Stratigraphy of the Basalt Flows of the Formação Serra Geral (Ribeirão Preto - SP) Based on Physical Geology, Petrography and Geochemistry

A motivação que levou ao estudo da geologia física e química dos basaltos de Ribeirão Preto foi investigar a existência de recarga do Sistema Aquífero Guarani (SAG) através dos basaltos do Aquífero Serra Geral (ASG), objetivo do projeto abreviadamente denominado FRATASG. Além de métodos hidrogeológicos, a pesquisa demandou uma investigação geológica de detalhe, a qual é essencial para a elaboração de modelos conceituais de circulação de água subterrânea em aquíferos complexos, caso dos basaltos do ASG. Assim, o estudo contemplou trabalhos de campo para descrição dos aspectos macroscópicos e das relações entre os basaltos e os arenitos subjacentes, coleta de amostras e análises petrográficas e químicas. Também foram utilizados dados de perfis litológicos de cinco poços construídos no projeto FRATASG, fundamentais para o estabelecimento da estratigrafia em subsuperfície. O estudo concluiu que, na área de Bonfim Paulista, ocorrem quatro derrames de basaltos, denominados B1, B2, B3 e B4, do mais antigo para o mais jovem. A ocorrência de B4 é muito restrita, pois foi erodido em grande parte. B1 e B2 apresentam espessuras de, em média, 45 e 55 m, respectivamente. Todos os quatro basaltos são do tipo sheet like lobes e devem ter sido colocados pelo mecanismo de inflação. B1 apresenta espessa crosta vesicular superior e, assim como em B2, pode apresentar mais de um nível vesicular no topo. Colunas de resfriamento foram observadas em B2 e B3, sendo mais espetaculares em B3 devido à presença de uma camada colunada inferior (B3-C) e uma sobreposta com entablamento (B3-E). B3 é o derrame mais espesso (75 a 100 m) e contém brechas hidráulicas distribuídas em bolsões, posicionados na camada B3-C, ou ao longo de fraturas sub-horizontais que até hoje permitem circulação de fluidos (água subterrânea). B3 apresenta composição química homogênea e é perfeitamente distinguível de B1 e B2 com relação a vários óxidos (Al2O3, P2O5, Fe2O3, TiO2 e MgO) e elementos traço (Ni, Zn, Cu, Y). A distinção entre B1 e B2 restringe-se aos óxidos P2O5 e TiO2 e aos elementos Cu, Zn, Y e Ni.The study of the physical geology and geochemistry of the basalts of Ribeirão Preto was part of a hydrogeological research that aimed at investigating the recharge of the Guarani Aquifer System (SAG) through the basalts of the Serra Geral Aquifer (ASG), a project shortly named FRATASG. In addition to hydrogeological methods, the research demanded a detailed geological investigation, which is essential for the elaboration of conceptual models of groundwater circulation in complex aquifers, as is the case of the fractured basalts of the ASG. Thus, the study encompassed field work for the description of the macroscopic aspects and relationships among the basalts and the underlying sandstones, as well as, rock sampling and petrographic and chemical analysis. Furthermore, the use of lithologic logs of five wells drilled in FRATASG project was essential for the establishment of the subsurface basalt stratigraphy. The study concluded that, in Bonfim Paulista region, there are four basalt floods, namely B1, B2, B3 and B4. The B4 occurrence is very restricted as it was largely eroded. B1 and B2 average thicknesses are 45 and 60 m, respectively. All four basalts are of sheet-like lobe types and were probably emplaced by inflation, B1 being the one that presents more evidence in that respect. B1 presents a thick vesicular top and, as well as B2, can show more than one vesicular layer at the top. Columnar joints were observed in B2 and B3 and are more remarkable in B3, where a lower colonnade tier (B3-C) is overlain by an entablature layer (B3-E). B3 is the thickest flow (75 to 105 m) and contains irregular and roughly round patches of hydraulic breccia in B3-C or along sub-horizontal fractures that allow the circulation of fluids (groundwater at the present). The chemical composition of B3 is homogeneous and very different from B1 and B2 with regard to several oxides (Al2O3, P2O5, Fe2O3, TiO2 e MgO) and trace elements (Ni, Zn, Cu, Y). B1 is very different from B2 with regard to P2O5, TiO2, Cu, Zn, Y and Ni

ARGILOMINERAIS DA ALOFORMAÇÃO PARANAVAÍ (SP, PR E MS)

A Aloformação Paranavaí é uma unidade geológica quaternária, composta essencialmente de depósitos arenosos de origem coluvial, que ocorre na Bacia Hidrográfica do Alto Rio Paraná. Através de análise granulométrica e difratometria de raios X, foi identificada a assembléia de argilominerais presentes na fração argila de amostras coletadas em superfície e subsuperfície, na ampla área de ocorrência desta unidade geológica. A Aloformação Paranavaí contem até 47% de fração argila em sua composição, sendo identificados argilominerais bilaminares em todas as amostras: o argilomineral caulinita, seguido da mica/illita e, em menor quantidade, a presença de camada mista esmectita e inter-estratrificados de illita. Os sedimentos da Aloformação Paranavaí apresentam composições e proporções de argilominerais semelhantes, indicando pequena variabilidade mineralógica em superfície e subsuperfície da fração argila. Palavras-chave: argilominerais, Aloformação Paranavaí, Alto Rio Paraná

Seções de referência de subsuperfície da aloformação Paranavaí

A Aloformação Paranavaí é uma unidade geológica quaternária definida na Bacia Hidrográfica do Alto Rio Paraná (SP, PR e MS), composta por depósitos coluviais originados a partir de unidades litoestratigráficas cretáceas da Bacia do Paraná. Os depósitos sedimentares são arenosos, inconsolidados, de coloração vermelho-acastanhada, homogêneos e maciços, comumente confundidos com solos e formações superficiais. Para o estabelecimento de seções de referência de subsuperfície para a Aloformação Paranavaí, foram obtidos testemunhos de sondagem em duas regiões no oeste paulista. Foi conduzido um estudo com diversos parâmetros (texturais, mineralógicos, geoquímicos, isotópicos e geocronológicos) nos sedimentos da Aloformação Paranavaí e do Grupo Bauru. Foram estabelecidas duas novas seções de referência para completar o estratótipo-de-unidade composto estabelecido: seção de referência Rancharia (idades luminescentes entre 71.650 ± 9.000 a 557.000 ± 65.000 AP) e seção de referência Oriente (83.000 ± 8.500 a 436 ± 53.000 anos AP). Idades luminescentes obtidas são crescentes de acordo com a profundidade da Aloformação Paranavaí, enquanto que os sedimentos do Grupo Bauru apresentam idades superiores ao alcance do método geocronológico empregado. Os dados obtidos nas seções de referência apresentam variabilidade em padrões de diversos parâmetros, comprovando diferentes gerações de deposição coluvial ao longo do Quaternário, no oeste paulista.The Paranavaí Alloformation is a Quaternary geological formation found in the Upper Paraná River Hydrographic Basin (states of São Paulo, Paraná and Mato Grosso do Sul), composed of colluvial deposits originated from the Cretaceous lithostratigraphic units of the Paraná Basin. The sedimentary deposits are reddish brown in color, sandy, non-consolidated, homogeneous, massive, and commonly confused with surface soils and formations. In order to obtain subsurface reference sections for the Paranavaí Alloformation, core samples were collected in two regions of the western part of the state of São Paulo. The study was conducted involving several parameters (textural, mineralogical, geochemical, isotopic and geochronological) of the sediments of the Paranavaí Alloformation and Bauru Group. Two new reference sections were obtained in order to establish the composite-stratotype of its constituent formations: Rancharia reference section (luminescence ages between 71650 ± 9000 and 557000 ± 65000 years BP) and Oriente reference section (luminescence ages between 83000 ± 8500 and 436 ± 53000 years BP). The luminescent ages obtained in this study increase according to the depth of the Paranavaí Alloformation, whereas the sediments of the Bauru Group have ages greater than the maximum limit of the geochronological method used. The information obtained from the reference sections shows variability in the patterns of various parameters, proving there were different generations of colluvial deposition throughout the Quaternary period in the western part of the state of São Paulo

Prevalence of human papillomavirus in archival samples obtained from patients with cervical pre-malignant and malignant lesions from Northeast Brazil

<p>Abstract</p> <p>Background</p> <p>Human Papillomavirus (HPV) is considered as a necessary, but not sufficient, cause of cervical cancer. In this study, we aimed to assess the prevalence of HPV in a series of pre-malignant and malignant cervical lesion cases, to identify the virus genotypes, and to assess their distribution pattern according to lesion type, age range, and other considered variables. The samples were submitted to histopathological revision examination and analysed by polymerase chain reaction (PCR) for the presence of HPV DNA, followed by HPV typing by dot blot hybridisation.</p> <p>Findings</p> <p>Of the analysed samples, 53.7% showed pre-malignant cervical lesions, and 46.3% presented with cervical cancer. Most cancer samples (84.1%) were classified as invasive carcinoma. The mean age of these cancer patients was 47.3 years. The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cancer patients. HPV 16 was the most prevalent type, followed by HPV 18 and 58, including both single and double infections. Double infection was detected in 11.6% of the samples, and the most common combination was HPV 16+18.</p> <p>Conclusions</p> <p>Cervical cancer appears to occur in women in a lower age range in the studied area, compared to the situation in other Brazilian regions. Furthermore, among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts.</p> <p>Findings</p> <p>The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cervical cancer patients from Northeast Brazil. HPV 16 was the most prevalent type, followed by HPV 18 and 58. The most common double infection was HPV 16+18. Cervical cancer appears to occur in women in a lower age range in the Northeast Brazil. Among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts.</p

The inventory of geological heritage of the state of São Paulo, Brazil: Methodological basis, results and perspectives

An inventory of geological sites based on solid and clear criteria is a first step for any geoconservation strategy. This paper describes the method used in the geoheritage inventory of the State of São Paulo, Brazil, and presents its main results. This inventory developed by the geoscientific community aimed to identify geosites with scientific value in the whole state, using a systematic approach. All 142 geosites representative of 11 geological frameworks were characterised and quantitatively evaluated according to their scientific value and risk of degradation, in order to establish priorities for their future management. An online database of the inventory is under construction, which will be available to be easily consulted and updated by the geoscientific community. All data were made available to the State Geological Institute as the backbone for the implementation of a future state geoconservation strategy.The authors acknowledge the Science Without Borders Programme, Process 075/2012, which supported this study and the São Paulo Research Foundation (FAPESP), Process 2011/17261-6. We also thanks C. Mazoca for his help with maps and figures.info:eu-repo/semantics/acceptedVersio

Sedimetology of the Paranavaí Alloformation, Upper Paraná River Hydrographic Basin (São Paulo, Paraná and Mato Grosso do Sul States, Brazil

The Paranavaí Alloformation is composed of Quaternary colluvial deposits, that are irregularly distributed throughout the Upper Paraná River Hydrographic Basin. This unit overlies of the Cretaceous superimposed to the sedimentary rocks Bauru Supersequence and basalts of the Serra Geral Formation. This work aims to provide a better definition of the Paranavaí Alloformation throught sedimentological characterization and provenance studies of its sediments, through textural and mineralogical analyses.The Paranavaí Alloformation is constituted by colluvial deposits, mainly composed by unconsolidated reddish colour sands. The contacts between these deposits and the underlying rocks are unconformable and marked by ferricrete and/or stonelines. The ferricretes constitute irregularly aggregated, millimetric to centimetric nodules, which exhibit reddish brown roughly concentric structures, with high SiO2 contents. Fine to coarse, quartzose sands exhibit corrosion features (microfissures), filled by goethite (ferric hydroxide). These sediments present 17 textural classes, with dominance of sand and clayey sand. The heavy mineral content of the Paranavaí Alloformation can reach 21,4% in weight, when overling the Serra Geral Formation. Superabundant minerals zircon, tourmaline, staurolite, rutile, kyanite in fine to very fine sands include pyroxene, hornblende, garnet, epidote, anatase and fluorite, with scarce spinel, apatite, sillimanite, monazite, brookite and andaluzite. The Paranavaí Alloformation presents, in general, homogeneous textural characteristics, and are very similar to the substrate rocks, suggesting the Bauru Supersequence and the Serra Geral Formation as source rocks.The Paranavaí Alloformation is composed of Quaternary colluvial deposits, that are irregularly distributed throughout the Upper Paraná River Hydrographic Basin. This unit overlies of the Cretaceous superimposed to the sedimentary rocks Bauru Supersequence and basalts of the Serra Geral Formation. This work aims to provide a better definition of the Paranavaí Alloformation throught sedimentological characterization and provenance studies of its sediments, through textural and mineralogical analyses.The Paranavaí Alloformation is constituted by colluvial deposits, mainly composed by unconsolidated reddish colour sands. The contacts between these deposits and the underlying rocks are unconformable and marked by ferricrete and/or stonelines. The ferricretes constitute irregularly aggregated, millimetric to centimetric nodules, which exhibit reddish brown roughly concentric structures, with high SiO2 contents. Fine to coarse, quartzose sands exhibit corrosion features (microfissures), filled by goethite (ferric hydroxide). These sediments present 17 textural classes, with dominance of sand and clayey sand. The heavy mineral content of the Paranavaí Alloformation can reach 21,4% in weight, when overling the Serra Geral Formation. Superabundant minerals zircon, tourmaline, staurolite, rutile, kyanite in fine to very fine sands include pyroxene, hornblende, garnet, epidote, anatase and fluorite, with scarce spinel, apatite, sillimanite, monazite, brookite and andaluzite. The Paranavaí Alloformation presents, in general, homogeneous textural characteristics, and are very similar to the substrate rocks, suggesting the Bauru Supersequence and the Serra Geral Formation as source rocks

Local geological sections and regional stratigraphy based on physical geology and chemical stratigraphy of the Serra Geral Group from Araraquara to Avaré, SP

<div><p>ABSTRACT: From Araraquara to Avaré, in the Serra Geral Group outcropping area, 22 detailed geological sections were elaborated. The stratigraphic relationships and the chemical analysis allowed the identification of seven [P2O5] basalt classes, all of them pertaining to the Pitanga type, showing a consistent stacking order across the studied region. Thus, each class is considered to correspond to a specific lava flow, allowing a general stratigraphic column to be proposed. Besides the stacking order, the validation of P2O5 as a tool for lava correlation at great distances was also based on the values obtained from samples collected at different positions in a single flow, and on the remarkable [P2O5] contrast between adjacent flows. Minimum lateral extensions range from 75 to 185 km, and thickness from 20 to 80 m. Vertical tectonic displacements, which took place in different periods, were inferred from the altitude of specific flows, and also from the Botucatu and Piramboia formations. They are noticeable in a region bounded by EW drainage lineaments, which contains a large area where Piramboia and Botucatu formations crop out, probably due to the tectonic activity causing this region to be a generalized structural high.</p></div

CIENTIFIC, EDUCATIONAL AND LUDIC POTENCIALITIES OF THE GEOLOGICAL RECORDS PRESENT IN THE ANHANGUERA MUNICIPAL PARK, SÃO PAULO, BRAZIL

O Parque Municipal Anhanguera dista 30 km a NW do marco referencial geográfico zero do município de São Paulo e, com uma extensão de 950 hectares, representa a maior área verde preservada de uso público da cidade. Com base na interpretação de imagens de satélite e no levantamento dos registros geológicos foram identificados sítios que exemplificam, de maneira clara e objetiva, diversos processos e ambientes geológicos formadores de rochas. Uma avaliação pormenorizada desses afloramentos permitiu a caracterização de vários tipos de rochas metamórficas e estruturas tectônicas com elevada potencialidade científica, educacional e lúdica. A integração dos resultados aqui reunidos com os novos preceitos da conservação ambiental deve tornar possível a implementação de um plano de manejo estratégico, visando uma ação efetiva de ordenamento e gestão, para que os recursos naturais presentes no parque possam ser preservados e aproveitados de maneira mais ampla pela comunidade em geral.O Parque Municipal Anhanguera dista 30 km a NW do marco referencial geográfico zero do município de São Paulo e, com uma extensão de 950 hectares, representa a maior área verde preservada de uso público da cidade. Com base na interpretação de imagens de satélite e no levantamento dos registros geológicos foram identificados sítios que exemplificam, de maneira clara e objetiva, diversos processos e ambientes geológicos formadores de rochas. Uma avaliação pormenorizada desses afloramentos permitiu a caracterização de vários tipos de rochas metamórficas e estruturas tectônicas com elevada potencialidade científica, educacional e lúdica. A integração dos resultados aqui reunidos com os novos preceitos da conservação ambiental deve tornar possível a implementação de um plano de manejo estratégico, visando uma ação efetiva de ordenamento e gestão, para que os recursos naturais presentes no parque possam ser preservados e aproveitados de maneira mais ampla pela comunidade em geral.With a total of 950 hectares, the Anhanguera Municipal Park is distant 30 km to the NW from the São Paulo city centre and represents the largest protected green area of public use of the city. Based on the interpretation of remote sensing images and the survey of geological records were identified sites that exemplify in a clear and objective manner the multiple environments and geological processes in which the rocks are formed. A comprehensive analysis of these outcrops allowed the characterisation of various types of metamorphic rocks and tectonic structures with high scientific, educational and ludic potentiality. The integration of the results gathered here with the new precepts of environmental conservation may make possible the implementation of a strategic management plan, so that the natural resources present in the park can be preserved and used in a wide manner by the community in general

Local geological sections and regional stratigraphy based on physical geology and chemical stratigraphy of the Serra Geral Group from Araraquara to Avaré, SP

<div><p>ABSTRACT: From Araraquara to Avaré, in the Serra Geral Group outcropping area, 22 detailed geological sections were elaborated. The stratigraphic relationships and the chemical analysis allowed the identification of seven [P2O5] basalt classes, all of them pertaining to the Pitanga type, showing a consistent stacking order across the studied region. Thus, each class is considered to correspond to a specific lava flow, allowing a general stratigraphic column to be proposed. Besides the stacking order, the validation of P2O5 as a tool for lava correlation at great distances was also based on the values obtained from samples collected at different positions in a single flow, and on the remarkable [P2O5] contrast between adjacent flows. Minimum lateral extensions range from 75 to 185 km, and thickness from 20 to 80 m. Vertical tectonic displacements, which took place in different periods, were inferred from the altitude of specific flows, and also from the Botucatu and Piramboia formations. They are noticeable in a region bounded by EW drainage lineaments, which contains a large area where Piramboia and Botucatu formations crop out, probably due to the tectonic activity causing this region to be a generalized structural high.</p></div