Uso de água produzida na formulação de fluidos de perfuração

Drilling fluids have fundamental importance in the petroleum activities, since they are responsible for remove the cuttings, maintain pressure and well stability, preventing collapse and inflow of fluid into the rock formation and maintain lubrication and cooling the drill. There are basically three types of drilling fluids: water-based, non-aqueous and aerated based. The water-based drilling fluid is widely used because it is less aggressive to the environment and provide excellent stability and inhibition (when the water based drilling fluid is a inhibition fluid), among other qualities. Produced water is generated simultaneously with oil during production and has high concentrations of metals and contaminants, so it’s necessary to treat for disposal this water. The produced water from the fields of Urucu-AM and Riacho da forquilha-RN have high concentrations of contaminants, metals and salts such as calcium and magnesium, complicating their treatment and disposal. Thus, the objective was to analyze the use of synthetic produced water with similar characteristics of produced water from Urucu-AM and Riacho da Forquilha-RN for formulate a water-based drilling mud, noting the influence of varying the concentration of calcium and magnesium into filtered and rheology tests. We conducted a simple 32 factorial experimental design for statistical modeling of data. The results showed that the varying concentrations of calcium and magnesium did not influence the rheology of the fluid, where in the plastic viscosity, apparent viscosity and the initial and final gels does not varied significantly. For the filtrate tests, calcium concentration in a linear fashion influenced chloride concentration, where when we have a higher concentration of calcium we have a higher the concentration of chloride in the filtrate. For the Urucu’s produced water based fluids, volume of filtrate was observed that the calcium concentration influences quadratically, this means that high calcium concentrations interfere with the power of the inhibitors used in the formulation of the filtered fluid. For Riacho’s produced water based fluid, Calcium’s influences is linear for volume of filtrate. The magnesium concentration was significant only for chloride concentration in a quadratic way just for Urucu’s produced water based fluids. The mud with maximum concentration of magnesium (9,411g/L), but minimal concentration of calcium (0,733g/L) showed good results. Therefore, a maximum water produced by magnesium concentration of 9,411g/L and the maximum calcium concentration of 0,733g/L can be used for formulating water-based drilling fluids, providing appropriate properties for this kind of fluid.

Acompanhamento coletivo do crescimento e desenvolvimento infantil: participação de mães/cuidadores

This study aimed to analyze the participation of mothers/caregivers from the perspective of the health care model that directs the collective monitoring of child growth and development. This is an exploratory and descriptive research with qualitative approach, carried out in two Family Health Units located in the city of Natal/RN. Data were collected between August and September 2014, through participant observation and semi-structured interview technique, with mothers of infants seen at follow-up visits collective child growth and development. A total of 13 mothers were included who met the following inclusion criteria: being a mother/caregiver responsible for the care of children who have attended one or more meeting of collective monitoring of child growth and development. Exclusion criteria was established: users outside the area covered by the Health Unit Family and who did not use the National Health System as the primary health care service. For the treatment of the collected material, the content analysis was used, thematic Bardin. The study followed the ethical and legal principles governing the scientific research on human subjects recommended by Resolution nº. 466/2012 of the National Health Council and its realization occurred with the approval of the project in the Research Ethics Committee of the Federal University of Rio Grande do North, which was approved by Opinion Embodied nº. 719 949, of June 27, 2014, and Certificate Presentation of Findings Ethics No 32510514.7.0000.5537. Although not conceptualize theoretically mothers demonstrated that collective consultations of child growth and development are actions aimed at health surveillance model, since most pointed monitoring your child to actions that can be measured. Even with that, it was established the existence of health promotion actions by reporting the exchange of experience and leadership of the subjects in collective action, factor facilitated by the link established between users and professionals and users. In this action there is the induction of permanent horizontal relationship where we seek to combine popular knowledge to scientific knowledge in order to promote the integral care for the child. However, it is still possible to find professionals who directs its assistance only to pathological processes and fail to create comprehensive care alternatives. In addition, there is still embezzlement in multi that should provide care to the child population. This factor may be related to their professional training, and thus an issue that can last for a few years. We conclude that it is necessary to incorporate alternatives and models of care that support overcoming limitations and enhancing the health of the population, involving it in the prospect of a better quality of life and therefore health.

Resiliência e apoio social em gestantes tardias

The gestation process, in general, is a very important event on a woman’s life and it brings phisical, phisiological and emotional changes, which by itself is an experience full of intense feelings. By late-aged pregnancy we mean those which occurs at the age of 35 or further. The occurance of this type of pregnancy is rising in Brasil and throughout the world, factors such as, better access to birth control resources and the search for financial stability explains the pregnancy delay. Important processes like resilience and social support can help late-aged pregnant women, in a benefical way, to adapt to the gestation process. Resilience is the capacity that a certain individual or group of individuals have to go through an adverse situation, be able to overcome it and become streghtened, transforming it in motivation for its biopsichosocial development. Social support is a complex and dinamic process that involves transactions between individuals and their social networks, meeting the social needs, promoting and complementing the personal resources that they have to face new demands. This research has the intention of raising information about the issues of late-aged pregnant women in the County of Natal- RN, the main objective was to evaluate the resilience indicators and the social support on late-aged pregnant women in the Natal-RN County. A transversal cut, correlational and descriptive research that was done with 150 lateaged pregnant women. The tools that were used were: A form with sociodemographic and gestation info, the scale of resilience and social support. An eletronic spreadsheet sofware (Excel e SPSS 21.0) was used to analize data which helped on the statistics according to its variables and the objective of this work. For the nominal variables, relative frequencies were used and for continuous the Pearson correlation and determination coefficient were used, regarding that; the sample had a normal distribution. The project fulfilled the ethnic aspects prescribed by Resolution 466/12 of the National Health Council, with a favorable decision (356.436/ 2013) of the UFRN Ethics on Research Committee. Most of the pregnant women had a low money income and education level, born in the state of Rio Grande do Norte they had an average age of 37,49 (±2,577), catholic, married, house wives, they had more than one child and were on their third trimester of pregnancy; they also had a low past abortion rate, not having planned their pregnancy, with an average of 4,22 (±2,506) pre-natal appointments, residing with an average of 3,673 (±1,397) people, having used any sort of birth control device and having high indicators of resilience and social support. The correlations kept between resilience, social support and some of the social demographics and gestation variables were considered low. Such data points out the fact that most of these women were in a stable relationship; they hadn’t had a past of abortion, they were involved with some kind of religion, they were not first pregnancy mothers, had an age on which they are not considered inexperienced mothers and even had scored high on the social support scale, these may all possibly be the most contributing factors on development and resilience building on these 35 years or more mothers. We expect that the data and information from this research may add up knowledge, actions and improvements regarding late-aged pregnant women and the pregnancy phenomena in general.

Influência de eventos hidrológicos extremos na qualidade da água de reservatórios na região tropical semiárida

Reservoirs are artificial ecosystems, intermediate between rivers and lakes, with diferent morphological and hydrological characteristics that can provide many important benefits to society. However, the use of this water for human consumption, watering livestock, leisure, irrigated agricultural production and pisciculture development, directly influence the increase loading of nutrients to aquatic environments and contribute to acceleration of eutrophication. Furthermore, global climate models are predicting a higher occurrence of extreme events such as floods and severe droughts, which will create hydrological stresses in lakes. In the semiarid northeast we can see the occurrence of these events, the drought of the years 2012, 2013 and 2014 was the worst drought in 60 years, according to the National Water Agency (ANA). Thus, this study aimed to evaluate the quality of the semiarid tropical water sources, identifying temporal patterns in periods with extreme hydrological events (floods and severe droughts). The study results showed that Gargalheiras and Cruzeta reservoirs presented significative changes in the limnological variables between rain and severe drought periods, with better appearance and in the most of the water quality variables in the rainy season and higher nutrientes concentrations and high electrical conductivity values in severe season, indicating decay of its quality. However, we found diferent behaviors between the reservoirs in severe drought. While Gargalheiras showed a typical behavior of the region, with high concentrations of algal biomass, indicating the worsening eutrophication, Cruzeta demonstrated a colapse in the total phytoplankton biomass, evidenced by the decrease in chla concentrations. This fact occurred because the low depth and proximity with the sediment facilited the inorganic solids resuspension and, consequently, resulted in turbid water column and light by limitation. In addition, the different behaviors between the reservoirs indicate that the responses of these environments problems such as extreme events must take into account factors such the region climate, size, depth of the reservoir and the basin characteristics.

Modelagem estatística e atribuições dos eventos de precipitação extrema na Amazônia brasileira

Intense precipitation events (IPE) have been causing great social and economic losses in the affected regions. In the Amazon, these events can have serious impacts, primarily for populations living on the margins of its countless rivers, because when water levels are elevated, floods and/or inundations are generally observed. Thus, the main objective of this research is to study IPE, through Extreme Value Theory (EVT), to estimate return periods of these events and identify regions of the Brazilian Amazon where IPE have the largest values. The study was performed using daily rainfall data of the hydrometeorological network managed by the National Water Agency (Agência Nacional de Água) and the Meteorological Data Bank for Education and Research (Banco de Dados Meteorológicos para Ensino e Pesquisa) of the National Institute of Meteorology (Instituto Nacional de Meteorologia), covering the period 1983-2012. First, homogeneous rainfall regions were determined through cluster analysis, using the hierarchical agglomerative Ward method. Then synthetic series to represent the homogeneous regions were created. Next EVT, was applied in these series, through Generalized Extreme Value (GEV) and the Generalized Pareto Distribution (GPD). The goodness of fit of these distributions were evaluated by the application of the Kolmogorov-Smirnov test, which compares the cumulated empirical distributions with the theoretical ones. Finally, the composition technique was used to characterize the prevailing atmospheric patterns for the occurrence of IPE. The results suggest that the Brazilian Amazon has six pluvial homogeneous regions. It is expected more severe IPE to occur in the south and in the Amazon coast. More intense rainfall events are expected during the rainy or transitions seasons of each sub-region, with total daily precipitation of 146.1, 143.1 and 109.4 mm (GEV) and 201.6, 209.5 and 152.4 mm (GPD), at least once year, in the south, in the coast and in the northwest of the Brazilian Amazon, respectively. For the south Amazonia, the composition analysis revealed that IPE are associated with the configuration and formation of the South Atlantic Convergence Zone. Along the coast, intense precipitation events are associated with mesoscale systems, such Squall Lines. In Northwest Amazonia IPE are apparently associated with the Intertropical Convergence Zone and/or local convection.

Processo de construção do conhecimento a partir do diálogo ensino-serviço na ótica dos profissionais de saúde

INTRODUCTION: In Brazil, the health training policies have been going through deep changes, which are the fruits of the sanitary reform and of the breakage with the biomedical model, still hegemonic. Nevertheless, the paradigm of comprehensiveness is being introduced in health and, in order to consolidate this concept, the training has been gaining new methodological approaches. One can mention the teaching-service interaction (education-health system/citizenship health), whose proposal enables the expansion of the perception of the health-disease process, as well as the warranty of compromises of training in relation to SUS. OBJECTIVE: Understand, from health professionals, the relevance of teaching-service-community interaction, vocational training of students of the Faculty of Health Sciences / UFRN. METHODOLOGICAL PROCEDURES: This study is grounded on qualitative approach. The technique used to obtain research data was the focus group. Two focus groups (FG) were accomplished in two family basic health units of the municipality of Santa Cruz – RN, where there is participation of professionals of the Family Health Strategy. The discussions were performed from a previously elaborated script. The analysis of results was held from the categorical thematic content technique. RESULTS: The study had the participation of 18 health professionals, and 13 (72%) were females. For these professionals, the teaching-service interaction enables the student to understand the model of comprehensive health care, since the contact with the community enhances its perception about the health-disease process, but also enables recognizing the importance of teamwork to comprehensive health care. FINAL CONSIDERATIONS: The results highlight the importance of a policy of reorientation within the context of training so that students have an early contact with the service and therefore develop technical skills within the context in which they are inserted.

A atenção à crise e o apoio matricial: analisadores da estratégia atenção psicossocial

The National Policy on Mental Health is characterized as a territorial - political community , and it has the Psychoso cial Care Strategy (Eaps) as guideline for the proposal and the development of their actions. In its design, CAPS is idealized to be a strategic equipment within the Psychoso cial Care Network/RAPS. Matricial support and at tention to the crisis constitute strategic areas of action of CAPS in its replacement mission , and as it is g uided by the scope of deinstitutionalization, those are essential to the success of these services. We argue that sustain crises in existential territories of life is a condition for the effectiveness of psychosocial care and, ultimately, to the sustainability of its Reform. In this direction, the matricial support tool reveals a territorial supporter, intercessory and powerful in building a psychosocial care to the crisis. Recognized as one of the major challenges by the Brazilian Ministry of Health, forward these fronts materializes for workers in their mi cropolitical crafts. Our research arises as an investment toward empower them , and aimed to understand the operationalization of attention to the crisis and matricial support in a CAPS II, in the view of its workers . Besides, it aims to examine such practi ces forward the principles and purposes of Psychosocial Care Strategy. Inspired by the research - intervention and by the political and social ideas of Institutiona l Analysis, we offer a space for reflection and exchange, by implicational interviews , enablin g workers to launch them in analysis of practices in the EAPs view. We have done a documentary consulting CAPS Technical Project, and a return stage to the institution, by organizing workshop and conversation groups with CAPS workers. The results have show n that there are institutional logics in competition on that service. When operating the logic risk, some difficulties in sustaining most intense crisis situations were identified, the psychiatric hospital internment is used as a facility, particularly in view of some cases, in which the aggressiveness of the person in crises becomes aggressive, and when the brackets SAMU, the CAPS III and Comprehensive Care Beds do not respond satisfactorily to their users requests. Order weaknesses were indicated in this thesis as macropolitical and micropolitical interfering in network support. The matricial actions were identified as a powerful intercessor resource in crisis care appeared weakened, and indicates little porosity in the relationship between the Service and the territory where it takes place. Noticed by the logic of home care, without operate primarily as a knowledge exchange device, we saw capture points in the logic of assistance with ambulatoriza tion production of CAPS, welfare practices and "ext empore " . T he E APs , although it emerge s as a guiding, it is not seen to workers as effective practice. On the one hand, the results signaled that the attention to the crisis and the matricial actions are developed without tenacious connection with the purposes of EA Ps, on the other hand, successful cases were indicated with the main leads to conducting wire of intersectoral actions to the powerful bonds and to the participation of user in their care process es , indicating insurgent forces tha t intend by traditional lo gic .

Tensoativo derivado do ácido cítrico: síntese e aplicação em fluidos de perfuração de emulsão inversa

This work describes the synthesis and study of the application of a new surfactant (Triester Lipophilic – TEL) obtained by citric acid with octanol. It is reaction was followed by thin layer chromatography (TLC) and after purification the product was characterized by proton and 13 – carbon nuclear magnetic resonance spectroscopy ( H and 13C NMR), thermogravimetric analysis (TGA) and surface tension analysis of oil-in-water emulsions. The TEL performance as surfactant in ester, n-paraffin and biodiesel based drilling fluids on the 70/30 and 60/40 water- oil rations (WOR) was evaluated by comparative tests of two commercial products used in the fields. These drilling fluids were aged in roller oven at 200 0 F during 16 h. The rheological and electric stability measurements were carried out at 135 ºF, the phase separation was evaluated after seven days at rest and the filtrate volume of drilling fluids was determined at high temperature and high pressure. The rheological behavior of the drilling fluids was evaluated by the flow curves. The results showed that the drilling fluids studied here presented Binghamian behavior as well as the used in the oil fields. The laboratory tests showed that the TEL reduced the filtrate volume and promoted the enhance of the thermal and mechanical stabilities.

AdaptMCloud: uma estratégia para adaptação dinâmica de aplicações Multi-Cloud

Multi-Cloud Applications are composed of services offered by multiple cloud platforms where the user/developer has full knowledge of the use of such platforms. The use of multiple cloud platforms avoids the following problems: (i) vendor lock-in, which is dependency on the application of a certain cloud platform, which is prejudicial in the case of degradation or failure of platform services, or even price increasing on service usage; (ii) degradation or failure of the application due to fluctuations in quality of service (QoS) provided by some cloud platform, or even due to a failure of any service. In multi-cloud scenario is possible to change a service in failure or with QoS problems for an equivalent of another cloud platform. So that an application can adopt the perspective multi-cloud is necessary to create mechanisms that are able to select which cloud services/platforms should be used in accordance with the requirements determined by the programmer/user. In this context, the major challenges in terms of development of such applications include questions such as: (i) the choice of which underlying services and cloud computing platforms should be used based on the defined user requirements in terms of functionality and quality (ii) the need to continually monitor the dynamic information (such as response time, availability, price, availability), related to cloud services, in addition to the wide variety of services, and (iii) the need to adapt the application if QoS violations affect user defined requirements. This PhD thesis proposes an approach for dynamic adaptation of multi-cloud applications to be applied when a service is unavailable or when the requirements set by the user/developer point out that other available multi-cloud configuration meets more efficiently. Thus, this work proposes a strategy composed of two phases. The first phase consists of the application modeling, exploring the similarities representation capacity and variability proposals in the context of the paradigm of Software Product Lines (SPL). In this phase it is used an extended feature model to specify the cloud service configuration to be used by the application (similarities) and the different possible providers for each service (variability). Furthermore, the non-functional requirements associated with cloud services are specified by properties in this model by describing dynamic information about these services. The second phase consists of an autonomic process based on MAPE-K control loop, which is responsible for selecting, optimally, a multicloud configuration that meets the established requirements, and perform the adaptation. The adaptation strategy proposed is independent of the used programming technique for performing the adaptation. In this work we implement the adaptation strategy using various programming techniques such as aspect-oriented programming, context-oriented programming and components and services oriented programming. Based on the proposed steps, we tried to assess the following: (i) the process of modeling and the specification of non-functional requirements can ensure effective monitoring of user satisfaction; (ii) if the optimal selection process presents significant gains compared to sequential approach; and (iii) which techniques have the best trade-off when compared efforts to development/modularity and performance.

Modelagem matemática e experimental da perda de injetividade em poços canhoneados

Water injection in oil reservoirs is a recovery technique widely used for oil recovery. However, the injected water contains suspended particles that can be trapped, causing formation damage and injectivity decline. In such cases, it is necessary to stimulate the damaged formation looking forward to restore the injectivity of the injection wells. Injectivity decline causes a major negative impact to the economy of oil production, which is why, it is important to foresee the injectivity behavior for a good waterflooding management project. Mathematical models for injectivity losses allow studying the effect of the injected water quality, also the well and formation characteristics. Therefore, a mathematical model of injectivity losses for perforated injection wells was developed. The scientific novelty of this work relates to the modeling and prediction of injectivity decline in perforated injection wells, considering deep filtration and the formation of external cake in spheroidal perforations. The classic modeling for deep filtration was rewritten using spheroidal coordinates. The solution to the concentration of suspended particles was obtained analytically and the concentration of the retained particles, which cause formation damage, was solved numerically. The acquisition of the solution to impedance assumed a constant injection rate and the modified Darcy´s Law, defined as being the inverse of the normalized injectivity by the inverse of the initial injectivity. Finally, classic linear flow injectivity tests were performed within Berea sandstone samples, and within perforated samples. The parameters of the model, filtration and formation damage coefficients, obtained from the data, were used to verify the proposed modeling. The simulations showed a good fit to the experimental data, it was observed that the ratio between the particle size and pore has a large influence on the behavior of injectivity decline.

Correlação entre imagem corporal e autoestima em pessoas com ostomias intestinais

Ostomized is every individual that, because of a traumatic or clinical condition, it required a surgery resulting in the externalization of a hollow organ through the skin, and such temporary or permanent condition. This study has the general objective to investigate the relationship between body image and self-esteem in these individuals; as well as to verify their levels of satisfaction with their body image regarding the aspect of appearance and to evaluate the degree of self-esteem related to that condition. This is a correlational research, cross-sectional, which was accomplished in an institution in support of these users of Rio Grande do Norte state, with location in Natal. There were used three sampling instruments: a structured general questionnaire covering socio-demographic and clinical data; the Satisfaction Scale with Appearance (SSA) and the Rosenberg Self-Esteem Scale (RSS). The information obtained was analyzed with the aid of an electronic spreadsheet software. The project is according with the resolution 466/12 of the National Health Council, It was approved by the Research Ethics Committee of UFRN, under number CAAE 19159713.5.0000.5537 in August 2013. The sample consisted of 93 participants with an average age of 50.4 years (SD = 15.4). In general they had low satisfaction with their body image (M = 66.9), as regards the appearance, although maintained high levels of self-esteem (M = 34.8). Therefore, It was found a positive correlation, moderate (ρ = 0.426) and statistically significant was found (p <0.001) from the application of the Spearman correlation test. Therefore, dissatisfaction with body image is an important issue to be observed by professionals who attend ostomizeds. however, it seems, other aspects are also influencing the level of self-esteem of these individuals, who were not able to be determined in this study.

Estudo da influência de sistemas microemulsionados na molhabilidade de arenitos e na recuperação avançada de petróleo

Sandstone-type reservoir rocks are commonly responsible for oil accumulation. The wettability is an important parameter for the physical properties of the container, since it interferes in characteristics such as relative permeability to the aqueous phase, residual oil distribution in the reservoir, operating characteristics with waterflood and recovery of crude oil. This study applied different types of microemulsion systems - MES - in sandstone reservoirs and evaluated their influences on wettability and residual oil recovery. For this purpose, four microemulsion were prepared by changing the nature of ionic surfactants (ionic and nonionic). Microemulsions could then be characterized by surface tension analysis, density, particle diameter and viscosity in the temperature range 30° C to 70° C. The studied oil was described as light and the sandstone rock was derived from the Botucatu formation. The study of the influence of microemulsion systems on sandstone wettability was performed by contact angle measurements using as parameters the rock treatment time with the MES and the time after the brine surface contact by checking the angle variation behavior. In the study results, the rock was initially wettable to oil and had its wettability changed to mixed wettability after treatment with MES, obtaining preference for water. Regarding rock-MES contact time, it was observed that the rock wettability changed more when the contact time between the surface and the microemulsion systems was longer. It was also noted only a significant reduction for the first 5 minutes of interaction between the treated surface and brine. The synthesized anionic surfactant, commercial cationic, commercial anionic and commercial nonionic microemulsion systems presented the best results, respectively. With regard to enhanced oil recovery performance, all systems showed a significant percentage of recovered oil, with the anionic systems presenting the best results. A percentage of 80% recovery was reached, confirming the wettability study results, which pointed the influence of this property on the interaction of fluids and reservoir rock, and the ability of microemulsion systems to perform enhanced oil recovery in sandstone reservoirs.

Estudo da influência de sistemas microemulsionados na molhabilidade de arenitos e na recuperação avançada de petróleo

Sandstone-type reservoir rocks are commonly responsible for oil accumulation. The wettability is an important parameter for the physical properties of the container, since it interferes in characteristics such as relative permeability to the aqueous phase, residual oil distribution in the reservoir, operating characteristics with waterflood and recovery of crude oil. This study applied different types of microemulsion systems - MES - in sandstone reservoirs and evaluated their influences on wettability and residual oil recovery. For this purpose, four microemulsion were prepared by changing the nature of ionic surfactants (ionic and nonionic). Microemulsions could then be characterized by surface tension analysis, density, particle diameter and viscosity in the temperature range 30° C to 70° C. The studied oil was described as light and the sandstone rock was derived from the Botucatu formation. The study of the influence of microemulsion systems on sandstone wettability was performed by contact angle measurements using as parameters the rock treatment time with the MES and the time after the brine surface contact by checking the angle variation behavior. In the study results, the rock was initially wettable to oil and had its wettability changed to mixed wettability after treatment with MES, obtaining preference for water. Regarding rock-MES contact time, it was observed that the rock wettability changed more when the contact time between the surface and the microemulsion systems was longer. It was also noted only a significant reduction for the first 5 minutes of interaction between the treated surface and brine. The synthesized anionic surfactant, commercial cationic, commercial anionic and commercial nonionic microemulsion systems presented the best results, respectively. With regard to enhanced oil recovery performance, all systems showed a significant percentage of recovered oil, with the anionic systems presenting the best results. A percentage of 80% recovery was reached, confirming the wettability study results, which pointed the influence of this property on the interaction of fluids and reservoir rock, and the ability of microemulsion systems to perform enhanced oil recovery in sandstone reservoirs.

Expressão geofísica-estrutural do lineamento transbrasiliano na porção central da Bacia do Parnaíba (Maranhão-Piauí)

The objective of this study was to characterize the structural-geophysical expression of the Transbrasiliano Lineament (TBL) in the east-central portion of the Parnaíba Basin. The TBL corresponds to a major Neoproterozoic NE-trending shear zone related to the Brasiliano orogenic cycle, with dextral strike-slip kinematics, underlying (but also laterally exposed in the NE and SW basin edges) the sedimentary section of the Parnaíba Basin. In this study, the interpretation of gravity and magnetic anomaly maps is consistent with the TBL kinematics, the signature of the geophysical anomalies corresponding to the high (plastic behaviour) and subsequent declining temperature (ductile to brittle behaviour) stages during Brasiliano and late Brasiliano times. The pattern of residual gravity anomalies is compatible with an S-C dextral pair shaping the geological bodies of an heterogeneous basement, such as slices of gneisses and granulites (positive anomalies), granitic and low-medium grade metasedimentary rocks (negative anomalies). Such anomalies curvilinear trends, ranging from NNE (interpreted as S surfaces) to NE (C surfaces), correspond to flattening surfaces (S), while the NE rectilinear trend must represent a C band. The narrower magnetic anomalies also display NNE to NE (S surfaces) trends and should correspond to similar (although narrower and more discontinuous) sources in the equivalent anomaly patterns. Pre-Silurian pull-apart style grabens may contribute to the NE negative gravimetric anomalies, although this interpretation demands control by seismic data analysis. On the other hand, the curvilinear anomalies associated to contractional trends are incompatible with their interpretation as pre-Silurian graben, in both maps. In the (reduced to the pole) magnetic anomalies map, most of these are again associated to low-temperature shear zones (C planes) and faults, juxtaposing distinct blocks in terms of magnetic properties, or eventually filled with basic bodies. It is also possible that some isolated magnetic anomalies correspond to igneous bodies of late-Brasiliano or Mesozoic age. The basement late discontinuities pattern can be interpreted in analogy to the Riedel fractures model, with steep dipping surfaces and a sub-horizontal movement section. This study also explored 2D gravity modeling controlled by the interpretation of a dip seismic line as regards to the Transbrasiliano Lineament. The rock section equivalent to the Jaibaras Group occupying a graben structure (as identified in the seismic line) corresponds to a discrete negative anomaly superimposed to a gravimetric high, once again indicating a stronger influence of older crystalline basement rocks as gravimetric sources, mainly reflecting the heterogeneities and anisotropies generated at high temperature conditions and their subsequent cooling along the TBL, during the Brasiliano cycle.

Expressão geofísica-estrutural do lineamento transbrasiliano na porção central da Bacia do Parnaíba (Maranhão-Piauí)

The objective of this study was to characterize the structural-geophysical expression of the Transbrasiliano Lineament (TBL) in the east-central portion of the Parnaíba Basin. The TBL corresponds to a major Neoproterozoic NE-trending shear zone related to the Brasiliano orogenic cycle, with dextral strike-slip kinematics, underlying (but also laterally exposed in the NE and SW basin edges) the sedimentary section of the Parnaíba Basin. In this study, the interpretation of gravity and magnetic anomaly maps is consistent with the TBL kinematics, the signature of the geophysical anomalies corresponding to the high (plastic behaviour) and subsequent declining temperature (ductile to brittle behaviour) stages during Brasiliano and late Brasiliano times. The pattern of residual gravity anomalies is compatible with an S-C dextral pair shaping the geological bodies of an heterogeneous basement, such as slices of gneisses and granulites (positive anomalies), granitic and low-medium grade metasedimentary rocks (negative anomalies). Such anomalies curvilinear trends, ranging from NNE (interpreted as S surfaces) to NE (C surfaces), correspond to flattening surfaces (S), while the NE rectilinear trend must represent a C band. The narrower magnetic anomalies also display NNE to NE (S surfaces) trends and should correspond to similar (although narrower and more discontinuous) sources in the equivalent anomaly patterns. Pre-Silurian pull-apart style grabens may contribute to the NE negative gravimetric anomalies, although this interpretation demands control by seismic data analysis. On the other hand, the curvilinear anomalies associated to contractional trends are incompatible with their interpretation as pre-Silurian graben, in both maps. In the (reduced to the pole) magnetic anomalies map, most of these are again associated to low-temperature shear zones (C planes) and faults, juxtaposing distinct blocks in terms of magnetic properties, or eventually filled with basic bodies. It is also possible that some isolated magnetic anomalies correspond to igneous bodies of late-Brasiliano or Mesozoic age. The basement late discontinuities pattern can be interpreted in analogy to the Riedel fractures model, with steep dipping surfaces and a sub-horizontal movement section. This study also explored 2D gravity modeling controlled by the interpretation of a dip seismic line as regards to the Transbrasiliano Lineament. The rock section equivalent to the Jaibaras Group occupying a graben structure (as identified in the seismic line) corresponds to a discrete negative anomaly superimposed to a gravimetric high, once again indicating a stronger influence of older crystalline basement rocks as gravimetric sources, mainly reflecting the heterogeneities and anisotropies generated at high temperature conditions and their subsequent cooling along the TBL, during the Brasiliano cycle.