Comportamento e ecologia acústica da baleia jubarte (Megaptera novaeangliae) na região Nordeste do Brasil

The acoustic ecology concept involve the relation between the live organisms and their sound environment and is applied in the present work to study the context in which the humpback whale (Megaptera novaeangliae) singing behavior, known as the most complex display in the nature, occurred in the northeastern Brazilian coast, outside the core area of Abrolhos Bank, between 2005 and 2010.I analyze the singer male occurrence , their spatial distribution and probable relations with oceanographic features, such as depth, tide regimen and moon phases. I also describe the acoustic structure and temporal variation of the singing behavior, based on song frequency and time measurements outside the Abrolhos Bank, and further compare the song complexity, registered in the same period, between Abrolhos Bank (16°- 19° S, 37°- 39° W) and the adjacent North Coast, herein considered from Itacaré (14° S, 38° W) to Aracaju (11° S, 37° W). Additionally, I look for describe and analyze anthropogenic noise sources in the marine environment of the study area, produced by the oil industry as well as by the whale watching operation, relating their frequencies to the acoustic niche utilized by the humpbacks. The results indicated a great plasticity in the singing behavior, evidenced by the occurrence of singer males in diverse social structures, from solitary individuals to other groups, even containing females and calves, as well as by the diversity which compound the song, when compared between two regions inside the same breeding area, which present distinct oceanographic characteristics. The singer male distribution may be related with the continental shelf extent along the study area. The anthropogenic noise presented frequency range, amplitude and sound intensity in potential to interfere acoustically in the singing behavior of the species, may resulting in disturbance during the breeding season in the Brazilian coast. Implications about the obtained results in the humpback whale mating system are discussed. In this way, I pretend to contribute with the acoustic ecology subject and provide information to subsidize humpback whale conservation

Uso de habitat, orçamento temporal e influência da maré da geomorfologia do fundo sobre o comportamento do boto Sotalia guianensis Van Bénéden, 1864 (Cetacea: Delphinidae) no Porto de Maceió - Alagoas, Brasil

The physical and environmental factors presented by each habitat and the rhythm of behavior patterns strongly influence the ecology and behavior of the all living beings. At same time this factors may provide clues about the structure of a population and its ecological balance. The organizational structure, ecology and behavior of a species appraised in a region if we know be in balance when compared to the same type of appraisal made in a degraded area can provide a clear view of how the anthropogenic influences acted on these species and what steps can be taken in order to mitigate the effects and keep the population. The region where this study was conducted is, like most areas of port, subject to intense physical and environmental degradation. With the emerging interest of change in the quality of these environments also by the companies themselves that use the port services, the proposed study aimed to characterize the use of habitat, the distribution of behavioral activities carried out throughout the day and influence of geomorphology of the bed, depth and variation of tide on the expression of the behavior of Sotalia guianensis in the port of Maceio - Alagoas. From this information will be possible establish parameters for comparison with other populations of S. guianensis and establish conservation measures for the population occurring in the port of Maceio - AL, serving also as a basis for conservation actions future performed in other port regions

Caracterização do repertório acústico do botocinza, sotalia guianensis, e impacto de embarcações no nordeste do brasil

The wide distribution along the Brazilian coast of specie Sotalia guianensis has been growing interest in searchers on the ecology of this species, addition to commercial interests by whalewatching. This work described the accoustic repertory of S. guianensis and their behavior associated and found if underwater noises affect this repertorie in Pipa-RN. It were analyzed 18:49h of recordings maked between april and june/2009. It were found 3258 whistles, 289 calls, 873 clicks and no gargle. The frequencies range of guiana dolphins was 1 a 48kHz and may be related to system response recorder and population s regionalization. The frequencies overlaps the noise made by motorboats, schooners and water bomb. The behavior travelling ocurred siletly in 72,58% and socialization presented no sound (56,4%) and presence of sound (43,6%). This great absence of sound may be relacioned to saving energy, probably because in this behaviors they can use physical and visual contacts. The foraging presented highest records of all class noise with 46,84% clicks, 33,84% whistles and 9,02% calls. All this sounds occurred differently in each behavior (travelling: x2 = 134,35 df = 3 p = 0,0001; foraging: x2 = 19,83 df = 3 p= 0,00018 and socialization x2 = 60,35 df = 3 p = 0,0001). It was possible to determine that underwater noise cause changes in the repertorie and does a considerable increase in whistle s number and reduce clicks. Also occurs changes in some whistles (FI: t=2,42, p=0,015; FF: t= -2,22, p=0,025), calls (FMI: t= -3,13, p=0,001; FMA: t= -3,49, p=0,0005; FD: t= -2,21, p=0,027; D: t=2,89, p=0,004) and clicks parameters (D: t= -3,85, p=0,0001; I: t= -5,32, p=0,0001) during presence of noise. These changes may be a strategy of these animals to win this sound barrier. We can not say which noise has more impact, ix however the water bomb seems to affect more the clicks and the motorboats seems to affect the others sounds. Little is know about auditive sensibility of this specie, but daily exposure to this noise may cause damage and this specie appears to have residence. The specie conservation is necessary because the population already seems to suffer damage as decrease in length of stay, number of individuals entering the inlet and the apparent diminution in the foragind during vessels presence and control standards and ambiental education can help. So, we can advance in knowledge about the ecology of this specie especially when it come to bioacoustics and their behaviors associated and reveals some of the impacts that the noise have brought to this population

Ausência do pai ao longo do desenvolvimento ontogenético e indicadores de desconto de futuro: uma contribuição da psicologia evolucionista

The new Evolutionary Psychology (E. P.) paradigm has been trying to understand how the human beings make their decisions over time regarding the most diverse variables, always bearing in mind that such a cognitive process is due to a complex natural selection process that occurred millions of years ago. One of the main topics discussed by this new paradigm is the issue of parental investment, i.e., the care the parents provide to an offspring at the expense of the investment into a new one. The present work sought to integrate these two topics, trying to understand how some variables modulate the process of decision making in a sample of the city of Natal, Rio Grande do Norte state. It was investigated the hypothesis that the presence of both parents, along the individual development, could signal a more favorable environment, providing clues to the individual that he could assume a competitive position at the socio-biological market. His decisions, therefore, could be guided by long-term investments with aims to obtain more robust rewards. On the contrary, those who has suffered for some moment the absence of one the parents could develop theirselves in a not so competitive way, starting to choose immediate benefits - but lesser ones -, since the future would be less predictable due to their worse development conditions. This study involved 152 individuals from three higher education institutions, one of them being public and the others being private ones. In the results found, there was no difference between children of coupled parents and children of deceased or divorced parents concerning discount rates. The levels of hopelessness did not affect the discount rates of children of single parents when compared to children of coupled parents. Not having one of the parents because of divorce made the child to tend to present lower scores in the domain of social relations of WHOQOL - Bref, whilst the absence of the father by death made the scores lower in the domain of environment. The results indicate that loosing one of the parents along the development influences the individual's quality of life perception, but the measurement method of future discounting rates by means of financial choices is not sensitive to this variation

Ocupação de área e interações de golfinhos-rotadores (Stenella longirostris) com o turismo náutico no Arquipélago de Noronha/PE, Brasil

Several works characterize the presence of spinner dolphins at Fernando de Noronha Archipelago in the Dolphins Bay. Though, the dolphins abidance inside this cove has decreased and a new area has been occupied by the animals to achieve the same behaviors, that are resting, breeding and nursing. This area comprises the Inside Sea northeast border of Fernando s de Noronha Island, including the opposing Middle and Dog shore area, the San Antonio Bay and the Between Islands region. The aim was to characterize the dolphins occupation and describe their interactions with the tourism in this area. Data were collected in 2008 and 2009 through a fixed point observation. The study area was divided into seven sub-areas, recording: presence/absence of dolphins, days abidance endurance, abidance length in each area, estimated number of individuals, dolphins direction and speed of displacement, boats presence, interaction period, monitoring, boats attitude and velocity. The dolphins abidance time displayed the same pattern during both years of study, with the higher occupancy in the Between Islands region. Groups with farther than 200 individuals were more frequent both 2008 (46.2%) and 2009 (42.3%). Thus the displacement s slow speed as the preferred direction towards Rat Island also showed the same pattern in both years. The Between Islands region also presented the boats major abidance near the dolphins groups. Boats moved farther in slow speed (95%) than at high speed (5%). The legislation s compliance for the cetaceans protection occurred in 89.7% of 2.839 interactions between boats and spinners, in which this variable was recorded. Whenever boats moved at a slow speed during the meetings with spinner dolphins groups, animals also moved at a slow speed (n = 337), significantly more than the fast displacements (n = 128) ix or "porpoise" (n = 4) (X2 = 318.543, p = -0.001). When boats quickly passed by groups, a significant difference between the dolphins displacement speeds was observed (X2 = 18.264, p =- 0.001), however, the slow (47%) and fast (47% ) displacements frequency was equal, noted the difference with the porpoise displacements (6%), which had the lowest frequency. Data indicate the establishment of a new occupation pattern of the spinner dolphins at Fernando de Noronha, with the Between Islands area being of great importance to the dolphins habits and currently the main area of the boats meeting with the dolphins, showing the need of new conservation measures in this area

Comportamento de mergulho do boto-cinza, Sotalia guianensis, na enseada do Curral, Praia de Pipa-RN, Brasil :possíveis adaptações cardíacas ao mergulho

The marine tucuxi, Sotalia guianensis, is one of the smallest known cetaceans, has coastal habits, and occurs from Hondures to Santa Catarina, in southern Brazil. The objective of this dissertation was to describe diving behavior of the marine tucuxi in three age classes and to analyze the cardiac capacity to dive through the examination of hearts of stranded specimens. Observations were made from October 2004 to November 2005 from a vantage point, in Curral Bay at Pipa beach-RN. We used Ad Libitum sampling and All occurrences to record the behaviors. The diving was characterized by the total exposition of the tail fluke for a few seconds, in 90° or 45° angles. Were recorded 131 dives in three behavioral contexts: foraging, traveling and socialization. The difference between juveniles and adults in dive time and fluke out at 45° or 90° to search and/or capture prey is probably influenced by the strategy used and ability to capture the prey. The frequency of fluke out at 90° for foraging in adults may be related to increased physiological efficiency of adults in comparison to juveniles. However, in the context of travel and socialization the dive time and fluke out were independent between the age classes. Dive in calves were frequent during socialization (play behavior) and traveling. This, associated with synchronic calve-adult diving suggests that a relationship of these behaviors and the acquisition of experience and foraging skills. As observed in other cetaceans, the heart (n=12) of the estuarine dolphin is broad and presents long ventricles which form a round apex. The right ventricle is long and narrow. The degree of dilatation of the aortic bulb may support the heart during diastole. The characteristic morphology of the heart and short dive duration < 2 min and depth ranged from 10m in the estuarine dolphin, can be likely at physiological adaptation for diving, typical de dolphins with coastal habits. The limitation of diving time in this specie may be influenced by anatomical and physiological restrictions

Hidrocarbonetos policíclicos aromáticos no meio ambiente: diferenciação de fontes em sedimentos e metabólitos em bile de peixes

Many studies on environmental ecosystems quality related to polycyclic aromatic hydrocarbons (PAH) have been carried out routinely due to their ubiquotus presence worldwide and to their potential toxicity after its biotransformation. PAH may be introduced into the environmet by natural and anthropogenic processes from direct runoff and discharges and indirect atmospheric deposition. Sources of naturally occurring PAHs include natural fires, natural oil seepage and recent biological or diagenetic processes. Anthropogenic sources of PAHs, acute or chronic, are combustion of organic matter (petroleum, coal, wood), waste and releases/spills of petroleum and derivatives (river runoff, sewage outfalls, maritime transport, pipelines). Besides the co-existence of multiples sources of PAH in the environmental samples, these compounds are subject to many processes that lead to geochemical fates (physical-chemical transformation, biodegradation and photo-oxidation), which leads to an alteration of their composition. All these facts make the identification of the hydrocarbons sources, if petrogenic, pyrolytic or natural, a challenge. One of the objectives of this study is to establish tools to identify the origin of hydrocarbons in environmental samples. PAH diagnostic ratios and PAH principal component analysis were tested on a critical area: Guanabara Bay sediments. Guanabara Bay is located in a complex urban area of Rio de Janeiro with a high anthropogenic influence, being an endpoint of chronic pollution from the Greater Rio and it was the scenario of an acute event of oil release in January 2000. It were quantified 38 compounds, parental and alkylated PAH, in 21 sediment samples collected in two surveys: 2000 and 2003. The PAH levels varied from 400 to 58439 ng g-1. Both tested techniques for origin identification of hydrocarbons have shown their applicability, being able to discriminate the PAH sources for the majority of the samples analysed. The bay sediments were separated into two big clusters: sediments with a clear pattern of petrogenic introduction of hydrocarbons (from intertidal area) and sediments with combustion characteristics (from subtidal region). Only a minority of the samples could not display a clear contribution of petrogenic or pyrolytic input. The diagnostic ratios that have exhibited high ability to distinguish combustion- and petroleum-derived PAH inputs for Guanabara Bay sediments were Phenanthrene+Anthracene/(Phenanthrene+Anthracene+C1Phenanthrene); Fluorantene/(Fluorantene+Pyrene); Σ (other 3-6 ring PAHs)/ Σ (5 alkylated PAH series). The PCA results prooved to be a useful tool for PAH source identification in the environment, corroborating the diagnostic indexes. In relation to the temporal evaluation carried out in this study, it was not verified significant changes on the class of predominant source of the samples. This result indicates that the hydrocarbons present in the Guanabara Bay sediments are mainly related to the long-term anthropogenic input and not directly related to acute events such as the oil spill of January 2000. This findings were similar to various international estuarine sites. Finally, this work had a complementary objective of evaluating the level of hydrocarbons exposure of the aquatic organisms of Guanabara Bay. It was a preliminary study in which a quantification of 12 individual biliar metabolites of PAH was performed in four demersal fish representing three different families. The analysed metabolites were 1-hydroxynaphtalene, 2-hidroxinaphtalene, 1hydroxyphenanthrene, 9-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1hydroxypyrene, 3-hidroxibiphenil, 3- hydroxyphenanthrene, 1-hydroxychrysene, 9hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxybenz(a)pyrene. The metabolites concentrations were found to be high, ranging from 13 to 177 µg g-1, however they were similar to worldwide regions under high anthropogenic input. Besides the metabolites established by the used protocol, it was possible to verified high concentrations of three other compounds not yet reported in the literature. They were related to pyrolytic PAH contribution to Guanabara Bay aquatic biota: 1-hydroxypyrine and 3-hydroxybenz(a)pyrine isomers

As organizações não-governamentais (ONGs) de atenção à criança e ao adolescente em Natal/RN: contribuição na garantia de direitos?

In contemporaneousness watches in Brazil the emergence of a "new" relationship between State and society based on partnership, which will allow the growing playacting organizations "non-profit" and "public interest" in the management of social public policies. In that sense, as part of a logic of global restructuring of the Capital, under the aegis of the neoliberal project, starting from the years of 1990, an administration model is had in favor of the market that looks for to minimize the actions of the State, reinforcing the outsourcing of the social public politics, and consequently, debilitating rights legally conquered. In that way, with this study it was pursued as general objective to apprehend the actions developed by Non-governmental Organizations NGOs in the child's area and of the adolescent in Natal / RN, verifying in that measured, these contribute to the warranty of rights or they reproduce practices of welfare work, and as specific objectives: to identify the group of the actions developed by NGOs in the child's area and of the adolescent in Natal / RN; to analyze the practice of NGOs of the point of view of the human resources, of the administration, of the financing, of the user's participation in the decision processes, as well as the quality of the services and the continuity of the actions of these organizations; and to apprehend the relationship between the researched organizations and users in the process of implantation of the actions, in order to identify the perspective that guide the practice of NGOs is going in the direction of contributing in the warranty of rights or in the reinforcement to the welfare work. In summary the results showed two trends in the actions of the NGOs, in the direction of the provision of services, which still unfurls in two perspectives of handouts. The other trend will give priority to the defense of rights of children and adolescents, with actions of political impact strengthen the promotion of public policies state, thus contributing to guarantee rights

Instrumentalidade do serviço social na previdência social no Brasil contemporâneo

In the sociability of the capital, the challenges to the consolidation of social security as a public policy become expressive, which has implications for social security services, particularly for Social Works who works for the security and fulfillment of social rights. Therefore, in this context of denial of these rights becomes relevant the work of social worker, as a professional committed to the ethical-political project and the Matrix Theory and Methodology of Social work, which potentiate the action able to establish professional articulated strategies for the strengthening of collective struggles for equality in society. Thus, this study examines the instrumentality of social work in the contemporary world and its contribution to the realization of rights. For this, we conducted a literature review, using authors dealing with the issue, as Behring (2008), Boschetti (2003), Mota (1995), Guerra (2007) among others, as well as documentary research through laws, decrees, instructions Normative, Internal Guidelines, and especially the analysis of the Matrix itself of Social Work in welfare. We use also of paramount importance to our analysis - the field research, using techniques such as semi-structured interview and questionnaire. The research enables the identification of important aspects of the subject studied, as the understanding of professionals about the instrumentality of Social Works in its ethical-political aspects, both theoretical and methodological and technicaloperative. The demands made by the managers for the profession on the sociooccupational have extrapolated the powers and duties of the Law Regulating the Profession and the Matrix of Social Work in welfare. The subjects of this study emphasize the role of social category of the National Institute of Social Security and the Federal Council of Social Service in defense of Social Works. The knowledge of social and institutional framework is critical to building control strategies that strengthen social security and public policy, the guarantor of social rights for workers in Brazil

A contribuição da asstênia técnica no desenvolvimento desenvolvimento de projetos de assentamento no estado do Rio Grande do Norte

The public policies must have as their aimed the primordial at improving quality of life of families of a given population, however, its performance must be constantly monitored and evaluated scoped to ascertain whether these policies are reaching those goals. This work consisted in search of bibliographies and analysis that addressed the historical evolution of the debate on the subject of agrarian reform in Brazil as public policy and on the policy of technical assistance and rural extension, and collecting data in loco, in order to assess whether the actions implemented under this latter contribute to improvements in local development of settlements projects (PA) land reform in the state of Rio Grande do Norte (RN), this given the constant presented criticisms regarding their effectiveness, considering that it is difficult to empirically differentiate settlements they received of those who did not receive the technical assistance services. In this way, was held the data collection for comparison of characteristics (social organization, relationship with the local environment, form of producing and evaluation of technical assistance services) of two settlements in RN, being one you have received the technical assistance services and another who has not had access to these services in the past five years, at least, to confirm whether those who had access to the above services presents best features of social organization and the relationship with the local environment, mainly, which was confirmed in the results obtained, which still demonstrated that no significant differences on the forma to produce and of commercialization in PA studied. It was also found that the problems faced by families settled in PA studied resemble those seen verified in many other Brazilian states, especially as to how to use natural resources in the areas of land reform and the instability of the availability of technical assistance services. Should be guaranteed at continuity and universality of technical assistance services to settlements, seeking a higher focus on productive issues, which provide the income necessary for families settled can have a better quality of life

O desenvolvimento da indústria da reciclagem dos materiais no Brasil: motivação econômica ou benefício ambiental conseguido com a atividade?

A indústria de reciclagem vem se desenvolvendo no Brasil desde o começo dos anos noventa, o que resulta em elevados índices de reciclagem e tecnologia de ponta na reciclagem de alguns materiais. Requisitada como estratégia para a gestão dos resíduos no destino final, a reciclagem possui a particularidade de ser uma atividade econômica bastante rentável. Este artigo analisa os índices da indústria de reciclagem dos materiais no Brasil. Com base nos resultados obtidos através da consulta bibliográfica e dados estatísticos oriundos de fontes primárias e secundárias, conclui-se que a atividade da reciclagem dos materiais no Brasil se presta a satisfazer exclusivamente às demandas econômicas do setor. Neste sentido, a contribuição ambiental da reciclagem perde relevância visto que o crescimento da atividade está condicionado às demandas da cadeia produtiva industrial

Projeto político de formação do enfermeiro: contextos, textos, (re)construções

This research analyses politic Project for nursing education, in its articulation with economical, political and social context of 1970s and 1980s in national level and, in special, nurse formation process in FAEN/UERN space, situating it on the context of Brazilian sanitary reformation movement and participation movement. The thesis is firmed on the sense of explaining whether that movement circa the nurse formation process has been able to build necessary instruments for the transformation of biomedical formation model historically consolidated, in the perspective of conceiving another model anchored on social determination of health/illness process, with the purpose of assuring ethical and political commitment with the SUS praised by sanitary reformation. The study visualized the object considering its specificity, its concrete historical determinations and institutional as well as organizational relationships that permeate possibilities of valorizing it, analyzing it, interpreting it and rebuilding it. Its operationalization occurred in three movements, it means, bibliographical review; documents study; interviews and focal groups realized with professors of the institution. We can apprehend as main results that the nurse formation process has incorporated widely spread conceptions by the sanitary reformation movement and participation movement, assuming the commitment with transformation of health services and social reality. Nevertheless it prevails, still, amongst some professors in the same institutional space, the commitment to a predominantly technicist formation, focused on instrumental knowledge. Opinion divergence explicit diversity of conceptions circa education and, as consequence, distinct political commitments, also contradictory to formation. Thus, there is a lacuna between what is foreseen on political pedagogical project and what is rendered in FAEN/UERN, evidencing the clash related to conceptual bases of formation project. Interpretations, divergent political attitudes and resistances to the process allowed several formation ways. However, formation under new conceptual bases, find limits on the context of social politics implemented in Brazil during the 1990s, neoliberal-based, expressed on expansion and consolidation of health private system, managed by market rules, strengthening biomedical formation model. Notwithstanding, there is a favorable to its implementation, starting from the first years of 21st century, moment when Brazilian sanitary reformation reappear on health speech, as well as facing the policy of permanent education in health. This reality explicit a process of dialectical tension between instituted and institutor, anticipating the moment of scission or adaptation and return to what is already known. Despite of clashed, knowledge, accumulated experience, contribution to services, the construction of partnerships out of university space and articulation with national movement of (re)orientation of nurse formation, have been constituted as vital instruments to offer support to formation in FAEN/UERN. Still, we consider necessary the (re)visitation to FAEN/UERN politic pedagogical Project considering the existing and implemented construction, without, yet, depreciate the norther axis of the project at the reaching of its intentionality

O ensino da língua portuguesa na televisão: uma análise através do programa afinando a língua

The present dissertation aims to an approach of the teaching of Portuguese language on television, trying to find how possible is the contribution of this communication media in the sense to give a higher classroom dynamism and to excite the students for that subject. The TV show Afinando a Língua (roughly, putting the language in tune ), a Canal Futura feature, have as one of these main purpose be shown on the classrooms as a tool that could enlarge the possibilities of a subject often took as particularly difficult. Blocked by the traditional grammatical teaching, the Portuguese lessons have been for years pictured as hermetic and far from the Brazilian speakers reality. So, people create myths around the language that earns adjectives as complicate and inaccessible and that Brazilians can t speak the Portuguese really good, because it only happens in Portugal, the original country of the language. These myths start exactly because the teaching orientation take their basis only on the standard language, in fact just one of the language variations by the way, anywhere in the world dictated by ancestral rules, once produced in Portugal. The regular school don t accept the Portuguese variation as a natural fact for a huge country as Brazil, with almost 190 million people, regarding it as a wrong way of talking. The repression that follows the students from the early school days make them repel the language supposedly learned at school. In fact, they normally face it as something unfamiliar, different from the language that they have use to learn at home, from the family and neighbors Instead of giving new possibilities for the language learning, the television, a powerful audiovisual device, only reinforces the idea that everyone, in any life situation, should talk the standard Portuguese, turning its back to the learning acquired much earlier that any person reach the school. This conservative attitude brings almost no changes, between the shows that try to teach the idiom and the traditional Portuguese lessons, wasting valuable tools that could lead to the possibility to open the classroom to the outside world, and to the wider knowledge of the differences from each Brazilian region culture, a positive attitude that could much enlarge the cultural and linguistic students universe

A história do intemperismo na Província Borborema Oriental, Nordeste do Brasil: implicações paleoclimáticas e tectônicas

Until some years ago, weathering geochronology was primarily based on the K-Ar and 40Ar/39Ar dating of supergene minerals. Recent advances in the analysis of supergene goethite by the (U-Th)/He method expanded the number of suitable minerals for such purpose, as well as the time of application for weathering geochronology. This study represents the first systematic approach in Brazil, combining both the 40Ar/39Ar e (U-Th)/He methodologies to improve the knowledge on the weathering and the age of nonfossiliferous sediments. Supported by geologic and geomorphologic correlations, we identified different types of weathering profiles occurring in the interior and coastal areas of northeastern Brazil. These profiles were correlated to main regional geomorphological domains: the Borborema Plateau , the Sertaneja Depression , and the Coastal Cuestas and Plains, and respective planation surfaces, which study is fundamental to understand the landscape evolution of the northern portion of the eastern Borborema Province. The depth and stratigraphic organization of the weathering profiles in each of the geomorphological domains permitted to establish that: (i) the profiles on the highlands that cap the Borborema Surface are deeper (up to 100 m) and can be considered as typical lateritic profiles; (ii) on the lowlands that form the Sertaneja Surface , the weathering profiles are shallow and poorly developed (2-5 m deep); (iii) the profiles along the coastal area are moderately developed (up to 25 m deep), and are characterized by thick saprolites and mottle zones. Aiming to establish the timing of the evolution of northeastern Brazil, we studied 29 weathering profiles representing distinct topographic levels of the Borborema Province, from the highlands to the coast, through the analysis of 248 grains of supergene manganese oxides using laser step-heating 40Ar/39Ar geochronology. Additionally, we applied the (U-Th)/He method in 20 weathering profiles, by dating 171 grains of supergene iron oxides and hydroxides. Geochronological results for 248 grains of manganese oxides analyzed by the 40Ar/39Ar method indicate that the weathering profiles in the study area record the history of weathering from the Oligocene to the Pleistocene, with ages in the order of 31.4 ± 1.0 Ma to 0.8 ± 0.4 Ma. Dating of 171 grains of goethite by the (U-Th)/He method yielded ages ranging from 43.2 ± 4.3 Ma to 0.8 ± 0.1 Ma, suggesting the weathering processes last from the Eocene to the Pleistocene. The precipitation of supergene goethite in this interval confirms the age of the weathering processes identified from the manganese oxides record. 105 goethite grains from 8 different occurrences of the Barreiras Formation were dated by the (U-Th)/He method. Five grains collected from the cement in the Barreiras Formation sandstones, in the Lagoa Salgada and Rio do Fogo coastal cuestas, yielded ages of 17.6 ± 1.8 Ma, 17.3 ± 1.7 Ma, 16.3 ± 1.6 Ma, 16.2 ± 1.6 Ma and 13.6 ± 1.4 Ma. Results of 69 goethite grains from authigenic pisoliths collected in 7 different localities also yielded concordant ages, varying from 17.8 ± 1.8 to 7.5 ± 0.8 Ma. Results obtained from 31 detrital grains are concordant in 3 distinct localities (Lagoa Salgada, Praia da Garças e Ponta Grossa); they vary in the range of 43.2 ± 4.3 to 21.6 ± 2.2 Ma, and indicate that the maximum age for the Barreiras Formation deposition is around 22 Ma. 40Ar/39Ar results for 15 manganese oxides grains associated with the Barreiras Formation weathering profiles, in 3 different localities, vary from 13.1 ± 0.9 to 7.7 ± 0.4 Ma, in the same range of ages obtained by the (U-Th)/He method. The systematic application of the 40Ar/39Ar and (U-Th)/He methods, respectively for manganese oxides and goethites, show that the Barreiras Formation sediments were already deposited since ca. 17 Ma, and that the weathering processes were active until ca. 7 Ma ago. The ages obtained from manganese oxides collected in the Cenozoic basalts (Macau Formation) also reveal a weathering history between 19 and 7 Ma, pointing to hot and humid conditions during most of the Miocene. 40Ar/39Ar ages yielded by manganese oxides associated with the Serra do Martins Formation vary from 14.1 ± 0.4 to 10.5 ± 0.3 Ma. On the other hand, (U-Th)/He ages from iron oxides/hydroxides collected in the Serra do Martins Formation mesas vary from 20.0 ± 2.0 to 5.5 ± 0.6 Ma, indicating that those sediments are older than 20 Ma. 40Ar/39Ar and (U-Th)/He results produced in this study are in agreement with paleoclimatic interpretations based on stable isotopes and clay index values measured in the Atlantic Ocean sediments, validating the use of weathering geochronology to investigate paleoclimatic variations. The direct dating of the Barreiras Formation permitted, for the first time, confident inferences on the age of the brittle deformation recorded by this sedimentary unit in the Rio Grande do Norte and Ceará states. The first event, syn-deposition, occurred during the early Miocene; an younger event, related to the post-depositional deformation of the Barreiras Formation, is associated with tectonic activity from the very early Miocene to the Holocene. In agreement with data from other areas, results obtained in this study reveal that the depth and complexity of the weathering profiles reflect the time of exposition of such areas to the weathering agents close to the surface. However, there is no clear relationship between ages vs. altitude. The depth and the stratigraphic organization of weathering profiles in northeastern Brazil, contrary to the southeastern Brazil pattern, do not vary toward the coast. In our study area, field observations reveal the presence of ancient, thick and complex lateritic profiles preserved in the sedimentary mesas on the Borborema Plateau, as younger, narrow and incipient ones occur in the dissected areas. Geochronological results obtained for these profiles yielded older ages on the high altitudes, and younger ages in the lowlands, suggesting the scarp retreatment is the most reliable model to explain the regional landscape evolution. However, in the coastal lowlands, the relatively older ages obtained indicate that more complexes processes were involved in the modeling of the local relief

Caracterização geológico-geofísica do meio aqüífero fissural : uma contribuição aos modelos de fluxo e armazenamento de água subterrânea

Northeastern Brazil is mainly formed by crystalline terrains (around 60% in area). Moreover, this region presents a semi-arid climate so that it is periodically subject to drought seasons. Furthermore, ground water quality extracted fromwells usually presents poor quality because of their high salinity contents. Nevertheless, ground water is still a very important source of water for human and animal consumption in this region. Well sitting in hard rocks terrains in Northeastern Brazil offers a mean success index of aboul 60%, given that a successful siting is defined by a well producing at least 0.5 m³/h. This low index reveals lack of knowledga about the true conditions of storage and percolation of ground water in crystalline rocks. Two models for structures storing and producing ground water in crystalline rocks in Northeastem Brazil have been proposed in the literature. The first model,tradnionally used for well sitting since the sixties are controlled by faults or fractures zones. This model is commonly referred, in Brazilian hydrogeological literature, as the "creek-crack" model (riacho-fenda in Portuguese). Sites appearing to present dense drainage network are preferred for water well siting - particularly at points where the drainages cross-cul each other. Field follow up work is usually based only on geological criteria. The second model is the "eluvio-alluvial through" (calha eluvio-aluvionar in Portuguese); it is also described in the literature but it is not yet incorporated in well sitting practice. This model is based on the hypothesis that reclilinear drainages can also be controlled by the folietion of the rock. Eventually, depending upon the degree of weathering, a through-shaped structure filled with sediments (alluvium and regolith) can be developed which can store and water can be produced from. Using severalfield case studies, this Thesis presents a thorough analysis ofthe two above cited models and proposes a new model. The analysis is based on an integrated methodological approach using geophysics and structural geology. Both land (Resitiviy and Ground Penetrating Radar- GPR) and aerogeophysical (magnetics and frequency domain eletromagnetics) surveys were used. Slructural analysis emphasized neolectonic aspects; in general, itwas found that fractures in the E-W direction are relatively open, as compared to fracturas inthe N-S direction, probably because E-W fractures were opened by the neotectonic stress regime in Northeastern Brazil, which is controlled by E-W compression and N-S extension. The riacho-fenda model is valid where drainages are controlled by fractures. The degree of fracturing and associated weathering dictale the hydrogeological potential of the structure. Field work in structural analogues reveals that subvertical fractures show consistent directions both in outcrop and aerophotograph scales. Geophysical surveys reveal subvertical conductive anomalies associated to the fracture network controlling the drainage; one of the borders of the conductive anomaly usually coincide wih the drainage. An aspect of particular importance to the validation of fracture control are the possible presence of relalively deep conductive anomalies wihoul continuation or propagalion to the surface. The conductive nature of lhe anomaly is due to the presence of wealhered rock and sedirnenls (alluvium and/or regolilh) storing ground waler which occur associated to the fracture network. Magnetic surveys are not very sensisnive to these structures.lf soil or covering sedirnents are resislive (> 100 Ohm.m), GPR can ba used to image precisely lhe fracture network. A major limialion of riacho-fenda model, revealed by GPR images, is associated to the fact thal subhorizontal fractures do play a very important role in connecting the fracture network, besides connect shallow recharge zones to relalively deep subvertical frecture zones. Iffractures play just a secondary control on the drainage, however, r/acho-fenda model may have a very limiled validny; in these cases, large portions oflhe drainage do nol coincide wilh frectures and mosl oflhewells localed in lhe drainage surrounding would resull dry. Usually, a secondary conlrol on lhe drainage by Ihefraclure networkcan be revealed only wilh detailed geophysical survey. The calha elClv1o-aluvlonarmodel is valid where drainages are conlrolled by folialion. The degree 01 wealhering 01 lhe lolialion planes dictales lhe hydrogeological polenlial 01 lhe slruclure. Outcrop analysis reveals Ihal lolialion and drainage direclions are parallel and Ihal no Iraclures, orfraclures wilh diflerent directions 01 lhe drainage direclion occur. Geophysical surveys reveal conduclive anomalies in a slab lorm associaled 10 lhe Ihrough 01 lhe wealhered rock and sedimenls (alluvium and/or regolith). Magnelic surveys can ofler a very good conlrol on lolialion direclion. An importanl aspect 10 validale lolialion conlrol are lhe presence 01 conductive anomalies showing shallow and deep portions area which are linked. Illhere is an exlensive soil cover, r/acho-fenda and calha eIClv1o-aluv/onar conlrols can be easily misinlerpreled in lhe absence 01 geophysical conlrol. Certainly, Ihis lacl could explain at leasl a part of lhe failure index in well sitting. The model wealhering sack (bolsllo de Intempertsmo in Portuguese) is proposed to explain cases where a very inlensive wealhering occur over lhe crystalline rock so Ihal a secondary inlerslilial porosity is crealed. The waler is Ihen stored in lhe porous of lhe regolilh in a similar mannerlo sedimentary rocks. A possible example ofthis model was delecled by using land geophysical survey where a relalivelyvery deep isolaled conduclive anomaly, in a slab form, was delected. Iflhis structure does store ground waler, certainly Ihere must be a link 01 lhe deep slructure wilh lhe surface in orderlo provide walerfeeding. This model mighl explain anomalous waler yields as greal as 50 m³/h Ihalsomelimescan occur in crystalline rocks in Northeaslern Brazil