Landslides risk evaluation: proposal of a methodology

Este trabalho apresenta uma abordagem metodológica simples para a avaliação e cartografia de zonas susceptíveis à ocorrência de movimentos de massa. Assume-se assim como um contributo para o ordenamento do território, nomeadamente, ao nível do planeamento urbanístico e rodoviário, na medida em que gera instrumentos que podem evitar, ou pelo menos minorar, a ocorrência de acidentes com danos materiais e humanos.This work aims to present a simple methodological approach for the assessment and mapping of areas susceptible to the occurrence of landslides. Thus, it represents a contribution to land management, in particular regarding urban and road planning, in that it generates management tools appropriate to avoid or mitigate the occurrence of accidents with material and human damage.(undefined

Occurrence, properties and pollution potential of environmental minerals in acid mine drainage

This paper describes the occurrences, the mineralogical assemblages and the environmental relevance of the AMD-precipitates from the abandoned mine of Valdarcas, Northern Portugal. At this mining site, these precipitates are particularly related with the chemical speciation of iron, which is in according to the abundance of mine wastes enriched in pyrrhotite and pyrite. The more relevant supergene mineralogical assemblages include the following environmental minerals: soluble metal-salts, mainly sulphates, revealing seasonal behaviour, iron-hydroxysulphates and iron-oxyhydroxides, both forming ochre precipitates of poorly and well-crystalline minerals. Pollution potential of the most highly water soluble salts was analysed in order to evaluate the environmental effect of their dissolution by rainfall. Laboratory experiments, carried out with iron and aluminium sulphates, demonstrated the facility to release metals, sulphate and acidity upon dissolution. Regarding the ochre precipitates, composed by several less soluble iron (III)-minerals, the spatial distribution on the nearby aqueous system as well as the proportion of Jarosite, Schwertmannite and Goethite in the mixtures gave information about the halo’s contamination promoted by the AMD emerging from the waste-dump

Editorial for special issue “Pollutants in Acid Mine Drainage”

[Excerpt] Acid mine drainage (AMD) is among the major environmental concerns related to mining activity and often causes the complete degradation of affected ecosystems during and/or after mine closure [...]This research was funded by FCT—Fundação para a Ciência and Tecnologia through projects UIDB/04683/2020, UIDP/04683/2020, and Nano-MINENV 029259 (PTDC/CTA-AMB/29259/2017)

Natural remediation of mine waste-dumps: mapping the evolution of vegetation cover in distinctive geochemical environments

Abandoned mine waste-dumps are focus of environmental impact, especially when there are reactive minerals, such as sulfides. From their oxidation results long lasting typical impacts, especially acid mine drainage (AMD)and contamination of soil. Natural attenuation is often relevant and sometimes is enough to promote remediation. However, in the presence of abundant sulfide-rich wastes, technical intervention is generally necessary. In this context, phytoremediation has been considered appropriate, since it is a cost-effective strategy, which is a crucial expectation for abandoned mines. The present work is focused on remediation promoted by natural vegetation of distinctive mine waste-dumps. They were analyzed with the following objectives: i) mapping cover vegetation and monitoring the success of environmental rehabilitation; ii) study the influence of geochemical and mineralogical parameters in natural colonization; iii) estimate the value of local flora for phytoremediation.Fundação para a Ciência e a Tecnologia (FCT

Water quality in the Municipality of São Domingos (Santiago island, Cape Verde)

O presente estudo tem como objetivo avaliar a qualidade da água e potencialidades de uso no concelho de São Domingos, na ilha de Santiago (Cabo Verde). Os resultados obtidos mostram, o carácter mineralizado destas águas, com valor médio de condutividade elétrica de 1361 µS/cm. A classificação hidroquímica, de acordo com o diagrama de Piper, conduziu à discriminação dos seguintes tipos: águas mistas (bicarbonatadas, cloretadas) e mistas sódicas (cloretadas e bicarbonatadas). Considerando o que está estabelecido na legislação Cabo-verdiana e Portuguesa relativamente à qualidade da água, verificouse que apenas 36 % das amostras têm qualidade suficiente para consumo humano. No que respeita à utilização da água para rega, cerca de 68 % das amostras apresentam evidências de risco de salinização alto a muito alto.This research aims the evaluation of water quality and potential uses at São Domingos municipality, at Santiago Island (Cape Verde). The results show the mineralized nature of these waters, with an average electrical conductivity of 1361 μS/cm. The hydrochemical classification, according to the Piper diagram, led to the following types: mixed (bicarbonate and chloride) and mixed with sodium (chloride and bicarbonate). Considering what is established for water quality in the Cape Verde and Portuguese legislation, only 36 % of the water samples are able for human consumption. Regarding irrigation use, approximately 68 % of the samples present high-to-very-high salinization risk.(undefined)info:eu-repo/semantics/publishedVersio

A model for the characterization and promotion of forsaken mining sites – The case of Lagares do Estanho, Vila Nova de Paiva

"Apresentado no VIII Congresso Nacional de Geologia 2010, Braga, 12-16 Julho"Apresenta-se um modelo conceptual para a valorização de locais de interesse geomineiro atribuíveis ao Couto Mineiro de Lagares do Estanho. Esta fez-se segundo um protocolo de procedimentos que encara o espaço mineiro (EM) devoluto como uma unidade territorial com atributos geológicos e industriais relevantes para o ordenamento e desenvolvimento territorial. A promoção deste EM representa um extremo de máxima especificidade e diversidade e decorre de uma caracterização abrangente, geológica, mineralógica, fisiográfica, arqueológica, sócio-económica e ambiental, o que potencia variadas formas de usufruto.The conceptual model for promotion of interesting mining sites in the area of Lagares follows a protocol of procedures which considers the abandoned mining space (MS) as a territorial unit with relevant geological and industrial attributes in what concerns territorial planning and land-use management. The assessment to this specific MS represents an extreme of strong identity and maximal diversity and results from an holist characterization – geological, mineralogical, physiographic, archaeological, socio-economical and environmental, which enhance some peculiar trends of space-use

Derelict mines in the land management: conceptual model for the Lagares Mines - Vila Nova de Paiva

Em Portugal, na última década, as ações dirigidas à reabilitação de espaços mineiros abandonados tiveram principalmente incidência ambiental, ou dedicaram‑se à anulação do risco geotécnico associado às escavações mineiras. Apresenta‑se aqui um modelo conceptual sobre valorização de um local de interesse geológico e mineiro, onde se encara de forma mais abrangente o espaço mineiro devoluto (EMD) como uma unidade territorial com atributos geológicos e industriais relevantes a incluir no ordenamento territorial. A promoção deste EMD representa um extremo de especificidade e diversidade e baseia‑se numa caracterização abrangente, geológica, mineralógica, fisiográfica, arqueológica, sócio‑económica e ambiental, o que potencia variadas formas de usufruto equacionadas, atualmente, para o Couto Mineiro de Lagares. Abstract: In Portugal, in the last decade, programs and actions dedicated to the rehabilitation of abandoned mining areas included environmental purposes and obliteration on hazard related to mine diggings. The conceptual model for the Lagares Mines follows a protocol of procedures which considers the abandoned mine land (AML) as a territorial unit with geological and industrial attributes, which must be considered in land‑use planning. This specific AML represents an extreme of identity and maximal diversity in what concerns the Northern Portugal mining industry. Its holist characterization included geological, mineralogical, physiographic, archaeological, socio‑economic and environmental studies, which suggest and enhance some peculiar components of the land and local management.In Portugal, in the last decade, programs and actions dedicated to the rehabilitation of abandoned mining areas included environmental purposes and obliteration on hazard related to mine diggings. The conceptual model for the Lagares Mines follows a protocol of procedures which considers the mining site (MS) as a territorial unit with geological and industrial attributes, which must be considered in land‑use planning. This specific MS represents an extreme of identity and maximal diversity in what concerns the Northern Portugal mining industry. Its holist characterization included geological, mineralogical, physiographic, archaeological, socio‑economic and environmental studies, which suggest and enhance some peculiar components of the land and local management

Scorodite stability in mine drainage : Northern Portugal

Apresenta-se uma síntese de resultados procedentes de um programa alargado de reconhecimento de neoformações mineralógicas em rejeitos mineiros. Neste caso deu-se especial atenção às paragéneses secundárias em que a scorodite (FeAsO4·2H2O) é fase essencial, ocorrendo sob a forma de cristais isolados, agregados ou ainda em crustificações com diferentes estados de consolidação e níveis de compacidade. Foram selecionados espaços mineiros do N de Portugal, com depósitos hidrotermais de quartzo com sulfuretos metálicos: Castelhão, Argas-Cerquido, Tibães, Adoria e Penedono. Foram analisadas águas de efluente mineiro afetadas pela interação com escombreiras e escavações, e comparadas com águas do fundo regional de cada um dos espaços mineiros. Nos casos estudados, dependendo da interação água – mineral e na sequência da oxidação da arsenopirite, as águas de embebimento e escorrência seguem uma tendência definida até às condições de sobre-saturação e precipitação da scorodite, para um incremento de Eh e decréscimo de pH, a Eh>150 mV e [As] > 90ppb. Abstract:This work synthesizes some results of an extended program of recognition of minerals newly formed in mine wastes and diggings. In this case, it deals with the secondary paragenesis holding scorodite (FeAsO4 • 2H2O) as an essential species, occurring as isolated crystals, aggregates or crusts, with different degrees of consolidation and compaction. The selected mining sites, in Northern Portugal, corresponded to sulphide+quartz hydrothermal veins and mineralizations: Castelhão, Argas-Cerquido, Tibães, Adoria and Penedono. Mining effluents affected by the waste dumps, and the background water in each site were analysed. In the studied effluents, depending on the conditions of water-mineral interaction and arsenopirite oxidation, the composition of affected solutions follow a definite path, till de oversaturation and scorodite precipitation: increasing Eh /decreasing pH at Eh>150mV and As concentration higher than 90 ppb.This work synthesizes some results of an extended program of recognition of minerals newly formed in mine wastes and diggings. In this case, it deals with the secondary paragenesis holding scorodite (FeAsO4 • 2H2O) as an essential species, occurring as isolated crystals, aggregates or crusts, with different degrees of consolidation and compaction. The selected mining sites, in North-ern Portugal, corresponded to sulphide+quartz hydrothermal veins and mineralizations: Castelhão, Argas-Cerquido, Tibães, Adoria and Penedono. Mining effluents affected by the waste dumps, and the background water in each site were analysed. In the studied effluents, depending on the conditions of water-mineral interaction and arsenopirite oxidation, the composition of affected solutions follow a definite path, till de oversaturation and scorodite precipitation: increasing Eh / decreasing pH at Eh>150mV and As concentration higher than 90 ppb

Mining traditions in the promotion of Local Heritage. Geological component in the natural and cultural valuing of Serra d’Arga (NW Portugal)

Serie : Cuadernos del Museo Geominero, n.º 12A selecção de conteúdos geológicos e mineiros, que integram o Centro de Interpretação da Serra d’Arga (CISA), apela fundamentalmente à tradição mineira que vigorou durante o Séc. XX e às suas evidências no património natural e cultural. O tema escolhido - “Minerais Úteis”- preconiza, num primeiro momento, a estratégia de promoção do Património Geológico e Mineiro da Serra d’Arga, desencadeada pelo CISA. Neste intuito, foram elaborados e organizados materiais dos quais aqui se faz nota, como sejam fotografias dos minérios mais comuns e ilustrações de infra-estruturas mineiras. Ainda, a integrar uma exposição de minerais e paragéneses, foram seleccionadas amostras tendo em conta o seu fácil reconhecimento pelas gentes locais. Como testemunhos materiais das tradições mineiras potenciam a valorização patrimonial tanto na acepção cultural – mineira – como na diversidade geológica, no que respeita ao tipo de rochas portadoras e sua mineralogia.La selección de los contenidos geológicos y mineros, que integran el Centro de Interpretación de la Sierra d’Arga (CISA), apelan fundamentalmente a la tradición minera que prevaleció durante el siglo XX y sus evidencias en el patrimonio natural y cultural. El tema elegido - “Los minerales útiles” – representa la estrategia iniciada por el CISA para la promoción del Patrimonio Geológico y Minero. Con este objetivo se han preparado y organizado materiales ilustrativos de los cuales se hizo la presente nota, concretamente fotografías de los minerales más comunes y ilustraciones de infraestructuras mineras. Además se hay organizado una muestra de minerales y paragénesis que fueron seleccionados teniendo en cuenta su fácil reconocimiento por la población local. Como prueba material de las tradiciones mineras, dan relieve a la valorización del patrimonio, tanto en el sentido cultural – adonde se incluí la minería – como a la diversidad geológica y mineralógica.The selection of geological and miners content, comprising the Interpretation Center of Arga (ICA), appeals to the mining tradition that prevailed during the XX century and its evidence in the natural and cultural heritage. The chosen theme - “Useful Minerals” - suggests, at first, the strategy of promoting the Geological and Mining Heritage of Arga triggered by ICA. To this end have been prepared and organized photographs of the most common ores and illustrations of mining infrastructure. Also, to integrate a display of minerals and paragenesis, were selected representative samples taking into account its easy recognition by the locals. Those constitutes material evidence of mining tradition, who value the cultural heritage and the geological diversity

A associação yanomamite-scorodite e a mineralização supergénica de In em detritos mineiros de zonas de cisalhamento com W-Au-As-Zn - Norte de Portugal

"Apresentado no VIII Congresso Nacional de Geologia 2010, Braga, 12-16 Julho"No âmbito de um programa de caracterização mineralógica de escombreiras, em sítios mineiros abandonados, detectou-se uma mineralização invulgar de índio (In) associada a detritos de grão grosseiro, provenientes de antigas lavras subterrâneas, em zonas de cisalhamento com W e/ou Au. A ocorrência mais significativa revela crescimento epitaxial de scorodite sobre núcleos de yanomamite, neoformados em cavidades de corrosão de sulfuretos em blocos soltos. O depósito primário, em Tibães (Braga), corresponde a veios hidrotermais em zonas de cisalhamento, com texturas do tipo fracturação-selagem (“crack-seal").Systematic characterization of waste dumps mineralogy in several abandoned mining sites allowed the detection of an unusual indium (In) mineralization associated with coarse grained debris from small scale underground workings in shear zones with W and/or Au. The most significant occurrence reveals epitaxic overgrowth of scorodite in transition to yanomamite cores, newly formed in corrosion cavities of sulphides in wasted boulders. Primary deposit is a hydrothermally veined and cracksealed shear zone in Tibães (Braga)