Ocorrências Hidrominerais do NE de Portugal Continental: Inventariação, Sistematização e Aproveitamentos Didácticos
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2009
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O presente trabalho surge da necessidade em tornar público o actual estado das ocorrências hidrominerais do NE de Portugal Continental. Sem querermos estar a substituir as entidades competentes, o trabalho apresenta-se não só como um inventário completo e detalhado da diversidade hidromineral do NE de Portugal Continental, que permitiu a descoberta de novas ocorrências e a recolha de imagens inéditas, mas também como uma sistematização que possibilitou identificar famílias hidroquímicas e retirarem-se conclusões acerca das associações entre sua composição química e a litologia envolvente. O trabalho integra ainda uma breve revisão histórica sobre a relação entre o Homem, as Divindades e a água, a evolução e classificação das águas minerais em Portugal e, no sentido de promover acções pedagógicas que levem ao conhecimento e divulgação das ocorrências hidrominerais, foram desenvolvidos diversos aproveitamentos didácticos na forma de um roteiro ou guia de observação com exemplos de actividades de ensino-aprendizagem e que podem ser aplicadas por professores, formadores ou outros a alunos. Ocorrem no NE de Portugal, em terrenos pertencentes à Zona Centro Ibérica (ZCI) e Zona da Galiza – Trás-os-Montes (ZGTM) diversas águas minerais, que se podem integrar em pólos hidrominerais, que no seu conjunto formam os dois grandes grupos as ocorrências hidrominerais de águas sulfidratadas e bicarbonatada sódica, gasocarbónica. A zona em estudo, ocupa uma área com cerca de 8 000 km2, tendo sido feita a caracterização geral geográfica, geomorfológica, geológica, neotectónica e de igual modo, o enquadramento hidrogeológico das cerca de setenta ocorrências hidrominerais do NE de Portugal Continental distribuídas por um universo de 36 pólos hidrominerais. Todos os pólos hidrominerais da área de trabalho foram visitados durante os trabalhos de campo, tendo sido descobertas novas ocorrências hidrominerais, recolhidas imagens inéditas e acrescentados novos dados como: a Nascente do Filão (Lagoaça); o furo da Junqueira (Piscina da Junqueira/Vilariça); a Oliveira do Muro do Regato (Junqueira); a Fonte das Mudas (Reigaz); o poço do Grande Hotel de Chaves; a ocorrência da Hospedaria Caldas (Chaves); a Nascente Nº3 (Moimenta da Raia); o ACP3 (Vilarelho da Raia); o interior do edifício balnear de Santa Cruz, etc. Após os trabalhos de campo procedeu-se ao registo e caracterização da diversidade hidromineral do NE de Portugal Continental por três sectores de Trás-os-Montes (ocidental, central e oriental) e no sector do Alto Douro no sentido SW para NE em dezassete subcapítulos: 1) Moledo; 2) Carvalhelhos; 3) região de Pedras Salgadas; 4) região de Vidago; 5) Chaves; 6) Vilarelho da Raia; 7) S. Lourenço e Carlão; 8) Seixo de Ansiães; 9) Segirei e Sandim; 10) Marmelos; 11) Ribeirinha e Fornos de Ledra; 12) região de Vilariça; 13) Santa Cruz e Moimenta da Raia; 14) Castro de Avelãs e Alfaião; 15) Escarledo e Abelheira; 16) Lagoaça e Zambulhal e 17) Angueira e Terronha. Para cada uma destas ocorrências hidrominerais, fez-se a caracterização em termos de localização e acessos, tipo de captação, enquadramento geomorfológico e lito-estrutural, parâmetros físico-químicos, aproveitamentos e usos e as crenças e tradições associadas. Com base na informação recolhida “in situ” e na pesquisa bibliográfica existente fez-se o tratamento estatístico de mais de 125 análises químicas referentes às ocorrências hidrominerais tendo sido estas conjugadas estatisticamente em quarenta amostras cujos valores médios representam o universo de ocorrências hidrominerais do sector em análise. A partir dos valores médios dos parâmetros estatísticos, realizaram-se diversos estudos hidroquímicos desde a construção de diagramas hidroquímicos de Stiff, de Piper e de Schoeller-Berkaloff. Foi ainda feita uma abordagem à origem das diversas substâncias dissolvidas nas águas minerais, desde aniões, catiões e gases dissolvidos. Neste estudo hidrogeoquímico, foram também determinadas as correlações dos iões maiores com o cloro e calculados vários índices hidrogeoquímicos. Por fim, fez-se uma breve abordagem na definição de famílias hidroquímicas recorrendo aos métodos estatísticos de análise de grupos e de correspondências. Como principais conclusões verifica-se a existência de uma grande heterogeneidade hidroquímica entre as ocorrências hidrominerais de Portugal Continental podendo determinar-se diversos grupos e subgrupos hidrogeoquímicos. De um modo geral podemos dizer que todas as águas são bicarbonatadas sódicas com excepção das sulfidratadas hiperalcalinas de Castro de Avelãs, Escarledo e Abelheira que são carbonatadas sódicas embora contenham na sua composição o ião bicarbonato, variando a sua composição química em função do ambiente litológico do aquífero, do tipo de circuito hidromineral, do tempo de residência, da interacção água-rocha, da existência ou não de mega-fracturas e cisalhamentos, da profundidade do aquífero, etc. Assim, e em termos gerais existem no NE de Portugal Continental os seguintes grupos hidrogeoquímicos: 1) as bicarbonatadas sódicas gasocarbónicas ácidas; 2) as sulfidratadas, bicarbonatadas sódicas silicatadas, fluoretadas, com N2, alcalina; 3) as sulfidratadas, silicatadas, carbonatadas sódicas, hiperalcalinas; 4) as sulfidratadas, bicarbonatadas sódicas, cloretadas, fluoretada e 5) as sulfidratadas, bicarbonatadas sódicas, neutras. Dentro destes grupos ainda é possível distinguirem-se subgrupos. A ocorrência hidromineral de Ribeirinha representa a transição entre o grupo das gasocarbónicas e das sulfidratadas enquanto as ocorrências de Sandim e de Segirei representam uma transição entre as próprias gasocarbónicas. De facto, dentro do grupo das gasocarbónicas, as ocorrências hidrominerais de Pedras Salgadas, Oura, Romanas e Cardal distinguem-se das restantes gasocarbónicas colocando-se a suas anteriores num patamar transitório. Os extremos entre os grupos das gasocarbónicas e sulfidratadas são marcados pela ocorrência de Junqueira para o primeiro grupo e de Terronha para o segundo. A ocorrência hidromineral de Carvalhelhos surge sem “qualquer” dúvida intimamente associada às sulfidratadas fruto da sua sulfuração (HS= 0,15mg/l) e do seu pH alcalino (pH=7,96). Quanto aos aproveitamentos são diversos destacando-se principalmente o engarrafamento em unidades industriais, e também o termalismo e geotermia associados ao grupo das gasocarbónicas. Regista-se ainda apenas dois aproveitamentos termais no grupo das sulfidratadas sendo que as demais não têm sido alvo de qualquer tipo de aproveitamento a não ser algumas utilizações populares. A região em estudo apresenta um valioso património histórico no que diz respeito ao termalismo e são inúmeros os projectos que visão conciliar este património histórico com o ambiente e o turismo como um dos principais factores de desenvolvimento regional. Na última fase do trabalho, procedeu-se, dentro das diferentes valências hidroquímicas, contexto geológico, aproveitamentos e acessos, à elaboração de um roteiro geológico, onde foi salientada a importância das aulas práticas no ensino da geologia e do trabalho de campo. Foram então preparadas aulas de campo, através da elaboração de um guia de observação a ser utilizado pelos alunos, tendo sido planificadas diversas actividades de aprendizagem para quatro estações (Vilarelho da Raia, Chaves, Pedras Salgadas e Moledo), tendo como base os conteúdos programáticos da disciplina de Biologia e Geologia do 11º ano de escolaridade do ensino secundário que o autor lecciona.
This work arises from the need to make public the current state of hydromineral occurrences in the NE of Continental Portugal. Without wishing to be replacing the relevant authorities, the dissertation presents not only as a complete and detailed inventory of the hydromineral diversity in the NE of Continental Portugal that led to the discovery of new hydromineral occurrences and unpublished collection of images, but also made possible a systematic determined by the hydrochemical and families retreat conclusions about the associations between their chemical composition and geologic environment. The present work also gave a brief historical review of the relationship between man, the deities and water, the evolution and classification of mineral waters in Portugal and in order to promote educational activities that lead to knowledge and dissemination of hydromineral occurrences have been developed various uses learning as a road map or a guide for observation with examples of teaching-learning process and that can be applied by teachers, trainers and others students. Occur in the NE of Continental Portugal, on land belonging to the Central Iberian Zone (ZCI) and Zone of Galicia - Trás-os-Montes (ZGTM) several mineral waters that can be associated in hydromineral poles that together form two big groups of hydromineral occurrences of sulfihydrated water and sodium bicarbonate, carbonic gaseous water. The area under study covers about 8 000 km2 and has been characterized general, geographical, geomorphological, geological, neotectonic and also, the hydrogeological environment of about seventy hydromineral occurrences in the NE of Continental Portugal distributed by an universe of 36 hydromineral poles. All hydromineral poles in the work area were visited during the fieldwork, and were discovered new hydromineral occurrences, collected unpublished images and added new data as the Vein east (Lagoaça), the hole of Junqueira (Swimming-pool of Junqueira/Vilariça), the Olive-tree of the brook wall (Junqueira), the Spring of the unspeakable (Reigaz), the pit of the Grande Hotel of Chaves, the occurrence of the Caldas boarding-house (Chaves), the East No. 3 (Moimenta da Raia), the ACP3 (Vilarelho da Raia), the interior of the building of Santa Cruz baths, etc. After the field work it was register and characterized the hydromineral diversity in the NE of Continental Portugal for three sectors of Trás-os-Montes (western, central and eastern) and in the Alto Douro towards SW to NE in seventeen sub-chapters: 1) Moledo, 2) Carvalhelhos, 3) region of Pedras Salgadas, 4) region of Vidago; 5) Chaves, 6) Vilarelho da Raia; 7) S. Lourenço and Carlão, 8) Seixo de Ansiães, 9) Segirei and Sandim; 10) Marmelos, 11) Ribeirinha e Fornos de Ledra, 12) region of Vilariça; 13) Santa Cruz and Moimenta da Raia, 14) Castro de Avelãs and Alfaião, 15) Escarledo and Abelheira, 16) Lagoaça and Zambulhal and 17) Angueira and Terronha. For each of one these hydromineral occurrences, was made the characterization in terms of location and access, type of funding, geomorphological and litho-structural environment, physicalchemical parameters, usages and customs and the beliefs and traditions associated. Based on information gathered and in the existing literature it was made the statistical analysis of more than 125 chemical analyses relating to the hydromineral occurrences and they were statistically combined in forty samples whose values represent the universe of hydromineral occurrences in the NE of Contiental Portugal. From the average values of statistical parameters, there were made several hydrochemical studies like the construction of hydrochemical diagrams of Stiff, of Piper and Schoeller-Berkaloff. We also made an approach to the origin of the various substances dissolved in the mineral waters, since anions, cations and dissolved gases. In this hydrochemical study were also determined correlations of major ions with chlorine and calculated various hydrogeochemical indexes. Finally, was made a brief approach in the determination of hydrochemical families using analysis of groups and correspondence as statistical methods. Like main conclusions it was confirmed the existence of a large hydrochemical heterogeneity between hydromineral occurrences in the NE of Continental Portugal so that we can determine various hydrogeochemical groups and subgroups. In general we can say that all waters are sodium bicarbonate, with the exception of the hyperalkaline sulfihydrated of Castro de Avelãs, Escarledo e Abelheira that are sodium carbonate which contains in their composition bicarbonate, varying the chemical composition in response to the lithological of the aquifer, type of hydromineral circuit, the residence time of water-rock interaction, the existence of mega-fracture and shear, the depth of the aquifer, etc. Thus, in general exist in NE of Continental Portugal the following hydrogeochemical groups: 1) the sodium bicarbonate carbonic gaseous acid, 2) the sulfihydrated, bicarbonate sodium silicate, fluoride, with N2, alkaline, and 3) the sulfihydrated, silicate, sodium carbonate , hyperalkaline, 4) the sulfihydrated, sodium bicarbonate, chloride, fluoride, and 5) the sulfihydrated, sodium bicarbonate, neutral. Within these groups is still possible to distinguish subgroups. The hydromineral occurrence of Ribeirinha represents the transition between the group of carbonic gaseous water and sulfihydrated while the hydromineral occurrences of Sandim and Segirei represent a transition between individual carbonic gaseous water. In fact, within the group of carbonic gaseous water, the hydromineral occurrences of Pedras Salgadas, Oura, Romanas and Cardal are distinguished from other carbonic gaseous waters placing the last two ones in the transition landing. The extreme between the groups of gaseous water and sulfihydrated water are marked by the Junqueira occurrence for the first group and by the Terronha occurrence for the second one. The hydromineral occurrence of Carvalhelhos comes without "any" doubt closely associated with the sulfihydrated waters because of their sulfidation (HS = 0.15 mg / l) and its alkaline pH (pH = 7.96). As for the various usages mainly are bottling plants, and also in spa and geothermal energy associated with the group of gaseous water. There´s still only two thermal usages in the sulfihydrated occurences group while the others have not been subject to any kind of use except for a few popular ones. The area under study presents a valuable historical heritage with regard to the spa and there are many projects that reconcile this view with the environment and tourism as a major factor in regional development. In the last phase of the work, proceeded to draw up a geological roadmap where we stressed the importance of practical classes in the geology teaching and field work. They were then prepared lessons from the field, by developing an observation guide for use by students, was planned several learning activities for four seasons (Vilarelho da Raia, Chaves, Pedras Salgadas and Moledo), based on the course outline discipline of biology and geology of the 11th grade of secondary school that the author teaches.
This work arises from the need to make public the current state of hydromineral occurrences in the NE of Continental Portugal. Without wishing to be replacing the relevant authorities, the dissertation presents not only as a complete and detailed inventory of the hydromineral diversity in the NE of Continental Portugal that led to the discovery of new hydromineral occurrences and unpublished collection of images, but also made possible a systematic determined by the hydrochemical and families retreat conclusions about the associations between their chemical composition and geologic environment. The present work also gave a brief historical review of the relationship between man, the deities and water, the evolution and classification of mineral waters in Portugal and in order to promote educational activities that lead to knowledge and dissemination of hydromineral occurrences have been developed various uses learning as a road map or a guide for observation with examples of teaching-learning process and that can be applied by teachers, trainers and others students. Occur in the NE of Continental Portugal, on land belonging to the Central Iberian Zone (ZCI) and Zone of Galicia - Trás-os-Montes (ZGTM) several mineral waters that can be associated in hydromineral poles that together form two big groups of hydromineral occurrences of sulfihydrated water and sodium bicarbonate, carbonic gaseous water. The area under study covers about 8 000 km2 and has been characterized general, geographical, geomorphological, geological, neotectonic and also, the hydrogeological environment of about seventy hydromineral occurrences in the NE of Continental Portugal distributed by an universe of 36 hydromineral poles. All hydromineral poles in the work area were visited during the fieldwork, and were discovered new hydromineral occurrences, collected unpublished images and added new data as the Vein east (Lagoaça), the hole of Junqueira (Swimming-pool of Junqueira/Vilariça), the Olive-tree of the brook wall (Junqueira), the Spring of the unspeakable (Reigaz), the pit of the Grande Hotel of Chaves, the occurrence of the Caldas boarding-house (Chaves), the East No. 3 (Moimenta da Raia), the ACP3 (Vilarelho da Raia), the interior of the building of Santa Cruz baths, etc. After the field work it was register and characterized the hydromineral diversity in the NE of Continental Portugal for three sectors of Trás-os-Montes (western, central and eastern) and in the Alto Douro towards SW to NE in seventeen sub-chapters: 1) Moledo, 2) Carvalhelhos, 3) region of Pedras Salgadas, 4) region of Vidago; 5) Chaves, 6) Vilarelho da Raia; 7) S. Lourenço and Carlão, 8) Seixo de Ansiães, 9) Segirei and Sandim; 10) Marmelos, 11) Ribeirinha e Fornos de Ledra, 12) region of Vilariça; 13) Santa Cruz and Moimenta da Raia, 14) Castro de Avelãs and Alfaião, 15) Escarledo and Abelheira, 16) Lagoaça and Zambulhal and 17) Angueira and Terronha. For each of one these hydromineral occurrences, was made the characterization in terms of location and access, type of funding, geomorphological and litho-structural environment, physicalchemical parameters, usages and customs and the beliefs and traditions associated. Based on information gathered and in the existing literature it was made the statistical analysis of more than 125 chemical analyses relating to the hydromineral occurrences and they were statistically combined in forty samples whose values represent the universe of hydromineral occurrences in the NE of Contiental Portugal. From the average values of statistical parameters, there were made several hydrochemical studies like the construction of hydrochemical diagrams of Stiff, of Piper and Schoeller-Berkaloff. We also made an approach to the origin of the various substances dissolved in the mineral waters, since anions, cations and dissolved gases. In this hydrochemical study were also determined correlations of major ions with chlorine and calculated various hydrogeochemical indexes. Finally, was made a brief approach in the determination of hydrochemical families using analysis of groups and correspondence as statistical methods. Like main conclusions it was confirmed the existence of a large hydrochemical heterogeneity between hydromineral occurrences in the NE of Continental Portugal so that we can determine various hydrogeochemical groups and subgroups. In general we can say that all waters are sodium bicarbonate, with the exception of the hyperalkaline sulfihydrated of Castro de Avelãs, Escarledo e Abelheira that are sodium carbonate which contains in their composition bicarbonate, varying the chemical composition in response to the lithological of the aquifer, type of hydromineral circuit, the residence time of water-rock interaction, the existence of mega-fracture and shear, the depth of the aquifer, etc. Thus, in general exist in NE of Continental Portugal the following hydrogeochemical groups: 1) the sodium bicarbonate carbonic gaseous acid, 2) the sulfihydrated, bicarbonate sodium silicate, fluoride, with N2, alkaline, and 3) the sulfihydrated, silicate, sodium carbonate , hyperalkaline, 4) the sulfihydrated, sodium bicarbonate, chloride, fluoride, and 5) the sulfihydrated, sodium bicarbonate, neutral. Within these groups is still possible to distinguish subgroups. The hydromineral occurrence of Ribeirinha represents the transition between the group of carbonic gaseous water and sulfihydrated while the hydromineral occurrences of Sandim and Segirei represent a transition between individual carbonic gaseous water. In fact, within the group of carbonic gaseous water, the hydromineral occurrences of Pedras Salgadas, Oura, Romanas and Cardal are distinguished from other carbonic gaseous waters placing the last two ones in the transition landing. The extreme between the groups of gaseous water and sulfihydrated water are marked by the Junqueira occurrence for the first group and by the Terronha occurrence for the second one. The hydromineral occurrence of Carvalhelhos comes without "any" doubt closely associated with the sulfihydrated waters because of their sulfidation (HS = 0.15 mg / l) and its alkaline pH (pH = 7.96). As for the various usages mainly are bottling plants, and also in spa and geothermal energy associated with the group of gaseous water. There´s still only two thermal usages in the sulfihydrated occurences group while the others have not been subject to any kind of use except for a few popular ones. The area under study presents a valuable historical heritage with regard to the spa and there are many projects that reconcile this view with the environment and tourism as a major factor in regional development. In the last phase of the work, proceeded to draw up a geological roadmap where we stressed the importance of practical classes in the geology teaching and field work. They were then prepared lessons from the field, by developing an observation guide for use by students, was planned several learning activities for four seasons (Vilarelho da Raia, Chaves, Pedras Salgadas and Moledo), based on the course outline discipline of biology and geology of the 11th grade of secondary school that the author teaches.
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Dissertação de Mestrado em Geologia