HAL (Le Centre pour la Communication Scientifique Directe), 2012
Geophagy is a universal practice for humans and animals. It is the source of many questions in bo... more Geophagy is a universal practice for humans and animals. It is the source of many questions in both humanities and scientific backgrounds. Products existing in soils, easily accessible, have been mainly used, reason why soil science has provided an active and important contribution in order to understand the motivation of such amazing food consumption. Progress has been gradually achieved, as the result of interdisciplinary cooperative contributions. One geomaterial plays a fundamental role in the practice of geophagy. It is the clay, a common soil constituent that has justified the involvement of soil scientists in the studies on geophagy. Among them the important contribution of Georges Pedro favoured the shaping of this topic on mineralogical solid bases. The outcome of his contribution is reflected in other scientific domains, allowing, for instance, the consistent interpretation of ancient Greek, Arabic, Chinese or Mayan texts. The importance of the subject herein dealt with directly affects the socioeconomic impact in the medical field that, in the future, will be forced to take these developments into account.
The usually textural parameters of sand sediments employed in order to distinguish present-day be... more The usually textural parameters of sand sediments employed in order to distinguish present-day beach and dune deposits has been a matter of discussion in coastal studies. The results of these studies suggest that it may not be efficient to discriminate when the referred deposits exhibit well-sorted coastal sands, as was observed in limited coastal sections of the Portuguese coast. An innovative mineralogical approach based upon the study of the finegrained fraction trapped in coastal sands, supported on univariate and multivariate statistical analysis, has been previously applied to a test area in the western Portuguese coast. This paper presents results from the mineralogical study of the clay fraction entrapped in coastal sand samples from the Espinho-Mondego Cape coastal sector in the north of the country following the same methodology. In 45 cross-shore profiles, spaced 2000 m, 130 samples were collected. Three sand samples were taken from each profile, at the beachface, berm and foredune. The mineralogical composition of the clay fraction was analyzed by XRD. Distinct clay mineral associations were identified expressing the relative importance of terrigenous contributions to the beach and dune sediments, stressed by a number of content differences between beachface (illite>> kaolinite, random mixed layers>chlorite), berm (illite>> random mixed layers, kaolinite>chlorite) and foredune deposits (illite>> kaolinite>random mixed layers, chlorite) with significant statistical results. The environmental contrasts exhibited along this coastal sector suggest that this ability might be related with functional factors and not just a product of local constraints.
A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso.
Os minerais, no conceito mais lato do termo, e o corpo humano, são sistemas químicos nos quais po... more Os minerais, no conceito mais lato do termo, e o corpo humano, são sistemas químicos nos quais podem participar todos os elementos químicos ditos naturais. Eles desempenham papéis centrais na vida animal e vegetal, podendo proporcionar tanto impactos positivos como negativos na vida humana e, também, nos ambientes naturais-qualidade da rocha, do solo, do ar e da água-onde a referida vida ocorre, impactos que, no que respeita à saúde humana, têm sido os alvos principais da Geologia Médica. Nesta entrada é dada maior relevância aos impactos positivos relativamente aos impactos negativos dos minerais, no conceito lato do termo, têm na saúde e na qualidade da vida humana. Os minerais, sistemas químicos naturais, são constituintes fundamentais do ambiente natural onde o homem vive e os utiliza para sua sobrevivência e melhoria da qualidade de vida. Naturalmente, interações tanto positivas como negativas podem ocorrer entre minerais e humanos e, os estudos realizados nas duas últimas décadas sobre estas duas vertentes, têm sido desenvolvidos na esfera de ação do emergente campo científico chamado Geologia Médica. A investigação em Geologia Médica procura estabelecer relações entre o ambiente natural, particularmente o ambiente geológico, e a saúde humana e, para o efeito, deve envolver um grande número de especialistas diferenciados. Efetivamente a diagnose, a prevenção e o tratamento personalizado das doenças relacionadas com o ambiente geológico só pode ser alcançado através de ampla colaboração multidisciplinar de profissionais treinados em diversas disciplinas científicas, tais
Psammotherapy or arenotherapy or yet sand-bathing is a traditional practice in some countries whi... more Psammotherapy or arenotherapy or yet sand-bathing is a traditional practice in some countries which have appropriate natural mineral resources for that. This chapter reports examples of sand-bathing based on three distinctive types of sand: biogenic carbonate sand, radioactive monazite-rich sand, and volcanic basaltic black sand. Attempts are recorded in order to scientifically explain the therapeutic effects of these traditional practices, particularly those involving the biogenic carbonate sand in Porto Santo, Madeira Archipelago, Portugal, and the radioactive monazite-rich sand in Guarapari, Vitória do Espírito Santo, Brazil. In the particular case of Porto Santo, the methodologies employed in sand-bathing, which can be taken either in the natural environment (in the transition zone beach/ frontal dune) or inside the facilities of spas, for the treatment of musculoskeletal disorders are described and interpreted. 12.1 Background Data Some special sands are being used worldwide in a therapeutic application called psammotherapy, particularly for the treatment of musculoskeletal diseases, under the form of sand-bath. The word psammotherapy comes from the word psammos, which is the Greek word for sand, and its origins date back thousands of years ago to Ancient Egypt. The Egyptians took "baths" in the hot desert sand, which was naturally heated by the sun's rays, to treat a number of ailments, from scoliosis to inflammatory diseases. According to Federicci (1980), when marine sand is used as a therapeutic agent, it provides tonicity to the muscular and the locomotor systems. The author says that a sand-bath or psammotherapy is a 10-20 min application of a layer of sand, extracted from the beach down to depths not higher than 30 cm. Also, the author attributes its therapeutic action to the thermal capacity of the sand.
espanolSe ha realizado un estudio bibliometrico de la produccion cientifica presentada en los Con... more espanolSe ha realizado un estudio bibliometrico de la produccion cientifica presentada en los Congresos Iberoamericanos dePeloides (CIBAP) durante el periodo 2007-2019. Para ello se analizaron los libros de resumenes mediante la aplicacion delos principales indicadores de bibliometria: tipo de trabajo, produccion y estimacion de Lotka, materia de los trabajos, procedencia geografica y procedencia institucional. Las Universidades de Vigo, Complutense de Madrid, Aveiro y Oporto sonlas que concentran mayor porcentaje de la produccion cientifica. La procedencia de los trabajos fue principalmente espanola,portuguesa y argentina. Las materias mas estudiadas fueron la terapia termal y las propiedades fisicas y quimicas de lospeloides. EnglishA bibliometric study of the scientific production presented at the Ibero-American Congresses of Peloids (CIBAP) during the2007-2019 period was carried out. For this purpose, the type of work, production, estimation of Lotka, subject matter ofwork, geog...
A geologia de engenharia e os recursos geológicos. Vol. 2: Recursos geológicos e formação
A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso.
The main goal cf'the present work is the use of mineralogical data corresponding to sedime nt fin... more The main goal cf'the present work is the use of mineralogical data corresponding to sedime nt fine fractions (silt and clay) of Quaternary littoral deposits for the defini tion of a more detai led vertical zonography and to discri mina te the most significant morphoclimatic changes concerned with sediment source areas and sediment deposition areas. The analysis of the available mineralogica l data reveals a vertica l evolution of the mineral composi tion. The following aspects deserv e particular reference: I) fine fractions « 38!.lm) are composed ofquartz and phyllosiiicares associated to feldspa rs, preva iling ove r other minerals; howe ver in certain section s iron hydro xides and eva poritic minerals occur in significant amounts; 2) clay fractions « 211m) show a gene ral
Geophagy is a universal practice for humans and animals. It is the source of many questions in bo... more Geophagy is a universal practice for humans and animals. It is the source of many questions in both humanities and scientific backgrounds. Products existing in soils, easily accessible, have been mainly used, reason why soil science has provided an active and important contribution in order to understand the motivation of such amazing food consumption. Progress has been gradually achieved, as the result of interdisciplinary cooperative contributions. One geomaterial plays a fundamental role in the practice of geophagy. It is the clay, a common soil constituent that has justified the involvement of soil scientists in the studies on geophagy. Among them the important contribution of Georges Pedro favoured the shaping of this topic on mineralogical solid bases. The outcome of his contribution is reflected in other scientific domains, allowing, for instance, the consistent interpretation of ancient Greek, Arabic, Chinese or Mayan texts. The importance of the subject herein dealt with directly affects the socioeconomic impact in the medical field that, in the future, will be forced to take these developments into account.
Smectitic clays from 12 deposits located in the Meridional Atlas domain (Tunisia) are explored fo... more Smectitic clays from 12 deposits located in the Meridional Atlas domain (Tunisia) are explored for manufacturing of expanded aggregates. Two types of firing processes (slow and quick firing) were carried out, and properties of the bloated products were examined. Used raw materials are mainly composed of smectite, kaolinite and illite phases with quartz, calcite, dolomite and feldspars as impurities. They contain high amounts of fluxes (Fe 2 O 3 , CaO, MgO, Na 2 O and K 2 O) with CaO and Fe 2 O 3 dominating others. Quick firing or "flash heat" must be preceded by two hours drying at 350°C in order to avoid any aggregate explosion which seems to be related to the fineness of a raw material. The clay fineness appears to be the cause of ball explosion. Clay aggregates were heated at the maximum bloating temperature (1170 °C) during 5 min. and then characterized through a determination of the apparent density, the mechanical resistance corresponding to the rupture under point c...
The use of clays for therapeutic purposes is mainly related to their high absorbent and adsorbent... more The use of clays for therapeutic purposes is mainly related to their high absorbent and adsorbent properties. In dermatology and cosmeties (topical applications), clays are used due to their high swelling, high plasticity, high specific surface and high ion exchange properties. In this paper, mineralogical, chemical and technological properties of some Tunisian smectitic clays are reported with the aim to assess their suitability to be used for therapeutic external applications. Properties of these clays have been compared to those of the bentonite of Porto Santo Island (PSBT) of the Madeira archipelago (Portugal), considered to be very interesting for therapeutic treatment on the basis of their technological characterization (CEC, specific surface, exchangeable cations, specific heat, cooling rate and abrasivity). Among the investigated clays the HMD1, TFL1, BRD1 and AYD1 seem to be the most appropriate for topical applications as cataplasms or mud baths. This work is conducted to ...
This study presents an application of environmental magnetism techniques for the characterisation... more This study presents an application of environmental magnetism techniques for the characterisation of the soils near Coimbra (central Portugal). Magnetic measurements, scanning electron microscopy and geochemical studies were carried out on samples collected in 6 soil profiles in order to find possible relationships and to interpret environmental implications. Magnetic susceptibility, saturation isothermal remanent magnetisation and isothermal remanent magnetisation at the backfield of 100 mT and 300 mT were measured. HardIRM %, SIRM/χ and S-ratios were also calculated. Polluted soils showed higher values of magnetic parameters in the superficial soil horizons closer to the roads, plants and urban areas. The lowest values were observed in the deeper horizons of the soil and in the areas least disturbed by human activity. The magnetic results also suggested that the magnetic signal of these soils is mainly influenced by ferrimagnetic magnetite-like minerals and with only a minor contribution from antiferromagnetic carriers (such as hematite minerals). In unpolluted soils, lithogenic contribution is reflected by the enhancement of magnetic susceptibility near parental rock material. Scanning electron microscope images of the topsoil samples revealed the presence of magnetic spherules typical of vehicular exhaust and combustion processes. This evidence suggests that the atmospheric deposition of fly ash is the main reason for the enhancement of the magnetic signal in the topsoil. Chemical analyses showed that the concentration of various heavy metals was higher than the mean background values for Portuguese soils, and higher in superficial soils. Heavy metals showed significant positive correlation with magnetic properties. The conclusions highlight the importance of using environmental magnetism methods and techniques in the evaluation process of soil evolution and pollution history throughout time.
The common sedimentological studies of littoral deposits, namely in the Atlantic coastal sector c... more The common sedimentological studies of littoral deposits, namely in the Atlantic coastal sector comprised between Espinho and Mondego Cape (NW Portugal), are focused on the sand fractions, which results from the fact that the main coastal environments are arenaceous, in spite of the occurrence of silt and clay sediments in the solid load. Two continental areas drain to this coastal sector. The Douro and Vouga watershed drains to the designed as northern sector and southern sector, respectively, with the last one draining to the Atlantic Ocean through Aveiro lagoon, that is connected by an artificial outlet. The fine-grained fraction (lower than 63µm) minerals suites consist mainly in phyllossilicates (F), quartz (Qz), k-feldspars (Fk), plagioclases (P), opal c/ct (Op), zeolites (Z), calcite (C), dolomite (D), anhydrite (An), pyrite (Py) and siderite (Sy). Significant different contents it was found in some minerals between the beach and dune deposits of the coastal sectors considered above. The phyllosilicates and anhydrite show a significant higher content in the beach and dune deposits from the northern sector, while plagioclase, k-feldspar and calcite exhibit significant higher contents in the beach and dune deposits from the southern sector. The observed longshore content evolution, of the most representative minerals identified, make remarkable the nourishment of the Douro and Vouga watersheds and additionally of the coastal sandy formations by erosion. The same content evolution allows concluding that the Douro watershed extends its sedimentological influence until Aveiro lagoon inlet, while Vouga watershed imprints its sedimentary contribution in the coastal deposits away from that morphological accident and to the south direction.
The clay deposit of Vila Nova da Rainha (VNR) is included in the lithostratigraphic formation nam... more The clay deposit of Vila Nova da Rainha (VNR) is included in the lithostratigraphic formation named "Argilas de Tomar", and is located at the lower section of the Tertiary Tagus' river basin. Clay from one quarry is being extracted for the production of construction ceramics. In this work the firing transformations undergone by VNR clays containing quartz, alkaline feldspar, iron oxy-hydroxides, and clay minerals have been studied. Carbonates have not been identified in these raw materials. The clay layers can be subdivided in three groups based upon composition and ceramic properties. The first group, VNR0, is represented by smectite-kaolinite sandy-silty clay, the second group (VNR1 and VNR2) corresponds to illite-kaolinite bearing clay and the third group (VNR3 and VNR4) is represented by illite-smectite silty clay. The firing process involves the formation of hematite and mullite both influencing the technical properties of the fired products. With regards to the ceramic properties assessed at 1100 ºC the first group showed the lowest total shrinkage value (7.35 %) the highest water absorption value (12.2 %) and the lowest mechanical bending strength value (12.0 MPa); the same properties assessed in the second group provided the highest firing shrinkage values (7.0-5.0 %), the lowest values of water absorption (0.1-0.2 %) and relatively high mechanical bending strength values (47.8-48.0 MPa); the third group showed firing shrinkage values within the range 3.5-4.2 %, water absorption values within the range 1.4-4.5 %, and the highest mechanical bending strength values (49.2-52.0 MPa). The results of the ceramic properties being appraised indicate that the raw materials being studied are suitable for the production of high-quality construction ceramics, such as brick, roof tile and rustic floor tile.
Clay mineralogical studies have been undertaken on the OMEX core KSGX40 (164cm long) recovered fr... more Clay mineralogical studies have been undertaken on the OMEX core KSGX40 (164cm long) recovered from the Galicia Muddy Deposit of the continental shelf off Ria de Vigo. The chronology for this work is several intervals of warmth, for instance the Roman Warm Period (•`2500-1950 cal years BP) and the Medieval Warm Period (•`1100 and 700 cal years BP), intercalating cyclic colder events, like the Ice Age Cold Epoch (•`3300-2500 cal years BP) and the Little Ice Age (•`500-150 cal years BP). This work shows the potential of clay minerals to identify weak-amplitude and short climatic changes in Galicia Muddy Deposit.
The site under study (Cortegaça beach) belongs to the Ovar municipality and is part of an extensi... more The site under study (Cortegaça beach) belongs to the Ovar municipality and is part of an extensiveregion characterized by flat terrains, consisting mainly of old beach and dunar deposits. Coastal erosionhad exposed the so called Cortegaça beach formation showing the following three sedimentary sequences,from the basis to the top: 1) greenish sandy clay; 2) sand layers with marked cross-bedded showing ontop a bioturbated podzol; 3) bioturbated beach sand and dune sand. The main goal of the present paper isthe establishment of relationships between heavy metals nature and content with the mineral composition,particularly of the clay component, of those sediments. The study of the fine fraction (less than 38 mm)of forty samples collected along three profiles has been carried out. X-ray diffraction was used for mineralogicaldeterminations, whereas atomic absorption spectrometry was used for the determination of theheavy metals: Cu, Ni, Co, Zn, Pb, Cd, Mn and Cr. Mineralogical studies m...
In the present study, Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Cd concentrations were deter... more In the present study, Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Cd concentrations were determined in the sediments of the KSGX 40 core collected from the Galicia muddy patch (NW Iberian continental shelf). The results were integrated together with textural, mineralogical and micropaleontological (foraminifera) data in order to determine the possible climatic influence on the type of sedimentation that took place in the muddy patch. The geochemical data of the KSGX 40 core suggest that sediment composition and texture were significantly influenced, over the last 5.2 kyr, by the Holocene sea transgression and by climatic oscillations consisting of both relatively temperate/cold periods and relatively warm/wet periods.
Samples taken from pieces of two clays being commercialized for medicinal purposes (alleviation o... more Samples taken from pieces of two clays being commercialized for medicinal purposes (alleviation of gastrointestinal problems, treatment of abscesses, furuncles and wounds, as well as of skin ailments, and cosmetic applications) by saleswomen of natural products at the public market of the town of Praia, in the island of Santiago, archipelago of Cape Verde, were submitted to several analyses, such as, granulometric analysis, mineralogical analysis, chemical analysis, cation exchange capacity and exchangeable cations, and plasticity, in order to find out any scientific justification for the applications referred to. One of the studied clay is composed of dioctahedral illite, and the other clay is composed of dioctahedral smectite, dioctahedral illite and kaolinite. Other analytical data support the capacities of the studied clays to be used as healing materials. These clays as other natural healing clays are traditionally used for internal detoxification (particularly in the gastroint...
HAL (Le Centre pour la Communication Scientifique Directe), 2012
Geophagy is a universal practice for humans and animals. It is the source of many questions in bo... more Geophagy is a universal practice for humans and animals. It is the source of many questions in both humanities and scientific backgrounds. Products existing in soils, easily accessible, have been mainly used, reason why soil science has provided an active and important contribution in order to understand the motivation of such amazing food consumption. Progress has been gradually achieved, as the result of interdisciplinary cooperative contributions. One geomaterial plays a fundamental role in the practice of geophagy. It is the clay, a common soil constituent that has justified the involvement of soil scientists in the studies on geophagy. Among them the important contribution of Georges Pedro favoured the shaping of this topic on mineralogical solid bases. The outcome of his contribution is reflected in other scientific domains, allowing, for instance, the consistent interpretation of ancient Greek, Arabic, Chinese or Mayan texts. The importance of the subject herein dealt with directly affects the socioeconomic impact in the medical field that, in the future, will be forced to take these developments into account.
The usually textural parameters of sand sediments employed in order to distinguish present-day be... more The usually textural parameters of sand sediments employed in order to distinguish present-day beach and dune deposits has been a matter of discussion in coastal studies. The results of these studies suggest that it may not be efficient to discriminate when the referred deposits exhibit well-sorted coastal sands, as was observed in limited coastal sections of the Portuguese coast. An innovative mineralogical approach based upon the study of the finegrained fraction trapped in coastal sands, supported on univariate and multivariate statistical analysis, has been previously applied to a test area in the western Portuguese coast. This paper presents results from the mineralogical study of the clay fraction entrapped in coastal sand samples from the Espinho-Mondego Cape coastal sector in the north of the country following the same methodology. In 45 cross-shore profiles, spaced 2000 m, 130 samples were collected. Three sand samples were taken from each profile, at the beachface, berm and foredune. The mineralogical composition of the clay fraction was analyzed by XRD. Distinct clay mineral associations were identified expressing the relative importance of terrigenous contributions to the beach and dune sediments, stressed by a number of content differences between beachface (illite>> kaolinite, random mixed layers>chlorite), berm (illite>> random mixed layers, kaolinite>chlorite) and foredune deposits (illite>> kaolinite>random mixed layers, chlorite) with significant statistical results. The environmental contrasts exhibited along this coastal sector suggest that this ability might be related with functional factors and not just a product of local constraints.
A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso.
Os minerais, no conceito mais lato do termo, e o corpo humano, são sistemas químicos nos quais po... more Os minerais, no conceito mais lato do termo, e o corpo humano, são sistemas químicos nos quais podem participar todos os elementos químicos ditos naturais. Eles desempenham papéis centrais na vida animal e vegetal, podendo proporcionar tanto impactos positivos como negativos na vida humana e, também, nos ambientes naturais-qualidade da rocha, do solo, do ar e da água-onde a referida vida ocorre, impactos que, no que respeita à saúde humana, têm sido os alvos principais da Geologia Médica. Nesta entrada é dada maior relevância aos impactos positivos relativamente aos impactos negativos dos minerais, no conceito lato do termo, têm na saúde e na qualidade da vida humana. Os minerais, sistemas químicos naturais, são constituintes fundamentais do ambiente natural onde o homem vive e os utiliza para sua sobrevivência e melhoria da qualidade de vida. Naturalmente, interações tanto positivas como negativas podem ocorrer entre minerais e humanos e, os estudos realizados nas duas últimas décadas sobre estas duas vertentes, têm sido desenvolvidos na esfera de ação do emergente campo científico chamado Geologia Médica. A investigação em Geologia Médica procura estabelecer relações entre o ambiente natural, particularmente o ambiente geológico, e a saúde humana e, para o efeito, deve envolver um grande número de especialistas diferenciados. Efetivamente a diagnose, a prevenção e o tratamento personalizado das doenças relacionadas com o ambiente geológico só pode ser alcançado através de ampla colaboração multidisciplinar de profissionais treinados em diversas disciplinas científicas, tais
Psammotherapy or arenotherapy or yet sand-bathing is a traditional practice in some countries whi... more Psammotherapy or arenotherapy or yet sand-bathing is a traditional practice in some countries which have appropriate natural mineral resources for that. This chapter reports examples of sand-bathing based on three distinctive types of sand: biogenic carbonate sand, radioactive monazite-rich sand, and volcanic basaltic black sand. Attempts are recorded in order to scientifically explain the therapeutic effects of these traditional practices, particularly those involving the biogenic carbonate sand in Porto Santo, Madeira Archipelago, Portugal, and the radioactive monazite-rich sand in Guarapari, Vitória do Espírito Santo, Brazil. In the particular case of Porto Santo, the methodologies employed in sand-bathing, which can be taken either in the natural environment (in the transition zone beach/ frontal dune) or inside the facilities of spas, for the treatment of musculoskeletal disorders are described and interpreted. 12.1 Background Data Some special sands are being used worldwide in a therapeutic application called psammotherapy, particularly for the treatment of musculoskeletal diseases, under the form of sand-bath. The word psammotherapy comes from the word psammos, which is the Greek word for sand, and its origins date back thousands of years ago to Ancient Egypt. The Egyptians took "baths" in the hot desert sand, which was naturally heated by the sun's rays, to treat a number of ailments, from scoliosis to inflammatory diseases. According to Federicci (1980), when marine sand is used as a therapeutic agent, it provides tonicity to the muscular and the locomotor systems. The author says that a sand-bath or psammotherapy is a 10-20 min application of a layer of sand, extracted from the beach down to depths not higher than 30 cm. Also, the author attributes its therapeutic action to the thermal capacity of the sand.
espanolSe ha realizado un estudio bibliometrico de la produccion cientifica presentada en los Con... more espanolSe ha realizado un estudio bibliometrico de la produccion cientifica presentada en los Congresos Iberoamericanos dePeloides (CIBAP) durante el periodo 2007-2019. Para ello se analizaron los libros de resumenes mediante la aplicacion delos principales indicadores de bibliometria: tipo de trabajo, produccion y estimacion de Lotka, materia de los trabajos, procedencia geografica y procedencia institucional. Las Universidades de Vigo, Complutense de Madrid, Aveiro y Oporto sonlas que concentran mayor porcentaje de la produccion cientifica. La procedencia de los trabajos fue principalmente espanola,portuguesa y argentina. Las materias mas estudiadas fueron la terapia termal y las propiedades fisicas y quimicas de lospeloides. EnglishA bibliometric study of the scientific production presented at the Ibero-American Congresses of Peloids (CIBAP) during the2007-2019 period was carried out. For this purpose, the type of work, production, estimation of Lotka, subject matter ofwork, geog...
A geologia de engenharia e os recursos geológicos. Vol. 2: Recursos geológicos e formação
A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso.
The main goal cf'the present work is the use of mineralogical data corresponding to sedime nt fin... more The main goal cf'the present work is the use of mineralogical data corresponding to sedime nt fine fractions (silt and clay) of Quaternary littoral deposits for the defini tion of a more detai led vertical zonography and to discri mina te the most significant morphoclimatic changes concerned with sediment source areas and sediment deposition areas. The analysis of the available mineralogica l data reveals a vertica l evolution of the mineral composi tion. The following aspects deserv e particular reference: I) fine fractions « 38!.lm) are composed ofquartz and phyllosiiicares associated to feldspa rs, preva iling ove r other minerals; howe ver in certain section s iron hydro xides and eva poritic minerals occur in significant amounts; 2) clay fractions « 211m) show a gene ral
Geophagy is a universal practice for humans and animals. It is the source of many questions in bo... more Geophagy is a universal practice for humans and animals. It is the source of many questions in both humanities and scientific backgrounds. Products existing in soils, easily accessible, have been mainly used, reason why soil science has provided an active and important contribution in order to understand the motivation of such amazing food consumption. Progress has been gradually achieved, as the result of interdisciplinary cooperative contributions. One geomaterial plays a fundamental role in the practice of geophagy. It is the clay, a common soil constituent that has justified the involvement of soil scientists in the studies on geophagy. Among them the important contribution of Georges Pedro favoured the shaping of this topic on mineralogical solid bases. The outcome of his contribution is reflected in other scientific domains, allowing, for instance, the consistent interpretation of ancient Greek, Arabic, Chinese or Mayan texts. The importance of the subject herein dealt with directly affects the socioeconomic impact in the medical field that, in the future, will be forced to take these developments into account.
Smectitic clays from 12 deposits located in the Meridional Atlas domain (Tunisia) are explored fo... more Smectitic clays from 12 deposits located in the Meridional Atlas domain (Tunisia) are explored for manufacturing of expanded aggregates. Two types of firing processes (slow and quick firing) were carried out, and properties of the bloated products were examined. Used raw materials are mainly composed of smectite, kaolinite and illite phases with quartz, calcite, dolomite and feldspars as impurities. They contain high amounts of fluxes (Fe 2 O 3 , CaO, MgO, Na 2 O and K 2 O) with CaO and Fe 2 O 3 dominating others. Quick firing or "flash heat" must be preceded by two hours drying at 350°C in order to avoid any aggregate explosion which seems to be related to the fineness of a raw material. The clay fineness appears to be the cause of ball explosion. Clay aggregates were heated at the maximum bloating temperature (1170 °C) during 5 min. and then characterized through a determination of the apparent density, the mechanical resistance corresponding to the rupture under point c...
The use of clays for therapeutic purposes is mainly related to their high absorbent and adsorbent... more The use of clays for therapeutic purposes is mainly related to their high absorbent and adsorbent properties. In dermatology and cosmeties (topical applications), clays are used due to their high swelling, high plasticity, high specific surface and high ion exchange properties. In this paper, mineralogical, chemical and technological properties of some Tunisian smectitic clays are reported with the aim to assess their suitability to be used for therapeutic external applications. Properties of these clays have been compared to those of the bentonite of Porto Santo Island (PSBT) of the Madeira archipelago (Portugal), considered to be very interesting for therapeutic treatment on the basis of their technological characterization (CEC, specific surface, exchangeable cations, specific heat, cooling rate and abrasivity). Among the investigated clays the HMD1, TFL1, BRD1 and AYD1 seem to be the most appropriate for topical applications as cataplasms or mud baths. This work is conducted to ...
This study presents an application of environmental magnetism techniques for the characterisation... more This study presents an application of environmental magnetism techniques for the characterisation of the soils near Coimbra (central Portugal). Magnetic measurements, scanning electron microscopy and geochemical studies were carried out on samples collected in 6 soil profiles in order to find possible relationships and to interpret environmental implications. Magnetic susceptibility, saturation isothermal remanent magnetisation and isothermal remanent magnetisation at the backfield of 100 mT and 300 mT were measured. HardIRM %, SIRM/χ and S-ratios were also calculated. Polluted soils showed higher values of magnetic parameters in the superficial soil horizons closer to the roads, plants and urban areas. The lowest values were observed in the deeper horizons of the soil and in the areas least disturbed by human activity. The magnetic results also suggested that the magnetic signal of these soils is mainly influenced by ferrimagnetic magnetite-like minerals and with only a minor contribution from antiferromagnetic carriers (such as hematite minerals). In unpolluted soils, lithogenic contribution is reflected by the enhancement of magnetic susceptibility near parental rock material. Scanning electron microscope images of the topsoil samples revealed the presence of magnetic spherules typical of vehicular exhaust and combustion processes. This evidence suggests that the atmospheric deposition of fly ash is the main reason for the enhancement of the magnetic signal in the topsoil. Chemical analyses showed that the concentration of various heavy metals was higher than the mean background values for Portuguese soils, and higher in superficial soils. Heavy metals showed significant positive correlation with magnetic properties. The conclusions highlight the importance of using environmental magnetism methods and techniques in the evaluation process of soil evolution and pollution history throughout time.
The common sedimentological studies of littoral deposits, namely in the Atlantic coastal sector c... more The common sedimentological studies of littoral deposits, namely in the Atlantic coastal sector comprised between Espinho and Mondego Cape (NW Portugal), are focused on the sand fractions, which results from the fact that the main coastal environments are arenaceous, in spite of the occurrence of silt and clay sediments in the solid load. Two continental areas drain to this coastal sector. The Douro and Vouga watershed drains to the designed as northern sector and southern sector, respectively, with the last one draining to the Atlantic Ocean through Aveiro lagoon, that is connected by an artificial outlet. The fine-grained fraction (lower than 63µm) minerals suites consist mainly in phyllossilicates (F), quartz (Qz), k-feldspars (Fk), plagioclases (P), opal c/ct (Op), zeolites (Z), calcite (C), dolomite (D), anhydrite (An), pyrite (Py) and siderite (Sy). Significant different contents it was found in some minerals between the beach and dune deposits of the coastal sectors considered above. The phyllosilicates and anhydrite show a significant higher content in the beach and dune deposits from the northern sector, while plagioclase, k-feldspar and calcite exhibit significant higher contents in the beach and dune deposits from the southern sector. The observed longshore content evolution, of the most representative minerals identified, make remarkable the nourishment of the Douro and Vouga watersheds and additionally of the coastal sandy formations by erosion. The same content evolution allows concluding that the Douro watershed extends its sedimentological influence until Aveiro lagoon inlet, while Vouga watershed imprints its sedimentary contribution in the coastal deposits away from that morphological accident and to the south direction.
The clay deposit of Vila Nova da Rainha (VNR) is included in the lithostratigraphic formation nam... more The clay deposit of Vila Nova da Rainha (VNR) is included in the lithostratigraphic formation named "Argilas de Tomar", and is located at the lower section of the Tertiary Tagus' river basin. Clay from one quarry is being extracted for the production of construction ceramics. In this work the firing transformations undergone by VNR clays containing quartz, alkaline feldspar, iron oxy-hydroxides, and clay minerals have been studied. Carbonates have not been identified in these raw materials. The clay layers can be subdivided in three groups based upon composition and ceramic properties. The first group, VNR0, is represented by smectite-kaolinite sandy-silty clay, the second group (VNR1 and VNR2) corresponds to illite-kaolinite bearing clay and the third group (VNR3 and VNR4) is represented by illite-smectite silty clay. The firing process involves the formation of hematite and mullite both influencing the technical properties of the fired products. With regards to the ceramic properties assessed at 1100 ºC the first group showed the lowest total shrinkage value (7.35 %) the highest water absorption value (12.2 %) and the lowest mechanical bending strength value (12.0 MPa); the same properties assessed in the second group provided the highest firing shrinkage values (7.0-5.0 %), the lowest values of water absorption (0.1-0.2 %) and relatively high mechanical bending strength values (47.8-48.0 MPa); the third group showed firing shrinkage values within the range 3.5-4.2 %, water absorption values within the range 1.4-4.5 %, and the highest mechanical bending strength values (49.2-52.0 MPa). The results of the ceramic properties being appraised indicate that the raw materials being studied are suitable for the production of high-quality construction ceramics, such as brick, roof tile and rustic floor tile.
Clay mineralogical studies have been undertaken on the OMEX core KSGX40 (164cm long) recovered fr... more Clay mineralogical studies have been undertaken on the OMEX core KSGX40 (164cm long) recovered from the Galicia Muddy Deposit of the continental shelf off Ria de Vigo. The chronology for this work is several intervals of warmth, for instance the Roman Warm Period (•`2500-1950 cal years BP) and the Medieval Warm Period (•`1100 and 700 cal years BP), intercalating cyclic colder events, like the Ice Age Cold Epoch (•`3300-2500 cal years BP) and the Little Ice Age (•`500-150 cal years BP). This work shows the potential of clay minerals to identify weak-amplitude and short climatic changes in Galicia Muddy Deposit.
The site under study (Cortegaça beach) belongs to the Ovar municipality and is part of an extensi... more The site under study (Cortegaça beach) belongs to the Ovar municipality and is part of an extensiveregion characterized by flat terrains, consisting mainly of old beach and dunar deposits. Coastal erosionhad exposed the so called Cortegaça beach formation showing the following three sedimentary sequences,from the basis to the top: 1) greenish sandy clay; 2) sand layers with marked cross-bedded showing ontop a bioturbated podzol; 3) bioturbated beach sand and dune sand. The main goal of the present paper isthe establishment of relationships between heavy metals nature and content with the mineral composition,particularly of the clay component, of those sediments. The study of the fine fraction (less than 38 mm)of forty samples collected along three profiles has been carried out. X-ray diffraction was used for mineralogicaldeterminations, whereas atomic absorption spectrometry was used for the determination of theheavy metals: Cu, Ni, Co, Zn, Pb, Cd, Mn and Cr. Mineralogical studies m...
In the present study, Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Cd concentrations were deter... more In the present study, Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Cd concentrations were determined in the sediments of the KSGX 40 core collected from the Galicia muddy patch (NW Iberian continental shelf). The results were integrated together with textural, mineralogical and micropaleontological (foraminifera) data in order to determine the possible climatic influence on the type of sedimentation that took place in the muddy patch. The geochemical data of the KSGX 40 core suggest that sediment composition and texture were significantly influenced, over the last 5.2 kyr, by the Holocene sea transgression and by climatic oscillations consisting of both relatively temperate/cold periods and relatively warm/wet periods.
Samples taken from pieces of two clays being commercialized for medicinal purposes (alleviation o... more Samples taken from pieces of two clays being commercialized for medicinal purposes (alleviation of gastrointestinal problems, treatment of abscesses, furuncles and wounds, as well as of skin ailments, and cosmetic applications) by saleswomen of natural products at the public market of the town of Praia, in the island of Santiago, archipelago of Cape Verde, were submitted to several analyses, such as, granulometric analysis, mineralogical analysis, chemical analysis, cation exchange capacity and exchangeable cations, and plasticity, in order to find out any scientific justification for the applications referred to. One of the studied clay is composed of dioctahedral illite, and the other clay is composed of dioctahedral smectite, dioctahedral illite and kaolinite. Other analytical data support the capacities of the studied clays to be used as healing materials. These clays as other natural healing clays are traditionally used for internal detoxification (particularly in the gastroint...
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