Gastos públicos em educação municipal: uma análise da eficiência-custo na gestão dos recursos no ensino fundamental no estado do Rio Grande do Norte

This study evaluates the cost effectiveness of municipalities in the state of Rio Grande do Norte in the execution of spending in basic education carried out in 2011, as well as analyze the determinants of the inefficiency of the same. For this, we used two methodological approaches (i) stochastic frontier cost, and (ii) analyze data envelopment (DEA), which allows to identify the efficient frontier of the municipalities analyzed non-parametrically. Results show that municipalities under review achieved low efficiency rates in the stochastic frontier cost, while the DEA method they achieved higher rates where nineteen among them reached full efficiency. The results suggest that a significant portion of the Potiguar municipalities should review its administrative practices, especially the means of allocation of resources. In regard to determining the efficiency observed distinct results by the two methods.

Ocorrência de leite instável na região semiárida do Rio Grande do Norte e sua correlação com a qualidade do leite

The unstable non acid milk (UNAM) is characterized by coagulation in the alcohol test and wanted acidity (14-18°D). Among Brazilian regions, the South and Southeast have the highest occurrence of LINA, which has been causing problems for both producers and for industries, due to the disposal or undervaluation of milk. In the Northeast there are few studies that indicate their occurrence and quality. The objective of this study was to identify the occurrence of unstable non-acid milk in the west and central mesoregions of Rio Grande do Norte, determine their physicochemical characteristics, test alcoholic graduations and evaluate their correlation with the quality of milk. 176 raw milk samples were analyzed in the period from September to December /2014 from 23 APASA’s cooling tanks, located in 7 cities of west and central mesoregions RN. The samples were collected in duplicate, one sample used for alcohol testing at 68, 72 and 76%, measurement of pH, acidity, electrical conductivity and boiling proof, made in LABOLEITE / UFRN; and the other sample containing Bronopol® preservative, was sent to the APCBRH (Cattle Breeders Association Paranaense Holstein) laboratory in Curitiba-PR, which were analyzed fat, protein, total solids, lactose, casein, urea nitrogen and somatic cell count. The test alcohol samples disapproved 31.82%, of which 30% proved to be non-acid, and 30% had high acidity. The samples were divided into three classes: Stable Milk, UNAM and acid milk. 3% Tukey test was used for comparison of stable milk components and UNAM and there was no significant difference between them. Both classes obtained averages within the standard required by IN 62. The average value of electric conductivity was 4.84 mS/cm for stable milk, 4.55 mS/cm for unstable and acid milk and 4.53 mS/cm for non-acid unstable milk. The electrical conductivity was positively correlated with alcohol stability of milk and negative correlation with acidity and pH. Could not observe direct relationship between the electrical conductivity and the somatic cell count.The boiling test was negative for all samples UNAM. It can be concluded that the incidence of UNAM in the studied region is low, although the predisposing factors such as heat stress, drought and nutritional deficiency. In conclusion, the UNAM has quality similar to stable milk, conform the norms required by Agriculture Ministry, and with adequate thermal stability, which proves that there is no reason to reject this milk by industry.

Serviços-escola de psicologia do Rio Grande do Norte: formação profissional e política pública de saúde em debate

The Psychology University Services is stablished normatively as an indispensable equipment to the recognition of the graduation courses of psychologists by the Brazilian Education Ministery. The Public Healthcare Policies (Universal Health System/SUS) constitutes itself as a input field of the professional category, but shows huge challenges in the formation of these professionals. The objective of this work is to analyse the functioning of the Psychology University Services (SEP) and the Superior Educational Institutions from Natal, understood as important formation devices to attend the actual demands of the psychologist's work on SUS. For this, it sought a) characterize the psychological practices developed in the SEP; b) relate the National Curricular Lines of Direction of the psychology courses to the skills and competences developed in the SEP to the performance on the public healthcare policies; c) mapping ways of including the SEP in the network designed by the healthcare policy. Interviews were performed with 13 academic supervisors, 8 field supervisors and technicians of superior level (TNC), along with 9 managers, being for of the Psychology University Services and 5 of the graduation programs. Questionnaires were also applied to 57 interns and 24 graduates. Besides that, two conversation circles were performed with the faculty and technician members from two of the Educational Institutions that were participating of the research, as well as a workshop with students and psychologists, promoted by the CRP 17. We observed that most part of the faculty members and managers know the DCN and comprehend that the formation is in process of change in what concerns to the extension of the formation to the performance of the psychologists in various contexts. However, most part of the TNC don't know about them. Moreover, the results point to the predominance of the assisting model based on the traditional clinic psychology, although the articulation with the public healthcare and social assistance networks can already be timidly visualized. Different modalities of practices in theses Psychology University Services were also detected, such as conversation groups, thematic workshops, organizational consultancies, team meetings with the interns and TNS in a daily basis, matriciament in mental health, therapeutic monitoring, among others. Yet, the SEP in Rio Grande do Norte are still isolated from the other courses that perform in the healthcare area and also from the services that compose the public healthcare and public policies.

Os usos do território e a economia solidária no Rio Grande do Norte

The solidary economy as the organization of production, alternative to the capitalist economy provides new forms of organization and social behavior, that, in the sight of geography, it is shown by the different territory uses. The territory assume new meanings that, influenced by the Solidary Economy movement, tries to reach for new ways of acting that differ from social order already stablished. However, the different uses show themselves in a more complex and contradictory way, given that, in solidary undertakings, different corporative agents start to act, the State being a last resource on this process. Given this reality, our goal on the present paper is to analyze the different uses of the territory from the rural economic solidary undertakings and the relationship it establishes to the different agents involved on the socio-territorial dynamics on Rio Grande do Norte. Starting from a study that contemplates the territorial organization forms and contents of the analyzed phenomena, the methodology utilized for this research is based on a bibliographic review, with authors from the geography and areas related to the Solidary Economy, besides the use of secondary data, acquired from official offices such as SIES and IBGE, from the documented research, SENAES and field interviews conducted with local solidary undertakings. The results obtained in the study reveal the complexity of the agricultural use of the territory by Solidary Economy on the RN, while a resource of intensified use, from the state actions and important economical agents, and regulating the use while shelter, that marginalize solidary workers, making them subdued to the hegemonic logic. Therefore, we can infer that the solidary economy, despite its image of new form of organization between agricultural workers, given the expressivity of the rural solidary undertakings presented on RN, it hasn’t shown a full social development as an instrument of reproduction and emancipation of the associates. Nevertheless, the undertakings articulated in nets excel, even when considering its punctual and residual form. The given contradictions show that it is necessary to fortify the building of the solidary economy as being horizontal and popular based for it to have strength to surpass the regulative actions of the capitalist state and ownership created by the Capital.

Um brinde à cachaça: o patrimônio históricocultural e seus usos turísticos nos alambiques do Rio Grande do Norte

The study proposes to present a discussion about the value of cachaça as a cultural heritage and its relation with the touristic activities in the State of Rio Grande do Norte. Based on a discussion originated from historic studies related to the touristic sector, especially when it comes to gastronomy, cachaça is defined not only as an important instrument to the construction of identities, but, also, as an element able to weave social, political and economic relations. Therefore, a touristic product that can provide new destinations. The research was made through five alembics located on the East and Seridó regions of Rio Grande do Norte. To define the focus, it is necessary to refine this selection, especially when dealing with historical facts and memories from these establishment owners. Thus, it becomes necessary to consider the alembic trajectory, periods of larger productions and insertion in the touristic market. Through documental data collection and observations made in field tours, the research has a qualitative approach with descriptive and exploratory goal, methodology that allows us to approach issues around articulations among heritage, identity and tourism. "It was concluded that the state of Rio Grande do Norte has many tourist routes where handmade cachaça produced in the State can be inserted in any of these routes due to its potential searched in the research, as well as, it is possible to work in other perspective when it comes to ways of protecting this patrimony and strategies of incentive of the activity for the development and appreciation of local economy.

A paisagem da Mata Atlântica do estado do Rio Grande do Norte: remanescentes, configuração espacial e disponibilidade de habitat

The Atlantic Forest in Rio Grande do Norte (RN) is included in Pernambuco biogeographic sub-region and it is composed by Semi-deciduous Forest, deciduous Forest, Mangrove and Restinga. We assessed the conservation status of Atlantic Forest in the RN through remnants mapping using high resolution satellite images and landscape ecology approaches. We evaluated if there is difference between the north and south coastal regions considering their natural a historical land use differences. We also assessed the influence of the small remnants on landscape cover and configuration. The proportion of the original biome area with remnants larger than 3 hectares is 15.60% for the official governmental limit and is 16.60% for the alternative limit (SNE, 2002). This remnants proportion varies between 0.56 and 46.52% in the hydrographic basins. 89.70% of the remnants are smaller than 50 hectares. Only 6.00% of the remnants are greater than 100 hectares, and these remnants are responsible by 65% of remaining area. The patches with smaller area influence all calculated metrics. The south coastal hydrographic basins have higher percentage of coverage of remnants, larger patch densities and fragments with larger areas than north coastal hydrographic basins. The diffuse drainage basins of the southern coastal have the highest percentage of coverage with remnants. 18.28% and 10% of the biome area are protected by reserves, according to the official governmental and alternative limits respectively. The reserves are mainly of sustainable use (IUCN V-VI). Therefore, the Atlantic Forest in Rio Grande do Norte is in critical situation, with low proportion of remaining area and high fragmentation level. It’s indispensable to biome conservation keep all the remaining area, especially the large remnants, and restore areas to increase remnants proportion and to increase landscape connectivity

A questão ambiental nos cursos de graduação em Educação Física no estado do Rio Grande do Norte

Environmental education started to be discussed since the intensification of the human activity, as a consequence of the industrial revolution. In Brazil, the proposal has gained attention due to the National Environmental Policy, which suggested inserting environmental education in all education levels and later as a crosscutting topic pervading the contents offered in all courses, according to the National Curricula Parameters. Faced with such a challenge, this work aimed to identify how environmental concerns is being considered in physical education licentiate courses at Rio Grande do Norte. For this purpose, we have adopted a descriptive method starting from interviews with coordinators of six institutions offering a physical education licentiate degree (UFRN, UNI-RN, UNIFACEX, FANEC, and UERN – Mossoró and Pau dos Ferros Campi), the application of a questionnaire with 30% of graduating students in the second half of 2015, and observations from the pedagogical projects and syllabi of the institutions that have provided such documents. Results have pointed out the acknowledgement of students and coordinators on the importance of addressing environmental concerns in physical education. However, coordinators and students contradict each other in all investigated institutions. According to the coordinators, environmental education effectively is in some courses of the curriculum as a mandatory requirement from the Brazilian National Ministry of Education. Nonetheless, in practice, most graduating students have no knowledge about environmental education in their courses, stating that they do not have training suited to meet these concerns. When requested to exemplify how they would deal with environmental education, a fragile education to address this topic in their future workspaces was revealed, showing uncritical activities. Despite the obligatoriness in the educational context already exists for decades and the importance of this topic revealed in the speeches of professionals, environmental education is still shy in physical education curricula and education courses, thereby showing the need of a curricular restructuration and a new understanding on this topic, as well as making it to be more present in the daily activities of the future teachers who should take it into consideration in their classes.

A questão ambiental nos cursos de graduação em Educação Física no estado do Rio Grande do Norte

Environmental education started to be discussed since the intensification of the human activity, as a consequence of the industrial revolution. In Brazil, the proposal has gained attention due to the National Environmental Policy, which suggested inserting environmental education in all education levels and later as a crosscutting topic pervading the contents offered in all courses, according to the National Curricula Parameters. Faced with such a challenge, this work aimed to identify how environmental concerns is being considered in physical education licentiate courses at Rio Grande do Norte. For this purpose, we have adopted a descriptive method starting from interviews with coordinators of six institutions offering a physical education licentiate degree (UFRN, UNI-RN, UNIFACEX, FANEC, and UERN – Mossoró and Pau dos Ferros Campi), the application of a questionnaire with 30% of graduating students in the second half of 2015, and observations from the pedagogical projects and syllabi of the institutions that have provided such documents. Results have pointed out the acknowledgement of students and coordinators on the importance of addressing environmental concerns in physical education. However, coordinators and students contradict each other in all investigated institutions. According to the coordinators, environmental education effectively is in some courses of the curriculum as a mandatory requirement from the Brazilian National Ministry of Education. Nonetheless, in practice, most graduating students have no knowledge about environmental education in their courses, stating that they do not have training suited to meet these concerns. When requested to exemplify how they would deal with environmental education, a fragile education to address this topic in their future workspaces was revealed, showing uncritical activities. Despite the obligatoriness in the educational context already exists for decades and the importance of this topic revealed in the speeches of professionals, environmental education is still shy in physical education curricula and education courses, thereby showing the need of a curricular restructuration and a new understanding on this topic, as well as making it to be more present in the daily activities of the future teachers who should take it into consideration in their classes.

Estratégia de capacitação pedagógica do residente: uma perspectiva para melhoria do ensino na Universidade Federal do Rio Grande do Norte

Studies have shown that resident informally plays the role of teacher. It is estimated that up to 25% of the residents of the time is devoted to teaching, mainly contributing as a facilitator, however, almost the entire medical residency programs in Brazil did not offer teacher training during residency education. This paper aims to introduce educational content initiation to teaching as part of the training of resident physician inserted in residency program of the University Hospital Onofre Lopes (HUOL). It is an exploratory, descriptive and prospective study in HUOL the Federal University of Rio Grande do Norte. Three steps were developed: preparation and planning of a pedagogic course, associated with a motivating technical content (basic and advanced life support); second stage, testing of pedagogical model for medical students; and finally, replication to residents. The interventions were made two practice stations life support with performance evaluation in practical activity through OSPE (Objective Structured Practical Examination). The techniques presented teachings were one-minute preceptor and feedback. Data collection was conducted through a structured evaluation form during the life support stations and at the end of the course, and analyzed using descriptive statistics. The results showed that the feedback and one minute preceptor were considered important for teaching and learning for more than 85% of participants. The feedback from evaluators practices stations added information about the performance and were held appreciatively way, according to 100% of the participants. Positive aspects highlighted by the participants were related to educational content, especially the participants of the first intervention. The time of the lectures of motivating technical content was the most repeated negative. Based on the good acceptance of pedagogical contents, this pioneer teacher training strategy was included in the formal residency program in Cardiology of our institution. It is considered therefore that the educational training model with motivating technical content was feasible and had a good evaluation and acceptance by most participants in both interventions. Thus, we believe that the educational content can be inserted in the formal curriculum of medical residency of other programs at HUOL through the training model developed in this study.

Estratégia de capacitação pedagógica do residente: uma perspectiva para melhoria do ensino na Universidade Federal do Rio Grande do Norte

Studies have shown that resident informally plays the role of teacher. It is estimated that up to 25% of the residents of the time is devoted to teaching, mainly contributing as a facilitator, however, almost the entire medical residency programs in Brazil did not offer teacher training during residency education. This paper aims to introduce educational content initiation to teaching as part of the training of resident physician inserted in residency program of the University Hospital Onofre Lopes (HUOL). It is an exploratory, descriptive and prospective study in HUOL the Federal University of Rio Grande do Norte. Three steps were developed: preparation and planning of a pedagogic course, associated with a motivating technical content (basic and advanced life support); second stage, testing of pedagogical model for medical students; and finally, replication to residents. The interventions were made two practice stations life support with performance evaluation in practical activity through OSPE (Objective Structured Practical Examination). The techniques presented teachings were one-minute preceptor and feedback. Data collection was conducted through a structured evaluation form during the life support stations and at the end of the course, and analyzed using descriptive statistics. The results showed that the feedback and one minute preceptor were considered important for teaching and learning for more than 85% of participants. The feedback from evaluators practices stations added information about the performance and were held appreciatively way, according to 100% of the participants. Positive aspects highlighted by the participants were related to educational content, especially the participants of the first intervention. The time of the lectures of motivating technical content was the most repeated negative. Based on the good acceptance of pedagogical contents, this pioneer teacher training strategy was included in the formal residency program in Cardiology of our institution. It is considered therefore that the educational training model with motivating technical content was feasible and had a good evaluation and acceptance by most participants in both interventions. Thus, we believe that the educational content can be inserted in the formal curriculum of medical residency of other programs at HUOL through the training model developed in this study.

Visões de República: ideias e práticas no Rio Grande do Norte (1880-1895)

A obra estuda as principais correntes político-ideológicas existentes no Rio Grande do Norte no período de transição entre o final do Império e os primeiros anos da República. Através de uma exaustiva pesquisa em fontes jornalísticas e documentais, o autor introduz o leitor no universo das ideias e práticas políticas que marcaram a tensa implantação do regime republicano no Brasil e especialmente no Rio Grande do Norte.

Variabilidade genética de Leishmania spp. circulantes entre seres humanos e cães e infecção de flebotomíneos em áreas endêmicas para as leishmanioses no Rio Grande do Norte

Leishmania infantum is the main etiologic agent of visceral leishmaniasis in the New World. The pattern of distribution of leishmaniasis has changed substantially and has presented an emerging profile within the periphery of the Large Urban Centers. Leishmania infection can compromise skin, mucosa and viscera. Only 10% of the individuals infected develop the disease and 90% of human infection is asymptomatic. The main factors involved in the development of the disease are the host immune response, the vector’s species and the parasite’s genetic content. The sequencing of Leishmania isolated seeks to increase the understanding of the symptoms of individuals. The aim of this study was to evaluate the genetic diversity of circulating Leishmania strains among humans, and symptomatic and asymptomatic, and dogs from endemic areas of Rio Grande do Norte State and analyze sandflies from endemic areas for cutaneous and visceral disease. The genetic variability was evaluated by the use of markers hsp70 , ITS1 and a whole genome sequencing was also carried out. The amplified hsp70 and ITS1 of samples were analyzed and assembled using a Phred / Phrap package. The dendograms were constructed using the same methodology, but adding 500 bootstraps, followed by inferences on the relationships between Leishmania variants. The sequences of the 20 Brazilian isolates were mapped to the reference genome L. infantum JPCM5, using the Bowtie2 program and the identification of 36 contigs. The information of the valid SNPs were used in the PCA. SNPs were visualized by Geneious 7.1 and IGV. The genome annotations were transferred to their respective chromosomes and displayed on Geneious. The matching sequences of all chromosomes were aligned using Mauve. The phylogenetic trees were calculated according to maximum likelihood and JTT models. Sandflies were analyzed by PCR for the identification of Leishmania infection, a blood meal source and GAPDH sand fly. As a result, hsp70 and ITS1 were not capable of identifying genetic variability among human isolates from symptomatic and asymptomatic, and dogs. The complete sequencing of the 20 Brazilian isolates revealed a strong similarity between the circulating Leishmania strains in Rio Grande do Norte. The isolates collected in the city of Natal from humans and canines remained grouped in all analyzes, suggesting that there is genotypic and geographic proximity among the isolates. The isolated samples in the 1990s had a higher genotypic diversity when compared to freshly isolated samples. All isolates presented 36 chromosomes with variable ploidy among them, no correlation was found between the number of amastina genes copies, gp63, A2 and SSG with such clinic forms. In general, we did not find correlation between symptomatic and asymptomatic clinical forms and the gene content of the Brazilian isolates of Leishmania. 34,28% of the sandflies collected in the upper west region were L. longipalpis and the main sources of blood meal were humans, dogs and chickens.

Variabilidade genética de Leishmania spp. circulantes entre seres humanos e cães e infecção de flebotomíneos em áreas endêmicas para as leishmanioses no Rio Grande do Norte

Leishmania infantum is the main etiologic agent of visceral leishmaniasis in the New World. The pattern of distribution of leishmaniasis has changed substantially and has presented an emerging profile within the periphery of the Large Urban Centers. Leishmania infection can compromise skin, mucosa and viscera. Only 10% of the individuals infected develop the disease and 90% of human infection is asymptomatic. The main factors involved in the development of the disease are the host immune response, the vector’s species and the parasite’s genetic content. The sequencing of Leishmania isolated seeks to increase the understanding of the symptoms of individuals. The aim of this study was to evaluate the genetic diversity of circulating Leishmania strains among humans, and symptomatic and asymptomatic, and dogs from endemic areas of Rio Grande do Norte State and analyze sandflies from endemic areas for cutaneous and visceral disease. The genetic variability was evaluated by the use of markers hsp70 , ITS1 and a whole genome sequencing was also carried out. The amplified hsp70 and ITS1 of samples were analyzed and assembled using a Phred / Phrap package. The dendograms were constructed using the same methodology, but adding 500 bootstraps, followed by inferences on the relationships between Leishmania variants. The sequences of the 20 Brazilian isolates were mapped to the reference genome L. infantum JPCM5, using the Bowtie2 program and the identification of 36 contigs. The information of the valid SNPs were used in the PCA. SNPs were visualized by Geneious 7.1 and IGV. The genome annotations were transferred to their respective chromosomes and displayed on Geneious. The matching sequences of all chromosomes were aligned using Mauve. The phylogenetic trees were calculated according to maximum likelihood and JTT models. Sandflies were analyzed by PCR for the identification of Leishmania infection, a blood meal source and GAPDH sand fly. As a result, hsp70 and ITS1 were not capable of identifying genetic variability among human isolates from symptomatic and asymptomatic, and dogs. The complete sequencing of the 20 Brazilian isolates revealed a strong similarity between the circulating Leishmania strains in Rio Grande do Norte. The isolates collected in the city of Natal from humans and canines remained grouped in all analyzes, suggesting that there is genotypic and geographic proximity among the isolates. The isolated samples in the 1990s had a higher genotypic diversity when compared to freshly isolated samples. All isolates presented 36 chromosomes with variable ploidy among them, no correlation was found between the number of amastina genes copies, gp63, A2 and SSG with such clinic forms. In general, we did not find correlation between symptomatic and asymptomatic clinical forms and the gene content of the Brazilian isolates of Leishmania. 34,28% of the sandflies collected in the upper west region were L. longipalpis and the main sources of blood meal were humans, dogs and chickens.

Petrologia e geoquímica do magmatismo ediacarano Serra do Caramuru, Rio Grande do Norte, NE do Brasil

The Serra do Caramuru and Tapuio stocks, located in the extreme NE of Rio Piranhas-Seridó Domain (RN), are representative of the Ediacaran-Cambrian magmatism, an important magmatic feature of the Brasilian / Panafrican orogeny of the Borborema Province. These bodies are lithologically similar, intrusive in paleoproterozoic gneiss embasement, being separated by a thin belt of mylonitic orthogneiss. The field relations show a magmatic stratigraphy initiated by dioritic facies that coexists with the porphyritic granitic and equigranular granitic I facies, and less frequently with equigranular granitic II facies. These rocks are crosscut by late granitic dykes and sheets with NE-SW / NNE-SSW orientation. The dioritic facies (diorite, quartz diorite, quartz monzodiorites, tonalite and granodiorite) is leucocratic to melanocratic, rich in biotite and hornblende. The granitic facies are hololeucocratic to leucocratic, and have biotite ± hornblende. Petrographic and geochemical (whole rock) data, especially from Serra do Caramuru pluton, suggest fractionation of zircon, apatite, clinopyroxene (in diorites), opaque minerals, titanite, biotite, hornblende, allanite, plagioclase, microcline and garnet (in dykes). The behavior of trace elements such as Zr, La and Yb indicates that the dioritic magma does not constitute the parental magma for the granitic facies. On the other hand, the granitic facies seems to be cogenetic to each other, displaying differentiation trends and very similar rare earth elements (REE) spectra [12.3≤(La/Yb)N≤190.8; Eu/Eu*=0.30-0.68]. Field relationships and REE patterns [6.96≤(La/Yb)N≤277.8; Eu/Eu*=0.18-0.58] demonstrate that the granitic dykes and sheets are not cogenetically related to the Serra do Caramuru magmatism. The dioritic facies is metaluminous (A/CNK = 0.88-0.74) and shoshonitic, whereas the granitic ones are metaluminous to peraluminous (A/CNK = 1.08-0.93) and high potassium calc-alkaline. Dykes and sheets are strictly peraluminous (A/CNK = 1.01-1.04). Binary diagrams relating compatible and incompatible trace elements and microtextures indicate the fractional crystallization as the dominant mechanism of magmatic evolution of the various facies. The Serra do Caramuru and Tapuio stocks have well preserved magmatic fabric, do not show metamorphic minerals and are structurally isotropic, showing crosscutting contact with the ductile fabric of the basement. These observations lead to interpretate a stage of relative tectonic stability, consistent with the orogenic relaxation period of the Brasiliano / Pan-African orogeny. Chemical plots involving oxides and trace elements indicate late to post-collisional emplacement. In this context, the assumed better mechanism to describe the stocks emplacement within an extensional T Riedel joint, with ENE-WSW extensional vector. The U-Pb zircon age of 553 ± 10 Ma allows correlating the Serra do Caramuru magmatism to the group of post-collisional bodies, equigranular high potassium calc-alkaline granites of the NE of Rio Piranhas-Seridó Domain.

Petrologia e geoquímica do magmatismo ediacarano Serra do Caramuru, Rio Grande do Norte, NE do Brasil

The Serra do Caramuru and Tapuio stocks, located in the extreme NE of Rio Piranhas-Seridó Domain (RN), are representative of the Ediacaran-Cambrian magmatism, an important magmatic feature of the Brasilian / Panafrican orogeny of the Borborema Province. These bodies are lithologically similar, intrusive in paleoproterozoic gneiss embasement, being separated by a thin belt of mylonitic orthogneiss. The field relations show a magmatic stratigraphy initiated by dioritic facies that coexists with the porphyritic granitic and equigranular granitic I facies, and less frequently with equigranular granitic II facies. These rocks are crosscut by late granitic dykes and sheets with NE-SW / NNE-SSW orientation. The dioritic facies (diorite, quartz diorite, quartz monzodiorites, tonalite and granodiorite) is leucocratic to melanocratic, rich in biotite and hornblende. The granitic facies are hololeucocratic to leucocratic, and have biotite ± hornblende. Petrographic and geochemical (whole rock) data, especially from Serra do Caramuru pluton, suggest fractionation of zircon, apatite, clinopyroxene (in diorites), opaque minerals, titanite, biotite, hornblende, allanite, plagioclase, microcline and garnet (in dykes). The behavior of trace elements such as Zr, La and Yb indicates that the dioritic magma does not constitute the parental magma for the granitic facies. On the other hand, the granitic facies seems to be cogenetic to each other, displaying differentiation trends and very similar rare earth elements (REE) spectra [12.3≤(La/Yb)N≤190.8; Eu/Eu*=0.30-0.68]. Field relationships and REE patterns [6.96≤(La/Yb)N≤277.8; Eu/Eu*=0.18-0.58] demonstrate that the granitic dykes and sheets are not cogenetically related to the Serra do Caramuru magmatism. The dioritic facies is metaluminous (A/CNK = 0.88-0.74) and shoshonitic, whereas the granitic ones are metaluminous to peraluminous (A/CNK = 1.08-0.93) and high potassium calc-alkaline. Dykes and sheets are strictly peraluminous (A/CNK = 1.01-1.04). Binary diagrams relating compatible and incompatible trace elements and microtextures indicate the fractional crystallization as the dominant mechanism of magmatic evolution of the various facies. The Serra do Caramuru and Tapuio stocks have well preserved magmatic fabric, do not show metamorphic minerals and are structurally isotropic, showing crosscutting contact with the ductile fabric of the basement. These observations lead to interpretate a stage of relative tectonic stability, consistent with the orogenic relaxation period of the Brasiliano / Pan-African orogeny. Chemical plots involving oxides and trace elements indicate late to post-collisional emplacement. In this context, the assumed better mechanism to describe the stocks emplacement within an extensional T Riedel joint, with ENE-WSW extensional vector. The U-Pb zircon age of 553 ± 10 Ma allows correlating the Serra do Caramuru magmatism to the group of post-collisional bodies, equigranular high potassium calc-alkaline granites of the NE of Rio Piranhas-Seridó Domain.