Programa de Pós-Graduação em Geodinâmica e Geofísica
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Doctoral Thesis Avaliação do impacto de recarga variável no Aquífero Barreiras em Natal-RN, associado com a urbanização e ampliação da rede de coleta de efluentes sanitários(Universidade Federal do Rio Grande do Norte, 2022-08-31) Campos, Benedita Cleide de Souza; Lucena, Leandson Roberto Fernandes de; Righetto, Antônio Marozzi; http://lattes.cnpq.br/4673404543485023; http://lattes.cnpq.br/1569493583324352; Coimbra, Keyla Thayrinne Oliveira; Cabral, Natalina Maria Tinoco; Cunha, Paulo Eduardo Vieira; Castro, Vera Lucia Lopes deThe recharge of unconfined urban aquifers is substantially affected by high rates of soil sealing, while, occasionally, it may present additional components to those from rainwater infiltration. In this case, infiltrations caused by leaks in sewage and water supply networks can represent significant contributions to these recharge rates. This situation is common in some areas of Northeast Brazil, especially in places with high population density and deficiencies in wastewater collection and supply networks. In this last aspect, it is not uncommon to have the contamination of urban aquifers by nitrate resulting from the infiltration of untreated wastewater. This research aimed to evaluate the effects of a variable recharge resulting from land use and occupation, as well as artificial contributions, in the Aquífero Barreiras, of a predominantly unconfined hydraulic character, in the city of Natal-RN. Additionally, we conducted simulations about the prospects of natural purification of waters with high nitrate contents, previously characterised by different renewal times associated with the changes in saturated zones due to decreases in recharge rates. The methodology used was based on the elaboration of numerical models and scenario analysis, emphasising the variations of artificial recharges resulting from wastewater infiltration and losses by the public supply network. Thus, the total recharge rates were calculated by individualizing areas with higher and lower population density, with subsequent simulations of different natural and artificial contributions. The results demonstrate significant variations in the potentiometric surface of up to 15 meters in several areas presented in the critical scenario, which considered the removal of artificial recharge and inversions of the groundwater flow. In this context, the saturated zones showed a variation of about 44 million m3 between the current and critical scenarios, associated with the suppression of 100% of the contribution from losses by the supply network and wastewater infiltration. In terms of prospects for natural purification of waters with high nitrate contents, from the analysis of renewal times and based on the variations of saturated zones calculated in the numerical models, values ranging from 6.5 to 12.9 years were obtained, this time being longer considering the most critical scenario reported in terms of recharge. The results presented here may contribute to the management of shallow aquifers in similar scenarios, especially regarding urbanization rates and efficiency in supply and sewage networks.Master Thesis Petrografia, litoquímica, química mineral e termobarometria de rochas cálcioalcalinas de alto K de textura porfirítica, ediacaranas, no extremo NE da Província Borborema (NE do Brasil)(Universidade Federal do Rio Grande do Norte, 2016-02-26) Campos, Benedita Cleide de Souza; Nascimento, Marcos Antonio Leite do; Vilalva, Frederico Castro Jobim; ; http://lattes.cnpq.br/6227637633613443; ; http://lattes.cnpq.br/5356037408083015; ; http://lattes.cnpq.br/1569493583324352; Mariano, Gorki; ; http://lattes.cnpq.br/9480872229631779; Medeiros, Vladimir Cruz de; ; http://lattes.cnpq.br/9369889068441214The mineral chemistry from granites, chemical of whole rock and review of petrography were used to determine the crystallization conditions and the implications in the genesis of high-K calc-akaline granites that are porphyritics, localizated in the Rio Piranhas-Seridó (RPSD) and São José de Campestre Domains (SJCD). Six granitic bodies were analyzed and that for the intrusive granites within the SJCD were named East granites: Monte das Gameleiras, Barcelona. The Acari granite intrudes the area RPSD, however, was called as granite east due to the characteristics of mineral chemistry is similar to east granites. Granites Caraúbas, Tourão and Catolé do Rocha are intrusive in the RPSD and called west granites. The six bodies are located in the northeast of the Borborema Province, NE Brazil. The plutons are represented by monzogranites wich have porphyritic facies with phenocrysts of K-feldspar with sizes between 5 and 15 cm. The K-feldspar, plagioclase and quartz are the dominant paragenesis; while the biotite and amphibole are the main mafic minerals; and titanite, opaque minerals, allanite, epidote, apatite and zircon are the accessories minerals. The Monte das Gameleiras granite shows metaluminous aluminium saturation index, whereas the others plutons metaluminous to peraluminous. In geochemical diagrams, the granites present with transitional character (subalcalino). The petrographic and geochemical analysis didn't show the differences between the plutons, but according to the mineral chemistry they can be divided into two groups: Monte das Gameleiras, Barcelona and Acari (east) and Caraúbas, Tourão e Catolé do Rocha (west). The Fe/(Fe + Mg) ratio of biotite shows an increase from east to west group with values from 0.45 to 0.64 and 0.66 to 0.92 respectively, and the Mg / (Mg + Fe2) of amphibole decreases with values from 0.40 to 0.57 and from 0.07 to 0.31. The crystallization parameters of east granites, The crystallization conditions for granites east (Monte das Gameleiras, Barcelona and Acari) show pressure between 3.8 kbar to 5.5 kbar, with depths ranging from 14 km to 21 km at a temperature between 701 ° C to 742ºC and west (Caraúbas, Tourão and Catolé Rock) with pressures to 4.8 kbar to 6.2 kbar and depths ranging from 18 km to 23 km at a temperature between 723 ° C - 776 ° C. Both areas, east and west were generated from magmas oxidized with ΔFQM values (-1 a +2.0). The depths of granite intrusion failures may be related to offsets and high water content and volatile that allow the magma some plutons reaches shallower levels in relation to the other. The results show a systematic increase in temperature and crystallization pressure east of plutons west suggesting crustal thickening in that direction. The results show a systematic increase in temperature and crystallization pressure east to west plutons, suggesting crustal thickening in that direction in the two domains studied.