of free-living protozoa was recorded, of these, 33 were ciliates, 19 flagellates and 24 sarcodia. The spatial and temporal patterns of these organisms to both points studied revealed the bioindicator potentiality of some effective species identified. However, knowledge about the free-living protozoa proved quite lagged, presenting misconceptions that show them as pathogenic organisms exclusively, totally disregarding their ecological role. In order to remedy the flaws existing in students in relation to the functional role of protozoa, workshops were planned on these microorganisms while also addressing issues related to hydric transmission diseases through lectures, recreational activities and interactive presentations. These practical activities of Science Education had the goal of bringing students the context of local water resources, aiming to promote a greater clarification regarding of the functional role of free-living protozoa in aquatic environments

Arcabouço geofísico, isostasia e causas do magmatismo cenozóico da província Borborema e de sua margem continental (Nordeste do Brasil)

The Borborema Province (BP) is a geologic domain located in Northeastern Brazil. The BP is limited at the south by the São Francisco craton, at the west by the Parnaíba basin, and both at the north and east by coastal sedimentary basins. Nonetheless the BP surface geology is well known, several key aspects of its evolution are still open, notably: i)its tectonic compartmentalization established after the Brasiliano orogenesis, ii) the architecture of its cretaceous continental margin, iii) the elastic properties of its lithosphere, and iv) the causes of magmatism and uplifting which occurred in the Cenozoic. In this thesis, a regional coverage of geophysical data (elevation, gravity, magnetic, geoid height, and surface wave global tomography) were integrated with surface geologic information aiming to attain a better understanding of the above questions. In the Riacho do Pontal belt and in the western sector of the Sergipano belt, the neoproterozoic suture of the collision of the Sul domain of the BP with the Sanfranciscana plate (SFP) is correlated with an expressive dipolar gravity anomaly. The positive lobule of this anomaly is due to the BP lower continental crust uplifting whilst the negative lobule is due to the supracrustal nappes overthrusting the SFP. In the eastern sector of the Sergipano belt, this dipolar gravity anomaly does not exist. However the suture still can be identified at the southern sector of the Marancó complex arc, alongside of the Porto da Folha shear zone, where the SFP N-S geophysical alignments are truncated. The boundary associated to the collision of the Ceará domain of the BP with the West African craton is also correlated with a dipolar gravity anomaly. The positive lobule of this anomaly coincides with the Sobral-Pedro II shear zone whilst the negative lobule is associated with the Santa Quitéria magmatic arc. Judging by their geophysical signatures, the major BP internal boundaries are: i)the western sector of the Pernambuco shear zone and the eastern continuation of this shear zone as the Congo shear zone, ii) the Patos shear zone, and iii) the Jaguaribe shear zone and its southwestern continuation as the Tatajuba shear zone. These boundaries divide the BP in five tectonic domains in the geophysical criteria: Sul, Transversal, Rio Grande do Norte, Ceará, and Médio Coreaú. The Sul domain is characterized by geophysical signatures associated with the BP and SFP collision. The fact that Congo shear zone is now proposed as part of the Transversal domain boundary implies an important change in the original definition of this domain. The Rio Grande do Norte domain presents a highly magnetized crust resulted from the superposition of precambrian and phanerozoic events. The Ceará domain is divided by the Senador Pompeu shear zone in two subdomains: the eastern one corresponds to the Orós-Jaguaribe belt and the western one to the Ceará-Central subdomain. The latter subdomain exhibits a positive ENE-W SW gravity anomaly which was associated to a crustal discontinuity. This discontinuity would have acted as a rampart against to the N-S Brasiliano orogenic nappes. The Médio Coreaú domain also presents a dipolar gravity anomaly. Its positive lobule is due to granulitic rocks whereas the negative one is caused by supracrustal rocks. The boundary between Médio Coreaú and Ceará domains can be traced below the Parnaíba basin sediments by its geophysical signature. The joint analysis of free air anomalies, free air admittances, and effective elastic thickness estimates (Te) revealed that the Brazilian East and Equatorial continental margins have quite different elastic properties. In the first one 10 km < Te < 20 km whereas in the second one Te ≤ 10 km. The weakness of the Equatorial margin lithosphere was caused by the cenozoic magmatism. The BP continental margin presents segmentations; some of them have inheritance from precambrian structures and domains. The segmentations conform markedly with some sedimentary basin features which are below described from south to north. The limit between Sergipe and Alagoas subbasins coincides with the suture between BP and SFP. Te estimates indicates concordantly that in Sergipe subbasin Te is around 20 km while Alagoas subbasin has Te around 10 km, thus revealing that the lithosphere in the Sergipe subbasin has a greater rigidity than the lithosphere in the Alagoas subbasin. Additionally inside the crust beneath Sergipe subbasin occurs a very dense body (underplating or crustal heritage?) which is not present in the crust beneath Alagoas subbasin. The continental margin of the Pernambuco basin (15 < Te < 25 km) presents a very distinct free air edge effect displaying two anomalies. This fact indicates the existence in the Pernambuco plateau of a relatively thick crust. In the Paraíba basin the free air edge effect is quite uniform, Te ≈ 15 km, and the lower crust is abnormally dense probably due to its alteration by a magmatic underplating in the Cenozoic. The Potiguar basin segmentation in three parts was corroborated by the Te estimates: in the Potiguar rift Te ≅ 5 km, in the Aracati platform Te ≅ 25 km, and in the Touros platform Te ≅ 10 km. The observed weakness of the lithosphere in the Potiguar rift segment is due to the high heat flux while the relatively high strength of the lithosphere in the Touros platform may be due to the existence of an archaean crust. The Ceará basin, in the region of Mundaú and Icaraí subbasins, presents a quite uniform free air edge effect and Te ranges from 10 to 15 km. The analysis of the Bouguer admittance revealed that isostasy in BP can be explained with an isostatic model where combined surface and buried loadings are present. The estimated ratio of the buried loading relative to the surface loading is equal to 15. In addition, the lower crust in BP is abnormally dense. These affirmations are particularly adequate to the northern portion of BP where adherence of the observed data to the isostatic model is quite good. Using the same above described isostatic model to calculate the coherence function, it was obtained that a single Te estimate for the entire BP must be lower than 60 km; in addition, the BP north portion has Te around 20 km. Using the conventional elastic flexural model to isostasy, an inversion of crust thickness was performed. It was identified two regions in BP where the crust is thickened: one below the Borborema plateau (associated to an uplifting in the Cenozoic) and the other one in the Ceará domain beneath the Santa Quitéria magmatic arc (a residue associated to the Brasiliano orogenesis). On the other hand, along the Cariri-Potiguar trend, the crust is thinned due to an aborted rifting in the Cretaceous. Based on the interpretation of free air anomalies, it was inferred the existence of a large magmatism in the oceanic crust surrounding the BP, in contrast with the incipient magmatism in the continent as shown by surface geology. In BP a quite important positive geoid anomaly exists. This anomaly is spatially correlated with the Borborema plateau and the Macaú-Queimadas volcanic lineament. The integrated interpretation of geoid height anomaly data, global shear velocity model, and geologic data allow to propose that and Edge Driven Convection (EDC) may have caused the Cenozoic magmatism. The EDC is an instability that presumably occurs at the boundary between thick stable lithosphere and oceanic thin lithosphere. In the BP lithosphere, the EDC mechanism would have dragged the cold lithospheric mantle into the hot asthenospheric mantle thus causing a positive density contrast that would have generated the main component of the geoid height anomaly. In addition, the compatibility of the gravity data with the isostatic model, where combined surface and buried loadings are present, together with the temporal correlation between the Cenozoic magmatism and the Borborema plateau uplifting allow to propose that this uplifting would have been caused by the buoyancy effect of a crustal root generated by a magmatic underplating in the Cenozoic

Caracterização tectono-estratigráfica da sequência transicional na sub-bacia de Sergipe

This thesis deals with the tectonic-stratigraphic evolution of the Transitional Sequence in the Sergipe Sub-basin (the southern segment of the Sergipe-Alagoas Basin, Northeast Brazil), deposited in the time interval of the upper Alagoas/Aptian stage. Sequence boundaries and higher order internal sequences were identified, as well as the structures that affect or control its deposition. This integrated approach aimed to characterize the geodynamic setting and processes active during deposition of the Transitional Sequence, and its relations with the evolutionary tectonic stages recognized in the East Brazilian Margin basins. This subject addresses more general questions discussed in the literature, regarding the evolution from the Rift to the Drift stages, the expression and significance of the breakup unconformity, the relationships between sedimentation and tectonics at extensional settings, as well as the control on subsidence processes during this time interval. The tectonic-stratigraphic analysis of the Transitional Sequence was based on seismic sections and well logs, distributed along the Sergipe Sub-basin (SBSE). Geoseismic sections and seismic facies analysis, stratigraphic profiles and sections, were compiled through the main structural blocks of this sub-basin. These products support the depositional and tectonic-stratigraphic evolutionary models built for this sequence. The structural analysis highlighted similarities in deformation styles and kinematics during deposition of the Rift and Transitional sequences, pointing to continuing lithospheric extensional processes along a NW trend (X strain axis) until the end of deposition of the latter sequence was finished by the end of late Aptian. The late stage of extension/rifting was marked by (i) continuous (or as pulses) fault activity along the basin, controling subsidence and creation of depositional space, thereby characterizing upper crustal thinning and (ii) sagstyle deposition of the Transitional Sequence at a larger scale, reflecting the ductile stretching and thinnning of lower and sub crustal layers combined with an increasing importance of the thermal subsidence regime. Besides the late increments of rift tectonics, the Transitional Sequence is also affected by reactivation of the border faults of SBSE, during and after deposition of the Riachuelo Formation (lower section of the Transgressive Marine Sequence, of Albian age). It is possible that this reactivation reflects (through stress propagation along the newlycreated continental margin) the rifting processes still active further north, between the Alagoas Sub-basin and the Pernambuco-Paraíba Basin. The evaporitic beds of the Transitional Sequence contributed to the development of post-rift structures related to halokinesis and the continental margin collapse, affecting strata of the overlying marine sequences during the Middle Albian to the Maastrichtian, or even the Paleogene time interval. The stratigraphic analysis evidenced 5 depositional sequences of higher order, whose vertical succession indicates an upward increase of the base level, marked by deposition of continental siliciclastic systems overlain by lagunar-evaporitic and restricted marine systems, indicating that the Transitional Sequence was deposited during relative increase of the eustatic sea level. At a 2nd order cycle, the Transitional Sequence may represent the initial deposition of a Transgressive Systems Tract, whose passage to a Marine Transgressive Sequence would also be marked by the drowning of the depositional systems. At a 3rd order cycle, the sequence boundary corresponds to a local unconformity that laterally grades to a widespread correlative conformity. This boundary surface corresponds to a breakup unconformity , being equivalent to the Pre-Albian Unconformity at the SBSE and contrasting with the outstanding Pre-upper Alagoas Unconformity at the base of the Transitional Sequence; the latter is alternatively referred, in the literature, as the breakup unconformity. This Thesis supports the Pre-Albian Unconformity as marker of a major change in the (Rift-Drift) depositional and tectonic setting at SBSE, with equivalent but also diachronous boundary surfaces in other basins of the Atlantic margin. The Pre-upper Alagoas Unconformity developed due to astenosphere uplift (heating under high lithospheric extension rates) and post-dates the last major fault pulse and subsequent extensive block erosion. Later on, the number and net slip of active faults significantly decrease. At deep to ultra deep water basin segments, seaward-dipping reflectors (SDRs) are unconformably overlain by the seismic horizons correlated to the Transitional Sequence. The SDRs volcanic rocks overly (at least in part) continental crust and are tentatively ascribed to melting by adiabatic decompression of the rising astenospheric mantle. Even though being a major feature of SBSE (and possibly of other basins), the Pre-upper Alagoas Unconformity do not correspond to the end of lithospheric extension processes and beginning of seafloor spreading, as shown by the crustal-scale extensional structures that post-date the Transitional Sequence. Based on this whole context, deposition of the Transitional Sequence is better placed at a late interval of the Rift Stage, with the advance of an epicontinental sea over a crustal segment still undergoing extension. Along this segment, sedimentation was controled by a combination of thermal and mechanical subsidence. In continuation, the creation of oceanic lithosphere led to a decline in the mechanical subsidence component, extension was transferred to the mesoceanic ridge and the newly-formed continental margin (and the corresponding Marine Sequence) began to be controlled exclusively by the thermal subsidence component. Classical concepts, multidisciplinary data and new architectural and evolutionary crustal models can be reconciled and better understood under these lines