Pub Date : 2020-02-23DOI: 10.21715/gb2358-2812.2019334341
Ciro Couto Bento, G. Lima, H. Baggio, A. Horn
O presente trabalho consiste em uma analise geoquimica ambiental da agua superficial para a identificacao de contaminacao no lago da Barragem da Usina Hidreletrica de Tres Marias da CEMIG, localizada na parte central-norte de Minas Gerais. Tem como proposta avaliar a situacao ambiental que se encontra a agua superficial da area de estudo, considerando as particularidades naturais e as caracteristicas antropicas da regiao. Este lago abrange oito municipios situados entre os paralelos 19,05oS e 18,20°S e os meridianos 44,95oW e 45,50oW. A amostragem de aguas superficiais foi feita em julho de 2018 em 58 pontos, distribuidos ao longo do segmento fluvial represado pela barragem hidreletrica. Analisaram-se os parâmetros quimicos totais (detergente; sulfato; amonia; nitrito; nitrato; fosforo; aluminio; zinco; ferro; manganes; boro) e os parâmetros fisico-quimicos in situ (temperatura, pH, condutividade eletrica, oxigenio dissolvido, total de solidos dissolvidos, turbidez, cor aparente). Os resultados foram comparados a Resolucao do Concelho Nacional de Meio Ambiente (CONAMA) 357/05 e Portaria do Ministerio da Saude (MS) n°518. Alguns resultados obtidos estao no limite dos valores estabelecidos pela legislacao, outros ultrapassam o limite, mostrando o potencial de suscetibilidade ambiental da area. Destaca-se negativamente a concentracao do Aluminio que ultrapassou em todos os pontos o limite legal. A concentracao do sulfato e dos compostos nitrogenados, nao ultrapassaram as concentracoes dos limite normativos. Quanto os parâmetros in situ somente o oxigenio dissolvido apresentou em desconformidade com as normas.
本工作包括对地表水进行环境地球化学分析，以确定位于米纳斯吉拉斯州中北部的CEMIG Tres Marias水电站大坝湖泊中的污染。其目的是评估研究区域的地表水环境状况，考虑该区域的自然特性和人文特征。该湖由八个市镇组成，位于19.05°S和18.20°S平行线与44.95°W和45.50°W经线之间。地表水采样于2018年7月在水电大坝筑坝河段分布的58个点进行。分析了总化学参数（洗涤剂；硫酸盐；氨；亚硝酸盐；硝酸盐；磷；铝；锌；铁；锰；硼）和原位物理化学参数（温度、pH、电导率、溶解氧、总溶解固体、浊度、表观颜色）。将结果与国家环境委员会第357/05号决议和卫生部第518号法令进行了比较。一些结果在立法规定的数值范围内，另一些则超过了极限，显示出该地区潜在的环境敏感性。消极地指出铝的浓度在所有方面都超过了法律限制。硫酸盐和氮化合物的浓度未超过标准限值。对于现场参数，只有溶解氧不符合规范。
{"title":"Avaliação de qualidade das águas superficiais no lago da barragem de Três Marias-MG","authors":"Ciro Couto Bento, G. Lima, H. Baggio, A. Horn","doi":"10.21715/gb2358-2812.2019334341","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019334341","url":null,"abstract":"O presente trabalho consiste em uma analise geoquimica ambiental da agua superficial para a identificacao de contaminacao no lago da Barragem da Usina Hidreletrica de Tres Marias da CEMIG, localizada na parte central-norte de Minas Gerais. Tem como proposta avaliar a situacao ambiental que se encontra a agua superficial da area de estudo, considerando as particularidades naturais e as caracteristicas antropicas da regiao. Este lago abrange oito municipios situados entre os paralelos 19,05oS e 18,20°S e os meridianos 44,95oW e 45,50oW. A amostragem de aguas superficiais foi feita em julho de 2018 em 58 pontos, distribuidos ao longo do segmento fluvial represado pela barragem hidreletrica. Analisaram-se os parâmetros quimicos totais (detergente; sulfato; amonia; nitrito; nitrato; fosforo; aluminio; zinco; ferro; manganes; boro) e os parâmetros fisico-quimicos in situ (temperatura, pH, condutividade eletrica, oxigenio dissolvido, total de solidos dissolvidos, turbidez, cor aparente). Os resultados foram comparados a Resolucao do Concelho Nacional de Meio Ambiente (CONAMA) 357/05 e Portaria do Ministerio da Saude (MS) n°518. Alguns resultados obtidos estao no limite dos valores estabelecidos pela legislacao, outros ultrapassam o limite, mostrando o potencial de suscetibilidade ambiental da area. Destaca-se negativamente a concentracao do Aluminio que ultrapassou em todos os pontos o limite legal. A concentracao do sulfato e dos compostos nitrogenados, nao ultrapassaram as concentracoes dos limite normativos. Quanto os parâmetros in situ somente o oxigenio dissolvido apresentou em desconformidade com as normas.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45738642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-23DOI: 10.21715/gb2358-2812.2019334378
P. Aranha, A. Horn, P. Morais
This work shows a correlation between the GPR (Ground Penetrating Radar) data and the geochemical distribution of the selected soil profiles in the Formoso river basin, to show the correlation between the vertical distribution of the soil units and the GPR profile. This interpretation is important to easily demonstrate the evolution of these important geomorphological units with the increase in human activities in the cerrado. Thus, it is extremely important to implement the necessary mechanisms to protect these environments as water sources in the region. This research can contribute to the creation of protected areas of sustainable use, specifically areas of ecological interest (ARIE) for the protection of paths considered strategic for the conservation of soil and water.
{"title":"Interpretation of GPR (Ground Penetrating Radar) and soil profiles at selected veredas of the Formoso River Basin, Buritizeiro, Minas Gerais, Brazil","authors":"P. Aranha, A. Horn, P. Morais","doi":"10.21715/gb2358-2812.2019334378","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019334378","url":null,"abstract":"This work shows a correlation between the GPR (Ground Penetrating Radar) data and the geochemical distribution of the selected soil profiles in the Formoso river basin, to show the correlation between the vertical distribution of the soil units and the GPR profile. This interpretation is important to easily demonstrate the evolution of these important geomorphological units with the increase in human activities in the cerrado. Thus, it is extremely important to implement the necessary mechanisms to protect these environments as water sources in the region. This research can contribute to the creation of protected areas of sustainable use, specifically areas of ecological interest (ARIE) for the protection of paths considered strategic for the conservation of soil and water.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47443601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-23DOI: 10.21715/gb2358-2812.2019334394
C. Oliveira, B. Camilo
Given a panorama of few studies that paralleled the perceptions of people affected by the Fundão dam rupture in Mariana, Minas Gerais, Brazil, and the concentrations of heavy metals present in the affected areas along the Doce River, this study aimed to identify this relationship. The methods used were semi-structured interviews with affected people and collection of water and sediment samples from the river along the Rio Doce basin to measure the concentration of heavy metals.The sediment was processed according to EPA 3051-16 (Environmental Protection Agency) method. Heavy metals in the water and sediment were analyzed with ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) and AAS (Atomic Absorption Spectrometry) at IGC / UFMG (Institute of Geosciences / Federal University of Minas Gerais) and COPASA (Minas Gerais Sanitation Company). Water samples showed excessive concentrations for Al (aluminum), Fe (iron) and Mn (manganese) in a Class II river according to CONAMA (National Environmental Council, 2009). Sediment samples contained Zn (zinc), Cr (chrome), Cu (copper) and Pb (lead) reversibly connected above the quality reference value according to CETESB (São Paulo State Environmental Company, 2005). The interviews were analyzed by the Content Analysis method and pointed to the misinformation of those affected in relation to the heavy metals in the Doce River. The study showed that the mud contributed to the contamination of heavy metals in the affected rivers, mainly by
{"title":"Entrevistas e análise de metais pesados ao longo do rio Doce","authors":"C. Oliveira, B. Camilo","doi":"10.21715/gb2358-2812.2019334394","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019334394","url":null,"abstract":"Given a panorama of few studies that paralleled the perceptions of people affected by the Fundão dam rupture in Mariana, Minas Gerais, Brazil, and the concentrations of heavy metals present in the affected areas along the Doce River, this study aimed to identify this relationship. The methods used were semi-structured interviews with affected people and collection of water and sediment samples from the river along the Rio Doce basin to measure the concentration of heavy metals.The sediment was processed according to EPA 3051-16 (Environmental Protection Agency) method. Heavy metals in the water and sediment were analyzed with ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) and AAS (Atomic Absorption Spectrometry) at IGC / UFMG (Institute of Geosciences / Federal University of Minas Gerais) and COPASA (Minas Gerais Sanitation Company). Water samples showed excessive concentrations for Al (aluminum), Fe (iron) and Mn (manganese) in a Class II river according to CONAMA (National Environmental Council, 2009). Sediment samples contained Zn (zinc), Cr (chrome), Cu (copper) and Pb (lead) reversibly connected above the quality reference value according to CETESB (São Paulo State Environmental Company, 2005). The interviews were analyzed by the Content Analysis method and pointed to the misinformation of those affected in relation to the heavy metals in the Doce River. The study showed that the mud contributed to the contamination of heavy metals in the affected rivers, mainly by","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46861527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-29DOI: 10.21715/gb2358-2812.2019333273
L. Marques, D. Reis, Laura Pereira do Nascimento, E. G. Oliveira, A. Santiago, H. Roeser
The dynamics of the behavior of metals in freshwater environments has been one of the main focuses of environmental monitoring in the last years. The present study investigated the distribution of heavy metals in the river sediments of the Santa Bárbara River Watershed (Minas Gerais, Brazil). The study area suffered from problems related to mining and several high impact activities, such as farming, forestry, and reforestation for charcoal production. Surface sediments were collected at four points in the Conceição, Caraça, and Santa Bárbara rivers. These sediments were analyzed for exchangeable, reducible, oxidizible, and residual fractions through the sequential extraction procedure that was proposed by the European Community Bureau of Reference (BCR). The results indicate that the Cd and Pb are mostly present in the reducible fraction, while Fe, Ni, Cr, and Zn were predominantly found in the residual fraction, Mn and Cu are the elements that proportionally present more exchangeable fractions and greater mobility. Factors such as pH and redox potential influence several processes which alter the mobility of metals, such as adsorption and complexation. The values of these parameters have shown that the sampled points have reducing and acidic characteristics. The identification of the geochemical stages of metals in sediments allowed for the comprehension of the contamination in the medium and the identification of possible sources. This enables the assessment of the quality of the sediments in the studied watershed and serves as a reference for the monitoring of the anthropic effect to the environment.
{"title":"Mobility of metals in river sediments from a watershed in the Iron Quadrangle, Brazil","authors":"L. Marques, D. Reis, Laura Pereira do Nascimento, E. G. Oliveira, A. Santiago, H. Roeser","doi":"10.21715/gb2358-2812.2019333273","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019333273","url":null,"abstract":"The dynamics of the behavior of metals in freshwater environments has been one of the main focuses of environmental monitoring in the last years. The present study investigated the distribution of heavy metals in the river sediments of the Santa Bárbara River Watershed (Minas Gerais, Brazil). The study area suffered from problems related to mining and several high impact activities, such as farming, forestry, and reforestation for charcoal production. Surface sediments were collected at four points in the Conceição, Caraça, and Santa Bárbara rivers. These sediments were analyzed for exchangeable, reducible, oxidizible, and residual fractions through the sequential extraction procedure that was proposed by the European Community Bureau of Reference (BCR). The results indicate that the Cd and Pb are mostly present in the reducible fraction, while Fe, Ni, Cr, and Zn were predominantly found in the residual fraction, Mn and Cu are the elements that proportionally present more exchangeable fractions and greater mobility. Factors such as pH and redox potential influence several processes which alter the mobility of metals, such as adsorption and complexation. The values of these parameters have shown that the sampled points have reducing and acidic characteristics. The identification of the geochemical stages of metals in sediments allowed for the comprehension of the contamination in the medium and the identification of possible sources. This enables the assessment of the quality of the sediments in the studied watershed and serves as a reference for the monitoring of the anthropic effect to the environment.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46620925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-29DOI: 10.21715/gb2358-2812.2019333260
E. Teramoto, H. K. Chang, Marcus Paulus Martins Bressa, Adriano Soriano
The ability of native bacteria to biodegrade subsurface hydrocarbons has been studied consistently since the 1970s, since this class of contaminants may pose severe human health risks. Understanding the mechanisms that govern hydrocarbons biodegradation represents a crucial issue for the management of contaminated areas. For this reason, numerical simulations of reactive transport were performed to evaluate the conceptual geochemical model and to helpunderstand the mechanisms that govern BTEX biodegradation in a lateritic aquifer contaminated by large aviation fuel. The feasibility of previously proposed conceptual model linking geochemical zonation with BTEX mineralization and secondary reactions was evaluated by means of reactive transport models. The representation of the simulated chemical speciation of the studied hydrocarbon-contaminated aquifer is best supported when PCO 2 is fixed and dissolved oxygen, potentially present due to mass transfer from entrapped air, is considered in the model. These findings suggest the need for both constraints to be considered in the reactive transport models involving hydrocarbon biodegradation.
{"title":"Simulações de transporte reativo em um aquífero contaminado por querosene de aviação","authors":"E. Teramoto, H. K. Chang, Marcus Paulus Martins Bressa, Adriano Soriano","doi":"10.21715/gb2358-2812.2019333260","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019333260","url":null,"abstract":"The ability of native bacteria to biodegrade subsurface hydrocarbons has been studied consistently since the 1970s, since this class of contaminants may pose severe human health risks. Understanding the mechanisms that govern hydrocarbons biodegradation represents a crucial issue for the management of contaminated areas. For this reason, numerical simulations of reactive transport were performed to evaluate the conceptual geochemical model and to helpunderstand the mechanisms that govern BTEX biodegradation in a lateritic aquifer contaminated by large aviation fuel. The feasibility of previously proposed conceptual model linking geochemical zonation with BTEX mineralization and secondary reactions was evaluated by means of reactive transport models. The representation of the simulated chemical speciation of the studied hydrocarbon-contaminated aquifer is best supported when PCO 2 is fixed and dissolved oxygen, potentially present due to mass transfer from entrapped air, is considered in the model. These findings suggest the need for both constraints to be considered in the reactive transport models involving hydrocarbon biodegradation.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47993445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-29DOI: 10.21715/gb2358-2812.2019333303
G. Silva, Márcio Roberto Silva, Eduardo Ferreira de Oliveira, A. Gomes
Fossils are of great importance for building knowledge of the history of life on Earth. However, it demands a careful handling from its collecting at the field to curatorship in laboratory and its incorporation in a collection. Preparation, a part of that process, evolves the removal of the fossils from the rock matrix, through mechanic and/or chemical attrition. Despite the relevance of such procedure, the access to its knowledge keeps itself relatively restricted to paleontology laboratories, lacking such type of publications. Then, this work was realized aiming to test the utilization of different types and concentrations of acids in preparation process of calcareous fossils. The tests with acetic, hydrochloric, phosphoric and sulfamic acids were executed in twelve fragments of calcareous concretions (ichthyolites) of the Santana Formation, Lower Cretaceous of the Araripe Basin. Acetic acid had showed itself the most appropriated for the treatment of calcareous concretions for its elongated and soft action.
{"title":"Análise da ação de ácidos sobre ictiólitos da Formação Santana, Cretáceo Inferior da Bacia do Araripe, Nordeste do Brasil","authors":"G. Silva, Márcio Roberto Silva, Eduardo Ferreira de Oliveira, A. Gomes","doi":"10.21715/gb2358-2812.2019333303","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019333303","url":null,"abstract":"Fossils are of great importance for building knowledge of the history of life on Earth. However, it demands a careful handling from its collecting at the field to curatorship in laboratory and its incorporation in a collection. Preparation, a part of that process, evolves the removal of the fossils from the rock matrix, through mechanic and/or chemical attrition. Despite the relevance of such procedure, the access to its knowledge keeps itself relatively restricted to paleontology laboratories, lacking such type of publications. Then, this work was realized aiming to test the utilization of different types and concentrations of acids in preparation process of calcareous fossils. The tests with acetic, hydrochloric, phosphoric and sulfamic acids were executed in twelve fragments of calcareous concretions (ichthyolites) of the Santana Formation, Lower Cretaceous of the Araripe Basin. Acetic acid had showed itself the most appropriated for the treatment of calcareous concretions for its elongated and soft action.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43017989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-29DOI: 10.21715/gb2358-2812.2019333286
Sheila Bonfim de Jesus, M. Cruz
With a vast estuarine area, southern Bahia (Brazil) has large natural resources. Estuaries aggregate various ecological dynamics that contribute significantly to ecosystem balance, bringing valuable sustainable resources to the community. These resources are now being drastically exploited in disarray, and local communities are the first to be harmed. Understanding and knowing the estuarine geochemical behavior allows us to identify environmental strategies for a balanced exploitation of these ecosystems. The present work aimed to geochemically characterize the low course of the Una River through the analysis of physical-chemical parameters in water (temperature, pH, dissolved oxygen, salinity, Eh, conductivity, turbidity and total dissolved solids) and metals (Ni, Cu, Cd, Pb and Cr) in water and suspended particulate matter. The samples were collected in the dry season in October 2012 and in the rainy season in May 2013. The highest values of metals were Ni, Cu and Pb in the suspended particulate matter. Cd was the only trace element present in the dissolved fraction, indicating a possibility of water contamination due to the surrounding anthropic activities. In general, the values of trace metals are considered high when compared with the established sediment indices.
{"title":"Caracterização geoquímica do Estuário do Rio Una, BA, Brasil","authors":"Sheila Bonfim de Jesus, M. Cruz","doi":"10.21715/gb2358-2812.2019333286","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019333286","url":null,"abstract":"With a vast estuarine area, southern Bahia (Brazil) has large natural resources. Estuaries aggregate various ecological dynamics that contribute significantly to ecosystem balance, bringing valuable sustainable resources to the community. These resources are now being drastically exploited in disarray, and local communities are the first to be harmed. Understanding and knowing the estuarine geochemical behavior allows us to identify environmental strategies for a balanced exploitation of these ecosystems. The present work aimed to geochemically characterize the low course of the Una River through the analysis of physical-chemical parameters in water (temperature, pH, dissolved oxygen, salinity, Eh, conductivity, turbidity and total dissolved solids) and metals (Ni, Cu, Cd, Pb and Cr) in water and suspended particulate matter. The samples were collected in the dry season in October 2012 and in the rainy season in May 2013. The highest values of metals were Ni, Cu and Pb in the suspended particulate matter. Cd was the only trace element present in the dissolved fraction, indicating a possibility of water contamination due to the surrounding anthropic activities. In general, the values of trace metals are considered high when compared with the established sediment indices.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49034150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-29DOI: 10.21715/gb2358-2812.2019333234
Fabio Crisigiovanni, O. Licht, V. Ferrari, C. Porto
A collection of 6,587 active stream sediment samples covering about 4,800 km2 in the Paraná Shield, southern Brazil was used to produce 75 composite samples each representing a 5’ x 5’ cell. The original samples were retrieved from the archives of the Geological Service of Paraná MINEROPAR and the Geological Service of Brazil SGB / CPRM. The composite samples were submitted to four analytical methods with the determination of 66 elements. Geochemical maps of the isolated elements along with bivariate correlation analysis showed six associations between elements, each representing specific lithologies and at least one area with high exploratory potential, which was previously unknown given the small amount of elements analyzed in the original samples. The geochemical maps were produced either by cell classification (pixel maps) or by the application of the minimum
{"title":"Geochemical mapping based on regularly spaced composite stream sediment samples produced from stored aliquots - State of Paraná Pre-Cambrian shield, Brazil","authors":"Fabio Crisigiovanni, O. Licht, V. Ferrari, C. Porto","doi":"10.21715/gb2358-2812.2019333234","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019333234","url":null,"abstract":"A collection of 6,587 active stream sediment samples covering about 4,800 km2 in the Paraná Shield, southern Brazil was used to produce 75 composite samples each representing a 5’ x 5’ cell. The original samples were retrieved from the archives of the Geological Service of Paraná MINEROPAR and the Geological Service of Brazil SGB / CPRM. The composite samples were submitted to four analytical methods with the determination of 66 elements. Geochemical maps of the isolated elements along with bivariate correlation analysis showed six associations between elements, each representing specific lithologies and at least one area with high exploratory potential, which was previously unknown given the small amount of elements analyzed in the original samples. The geochemical maps were produced either by cell classification (pixel maps) or by the application of the minimum","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47329731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-29DOI: 10.21715/gb2358-2812.2019333313
Manuel Vitor Portugal Gonçalves, R. Santos, A. B. S. R. Junior, F. S. Batista, M. Cruz, Alexandre Barreto Costa, Mônica Pringsheim Cunha
Esta pesquisa pretendeu caracterizar a composicao isotopica das aguas subterrâneas dos municipios de Feira da Mata e de Santana, no oeste da Bahia, Brasil. Foram coletadas aguas em quinze pocos perfurados nas rochas pelito-carbonaticas do Grupo Bambui. As variaveis fisico-quimicas foram mensuradas in situ, por meio de sonda multiparâmetros, os cations por ICP-OES e os ânions por titrimetria e espectrofotometria. Os valores da razao isotopica em δ2H e δ18O destacaram o papel da recarga pelas chuvas locais, infiltracao rapida e pouca evaporacao. Tambem, revelaram que as aguas subterrâneas de Santana foram as mais evaporadas. A composicao isotopica em δ13CCID foi relacionada a um pequeno tempo de residencia da agua no aquifero, predominando valores similares a assinatura isotopica das plantas de ciclo fotossintetico C4 e das rochas carbonaticas. Esta tendencia foi corroborada pela caracterizacao hidroquimicas. A analise de agrupamentos mostrou que os grupos hidroquimicos se distinguiram quanto aos valores da mineralizacao, saturacao da solucao nos minerais calcita e dolomita e razao isotopica em δ13CCID nas amostras de Feira da Mata ou de Santana. As alteracoes nestas variaveis acompanham a evolucao geoquimica das aguas bicarbonatadas calcicas para as bicarbonatadas ou cloretadas sodicas, a partir das reacoes de troca de bases e da circulacao da agua no aquifero. A integracao dos resultados isotopicos, razoes geoquimicas, indice de saturacao e a estatistica multivariada revelou a relevância do intemperismo quimicos de carbonatos e pelitos a qualidade da agua.
本研究旨在表征巴西巴伊亚州西部菲拉-达马塔市和桑塔纳市地下水的同位素组成。在班布组泥质碳酸盐岩中钻了15个孔，收集了水。物理化学变量采用多参数探针原位测量，阳离子采用ICP-OES法测量，阴离子采用滴定法和分光光度法测量。δ2H和δ18O的同位素比值突出了局部降雨补给、快速渗透和低蒸发的作用。他们还透露，桑塔纳的地下水蒸发量最大。δ13CCID中的同位素组成与水在含水层中的停留时间短有关，其值与C4光合循环植物和碳酸盐岩的同位素特征相似。水化学特征证实了这一趋势。聚类分析表明，Feira da Mata和Santana样品的水化学组在矿化值、方解石和白云石矿物的溶液饱和度以及δ13CCID的同位素比例方面存在差异。这些变量的变化遵循含水层中碱交换反应和水循环引起的碳酸氢钙水向碳酸氢钠或氯化物的地球化学演化。综合同位素结果、地球化学比值、饱和度指数和多元统计数据，揭示了碳酸盐岩和泥质岩的化学风化与水质的相关性。
{"title":"Composição isotópica (δ18O, δ2H e δ13CCID) das águas subterrâneas dos municípios de Feira da Mata e Santana (BA)","authors":"Manuel Vitor Portugal Gonçalves, R. Santos, A. B. S. R. Junior, F. S. Batista, M. Cruz, Alexandre Barreto Costa, Mônica Pringsheim Cunha","doi":"10.21715/gb2358-2812.2019333313","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019333313","url":null,"abstract":"Esta pesquisa pretendeu caracterizar a composicao isotopica das aguas subterrâneas dos municipios de Feira da Mata e de Santana, no oeste da Bahia, Brasil. Foram coletadas aguas em quinze pocos perfurados nas rochas pelito-carbonaticas do Grupo Bambui. As variaveis fisico-quimicas foram mensuradas in situ, por meio de sonda multiparâmetros, os cations por ICP-OES e os ânions por titrimetria e espectrofotometria. Os valores da razao isotopica em δ2H e δ18O destacaram o papel da recarga pelas chuvas locais, infiltracao rapida e pouca evaporacao. Tambem, revelaram que as aguas subterrâneas de Santana foram as mais evaporadas. A composicao isotopica em δ13CCID foi relacionada a um pequeno tempo de residencia da agua no aquifero, predominando valores similares a assinatura isotopica das plantas de ciclo fotossintetico C4 e das rochas carbonaticas. Esta tendencia foi corroborada pela caracterizacao hidroquimicas. A analise de agrupamentos mostrou que os grupos hidroquimicos se distinguiram quanto aos valores da mineralizacao, saturacao da solucao nos minerais calcita e dolomita e razao isotopica em δ13CCID nas amostras de Feira da Mata ou de Santana. As alteracoes nestas variaveis acompanham a evolucao geoquimica das aguas bicarbonatadas calcicas para as bicarbonatadas ou cloretadas sodicas, a partir das reacoes de troca de bases e da circulacao da agua no aquifero. A integracao dos resultados isotopicos, razoes geoquimicas, indice de saturacao e a estatistica multivariada revelou a relevância do intemperismo quimicos de carbonatos e pelitos a qualidade da agua.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49043375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-29DOI: 10.21715/gb2358-2812.2019333325
A. Santos, N. S. Pereira, A. N. Sial
Corals are often used as natural archives for climate research. These organisms have the ability to incorporate geochemical data into their exoskeletons, which can be used as proxies for different environmental variables. In this work, multiple carbon stable isotope profiles (δC) were used in different sections of a Porites astreoides (PTM-1) coral colony, collected at Rocas Atoll South Atlantic. This approach aims to verify the effectiveness of this method as an alternative for the evaluation of coral growth rate of the Scleractinia group. Such method is based on the idea that the coral δC varies according to the luminosity (i.e. cloud cover), which presents seasonal variability and leave the annual cycles recorded in the corals. Thus, the length of each isotopic cycle corresponds to the growth rate of a coral. In this work, 4 isotopic profiles with 0.5 mm sampling resolution were carried out. The δC cycles were used to evaluate the growth rate of the PTM-1 colony. The length of the δC cycles varied from 3 to 12 mm along the profiles and the overall average growth rate estimated for this colony was 6.69 ± 2.39 mm/year, close to those reported for this species in other species. regions, indicating the effectiveness of this method in assessing coral growth rate.
{"title":"Aplicação de isótopos estáveis de carbono na avaliação da taxa de crescimento do coral Porites astreoides (Lamarck, 1816) do Atol das Rocas - Atlântico Sul","authors":"A. Santos, N. S. Pereira, A. N. Sial","doi":"10.21715/gb2358-2812.2019333325","DOIUrl":"https://doi.org/10.21715/gb2358-2812.2019333325","url":null,"abstract":"Corals are often used as natural archives for climate research. These organisms have the ability to incorporate geochemical data into their exoskeletons, which can be used as proxies for different environmental variables. In this work, multiple carbon stable isotope profiles (δC) were used in different sections of a Porites astreoides (PTM-1) coral colony, collected at Rocas Atoll South Atlantic. This approach aims to verify the effectiveness of this method as an alternative for the evaluation of coral growth rate of the Scleractinia group. Such method is based on the idea that the coral δC varies according to the luminosity (i.e. cloud cover), which presents seasonal variability and leave the annual cycles recorded in the corals. Thus, the length of each isotopic cycle corresponds to the growth rate of a coral. In this work, 4 isotopic profiles with 0.5 mm sampling resolution were carried out. The δC cycles were used to evaluate the growth rate of the PTM-1 colony. The length of the δC cycles varied from 3 to 12 mm along the profiles and the overall average growth rate estimated for this colony was 6.69 ± 2.39 mm/year, close to those reported for this species in other species. regions, indicating the effectiveness of this method in assessing coral growth rate.","PeriodicalId":34597,"journal":{"name":"Geochimica Brasiliensis","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42190139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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