Análisis litoestratigráfico del keuper urpirenaico central

[email protected] ha estudiado la litoestratigrafía del Keuper surpirenaico central en los afloramientos de dos sectores: las Sierras Marginales (sector sur) y Les Nogueres (sector norte). En el Keuper de las Sierras Marginales se han distinguido tres unidades litológicas: Formación Yesos de Canelles, Formación Yesos de Boix y Formación Arcillas y Carbonatos de Les Avellanes, con una potencia conjunta de 200 a 400 m. En el Keuper de Les Nogueres se han distinguido cuatro unidades litológicas: Formación Arcillas y Carbonatos de Adons, Formación Yesos de Boix, Formación Yesos de Senterada y Formación Arcillas y Carbonatos de Les Avellanes, con una potencia conjunta de más de 200 m. Las litologías principales del Keuper estudiado son yesos, carbonatos y arcillas. A diferencia de lo que ocurre en otras regiones, hay una ausencia total de areniscas. Los yesos presentan litofacies laminada y nodular similares a las de otras regiones, aunque es de destacar el desarrollo de yesos laminados con estructuras de corriente en la Formación Canelles, poco frecuentes o desconocidos en otras regiones. Los carbonatos son de composición dolomítica dominante y están principalmente desarrollados en los niveles basales o superiores de las series. Presentan litofacies de dolomicrita masiva-laminada y foliada, grainstone-wackestone de oolitos o peloides y brechas. Las arcillas son de composición mineral esencialmente illítica, con cantidades variables de clorita e interestratificados clorita-esmectita. Es de destacar la ausencia de minerales de neoformación, que son característicos del Keuper de otras regiones, lo que sugiere un origen esencialmente detrítico para estos depósitos. La correlación entre el Keuper de las Sierras Marginales y Les Nogueres permite identificar tres ciclos evaporíticos: un ciclo inferior, formado por las formaciones Canelles y Adons; un ciclo intermedio, formado por la Formación Boix; y un ciclo superior, formado por las formaciones Les Avellanes y Senterada. El primer ciclo representa una cuenca evaporítica desarrollada sobre las Sierras Marginales, que grada lateralmente hacia el norte a depósitos arcilloso-carbonatados. El segundo ciclo representa una cuenca evaporítica extensa, que cubrió los dos sectores, con mayor subsidencia en las Sierras Marginales que en Les Nogueres. Esta sería la etapa de principal desarrollo de los depósitos evaporíticos (sulfatos y sal) del Keuper estudiado. Durante el tercer ciclo la cuenca evaporítica se desarrolla en Les Nogueres, con sedimentación arcillosa-carbonatada en las Sierras Marginales. Este esquema paleoestratigráfico pone de manifiesto que durante la sedimentación del Keuper surpirenaico ha tenido lugar una progresiva migración de las evaporitas hacia el norte. Posteriormente la cuenca ha sido acortada por el levantamiento del Pirineo.The lithostratigraphy of the south-central Pyrenean Keuper was studied from exposures in two areas: Sierras Marginales (southern area) and Les Nogueres (northern area). Keuper deposits in Sierras Marginales can be grouped in three lithostratigraphic units: Canelles Gypsum Formation, Boix Gypsum Formation and Les Avellanes Claystone and Carbonate Formation, which form together a 200 to 400 m thick sequence. The Keuper deposits of Les Nogueres area can be grouped in four lithostratigraphic units: Adons Claystone and Carbonate Formation, Boix Gypsum Formation, Senterada Gypsum Formation and Les Avellanes Claystone and Carbonate Formation, forming a more than 200 m thick sequence. The studied Keuper is made up of gypsum, carbonates and claystone. Sandstone facies that are common in other regions are lacking. Gypsum displays similar laminated and nodular lithofacies than in other regions of Spain. However, it is significantly a good development of laminated gypsum with tractive structures in the Canelles Fm., which is rare or unknown in other regions. Carbonates, mainly of dolomitic composition, are laminated-massive and foliated mudstones, oolitic or peletoidal grainstonwackestones, and breccias, all of them well developed mainly in the upper and lower Keuper units. Clay minerals in lutites and marls are of dominant illitic composition, with variable amounts of chlorite and interlaid chlorite-smectites. Opposite to other regions the lack of autigenic clay minerals is characteristic of Keuper in this region, which suggest a dominant detrital origin for these deposits. The Keuper correlation between two south-Pyrenean areas allows to recognizing three evaporitic cycles: a lower cycle that comprises the Canelles Gypsum Formation and the Adons Claystone and Carbonate Formation; an intermediate cycle that comprises the Boix Gypsum Formation; and an upper cycle that comprises the Les Avellanes Claystone and Carbonate Formation and the Senterada Gypsum Formation. The first cycle represents an evaporitic basin that developed on the southern area while marginal carbonates deposited towards the north. The second cycle represents a large evaporitic basin that covered both areas. This was the main evaporitic sedimentation in the Keuper, with a large accumulation of sulphates and salt along a basin which subsided more in the southern area than in the northern. During the third cycle evaporites developed mainly on the northern area, while to the south carbonates deposited. This paleogeographic framework evidences that an evaporitic basin surrounded by carbonate deposits shifted towards the north during the Keuper sedimentation. A basin that later was shortened by the Pyrenees uplift

Metodología de reclutamiento y características de una cohorte de jóvenes consumidores habituales de cocaína de tres ciudades españolas (Proyecto Itínere-cocaína)

ResumenFundamentoLos sistemas de información sociosanitaria que monitorizan el consumo de drogas no profundizan en el análisis de las características sociodemográficas y de los patrones de consumo, ni en los factores que condicionan los problemas de salud. Se describe la metodología de reclutamiento y las características de una cohorte de jóvenes consumidores de cocaína.MétodosCohorte prospectiva de 720 consumidores de cocaína que no consumen habitualmente heroína, captados en la comunidad, independientemente de los servicios asistenciales, mediante métodos de referencia en cadena en las áreas metropolitanas de Madrid, Barcelona y Sevilla. Cuestionario administrado por ordenador y parcialmente autoadministrado. Análisis estratificado por ciudad y por frecuencia de consumo de cocaína base.ResultadosEn los últimos 12 meses el 58,8% había consumido cocaína entre 1 y 2 días por semana; el 91,9% habitualmente la había esnifado, un 5,3% fumado y sólo un 2,8% inyectado; el 6,1% la había utilizado la mitad de las veces o más en forma de base. Hubo policonsumo con cannabis (93,6%), éxtasis (73,2%) y anfetaminas (60,6%); un 4,0% se había inyectado alguna droga. Los que habían usado «crack» (22,1%) tenían un menor nivel educativo, un consumo de cocaína más intenso, mayor prevalencia de consumo de otras drogas, en especial opioides, y prevalencia de inyección mucho más alta.ConclusionesEl estudio confirma y completa el perfil sociodemográfico y de consumo ofrecido por los sistemas de información basados en servicios o las encuestas poblacionales, en especial que una gran parte de los consumidores jóvenes son esporádicos y que existen dos subpoblaciones muy diferenciadas según el consumo o no de cocaína base.AbstractBackgroundHealth information systems that monitor drug use do not perform in-depth analyses of sociodemographic characteristics and patterns of use, or of the factors that influence health problems. We describe the recruitment methodology and characteristics of a cohort of young cocaine users.MethodsA prospective cohort of 720 cocaine users who were not regular heroin users, recruited in the community independently of the health services by chain referral methods in the metropolitan areas of Madrid, Barcelona and Seville was studied. A computer-administered and partially self-administered questionnaire was used. A stratified analysis by city and by frequency of base cocaine use was performed.ResultsIn the previous 12 months, 58.8% had used cocaine 1-2 days/week; 91.9% sniffed it regularly, 5.3 smoked it, and only 2.8% injected it; 6.1% had used it at least half the time in the form of base cocaine. Polydrug use was observed with cannabis (93.6%), ecstasy (73.2%) and amphetamines (60.6%). Approximately 4.0% had injected at least one drug. Crack users (22.1%) had a lower educational level, more intensive cocaine use, a higher prevalence of other drug use, especially opioids, and a much higher prevalence of injection.ConclusionsThis study confirms and completes the sociodemographic and drug profile provided by the information systems based on health services or population surveys. The results show that a large proportion of young cocaine users consume the drug sporadically and that two very different subpopulations exist, according to whether or not they use base cocaine

Scientific drilling in the campus: Almera-1 borehole, unraveling urban subsurface geology in Barcelona (Spain)

Almera-1 borehole was drilled to provide a borehole geophysical logging and downhole monitoring research and training facility. Also a main objective was the exploration of the urban subsurface geology adjacent to the Institute of Earth Sciences Jaume Almera (CSIC) in Barcelona the University of Barcelona Pedralbes. Wireline drilling continuous coring was successfully applied to recover cores from the entire section (214m). Since 2011 Almera-1 hole has been extensively used for slim hole logging, coring and monitoring. Total depth was reached after drilling a Quaternary to Paleozoic section. The upper section of Almera-1 hole is cased with PVC and the lowermost is an open hole section within the Paleozoic section. A complete set of geophysical logging measurements and oriented borehole images was acquired with CSIC own slim hole logging equipment both in open hole mode and through the PVC casing. Logging measurements were acquired over the entire section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer.Postprint (published version

Scientific drilling in the campus: Almera-1 borehole, unraveling urban subsurface geology in Barcelona (Spain)

Almera-1 borehole was drilled to provide a borehole geophysical logging and downhole monitoring research and training facility. Also a main objective was the exploration of the urban subsurface geology adjacent to the Institute of Earth Sciences Jaume Almera (CSIC) in Barcelona the University of Barcelona Pedralbes. Wireline drilling continuous coring was successfully applied to recover cores from the entire section (214m). Since 2011 Almera-1 hole has been extensively used for slim hole logging, coring and monitoring. Total depth was reached after drilling a Quaternary to Paleozoic section. The upper section of Almera-1 hole is cased with PVC and the lowermost is an open hole section within the Paleozoic section. A complete set of geophysical logging measurements and oriented borehole images was acquired with CSIC own slim hole logging equipment both in open hole mode and through the PVC casing. Logging measurements were acquired over the entire section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer

Tomografía eléctrica aplicada a la evaluación de depósitos glauberíticos en el área de Montes de Torrero (Zaragoza)

La glauberita es un sulfato sódico que se explota con fines industriales. En el año 2002 en los depósitos evaporíticos miocenos de la formación Yesos y Anhidritas de Zaragoza se encontró glauberita en profundidad en una campaña de sondeos. Mediante la técnica geofísica de la tomografía eléctrica se han llevado a cabo una serie de perfiles de resistividad eléctrica del terreno. Los datos obtenidos en el estudio se han comparado con la información previa de los sondeos y se ha podido constatar que partiendo de estos, es posible obtener información de los depósitos y observar como evolucionan lateralmente. Debido a la importante presencia de encajante no se ha podido definir el rango de valores geoeléctricos de resistividad propios de la glauberita pura pero si se han reconocido estructuras kársticas y deposicionale

Organic matter contents in the evaporitic formations of Iberian Peninsula

More than two hundred lutitic samples belonging to severa/ marine and non-marine evaporitic formations (Triassic to Upper Miocene) in the Iberian Peninsula were studied by the Rock Eval pyrolysis method and gas chromatography in order to document their potentia/ interest as source rocks for hydrocarbons. In general, all samples which are stratigraphically located close to or inter/ayered within sulfate or chloride (halite) layers show negative values. By contrast, sorne lutitic sequences displaying typical pre-evaporitic conditions in the marine Tertiary (Eocene, Messinian) basins give positive value

Variations in sedimentation rates, Llobregat Delta (Barcelona): comparisons with eustatic, climatic and antropic records

Sediment accumulation rates have been calculated for the Llobregat Delta and compared to eustasy, climate and land use. Radiometric ages show slow (less than 1 mm/yr) sediment accumulations between 12180±60 BP (14565±715 cal BP) and ~4100 BP (4500 cal BP) and faster rates (12 to 25 mm/yr) younger than ~4100 BP (4500 cal BP). Within this trend of increasing sediment accumulation rates are two peaks of high sediment accumulation; one occurring during the Visigoth period (VI-VIII century) to Upper Medieval Age (X-XIV century) and the second during the economic recuperation (XVIII century). The initial slow sediment accumulation rate is attributed to high rates of accommodation produced by the rapid Holocene transgression and little sediment supply. Following a slower rate of creation of accommodation space, sediment started to accumulate at the mouth of the river and prograde on the shallow shelf. The pulses in sediment accumulation coincide with and are interpreted to increasing pressure anthropomorphic activity together with peaks of aridit

Facies Architecture of the Llobregat River Quaternary Deltas, Barcelona, Spain

The Llobregat River has accumulated multiple deltas through Quaternary eustatic cycles. The rapid rises and step-wise, relatively slower falls in sea level have produced a bias towards preserving forced regressive system tracks and eroding the high-stand system tracks with the exception of the Holocene delta. Subsurface data indicates that the Quaternary deltas were feed by the Llobregat river and «rieras» derived from Garraf and Collserola, but the sediment was probably redistributed by long-shore currents to form a unique delta front. The Holocene Llobregat River high-stand delta progrades over older fluvial, flood-plain and shoreline deposits equivalent to the older deltas now preserved at the continental margin. A number of paleo-flow channels feeding the older Quaternary deltas illustrate the complexity for the exploitation and protection of groundwater found in these deposit

[The Spanish version of the Short Form 36 Health Survey: a decade of experience and new developments].

OBJECTIVE: The Short Form-36 Health Survey (SF-36) is one of the most widely used and evaluated generic health-related quality of life (HRQL) questionnaires. After almost a decade of use in Spain, the present article critically reviews the content and metric properties of the Spanish version, as well as its new developments. METHODS: A review of indexed articles that used the Spanish version of the SF-36 was performed in Medline (PubMed), the Spanish bibliographic databases IBECS and IME. Articles that provided information on the measurement model, reliability, validity, and responsiveness to change of the instrument were selected. RESULTS: Seventy-nine articles were found, of which 17 evaluated the metric characteristics of the questionnaire. The reliability of the SF-36 scales was higher than the suggested standard (Cronbach's alpha) of 0.7 in 96% of the evaluations. Grouped evaluations obtained by meta-analysis were higher than 0.7 in all cases. The SF-36 showed good discrimination among severity groups, moderate correlations with clinical indicators, and high correlations with other HRQL instruments. Moreover, questionnaire scores predicted mortality and were able to detect improvement due to therapeutic interventions such as coronary angioplasty, benign prostatic hyperplasia surgery, and non-invasive positive pressure home ventilation. The new developments (norm-based scoring, version 2, the SF-12 and SF-8) improved both the metric properties and interpretation of the questionnaire. CONCLUSIONS: The Spanish version of the SF-36 and its recently developed versions is a suitable instrument for use in medical research, as well as in clinical practice