Petrologia do magmatismo tardi-brasiliano no Maciço São José de Campestre(RN/PB), com ênfase no Plúton Alcalino Caxexa

The area studied is located on the north-easternmost portion of the Borborema Province, on the so-called São José de Campestre Massif, States of RN and PB, Northeast Brazil. Field relations and petrographic, geochemical and isotope data permitted the separation of five suites of plutonic rocks: alkali-feldspar granite (Caxexa Pluton), which constitutes the main subject of this dissertation, amphibole-biotite granite (Cabeçudo Pluton), biotite microgranite, gabbronorite to monzonite (Basic to Intermediate Suite) and aluminous granitoid. The Caxexa Pluton is laterally associated to the Remígio Pocinhos Shear Zone, with its emplacement along the mylonitic contact between the gneissic basement and the micashists. This pluton corresponds to a syntectonic intrusion elongated in the N-S direction, with about 50 km2 of outcropping surface. It is composed exclusively of alkali-feldspar granites, having clinopyroxene (aegirine-augite and hedenbergite), andradite-rich garnet, sphene and magnetite. It is classified geochemically as high silica rocks (>70 % wt), metaluminous to slightly peraluminous (normative corindon < 1%), with high total alkalis (>10% wt), Sr, iron number (#Fe=90-98) and agpaitic index (0.86-1.00), and positive europium anomaly. The Cabeçudo Pluton is composed of porphyritic rocks, commonly containing basic to intermediate magmatic enclaves often with mingling and mixing textures. Petrographically, it presents k-feldspar and plagioclase phenocrysts as the essential minerals, besides the accessories amphibole, biotite, sphene and magnetite. It is metaluminous and shows characteristics transitional between the calc-alkaline and alkaline series (or monzonitic subalkaline). Its REE content is greater than those ones of the Caxexa Pluton and biotite microgranite, and all spectra have negative europium anomalies. The biotite microgranites occur mainly on the central and eastern portion of the mapped area, as dykes and sheets with decimetric thickness, hosted principally in orthogneisses and micashists. Their field relationships as regards the Caxexa and Cabeçudo plutons suggested that they are late-tectonic intrusions. They are typically biotite granites, having also sphene, amphibole, allanite, opaques and zircon in the accessory assemblage. Geochemically they can be distinguished from the porphyritic types because the biotite microgranites are more evolved, peraluminous, and have more fractionated REE spectra. The Basic to Intermediate rocks form a volumetrically expressive elliptical, kilometric scale body on the Southeast, as well as sheets in micashists. They are classified as gabbronorites to monzonites, with the two pyroxenes and biotite, besides subordinated amounts of amphibole, sphene, ilmenite and allanite. These rocks do not show a well-defined geochemical trend, however they may possibly represent a monzonitic (shoshonitic) series. Their REE spectra have negative europium anomalies and REE contents greater than the other suites. The aluminous granitoids are volumetrically restricted, and have been observed in close association with migmatised micashists bordering the gabbronorite pluton. They are composed of almandine-rich garnet, andalusite, biotite and muscovite, and are akin to the peraluminous suites. Rb-Sr (whole rock) and Sm-Nd (whole-rock and mineral) isotopes furnished a minimum estimate of the crystallization (578±14 Ma) and the final resetting age of the Rb-Sr system (536±4 Ma) in the Caxexa Pluton. The aluminous granitoid has a Sm-Nd garnet age similar to that one of the Caxexa Pluton, that is 574±67 Ma. The strong interaction of shear bands and pegmatite dykes favoured the opening of the Rb-Sr system for the Caxexa Pluton and biotite microgranite. The amphibole-plagioclase geothermometer and the Al-in amphibole geobarometer indicate minimum conditions of 560°C and 7 kbar for the Cabeçudo Pluton, 730°C and 6 kbar for the microgranite and 743°C and 5 kbar for the basic to intermediate suite. The Zr saturation geothermometer reveals temperatures of respectively 855°C, 812°C and 957°C for those suites, whereas the Caxexa Pluton shows temperatures of around 757°C. The Caxexa, Cabeçudo and microgranites suites crystallized under high fO2 (presence of magnetite). On the other hand, the occurrence of ilmenite suggests less oxidant conditions in the basic to intermediate suite. Field relations demonstrate the intrusive character of the granitoids into a tectonically relatively stable continental crust. This is corroborated by petrographic and geochemical data, which suggest a late- or post-collisional tectonic context. It follows that the generation and emplacement of those granitoid suites is related to the latest events of the Brasiliano orogeny. Finally, the relationships between eNd (600 Ma), TDM (Nd) and initial Sr isotope ratio (ISr) do not permit to define the precise sources of the granitoids. Nevertheless, trace element modelling and isotopic comparisons suggest the participation of the metasomatised mantle in the generation of these suites, probably modified by different degrees of crustal contamination. In this way, a metasomatised mantle would not be a particular characteristic of the Neoproterozoic lithosphere, but a remarkable feature of this portion of the Borborema Province since Archaean and Paleoproterozoic times.

Mecanismos de alojamento de magmas granitóides :exemplo do plúton de Japi(RN)

This dissertation describes the igneous suites of the Japi granitoid pluton, intrusive in the Paleoproterozoic gneiss-migmatite complex of the eastern domain of the Seridó Belt, northeastern Brazil. Field relations show that the pluton is affected by strong deformation associated to the Brasiliano orogeny (known as the D3 phase) , with a NW-trending extensionalleft-hand senestral shear zone (the Japi Shear Zone, JSZ) bordering the intrusive body to the west. Four plutonic suites are found in the main pluton and as satellyte intrusions, besides Iate pegmatite and pink leucogranites. An alkaline granitoid suite, dominated by syenogranites bearing sodic augite (and subordinate hornblende), define a main elliptical intrusion. In its northern part, this intrusion is made up by concentric sheets, contrasting with a smaller rounded stock to the south. These granites display a pervasive solid-state S>L fabric developed under high T conditions, characterized by plastic deformation of quartz and feldspar. It is especially, developed along the border of the pluton, with inward dips. A regular magmatic layering is present sometimes, parallel to the tectonic foliation. The syntectonic emplacement as regards to the Brasiliano (D3) event is indicated by the common occurrence of dykes and sheets along transtensional or extensional sites of the major structure. Field relations attest to the early emplacement of the alkaline granites as regards to the other suites. A basic-to-intermediate suite occurs as a western satellyte body and occupying the southern tail of the main alkaline pluton. It comprises a wide variety of compositional terms, including primitive gabbros and gabbro-norites, differentiated to monzonitic intermediate facies containing amphibole and biotite as their main mafic phases. These rocks display transitional high-K calc-alkaline to shoshonitic affinities. Porphyritic monzogranite suítes commonly occur as dykes and minor intrusives, isolated or associated with the basic-tointermediate rocks. In the latter case, magma mingling and mixing features attest that these are contemporaneous igneous suites. These granites show K-feldspar phenocrysts and a hornblende+biotite+titanite assemblage, displaying subalkaline/monzonitic geochemical affinities. Both suites exhibit SL magmatic fabrics overprinting or transitional to solid-state D3 deformation related to the JSI. Chemical data clearly show that they are related to different parental magmas. Finally, a microgranite suite occurs along a few topographic ridges paralell to the JSI. It comprises dominantly granodiorites with a mineralogy similar to the one of the porphyritic granitoids. However, discriminant diagrams show their distinct calc-alkaline affinity. The granodiorites display an essencially magmatic fabric, even though an incipient D3 solid-state structure may be developed along the JSI. Intrusion relationships with the previous suites, as well as regards to the D3 structures, point to their Iate emplacement. All these suites are intrusive in a Paleoproterozoic, high-grade gneiss-migmatite complex affected by two previous deformation phases (D1, D2). The fabrics associated with these earlier events are folded and overprinted by the younger D3 structures along the JSZ. The younger deformation is characterized by NE-dipping foliations and N/NE-plunging stretching lineations. In the JSZ northern termination the foliation acquires an ENE orientation, containing a stretching lineation plunging to the south. Symmetric kinematic cri teria developed at this site confirms the transpressional termination of the JSZ, as also shown by orthorrombic quartz c-axis patterns. E-W-trending d extra I shear zones developed in the central part of the JSZ are interpreted as antithetic structures associated to the transtensional deformation along the JSZ. This is consistent with its extensional-transcurrent kinematics and a flat-and-ramp geometry at depth, as shown by gravimetric data. The lateral displacement of the negative residual Bouguer anomalies, as regards to the main outcropping alkaline pluton, may be modelized by other deeper-seated granite bodies. Based on numerical modelling it was possible to infer two distinct intrusion styles for the alkaline pluton. The calculated model values are consistent with an emplacement by sheeting for the northern body, as already suggested by satellyte imagery and field mapping. On the other hand, the results point to a transition towards a diapir-related style associated to the smaller. southern stock. This difference in intrusion styles may relate to intensity variations and transtensional sites of the shear deformation along the JSZ. Trace element and Sr and Nd isotopes of the alkaline granites are compatible with their derivation trom a more basic crustal source, as compared to the presently outcropping highgrade gneisses, with participation (or alternatively dominated by) of an enriched lithospheric mantle component. Like other igneous suites in the Seridó Belt, the high LlL contents and fractionated REE patterns of the basic rocks also point to an enriched mantle as the source for this kind of magmatism. Geochemical and isotope data are compatible with a lower crustal origin for the porphyritic granites. On the basis of the strong control of the JSZ on the emplacement of lower crustal (porphyritic and alkaline granites) or lithospheric mantle (basic rocks, alkaline granites or a component of them) magmas, one may infer a deep root for this structure, bearing an important role in magma extraction, transport and emplacement in the Japi region, eastern domain of the Seridó Belt

Contra as Secas: a engenharia e as origens de um planejamento regional no nordeste brasileiro

Droughts surfaced in 1877 as a crucial problem for the birthing Brazilian nation. Engineers, who formed the country's technical and scientific elite, took it upon themselves to study, understand and fight the problem through planned actions of intervention on space. This work, based on proposals and discussions contained in engineering magazines and reports, aims to provide elements for the comprehension of how these systematized actions against droughts, in the Iate nineteenth and early twentieth century, contributed to spatial analysis and the formation of a (then-inexistent) regional and territorial planning discipline in Brazi!. Engineers, by taking up the position of masterminds in the country's modernization, guaranteed for themselves personal economic stability, social prestige and political power. By understanding nature, either as a resource to be exploited or an adversary to national progress, they contributed to the delimitation of the region now known as the Northeast. By seeking to understand the drought phenomenon, they created knowledge about the space they sought to intervene on; by constructing their projects amid political and economical difficulty, they changed the organizational structures of cities and country in the northeast. The proposals for açudes (Iarge water reservoirs) allowed the fixation of population and the resistance against droughts; the roads - railroads and automotive roadways - connected the sertão to the capitais and the coast, speeding up help to the affected populations during droughts and allowing the circulation of goods so as to strengthen the local economies in normal rimes. The adopted practices and techniques, adapted from foreign experience and developed through trial and improvement, were consolidated as an eminently spatial intervention course, even if a theoretical body of regional or territorial planning wasn't formed in Brazil. Regional Planning proper was first applied in the country in the Northeast itself, in the 1950s, based off an economical view of reality in order to achieve development. The engineer's work prior tothat date, however, cannot be dlsconsldered. It was proved that, despite facing financial and political hurdles, engineers had a profound commitment to the problem and intended to act systematically to transform the economical and social relations in the region, in order to be victorious in their struggle against droughts

Natal qual é a sua cara?: análise do perfil edilício da avenida Eng. Roberto Freire (Natal/RN) à luz da acessibilidade

This study focuses on the building ensemble of Avenida Roberto Freire, a main road in Natal, Brazil, as a material expression of the confluence of various factors among which the following may be emphasized: high level of accessibility due to urban spatial re-structuring and the growth of the real estate market, in view of the increasing number of consumers, who arrived in Natal within the last decades. The intense urban modification process that has been going on in Natal since at least the 1980s, has engendered the formation of long axial lines which express the expansion dynamics and some of the forces subjacent to it. Avenida Roberto Freire has been an iconic example of an urban thoroughfare where architecture becomes primarily a communication support that can be perceived by fast moving passers-by, what brings it close to the venturian concept of strip (Venturi at al, 1972). The building types that line the road not only respond to the dynamics in process but also contribute to intensify it, as they house a variety of uses which attract people and generate more movement. The dynamics is further strengthened by the action of the real estate business which benefits from the increase of highly accessible locations, and from the private and public investments and incentives to tourism that aim to insert this city into the globalized world. Although the intention of reconstituting part of the history of density increase on this avenue in a diachronical perspective was attempted within the limits of the available references and documentation, the central contribution of this study is to understand the relations between topological accessibility and the typological nature of the building ensemble. By observing the synchronic morphological frame resulting from the spatial configuration analysis pertinent to this avenue (cf. Hillier and Hanson,1984) and the inventory and classification of the building ensemble there existing, this study aims to understand how architecture responds to accessibility in view of the real estate pressure, boosted by a cosmopolitanizing process brought about by the continuous flow of foreign and Brazilian arrivals as visitors, temporary or permanent residents

Modos de ser e modos de viver : a trajetória dos estrangeiros em Natal/RN

This work aims to understand the trajectory of immigrants living in Natal / RN, between the years 1990 and 2009, their motivations for this change, their sociability relations, as well as the impact of this group in Natal and specifically, in the district of Ponta Negra, where most of them established their residences or work. Considering that the historical, political, economical and social environment where these immigrants are inserted, are different from that experienced by former immigrants who came to Brazil in the late nineteenth and early twentieth centuries, a period of mass migration, it was revealed that immigration studied in contemporary Natal constitutes a new configuration (Elias, 1994). This new configuration is represented by several characteristics that distinguish this contemporary immigration, as: the relationship established by these foreigners, both with their country of origin and the destination, the formation of social networks that offer support to newcomers and those already installed, the relations of sociability with locals and a new relationship of belonging with the space, since the possibility of coming and going from one country to the other, allows a (re)production of their original ?? social and economic life in the new space. The research methodology was based on the analysis of narrative interviews, in light of the theory of Schütze (1977) in order to understand the faces of this immigration. As theoretical support for the data analysis the theories of authors such as Norbert Elias, presentedin his work about the established and outsiders, Pierre Bourdieu, and his concept of habitus, distinction and style of life, Georg Simmel, and his study of life in the metropolis, his analysis of the foreigner and his theory of sociability, among others. This study attempted to give visibility to foreigners living in Natal, who experience the dynamics of the district of Ponta Negra and reconstruct their daily relations of sociability in this space. In fact, the presence of foreigners in this urban context allows for the construction of new configurations, both in terms of the physical space of the neighborhood, which has been modified by the touristification process and the real estate market, which is molded to meet this demand, but also in their social sphere, with regard to the relations established between foreign residents and locals. In seeking to characterize these migratory experiences it could be understood that the trajectories of each foreigner is part of a broader social structure, which cannot be evaluated neither disconnected from the contexts in which they operate, nor under a single point of view

Relações internacionais: o comércio exterior do Brasil e Rio Grande do Norte no período de 1999 a 2008

The period post-war promoted several changes in relations economic, political and social world. Since then, a new division international of labor has delineated, with the great growth of Asian countries. In the field of international relations, the world still appears to transition is not completed because the old institutions were not replaced by new ones and the power of the United States as a major capitalist country remains unshaken, even with the emergence and strengthening of new economic global blocs. With globalization, Brazil emerges with more intensity in the face of new issues global, although its share in transactions trade global hasn‟t changed accordingly. In this sense, the objective of this dissertation is to examine, in a descriptive and critical the development of international relations and trade of Brazil and Rio Grande do Norte with the main blocs in the world from 1999 to 2008. As a secondary objective: to identify the assumptions theoretical that underpinned the decisions governments of the FHC and Lula, in particular, the interference of these terms in international relations and foreign trade. Adopted as the procedure methodological the literature review of the subject, as well as collection and processing of the data of foreign trade. During the Cardoso government has undergone the substantial growth in imports, as part of the economic policy of anti-inflationary, generating large deficits trade. From the first to the second term, with the inflection of exchange rate policy the country has resumed surpluses trade. The choice of government of the autonomy participation increased the relative share of the traditional blocks in total foreign trade and reduced the share of MERCOSUL. In the Lula government, there is the maintenance of some elements of the economic policy of the previous government and the partial shift in the conduct of foreign policy, with the option of autonomy through diversification, raising its stake on the blocks and other emerging countries in total foreign trade Brazilian and reducing the contribution of the traditional blocks such as NAFTA and the European Union. A trend observed in the previous government and deepened in the Lula government was the growth in commodity exports and the decline of manufactured products, confirming the model of conservative insertion of Brazilian exports. The Rio Grande do Norte followed the trend Brazilian in the growth of foreign trade, including in participating conservative, given that the products exported by the state are basically coming from horticulture irrigated and agribusiness. However, in the aspect of destination export, the state followed trajectory distinct from that in the Lula government, with the deepening of trade relations with traditional blocks, especially with the European Union and NAFTA

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

Contra as Secas: a engenharia e as origens de um planejamento regional no nordeste brasileiro

Droughts surfaced in 1877 as a crucial problem for the birthing Brazilian nation. Engineers, who formed the country's technical and scientific elite, took it upon themselves to study, understand and fight the problem through planned actions of intervention on space. This work, based on proposals and discussions contained in engineering magazines and reports, aims to provide elements for the comprehension of how these systematized actions against droughts, in the Iate nineteenth and early twentieth century, contributed to spatial analysis and the formation of a (then-inexistent) regional and territorial planning discipline in Brazi!. Engineers, by taking up the position of masterminds in the country's modernization, guaranteed for themselves personal economic stability, social prestige and political power. By understanding nature, either as a resource to be exploited or an adversary to national progress, they contributed to the delimitation of the region now known as the Northeast. By seeking to understand the drought phenomenon, they created knowledge about the space they sought to intervene on; by constructing their projects amid political and economical difficulty, they changed the organizational structures of cities and country in the northeast. The proposals for açudes (Iarge water reservoirs) allowed the fixation of population and the resistance against droughts; the roads - railroads and automotive roadways - connected the sertão to the capitais and the coast, speeding up help to the affected populations during droughts and allowing the circulation of goods so as to strengthen the local economies in normal rimes. The adopted practices and techniques, adapted from foreign experience and developed through trial and improvement, were consolidated as an eminently spatial intervention course, even if a theoretical body of regional or territorial planning wasn't formed in Brazil. Regional Planning proper was first applied in the country in the Northeast itself, in the 1950s, based off an economical view of reality in order to achieve development. The engineer's work prior tothat date, however, cannot be dlsconsldered. It was proved that, despite facing financial and political hurdles, engineers had a profound commitment to the problem and intended to act systematically to transform the economical and social relations in the region, in order to be victorious in their struggle against droughts

Natal qual é a sua cara?: análise do perfil edilício da avenida Eng. Roberto Freire (Natal/RN) à luz da acessibilidade

This study focuses on the building ensemble of Avenida Roberto Freire, a main road in Natal, Brazil, as a material expression of the confluence of various factors among which the following may be emphasized: high level of accessibility due to urban spatial re-structuring and the growth of the real estate market, in view of the increasing number of consumers, who arrived in Natal within the last decades. The intense urban modification process that has been going on in Natal since at least the 1980s, has engendered the formation of long axial lines which express the expansion dynamics and some of the forces subjacent to it. Avenida Roberto Freire has been an iconic example of an urban thoroughfare where architecture becomes primarily a communication support that can be perceived by fast moving passers-by, what brings it close to the venturian concept of strip (Venturi at al, 1972). The building types that line the road not only respond to the dynamics in process but also contribute to intensify it, as they house a variety of uses which attract people and generate more movement. The dynamics is further strengthened by the action of the real estate business which benefits from the increase of highly accessible locations, and from the private and public investments and incentives to tourism that aim to insert this city into the globalized world. Although the intention of reconstituting part of the history of density increase on this avenue in a diachronical perspective was attempted within the limits of the available references and documentation, the central contribution of this study is to understand the relations between topological accessibility and the typological nature of the building ensemble. By observing the synchronic morphological frame resulting from the spatial configuration analysis pertinent to this avenue (cf. Hillier and Hanson,1984) and the inventory and classification of the building ensemble there existing, this study aims to understand how architecture responds to accessibility in view of the real estate pressure, boosted by a cosmopolitanizing process brought about by the continuous flow of foreign and Brazilian arrivals as visitors, temporary or permanent residents