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Sample records for cerro los cardos

  1. La avalancha de rocas del cerro Los Cardos (37°10´S,70°53´O en la región norte de la provincia del Neuquén The rock avalanche of Cerro Los Cardos (37° 10´S, 70° 53´ W in the northern region of the province of Neuquén

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    E.F. González Díaz

    2005-03-01

    Full Text Available Se describe una nueva e importante avalancha de rocas, no reconocida hasta ahora, localizada a unos 25 km al oeste de la población de Andacollo. Muestra dos cicatrices o muescas de desprendimiento, de las cuales la austral es interpretada como la muesca principal de su desprendimiento y se halla al pie del borde occidental de una planicie estructural lávica, sobre cuyo extremo norte se ubica el cerro Los Cardos. Es un complejo movimiento, con numerosas escarpas de arranque internas en la masa movilizada, consideradas secundarias, las que al igual que la principal, tienen una general orientación noroeste-sureste. Su mecánica aparenta haberse iniciado como un movimiento translacional (planar a favor de la disposición casi vertical, con fuerte buzamiento hacia el oeste de las capas de la Formación Lileo. Sin embargo, la disposición espacial (cóncavas que adoptan las distintas muescas de arranque (tanto principales como secundarias, permite sugerir un desarrollo y continuación del movimiento como afín a un deslizamiento rotacional. A partir del desprendimiento austral el movimiento general se orientó hacia el sur, hacia el valle del arroyo Lileo, presumiblemente en sucesivos pulsos, identificables por escarpas de arranque internas. En el correspondiente al septentrional el desplazamiento se dirigió hacia el oeste hacia el valle del arroyo Palao. Con posterioridad el movimiento parece estar controlado por la pendiente de dicho valle hacia la afluencia al arroyo Lileo. La porción distal de sus acumulaciones alcanzó a trepar (run-up, el lateral opuesto del valle del arroyo Palao. La laguna de los Rojos se halla en una depresión supuestamente generada por el deslizamiento y fracturamiento de un bloque rocoso desprendido de la planicie estructural lávica de Los Cardos. Diversos factores intrínsecos, establecieron previamente al fenómeno condiciones favorables para el desprendimiento. Se propone como promotor de la avalancha de rocas a

  2. El recorrido al Cerro Gordo y el ritual tepehuano de las ofrendas en los cerros de la comunidad de San Bernardino de Milpillas

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    Chantal CRAMAUSSEL

    2014-01-01

    Full Text Available El ritual de las ofrendas es una ceremonia propiciatoria de la lluvia que se efectúa al terminar la estación seca en los cerros más altos de la comunidad de San Bernardino de Milpillas Chico, en la Sierra Tepehuana del estado de Durango. A esos rituales distintos de los cató- licos que forman parte del ciclo anual de costumbre concurren las autoridades civiles, los curanderos y miembros del Consejo de ancianos. Es un momento muy importante en el que se refuerza la cohesión de los tepehuanos que tienen un patrón de asentamiento muy disperso, como los demás grupos del norte, pero sus rituales presentan también similitudes con los mesoamericanos.

  3. Cardo Remmeli kodust sai restoran / Svea Aavik

    Index Scriptorium Estoniae

    Aavik, Svea, 1965-

    2009-01-01

    Cardo Remmel avas Pärnus oma kodumaja esimesel korrusel itaalia restorani "Si-Si". Hoone ehitati 1913.-1914. a. arhitekt Erich von Wolffeldti projekti järgi. Ruumid renoveeriti arhitekt Rein Raie ja sisekujundaja Tiiu Pärna nõuandeid järgides

  4. 3-cerro y 4-mundo: los números del banquete en las ofrendas quechuas

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    David Lorente Fernández

    2010-12-01

    Full Text Available Las ofrendas quechuas del sur del Perú son platos alimenticios, banquetes destinados principalmente a la pachamama y los apus, pero también elaborados sistemas matemáticos regidos por operaciones sofisticadas. Sirviéndose de dos números fundamentales, el 3 y el 4, los especialistas rituales son capaces de transmitir mensajes polisémicos. Mediante el número 3 aglutinan clientes, parajes y cerros, en suma, «personas» capaces de interactuar entre sí. El 3 aparece en los k’intus de hojas de coca y en las oraciones que se recitan durante el proceso de realizar la ofrenda. Por el contrario, el número 4 no indica relaciones sino formas espaciales: es un operador geométrico que unifica la servilleta ceremonial (unk’uña, el papel envoltorio y el paquete acabado para representar las cuatro direcciones del mundo y hacer de la ofrenda un mundo en miniatura. Gracias a los dos números el ritualista puede recrear el cosmos, establecer convenios con los dioses y definir nuevas situaciones favorables para la vida de sus clientes.

  5. Measurements of air contaminants during the Cerro Grande fire at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Eberhart, Craig

    2010-08-01

    Ambient air sampling for radioactive air contaminants was continued throughout the Cerro Grande fire that burned part of Los Alamos National Laboratory. During the fire, samples were collected more frequently than normal because buildup of smoke particles on the filters was decreasing the air flow. Overall, actual sampling time was 96% of the total possible sampling time for the May 2000 samples. To evaluate potential human exposure to air contaminants, the samples were analyzed as soon as possible and for additional specific radionuclides. Analyses showed that the smoke from the fire included resuspended radon decay products that had been accumulating for many years on the vegetation and the forest floor that burned. Concentrations of plutonium, americium, and depleted uranium were also measurable, but at locations and concentrations comparable to non-fire periods. A continuous particulate matter sampler measured concentrations that exceeded the National Ambient Air Quality Standard for PM-10 (particles less than 10 micrometers in diameter). These high concentrations were caused by smoke from the fire when it was close to the sampler.

  6. Areas to explore surrounding the Cerro Prieto geothermal field, BC; Areas para exploracion en los alrededores del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar Dumas, Alvaro [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: alvaro.aguilar@cfe.gob.mx

    2009-07-15

    Exploration plays an important role in tapping underground natural resources-whether water, oil, natural gas or minerals. Exploratory data allow us to learn reservoir conditions, increasing probable reserves and reservoir life span. Around the Cerro Prieto geothermal field, BC, and in the Mexicali Valley in general, exploration had almost stopped but recently was resumed by the Studies Division of Comision Federal de ELectricidad (CFE)'s Gerencia de Proyectos Geotermoelectricos. The division sent technical personnel to structurally map the northern and eastern portions of Laguna Salada. The paper offers a general outline of the main zones undergoing exploratory studies-studies perhaps culminating in siting exploratory wells to locate more geothermal resources (and ultimately producing them using binary power plants). CFE also wants to site injection wells west of the current production zone, and this is covered, as well. All activities are meant to increase the productive lifespan of the geothermal reservoir. [Spanish] Cuando se trata de la explotacion de recursos naturales del subsuelo, sea agua, gas, petroleo o minerales, la exploracion juega un papel muy importante, ya que permite conocer las condiciones del yacimiento que pudieran llevar a incrementar las reservas de los recursos explotados y extender su vida util. En las zonas aledanas al campo geotermico de Cerro Prieto, BC, y en general en el Valle de Mexicali, la exploracion estaba practicamente detenida habiendose reactivado a raiz de que la Subgerencia de Estudios de la Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad (CFE) envio personal para realizar mapeos estructurales en las porciones norte y oriente de la Laguna Salada. Este trabajo presenta un panorama general de las areas prioritarias para realizar estudios exploratorios y poder programar, con mas bases, pozos exploratorios enfocados a localizar mas recursos geotermicos, inclusive para generar energia por medio

  7. Los granitos peraluminosos de las Sierras de Vinquis, Cerro Negro y Zapata (Sierras Pampeanas, provincia de Catamarca, Argentina

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    Medina, M. E.

    1992-12-01

    Full Text Available The studied plutons are close to several batholiths of this region, as Sierra de Mazán and other, but with some mineralogical peculiarities. The magmatic cordierite, common in proximate places, is scarce, as sillimanite, while the andalusite is very rare, with few tourmaline. Fluorite and allanite are also typical accasories only in the granites of the Sierra de Zapata. All plutons are peraluminous of potassic tendency, with cortical affinity.The interpretation of the geochemical values distinguishes between granites of different maturity, emplaced under a predominant influence of active margin for Cerro Negro and Vinquis, while the batholith of Zapata has, below these concepts, a marked feature of within plate.The mineralogical associations suggest that the granites of Cerro Negro and Vinquis were emplaced to pressures of 2 kb or less and temperature of 650º C, while the granites of Zapata had done under conditions of lesser pressure, between 1.5 and 2.0 kb and lower temperature, 600-650º C.A grandes rasgos, los plutones estudiados tienen semejanzas con otros del entorno regional, tal como los de la Sierra de Mazán, pero con peculiaridades mineralógicas. La cordierita magmática, que en lugares próximos es muy abundante, es aquí escasa, al igual que la sillimanita, mientras que la andalucita es muy rara y la turmalina poco frecuente. La fluorita y allanita son accesorios comunes y de cierta abundancia sólo en los granitos de la Sierra de Zapata.Todos los plutones son peralumínicos y de tendencia potásica, con neta afinidad cortical. El estudio estadístico de datos geoquímicos seleccionados, permite diferenciar agrupaciones que tienen un reflejo satisfactorio en los plutones caracterizados, por encima de las variaciones de facies. La interpretación de los valores geoquímicos distingue granitos de desigual madurez, emplazados bajo una influencia predominante de margen activo o intraplaca de características continentales, en

  8. El sistema de yacimientos de mamíferos miocenos del Cerro de los Batallones, Cuenca de Madrid: estado actual y perspectivas

    NARCIS (Netherlands)

    Morales, J.; Pozo, M.; Silva, P.G.; Domingo, M.S.; López-Antoñanzas, R.; Álvarez Sierra, A.; Antón, M.; Martín Escorza, C.; Quiralte, V.; Salesa, M.J.; Sánchez, I.M.; Azanza, B.; Calvo, J.P.; Carrasco, P.; García-Paredes, I.; Knoll, F.; Hernández Fernández, M.; Hoek Ostende, van den L.W.; Merino, L.; Meulen, van der A.J.; Montoya, P.; Peigné, S.; Peláez-Campomanes, P.; Sánchez-Marco, A.; Turner, A.; Abella, J.; Alcalde, G.M.; Andrés, M.; DeMiguel, D.; Cantalapiedra, J.L.; Fraile, S.; García Yelo, B.A.; Gómez Cano, A.R.; López Guerrero, P.; Oliver Pérez, A.; Siliceo, G.

    2008-01-01

    The Cerro de los Batallones (Los Batallones Butte) is located in the central-northern area of the Madrid Basin, central Spain. Nine vertebrates localities containing a large variety of mammals of Upper Vallesian Age (Late Miocene) have been found associated with the sediments forming the butte. From

  9. Positron annihilation in cardo-based polymer membranes.

    Science.gov (United States)

    Kobayashi, Y; Kazama, Shingo; Inoue, K; Toyama, T; Nagai, Y; Haraya, K; Mohamed, Hamdy F M; O'Rouke, B E; Oshima, N; Kinomura, A; Suzuki, R

    2014-06-05

    Positron annihilation lifetime spectroscopy (PALS) is applied to a series of bis(aniline)fluorene and bis(xylidine)fluorene-based cardo polyimide and bis(phenol)fluorene-based polysulfone membranes. It was found that favorable amounts of positronium (Ps, the positron-electron bound state) form in cardo polyimides with the 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) moiety and bis(phenol)fluorene-based cardo polysulfone, but no Ps forms in most of the polyimides with pyromellitic dianhydride (PMDA) and 3,3',4,4'-biphenyltetracarboxylic dianhydride (BTDA) moieties. A bis(xylidine)fluorene-based polyimide membrane containing PMDA and BTDA moieties exhibits a little Ps formation but the ortho-positronium (o-Ps, the triplet state of Ps) lifetime of this membrane anomalously shortens with increasing temperature, which we attribute to chemical reaction of o-Ps. Correlation between the hole size (V(h)) deduced from the o-Ps lifetime and diffusion coefficients of O2 and N2 for polyimides with the 6FDA moiety and cardo polysulfone showing favorable Ps formation is discussed based on free volume theory of gas diffusion. It is suggested that o-Ps has a strong tendency to probe larger holes in rigid chain polymers with wide hole size distributions such as those containing cardo moieties, resulting in deviations from the previously reported correlations for common polymers such as polystyrene, polycarbonate, polysulfone, and so forth.

  10. Los marsupiales (Mammalia del Mioceno Superior de la Formación Cerro Azul (Provincia de La Pampa, Argentina

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    Visconti, G.

    2000-04-01

    first lower molar. Microtragulus rusconii (Argirolagida, Argirolagidae is generalized with respect to the other species of this genus in having a less reduced talonid in the m4, and shows closer affinities with M. catamarcensis than with M. reigi. Hyperdidelphys, Lutreolina, Thylatheridium, Achlysictis, and, probably Microtragulus, are common taxa with those of the Valle de Santa María and Puerta de Corral Quemado, in Catamarca province (northwestern Argentina. On the contrary, Pliolestes and Zygolestes constitute exclusive taxa of Cerro Azul Fm. for central Argentina during the Huayquerian Age. The marsupial association recovered from levels of Cerro Azul Fm. is the most abundantly recorded from Upper Miocene levels in South America. Its taxonomic composition confirms previous hypotheses on the important faunal turnover that happened in this continent, as a consequence of the environmental changes occurred since the medial Miocene.Se describe la asociación de marsupiales sudamericanos fósiles de edad Huayqueriense (Mioceno tardío más completa hasta ahora conocida. Los ejemplares fueron exhumados de varias localidades fosilíferas nuevas del centro y norte de la provincia de La Pampa (Argentina central, en sedimentos asignables a la Formación Cerro Azul: Bajo Giuliani, Quehué, Telén, El Guanaco y Laguna Chillhué. El conjunto de las sedimentitas loessoides analizadas en los diferentes afloramientos de esta formación indica la existencia de depósitos lacustres en la base, a los que suprayacen niveles eólicos, ambos con evidencias pedogenéticas. El análisis de estas sedimentitas en cada una de las localidades estudiadas, permitió correlacionarlas en un perfil integrado de la Formación Cerro Azul. Esta formación es correlacionable con la «Formación Epecuén», al menos en la localidad Salinas Grandes de Hidalgo y, probablemente, con los términos superiores de la Formación Arroyo Chasicó. Los marsupiales fósiles exhumados representan la casi

  11. El frente de corrimiento andino al nivel de los cerros Penitentes y Visera (alta Cordillera de Mendoza: aspectos cronológicos y cartográficos

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    Jean-Claude Vicente

    2009-10-01

    Full Text Available El hallazgo de una iportante fauna de invertebrados marinos del Tithoniano superior a espaldas del cerro Penitentes en la secuencia carbonática basal de la primera escama del frente de corrimiento andino, confirma la lógica tectónica de un despegue de esta unidad a nivel del Yeso Principal y lleva a invalidar ciertas correlaciones litoestratigráficas y bosquejos paleogeográficos asignados a la Formación La Manga. Por otro lado, el análisis de algunos perfiles claves en torno al cerro Penitentes entre la quebrada Vargas y el cerro Visera permite presentar una reinterpretación tectónica del sector. Esta se sustenta en el reconocimiento y la diferenciación de las unidades terciarias básicas representadas por los Conglomerados Penitentes (Mioceno inferior y los Aglomerados Santa María (Mioceno superior en una relación muy similar a la descrita anteriormente al norte de Puente del Inca. El estudio permite seguir las interferencias, en un contexto polifásico, entre las reactivaciones del corrimiento Penitentes de piel fina y un cabalgamiento frontal de piel gruesa que repite la secuencia terciaria. La discordancia entre las secuencias terciarias y el emplazamiento de una klippe de Malm sobre los Conglomerados Penitentes del sinclinal del cerro Visera, conduce a otorgar cierta importancia a la fase del final del Mioceno inferior.

  12. Geographic Information System (GIS) Emergency Support for the May 2000 Cerro Grande Wildfire, Los Alamos, New Mexico, USA

    Energy Technology Data Exchange (ETDEWEB)

    C.R.Mynard; G.N.Keating; P.M.Rich; D.R. Bleakly

    2003-05-01

    In May 2000 the Cerro Grande wildfire swept through Los Alamos, New Mexico, burning approximately 17,400 ha (43,000 acres) and causing evacuation of Los Alamos National Laboratory (LANL) and the communities of Los Alamos and White Rock. An integral part of emergency response during the fire was the use of geographic information system (GIS) technology, which continues to be used in support of post-fire restoration and environmental monitoring. During the fire Laboratory GIS staff and volunteers from other organizations worked to produce maps and provide support for emergency managers, including at an emergency GIS facility in Santa Fe. Subsequent to the fire, Laboratory GIS teams supported the multiagency Burned Area Emergency Rehabilitation (BAER) team to provide GIS data and maps for planning mitigation efforts. The GIS teams continue to help researchers, operations personnel, and managers deal with the tremendous changes caused by the fire. Much of the work is under the auspices of the Cerro Grande Rehabilitation Project (CGRP) to promote recovery from fire damage, improve information exchange, enhance emergency management, and conduct mitigation activities. GIS efforts during the fire provided important lessons about institutional matters, working relationships, and emergency preparedness. These lessons include the importance of (1) an integrated framework for assessing natural and human hazards in a landscape context; (2) a strong GIS capability for emergency response; (3) coordinated emergency plans for GIS operations; (4) a method for employees to report their whereabouts and receive authoritative information during an evacuation; (5) GIS data that are complete, backed-up, and available during an emergency; (6) adaptation of GIS to the circumstances of the emergency; (7) better coordination in the GIS community; (8) better integration of GIS into LANL operations; and (9) a central data warehouse for data and metadata. These lessons are important for planning

  13. ESTRATEGIA DE REMONTAJE APLICADA SOBRE EL REGISTRO CERÁMICO DEL SITIO LOS TRES CERROS 1 (DELTA SUPERIOR DEL RÍO PARANÁ / Refitting applied to pottery from Los Tres Cerros 1 site (Upper Delta of Paraná River

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    Violeta Soledad Di Prado

    2014-12-01

    Full Text Available El sitio arqueológico Los Tres Cerros 1 se encuentra ubicado en el departamento Victoria, Entre Ríos, y consiste en una estructura monticular con una compleja historia ocupacional. La abundancia y fragmentación del registro cerámico del sitio, llevaron a aplicar la estrategia de remontajes, con el propósito de reconstruir la historia de vida de las vasijas e identificar las prácticas humanas y los agentes naturales que actuaron en la configuración del depósito. Sobre una muestra del total de tiestos recuperados en la cuadrícula 1, se realizaron 43 remontajes, que unen fragmentos del mismo nivel y de diferentes niveles. Se identificaron semejanzas en las elecciones técnicas similares (i.e., agregado de tiesto molido, aplicación de pigmento y de surco rítmico efectuadas en distintas etapas del proceso de elaboración del número mínimo de vasijas estimado (NMV= 49. Se reconocieron contenedores utilizados sobre el fuego, posiblemente para la cocción, y piezas probablemente empleadas para servir. Por último, se propusieron hipótesis en torno a la integridad del registro y, al menos para el sector superior de la secuencia estratigráfica, se infirió un evento de ocupación que no fue mayormente disturbado en momentos posteriores al descarte.   Palabras clave: alfarería, remontajes, elecciones tecnológicas, prácticas de uso, procesos de formación de sitio.   Abstract Los Tres Cerros 1 archaeological site is located in Victoria department, Entre Ríos province, and it is a mound with a complex occupational history. The abundance and fragmentation of the ceramic record recovered from this site, led to apply the refitting strategy in order to reconstruct the vessels’ life history and identify human practices and natural agents that took part in the site configuration. From a ceramic sample of the whole recovered in grid 1, 43 reassemblies were made, joining sherds from the same level, as well as from different levels. Similar

  14. Cerro Grande Fire Impact to Water Quality and Stream Flow near Los Alamos National Laboratory: Results of Four Years of Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    B.M. Gallaher; R.J. Koch

    2004-09-15

    In May 2000, the Cerro Grande fire burned about 7400 acres of mixed conifer forest on the Los Alamos National Laboratory (LANL), and much of the 10,000 acres of mountainside draining onto LANL was severely burned. The resulting burned landscapes raised concerns of increased storm runoff and transport of contaminants by runoff in the canyons traversing LANL. The first storms after the fire produced runoff peaks that were more than 200 times greater than prefire levels. Total runoff volume for the year 2000 increased 50% over prefire years, despite a decline in total precipitation of 13% below normal and a general decrease in the number of monsoonal thunderstorms. The majority of runoff in 2000 occurred in the canyons at LANL south of Pueblo Canyon (70%), where the highest runoff volume occurred in Water Canyon and the peak discharge occurred in Pajarito Canyon. This report describes the observed effects of the Cerro Grande fire and related environmental impacts to watersheds at and near Los Alamos National Laboratory (LANL) for the first four runoff seasons after the fire, from 2000 through 2003. Spatial and temporal trends in radiological and chemical constituents that were identified as being associated with the Cerro Grande fire and those that were identified as being associated with historic LANL discharges are evaluated with regard to impacts to the Rio Grande and area reservoirs downstream of LANL. The results of environmental sampling performed by LANL, the New Mexico Environment Department (NMED), and U.S. Geological Survey (USGS) after the Cerro Grande fire are included in the evaluation. Effects are described for storm runoff, baseflow, stream sediments, and area regional reservoir sediment.

  15. Cerro prieto y su correlación con los centros de dispersión del Golfo de California

    OpenAIRE

    Francisco Suárez Vidal; Ana Luz Quintanilla Montoya

    1996-01-01

    The Cerro Prieto geothermal tield is located in the Mexicali Valley, Baia California. Tectonically, this northern part of the Gulf of California has been classitied as a spreadmg center, within a transitional area of oceanic to continental conditions. Thermal, geologic-tectonic and magnetic evidente has been used to postulate the existence of a heat source in the area that is associated with magmatic processes, similar to those that occur in a typical oceanic spreading center. Based on the pe...

  16. El Cerro de los Santos: paisaje, negociación social y ritualidad entre el mundo ibérico y el hispano

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    García Cardiel, Jorge

    2015-12-01

    Full Text Available The Iberian shrine of Cerro de los Santos is located next to one of the main roads in the Southeast of the Meseta, in the middle of an area without any town of some entity. This paper aims to highlight its status as a shrine of passage, i.e. as a sacred, safe point where voyagers could rest overnight under the protection of the god. The creation of a statio by the Romans in such a place and its dedication to the goddess Pales provide more circumstantial evidence for this theory. Furthermore, some domestic material contexts can be defined, probably connected with this activity, and clearly different from the well-known ritual contexts of the shrine.La ubicación del santuario ibérico del Cerro de los Santos junto a una de las principales vías de comunicación del sureste meseteño y en el centro de una comarca desprovista de núcleos urbanos de cierta entidad permite subrayar en este artículo su uso continuado como santuario de paso, lugar sacro y seguro al que los caminantes podrían acogerse para pernoctar bajo la protección de la divinidad. La creación de una statio en el enclave en época romana y su dedicación a la diosa Pales no son sino argumentos ulteriores en este sentido. Se identifican además contextos materiales domésticos, distintos de los espacios de culto bien conocidos del santuario, relacionables con esta otra actividad.

  17. Entre el sueño del proyecto y la lógica del lugar. La arquitectura imposible de los cerros de Valparaíso

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    Pablo M. Millán-Millán

    2016-04-01

    Full Text Available Valparaíso es el resultado de la unión de dos ciudades en una: la ciudad vertical de los cerros y la ciudad horizontal del Plan –parte plana–. Esta doble naturaleza ha ido configurando una dualidad obligada a convivir y a establecer un continuo diálogo, acabando en la mayoría de los casos en conflicto. Si por un lado está la ciudad global y ortogonal como resultado de la ocupación europea, por otro lado estará la ciudad onírica agarrada a los acantilados ajena a cualquier orden preestablecido. Cada una de estas dos ciudades irá materializando su propia arquitectura: una real y estandarizada, propia de cualquier periferia de ciudad, y otra imposible. Será esta segunda la que vaya evolucionando en un intento continuo de adaptación y será el propio lugar el encargado de rechazar cualquier construcción que no le sea propia. Esta dicotomía quedará plasmada en numerosos proyectos que nunca verán la luz. El objetivo del artículo será mostrar, a partir de numerosos proyectos inéditos descubiertos en Valparaíso, cómo la arquitectura pensada para los cerros nunca llegó a construirse y fue dando paso a unas construcciones a medio camino entre lo real y lo imaginario, entre la lógica y el sueño.

  18. THE EFFECT OF IRRADIATION ON THE POLYETHERKETONE WITH CARDO GROUP

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wanxi; XU Jun; YAN Meilan; BUO Shuqin; CHEN Tianlu

    1991-01-01

    The effects of irradiation on the polyetherketone with cardo group(PEK-C) were studied. It was found that PEK-C can be crosslinked by irradiation under vacuum, while degradation reaction occurred in PEK-C at room temperature in the presence of air. Moreover, it was also found that Tg value of the crosslinked PEK-C at high temperature is higher than that at room temperature in the case of the same gel content, whose value is about 8 ℃ higher than that of unirradiated PEK-C. The gelation dose of PEK-C at 300 ℃ under vacuum is 1.S× 104Gy, which is about hundred times smaller than that at room temperature.

  19. Estudio de los fundentes utilizados en la metalurgia del cobre en Cerro Muriano (Córdoba durante el período Romano Altoimperial

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    Criado, A. J.

    1996-10-01

    Full Text Available There are no doubts that Hispania was, under the Roman Empire, the most profitable and abundant in resources of all the mining districts exploded by Rome -Hispania, Galia, Danubian Provinces, Dacia, Greece, Asia Minor, Syria, Egypt and North Africa-. Plinius gives the same data and hands many more in the passages dedicated to the mining and the working of the metals in his Natural History. Of all the many mining places that this author refers, the exploiting in copper at Cerro Muriano presents the main interest; of this he says that it was of an unbeatable quality, used, among other applications, to manufacture the very famous "Copper of Campania". The utilization of fusing agents, adapted to the process of copper obtainment, is fundamental for obtaining this high quality. The addition of these fusing agents was very important for the control of the work parameters and to reach the required temperatures. The high purity of the obtained copper shows a very close knowledge of the phenomena involved in the process.

    Durante el Imperio Romano, de todos los distritos mineros explotados por Roma -Hispania, Galia, las provincias danubianas, Dacia, Grecia, Asia Menor, Siria, Egipto y el Norte de África-, sin duda el más rentable y más abundante en recursos era Hispania. Plinio facilita muchos datos en los pasajes dedicados a la minería y el trabajo de los metales en su Historia Natural. Entre los muchos lugares mineros que este autor cita, nos interesa ahora la explotación de cobre en Cerro Muriano, del cual dice que era de una calidad inmejorable, utilizado, entre otras aplicaciones, para fabricar el famosísimo cobre de Campania. Para poder obtener esta elevada calidad, es fundamental la utilización de fundentes adecuados en el proceso de obtención de cobre. La adición de estos fundentes era vital para controlar los parámetros de trabajo y alcanzar las temperaturas requeridas. La elevada pureza del cobre obtenido demuestra un

  20. Volcanismo máfico terciario de la Puna jujeña, los Cerros Negros de Jama.

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    Caffe, Pablo, J.

    2011-12-01

    Full Text Available Tertiary mafic volcanism of the Jujuy Puna, the Cerros Negros de Jama. The Cerros Negros de Jama (23°29’ S – 66°56’ W monogenetic volcanoes belong to a group of eruptive centers that are representative of the most mafic magmatism in the northern Puna during the Cenozoic. They comprise scoria cones and associated lava flows erupted during coeval strombolian and effusive volcanic activity.Aphyric to microporphyritic skeletal textures and microphenocryst assemblages dominated by olivine and/or orthopyroxene suggest inexistent or short residence times in supracrustal magma chambers, as well as magma temperatures higher than 1000º C and near to water saturation conditions. The frequent occurrence of magmatic quartz xenocrysts with different degrees of reaction suggests assimilation of silicic magmas/igneous rocks under variable P-T conditions. A combination of large ascent rates and strong turbulence, together with an overheating of the magmas would have been crucial for this in-route contamination process.The Jama volcanic rocks are basaltic andesites and andesites to trachyandesites which belong to the high-K calcalkaline series. The observed geochemical signature is typical of continental arc magmas, showing negative anomalies of Nb, Ta and P, La/Ta > 30 and Ba/Nb > 25. Two main groups of rocks with different evolution patterns can be distinguished from major and trace element diagrams. Different concentrations of some elements at intermediate degrees of evolution point to variable degrees of incompatibility for them, which in turn may have been caused by magma evolution at different depths from the same or different primary magmas.

  1. El frente de corrimiento andino al nivel de los cerros Penitentes y Visera (alta Cordillera de Mendoza: aspectos cronológicos y cartográficos The Andean thrust front in the Cerros Penitentes and Visera (High Cordillera of Mendoza: chronological and cartographic aspects

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    Jean-Claude Vicente

    2009-10-01

    Full Text Available El hallazgo de una iportante fauna de invertebrados marinos del Tithoniano superior a espaldas del cerro Penitentes en la secuencia carbonática basal de la primera escama del frente de corrimiento andino, confirma la lógica tectónica de un despegue de esta unidad a nivel del Yeso Principal y lleva a invalidar ciertas correlaciones litoestratigráficas y bosquejos paleogeográficos asignados a la Formación La Manga. Por otro lado, el análisis de algunos perfiles claves en torno al cerro Penitentes entre la quebrada Vargas y el cerro Visera permite presentar una reinterpretación tectónica del sector. Esta se sustenta en el reconocimiento y la diferenciación de las unidades terciarias básicas representadas por los Conglomerados Penitentes (Mioceno inferior y los Aglomerados Santa María (Mioceno superior en una relación muy similar a la descrita anteriormente al norte de Puente del Inca. El estudio permite seguir las interferencias, en un contexto polifásico, entre las reactivaciones del corrimiento Penitentes de piel fina y un cabalgamiento frontal de piel gruesa que repite la secuencia terciaria. La discordancia entre las secuencias terciarias y el emplazamiento de una klippe de Malm sobre los Conglomerados Penitentes del sinclinal del cerro Visera, conduce a otorgar cierta importancia a la fase del final del Mioceno inferior.The finding of an important marine invertebrate fauna of Upper Tithonian age at the shoulders of the Penitentes hill, in the basal carbonatic sequence of the first Andean wedge confirms the tectonic logic of a detachment of this unit at the level of the Yeso Principal. This allows invalidating certain lithostratigraphic correlations and paleogeographic sketches ascribed to the La Manga Formation. On the other hand, the analysis of some key sections around the Penitentes hill area between the Quebrada de Vargas and the Cerro Visera, allows presenting a tectonic reinterpretation of the sector. This is based on the

  2. Researching of cardos activity for chronic heart failure treatment in case of concomitant chronic kidney disease (stage V, conventional hemodialysis

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    Chepurina N.G.

    2011-06-01

    Full Text Available Aim: comparative investigation of cardos (antibodies to angiotensin II receptor subtype 1 (AT., C-terminal fragment, diovan (Valsartan or both drug combination effects (changing of clinical picture, physical exertion tolerance and quality of life for treatment chronic heart failure (CHF patients. Methods. 12-month open-label randomized research was performed. CHF patients (NYHA Class l-ll, n=30 with concomitant chronic kidney disease (stage V, conventional hemodialysis were randomized (10 patients in each group for 6-month treatment by cardos (group I, average dose 1,8g/day, diovan (group II, average dose 80mg/dayorboth drug combination (group III, cardos 1,8g/day and diovan 80mg/day. CHD basic treatment was prescribed for all patients. In a 6-month drug crossover between groups I and I was performed, group III was divided into 2 subgroups (subgroup IIIA— cardos, subgroup NIB — diovan followed by next 6-month treatment. Results. Long-term treatment by cardos has improved functional class (NYHA of CHF patients with concomitant chronic kidney disease (stage V, conventional hemodialysis. cardos, diovan and both drug combination have demonstrated improvement of physical exertion tolerance, quality of life and patient clinical status during 6-min walking test. Conclusion. Cardos and diovan have shown the same efficacy. Cardos can be used as real alternative in case of ARA administration necessity

  3. Evaluación del estado de conservación de las microcuencas pertenecientes a los Cerros Orientales de Chía, Cundinamarca, Colombia

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    Arévalo Santos Carolina

    2006-06-01

    Full Text Available El trabajo se realizó en colaboración con la Alcaldía Municipal de Chía, Cundinamarca, Colombia, con el fin de
    aproximarnos al estado de conservación de las microcuencas localizadas sobre la cota de altitud 2.600-3.200 msnm, en las veredas de Yerbabuena y Fusca, donde se identificaron cuatro microcuencas de interés: Mana- Yerbabuena, Coseteja, Fusca y Honda-Pan de Azúcar. El documento final se presenta como un instrumento para el conocimiento de los cerros Orientales de Chía a una escala municipal, cuyo enfoque establece los diferentes tipos de cobertura de vegetación existentes como indicador del estado actual de las microcuencas y evidencia situaciones críticas que pueden propiciar su total degradación. Los resultados permiten concluir que los procesos de transformación son bastante intensos, debido básicamente a la acción antrópica que ha hecho de los procesos urbanísticos el factor de amenaza más significativo, que ha conducido a la pérdida acelerada de la vegetación, apertura de vías de acceso, uso inadecuado de las fuentes hídricas etc. El producto principal de este  análisis es la generación de un mapa de áreas de interés ambiental que proponemos deben ser proyectadas ya sea
    para fines de conservación, restauración, recuperación y áreas cuyo manejo de conflictos debe ser prioridad. La
    importancia de establecer el estado de conservación deriva de la necesidad de proporcionar bases para el desarrollo de planes de manejo ambiental.

  4. Analysis of the automation and control of the well production conditions in the Cerro Prieto geothermal field, Mexico; Analisis de la automatizacion y del control de las condiciones de produccion de los pozos del campo geotermico de Cerro Prieto, BC, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Murillo Zamora, Isaac [Comision Federal de Electricidad, Mexicali, BC, (Mexico); Ocampo Diaz, Juan de Dios [Universidad Autonoma de Baja California, Mexicali, BC, (Mexico); De la Pena Reyna, Gilberto [Comision Federal de Electricidad, Morelia, Michoacan (Mexico)

    2005-12-01

    Through 31 years of development of the Cerro Prieto geothermal field, the number of wells in operation and the distances between them has been increasing. Now there are 150 wells producing a mixture of water and steam at different ratios, depending on the reservoir characteristics (pressure, temperature, depth, etc.) and the operation conditions in the superficial installations (obstructions in the orifice plates diameter, separator pressures, etc.). Therefore, Comision Federal de Electricidad (CFE) has started a pilot plan to handle the automation and control of the operating conditions of production wells, and to install a data production acquisition system. The initial results of the system are in this paper. [Spanish] A traves de los 31 anos de desarrollo del campo geotermico de Cerro Prieto el numero de pozos en operacion asi como la distancia entre ellos se ha estado incrementando. Ahora hay mas de 150 pozos produciendo una cantidad de mezcla de agua y vapor a diferentes rangos, dependiendo de las caracteristicas del yacimiento (presion, temperatura, profundidad, etc.) y de las condiciones de operacion de las instalaciones superficiales (diametros de placas de orificio obstruidos, presion de los separadores, etc.). Como resultado la Comision Federal de Electricidad (CFE) ha dado inicio a un plan de pruebas para llevar a cabo la automatizacion y control de las condiciones de operacion de los pozos productores, e instalar un sistema con equipos para recoleccion de datos del campo, cuyos primeros resultados se presentan en este articulo.

  5. ANÁLISIS DE MACRORRESTOS VEGETALES EN EL SITIO ARQUEOLÓGICO LOS TRES CERROS 1 (ISLA LAS MORAS, VICTORIA, ENTRE RÍOS / Macroremains plant analysis on the Tres Cerros 1 archaeological site (Las Moras island, Victoria, Entre Ríos.

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    María de los Milagros Colobig

    2015-06-01

    Full Text Available El presente trabajo es la primera aproximación al estudio de macrorrestos botánicos en el sitio Los Tres Cerros 1 (isla Las Moras, Victoria, Entre Ríos. Estos restos fueron recuperados mediante la técnica de flotación manual. A partir del material extraído, se exploró el rol de los recursos vegetales y su importancia en la subsistencia en los grupos humanos que habitaron el Delta Superior del río Paraná durante el Holoceno tardío. Se identificaron cinco familias: Solanaceae, Chenopodiaceae, Polygonaceae, Poaceae (Maideae y Oryzoideae y Amaranthaceae. Los estudios permitieron estimar que a partir de 700 ARCP hubo un incremento en la abundancia y variabilidad de recursos vegetales utilizados con respecto a períodos anteriores. La presencia de elementos oryzoides, y graminoides (específicamente Maideae evidenció la existencia de vegetales silvestres y domesticados, aportando nuevos registros sobre el aprovechamiento, manejo y cultivo de las plantas en el área de estudio en el Holoceno tardío.   Abstract  This paper entails the first approach to macrobotanical remains obtained from Los Tres Cerros 1 (Isla Las Moras, Victoria, Entre Ríos. The remains were recovered by means of manual flotation technique. The extracted material allowed us to explore the role played by vegetable resources role and their importance to the subsistence of human populations of Upper Paraná Delta during the late Holocene. Five botanical families were recognized: Solanaceae, Chenopodiaceae, Polygonaceae, Poaceae (Maideae and Ehrhartoideae and Amaranthaceae. Studies estimate that from 700 RCYBP, there was an increase in the abundance and variability of plant resources used, as compared to previous periods. The presence of oryzoides and graminoid elements (specifically Maideae showed the presence of wild and domesticated plants, providing new records on the use of plants in the area studied, in the late Holocene.

  6. PRIMEROS RESULTADOS SOBRE EL USO PREHISPÁNICO DE LOS VEGETALES EN EL SITIO ARQUEOLÓGICO LOS TRES CERROS 1 (VICTORIA, ENTRE RÍOS, ARGENTINA: ANÁLISIS DEL REGISTRO BIOSILÍCEO.

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    Jorge O. Sánchez

    2013-01-01

    Full Text Available El registro de microfósiles biosilíceos posee un alto grado de preservación en distintos contextos naturales y culturales. Por esta razón, el estudio de los fitolitos y otros microrrestos biosilíceos puede contribuir a determinar las condiciones ambientales de las comunidades vegetales que rodearon un sitio arqueológico, así como también identificar especies vegetales domesticadas. En esta contribución se rea- lizó el análisis de fitolitos en el marco de otros bioindicadores de los depósitos superiores de la secuencia sedimentaria antrópica del sitio Los Tres Cerros 1 (LTC1, isla Las Moras, Departamento Victoria, Entre Ríos, Argentina. Los análisis desarrollados permitieron identificar morfotipos silíceos relacionados con la presencia de vegetales silvestres que caracterizan a la unidad fitogeográfica actual del área de em- plazamiento, y morfotipos silíceos asignables a recursos vegetales de interés cultural, pertenecientes a las familias Arecaceae, Cucurbitaceae, y Poaceae (subfamilias Maideae y Oryzoideae. El registro de microfósiles biosilíceos del perfil del sitio LTC1 tiene un cambio neto que puede ser correlacionado con diferentes actividades culturales desempeñadas durante el proceso de construcción del montículo, que tuvo lugar durante ca.1000 - 500 años 14C AP.

  7. Análisis e interpretación de los materiales volcánicos del Cerro de los Frailes (Cabo de Gata. Almería

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    Fernández Soler, J. M.

    1987-12-01

    Full Text Available The formation of Los Frailes volcano had two stages, which produced amphibole andesites (Frailes-I and two-pyroxene andesites (Frailes-II respectively, Iying on the extension of the dacites and andesites of the southernmost Cabo de Gata volcanoes (Revancha-Sabinal. The FRAILES-I stage is discontinuous, and has mainly produced domes and autoclastic breccias, in addition to an intermediate level of pumice-and-ash flow; this unit has some intercalated sedimentary levels. To the NE it is covered by a formation of sedimentary and hydroclastic rocks. The Frailes-II stage is continuous, and has formed some lava flows, the two summit domes, and sorne pyroclastic rocks of scarcely explosive origin. Other volcanic features are some domes and dikes of biotite-amphibole dacites, which affect to the Frailes-I-group; these are the southern continuation of the dacitic volcanic group of Rodalquilar-Rellana-Garbanzal. The generally accepted idea of a succesion in Cabo de Gata of cycles which started very explosively and ended with subvolcanic extrussions (domes does not seem to be very realistic at least in the building of Los Frailes. A review of geochronological data, and the field disposition of the described materials does not discard the hypothesis that the pyroxene andesites of FrailesI-I might have been formed simultaneously or even than later the ignimbritic dacites of the Rodalquilar group.La formación del volcán de Los Frailes se produjo en dos ciclos, de composiciones andesítica anfibólica (Frailes-I y andesitica de dos piroxenos (Frailes-II, apoyadas sobre la prolongación hacia el este de las andesitas y dacitas del extremo sur de Cabo de Gata (edificio de Revancha-Sabinal-Cabo de Gata. El ciclo Frailes-I es discontínuo y ha formado domos y brechas autoclásticas principalmente, mas un nivel intermedio de colada piroclástica pumítica; este ciclo contiene niveles sedimentarios intercalados. Al NE es cubierto por una formación de rocas

  8. Nuevos datos, viejas colecciones: los conjuntos óseos de Cerro Casa de Piedra Cueva 5 (Parque Nacional Perito Moreno, Santa Cruz New data, old collections: Cerro Casa de Piedra 5 bone assemblages (Perito Moreno National Park, Santa Cruz Province, Argentina

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    Mariana E. De Nigris

    2007-12-01

    Full Text Available En este trabajo se presentan los resultados de un nuevo análisis de las colecciones óseas de Cerro Casa de Piedra Cueva 5, emplazado en el Parque Nacional Perito Moreno, provincia de Santa Cruz. Las muestras óseas fueron recuperadas en excavaciones sistemáticas realizadas en la década del ´80 y se ubican temporalmente en el Holoceno medio y tardío (ca. 2500-6500 años. El principal objetivo de este estudio es identificar las posibles variaciones existentes en el aprovechamiento de los recursos faunísticos con el fin de alcanzar un mayor entendimiento de las estrategias que implementaron las sociedades cazadoras recolectoras en torno a la utilización de los recursos de origen animal. Los resultados señalan al guanaco (Lama guanicoe como la especie dominante si bien el huemul (Hippocamelus bisulcus forma parte importante de la dieta. En ambos ungulados se observa un predominio del esqueleto apendicular por sobre el axial y una gran diversidad de marcas de procesamiento compatibles con situaciones de consumo. Sin embargo, a pesar de estas regularidades se han registrado también diferencias en el aprovechamiento de las presas a través del tiempo.This paper presents the results of a new analysis of bone collections from Cerro Casa de Piedra Cueva 5. The archaeological site is a large cave positioned on the north side of a volcanic hill located on the southern bank of Roble river (900 masl in a transitional area between the forest and the shrubby Patagonian steppe within the Perito Moreno National Park, northwest of Santa Cruz, Argentina. The occupational sequence is formed by four stratigraphic layers radiocarbon dated between ca. 2500 and 6500 years BP. Bone samples had been recovered during the 1980s but have received no attention since. The main aim of this paper is to identify continuities and changes in faunal resource consumption to better understand hunter-gatherer strategies during the Middle and Late Holocene. The analyzed

  9. Los depósitos de bentonita de Barda Negra y cerro Bandera, departamento Zapala, provincia del Neuquén, Argentina Bentonite deposits of Barda Negra and Cerro Bandera, Zapala Department, Neuquén Province, Argentina

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    A. Impiccini

    2002-09-01

    Full Text Available Las bentonitas de la región nordpatagónica pueden ser agrupadas en dos distritos mineralogenéticos caracterizados desde el punto de vista geológico, geográfico y estratigráfico. En este trabajo se considera a las bentonitas terciarias localizadas en la región occidental, en el departamento Zapala, provincia del Neuquén. Los depósitos consisten en estratos lenticulares, subhorizontales, de 2 a 15 metros de espesor, la mayoría de ellos aflorantes. Están incluidos en la Formación Collón Curá, una secuencia miocena continental donde alternan tobas y areniscas. Los cuerpos de arcilla son productos de alteración de materiales piroclásticos vítreos en ambientes húmedos confinados, tales como cuerpos de agua someros. Los análisis por difracción de rayos X muestran que prevalece una esmectita dioctaédrica - montmorillonita - como único mineral arcilloso en la mayoría de los depósitos. Los minerales accesorios son cuarzo, feldespato, plagioclasa y cristobalita (ópalo-CT, y en menor proporción, ceolitas y yeso. El Na+ es el ión intercambiable dominante, junto con Ca++, Mg++ y K+. El contenido en Fe2O3 es muy alto. Estas bentonitas son buenos agentes ligantes en arenas de moldeo para fundición, pero sus propiedades reológicas y el test de filtrado no cumplen exactamente con las normas API para lodos de perforación de petróleo.Bentonites from the North Patagonia region can be grouped in two mineralogenic districts distinguishable on geological, geographical, and stratigraphical criteria. In this paper, we consider the Tertiary bentonites located in the western region, Zapala Department, Neuquén Province. The deposits occur in sub-horizontal lenticular beds, 2 to 15 m in thickness, most of which crop out at the surface. They lie within the Collón Curá Formation, a Miocene continental sequence of alternating tuffs and sandstones. The clay bodies are alteration products of pyroclastic glassy materials in confined wet

  10. Reproductive Dynamics of Sterna hirundinacea Lesson, 1831 in Ilha dos Cardos, Santa Catarina, Brazil

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    Hélio Augusto Alves Fracasso

    2014-01-01

    Full Text Available In this work, we intend to describe the reproductive dynamics of Sterna hirundinacea in an island from South Brazil. We studied the reproductive biology of this species in its natural environment and provide data on their growth, survival, and reproductive success in Ilha dos Cardos, Santa Catarina, South Brazil. Samplings were carried out daily on the island throughout the reproductive seasons of 2003, 2005, and 2006 and the different stages of development of the chicks were characterized according to age, length of the beak, and plumage characteristics. We provide a basic equation Lm=167.91 (1-e-0.062t--0.23 to determine the approximate age of individuals using their body mass. The main cause of chick mortality on the island was natural (63.17% in 2003, 81.41% in 2005, and 79.96% in 2006, whereas predation contributed to mortality in a proportion of 38.83% in 2003, 18.59% in 2005, and 20.04% in 2006. The absence in the area of the chicks’ main predator, Kelp gull (Larus dominicanus, the large number of chicks that reached the final stages of development, and their reproductive success demonstrate that Ilha dos Cardos is an important breeding site for the species in southern Brazil.

  11. Hole size distributions in cardo-based polymer membranes deduced from the lifetimes of ortho-positronium

    Science.gov (United States)

    Kobayashi, Y.; Kinomura, A.; Kazama, S.; Inoue, K.; Toyama, T.; Nagai, Y.; Haraya, K.; Mohamed, H. F. M.; O'Rourke, B. E.; Oshima, N.; Suzuki, R.

    2016-01-01

    To clarify the free volume size distributions of the cardo-based polymer membranes, where ortho-positronium (o-Ps) undergoes pick-off annihilation, the o-Ps lifetime distributions were analyzed by the LT9 programme. It was found that the cardo-based polysulfone membrane has much narrower o-Ps lifetime/hole size distributions than the cardo-based polyimide membranes with the 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) moiety. Further, the lifetime/hole size distributions of the cardo-based polymer membranes are appreciably broadened with increasing temperature. This suggests that in these membranes there are holes not only of different sizes but also of different thermal expansion coefficients. It is also shown that in a membrane with a wider hole size distribution the average o-Ps lifetime tends to be longer than would be expected from the correlation between the o-Ps lifetime and the total free volume for common polymers.

  12. Los cuerpos ígneos neógenos del cerro de Las Minas (35,3°S - 69,9°O, Cordillera Principal de los Andes, SO de Mendoza: geología, petrografía y geoquímica The Neogene igneous bodies of the Cerro de las Minas (35.3°S-69.9°W, Main Cordillera of the Andes, SW of Mendoza: geology, petrography and geochemistry

    Directory of Open Access Journals (Sweden)

    M.J. Pons

    2007-06-01

    Full Text Available El cerro de Las Minas (35,3°S - 69,9°O consiste en cuatro unidades ígneas epizonales: plutón diorítico-tonalítico, plutón granodiorítico, plutón granítico y diques -filones capa andesíticos. Estas unidades forman parte del arco magmático neógeno del SO de Mendoza correspondiente a la Andesita Huincán. Intruyen a rocas sedimentarias jurásicas de las Formaciones Puchenque y Auquilco y las que en las cercanías del contacto con los plutones diorítico y granítico, están modificadas a hornfels, calizas recristalizadas y skarns bandeados con mineralización de Fe. Geoquímicamente, constituyen un conjunto de plutones cogenéticos de amplio rango composicional, metaluminosos, subalcalinos con afinidad calcoalcalina y del tipo I, características que son semejantes a las de otros plutones de márgenes convergentes vinculados a skarns de Fe. Han evolucionado por cristalización fraccionada de sus componentes minerales principales (plagioclasa-piroxeno-anfíbol-magnetita-titanita y mezcla localizada entre los magmas diorítico y granodiorítico. Sus patrones de elementos trazas incompatibles y tierras raras son similares a los observados en las rocas ígneas: a del arco volcánico neógeno (Andesita Huincán, b vinculadas a otros skarns de Fe del SO de Mendoza (Hierro Indio y El Kaiser, c del cerro Nevazón (37,5°S perteneciente al arco volcánico paleógeno del NO de Neuquén y, finalmente, d del arco volcánico cuaternario de un sector de la zona volcánica sur (TSVZ (34,5°-37°S de los Andes, emplazados en una corteza continental relativamente delgada (35-50 km. Esto sugiere que las rocas ígneas del cerro de las Minas se formaron a partir de magmas parentales calcoalcalinos y metaluminosos, derivados de una fuente mantélica similar, con escasez o ausencia de granate residual en la fuente.The cerro de las Minas (35.3°S-69.9°W consists of four epizonal igneous units: diorite-tonalite, granodiorite and granite plutons and andesite

  13. Los cuerpos ígneos neógenos del cerro de Las Minas (35,3°S - 69,9°O, Cordillera Principal de los Andes, SO de Mendoza: geología, petrografía y geoquímica

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    M.J. Pons

    2007-06-01

    Full Text Available El cerro de Las Minas (35,3°S - 69,9°O consiste en cuatro unidades ígneas epizonales: plutón diorítico-tonalítico, plutón granodiorítico, plutón granítico y diques -filones capa andesíticos. Estas unidades forman parte del arco magmático neógeno del SO de Mendoza correspondiente a la Andesita Huincán. Intruyen a rocas sedimentarias jurásicas de las Formaciones Puchenque y Auquilco y las que en las cercanías del contacto con los plutones diorítico y granítico, están modificadas a hornfels, calizas recristalizadas y skarns bandeados con mineralización de Fe. Geoquímicamente, constituyen un conjunto de plutones cogenéticos de amplio rango composicional, metaluminosos, subalcalinos con afinidad calcoalcalina y del tipo I, características que son semejantes a las de otros plutones de márgenes convergentes vinculados a skarns de Fe. Han evolucionado por cristalización fraccionada de sus componentes minerales principales (plagioclasa-piroxeno-anfíbol-magnetita-titanita y mezcla localizada entre los magmas diorítico y granodiorítico. Sus patrones de elementos trazas incompatibles y tierras raras son similares a los observados en las rocas ígneas: a del arco volcánico neógeno (Andesita Huincán, b vinculadas a otros skarns de Fe del SO de Mendoza (Hierro Indio y El Kaiser, c del cerro Nevazón (37,5°S perteneciente al arco volcánico paleógeno del NO de Neuquén y, finalmente, d del arco volcánico cuaternario de un sector de la zona volcánica sur (TSVZ (34,5°-37°S de los Andes, emplazados en una corteza continental relativamente delgada (35-50 km. Esto sugiere que las rocas ígneas del cerro de las Minas se formaron a partir de magmas parentales calcoalcalinos y metaluminosos, derivados de una fuente mantélica similar, con escasez o ausencia de granate residual en la fuente.

  14. Los depósitos de bentonita de Barda Negra y cerro Bandera, departamento Zapala, provincia del Neuquén, Argentina

    Directory of Open Access Journals (Sweden)

    A. Impiccini

    2002-09-01

    Full Text Available Las bentonitas de la región nordpatagónica pueden ser agrupadas en dos distritos mineralogenéticos caracterizados desde el punto de vista geológico, geográfico y estratigráfico. En este trabajo se considera a las bentonitas terciarias localizadas en la región occidental, en el departamento Zapala, provincia del Neuquén. Los depósitos consisten en estratos lenticulares, subhorizontales, de 2 a 15 metros de espesor, la mayoría de ellos aflorantes. Están incluidos en la Formación Collón Curá, una secuencia miocena continental donde alternan tobas y areniscas. Los cuerpos de arcilla son productos de alteración de materiales piroclásticos vítreos en ambientes húmedos confinados, tales como cuerpos de agua someros. Los análisis por difracción de rayos X muestran que prevalece una esmectita dioctaédrica - montmorillonita - como único mineral arcilloso en la mayoría de los depósitos. Los minerales accesorios son cuarzo, feldespato, plagioclasa y cristobalita (ópalo-CT, y en menor proporción, ceolitas y yeso. El Na+ es el ión intercambiable dominante, junto con Ca++, Mg++ y K+. El contenido en Fe2O3 es muy alto. Estas bentonitas son buenos agentes ligantes en arenas de moldeo para fundición, pero sus propiedades reológicas y el test de filtrado no cumplen exactamente con las normas API para lodos de perforación de petróleo.

  15. La política pública para los cerros orientales de Bogotá: Una revisión en perspectiva y comentada

    Directory of Open Access Journals (Sweden)

    Ivonne Alexandra Bohu00F3rquez Alfonso

    2008-01-01

    Full Text Available Desde los años setenta diferentes entidades de la administración pública han planteado intervenciones sobre el espacio natural denominado Reserva Forestal Protectora Bosque Oriental de Bogotá, con la intención de preservarlo frente a las alteraciones de las que venía siendo objeto históricamente. Sin embargo, todas estas intervenciones fueron infructuosas debido a que nunca se integró la visión urbana de este problema ambiental. Las nuevas propuestas de política pública, reproducen dicha tendencia, llevando irrefrenablemente al fracaso de la política pública y a perpetuar las tendencias del mercado inmobiliario.

  16. Seismological studies at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Majer, E.L.; McEvilly, T.V.; Albores, A.; Diaz, S.C.

    1980-01-01

    A radio-telemetered 12-station seismographic network was operated in a dense-array configuration over the Cerro Prieto field as shown in Fig. 1. Horizontal and vertical 4.5-Hz geophones were deployed with interstation distances of order 1 km in a multi-purpose survey for microearthquake occurrence and possible anomalies in P- and S-wave velocities and attenuation associated with the field. Although data obtained thus far are limited, attenuation and velocity studies at Cerro Prieto show anomalies related to the production area. This suggests that these data might be useful for delineating the field boundaries. 16 refs.

  17. Overview of Cerro Prieto studies

    Energy Technology Data Exchange (ETDEWEB)

    Lippmann, M.J.

    1983-01-01

    The studies performed on the Cerro Prieto geothermal field, Mexico, since the late 1950's are summarized. Emphasis is given to those activities leading to the identification of the sources of heat and mass, the fluid flow paths, and the phenomena occurring in the field in its natural state and under exploitation.

  18. Geothermal drilling in Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez A., Bernardo

    1982-08-10

    The number of characteristics of the different wells that have been drilled in the Cerro Prieto geothermal field to date enable one to summarize the basic factors in the applied technology, draw some conclusions, improve systems and procedures, and define some problems that have not yet been satisfactorily solved, although the existing solution is the best now available. For all practical purposes, the 100 wells drilled in the three areas or blocks into which the Cerro Prieto field has been divided have been completed. Both exploratory and production wells have been drilled; problems of partial or total lack of control have made it necessary to abandon some of these wells, since they were unsafe to keep in production or even to be used for observation and/or study. The wells and their type, the type of constructed wells and the accumulative meters that have been drilled for such wells are summarized.

  19. The Cerro Grande Fire - From Wildlife Modeling Through the Fire Aftermath

    Energy Technology Data Exchange (ETDEWEB)

    Rudell, T. M. (Theresa M.); Gille, R. W. (Roland W.)

    2001-01-01

    The Cerro Grande Fire developed from a prescribed burn by the National Park Service at Bandelier National Monument near Los Alamos, New Mexico. When the burn went out of control and became a wildfire, it attracted worldwide attention because it threatened the birthplace of the atomic bomb, Los Alamos National Laboratory (LANL). Was LANL prepared for a fire? What lessons have been learned?

  20. Reproductive success of South American terns (Sterna hirundinacea from Cardos Islands, Florianópolis, SC, Brazil

    Directory of Open Access Journals (Sweden)

    Hélio A.A. Fracasso

    2012-06-01

    Full Text Available Sterna hirundinacea (Lesson, 1831 is a migratory seabird that breeds in the Pacific Coast (from Peru to Chile and along the Atlantic coast of South America from Espírito Santo (Brazil to Terra del Fuego (Argentina. This paper describes the reproductive success of South American Terns on Cardos Island, Florianopolis, Brazil in the breeding seasons of 2003, 2005 and 2006. The colony was formed in mid-May in 2003 and early April in other years, with the total number of nests ranging from 1,852 in 2006 to 2,486 in 2005. Hatching success was estimated at 76.39% in 2006, 62.73% in 2003 and 41.1% in 2005, the lowest value that could be attributed to predation by hawks Caracara plancus, lizards Tupinambis merianae and black vulture Coragyps atratus. The chicks hatched in July in 2003, and in June 2005 and 2006, and fledging success was 50.94%, 35.96 and 53.47% respectively. Cardos Island has been constantly used as a breeding site by South American Terns, and therefore represents an important area for conservation of this species. This success could be attributed to low pressure of Kelp gulls (Larus dominicanus, the main predator of seabirds along the Brazilian coast.Sterna hirundinacea (Lesson, 1831 é uma ave migratória que nidifica na costa do Pacífico (do Peru ao Chile e ao longo do Atlântico Sul do Espírito Santo (Brasil até a Terra do Fogo (Argentina. Este trabalho descreve o sucesso reprodutivo do trinta-réis do bico-vermelho na ilha dos Cardos, Florianópolis, Brasil, durante as temporadas reprodutivas de 2003, 2005 e 2006. A formação da colônia ocorreu em maio de 2003 e inicio de abril nos outros anos, com um total de ninhos variando entre 1.852 em 2006 a 2.486 em 2005. O sucesso de incubação foi estimado em 76,39% (2006, 62,73% (2003 e 41,1% em 2005, sendo que os menores valores puderam ser atribuídos a predação dos gaviões Caracara plancus, lagartos Tupinambis merianae e urubus Coragyps atratus. As primeiras eclosões foram

  1. Evolución petrotectónica del distrito minero Cerro Áspero y modelo de emplazamiento de los depósitos wolframíferos, Córdoba Petrotectonic evolution of the Cerro Aspero mining district and emplacement model of the wolframiferous deposits, Córdoba

    Directory of Open Access Journals (Sweden)

    D. Mutti

    2005-03-01

    Full Text Available La geología relacionada con la intrusión granítica Cerro Áspero expone en el faldeo oriental de la sierra de Comechingones, mineralización metalífera diseminada y en brechas hidráulicas, conectada genéticamente a un grupo minero integrado por un sistema de enjambres de venas, vetas y mantos cuarzosos con direcciones NNO, ONO y N. La comarca presenta polimetamorfismo y al menos, dos eventos de cizallamiento simple (D3 y D4 y estructuras penetrativas (S2, S3 y S4 que se desarrollaron desde el Pampeano hasta el Famatiniano inclusive, favoreciendo la intrusión anorogénica del batolito Cerro Áspero a partir del Devónico tardío. Como consecuencia del evento magmático fueron reactivadas las estructuras, movilizando fluidos hidrotermales por las anisotropías del terreno y debajo de un nivel de anfibolitas macizo que actuó como una barrera impermeable. La acción de un esfuerzo máximo s1 (330º contribuyó al desarrollo del sistema mineralizado siguiendo el patrón de fracturamiento del modelo de Riedel y propició la construcción del lineamiento mineral principal en una faja de cizalla simple dextral de posición 285º (S5. El fluido magmático - hidrotermal evolucionó mediante numerosos pulsos de ruptura y apertura de las inhomogeneidades rocosas, con sellado de cavidades por mecanismos de cierre con fracturamiento y relleno y disolución por presión. Estos mecanismos precipitaron sílice con hábito fibroso y reconcentraron elementos metálicos bajo un régimen de tracción y presión de fluido de poro estimada en 195 MPa. La edad de la mineralización de uno de sus estadios fue determinada en 343,8 ± 10,8 Ma, mediante una datación K/Ar en muscovita.Metalliferous mineralization, disseminated and in hydraulic breccias, in connection with a mining group composed of three swarm systems of quartz veinlets, veins and sills striking NNW, WNW and N, is exposed in the geological setting related to the Cerro Aspero granitic intrusion

  2. “La parte alta del cerro es para los pequeños mineros”. Sobre la vigencia del régimen minero especial para Marmato y su influencia en la construcción de territorialidad

    Directory of Open Access Journals (Sweden)

    Gloria Patricia Lopera Mesa

    2015-12-01

    Full Text Available Este artículo examina las circunstancias que motivaron la expedición de un régimen especial para las minas de Marmato a mediados del siglo XX, el cual reserva la parte alta del cerro para el ejercicio de la pequeña minería. Asimismo, explora la vigencia de dichas normas y la manera en que ellas han influido la construcción de territorialidad y el desarrollo de una forma de vida en torno al ejercicio de la pequeña minería tradicional.

  3. Del valle al cerro: el sitio del Cerro Zapotecas durante el Epiclásico

    OpenAIRE

    Salomón Salazar, María Teresa

    2008-01-01

    El objetivo de esta tesis es definir qué tipo de asentamiento era el Cerro Zapotecas durante el periodo Epiclásico (600-900 d.C.), ubicado a escasos tres kilómetros de Cholula. Los antecedentes de investigación en este sitio lo señalan como un centro focal de las actividades del valle de Puebla-Tlaxcala durante la transición del Clásico al Posclásico. Esta investigación llevó a cabo un nuevo recorrido de superficie con el cual se documentó la composición arquitectónica y ...

  4. Santuarios prehispánicos identificados sobre cimas de cerros en Aguascalientes, México

    OpenAIRE

    Macías Quintero, Juan Ignacio; Villagrana Prieto, Citlallitl Selene

    2016-01-01

    Este trabajo considera la presencia de estructuras arqueológicas dispuestas sobre la cima de cerros en la región Centro-Norte de México, con énfasis en el valle del río Verde-San Pedro, Aguascalientes. Regularmente, los sitios dispuestos en cerros aislados y cimas escarpadas se han contemplado como fortificaciones que reflejaban conflictos e inestabilidad. Sin embargo, hemos identificado que estos asentamientos podrían ser de santuarios que, junto con otros elementos naturales y culturales (p...

  5. ¿Quién está contra quién en los cerros orientales de Bogotá? La perspectiva local desde el barrio la Cecilia = Who is against who in the eastern hills of Bogotá? The local perspective from the neighborhood of la Cecilia

    Directory of Open Access Journals (Sweden)

    Ana María López Ortego

    2016-09-01

    Full Text Available Este trabajo aborda las controversias medioambientales, jurídicas y habitacionales que confluyen en el área de reserva medioambiental de los Cerros Orientales de Bogotá. La lógica socio-urbanística de la ciudad -ligada a las urbanizaciones piratas y la invasión-; los movimientos migratorios -acentuados por el conflicto armado- y la falta de definición de una política pública clara en los últimos 30 años, ha desembocado en un conflicto entre pobladores, organizaciones civiles de defensa del medioambiente, empresas privadas e instituciones públicas, mediados casi exclusivamente por resoluciones judiciales puntuales. Este trabajo recoge -a través de fuentes secundarias- las que se consideran principales iniciativas y acciones de gobierno impartidas de arriba a abajo (Top Down e investiga -a través de fuentes primarias recogidas en el barrio La Cecilia-, las percepciones territoriales e iniciativas de acción comunitaria de abajo a arriba (Bottom up, indagando en los estériles procesos de diálogo entre estas dos formas de hacer ciudad.This paper addresses the environmental, legal and housing disputes that converge in the environmental reserve located at the Cerros Orientales (eastern hills of Bogota. The socio-urban logic of the city -linked to pirate developments and invasion-, the migration flows -emphasized by the armed conflict- and the lack of definition of a clear public policy for the last 30 years, has led to a conflict between residents, civil environmental protection organizations, private companies and public institutions in which almost only specific judgments have interceded. This paper duly reflects -through secondary sources- those considered main government initiatives and actions implemented with a top-down approach and it investigates -through primary sources collected in the neighborhood La Cecilia- the bottom-up community action initiatives and territorial perceptions, looking into

  6. Synthesis and characterization of sulfonated cardo poly(arylene ether sulfone)s for fuel cell proton exchange membrane application

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.M.; Jang, H.H.; Lim, Y.D.; Seo, D.W.; Kim, W.G. [Department of Applied Chemistry, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, T.H.; Hong, Y.T. [Energy Material Research Center, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Kim, D.M. [Material Engineering and Science, Hongik Univ, Jochiwon-eup, Yeongi-gun, Chungnam (Korea, Republic of)

    2012-12-15

    Sulfonated cardo poly(arylene ether sulfone)s (SPPA-PES) with various degrees of sulfonation (DS) were prepared by post-sulfonation of synthesized phenolphthalein anilide (PPA; N-phenyl-3,3'-bis(4-hydroxyphenyl)-1-isobenzopyrolidone) poly(arylene ether sulfone)s (PPA-PES) by using concentrated sulfuric acid. PPA-PES copolymers were synthesized by direct polycondensation of PPA with bis-(4-fluorophenyl)-sulfone and 4,4'-sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA-PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT-IR) spectroscopy, {sup 1}H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA-PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA-PES membranes was in the range of 20-72%, compared with 28% for Nafion 211 registered. The SPPA-PES membranes showed proton conductivities of 23-82 mS cm{sup -1}, compared with 194 mS cm{sup -1} for Nafion 211 registered, under 100% relative humidity (RH) at 80 C. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Evolución petrotectónica del distrito minero Cerro Áspero y modelo de emplazamiento de los depósitos wolframíferos, Córdoba

    Directory of Open Access Journals (Sweden)

    D. Mutti

    2005-03-01

    Full Text Available La geología relacionada con la intrusión granítica Cerro Áspero expone en el faldeo oriental de la sierra de Comechingones, mineralización metalífera diseminada y en brechas hidráulicas, conectada genéticamente a un grupo minero integrado por un sistema de enjambres de venas, vetas y mantos cuarzosos con direcciones NNO, ONO y N. La comarca presenta polimetamorfismo y al menos, dos eventos de cizallamiento simple (D3 y D4 y estructuras penetrativas (S2, S3 y S4 que se desarrollaron desde el Pampeano hasta el Famatiniano inclusive, favoreciendo la intrusión anorogénica del batolito Cerro Áspero a partir del Devónico tardío. Como consecuencia del evento magmático fueron reactivadas las estructuras, movilizando fluidos hidrotermales por las anisotropías del terreno y debajo de un nivel de anfibolitas macizo que actuó como una barrera impermeable. La acción de un esfuerzo máximo s1 (330º contribuyó al desarrollo del sistema mineralizado siguiendo el patrón de fracturamiento del modelo de Riedel y propició la construcción del lineamiento mineral principal en una faja de cizalla simple dextral de posición 285º (S5. El fluido magmático - hidrotermal evolucionó mediante numerosos pulsos de ruptura y apertura de las inhomogeneidades rocosas, con sellado de cavidades por mecanismos de cierre con fracturamiento y relleno y disolución por presión. Estos mecanismos precipitaron sílice con hábito fibroso y reconcentraron elementos metálicos bajo un régimen de tracción y presión de fluido de poro estimada en 195 MPa. La edad de la mineralización de uno de sus estadios fue determinada en 343,8 ± 10,8 Ma, mediante una datación K/Ar en muscovita.

  8. Geohydrology of the Cerro Prieto geothermal aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez R, J.; de la Pena L, A.

    1981-01-01

    The most recent information on the Cerro Prieto geothermal aquifer is summarized, with special emphasis on the initial production zone where the wells completed in the Alpha aquifer are located. These wells produce steam for power plant units 1 and 2. Brief comments also are made on the Beta aquifer, which underlies the Alpha aquifer in the Cerro Prieto I area and which extends to the east to what is known as the Cerro Prieto II and Cerro Prieto III areas. The location of the area studied is shown. The Alpha and Beta aquifers differ in their mineralogy and cementing mineral composition, temperatures, and piezometric levels. The difference in piezometric levels indicates that there is no local communication between the two aquifers. This situation has been verified by a well interference test, using well E-1 as a producer in the Beta aquifer and well M-46 as the observation well in the Alpha aquifer. No interference between them was observed. Information on the geology, geohydrology, and geochemistry of Cerro Prieto is presented.

  9. Update of the conceptual geological model for the geothermal reservoir in Cerro Prieto, BC; Actualizacion del modelo geologico conceptual del yacimiento geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Lira Herrera, Hector [Comision Federal de Electricidad, Mexicali, B.C., (Mexico)

    2005-06-01

    noroeste de Mexico durante el Terciario Superior, en el area de Cerro Prieto dio como resultado la formacion de una cuenca de tipo medio graben, entre las fallas Cerro Prieto Imperial (Cuenca Cerro Prieto), en la que se interpreta la existencia de fallas listricas con direccion predominante noroeste-sureste y noreste-suroeste, que se escalonan en forma general al NE. La zona de debilidad cortical generada durante el Terciario permitio el emplazamiento de un intrusito de composicion basica dentro de la cuenca tectonica, el cual ha sido asociado con una anomalia magnetica, denominada Nuevo Leon; este intrusivo ha sido alimentado por nuevas instrusiones magmaticas originadas por la actual tectonica extensional del Golfo de California. Las rocas mas antiguas identificadas en la zona estan compuestas por gneiss y esquistos de biotita de edad Permico-Jurasico, y tonalitas del Jurasico-Cretacico que estan en contacto con granitos del Cretacico, que en conjunto representan el basamento de la region. La columna litologica en el subsuelo de la cuenta tectonica de Cerro Prieto esta formada por un basamento compuesto por granitos del Cretacico; un paquete arcilloso representado por lutitas grises con intercalaciones de areniscas, lutitas cafes del Terciario y lodolitas, con un espesor promedio de 2700 m, que descansan sobre el basamento; y, finalmente sedimentos clasticos de edad Cuaternaria producto del material depositado por el Rio Colorado y los abanicos aluviales de la sierra Cucapa, compuestos por gravas, arenas y arcillas que cubren el paquete de lutitas, alcanzando un espesor promedio de 2500 m. Los fluidos que alimentan al yacimiento geotermico son calentados al pasar por la zona donde se localiza el intrusivo basico (fuente de calor) y migran a traves de las fallas listricas hacia estratos permeables (areniscas), que se localizan dentro del paquete de lutitas grises terciarias.

  10. Recent activities at the Cerro Prieto field

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, E. H.; Dominguez, A.B.; Lippmann, M.J.; Manon, M.A.; Schroeder, R.C.; Witherspoon, P.A.

    1978-01-01

    The purpose of this paper is to describe some of the latest activities of interest to reservoir engineers at the Cerro Prieto geothermal field. Special emphasis is given to the wells drilled in 1978 for exploration purposes and to provide steam to the existing and future power plants. The present power output is 75MW. Two additional 37.5MW units are scheduled to go on line in March and May 1979, while the total generating capacity at Cerro Prieto will reach about 400MW in 1985. Additional information is available in a number of papers in References 1 and 2.

  11. Material progress at Cerro Prieto, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, A.M.

    1978-01-01

    A brief general description is presented about the principal problems observed on the materials used in the Cerro Prieto geothermal project. These include those problems that have been observed in drill pipes, well casing separation equipment and conduction pipes for geothermal water and steam as well as the problems observed in geothermal power plant materials.

  12. El cardo, el ave y la verdad. Entrevista con el pintor Antonio López

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Peynot

    2016-01-01

    Full Text Available Antonio López es reconocido como uno de los más grandes pintores actuales por numerosas instituciones y por un público muy amplio. Al escoger pintar su entorno más cercano, de manera realista y sin imponer siquiera un estilo, supo que su camino sería difícil y solitario, lejos de los críticos de arte, curadores, galeristas y otros actores de la escena contemporánea. De la fidelidad de su mirada nació una obra, y de esta obra nació el pintor, que nos habla en esta entrevista, al horizonte de una verdad. Entre otros reconocimientos Antonio López recibió el Premio Príncipe de Asturias de las Artes en 1985 y el Premio Velázquez de Artes Plásticas en 2006.

  13. Exploration and development of Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Teilman, M.A.; Cordon, U.J.

    1981-01-01

    A brief retrospective of the exploration and field model development at Cerro Prieto are presented. Representative field models are presented for each of the work phases. These models demonstrate how the concept of the field evolved - from a small 2 km/sup 2/ area with a relatively unknown reservoir configuration - to a geothermal resource area over 20 km/sup 2/ where the hydrothermal processes and structural environment are being studied in detail. A model integrating information from these studies was developed.

  14. Geología de la región del Cerro Guanaquero, Río Diamante, Mendoza Geology of Cerro Guanaquero region, Diamante River, Mendoza

    OpenAIRE

    Federico Fuentes; Ramos,Victor A.

    2008-01-01

    El estudio realizado presenta nuevos datos sobre un sector poco conocido de la Cordillera Principal de Mendoza, en la alta cuenca del río Diamante en las adyacencias del cerro Guanaquero, y los primeros datos geocronológicos de sus rocas volcánicas. Las unidades geológicas presentes en el área se dividen en cuatro grupos principales: secuencias sedimentarias mesozoicas marinas y continentales intensamente plegadas y falladas; intrusivos y volcanitas intermedias de edad neógena; rocas volcánic...

  15. Minimal thermodynamic conditions in the reservoir to produce steam at the Cerro Prieto geothermal field, BC; Condiciones termodinamicas minimas del yacimiento para producir vapor en el campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez; Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2009-01-15

    Minimal thermodynamic conditions in the Cerro Prieto geothermal reservoir for steam production are defined, taking into account the minimal acceptable steam production at the surface, considering a rank of mixed-enthalpies for different well-depths, and allowing proper assessments for the impacts of the changes in fluid reservoir pressure and enthalpy. Factors able to influence steam production are discussed. They have to be considered when deciding whether or not to drill or repair a well in a particular area of the reservoir. These evaluations become much more relevant by considering the huge thermodynamic changes that have occurred at the Cerro Prieto geothermal reservoir from its development, starting in 1973, which has lead to abandoning some steam producing areas in the field. [Spanish] Las condiciones termodinamicas minimas del yacimiento geotermico de Cerro Prieto, BC, para producir vapor se determinan tomando en cuenta la minima produccion de vapor aceptable en superficie, considerando un rango de entalpias de la mezcla y para diferentes profundidades de pozos, lo que permite valorar adecuadamente el impacto de la evolucion de la presion y entalpia del fluido en el yacimiento. Se discuten los factores que pueden afectar la produccion de vapor, los cuales se deben tomar en cuenta para determinar la conveniencia o no de perforar o reparar un pozo en determinada zona del yacimiento. Estas evaluaciones adquieren gran relevancia al considerar los enormes cambios termodinamicos que ha presentado el yacimiento geotermico de Cerro Prieto, como resultado de su explotacion iniciada en 1973, lo que ha llevado a abandonar algunas zonas del campo para la produccion de vapor. Palabras Clave: Cerro Prieto, entalpia, evaluacion de yacimientos, politicas de explotacion, presion, produccion de vapor.

  16. Geologic model of the Cerro Prieto geothermal field

    Science.gov (United States)

    Halfman, S. E.; Howard, J. H.; Vonderhaar, S. P.

    1982-09-01

    One of the tasks under the Mexican-American cooperative agreement is the comprehensive geologic study of the Cerro Prieto geothermal field. Using logs from over seventy deep wells as the basic source of information on the subsurface geology, a working model of the Cerro Prieto geothermal field is developed.

  17. Materiales del Poblado de las Paredejas en el Cerro del Berrueco. Una Nueva Arracada

    Directory of Open Access Journals (Sweden)

    Carlos PIÑEL

    2009-10-01

    Full Text Available Queremos dar a conocer con esta nota el interesante hallazgo de una arracada de oro en el yacimiento de «Las Paredejas» o «Santa Lucía», en el Cerro del Berrueco, así como de otros objetos, procedentes del mismo lugar, que quizá nos acerquen a un conocimiento de la joyería occidental durante la 2.a Edad del Hierro en la Península y por otra parte a una mayor aclaración del conjunto arqueológico que constituye el Cerro del Berrueco, dos de cuyos poblados fueron estudiados por Maluquer: el yacimiento de «La Mariselva», situado en la ladera meridional del Berroquillo, perteneciente al Bronce I y II y el del «Canoho Enamorado», situado este último en la parte alta del Cerro y desarrollándose durante la 1.a Edad del Hierro, a partir de cuya fecha surgen los poblados que se localizan en la base.

  18. Archaeological fieldwork in the Bronze Age site of Cerro de la Encina (Monachil, Granada

    Directory of Open Access Journals (Sweden)

    Aranda Jiménez, Gonzalo

    2005-06-01

    Full Text Available New archaeological fieldwork has been carried out from November 2003 to May 2004 in the Bronze Age site of Cerro de la Encina, due to the interest of the regional government of Andalusia in displaying the settlement for visitors. The aim of this fieldwork has been the systematic excavation of a large settlement area partially known thanks to the excavations developed at the beginning of 1980s. A first toccupation period belonging to the Argaric Culture has been documented, highlighting specially the funerary ritual characterized by individual inhumations located below dwellings. After a gap in the occupation of the settlement a new social group belonging to the Late Bronze Age Culture of Southeast of Spain inhabits the Cerro de la Encina.

    El interés de la Consejería de Cultura de la Junta de Andalucía por la musealización del yacimiento del Cerro de la Encina ha motivado el desarrollo de nuevas investigaciones arqueológicas cuya primera fase se ha desarrollado entre Noviembre de 2003 y Mayo de 2004. Los trabajos han consistido en la excavación sistemática de un área de poblado de grandes dimensiones parcialmente conocida por las investigaciones realizadas a principios de los años 80. Los resultados han sido del máximo interés documentándose un primer momento de ocupación perteneciente a la Cultura de El Argar en el que destaca su espectacular registro funerario integrado dentro de las áreas de habitación. Tras un periodo de abandono del yacimiento se produce una nueva ocupación correspondiente a una comunidad del Bronce Final del Sureste.

  19. Corrosion in pipelines and well casings at the Cerro Prieto geothermal field, BC; Corrosion en tuberias de linea y de revestimiento de pozos del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Herrera, Carlos A.; Canchola Felix, Ismael; Raygoza Flores, Joaquin; Mora Perez, Othon [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: carlos.miranda02@cfe.gob.mx

    2009-07-15

    In the area called Poligono Hidalgo, inside the Cerro Prieto IV zone in the Cerro Prieto geothermal field, BC, corrosion has occurred in the last few years on well casings and pipelines used for geothermal fluids. Corrosion test results are presented here for pipes, type API L-80 and ASTM A-53 grade B, which were subjected to condensate from wells 403 and 424. These wells have thrown corroded material from their respective casings. With these data we pinpoint corrosive conditions in this field area and determine which pipes are adequate to case wells in similar chemical, production conditions to minimize adverse effects and extend the life of the well, allowing more efficient exploitation of the deepest production zones in the reservoir. [Spanish] En el campo geotermico de Cerro Prieto, BC, dentro del area del Poligono Hidalgo en el sector conocido como Cerro Prieto IV, algunos pozos han presentado en los ultimos anos desgastes en sus tuberias de revestimiento y en las tuberias de linea para el transporte del fluido geotermico. Se presentan resultados de pruebas de corrosion con tuberias tipo API L-80 y ASTM A-53 grado B al ser sometidas al condensado de los pozos 403 y 424, los cuales han estado arrojando material de sus respectivas tuberias de revestimiento. Con estos datos se pretende conocer las condiciones corrosivas de esa zona del campo y determinar cual seria la tuberia ideal a utilizar en pozos con condiciones quimicas de produccion semejantes a fin de minimizar este efecto adverso y prolongar la vida de los pozos, a la vez que se permita la explotacion eficiente de las zonas productoras mas profundas del yacimiento.

  20. Parabolic trough Project in Cerro Prieto, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, A.; Cadenas, R.; Almanza, R.; Martinez, I.; Ruiz, V.

    2006-07-01

    Federal Electricity Commission (CFE), the most important electricity Company in Mexico wants to install a parabolic trough row in the Cerro Prieto Geothermal field. Cerro Prieto (CP) is the most important geothermal field in Mexico; this area has the highest levels of irradiance in the country. The levels of irradiance make it feasible to set up a solar collector field in the geothermal field to build a hybrid system in order to increase the steam and electricity production. There are several alternative in the hybrid system, depending where the solar field place is located. Two new options are presented in this paper. The first one uses water from the condenser in DSG with the solar field and steam is separated in the first separator. The second option (DSG), the steam produced is separated in an expansion vessel; the water is reinjected in the solar field and the steam goes to the turbine. This project plans to install an experimental facility to research and learning about the technology, CFE main objective will be the electricity generation; using steam from solar collectors using the existing turbines in CPIV; the second objective is to instruct the workers in the operation of the real facility. The third objective is to study the geothermal flow in the absorbers in Direct Steam Generation (DSG), which has salt and silica dissolved, and look for a possible solution for steam generation. The geothermal facilities have considerable experience using the brine flow, so it is not considered an impediment in the solar-geothermal hybrid system. (Author)

  1. Seismological studies at the Cerro Prieto field, 1978 - 1982

    Science.gov (United States)

    Majer, E. L.; McEvilly, T. V.

    1982-10-01

    Varied seismological studies were conducted to determine the static and dynamic properties of the Cerro Prieto geothermal field. Sought were the relation of wave propagation characteristics and microearthquake activity to such features as production boundaries, recharge zones, heat sources, fluid strata, lithology and structure. Discussed are the results of the studies carried out since 1978 in light of the current knowledge of the Cerro Prieto field. Also included are interpretations of the reflection surveys carried out in the immediate production areas.

  2. Criteria to determine the depth of the production interval in wells of the Cerro Prieto geothermal field, Mexico; Criterios para determinar la profundidad del intervalo productor en pozos del campo geotermico de Cerro Prieto, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Leon Vivar, Jesus Saul de [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: jesus.deleon@cfe.gob.mx

    2006-07-15

    Ways to select the depth of the production interval or to complete wells in the Cerro Prieto geothermal field have changed during the development of the field. From 1961 when drilling began to the middle of 2005, a total of 325 wells were drilled. The paper compares the approaches used in the past with those of the last ten years. The Cerro Prieto system has been classified as being of liquid-dominated and high-temperature. Today, after 33 years of commercial exploitation, it has experienced a series of thermal and geochemical fluid changes making it necessary to modify the ways to select the depth of the well production intervals, according to the observed behavior of the reservoir. The new criteria include the thermal approach, the geological approach, the geochemical approach and a comparative approach with neighboring wells. If most of these criteria are interpreted correctly, the success of a well is ensured. [Spanish] Los criterios para seleccionar la profundidad del intervalo productor o la terminacion de los pozos en el campo geotermico de Cerro Prieto han cambiado durante el desarrollo del mismo. De 1961, cuando se perforaron los primeros pozos, hasta mediados del 2005 se han perforado un total de 325 pozos. En el presente articulo se hara una breve revision de cuales han sido los criterios usados en el pasado y los que se han venido empleando en los ultimos diez anos. El yacimiento de Cerro Prieto ha sido clasificado como de liquido dominante, de alta temperatura, pero actualmente, despues de 33 anos de explotacion comercial, ha sufrido una serie de cambios termicos y geoquimicos en sus fluidos, por lo que ha sido necesario modificar los criterios para seleccionar la profundidad del intervalo productor de los pozos de acuerdo al comportamiento observado en el yacimiento. Los criterios actuales se dividen en cuatro: 1. Criterio termico, 2. Criterio geologico, 3. Criterio geoquimico y 4. Criterio comparativo de los pozos vecinos. Cuando la mayoria de estos

  3. Surface Deformation Associated with Geothermal Fluids Extraction at the Cerro Prieto Geothermal Field, Baja California, Mexico Revealed by DInSAR Technique

    Science.gov (United States)

    Sarychikhina, O.; Glowacka, E.; Mojarro, J.

    2016-08-01

    The Differential Synthetic Aperture Radar Interferometry (DInSAR) is widely used for surface deformation detection and monitoring.In this paper, ERS-1/2, ENVISAT and RADARSAT-2 synthetic aperture radar (SAR) images acquired between 1993 and 2014 were processed to investigate the evolution of surface deformation at the Cerro Prieto geothermal field, Baja California, Mexico. The conventional DInSAR together with the interferogram stacking method was applied. Average LOS (line of sight) displacement velocity maps were generated for different periods: 1993 - 1997, 1998 - 2000, 2004, 2005, 2007, 2009, and 2012 - 2014, revealing that the area corresponding to Cerro Prieto basin presented the important surface deformation (mainly subsidence) during the entire time of investigation. The changes in the surface deformation pattern and rate were identified. These changes have a good correlation in time with the changes of production in the Cerro Prieto geothermal field.

  4. Basic aspects of the Cerro Prieto reservoir water recharge; Aspectos basicos de la recarga de agua al reservorio de Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, Sergio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    The Cerro Prieto geothermal field, located 30 km South of Mexicali City, Baja California, has at present an installed capacity of 620 MW in geothermal power plants, that operating with endogenous steam, make use of the underground energy by means of deep wells, from which about 80 million cubic meters per year of high enthalpy water and steam mixture are extracted. During the exploitation physical an chemical changes in the hydrothermal fluids discharged by the wells have been detected, which shows, among other things, an elevated water recharge, located towards the West area of the field and a low recharge in the part of the east zone area. For this reason the hot brine waste re-injection is recommended, (previously treated to eliminate the silica excess) to thermally an hydraulically recharge the reservoir in that part of the field. [Espanol] El campo geotermico de Cerro Prieto, situado a 30 km al sur de la ciudad de Mexicali, Baja California, cuenta actualmente, despues de 18 anos en explotacion, con 620 MW de capacidad instalada en plantas geotermoelectricas que, operando con vapor endogeno, aprovechan la energia del subsuelo mediante pozos profundos de los que se extraen alrededor de 80 millones de metros cubicos por ano de una mezcla de agua vapor de elevada entalpia. Durante la explotacion se han percibido cambios fisicos y quimicos en los fluidos hidrotermales descargados por los pozos, lo que indica, entre otras cosas, una recarga elevada de agua localizada hacia el poniente del campo y una recarga baja en una zona de la parte oriental. Por ello se recomienda la reinyeccion de salmuera geotermica caliente de desecho (previamente tratada para eliminar el exceso de silice) para recargar termica e hidraulicamente el reservorio en esa parte del campo.

  5. Evaluation of geologic characteristics at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Halfman, S.E.; Vonder Haar, S.P.

    1981-01-01

    Computerized well-log analysis of Cerro Prieto has led to the identification of a relatively large and irregular low-density volume extending from near the surface in the vicinity of Laguna Volcano to greater depths toward the northeast. This low-density volume is located about a plane of symmetry of a self-potential anomaly and a group of northeast trending active faults. The presence of a volume of relatively high-density rock has been recognized at shallow depths in the initially developed part of the resource. It is believed to be due to minerals deposited by cooled, rising geothermal brine. Storativity calculated from well logs at the south end of the western part of the field shows acceptable comparison with storativity calculated from well tests. The amount of fluid produced from the field during the period 1973-1977 is greater than the amount in situ calculated from the completed interval thicknesses. Because this part of the field is still producing today, fluid must be recharging this part of the field.

  6. Edad, caracterización petrográfica y Geoquímica del Granitoide del Cerro Falkner, Neuquén Age, petrography and geochemistry of Cerro Falkner's granitoid

    Directory of Open Access Journals (Sweden)

    Sabrina Crosta

    2008-03-01

    Full Text Available El Cerro Falkner se halla constituido por rocas graníticas infrayacentes a las volcanitas de la Formación Ventana de edad paleógena. Dichos intrusivos son de composición granodiorítica, metaluminosos a peraluminosos, subalcalinos, con características de granitos de arco volcánico concordantes con otros granitoides del segmento norte de la Cordillera Patagónica Septentrional. La edad obtenida por el método K-Ar sobre anfíboles de composición tschermakítica (125 ± 20 Ma indica una edad mínima perteneciente al Cretácico inferior para la granodiorita del cerro Falkner, por lo que sería incorrecto utilizar la denominación Formación Los Machis (Cretácico superior para estas rocas. Esta edad, permite vincular las rocas graníticas del área de estudio con el volcanismo representado por el Grupo Divisadero de edad predominantemente cretácica inferior.Cerro Falkner is composed of granitic rocks underlying volcanic rocks of the Ventana Formation of Paleogene age. Those intrusives are granodioritic in composition, metaluminous to peraluminous, subalkaline, with characteristics of volcanic arc granites that are concordant with other granitoids of the Cordillera Patagónica Septentrional's northern segment. The age obtained by the K-Ar method on tschemakitic amphiboles (125 ± 20 Ma points out a minimun age from the lower Cretaceous for the Cerro Falkner's granodiorite. Therefore the use of the term Los Machis Formation (Upper Cretaceous would be incorrect for these rocks. This age, allows us to relate the granitic rocks on the study area to the lower Cretaceous, coeval with the volcanism of the Divisadero Group.

  7. Los avatares de la primera expedición misionera a las posesiones españolas del Golfo de Guinea a cargo de los eclesiásticos ilustrados Jerónimo Mariano Usera y Alarcón y Juan del Cerro

    OpenAIRE

    Vilaró i Güell, Miquel

    2009-01-01

    En 1844, Jerónimo Mariano Usera y Alarcón recibió el encargo de fundar la primera misión católica en Fernando Poo, una vez tomada la decisión de iniciar el proceso definitivo de colonización después de 70 años de abandono por dudas sobre los negocios que podían hacerse en aquella desconocida colonia africana. En Santa Isabel (Clarence City para los ingleses), los dos clérigos designados tuvieron que hacer frente tanto a las incomodidades materiales de un lugar en el que la presencia española ...

  8. MOVIMIENTOS DE LADERA Y PLANEAMIENTO URBANÍSTICO: EL CONFLICTO DEL CERRO DEL OPE, ARCHENA (MURCIA

    Directory of Open Access Journals (Sweden)

    María Dolores Gómez Moreno

    2009-01-01

    Full Text Available Los desprendimientos son un proceso natural que afecta, de forma generalizada en el Valle de Ricote, a las laderas del tipo cantil-talud. Su peligrosidad radica en que los bloques desprendidos del escarpe ruedan con facilidad, talud abajo, cuando son descalzados por efecto de la escorrentía superfi cial o desestabilizados por movimientos sísmicos. El planeamiento urbanístico se convierte en factor inductor del riesgo al clasifi car como urbanizables y urbanos suelos que, por su ubicación en pie de ladera, deberían excluirse de cualquier proceso urbanizador. Este es el caso de Archena en el entorno inmediato del cerro del Ope.

  9. Presence of cross flow in the Cerro Prieto geothermal field, BC; Presencia de flujo cruzado en el campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez, Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2011-01-15

    During the development of Cerro Prieto geothermal field, BC, exploitation has increased gradually, causing a continuous drop in pressure to almost 100 bars in the central and eastern parts of the field. This has occurred despite the high natural recharge induced by the reservoir exploitation and helped by the high permeability of the reservoir and the wide availability of natural recharge of low-temperature water in the vicinity. The strata above the production zones have significantly lower temperatures than these zones, but due to the particular characteristics of the reservoir, do not have pressure drops. As the pressure of producing strata declines, the hydraulic pressure differential between them and the overlying strata increases. Thus in recent years the phenomenon of cross flow occurs with greater frequency and severity. In this paper, this phenomenon is analyzed, detailing the specific mechanisms favoring it and identifying the stage (drilling or workover) in which it commonly occurs. Rigorous supervision during these stages is crucial to identifying cross flow and to taking necessary measures to save the well. Cross flow cases are presented at different stages in the history of a well: during drilling, repair, before and during the stimulation, and during production. [Spanish] Durante el desarrollo del campo geotermico de Cerro Prieto, BC, la explotacion se ha incrementado en forma gradual provocando una continua caida de presion, que en las porciones central y oriente ha sido de casi 100 bars. Esto ha ocurrido a pesar de la enorme recarga natural inducida por la explotacion, favorecida por la alta permeabilidad del yacimiento y la gran disponibilidad de recarga natural de agua de baja temperatura en los alrededores del mismo. Los estratos ubicados encima de las zonas productoras presentan temperaturas significativamente menores que estos, pero debido a las caracteristicas particulares del yacimiento, no han presentado abatimiento en su presion. En la

  10. Transport of Cerro Hudson SO2 clouds

    Science.gov (United States)

    Doiron, Scott D.; Bluth, Gregg J. S.; Schnetzler, Charles C.; Krueger, Arlin J.; Walter, Louis S.

    The Cerro Hudson volcano in southern Chile (45.92°S, 73.0°W) emitted large ash and sulfur dioxide clouds on August 12-15, following several days of minor activity [Global Volcanism Network Bulletin, 1991]. The SO2 clouds were observed using (preliminary) near real-time data from the Total Ozone Mapping Spectrometer (TOMS) as they encircled the south polar region. The injection of SO2 into the stratosphere has essentially created a gigantic chemical tracer that could provide new insights into the wind patterns and seasonal circulation around the Antarctic region.around the Antarctic region. The TOMS instrument, on board the National Aeronautic and Space Administration's Nimbus 7 satellite, measures the ratio of backscattered Earth radiance to incoming solar irradiance in the ultraviolet spectrum. Although originally designed to measure ozone, it was later discovered that the TOMS instrument could also detect and quantify SO2 [Krueger, 1985]. After this discovery, measurements from TOMS were examined for SO2 emissions for all recorded volcanic eruptions since Nimbus-7 was launched in October 1978, and current data are analyzed as new eruptions occur. The satellite is in a polar, Sun-synchronous orbit so that it crosses the equator at local noon and observes the whole sunlit Earth in approximately 14 orbits each day. Total column amounts of SO2 are determined that represent the amount of gas affecting the reflection of ultraviolet light through a column of the atmosphere from the satellite to the reflecting surface, Earth, given in terms of milli atmospheres centimeter (1000 milli atm cm = a gas layer 1-cm thick at STP). The mass of SO2 is calculated by integrating over the cloud area to obtain a volume, then converting to tons.

  11. SITE CHARACTERISTICS OF THE SUMMIT OF CERRO CHAJNANTOR AT THE 5640 M ALTITUDE

    Directory of Open Access Journals (Sweden)

    K. Motohara

    2011-01-01

    Full Text Available Instituto de Astronomía de la Universidad de Tokio está promoviendo el proyecto TAO (University of Tokyo Atacama Observatory; Yoshii et al. 2010 para construir un telescopio infrarrojo en la cima de Cerro Chajnantor (altitud 5640 m en el desierto de Atacama en el Norte de Chile. Para la evaluación de las características del sitio, primero se realizó el monitoreo del tiempo atmosférico, la emisividad de nubes y el seeing durante 2006. 2007. La fracción despejada fue alta (>80% y la mediana del seeing en la banda V fue de tan solo 0."69. Un telescopio explorador de 1 m llamado miniTAO fue instalado y comenzó a observar en 2009. Con éste se han obtenido imágenes satisfactorias de Paα de hidrógeno 1.875 μm como también imágenes de 30.40 μm por primera vez desde un telescopio en tierra. Estos resultados demuestran que la cima de Cerro Chajnantor es uno de los mejores sitios para la astronomía infrarroja en la Tierra.

  12. Geophysical monitoring at the Cerro Prieto geothermal field

    Science.gov (United States)

    Wilt, M.; Zelwer, R.; Majer, E. L.

    1982-09-01

    A program of reservoir monitoring at the Cerro Prieto geothermal field using surface geophysical methods with the objective of observing changes resulting from production is described. The three methods used, dipole-dipole resistivity, precision gravity, and passive seismic monitoring, are discussed.

  13. Geología de la región del Cerro Guanaquero, Río Diamante, Mendoza

    OpenAIRE

    Federico Fuentes; Ramos,Victor A.

    2008-01-01

    El estudio realizado presenta nuevos datos sobre un sector poco conocido de la Cordillera Principal de Mendoza, en la alta cuenca del río Diamante en las adyacencias del cerro Guanaquero, y los primeros datos geocronológicos de sus rocas volcánicas. Las unidades geológicas presentes en el área se dividen en cuatro grupos principales: secuencias sedimentarias mesozoicas marinas y continentales intensamente plegadas y falladas; intrusivos y volcanitas intermedias de edad neógena; rocas volcánic...

  14. Brine treatment test for reinjection on Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Hurtado, R.; Mercado, S.; Gamino, H. (Departamento de Geotermia, Division de Fuentes de Energia, Instituto de Investigaciones Electricas, Justo Sierra y Herreros Sur 2098-Altos C.P. 21020, Mexicali, B.C. (MX))

    1989-01-01

    Reinjection of disposal brine from the Cerro Prieto Geothermal Power Plant System is attractive mainly because, on top of solving the brine disposal problem, it may significantly contribute to extend the reservoir useful lifetime, through thermal and hydraulic recharge. Because the high concentration of colloidal silica in the disposal brine, laboratory and pilot plant tests were conducted in order to develop the brine treatment process. Addition of 20-40 mg/1 lime to flashed and aged brine for 10-20 minutes yields a clarified brine relatively low in suspended solids (10-30 mg/1) when the over flow rate is 38.5 1/min-m/sup 2/. 1.1 mills/kWh was the estimated cost for treatment of 800 kg/s of separated brine from the Cerro Prieto I power station.

  15. Criteria for determining casing depth in Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Olivas M., H.M.; Vaca S., J.M.E.

    1982-08-10

    On the basis of geological data obtained during drilling and its relation to electric logs, together with the problems that arose when drilling through formations until the production zone was reached, it is possible to establish the most suitable manner to line a well and thus formulate an optimum casings program. The main criteria to be taken into consideration in preparing such a program and its application in the drilling of wells programmed in Cerro Prieto to optimize and economize such drilling and achieve suitable techniques for well completion are presented. The criteria are based on the characteristics of the Cerro Prieto field and on casing design factors, as well as a experience gained during drilling in such a field.

  16. Open file data on the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Lippman, M.J.; Aguirre, B.D.; Wollenberg, H.A.; Witherspoon, P.A.

    1977-04-01

    Some of the unpublished data presently available on open file at the Lawrence Berkeley Laboratory are listed and described. In addition, in the files are a number of internal memoranda of the Commission Federal de Electricidad of Mexico (CFE) on chemical characteristics of the produced fluids and incrustations; published papers on Cerro Prieto and the geologic setting of the Salton Trough; and data on the hydrogeology of the Mexicali Valley. (MHR)

  17. Dating thermal events at Cerro Prieto using fission track annealing

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, S.J.; Elders, W..

    1981-01-01

    Data from laboratory experiments and geologic fading studies were compiled from published sources to produce lines of iso-annealing for apatite in time-temperature space. Fission track ages were calculated for samples from two wells at Cerro Prieto, one with an apparently simple and one with an apparently complex thermal history. Temperatures were estimated by empirical vitrinite reflectance geothermometry, fluid inclusion homogenization and oxygen isotope equilibrium. These estimates were compared with logs of measured borehole temperatures.

  18. Early mineralization at Cerro de Pasco (central Peru) revisited

    OpenAIRE

    Rottier, Bertrand; Casanova, Vincent; Fontboté, Lluis; Kouzmanov, Kalin; Alvarez, Hugo; Bendezú, Ronner

    2013-01-01

    The large Cerro de Pasco Cordilleran base metal deposit in central Peru is located on the eastern margin of a Middle Miocene diatreme-dome complex. A striking characteristic is the presence of a N-S trending massive funnel-shape pyrite-quartz replacement ore body that contains pyrrhotite pipes grading outwards to lead-zinc replacement bodies, along the eastern contact of the diatreme-dome complex. Earlier workers interpreted the pyrrhotite pipes as postdating the pyritequartz body. This study...

  19. Estratigrafia e estrutura do Cerro do Jarau: nova proposta

    Directory of Open Access Journals (Sweden)

    Joana Paula Sánchez

    Full Text Available A estrutura do Cerro do Jarau está localizada no Estado do Rio Grande do Sul, nas proximidades de Quarai, divisa com o Uruguai. É uma estrutura circular de aproximadamente 8 km de diâmetro, cujos dados geológicos apontam para uma origem por impacto meteorítico. Está situada na Bacia do Paraná e compreende uma área de afloramento de arenitos na porção central, circundada por basaltos da Formação Serra Geral. Nos trabalhos publicados, o arenito da porção central é interpretado como pertencente à Formação Botucatu, soerguido em meio aos basaltos da Formação Serra Geral, correspondendo, para muitos autores, a uma feição dômica. O objetivo do presente trabalho é apresentar novos dados sobre a estratigrafia e estrutura do Cerro do Jarau, que mostram que os arenitos estão estrutural e estratigraficamente sobrepostos aos basaltos e ambas unidades exibem mergulhos centrípetos. A estrutura do Cerro do Jarau é, portanto, uma bacia com a porção central rebaixada, e não um domo como antes admitido.

  20. Current state of the hydrothermal geochemistry studies at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Fausto L, J.J.; Jimenez S, M.E.; Esquer P, I.

    1981-01-01

    The current state of hydrothermal geochemistry studies being carried out at the field are reported. These studies are based on the results of chemical analysis of water samples collected during 1979 and 1980 at the geothermal wells of the area known as Cerro Prieto I, as well as from those located in the Cerro Prieto II and Cerro Prieto III areas, some of which have only recently started flowing. Data are presented on the chemical variations of the main chemical constituents dissolved in the waters, as well as on the Na/K and Na-K-Ca chemical relations and the temperatures calculated from them and from SiO/sub 2/. Fluid recharge into the reservoir and its direction of flow are interpreted from isotherm contour maps of the field prepared from Na/K and Na-K-Ca geothermometry and from concentration contour maps of some of the main chemical constituents. Well M-43 is discussed as an example of a well affected by well completion problems in its production casing. Its behavior is explained on the basis of the chemical characteristics of the produced water. The chemical changes that have taken place in some of the wells during production are explained by correlating the chemistry with the production mechanisms of the well (steam-water production rates).

  1. Correlation between precision gravity and subsidence measurements at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Zelwer, R.; Grannell, R.B.

    1982-10-01

    Precision gravity measurements were made in the region of the Cerro Prieto geothermal field at yearly intervals from 1977 to 1981 to assess the feasibility of using gravity to determine subsurface reservoir changes with time. The extent of mass recharge in response to the continued production of fluids from this field was studied. Changes in gravity and ground elevation were observed throughout the region for the period of observation. Results indicate that the largest changes observed were the result of the Magnitude 6.1 (Caltech) Victoria earthquake of 8 June 1980. The epicenter of this earthquake was located 25 km southeast of the field on the Cerro Prieto Fault, which bounds the field on the southwest. Subsidence of up to 55 cm was measured east of the power plant, in the region between the northern end of the Cerro Prieto Fault and the southern end of the Imperial Fault. This area has been postulated to be the site of an active spreading center or pull-apart basin, and has been characterized by a high level of seismic activity during the last 10 years. Minor subsidence and small related gravity changes for the period preceeding the Victoria earthquake suggest that in spite of large fluid production rates, the reservoir is being almost completely recharged and that a measurable increase in subsurface density may be taking place. The results of measurements of horizontal ground motions made in this area are discussed in relation to the gravity and subsidence observations.

  2. Microfossils from Cerro Prieto geothermal wells, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, M.L.; Haar, S.V.

    1982-08-10

    To aid in a paleonenvironmental and age reconstruction of the Cerro Prieto reservoir system, 59 samples of well cuttings were analyzed for microfossils. The cuttings were obtained at depths from 351 to 3495m in 14 geothermal wells in the Cerro Prieto field, Baja California, Mexico. Foraminifera was found in 6 samples, ostracodes in 19 samples and mannoplankton as coccoliths in 24 samples. Other groups, such as molluscus, insects, fish skeletal parts, and plant material were occasionally present. Detailed interpretations at this time cannot be made because of poor preservation of samples. This is primarily due to causes: dissolution by geothermal fluids that reach 350/sup 0/C, and the extensive mixing of filled Cretaceous forms (reworked from the Colorado Plateau region) with Tertiary species during drilling. Further studies of ostracodes and foraminifera from colder portions of the wells are needed. The abundant and well-preserved ostracodes indicate marine to backish water inviroments that correspond in part, to lagoonal or estuarine facies. The presence of the mid-Tertiary (15-m.y.-old) marine foraminifera, Cassigerinela chipolensis, in wells M-11 and M-38, 350 to 500m deep, is perplexing. These are not laboratory contaminates and, as yet have not been found in the drilling mud. If further studies confirm their presence at Cerro Prieto, established ideas about the opening of the Gulf of California and about Pacific Coast mid-Tertiary history will need to be rewritten.

  3. Correlation between precision gravity and subsidence measurements at Cerro Prieto

    Science.gov (United States)

    Zelwer, R.; Grannell, R. B.

    1982-10-01

    Precision gravity measurements were made in the region of the Cerro Prieto geothermal field at yearly intervals from 1977 to 1981 to assess the feasibility of using gravity to determine subsurface reservoir changes with time. The extent of mass recharge in response to the continued production of fluids from this field was studied. Changes in gravity and ground elevation were observed throughout the region for the period of observation. Results indicate that the largest changes observed were the result of the Magnitude 6.1 (Caltech) Victoria earthquake of 8 June 1980. The epicenter of this earthquake was located 25 km southeast of the field on the Cerro Prieto Fault, which bounds the field on the southwest. Subsidence of up to 55 cm was measured east of the power plant, in the region between the northern end of the Cerro Prieto Fault and the southern end of the Imperial Fault. This area has been postulated to be the site of an active spreading center or pull-apart basin, and has been characterized by a high level of seismic activity during the last 10 years.

  4. Microfossils from Cerro Prieto geothermal wells, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, M.L.; Vonder Haar, S.

    1980-01-01

    To aid in a paleoenvironmental and age reconstruction of the Cerro Prieto reservoir system, 59 samples of well cuttings were analyzed for microfossils. The cuttings were obtained at depths from 351 to 3495 m in 14 geothermal wells in the Cerro Prieto field, Baja California, Mexico. We found foraminifera in 6 samples, ostracodes in 19 samples, and nannoplankton as coccoliths in 24 samples. Other groups, such as molluscs, insects, fish skeletal parts, and plant material were occasionally present. Detailed interpretations are not possible at this time because of poor preservation of samples. This is primarily due to causes: dissolution by geothermal fluids that reach 350{sup 0}C, and the extensive mixing of filled Cretaceous forms (reworked from the Colorado Plateau region) with Tertiary species during drilling. Further studies of ostracodes and foraminifera from colder portions of the wells are needed. The abundant and well-preserved ostracodes indicate marine to brackish water environments that correspond, in part, to lagoonal or estuarine facies. The presence of the mid-Tertiary (15-My-old) marine foraminifera, Cassigerinela chipolensis, in wells M-11 and M-38, 350 to 500 m deep, is perplexing. These are not laboratory contaminates and, as yet, have not been found in the drilling mud. If further studies confirm their presence at Cerro Prieto, established ideas about the opening of the Gulf of California and about Pacific Coast mid-Tertiary history will need to be rewritten.

  5. Update of the basement model of the Cerro Prieto, B. C., geothermal field, Mexico; Actualizacion del modelo del basamento en el campo geotermico de Cerro Prieto, B.C., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Lopez, Macario [Residencia General de Cerro Prieto, Comision Federal de Electricidad, Mexicali, Baja California (Mexico)

    1999-04-01

    With the aim to actualize the basement model of the Cerro Prieto Geothermal Field, a gravity interpretation has been held. We modeled in 2.5 D, nine profiles traced over the Bouguer anomaly map. Well data concerning lithology and density changes were used to fit the gravity models. Results of this work confirm that the geometry of the basement of Cerro Prieto, corresponds to a structural sequence. From west to east it starts as a big depression, continues with a strong uplift of the basement in the middle sector and finally deepens eastward in steps. The basement model proposed in the present work, defines a similar trend to that established by Fonseca y Razo (1980), but there are differences in basement depth in some areas. In the present model we interpret basement depths between 200 and 400 m deeper than in previous models to the south and northwest of the actual exploitation zone. [Spanish] Con el fin de actualizar el modelo del basamento en el Campo Geotermico de Cerro Prieto, se realizo una reinterpretacion gravimetrica, modelando en 2.5 D, 9 perfiles trazados sobre el mapa de anomalia de Bouguer. Utilizando la informacion litologica obtenida a traves de numerosas perforaciones profundas, se hicieron coincidir, dentro de los mofelos gravimetricos, las principales variaciones litologicas con cambios en la densidad. Los resultados de este trabajo reiteran que la geometria del basamento del Campo de Cerro Prieto, vista de W a E, corresponde con una secuencia estructural que se inicia con una gran depresion en el W, continua con un fuerte levantamiento y finalmente se extiende con una tendencia a profundizarse hacia el E de forma escalonada. El modelo de basamento derivado del presente trabajo, define una tendencia muy similar al modelo de basamento establecido (Fonseca y Razo, 1980), pero difiere en cuanto a la profundidad en algunos sectores del campo. En el actual trabajo se interpreta una profundidad entre 200 y 400 m mayor hacia el sur y noroeste de la

  6. Panama Canal Zone. Cerro Tigre, Fort Gulick, Gamboa Met Van No. 1.

    Science.gov (United States)

    The report contains the following meteorological data collected at sites within Fort Gulick and Cerro Tigre , Panama during December 1970: Atmospheric precipitation; Atmospheric temperature; Wind; Atmospheric pressure.

  7. Seismotectonics of the Cerro Prieto Geothermal Field, Baja California, Mexico.

    Science.gov (United States)

    Rebollar, C. J.; Reyes, L. M.; Quintanar, L.; Arellano, J. F.

    2002-12-01

    We studied the background seismic activity in the Cerro Prieto geothermal field (CPGF) using a network of 21 digital stations. Earthquakes are located below the exploitation area of the CPGF, between 3 and 12 km depth, within the basement. Earthquakes follow roughly a N30°E trend perpendicular to the Cerro Prieto fault. This activity is located on a horst-like structure below the geothermal field and coincides with the zone of maximum subsidence in the CPGF. Two earthquake swarms occurred along the SE-NW strike of the Cerro Prieto fault and in the neighborhood of the Cerro Prieto volcano. Magnitudes range from -0.3 to 2.5. A Vp/Vs=1.91 ratio of the activity below the volcano suggests a water-saturated medium and/or a partial-melt medium. We calculated 76 focal mechanisms of individual events. On June 1 and September 10, 1999, two earthquakes of Mw 5.2 and 5.3 occurred in the basement at depths of 7.4 and 3.8 km below the CPGF. Maximum peak accelerations above the hypocenter ranged from 128.0 to 432.0 cm/s2. Waveform modeling results in a fault geometries given by strike=236°, dip=60°, rake=-58° (normal) and strike=10°, dip=90°, rake=159° (right lateral strike-slip) for the June and September events. Observed triangular source time function of 0.7 seconds and a double source with a total duration of 1.9 seconds for the June and September events were used to calculate the synthetics seismograms. Static stress drops and seismic moments for the June and September events are: Δ\\sigma=82.5 MPa (825 bars), Mo= 7.65x1016 Nm (7.65x1023 dyne-cm) and Δ\\sigma=31.3 MPa (313 bars) and Mo=1.27x1017 Nm (1.27x1024 dyne-cm). These stress drops are typical of continental events rather than stress drops of events originated in spreading centers. We concluded from the focal mechanisms of the background seismicity and June and September 1999 events, that a complex stress environment exits in the CPGF due to the continual thinning of the crust in the Cerro Prieto basin.

  8. Procesos históricos y ambientales en Cerro de San Pedro, San Luis Potosí, México, 1948-1997

    OpenAIRE

    Paula Andrea Martínez Chaves; Alexander Betancourt Mendieta; Miguel Nicolás Caretta; Miguel Aguilar Robledo

    2010-01-01

    Los estudios sobre el municipio Cerro de San Pedro enfatizan la continuidad ambiental aparente que estimula la minería; sin embargo, esta lectura subvalora otras dinámicas que ocurren en la zona. Con base en observaciones directas de trabajo en campo, para realizar análisis de coberturas vegetales, entrevistas con los habitantes de la zona, revisión de cartografía e investigación de archivo, el presente trabajo muestra procesos como la explotación de recursos vegetales y el pastoreo, como act...

  9. Evolution of the CP-I sector of the Cerro Prieto geothermal reservoir, BC, and exploitation alternatives; Evolucion del sector CP-I del yacimiento geotermico de Cerro Prieto, BC, y alternativas de explotacion

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Rodriguez, Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2010-01-15

    After 35 years of exploitation of the CP-I (Cerro Prieto I) sector of the Cerro Prieto geothermal field, its thermal conditions have been declined substantially; the number of production wells is reduced and exploitation has been abandoned in some zones. However with a binary cycle, it is still possible to generate electricity from the remaining reservoir energy. To do so, one needs to know a detailed reservoir history of the sector, identifying the best potential strata to be assessed. In this paper, the CP-I reservoir evolution is presented and its exploitation and main reservoir characteristics -which play important roles- are identified. The CP-I zones offering the best conditions for binary cycle exploitation are identified. Exploiting partially abandoned reservoir sections is crucial for the future of the field. If such sections can be made to produce, this will help reduce the progressive steam-production decline in the occurring since production began. The production decline had been mitigated by a large area available for drilling replacement production wells, but such an area is limited now, due to the vast number of operating wells. [Spanish] Despues de 35 anos de explotacion del yacimiento en el sector de CP-I (Cerro Prieto I) del campo geotermico de Cerro Prieto, BC, sus condiciones termicas han declinado considerablemente, por lo que el numero de pozos productores ha disminuido, dejando algunas zonas abandonadas a la explotacion. Sin embargo, aun es posible aprovechar la energia que contiene este sector del yacimiento para la generacion de electricidad mediante ciclo binario. Para ello primeramente se debe conocer en detalle cual ha sido la evolucion del yacimiento en este sector, identificando los estratos de mejor potencial para evaluarlos posteriormente. En este estudio se presenta la evolucion del yacimiento de CP-I como respuesta a su explotacion, identificando las principales caracteristicas del yacimiento que determinan su comportamiento. Asi

  10. Geología de la región del Cerro Guanaquero, Río Diamante, Mendoza Geology of Cerro Guanaquero region, Diamante River, Mendoza

    Directory of Open Access Journals (Sweden)

    Federico Fuentes

    2008-03-01

    Full Text Available El estudio realizado presenta nuevos datos sobre un sector poco conocido de la Cordillera Principal de Mendoza, en la alta cuenca del río Diamante en las adyacencias del cerro Guanaquero, y los primeros datos geocronológicos de sus rocas volcánicas. Las unidades geológicas presentes en el área se dividen en cuatro grupos principales: secuencias sedimentarias mesozoicas marinas y continentales intensamente plegadas y falladas; intrusivos y volcanitas intermedias de edad neógena; rocas volcánicas pliocenas a recientes de composición intermedia a básica, y depósitos cuaternarios inconsolidados. El cerro Guanaquero, un estratovolcán pliocuaternario intensamente erosionado por glaciares pleistocenos, con sus 4.841 metros es el rasgo orográfico más prominente. Está constituido esencialmente por andesitas grises porfíricas, piroxénicas a biotíticas. Intercaladas con las coladas andesíticas se presentan depósitos piroclásticos, aglomerados volcánicos, ignimbritas y basaltos. La datación de una andesita por el método K-Ar en roca total arrojó una edad de 1,4 ± 0,1 Ma. La deformación ándica comenzó en forma de una faja plegada y corrida de piel fina, con pliegues por despegue en el sector occidental y por propagación de falla en el oriental. La compresión al oeste de los 69º47´O terminó por invertir la fallas normales del rift mesozoico. A lo largo de este meridiano se encuentra la falla más importante de la región, la que se ha correlacionado con la falla Malargüe, bien desarrollada en latitudes más australes. Esta falla limita la faja plegada y corrida del Aconcagua, de naturaleza epidérmica, y la faja plegada y corrida de Malargüe, controlada por la inversión tectónica del basamento. El volcanismo fue muy intenso en el Plioceno y el Cuaternario, correspondiendo a un período de empinamiento de la placa oceánica subducida, en el que la región ha sido levantada pasivamente. La alta resistencia a la erosión de

  11. Atmospheric conditions at Cerro Armazones derived from astronomical data

    Science.gov (United States)

    Lakićević, Maša; Kimeswenger, Stefan; Noll, Stefan; Kausch, Wolfgang; Unterguggenberger, Stefanie; Kerber, Florian

    2016-04-01

    Aims: We studied the precipitable water vapour (PWV) content near Cerro Armazones and discuss the potential use of our technique of modelling the telluric absorbtion lines for the investigation of other molecular layers. The site is designated for the European Extremely Large Telescope (E-ELT) and the nearby planned site for the Čerenkov Telescope Array (CTA). Methods: Spectroscopic data from the Bochum Echelle Spectroscopic Observer (BESO) instrument were investigated by using a line-by-line radiative transfer model (LBLRTM) for the Earth's atmosphere with the telluric absorption correction tool molecfit. All observations from the archive in the period from December 2008 to the end of 2014 were investigated. The dataset completely covers the El Niño event registered in the period 2009-2010. Models of the 3D Global Data Assimilation System (GDAS) were used for further comparison. Moreover, we present a direct comparison for those days for which data from a similar study with VLT/X-Shooter and microwave radiometer LHATPRO at Cerro Paranal are available. Results: This analysis shows that the site has systematically lower PWV values, even after accounting for the decrease in PWV expected from the higher altitude of the site with respect to Cerro Paranal, using the average atmosphere found with radiosondes. We found that GDAS data are not a suitable basis for predicting local atmospheric conditions - they usually systematically overestimate the PWV values. The large sample furthermore enabled us to characterize the site with respect to symmetry across the sky and variation with the years and within the seasons. This technique of studying the atmospheric conditions is shown to be a promising step into a possible monitoring equipment for the CTA. Based on archival observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile and of the Cerro Armazones Observatory facilities of the Ruhr Universität Bochum.Full Table 1

  12. Connected magma plumbing system between Cerro Negro and El Hoyo Complex, Nicaragua revealed by gravity survey

    Science.gov (United States)

    MacQueen, Patricia; Zurek, Jeffrey; Williams-Jones, Glyn

    2016-11-01

    Cerro Negro, near León, Nicaragua is a young, relatively small basaltic cinder cone volcano that has been unusually active during its short lifespan. Multiple explosive eruptions have deposited significant amounts of ash on León and the surrounding rural communities. While a number of studies investigate the geochemistry and stress regime of the volcano, subsurface structures have only been studied by diffuse soil gas surveys. These studies have raised several questions as to the proper classification of Cerro Negro and its relation to neighboring volcanic features. To address these questions, we collected 119 gravity measurements around Cerro Negro volcano in an attempt to delineate deep structures at the volcano. The resulting complete Bouguer anomaly map revealed local positive gravity anomalies (wavelength 0.5 to 2 km, magnitude +4 mGal) and regional positive (10 km wavelength, magnitudes +10 and +8 mGal) and negative (12 and 6 km wavelength, magnitudes -18 and -13 mGal) Bouguer anomalies. Further analysis of these gravity data through inversion has revealed both local and regional density anomalies that we interpret as intrusive complexes at Cerro Negro and in the Nicaraguan Volcanic Arc. The local density anomalies at Cerro Negro have a density of 2700 kg m-3 (basalt) and are located between -250 and -2000 m above sea level. The distribution of recovered density anomalies suggests that eruptions at Cerro Negro may be tapping an interconnected magma plumbing system beneath El Hoyo, Cerro La Mula, and Cerro Negro, and more than seven other proximal volcanic features, implying that Cerro Negro should be considered the newest cone of a Cerro Negro-El Hoyo volcanic complex.

  13. Noise reduction in steam-vent points at the Cerro Prieto geothermal field, BC; Reduccion del ruido en puntos de desfogue en el campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Herrera, Carlos A [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, B.C (Mexico)]. E-mail: carlos.miranda02@cfe.gob.mx

    2008-01-15

    Steam silencers have been placed on the power units regulation system of the Cerro Prieto geothermal field, but not where the steam-pipes vent high-pressure steam (rupture disks). Moreover, the power-unit silencers are large and their abilities to reduce noise depend on an external, uncontrollable factor: pores sizes in the volcanic rocks they are made of. Thus a compact, economic and relatively easy to construct metallic silencer was designed to be used at several points of dry-steam venting to minimize the noise. The design was based on orifice-plate equations and a prototype was constructed and tested. It proved capable of reducing noise by 30 decibels for atmospheric discharges of primary steam at operating pressures. The size of the silencer can be adjusted to the particular needs of each vent case. [Spanish] En el campo geotermico de Cerro Prieto solo existen silenciadores de vapor en el sistema de regulacion de las plantas generadoras, pero no en los sitios de desfogue de vapor a alta presion en los vaporductos (discos de ruptura). Ademas, los silenciadores de las plantas son muy robustos y su capacidad de reduccion del ruido depende de un factor externo no controlable, como es el tamano del poro de la roca volcanica con el que estan construidos. Por lo tanto, se diseno un silenciador metalico compacto, economico y relativamente facil de fabricar, para utilizarse en diversos puntos de descarga de vapor seco a fin de minimizar el ruido. El diseno se realizo con base en las ecuaciones de la placa de orificio. Se construyo un prototipo cuyas pruebas demostraron que es capaz de reducir el ruido hasta en 30 decibeles, al descargar desde la presion de operacion de vapor primario hacia la presion atmosferica. Las dimensiones del silenciador pueden ajustarse a las necesidades particulares de cada caso de desfogue.

  14. Studies for recovering injection capacity in wells of the Cerro Prieto, BC, geothermal field; Estudios para recuperar la capacidad de aceptacion en pozos inyectores del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Rosales, Julio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: julio.alvarez@cfe.gob.mx

    2010-01-15

    As in geothermal fields around the world, at Cerro Prieto geothermal field, Baja California, former exploratory and production wells are used to inject residual brine. Since the 1980s, studies and activities have been carried out to find ways to recharge the reservoir and dispose of brine without harming the environment or underground aquifers. These include infiltration and cold-and-hot injection. Some of the studies are presented here, including analyses of litho-facies; core samples; pressure, temperature and spinner logs; well tests and injection rates-plus some studies on the shallow aquifer. All have been useful in fulfilling requirements made by environmental authorities. Because injection rates constantly decrease due to formation damage, it is proposed an additional technique be used to reduce such damages and prolong the lifetime of cold-and-hot injection wells-while ensuring the environment and shallow aquifers are not affected. [Spanish] Al igual que en diversos campos geotermicos en el mundo, en el de Cerro Prieto, Baja California se han utilizado tanto pozos inyectores perforados ex profeso como antiguos pozos exploratorios y productores para inyectar el fluido residual al subsuelo. Desde la decada de los 80 se han realizado diversos estudios y acciones en ese campo geotermico para recargar al yacimiento y para disponer del fluido residual, sin ocasionar danos al ambiente ni a los cuerpos hidricos del subsuelo, que van desde la infiltracion hasta la inyeccion en frio y en caliente. Este articulo presenta los diferentes estudios realizados con ese objetivo en el campo, incluyendo el analisis de litofacies, de nucleos de formacion, de registros de presion, temperatura y spinner, las pruebas en pozos y analisis de tasas de aceptacion, asi como los efectuados en el acuifero superficial. Todos ellos han sido de utilidad para atender los requerimientos de las autoridades ambientales. Finalmente, y en virtud de que las tasas de aceptacion de los pozos

  15. Two-phase characteristics of the feeding fluid of Cerro Prieto IV wells (Mexico) obtained by gas equilibrium; Caracteristicas bifasicas del fluido de alimentacion de pozos de Cerro Prieto IV (Mexico), obtenidas por equilibrio gaseoso

    Energy Technology Data Exchange (ETDEWEB)

    Barragan-Reyes, Rosa Maria; Arellano-Gomez, Victor Manuel; Portugal-Marin, Enrique [Instituto de Investigaciones Electricas (Mexico); De Leon-Vivar, Jesus [Comision Federal de Electricidad, Residencia General de Cerro Prieto, B.C (Mexico)

    2008-10-15

    The gas composition of fluids produced by CP IV geothermal wells from the Cerro Prieto field was studied in order to identify different types of fluids entering the wells by estimating their temperature and excess steam. A method based on the Fischer Tropsch reaction and H2S equilibrium with pyrite-pyrrhotite as mineral buffer (FTHSH3) was used. The results for the reservoir natural state indicated the presence of fluids with heterogeneous reservoir temperature (between 275 and 310 degrees Celsius) and excess steam values, which were found from negative (boiled liquid that has lost steam when flowing to the well) to one (steam phase with zero liquid saturation). The study for individual wells in which boiling processes were identified, showed that through time, the feeding fluids consist of a two-phase mixture with different liquid/steam proportions. Also, the results suggested that a steam phase could occur at CP IV which is added to the feeding fluid, depending on the operation conditions of the wells. The origin of this steam could be the boiling of the deeper liquid due to a pressure drop. [Spanish] Se estudio la composicion gaseosa de los fluidos producidos por pozos geotermicos del sector CP IV del campo de Cerro Prieto para tratar de distinguir aportes de fluidos diferentes mediante la estimacion de su temperatura de yacimiento y del exceso de vapor. Se utilizo un metodo de equilibrio gaseoso basado en la reaccion de Fischer Tropsch y el equilibrio combinado pirita-pirrotita (FT-HSH3). Los resultados obtenidos indican que en el estado inicial del yacimiento existen fluidos que muestran heterogeneidad en los valores de temperatura de yacimiento (entre 275 y 310 grados Celsius), asi como en el exceso de vapor con valores desde negativos (liquido que despues de ebullir ha perdido vapor en su trayecto hacia el pozo) hasta uno (vapor con cero saturacion de liquido). El estudio individual de los pozos con fenomenos de ebullicion muestra que a traves del tiempo

  16. Exploration and development of the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Lippmann, M.J.; Goldstein, N.E.; Halfman, S.E.; Witherspoon, P.A.

    1983-07-01

    A multidisciplinary effort to locate, delineate, and characterize the geothermal system at Cerro Prieto, Baja California, Mexico, began about 25 years ago. It led to the identification of an important high-temperature, liquid-dominated geothermal system which went into production in 1973. Initially, the effort was undertaken principally by the Mexican electric power agency, the Comision Federal de Electricidad (CFE). Starting in 1977 a group of US organizations sponsored by the US Department of Energy, joined CFE in this endeavor. An evaluation of the different studies carried out at Cerro Prieto has shown that: (1) surface electrical resistivity and seismic reflection surveys are useful in defining targets for exploratory drilling; (2) the mineralogical studies of cores and cuttings and the analysis of well logs are important in designing the completion of wells, identifying geological controls on fluid movement, determining thermal effects and inferring the thermal history of the field; (3) geochemical surveys help to define zones of recharge and paths of fluid migration; and (4) reservoir engineering studies are necessary in establishing the characteristics of the reservoir and in predicting its response to fluid production.

  17. Precision gravity studies at Cerro Prieto: a progress report

    Energy Technology Data Exchange (ETDEWEB)

    Grannell, R.B. (California State Univ., Long Beach); Kroll, R.C.; Wyman, R.M.; Aronstam, P.S.

    1981-01-01

    A third and fourth year of precision gravity data collection and reduction have now been completed at the Cerro Prieto geothermal field. In summary, 66 permanently monumented stations were occupied between December and April of 1979 to 1980 and 1980 to 1981 by a LaCoste and Romberg gravity meter (G300) at least twice, with a minimum of four replicate values obtained each time. Station 20 alternate, a stable base located on Cerro Prieto volcano, was used as the reference base for the third year and all the stations were tied to this base, using four to five hour loops. The field data were reduced to observed gravity values by (1) multiplication with the appropriate calibration factor; (2) removal of calculated tidal effects; (3) calculation of average values at each station, and (4) linear removal of accumulated instrumental drift which remained after carrying out the first three reductions. Following the reduction of values and calculation of gravity differences between individual stations and the base stations, standard deviations were calculated for the averaged occupation values (two to three per station). In addition, pooled variance calculations were carried out to estimate precision for the surveys as a whole.

  18. Hydrocarbons emissions from Cerro Prieto Geothermal Power Plant, Mexico

    Science.gov (United States)

    Navarro, Karina; Navarro-González, Rafael; de la Rosa, José; Peralta, Oscar; Castro, Telma; Imaz, Mireya

    2014-05-01

    One of the most important environmental issues related to the use of geothermal fluids to generate electricity is the emission of non-condensable gases to the atmosphere. Mexico has one of the largest geothermal plants in the world. The facility is located at Cerro Prieto, Baja California, roughly 30 km south of Mexicali and the international boundary between Mexico and United States. The Cerro Prieto power plant has 13 units grouped on four individual powerhouses. Gas samples from 9 units of the four powerhouses were collected during 4 campaigns conducted in May-July, 2010, February, 2012, December, 2012, and May, 2013. Gas samples from the stacks were collected in 1000 ml Pyrex round flasks with Teflon stopcocks, and analyzed by gas chromatography-mass spectrometry. Methane was the most abundant aliphatic hydrocarbon, with a concentration that ranged from less than 1% up to 3.5% of the total gas mixture. Normal alkanes represented the second most abundant species, and displayed a decreasing abundance with increasing carbon number in the homologous series. Isoalkanes were also present as isobutane and isopentane. Cycloalkanes occurring as cyclopentane and cyclohexane, were detected only at trace level. Unsaturated hydrocarbons (alkenes and alkynes) were not detected. Benzene was detected at levels ranging from less than 1% up to 3.4% of the total gas mixture. Other aromatic hydrocarbons detected were toluene, and xylenes, and were present at lower concentrations (

  19. Characterization of pottery from Cerro de Las Ventanas, Zacatecas, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-del-Rio, H.; Mireles-Garcia, F. [Unidad Academica de Estudios Nucleares, UAZ, Zacatecas (Mexico); Mendez-Cardona, R.Y. [Unidad Academica de Antropologia, UAZ, Zacatecas (Mexico); Nicolas-Caretta, M. [INAH Delegacion Zacatecas (Mexico); Coordinacion de Ciencias Sociales y Humanidades, UASLP, Fracc. Talleres, SLP (Mexico); Speakman, R.J. [Museum Conservation Inst., Smithsonian Institution, Suitland, MD (United States); Glascock, M.D. [Research Reactor Center, Univ. of Missouri, Columbia, MO (United States)

    2009-09-15

    With the aim of classifying prehispanic pottery from Cerro de Las Ventanas site, Juchipila, Zacatecas, Mexico, instrumental neutron activation analysis (INAA) was used to analyze ceramic samples at the University of Missouri Research Reactor Center. Thirty-two chemical elements were measured: Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Ti, Th, U, V, Yb, Zn, and Zr. Two multivariate statistical methods, cluster analysis and principal component analysis, were performed on the dataset to examine similarities between samples and to establish compositional groups. The statistical analyses of the dataset suggest that the pottery samples form a unique chemically homogeneous group, with the exception of one pottery sample. The compositional data were compared to an existing Mesoamerican ceramic database. It was found that the newly generated data fit best with data from a previous chemical analysis of pottery from the Malpaso Valley. However, despite the apparent similarity, pottery samples from the site of Cerro de Las Ventanas represent a new and unique chemical fingerprint in the region. (orig.)

  20. A review of progress in understanding the fluid geochemistry of the Cerro Prieto geothermal system

    Science.gov (United States)

    Truesdell, A.H.; Nehring, N.L.; Thompson, J.M.; Janik, C.J.; Coplen, T.B.

    1984-01-01

    Fluid geochemistry has played a major role in our present understanding of the Cerro Prieto geothermal system. Fluid chemical and isotopic compositions have been used to indicate the origin of water, salts and gases, original subsurface temperature and fluid flow, fluid-production mechanisms, and production-induced aquifer boiling and cold-water entry. The extensive geochemical data and interpretations for Cerro Prieto published from 1964 to 1981 are reviewed and discussed. Fluid geochemistry must continue to play an important role in the further development of the Cerro Prieto field. ?? 1984.

  1. Cost model for geothermal wells applied to the Cerro Prieto geothermal field case, BC Abstract; Modelo de costeo de pozos geotermicos aplicado para el caso del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Vaca Serrano, Jaime M.E [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: jaime.vaca@cfe.gob.mx

    2008-01-15

    A project for drilling geothermal wells to produce electrical energy can be defined as a sequence of plans to get steam or geothermal fluids to satisfy a previously known demand, and, under the best possible conditions, to obtain payment. This paper presents a cost model for nine wells drilled at the Cerro Prieto geothermal field in 2005 and 2006 to supply steam to the power plants operating in the field. The cost model is based on the well cost, the initial steam production, the annual decline of steam, the drilling schedule and the break-even point for each well. The model shows the cost of steam by the ton and the sale price needed to determine the discount rate and the investment return time. [Spanish] Un proyecto de perforacion de pozos geotermicos puede definirse como una secuencia o sucesion de planes para obtener vapor o fluidos geotermicos destinados a satisfacer una demanda previamente determinada, que se emplearan principalmente para generar energia electrica, bajo las mejores condiciones para obtener un pago. Este trabajo presenta un modelo de costeo para nueve pozos en el campo geotermico de Cerro Prieto, que fueron perforados entre 2005 y 2006 como parte del suministro de vapor para las plantas generadoras que operan en este campo. El modelo de costeo se basa en el costo por pozo, la produccion inicial de vapor, la declinacion anual de vapor, los intereses de las obras de perforacion y el punto de equilibrio para cada pozo. Los resultados permiten conocer el costo de la tonelada de vapor y el precio de venta para determinar la tasa de descuento y el tiempo de retorno de la inversion.

  2. Estudio de la líqueno flora encontrada en el Cerro de Quininí, Tibacuy, Cundinamarca

    Directory of Open Access Journals (Sweden)

    Hormaza Francisco

    2000-12-01

    Full Text Available

    Se realizó un muestreo de la liquen o flora del cerro de Quininí, Tibacuy, Cundinamarca para estudiar las características morfológicas externas de los géneros de líquenes encontrados en el. A su vez se hizo la revisión bibliográfica acerca de dichos géneros, datando así la riqueza de líquenes en la zona con 8 géneros en total y con respecto al papel de bioindicadores se mostró el grado de intervención para el lugar.

  3. Progress on the biphase turbine at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Cerini, D.; Hays, L.; Studhalter, W. [Douglas Energy Company, Placentia, CA (United States)

    1997-12-31

    The status of a Biphase turbine power plant being installed at the Cerro Prieto geothermal field is presented. The major modules for the power plant are completed except for a back pressure steam turbine. The power plant will be started in April 1997 with the Biphase turbine alone followed by the addition of the steam turbine module two months later. The current power plant performance level is 2780 kWe due to a decline in the well. An increase in power output to 4060 kWe by adding the flow from another well is planned. The addition of five Biphase power plants with a total power output of 21.2 megawatts is described.

  4. Geochemical evidence of drawdown in the Cerro Prieto geothermal field

    Science.gov (United States)

    Truesdell, A.H.; Manon, M.A.; Jimenez, S.M.E.; Sanchez, A.A.; Fausto, L.J.J.

    1979-01-01

    Some wells of the Cerro Prieto geothermal field have undergone changes in the chemistry of fluids produced which reflect reservoir processes. Pressure decreases due to production in the southeastern part of the field have produced both drawdown of lower chloride fluids from an overlying aquifer and boiling in the aquifer with excess steam reaching the wells. These reservoir changes are indicated by changes in fluid chloride concentrations, Na/K ratios and measured enthalpies and by comparisons of aquifer fluid temperatures and chloride concentrations calculated from enthalpy and chemical measurements. Fluid temperatures have not been greatly affected by this drawdown because heat contained in the rock was transferred to the fluid. When this heat is exhausted, fluid temperatures may drop rapidly. ?? 1979.

  5. The origin of the Cerro Prieto geothermal brine

    Science.gov (United States)

    Truesdell, A.H.; Thompson, J.M.; Coplen, T.B.; Nehring, N.L.; Janik, C.J.

    1981-01-01

    The Cerro Prieto geothermal brine may have originated from mixing of Colorado River water with seawater evaporated to about six times its normal salinity. This mixture circulated deeply and was heated by magmatic processes. During deep circulation, Li, K, Ca, B, SiO2 and rare alkalis were transferred from rock minerals to the water, and Mg, SO4, and a minor quantity of Na were transferred to the rock. Similar alteration of seawater salt chemistry has been observed in coastal geothermal systems and produced in laboratory experiments. After heating and alteration the brine was further diluted to its present range of composition. Oxygen isotopes in the fluid are in equilibrium with reservoir calcite and have been affected by exploitation-induced boiling and dilution. ?? 1981.

  6. Reservoir engineering studies of the Cerro Prieto geothermal field

    Science.gov (United States)

    Goyal, K. P.; Lippmann, M. J.; Tsang, C. F.

    1982-09-01

    Reservoir engineering studies of the Cerro Prieto geothermal field began in 1978 under a five-year cooperative agreement between the US Department of Energy and the Comision Federal de Electricidad de Mexico, with the ultimate objective of simulating the reservoir to forecast its production capacity, energy longevity, and recharge capability under various production and injection scenarios. During the fiscal year 1981, attempts were made to collect information on the evolution history of the field since exploitation began; the information is to be used later to validate the reservoir model. To this end, wellhead production data were analyzed for heat and mass flow and also for changes in reservoir pressures, temperatures, and saturations for the period from March 1973 to November 1980.

  7. Geothermal emissions data base: Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, S.R. (comp.)

    1978-04-01

    A new database subset on the gaseous emissions from the Cerro Prieto geothermal field is presented. Properties and states of the reservoir fluid such as flow rates, wellhead pressure, and enthalpy are included in the file along with the well name and constituent measurement. This subset is the result of an initial screening of the data covering 1967 to 1969, and new additions will be appended periodically to the file. The data are accessed by a database management system as are all other subsets in the file. Thereby, one may search the database for specific data requirements and print selective output. For example, one may wish to locate reservoir conditions for cases only when the level of the constituent exceeded a designated value. Data output is available in the form of numerical compilations such as the attached, or graphical displays disposed to paper, film, or magnetic tape.

  8. El megadeslizamiento del cerro Uritorco, ladera occidental de la Sierra chica de Córdoba

    Directory of Open Access Journals (Sweden)

    Claudio A Carignano

    2014-03-01

    Full Text Available En el extremo norte de la Sierra Chica de Córdoba, sobre el flanco oeste del cerro Uritorco (1.949 m s.n.m., se ha identificado un megadeslizamiento (30°49'55,46"S y 64°29'50,31"O. Los materiales movilizados del frente del escarpe de la falla Sierra Chica, han cubierto parcialmente el granito de Capilla del Monte y los abanicos aluviales pleistocenos del piedemonte. El lóbulo y bloques rotados del deslizamiento conforman un alto topográfico que oficia de límite entre los valles de Punilla (al sur y de Charbonier (al noroeste. Mediante técnicas de procesamiento e interpretación de imágenes satelitales multiespectrales de media (Landsat-ETM y muy alta resolución (GeoEye-1, análisis digital del terreno a partir de modelos de elevación (SRTM y Aster-GDEM y el correspondiente control de campo, se ha delimitado y caracterizado esta megageoforma nunca antes advertida. Dada la elevada sismicidad actual e histórica de la zona y los indicios morfotectónicos que señalan como activas a las fallas Sierra Chica y Pajarillo-Copacabana-Masa, se estima que este deslizamiento posiblemente fue gatillado por un evento sísmico, acontecido en alguna de esas estructuras. Tanto el depósito del deslizamiento como su cicatriz de despegue presentan un significativo grado de erosión hídrica. Por análisis comparativos con otros deslizamientos ya datados y de características similares, situados en el escarpe occidental de las Sierras de San Luis, se le asigna una edad pleistocena medio-tardía. Por su volumen y características (2,1 x109 m³ se estableció que se trata de un megadeslizamiento único en las Sierras de Córdoba y constituye uno de los deslizamientos de mayor tamaño entre los registrados hasta el presente en Argentina.

  9. [R_Arnedo_SanMiguel] Documentación geométrica de las excavaciones arqueológicas del Cerro de San Miguel (Arnedo, La Rioja)

    OpenAIRE

    2007-01-01

    [ES] El cerro de San Miguel de Arnedo alberga un importante asentamiento plenamente adscrito a la cultura celtibérica. Los restos documentados corresponden a dos conjuntos de viviendas y una estructura defensiva compuesta por un foso y restos de muralla. La documentación se ha realizado mediante estación total. Además, la muralla se ha documentado mediante fotogrametría estereoscópica. [EN] San Miguel’s hill houses an important archaeological site which dates back to the Celtiberian cul...

  10. IMPACTO EN AFLUENTES DEL RÍO PILCOMAYO POR CONTAMINANTES ADICIONALES DE DRENAJE ÁCIDO DE MINAS DESDE CERRO RICO, POTOSÍ-BOLIVIA

    OpenAIRE

    William H.J. Strosnider; Freddy S. Llanos; Cristina E. Marcillo; Ruben R. Callapa; Robert W. Nairn

    2014-01-01

    La minería intensiva y el procesamiento del cuerpo mineralizado del Cerro Rico de Potosí (Bolivia) ha ocurrido desde 1545. Para avanzar la investigación sobre descargas de drenaje acido de minas (DAM) y su conexión a la contaminación río abajo, se generaron datos en dos muestreos durante la temporada más extrema de lluvia y sequía. Las concentraciones en el DAM y arroyos receptores de Ag, B, Ba, Mo, Sb, Se, Sn, y V fueron superiores a los límites de descarga permitidos por la legislación Boli...

  11. Tecnología, subsistencia y cronología del sitio El Cerro, Departamento de Río Negro,Uruguaya

    OpenAIRE

    Gascue, Andrés; Loponte, Daniel M.; Moreno, Federica; Bortolotto, Noelia; Rodríguez, Ximena; Figueiro, Gonzalo; Teixeira, Franco; de Acosta, Alejandro

    2016-01-01

    En este trabajo se efectúa una revisión de los materiales obtenidos en El Cerro, excavado por Boretto y colaboradores en la segunda mitad del siglo pasado. El sitio se ubica sobre una suave colina natural en la margen derecha del Río Negro (República Oriental del Uruguay). La estratigrafía observada en sondeos recientemente efectuados en el sitio, indican que se trata de una elevación natural constituida por un albardón de arena edafizada. El conjunto arqueológico fue generado por grupos de c...

  12. Results from two years of resistivity monitoring at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Wilt, M.J.; Goldstein, N.E.

    1981-01-01

    Dipole-dipole resistivity measurements for the combined purposes of reservoir delineation and resistivity monitoring were first made at Cerro Prieto in 1978 and have continued on an annual basis since then. Two 20 km long dipole-dipole lines with permanently emplaced electrodes at one kilometer spacings were established over the field area; one of these lines is remeasured annually. Resistivity measurements are taken using a 25 kW generator capable of up to 80A output and a microprocessor controlled signal averaging receiver; this high power-low noise system is capable of highly accurate measurements even at large transmitter-receiver separations. Standard error calculations for collected data indicate errors less than 5% for all points, but 95% confidence intervals show error limits about 2 to 4 times higher. Analysis of collected data indicate little change in the apparent resistivity of the upper 300 m over the field production zone and that in this section measurements are relatively insensitive to the annual rainfall cycle. Apparent resistivity increases were observed over the older producing zone at Cerro Prieto at depths of 1 km and greater. Large zones of decreasing apparent resistivity were observed flanking the zone of increases on both sides. The increase in apparent resistivity in the production region may be due to an increasing fraction of steam in the reservoir resulting from a production related decline in reservoir pressure. Alternatively the increases may be the result of fresh water influx from the Colorado River. The zone of declining resistivity flanking the area of increase may be due to the movement of saline waters into the reservoir region as a result of the pressure decline. Quantitative modeling of observed changes is impractical owing to the high uncertainty in estimating apparent resistivity changes and the nonuniqueness of models.

  13. Microestructuras de deformación en rocas granulíticas, Cerro La Crespa, Tandilia, Provincia de Buenos Aires

    Directory of Open Access Journals (Sweden)

    Lucrecia Jorgensen

    2008-06-01

    Full Text Available El cerro La Crespa, localizado un kilómetro al sur de la megacizalla de Azul, integra las sierras de Azul, las cuales componen parte del Sistema de Tandilia. El presente trabajo trata sobre el estudio petrográfico-microestructural, donde se determina la composición modal y arreglos texturales a escala de grano y una primera caracterización geoquímica de rocas granulíticas aflorantes en el sector NO del cerro La Crespa. A partir de tales análisis, se intenta dilucidar los mecanismos de deformación actuantes y las condiciones metamórficas alcanzadas. Se reconocen rocas con texturas granoblásticas de composición básica e intermedia. Dichas rocas evidencian deformación frágil-dúctil heterogénea, con desarrollo de fábricas miloníticas, acaecida luego de que el evento metamórfico alcanzara su máximo desarrollo. Las texturas primitivas y la asociación de minerales anhidros presentes indicarían que dichas rocas podrían ser consideradas dentro de la serie de las granulitas. En las milonitas se aprecian significativos cambios mineralógicos, ya que al aumentar la deformación se incrementa la proporción de minerales hidratados y simultáneamente se reduce la cantidad de minerales anhidros. Estas modificaciones hacen suponer que la deformación actuó bajo condiciones metamórficas medias a altas, en facies de anfibolita superior-granulita inferior. Esta interpretación está apoyada por los mecanismos de deformación observados, a saber, recristalización dinámica de feldespatos, piroxenos, anfíboles, biotita y cuarzo; elongación de piroxenos y desarrollo de microboudinage.

  14. EFFECTS OF LOCALIZED AQUIFER BOILING ON FLUID PRODUCTION AT CERRO PRIETO.

    Science.gov (United States)

    Truesdell, Alfred H.; D'Amore, Franco; Nieva, David

    1984-01-01

    Localized aquifer boiling in the shallow two-phase reservoir of Cerro Prieto has produced excess steam and increased electrical output. Unfortunately it has also caused near-well mineral deposition that has decreased permeability and fluid flow. Inflow of cold water has limited the extent of aquifer boiling and permeability loss. The deeper reservoir at Cerro Prieto may need injection of cold water to decrease boiling and prevent loss of production. Refs.

  15. Evaluación integral del riesgo volcánico del Cerro Machín, Colombia

    Directory of Open Access Journals (Sweden)

    Leonel Vega Mora

    2013-01-01

    Full Text Available El volcán Cerro Machín (VCM se encuentra situado en la Cordillera Central de Colombia. Por la com- posición química, magnitud y extensión de sus erupciones pasadas, se reconoce como un volcán explosivo de gran potencial de daño, cuya actividad futura podría afectar intensamente durante mucho tiempo (meses hasta años una región muy estratégica para la economía del país, que cubre áreas pertenecientes a los departamentos de Tolima, Quindío, Valle del Cauca y Cundinamarca, en las cuales habitan cerca de un millón de personas. En este artículo se muestra la metodología y resultados del estudio de “Evaluación Integral del Riesgo del Cerro Machín – Colombia”, realizado durante 2009 por el Grupo PIGA de Investigación en Política, Información y Gestión Ambiental de la Facultad de Ingeniería de la Universidad Nacional de Colombia, tomando como punto de partida el estudio de “Evaluación de la Amenaza Volcánica Potencial del Cerro Machín” adelantado en el 2002 por el Servicio Geológico Colombiano (SGC. En consecuencia, se genera y ajusta una nueva ecuación para la determinación del riesgo, basada en la valoración de índices de amenaza intrínseca e índices de vulnerabilidad, los primeros en función del grado de intensidad, duración, extensión y acumulación de las amenazas, y los segundos, en función del grado de exposición espacial y temporal de los elementos (sociales, económicos, institucionales y ecosisté- micos y de su capacidad de respuesta intrínseca y extrínseca ante las amenazas. Con estas ecuaciones y mediante el uso de sistemas de información geográfica (SIG, se realiza para cada escenario de análisis considerando la modelación geoespacial del riesgo a nivel de cada pixel cartográfico del área territorial de estudio. En esta modelación se integra toda la informa- ción territorial del área en estudio, lo que permite obtener, de acuerdo con el marco lógico de evaluación preestablecido

  16. Geochemistry of igneous rocks from the Cerro Prieto geothermal field, northern Baja California, Mexico

    Science.gov (United States)

    Herzig, C. T.

    1990-08-01

    Fractional crystallization of basaltic magma, derived from an oceanic affinity source region present beneath the Salton Trough and emplaced into a pull-apart basin of this continental rift regime, produced a tholeiitic suite of hypabyssal rocks consisting of basalt, andesite and dacite within the Cerro Prieto geothermal field, located in northern Baja California, Mexico. Higher light-rare-earth-element abundances for a basalt from the Cerro Prieto geothermal field in comparison to basalts from the Gulf of California and the East Pacific Rise suggest partial assimilation of crustal materials into the parental magmas generated beneath the Salton Trough. The crustal contaminant may be present near the surface today in the form of granitoids of the Peninsular Ranges batholith, at deeper levels as hydrothermally altered materials near the base of the Salton Trough, or may be a relict feature of Tertiary subduction contained within the upper mantle beneath the Salton Trough. The Sr isotopic compositions of dacites from the nearby Cerro Prieto volcano range from 0.7029 to 0.7036, indicating an oceanic affinity source for these rocks. The suite of hypabyssal rocks of tholeiitic affinity present within the Cerro Prieto geothermal field, related by fractional crystallization, link the dacite volcano of Cerro Prieto to gabbroic plutons inferred to exist beneath the Cerro Prieto geothermal field.

  17. Composición, estructura y diversidad del cerro El Águila, Michoacán, México Composition, structure and diversity of the cerro El Águila, Michoacán, Mexico

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Zacarias-Eslava

    2011-09-01

    Full Text Available Se describe la composición, estructura y diversidad de la vegetación presente en el cerro El Águila, Michoacán. Se reconocieron fisonómicamente 5 tipos de vegetación y en cada uno se establecieron 16 parcelas circulares de 400 m² (3.2 ha para censar los individuos leñosos ≥ 10 cm d.a.p., con una parcela anidada de 100 m² (0.8 ha para los individuos entre 2.5 y 9.9 cm d.a.p. El muestreo incluyó 46 especies agrupadas en 33 géneros y 21 familias. Los bosques tropical caducifolio y de Quercus deserticola tuvieron los valores más bajos de altura promedio ( 11 m y área basal (> 40 m²/ha. La diversidad fue mayor en el bosque tropical caducifolio (S=23 y α =5.4 y menor en el de Quercus-Pinus (S= 13 y α= 2.71. En general, los tipos de vegetación mostraron diferentes especies dominantes y una alta diversidad beta. La composición y estructura de estas comunidades puede asociarse a cambios en altitud y a la perturbación por actividades humanas. No obstante, la zona de estudio aún presenta áreas en buen estado de conservación, particularmente los bosques templados hacia las zonas con mayor altitud, por lo que se sugiere que en un futuro cercano sea incluida dentro de alguna categoría de protección estatal.This study describes composition, structure and diversity of vegetation in the Cerro El Águila, Michoacán. Five plant communities were recognized and for each one all woody individuals ≥10 cm DBH were tallied in sixteen 400 m² circular plots, whereas individuals between 2.5 and 9.9 cm DBH were measured in a 100 m² circular sub-plot centered within each larger plot. A total of 46 species, 33 genera and 21 families were recorded. The tropical deciduous forest and Quercus deserticola forest had low values of mean plant height ( 11 m and basal area (> 40 m²/ha. Diversity was greater in the tropical deciduous forest (S= 23 and α= 5.4, respectively and lower in the oak-pine forest (S= 13 and α= 2.71. All communities displayed

  18. Analysis of two catalogues of seismicity at the Cerro Prieto geothermal area (Baja California) from 1988 to 1995, relationship with reinjection; Analisis de dos catalogos de sismicidad en el area geotermica de Cerro Prieto (Baja California) de 1988 a 1995, relacion con la reinyeccion

    Energy Technology Data Exchange (ETDEWEB)

    Fabriol, Hubert [Centro de Investigacion y de Ensenanza Superior de Ensenada (CICESE), Ensenada (Mexico)

    1996-09-01

    In order to study the effects of fluid reinjection in the Cerro Prieto geothermal field, started in 1989, seismicity recorded in this area and included in the USGS-Caltech (California Technology) (US) and the Red Sismologica del Noreste de Mexico (RESNOM) of the Centro de Investigacion Cientifica y de Ensenanza Superior (CICESE, Mexico) catalogues is reviewed since 1988. The precision of determination of epicenters is compared with the location of moderate events recorded by a local array, setup around Cerro Prieto since August 1994. We note a bias in both catalogues, as events located by USGS-Caltech are shifted between 5 to 10 km towards south and events of RESNOM are shifted between 4 to 8 km towards northeast. That limits the use of these catalogues for precise studies of reinjection effects in the geothermal field. Seismic activity is low until 1991 and increases afterwards, particularly in 1993 and 1995. Comparison of USGS-Caltech catalogue with changes in reinjection flow rates show at beginning of 1995 only one example of short-range effect between reinjection and seismicity (but using the epicenter determination of the local network) and possibly several medium-range effects (between 6 and 8 months). In that case, the flow rate increase corresponding to the beginning of winter, could be followed by one or more events of magnitude ranging from Ml=3 to Ml=4 during midsummer. Taking into account the tectonic context of the area, it is also possible that those event could be associated either to Cerro Prieto fault or to the spreading center source of the thermal anomaly. The continuous monitoring with a local network will allow to precise those preliminary results, obtained with regional networks. [Espanol] Como parte del estudio sobre los efectos de la reinyeccion de fluido en el campo geotermico de Cerro Prieto, iniciado en 1989, se analiza de manera critica la sismicidad registrada en el area y reportada en los catalogos de USGS-Caltech (Tecnologico de

  19. Hydraulic model of the steam-lines network of the Cerro Prieto, B.C., geothermal field; Modelo hidraulico de la red de vaporductos del campo geotermico de Cerro Prieto, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Salaices, E; Garcia, A; Martinez J I; Ovando, R; Cecenas, M; Hernandez A F [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: salaices@iie.org.mx; Canchola, I; Mora, O; Miranda, C; Herandez, M; Lopez, S; Murillo, I [Comision Federal de Electricidad, B.C (Mexico)

    2007-01-15

    The steam-line network of the Cerro Prieto geothermal field is composed of 184 wells, and 162 of the wells are integrated and connected by pipes. Thirteen power units, with an installed electrical capacity of 720 MW, are fed by that network. The network length is 120 km, including pipes of several diameters with branches and interconnections. The extension and complexity of the steam-line system make it difficult to analyze the transport and supply of steam to the power plants. For that it was necessary to have a tool capable of analyzing the system and the performance of the network as a whole, as well as the direction and flow volumes in each part of the system. In this paper, a hydraulic model of the Cerro Prieto steam-line network is presented. The model can determine the performance of the whole network by quantifying the pressure drops, flows and heat losses of the components. The model analyses the consequences of changes in operating conditions, steam production, maintenance activities and design (such as the integration of new wells). The model was developed using PIPEPHASE 9.0, a numeric simulator of multi-phase flow in steady state with heat transfer. It is used to model systems and pipe networks for steam- and condensate-transport. [Spanish] La red de vaporductos del campo geotermico de Cerro Prieto esta compuesta por un conjunto de 184 pozos, de los cuales 162 son pozos integrados, interconectados entre si a traves de una red de tuberias. Por medio de esta red se alimentan 13 unidades generadoras de electricidad con una capacidad total instalada de 720 MWe. La red tiene una longitud aproximada de 120 kilometros y esta compuesta por tuberias de diferentes diametros, ramales, interconexiones, etc. La complejidad y extension del sistema de vaporductos hace muy dificil el analisis del transporte y suministro de vapor a las plantas generadoras. Lo anterior creo la necesidad de contar con una herramienta que ayudara en el analisis del sistema con el fin de

  20. Evidence of recent deep magmatic activity at Cerro Bravo-Cerro Machín volcanic complex, central Colombia. Implications for future volcanic activity at Nevado del Ruiz, Cerro Machín and other volcanoes

    Science.gov (United States)

    Londono, John Makario

    2016-09-01

    In the last nine years (2007-2015), the Cerro Bravo-Cerro Machín volcanic complex (CBCMVC), located in central Colombia, has experienced many changes in volcanic activity. In particular at Nevado del Ruiz volcano (NRV), Cerro Machin volcano (CMV) and Cerro Bravo (CBV) volcano. The recent activity of NRV, as well as increasing seismic activity at other volcanic centers of the CBCMVC, were preceded by notable changes in various geophysical and geochemical parameters, that suggests renewed magmatic activity is occurring at the volcanic complex. The onset of this activity started with seismicity located west of the volcanic complex, followed by seismicity at CBV and CMV. Later in 2010, strong seismicity was observed at NRV, with two small eruptions in 2012. After that, seismicity has been observed intermittently at other volcanic centers such as Santa Isabel, Cerro España, Paramillo de Santa Rosa, Quindío and Tolima volcanoes, which persists until today. Local deformation was observed from 2007 at NRV, followed by possible regional deformation at various volcanic centers between 2011 and 2013. In 2008, an increase in CO2 and Radon in soil was observed at CBV, followed by a change in helium isotopes at CMV between 2009 and 2011. Moreover, SO2 showed an increase from 2010 at NRV, with values remaining high until the present. These observations suggest that renewed magmatic activity is currently occurring at CBCMVC. NRV shows changes in its activity that may be related to this new magmatic activity. NRV is currently exhibiting the most activity of any volcano in the CBCMVC, which may be due to it being the only open volcanic system at this time. This suggests that over the coming years, there is a high probability of new unrest or an increase in volcanic activity of other volcanoes of the CBCMVC.

  1. "Oasis de neblina" en los cerros costeros del sur de Iquique, región de Tarapacá, Chile, durante el evento El Niño 1997-1998 Fog oases during the El Niño Southern Oscillation 1997-1998, in the coastal hills south of Iquique, Tarapacá region, Chile

    Directory of Open Access Journals (Sweden)

    MÉLICA MUÑOZ-SCHICK

    2001-06-01

    Full Text Available Se describe la flora de cuatro sitios de "oasis de neblina" del desierto costero del Norte de Chile, entre Iquique y la desembocadura del río Loa, muestreados entre los meses de octubre de 1997 y enero de 1998. No existían muestreos anteriores en tres de los sitios: Alto Patache, Punta Lobos y Alto Chipana. Se registraron en esta ocasión 72 especies de plantas vasculares, lo que amplía notablemente el conocimiento florístico de este sector, que poseía a la fecha apenas una veintena de especies registradas. De las especies recolectadas, tres constituyen nuevos registros para la flora chilena: Nolana adansonii (Roem. et Schult. Johnst., Solanum cfr. montanum L. y Ophryosporus cfr. floribundus (DC. King et Rob., mientras que Alstroemeria lutea (Muñoz 2000 constituye una especie nueva para la ciencia. Esta última, junto a Eulychnia aricensis Ritter, Pyrrhocactus saxifragus Ritter y Nolana intonsa Johnst., son endémicas locales. Del total de especies, un 43 % son endémicas y un 52,8 % son nativas no endémicas, existiendo un bajo porcentaje (4,2 % de especies adventicias; 34 especies (47,2 % comparten su área de distribución con el Perú. Las familias Asteraceae, Nolanaceae y Solanaceae son las mejor representadas en el área con más de siete especies cada una. Las condiciones climáticas derivadas del evento El Niño 1997-1998 han favorecido el desarrollo de la vegetación en los oasis de neblina al sur de Iquique. Aunque no hay un aumento de las precipitaciones durante el período 1997-1998, sí se aprecia un incremento en las temperaturas así como en el contenido líquido de la neblina, lo que favorecería el desarrollo de una vegetación más exuberante y la expansión del área de ocupación de algunos elementos florísticosThe flora of four fog oases in the northern Chilean coastal desert, visited between October 1997 and January 1998, is described. These botanical collections are new for Alto Patache, Punta Lobos and Alto Chipana

  2. Hydrogeophysics and Water Balance of Cerro Prieto Dam, NE Mexico

    Science.gov (United States)

    Yutsis, V.; de León Gómez, H.; Masuch Oesterreich, D.; Izaguirre, F.

    2007-05-01

    The geographical location of the State of Nuevo Leon, due to its physiographic features, has temperate and arid climate; undeveloped drainage, low precipitations, and high evapotranspiration rates, as well as rapid demographic growth. The hydrological data of the Pablillo basin, registered in the hydrometric station Cerro Prieto, showed an annual precipitation from 415 up to 1130 mm/a , the mean evaporation of 705 mm/a (up to 2460 mm/a in 1996). The maximum water storage of the Cerro Prieto reservoir is 395 millions m3 which corresponds to a water level of 295 meters. However, this level was reached only three times after the dam's construction. By the end of June 2006 the water level was at 276.2 m which corresponds to a water volume of about 127,806,300 m3 which is less than a third of maximum storage. Analysis of hydrological data showed sufficient misbalance between water recharge (by rain, river flow) and loss due to evaporation, filtration, extraction, discharge, etc. 160 gravity reading points, 400 onshore magnetic field readings as well as about 250 offshore magnetic points were carried out. The standard corrections as instrumental drift, latitude, elevation, IGRF, etc. were applied to obtained data. Data procession includes Fourier transformation, wavelength filters, upward continuation, vertical and horizontal derivates, etc. As a result a 2D geological-geophysical models and 3D maps were elaborated. The general trend of the magnetic field reduced to a pole is NW - SE on which background anomalies of northeast trend are obviously traced. The general trend of the gravity field received as a result of our works is the same. However, local magnetic and residual gravity anomalies have mosaic character and, being morphologically extended in a NE direction, grouped in chains of northwest trend. Potential data interpretation allows assuming a series of the superficial fractures focused in a NE direction, perpendicular (NW-SE) to the general deep fault. The

  3. A preliminary interpretation of gas composition in the CP IV sector wells, Cerro Prieto geothermal field, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Barragan Reyes, Rosa Maria; Arellano Gomez, Victor M; Portugal Marin, Enrique [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Perez Hernandez, Alfredo; Rodriguez Rodriguez, Marco Helio; Leon Vivar, Jesus de [Comision Federal de Electricidad, Residencia General Cerro Prieto, B.C. (Mexico)

    2007-07-15

    -temperature fluids descending through the H fault to the reservoir was inferred, since results for the wells affected by this process (located at the center of the CP IV area) showed small or negative excess steam values and slightly lower temperatures (265-270 degrees Celsius). [Spanish] A fin de aumentar la capacidad de generacion de 620 a 720 MW, se desarrollo el sector Cerro Prieto IV (CP IV) en la porcion NE del campo geotermico de Cerro Prieto, donde se perforaron catorce pozos nuevos a partir del ano 2000. Los pozos de la zona de CP IV producen fluidos bifasicos con caracteristicas heterogeneas en cuanto a la fraccion de vapor: en la porcion central y hacia el NW los pozos producen liquido dominante mientras que hacia el E y S producen una fraccion de vapor relativamente alta. En este trabajo se estudia la composicion gaseosa de los fluidos producidos para obtener parametros del yacimiento tales como la temperatura y la fraccion de vapor e identificar diferentes aportes de fluidos a los pozos. Se utilizo un metodo basado en la reaccion de Fischer Tropsch y el equilibrio del H{sub 2}S con pirita-pirrotita como amortiguador (FT-HSH3). Los resultados para el estado inicial indican que existen fluidos con temperaturas de yacimiento entre 275 y 310 grados Celsius asi valores de exceso de vapor entre -1 y 50%. Los resultados se alinean en un patron de mezcla FT-HSH3 que sugiere que los pozos descargan una mezcla de los dos miembros finales en diferentes proporciones. Uno de ellos parece ser un liquido con una temperatura superior a los 300 grados Celsius con exceso de vapor negativo o insignificante. El otro parece ser un fluido bifasico con temperatura de unos 275 grados Celsius y un exceso de fraccion de vapor de aproximadamente 0.5. De acuerdo con datos de cada pozo y dependiendo de las condiciones de produccion de cada uno, pueden ocurrir mezclas de fluidos con diferentes proporciones de liquido y vapor en el yacimiento. Datos de 2005 de pozos perforados despues del ano 2000

  4. Dieta de murciélagos nectarívoros del Parque Nacional Cerros de Amotape, Tumbes

    Directory of Open Access Journals (Sweden)

    Edith Arias

    2011-07-01

    Full Text Available En el Perú se reporta la presencia de 18 especies de murciélagos nectarívoros, sin embargo se cuenta con poca información sobre la dieta de estas especies. En este estudio se reporta por primera vez la dieta de los nectarívoros Glossophaga soricina, Lonchophylla hesperia y Anoura geoffroyi en el bosque seco ecuatorial y del bosque tropical del Pacífico del Parque Nacional Cerros de Amotape, Tumbes. Analizamos 21 contenidos gastrointestinales e identificamos ocho morfotipos de polen pertenecientes a las familias Bombacaceae, Cactaceae, Fabaceae, Solanaceae, Rubiaceae, Myrtaceae, Malvaceae y Rosaceae. Encontramos evidencia del síndrome de quiropterofilia en Bombacaceae, Cactaceae, Fabaceae, Solanaceae y Rubiaceae. Observamos que A. geoffroyi consume polen de Ceiba trichistandra, Solanaceae y Rubiacea; G. soricina consume de Abutilon reflexum, Armathocereus cartwrightianus, C. trichistandra y Rubiaceae; y L. hesperia de A. cartwrightianus, Eriobotrya japonica, Fabaceae y Psidium sp.; sugiriendo una dieta generalista en estas especies. Los murciélagos G. soricina y A. geoffroyi comparten el consumo del ceibo C. trichistandra y de la Rubiaceae, mientras que G. soricina comparte con L. hesperia el consumo del cactus A. cartwrightianus. Los otros morfotipos de polen no fueron compartidos entre murciélagos. Se encuentra además que el ceibo C. trichistandra fue la especie más consumida, especialmente por G. soricina.

  5. Minería, conflicto y mediadores locales: Minera San Xavier en Cerro de San Pedro, México Mineira, conflito e mediadores locais: Minera San Xavier em Cerro de San Pedro Mining, conflict and local brokers: Minera San Xavier in Cerro de San Pedro

    Directory of Open Access Journals (Sweden)

    Hernán Horacio Schiaffini

    2011-12-01

    Full Text Available Este trabajo indaga en las instancias de mediación que intervienen en la articulación de procesos económicos de gran escala y su puesta en práctica local. Basándonos en el conflicto que se produjo en el Municipio de Cerro de San Pedro (San Luis Potosí, México entre la empresa Minera San Xavier y el Frente Amplio Opositor (FAO a la misma, aplicamos el método etnográfico con el objetivo de describir las estructuras locales de mediación política y analizar sus prácticas y racionalidad. Intentamos demostrar así la importancia de los factores políticos locales en las vinculaciones entre estado, empresa y población.Este trabalho indaga nas instâncias de mediação que intervêm em processos econômicos de grande escala e sua posta em prática local. Baseando-nos no conflito no Cerro de San Pedro (San Luis Potosí, México entre a empresa Minera San Xavier e a Frente Amplio Opositor (FAO aplicamos o método etnográfico pra descrever as estruturas de mediação política locais e analisar suas práticas e racionalidade. Tenta-se demonstrar assim a importância dos fatores políticos locais nas vinculações entre estado, empresa e população.This paper investigates in instances of mediation involved in large-scale economic processes and local implementation. Analyzing the conflict in Cerro de San Pedro (San Luis Potosí, México among San Xavier mining company and the Frente Amplio Opositor (FAO, it applies an ethnographic approach to describe the local structures of political mediation and its practices and rationality. The work shows the relevance of local factors in the relationships between State, company and people.

  6. Una fosa-vertedero de época vettona en el Cerro de la Mesa (Alcolea de Tajo, Toledo

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    Chapa Brunet, Teresa

    2013-06-01

    Full Text Available The existence of pits filled with earth, ashes, pottery fragments and fauna, usually known as ash pits, rubbish pits or dumps, has been recognized on many Second Iron Age settlements of the Spanish Northern Plateau, generally linked with Vaccean and Vettonian groups. However, its distribution should be extended to the west of the Southern Plateau and eastern Extremadura, as evidenced by the example of the Cerro de la Mesa village and indications coming from other western sites. We offer here a detailed study of part of a rubbish pit where certain domestic remains were withdrawn in connection with a new project of urbanisation of the Vettonian village held on the transition from the 3rd to the 2nd centuries BC.La existencia de fosas rellenas con tierra, cenizas, fragmentos cerámicos y fauna denominadas genéricamente como cenizales, basureros o vertederos, es un hecho bien conocido en la Meseta Norte durante la Segunda Edad del Hierro, vinculándose con los grupos Vacceos y Vettones. Sin embargo, su distribución debe ampliarse al occidente de la Meseta Sur y oriente extremeño, como se evidencia tanto en el Cerro de la Mesa como a través de indicios documentados en otros yacimientos más occidentales. Se presenta aquí un detallado estudio de un sector de la fosa que actuó como vertedero para la retirada de ciertos restos domésticos con ocasión de la reurbanización en profundidad del poblado vettón que tuvo lugar en la transición del siglo III al II a.C.

  7. Investigating the subsurface connection beneath Cerro Negro volcano and the El Hoyo Complex, Nicaragua

    Science.gov (United States)

    Venugopal, Swetha; Moune, Séverine; Williams-Jones, Glyn

    2016-10-01

    Cerro Negro, the youngest volcano along the Central American Volcanic Belt (CAVB), is a polygenetic cinder cone with relatively frequent basaltic eruptions. The neighbouring El Hoyo complex, of which Las Pilas is the dominant edifice, is a much larger and older complex with milder and less frequent eruptions. Previous studies have suggested a deep link beneath these two closely spaced volcanoes (McKnight, 1995; MacQueen, 2013). Melt inclusions were collected from various tephra samples in order to determine whether a connection exists and to delineate the features of this link. Major, volatile, and trace elemental compositions reveal a distinct geochemical continuum with Cerro Negro defining the primitive endmember and El Hoyo representing the evolved endmember. Magmatic conditions at the time of melt inclusion entrapment were estimated with major and volatile contents: 2.4 kbar and 1170 °C for Cerro Negro melts and 1.3 kbar and 1130 °C for El Hoyo melts with an overall oxygen fugacity at the NNO buffer. Trace element contents are distinct and suggest Cerro Negro magmas fractionally crystallise while El Hoyo magmas are a mix between primitive Cerro Negro melts and residual and evolved El Hoyo magma. Modelling of end member compositions with alphaMELTS confirms the unique nature of El Hoyo magmas as resulting from incremental mixing between Cerro Negro and residual evolved magma at 4 km depth. Combining all available literature data, this study presents a model of the interconnected subsurface plumbing system. This model considers the modern day analogue of the Lemptégy cinder cones in Massif Central, France and incorporates structurally controlled dykes. The main implications of this study are the classification of Cerro Negro as the newest conduit within the El Hoyo Complex as well as the potential re-activation of the El Hoyo edifice.

  8. Detailed microearthquake studies at the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Majer, E.L. (Lawrence Berkeley Lab., CA); McEvilly, T.V.

    1981-01-01

    There appears to be an increase in seismic activity within the Cerro Prieto production zone since early 1978. The microearthquake activity is now more or less constant at a rate of 2 to 3 events per day. The b-values within the field are significantly higher inside the production zone than are those for events on faults outside of the production region. The earthquakes seem to be controlled by the Hidalgo fault, although slight clustering was observed in the center of the main production region. The earthquakes within the production zone may reflect the reservoir dynamics associated with heat and mass withdrawal. Mechanisms such as volume change, thermal stresses and weakening of materials associated with boiling (i.e., phase changes, dissolution) may all be responsible for the increased seismic activity. Although a small reinjection program has started, the pressure drawdown conditions existing within the field would imply that increased pore pressure resulting from the injection activities is not responsible for the increased seismic activity.

  9. Evolution of the Cerro Prieto reservoirs under exploitation

    Energy Technology Data Exchange (ETDEWEB)

    Truesdell, A.H.; Lippmann, M.J. [Lawrence Berkeley National Lab., CA (United States); Puente, H.G. [Comision Federal de Electricidad, Mexicali (Mexico)

    1997-07-01

    The Cerro Prieto Geothermal field of Baja California (Mexico) has been under commercial production to generate electricity since 1973. Over the years, the large amount of Geothermal fluids extracted (at present about 12,000 tons per hour) to supply steam to the power plants has resulted in a reduction of pressures, changes in reservoir processes, and increased flow of cooler groundwater into the geothermal system. The groundwater recharging the reservoir moves horizontally through permeable layers, as well as vertically through permeable fault zones. In addition, the supply of deep hot waters has continued unabated, and perhaps has increased as reservoir pressure decreased. Since 1989, this natural fluid recharge has been supplemented by injection which presently amounts to about 20% of the fluid produced. Changes in the chemical and physical characteristics of the reservoir fluids due to the drop in pressures and the inflow of cooler groundwaters and injectate have been detected on the basis of wellhead data. These changes point to reservoir processes like local boiling, phase segregation, steam condensation, mixing and dilution. Finally, the study identified areas where fluids are entering the reservoir, as well as indicated their source (i.e. natural Groundwater recharge versus injectate) and established the controlling geologic structures.

  10. Cerro Prieto cold water injection: effects on nearby production wells

    Energy Technology Data Exchange (ETDEWEB)

    Truesdell, A.H.; Lippmann, M.J.; De Leon, J.; Rodriguez, M.H.

    1999-07-01

    The liquid-dominated Cerro Prieto geothermal field of northern Baja California, Mexico has been under commercial exploitation since 1973. During the early years of operation, all waste brines were sent to an evaporation pond built west of the production area. In 1989, cooled pond brines began to be successfully injected into the reservoir along the western boundary of the geothermal system. The injection rate varied over the years, and is at present about 20% of the total fluid extracted. As expected under the continental desert conditions prevailing in the area, the temperature and salinity of the pond brines change with the seasons, being higher during the summer and lower during the winter. The chemistry of pond brines is also affected by precipitation of silica, oxidation of H{sub 2}S and reaction with airborne clays. Several production wells in the western part of the field (CP-I area) showed beneficial effects from injection. The chemical (chloride, isotopic) and physical (enthalpy, flow rate) changes observed in producers close to the injectors are reviewed. Some wells showed steam flow increases, in others steam flow decline rates flattened. Because of their higher density, injected brines migrated downward in the reservoir and showed up in deep wells.

  11. What lies beneath the Cerro Prieto geothermal field?

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Williams, A.E.; Biehler, S. [Univ. of California, Riverside, CA (United States)

    1997-12-31

    Although the Cerro Prieto geothermal reservoir is one of the world`s largest geothermal developments, conflicting ideas persist about the basement beneath it. The current plan to drill a 6 km deep exploratory well in the eastern part of the field has brought this controversy into sharper focus. This paper discusses criteria which any model of what lies beneath the reservoir must meet, in terms of regional tectonics and geophysics, of the metamorphic and igneous rocks thus far encountered in drilling, and of models of possible heat sources and coupling between the hydrothermal and magmatic systems. Our analysis confirms the interpretation that the crystalline basement beneath the sediments, rather than being granitic, is oceanic in character, resembling an ophiolite complex. The heat source is most likely a cooling gabbroic intrusion, several kilometers in diameter, overlain by a sheeted dike swarm. A 6 km deep bore-hole centered over such an intrusion would not only be one of the world`s deepest geothermal wells but could also be one of the hottest.

  12. Performance of casings in Cerro Prieto production wells

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez A, B.; Vital B, F.; Bermejo M, F.; Sanchez G, G.

    1981-01-01

    A careful evaluation of different production casings used at Cerro Prieto from 1964 to date has shown that the following casings have yielded particularly impressive results: 7 5/8-in. diameter, J-55, 26 lb/ft; 7 5/8-in. diameter, K-55, 45.3 lb/ft; and 5-in. diameter, K-55, 23.2 lb/ft. These casings differ from others of the same diameter but lighter weight which were also used at the field. The results are favorable in spite of severe construction problems, especially the loss of circulation during cementing operations, which we encountered in some of the wells where these casings were used. The use of gravity-fed fine sand as packing material and the arrangement of the production and intermediate casings were important in avoiding damage due to tension-compression stresses and, above all, damage due to internal or external corrosion over time. This situation is clearly evidenced if we compare the damage to the above casings with that experienced by grade N-80 production casings, especially in a corrosive environment.

  13. Geología de la Formación Cerro Negro (Cretácico en Isla Livingston: aportes a su geocronología y contenido paleontológico Geology of the Cerro Negro Formation (Cretaceous in Livingston Island: contributions to its geochronology and paleontological content

    Directory of Open Access Journals (Sweden)

    C.A. Parica

    2007-12-01

    Full Text Available La península Byers se encuentra en el extremo occidental de la isla Livingston, archipiélago de las islas Shetland del Sur. Geológicamente está caracterizada por depósitos marinos, continentales y volcanismo cretácico-terciario que son incluidos en la Formación Cerro Negro de la sección superior del Grupo Byers. Las secuencias magmáticas han sido divididas en dos grupos principales, el primero comprende a las rocas piroclásticas y reúne cinco unidades con un importante desarrollo y distribución en el área. Por su parte, el segundo grupo comprende lavas e intrusivos aflorantes en cerros Don Carlos, Usnea (Usnea Plug, Chester (Chester Cone, Sealer (Sealer Hill y Negro (Negro Hill. Los términos sedimentarios incluyen conglomerados, areniscas y pelitas, de color gris verdoso con estratificación entrecruzada (tanto tabular como en artesa, raramente estratos macizos, laminación horizontal (en algunos casos de naturaleza rítmica, y estructuras de deformación sinsedimentaria (principalmente laminación convoluta. Se propone un ambiente fluvial de depositación, con canales dominados por carga de lecho y barras areno-gravosas bien desarrolladas. En lo que corresponde al sector de planicie de inundación, predominó allí la depositación de material limo-arcilloso por corrientes tractivas débiles durante las crecientes. En las áreas deprimidas de las planicies habría tenido lugar la formación de cuerpos de aguas de poca profundidad en los que se vió favorecida la preservación de la macro y microflora. En las nuevas localidades fosilíferas de península Byers, Domo Rotch (Rotch Dome, cerro Don Carlos, Lomada de las Plantas y 904, ha sido reconocida la presencia de las especies: Araucarites sp., Archangelskya furcata Herbst, Cladophlebis sp., Dictyozamites sp., Elatocladus sp, Phyllopteroides sp., Pseudoctenis sp., Ptyllophyllum menendezii Cantrill, Sphenopteris sp., Eocyathea remesaliae Césari, Sergioa austrina Césari y

  14. [R_Arnedo_SanMiguel] Documentación geométrica de las excavaciones arqueológicas del Cerro de San Miguel (Arnedo, La Rioja). Campaña 2007

    OpenAIRE

    2007-01-01

    [ES] El cerro de San Miguel de Arnedo alberga un importante asentamiento plenamente adscrito a la cultura celtibérica. Los restos documentados corresponden a dos conjuntos de viviendas y una estructura defensiva compuesta por un foso y restos de muralla. En la presente campaña se han incorporado los restos excavados desde la documentación anterior y el perímetro del yacimiento. Además, se ha calculado el cambio de sistema de referencia de ED50 a ETRS89. [EN] San Miguel’s hill houses an ...

  15. Petrological and Geochemical Studies of the Igneous Rocks at Cerro EL Borrego, Chihuahua, Mexico

    Science.gov (United States)

    Estrada, V. M.; Espejel-Garcia, V. V.; Villalobos-Aragon, A.

    2013-05-01

    Cerro El Borrego, which is a hill composed of igneous rocks, is located 13.7 km to the SW of Chihuahua city, in northern Mexico. The coordinates of the hill are 28° 11' 07'' N latitude and 105° 33' 23'' W longitude. The study area is within the Basin and Range Physiographic Province, characterized by a complex tectonic-structural pattern, such as elongated ranges with folds and igneous rock formations of Paleogene age. A lava flow of Oligocene age is part of the large volcanic and plutonic activity at the early times of the Cenozoic, which occurred to the NW portion of Mexico. In Cerro El Borrego, the rocks that outcrop are middle Oligocene's rhyolitic tuff to the NW of the hill, while to its SE there is a Pleistocene polymictic conglomerate. Previous work shows different interpretations about the origin and composition of the igneous rocks at Cerro El Borrego. This project includes whole rock and textural analyses, which helped to discern the petrogenesis of these rocks. Preliminary petrographic analyses indicate that the Cerro El Borrego, is a structural dome, and its feldspar-rich rocks contain large crystals that can be appreciated without a microscope. The presence of a porphyritic texture, suggest a sallow intrusion origin. A preliminary conclusion is that Cerro El Borrego is a shallow depth intrusive body with a syenitic composition derived from the Oligocene plutonic activity.

  16. Al Este del Cerro Pampa: ampliación del área de disponibilidad de obsidiana de la Pampa del Asador (Provincia de Santa Cruz East of the Cerro Pampa: enlargement of the obsidian availability area from Pampa del Asador (Santa Cruz Province

    Directory of Open Access Journals (Sweden)

    Juan Bautista Belardi

    2006-12-01

    Full Text Available La Pampa del Asador ha sido identificada como el lugar de proveniencia de distintos tipos de obsidiana, mayoritariamente negra, y el Cerro Pampa, ubicado en el extremo suroeste de la pampa, ha sido un punto central a partir del cual se ha medido la dispersión de los artefactos confeccionados en esta materia prima. Sobre la base de la interpretación de imágenes satelitales, análisis químicos y trabajos de campo se presenta y discute la evidencia provista por nódulos y artefactos de obsidiana recuperados en paleocauces y un abanico aluvial que se origina en la Pampa del Asador. Los resultados muestran la ampliación del área de disponibilidad de obsidiana 65 km hacia el este y 75 km al noreste del Cerro Pampa y, aunque presentando menor frecuencia relativa de nódulos y el decrecimiento de sus tamaños, el área se amplía a lo largo de la Pampa La Chispa. Estos resultados tienen implicaciones tanto en términos de la distribución de frecuencias de artefactos de obsidiana en el registro arqueológico regional como en los costos de aprovisionamiento de la roca.Pampa del Asador has been identified as the source of distinct types of obsidian (generally black, and Cerro Pampa, located in the extreme southwest of the Pampas, has been the central point from which the dispersal of artifacts fashioned from this obsidian has been measured. Based on the interpretation of satellite images, geochemical analysis, and field work, we present and discuss evidence provided by nodules and artifacts of obsidian recovered from paleo-drainage channels and an alluvial fan which originates in Pampa del Asador. The results expand the area of availability of obsidian 65 km east and 75 km northeast of Cerro Pampa, and also across Pampa La Chispa, although the relative frequency of nodules decreases and smaller size increases. These results have implications both in terms of the distribution and frequency of obsidian artifacts in the regional archaeological record

  17. Procesos históricos y ambientales en Cerro de San Pedro, San Luis Potosí, México, 1948-1997

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    Paula Andrea Martínez Chaves

    2010-01-01

    Full Text Available Los estudios sobre el municipio Cerro de San Pedro enfatizan la continuidad ambiental aparente que estimula la minería; sin embargo, esta lectura subvalora otras dinámicas que ocurren en la zona. Con base en observaciones directas de trabajo en campo, para realizar análisis de coberturas vegetales, entrevistas con los habitantes de la zona, revisión de cartografía e investigación de archivo, el presente trabajo muestra procesos como la explotación de recursos vegetales y el pastoreo, como actividades económicas paralelas a las labores mineras, y que no habían sido tratados hasta ahora.

  18. Geología de la Formación Cerro Negro (Cretácico en Isla Livingston: aportes a su geocronología y contenido paleontológico

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    C.A. Parica

    2007-12-01

    Full Text Available La península Byers se encuentra en el extremo occidental de la isla Livingston, archipiélago de las islas Shetland del Sur. Geológicamente está caracterizada por depósitos marinos, continentales y volcanismo cretácico-terciario que son incluidos en la Formación Cerro Negro de la sección superior del Grupo Byers. Las secuencias magmáticas han sido divididas en dos grupos principales, el primero comprende a las rocas piroclásticas y reúne cinco unidades con un importante desarrollo y distribución en el área. Por su parte, el segundo grupo comprende lavas e intrusivos aflorantes en cerros Don Carlos, Usnea (Usnea Plug, Chester (Chester Cone, Sealer (Sealer Hill y Negro (Negro Hill. Los términos sedimentarios incluyen conglomerados, areniscas y pelitas, de color gris verdoso con estratificación entrecruzada (tanto tabular como en artesa, raramente estratos macizos, laminación horizontal (en algunos casos de naturaleza rítmica, y estructuras de deformación sinsedimentaria (principalmente laminación convoluta. Se propone un ambiente fluvial de depositación, con canales dominados por carga de lecho y barras areno-gravosas bien desarrolladas. En lo que corresponde al sector de planicie de inundación, predominó allí la depositación de material limo-arcilloso por corrientes tractivas débiles durante las crecientes. En las áreas deprimidas de las planicies habría tenido lugar la formación de cuerpos de aguas de poca profundidad en los que se vió favorecida la preservación de la macro y microflora. En las nuevas localidades fosilíferas de península Byers, Domo Rotch (Rotch Dome, cerro Don Carlos, Lomada de las Plantas y 904, ha sido reconocida la presencia de las especies: Araucarites sp., Archangelskya furcata Herbst, Cladophlebis sp., Dictyozamites sp., Elatocladus sp, Phyllopteroides sp., Pseudoctenis sp., Ptyllophyllum menendezii Cantrill, Sphenopteris sp., Eocyathea remesaliae Césari, Sergioa austrina Césari y

  19. Measured ground-surface movements, Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Massey, B.L.

    1981-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley, 30 kilometers southeast of Mexicali, Baja California, incurred slight deformation because of the extraction of hot water and steam, and probably, active tectonism. During 1977 to 1978, the US Geological Survey established and measured two networks of horizontal control in an effort to define both types of movement. These networks consisted of: (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from stations on an existing US Geological Survey crustal-strain network north of the international border; and (2) a local net tied to stations in the regional net and encompassing the present and planned geothermal production area. Electronic distance measuring instruments were used to measure the distances between stations in both networks in 1978, 1979 and 1981. Lines in the regional net averaged 25 km. in length and the standard deviation of an individual measurement is estimated to be approx. 0.3 part per million of line length. The local network was measured using different instrumentation and techniques. The average line length was about 5 km. and the standard deviation of an individual measurement approached 3 parts per million per line length. Ground-surface movements in the regional net, as measured by both the 1979 and 1981 resurveys, were small and did not exceed the noise level. The 1979 resurvey of the local net showed an apparent movement of 2 to 3 centimeters inward toward the center of the production area. This apparent movement was restricted to the general limits of the production area. The 1981 resurvey of the local net did not show increased movement attributable to fluid extraction.

  20. Interaction of cold-water aquifers with exploited reservoirs of the Cerro Prieto geothermal system

    Science.gov (United States)

    Truesdell, Alfred; Lippmann, Marcelo

    1990-01-01

    Cerro Prieto geothermal reservoirs tend to exhibit good hydraulic communication with adjacent cool groundwater aquifers. Under natural state conditions the hot fluids mix with the surrounding colder waters along the margins of the geothermal system, or discharge to shallow levels by flowing up fault L. In response to exploitation reservoir pressures decrease, leading to changes in the fluid flow pattern in the system and to groundwater influx. The various Cerro Prieto reservoirs have responded differently to production, showing localized near-well or generalized boiling, depending on their access to cool-water recharge. Significant cooling by dilution with groundwater has only been observed in wells located near the edges of the field. In general, entry of cool water at Cerro Prieto is beneficial because it tends to maintain reservoir pressures, restrict boiling, and lengthen the life and productivity of wells.

  1. SELF-POTENTIAL SURVEY AT THE CERRO PRIETO GEOTHERMAL FIELD, BAJA CALIFORNIA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Corwin, R.F.; Diaz C., S.; Rodriguez B., J.

    1978-06-01

    In December 1977, two self-potential survey lines were run across the producing area of the Cerro Prieto geothermal field, located about 30 km south of Mexicali, Baja California, Mexico. The purpose of the survey was to determine whether significant self-potential variations were related to the known geothermal activity. Large-amplitude, long-wavelength self-potential anomalies are seen in the Cerro Prieto geothermal field. The inflection points of the anomalies are roughly centered over two major faults thought to act as conduits for the thermal fluids, and the form of the anomalies indicates that they may be generated by electrical activity extending to a depth of several km along the fault zones. Thus, self-potential measurements may be helpful in tracing thermally active fault zones in the Cerro Prieto area.

  2. EMPLEO DEL PROGRAMA VOLCFLOW PARA SIMULAR FLUJOS PIROCLÁSTICOS DEL VOLCÁN CERRO MACHÍN, TOLIMA, COLOMBIA

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    Elsa Adriana Cárdenas Quiroga

    2013-01-01

    Full Text Available Se presentan los resultados de simular futuros flujos piroclásticos que podría producir el Volcán Cerro Machín, ubicado en la Cordillera Central de Colombia. Esta simulación se realizó con el programa VolcFlow desarrollado por el Laboratorio de Magmas y Volcanes de la Universidad Blaise Pascal, Francia, diseñado especialmente para modelar el comportamiento de este tipo de productos volcánicos, ya que está basado en las características reológicas de esos flujos. Se comparan las áreas que serían potencialmente afectadas por una erupción de ese tipo y los espesores del material que se depositaría con resultados obtenidos de simulaciones realizadas con un Model Builder desarrollado en ARC GIS por el Grupo de Investigación Geomática Aplicada de la Universidad Militar Nueva Granada en Colombia, obteniéndose resultados similares.

  3. Babel en la mina. El campamento minero como modelo de asentamiento en el mundo industrializado: Cerro Muriano (Córdoba.

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    Cano Sanchiz, J.M.

    2012-01-01

    Full Text Available El campamento minero contemporáneo es un tipo de asentamiento muy concreto, configurado bajo unos cánones que, con matices, suelen repetirse a escala internacional. Se trata de un lugar de convergencia, de fricción de clases. También, de un espacio heterogéneo desde el punto de vista cultural donde, sin embargo, el grupo humano formado por los obreros suele aparecer cohesionado por unas circunstancias comunes. Estas características se acentúan allí donde la inversión procede de un país distinto al de la mina. Hablamos, muchas veces, de territorios ocupados en el marco de una actividad económica de corte colonialista. Estas páginas recogen un análisis arqueológico del asentamiento surgido en torno a las minas de Cerro Muriano (Córdoba durante su explotación inglesa a principios del siglo XX. El ejemplo seleccionado nos sirve para ilustrar cómo fueron aquellos campamentos, muchos de los cuales sobrevivieron a la desaparición de la actividad minera y evolucionaron hacia núcleos de población consolidados, como es el caso.

  4. Gas equilibria in Cerro Prieto geothermal field, B.C., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Portugal, E.; Barragan, R.M.; Izquierdo, G. [Inst. de Investigaciones Electricas, Morelos (Mexico); Leon, J. de [Comision Federal de Electricidad, Mexicali B.C. (Mexico)

    2003-07-01

    Gas equlibria methods involving fischer-tropsch-pyrite-magnetite; and fischer-tropsch-pyrite-hematite-pyrite-magnetite reactions were used to evaluate reservoir temperature and a mass steam fraction in Cerro Prieto geothermal field. These approaches have been applied in some selected producing wells from four areas under exploitation. The results show good correlation for both equilibria methods; however fischer-tropsch; pyrite-magnetite reactions provide the best estimation of the physical reservoir parameters. The main processes found for Cerro Prieto IV area are lateral vapor contribution and the inflow of hotter and deeper fluid with high liquid saturation. (orig.)

  5. Indios y blancos en la ciudad minera: Cerro de Pasco en el siglo XIX1

    OpenAIRE

    Contreras, Carlos

    2014-01-01

    En este artículo se presenta una descripción de las condiciones de vida, materiales y culturales en Cerro de Pasco durante el siglo pasado, cuando era una de las principales ciudades de la sierra peruana, tanto en lo económico como en lo demográfico.El autor discute las características de la estructura social de Cerro de Pasco, recalcando la yuxtaposición de elementos económicos y étnico-culturales y el tipo de relaciones sociales prevalecientes. Luego describe las características y condicion...

  6. ANALISIS DEL CO-TRATAMIENTO PASIVO DE AGUAS RESIDUALES MUNICIPALES Y DRENAJE ACIDO DE MINAS EN CERRO RICO DE POTOSÍ, BOLIVIA

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    William H.J. Strosnider

    2015-01-01

    Full Text Available El drenaje acido de minas (DAM es un problema a nivel mundial. El co-tratamiento pasivo de DAM con aguas residuales municipales (ARM es una manera efectiva y de bajo costo que utiliza los nutrientes de ARM para tratar las concentraciones de metales y sulfato en DAM. Cerro Rico de Potosí, Bolivia es una de las grandes ciudades mineras en el mundo que tiene muchos problemas con el DAM. El objetivo de este estudio fue determinar velocidades de reacción de Al, Fe, Mn, Zn, y otros metales en DAM provenientes de un flujo de agua en Cerro Rico usando un sistema reactor de tres etapas. El DAM tenía un pH de 3.58, acidez de 1080 mg/L equivalente a CaCO3 conteniendo concentraciones de 12, 68, 17, y 550 mg/L de Al, Fe, Mn y Zn respectivamente. Las velocidades de reacción de Al, Fe, Mn y Zn fueron de 1.43, 2.09, 0.01 y 0.10 d-1, respectivamente.

  7. Edad, caracterización petrográfica y Geoquímica del Granitoide del Cerro Falkner, Neuquén

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    Sabrina Crosta

    2008-03-01

    Full Text Available El Cerro Falkner se halla constituido por rocas graníticas infrayacentes a las volcanitas de la Formación Ventana de edad paleógena. Dichos intrusivos son de composición granodiorítica, metaluminosos a peraluminosos, subalcalinos, con características de granitos de arco volcánico concordantes con otros granitoides del segmento norte de la Cordillera Patagónica Septentrional. La edad obtenida por el método K-Ar sobre anfíboles de composición tschermakítica (125 ± 20 Ma indica una edad mínima perteneciente al Cretácico inferior para la granodiorita del cerro Falkner, por lo que sería incorrecto utilizar la denominación Formación Los Machis (Cretácico superior para estas rocas. Esta edad, permite vincular las rocas graníticas del área de estudio con el volcanismo representado por el Grupo Divisadero de edad predominantemente cretácica inferior.

  8. Microestructuras de deformación en rocas granulíticas, Cerro La Crespa, Tandilia, Provincia de Buenos Aires Deformation microstructures in granulitic rocks, Cerro La Crespa, Tandilia, province of Buenos Aires

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    Lucrecia Jorgensen

    2008-06-01

    Full Text Available El cerro La Crespa, localizado un kilómetro al sur de la megacizalla de Azul, integra las sierras de Azul, las cuales componen parte del Sistema de Tandilia. El presente trabajo trata sobre el estudio petrográfico-microestructural, donde se determina la composición modal y arreglos texturales a escala de grano y una primera caracterización geoquímica de rocas granulíticas aflorantes en el sector NO del cerro La Crespa. A partir de tales análisis, se intenta dilucidar los mecanismos de deformación actuantes y las condiciones metamórficas alcanzadas. Se reconocen rocas con texturas granoblásticas de composición básica e intermedia. Dichas rocas evidencian deformación frágil-dúctil heterogénea, con desarrollo de fábricas miloníticas, acaecida luego de que el evento metamórfico alcanzara su máximo desarrollo. Las texturas primitivas y la asociación de minerales anhidros presentes indicarían que dichas rocas podrían ser consideradas dentro de la serie de las granulitas. En las milonitas se aprecian significativos cambios mineralógicos, ya que al aumentar la deformación se incrementa la proporción de minerales hidratados y simultáneamente se reduce la cantidad de minerales anhidros. Estas modificaciones hacen suponer que la deformación actuó bajo condiciones metamórficas medias a altas, en facies de anfibolita superior-granulita inferior. Esta interpretación está apoyada por los mecanismos de deformación observados, a saber, recristalización dinámica de feldespatos, piroxenos, anfíboles, biotita y cuarzo; elongación de piroxenos y desarrollo de microboudinage.This work deals with a petrographic- microstructural study in order to determine the modal composition and textural arrangement on a grain scale and the first geochemistry characterization of granulitic rocks on the NW of the cerro La Crespa, which is located about 1 km south of the Azul Megashear and forms part of the sierras de Azul in the Tandilia System

  9. Evolución magmática del Granito Peñón Rosado, Cerro Asperecito, flanco occidental de la sierra de Famatina

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    J.A. Dahlquist

    2006-03-01

    Full Text Available El granate es un mineral accesorio poco común en rocas ígneas y constituye un tema relevante de la petrología ígnea. Estudios combinados de petrología, química mineral, geoquímica de roca total y geoquímica isotópica en el cerro Asperecito indican que los granitoides con granate que forman el Granito Peñón Rosado (GPR fueron producidos por la fusión parcial de rocas metasedimentarias con subsecuente diferenciación durante su emplazamiento en el Ordovícico inferior-medio. En este sentido, la facies GPR1 representa un cristalizado temprano, la facies GPR2 representa un fundido diferenciado, y la facies GPR3 un fundido residual. El Granito Peñón Rosado, fue emplazado en condiciones de moderada temperatura (785ºC y presión media (4,4 kb en profundidades de la corteza media (~15 km. El emplazamiento casi sincrónico en la corteza media de una abundante suite metaluminosa durante el Ordovícico inferior-medio (468 Ma en el cerro Asperecito fue suficiente para inducir anatexis local de los metasedimentos circundantes. Los contenidos de elementos mayoritarios (CaO, Na2O y elementos traza (Rb, Sr, Ba en el Granito Peñón Rosado sugieren anatexis a partir de un material inmaduro acumulado en un plataforma continental. Así, el Granito Peñón Rosado es un típico granitoide tipo-S con granate y el modelo establecido aquí puede contribuir a un mejor entendimiento acerca de la cristalización del granate en rocas graníticas.

  10. Gaseous equilibrium in sector CP IV of the Cerro Prieto, B.C. Mexico geothermal field; Equilibrio gaseoso en el sector CP IV del campo geotermico Cerro Prieto, B.C., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel; Portugal Marin, Enrique [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); De Leon Vivar, Jesus [Comision Federal de Electricidad, Campo Geotermico Cerro Prieto, Cerro Prieto, B. C. (Mexico)

    2007-07-01

    Sector CP IV is located in the NE portion of the Cerrro Prieto geothermal field. The wells of this zone produce two-phase fluids, with different characteristics as far as their steam fraction content; in the central part and towards the NW the fluids are of dominant liquid type whereas towards the E and the S, the fluid contains a relatively higher steam fraction. The results of gaseous equilibrium FT- HSH3 showed that the fluids in the deposit are at temperatures between 275 Celsius degrees and 310 Celsius degrees and contain steam fractions between 0.01 and 0.5. The data found for the natural state are aligned in a tendency defined in the diagram FT- HSH3, that suggest the wells receive different proportions from preexisting steam in the deposit, which are mixed with the liquid phase to produce the observed discharges. The present data, besides showing the presence of deposit steam, also indicates the entrance of lower temperature fluid in the central part of sector CP IV. [Spanish] El sector CP IV se localiza en la porcion NE del campo geotermico Cerro Prieto. Los pozos de esta zona producen fluidos bifasicos, con diferentes caracteristicas en cuanto a su contenido de fraccion de vapor: en la parte central y hacia el NW los fluidos son de tipo liquido dominante mientras que hacia el E y hacia el S, el fluido contiene una fraccion relativamente alta de vapor. Los resultados de equilibrio gaseoso FT-HSH3 mostraron que los fluidos en el yacimiento se encuentran a temperaturas de entre 275 grados Celsius y 310 grados Celsius y contienen fracciones de vapor de entre -.01 y .5. Los datos hallados para el estado natural se alinean en una tendencia definida en el diagrama FT-HSH3, que sugiere que los pozos reciben diferentes proporciones de vapor pre-existente en el yacimiento, que se mezclan con fase liquida para producir las descargas que se observan. Los datos actuales, ademas de mostrar la presencia de vapor de yacimiento, tambien indican la entrada de fluidos de

  11. Análisis del espacio geográfico y el paisaje de un campus universitario mexicano. Cerro de Coatepec, Universidad Autónoma del Estado de México

    Directory of Open Access Journals (Sweden)

    José Isabel Juan Pérez

    2016-01-01

    Full Text Available Este artículo es resultado de un proyecto de investigación que se realiza en todos los espacios de la Universidad Autónoma del Estado de México. Con la aplicación de fundamentos geográficos, ecológicos y técnicas de trabajo de campo (observación directa, identificación, cuantificación y registros se hizo la caracterización y el análisis del espacio geográfico, el paisaje y los cambios de uso del suelo del Cerro de Coatepec. La investigación es de tipo descriptivo y cualitativo, y se realizó a nivel de ecosistema urbano. Se demuestra que el Cerro de Coatepec es un espacio geográfico importante para los universitarios ya que desempeña múltiples funciones, pero es urgente aplicar estrategias para mitigar o compensar los impactos ocasionados al paisaje.

  12. PATRONES DE CONSUMO FINAL DE CÉRVIDOS EN EL PARANÁ MEDIO: EL CASO DEL SITIO CERRO AGUARÁ / Cervids final consumption patterns in middle Paraná River: the case of Cerro Aguará archaeological site

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    Leonardo Mucciolo

    2015-06-01

    Full Text Available Los cérvidos fueron amplia y regularmente explotados por los cazadores-recolectores que habitaron la macroregión del Paraná-Plata durante el Holoceno tardío. En la cuenca media del Paraná, sin embargo, muy pocos estudios han enfocado sobre las estrategias empleadas para su obtención, procesamiento y consumo. Teniendo en cuenta esto, el objetivo de este trabajo es explorar dichos aspectos a partir del análisis de los conjuntos de cérvidos provenientes del sitio arqueológico Cerro Aguará, localizado en el departamento General Obligado (provincia de Santa Fe. La perspectiva seleccionada propone al consumo como factor preponderante en la configuración del registro zooarqueológico dentro del continuum de actividades que componen la explotación faunística. Desde esta perspectiva, y tomando en consideración que las carcasas de los cérvidos proveen distintos tipos de recursos alimenticios con diferentes costos de extracción (carne, médula y grasa ósea, se evalúan diferentes indicadores para establecer si existió diferente intensidad en su procesamiento. Los resultados indican que las dos especies de cérvidos identificadas en el sitio, Blastocerus dichotomus y Ozotoceros bezoarticus, ocuparon un rol preponderante en la dieta, aunque las carcasas del primero fueron empleadas más intensivamente probablemente en correlación con su mayor disponibilidad de nutrientes internos, tales como la médula y posiblemente la grasa ósea.  Abstract  Cervids were wide and regularly exploited by several Late Holocene hunter-gatherers inhabiting Paraná Plata macroregion. In the middle Paraná river, however, few research has been made on strategies involving their procurement, processing and consumption. The purpose of this article is to explore those aspects from the analysis of cervid assemblages of Cerro Aguará archaeological site (General Obligado, Santa Fe province. The selected perspective proposes final consumption as one of the most

  13. Analysis of productive evolution of well M-19A, Cerro Prieto geothermal field, BC; Analisis de la evolucion productiva del pozo M-19A del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Rodriguez, Marco H; Romero-Rios, Francisco [Comision Federal de Electricidad, Residencia General de Cerro Prieto, B.C (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx

    2007-07-15

    Well M-19A has been the most productive in the Cerro Prieto field, producing around 40 million tons of fluid. The well went on line in February 1975 and was in continuous operation until June 2006. Monthly measurements for over 30 years of operating conditions and chemical and isotopic analyses of the fluids allow identification of the most significant processes occurring in the zone where the well is located. Three dominant recharge types have been identified, each lasting about 10 years. They are a) a recharge of fluids of lower temperature than the production fluids, even though the chemical and isotopic compositions are similar; b) a recharge of lower-temperature fluids with diluted chemical and isotopic compositions; and c) a progressive recharge of reinjected water with a higher chloride concentration and heavy isotopic composition. The production and reinjection rates for over 30 years of production history in the M-19A well zone allow for speculation of a reservoir pressure recovery, which is confirmed with a calculation using production data from well M-19A. The evolution of the reservoir pressure in the zone contrasts with the rest of the reservoir, where a constant pressure drop is observed, particularly toward the central and eastern parts of the field. [Spanish] El pozo M-19A ha sido el mas productivo del campo geotermico de Cerro Prieto, BC, alcanzando una extraccion de mas de 40 millones de toneladas de fluido. Fue integrado a produccion en febrero de 1975 y hasta junio de 2006 ha permanecido en produccion en forma continua. Las mediciones mensuales de sus condiciones operativas y los analisis quimicos e isotopicos del agua producida permiten identificar los procesos mas significativos que han ocurrido a lo largo de esos mas de 30 anos en la zona donde se localiza el pozo. Se han identificado tres tipos de recarga dominantes que se presentan durante un periodo cercano a 10 anos cada uno, los cuales son: a) una recarga de fluidos de menor temperatura

  14. Mineralogy of the silica-epidote mineralized zone (SEMZ) in the Cerro Prieto geothermal reservoir, B.C., Mexico; Mineralogia de la zona mineralizada de silice-epidota (ZMSE) del yacimiento geotermico de Cerro Prieto, B.C., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Georgina; Aragon, Alfonso; Portugal, Enrique; Arellano; Victor M [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: gim@iie.org.mx; Leon, Jesus de; Alvarez, Julio [Comision Federal de Electricidad, B.C. (Mexico)

    2006-07-15

    The distribution of hydrothermal minerals, mineral assemblages and fluid inclusion data were taken from drill cuttings from the production zone of wells all over the Cerro Prieto geothermal field. The production zone has been termed the silica-epidote mineralized zone (SEMZ), and is located in the deep part of the gray shale where thick layers of sandstone are found. Common mineral assemblages show three temperature ranges in the SEMZ: <200 degrees Celsius, 200-250 degrees Celsius and 250-300 degrees Celsius. The first range is characterized by clays, calcite and quartz; the second by quartz, epidote, chlorite and mica, and the third by epidote, amphibole, illite and chlorite. The study of fluid inclusions in authigenic grain quartz has shown two-phase fluid inclusions (liquid + vapor) of different salinities. A wide range exists of homogenization temperatures (Th) and for some wells there is a good agreement between Th and direct temperature measurements. [Spanish] Se determino la distribucion de minerales hidrotermales y las asociaciones parageneticas y se realizo el estudio microtermometrico de inclusiones fluidas a partir de recortes de perforacion de pozos de las distintas areas del campo geotermico de Cerro Prieto. Las muestras de recortes y nucleos de perforacion estudiados provienen de la zona de produccion a la que se le ha denominado Zona Mineralizada de Silice-Epidota (ZMSE), que se encuentra en la parte profunda de la lutita gris con importantes horizontes de areniscas. En esta zona las asociaciones parageneticas mas comunes han mostrado tres intervalos de temperatura para la ZMSE: <200 degrees Celsius, 200-250 degrees Celsius, 250-300 degrees Celsius. El primer intervalo esta caracterizado principalmente por arcillas, calcita y cuarzo; el segundo por cuarzo, epidota, clorita y micas, y el tercero por epidota, anfiboles, illita y clorita. El estudio de inclusiones fluidas en fragmentos de cuarzo autigenico mostro la presencia de inclusiones de dos fases

  15. Geological and production analyses focused on exploration of the eastern part of the Cerro Prieto geothermal field, BC; Analisis geologico-productivo enfocado a la exploracion de la parte oriental del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar Dumas, Alvaro [Comision Federal de Electricidad, Residencia General de Cerro Prieto, B.C (Mexico)]. E-mail: alvaro.aguilar@cfe.gob.mx

    2008-01-15

    The eastern part of the Cerro Prieto geothermal field (CGCP), known as Poligono Nuevo Leon, is an area with proven geothermal resources, as confirmed by seven directional wells located toward the east and by vertical well M-200 located inside the polygon. Well M-200 was drilled in 1984 and has produced about 4 million tons of steam to date. It is integrated into the CP-2 sector, producing 68 t/h of steam. Presently the eastern part of CGCP, representing 25% of the total field area, is producing over half of the steam for the entire field. In the last few years, the steam has come only after increasing the number of production wells located in the eastern zone of CGCP (Rodriguez, 2006), where pressure, enthalpy and temperature conditions are better than in other parts of the field. However in the long term it will be necessary to incorporate Poligono Nuevo Leon into the productive area to expand the productive life of CGCP. This paper includes a geological analysis, plus models for steam production, temperature and enthalpy for Poligono Nuevo Leon. [Spanish] La parte oriental del Campo Geotermico de Cerro Prieto (CGCP), conocida como Poligono Nuevo Leon, representa una area potencial con recursos geotermicos comprobados, lo que demuestran siete pozos direccionales que se han perforado hacia el este, asi como el pozo vertical M-200, localizado dentro del poligono. El pozo M-200 se perforo en 1984 y ha producido a la fecha alrededor de 4 millones de toneladas de vapor, estando integrado al sector CP-2 una produccion de 68 t/h de vapor. Actualmente la parte oriental del CGCP, que representa el 25% del area total del campo, produce mas de la mitad del total de vapor del campo. El suministro de vapor en los ultimos anos se ha logrado cubrir aumentando el numero de pozos en operacion localizados en la zona oriente del CGCP (Rodriguez, 2006), ya que es aqui donde hay condiciones de presion, entalpia y temperatura del yacimiento que son mejores que en otras areas del campo

  16. El patrimonio industrial petrolero en la Patagonia: Comodoro Rivadavia (Argentina y Cerro Sombrero (Chile. Una perspectiva comparada

    Directory of Open Access Journals (Sweden)

    Pía Acevedo Méndez

    2016-01-01

    Full Text Available El hallazgo de petróleo en Comodoro Rivadavia (Chubut, Argentina y en Manantiales (Tierra del Fuego, lado chileno, motivó la construcción de espacios socioproductivos bajo el modelo de Company Towns. En el caso argentino la empresa estatal Yacimientos Petrolíferos Fiscales (Y.P.F creó el Campamento Central y la Empresa Nacional del Petróleo (ENAP creó Cerro Sombrero en Chile, los que en la década de 1970 formaron dos tejidos urbanos (barrio en el caso argentino y pueblo en el caso chileno. En esta dinámica se transformó el modo de habitar de ambos espacios, que se convirtieron en potenciales elementos turísticos, teniendo en cuenta que desde el año 2014 poseen reconocimiento patrimonial relacionado con su pasado petrolero y su arquitectura moderna. El objetivo es comparar cómo ambas empresas petroleras estatales construyeron dichos espacios “urbanos” y sus comunidades sociolaborales e indagar en la relación identidad/ patrimonio de ypefeanos y enapinos.

  17. Zonificación ecológica del cerro "El Potosí", Galeana, Nuevo León, México

    Directory of Open Access Journals (Sweden)

    Mario A. García A.

    1999-01-01

    Full Text Available Como parte de la propuesta para definir al cerro "El Potosi" como Reserva Especial de la Biosfera, se elaboró un mapa de zonificacion que considera las zonas núcleo, de amortiguamiento y de recuperacion de habitat. Los criterios para la zonificación se consideraron la distribución de la vegetación y las poblaciones de fauna silvestre, derivada de la interpretacion cartográfica elaborada ad hoc, utilizand una imagen de stélite, además de la información sobre la biodiversidad. Se definiereon para la región diez tipos de vegetación y cuatro tipos de uso del suelo, en donde se distribuyen 45 especies bajo estatus de conservación: 19 de plantas y 26 de animales

  18. Sedimentología y estratigrafía de la Formación Vaca Muerta (Tithoniano-Berriasiano) en el área del cerro Domuyo, norte de Neuquén, Argentina

    OpenAIRE

    Kietzmann,Diego A; Vennari,Verónica V

    2013-01-01

    Los depósitos de la Formación Vaca Muerta en el área del cerro Domuyo muestran una interesante interca-laclón de depósitos con paleocorrientes opuestas. La unidad está representada por facies de cuenca y rampa externa con dirección de progradación hacia el oeste. Sin embargo, en su parte media se intercalan depósitos de talud, con desarrollo de deslizamientos sinsedimentarios hacia el NE, que pueden asignarse al Miembro Huncal. Este intervalo se compone de facies carbonáticas que probablement...

  19. Sedimentología y estratigrafía de la Formación Vaca Muerta (Tithoniano- Berriasiano) en el área del cerro Domuyo, norte de Neuquén, Argentina

    OpenAIRE

    Kietzmann, Diego Alejandro; Vennari, Verónica Vanesa

    2015-01-01

    Los depósitos de la Formación Vaca Muerta en el área del cerro Domuyo muestran una interesante intercalación de depósitos con paleocorrientes opuestas. La unidad está representada por facies de cuenca y rampa externa con dirección de progradación hacia el oeste. Sin embargo, en su parte media se intercalan depósitos de talud, con desarrollo de deslizamientos sinsedimentarios hacia el NE, que pueden asignarse al Miembro Huncal. Este intervalo se compone de facies carbonáticas que probablemente...

  20. El hábitat carpetano del cerro del Gollino

    OpenAIRE

    Perea Caveda, Alicia; Lourdes PRADOS TORREIRA; Santos Velasco, Juan Antonio

    1998-01-01

    [ES] Los resultados de las dos campairas de excavación en el yacimiento han permitido la identificación de un gran hábitat amurallado datable entre fines del siglo III a.c. y el primer tercio del siglo I a.c., que aporta datos significativos sobre el proceso de rornanización de la Carpetania.

  1. SIMULACIÓN DE FLUJOS PIROCLÁSTICOS DEL VOLCÁN CERRO MACHÍN, COLOMBIA, MEDIANTE LA APLICACIÓN DE HERRAMIENTAS DE ARCGIS©

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    Elsa Adriana Cárdenas Quiroga

    2012-01-01

    Full Text Available Cerro Machín es un volcán activo, caracterizado en el pasado por erupciones explosivas de tipo pliniano y ubicado en un sector de gran importancia económica. Desde la década de los noventa se han desarrollado varios modelos de simulación para determinar el área que podría resultar afectada en una nueva erupción, pero estos modelos se basan en programas con variables predeterminadas que no son fácilmente modificables. Por tanto, se diseñó una aplicación del modelo de simulación Model Builder de las herramientas del software ArcGIS© para facilitar el proceso de análisis de los flujos piroclásticos expulsados por ese volcán en tres eventos eruptivos identificados y modelados previamente, con el objetivo de crear una aplicación fácilmente adaptable a cambios en las variables de simulación y que pudiera ser empleada también para modelar otros volcanes. Los resultados obtenidos resultan compatibles y similares a los obtenidos en simulaciones previas, lo que indica que la aplicación desarrollada es funcional.

  2. Control estructural de las mineralizaciones de fluorita del batolito Cerro Áspero, Sierras Pampeanas de Córdoba

    Directory of Open Access Journals (Sweden)

    Jorge E Coniglio

    2010-12-01

    Full Text Available Con más de 1.000.000 t de reservas totales el batolito Cerro Áspero, magmatismo devónico de alto potasio, es portador de las mayores concentraciones de fluorita de las Sierras Pampeanas. Las vetas epitermales son de edad cretácica, subverticales, poseen potencias generalmente menores a 3 m y se extienden a profundidades mayores a 200 metros. Ocurren en un área de 440 km² con una distribución intrabatolítica predominante. La geometría y la cinemática de las estructuras mineralizadas son consistentes con deformación por cizalla simple, dextrógira, con el eje extensional principal (σ3 orientado hacia el NNO. Esta situación implantó en el área estructuras extensionales N70ºE ( 4 km de corrida, que presentan patrones de fallas transcurrentes, con bifurcaciones, deflexiones, aperturas, saltos, cierres y fracturas en échelon asociadas. Los estudios texturales y estructurales en las vetas han permitido distinguir cuatro estadios sucesivos de mineralización que fueron controlados por una actividad discontinua de la cupla dextral. Este modelo estructural es similar a aquéllos propuestos para mineralizaciones de fluorita emplazadas en otros sectores del continente durante el mismo período, los que vinculan el control tectónico con la apertura del océano Atlántico sur. El registro del relleno hidrotermal permitió reconstruir la historia de apertura de las estructuras y puede usarse como un criterio efectivo de prospección y exploración. Las mayores concentraciones de mineral ocurren en las estructuras extensionales y en las flexiones dilatantes de las estructuras asociadas con la zona de cizallamiento principal NNE-SSO, que registran la secuencia mineralizada completa.

  3. Apresentacão do Projeto de extensão universitaria "Fortalecimento das Capacidades das Educadoras do Programa CAIF no estado de Cerro Largo-Uruguai"

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    Mariana Porta Galván

    2015-12-01

    Full Text Available Dentro de la línea de investigación Estado, políticas sociales y ciudadanía en frontera, es relevante conocer la realidad de las políticas sociales orientadas a la primera infancia y sus implementaciones. Esta ponencia presenta un proyecto de extensión universitaria realizada con los centros CAIF de Cerro Largo con el propósito de fortalecer las prácticas de los operadores sociales de estos centros, a partir de las siguientes preguntas: ¿Qué características asume la implementación de esta política pública en un departamento fronterizo? ¿Qué desafíos plantea a sus operadores? Consideramos que la implementación de una política social, más allá de la forma en que se concibe, diseña y expresa en sus documentos, implica un proceso de apropiación que conlleva interpretaciones y adaptaciones que se manifiestan en prácticas. Estas, a su vez, responden a disposiciones, hábitos y saberes (entendidos como conocimientos tácitos y explícitos de los operadores involucrados, en un vínculo directo con la cultura propia de los contextos en los que se desarrollan. En ese proceso de implementación y sus múltiples niveles de gestión, se encuentran los desafíos a los cuales pretendemos aportar desde una propuesta de capacitación de operadores, que responda a la diversidad de cada territorio y de cada contexto social.

  4. Case history report on East Mesa and Cerro Prieto geothermal fields

    Energy Technology Data Exchange (ETDEWEB)

    Davis, DG.; Sanyal, S.K.

    1979-06-01

    Well log analysis as applied to the geothermal industry is one of the areas of technology in great need of further development. One means of improving log analysis technology is to study case histories of the past uses of log analysis as applied to specific fields. The project described in this report involved case history studies on two well-known geothermal areas in North America: the East Mesa field in California and the Cerro Prieto field in Mexico. Since there was considerably more pertinent material available on East Mesa, a major part of the effort on this project was devoted to studying the East Mesa field. One particular problem that first came to attention when studying the Cerro Prieto data was the difficulty in determining actual formation temperature at the time of logging. Since the temperature can have a significant effect on well log readings, an accurate temperature determination was considered to be important.

  5. H2S and CO2 emissions from Cerro Prieto geothermal power plant, Mexico

    Science.gov (United States)

    Peralta, Oscar; Franco, Luis; Castro, Telma; Taran, Yuri; Bernard, Ruben; Inguaggiato, Salvatore; Navarro, Rafael; Saavedra, Isabel

    2014-05-01

    Cerro Prieto geothermal power plant has an operation capacity of 570 MW distributed in four powerhouses being the largest geothermal plant in Mexico. The geothermal field has 149 production wells. It is located in Cerro Prieto, Baja California, 30 km to the south of the Mexico-US border. Two sampling campaigns were performed in December 2012 and May 2013 where geothermal fluids from 46 production wells and 10 venting stacks were obtained and analyzed by gas chromatography coupled to mass spectrometry. Average CO2 and H2S composition of samples from venting stacks were 49.4% and 4.79%, respectively. Based on the chemical composition of samples, the geothermal power plant emits every day from venting stacks 869 tons of CO2, plus 68 tons of H2S, among other non-condensable gases.

  6. Occurrences of alunite, prophyllite, and clays in the Cerro La Tiza area, Puerto Rico

    Science.gov (United States)

    Hildebrand, Fred Adelbert; Smith, Raymond J.

    1959-01-01

    A deposit of hydrothermally altered rocks in the Cerro La Tiza area located between the towns of Comerio and Aguas Buenas, approximately 25 kilometers southwest of San Juan, Puerto Rico, was mapped and studied to determine the principal minerals, their extent distribution and origin, and the possibility of their economic utilization, especially in Puerto Rico. The Cerro la Tiza area is about 7? kilometers long, has an average width of about 1? kilometers and embraces a total area of approximately 15 square kilometers. The principal mineralized zone, a dike-like mass of light-colored rocks surrounded by dark-colored volcanic country rocks, occupies the crest and upper slopes of east-trending Cerro La Tiza ridge and is believed to be of Late Cretaceous or Eocene age. This zone is approximately 5,300 meters long, 430 meters wide and has an area of approximately 225 hectares (556 acres). The rocks of the mineralized zone are of mixed character and consist mainly of massive quartzose rocks and banded quartz-alunite rocks closely associated with foliated pyrophyllitic, sericitic and clayey rocks. The principal minerals in probably order of abundance are quartz, alunite, pyrophyllite, kaolin group clays (kaolinite and halloysite) and sericite. Minerals of minor abundance are native sulfure, diaspore, svanbergite (?), sunyite (?), hematite, goethite, pyrite, rutile (?) and very small quantities of unidentified minerals. The mineralized zone has broken down to deposits of earth-rock debris of Quaternary age that cover much of the slopes and flanks of Cerro La Tiza. This debris consists generally of fragments and boulders with a very large size range embedded in a clayey matrix. The distribution of the earth-rock debris with respect to the present topography and drainage suggests that it may have undergone at least two cycles of erosion. Underlying the earth-rock debris and completely enclosing the mineralized zone are country rocks of probably Late Cretaceous age. These

  7. Progress report on LBL's numerical modeling studies on Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Halfman-Dooley, S.E.; Lippman, M.J.; Bodvarsson, G.S.

    1989-04-01

    An exploitation model of the Cerro Prieto geothermal system is needed to assess the energy capacity of the field, estimate its productive lifetime and develop an optimal reservoir management plan. The model must consider the natural state (i.e., pre-exploitation) conditions of the system and be able to predict changes in the reservoir thermodynamic conditions (and fluid chemistry) in response to fluid production (and injection). This paper discusses the results of a three-dimensional numerical simulation of the natural state conditions of the Cerro Prieto field and compares computed and observed pressure and temperature/enthalpy changes for the 1973--1987 production period. 16 refs., 24 figs., 2 tabs.

  8. Seismicity studies in the region of the Cerro Prieto Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Albores, A.; Reyes, A.; Brune, J.N.; Gonzalez, J.; Garcilazo, L.; Suarez, F.

    1980-01-01

    This paper reports results from seismicity studies in the region of the Cerro Prieto geothermal field. These studies were conducted with local short period seismic arrays during 1974-1975 and 1977-1978. During the latter period, horizontal seismometers were used for better control on the S-wave arrival times. Locations were obtained for about 200 events and composite fault plane solutions were obtained for five groups of events. 16 refs.

  9. Identification of fluid-flow paths in the Cerro Prieto geothermal field

    Science.gov (United States)

    Halfman, S. E.; Lippmann, M. J.; Zelwer, R.; Howard, J. H.

    1982-05-01

    A hydrogeologic model of the Cerro Prieto geothermal field has been developed based on geophysical and lithologic well logs, downhole temperature, and well completion data from about 90 deep wells. The hot brines seem to originate in the eastern part of the field, flowing in a westward direction and rising through gaps in the shaly layers which otherwise act as partial caprocks to the geothermal resource.

  10. The age and constitution of Cerro Campanario, a mafic stratovolcano in the Andes of central Chile

    Science.gov (United States)

    Hildreth, W.; Singer, B.; Godoy, E.; Munizaga, F.

    1998-01-01

    Cerro Campanario, a towering landmark on the continental divide near Paso Pehuenche, is a glacially eroded remnant of a mafic stratovolcano that is much younger than previously supposed. Consisting of fairly uniform basaltic andesite, rich in olivine and plagioclase, the 10-15 km3 edifice grew rapidly near the end of the middle Pleistocene, about 150-160 ka, as indicated by 40Ar/39Ar and unspiked K-Ar analyses of its lavas.

  11. Geología de la región del Cerro Guanaquero, Río Diamante, Mendoza

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    Federico Fuentes

    2008-03-01

    Full Text Available El estudio realizado presenta nuevos datos sobre un sector poco conocido de la Cordillera Principal de Mendoza, en la alta cuenca del río Diamante en las adyacencias del cerro Guanaquero, y los primeros datos geocronológicos de sus rocas volcánicas. Las unidades geológicas presentes en el área se dividen en cuatro grupos principales: secuencias sedimentarias mesozoicas marinas y continentales intensamente plegadas y falladas; intrusivos y volcanitas intermedias de edad neógena; rocas volcánicas pliocenas a recientes de composición intermedia a básica, y depósitos cuaternarios inconsolidados. El cerro Guanaquero, un estratovolcán pliocuaternario intensamente erosionado por glaciares pleistocenos, con sus 4.841 metros es el rasgo orográfico más prominente. Está constituido esencialmente por andesitas grises porfíricas, piroxénicas a biotíticas. Intercaladas con las coladas andesíticas se presentan depósitos piroclásticos, aglomerados volcánicos, ignimbritas y basaltos. La datación de una andesita por el método K-Ar en roca total arrojó una edad de 1,4 ± 0,1 Ma. La deformación ándica comenzó en forma de una faja plegada y corrida de piel fina, con pliegues por despegue en el sector occidental y por propagación de falla en el oriental. La compresión al oeste de los 69º47´O terminó por invertir la fallas normales del rift mesozoico. A lo largo de este meridiano se encuentra la falla más importante de la región, la que se ha correlacionado con la falla Malargüe, bien desarrollada en latitudes más australes. Esta falla limita la faja plegada y corrida del Aconcagua, de naturaleza epidérmica, y la faja plegada y corrida de Malargüe, controlada por la inversión tectónica del basamento. El volcanismo fue muy intenso en el Plioceno y el Cuaternario, correspondiendo a un período de empinamiento de la placa oceánica subducida, en el que la región ha sido levantada pasivamente. La alta resistencia a la erosión de

  12. A review of the hydrogeologic-geochemical model for Cerro Prieto

    Science.gov (United States)

    Lippmann, M.J.; Truesdell, A.H.; Halfman-Dooley, S. E.; Mañónm, A.

    1991-01-01

    With continued exploitation of the Cerro Prieto, Mexico, geothermal field, there is increasing evidence that the hydrogeologic model developed by Halfman and co-workers presents the basic features controlling the movement of geothermal fluids in the system. In mid-1987 the total installed capacity at Cerro Prieto reached 620 MWc, requiring a large rate of fluid production (more than 10,500 tonnes/hr of a brine-steam mixture; August 1988). This significant mass extraction has led to changes in reservoir thermodynamic conditions and in the chemistry of the produced fluids. Pressure drawdown has caused an increase in cold water recharge in the southern and western edges of the field, and local and general reservoir boiling in parts of the geothermal system. After reviewing the hydrogeologic and geochemical models of Cerro Prieto, the exploitation-induced cold water recharge and reservoir boiling (and plugging) observed in different areas of the field, are discussed and interpreted on the basis of these models and schematic flow models that describe the hydrogeology. ?? 1991.

  13. Evolution of the Cerro Prieto geothermal system as interpreted from vitrinite reflectance under isothermal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Barker, C.E. (US Geological Survey, Denver, CO); Pawlewicz, M.J.; Bostick, N.H.; Elders, W.A.

    1981-01-01

    Temperature estimates from reflectance data in the Cerro Prieto system correlate with modern temperature logs and temperature estimates from fluid inclusion and oxygen isotope geothermometry indicating that the temperature in the central portion of the Cerro Prieto System is now at its historical maximum. Isoreflectance lines formed by contouring vitrinite reflectance data for a given isothermal surface define an imaginary surface that indicates an apparent duration of heating in the system. The 250/sup 0/C isothermal surface has a complex dome-like form suggesting a localized heat source that has caused shallow heating in the central portion of this system. Isoreflectance lines relative to this 250/sup 0/C isothermal surface define a zone of low reflectance roughly corresponding to the crest of the isothermal surface. Comparison of these two surfaces suggest that the shallow heating in the central portion of Cerro Prieto is young relative to the heating (to 250/sup 0/C) on the system margins. Laboratory and theoretical models of hydrothermal convection cells suggest that the form of the observed 250/sup 0/C isothermal surface and the reflectance surface derived relative to it results from the convective rise of thermal fluids under the influence of a regional hydrodynamic gradient that induces a shift of the hydrothermal heating effects to the southwest.

  14. Relationship between water chemistry and sediment mineralogy in the Cerro Prieto geothermal field: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Valette-Silver, J.N. (Univ. de Perpignan, France); Thompson, J.M.; Ball, J.W.

    1981-01-01

    The chemical compositions of waters collected from the Cerro Prieto geothermal production wells and hydrothermal emanations are different. Compared to the Cerro Prieto well waters, the surficial waters generally contain significantly less potassium, slightly less calcium and chloride, and significantly more magnesium and sulfate. In comparison to the unaltered sediments, the changes in the mineralogy of the altered sediments appear to be controlled by the type of emanation (well, spring, mud pot, geyser, fumarole, or cold pool). However, an increase in quartz and potassium feldspar percentages seems to be characteristic of the majority of the sediments in contact with geothermal fluids. Preliminary attempts to model the chemical processes occurring in the Cerro Prieto geothermal field using chemical equilibrium calculations are reported. For this purpose the chemical compositions of thermal waters (well and surficial emanation) were used as input data to make calculations with SOLMNEQ and WATEQ2 computer programs. Then the theoretical mineral composition of altered sediments was predicted and compared to the mineralogy actually observed in the solid samples.

  15. NUEVOS APORTES AL CONOCIMIENTO DE LA HERPETOFAUNA DE LA FORMACIÓN CERRO AZUL (MIOCENO SUPERIOR, PROVINCIA DE LA PAMPA, ARGENTINA

    Directory of Open Access Journals (Sweden)

    AGUSTÍN SCANFERLA

    2015-01-01

    Full Text Available RESUMENSe describen nuevos materiales fósiles de anfibios y reptiles hallados en sedimentos referidos a la Formación Cerro Azul (Mioceno Superior, procedentes de numerosas localidades de la provincia de La Pampa, Argentina. Los nuevos registros se basan en un resto craneano de anuro asignado al géneroCeratophrys, restos de caparazón de tortugas terrestres del géneroChelonoidis, vértebras asignables al lagarto de la familia TeiidaeTupinambis, y una vértebra troncal de serpiente comparable al género de colubroideos actualesPhilodryas. Tanto los registros terciarios previos de géneros actuales de anfibios y reptiles en América del Sur, como así también la asociación recuperada en el Mioceno Superior de La Pampa sugieren que la mayoría de los géneros que componen la herpetofauna Neotropical estaban presentes en el Mioceno, patrón similar al observado en otras regiones del mundo.

  16. New data on the bottom topography, recent sedimentation and water balance of Cerro Prieto dam, Mexico

    Science.gov (United States)

    Yutsis, Vsevolod; Levchenko, Oleg; Lowag, Jens; Krivosheya, Konstantin; de León Gómez, Héctor; Kotsarenko, Anatolyi

    2010-05-01

    Cerro Prieto Dam, a small water reservoir in the NE Mexico, is characterized by very high velocity of recent sedimentation, high sub-bottom seepage and erosion, and as a result, nonlinear water balance. These phenomenons never were studied since construction of the dam in the beginning of 1980th. So the goal of our work was to investigate the bottom topography and also sub-bottom near surface structure using the parametric acoustical effect. High-resolution sub-bottom profiling, using the Innomar SES-2000 compact echosounder, was carried out in Cerro Prieto Dam during February-April of 2008. The survey was conducted onboard of a small motor boat. The SES transducer was mounted on the front side of the boat using light metal pipe, and all electronic equipment was installed on the deck. Accurate positioning of the boat was reached by GPS. Average speed was 8-10 km/h. Innomar's software tool ISE was provides near real-time post-processing of the collected SES data and operation procedure could be corrected on-line. Acoustic signal ensured vertical resolution of 10-15 cm at acceptable penetration up to 15 m. Bathymetry map was compiled assuming average sound velocity of 1450 m/s. The irregular bottom topography of Cerro Prieto dam was discovered. The present elevation of the water surface is about 181 m above see level, and the lake depth varies from 1-2 to 28 m. The SES records show a distinct bottom layer of recent sediments by 0.5 - 4 m thickness which follows reservoir floor topography. Very specific acoustic anomalies, which seem to be related with gas sediments, are observed. The integrated SES, gravity, magnetic and geoelectrical data interpretation allows assuming a series of the superficial fractures focused in a NW direction, perpendicular (NE-SW) to the general deep fault zone. Hydrological balance for the Cerro Prieto water reservoir has been analyzed for last two decades. There are three types of water level fluctuations on the Cerro Prieto dam: long

  17. Estudio metalográfico de la calidad del cobre producido en las fundiciones de Cerro Muriano (Córdoba durante el Período Romano Altoimperial

    Directory of Open Access Journals (Sweden)

    Calabrés, R.

    1995-10-01

    Full Text Available The copper obtaining process depends on a great quantity of variables and presents complex controlling. The mentioned obtaining process was well known since the Roman Age. The knowledge of copper of the casting process was higher than expected, taking account of the studies with first melting copper samples localized at an archaeological deposit in Cerro Muriano (Córdoba, Spain and dated at the 1st Century B.C. and 1st Century A.C. The existence of a cellular and dendritic-cellular solidification in the studied samples, together with other realized analysis, show a production of copper with high purity. Present work allows to conclude that the three basic processes on copper casting (roasting, smelting, slagging and conversion were well known. This knowledge was due to the experience, although they did not know the chemical and physical phenomena.

    El proceso de obtención de un cobre, más o menos puro, depende de gran cantidad de variables y es difícil de controlar. Antes de la romanización, dicho proceso de obtención ya era conocido. Utilizando cobres de primera fusión localizados en un yacimiento arqueológico sito en Cerro Muriano (Córdoba datados en los siglos I a.C. y I d.C., se ha determinado que sus elaboradores tenían un conocimiento del proceso de fundición de cobre superior al esperado. La existencia de una solidificación celular y celular dendrítica en las muestras estudiadas, así como los análisis realizados, indican una producción de cobre de alta pureza. El estudio permite concluir que, en época romana, ya se conocían los tres procesos básicos de la obtención de cobre: tostación, fusión y escorificación y conversión. Dicho proceso era conocido gracias a la gran experiencia acumulada, aunque estos metalurgistas desconocían las causas que originaban los resultados finales obtenidos.

  18. Cambio del uso de la tierra y pérdida de la cobertura boscosa, comunidades agrarias Sechina, La Ensenada y Cerro San Gil, Izabal Guatemala

    Directory of Open Access Journals (Sweden)

    Eddi Alejandro Vanegas Chacón

    2016-07-01

    Full Text Available En Guatemala, pocas temáticas son abordadas con tanta pasión como el acceso a la tierra y sus relaciones de productividad. Ante el juicio histórico y la evidencia de las estadísticas se deslumbra que las políticas agrarias de los últimos cincuenta años, si bien mitigaron la pobreza en el agro rural conllevaron con ellas daños ambientales irreversibles y deudas agrarias millonarias. Se estudió la dinámica del cambio de uso de la tierra y la pérdida de la cobertura boscosa en las comunidades agrarias beneficiadas por la Ley de Transformación Agraria, Sechina, La Ensenada y Cerro San Gil ubicadas en el departamento de Izabal. Se utilizó fotointerpretación y se realizaron estudios semidetallados de la intensidad de la tierra para el periodo 1958 a 2010. Se concluyó que bajo las premisas de “mejora a la tierra” de la Ley de Transformación Agraria ocurrió cambio de uso y cobertura de la tierra, de forestal a agropecuaria, en las comunidades agrarias Sechina 42%, La Ensenada 46,2% y Cerro San Gil 48,6%, donde se promovieron sistemas de aprovechamiento agrícola que conllevaron al sobre-uso de las tierras en 42%, 78% y 30%, respectivamente. Esto sugiere, que la adquisición de la tierra no es el fin, más bien es el medio, para promover desarrollo rural sostenible, a través de acompañamiento técnico agropecuario, monitoreo y evaluación tanto económica como ambiental.

  19. Control estructural de las mineralizaciones de fluorita del batolito Cerro Áspero, Sierras Pampeanas de Córdoba Structural control of vein-type fluorite deposits of Cerro Áspero batholith, Sierras Pampeanas of Córdoba

    Directory of Open Access Journals (Sweden)

    Jorge E Coniglio

    2010-12-01

    Full Text Available Con más de 1.000.000 t de reservas totales el batolito Cerro Áspero, magmatismo devónico de alto potasio, es portador de las mayores concentraciones de fluorita de las Sierras Pampeanas. Las vetas epitermales son de edad cretácica, subverticales, poseen potencias generalmente menores a 3 m y se extienden a profundidades mayores a 200 metros. Ocurren en un área de 440 km² con una distribución intrabatolítica predominante. La geometría y la cinemática de las estructuras mineralizadas son consistentes con deformación por cizalla simple, dextrógira, con el eje extensional principal (σ3 orientado hacia el NNO. Esta situación implantó en el área estructuras extensionales N70ºE ( 4 km de corrida, que presentan patrones de fallas transcurrentes, con bifurcaciones, deflexiones, aperturas, saltos, cierres y fracturas en échelon asociadas. Los estudios texturales y estructurales en las vetas han permitido distinguir cuatro estadios sucesivos de mineralización que fueron controlados por una actividad discontinua de la cupla dextral. Este modelo estructural es similar a aquéllos propuestos para mineralizaciones de fluorita emplazadas en otros sectores del continente durante el mismo período, los que vinculan el control tectónico con la apertura del océano Atlántico sur. El registro del relleno hidrotermal permitió reconstruir la historia de apertura de las estructuras y puede usarse como un criterio efectivo de prospección y exploración. Las mayores concentraciones de mineral ocurren en las estructuras extensionales y en las flexiones dilatantes de las estructuras asociadas con la zona de cizallamiento principal NNE-SSO, que registran la secuencia mineralizada completa.With over 1,000,000 t of total reserves, the high-K devonian granites of the Cerro Áspero batholith (440 km² are the most important fluorite-bearing granitic suite in the Sierras Pampeanas. The epithermal fluorite veins, of Cretaceous age, fill in steeply dipping

  20. El volcanismo bimodal del volcán cerro Corona, Alta Sierra de Somún Curá, provincia de Río Negro Bimodal volcanism of the Cerro Corona volcano in the Alta Sierra de Somún Curá (Río Negro province

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    Guadalupe Maro

    2012-03-01

    Full Text Available La Alta Sierra de Somún Curá es uno de los complejos volcánicos terciarios postplateau en el ambiente de la meseta basáltica de Somún Curá, en la Patagonia extrandina. En ella se encuentra el cerro Corona, un volcán en escudo que corresponde al centro de mayor altura en la región. Está construido por rocas efusivas y piroclásticas subordinadas, fundamentalmente traquiandesíticas-basálticas, con variaciones traquíticas tanto en sus flancos como en su cráter. A pesar de la bimodalidad compositional con una importante discontinuidad entre el 54 y 58 % en peso de SiO2, el presente trabajo propone que las traquitas son el producto de la evolución por cristalización fraccionada de las traquiandesitas basálticas, con cierta influencia de recargas máficas a la cámara magmática de acuerdo a la presencia de texturas de desequilibrio en los fenocristales, principalmente de las rocas félsicas.The Cerro Corona is a shield volcano situated in the Alta Sierra de Somún Curá, one of the tertiary volcanic complex that constitute the Meseta de Somún Curá, in the Extrandean Patagonia. It is the highest center in the region and it is compound mainly of basaltic trachyandesites, with trachytic variations on its flanks and crater. Despite the compositional bimodality with an important compositional gap between 54% and 58% in weight in SiO2, this work suggests that trachytes are the product of the evolution of basaltic trachyandesites through fractional crystallization, with some influence of mafic recharge to the magmatic chamber, in agreement with the presence of disequilibrium textures in fenocrystals, essentially in felsic rocks.

  1. Aspectos de los sobrenatural en Pampas-La Florida (Chancay

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    Isabelle Lausent

    1984-12-01

    Full Text Available La Pacarina del pueblo de "San Salvador del Mundo" de Pampas (valle de Chancay es el cerro Mango. Las repetidas Extirpaciones de Idolatría que sufrieron "sus hijos", el mestizaje y el transcurso del tiempo han, poco a poco, hecho desaparecer los mitos que frataban del Mango. La tradición oral de Pampas que da mucha importercia al mundo de lo sobrenatural sigue, sin embargo, ofreciendo numerosos cuentos y leyendas mencionando este cerro ya no como pacarina sino como una mina fuente de riqueza y lugar de encanto.El análisis que sigue ha sido realizado a partir de Ics cuentos recopilados por Jorgc Osterling durante la Semana Santa del año de 1980 en el rnismo Pampas La Florida.

  2. Hydrothermal alteration zones and present reservoir conditions: an approach to define production zones at the eastern portion of the Cerro Prieto geothermal field, BC; Zonas de alteracion hidrotermal y condiciones actuales del yacimiento: un enfoque para determinar zonas productoras al oriente del campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Camacho Hernandez, Juan Manuel [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: juan.camacho02@cfe.gob.mx

    2009-07-15

    Geological factors are as essential for locating new wells as they are for defining the production zones of these wells. At the Cerro Prieto geothermal field (CGCP), one of the most important geological factors is identification of the hydrothermal alteration zones (ZAH). These are divided into silica and epidote mineralogical zones (ZMSE), without CaCO{sub 3}, and silica and epidote mineralogical transition zones (ZTMSE), with CaCO{sub 3}. It has been observed that the continuous variation of reservoir thermodynamic conditions (temperature, pressure and enthalpy) is due mainly to the exploitation of geothermal resources. The presence of new thermodynamic conditions recorded at the reservoir has led to the re-location of production wells originally located during the drilling campaign of 2004 to 2006. At the geological sections on the eastern part of the CGCP, adjustments made to the well completions lie on the limits between the ZMSE and ZTMSE zones. In turn, this is related to the current, superior, thermodynamic reservoir conditions. Based on this, a new geologic approach is proposed to define possible production zones for new wells, relating the ZAH zones to current thermodynamic reservoir conditions. [Spanish] Los factores geologicos son determinantes, tanto para establecer nuevos sitios de perforacion como para determinar el intervalo productor de un pozo nuevo. En el campo geotermico de Cerro Prieto (CGCP) una de los factores mas importantes es la determinacion de las zonas de alteracion hidrotermal (ZAH) que se dividen en dos: zona mineralogica de silice y epidota (ZMSE), sin presencia de CaCO{sub 3}, y zona de transicion mineralogica de silice y epidota (ZTMSE), con presencia de CaCO{sub 3}. Por otra parte, tambien se ha constatado que la continua variacion de las condiciones termodinamicas del yacimiento (temperatura, presion y entalpia) es originada en buena medida por la explotacion del recurso geotermico. La ocurrencia de nuevas condiciones

  3. Reconnaissance study of late quaternary faulting along cerro GoDen fault zone, western Puerto Rico

    Science.gov (United States)

    Mann, P.; Prentice, C.S.; Hippolyte, J.-C.; Grindlay, N.R.; Abrams, L.J.; Lao-Davila, D.

    2005-01-01

    The Cerro GoDen fault zone is associated with a curvilinear, continuous, and prominent topographic lineament in western Puerto Rico. The fault varies in strike from northwest to west. In its westernmost section, the fault is ???500 m south of an abrupt, curvilinear mountain front separating the 270- to 361-m-high La CaDena De San Francisco range from the Rio A??asco alluvial valley. The Quaternary fault of the A??asco Valley is in alignment with the bedrock fault mapped by D. McIntyre (1971) in the Central La Plata quadrangle sheet east of A??asco Valley. Previous workers have postulated that the Cerro GoDen fault zone continues southeast from the A??asco Valley and merges with the Great Southern Puerto Rico fault zone of south-central Puerto Rico. West of the A??asco Valley, the fault continues offshore into the Mona Passage (Caribbean Sea) where it is characterized by offsets of seafloor sediments estimated to be of late Quaternary age. Using both 1:18,500 scale air photographs taken in 1936 and 1:40,000 scale photographs taken by the U.S. Department of Agriculture in 1986, we iDentified geomorphic features suggestive of Quaternary fault movement in the A??asco Valley, including aligned and Deflected drainages, apparently offset terrace risers, and mountain-facing scarps. Many of these features suggest right-lateral displacement. Mapping of Paleogene bedrock units in the uplifted La CaDena range adjacent to the Cerro GoDen fault zone reveals the main tectonic events that have culminated in late Quaternary normal-oblique displacement across the Cerro GoDen fault. Cretaceous to Eocene rocks of the La CaDena range exhibit large folds with wavelengths of several kms. The orientation of folds and analysis of fault striations within the folds indicate that the folds formed by northeast-southwest shorTening in present-day geographic coordinates. The age of Deformation is well constrained as late Eocene-early Oligocene by an angular unconformity separating folDed, Deep

  4. Vitrinite reflectance geothermometry and apparent heating duration in the Cerro Prieto geothermal field

    Science.gov (United States)

    Barker, C.E.; Elders, W.A.

    1981-01-01

    Vitrinite reflectance measured in immersion oil (Ro) on kerogen extracted from hydrothermally altered mudstones in borehole M-84 at the Cerro Prieto geothermal field exhibit an increase in mean reflectance (Ro) from 0.12 per cent at 0.24 km depth to 4.1 per cent at 1.7 km depth. Downhole temperatures measured over this interval increase from about 60?? to 340??C. These Ro data plotted against temperature fall along an exponential curve with a coefficient of determination of about 0.8. Other boreholes sampled in the field show similar relationships. A regression curve calculated for temperature and Ro in borehole M-105 correctly predicts temperatures in other boreholes within the central portion of the geothermal system. The correlation between the reflectance values and logged temperature, together with consistent temperature estimates from fluid inclusion and oxygen isotope geothermometry, indicates that changes in Ro are an accurate and sensitive recorder of the maximum temperature attained. Therefore, vitrinite reflectance can be used in this geothermal system to predict the undisturbed temperature in a geothermal borehole during drilling before it regains thermal equilibrium. Although existing theoretical functions which relate Ro to temperature and duration of heating are inaccurate, empirical temperature-Ro curves are still useful for geothermometry. A comparison of temperature-Ro regression curves derived from nine boreholes within the Cerro Prieto system suggests that heating across the central portion of the field occurred penecontemporaneously, but varies near margins. Boreholes M-93 and M-94 appear to have cooled from their maximum temperatures, whereas M-3 and Prian-1 have only recently been heated. Comparison of the temperature-Ro data from the Salton Sea, California, geothermal system indicates that the duration of heating has been longer there than at the Cerro Prieto field. ?? 1981.

  5. El volcanismo bimodal del volcán cerro Corona, Alta Sierra de Somún Curá, provincia de Río Negro

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    Guadalupe Maro

    2012-03-01

    Full Text Available La Alta Sierra de Somún Curá es uno de los complejos volcánicos terciarios postplateau en el ambiente de la meseta basáltica de Somún Curá, en la Patagonia extrandina. En ella se encuentra el cerro Corona, un volcán en escudo que corresponde al centro de mayor altura en la región. Está construido por rocas efusivas y piroclásticas subordinadas, fundamentalmente traquiandesíticas-basálticas, con variaciones traquíticas tanto en sus flancos como en su cráter. A pesar de la bimodalidad compositional con una importante discontinuidad entre el 54 y 58 % en peso de SiO2, el presente trabajo propone que las traquitas son el producto de la evolución por cristalización fraccionada de las traquiandesitas basálticas, con cierta influencia de recargas máficas a la cámara magmática de acuerdo a la presencia de texturas de desequilibrio en los fenocristales, principalmente de las rocas félsicas.

  6. IMPACTO EN AFLUENTES DEL RÍO PILCOMAYO POR CONTAMINANTES ADICIONALES DE DRENAJE ÁCIDO DE MINAS DESDE CERRO RICO, POTOSÍ-BOLIVIA

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    William H.J. Strosnider

    2014-01-01

    Full Text Available La minería intensiva y el procesamiento del cuerpo mineralizado del Cerro Rico de Potosí (Bolivia ha ocurrido desde 1545. Para avanzar la investigación sobre descargas de drenaje acido de minas (DAM y su conexión a la contaminación río abajo, se generaron datos en dos muestreos durante la temporada más extrema de lluvia y sequía. Las concentraciones en el DAM y arroyos receptores de Ag, B, Ba, Mo, Sb, Se, Sn, y V fueron superiores a los límites de descarga permitidos por la legislación Boliviana y las directrices sobre arroyos receptores del DAM, tal como las normas de agricultura internacionales. Concen traciones elevadas de elementos de tierras raras han sido documentados en esta ubicación. Los resultados del estudio indican que la contaminación por minería impactan significativamente el río estudiado, y pone de manifiesto la importancia de su remediación.

  7. Cerro Papayo: an astronomical, calendrical and traditional landmark in Ancient Mexico.

    Science.gov (United States)

    Galindo Trejo, J.; Aguilera, T.; Montero García, I. A.

    Cerro Papayo is a peculiar formed hill (almost perfect semisphere, 3,630 m) situated at the east side of the Valley of Mexico. According to surface reconnaissance there is on its cusp a prehispanic site and a modern shrine dedicated to the Virgin of Guadalupe. Its striking appearance and its unobstructed visibility from anyplace in the Valley were used, since preclassic up to postclassic periods, to mark at sunrise the moment of precise astronomical, calendrical and traditional events. The present work shows observational evidence from Cuicuilco, the Templo Mayor of Tenochtitlan and Tepeyacac.

  8. Numerical modeling of high-temperature deep wells in the Cerro Prieto geothermal field, Mexico

    OpenAIRE

    García, A.; F. Ascencio; Espinosa, G.; E. Santoyo; H. Gutiérrez; V. Arellano

    1999-01-01

    A numerical modeling study of three non-producing deep geothermal wells from Cerro Prieto is presented. We compute the expected production characteristics of these wells in order to determine if their inability to sustain flow was due to (i) heat loss effects in the well, (ii) the influence of production casing diameters, (iii) the transient heat loss during the first few days of well discharge, or (iv) the effect of secondary low-enthalpy inflows. A new version of the wellbore flow simulator...

  9. Two-dimensional modeling of apparent resistivity pseudosections in the Cerro Prieto region

    Energy Technology Data Exchange (ETDEWEB)

    Vega, R.; Martinez, M.

    1981-01-01

    Using a finite-difference program (Dey, 1976) for two-dimensional modeling of apparent resistivity pseudosections obtained by different measuring arrays, four apparent resistivity pseudosections obtained at Cerro Prieto with a Schlumberger array by CFE personnel were modeled (Razo, 1978). Using geologic (Puente and de la Pena, 1978) and lithologic (Diaz, et al., 1981) data from the geothermal region, models were obtained which show clearly that, for the actual resistivity present in the zone, the information contained in the measured pseudosections is primarily due to the near-surface structure and does not show either the presence of the geothermal reservoir or the granitic basement which underlies it.

  10. Goldgroup矿业公司Cerro Prieto金矿投入商业化生产

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Goldgroup矿业公司(Goldgroup Mining Inc.)日前宣布,公司所属墨西哥Sonora地区Cerro Prieto金矿从6月1日起正式投入商业化生产。此前从2013年12月起该金矿就一直在进行小规模中试,预计2016年该金矿黄金产量将达到15000盎司。

  11. Overview of the Mexican-American cooperative program at the Cerro Prieto geothermal field

    Science.gov (United States)

    Lippmann, M. J.; Zelwer, R.

    1982-09-01

    The Lawrence Berkeley Laboratory is coordinating the US technical activities being carried out at Cerro Prieto under a five-year agreement between the US Department of Energy and the Comission Federal de Electricidad de Mexico. This agreement, signed in July 1977, is expected to expire in July 1982. Efforts are being made to continue some of the research beyond the formal termination of the agreement. A description of the program, which involves studies of geology, geophysics, hydrodynamics, subsidence, geothermal wells and reservoirs, and aquifers, is discussed.

  12. Preliminary plasma spectrometric analyses for selected elements in some geothermal waters from Cerro Prieto, Mexico

    Science.gov (United States)

    Ball, J.W.; Jenne, E.A.

    1983-01-01

    As part of a cooperative study with Dr. Alfred Truesdell, water samples collected from geothermal power production wells at Cerro Prieto, Mexico, were analyzed for selected elements by d.c. argon plasma emission spectroscopy. Spectral interferences due to the presence of high concentrations of Ca, Si, Na and K in these water affected the apparent concentration values obtained. These effects were evaluated and correction techniques were developed and applied to the analytical values. Precipitates present in the samples at the time of analysis adversely affected the accuracy, precision and interpretability of the data. (USGS)

  13. Andesita Cerro Bola: Nueva unidad vinculada al magmatismo mioceno de la Cordillera de Olivares, San Juan, Argentina (30°35´S; 69°30´O Cerro Bola Andesite: New unit linked to the Miocene magmatism of the Olivares Cordillera, San Juan (30°35' S ; 68°30' W

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    A.F. Wetten

    2005-03-01

    Full Text Available El área de estudio se halla en la zona de Tocota, inmediatamente al este de la Cordillera de Olivares, en el borde oriental de la Cordillera Frontal, provincia de San Juan. En ella se encuentran unidades ígneas y sedimentarias del ciclo gondwánico, las que fueron intruidas y cubiertas en relación discordante por cuerpos subvolcánicos y volcánicos asignados anteriormente al ciclo ándico en sentido amplio, los cuales constituyen el principal objeto del presente estudio. Estos cuerpos han sido mapeados a fin de poder caracterizarlos adecuadamente, en el contexto estratigráfico de la región. Los afloramientos de interés han sido reconocidos en el cerro Bola y alrededores, donde se observan distribuidos irregularmente, cubriendo un área superior a 5 km². Las rocas, de coloración gris clara y composición andesítica - fenoandesítica, presentan estructuras de domo y colada. Estos afloramientos serían correlacionables con la unidad volcánica Pircas (Mioceno, la que aflora al oeste, y conformarían un evento magmático posterior al de pórfidos de diferente composición situados tanto en el arroyo Chita como en el cerro Divisadero. La extensión del área involucrada, la uniformidad litológica, el bajo grado de alteración y una edad radimétrica obtenida por el método K/Ar, fueron considerados para proponer a estas volcanitas como una unidad litoestratigráfica de edad miocena superior, con la denominación de Andesita Cerro Bola.The study area is located in the region of Tocota Creek, close to the Cordillera Olivares, eastern border of the Frontal Range, San Juan province. In this place, igneous and sedimentary units belonging to the Gondwanic cycle, were recognized. These units were intruded and unconformably covered by subvolcanic and volcanic bodies, which were commonly referred to the Tertiary or Andean cycle. The study of these bodies is the main proposal of this work. These bodies had been mapped in order to characterize them

  14. 222Radon Concentration Measurements biased to Cerro Prieto Fault for Verify its Continuity to the Northwest of the Mexicali Valley.

    Science.gov (United States)

    Lazaro-Mancilla, O.; Lopez, D. L.; Reyes-Lopez, J. A.; Carreón-Diazconti, C.; Ramirez-Hernandez, J.

    2009-05-01

    The need to know the exact location in the field of the fault traces in Mexicali has been an important affair due that the topography in this valley is almost flat and fault traces are hidden by plow zone, for this reason, the southern and northern ends of the San Jacinto and Cerro Prieto fault zones, respectively, are not well defined beneath the thick sequence of late Holocene Lake Cahuilla deposits. The purpose of this study was to verify if Cerro Prieto fault is the continuation to the southeast of the San Jacinto Fault proposed by Hogan in 2002 who based his analysis on pre-agriculture geomorphy, relocation and analysis of regional microseismicity, and trench exposures from a paleoseismic site in Laguna Xochimilco, Mexicali. In this study, four radon (222Rn) profiles were carried out in the Mexicali Valley, first, to the SW-NE of Cerro Prieto Volcano, second, to the W-E along the highway Libramiento San Luis Río Colorado-Tecate, third, to the W-E of Laguna Xochimilco and fourth, to the W-E of the Colonia Progreso. The Radon results allow us to identify in the Cerro Prieto profile four regions where the values exceed 100 picocuries per liter (pCi/L), these regions can be associated to fault traces, one of them associated to the Cerro Prieto Fault (200 pCi/L) and other related with Michoacán de Ocampo Fault (450 pCi/L). The profile Libramiento San Luis Río Colorado-Tecate, show three regions above 100 pCi/L, two of them related to the same faults. In spite of the results of the Laguna Xochimilco, site used by Hogan (2002), the profile permit us observe three regions above the 100 pCi/L, but we can associate only one of the regions above this level to the Michoacán de Ocampo Fault, but none region to the Cerro Prieto Fault. Finally in spite of the Colonia Progreso is the shortest profile with only five stations, it shows one region with a value of 270 pCi/L that we can correlate with the Cerro Prieto Fault. The results of this study allow us to think in the

  15. Prácticas de sacrificio en el Cerro de la Mesa (Alcolea de Tajo, Toledo: el depósito ritual de la Casa 1

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    Ana CABRERA DÍEZ

    2014-06-01

    Full Text Available Los depósitos con restos óseos animales enterrados bajo el pavimento en ámbitos domésticos forman parte de prácticas rituales bien conocidas en la Protohistoria peninsular, tradicionalmente asociadas a la fundación o remodelación de nuevos edificios o a ritos vinculados a la propiciación y la fertilidad. Aunque los ejemplos mejor estudiados se encuentran en la zona levantina, el fenómeno también se conoce en yacimientos del interior. Este artículo tiene por objeto presentar un depósito ritual excavado en el poblado vetón del Cerro de la Mesa, en el valle medio del Tajo, cuyas características formales lo emparentan con las ofrendas domésticas de la zona ibérica. Se trata de un hoyo situado en el umbral de la Casa 1, que contiene los restos seleccionados de varios ovinos y un pequeño cuenco cerámico colocado en posición invertida. El análisis de los restos óseos, el contenido del cuenco y el estudio del contexto arqueológico en que se situaba el depósito han permitido relacionarlo con prácticas de sacrificio y libación dentro del marco de la religiosidad vetona. Este trabajo pretende igualmente contribuir a la formación de un corpus peninsular de inhumaciones rituales de animales en contextos domésticos, que impulse el adecuado estudio de la ritualidad protohistórica.

  16. Las mineralizaciones de barita de Cerro del Hierro (Sevilla. Características mineralógicas y geoquímica

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    Galán Huertos, E.

    1992-08-01

    Full Text Available Different barite deposits (stratabound, vein and karstic types are occurring in the Lower Cambrian carbonatic materials of the Cerro del Hierro, Sevilla (Ossa-Morena Zone. Calcite, hematite, goethite and minor chalcopyrite are common associated minerals, with limonite and malachite as alterations. The content of barite can be as high as 98 %. There is a close relationship between barite type and Sr content (vein 34S ranges between 32,7 ‰ (stratiform barites and 20,7 ‰ (epigenetic barites. The 87Sr/86Sr ratio for the epigenetic barites oscillates between 0.70873 and 0.71112 which could be the result of the infiuence of different mineralization solutions. A primary origin for the stratabound barites is proposed, in relation with the diagenesis of the limestones occurred during the Lower Cambrian. Epigenetic barites were formed after the Hercynian Orogenesis by remobilization of the stratiform ores, with Ba and Sr supplied from the lixiviation of the host rocks. The last process could be much more important for the karstic barite formation.En los materiales carbonatados del Cámbrico inferior del Cerro del Hierro (Zona de Ossa-Morena existen diversos tipos de mineralizaciones de barita (estratoligadas, filonianas y kársticas. La barita está acompañada de calcita, hematites, goethita, y calcopirita accesoria, y limonitas y malaquita como fases tardías de alteración, y presenta una gran pureza química [ > 98% SO4(Ba,Sr]. Existe una relación entre la tipología de la barita y el contenido en Sr, en el sentido de filonianas 34S en las baritas oscila entre 32,7 ‰ para las estratoligadas y 20,7 ‰ para las epigenéticas. Las razones 87Sr/86Sr determinadas sobre baritas epigenéticas varían entre 0.70873 y 0.71112, lo que puede interpretarse como consecuencia de la participación de diversos tipos de soluciones mineralizantes. Se propone un origen primario de las baritas estratoligadas, en relación con la diagénesis de los

  17. A first shallow firn-core record from Glaciar La Ollada, Cerro Mercedario, central Argentine Andes

    Science.gov (United States)

    Bolius, David; Schwikowski, Margit; Jenk, Theo; Gäggeler, Heinz W.; Casassa, Gino; Rivera, Andrés

    In January 2003, shallow firn cores were recovered from Glaciar Esmeralda on Cerro del Plomo (33°14‧ S, 70°13‧ W; 5300 ma.s.l.), central Chile, and from Glaciar La Ollada on Cerro Mercedario (31°58‧ S, 70°07‧ W; 6070 ma.s.l.), Argentina, in order to find a suitable archive for paleoclimate reconstruction in a region strongly influenced by the El Niño-Southern Oscillation. In the area between 28° S and 35° S, the amount of winter precipitation is significantly correlated to the Southern Oscillation Index, with higher values during El Niño years. Glaciochemical analysis indicates that the paleo-record at Glaciar La Ollada is well preserved, whereas at Glaciar Esmeralda the record is strongly influenced by meltwater formation and percolation. A preliminary dating of the Mercedario core by annual-layer counting results in a time-span of 17 years (1986-2002), yielding an average annual net accumulation of 0.45 m w.e.

  18. Optical Sky Brightness at Cerro Tololo Inter-American Observatory from 1992 to 2006

    CERN Document Server

    Krisciunas, Kevin; Sanhueza, Pedro; Schwarz, Hugo E; Semler, Dylan R; Suntzeff, Nicholas B; Vera, Sergio

    2007-01-01

    We present optical UBVRI sky brightness measures from 1992 through 2006. The data are based on CCD imagery obtained with the CTIO 0.9-m, 1.3-m, and 1.5-m telescopes. The B- and V-band data are in reasonable agreement with measurements previously made at Mauna Kea, though on the basis of a small number of images per year there are discrepancies for the years 1992 through 1994. Our CCD-based data are not significantly different than values obtained at Cerro Paranal. We find that the yearly averages of V-band sky brightness are best correlated with the 10.7-cm solar flux taken 5 days prior to the sky brightness measures. This implies an average speed of 350 km/sec for the solar wind. While we can measure an enhancement of the night sky levels over La Serena 10 degrees above the horizon, at elevation angles above 45 degrees we find no evidence that the night sky brightness at Cerro Tololo is affected by artificial light of nearby towns and cities.

  19. Cerro de Pasco and other massive sulfide deposits of central Peru

    Energy Technology Data Exchange (ETDEWEB)

    Cheney, E.S.

    1985-01-01

    The famous Cerro de Pasco Pb-Zn-Ag deposit historically has been considered to be hydrothermally derived from an adjacent Tertiary volcanic vent. However, texturally massive pyrite-chert and pyrite-sphalerite-galena in the deposit have the same strike and cross folds as the adjacent pre-Tertiary strata. Both the deposit and the strata are cut by one of the large Longitudinal Faults. Both dikes and pyrite-enargite veins associated with the vent cut the massive sulfides; fragments of massive pyrite occur in the vent. A few examples of laminated pyrite and chert, banded pyrite and chert, banded pyrite and sphalerite, and banded pyrite, sphalerite, and galena are preserved in the massive sulfide portion of the deposit. The deposit has the composition and zoning patterns typical of shale-hosted massive sulfides. Cerro de Pasco probably in part of the pelitic Devonian Excelsior formation. The Colquijirca deposit 8 km to the south and the San Cristobal district 110 km to the south likewise have been considered to be Tertiary volcanic hydrothermal deposits. Colquijirca consists of stratigraphically controlled mantos of layered pyrite, chert and tuff in the Tertiary Calera formation. The mantos of the San Cristobal district are along the upper contact of the pyritic, Permian, Catalina felsic volcanic rocks; some ore consists of laminated pyrite and sphalerite. Tertiary plutons are conspicuously absent at San Cristobal, and the ores are brecciated by Tertiary folding.

  20. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.

    1983-12-15

    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  1. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum

    Energy Technology Data Exchange (ETDEWEB)

    Carbognani, L.; Hazos, M.; Sanchez, V. (INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela)); Green, J.A.; Green, J.B.; Grigsby, R.D.; Pearson, C.D.; Reynolds, J.W.; Shay, J.Y.; Sturm, G.P. Jr.; Thomson, J.S.; Vogh, J.W.; Vrana, R.P.; Yu, S.K.T.; Diehl, B.H.; Grizzle, P.L.; Hirsch, D.E; Hornung, K.W.; Tang, S.Y.

    1989-12-01

    On March 6, 1980, the US Department of Energy (DOE) and the Ministry of Energy and Mines of Venezuela (MEMV) entered into a joint agreement which included analysis of heavy crude oils from the Venezuelan Orinoco oil belt.The purpose of this report is to present compositional data and describe new analytical methods obtained from work on the Cerro Negro Orinoco belt crude oil since 1980. Most of the chapters focus on the methods rather than the resulting data on Cerro Negro oil, and results from other oils obtained during the verification of the method are included. In addition, published work on analysis of heavy oils, tar sand bitumens, and like materials is reviewed, and the overall state of the art in analytical methodology for heavy fossil liquids is assessed. The various phases of the work included: distillation and determination of routine'' physical/chemical properties (Chapter 1); preliminary separation of >200{degree}C distillates and the residue into acid, base, neutral, saturated hydrocarbon and neutral-aromatic concentrates (Chapter 2); further separation of acid, base, and neutral concentrates into subtypes (Chapters 3-5); and determination of the distribution of metal-containing compounds in all fractions (Chapter 6).

  2. Elemental analysis of pottery from Cerro de las Ventanas, Zacatecas, by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Lopez del Rio, H.; Mireles G, F. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Mendez C, R. Y. [Universidad Autonoma de Zacatecas, Unidad Academica de Antropologia, Apdo. Postal 555 Suc. C, Zacatecas (Mexico); Nicolas C, M. [Universidad Autonoma de San Luis Potosi, Coordinacion de Ciencias Sociales y Humanidades, Av. Industrias 101-A, Fracc. Talleres, 78494 San Luis Potosi (Mexico); Speakman, R. J. [Museum Conservation Institute, Smithsonian Institution, Suitland, 20746 Maryland (United States); Glascock, M. D. [Reactor Center, University of Missouri, Columbia, 65211 Missouri (United States)

    2009-10-15

    Fifteen ceramic fragments samples from Cerro de las Ventanas site, Zacatecas, were analyzed by instrumental neutron activation analysis. Thirty-two elements were measured: Al, As, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Ti, Th, U, V, Yb, Zn, and Zr. Cluster analysis and principal component analysis were performed on the dataset to examine similarities between samples and to establish compositional groups. The statistical analyses of the dataset suggest that the pottery samples form a unique chemically homogeneous group, with the exception of one pottery sample. The compositional data were compared to an existing Meso american ceramic database. It was found that the newly generated data fit best with data from a previous chemical analysis of pottery from the Mal paso Valley. However, despite the apparent similarity, pottery samples from the site of Cerro de las Ventanas represent a new and unique chemical fingerprint in the region. (Author)

  3. Cerro Negro field, Venezuela: geological images from a high resolution 3-D survey

    Energy Technology Data Exchange (ETDEWEB)

    Woller, Kevin L. [Mobil Technology Co. (WEC)

    1999-07-01

    Following a pilot 3-D survey, Petrolera Cerro Negro acquired and processed a 3-D dynamite survey over the Cerro Negro Field in Venezuela. We designed the survey to achieve high frequency imaging at the relatively shallow (< 1000 m) objectives in the Morichal formation. The data exhibits usable frequencies in the 10-120 Hz range after migration. The results of the survey have satisfied the original objective of imaging the faults and basement structure in the field. Use of continuity measurements on the data has resulted in a photographic quality image of the faults at the basement level. The pattern of the faults indicates an unexpected degree of complexity, indicating a richer structural history than originally thought. The continuity data also shows depositional details in the Morichal, which in accordance with geological history of the area. The operatorship is currently in the process of drilling many horizontal development wells. The patterns of the wells bores and variations in the rock types present a challenge to the usage of the 3-D seismic. The operatorship is working to raise the understanding and utility of the seismic data to another plateau. (author)

  4. Mega-deslizamientos de la pared sur del cerro Aconcagua y su relación con depósitos asignados a la glaciación pleistocena

    Directory of Open Access Journals (Sweden)

    Luis Fauqué

    2009-12-01

    Full Text Available Con motivo de la confección de un mapa de susceptibilidad a los procesos de remoción en masa que afectan a la localidad de Puente del Inca, se procedió a revisar la controvertida génesis del depósito Horcones. Se analizó la morfología del depósito y del paisaje circundante, la mineralogía y textura de sus materiales y finalmente se realizaron dataciones radimétricas. Sobre la base de estos estudios se concluye que el depósito de Horcones es el resultado de un flujo saturado derivado de una avalancha de rocas o mega-deslizamiento, originada por el colapso de una divisoria de aguas en la pared sur del cerro Aconcagua, durante tiempos tardioglaciales o postglaciales. Depósitos similares al de Horcones rellenan el valle del río Cuevas hacia el este y son cubiertos por otros, que también previamente fueron considerados como glaciarios (e.g. morena terminal del Drift Penitentes. El análisis de este material en las cercanías de la localidad de Penitentes, utilizando una metodología semejante, revela que corresponde a un flujo de gran envergadura proveniente de la quebrada Mario Ardito. De acuerdo a estas nuevas interpretaciones resulta clara la necesidad de realizar una exhaustiva revisión de la estratigrafía glaciaria en la zona. Surgen además nuevas ideas en cuanto a la génesis del monumento natural Puente del Inca. Finalmente, la comprensión de la evolución geomorfológica de la pared sur del cerro Aconcagua arroja luz sobre los surge del glaciar Horcones Inferior, revistiendo una gran importancia para la evaluación de los riesgos geológicos del Parque Provincial Aconcagua.

  5. Extension of the Cerro Prieto field and zones in the Mexicali Valley with geothermal possibilities in the future

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca L, H.L.; de la Pena L, A.; Puente C, I.; Diaz C, E.

    1981-01-01

    This study concerns the possible extension of the Cerro Prieto field and identification of other zones in the Mexicali Valley with geothermal development potential by assessing the structural geologic conditions in relation to the regional tectonic framework and the integration of geologic and geophysical surveys carried out at Cerro Prieto. This study is based on data obtained from the wells drilled to date and the available geological and geophysical information. With this information, a geologic model of the field is developed as a general description of the geometry of what might be the geothermal reservoir of the Cerro Prieto field. In areas with geothermal potential within the Mexicali Valley, the location of irrigation wells with anomalous temperatures was taken as a point of departure for subsequent studies. Based on this initial information, gravity and magnetic surveys were made, followed by seismic reflection and refraction surveys and the drilling of 1200-m-deep multiple-use wells. Based on the results of the final integration of these studies with the geology of the region, it is suggested that the following areas should be explored further: east of Cerro Prieto, Tulecheck, Riito, Aeropuerto-Algodones, and San Luis Rio Colorado, Sonora.

  6. EL FUEGO Y EL AGUA EN LOS RITUALES DE CURANDEROS OTOMÍES

    Directory of Open Access Journals (Sweden)

    Felipe Gonz\\u00E1lez Ortiz

    2012-01-01

    Full Text Available A partir de un intenso trabajo etnográfico con grupos de curación otomíes que habitan en zonas metropolitanas del México central, se presenta una descripción e interpretación de sus prácticas rituales para curar a los individuos y ofrecer ceremonias a los Dioses en los cerros y manantiales. El fuego y el agua contienen las cualidades de calor y frío; húmero y seco, vida y muerte.

  7. Edad y rasgos petrográficos y geoquímicos de cuerpos subvolcánicos asignables a la Formación Cerro León, este del Macizo del Deseado, Santa Cruz Age and petrography and geochemistry features of subvolcanic outcrops from Cerro León Formation, east of the Deseado Massif, Santa Cruz

    Directory of Open Access Journals (Sweden)

    D. Guido

    2004-12-01

    Full Text Available Se presentan nuevos afloramientos de cuerpos subvolcánicos correlacionables con la Formación Cerro León en el sector oriental del Macizo del Deseado. Esta unidad aflora en dos sectores, en el bajo Leonardo y en el afloramiento Bahía Laura del Complejo Río Deseado. El primer sector presenta trece diques y un filón capa intruyendo a las sedimentitas pérmicas de la Formación La Golondrina y el segundo sector comprende tres diques que intruyen a rocas del basamento. Se trata de rocas de color gris a negro, frecuentemente alteradas, con textura microgranuda a porfírica, con fenocristales de plagioclasa, diópsido (En42 Fs11 Wo47 y en menor medida de hornblendas ricas en Mg (magnesio hastingsita, en una matriz holocristalina de textura intergranular. Son rocas subalcalinas de composiciones basalto-andesita y con afinidades calcoalcalinas. La edad Ar/Ar obtenida en una de estas muestras (180,1±1,5 Ma representa la primer determinación realizada en esta unidad y es coherente con las relaciones estratigráficas observadas para esta formación. La comparación con rocas ígneas jurásicas de la provincia geológica Macizo del Deseado, favorece la vinculación temporal y genética con el evento volcánico-piroclástico del Jurásico medio a superior (Formación Bajo Pobre y Grupo Bahía Laura. Sin embargo, la diferencia en las edades Ar/Ar, sugieren una interrupción entre el evento subvolcánico (180 Ma y el volcanismo Jurásico medio a superior (177 a 150 Ma. Se considera, preliminarmente, que los cuerpos subvolcánicos de la Formación Cerro León representarían las primeras evidencias magmáticas del rift jurásico en el Macizo del Deseado.New subvolcanic outcrops, correlated with the Cerro León Formation and located in the eastern Deseado Massif, are presented. This unit outcrops in two sectors, the Leonardo depression and the Bahía Laura outcrop of the Río Deseado Complex. In the first sector there are thirteen dikes and a sill

  8. Jurassic tetrapods and flora of Cañadón Asfalto Formation in Cerro Cóndor area, Chubut Province Flora y tetrápodos del Jurásico de la Formación Cañadón Asfalto en el área de Cerro Cóndor, provincia de Chubut

    Directory of Open Access Journals (Sweden)

    Ignacio H. Escapa

    2008-12-01

    Full Text Available The plant and tetrapod fossil record of the Cañadón Asfalto Formation (Middle to Late Jurassic found in Cerro Cóndor area (Chubut Province is summarized here. The flora is dominated by conifers (Araucariaceae, Cupressaceae sensu lato but also includes ferns and equisetaleans. The tetrapod fauna is composed of dinosaur taxa described in the 70's as well as other remains recently described and other vertebrate groups such as amphibians, turtles, and mammals. The amphibian remains have been interpreted as representatives of a new species of Notobatrachus, considered one of the most basal members of the anuran lineage. Similarly, turtle remains have been recently recognized as a new species of basal turtle, bringing valuable information about the early evolution of this group. The dinosaur remains are largely dominated by saurischian taxa, represented by basal forms of Eusauropoda and Tetanurae. In addition, three different mammalian species have been identified and considered as early representatives of an endemic Gondwanan mammalian fauna. The fossil record of this formation represents the most completely known biota from the continental Middle to Late Jurassic of the Southern Hemisphere and one of the most complete of the entire world.Se resume brevemente el registro de plantas y tetrápodos fósiles de la Formación Cañadón Asfalto (Jurásico Medio a Superior en el área de Cerro Cóndor, provincia de Chubut. La flora está conformada por coníferas de las familias Araucariaceae y Cupressaceae sensu lato dominando la asociación, la cual se completa con helechos y equisetales en proporciones menores. La fauna de tetrápodos se compone por los clásicos dinosaurios descriptos en los 70`s, a los que se suman nuevos restos pertenecientes a este grupo, así como anfibios, tortugas y mamíferos coleccionados en la última década. Los restos de anfibios han sido interpretados como representantes de una nueva especie de Notobatrachus, considerado

  9. Microfaunal evidence of age and depositional environments of the Cerro Prieto section (Plio-Pleistocene), Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ingle, J.C. Jr.

    1982-01-01

    Microfossils including benthic and planktic foraminifera, ostracodes, calcareous algae, fish skeletal material, and fragments of pelecypods were found in 14 core samples from depths of 185 to 1952 m in the Cerro Prieto geothermal field, providing evidence of both the age and depositional history of sediments comprising the 3000-m-thick Pliocene and Pleistocene section in this area. Ostracodes of brackish water and marine origin constitute the most common microfossils present in this sequence occurring in 8 samples; in situ littoral and neritic species of benthic foraminifera occur in 5 samples with planktic species present in 2 samples. Distributional patterns of ostracodes and foraminifera together with previously analyzed lithofacies (Lyons and van de Kamp, 1980) indicate that the Cerro Prieto section represents an intertonguing complex of alluvial, deltaic, estuarine, and shallow marine environments deposited along the front of the Colorado River delta as it prograded across the Salton Trough during Pliocene and Pleistocene time. Foraminiferal evidence indicates that a sand and shale unit commonly present at depths between 700 and 1100 m represents a significant mid-Pleistocene marine incursion in the Cerro Prieto area. Tentative correlation of the Cerro Prieto section with the well dated Palm Springs Formation of the Imperial Valley, California area suggests that the Pliocene/Pleistocene boundary occurs at a depth of approximately 2000 m in the area of well M-93. Reworked specimens of Cretaceous foraminifera and fragments of the Cretaceous pelecypod Inoceramus were found in five samples further substantiating the Colorado Plateau provenance of a significant portion of the Colorado River deltaic sediments in the Cerro Prieto area.

  10. Arterial oxygen saturation in healthy newborns delivered at term in Cerro de Pasco (4340 m and Lima (150 m

    Directory of Open Access Journals (Sweden)

    Gonzales Gustavo F

    2005-09-01

    Full Text Available Abstract Background High altitude is associated with both low pulse oxygen saturation at birth and more pre-term deliveries. The present study was performed to determine pulse oxygen saturation in newborns at term in Cerro de Pasco (4340 m and Lima (150 m to test the hypothesis that low pulse oxygen saturation at birth at high altitudes was not observed at term deliveries. Methods The present study was designed to determine pulse oxygen saturation values through 1 minute to 24 hours and values of Apgar score at 1 and 5 minutes in newborns delivered at term in Cerro de Pasco (4340 m and Lima (150 m. Pulse oxygen saturation was recorded in 39 newborns from Cerro de Pasco (4340 m and 131 from Lima (150 m at 1, 2, 3, 4, 5, 10, 15, 30 minutes and 1, 2, 8 and 24 hours after delivery. Apgar score was assessed at 1 and 5 minutes after birth. Neurological score was assessed at 24 h of birth by Dubowitz exam. Results Pulse oxygen saturation increased significantly from 1 to 15 min after birth at sea level and from 1 to 30 minutes at Cerro de Pasco. Thereafter, it increased slightly such that at 30 min at sea level and at 60 minutes in Cerro de Pasco it reached a plateau up to 24 hours after birth. At all times, pulse oxygen saturation was significantly higher at sea level than at high altitude (P Conclusion From these analyses may be concluded that pulse oxygen saturation at 4340 m was significantly low despite the fact that births occurred at term. Apgar scores at first minute and neurological scores were also lower at high altitudes.

  11. Problemática histórico-metodológica del arte rupestre del Sur de la Sierra de Comechingones : El Cerro Intihuasi, Pedanía Achiras, Córdoba

    OpenAIRE

    Gili, Maria Laura

    2011-01-01

    La presente investigación consiste en un análisis sobre las pinturas rupestres del Cerro Intihuasi, ubicado en el sector sur de la región arqueológica Sierras Centrales y en el tramo sur de las Sierra de Comechingones, Pedanía Achiras, Córdoba. Nuestro interés ha sido estudiar los aspectos más relevantes en su registro y ampliar el conocimiento sobre una sociedad que se situó históricamente en una expansión temporal de tres mil años en la localidad arqueológica y su piedemonte circundante, co...

  12. Hydrothermal alteration of sediments associated with surface emissions from the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Valette-Silver, J.N.; Esquer P., I.; Elders, W.A.; Collier, P.C.; Hoagland, J.R.

    1981-01-01

    A study of the mineralogical changes associated with these hydrothermal vents was initiated with the aim of developing possible exploration tools for geothermal resources. The Cerro Prieto reservoir has already been explored by extensive deep drilling so that relationships between surface manifestations and deeper hydrothermal processes could be established directly. Approximately 120 samples of surface sediments were collected both inside and outside of the vents. The mineralogy of the altered sediments studied appears to be controlled by the type of emission. A comparison between the changes in mineralogy due to low temperature hydrothermal activity in the reservoir, seen in samples from boreholes, and mineralogical changes in the surface emission samples shows similar general trends below 180 C: increase of quartz, feldspar and illite, with subsequent disappearance of kaolinite, montmorillonite, calcite and dolomite. These mineral assemblages seem to be characteristic products of the discharge from high intensity geothermal fields.

  13. Comments on some of the drilling and completion problems in Cerro Prieto geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez A, B.; Sanchez G, G.

    1981-01-01

    From 1960 to the present, 85 wells with a total drilling length exceeding 160,000 m have been constructed at Cerro Prieto, a modest figure compared to an oil field. This activity took place in five stages, each characterized by changes and modifications required by various drilling and well-completion problems. Initially, the technical procedures followed were similar to those used in the oil industry. However, several problems emerged as a result of the relatively high temperatures found in the geothermal reservoir. The various problems that have been encountered can be considered to be related to drilling fluids, cements and cementing operations, lithology, geothermal fluid characteristics, and casings and their accessories. As the importance of high temperatures and the characteristics of the geothermal reservoir fluids were better understood, the criteria were modified to optimize well-completion operations, and satisfactory results have been achieved to date.

  14. Isotopic changes in the fluids of the Cerro Prieto {Beta} Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Mahendra; Quijano, Luis; Gutierrez, Hector; Iglesias, Eduardo; Truesdell, Alfred

    1996-01-24

    Monitoring changes with time of the isotopes of water (18O and D) in wellhead fluids is an effective way of indicating reservoir changes and processes. Because 18O concentrations in water are altered by high-temperature exchange with rock oxygen and because both 18O and D are fractionated in vapor-liquid separation processes at the surface (separators and cooling towers), these isotopes are excellent indicators of inflow and distribution of fluids from outside the reservoir, either natural or injected. Studies of the isotopic compositions of fluids from the Cerro Prieto field in Baja California, Mexico show that pressure drawdown in the major β (beta) reservoir has caused intense boiling followed by inflow of water from outside the reservoir. A method of field exploitation based on this behavior is discussed.

  15. Dynamics of a geothermal field traced by noble gases: Cerro Prieto, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Mazor, E. (Weizmann Inst. of Science, Rehovot, Israel); Truesdell, A.H.

    1981-01-01

    Noble gases have been measured mass spectrometrically in samples collected during 1977 from producing wells at Cerro Prieto. Positive correlations between concentrations of radiogenic (He, /sup 40/Ar) and atmospheric noble gases (Ne, Ar, and Kr) suggest the following dynamic model: the geothermal fluids originated from meteoric water penetrated to more than 2500 m depth (below the level of first boiling) and mixed with radiogenic helium and argon-40 formed in the aquifer rocks. Subsequently, small amounts of steam were lost by a Raleigh process (0 to 3%) and mixing with shallow cold water occurred (0 to 30%). Noble gases are sensitive tracers of boiling in the initial stages of 0 to 3% steam separation and complement other tracers, such as Cl or temperature, which are effective only beyond this range.

  16. BESO échelle spectroscopy of solar-type stars at Cerro Armazones

    Science.gov (United States)

    Fuhrmann, K.; Chini, R.; Hoffmeister, V. H.; Lemke, R.; Murphy, M.; Seifert, W.; Stahl, O.

    2011-03-01

    The Bochum Échelle Spectroscopic Observer BESO is a fibre-fed high-resolution spectrograph for the 1.5-m Hexapod Telescope at the Cerro Armazones Observatory in the Atacama desert in Chile. Here we report on the first BESO observations and model atmosphere analyses of solar-type stars secured in 2010 April. The quality of the data is first tested with a reflected sunlight spectrum as well as the standard G-type subgiant 70 Vir. We then investigate the bright and supposedly single F-type star ξ Gem and present the spectroscopic evidence that instead favours an equal-mass binary. We present also the first composite synthetic modelling of the G-type visual binary HR 3430 and discuss the spectroscopic observations that identify this as a triple system. We conclude with another triple, the famous and very nearby α Cen, and the basic stellar parameters of its inner, solar-type visual binary.

  17. Bottom Topography, Recent Sedimentation and Water Volume of the Cerro Prieto Dam, NE Mexico

    Science.gov (United States)

    Yutsis, V. V.

    2012-12-01

    Cerro Prieto dam, relatively small water reservoir in the NE of Mexico, is characterized by a very high velocity of recent sedimentation, irregular bottom topography and sub-bottom seepage. Very high resolution seismic study using non-linear parametric echo sounder SES-2000 was carried out in this water reservoir, which is one of the main resources of potable water for the Monterrey, the city with a population of about four million inhabitants. A strong difference between water depth and hence the volume capacity calculated by National Commission of Water (Comision Nacional del Agua, CNA), Digital Elevation Model (DEM), and acoustic data was discovered. Very high rate of recent sedimentation due to damming is discussed. SES data interpretation shows that the thickness of recent sediments due to siltation of the reservoir reaches 3.5-4.0 m. Differences between the CNA and SES data indicate storage losses from 8-10 up to 30 million cubic meters due to sedimentation.

  18. Did stresses from the Cerro Prieto Geothermal Field influence the El Mayor-Cucapah rupture sequence?

    Science.gov (United States)

    Trugman, Daniel T.; Borsa, Adrian A.; Sandwell, David T.

    2014-12-01

    The Mw 7.2 El Mayor-Cucapah (EMC) earthquake ruptured a complex fault system in northern Baja California that was previously considered inactive. The Cerro Prieto Geothermal Field (CPGF), site of the world's second largest geothermal power plant, is located approximately 15 km to the northeast of the EMC hypocenter. We investigate whether anthropogenic fluid extraction at the CPGF caused a significant perturbation to the stress field in the EMC rupture zone. We use Advanced Land Observing Satellite interferometric synthetic aperture radar data to develop a laterally heterogeneous model of fluid extraction at the CPGF and estimate that this extraction generates positive Coulomb stressing rates of order 15 kPa/yr near the EMC hypocenter, a value which exceeds the local tectonic stressing rate. Although we cannot definitively conclude that production at the CPGF triggered the EMC earthquake, its influence on the local stress field is substantial and should not be neglected in local seismic hazard assessments.

  19. Lithology and hydrothermal alteration determination from well logs for the Cerro Prieto Wells, Mexico

    Science.gov (United States)

    Ershaghi, I.; Ghaemian, S.; Abdassah, D.

    1981-10-01

    The characteristics of geophysical well logs are compared against the sand-shale series of the sedimentary column of the Cerro Prieto Geothermal Field, Mexico. It is shown that the changes in mineralogy of the rocks because of hydrothermal alteration are not easily detectable on the existing logs. However, if the behavior of clay minerals alone is monitored, the onset of the hydrothermally altered zones may be estimated from the well logs. The effective concentration of clay-exchange cations, Q/sub v/, is computed using the data available from conventional well logs. Zones indicating the disappearance of low temperature clays are considered hydrothermally altered formations with moderate to high permeability and temperature, and suitable for completion purposes.

  20. Dynamics of a geothermal field traced by noble gases: Cerro Prieto, Mexico

    Science.gov (United States)

    Mazor, E.; Truesdell, A.H.

    1984-01-01

    Noble gases have been measured mass spectrometrically in samples collected during 1977 from producing wells at Cerro Prieto. Positive correlations between concentrations of radiogenic (He and 40Ar) and atmospheric noble gases (Ne, Ar and Kr) suggest the following dynamic model: the geothermal fluids originated from meteoric water that penetrated to more than 2500 m depth (below the level of first boiling) and mixed with radiogenic He and 40Ar formed in the aquifer rocks. Subsequently, small amounts of steam were lost by a Raleigh process (0 - 30%) and mixing with shallow cold water occurred (0 - 30%). Noble gases are sensitive tracers of boiling in the initial stages of 0 - 3% steam separation and complement other tracers, such as C1 or temperature, which are effective only beyond this range. ?? 1984.

  1. Study of the atmospheric conditions at Cerro Armazones using astronomical data

    CERN Document Server

    Lakicevic, Masha; Noll, Stefan; Kausch, Wolfgang; Unterguggenberger, Stefanie; Kerber, Florian

    2016-01-01

    Aims: We studied the precipitable water vapour (PWV) content near Cerro Armazones and discuss the potential use of our technique of modelling the telluric absorbtion lines for the investigation of other molecular layers. The site is designated for the European Extremely Large Telescope (E-ELT) and the nearby planned site for the Cherenkov Telescope Array (CTA). Methods: Spectroscopic data from the Bochum Echelle Spectroscopic Observer (BESO) instrument were investigated by using line-by-line radiative transfer model (LBLRTM) radiative transfer models for the Earths atmosphere with the telluric absorption correction tool molecfit. All observations from the archive in the period from December 2008 to the end of 2014 were investigated. The dataset completely covers the El Nino event registered in the period 2009-2010. Models of the 3D Global Data Assimilation System (GDAS) were used for further comparison. Moreover, for those days with coincidence of data from a similar study with VLT/X-shooter and microwave rad...

  2. Mathematical Modeling of the Dynamics of Salmonella Cerro Infection in a US Dairy Herd

    Science.gov (United States)

    Chapagain, Prem; van Kessel, Jo Ann; Karns, Jeffrey; Wolfgang, David; Schukken, Ynte; Grohn, Yrjo

    2006-03-01

    Salmonellosis has been one of the major causes of human foodborne illness in the US. The high prevalence of infections makes transmission dynamics of Salmonella in a farm environment of interest both from animal and human health perspectives. Mathematical modeling approaches are increasingly being applied to understand the dynamics of various infectious diseases in dairy herds. Here, we describe the transmission dynamics of Salmonella infection in a dairy herd with a set of non-linear differential equations. Although the infection dynamics of different serotypes of Salmonella in cattle are likely to be different, we find that a relatively simple SIR-type model can describe the observed dynamics of the Salmonella enterica serotype Cerro infection in the herd.

  3. Results of the latest transient well pressure tests at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Abril G, A.; Vargas G, C.

    1981-01-01

    The equipment used in the interference and two-rate flow tests carried out at the Cerro Prieto geothermal field during 1980 are described. The results of two interference tests are presented, one between wells M-110 and M-104, and the other between wells M-7 and Q-757. The data was interpreted using type curve matching analysis. Results of two-rate flow tests carried out in wells M-102 and M-7 are also discussed. A technique for making two-rate flow tests is proposed. This approach, which attempts to avoid the uncertainty of present flow-rate measurements, makes use of devices for direct measurements of separated water and steam. Conclusions based on the above interpretations and recommendations for future tests are presented.

  4. Structure and age of the Cerro de Pasco Cu-Zn-Pb-Ag deposit, Peru

    Science.gov (United States)

    Cheney, E. S.

    1991-04-01

    The world-famous Cu-Zn-Pb-Ag deposit at Cerro de Pasco, Peru, consists of texturally massive pyrite, texturally massive sphalerite-galena-pyrite, and veins containing pyrite and enargite. Historically the deposit has been considered to be the hydrothermal product of the adjacent Miocene volcanic and intrusive complex (locally known as the “Vent”). However, both the texturally massive sulfides of the deposit and the pre-Miocene strata are cut by the Longitudinal fault, one of the largest faults in the district, but the Vent is not. Imbrication by the Longitudinal fault zone (duplex structures) has thickened the deposit so that it is amenable to open-pit mining. Dikes and pyrite-enargite veins pass from the Vent into the massive sulfides; fragments of massive pyrite occur in the Vent. Thus, no matter what their origin, the texturally massive sulfides are older and, therefore, genetically unrelated to the Vent.

  5. Burning down the brewery: establishing and evacuating an ancient imperial colony at Cerro Baul, Peru.

    Science.gov (United States)

    Moseley, Michael E; Nash, Donna J; Williams, Patrick Ryan; DeFrance, Susan D; Miranda, Ana; Ruales, Mario

    2005-11-29

    Before the Inca reigned, two empires held sway over the central Andes from anno Domini 600 to 1000: the Wari empire to the north ruled much of Peru, and Tiwanaku to the south reigned in Bolivia. Face-to-face contact came when both colonized the Moquegua Valley sierra in southern Peru. The state-sponsored Wari incursion, described here, entailed large-scale agrarian reclamation to sustain the occupation of two hills and the adjacent high mesa of Cerro Baúl. Monumental buildings were erected atop the mesa to serve an embassy-like delegation of nobles and attendant personnel that endured for centuries. Final evacuation of the Baúl enclave was accompanied by elaborate ceremonies with brewing, drinking, feasting, vessel smashing, and building burning.

  6. Volcanic hazard map for Telica, Cerro Negro and El Hoyo volcanoes, Nicaragua

    Science.gov (United States)

    Asahina, T.; Navarro, M.; Strauch, W.

    2007-05-01

    A volcano hazard study was conducted for Telica, Cerro Negro and El Hoyo volcanoes, Nicaragua, based on geological and volcanological field investigations, air photo analyses, and numerical eruption simulation. These volcanoes are among the most active volcanoes of the country. This study was realized 2004-2006 through technical cooperation of Japan International Cooperation Agency (JICA) with INETER, upon the request of the Government of Nicaragua. The resulting volcanic hazard map on 1:50,000 scale displays the hazards of lava flow, pyroclastic flows, lahars, tephra fall, volcanic bombs for an area of 1,300 square kilometers. The map and corresponding GIS coverage was handed out to Central, Departmental and Municipal authorities for their use and is included in a National GIS on Georisks developed and maintained by INETER.

  7. Mid amphibolite facies metamorphism of harzburgites in the Neoproterozoic Cerro Mantiqueiras Ophiolite, southernmost Brazil

    Directory of Open Access Journals (Sweden)

    HARTMANN LÉO A.

    2003-01-01

    Full Text Available Valuable information is retrieved from the integrated investigation of the field relationships, microstructure and mineral compositions of harzburgites from the Neoproterozoic Cerro Mantiqueiras Ophiolite. This important tectonic marker of the geological evolution of southernmost Brazilian Shield was thoroughly serpentinized during progressive metamorphism, because the oldest mineral assemblage is: olivine + orthopyroxene + tremolite + chlorite + chromite. This M1 was stabilized in mid amphibolite facies - 550-600ºC as calculated from mineral equilibria. No microstructural (e.g. ductile deformation of olivine or chromite or compositional (e.g. mantle spinel remnant of mantle history was identified. A metamorphic event M2 occurred in the low amphibolite facies along 100 m-wide shear zones, followed by intense serpentinization (M3 and narrow 1-3 m-wide shear zones (M4 containing asbestos.

  8. Burn Severities, Fire Intensities, and Impacts to Major Vegetation Types from the Cerro Grande Fire

    Energy Technology Data Exchange (ETDEWEB)

    Balice, Randy G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bennett, Kathryn D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wright, Marjorie A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2004-12-15

    The Cerro Grande Fire resulted in major impacts and changes to the ecosystems that were burned. To partially document these effects, we estimated the acreage of major vegetation types that were burned at selected burn severity levels and fire intensity levels. To accomplish this, we adopted independently developed burn severity and fire intensity maps, in combination with a land cover map developed for habitat management purposes, as a basis for the analysis. To provide a measure of confidence in the acreage estimates, the accuracies of these maps were also assessed. In addition, two other maps of comparable quality were assessed for accuracy: one that was developed for mapping fuel risk and a second map that resulted from a preliminary application of an evolutionary computation software system, called GENIE.

  9. Los volcanes y los hombres

    OpenAIRE

    García, Carmen

    2007-01-01

    Desde las entrañas de la tierra, los volcanes han creado la atmósfera, el agua de los océanos, y esculpido los relieves del planeta: son, pues, los zahoríes de la vida. Existen volcanes que los hombres explotan o cultivan, y otros sobre los cuales se han construido observatorios en los que se llevan a cabo avanzadas investigaciones científicas.

  10. La necrópolis medieval del Cerro de la Horca de Toledo

    Directory of Open Access Journals (Sweden)

    Ruiz Taboada, Arturo

    2009-06-01

    Full Text Available The archaeological excavation of part of a medieval necropolis at the Cerro de la Horca (Toledo has provided new information regarding burial traditions in Toledo. One formal aspect is common to the broad range of graves that have been brought to light, namely the pit that was dug for the burial, being of considerable depth in a number of cases. Because little is known of the funerary practices in Toledo during the Middle Ages and hardly any objects have been recovered in the excavation, it is difficult to identify the religious community to which it belonged. Whereas the location of Muslim and Christian cemeteries have been known through documentary and archaeological sources, only popular traditions quoted so far the Jewish necropolis, its location remaining thus a mystery.

    La excavación arqueológica desarrollada en un sector del Cerro de La Horca ha permitido conocer aspectos inéditos del ritual de enterramiento medieval en Toledo. Se ha documentado una amplia tipología de tumbas con un único elemento constructivo común para todas ellas, la excavación previa de una fosa que, en numerosos casos, alcanza gran profundidad. El desconocimiento sobre el mundo funerario medieval toledano y la falta de materiales arqueológicos representativos en esta necrópolis han obligado a reflexionar sobre la comunidad religiosa a la que pertenecen estos enterramientos. Por fuentes históricas y excavaciones previas, conocemos la localización de necrópolis musulmanas y cristianas. La localización de la(s judía(s había sido, al menos hasta ahora, una incógnita.

  11. Determination of heat losses in the Cerro Prieto, Baja California, geothermal field steam transportation network based on the thermal insulation condition of the steam pipelines; Determinacion de perdidas de calor en la red de transporte de vapor del campo geotermico de Cerro Prieto, Baja California, con base en el estado fisico del aislamiento termico de vaporductos

    Energy Technology Data Exchange (ETDEWEB)

    Ovando Castelar, Rosember; Garcia Gutierrez, Alfonso; Martinez Estrella, Juan Ignacio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rovando@iie.org.mx; Canchola Felix, Ismael; Jacobo Galvan, Paul; Miranda Herrera, Carlos; Mora Perez, Othon [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)

    2011-07-15

    In Cerro Prieto Geothermal Field (CPGF), the steam from producing wells is transported to power plants through a large and complex system of pipes thermally insulated with a 2 inches thick mineral wool or a fiber glass layer and an external aluminum or iron cover. The insulation material has been exposed to weather conditions during the field operation and has suffered density and thickness changes. In some cases the insulation has been lost completely, increasing heat transfer from the pipes to the environment. This paper analyzes the impact of the conditions of thermal insulation on heat losses in the CPGF steam-pipeline network. The heat losses are calculated by applying an iterative method to determine the surface temperature based on a heat balance calculated from the three basic mechanisms of heat transfer: conduction, convection, and radiation. Finally, using length and diameter data corresponding to the condition of the thermal insulation of each pipeline-and field operation data, the overall heat losses are quantified for steam lines throughout the pipeline network in the field. The results allow us to evaluate the magnitude of the heat losses in comparison with the overall energy losses occurring during steam transport from wells to the power plants. [Spanish] En el Campo Geotermico de Cerro Prieto (CGCP), BC, el transporte de vapor desde los pozos hasta las plantas generadoras de electricidad se lleva a cabo mediante un extenso y complejo sistema de tuberias que tipicamente se encuentran aisladas termicamente con una capa de 2 pulgadas de material aislante a base de lana mineral o fibra de vidrio, y una proteccion mecanica de aluminio o hierro galvanizado. Debido a la exposicion a las condiciones meteorologicas a traves del tiempo de operacion del campo, el aislamiento ha experimentado cambios en su densidad y espesor y en ocasiones se ha perdido por completo, lo cual repercute en una mayor transferencia de calor de las tuberias hacia el medio ambiente

  12. Study of the structural control of fluid flow within the Cerro Prieto Geothermal Field, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Noble, J.E.; Manon, M.A.; Lippmann, M.J.; Witherspoon, P.A.

    1977-10-01

    The Lawrence Berkeley Laboratory and the Comision Federal de Electricidad of Mexico are conducting a joint investigation of the Cerro Prieto Geothermal Field, located approximately 35 km south of Mexicali, Baja California, Mexico, in the Sea of Cortez-Salton Trough. Recent analyses of various geophysical/electrical logs, temperature logs, production and geochemical data and the subsequently developed preliminary model of the structure of the geothermal system and the distribution of geothermal fluids are presented. Techniques routinely applied to petroleum exploration were successfully used in the development of a preliminary model of this water-dominated system. The study indicates the upwelling of geothermal fluids along an east bounding fault from a deep, as yet unexplored source. The fluids dissipate into various sand horizons at various depths. The resulting stratigraphic and fluid flow model is of importance in planning additional developments of the Cerro Prieto Geothermal Field.

  13. Relationshipe Between Self-potential Anomalies and Hydraulic Flow In A Geothermal System: Application To Cerro-prieto, Baja California

    Science.gov (United States)

    Saracco, G.; Revil, A.; Pessel, M.

    The Cerro Prieto geothermal field is located in the alluvial plain of the Mexicali Valley, northern Baja California, Mexico, at about 35 km southeast of the city of Mexicali. The Cerro Prieto geothermal field is one of several high temperature water-dominated geothermal fields within the Salton Trough. We analyze here the self-potential distri- bution at the ground surface in order to determine the pattern of fluid flow in te sub- surface of this geothermal field. Various methods of analysis of self-potential anoma- lies are employed to reach this purpose. We use density probability tomography of monopolar and dipolar electrical sources and an Euler-type analysis. The hydraulic flow pattern found in this geothermal field is in agreement with that detemined from the heat flux inside the structure.

  14. CATÁLOGO COMENTADO DE LAS HEPÁTICAS DEL CERRO DE MAMAPACHA, MUNICIPIO DE CHINAVITA-BOYACÁ, COLOMBIA

    Directory of Open Access Journals (Sweden)

    WILSON RICARDO ÁLVARO ALBA

    2007-01-01

    Full Text Available Se presenta el catálogo comentado de 77 especies de hepáticas presentes en el cerro de Mamapacha en donde se organizan alfabéticamente las familias, géneros y es- pecies. Se proporciona información sobre la forma de crecimiento, abundancia, hábitat y distribución. Se resalta la presencia de 23 especies como nuevos registros para Boyacá.

  15. Oxygen isotope exchange in rocks and minerals from the Cerro Prieto geothermal system: Indicators of temperature distribution and fluid flow

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.E.; Elders, W.A.

    1981-01-01

    Oxygen isotopic compositions have been measured in drill cuttings and core samples from more than 40 wells ranging in depth to more than 3.5 km in the Cerro Prieto geothermal field. Profiles of isotopic ratios versus sampling depths provide information on the three-dimensional distribution of temperature and fluid flow. These parameters also indicate variations in the history of hydrothermal processes in different areas of the geothermal field.

  16. Xenoliths of Cerro las Mercedes, Costa Rica: a Geochemical Record of Arc History?

    Science.gov (United States)

    Lindsay, F. N.; Gazel, E.; Herzberg, C. T.; Carr, M. J.; Feigenson, M. D.

    2006-12-01

    Over 70 ultramafic xenoliths, many with diameters of at least 3cm, open a window into the mantle beneath Cerro las Mercedes, Costa Rica. This quaternary vent is 70km behind the active volcanic front and near the northern boundary of the Caribbean Plateau. Both xenoliths and host lava remain well preserved in spite of substantial soil development in a rain forest environment. We analyzed the host lava and a subset of 30 rocks for bulk and mineral chemistry, which include both peridotite and pyroxenite populations. The host rock is Plio-Quaternary potassic alkaline basalt; depleted in SiO2 and Al2O3 and enriched in MgO and P2O5 relative to both present day and Miocene volcanics. In terms of trace elements, the host basalt has enriched LREEs and relative depletion of HFSEs, typical of island-arc basalt, both present and past. The coarse-grained pyroxenites have trace element chemistry akin to the volcanic front lavas of Costa Rica, although they are closer to chondritic values. Truly, they are more similar to basalts from Sarapiquí Miocene arc than to present day volcanic front basalts. Although there is enrichment in incompatible elements such as Ba and U and depletions in HFSEs, common in island arc basalts, the pyroxenites have a strong positive Pb anomaly that is characteristic only of the Miocene arc, not present day lavas. We interpret the pyroxenites as cumulates. The peridotite population includes dunites, spinel lherzolites and lherzolites. These rocks have Mg-numbers ranging from 87 to 92 and Cr-numbers ranging from 6 to 61. Whole rock geochemistry indicates that the peridotite xenoliths are fragments of mantle associated with the western Caribbean Plateau. SiO2, FeO, Al2O3 and MgO contents of several Cerro Mercedes peridotites are similar to those expected of hot residues that would form in a plume environment. Trace elements reveal some samples with enrichment of Ba and U, and depletion in Nb and Ta indicating variable extents of melt-rock reaction and

  17. ANALYSIS OF RECHARGE COOLDOWN AT THE WESTERN BOUNDARY OF CERRO PRIETO I GEOTHERMAL FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.; Lam, S.; Hunsbedt, A.; Esquer, C.; Marquez, R.; Hernandez, L. Cobo, J.

    1985-01-22

    Extensive study of the Cerro Prieto geothermal field has provided much geologic and thermodynamic data of its structurally-complex, liquid-dominated reservoir. Several of the studies investigated the resource characteristics of fluid and energy flow. An early report by Mercado (1975) showed that the heat source for the part of the reservoir under development, now called Cerro Prieto I (CPI), originated in the eastern part of the field. Subsequent studies confirmed the flow of hot water from the east. A summary of several experimental and numerical studies of fluid and energy transport in the field was given by Lippmann and Bodvarsson (1983). The hydrogeologic model of Halfman et al. (1982) shows hot-water flow from the east divided into a shallow (alpha) aquifer at about 120Om and a deeper (beta) aquifer at about 170Om depth. A cross section along an east-west direction shows a central upflow to the two aquifers and uncertain geology beyond the western border of the field near well M-9. It also shows a fault dividing the line of border wells at M-29 from the inner wells at M-25 to the east. The hydrogeology of the field was described by Sanchez and de la Pena (1981) as an alluvial unit from the surface to about 700 m over the production zone and a shale-sandstone unit comprising an upper, shallow (alpha) aquifer bounded below by a basement horst overlying a deeper (beta) aquifer. To date, much of the cumulative production at Cerro Prieto I has been from the alpha aquifer. Piezometric level measurements over the first 5 years of operation showed a decline in the western zone beyond the production wells. Over the 10-year period of continuous production, a significant temperature decline has been observed along the westernmost line of wells. Several investigations of the recharge characteristics of the field have been reported. Mercado (1975) and Elders et al. (1984) indicated a flow of cold groundwater from the east. Mercado also noted that cold water was entering

  18. Intense Seismic Activity at Chiles and Cerro Negro Volcanoes on the Colombia-Ecuador Border

    Science.gov (United States)

    Torres, R. A.; Cadena, O.; Gomez, D.; Ruiz, M. C.; Prejean, S. G.; Lyons, J. J.; White, R. A.

    2015-12-01

    The region of Chiles and Cerro Negro volcanoes, located on the Colombian-Ecuadorian border, has experienced an ongoing seismic swarm beginning in Aug. 2013. Based on concern for local residents and authorities, a cooperative broadband monitoring network was installed by the Servicio Geológico Colombiano in Colombia and the Instituto Geofísico of the Escuela Politécnica Nacional in Ecuador. Since November 2013 more than 538,000 earthquakes were recorded; although since May 2015 the seismicity has decreased significantly to an average of 70 events per day. Three large earthquake swarms with increasing energy occurred in Aug.-Oct. 2013, March-May 2014, and Sept.-Dec. 2014. By the end of 2014, roughly 400 earthquakes greater than M 3 had occurred with a maximum rate of 8000 earthquakes per day. The largest earthquake was a 5.6 ML on Oct. 20, 2014. This event produced an InSAR coseismic deformation of ~23 cm (S. Ebmeier, personal communication). Most events are typical brittle failure volcano-tectonic (VT) earthquakes that are located in a cluster beneath the southern flank of Chiles volcano, with depths between 1.5 and 10 km. Although the great majority of earthquakes are VT, some low-frequency (LF, ~0.5 Hz) and very-low-frequency (VLF) events have occurred. Particle motion analysis suggests that the VLF source migrated with time. While a VLF on Oct. 15, 2014 was located south of Chiles volcano, near the InSAR source, the VLF registered on Feb. 14, 2015 was likely located very close to Chiles Volcano. We infer that magma intrusion and resulting fluid exsolution at depths greater than 5 km are driving seismicity in the Chiles-Cerro Negro region. However earthquakes are failing in a manner consistent with regional tectonics. Relative relocations reveal a structure consistent with mapped regional faults. Thus seismicity is likely controlled by an interaction of magmatic and tectonic processes. Because the regional stress field is highly compressional and the volcanoes

  19. Subsurface Connections and Magma Mixing as revealed by Olivine- and Pyroxene-Hosted Melt Inclusions from Cerro Negro Volcano and the Las Pilas-El Hoyo Complex, Nicaragua.

    Science.gov (United States)

    Venugopal, S.; Moune, S.; Williams-Jones, G.

    2015-12-01

    Cerro Negro, the youngest volcano in the Central American Volcanic Belt, is a polygenetic cinder cone with relatively frequent explosive basaltic eruptions. Las Pilas, on the other hand, is a much larger and older complex with milder and less frequent eruptions. Based on historical data, these two closely spaced volcanoes have shown concurrent eruptive behavior, suggesting a subsurface connection. To further investigate this link, melt inclusions, which are blebs of melt trapped in growing crystals, were the obvious choice for optimal comparison of sources and determination of pre-eruptive volatile contents and magmatic conditions. Olivine-hosted inclusions were chosen for both volcanoes and pyroxene-hosted inclusions were also sampled from Las Pilas to represent the evolved melt. Major, volatile and trace elements reveal a distinct geochemical continuum with Cerro Negro defining the primitive end member and Las Pilas representing the evolved end member. Volatile contents are high for Cerro Negro (up to 1260 ppm CO2, 4.27 wt% H2O and 1700 ppm S) suggesting that volatile exsolution is likely the trigger for Cerro Negro's explosive eruptions. Las Pilas volatile contents are lower but consistent with degassing and evolutionary trends shown by major oxides. Trace element contents are rather unique and suggest Cerro Negro magmas fractionally crystallize while Las Pilas magmas are the products of mixing. Magmatic conditions were estimated with major and volatile contents: at least 2.4 kbar and 1170 °C for Cerro Negro melts and 1.3 kbar and 1130 °C for Las Pilas melts with an overall oxygen fugacity at the NNO buffer. In combination with available literature data, this study suggests an interconnected subsurface plumbing system and thus Cerro Negro should be considered as the newest vent within the Las Pilas-El Hoyo Complex.

  20. The Final Days of Paracas in Cerro del Gentil, Chincha Valley, Peru.

    Directory of Open Access Journals (Sweden)

    Henry Tantaleán

    Full Text Available This article describes and analyzes a highly significant archaeological context discovered in a late Paracas (400-200 BCE sunken patio in the monumental platform mound of Cerro Gentil, located in the Chincha Valley, Peru. This patio area was used for several centuries for ritual activities, including large-scale feasting and other public gatherings. At one point late in this historical sequence people deposited a great deal of objects in what is demonstrably a single historical event. This was quickly followed by a series of minor events stratigraphically immediately above this larger event. This entire ritual process included the consumption of liquids and food, and involved the offering of whole pottery, pottery fragments, botanical remains, bone, lithics, baskets, pyro-engraved gourds, mummies, and other objects. We interpret these events as an "abandonment ceremony" or "termination ritual" during the late Paracas period, one that may have lasted for weeks or even months. The subsequent Topará occupation at the site (ca. 200 BCE- AD 100 involved the architectural enhancement of the mound area, but the pattern of use of the patio itself ended. Such a termination ritual signals a reorganization in the regional political structure of Paracas society.

  1. Forecast of surface layer meteorological parameters at Cerro Paranal with a mesoscale atmospherical model

    CERN Document Server

    Lascaux, Franck; Fini, Luca

    2015-01-01

    This article aims at proving the feasibility of the forecast of all the most relevant classical atmospherical parameters for astronomical applications (wind speed and direction, temperature) above the ESO ground-base site of Cerro Paranal with a mesoscale atmospherical model called Meso-Nh. In a precedent paper we have preliminarily treated the model performances obtained in reconstructing some key atmospherical parameters in the surface layer 0-30~m studying the bias and the RMSE on a statistical sample of 20 nights. Results were very encouraging and it appeared therefore mandatory to confirm such a good result on a much richer statistical sample. In this paper, the study was extended to a total sample of 129 nights between 2007 and 2011 distributed in different parts of the solar year. This large sample made our analysis more robust and definitive in terms of the model performances and permitted us to confirm the excellent performances of the model. Besides, we present an independent analysis of the model p...

  2. Intersecting faults and sandstone stratigraphy at the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Vonder Haar, S.; Howard, J.H.

    1980-02-01

    The northwest-southeast trending Cerro Prieto fault is part of a major regional lineament that extends into Sonaro and has characteristics of both a wrench fault and an oceanic transform fault. The distribution of lithologies and temperature within the field was studied by comparing data from well cuttings, cores, well logs, and geochemical analyses. Across the earliest developed portion of the field, in particular along a 1.25-km northeast-southwest section from well M-9 to M-10, interesting correlations emerge that indicate a relationship among lithology, microfracturing, and temperature distribution. In the upper portion of Reservoir A of this stratigraphic section, between 1200 and 1400 m, the percentage of sandstones ranges from 20 to 55. Temperatures are 225/sup 0/ to 275/sup 0/C based on well logs, calcite isotope maxima, and Na-K-Ca indices. The study shows that an isothermal high in this vicinity corresponds to the lowest total percentage of sandstones. Scanning electron microphotographs of well cores and cuttings from sandstone and shale units reveal clogging, mineral dissolution, and mineral precipitation along microfractures. The working hypothesis is that these sandy shale and siltstone facies are most amenable to increased microfracturing and, in turn, such microfracturing allows for higher temperature fluid to rise to shallower depths in the reservoir.

  3. A simulation of the Cerro Hudson SO[sub 2] cloud

    Energy Technology Data Exchange (ETDEWEB)

    Schoeberl, M.R.; Lait, L.R.; Newman, P.A.; Krueger, A.J. (NASA Goddard Space Flight Center, Greenbelt, MD (United States)); Doiron, S.D. (Hughes STX Corp., Lanham, MD (United States))

    1993-02-20

    An isentropic trajectory model is used to simulate the evolution of the southern hemisphere SO[sub 2] cloud associated with the eruption of Cerro Hudson. By matching the parcel trajectories with total ozone mapping spectrometer SO[sub 2] retrievals, the principal stratospheric injection region is determined to be between 11 and 16 km in altitude. This region is characterized by weak wind shears and is located just poleward of the subtropical jet in the outer fringe of the stratospheric polar vortex. The lack of wind shear in the injection region explains the slow zonal dispersal of the SO[sub 2] cloud which was still clearly observed 19 days after the eruption. The trajectory model simulation of the SO[sub 2] cloud shows good agreement with observations for 7 days after the eruption. Using the potential vorticity and potential temperature estimates of the initial eruption cloud, the cloud position relative to the polar night jet is shown to be nearly fixed up to September 2, 1991, which was as long as the cloud was observed. This result suggests that the lower stratopsheric polar and mid-latitude regions are nearly isolated from each other during the late August period. 9 refs., 5 figs.

  4. Repetitive precision gravity studies at the Cerro Prieto and Heber geothermal fields

    Science.gov (United States)

    Grannell, R. B.

    1982-09-01

    To study subsidence and mass removal, a precise gravity network was established on 60 permanent monuments in the Cerro Prieto geothermal field in early 1978, and repeated annually through early 1981; the survey was tied to two bedrock sites outside the limits of the current production zone. The looping technique of station occupation was utilized, in which occupation of the base was followed by occupation of several stations, followed by a return to the base. Use of two LaCoste and Romberg gravity meters, and replication of values within loops as well as entire loops, enhanced precision such that the median standard deviations of the base-to-station differences, reduced to observed gravity values, ranged from 7 to 15 microgals for individual surveys. The smaller values were obtained as field and data reduction techniques were improved and experience was gained. A similar survey was initiated in the Heber area just north of the Mexican border in early 1980. It too was established on permanent monuments, was tied to bedrock stations outside the geothermal area, and used multiple repetitions of values with two meters to achieve high precision.

  5. Preliminary isotopic studies of fluids from the Cerro Prieto geothermal field

    Science.gov (United States)

    Truesdell, A.H.; Rye, R.O.; Pearson, F.J.; Olson, E.R.; Nehring, N.L.; Whelan, J.F.; Huebner, M.A.; Coplen, T.B.

    1979-01-01

    Preliminary isotopic studies of Cerro Prieto geothermal fluids and earlier studies of Mexicali Valley ground waters suggest local recharge of the geothermal system from the area immediately to the west. Oxygen isotope exchange of water with reservoir rock minerals at temperatures increasing with depth has produced fluids with oxygen-18 contents increasing with depth, and pressure drawdown in the southeastern part of the field has allowed lower oxygen-18 fluids to invade the production aquifer from above. The contents of tritium and carbon-14 in the fluid suggest only that the age of the fluid is between 50 and 10,000 years. The isotopic compositions of carbon and sulfur are consistent with a magmatic origin of these elements but a mixed sedimentary-organic origin appears more likely for carbon and is also possible for sulfur. Investigations of the isotopic compositions of geothermal and cold ground waters continue and are being expanded as fluids become available and as separation and analysis methods are improved. ?? 1979.

  6. Numerical Studies of the Heat and Mass Transport in the Cerro Prieto Geothermal Field, Mexico

    Science.gov (United States)

    Lippmann, M. J.; Bodavarsson, G. S.

    1983-06-01

    Numerical simulation techniques are employed in studies of the natural flow of heat and mass through the Cerro Prieto reservoir, Mexico and of the effects of exploitation on the field's behavior. The reservoir model is a two-dimensional vertical east to west-southwest cross section, which is based on a recent hydrogeologic model of this geothermal system. The numerical code MULKOM is used in the simulation studies. The steady state pressure and temperature distributions are computed and compared against observed preproduction pressures and temperatures; a reasonable match is obtained. A natural hot water recharge rate of about 1×10-2 kg/s per meter of field length (measured in a north-south direction) is obtained. The model is then used to simulate the behavior of the field during the 1973-1978 production period. The response of the model to fluid extraction agrees to what has been observed in the field or postulated by other authors. There is a decrease in temperatures and pressures in the produced region. No extensive two-phase zone develops in the reservoir because of the strong fluid recharge. Most of the fluid recharging the system comes from colder regions located above and west of the produced reservoir.

  7. Gas chemistry and thermometry of the Cerro Prieto, Mexico, geothermal field

    Science.gov (United States)

    Nehring, N.L.; D'Amore, F.

    1984-01-01

    Gas compositions of Cerro Prieto wells in 1977 reflected strong boiling in the reservoir around wells M-20 and M-25. This boiling zone appeared to be collapsing in 1982 when a number of wells in this area of the field were shut-in. In 1977 and 1982, gas compositions also showed boiling zones corresponding to faults H and L postulated by Halfman et al. (1982). Four gas geothermometers were applied, based on reservoir equilibria and calculated fugacities. The Fisher - Tropsch reaction predicted high temperatures and appeared to re-equilibrate slowly, whereas the H2S reaction predicted low temperatures and appeared to re-equilibrate rapidly. Hydrogen and NH3 reactions were intermediate. Like gas compositions, the geothermometers reflected reservoir processes, such as boiling. Surface gas compositions are related to well compositions, but contain large concentrations of N2 originating from air dissolved in groundwater. The groundwater appears to originate in the east and flow over the production field before mixing with reservoir gases near the surface. ?? 1984.

  8. Subsidence and Stress Change in the Cerro Prieto Geothermal Field, B. C., Mexico

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Nava, F. A.

    2005-11-01

    Previous works have shown that ground deformation and seismicity in the Cerro Prieto geothermal field (CPGF) are due to both tectonics and field exploitation. Here, we use information about current tectonics and data from precision leveling surveys, to model tectonic and anthropogenic subsidence. Our results show that tectonic subsidence constitutes only ˜4% of the measured subsidence. Anthropogenic subsidence was evaluated using a model of rectangular tensional cracks, based on the hydrological model of the field, together with the Coulomb 2.0 program. From the resulting values of the fissure parameters and from extraction and injection data, we calculate that the volume changes caused by closure of the geothermal and cold water reservoirs account for only ˜3% and ˜7%, respectively, of the volume change which should occur due to extraction. Since 18% of the extracted fluids are reinjected, external recharge must compensate for about 72% of the expected volume reduction. An analysis of the changes in Coulomb stress caused by exploitation of the geothermal field suggest that even though the anthropogenic stresses account for only a fraction of tectonic stresses, they are large enough to trigger seismicity.

  9. New mammalian records in the Parque Nacional Cerros de Amotape, northwestern Peru

    Directory of Open Access Journals (Sweden)

    Cindy M. Hurtado

    2015-04-01

    Full Text Available The Pacific Tropical Rainforest and Equatorial Dry Forest are found only in southern Ecuador and northern Peru, and are among the most poorly known ecosystems of South America. Even though these forests are protected in Parque Nacional Cerros de Amotape (PNCA, they are threatened by fragmentation because of farming and agriculture. The aim of this study was to determine the medium and large mammalian species richness, using transect census, camera trapping, and specimen bone collection. Nine transects were established and 21 camera trap stations were placed along 16 km2 in three localities of PNCA, from August 2012 to April 2013. Total sampling effort was 215 km of transects and 4077 camera-days. We documented 22 species; including 17 with camera trapping, 11 with transect census, and 10 with specimen collection.  Camera traps were the most effective method, and four species (Dasyprocta punctata, Cuniculus paca, Leopardus wiedii and Puma concolor were documented only with this method. This comprised the first Peruvian record for Dasyprocta punctata, and the first record for the western slope of the Peruvian Andes for Cuniculus paca. Also, both specimen collections and sightings confirm the presence of Potos flavus, first record in the western slope of the Peruvian Andes. Panthera onca, Tremarctos ornatus and Saimiri sciureus are considered locally extinct, while several species are in need of further research. We highlight the importance of the high diversity of this rainforests and encourage local authorities to give the area the highest priority in conservation.

  10. Soil mercury levels in the area surrounding the Cerro Prieto geothermal complex, MEXICO.

    Science.gov (United States)

    Pastrana-Corral, M A; Wakida, F T; García-Flores, E; Rodriguez-Mendivil, D D; Quiñonez-Plaza, A; Piñon-Colin, T D J

    2016-08-01

    Even though geothermal energy is a renewable energy source that is seen as cost-effective and environmentally friendly, emissions from geothermal plants can impact air, soil, and water in the vicinity of geothermal power plants. The Cerro Prieto geothermal complex is located 30 km southeast of the city of Mexicali in the Mexican state of Baja California. Its installed electricity generation capacity is 720 MW, being the largest geothermal complex in Mexico. The objective of this study was to evaluate whether the emissions generated by the geothermal complex have increased the soil mercury concentration in the surrounding areas. Fifty-four surface soil samples were collected from the perimeter up to an approximate distance of 7660 m from the complex. Additionally, four soil depth profiles were performed in the vicinity of the complex. Mercury concentration in 69 % of the samples was higher than the mercury concentration found at the baseline sites. The mercury concentration ranged from 0.01 to 0.26 mg/kg. Our results show that the activities of the geothermal complex have led to an accumulation of mercury in the soil of the surrounding area. More studies are needed to determine the risk to human health and the ecosystems in the study area.

  11. Research Experiences for Undergraduates at Cerro Tololo Inter-American Observatory

    Science.gov (United States)

    Hoard, D. W.; Smith, R. C.

    2000-12-01

    Each year, Cerro Tololo Inter-American Observatory (CTIO), located in La Serena, Chile, hosts a Research Experiences for Undergraduates (REU) Program funded by the National Science Foundation. In general, REU programs bring a group of undergraduate students to the host institute for 10 weeks, where they are teamed-up with staff members to perform research projects. Unlike REU programs at other U.S. institutions, the CTIO program takes place outside the United States and during the southern summer/northern winter months of January--March. This offers students not only a chance to perform research and participate in the day-to-day life at a major astronomical observatory, but also provides a unique exposure to a foreign culture and an option for students who can take advantage of a non-traditional work experience during the academic year. CTIO REU students also benefit from interaction with their Chilean counterparts participating in the Prácticas de Investigación en Astronomía, an REU-like program operated by CTIO for Chilean undergraduates. Since 1995, CTIO has hosted 20 REU students (with 4 more coming in 2001). Twenty (and counting) publications have resulted from CTIO REU projects. In addition, since 1999, 100% of the CTIO REU students have presented the results of their research projects at meetings of the American Astronomical Society. We present here an overview of the REU program at CTIO.

  12. Prototype of a Space Fluorescence Detector at Cerro La Negra Mountain Site

    Science.gov (United States)

    Cordero, A.; Robledo, C.; Moreno, E.; Salazar, H.; Martinez, O.; Villaseñor, L.; Zepeda, A.; Khrenov, B.; Garipov, G.

    2003-07-01

    The prototype of space fluorescence detector TUS (see V. Alexandrov et al., this conference) is begin prepared for operation at the mountain site Cerro La Negra (atmosphere depth 600g /cm2). The fluorescence detector (FD) field of view cover the atmosphere above the EAS array at the Pico de Orizaba site (see O. Martinez et al., this conference), separated from the FD by ˜ 5k m. At night at energies E0 > 0.05EeV both FD and EAS array will operate as an "hybrid detector." The range of atmosphere depths available for observation of EAS tracks by FD in hybrid mode is 200g /cm2. FD will also observe EAS tracks at energies of about 1 EeV at distances R=25-50 km, at zenith angles > 450 (when the atmosphere depth is more than 850g /cm2 ) with direction of tracks perpendicular to the FD axis. The FD design and preliminary data of the FD performance will be presented.

  13. Model for the heat source of the Cerro Prieto magma-hydrothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.; Cox, B.

    1981-01-01

    Earlier studies at Cerro Prieto led to the development of a qualitative model for fluid flow in the geothermal system before it was drilled and perturbed by production. Current efforts are directed towards numerical modeling of heat and mass transfer in the system in this undisturbed state. This one-dimensional model assumes that the heat source was a single basalt/gabbro intrusion which provided heat to the system as it cooled. After compilation of various information of the physical properties of the reservoir, the enthalpy contained in two 1 cm thick sections across the reservoir orthogonal to each other was calculated. Various shapes, sizes and depths for the intrusion were considered as initial conditions and boundary conditions for the calculations of heat transfer. A family of numerical models which so far gives the best matches to the conditions observed in the field today have in common a funnel-shaped intrusion with a top 4 km wide emplaced at a depth of 5 km some 30,000 to 50,000 years ago, providing heat to the geothermal system.

  14. Hydrothermal flow regime and magmatic heat source of the Cerro Prieto geothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Schiffman, P.; Williams, A.E.

    1984-01-01

    This detailed three-dimensional model of the natural flow regime of the Cerro Prieto geothermal field, before steam production began, is based on patterns of hydrothermal mineral zones and light stable isotopic ratios observed in rock samples from more than 50 deep wells, together with temperature gradients, wireline logs and other data. At the level so far penetrated by drilling, this hydrothermal system was heated by a thermal plume of water close to boiling, inclined at 45/sup 0/, rising from the northeast and discharging to the west. To the east a zone of cold water recharge overlies the inclined thermal plume. Fission track annealing studies show the reservoir reached 170/sup 0/C only 10/sup 4/ years ago. Oxygen isotope exchange data indicate that a 12 km/sup 3/ volume of rock subsequently reacted with three times its volume of water hotter than 200/sup 0/C. Averaged over the duration of the heating event this would require a flow velocity through a typical cross-section of the reservoir of about 6 m/year. The heat in storage in that part of the reservoir hotter than 200/sup 0/C and shallower than 3 km depth is equivalent to that which would be released by the cooling of about 1 or 2 km/sup 3/ of basalt or gabbro magma.

  15. Model of the heat source of the Cerro Prieto magma-hydrothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.; Cox, B.

    1982-08-10

    Earlier studies at Cerro Prieto by UCR have led to the development of a qualitative model for field flow in the geothermal system before it was drilled and perturbed by production. Current efforts are directed towards numerical modelling of heat and mass transfer in the system in this undisturbed state. A two-dimensional model assumes that the heat sources were a single basalt/gabbro intrusion which provided heat to the system as it cooled. After compiling various information on the physical properties of the reservoir, the enthalpy contained in two 1cm thick section across the reservoir orthogonal to each other was calculated. Next various shapes, sizes and depths for the intrusion as initial conditions and boundary conditions for the calculation of heat transfer were considered. A family of numerical models which so far gives the best matches to the conditions observed in the field today have in common a funnel-shaped intrusion with a top 4km wide emplaced at a depth of 5km some 30,000 to 50,000 years ago, providing heat to the geothermal system. Numerical modelling is still in progress. Although none of the models so far computed may be a perfect match for the thermal history of the reservoir, they all indicate that the intrusive heat source is young, close and large.

  16. Application of oil-field well log interpretation techniques to the Cerro Prieto Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Ershaghi, I.; Phillips, L.B.; Dougherty, E.L.; Handy, L.L.

    1979-10-01

    An example is presented of the application of oil-field techniques to the Cerro Prieto Field, Mexico. The lithology in this field (sand-shale lithology) is relatively similar to oil-field systems. The study was undertaken as a part of the first series of case studies supported by the Geothermal Log Interpretation Program (GLIP) of the US Department of Energy. The suites of logs for individual wells were far from complete. This was partly because of adverse borehole conditions but mostly because of unavailability of high-temperature tools. The most complete set of logs was a combination of Dual Induction Laterolog, Compensated Formation Density Gamma Ray, Compensated Neutron Log, and Saraband. Temperature data about the wells were sketchy, and the logs had been run under pre-cooled mud condition. A system of interpretation consisting of a combination of graphic and numerical studies was used to study the logs. From graphical studies, evidence of hydrothermal alteration may be established from the trend analysis of SP (self potential) and ILD (deep induction log). Furthermore, the cross plot techniques using data from density and neutron logs may help in establishing compaction as well as rock density profile with depth. In the numerical method, R/sub wa/ values from three different resistivity logs were computed and brought into agreement. From this approach, values of formation temperature and mud filtrate resistivity effective at the time of logging were established.

  17. Unrest of Chiles - Cerro Negro volcanic complex: A binational Ecuador - Colombia effort

    Science.gov (United States)

    Ruiz, M. C.; Gomez, D.; Torres, R.; Cadena, O.; Mothes, P. A.; Anzieta, J. C.; Pacheco, D. A.; Bernard, B.; Acero, W.; Hidalgo, S.; Enriquez, W.; Cordova, A.

    2014-12-01

    The increasing seismic activity at the area of Chiles - Cerro Negro volcanic complex, located at the Ecuador-Colombian border, has been jointly monitored by the Instituto Geofisico - Ecuador and the Observatorio Vulcanologico y Sismologico de Pasto OVSP, a division of the Servicio Geologico Colombiano. Since April 2013, three seismic swarms have been detected in this area and more than 100.000 events are recorded since November 2013. The largest and more recent swarm has a daily average of 676 events between March and June 2014. Currently a seismic network of 8 seismic stations (5 in the Colombian and 3 in Ecuadorean side) are deployed in this area. Epicenters of more than 315 seismic events with magnitudes Ml>2.0 and 10 or more phases are located in an area 1-4 km south of Chiles volcano with shallow depths (up to 14 km). Most of events have magnitudes between 1.0 to 4.0. Nine events have magnitudes larger than 4.0 and the largest event occurred on April 30. 2014 with a local magnitude of 4.7 and inverse-transcurrent component focal mechanism. Waveforms and spectral patterns define these events as volcano-tectonic. Events with large magnitudes (above 3.0) show a very long-period component. Hot spring and deformation measurements also show signals of volcanic unrest.

  18. Characterization of the sodium layer at Cerro Pachon, and impact on laser guide star performance

    CERN Document Server

    Neichel, Benoit; Callingham, Joseph; Rigaut, Francois; Winge, Claudia; Trancho, Gelys; 10.1093/mnras/sts631

    2013-01-01

    Detailed knowledge of the mesopheric sodium layer characteristics is crucial to estimate and optimize the performance of Laser Guide Star (LGS) assisted Adaptive Optics (AO) systems. In this paper, we present an analysis of two sets of data on the mesospheric sodium layer. The first set comes from a laser experiment that was carried out at Cerro Tololo to monitor the abundance and altitude of the mesospheric sodium in 2001, during six runs covering a period of one year. This data is used to derive the mesospheric sodium column density, the sodium layer thickness and the temporal behavior of the sodium layer mean altitude. The second set of data was gathered during the first year of the Gemini MCAO System (GeMS) commissioning and operations. GeMS uses five LGS to measure and compensate for atmospheric distortions. Analysis of the LGS wavefront sensor data provides information about the sodium photon return and the spot elongation seen by the WFS. All these parameters show large variations on a yearly, nightly ...

  19. Validating numerical simulations of snow avalanches using dendrochronology: the Cerro Ventana event in Northern Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    A. Casteller

    2008-05-01

    Full Text Available The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Argentinean Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On 1 September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological investigations to reconstruct this event. Using information released by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. Differences between the observed and the simulated avalanche, principally related to the snow height deposition in the run-out zone, are mostly attributed to the low resolution of the digital elevation model used to represent the valley topography. The main contributions of this study are (1 to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2 to highlight the potential of Nothofagus pumilio tree-ring records to reconstruct past snow-avalanche events in time and space. Future research should focus on testing this combined approach in other forested regions of the Andes.

  20. The CCAT-prime Extreme Field-of-View Submillimeter Telescope on Cerro Chajnantor

    Science.gov (United States)

    Koopman, Brian; Bertoldi, Frank; Chapman, Scott; Fich, Michel; Giovanelli, Riccardo; Haynes, Martha P.; Herter, Terry L.; Murray, Norman W.; Niemack, Michael D.; Riechers, Dominik; Schilke, Peter; Stacey, Gordon J.; Stutzki, Juergen; CCAT-prime Collaboration

    2017-01-01

    CCAT-prime is a six meter aperture off-axis submillimeter telescope that we plan to build at 5600m elevation on Cerro Chajnantor in Chile. The CCAT-prime optics are based on a cross-Dragone design with high throughput and a wide field-of-view optimized to increase the mapping speed of next generation cosmic microwave background (CMB) observations. These characteristics make CCAT-prime an excellent platform for a wide range of next generation millimeter and submillimeter science goals, and a potential platform for CMB stage-IV measurements. Here we present the telescope design for CCAT-prime and review the science goals.Taking advantage of the high elevation site, the first generation instrument for CCAT-prime will measure seven different frequency bands from 350um to 3mm. These seven bands will enable precise measurements of the Sunyaev-Zel’dovich effects (SZE) by separating contributions from CMB, thermal SZE, kinetic SZE, bright submm galaxies, and radio sources with a goal of extracting the peculiar velocities from a large number of galaxy clusters. Additional science priorities for CCAT-prime include: Galactic Ecology studies of the dynamic intersteller medium by mapping the fine structure lines [CI], [CII] and [NII] as well as high-excitation CO lines at the shortest wavelength bands; high redshift intensity mapping of [CII] emission from star-forming galaxies that likely dominates cosmic reionization at z~5-9 to probe the Epoch of Reionization; and next generation CMB polarization measurements to constrain inflation and cosmological models. The CCAT-prime facility will further our understanding of astrophysical processes from moments after the Big Bang to the present-day evolution of the Milky Way.

  1. Planning and Analysis of Fractured Rock Injection Tests in the Cerro Brillador Underground Laboratory, Northern Chile

    Science.gov (United States)

    Fairley, J. P., Jr.; Oyarzún L, R.; Villegas, G.

    2015-12-01

    Early theories of fluid migration in unsaturated fractured rock hypothesized that matrix suction would dominate flow up to the point of matrix saturation. However, experiments in underground laboratories such as the ESF (Yucca Mountain, NV) have demonstrated that liquid water can migrate significant distances through fractures in an unsaturated porous medium, suggesting limited interaction between fractures and unsaturated matrix blocks and potentially rapid transmission of recharge to the sat- urated zone. Determining the conditions under which this rapid recharge may take place is an important factor in understanding deep percolation processes in arid areas with thick unsaturated zones. As part of an on-going, Fondecyt-funded project (award 11150587) to study mountain block hydrological processes in arid regions, we are plan- ning a series of in-situ fracture flow injection tests in the Cerro Brillador/Mina Escuela, an underground laboratory and teaching facility belonging to the Universidad la Serena, Chile. Planning for the tests is based on an analytical model and curve-matching method, originally developed to evaluate data from injection tests at Yucca Mountain (Fairley, J.P., 2010, WRR 46:W08542), that uses a known rate of liquid injection to a fracture (for example, from a packed-off section of borehole) and the observed rate of seepage discharging from the fracture to estimate effective fracture aperture, matrix sorptivity, fracture/matrix flow partitioning, and the wetted fracture/matrix interac- tion area between the injection and recovery points. We briefly review the analytical approach and its application to test planning and analysis, and describe the proposed tests and their goals.

  2. Carbon-13 variations in fluids from the Cerro Prieto geothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Janik, C.J.; Nehring, N.L.; Huebner, M.A.; Truesdell, A.H.

    1982-08-10

    The carbon isotope compositions of CO/sub 2/ in steam from Cerro Prieto production well have been measured for 1977, 1979, and 1982. Variations in the delta/sup 13/C values are caused by production-related changes in the chemical and physical parameters of the geothermal system. In 1977, most CO/sub 2/ in the reservoir was isotopically light (delta/sup 13/C = -6.4 +/- 0.4). Heavier CO/sub 2/ was produced from wells in the center of the field (M5,M26,M27) due to deposition of isotopically light calcite caused by near-well boiling. In 1979 nearly all well showed relatively heavy CO/sub 2/, probably due to expansion of aquifer boiling and calcite precipitation. In 1982, many wells in the central part of the field were shut in. The amount of drawndown decreased and as temperatures and pressures near the wells increased, the boiling zones collapsed. The CO/sub 2/ in the fluid then exchanged with the precipitated calcite and became isotopically lighter. The sensitivity of carbon isotopes to calcite precipitations caused by aquifer boiling and to reequilibration with this deposited calcite upon decrease of boiling suggests use as an indicator of these aquifer processes. Surficial CO/sub 2/ of thermal origin was collected in 1981. Generally, the carbon-13 contents were close to CO/sub 2/ from production wells except for high-temperature mud pots and fumaroles containing isotopically light CO/sub 2/ derived from near surface alteration of organic matter.

  3. Mexicali aquifer and its relation with the Colorado river and the Cerro Prieto geothermal reservoir

    Science.gov (United States)

    Ramirez-Hernandez, J.; Reyes-Lopez, J. A.; Carreon-Diazconti, C.; Lazaro-Mancilla, O.

    2008-05-01

    Until some years ago the Colorado River has been the main recharge source of the Mexicali and the Imperial Valley aquifers. River discharge interruption after the constructions of dams upstream (i.e. Parker, Davis and Hoover) and the creation of great irrigation systems in both Valleys have modified their dynamics. Currently, the distribution of water recharge is the network of irrigation and drainage channels that distribute water to more than 500.000 ha. The chemical quality of the recharge water also has changed because the irrigation run-off water has become more mineralized. On the other hand, the intense steam exploitation of the Cerro Prieto geothermal reservoir has inverted the flow direction from the Volcano Lagoon area that until the 60s constituted the discharge zone of the aquifer and the geothermal reservoir. In this work, changes in the aquifer water recharge regime, the phreatic level and the water chemical quality are analyzed. It was found that after the reduction of the annual water extraction from aquifer up to 750X106 m3, the static levels have reached a dynamic balance that could be altered if water seepage from the irrigation channels, specially from the All American Channel, is reduced. The total dissolved solids (TDS) concentration has increased from 1000 ppm in 1970 to 1800 ppm in 2005. The water of recent infiltration, the gradual cooling of the shallowest strata of the geothermal reservoir, and the almost total disappearance of the hydrothermal surface manifestations are evidences of groundwater flow inversion. The new source of groundwater recharge due to seepage of evaporation disposal geothermal brine pond is documented. This pond incorporates water with a very different chemical composition to the groundwater system. Therefore, mineralization of the shallow aquifer layers and the soil contamination process are identified. It was concluded that the aquifer hydrodynamics in the Valley of Mexicali depends on the irrigation system more

  4. Regional and local networks of horizontal control, Cerro Prieto geothermal area

    Science.gov (United States)

    Massey, B.L.

    1979-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley 30 km southeast of Mexicali, Baja California, is probably deforming due to (1) the extraction of large volumes of steam and hot water, and (2) active tectonism. Two networks of precise horizontal control were established in Mexicali Valley by the U.S. Geological Survey in 1977 - 1978 to measure both types of movement as they occur. These networks consisted of (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from survey stations on an existing U.S. Geological Survey crustal-strain network north of the international border, and (2) a local net tied to stations in the regional net and encompassing the area of present and planned geothermal production. Survey lines in this net were selected to span areas of probable ground-surface movements in and around the geothermal area. Electronic distance measuring (EDM) instruments, operating with a modulated laser beam, were used to measure the distances between stations in both networks. The regional net was run using a highly precise long-range EDM instrument, helicopters for transportation of men and equipment to inaccessible stations on mountain peaks, and a fixed wing airplane flying along the line of sight. Precision of measurements with this complex long-range system approached 0-2 ppm of line length. The local net was measured with a medium-range EDM instrument requiring minimal ancillary equipment. Precision of measurements with this less complex system approached 3 ppm for the shorter line lengths. The detection and analysis of ground-surface movements resulting from tectonic strains or induced by geothermal fluid withdrawal is dependent on subsequent resurveys of these networks. ?? 1979.

  5. Validating numerical simulations of snow avalanches using dendrochronology: the Cerro Ventana event in Northern Patagonia, Argentina

    Science.gov (United States)

    Casteller, A.; Christen, M.; Villalba, R.; Martínez, H.; Stöckli, V.; Leiva, J. C.; Bartelt, P.

    2008-05-01

    The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Argentinean Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On 1 September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological investigations to reconstruct this event. Using information released by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. Differences between the observed and the simulated avalanche, principally related to the snow height deposition in the run-out zone, are mostly attributed to the low resolution of the digital elevation model used to represent the valley topography. The main contributions of this study are (1) to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2) to highlight the potential of textit{Nothofagus pumilio} tree-ring records to reconstruct past snow-avalanche events in time and space. Future research should focus on testing this combined approach in other forested regions of the Andes.

  6. Temporal Evolution of a Seismic Swarm at Chiles - Cerro Negro volcanic complex

    Science.gov (United States)

    Ruiz, Mario

    2015-04-01

    The increasing seismic activity in the area of the Chiles - Cerro Negro volcanic complex, located on the Ecuador-Colombian border, has been jointly monitored by the Instituto Geofisico - Ecuador and the Observatorio Vulcanologico y Sismologico de Pasto (OVSP), a division of the Servicio Geologico Colombiano. Since April 2013, three seismic swarms have been detected in this area, and more than 400.000 events have been recorded since November 2013. The largest and most recent swarm has a daily average of 3894 events between March and the 12th of December 2014. Currently a seismic network of 13 short- and broad-band stations (5 Colombian, 8 Ecuadorian) was deployed in this area. High quality epicenters of seismic events with magnitudes Ml>2.0, RMSChiles volcano with shallow depths (up to 14 km). Most events have magnitudes between 1.0 to 4.0. Fifteen events have magnitudes larger than 4.0 including an event that occurred on October 20, 2014. This event had a local magnitude of 5.7 and an oblique (strike-slip with some thrusting) focal mechanism. Waveforms and spectral patterns define these events as volcano-tectonic. However, events with moderate to large magnitudes (above 3.0) contain pronounced very-long-period components. Position time series recorded by a dual-frequency GPS receiver at the SE flank of Chiles show a slight departure from the normal tectonic trend beginning with the appearance of the last seismic swarm on or around September 30, 2014. This trend is subsequently punctuated by a sharp deformation transient related to the coseismic displacement of the October 20 event. After more than a year of very anomalous seismic activity and concurrent minor deformation, no evidence of surficial volcanic activity has been documented.

  7. Shallow earthquake inhibits unrest near Chiles-Cerro Negro volcanoes, Ecuador-Colombian border

    Science.gov (United States)

    Ebmeier, Susanna K.; Elliott, John R.; Nocquet, Jean-Mathieu; Biggs, Juliet; Mothes, Patricia; Jarrín, Paúl; Yépez, Marco; Aguaiza, Santiago; Lundgren, Paul; Samsonov, Sergey V.

    2016-09-01

    Magma movement or reservoir pressurisation can drive swarms of low-magnitude volcano-tectonic earthquakes, as well as occasional larger earthquakes (>M5) on local tectonic faults. Earthquakes >M5 near volcanoes are challenging to interpret in terms of evolving volcanic hazard, but are often associated with eruptions, and in some cases enhance the ascent of magma. We present geodetic observations from the first episode of unrest known to have occurred near Chiles and Cerro Negro de Mayasquer volcanoes on the Ecuador-Colombian border. A swarm of volcano-tectonic seismicity in October 2014 culminated in a Mw 5.6 earthquake south of the volcanoes. Satellite radar data spanning this earthquake detect displacements that are consistent with dextral oblique slip on a reverse fault at depths of 1.4-3.4 km within a SSW-NNE trending fault zone that last ruptured in 1886. GPS station measurements capture ∼20 days of uplift before the earthquake, probably originating from a pressure source ∼10-15 km south of Volcán Chiles, at depths exceeding 13 km. After the Mw 5.6 earthquake, uplift ceased and the rate of seismicity began to decrease. Potential mechanisms for this decline in activity include a decrease in the rate of movement of magma into the shallow crust, possibly caused by the restriction of fluid pathways. Our observations demonstrate that an earthquake triggered during volcanic unrest can inhibit magmatic processes, and have implications for the hazard interpretation of the interactions between earthquakes and volcanoes.

  8. Los adolescentes y los estigmas

    OpenAIRE

    Janin, Beatriz

    2013-01-01

    En este trabajo se desarrolla el tema de los diagnósticos tempranos en los que se rotula a un niño como deficitario y de las dificultades de los adolescentes que llegan a esa etapa crítica de la vida portando algún “cartel" que los señala como un “sindrome" o un “trastorno de...". Este estigma suele dificultarles el rearmado narcisista, la relación con el grupo de pares y la salida exogámica. Se habla de la crisis adolescente y de los avatares particulares de la sexualidad en estos casos. ...

  9. Structural control on geothermal circulation in the Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Argentina)

    Science.gov (United States)

    Giordano, Guido; Pinton, Annamaria; Cianfarra, Paola; Baez, Walter; Chiodi, Agostina; Viramonte, José; Norini, Gianluca; Groppelli, Gianluca

    2013-01-01

    The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous springs. This study presents new stratigraphic and hydrogeological data on the geothermal field, together with the analysis from remote sensed image analysis of morphostructural evidences associated with the structural framework and active tectonics. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field. Away from the main tectonic features, such as at the Cerro Tuzgle field, the less developed network of faults and fractures allows only a moderate upwelling of geothermal fluids and a mixing between hot and shallow cold waters. The integration of field-based and remote-sensing analyses at the Cerro Tuzgle-Tocomar area proved to be effective in approaching the prospection of remote geothermal fields, and in defining the conceptual model for geothermal circulation.

  10. Los caminos del aire. Las idas y venidas de los meteoros en La Montaña de Guerrero

    OpenAIRE

    Nuixa, Françoise Neff

    2013-01-01

    Note portant sur l’auteur Al sur de México, en la franja que bordea la costa del Océano Pacífico, atravesada por la Sierra Madre del Sur, se encuentra la región comúnmente llamada “La Montaña de Guerrero”. Se extiende por la parte este del estado de Guerrero y colinda con los estados de Oaxaca y Puebla. “La Montaña” se eleva desde la cuenca del río Balsas al norte y al oeste abarca los cerros que dominan la capital del estado, Chilpancingo, al norte, y al sur un eje constituido por la carrete...

  11. Oxygen isotope exchange in rocks and minerals from the Cerro Prieto geothermal system: Indicators of temperature distribution and fluid flow

    Science.gov (United States)

    Williams, A. E.; Elders, W. A.

    1981-12-01

    Paleotemperatures different from the present thermal regime were studied by examining coexisting mineral systems which exchanged their oxygen with the geothermal brines at different rates. Oxygen isotopic compositions were measured in drill cuttings and core and core samples from more than 40 wells. Oxygen isotopic profiles of pore filling calcites in sandstones are a measure of the recent equilibrium temperature distribution. A three dimensional map was developed, showing the equilibrium temperatures in the geothermal field. A mass balance calculation was performed using measured 18O enrichment of the geothermal brine. This calculation implies an overall water; rock volume ratio of approximately 3:1 during the history of the Cerro Prieto system.

  12. Production induced boiling and cold water entry in the Cerro Prieto geothermal reservoir indicated by chemical and physical measurements

    Science.gov (United States)

    Grant, M.A.; Truesdell, A.H.; Manon, M.A.

    1984-01-01

    Chemical and physical data suggest that the relatively shallow, western part of the Cerro Prieto reservoir is bounded below by low permeability rocks, and above and at the sides by an interface with cooler water. There is no continuous permeability barrier around or immediately above the reservoir. Permeability within the reservoir is dominantly intergranular. Mixture with cooler water rather than boiling is the dominant cooling process in the natural state, and production causes displacement of hot water by cooler water, not by vapour. Local boiling occurs near most wells in response to pressure decreases, but no general vapour zone has formed. ?? 1984.

  13. Arterial oxygen saturation in healthy newborns delivered at term in Cerro de Pasco (4340 m) and Lima (150 m)

    OpenAIRE

    Gonzales Gustavo F; Salirrosas Amelia

    2005-01-01

    Abstract Background High altitude is associated with both low pulse oxygen saturation at birth and more pre-term deliveries. The present study was performed to determine pulse oxygen saturation in newborns at term in Cerro de Pasco (4340 m) and Lima (150 m) to test the hypothesis that low pulse oxygen saturation at birth at high altitudes was not observed at term deliveries. Methods The present study was designed to determine pulse oxygen saturation values through 1 minute to 24 hours and val...

  14. Production induced boiling and cold water entry in the Cerro Prieto geothermal reservoir indicated by chemical and physical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Grant, M.A. (DSIR, Wellington, New Zealand); Truesdell, A.H.; Manon, A.

    1981-01-01

    Chemical and physical data suggest that the relatively shallow western part of the Cerro Prieto reservoir is bounded below by low permeability rocks, and above and at the sides by an interface with cooler water. There is no continuous permeability barrier around or immediately above the reservoir. Permeability within the reservoir is dominantly intergranular. Mixture with cooler water rather than boiling is the dominant cooling process in the natural state, and production causes displacement of hot water by cooler water, not by vapor. Local boiling occurs near most wells in response to pressure decreases, but no general vapor zone has formed.

  15. Fault Length Vs Fault Displacement Evaluation In The Case Of Cerro Prieto Pull-Apart Basin (Baja California, Mexico) Subsidence

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Nava Pichardo, F. A.; Farfan, F.; Garcia Arthur, M. A.; Orozco, L.; Brassea, J.

    2013-05-01

    The Cerro Prieto pull-apart basin is located in the southern part of San Andreas Fault system, and is characterized by high seismicity, recent volcanism, tectonic deformation and hydrothermal activity (Lomnitz et al, 1970; Elders et al., 1984; Suárez-Vidal et al., 2008). Since the Cerro Prieto geothermal field production started, in 1973, significant subsidence increase was observed (Glowacka and Nava, 1996, Glowacka et al., 1999), and a relation between fluid extraction rate and subsidence rate has been suggested (op. cit.). Analysis of existing deformation data (Glowacka et al., 1999, 2005, Sarychikhina 2011) points to the fact that, although the extraction changes influence the subsidence rate, the tectonic faults control the spatial extent of the observed subsidence. Tectonic faults act as water barriers in the direction perpendicular to the fault, and/or separate regions with different compaction, and as effect the significant part of the subsidence is released as vertical displacement on the ground surface along fault rupture. These faults ruptures cause damages to roads and irrigation canals and water leakage. Since 1996, a network of geotechnical instruments has operated in the Mexicali Valley, for continuous recording of deformation phenomena. To date, the network (REDECVAM: Mexicali Valley Crustal Strain Measurement Array) includes two crackmeters and eight tiltmeters installed on, or very close to, the main faults; all instruments have sampling intervals in the 1 to 20 minutes range. Additionally, there are benchmarks for measuring vertical fault displacements for which readings are recorded every 3 months. Since the crackmeter measures vertical displacement on the fault at one place only, the question appears: can we use the crackmeter data to evaluate how long is the lenth of the fractured fault, and how quickly it grows, so we can know where we can expect fractures in the canals or roads? We used the Wells and Coppersmith (1994) relations between

  16. Ecological Impacts of the Cerro Grande Fire: Predicting Elk Movement and Distribution Patterns in Response to Vegetative Recovery through Simulation Modeling October 2005

    Energy Technology Data Exchange (ETDEWEB)

    Rupp, Susan P. [Texas Tech Univ., Lubbock, TX (United States)

    2005-10-01

    In May 2000, the Cerro Grande Fire burned approximately 17,200 ha in north-central New Mexico as the result of an escaped prescribed burn initiated by Bandelier National Monument. The interaction of large-scale fires, vegetation, and elk is an important management issue, but few studies have addressed the ecological implications of vegetative succession and landscape heterogeneity on ungulate populations following large-scale disturbance events. Primary objectives of this research were to identify elk movement pathways on local and landscape scales, to determine environmental factors that influence elk movement, and to evaluate movement and distribution patterns in relation to spatial and temporal aspects of the Cerro Grande Fire. Data collection and assimilation reflect the collaborative efforts of National Park Service, U.S. Forest Service, and Department of Energy (Los Alamos National Laboratory) personnel. Geographic positioning system (GPS) collars were used to track 54 elk over a period of 3+ years and locational data were incorporated into a multi-layered geographic information system (GIS) for analysis. Preliminary tests of GPS collar accuracy indicated a strong effect of 2D fixes on position acquisition rates (PARs) depending on time of day and season of year. Slope, aspect, elevation, and land cover type affected dilution of precision (DOP) values for both 2D and 3D fixes, although significant relationships varied from positive to negative making it difficult to delineate the mechanism behind significant responses. Two-dimensional fixes accounted for 34% of all successfully acquired locations and may affect results in which those data were used. Overall position acquisition rate was 93.3% and mean DOP values were consistently in the range of 4.0 to 6.0 leading to the conclusion collar accuracy was acceptable for modeling purposes. SAVANNA, a spatially explicit, process-oriented ecosystem model, was used to simulate successional dynamics. Inputs to the

  17. Changes in steam production due to the reservoir conditions in Cerro Prieto, Baja California; Cambios en la produccion de vapor debido a las condiciones del yacimiento en Cerro Prieto, Baja California

    Energy Technology Data Exchange (ETDEWEB)

    Morales Cardenas, Ramon; Rodriguez Rodriguez, Marco H. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: marco.rodriguez01@gfe.gob.mx

    2011-07-15

    In more than 35 years of exploitation, thermodynamic conditions have changed in the Cerro Prieto geothermal reservoir. The effects are analyzed of the changes to the reservoir and their consequences to steam production in different field zones. For steam production, the most important features of reservoir fluids are enthalpies and pressures. The evolution of these features is presented in an enthalpy-pressure diagram. Here it can be seen that some reservoir zones have almost reached abandonment conditions. [Spanish] En mas de 35 anos de explotacion el yacimiento geotermico de Cerro Prieto ha experimentado cambios en sus condiciones termodinamicas. En este trabajo se analiza el efecto de esos cambios del yacimiento y su repercusion en la produccion de vapor para las diferentes zonas en las que se ha dividido el campo. Las propiedades mas importantes del fluido en el yacimiento para la produccion de vapor son su entalpia y su presion, por lo que se presenta la evolucion de esas propiedades en un diagrama de presion-entalpia, en el que se observa que hay zonas del yacimiento que estan proximas a alcanzar condiciones de abandono.

  18. Mexican-American Cooperative Program at the Cerro Prieto geothermal field: Analysis of the Nuevo Leon magnetic anomaly and its possible relation to the Cerro Prieto magmatic-hydrothermal system

    Science.gov (United States)

    Goldstein, N. E.; Wilt, M. J.; Corrigan, D. J.

    1982-10-01

    The broad dipolar magnetic anomaly whose positive peak is centered near Ejido Nuevo Leon, some 5 km east of the Cerro Prieto I Power Plant, has long been suspended to have a genetic relationship to the thermal source of the Cerro Prieto geothermal system. This suspicion was reinforced after several deep geothermal wells, drilled to depths of 3 to 3.5 km over the anomaly, intersected an apparent dike-sill complex consisting mainly of diabase but with minor rhyodacite. A detailed fit of the observed magnetic field to a computer model indicates that the source may be approximated by a tabular block 4 by 6 km in area, 3.7 km in depth, 2.3 km thick, and dipping slightly to the north. Mafic dike chips from one well, NL-1, were analyzed by means of electron microprobe analyses which showed them to contain a titanomagnetite that is paramagnetic at in-situ temperature conditions. As the dike mineralogy does not account for the magnetic anomaly, the magnetic source is believed to be a deeper, magnetite-rich assemblage of periodotite-gabbro plutons.

  19. Los insomnios

    OpenAIRE

    Takeuchi Tan, Yuri; Fundación Valle de Lili

    1998-01-01

    Los insomnios/El sueño normal/Otros trastornos de sueño que producen insomnio pero también hipersomnio (excesiva somnolencia diurna)/Manejo y tratamiento de los insomnios/Higiene del sueño/Instrucciones para la higiene del sueño/Técnicas conductuales/Terapia farmacológica.

  20. Stress orientation and anisotropy based on shear-wave splitting observations in the Cerro Prieto fault area, Baja California, Mexico

    Science.gov (United States)

    Zúñiga, F. R.; Castro, R. R.; Domínguez, T.

    1995-03-01

    Digital seismograms continuously recorded from 1988 to 1992 by two stations of the RESNOM seismic network in northern Baja California, Mexico, were used to search for probable shear-wave anisotropic characteristics in the region of the Cerro Prieto fault. Shear-wave splitting was identified in many of the three-component records analyzed. We measured the polarization direction of the leading S wave inside the S-wave window as well as the delay times between fast and slow phases on those records displaying shear-wave splitting. For station CPX, which is nearest the Imperial Valley region to the north, the preferred polarization direction found in this study (azimuth 180°±10°) coincides with the direction of the regional maximum compressive stress determined for the region. This polarization direction can be interpreted in terms of the “Extensive Dilatancy Anisotropy” model as the effect of vertical parallel aligned cracks. The preferred polarization direction measured at LMX, however, gives an azimuth of 45°±5°. Thus, it appears that faults and fractures aligned oblique to the main tectonic trend have a greater influence on the anisotropic characteristics of the crust south of Cerro Prieto volcano than that of the regional stress field. Time delays between slow and fast S waves observed at CPX appear constant from 1988 to 1992 while delays measured at LMX for the same interval indicate a small increase with time which cannot be attributed to azimuthal variations of paths.

  1. ANALYSIS OF MUNICIPAL WASTEWATER AND ACID MINE DRAINAGE PASSIVE CO-TREATMENT AT CERRO RICO DE POTOSÍ, BOLIVIA

    Directory of Open Access Journals (Sweden)

    William H.J. Strosnider

    2015-06-01

    Full Text Available Acid mine drainage (AMD is a worldwide environmental problem. The passive co-treatment of AMD with municipal waste water (MWW is a cost effective approach that uses nutrients in MWW in order to treat high concentrations of metals and sulfate found in AMD. Cerro Rico de Potosí in Bolivia is one of the biggest mining cities in the world, and it is constantly facing problems with AMD. The goal of this study was to determine the reaction rates of Al, Fe, Mn, Zn, and other metals found in an AMD discharge from Cerro Rico by a three-stage reactor system. The AMD had a pH of 3.58 and acidity of 1080 mg/L as CaCO3 equivalent containing 12, 68, 17 and 550 mg/L of dissolved Al, Fe, Mn, and Zn respectively. The reaction rates of Al, Fe, Mn, and Zn were 1.43, 2.09, 0.01, and 0.10 d-1, respectively.

  2. Importaciones áticas del siglo V a.C. del Cerro del Prado (Algeciras, Cádiz

    Directory of Open Access Journals (Sweden)

    Cabrera, Paloma

    1996-12-01

    Full Text Available In this paper we analyze a group of Attic imports, found in the excavations of Cerro del Prado, a settlement situated in the Bahía de Algeciras (Cádiz. The great interest of this group lies in the fact that it belongs to a particular chronological period, the last third of the 5th century B.C., as we have not found later imports, and in the almost exclusive presence of black glazed vases, which gives US an idea of a very definitive demand of the punic society of the Iberian Peninsula regarding the trade of greek goods.

    Presentamos en este trabajo un conjunto de importaciones áticas halladas en las excavaciones del Cerro del Prado, situado en la bahía de Algeciras (Cádiz. El interés de este conjunto reside en su pertenencia a un momento cronológico muy concreto: el último tercio del siglo V a.C., no habiéndose hallado importaciones más modernas y en la presencia absoluta de vasos de barniz negro, lo que nos habla de una demanda muy determinada de la sociedad púnica peninsular frente al comercio de productos griegos.

  3. Gases in steam from Cerro Prieto geothermal wells with a discussion of steam/gas ratio measurements

    Science.gov (United States)

    Nehring, N.L.; Fausto, L.J.J.

    1979-01-01

    As part of a joint USGS-CFE geochemical study of Cerro Prieto, steam samples were collected for gas analyses in April, 1977. Analyses of the major gas components of the steam were made by wet chemistry (for H2O,CO2,H2S and NH3) and by gas chromatography (He,H2,Ar,O2,N2 and hydrocarbons). The hydrocarbon gases in Cerro Prieto steam closely resemble hydrocarbons in steam from Larderello, Italy and The Geysers, California which, although they are vapor-dominated rather than hot-water geothermal systems, also have sedimentary aquifer rocks. These sedimentary geothermal hydrocarbons are characterized by the presence of branched C4-6 compounds and a lack of unsaturated compounds other than benzene. Relatively large amounts of benzene may be characteristic of high-temperature geothermal systems. All hydrocarbons in these gases other than methane most probably originate from the thermal metamorphosis of organic matter contained in the sediments. ?? 1979.

  4. Paleomagnetism in the Determination of the Emplacement Temperature of Cerro Colorado Tuff Cone, El Pinacate Volcanic Field, Sonora, Mexico.

    Science.gov (United States)

    Rodriguez Trejo, A.; Alva-Valdivia, L. M.; Vidal Solano, J. R.; Garcia Amador, B.; Gonzalez-Rangel, J. A.

    2014-12-01

    Cerro Colorado Maar is located at the World Heritage Site, biosphere reserve El Pinacate and Gran Desierto del Altar, at the NNW region of Sonora, Mexico (in El Pinacate Volcanic Field). It is a tuff cone, about 1 km diameter, result of several phreatomagmatic episodes during the late Quaternary. We report paleomagnetic and rock magnetic properties from fusiform volcanic bombs obtained from the borders of Cerro Colorado. This study is based in the thermoremanent magnetization TRM normally acquired by volcanic rocks, which can be used to estimate the emplacement temperature range. We performed the experiments on 20 lithic fragments (10 cm to 20 cm approximately), taking 6-8 paleomagnetic cores from each. Rock magnetic experiments (magnetic susceptibility vs. temperature (k-T), hysteresis curves and FORC analysis, shows that the main magnetic mineral carriers of magnetization are titanomagnetite and titanohematite in different levels of intergrowth. The k-T curves suggest in many cases, only one magnetic phase, but also in other cases a second magnetic phase. Thermal demagnetization was used to demagnetize the specimens in detailed short steps and make a well-defined emplacement temperature determination ranges. We found that temperature emplacement determination range for these two magnetic phases is between 350-450 °C, and 550-580 °C, respectively. These results are consistent with those expected in an eruption of Surtsey type, showing a distinct volcanic activity compared to the other craters from El Pinacate volcanic field.

  5. A process for fire-related debris flow initiation, Cerro Grande fire, New Mexico

    Science.gov (United States)

    Cannon, S.H.; Bigio, E.R.; Mine, E.

    2001-01-01

    In this study we examine factors that pertain to the generation of debris flows from a basin recently burned by wildfire. Throughout the summer 2000 thunderstorm season, we monitored rain gauges, channel cross-sections, hillslope transects, and nine sediment-runoff traps deployed in a steep, 0??15 km2 basin burned by the May 2000 Cerro Grande fire in New Mexico. Debris flows were triggered in the monitored basin during a rainstorm on July 16, 2000, in response to a maximum 30 min rainfall intensity of 31 mm h-1 (return period of approximately 2 years). Eleven other storms occurred before and after the July storm; these storms resulted in significant runoff, but did not generate debris flows. The debris flows generated by the July 16 storm initiated on a broad, open hillslope as levee-lined rills. The levees were composed of gravel- and cobble-sized material supported by an abundant fine-grained matrix. Debris-flow deposits were observed only on the hillslopes and in the first and second-order drainages of the monitored basin. No significant amounts of channel incision were measured following the passage of the debris flows, indicating that most of the material in the flows originated from the hillslopes. Sediment-runoff concentrations of between 0??23 and 0??81 kg 1-1 (with a mean of 0-42 kg 1-1) were measured from the hillslope traps following the debris-flow-producing storm. These concentrations, however, were not unique to the July 16 storm. The materials entrained by the July 16 storm contained a higher proportion of silt- plus clay-sized materials in the debris flows. The difference in materials demonstrates the critical role of the availability of fine-grained wood ash mantling the hillslopes in the runoff-dominated generation of post-wildfire debris flows. The highest sediment-runoff concentrations, again not unique to debris-flow production, were produced from maximum 30 min rainfall intensities greater than 20 mm h-1. Copyright ?? 2001 John Wiley and Sons

  6. Los Cactos

    Directory of Open Access Journals (Sweden)

    García Paredes Antonio

    1942-12-01

    Full Text Available El Cacto Cactus es uno de los géneros de plantas de la familia de las Cacteas Nopaleas que contiene muchas especies y variedades todas de formas extrañas, propias de la América intertropical y que habitan en los climas fríos y templados, en terrenos secos y estériles, desde el norte de Méjico hasta la Patagonia. Algunos cactos se cultivan por sus frutos que son sanosy sabrosos, otros como plantas ornamentales en los parques y jardines, otros como auxiliares para la industria, como los nopales en los que se cría la Cochinilla, insecto de la familia de los Hemípteros que produce la laca o carmín, materia colorante indispensable en la pintura al óleo y la acuarela, y por último, hoy están en moda y se cultivan con esmero una gran variedad de diminutos cactos exóticosque se mantienen sobre arena húmeda en pequeñas maceteras de porcelana, en los lugares más visibles de las habitaciones.

  7. Una sepultura con armas de baja época ibérica (o época romana republicana en la necrópolis del «Cerro de las Balas» (Écija, Sevilla

    Directory of Open Access Journals (Sweden)

    Núñez Pariente de León, Esther

    2000-12-01

    Full Text Available Iberian Iron-Age weapons are extremely rare in western Andalusia, due mainly to the absence of the normative cremation cemeteries typical of other areas in the Peninsula, cemeteries where nearly all of the approximately six thousand Iron Age weapons that we know have been documented. In this paper we present one of the very few exceptions to this rule: a ‘warrior’ burial found in the Iron Age cemetery cemetery at ‘Cerro de las Balas’ (or «bullets’ hill», so known after the many sling projectiles found in the neighbourhood. This is an important find due to three facts: the type of weapons (among them a sword of the gladius hispaniensis type and a dagger of a very late Celtiberian or very early Roman type; the date, between the Late Iberian period and Early Roman rule; and the closed assemblage of weapons: sword, dagger and two javelins or short spears. It is quite possible that the burial is to be dated to the beginning of the second century BC, and therefore that the sword found in it is the earliest known example of the Roman gladius hispaniensis sword... or the latest version of the Iberian prototype for it. Finally, we discuss the proximity of this burial to the caesarian battlefield of Munda (45 BC to conclude that in all probability these are two completely independent events, the burial being probably much earlier.

    Las armas de época ibérica son rarísimas en Andalucía Occidental, en buena parte debido a la práctica ausencia de necrópolis, que es donde las armas se han documentado en mayor número durante toda la Edad del Hierro peninsular. Se presenta en este trabajo una de las pocas excepciones a esta regla: una sepultura ‘de guerrero’ hallada en la necrópolis del ‘Cerro de las Balas’ (así llamado por los numerosos proyectiles de honda hallados en las cercanías. Es un hallazgo de importancia por el tipo de armas hallado (entre ellas una espada de hoja recta del tipo del

  8. An integrated model for the natural flow regime in the Cerro Prieto hydrothermal system based upon petrological and isotope geochemical criteria

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Williams, A.E.; Hoagland, J..

    1981-01-01

    Studies of cuttings and cores at Cerro Prieto have now been extended to more than 50 boreholes. The aims of this petrological and isotopic work are to determine the shape of the reservoir, its physical properties, and its temperature distribution and flow regime before the steam field was produced.

  9. Paleomagnetism of the Quaternary Cerro Prieto, Crater Elegante, and Salton Buttes volcanic domes in the northern part of the Gulf of California rhombochasm

    Energy Technology Data Exchange (ETDEWEB)

    de Boer, J.

    1980-02-01

    Deviating thermomagnetic directions in volcanics representing the second and fifth or sixth pulse of volcanism suggest that the Cerro Prieto volcano originated about 110,000 years B.P. and continued to be active intermittently until about 10,000 years ago.

  10. Land subsidence in the Cerro Prieto Geothermal Field, Baja California, Mexico, from 1994 to 2005: An integrated analysis of DInSAR, leveling and geological data

    Science.gov (United States)

    Sarychikhina, Olga; Glowacka, Ewa; Mellors, Robert; Vidal, Francisco Suárez

    2011-07-01

    Cerro Prieto is the oldest and largest Mexican geothermal field in operation and has been producing electricity since 1973. The large amount of geothermal fluids extracted to supply steam to the power plants has resulted in considerable deformation in and around the field. The deformation includes land subsidence and related ground fissuring and faulting. These phenomena have produced severe damages to the local infrastructure such as roads, irrigation canals and other facilities. In this paper, the technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) is applied using C-band ENVISAR ASAR data acquired between 2003 and 2006 to determine the extent and amount of land subsidence in the Mexicali Valley near Cerro Prieto Geothermal Field. The DInSAR results were compared with published data from precise leveling surveys (1994-1997 and 1997-2006) and detailed geological information in order to improve understanding of the temporal and spatial distributions of anthropogenic subsidence in the Mexicali Valley. The leveling and DInSAR data were modeled to characterize the observed deformation in terms of fluid extraction. The results confirm that the tectonic faults control the spatial extent of the observed subsidence. These faults likely act as groundwater flow barriers for aquifers and reservoirs. The shape of the subsiding area coincides with the Cerro Prieto pull-apart basin. In addition, the changes in spatial pattern and rate of the subsidence are correlated with the development of the Cerro Prieto Geothermal Field.

  11. Land subsidence in the Cerro Prieto Geothermal Field, 1 Baja California, Mexico, from 1994 to 2005. An integrated analysis of DInSAR, levelingand geological data.

    Energy Technology Data Exchange (ETDEWEB)

    Sarychikhina, O; Glowacka, E; Mellors, R; Vidal, F S

    2011-03-03

    Cerro Prieto is the oldest and largest Mexican geothermal field in operation and has been producing electricity since 1973. The large amount of geothermal fluids extracted to supply steam to the power plants has resulted in considerable deformation in and around the field. The deformation includes land subsidence and related ground fissuring and faulting. These phenomena have produced severe damages to infrastructure such as roads, irrigation canals and other facilities. In this paper, the technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) is applied using C-band ENVISAR ASAR data acquired between 2003 and 2006 to determine the extent and amount of land subsidence in the Mexicali Valley near Cerro Prieto Geothermal Field. The DInSAR results were compared with published data from precise leveling surveys (1994- 1997 and 1997-2006) and detailed geological information in order to improve the understanding of temporal and spatial distributions of anthropogenic subsidence in the Mexicali Valley. The leveling and DInSAR data were modeled to characterize the observed deformation in terms of fluid extraction. The results confirm that the tectonic faults control the spatial extent of the observed subsidence. These faults likely act as groundwater flow barriers for aquifers and reservoirs. The shape of the subsiding area coincides with the Cerro Prieto pull-apart basin. In addition, the spatial pattern of the subsidence as well as changes in rate are highly correlated with the development of the Cerro Prieto Geothermal Field.

  12. los aprendizajes

    Directory of Open Access Journals (Sweden)

    Graciela Pérez Rivera

    2007-01-01

    Full Text Available En este documento se presentan algunos resultados, obtenidos hasta el momento, de un estudio sobre las prácticas de evaluación de profesores universitarios. El propósito del estudio es participar en la búsqueda de las relaciones existentes entre los conceptos y las prácticas educativas, en este caso de evaluación. Se identifican las principales tendencias en cuanto a la concepción de la evaluación del aprendizaje y las funciones que se le otorgan, los propósitos con los que se evalúa, los objetos o contenidos a evaluar, las formas en que se lleva a cabo la evaluación y el uso que se da a los resultados. Identificar cuáles son las tendencias de las prácticas de evaluación en nuestras aulas universitarias representa un paso que puede ayudar a cuidar que este proceso tan importante recobre su papel formativo para todos aquellos quienes participamos en los procesos educativos; además, representa la posibilidad de construir formas para lograr mejorar nuestra labor docente en general, y en particular, nuestra práctica evaluativa.

  13. From the Copper Age to the Bronze Age in the Lower Guadalquivir Basin. The Cerro de San Juan settlement (Coria del Río, Seville, Spain and the ‘replacement model’

    Directory of Open Access Journals (Sweden)

    Daniel GARCÍA RIVERO

    2015-11-01

    Full Text Available The transition between Copper and Bronze Ages in the Southwest of the Iberian Peninsula is poorly known still, especially when compared with the transition between Los Millares culture to El Argar culture in the Southeast. The settlement of Cerro de San Juan, which controlled the Guadalquivir mouth at that time, shows some evidences of human occupations of both periods, an uncommon feature along the South of Iberian Peninsula. The data from this site suggest a sedimentary break between the two periods, and a strong cultural change as well. The culture material sets are different between the Bell Beaker phase and the Bronze Age, and several radiocarbon dates define consistently the chronology of the phenomenon. From this perspective, an analysis of every archaeological stratigraphy that has evidences of both periods is carried out. Against a model of cultural continuity, numerous archaeological features rather suggest a model of demographic replacement. Thus, the Bronze Age can be defined as a new way of life perhaps by human groups that were not direct descendants of the previous communities.

  14. Notes on the ecology of Phyllodactylus reissi (Phyllodactylidae: Sauria in Parque Nacional Cerros de Amotape (Tumbes, Peru

    Directory of Open Access Journals (Sweden)

    Juan Carlos Jordán Arizmendi

    2012-02-01

    Full Text Available Some basics aspects on the ecology of the nocturnal gecko Phyllodactylus reissi from Parque Nacional Cerros de Amotape (Tumbes, Peru are described. This species used rock boulders (57,4% and trees (31,9% as microhabitats primarily, exhibiting a nocturnal activity pattern, with a peak between 2100-2200 hours, remaining active until midnight. Body temperature (mean 24,4 ºC was correlated with both air and substrate temperature, with the last variable affecting in higher degree (47% the body temperature of this species. The slightly high body temperature of Phyllodactylus reissi, compared to other Phyllodactylus geckos, could be related to nocturnal microhabitat use and diurnal retreat site selection. More studies on lizard ecology from this endangered ecosystem are needed.

  15. Dry steam feed zones and silica scaling as major controls of total flow enthalpy at Cerro Prieto, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Beall, J.J. [Calpine Corp., Santa Rosa, CA (United States); Ledesma, A.P.; Dios Ocampo, J. de [Constructora y Perforadora Latina S.A., Baja California (Mexico)

    1997-12-31

    Enthalpy and chloride data for Cerro Prieto well fluids define a mixing line between original reservoir liquid (1,300-1,500 J/g, 9,000-11,000 ppm Cl) and superheated steam (2870 J/g, 0 ppm Cl). The mixing relationship establishes that dry steam feed zones contribute to the total fluid flow of many wells. Fluids produced from newly completed or worked over wells often show rapid movement in either direction along the enthalpy-chloride mixing line. The direction of movement along the enthalpy-chloride mixing line depends upon whether increased formation boiling (increasing the dry steam flow to the well) or silica scaling in the formation and on the surface of the well bore (which inhibits the flow of dry steam) is the dominant process.

  16. Results of the first order leveling surveys in the Mexicali Valley and at the Cerro Prieto field

    Energy Technology Data Exchange (ETDEWEB)

    de la Pena L, A.

    1981-01-01

    The results obtained from the third leveling survey carried out by the Direccion General de Geografia del Territorio Nacional (previously DETENAL) during November and December 1979 are presented. Calculations of the changes in field elevation and plots showing comparisons of the 1977, 1978, and 1979 surveys are also presented. Results from a second order leveling survey performed to ascertain the extent of ground motion resulting from the 8 June 1980 earthquake are presented. This magnitude ML = 6.7 earthquake with epicenter located 15 km southeast of the Guadalupe Victoria village, caused fissures on the surface, the formation of small sand volcanos, and the ejection of ground water in the vicinity of the Cerro Prieto field. This leveling survey was carried out between benchmark BN-10067 at the intersection of the Solfatara canal and the Sonora-Baja California railroad, and benchmark BN-10055 located at the Delta station.

  17. Curie point depth from spectral analysis of aeromagnetic data from Cerro Prieto geothermal area, Baja California, México

    Science.gov (United States)

    Espinosa-Cardeña, J. M.; Campos-Enriquez, J. O.

    2008-10-01

    Using aeromagnetic data acquired in the area from the Cerro Prieto geothermal field, we estimated the depth to the Curie point isotherm, interpreted as the base of the magnetic sources, following statistical spectral-based techniques. According to our results the Curie point isotherm is located at a depths ranging from 14 to 17 km. Our result is somewhat deeper than that obtained previously based only in 2-D and 3-D forward modeling of previous low-quality data. However, our results are supported by independent information comprising geothermal gradients, seismicity distribution in the crust, and gravity determined crustal thickness. Our results imply a high thermal gradient (ranging between 33 and 38 °C/km) and high heat flow (of about 100 mW/m 2) for the study area. The thermal regime for the area is inferred to be similar to that from the Salton trough.

  18. Active metasomatism in the Cerro Prieto geothermal system, Baja California, Mexico: a telescoped low pressure/temperature metamorphic facies series

    Energy Technology Data Exchange (ETDEWEB)

    Schiffman, P.; Elders, W.A.; Williams, A.E.; McDowell, S.D.; Bird, D.K.

    1983-01-01

    In the Cerro Prieto geothermal field, carbonate-cemented, quartzofeldspathic sediments of the Colorado River delta are being actively metasomatized into calc-silicate metamorphic rocks by reaction with alkali chloride brines between 200/sup 0/ and 370/sup 0/C, low fluid and lithostatic pressures, and low oxygen fugacities. Petrologic investigations of drill cores and cutting from over 50 wells in this field identified a prograde series of calc-silicate mineral zones which include as index minerals: wairakite, epidote, prehnite, and clinopyroxene. Associated divariant mineral assemblages are indicative of a very low pressure/temperature metamorphic facies series which encompasses the clay-carbonate, zeolite, greenschist, and amphibolite facies. This hydrothermal metamorphic facies series, which is becoming increasingly recognized in other active geothermal systems, is characterized by temperature-telescoped dehydration and decarbonation mineral equilibria. Its equivalent should now be sought in fossil hydrothermal systems.

  19. Burning down the brewery: Establishing and evacuating an ancient imperial colony at Cerro Baúl, Peru

    Science.gov (United States)

    Moseley, Michael E.; Nash, Donna J.; Williams, Patrick Ryan; deFrance, Susan D.; Miranda, Ana; Ruales, Mario

    2005-01-01

    Before the Inca reigned, two empires held sway over the central Andes from anno Domini 600 to 1000: the Wari empire to the north ruled much of Peru, and Tiwanaku to the south reigned in Bolivia. Face-to-face contact came when both colonized the Moquegua Valley sierra in southern Peru. The state-sponsored Wari incursion, described here, entailed large-scale agrarian reclamation to sustain the occupation of two hills and the adjacent high mesa of Cerro Baúl. Monumental buildings were erected atop the mesa to serve an embassy-like delegation of nobles and attendant personnel that endured for centuries. Final evacuation of the Baúl enclave was accompanied by elaborate ceremonies with brewing, drinking, feasting, vessel smashing, and building burning. PMID:16293691

  20. IMPACT OF ADDITIONALS CONTAMINANTS DUE TO ACID MINE DRAINAGE IN TRIBUTARIES OF THE PILCOMAYO RIVER FROM CERRO RICO, POTOSÍ, BOLIVIA

    Directory of Open Access Journals (Sweden)

    William H.J. Strosnider

    2014-09-01

    Full Text Available Intensive mining and processing of the polymetallic sulfide ore body of Cerro Rico de Potosí (Bolivia has occurred since 1545. To further investigate acid mine drainage (AMD discharges and their link to downstream contamination, data were gathered during two sampling events during the most extreme periods of the dry and wet seasons of one year. Concentrations of Ag, B, Ba, Mo, Sb, Se, Sn and V in AMD and receiving streams were greater than Bolivian discharge limits and receiving water body guidelines as well as international agricultural use standards. High concentrations of rare earth metals have been documented in this area. Results indicate that contamination from mining has a larger scope than previously thought and underscore the importance of remediation.

  1. The ash deposits of the 4200 BP Cerro Blanco eruption: the largest Holocene eruption of the Central Andes

    Science.gov (United States)

    Fernandez-Turiel, Jose-Luis; Saavedra, Julio; Perez-Torrado, Francisco-Jose; Rodriguez-Gonzalez, Alejandro; Carracedo, Juan-Carlos; Lobo, Agustin; Rejas, Marta; Gallardo, Juan-Fernando; Osterrieth, Margarita; Carrizo, Julieta; Esteban, Graciela; Martinez, Luis-Dante; Gil, Raul-Andres; Ratto, Norma; Baez, Walter

    2015-04-01

    We present new data about a major eruption -spreading approx. 110 km3 ashes over 440.000 km2- long thought to have occurred around 4200 years ago in the Cerro Blanco Volcanic Complex (CBVC) in the Central Andes of NW Argentina (Southern Puna, 26°45' S, 67°45' W). This eruption may be the biggest during the past five millennia in the Central Volcanic Zone of the Andes, and possibly one of the largest Holocene eruptions in the world. Discrimination and correlation of pyroclastic deposits of this eruption of Cerro Blanco was conducted comparing samples of proximal (domes, pyroclastic flow and fall deposits) with distal ash fall deposits (up to 400 km from de vent). They have been characterized using optical and electron microscopy (SEM), X-ray diffraction, particle-size distribution by laser diffraction and electron microprobe and HR-ICP-MS with laser ablation for major and trace element composition of glass, feldspars and biotite. New and published 14C ages were calibrated using Bayesian statistics. An one-at-a-time inversion method was used to reconstruct the eruption conditions using the Tephra2 code (Bonadonna et al. 2010, https://vhub.org/resources/tephra2). This method allowed setting the main features of the eruption that explains the field observations in terms of thickness and grain size distributions of the ash fall deposit. The main arguments that justify the correlation are four: 1) Compositional coincidence for glass, feldspars, and biotite in proximal and distal materials; 2) Stratigraphic and geomorphological relationships, including structure and thickness variation of the distal deposits; 3) Geochronological consistency, matching proximal and distal ages; and 4) Geographical distribution of correlated outcrops in relation to the eruption centre at the coordinates of Cerro Blanco. With a magnitude of 7.0 and a volcanic explosivity index or VEI 7, this eruption of ~4200 BP at Cerro Blanco is the largest in the last five millennia known in the Central

  2. Edad y rasgos petrográficos y geoquímicos de cuerpos subvolcánicos asignables a la Formación Cerro León, este del Macizo del Deseado, Santa Cruz

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    D. Guido

    2004-12-01

    Full Text Available Se presentan nuevos afloramientos de cuerpos subvolcánicos correlacionables con la Formación Cerro León en el sector oriental del Macizo del Deseado. Esta unidad aflora en dos sectores, en el bajo Leonardo y en el afloramiento Bahía Laura del Complejo Río Deseado. El primer sector presenta trece diques y un filón capa intruyendo a las sedimentitas pérmicas de la Formación La Golondrina y el segundo sector comprende tres diques que intruyen a rocas del basamento. Se trata de rocas de color gris a negro, frecuentemente alteradas, con textura microgranuda a porfírica, con fenocristales de plagioclasa, diópsido (En42 Fs11 Wo47 y en menor medida de hornblendas ricas en Mg (magnesio hastingsita, en una matriz holocristalina de textura intergranular. Son rocas subalcalinas de composiciones basalto-andesita y con afinidades calcoalcalinas. La edad Ar/Ar obtenida en una de estas muestras (180,1±1,5 Ma representa la primer determinación realizada en esta unidad y es coherente con las relaciones estratigráficas observadas para esta formación. La comparación con rocas ígneas jurásicas de la provincia geológica Macizo del Deseado, favorece la vinculación temporal y genética con el evento volcánico-piroclástico del Jurásico medio a superior (Formación Bajo Pobre y Grupo Bahía Laura. Sin embargo, la diferencia en las edades Ar/Ar, sugieren una interrupción entre el evento subvolcánico (180 Ma y el volcanismo Jurásico medio a superior (177 a 150 Ma. Se considera, preliminarmente, que los cuerpos subvolcánicos de la Formación Cerro León representarían las primeras evidencias magmáticas del rift jurásico en el Macizo del Deseado.

  3. Constraining the Paleogene of South America: Magnetostratigraphy and paleoclimate proxy records from Cerro Bayo (Provincia de Salta, Argentina)

    Science.gov (United States)

    Hyland, E.; Cotton, J. M.; Sheldon, N. D.

    2012-12-01

    Records of rapid climatic and ecological shifts in the past are crucial for understanding global systems and for predicting future impacts of climate change. Transient and broad scale hyperthermal events during the Paleogene, such as the Paleocene-Eocene Thermal Maximum (PETM) and Early Eocene Climatic Optimum (EECO), have been studied extensively through both marine records and a significant terrestrial record from North America. Despite this, little evidence exists from the climatic and ecological histories of other major landmasses, which limits the effectiveness of global climate response predictions. Here we present an integrated paleoenvironmental reconstruction of the early Paleogene from a site in central South America (Cerro Bayo, Argentina), including a new magnetostratigraphic age model, pedological and sedimentological interpretation, whole rock geochemical climate proxies, isotopic environmental proxies, and microfloral assemblages. Cerro Bayo is a 235-meter terrestrial section that exposes the Tunal, Mealla, and Maiz Gordo Formations, and based on magnetostratigraphic interpolation spans roughly 58—50 Mya, including both the PETM and EECO events. These formations are composed primarily of reddish sandstone and siltstone, much of which exhibits features characteristic of a moderate degree of pedogenesis (i.e., Inceptisols and Alfisols). High-resolution climate proxies derived from paleosol geochemical compositions highlight rapid increases in mean annual temperature (>5°C) and precipitation (>300 mm yr-1) during the PETM, as well as more gradual increasing temperature and precipitation trends leading up to the EECO. Carbon isotope stratigraphy through the section also indicates a sizable negative excursion (~4‰) during the PETM, and generally positive isotopic trends during the early Eocene. Phytolith biostratigraphy also details changes in local vegetation composition during climatic events that corresponds to similar patterns seen in terrestrial

  4. Stress controlled magma-earthquake interaction during unrest at Chiles-Cerro Negro Volcanoes (Ecuador-Colombian border)

    Science.gov (United States)

    Ebmeier, S. K.; Elliott, J. R.; Nocquet, J. M.; Biggs, J.; Mothes, P. A.; Lundgren, P.; Samsonov, S. V.; Jarrin, P.; Yepez, M.; Aguaiza, S.

    2015-12-01

    The movement of fluids beneath a volcano can cause deformation, and therefore changes to the subsurface stress field that manifest in swarms of low magnitude (Chiles-Cerro Negro volcanoes on the Ecuador-Colombian border. These volcanoes were previously considered to be historically inactive, but between 2013 and early 2015 there were three episodes of unrest characterised by VT swarms of increasing energy and duration. GPS measurements at two stations near Volcán Chiles show inflation over a time period of approximately twenty days prior to the 20th October, consistent with the intrusion of magma at half space depths >13 km. This inflation took place during a swarm of VT seismicity with thousands of low magnitude events per day and culminated in a M 5.6 earthquake on the 20th October, when inflation abruptly ceased. We measure coseismic displacements from the M 5.6 earthquake with data from three independent InSAR platforms and find that they are consistent with shallow slip of 1.2 m on an oblique reverse fault. This fault plane would have experienced positive Coulomb stress changes from some of the range of potential sources consistent with the inflation. Magmatic intrusion could therefore have contributed to the loading on the fault directly through stress changes caused by pressurisation, and indirectly through the decrease in effective friction coefficient due to elevated pore fluid pressure. The cessation of inflation immediately after the moderate earthquake suggests a link between the two events. We expect slip on the fault plane identified from the InSAR data to have resulted in compression in the shallow crust south of Volcán Chiles, above the source that had previously been inflating. This would have inhibited further ascent of magma. The Chiles-Cerro Nego unrest provides rare observations of interaction between magmatic intrusion and a moderate earthquake during volcanic unrest.

  5. Analysis of the Nuevo Leon Magnetic Anomaly and its possible relation to the Cerro Prieto magmatic-hydrothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, N.E.; Corrigan, D.J.; Wilt, M.J.

    1984-01-01

    The broad dipolar magnetic anomaly whose positive peak is centered near Ejido Nuevo Leon, some 5 km east of the Cerro Prieto I power plant, has long been suspected to have a genetic relationship to the thermal source of the Cerro Prieto geothermal system. This suspicion was reinforced after several deep geothermal wells, drilled to depths of 3-3.5 km over the anomaly, intersected an apparent dike-sill complex consisting mainly of diabase but with minor rhyodacite. A detailed fit of the observed magnetic field to a computer model indicates that the source may be approximated by a tabular block 4 x 6 km in area, 3.7 km in depth, 2.3 km thick, and dipping slightly to the north. Mafic dike chips from one well, NL-1, were analysed by means of electron microprobe analyses which showed them to contain a titanomagnetite that is paramagnetic at in situ temperature conditions. As the dike mineralogy does not account for the magnetic anomaly, the magnetic source is believed to be a deeper, magnetite-rich assemblage of peridotite-gabbro plutons. The suite of igneous rocks was probably emplaced at a shallow depth in response to crustal extension and thinning brought on by en echelon strike-slip faulting. The bottom of the magnetic source body, at an estimated depth of 6 km, is presumed to be at or near that of the Curie isotherm (575/sup 0/C) for magnetite, the principal ferromagnetic mineral in peridotiticgabbroic rocks. The geological model derived from the magnetic study is generally supported by other geophysical data. In particular, earthquake data suggest dike injection is occurring at depths of 6-11 km in an area beneath the magnetic source. Thus, it is possible that heat for the geothermal field is being maintained by continuing crustal extension and magmatic activity.

  6. Analysis of the Nuevo Leon magnetic anomaly and its possible relation to the Cerro Prieto magmatic-hydrothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, N.E.; Wilt, M.J.; Corrigan, D.J.

    1982-10-01

    The broad dipolar magnetic anomaly whose positive peak is centered near Ejido Nuevo Leon, some 5 km east of the Cerro Prieto I Power Plant, has long been suspected to have a genetic relationship to the thermal source of the Cerro Prieto geothermal system. This suspicion was reinforced after several deep geothermal wells, drilled to depths of 3 to 3.5 km over the anomaly, intersected an apparent dike-sill complex consisting mainly of diabase but with minor rhyodacite. A detailed fit of the observed magnetic field to a computer model indicates that the source may be approximated by a tabular block 4 by 6 km in area, 3.7 km in depth, 2.3 km thick, and dipping slightly to the north. Mafic dike chips from one well, NL-1, were analyzed by means of electron microprobe analyses which showed tham to contain a titanomagnetite that is paramagnetic at in-situ temperature conditions. As the dike mineralogy does not account for the magnetic anomaly, the magnetic source is believed to be a deeper, magnetite-rich assemblage of peridotite-gabbro plutons. the suite of igneous rocks was probably passively emplaced at a shallow depth in response to crustal extension and thinning brought on by strike-slip faulting. The bottom of the magnetic source body, at an estimated depth of 6 km, is presumed to be at or near that of the Curie isotherm (575/sup 0/C) for magnetite, the principal ferromagnetic mineral in peridotitic-gabbroic rocks. The geological model derived from the magnetic study is generally supported by other geophysical data. In particular, earthquake data suggest dike injection is occurring at depths of 6 to 11 km in an area beneath the magnetic source. Thus, it is possible that heat for the geothermal field is being maintained by continuing crustal extension and magmatic activity.

  7. Los compadres

    Directory of Open Access Journals (Sweden)

    Luis Muñoz

    2010-03-01

    Full Text Available De lejos parecen ser personas muy silenciosas y cuando hablan lo hacen con una entonación diferente. Comienza un día hermoso en el que vamos a visitarlos y el humor es la disculpa más agradable para hacer alianzas. La señora va y viene del cuarto oscuro donde se encuentra el fogón, interviniendo a veces, con su presencia viva en la charla, aunque no lo parece. Un café, una taza de leche y roscones, un vaso de guarapo, una y otra vez. No sé como llamarlos; si cuenteros, poetas, hombres hablando. Los percibo como portadores de una tradición oral, compartiendo con nosotros sus pensamientos y creencias más profundos, en tomo a todos los matices de su realidad social. En la tradición oral se piensa el mundo de una manera integral mientras la cotidianidad está cada vez más condicionada por un mundo segmentado y especializado. Los cuentos innumerables que conocen han sido escuchados y modificados por niños, hombres y mujeres de todas las edades. Cualquier actividad diaria es buena para contar. Las noches en la caza de Luis son acogedoras, la señora Angelita prepara una sopa de maíz y tomamos hasta dos platos llenos para calentamos. La única esperma que ilumina la penumbra de la conversación se consume poco a poco. Los primeros días de mi visita sentí lo que llamaría miedos culturales, como mi obsesión por los insectos que imaginaba dentro de la casa, la cual se fue disipando en la medida en que afirmábamos nuestros lazos. Noches de tertulia, de diálogo, de cuentos. Generalmente Luis pasa esas horas escribiendo o leyendo, dedicado a su mayor afición que es la literatura, conversando con doña Angelita y escuchando cuando ella relata cuentos y anécdotas. Al joven escritor autodidacta lo cautivan las vivencias y fantasías humanas. Escribe sobre su gente y está interesado en las tradiciones literarias de la región. Trabaja como jornalero en fincas o haciendas, realizando varios oficios como la carpintería, la agricultura, la

  8. Rehabilitación Unión Obrera: cerro Cordillera

    OpenAIRE

    Araya, Raúl; Castillo Couve, Maria Jose; Prado,Francisco

    2009-01-01

    La recuperación del edificio donado en 1898 por Juana Ross de Edwards, es la primera experiencia de rehabilitación de vivienda social con carácter patrimonial. Se destaca en la operación la decisión de los habitantes de permanecer viviendo en el inmueble, tras mejorar sus condiciones de habitabilidad y de equipamiento.

  9. Minería, conflicto y mediadores locales: Minera San Xavier en Cerro de San Pedro, México Mineira, conflito e mediadores locais: Minera San Xavier em Cerro de San Pedro Mining, conflict and local brokers: Minera San Xavier in Cerro de San Pedro

    OpenAIRE

    Hernán Horacio Schiaffini

    2011-01-01

    Este trabajo indaga en las instancias de mediación que intervienen en la articulación de procesos económicos de gran escala y su puesta en práctica local. Basándonos en el conflicto que se produjo en el Municipio de Cerro de San Pedro (San Luis Potosí, México) entre la empresa Minera San Xavier y el Frente Amplio Opositor (FAO) a la misma, aplicamos el método etnográfico con el objetivo de describir las estructuras locales de mediación política y analizar sus prácticas y racionalidad. Intenta...

  10. Configuration of the mudstones, gray- and coffee-colored shale lithologic units, zones of silica and epidote, and their relation to the tectonics of the Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Cobo R, J.M.

    1981-01-01

    Based on well cuttings, five lithological units have been recognized within the area of what is now the Cerro Prieto geothermal field. These five units are described. Differences in origin, mineralogy, grading, color, compaction, etc., are shown.

  11. Estratigrafía, análisis de facies y paleoambientes de la formación cañadón asfalto en el depocentro jurásico cerro Cóndor, provincia del Chubut Stratigraphy, facies analysis and paleoenvironments of the Cañadón Asfalto Formation, Jurassic Cerro Cóndor depocenter, Chubut province

    Directory of Open Access Journals (Sweden)

    Nora Cabaleri

    2010-05-01

    Full Text Available El depocentro Cerro Cóndor representa la secuencia estratigráfica del Jurásico continental más completa de la cuenca de Cañadón Asfalto y de Sudamérica austral. Se sitúa en la Patagonia extraandina, en ambas márgenes del río Chubut medio. La sedimentación en esta cuenca pull apart, acompañada por efusiones de basalto olivínico, comenzó en el Jurásico Medio temprano. Predominan en la Formación Cañadón Asfalto los depósitos lacustres caracterizados por asociaciones de facies carbonáticas y siliciclásticas intercaladas con rocas lávicas en la base y depósitos piroclásticos hacia el techo de la unidad. Se describe el desarrollo de facies a lo largo de un corte norte-sur que abarca las secciones de estancia El Torito y de los cañadones Los Loros, Las Chacritas, Carrizal, Asfalto y Lahuincó. Las facies/microfacies carbonáticas están representadas por mudstones, wackestones,packstones, grainstones y calizas microbialíticas características de ambientes litorales, marginales y palustres. En la Formación Cañadón Asfalto se distinguen un miembro inferior (Las Chacritas, constituido por calizas, lutitas, areniscas y conglomerados, intercalados con basaltos olivínicos y por otro superior (Puesto Almada compuesto por tobas, tufitas, lutitas y areniscas. El primero es portador de una asociación palinológica de edad bajociano-bathoniana y el segundo de dinosaurios de edad tithoniana. Se describen detalladamente e ilustran las secciones estratigráficas de ambos miembros de la formación en sus localidades tipo, cañadón Las Chacritas y estancia el Torito y se reconstruyen los paleoambientes del depocentro desde el Aaleniano al Tithoniano. La edad del miembro Puesto Almada en su localidad tipo se obtuvo mediante una datación radimétrica (K/Ar de biotitas provenientes de una delgada capa de toba volcánica (147,1 ± 3,3 Ma, Tithoniano proveniente de la parte superior de la unidad.The Cerro Cóndor depocenter represents the

  12. El complejo deslizamiento de Ailinco-Cerro Papas-Las Olletas (Departamento Minas, norte del Neuquén, Argentina The complex landslide of Ailinco-Cº Papas-Las Olletas, northern Neuquén, Argentina

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    E.F. González Díaz

    2003-06-01

    Full Text Available De acuerdo a los antecedentes disponibles, acumulaciones de aspecto tilloide que conforman el irregular paisaje de un amplio sector de la cuenca de drenaje del arroyo Ailinco y que se extiende al pie del extremo sur de la serranía de la Puntilla y del faldeo oeste del Cº Papas y en el paraje de las Olletas, han sido consideradas como propias de la génesis glaciaria (morenas; tills. Los autores las interpretan como correspondientes a depósitos de un complejo conjunto local de grandes movimientos gravitacionales, en el que se han distinguido tres avalanchas de rocas, siendo las mayores aquellas del Cº Las Papas y de Ailinco y otra de menor porte ocurrida en la zona de Las Olletas. Sólo se describe su distribución y sus principales características morfológicas Se propone como el promotor de los mismos a la energía sísmica, teniendo en cuenta las condiciones sismotectónicas de la región y antecedentes de otros similares movimientos cercanos, ya analizados por los autores En el mapa geomorfológico adjunto, que cubre prácticamente la totalidad del área de las cuencas de los arroyos Ailinco y Manchana Covunco, se distinguen la presencia y distribución de otras geoformas menores, cuyo origen está relacionado con procesos propios de la morfogenia glaciaria, de un ambiente local de condiciones periglaciarias actuales y de la remoción en masa.At the southern end of the Sierra de la Puntilla Range in northern Neuquén province, extensive deposits of "tilloid" features in a morphological environment with hummocky-topography were observed. Previous studies suggest their relation with glacial morphogenesis (moraines; tills. We propose instead here their relationship to large gravitational movements triggered by seismic shock, and we distinguish two rock-avalanches and a third considered as a minor landslide. The most important is the "Cerro Papas rock-avalanche" which occurred on its western slope. The "Ailinco rock-avalanche" is situated on

  13. Los ensayos

    Directory of Open Access Journals (Sweden)

    Beatriz Caballero

    2003-01-01

    Full Text Available Después de Suramérica, tierra del hombre y Latinoamérica, un mundo por hacer, al tiempo que papá es Swann, periodista, liberal, político, está escribiendo ensayo: en el 45 El nuevo príncipe, en el 47 el Breviario del Quijote. En el 48 asiste en Sevilla a la Asamblea Cervantina como delegado de la Academia Colombiana de la Lengua donde presenta y es publicada su Contribución de la crítica colombiana al estudio de Cervantes. En el 49 se edita Cartas colombianas, en el 50 Ancha es Castilla , en el 52 los Sueños gramaticales de Luciano Pulgar, en el 57 Americanos y europeos y en el 60 Historia privada de los colombianos. Los campesinos es una recopilación de notas periodísticas que puede considerarse un ensayo sobre la preocupación por el campo, y Yo, el alcalde del 72 puede considerarse un tratado sobre la administración municipal.

  14. Pucarilla-Cerro Tipillas volcanic complex: the oldest recognized caldera in the southeastern portion of central volcanic zone of Central Andes?

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, Silvina; Petrinovic, Ivan [CONICET -IBIGEO. Museo de Cs. Naturales, Universidad de Salta, Mendoza 2 (4400), Salta (Argentina)], E-mail: guzmansilvina@gmail.com

    2008-10-01

    We recognize the most eastern and oldest collapse caldera structure in the southern portion of the Central Volcanic Zone of the Andes. A description of Middle-Upper Miocene successions related to explosive- effusive events is presented. The location of this centre close to Cerro Galn Caldera attests a recurrence in the volcanism between 12 and 2 Ma in this portion of the Altiplano - Puna Plateau.

  15. Seismic activity at the Cerro Prieto Geothermal Area (Mexico) from August 1994 to December 1995, and its relationship with tectonics and fluid exploitation

    Science.gov (United States)

    Fabriol, H.; Munguía, L.

    A continuous monitoring of the Cerro Prieto geothermal field was carried out from August 1994 to December 1995 to investigate the seismicity of tectonic origin and the seismicity triggered by exploitation activities. Hypocenters for 148 events were located mainly around the northern end of the Cerro Prieto fault and within the geothermal zone. The estimated focal depths range mostly from 1 to 6 km, for earthquakes with magnitudes from 0.5 to 4.6. It was difficult to distinguish between natural and triggered seismicity. We observed a single case of an earthquake for which a correlation in time and space seems plausible with a sharp increase of fluid injection in a well located at less than 1 km from the epicenter. Fault plane solutions of 26 events with magnitudes between 2.8 and 4.6 indicate right-lateral strike-slip motion for earthquakes that occur near the Cerro Prieto and Imperial faults. Inside the geothermal zone, events with normal components of motion were recorded, as expected from the extensional stress regime of the pull-apart basin laying between both faults.

  16. Chemical variations in the Cerro de Mercado (Durango, Mexico) fluorapatite: Assessing the effect of heterogeneity on a geochronologic standard.

    Science.gov (United States)

    Boyce, J. W.; Hodges, K. V.

    2001-12-01

    Despite the lack of an official pronouncement, the fluorapatite of Cerro de Mercado, Durango, Mexico has become the de facto standard for (U-Th)/He geochronology. In addition to being relatively inclusion-free and easily obtained, these crystals are commonly in excess of 5mm in diameter, permitting the removal of the outer skin of the crystal, theoretically eliminating the alpha-ejection correction. However, bulk analyses of the Durango fluorapatite indicate a substantial variation in U and Th concentrations from aliquot to aliquot (167-238 ppm Th; 9.7-12.3 ppm U, [1]). If similar variations were to occur on the sub-grain scale, small fragments of single crystals could contain helium excesses or deficiencies due to alpha-ejection exchange between zones with varying parent element content. We have performed a series of experiments to quantify the intra-grain variation in U and Th, in order to model the effect of this variation on ages determined on Durango fluorapatite. X-ray maps show concentric zonation in U and Th, with similar, but more apparently pronounced zonation in Si and Cl. Preliminary laser-ablation ICPMS data indicate, not surprisingly, that intra-grain variations in U and Th concentrations obtained by analysis of ~35 μ m spots are larger than that which had been previously obtained by bulk analytical techniques (with overall concentrations greater than for bulk analyses). Thus far, analyses yield U concentrations varying from 11 to 16 ppm, and Th concentrations ranging from 220 to 340 ppm. Modeling underway suggests that parent element variations on the order of 50%, such as those observed, and the resulting differential alpha-exchange could lead to several percent error in age, for ~100 μ m fragments. The effect scales inversely with fragment size, with 300 μ m fragments (roughly the size of a large, single grain analysis) having only ~1% error. This may offer an explanation for the previously observed inability to reproduce ages for the Durango

  17. Estratigrafía, análisis de facies y paleoambientes de la formación cañadón asfalto en el depocentro jurásico cerro Cóndor, provincia del Chubut

    Directory of Open Access Journals (Sweden)

    Nora Cabaleri

    2010-05-01

    Full Text Available El depocentro Cerro Cóndor representa la secuencia estratigráfica del Jurásico continental más completa de la cuenca de Cañadón Asfalto y de Sudamérica austral. Se sitúa en la Patagonia extraandina, en ambas márgenes del río Chubut medio. La sedimentación en esta cuenca pull apart, acompañada por efusiones de basalto olivínico, comenzó en el Jurásico Medio temprano. Predominan en la Formación Cañadón Asfalto los depósitos lacustres caracterizados por asociaciones de facies carbonáticas y siliciclásticas intercaladas con rocas lávicas en la base y depósitos piroclásticos hacia el techo de la unidad. Se describe el desarrollo de facies a lo largo de un corte norte-sur que abarca las secciones de estancia El Torito y de los cañadones Los Loros, Las Chacritas, Carrizal, Asfalto y Lahuincó. Las facies/microfacies carbonáticas están representadas por mudstones, wackestones,packstones, grainstones y calizas microbialíticas características de ambientes litorales, marginales y palustres. En la Formación Cañadón Asfalto se distinguen un miembro inferior (Las Chacritas, constituido por calizas, lutitas, areniscas y conglomerados, intercalados con basaltos olivínicos y por otro superior (Puesto Almada compuesto por tobas, tufitas, lutitas y areniscas. El primero es portador de una asociación palinológica de edad bajociano-bathoniana y el segundo de dinosaurios de edad tithoniana. Se describen detalladamente e ilustran las secciones estratigráficas de ambos miembros de la formación en sus localidades tipo, cañadón Las Chacritas y estancia el Torito y se reconstruyen los paleoambientes del depocentro desde el Aaleniano al Tithoniano. La edad del miembro Puesto Almada en su localidad tipo se obtuvo mediante una datación radimétrica (K/Ar de biotitas provenientes de una delgada capa de toba volcánica (147,1 ± 3,3 Ma, Tithoniano proveniente de la parte superior de la unidad.

  18. Los inmigrados

    Directory of Open Access Journals (Sweden)

    Lojze Kovačič

    2007-12-01

    Full Text Available Lojze Kovačič nació el 9 de noviembre de 1928 en Basilea, Suiza, en una familia de emigrantes, de madre alemana y padre esloveno. En 1938, cuando las autoridades suizas expulsaron del país a todos los emigrantes que no tenían ciudadanía suiza, se fue a vivir con su familia a Eslovenia, primero a Novo mesto, luego a Ljubljana donde frecuentó la escuela primaria, secundaria y la academia de pedagogía. Vivió en Ljubljana donde trabajó primero como periodista y luego como pedagogo. Murió el 1 de mayo de 2004 en la capital eslovena. Escribió obras autobiográficas y de ficción: Ljubljanske razglednice / Postales de Ljubljana (1956, Ključi mesta / Las llaves de la ciudad (1967, Deček in smrt / El niño y la muerte (1968, Sporočila v spanju – Resničnost / Mensajes en el sueño – Realidad (1972, Pet fragmentov / Cinco fragmentos (1981, Pri{leki / Los inmigrados (trilogía 1983–85, Basel / Basilea (1986, Prah / Polvo (1988, Kristalni čas / Tiempo de cristal (1990, Zgodbe s panjskih končnic / Relatos de las tablas de la colmena (1992, Knji`evna delavnica – {ola pisanja / Taller de literatura – escuela de la escritura (1997. A continuación se presentan dos fragmentos de la primera parte de la trilogía Pri{leki / Los inmigrados, una historia marcadamente autobiográfica del retorno a Eslovenia de una familia desalojada de Basilea, narrada a través de la voz de un niño de diez años, traducida al castellano por Xavier Farré y publicada por la editorial Siruela de Madrid en 2007.

  19. Los Wayuu

    OpenAIRE

    Vásquez Hernán De Correa, Socorro; Investigadores Departamento de Antropología. Universidad Javeriana Este artículo hace parte de una investigación realizada para el Instituto Colombiano de Cultura Hispánica, 1991.

    2004-01-01

    Estar presentes hoy, luego de estos 500 años, le ha significado a los Wayuú, indígenas habitantes de la Península de La Guajira; pasar por profundos cambios culturales que han sido la urdimbre que ha sostenido su cultura y la ha fortalecido permitien­do la supervivencia misma del pueblo Wayuú, el cual no fue sometido, redu­cido o aniquilado como otros pueblos aborígenes del continente, y por el contrario ha consolidado en su terri­torio unas formas de vida propia y de convivencia con la socie...

  20. The Characterization of Biotic and Abiotic Media Upgradient and Downgradient of the Los Alamos Canyon Weir

    Energy Technology Data Exchange (ETDEWEB)

    P.R. Fresquez

    2006-01-15

    As per the Mitigation Action Plan for the Special Environmental Analysis of the actions taken in response to the Cerro Grande Fire, sediments, vegetation, and small mammals were collected directly up- and downgradient of the Los Alamos Canyon weir, a low-head sediment control structure located on the northeastern boundary of Los Alamos National Laboratory, to determine contaminant impacts, if any. All radionuclides ({sup 3}H, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, {sup 90}Sr, {sup 241}Am, {sup 234}U, {sup 235}U and {sup 238}U) and trace elements (Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, and Tl) in these media were low and most were below regional upper level background concentrations (mean plus three sigma). The very few constituents that were above regional background concentrations were far below screening levels (set from State and Federal standards) for the protection of the human food chain and the terrestrial environment.

  1. El hábitat carpetano del cerro del Gollino (Corral de Almaquer, Toledo)

    OpenAIRE

    Santos Velasco, Juan Antonio; Perea Caveda, Alicia; Lourdes PRADOS TORREIRA

    1998-01-01

    Los resultados de las dos campañas de excavación en el yacimiento han permitido la identificación de un gran hábitat amurallado datable entre fines del siglo III a. C. y el primer tercio del siglo I a. C., que aporta datos significativos sobre el proceso de romanización de la Carpetania. Les fouilles qui ont eu lieu dans cet oppidum permettent dater le gisement entre la fin du IIIème et le premier tiers du Ier siècle av.C., et offrent des éléments pour comprendre le procès d'aculturation d...

  2. Reproductive structures of Rhamnaceae from the Cerro del Pueblo (Late Cretaceous, Coahuila) and Coatzingo (Oligocene, Puebla) Formations, Mexico.

    Science.gov (United States)

    Calvillo-Canadell, Laura; Cevallos-Ferriz, Sergio R S

    2007-10-01

    Recently discovered fossil flowers from the Cretaceous Cerro del Pueblo and flowers and fruits from the Oligocene Coatzingo Formations are assigned to the Rhamnaceae. The Cretaceous flower, Coahuilanthus belindae Calvillo-Canadell and Cevallos-Ferriz, gen. et sp. nov., is actinomorphic with fused perianth parts forming a slightly campanulate to cupulate floral cup, with sepals slightly keeled and spatulate clawed petals. The Oligocene fossils include Nahinda axamilpensis Calvillo-Canadell and Cevallos-Ferriz, gen. et sp. nov. (characterized by its campanulate bisexual flower with stamens opposite, adnate to and enfolded by petals; and with the ovary ripening into a drupe), and a winged fruit assigned to Ventilago engoto Calvillo-Canadell and Cevallos-Ferriz, sp. nov. The flowers and drupe features indicate closer affinity to Zizipheae and/or Rhamneae, while the single samaroid fruit suggests the presence of Ventilagineae. However, the unique character combination in the fossil flowers precludes placing them in extant genera. Nevertheless, the history of the family is long and can be traced back to the Campanian. A detailed phylogenetic revision of the group that uses morphological characters from both extant and fossil plants is needed to better understand the significance of these records as well as other important fossils of the family.

  3. Effects of pressure drawdown and recovery on the Cerro Prieto beta reservoir in the CP-III area

    Energy Technology Data Exchange (ETDEWEB)

    Truesdell, A.H. [Truesdell (Alfred H.), Menlo Park, CA (United States); Lippmann, M.J. [Lawrence Berkeley National Lab., CA (United States)

    1998-02-01

    The production characteristics of wells in the northwestern Cerro Prieto III area changed greatly when the Cp-III power plant went on line in 1986. Fluid extraction in the field more than doubled and reservoir-wide boiling started immediately, greatly increasing the enthalpy of produced fluids. Some well fluids showed a decrease in chloride due to adiabatic steam condensation in the well and separator, and others were enriched in chloride due to boiling. As reservoir drawdown increased, entrance of cooler and more dilute groundwaters into the reservoir became evident (i.e., condensation stopped, and there was a decrease in enthalpy and chloride in produced fluids). Although some groundwater inflow was from the leaky western margin of the reservoir, the majority is in the northeast, inferred to be local and downward, possibly through more permeable zones associated with the normal fault H. This natural recharge and some reinjection have slowed and possibly reversed pressure drawdown throughout CP-III. Enthalpy has decreased and liquid saturation has increased as the steam-rich zone in the upper part of the reservoir has either disappeared or become thinner.

  4. Monitoring and modeling land subsidence at the Cerro Prieto Geothermal Field, Baja California, Mexico, using SAR interferometry

    Science.gov (United States)

    Carnec, Claudie; Fabriol, Hubert

    Images derived from repeat-pass spaceborne interferometric synthetic aperture radar (InSAR) systems offer the possibility of mapping surface deformation of small spatial extent and monitoring its spatio-temporal evolution. A slow local subsidence has been detected at the Cerro Prieto geothermal field from images acquired by the European Space Agency remote sensing satellites ERS-1/2 between 1993 and 1997. Although agricultural activity in the area limited the investigation, interferometric monitoring revealed that the ground deformation is associated with the withdrawal of geothermal fluid and agreed with the leveling data. Modeling of the subsidence was carried out assuming elastic deformation in a half-space from simple point sources, of which five were necessary to reproduce the fringe patterns observed on the interferograms. The depths and locations of three of the sources are compatible with the location of the known reservoir. The study improves prior knowledge of the displacement field and of the mecanisms involved in the subsidence phenomenon.

  5. Palynological analysis of camelid coprolites: seasonality in the use of the site Cerro Casa de Piedra 7 (Santa Cruz, Argentina)

    Science.gov (United States)

    Velázquez, Nadia Jimena; Burry, Lidia Susana; Fugassa, Martín Horacio; Civalero, María Teresa; Aschero, Carlos Alberto

    2014-01-01

    Palynological, palaeoparasitological and paleobotanical studies of coprolites found in archaeological sites from Perito Moreno National Park (47°57‧S72°05‧W) yielded information on diet, palaeoenvironment and health. These studies allowed adding evidence to the reconstruction of life history of the hunter-gatherers that inhabited Patagonia during the Holocene. We examined the season of the year when camelid Lama guanicoe coprolites (5400 ± 64 yr 14C BP to 9640 ± 190 yr 14C BP) were deposited at Cerro Casa de Piedra 7 (site CCP7). The study used palynological evidence and comparison with pollen spectra of modern feces collected during summer, fall, winter and spring of 2010. The dominant types were: pollen of Nothofagus, Empetrum rubrum, Asteraceae subfam. Asteroideae, Nassauvia, Caryophyllaceae and Poaceae; fern spores; remains of Eimeria macusaniensis; and plant remains of Poaceae, Festuca pallescens, Stipa speciosa, Armeria maritima, Gaultheria mucronata and E. rubrum. Pollen spectra of modern and fossil feces were used for multivariate analysis. Coprolites associated to fall and winter modern feces. These results and those obtained from pollen concentration values and the presence of pollen types indicators of seasonality, allowed the determination of summer, fall and winter coprolites. However, caution must be taken with the seasonality results of coprolites dated earlier than 9000 years BP since the environmental conditions differed from now. The site was probably a camelid shelter during the unfavorable seasons.

  6. The Cerro Bitiche Andesitic Field: petrological diversity and implications for magmatic evolution of mafic volcanic centers from the northern Puna

    Science.gov (United States)

    Maro, Guadalupe; Caffe, Pablo J.

    2016-07-01

    The Cerro Bitiche Andesitic Field (CBAF) is one of the two largest mafic volcanic fields in northern Puna (22-24° S) and is spatially and temporally associated with ignimbrites erupted from some central Andean Altiplano-Puna Volcanic Complex calderas. The CBAF comprises seven scoria cones and widespread high-K calcalkaline lava flows that cover an area of 200 km2. Although all erupted rocks have a relatively narrow chemical range (56-62 % SiO2, 3-6 % MgO), there is a broad diversity of mineral compositions and textures. The least evolved lavas (˜58-61 % SiO2) are high-Mg andesites with scarce (andesites (˜62 wt% SiO2), on the other hand, are porphyritic rocks with plagioclase + orthopyroxene + biotite and ubiquitous phenocryst disequilibrium textures. These magmas were likely stored in crustal reservoirs, where they experienced convection caused by mafic magma underplating, magma mixing, and/or assimilation. Trace element and mineral compositions of CBAF lavas provide evidence for complex evolution of distinct magma batches.

  7. Astronomical orientations in the Iberian oppidum of Cerro de las Cabezas (Valdepeñas, Ciudad Real

    Directory of Open Access Journals (Sweden)

    César Esteban

    2017-01-01

    Full Text Available We present an archaeoastronomical analysis of the orientations observed in the entrance-sanctuary and other enclosures at the Iberian oppidum Cerro de las Cabezas (Valdepeñas, Ciudad Real, Spain, located in the northern Oretania. The most important result of this work is that two of the perimeter walls of the entrance-sanctuary are oriented towards the sunrise, one at the equinoxes and the other at the summer solstice. As in other Iberian sanctuaries, an equinoctial marker is also found. This coincides with the top of one of the most distant mountains of the horizon. The possibility that other walls of the entrance-sanctuary may be oriented to the rising of several of the brightest stars in the sky is also discussed. Moreover, it is found that the east-west axis of the southern part of the oppidum (where an enclosure that some authors have interpreted as a possible sanctuary is located is oriented approximately toward the sunrise at the winter solstice. Finally a possible alignment between the entrance-sanctuary, a necropolis located at the east and the point of the horizon where the sunrise of the winter solstice occurs is also reported.

  8. Estudios sedimentológicos en los depósitos carboníferos y pérmicos del borde occidental de la puna Sedimentological study of Carboniferous and Permian deposits on the western edge of the Puna

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior y a las calizas marinas de la Formación Arizaro (Pérmico Inferior. La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución.The study of Carboniferous - Permian deposits exposed in the south-west of Salar del Rincón, on the western edge of

  9. Mejorando la preparación ante desastres en el Perú : ¿en qué medida se identifican y se aplican las lecciones aprendidas de los simulacros?

    OpenAIRE

    2015-01-01

    La presente investigación evalúa el aporte de ejercicios de preparación para desastres al nivel distrital en el Perú (simulacros) al mejoramiento de planes y políticas distritales, provinciales, regionales y nacionales para la preparación, reacción y respuesta ante los desastres. A través de un estudio de caso de un simulacro para la respuesta ante tsunamis en Cerro Azul, Cañete, de 2011 a 2012, este trabajo analiza hasta qué punto el marco para los ejercicios de respuesta f...

  10. Hydrothermal-flow regime and magmatic heat source of the Cerro Prieto geothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.

    1982-01-01

    This detailed three-dimensional model of the natural flow regime of the Cerro Prieto geothermal field, before steam production began, is based on patterns of hydrothermal mineral zones and light stable isotopic ratios observed in rock samples from more than fifty deep wells, together with temperature gradients, wireline logs and other data. At the level so far penetrated by drilling, this hydrothermal system was heated by a thermal plume of water close to boiling, inclined at 45/sup 0/, rising from the northeast and discharging to the west. To the east a zone of cold water recharge overlies the inclined thermal plume. Fission track annealing studies shows that the reservoir reached 170/sup 0/C only 10/sup 4/ years ago. Oxygen isotope exchange data indicate that a 12 km/sup 3/ volume of rock subsequently reacted with three times its volume of water hotter than 200/sup 0/C. Averaged over the duration of the heating event this would require a flow velocity of about 6 m/year through the pores of a typical cross section of the reservoir having an average porosity of 10%. Although this is an extensional tectonic environment of leaky transform faulting in which repeated intrusions of basalt magma are likely, for simplicity of computation possible heat sources were modelled as simple two dimensional basalt intrusions of various sizes, shapes and locations. We have calculated a series of two-dimensional convective heat transfer models, with different heat sources and permeability distributions. The models which produce the best fit for the temperature distributions observed in the field today have in common a heat source which is a funnel-shaped basalt intrusion, 4 km wide at the top, emplaced at a depth of 5 km to 6 km about 40,000 to 50,000 years ago.

  11. Magmatismo ácido del mioceno superior-cuaternario en el área de Cerro Blanco-La Hoyada, Puna Austral

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    María Carolina Montero López

    2010-11-01

    Full Text Available El volcanismo de composición ácida desarrollado en la Puna Austral entre el Mioceno superior y el Holoceno está representado en el extremo oriental de la cordillera de San Buenaventura (26°25'-27°00'S y 67°25'-67°50' O por dos unidades: Ignimbrita Aguada Alumbrera y Complejo Volcánico Cerro Blanco. Hacia el norte y noroeste de esta área afloran flujos piroclásticos (Ignimbrita Rosada cuyo análisis se presenta aquí a fines comparativos. Estas rocas volcánicas apoyan sobre un basamento metamórfico de mediano a alto grado con intrusivos del Neoproterozoico-Paleozoico inferior y rocas volcánicas de composición intermedia de ca. 9-7 Ma. Las rocas estudiadas abarcan un lapso entre el Mioceno superior (Ignimbrita Aguada Alumbrera e Ignimbrita Rosada hasta el Holoceno (Complejo Volcánico Cerro Blanco, tienen afinidad calcoalcalina y son principalmente de composición riolítica. En este estudio se presentan nuevos datos de campo que permiten ordenar la estratigrafía del sector de estudio, así como resultados de geoquímica. Las ignimbritas del Mioceno Superior-Plioceno estudiadas presentan características similares a las rocas ácidas aflorantes al oeste del área de estudio, las cuales fueron relacionadas por diversos autores a un ambiente de subducción procedentes de fuentes mantélicas con altos porcentajes de contaminación cortical, mientras que el Complejo Volcánico Cerro Blanco podría estar reflejando su procedencia de la fusión directa de la corteza, si bien esta hipótesis debe ser corroborada con mayor cantidad de datos geoquímicos.

  12. Chemical and mineralogical analyses of a weathering mantle developing on peridotite of the mining area for nickel in Cerro Matoso, Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, C.M.; Fabris, J.D. [Departamento de Quimica, UFMG (Brazil)], E-mail: claudiag@dedalus.lcc.ufmg.br, E-mail: fabris@dedalus.lcc.ufmg.br; Pacheco Serrano, W.A. [Departamento de Fisica (Colombia)], E-mail: wpacheco@donato.uptc.edu.co

    1999-11-15

    Four samples were collected at several depths in a weathering mantle developing on peridotite, found in a mining area for nickel of Cerro Matoso, about 20 km southwest of Monte Libano, Department of Cordoba, Colombia. Samples represent the main stratigraphy of the mantle. Powder X-ray diffractometry, RT Moessbauer spectroscopy, saturation magnetization measurements and conventional chemical analysis on the whole and chemically treated samples, and on some of their magnetic extracts, were used to give some details of the main occurring mineralogical phases in the mantle, particular of the magnetic iron oxides.

  13. Estudios sedimentológicos en los depósitos carboníferos y pérmicos del borde occidental de la puna

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    Claudia Inés Galli

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior y a las calizas marinas de la Formación Arizaro (Pérmico Inferior. La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución.

  14. Arquitectura rural de un pueblo en el borde del páramo de los Torozos. Urueña y sus construcciones auxiliares.

    OpenAIRE

    Abril Revuelta, Oscar

    2015-01-01

    Urueña es una pequeña localidad vallisoletana ubicada en un lugar especial, donde el páramo termina y comienza la gran llanura de Tierra de Campos, convirtiéndose en un mirador de bellas puestas de sol. Sobre ese borde accidentado se asientan las paredes del Castillo y la Muralla que rodean a la localidad. Su término municipal se extiende parte por la paramera, parte por los cerros y parte por el valle, donde aparece la ermita románica en honor a la Virgen de la Anunciada, patrona del pueb...

  15. Los árboles

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    Jaime Paredes Pardo

    1964-09-01

    Full Text Available Los árboles son hijos del viento que transporta las semillas. En los valles anda de prisa, tanto que a veces alcanza a los trenes y a la melena de los caballos que espanta la algarabía de los pasajeros. Como los trenes, el viento tiene una frente de humo. De niebla como las montañas. ¿Pensará el viento?

  16. Los Ritos de paso entre los bubi

    OpenAIRE

    Eteo Soriso, José Francisco

    2014-01-01

    Los ritos de paso entre los bubi es una etnografía sobre los rituales de nacimiento y de muerte entre los bubi de la isla de Bioko, Guinea Ecuatorial (África central). Está estructurada en dos partes: una etnográfica general y otra centrada en la ritualidad. La primera ofrece un marco suficientemente amplio sobre la sociedad bubi que permite introducir la segunda parte más específica sobre estructuras rituales. Los capítulos etnográficos introductorios se centran en algunos temas clave de la ...

  17. TECNOLOGÍA Y SUBSISTENCIA EN EL SITIO ARQUEOLÓGICO CERRO TAPERA VÁZQUEZ (PARQUE NACIONAL PRE-DELTA, REPÚBLICA ARGENTINA

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    Mariano Bonomo

    2014-10-01

    Full Text Available In this paper the results of the studies carried out on ceramic and bone materials recorded at Cerro Tapera Vázquez site (Argentinean Northeast are presented. Taxonomic, anatomic and taphonomic studies of bone assemblages and technological-decorative analysis and refitting of pottery were undertaken. The site is located on a mound next to El Ceibo Creek, where 16 m2 were excavated in 2008. Abundant smooth, incised and modeled pottery (handles and zoomorphic appendages and numerous bones remains of Myocastor coypus (most frequent taxon, Blastocerus dichotomus, Ozotoceros bezoarticus, Cavia aperea, Leopardus geoffroyi, Lycalopex gymnocercus, Hydrochaeris hydrochaeris, birds and fish (Siluriformes and Characiformes were recorded. Except Cavia aperea rodent and Dusicyon gimnocercus fox, all taxa show evidence of anthropic modification (cut marks, fresh fractures and burning. Two radiocarbon dates were obtained: 650 and 520 yrs. BP. The results reached in this study lead to the conclusion that the pre-Hispanic populations that occupied Cerro Tapera Vázquez by the end of the Late Holocene were riverine canoe peoples, with complex ceramic technology and subsistence based on hunting of coypu, capybara and cervids, fishing and small-scale horticulture.

  18. Geochemistry of the Neoproterozoic (800-767 Ma) Cerro Bori orthogneisses, Dom Feliciano Belt in Uruguay: tectonic evolution of an ancient continental arc

    Science.gov (United States)

    Lenz, C.; Porcher, C. C.; Fernandes, L. A. D.; Masquelin, H.; Koester, E.; Conceição, R. V.

    2013-10-01

    The Cerro Bori orthogneisses, crystallized between ca. 800 and 767 Ma, are composed of a sequence of mafic gneisses, with dioritic-gabbroic and dioritic composition tectonically interleaved with a sequence of tonalitic and granodioritic gneisses. These rocks intruded the Chafalote paragneisses (metapelites, semipelites, carbonate and mafic rocks) and they were metamorphosed of high P-T conditions at ca. 676-654 Ma. This paper presents the first major and trace geochemical signatures, as well as Sm and Pb isotopic composition for the Cerro Bori orthogneisses, which allow distinguishing three different groups of rocks. Type I rocks are mafic gneisses with tholeiitic affinity, whereas the Type II rocks are tonalitic and granodioritic gneisses with calc-alkaline affinity. The third type is composed of biotite-rich mafic gneisses with potassic and ultrapotassic affinities. All the three types of rocks have negative ℰND values (between -2.12 and -6.67) and old TDM ages (between 1.2 and 2.0 Ga), indicating that the process of crustal assimilation/contamination was an important process, together with fractional crystallization. An continental arc tectonic setting is suggested to this association of rocks between 800 and 767 Ma. This subduction suggests the existence of an ocean between Rio de La Plata and adjacent cratons during the break up of the Rodinia supercontinent.

  19. Rock-magnetism and ore microscopy of the magnetite-apatite ore deposit from Cerro de Mercado, Mexico

    Science.gov (United States)

    Alva-Valdivia, L. M.; Goguitchaichvili, A.; Urrutia-Fucugauchi, J.; Caballero-Miranda, C.; Vivallo, W.

    2001-03-01

    Rock-magnetic and microscopic studies of the iron ores and associated igneous rocks in the Cerro de Mercado, Mexico, were carried out to determine the magnetic mineralogy and origin of natural remanent magnetization (NRM), related to the thermo-chemical processes due to hydrothermalism. Chemical remanent magnetization (CRM) seems to be present in most of investigated ore and wall rock samples, replacing completely or partially an original thermoremanent magnetization (TRM). Magnetite (or Ti-poor titanomagnetite) and hematite are commonly found in the ores. Although hematite may carry a stable CRM, no secondary components are detected above 580°, which probably attests that oxidation occurred soon enough after the extrusion and cooling of the ore-bearing magma. NRM polarities for most of the studied units are reverse. There is some scatter in the cleaned remanence directions of the ores, which may result from physical movement of the ores during faulting or mining, or from perturbation of the ambient field during remanence acquisition by inhomogeneous internal fields within these strongly magnetic ore deposits. The microscopy study under reflected light shows that the magnetic carriers are mainly titanomagnetite, with significant amounts of ilmenite-hematite minerals, and goethite-limonite resulting from alteration processes. Magmatic titanomagnetites, which are found in igneous rocks, show trellis, sandwich, and composite textures, which are compatible with high temperature (deuteric) oxy-exsolution processes. Hydrothermal alteration in ore deposits is mainly indicated by martitization in oxide minerals. Grain sizes range from a few microns to >100 mm, and possible magnetic state from single to multidomain, in agreement with hysteresis measurements. Thermal spectra, continuous susceptibility measurements, and IRM (isothermal remanent magnetization) acquisition suggest a predominance of spinels as magnetic carriers, most probably titanomagnetites with low

  20. Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de la Muerte, Costa Rica.

    Science.gov (United States)

    Avalos, Gerardo; Soto, Alejandra; Alfaro, Willy

    2012-03-01

    Although sugar-water feeders are commonly used by enthusiasts to attract hummingbirds, little is known about how they affect hummingbird behavior and flower use. We studied the highland hummingbird assemblage of Cerro de La Muerte, Costa Rica, both at a site with permanent feeders (La Georgina Restaurant) and further from it. We examined how feeder use and monopolization affected seasonal changes in pollen loads during four sampling periods, including dry and wet seasons, from 2003-2005. We expected that species monopolizing the feeders would carry little or no pollen whatsoever, and would have pollen loads characterized by low floral diversity, in contrast with species less dependent on feeders. We obtained pollen samples from 183 individuals of four hummingbird species captured around the feeders using mist nets, which were compared with a pollen reference collection of plants with a pollination syndrome by hummingbirds. The same methods were implemented at a site 3km away from the feeders. Feeder usage was quantified by counting the number of times hummingbirds drank from the feeders in periods of 4min separated by 1min. The effects of hummingbird species and season on pollen load categories were assessed using a nominal logistic regression. The alpha species at the site, the Fiery-throated Hummingbird (Panterpe insignis), dominated the feeders during the dry season. Meanwhile, in the wet season, feeder usage was more evenly distributed across species, with the exception of the Volcano Hummingbird, Selasphorus flammula, which occupies the last place in the dominance hierarchy. Pollen loads of hummingbirds captured near feeders were low in abundance (more than 50% of captured individuals had zero or low pollen loads), and low in species richness (96% of the hummingbirds with pollen from only one plant genus, Centropogon). Overall pollen loads increased during the dry season coinciding with peaks in flower availability, although the majority of captured

  1. Recycling of water, carbon, and sulfur during subduction of serpentinites: A stable isotope study of Cerro del Almirez, Spain

    Science.gov (United States)

    Alt, Jeffrey C.; Garrido, Carlos J.; Shanks, Wayne C.; Turchyn, Alexandra; Padrón-Navarta, José Alberto; López Sánchez-Vizcaíno, Vicente; Gómez Pugnaire, María Teresa; Marchesi, Claudio

    2012-01-01

    We use the concentrations and isotope compositions of water, carbon, and sulfur in serpentinites and their dehydration products to trace the cycling of volatiles during subduction. Antigorite serpentinites from the Cerro del Almirez complex, Spain, contain 9–12 wt.% H2O and 910 ± 730 ppm sulfur, and have bulk δ18O values of 8.6 ± 0.4‰, δD = − 54 ± 5‰, and δ34S = 5.0‰, consistent with serpentinization at temperatures of ~ 200 °C by seawater hydrothermal fluids in a seafloor setting. The serpentinites were dehydrated to chlorite–harzburgite (olivine + orthopyroxene + chlorite) at 700 °C and 1.6–1.9 GPa during subduction metamorphism, resulting in loss of water, and sulfur. The chlorite–harzburgites contain 5.7 ± 1.9 wt.% H2O, and have bulk δ18O = 8.0 ± 0.9‰, and δD = − 77 ± 11‰. The rocks contain 650 ± 620 ppm sulfur having δ34S = 1.2‰. Dehydration of serpentinite resulted in loss of 5 wt.% H2O having δ18O = 8–10‰ and δD = − 27 to − 65‰, and loss of 260 ppm sulfur as sulfate, having δ34S = 14.5‰. The contents and δ13C of total carbon in the two rock types overlap, with a broad trend of decreasing carbon contents and δ13C from ~ 1300 to 200 ppm and − 9.6 to − 20.2‰. This reflects mixing between reduced carbon in the rocks (210 ppm, δ13C ≈ − 26‰) and seawater-derived carbonate (δ13C ≈ − 1‰). Our results indicate: 1) Serpentinized oceanic peridotites carry significant amounts of isotopically fractionated water, carbon and sulfur into subduction zones; 2) Subduction of serpentinites to high P and T results in loss of water, and sulfur, which can induce melting and contribute to 18O, D, and 34S enrichments and oxidation of the sub-arc mantle wedge; and 3) Isotopically fractionated water, carbon, and sulfur in serpentinite dehydration products are recycled deeper into the mantle where they can contribute to isotope heterogeneities and may be significant for volatile budgets of the deep Earth.

  2. Los pesticidas y los recursos costeros.

    Directory of Open Access Journals (Sweden)

    Evenor Martínez González.

    1998-10-01

    Full Text Available Los recursos costeros son de gran importancia para los países ribereños. Tanto la pesca como la acuicultura son actividades que generan divisas y dan empleo a una gran cantidad de personas. En nuestro país, la agricultura siempre ha sido dependiente del uso de los agroquímicos. Esta práctica, sumada al mal manejo de los suelos agrícolas y al despale en pendiente, ha tenido efectos negativos importantes en nuestros recursos acuáticos, la sedimentación. Los plaguicidas han contaminado a moluscos (conchas negras, peces y crustáceos (jaibas y camarones. En estos organismos los pesticidas se han acumulado causando su muerte.

  3. Bioestratigrafía de los materiales plio-cuaternarios del borde norte de la depresión de Granada

    Directory of Open Access Journals (Sweden)

    Vera, J. A.

    1990-08-01

    Full Text Available Four new sites of vertebrates are described in the continental deposits of the Granada basin. The dates obtained provide sorne new boundaries of age. The sites are located in the fifth depositional sequence distinguished by Rodríguez-Femández et al. (1989 in the infilling of the basin. Two of them (Cortijo de las Nieves and Cerro Parejo are placed near to the base of the mentioned sequence and belong to the lower Pleistocene and the other two situated c10se to the top correspond to the middle Pleistocene. This fifth depositional sequence represent the last depositional unit of the infilling of the basin. During upper Pleistocene time, as in the Guadix-Baza basin happens, a general erosion proccess took place, and the recent fluvial network was established.Se describen cuatro nuevos yacimientos de vertebrados en los materiales continentales de la Depresión de Granada. Las dataciones obtenidas permiten introducir unos jalones de edad en los mismos, de los que hasta ahora no se disponían. Los yacimientos se localizan en el seno de la quinta secuencia deposicional de las diferenciadas (Rodríguez-Femández et al., 1989 en los materiales de relleno de la depresión. Dos de ellos (Cortijo de las Nieves y Cerro Parejo se emplazan hacia el muro de dicha secuencia y datan del Pleistoceno inferior. Los otros dos se sitúan hacia la parte más alta de la misma y son del Pleistoceno medio. Esta quinta secuencia deposicional constituye la última unidad deposicional del relleno de la depresión, inmediatamente anterior al encajamiento de la red fluvial actual y al inicio de la erosión generalizada de la misma, evento que acaeció dentro del Pleistoceno superior, de manera análoga a la Depresión de Guadix-Baza.

  4. Chatkalita, nekrasovita y otros minerales del grupo de la estannita de Veta María Eugenia, Cerro Atajo, Catamarca Chatkalita, nekrasovita y otros minerales del grupo de la estannita de veta María Eugenia, Cerro Atajo, Catamarca

    Directory of Open Access Journals (Sweden)

    M. F. Márquez-Zavalía

    2007-06-01

    Full Text Available En veta María Eugenia, Cerro Atajo, Catamarca, se encontró una asociación de minerales de estaño integrada por: chatkalita Cu6Fe2+Sn2S8, nekrasovita Cu26V2(Sn,As,Sb6S32, colusita Cu26V2(As,Sn,Sb6S32, kësterita Cu2(Zn,FeSnS4 y estannoidita Cu8(Fe,Zn3Sn2S12. Estos minerales, incluidos en watanabeíta, están acompañados principalmente por pirita, esfalerita, calcopirita, tetraedrita, bornita y galena; aikinita, enargita, luzonita, marcasita, arsenopirita y pirrotina participan como minerales accesorios. Chatkalita se presenta en agregados irregulares de hasta 40 µm, asociados con kësterita y estannoidita, es de color rosa-anaranjado claro, birreflectante y anisótropa, con colores de polarización pardos; su composición química (% en peso es: S=29,76-30,37, Fe=4,53-7,92, Cu=39,13-43,21, Zn=0,75-5,53, As=0,19- 2,42, Sn=15,27-20,50 y Sb=0,00-0,32. Nekrasovita es isótropa, de color pardo con leve tinte rosa-violáceo y está asociada con estannoidita; su composición química es: S=30,29-30,63, Fe=3,41-4,75, Cu=44,26-45,70, Zn=0,56-1,00, As=4,18-4,71, Sn=12,53-13,64 y Sb=0,71- 0,77. Colusita es pardo amarillenta, isótropa, se presenta como parches irregulares y cintas discontinuas en tennantita; su composición química es: S=30,59-30,74, Fe=2,18-3,58, Cu=47,22-48,13, Zn=0,21-0,64, As=6,38-6,61, Sn=9,04-9,33 y Sb=0,49-1,66. Kësterita es pardo grisácea, con débil birreflectancia y anisotropía y colores de polarización pardos, a menudo se presenta bordeada por chatkalita; su composición química es: S=28,68-29,14, Fe=1,98-2,14, Cu=31,06-32,51, Zn=9,03-11,57 y Sn=26,39-27,03. Estannoidita es de color castaño, pleocroica (castaño-rosado a pardo-grisáceo y anisótropa con colores de polarización pardos y pardo-amarillentos, ocurre en parches irregulares y como bandas bordeando tennantita; su composición química es: S=29,11-29,83, Fe=8,45-10,30, Cu=38,05-41,01, Zn=3,18-4,90, y Sn=15,84-18,94. La reflectividad y dureza de pulido de

  5. APORTES PALEOBOTÁNICOS EN LA RECONSTRUCCIÓN DE PALEODIETAS. ANÁLISIS DE COPROLITOS DEL CERRO CASA DE PIEDRA, SANTA CRUZ/Palaeobotany contributions in palaeodiets reconstruction. Coprolites analysis of Cerro Casa de Piedra, Santa Cruz.

    Directory of Open Access Journals (Sweden)

    Ana Cecilia Martínez Tosto

    2012-11-01

    Full Text Available Los coprolitos son heces fósiles deshidratadas o mineralizadas que contienen inclusiones orgánicas e inorgánicas. El estudio de las inclusiones de origen vegetal de los coprolitos permite conocer los ítems vegetales consumidos por los organismos e inferir la estacionalidad en el uso del sitio. El objetivo de este trabajo es estudiar el contenido de polen y de microrrestos vegetales de un coprolito humano del sitio CCP7 relacionado a una capa arqueológica fechada en 8920±200 C14 (UGA 7383 años AP. El sitio CCP7 está ubicado en la provincia de Santa Cruz (Argentina en el ecotono bosque-estepa. Se realizaron los análisis polínicos y microhistológicos de los restos vegetales del coprolito. Se identificaron 13 tipos polínicos, tres de ellos pertenecientes a la vegetación del bosque y el resto a la estepa. Mediante el análisis microhistológico se identificaron las especies Azorella monanthos, Empetrum rubrum y Gaultheria mucronata. El análisis simultáneo de la información extraída de los datos palinológicos y de los microhistológicos mostró coincidencias parciales entre el contenido de polen y de restos vegetales, permitiendo reconstruir la porción vegetal de la paleodieta e inferir la época del año en que el hombre que dio origen al coprolito estuvo ocupando el sitio CCP7.   Abstract Coprolites are dehydrated or mineralized fossil feces containing organic and inorganic inclusions. The study of plant inclusions of coprolites allows knowing the vegetable items consumed by organisms and inferring the seasonality in the use of the site. This work aims at studying pollen and plant remains from a human coprolite in the CCP7 site related to an archaeological layer dated from around 8920±200 14C (UGA 7383 years BP. CCP7 is located in the province of Santa Cruz (Argentina within the forest-steppe ecotone. Pollen and microhistological analyses of coprolite plant remains were conducted. Thirteen pollen types were identified: three

  6. A Wildfire Behavior Modeling System at Los Alamos National Laboratory for Operational Applications

    Energy Technology Data Exchange (ETDEWEB)

    S.W. Koch; R.G.Balice

    2004-11-01

    To support efforts to protect facilities and property at Los Alamos National Laboratory from damages caused by wildfire, we completed a multiyear project to develop a system for modeling the behavior of wildfires in the Los Alamos region. This was accomplished by parameterizing the FARSITE wildfire behavior model with locally gathered data representing topography, fuels, and weather conditions from throughout the Los Alamos region. Detailed parameterization was made possible by an extensive monitoring network of permanent plots, weather towers, and other data collection facilities. We also incorporated a database of lightning strikes that can be used individually as repeatable ignition points or can be used as a group in Monte Carlo simulation exercises and in other randomization procedures. The assembled modeling system was subjected to sensitivity analyses and was validated against documented fires, including the Cerro Grande Fire. The resulting modeling system is a valuable tool for research and management. It also complements knowledge based on professional expertise and information gathered from other modeling technologies. However, the modeling system requires frequent updates of the input data layers to produce currently valid results, to adapt to changes in environmental conditions within the Los Alamos region, and to allow for the quick production of model outputs during emergency operations.

  7. Mapping the edge of the Cerros del Rio volcanic field, New Mexico: a piece of the puzzle to understanding a potential geothermal resource

    Science.gov (United States)

    Pellerin, L.; Gallegos, M.; Goebel, M.; Murphy, B. S.; Smith, J.; Soto, D.; Swiatlowski, J.; Volk, C.; Welch, M.; Feucht, D. W.; Hollingshaus, B.; Bedrosian, P. A.; McPhee, D. K.

    2012-12-01

    The Cerros del Rio volcanic field located west of Santa Fe, New Mexico spans the southwestern part of the Espanola Basin with the Rio Grande to the west. Underlying the volcanics are the Santa Fe Group sediments, which contain the Ancha Formation, an important aquifer in the region. High temperature gradients in water wells reveal a potential geothermal prospect. In 2012 the Summer of Applied Geophysical Experience (SAGE) program acquired transient electromagnetic (TEM), audiomagnetotelluric (AMT), gravity and ground magnetic data to determine the buried eastern margin of the volcanic field and the connectivity related to the underlying sediments. The roughly EW 5-km long transect was sited from USGS aeromagnetic data to cross the boundary of the Cerros del Rio volcanic field. TEM data collected at ten stations, at 200-400 m spacing, along the transect employed an in-loop configuration with a square 100 m x 100 m transmitter loop and both a Zonge receiver coil and a 5 m square receiver loop. The 5 m loop allowed for the recovery of early-time data that was saturated when using the Zonge coil. AMT data were acquired at eight stations, at 400-500 m spacing, using the Geometric Stratagem system recording from 92 kHz to 10 Hz; a horizontal magnetic dipole transmitter was used to augment low signal strength at around 1 kHz. Gravity data along the profile were acquired using CG-3 and CG-5 Scintrex gravimeters with a station interval >250 m. Magnetic data were acquired with a Geometrics Cesium vapor G-858 magnetometer for about 3500 m along the profile at a 0.5 second sampling rate. Two volcanic flows interbedded with Ancha Formation and overlying Santa Fe Group sediments were identified in both the TEM and AMT modeling. High surface resistivity zones (>300 ohm-m) with depths ranging from ~100 to 300 m define the volcanic flows and correspond to high densities (2.3 to 2.55 g/cm3), while low resistivity zones (<30 ohm-m) correspond to lower densities (~2.1 g/cm3). High

  8. Un proyecto educativo-cultural socialista: la Fundación Cesáreo del Cerro

    Directory of Open Access Journals (Sweden)

    Francisco de LUIS MARTÍN

    2010-03-01

    Full Text Available RESUMEN: Desde un principio, los trabajos de investigación sobre el socialismo español se han centrado preferentemente en aspectos como su historia política o los grandes debates ideológicos en que se vieron envueltas sus organizaciones. Como acertadamente señala Santos Julia, razones de afición y, sobre todo, de documentación explicarían esta preferencia. Sin embargo, desde hace unos años, la ampliación del elenco de temas de estudio, por una parte, y la aparición de análisis regionales y locales, por otra, ha contribuido, cuantitativa y cualitativamente, a profundizar y clarificar las claves del socialismo en nuestro país. En este esfuerzo de clarificación de capítulos hasta hace poco olvidados merece destacarse el relativo al universo educativo-cultural de nuestro socialismo. Aunque los problemas que enfrenta este campo son abundantes y la desaparición, escasez o dispersión de fuentes no es el menor, a los trabajos ya clásicos de un buen puñado de estudiosos se suma hoy un grupo escogido de jóvenes investigadores que tratan de sistematizar los planteamientos educativos del socialismo.

  9. Los valores distintivos de los panistas

    Directory of Open Access Journals (Sweden)

    Iván Zavala Echavarría

    2009-01-01

    Full Text Available En este artículo, el autor se propone demostrar que el hecho de ser simpatizante del partido Acción Nacional (pan es función de seis variables independientes: inculcar la fe, confiar en otros, interés en la política y auto-ubicación sobre los ejes izquierda-derecha, igualdad>desigualdad, y propiedad privada>gubernamental. La influencia de esas variables no es sólo aislada sino en conjunto. Estas variables son distintivas de los simpatizantes del Partido (de Acción Nacional, es decir los distinguen de los del Partido Revolucionario Institucional y de los del Partido de la Revolución Democrática.

  10. De los deslumbramientos a los alumbramientos

    Directory of Open Access Journals (Sweden)

    William Fernando Torres

    1996-10-01

    Full Text Available Este texto es un relato sobre las ansiedades que hoy abruman en secreto a los profesores de la escuela básica periférica. Sin embargo, no se queda en la anécdota: evidencia que esas inquietudes tienen raíz en las dificultades de los docentes para apropiarse críticamente las culturas escritas y audiovisuales/digitales electrónicas y, por tanto, para construirse una comprensión global de los procesos culturales contemporáneos. Estas circunstancias llevan a los maestros a incomunicarse y a entrar en conflicto con las y los jóvenes. Como alternativas posibles se propone autorreconocerse, aprender a crecer siendo vulnerables, engendrar un pensamiento del contexto y lo complejo.

  11. Operation and Performance of a Biphase Turbine Power Plant at the Cerro Prieto Geothermal Field (Final Report)

    Energy Technology Data Exchange (ETDEWEB)

    Hays, Lance G. [Douglas Energy Company, Placentia, CA (United States)

    2000-09-01

    A full scale, wellhead Biphase turbine was manufactured and installed with the balance of plant at Well 103 of the Cerro Prieto geothermal resource in Baja, California. The Biphase turbine was first synchronized with the electrical grid of Comision Federal de Electricidad on August 20, 1997. The Biphase power plant was operated from that time until May 23, 2000, a period of 2 years and 9 months. A total of 77,549 kWh were delivered to the grid. The power plant was subsequently placed in a standby condition pending replacement of the rotor with a newly designed, higher power rotor and replacement of the bearings and seals. The maximum measured power output of the Biphase turbine, 808 kWe at 640 psig wellhead pressure, agreed closely with the predicted output, 840 kWe. When combined with the backpressure steam turbine the total output power from that flow would be increased by 40% above the power derived only from the flow by the present flash steam plant. The design relations used to predict performance and design the turbine were verified by these tests. The performance and durability of the Biphase turbine support the conclusion of the Economics and Application Report previously published, (Appendix A). The newly designed rotor (the Dual Pressure Rotor) was analyzed for the above power condition. The Dual Pressure Rotor would increase the power output to 2064 kWe by incorporating two pressure letdown stages in the Biphase rotor, eliminating the requirement for a backpressure steam turbine. The power plant availability was low due to deposition of solids from the well on the Biphase rotor and balance of plant problems. A great deal of plant down time resulted from the requirement to develop methods to handle the solids and from testing the apparatus in the Biphase turbine. Finally an online, washing method using the high pressure two-phase flow was developed which completely eliminated the solids problem. The availability of the Biphase turbine itself was 100

  12. Chatkalita, nekrasovita y otros minerales del grupo de la estannita de Veta María Eugenia, Cerro Atajo, Catamarca

    Directory of Open Access Journals (Sweden)

    M. F. Márquez-Zavalía

    2007-06-01

    Full Text Available En veta María Eugenia, Cerro Atajo, Catamarca, se encontró una asociación de minerales de estaño integrada por: chatkalita Cu6Fe2+Sn2S8, nekrasovita Cu26V2(Sn,As,Sb6S32, colusita Cu26V2(As,Sn,Sb6S32, kësterita Cu2(Zn,FeSnS4 y estannoidita Cu8(Fe,Zn3Sn2S12. Estos minerales, incluidos en watanabeíta, están acompañados principalmente por pirita, esfalerita, calcopirita, tetraedrita, bornita y galena; aikinita, enargita, luzonita, marcasita, arsenopirita y pirrotina participan como minerales accesorios. Chatkalita se presenta en agregados irregulares de hasta 40 µm, asociados con kësterita y estannoidita, es de color rosa-anaranjado claro, birreflectante y anisótropa, con colores de polarización pardos; su composición química (% en peso es: S=29,76-30,37, Fe=4,53-7,92, Cu=39,13-43,21, Zn=0,75-5,53, As=0,19- 2,42, Sn=15,27-20,50 y Sb=0,00-0,32. Nekrasovita es isótropa, de color pardo con leve tinte rosa-violáceo y está asociada con estannoidita; su composición química es: S=30,29-30,63, Fe=3,41-4,75, Cu=44,26-45,70, Zn=0,56-1,00, As=4,18-4,71, Sn=12,53-13,64 y Sb=0,71- 0,77. Colusita es pardo amarillenta, isótropa, se presenta como parches irregulares y cintas discontinuas en tennantita; su composición química es: S=30,59-30,74, Fe=2,18-3,58, Cu=47,22-48,13, Zn=0,21-0,64, As=6,38-6,61, Sn=9,04-9,33 y Sb=0,49-1,66. Kësterita es pardo grisácea, con débil birreflectancia y anisotropía y colores de polarización pardos, a menudo se presenta bordeada por chatkalita; su composición química es: S=28,68-29,14, Fe=1,98-2,14, Cu=31,06-32,51, Zn=9,03-11,57 y Sn=26,39-27,03. Estannoidita es de color castaño, pleocroica (castaño-rosado a pardo-grisáceo y anisótropa con colores de polarización pardos y pardo-amarillentos, ocurre en parches irregulares y como bandas bordeando tennantita; su composición química es: S=29,11-29,83, Fe=8,45-10,30, Cu=38,05-41,01, Zn=3,18-4,90, y Sn=15,84-18,94. La reflectividad y dureza de pulido de

  13. Jurassic tetrapods and flora of Cañadón Asfalto Formation in Cerro Cóndor area, Chubut Province Flora y tetrápodos del Jurásico de la Formación Cañadón Asfalto en el área de Cerro Cóndor, provincia de Chubut

    OpenAIRE

    2008-01-01

    The plant and tetrapod fossil record of the Cañadón Asfalto Formation (Middle to Late Jurassic) found in Cerro Cóndor area (Chubut Province) is summarized here. The flora is dominated by conifers (Araucariaceae, Cupressaceae sensu lato) but also includes ferns and equisetaleans. The tetrapod fauna is composed of dinosaur taxa described in the 70's as well as other remains recently described and other vertebrate groups such as amphibians, turtles, and mammals. The amphibian remains have been i...

  14. Un corredor verde entre cerros desde 1934, y las posibilidades actuales desde un ejercicio académico de pregrado en Recoleta./ A green corridor between the hills since 1934, and its current possibilities, explored through an undergraduate academic exercise in Recoleta

    Directory of Open Access Journals (Sweden)

    María Isabel Pavez Reyes

    2013-12-01

    Full Text Available En el marco de una investigación FAU –U. Chile, “El antiguo sector de La Chimba: en defensa de sus vestigios patrimoniales, una vida comunitaria de escala barrial y un futuro ambiente sustentable” , y la reconsideración de una proposición de Karl Brunner en Recoleta, un grupo de estudiantes exploran un polígono del pericentro norte de Santiago, presentando las posibilidades y limitaciones actuales para lograr una cierta continuidad verde entre los cerros San Cristóbal y Blanco en la perspectiva de una renovación con mayor sustentabilidad urbana./ This article is part of the research project entitled “The old area of La Chimba: in defense of its heritage traces, a neighborhood scale community life and a sustainable environment for the future” (funded through the Universidad de Chile’s Faculty of Architecture and Urbanism research fund. A group of undergraduate architecture students revisit a proposition made by Karl Brunner for Recoleta, exploring the possibilities and limitations to achieve a continuity of green spaces between the San Cristobal and Blanco hills, from an urban sustainability perspective.

  15. Active metasomatism in the Cerro Prieto geothermal system, Baja California, Mexico: A telescoped low-pressure, low-temperature metamorphic facies series

    Science.gov (United States)

    Schiffman, P.; Elders, W. A.; Williams, A. E.; McDowell, S. D.; Bird, D. K.

    1984-01-01

    In the Cerro Prieto geothermal field, carbonate-cemented, quartzofeldspathic sediments of the Colorado River delta are being actively metasomatized into calc-silicate metamorphic rocks by reaction with alkali chloride brines between 200 and 370 °C, at low fluid and lithostatic pressures and low oxygen fugacities. Our petrologic investigations of drill cores and cuttings from more than 50 wells in this field identified a prograde series of zones that include as index minerals wairakite, epidote, prehnite, and clinopyroxene. Associated divariant mineral assemblages are indicative of a very low pressure, low-temperature metamorphic facies series spanning the clay-carbonate, zeolite, greenschist, and amphibolite facies. This hydro-thermal facies series, which is now recognized in other active geothermal systems, is characterized by temperature-telescoped dehydration and decarbonation. Its equivalent can now be sought in fossil hydrothermal systems.

  16. Recent Vertical Deformation in Mexicali Valley and its Relationship with Tectonics, Seismicity, and the Exploitation of the Cerro Prieto Geothermal Field, Mexico

    Science.gov (United States)

    Glowacka, E.; González, J.; Fabriol, H.

    The interpretation of the results of regional and local leveling which began in 1977 in the Mexicali Valley and the local short profile precision leveling which started in 1994 are discussed. The relation of vertical deformations around the Cerro Prieto Geothermal Field (CPGF) and along the Imperial fault, with local tectonics and seismicity in the Mexicali Valley, is reviewed. Also the relation between vertical deformation and fluid operation in the CPGF is analyzed. The subsidence observed in the field seems to be induced by fluid extraction. The way in which fluid production influences surface changes along the Imperial fault is not clear. The possibility that seismicity is triggering subsidence in the area and vertical movement on the Imperial fault is discussed.

  17. Contrasting compositional trends of rocks and olivine-hosted melt inclusions from Cerro Negro volcano (Central America): implications for decompression-driven fractionation of hydrous magmas

    Science.gov (United States)

    Portnyagin, Maxim V.; Hoernle, Kaj; Mironov, Nikita L.

    2014-10-01

    Melt inclusions in olivine Fo83-72 from tephras of 1867, 1971 and 1992 eruptions of Cerro Negro volcano represent a series of basaltic to andesitic melts of narrow range of MgO (5.6-8 wt %) formed by ~46 wt % fractional crystallization of olivine (~6 wt %), plagioclase (~27 wt %), pyroxene (~13 wt %) and magnetite (high-Mg basalts reflects the process of phenocryst re-distribution in progressively evolving melt. The crystallization scenario is anticipated to operate everywhere in dykes feeding basaltic volcanoes and can explain the predominance of plagioclase-rich high-Al basalts in island arc as well as typical compositional variations of magmas during single eruptions.

  18. Active metasomatism in the Cerro Prieto geothermal system, Baja California, Mexico: a telescoped low-pressure, low-temperature metamorphic facies series

    Energy Technology Data Exchange (ETDEWEB)

    Schiffman, P.; Elders, W.A.; Williams, A.E.; McDowell, S.D.; Bird, D.K.

    1984-01-01

    In the Cerro Prieto geothermal field, carbonate-cemented, quartzofeldspathic sediments of the Colorado River delta are being actively metasomatized into calc-silicate metamorphic rocks by reaction with alkali chloride brines between 200 and 370 C, at low fluid and lithostatic pressures and low oxygen fugacities. Their petrologic investigations of drill cores and cuttings from more than 50 wells in this field identified a prograde series of zones that include as index minerals wairakite, epidote, prehnite, and clinopyroxene. Associated divariant mineral assemblages are indicate of a very low pressure, low-temperature metamorphic facies series spanning the clay-carbonate, zeolite, greenschist, and amphibolite facies. This hydrothermal facies series, which is now recognized in other active geothermal systems, is characterized by temperature-telescoped dehydration and decarbonation. Its equivalent can now be sought in fossil hydrothermal systems.

  19. Approaching viscosity control: electrical heating of extra heavy oil as alternative to diluent injection in down hole in Cerro Negro Field, Faja Petrolifera del Orinoco

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Manuel [Petroleos de Venezuela SA, PDVSA (Venezuela)

    2011-07-01

    Electrical heating is a method used to enhance oil recovery in extra heavy oil reservoirs. This method can be used when diluent injection or other methods are not able to reduce oil viscosity sufficiently or when problems of product quality or quantity arise. The aim of this paper is to evaluate the performance of electrical heating, individually and simultaneously with injection of diluents. For this purpose, simulations were undertaken in one well with integrated electrical heating and diluent injection in Cerro Negro Field in the Orinoco oil belt, Venezuela. Results have shown that the application of both methods together is more profitable than the application of electrical heating alone. This paper demonstrated that the use of electrical heating and diluent injection combined is a valid alternative to diluent injection alone, reducing production loss.

  20. El complejo deslizamiento de Ailinco-Cerro Papas-Las Olletas (Departamento Minas, norte del Neuquén, Argentina

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    E.F. González Díaz

    2003-06-01

    Full Text Available De acuerdo a los antecedentes disponibles, acumulaciones de aspecto tilloide que conforman el irregular paisaje de un amplio sector de la cuenca de drenaje del arroyo Ailinco y que se extiende al pie del extremo sur de la serranía de la Puntilla y del faldeo oeste del Cº Papas y en el paraje de las Olletas, han sido consideradas como propias de la génesis glaciaria (morenas; tills. Los autores las interpretan como correspondientes a depósitos de un complejo conjunto local de grandes movimientos gravitacionales, en el que se han distinguido tres avalanchas de rocas, siendo las mayores aquellas del Cº Las Papas y de Ailinco y otra de menor porte ocurrida en la zona de Las Olletas. Sólo se describe su distribución y sus principales características morfológicas Se propone como el promotor de los mismos a la energía sísmica, teniendo en cuenta las condiciones sismotectónicas de la región y antecedentes de otros similares movimientos cercanos, ya analizados por los autores En el mapa geomorfológico adjunto, que cubre prácticamente la totalidad del área de las cuencas de los arroyos Ailinco y Manchana Covunco, se distinguen la presencia y distribución de otras geoformas menores, cuyo origen está relacionado con procesos propios de la morfogenia glaciaria, de un ambiente local de condiciones periglaciarias actuales y de la remoción en masa.

  1. Los presupuestos del Concurso

    OpenAIRE

    Línea de Investigación “De la Crisis Empresarial

    2006-01-01

    Este escrito es el resultado de uno de los proyectos de investigación adelantados por el Departamento de Derecho Comercial de la Universidad Externado de Colombia. En el se hace una aproximación histórica a los presupuestos para acceder a los trámites concursales en Perú, Argentina y España, analizándolos desde los puntos doctrinal, académico y legal.Así mismo, es parte integrante de un trabajo más amplio que pretende elaborar un documento contentivo del tratamiento que se da a los presupuest...

  2. Los nenes con los zombies, las nenas con los vampiros

    OpenAIRE

    López Corral, Manuela

    2012-01-01

    En este artículo nos circunscribiremos, dentro de este género literario, a las sagas de reciente salida editorial y, con mayor precisión, a las sagas de novelas románticas para adolescentes tales como Crepúsculo (Stephenie Meyer, 2005), Hush Hush (Becca Fitzpatrick, 2009), Cazadores de Sombras (Cassandra Clare, 2007), Fallen (Lauren Kate, 2010), y otras similares, dejando de lado sagas con otro tipo de particularidades como los citados libros de Harry Potter o los pertenecientes a la trilogía...

  3. Cerro Bombero: registro de Hippidion saldiasi Roth, 1899 (Equidae, Perissodactyla en el Holoceno temprano de Patagonia (Santa Cruz, Argentina

    Directory of Open Access Journals (Sweden)

    Alberdi, M. T.

    2008-06-01

    Full Text Available A new record of Hippidion saldiasi with new radiocarbon data referred to early Holocene (8,850 ± 80 year C-14 B.P of Patagonia is reported. Both its peculiar geographic location in a scarcely prospected zone and its radiocarbon age, provide new elements to discuss the previous hypotheses about the extinction of the horses and its relations with the human beings that inhabited the different environments of South America.Presentamos un nuevo registro de Hippidion saldiasi con datación radiocarbónica directa correspondiente al Holoceno temprano de Patagonia (8.850 ± 80 años C-14 AP. Su particular ubicación temporal y geográfica en una zona poco estudiada hasta ahora y su registro reciente, aportan nuevos elementos para discutir las hipótesis previas sobre la extinción de los caballos y su relación con los grupos humanos que colonizaron los diferentes ambientes de América del Sur.

  4. Los presupuestos del Concurso

    Directory of Open Access Journals (Sweden)

    Línea de Investigación “De la Crisis Empresarial

    2006-01-01

    Full Text Available Este escrito es el resultado de uno de los proyectos de investigación adelantados por el Departamento de Derecho Comercial de la Universidad Externado de Colombia. En el se hace una aproximación histórica a los presupuestos para acceder a los trámites concursales en Perú, Argentina y España, analizándolos desde los puntos doctrinal, académico y legal.Así mismo, es parte integrante de un trabajo más amplio que pretende elaborar un documento contentivo del tratamiento que se da a los presupuestos concursales a nivel mundial.En este orden de ideas, nos permitimos presentar un análisis minucioso de la legislación de los citados países iberoamericanos.

  5. Los presupuestos del Concurso

    Directory of Open Access Journals (Sweden)

    Línea de Investigación “De la Crisis Empresarial

    2006-12-01

    Full Text Available Este escrito es el resultado de uno de los proyectos de investigación adelantados por el Departamento de Derecho Comercial de la Universidad Externado de Colombia. En el se hace una aproximación histórica a los presupuestos para acceder a los trámites concursales en Perú, Argentina y España, analizándolos desde los puntos doctrinal, académico y legal.Así mismo, es parte integrante de un trabajo más amplio que pretende elaborar un documento contentivo del tratamiento que se da a los presupuestos concursales a nivel mundial. En este orden de ideas, nos permitimos presentar un análisis minucioso de la legislación de los citados países iberoamericanos.

  6. cultural de los chicanos

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    Patricia Casasa

    2003-01-01

    Full Text Available En Estados Unidos los diferentes grupos étnicos de habla hispana, entre ellos los chicanos, se enfrentan al problema de definir su identidad frente a la cultura anglosajona dominante, y este proceso puede ser descrito como un fenómeno de autoreconocimiento colectivo, o sea, la percepción diferencial de una colectividad suficientemente integrada y consistente, en contraposición con otras. Cualquier elemento que integra una configuración cultural, como son las pautas de comportamiento, los estilos de vida, las fiestas, los cantos, los mitos, los usos del ceremonial laico y religioso, la organización social del espacio, el lenguaje, la vida cotidiana o la utilización y percepción del medio físico, etcétera, pueden desempeñar este papel.

  7. en los nuevos medios

    Directory of Open Access Journals (Sweden)

    Jaime Alonso

    2005-01-01

    Full Text Available El presente artículo se plantea como objetivo mostrar algunas consideraciones acerca de una investigación realizada durante los años 2000-2004 sobre los procesos de comunicación en Internet, que se centró en el análisis de los “nuevos medios”: diarios digitales, buscadores y directorios, portales, comunidades virtuales, redes ciudadanas y bitácoras. La investigación desplegó una metodología fundamentalmente exploratoria, debido a la ausencia de investigaciones de carácter general sobre la cuestión –dada la novedad que implica Internet– , y se basó en el análisis de varios parámetros: análisis de los objetivos de los medios, contenidos (tipologías y sujetos (actividades de los sujetos en los medios. En este artículo se comentan, exclusivamente, algunas ideas referidas a este tercer parámetro: la actividad de los sujetos en los nuevos medios.

  8. Los cardinales romanos

    OpenAIRE

    Segura Ramos, Bartolomé

    2005-01-01

    Tratamos en el presente trabajo de estudiar los números cardinales romanos desde el punto de vista de su simbología (el origen de la misma), así como los principios subyacentes a dichos símbolos y la «mecánica» del sistema decimal romano (de proveniencia i.e.), a saber, el origen de los nombres de los números y el procedimiento de constitución de las decenas, especialmente. We are in this paper concerned with the study of the Roman cardinal numerals as symbolic signs, its origin and subjac...

  9. Mega-deslizamientos de la pared sur del cerro Aconcagua y su relación con depósitos asignados a la glaciación pleistocena Mega-landslide in the southern wall of the Aconcagua and its relationship with deposits assigned to Pleistocene glaciations

    Directory of Open Access Journals (Sweden)

    Luis Fauqué

    2009-12-01

    Full Text Available Con motivo de la confección de un mapa de susceptibilidad a los procesos de remoción en masa que afectan a la localidad de Puente del Inca, se procedió a revisar la controvertida génesis del depósito Horcones. Se analizó la morfología del depósito y del paisaje circundante, la mineralogía y textura de sus materiales y finalmente se realizaron dataciones radimétricas. Sobre la base de estos estudios se concluye que el depósito de Horcones es el resultado de un flujo saturado derivado de una avalancha de rocas o mega-deslizamiento, originada por el colapso de una divisoria de aguas en la pared sur del cerro Aconcagua, durante tiempos tardioglaciales o postglaciales. Depósitos similares al de Horcones rellenan el valle del río Cuevas hacia el este y son cubiertos por otros, que también previamente fueron considerados como glaciarios (e.g. morena terminal del Drift Penitentes. El análisis de este material en las cercanías de la localidad de Penitentes, utilizando una metodología semejante, revela que corresponde a un flujo de gran envergadura proveniente de la quebrada Mario Ardito. De acuerdo a estas nuevas interpretaciones resulta clara la necesidad de realizar una exhaustiva revisión de la estratigrafía glaciaria en la zona. Surgen además nuevas ideas en cuanto a la génesis del monumento natural Puente del Inca. Finalmente, la comprensión de la evolución geomorfológica de la pared sur del cerro Aconcagua arroja luz sobre los surge del glaciar Horcones Inferior, revistiendo una gran importancia para la evaluación de los riesgos geológicos del Parque Provincial Aconcagua.During the preparation of a susceptibility map of mass wasting processes affecting Puente del Inca town, the controversial genesis of the Horcones deposit was reviewed and discussed. The surrounding landscape, the morphology of the deposit along with its mineralogical and textural features were analysed; finally several radiometric data were performed

  10. Caracterización petrográfica y geoquímica del batolito Cerro Aspero-Alpa Corral (32°34'-32°42' LS y 64°43'-64°52' LO, provincia de Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    Porta, G.

    1992-12-01

    Full Text Available The Cerro Aspero-Alpa Corral (CA-AC batholith is a 440 km2 granite body present in the Southern edge of the Eastern Pampean Ranges, Córdoba province, central Argentina. The intrusive body of probably paleozoic age shows both post-tectonic and epizonal character. Country rocks include Upper Precambrian-Lower Paleozoic metasedimentary rocks mainly represented by mica-schists, gneisses and migmatites, locally interrupted by minor amphibolite and marble outcrops.This paper deals with representative petrographic and geochemical data that characterize a 150 km2 central stripe between 32°34'-32°42'S and 64°43'-64°52'W.Three granitic facies have been distinguished based on their distinctive modal mineralogy and texture, and upon well known chemical parameters.A K-feldspar megacryst porphydic-type is the areally prevalent facies, but dykes of micro- leucogranites and biotite-phenocryst bearing granite are also well represented. They are all monzogranites of subalkaline and peraluminous chemistry. Their mineralogy shows variable proportions of QAP constituents and micas, with minor phases represented by Fe-Ti oxides, apatite (Ap, titanite (Tt, allanite (Aln.Microgranular enclaves, abundantly distributed in the porphydic facies, provide valuable information for a better understanding of parental magma evolution.The high-Ca content of the melt makes this body quite distinctive compared to its larger northern neighbour, the Achala batholith.Pegmatite and aplite bodies, as well as fluorite bearing breccias and quartz veins, barren or mineralized, are also present within the CA-AC batholith.El batolito Cerro Aspero-Alpa Corral (CA-AC es un cuerpo granítico que aflora en el extremo sur de las Sierras Pampeanas Orientales, en la provincia de Córdoba, República Argentina, cubriendo una superficie cercana a los 440 km2.Es un cuerpo intrusivo postcinemático de probable edad paleozoica. Las rocas encajantes son metamorfitas correspondientes al Prec

  11. Origin and evolution of mineralizing fluids and exploration of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama) from a fluid inclusion and stable isotope perspective

    Science.gov (United States)

    Corral, Isaac; Cardellach, Esteve; Corbella, Merce; Canals, Angels; Griera, Albert; Gomez-Gras, David; Johnson, Craig A.

    2017-01-01

    Cerro Quema is a high sulfidation epithermal Au-Cu deposit with a measured, indicated and inferred resource of 35.98 Mt. @ 0.77 g/t Au containing 893,600 oz. Au (including 183,930 oz. Au equiv. of Cu ore). It is characterized by a large hydrothermal alteration zone which is interpreted to represent the lithocap of a porphyry system. The innermost zone of the lithocap is constituted by vuggy quartz with advanced argillic alteration locally developed on its margin, enclosed by a well-developed zone of argillic alteration, grading to an external halo of propylitic alteration. The mineralization occurs in the form of disseminations and microveinlets of pyrite, chalcopyrite, enargite, tennantite, and trace sphalerite, crosscut by quartz, barite, pyrite, chalcopyrite, sphalerite and galena veins.Microthermometric analyses of two phase (L + V) secondary fluid inclusions in igneous quartz phenocrysts in vuggy quartz and advanced argillically altered samples indicate low temperature (140–216 °C) and low salinity (0.5–4.8 wt% NaCl eq.) fluids, with hotter and more saline fluids identified in the east half of the deposit (Cerro Quema area).Stable isotope analyses (S, O, H) were performed on mineralization and alteration minerals, including pyrite, chalcopyrite, enargite, alunite, barite, kaolinite, dickite and vuggy quartz. The range of δ34S of sulfides is from − 4.8 to − 12.7‰, whereas δ34S of sulfates range from 14.1 to 17.4‰. The estimated δ34SΣS of the hydrothermal fluid is − 0.5‰. Within the advanced argillic altered zone the δ34S values of sulfides and sulfates are interpreted to reflect isotopic equilibrium at temperatures of ~ 240 °C. The δ18O values of vuggy quartz range from 9.0 to 17.5‰, and the δ18O values estimated for the vuggy quartz-forming fluid range from − 2.3 to 3.0‰, indicating that it precipitated from mixing of magmatic fluids with surficial fluids. The δ18O of kaolinite ranges from 12.7 to 18.1‰ and

  12. Los niños y los videojuegos

    OpenAIRE

    Orrego Gaviria, Jaime; Fundación Valle de Lili

    2007-01-01

    Los niños y los videojuegos / Efectos perjudiciales de la utilización de los videojuegos por los niños y adolescentes/ Efectos benéficos de la de la utilización de los videojuegos por los niños y adolescentes/ Recomendaciones para favorecer el uso adecuado/ Sistema de clasificación de los videojuegos

  13. Petrological evolution of subducted rodingite from seafloor metamorphism to dehydration of enclosing antigorite-serpentinite (Cerro del Almirez massif, southern Spain)

    Science.gov (United States)

    Laborda-López, Casto; López Sánchez-Vizcaíno, Vicente; Marchesi, Claudio; Gómez-Pugnaire, María Teresa; Garrido, Carlos J.; Jabaloy-Sánchez, Antonio; Padrón-Navarta, José Alberto

    2016-04-01

    Rodingites are common rocks associated with serpentinites in exhumed terrains that experienced subduction and high pressure metamorphism. However, the response of these rocks to devolatilization and redox reactions in subduction settings is not well constrained. In the Cerro del Almirez ultramafic massif (southern Spain) rodingites constitute about 1-2% of the total volume of exposed rocks. Metarodingites are enclosed in antigorite-serpentinite and chlorite-harzburgite separated by a transitional zone that represents the front of prograde serpentinite-dehydration in a paleo-subduction setting (Padrón-Navarta et al., 2011). Metarodingites occur as boudin lenses, 1 to 20 m in length and 30 cm to 2 m in thickness. During serpentinization of peridotite host rocks, dolerites and basalts precursor of rodingites underwent intense seafloor metasomatism, causing the enrichment in Ca and remobilization of Na and K. Subsequent metamorphism during subduction transformed the original igneous and seafloor metamorphic mineralogy into an assemblage of garnet (Ti-rich hydrogrossular), diopside, chlorite, and epidote. During prograde metamorphism, garnet composition changed towards higher andradite contents. High-pressure transformation of enclosing antigorite-serpentinite to chlorite-harzburgite released fluids which induced breakdown of garnet to epidote in metarodingites. Ti liberation by this latter reaction produced abundant titanite. Released fluids also triggered the formation of amphibole by alkalis addition. Highly recrystallized metarodingites in chlorite-harzburgite present a new generation of idiomorphic garnet with composition equal to 10-30% pyrope, 30-40% grossular and 35-55% almandine + spessartine. This garnet has titanite inclusions in the core and rutile inclusions in the rim. The contact between metarodingites and ultramafic rocks consists of a metasomatic zone (blackwall) with variable thickness (7 to 40 cm) constituted by chlorite, diopside, and titanite

  14. A Conceptual Model to Link Anomalously High Temperature Gradients in the Cerros del Rio Volcanic Field to Regional Flow in the Espanola Basin, New Mexico

    Science.gov (United States)

    Fillingham, E. J.; Keller, S. N.; McCullough, K. R.; Watters, J.; Weitering, B.; Wilce, A. M.; Folsom, M.; Kelley, S.; Pellerin, L.

    2015-12-01

    Temperature-depth well data along with electromagnetic (EM) data were collected by students of the Summer of Applied Geophysics Experience (SAGE) 2015 field season in the Espanola Basin, New Mexico. The data from this year, in addition to data acquired since 2013, were used to construct a conceptual east-west cross-section of the Espanola Basin and the adjacent highlands in order to evaluate the regional flow system. Vertical geothermal gradients from several monitoring wells were measured using a thermistor. Anomalously warm geothermal gradients were mapped in the Cerros del Rio volcanic field in the basin just east of the Rio Grande. Temperature gradients are up to 70℃/km, while the background geothermal gradients in the Rio Grande rift zone generally show 28℃-35℃/km. This anomaly extends to the Buckman well field, which supplies water to the city of Santa Fe. Overpumping of this well field has led to subsidence in the past. However, discharge temperature plots indicate that the temperature gradients of the Buckman field may be rebounding as pumping is reduced. Audiomagnetotelluric (AMT) and transient electromagnetic (TEM) data were acquired in the vicinity of three monitoring wells. TEM and AMT methods complement each other with the former having depths of investigation of less than ten to hundreds of meters and AMT having depths of investigation comparable to the wells deeper than 500m. These datasets were used collectively to image the subsurface stratigraphy and, more specifically, the hydrogeology related to shallow aquifers. The EM data collected at these wells showed a trend indicating a shallow aquifer with a shallower resistive layer of approximately 100 ohm-m at 70-100 meters depth. Beneath this resistive layer we resolved a more conductive, clay-rich layer of 10 ohm-m. These resistivity profiles compliment the electrical logs provided by Jet West, which indicate shallower sandstone interbedded with silt on top of more silt-dominant layers. Our

  15. Mecanismo de inserción del Laboratorio Tecnológico del Uruguay en el Parque Tecnológico Industrial del Cerro

    Directory of Open Access Journals (Sweden)

    Laura Márquez

    2011-05-01

    Full Text Available El Laboratorio Tecnológico del Uruguay, LATU, teniendo en cuenta su misión: "Impulsar el desarrollo sustentable del país y su inserción internacional a través de la innovación y transferencia de soluciones de valor, en servicios analíticos, metrológicos, tecnológicos, de gestión y evaluación de la conformidad de a cuerdo a la normativa aplicable", está trabajando en el apoyo a las micro, pequeñas y medianas empresas del país. Como estrategia para contribuir al logro de la misión, se ha iniciado una política de descentralización, eligiendo zonas de actividad con requerimientos similares, en cuanto a las necesidades de mejora de la competitividad de las empresas. En la zona de Montevideo llamada el Cerro, el gobierno municipal gestiona un Parque Tecnológico Industrial, PTIC, apoyando y alojando en su predio, 58 empresas. Este Parque se puede ver como un conglomerado de empresas, en una misma zona, con necesidades similares. El mecanismo de inserción del LATU en el PTIC, ha contado con una herramienta fundamental que es la instalación de una oficina en el propio Parque, cuyo objetivo principal es facilitar y asegurar la contribución del LATU al desarrollo y competitividad de las mipymes allí agrupadas.AbstractAttending to the Technological Laboratory of Uruguay (LATU's mission, to promote the sustainable development of the country and its international insertion through innovation and transfer of valuable solutions, it is working on support for micro, small and medium companies. As a management strategy to achieve the mission, a policy of decentralization, approaching to the enterprises, it's being implemented. In this context, it has been developed a methodology for insertion in the Industrial Technological Park of Cerro, PTIC. This park, which is managed by the municipal government, agglomerates a group of companies, in the same area with similar needs. The LATU's mechanism of insertion in the PTIC, has counted on with a

  16. Los apoyos en los centros docentes

    OpenAIRE

    2008-01-01

    Se describen las funciones del maestro de pedagogía terapéutica y de audición y lenguaje y de los educadores en la normativa de la Comunidad Valenciana. maestro de pedagogía terapéutica, maestro de audición y lenguaje, educadores

  17. Los libros de los moriscos y los eruditos orientales

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    Rodríguez Mediano, Fernando

    2010-12-01

    Full Text Available The aim of this paper is to show how the Orientalist scholarship of Christian Arabs who had come to Spain from the Middle East (via Italy adressed the literature of the Moriscos, to examine how it was understood by such scholars and what they used it for. We show that these scholars, from among whom we have chosen the examples of Marcus Dobelius and Miguel Casiri, could not carry out their Orientalist work using the Arabic manuscripts of the El Escorial library without confronting the Morisco problem in the form of Morisco texts held in several collections confiscated by the Inquisition. The knowledge and activities of these Moriscos served to trace the broad outlines of an intellectual history of the Arabic language in Europe, in which Morisco activity was interppreted in relation to its linguistic and doctrinal variables. This was achieved by means of the construction of a scholarly discipline (Orientalism at a time of religious polemic between the Reformation and the Counter-Reformation, i.e. during the period of the development of religious dissidence and skepticism in early modern Europe.Pretendemos, en este trabajo, mostrar cómo la erudición orientalista de árabes cristianos venidos a España desde Oriente (a través de Italia se aproximó a la literatura de los moriscos, cómo la entendió y para qué la utilizó. Mostramos que estos eruditos, de entre los que elegimos los casos de Marcos Dobelio y Miguel Casiri, no pudieron realizar su trabajo orientalista, que se basa en una fuerte vinculación con los manuscritos árabes de la Biblioteca de El Escorial, sin evitar el problema morisco en forma de su producción escrita aparecida en diversos fondos requisados por la Inquisición. Sus saberes y su actividad sirven para trazar los contornos amplios de una historia intelectual de la lengua árabe en Europa, en la que el hecho morisco es interpretado en función de sus variables lingüsticas y doctrinales, a partir de la constitución de

  18. Procedencia de los depósitos del Grupo Payogastilla (Cenozoico, río Calchaquí, provincia de Salta

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2011-06-01

    Full Text Available Se realiza el estudio de procedencias de los depósitos cenozoicos expuestos en la zona sur del valle Calchaquí, provincia de Salta que comprenden a sedimentitas fluviales del Grupo Payogastilla (Eoceno medio-Mioceno superior. La sucesión analizada se encuentra muy bien expuesta en ambas márgenes del río Calchaquí y consta de 5.400 metros de depósitos clásticos, integrada, de base a techo, por las formaciones Los Colorados, Angastaco, Palo Pintado y San Felipe. Se describen características mineralógicas, petrográficas, geoquímicas y de difracción de rayos X de las facies constituyentes de las formaciones Los Colorados, Angastaco y Palo Pintado, incorporándose el análisis de proveniencia asociado al estudio de paleocorrientes. El componente mayoritario, en las facies de areniscas, está caracterizado por granos de cuarzo, mientras que otros detritos son de: feldespatos potásicos, plagioclasas alteradas, pertitas y abundante micas. Los depósitos conglomerádicos matriz- soporte, siendo sus clastos mayoritarios de pegmatitas, granitos, cuarzos, esquistos, gneis y migmatitas. La geoquímica de elementos mayores y tierras raras de clastos de la Formación Angastaco muestran composiciones similares a la de rocas de la Faja Eruptiva de la Puna Oriental y cuerpos intrusivos ordovícicos-silúricos de Sierras Pampeanas. Los análisis de difracción de rayos X de muestras de arcillitas de la Formación Palo Pintado presentan illita y montmorillonita, que son interpretadas como de origen detrítico, mientras que la saponita ha sido generada por bisialitización (hidrólisis en un clima templado-húmedo. Las características composicionales y los datos de paleocorrientes medidos sugieren que durante el Eoceno medio al Mioceno superior el aporte principal de los materiales fue de zonas positivas de diferente composición de los afloramientos de cumbres de Luracatao y sierra de Vázquez, como así también de los cerros Runo, Durazno, sierra

  19. Los pasos cantados

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    Eduardo Carranza

    1969-03-01

    Full Text Available EL documento presenta los siguientes poemas: "Los pasos cantados"; "La patria es como una carta..."; "Preludio para un himno a la bandera de Colombia"; "El extranjero"; "Romanza con unas violetas"; "Nueva Kasida del vino"; "Día lejano"; "Decir amor"; "Hacia la soledad"; "El  capitan siembra una espada" y "El poeta canta desde lo alto de un caballo".

  20. los recursos culturales tangibles

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    Isabel Montero Muradas

    2005-01-01

    Full Text Available La formulación de estrategias de marketing de turismo cultural necesita una correcta evaluación de los recursos culturales tangibles disponibles para el soporte de las mismas. En esta investigación se desarrolla una metodología, basada en el Modelo de Rasch, para el diseño un instrumento de medida que nos permita jerarquizar, a partir de su nivel de disponibilidad, tanto los recursos culturales, como los municipios en que están ubicados. Los datos utilizados corresponden a los municipios de la Comunidad canaria registrados en la Guía de Recursos y Espacios Culturales de las Islas Canarias

  1. Evaluation of Macroinvertebrate Communities and Habitat for Selected Stream Reaches at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    L.J. Henne; K.J. Buckley

    2005-08-12

    This is the second aquatic biological monitoring report generated by Los Alamos National Laboratory's (LANL's) Water Quality and Hydrology Group. The study has been conducted to generate impact-based assessments of habitat and water quality for LANL waterways. The monitoring program was designed to allow for the detection of spatial and temporal trends in water and habitat quality through ongoing, biannual monitoring of habitat characteristics and benthic aquatic macroinvertebrate communities at six key sites in Los Alamos, Sandia, Water, Pajarito, and Starmer's Gulch Canyons. Data were collected on aquatic habitat characteristics, channel substrate, and macroinvertebrate communities during 2001 and 2002. Aquatic habitat scores were stable between 2001 and 2002 at all locations except Starmer's Gulch and Pajarito Canyon, which had lower scores in 2002 due to low flow conditions. Channel substrate changes were most evident at the upper Los Alamos and Pajarito study reaches. The macroinvertebrate Stream Condition Index (SCI) indicated moderate to severe impairment at upper Los Alamos Canyon, slight to moderate impairment at upper Sandia Canyon, and little or no impairment at lower Sandia Canyon, Starmer's Gulch, and Pajarito Canyon. Habitat, substrate, and macroinvertebrate data from the site in upper Los Alamos Canyon indicated severe impacts from the Cerro Grande Fire of 2000. Impairment in the macroinvertebrate community at upper Sandia Canyon was probably due to effluent-dominated flow at that site. The minimal impairment SCI scores for the lower Sandia site indicated that water quality improved with distance downstream from the outfall at upper Sandia Canyon.

  2. Implications for organic maturation studies of evidence of a geologically rapid increase and stabilization of vitrinite reflectance at peak temperature: Cerro Prieto geothermal system, Mexico

    Science.gov (United States)

    Barker, C.E.

    1991-01-01

    A short-term rapid heating and cooling of the rock in well M-94 below 1300 m was caused by a pulse of hot water passing through the edge of the Cerro Prieto, Mexico, geothermal system. Below 1300 m, the peak paleotemperatures were about 225-250??C, but equilibrium well log temperatures indicate a decrease to 150-210??C at present. This hot water pulse sharply increased vitrinite reflectance to levels comparable to those measured in the central part of the system, even though studies of apatite fission-track annealing indicate that the duration of heating was only 100-101 yr in M-94, in contrast to 103-104 yr in the central part of the system. The quick change of the vitrinite reflectance geothermometer indicates that thermal maturation reactions can stabilize, after a geologically short period of heating, to a level consistent with peak temperature under moderate to high-temperature diagenesis in open, fluid-rich, geothermal systems. -from Author

  3. Jurassic tetrapods and flora of Cañadón Asfalto Formation in Cerro Cóndor area, Chubut Province

    Directory of Open Access Journals (Sweden)

    Ignacio H. Escapa

    2008-12-01

    Full Text Available The plant and tetrapod fossil record of the Cañadón Asfalto Formation (Middle to Late Jurassic found in Cerro Cóndor area (Chubut Province is summarized here. The flora is dominated by conifers (Araucariaceae, Cupressaceae sensu lato but also includes ferns and equisetaleans. The tetrapod fauna is composed of dinosaur taxa described in the 70's as well as other remains recently described and other vertebrate groups such as amphibians, turtles, and mammals. The amphibian remains have been interpreted as representatives of a new species of Notobatrachus, considered one of the most basal members of the anuran lineage. Similarly, turtle remains have been recently recognized as a new species of basal turtle, bringing valuable information about the early evolution of this group. The dinosaur remains are largely dominated by saurischian taxa, represented by basal forms of Eusauropoda and Tetanurae. In addition, three different mammalian species have been identified and considered as early representatives of an endemic Gondwanan mammalian fauna. The fossil record of this formation represents the most completely known biota from the continental Middle to Late Jurassic of the Southern Hemisphere and one of the most complete of the entire world.

  4. Observation and modeling of gravity wave propagation through reflection and critical layers above Andes Lidar Observatory at Cerro Pachón, Chile

    Science.gov (United States)

    Cao, Bing; Heale, Christopher J.; Guo, Yafang; Liu, Alan Z.; Snively, Jonathan B.

    2016-11-01

    A complex gravity wave event was observed from 04:30 to 08:10 UTC on 16 January 2015 by a narrow-band sodium lidar and an all-sky airglow imager located at Andes Lidar Observatory (ALO) in Cerro Pachón (30.25°S, 70.73°W), Chile. The gravity wave packet had a period of 18-35 min and a horizontal wavelength of about 40-50 km. Strong enhancements of the vertical wind perturbation, exceeding 10 m s-1, were found at ˜90 km and ˜103 km, consistent with nearly evanescent wave behavior near a reflection layer. A reduction in vertical wavelength was found as the phase speed approached the background wind speed near ˜93 km. A distinct three-layered structure was observed in the lidar data due to refraction of the wave packet. A fully nonlinear model was used to simulate this event, which successfully reproduced the amplitudes and layered structure seen in observations. The model results provide dynamical insight, suggesting that a double reflection occurring at two separate heights caused the large vertical wind amplitudes, while the three-layered structure in the temperature perturbation was a result of relatively stable regions at those altitudes. The event provides a clear perspective on the filtering processes to which short-period, small-scale gravity waves are subject in mesosphere and lower thermosphere.

  5. de los derechos humanos

    Directory of Open Access Journals (Sweden)

    Javier Pardo Falcón

    2007-01-01

    Full Text Available A pesar de su uso en determinados foros políticos con connotaciones claramente negativas, el término globalización tiene un significado neutro que también puede hacer referencia a fines de bondad indudable. Así, tanto la Declaración Universal de los Derechos Humanos como otros instrumentos internacionales aprobados por las Naciones Unidas son normas jurídicas globalizadoras, surgidas con la idea de extender la vigencia de los derechos básicos de la persona a todos los países del mundo. Desde esta otra visión de la globalización, conseguir la efectiva vigencia de los derechos humanos en los países de Centroamérica resulta una tarea particularmente urgente y necesaria. En efecto, salvo Costa Rica, que puede considerarse una afortunada excepción en la turbulenta historia política centroamericana, todos los demás Estados de la región comparten un pasado marcado por los graves conflictos internos y el escaso desarrollo económico, circunstancias ambas que explican en buena parte un presente caracterizado por la debilidad de las instituciones, la falta de cohesión social y, en consecuencia, la insuficiente garantía de los derechos más básicos de la mayoría de la población. En este contexto, y desde su compromiso con la mejora de las condiciones materiales de vida de sus conciudadanos menos favorecidos, seis autores y autoras centroamericanos abordan, desde distintas perspectivas, la situación actual de los derechos fundamentales en sus respectivos países.

  6. Estudio anatómico, sistemático y paleobiológico de Bonitasaura salgadoi (Dinosauria: sauropoda): su importancia en el contexto de la evolución de los titanosaurios del cretácico superior de la Argentina

    OpenAIRE

    Gallina, Pablo Ariel

    2011-01-01

    En este trabajo de tesis se realiza un estudio de integración sobre el dinosaurio saurópodo Bonitasaura salgadoi Apesteguía 2004, hallado en la localidad de Cerro Policía, en la provincia de Río Negro. Para comenzar, se analiza el marco geológico mediante un análisis estratigráfico realizado en la localidad, y un estudio tafonómico de los restos óseos del holotipo de Bonitasaura para reconocer el contexto paleoambiental en el que el especímen habría pasado sus últimos momentos de vi...

  7. Remover los dogmas

    OpenAIRE

    Jaime Cárdenas Gracia

    2002-01-01

    El autor plantea una serie de reflexiones en torno a cinco temas a los que califica como dogmas de la teoría de la Constitución: el principio de legalidad, la división de poderes, el control de la constitucionalidad, el prevalecimiento del derecho interno sobre el externo y los métodos de interpretación. En su concepción, estos dogmas son barreras que desde la experiencia académica van incorporándose a los conceptos jurídicos, empobreciendo y reduciendo la realidad jurídica, al no tomar en cu...

  8. Rectores: los virreyes cautivos

    OpenAIRE

    2014-01-01

    Los rectores de las universidades españolas en la actualidad, particularmente los de las públicas, son una especia de virreyes, es decir, desempeñan un papel de administradores, pero no de creadores de auténticos objetivos para sus instituciones. Por eso la autonomía universitaria es hoy más un mecanismo de autogestión que de facilitamiento de estrategias concretas para cada universidad. Los rectores se convierten así, cautivos de un complejo e intrincado andamio legislativo. El papel del rec...

  9. Los calculistas mentales

    Directory of Open Access Journals (Sweden)

    Salvador Galindo Uribarri

    2014-01-01

    Full Text Available Los calculistas mentales, sujetos que realizan en un instante complejas operaciones aritméticas, han desarrollado habilidades que nos parecen -al resto de mortales- sorprendentes y aún increíbles. Estos sujetos se distinguen por su capacidad de concentración e increíble memoria y además emplean procedimientos de cálculo dis - tintos a los que ordinariamente ocupamos en nuestra vida cotidiana. Este trabajo trata sobre dichos procedimientos mostrando que difieren de los algoritmos tradicionales.

  10. Instrucciones para los autores

    Directory of Open Access Journals (Sweden)

    Revista Facultad de Ingenieria

    2010-11-01

    Full Text Available REVISTA FACULTAD DE INGENIERÍA, publicación editada por el Centro de Estudios, nvestigación y Educación Continuada de la Facultad de Ingeniería (CEDEC de la Universidad Pedagógica y Tecnológica de Colombia, UPTC, busca contribuir a la difusión de los nuevos conocimientos científicos y tecnológicos que se producen en el campo de las ingenierías, como resultados de los procesos investigativos que llevan a cabo los docentes y estudiantes, principalmente, de esta Facultad.

  11. Los beneficios del TLC

    Directory of Open Access Journals (Sweden)

    Martín Uribe Arbeláez

    2007-11-01

    Full Text Available El TLC usa-Colombia aumenta la protección de la propiedad intelectual por encima de la normatividad internacional plasmada en los Acuerdos adpic de la omc y en la Decisión 486 de 2000, de la Comunidad Andina de Naciones. Intensifica la llamada “apertura económica” consagrando un modelo exportador. El propósito de este ensayo es analizar lo que representa para el desarrollo económico y social, con énfasis en los dramáticos cambios que se introducen en el Régimen Común de Propiedad Industrial. El saqueo de la biodiversidad, “patentes a plantas o animales”, los enormes costos para la salud pública, la competitividad basada en las maquilas y la pauperización social, contradicen los sofismas que parecen evocar el realismo mágico como explicación de nuestra historia.

  12. Los pactos parasociales

    Directory of Open Access Journals (Sweden)

    Lina Henao

    2013-12-01

    Full Text Available Los pactos parasociales son acuerdos celebrados al margen de la regulación societaria, entre los socios, entre estos y la sociedad, o con terceros, que constituyen una herramienta de uso frecuente en el desarrollo de las relaciones corporativas pese a la ausencia de una regulación legal integral, y que tienen por finalidad regular extremos no recogidos estatutariamente. Su validez, eficacia e incumplimiento estarán determinados en mayor medida por las normas de derecho civil y en menor proporción por el orden jurídico societario. El artículo desarrolla una presentación de la noción, notas características, naturaleza jurídica y las vicisitudes que subyacen en esta materia a la luz de los principales ordenamientos jurídicos de los sistemas de Civil Law y de Common Law.

  13. Historia de los Medicamentos

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    Alfredo Jácome Roca

    2003-10-01

    Full Text Available

    Cómo evolucionaron los medicamentos

    La historia de los medicamentos hace parte del devenir del hombre y de la historia de la medicina.

    Desde siempre, el ser humano buscó una explicación a los fenómenos y una solución a sus males. El pensamiento mágico, más acentuado en las tribus y en las más antiguas civilizaciones, hizo importante el poder de los conjuros y la influencia de los dioses sobre las pócimas.

    Con algunas excepciones, hasta que Paracelso introdujo en terapéutica las sustancias inorgánicas, los medicamentos eran hierbas. Gobernantes estudiosos del tema (el Emperador Rojo -padre de la Herbología china- y Mitrìdates VI -inventor y consumidor consuetudinario de la famosa teriaca- vivieron obsesionados con el temor al envenenamiento. Tanto que el último, septuagenario y derrotado por sus antiguos aliados romanos, trató de envenenarse para acabar con su vida, mas no fue posible pues estaba inmunizado contra los tóxicos; tuvo que rogarle a un esclavo que atravesara su pecho con la espada. Dioscórides y Plinio el Viejo eran eruditos conocedores de la botánica; el primero escribió la “Materia Médica”, el segundo, la “Historia Natural”.

    La aparición de la medicina como oficio, en casos como los de Hipócrates y Galeno, estuvo rodeada de prestigio; pero en los más fue tarea de esclavos, labor de sirvientes. Estos colegas de la antigüedad aprendieron a manejar sus propios medicamentos, preparados en algunas trastiendas o “boticas”. Los farmacéuticos se iniciaron como simples dispensadores y tuvieron auge entre los árabes, civilización donde aparecieron también los primeros recetarios, listados de medicinas o primitivas farmacopeas. Pero siempre las mismas hierbas con los mismos hierbateros, para llamar de alguna manera a los empíricos que ejercían artesanalmente la medicina.

    Refiriéndose a las curas de su médico tratante, Adriano –considerado por aquel

  14. GRAVIMETRIC STUDY OF THE IXTLAN DE LOS HERVORES, GEOTHERMAL AREA, MIDWESTERN MEXICAN VOLCANIC BELT (MVB)

    Science.gov (United States)

    Gonzalez, T.; Ortiz, I.

    2009-12-01

    Analysis and interpretation of gravimetric anomalies over the Occidental-Central Mexican Volcanic Belt, sheds new light on the subsurface structure of the Ixtlan de los Hervores, geothermal area. In Mexico, there are several geothermal areas that have been exploited commercially (Cerro Prieto, Los Azufres, Los Humeros, Tres Virgenes fields). However, there are many other known fields that have not been exploited. This is the case in the area of "Ixtlan de los Hervores" in the state of Michoacan. The analyzed region covers a rectangular area, aproximality from 20o N to 20.5° N and 102° W to 102.2°W. In the region there are thick basalt flows. The area is characterized by low and elongated hills formed by volcanic flows and on a smaller scale lacustrian sediments and major normal faults with a NW-SE direction particularly, the Ixtlan-Encinal fault which controls the trace of the Duero River and the Pajacuarán fault. The anomaly map was compared with the surface geology and the anomalies were correlated with major volcanic features, since our main interest was in mapping the subsurface faults and volcanic bodies. Two profiles were selected that cross major anomalies and the geothermal zone of Ixtlan. The Talwani algorithm for 2-D polygonal bodies has been used for calculating the theoretical anomalies. The proposed models adequately explain the main observed geological features. The models are made up of two lithostratigraphic units of volcanic rocks, represented by the Tertiary basalts, which adequately reflect the area's volcanic environment. These basaltic units, corresponding to different volcanic events were cut by the Ixtlan well. Both models reflect the existence of the Ixtlan-Encinal fault, the most important feature in the area which is also responsible for the existence of the geothermal area.

  15. Boletines de calificaciones para los derechos de los refugiados

    OpenAIRE

    Forster, Bruce

    2011-01-01

    El Comité de los Estados Unidos para los Refugiados e Inmigrantes ha proporcionado información valiosa en sus “boletines de calificaciones en los derechos de los refugiados”, pero un análisis posterior produce información más útil todavía.

  16. LOS TRIBUNALES DE FAMILIA

    Directory of Open Access Journals (Sweden)

    Susan Turner Saelzer

    2002-01-01

    Full Text Available El proyecto de ley que crea los Tribunales de Familia, actualmente en tramitación, responde a imperativos provenientes tanto del derecho nacional como del derecho internacional. En efecto, en la formulación de un nuevo Derecho de Familia resulta indispensable adecuar los órganos jurisdiccionales llamados a conocer de los conflictos que se suscitan en el ámbito familiar y dotarlos de una competencia amplia para conocer de todos los asuntos que tengan repercusiones sobre la familia. En la primera parte del presente trabajo, se estudia el contexto que enmarca la idea de la creación de los Tribunales de Familia y en la segunda, se analiza en forma pormenorizada los aspectos del proyecto referidos a la estructura y composición de los Tribunales de Familia, a su competencia y procedimientos, y por último, a las vías de solución alternativa de conflictos consagrados.The current legislative draft that would introduce the so called «Family Courts» to the Chilean court system responds to both national and international law imperatives. In fact, it is necessary to reform the court system so as to allow that a single specialized court resolves all legal issues arising from a particular family conflict. The first part of this paper refers to the principles, ideas and institutional context behind the creation of the Family Courts. The second part contains a detailed analysis of the project regarding the organization and composition of the Family Courts, their jurisdiction, proceedings and alternative means of conflict resolution.

  17. Comparative study of the amplification of ground motion using seismic noise and recent earthquakes adjacent to the Cerro Prieto volcano, Baja California

    Science.gov (United States)

    Vega, F. D.; Vidal-Villegas, A.

    2009-12-01

    We have chosen an area of approximately 79 km2, centered around the Cerro Prieto volcano, in the Mexicalli valley, Baja California, based on elevated registered acceleration data. The GEO station, located in the Cerro Prieto geothermal field has registered seismic accelerations on the order of 492 gales. The local residents near the study area have reported feeling numerous smaller magnitude earthquakes, compared to those of the nearby populated city of Mexicalli. Does there exist an amplified seismic signal in the area? If so, what is the cause of the amplification? The objective of our study is to answer these questions and determine the subsurface (0-50 m) structure in 4 specific sites. To obtain these answers, we registered seismic noise samples using short period seismometers (1 s), intermediate (5 s) and 16 bit recorders, along a linear profile which crosses the volcano with an 18 degree NE orientation. Furthermore, we analyzed ground-motion data (from 2004-2006), obtained from 24-bit accelerographs. Using both types of data (noise and accelegraphs) we calculated the H/V spectral ratios, and the relative ratios between both sites. To determine the subsurface structure, we used a unidimensional model of the H/V ratios, based on the methodology used by Huerta-Lopez et al., 2005. The H/V spectral ratios from the seismic noise adjacent to the volcano display amplitude of 1 in the frequency range (0.8 - 30 Hz). In contrast, the amplitude in the volcano crater (159 m.a.s.l.) was 6 in the frequency range (0.8 - 3 Hz). The average H/V relative ratio of the crater and the adjacent sites is 4, with frequencies between 0.8 and 1.2 Hz. The S-wave H/V ratios for the VCP acceleration station (110 m.a.s.l.), are near 8, with frequencies between 1 and 2. The H/V spectral ratios from the seismic noise for the geothermal field display amplitude of 4 for frequencies between 0.8 and 1.3 Hz, while the results from the S wave display amplitudes of 5 between 1.5 and 3 Hz. In the

  18. los Derechos Humanos

    Directory of Open Access Journals (Sweden)

    Luciano Barp Fontana

    2005-01-01

    Full Text Available Una declaración universal de los derechos humanos es incompleta si se reduce a un conjunto de recomendaciones para que cada persona y cada organismo de la sociedad se esfuerce para promover, mediante la enseñanza y la educación, el respeto a una serie de valores y de derechos ligados a la dignidad humana. Así se va depauperando la expresión “derechos humanos”, que actualmente tiende a confundirse con unas instancias en las que pueden frustrarse frecuentemente las esperanzas de quien busca justicia. Para que una declaración sea completa es necesario fundamentarla en la constitución universal humana. Solamente así quedará asegurada y garantizada su inviolabilidad. En efecto, la primera violación a los derechos humanos consiste en descuidar el deber urgente de aclarar la respuesta a la pregunta “¿qué es el ser humano?” De hecho, el tema de los derechos humanos debe ser fundamentalmente ontológico-antropológico. De la postura antropológica derivará el tema axiológico de la dignidad del ser humano. De la postura axiológica brotará el tema deontológico del deber ser del ser humano. Finalmente, de la postura deontológica derivará el tema jurídico de los derechos humanos de todos los humanos. Brevemente. El punto de partida es necesariamente el ser. El segundo paso es el ser humano. El tercer paso es el valor (dignidad del ser humano. El cuarto paso será el deber ser del ser humano. La fundamentación de los derechos humanos que proponemos en este artículo consiste en un proceso dinámico-histórico de una humanización concebida y realizada como una liberación de cada hombre y de todos los hombres, sin concesiones a posturas totalitarias que devalúan el valor del individuo, o bien a posturas liberales que no respetan la igualdad de todos los grupos humanos. En realidad, cada persona goza de los mismos derechos humanos, no por un beneficio concedido por una cierta clase social o por el Estado, sino precisamente por la

  19. Models of Metabolic Community Structure in Martian Habitable Environments: Constraints from a Terrestrial Analog Acid-Sulfate Fumarole Environment, Cerro Negro Volcano, Nicaragua

    Science.gov (United States)

    Rogers, K. L.; McCollom, T. M.; Hynek, B. M.

    2014-12-01

    Microbial habitability in extreme environments on Earth is described by microscale geochemical conditions that constrain metabolic niches in concert with long-term habitat stability that is governed by dynamic geologic processes. Using terrestrial analogs to identify habitable martian environments requires correlating microscale geochemical constraints with reconstructions of past martian environments that are based on global-scale observations. While past martian environments can be characterized by primary parameters (e.g. pH, redox, mineralogy, thermal history), microbial habitability on Earth is a complex function of both primary and derived parameters (e.g. metabolic reaction energetics, chemical & thermal gradients, flow dynamics). In recent years we have been investigating acid-sulfate fumaroles at the Mars analog site, Cerro Negro Volcano, Nicaragua, where habitability is constrained by steep thermal gradients, spatially- and temporally-variable vent dynamics, and limited water and nutrient availability. The most common niche identified thus far is found in fumaroles that host mixed photosynthetic and chemosynthetic endolithic microbial communities. One such endolith is dominated by acidic red algae (Cyanidiales), aerobic bacterial heterotrophs (Ktedonobacteria), and archaeal thermoacidophiles (Hyperthermus, Caldisphaera, and Thermofilum). An analysis of the metabolic structure suggests that primary production by the red algae supports the growth of heterotrophic thermoacidophiles. Diversification among the chemoheterotrophs with respect to temperature and oxygen tolerance suggests community adaptation to environmental gradients or variable venting dynamics. Furthermore, individual cells within the endolith are silica-encrusted, providing the possibility for biosignature formation and preservation. Putative hydrothermal environments on early Mars with similar conditions could have supported endolithic communities with comparable metabolic strategies. Even

  20. Active hydrothermal metamorphism in the Cerro Prieto geothermal system, Baja California, Mexico: a telescoped low P/T facies series. [Abstract only

    Energy Technology Data Exchange (ETDEWEB)

    Schiffman, P. (Univ. of California, Riverside); Elders, W.A.; Williams, A.E.; McDowell, S.D.; Bird, D.K.

    1983-03-01

    In the Cerro Prieto geothermal system, carbonate-cemented, quartzo-feldspathic sediments of the Colorado River delta are being actively recrystallized into calc-silicate metamorphic rocks through intense fluid/rock interaction with alkali chloride brine (1.5 x 10/sup 4/ ppM TDS) at temperatures between 200/sup 0/ and 370/sup 0/C, fluid pressures <0.25 Kb, lithostatic pressures <1.0 Kb, and oxygen fugacities close to the QFM buffer. Petrologic investigations of cuttings and core from more than 50 wells in this field reveal a prograde series of calc-silicate mineral zones with index metamorphic minerals: wairakite (wr), epidote (ep), prehnite (pr), and calcic clinopyrosene (cpx). The compositions of these and other key phases: wr (Ca/Ca + Na + K + 0.97), ep (Fe/Fe + Al/sup vi/ = 0.11 to 0.31), pr (Fe/Fe + Al/sup vi/ = 0.01 to 0.28), cps (close to Wo/sub 50/ and Mg/Mg + Fe + Mn = 0.23 to 0.90), actinolite (0.20 Al/sup iv//15 cations and Mg/Mg + Fe + Mn = 0.67 to 0.82), biotite (Mg/Mg + Fe + Mn = 0.58 to 0.87) and microcline (Or/sub 96 to 100/) reflect recrystallization under low fluid pressures, relatively low f/sub O/sub 2//, and varying brine compositions. Divariant mineral assemblages in this system comprise a very low P/T facies series encompassing the clay-carbonate, zeolite, greenschist, and amphibolite facies and reflect equilibrium occurring in response to both increasing temperature and decreasing CO/sub 2/ pressure. Similar facies series, characterized by telescoped devolatization mineral reactions, are becoming increasingly recognized in other active geothermal systems above 300/sup 0/C. However, close analogues in the fossil geologic record are as yet unidentified.

  1. Quistes de los maxilares

    Directory of Open Access Journals (Sweden)

    Ivan Alberto Manotas Arevalo

    2013-12-01

    Full Text Available Los Grandes Quistes de los Maxilares han estado vinculados siempre a la humanidad, desde tiempos remotos, pues han sido halladas en restos de especimenes fosiles, han llamado la atencion de los clínicos, en torno a su etiologia, en la que se ha introducido la participacion de la genetica, (demostrada en el desarrollo de los queratoquistes maxilares, la fisiopatologia, caracteristicas histologicas (inmunohistoquimica, posibilidades diagnosticas por la imagen, (como la tomografia computarizada y la resonancia nuclear magnetica y otras pruebas. Además llaman la atención al estudio, por sus alternativas de manejo especialmente las formas radicales, y el analisis de asociaciones a otras patolo-gias benignas y malignas, y de la recurrencia muy alto de algunas de estas lesiones. Mucho se ha desarrollado para elucidar su naturaleza real, estadificar adecuadamente la lesion descartando asocia-ciones patologicas sindromicas, indicar un tratamiento apropiado, y realizar seguimientos a largo plazo. Este articulo pretende recaudar una information general que de parametros para abordar el estudio de los quistes maxilares a partir de la presentacion de un caso clinico.

  2. Los acueductos Romanos

    Directory of Open Access Journals (Sweden)

    Fernández Casado, C.

    1971-12-01

    Full Text Available Con este documentado trabajo —al igual que los anteriores— damos por terminada la serie de acueductos romanos que hemos ido publicando en números precedentes de nuestra revista «INFORMES». En fecha próxima aparecerá el libro que los reúne todos en un volumen de indudable interés. El Profesor Fernández Casado ha llevado a cabo, con gran cariño, la ímproba labor de recopilar y ordenar curiosos datos sobre cada uno de los acueductos que existen en España —unos en perfecto estado de conservación e incluso en servicio, otros transformados en ruinas grandiosas, y un tercer grupo, de los que no quedan más que restos gloriosos poco definidos—, buceando en todos los lugares donde pudiera existir algún vestigio de datos de partida, labor harto difícil, dada la evidente escasa: de fuentes precisas de tipo geográfico o literario. Gracias a su esfuerzo hemos podido exponer a la admiración de todos la belleza y la recia grandeza de estas muestras de la ingeniería romana en la que, como en tantas otras facetas del Arte, de la Técnica y de la Cultura, alcanzaron las más altas cotas. V. M.

  3. Large rock avalanches in southern Perù: the Cerro Caquilluco - Cerrillos Negros rock slide - avalanche (Tacna, Tomasiri, Perù)

    Science.gov (United States)

    Crosta, G.; Hermanns, R. L.; Murillo, P. V.

    2012-04-01

    The Andean bent which coincides with the Peruvian-Chilean border region is characterised by one of the largest relief contrasts on earth with depth of the subduction trench ranging from 5000 to 6000 m below sea level and mountain tops ranging from 5500 to 6300 m a.s.l.. The western flank of the Andes is subdivided in 4 major geologic zones (i.e. Coastal Cordillera, longitudinal Basin or depression, the Precordillera or western escarpment and western Cordillera). Local relief contrasts are also pronounced due to the incision of deep canyons into several million old uplifted surfaces, preserved because of the extremely dry climate with precipitation averaging a few mm and less per year. The Lluta collapse (minimum age of 2.5 Ma; volume 26 km3) is one of the largest non-volcanic non-marine landslides on Earth and has been mapped in that area (Wörner et al., 2002). Systematic mapping in northern Chile and Southern Peru has revealed that this is not the only gigantic landslide in the area but that further landslides of similar size occurred in the area, located both along the canyon slopes and along the western escarpment of the Cordillera. This suggests that landsliding has been a major factor in controlling erosion. This contribution describes first results on mapping a giant landslide complex in southern Perù called the Cerro Caquilluco - Cerrillos Negros Tomasiri rock slide - avalanche complex. The systematic mapping we have carried out in the area is presented in a further contribution to this conference. The Cerro Caquilluco - Cerrillos Negros Tomasiri rock slide - avalanche complex affected the upper part of a SW dipping paleosurface (8° to 9°) cut by a disconnected and regular primitive drainage network organized in a series of SW trending parallel valleys. This network developed within the lower Miocene pinkish tuffaceous deposits of the Huaylillas formation, whereas the main landslide scarp lies within the conglomerates of the Upper Moquegua formation

  4. Cooperación y conflicto entre empresas, comunidades, nuevos movimientos sociales y el papel del gobierno. el caso de cerro de san pedro (méxico)

    OpenAIRE

    Vargas-Hernández, José G.

    2009-01-01

    El objetivo de este trabajo es analizar las relaciones de cooperación y conflicto entre la Compañía Minera (MSX) y las comunidades de San Pedro, Soledad y San Luis Potosí, los Nuevos Movimientos Sociales y los tres niveles de gobierno involucrados. La compañía Minera inició operaciones en una mina a cielo abierto de oro y plata con el apoyo de oficiales de los gobiernos locales, estatales y federal. Los habitantes de estas comunidades apoyados por grupos ambientalistas y Organizaciones No Gub...

  5. Cooperación y conflicto entre empresas, comunidades, nuevos movimientos sociales y el papel del gobierno. El caso de Cerro de San Pedro

    OpenAIRE

    Vargas-Hernández, José G.

    2009-01-01

    El objetivo de este trabajo es analizar las relaciones de cooperación y conflicto entre la Compañía Minera (MSX) y las comunidades de San Pedro, Soledad y San Luis Potosí, los Nuevos Movimientos Sociales y los tres niveles de gobierno involucrados. La compañía Minera inició operaciones en una mina a cielo abierto de oro y plata con el apoyo de oficiales de los gobiernos locales, estatales y federal. Los habitantes de estas comunidades apoyados por grupos ambientalistas y Organizaciones No Gub...

  6. Normas internacionales de los alimentos

    OpenAIRE

    Comisión CODEX ALIMENTARIUS

    2015-01-01

    Todos los textos del Codex se encuentran a disposición del público en los sitios web que se indican a continuación: Todas las normas, las directrices, los códigos de prácticas y los textos consultivos que integran el Codex Alimentarius están disponibles en la Lista de normas.

  7. Los oficios del comunicador

    Directory of Open Access Journals (Sweden)

    Jesús Martín-Barbero

    2011-01-01

    Full Text Available En el presente ensayo se evalúan los oficios del comunicador a la luz de tres ámbitos problemáticos: las competencias y los oficios, las agencias de legitimación y las dinámicas de transformación. Se defiende la tesis de un cambio cualitativo, desde un comunicador-intermediario hacia un comunicador-mediador, que asume como base de su acción las asimetrías y las desigualdades sociales y culturales, al participar como actor en la construcción de una sociedad democrática. Se subraya en este contexto que, frente a las tecnologías incorporadas a los medios de comunicación, el ejercicio del comunicador debe comportar más inquietudes e interrogantes que respuestas.

  8. Los Cuchillos de Albacete

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    Rodríguez Lorente, Juan J.

    1967-12-01

    Full Text Available Not available.

    DE la larga honrosa tradición española en la fabricación artesana de aceros para armas blancas, que alcanzó su cima en los siglos XVI y XVII, y desapareció casi totalmente en el XVIII con la importación de los espadines franceses puestos de moda por la corte de don Felipe de Borbón, puede decirse que no queda en nuestros días vestigio alguno, si se exceptúan los modestos esfuerzos estatales centralizados en la Fábrica Nacional de Armas de Toledo, y la pujante industria cuchillera de Albacete.

  9. en los noventa

    Directory of Open Access Journals (Sweden)

    Gerardo Halpern

    2005-01-01

    Full Text Available Este trabajo analiza el papel del Estado en la formación, activación y administración de los marcos interpretativos respecto de los “inmigrantes paraguayos” que viven en Argentina, en tanto producto generado, ejecutado y administrado, entre otros, por los campos jurídico y laboral, fundamentales para comprender las delimitaciones de posiciones de agentes específicos en el espacio social y sus consecuentes respuestas. Estas delimitaciones se inscriben en relaciones de poder en las que el agente por excelencia es el Estado, el cual responde, a lo largo de la historia y las coyunturas, a las necesidades del capital en su relación respecto del trabajo

  10. Instrucciones para los autores

    Directory of Open Access Journals (Sweden)

    Revista Facultad de Ingenieria

    2010-12-01

    Full Text Available REVISTA FACULTAD DE INGENIERÍA, publicación editada por el Centro de Estudios, Investigación y Educación Continuada de la Facultad de Ingeniería (CEDEC de la Universidad Pedagógica  y Tecnológica de Colombia, UPTC, busca contribuir  a  la difusión de  los nuevos conocimientos científicos y tecnológicos que se producen en el campo de  las ingenierías, como resultados de los procesos  investigativos que llevan a cabo los docentes y estudiantes, principalmente, de esta Facultad.Se reciben colaboraciones de profesores, estudiantes y administrativos de la UPTC y de otras universidades,  tanto del país como del exterior, y de  investigadores en general y tratadistas de la temática de la revista.

  11. Instrucciones para los autores

    Directory of Open Access Journals (Sweden)

    Revista Facultad de Ingenieria

    2010-11-01

    Full Text Available REVISTA INGENIERÍA, publicación editada por el Centro de Estudios, Investigación y Educación Continuada  de  la  Facultad de  Ingeniería  (CEDEC  de  la Universidad Pedagógica y Tecnológica de Colombia, UPTC, busca contribuir a la difusión de los nuevos conocimientos científicos y desarrollos  tecnológicos que se producen en el campo de  las  ingenierías, como resultados de los procesos investigativos que llevan a cabo los docentes y estudiantes, principalmente, de esta Facultad.

  12. Una sepultura con armas de baja época ibérica (o época romana republicana) en la necrópolis del «Cerro de las Balas» (Écija, Sevilla)

    OpenAIRE

    2000-01-01

    Iberian Iron-Age weapons are extremely rare in western Andalusia, due mainly to the absence of the normative cremation cemeteries typical of other areas in the Peninsula, cemeteries where nearly all of the approximately six thousand Iron Age weapons that we know have been documented. In this paper we present one of the very few exceptions to this rule: a ‘warrior’ burial found in the Iron Age cemetery cemetery at ‘Cerro de las Balas’ (or «bullets’ hill», so known after the many sling projecti...

  13. Cuando atacan los animales

    OpenAIRE

    Erian, Alicia

    2000-01-01

    Los cuentos de Alicia Erian han aparecido recientemente en Zoetrope y Nerve. Su primera colección de narrativa breve, The Brutal Language of Love, la publicará la editorial Villard el año próximo. Alicia Erian vive en brooklyn, Nueva York, con su marido, David Franklin. «Cuando atacan los animales» es el primero de sus relatos traducidos al español. Traductor: Juan Gabriel López Guix es traductor del inglés y francés. Se dedica sobre todo a la traducción de narrativa, ensayo y divulgación cie...

  14. por los Estados parte

    Directory of Open Access Journals (Sweden)

    Boris Barrios González

    2006-01-01

    Full Text Available El autor realiza un análisis de la cosa juzgada nacional, la cual explica como una cuestión de prejudicialidad que se traduce en una condición de procedibilidad para concurrir al Sistema Interamericano de Protección de los Derechos Humanos; para luego abordar el cumplimiento de las sentencias de la Corte Interamericana, haciendo referencia a los casos más conflictivos que se destacan en la jurisprudencia de la Corte Interamericana de Derechos Humanos.

  15. Los pactos parasociales

    OpenAIRE

    Lina Henao

    2013-01-01

    Los pactos parasociales son acuerdos celebrados al margen de la regulación societaria, entre los socios, entre estos y la sociedad, o con terceros, que constituyen una herramienta de uso frecuente en el desarrollo de las relaciones corporativas pese a la ausencia de una regulación legal integral, y que tienen por finalidad regular extremos no recogidos estatutariamente. Su validez, eficacia e incumplimiento estarán determinados en mayor medida por las normas de derecho civil y en menor propor...

  16. Los poetas del Valle

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    Helcías Martán Góngora

    1963-10-01

    Full Text Available No es el "Azul" que sirvió a Rubén, "padre y maestro mágico", como telón de fondo en su magna aventura renovadora, sino el "Azul" Comarca serenísima -donde vive la eternidad-, el color que impera en los territorios mágicos ele Gilberto Garrido (1887, el insigne lírico nacido en las montañas de Supía, pero volcado como un río sobre el Valle del Cauca, desde los manantiales de su infancia.

  17. de los adolescentes

    Directory of Open Access Journals (Sweden)

    Laura Oliva Zárate

    2007-01-01

    Full Text Available Se evaluó el nivel de autoestima en los adolescentes que cursaban secundaria o bachillerato, cuya condición era la de ser hijos de padres emigrantes, mediante un enfoque mixto, utilizando instrumentos de evaluación y cuestionarios. Los resultados muestran que la tercera parte de dichos jóvenes manifiestan una baja autoestima en dos de las cuatro áreas valoradas, evidenciándose la necesidad de una intervención oportuna a fin de mejorarla.

  18. Los hijos de Kafka

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    William Díaz Villarreal

    2012-07-01

    Full Text Available Kafka intentó sin éxito publicar un libro, titulado Los hijos, en el que se reunían tres relatos compuestos en el invierno entre 1912 y 1913: “La condena”, “La metamorfosis” y “El fogonero”. En este ensayo, el autor interpreta estos tres relatos como una unidad, a partir del motivo que sugiere el título del libro proyectado por Kafka. Así, estos tres textos exploran los intentos fallidos del hijo por autoafirmarse dentro de la opresiva esfera de influencia del padre.

  19. Heat losses estimation associated with the physical state of the thermal insulation of pipes vaporductos network in Cerro Prieto geothermal field; Estimacion de perdidas de calor asociadas al estado fisico del aislamiento termico de las tuberias de la red de vaporductos del campo geotermico Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Ovando Castelar, Rosember; Martinez Estrella, Juan Ignacio; Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rovando@iie.org.mx; jime@iie.org.mx; aggarcia@iie.org.mx; Canchola Felix, Ismael; Miranda Herrera, Carlos; Jacobo Galvan, Paul [Campo Geotermico de Cerro Prieto, Comision Federal de Electricidad, Mexicali, B.C. (Mexico)

    2010-11-15

    The Cerro Prieto Geothermal Field (CPGF) steam transportation network is constituted by 140 km of pipes with diameters ranging from 8 to 48 inches, which transport the steam of 165 producing wells to 13 power plants which have a total installed capacity of 720 MWe. Originally, the pipes are thermally insulated with a mineral wool or fiber glass layer and an external aluminum or iron cover. Due to the insulation material has been exposed to weather conditions during the field operation it shows nowadays different grades of wear-out, or even it is lacking in some parts of the network, causing higher heat losses from the pipes to the environment. In this work, the magnitude of the heat losses related with the present condition of the thermal insulation throughout the pipeline network is assessed. This involved determining the longitude and diameter, as well as the insulation condition of each single pipeline section, and the calculation of the heat transfer coefficients for the different thermal insulation conditions defined for this study. [Spanish] La red de transporte de vapor del campo geotermico Cerro Prieto (CGCP) esta constituida por aproximadamente 140 km de tuberias de 8 a 48 pulgadas de diametro, las cuales conducen el vapor producido por 165 pozos hacia 13 plantas generadoras, cuya capacidad instalada es de 720 MWe. Originalmente, estas tuberias son aisladas termicamente con una capa de 2 pulgadas de material aislante a base de lana mineral o fibra de vidrio, y una proteccion exterior de aluminio o hierro. Debido principalmente al impacto de las condiciones meteorologicas durante el tiempo de operacion del campo, en algunas porciones de la red el aislante presenta actualmente distintos grados de deterioro, o incluso se encuentra ausente, lo cual se traduce en una mayor perdida de calor desde las tuberias hacia el medio ambiente. En el presente trabajo se evalua la magnitud de las perdidas de calor asociadas al estado fisico del aislamiento termico de las

  20. Tras los concursos

    OpenAIRE

    Pérez Oyarzun,Fernando 

    2007-01-01

    Los concursos de arquitectura parecen entregar garantías de la calidad del resultado, pueden promover a arquitectos jóvenes y evidencian las tensiones arquitectónicas presentes en un momento dado. El análisis a sus variantes permite entender mejor la problemática existente en torno a ellos

  1. Los beneficios del TLC

    Directory of Open Access Journals (Sweden)

    Martín Uribe Arbeláez

    2007-01-01

    Full Text Available El tlc usa-Colombia aumenta la protección de la propiedad intelectual por encima de la normatividad internacional plasmada en los Acuerdos adpic de la omc y en la Decisión 486 de 2000, de la Comunidad Andina de Naciones. Intensifica la llamada “apertura económica” consagrando un modelo exportador. El propósito de este ensayo es analizar lo que representa para el desarrollo económico y social, con énfasis en los dramáticos cambios que se introducen en el Régimen Común de Propiedad Industrial. El saqueo de la biodiversidad, “patentes a plantas o animales”, los enormes costos para la salud pública, la competitividad basada en las maquilas y la pauperización social, contradicen los sofismas que parecen evocar el realismo mágico como explicación de nuestra historia.�

  2. Los viajes de Ulises

    OpenAIRE

    Alzate, Gabriel Jaime

    2012-01-01

    El autor Gabriel Jaime Alzate nos da a conocer sobre los viajes de Ulises "Cuando emprende el viaje Ulises se entrena en el olvido y cada mañana lanza una saeta que va directa a sus mejores recuerdos. Lo que no sabe es que la saeta regresa a él

  3. Los dientes del caballo

    OpenAIRE

    García Verduch, Antonio

    1996-01-01

    El autor cuenta una historia sobre una discusión entre dos hombres por saber cuantos dientes tienen los caballos, recurren a escritos y libros para tratar de averiguarlo, al final se quedan sin resolverlo y todo por no mirarle la boca directamente al caballo

  4. EL ERYNGIUM ("CARDO" GIGANTE DEL DELTA DEL PARANA Y DE LA MESOPOTAMIA ARGENTINA

    Directory of Open Access Journals (Sweden)

    Troels Myndel Pedersen

    2010-11-01

    Full Text Available Un Eryngium gigante, espectacular por su tamaño y la abundancia donde se presenta, muy común a lo largo de la Mesopotamia argentina, el delta del Río Paraná, y la orilla sur del Río de la Plata, cuya identidad ha sido interpretada de diversas maneras, se describe como una nueva especie, Eryngium mesopotamicum Pedersen

  5. Tras las huella del silencio: Potosí, los incas y Toledo

    Directory of Open Access Journals (Sweden)

    Tristan Platt

    2010-12-01

    Full Text Available ¿Por qué los señores aymaras de Charcas y el Inca Paullo, después de entregar las minas de plata de Porco a Hernando Pizarro en 1538, guardaron silencio sobre Potosí (distante a unas pocas leguas, que no se descubrió hasta abril de 1545? Reuniendo un mosaico de datos aparentemente inconexos, este artículo revisa las versiones corrientes del descubrimiento del cerro e interroga un curioso silencio presente en las fuentes. Reconstruyendo una red previamente desconocida de incas y españoles, se propone que, más que el hallazgo providencial de un yanacona aislado (la versión recibida, Potosí se manifestó como continuación de la política de “obediencia” subyacente en la entrega de Porco, ahora dirigida por el rival del Inca Paullo: el Inca Manco refugiado en Vilcabamba. Esta política de Manco buscaba apoyar al Rey y las Nuevas Leyes (1542 en contra de la amenaza mayor representada por Gonzalo Pizarro y los encomenderos. El artículo comenta, asimismo, la promoción toledana de la “leyenda providencial”, retomando en cambio la interpretación de Guaman Poma de la entrega de Potosí como una iniciativa de los incas, quienes lo habrían fundado bajo Inca Túpac Yupanqui. Esta versión concuerda con las últimas investigaciones geológicas y arqueológicas.

  6. Palacio de los Deportes

    Directory of Open Access Journals (Sweden)

    Candela Outeriño, F.

    1968-11-01

    Full Text Available This building was specially built for the Mexico Olympic Games, and was the site for the basketball competition. But during the design stage it was foreseen that it could be later adapted to various other uses, such as boxing matches, ice skating displays, theatre, circus, shows, etc. It has 19.834 seats for spectators. Its circular planform has a 180 m diameter, and there are three levels of organisation. — on the lower level there is accommodation for the competitors, the press and the organisers of the Olympic Competitions; — the main level houses the entrance halls, the stairs, and access to the lower and middle spectator stands; — the top level has the washrooms for the public, the special stands and access to the middle and top stands. The outstanding feature of this sports palace is its general structure, which from the outset was regarded as the dominant element of the design, and also defined its plastic and spatial quality.Este edificio, construido para los Juegos Olímpicos de México, fue destinado a los juegos de baloncesto, pero al proyectarlo se previó que posteriormente pudiera servir para múltiples usos: celebración de combates de boxeo, espectáculos sobre hielo, teatro, circo, etc. Tiene capacidad para 19.824 espectadores sentados. Su planta es circular, con un diámetro total de 180 m, y está organizada en tres niveles: — en el nivel inferior se alojan: los servicios para deportistas, prensa y organización del Certamen Olímpico; —el nivel principal alberga: los vestíbulos, escaleras y accesos a gradería baja y media; — y en el nivel superior se distribuyen: los servicios para público, palcos y accesos a gradería media y alta. En este Palacio de los Deportes destaca su estructura general que fue considerada, desde la fase del proyecto, como el elemento dominante de la composición, y el determinante de su sentido plástico y espacial.

  7. Nota de los editores

    Directory of Open Access Journals (Sweden)

    Raquel Arias Careaga

    2007-12-01

    Full Text Available Verba Hispanica, sus editores junto con algunos de los amigos, colegas y antiguos alumnos de Julio Rodríguez Puértolas, han decidido elaborar este número especial de la revista dedicado a su obra y a su tdyectoria, no sólo por la dimensión de sus aportaciones al estudio de los hechos literarios como fenómenos propiamente históricos, haciendo de la literatura una herramienta esencial para el conocimiento -y reconocimiento material- del devenir de las sociedades -de las pocas y de sus culturas- como tales fenómenos materiales, sociales e históricos; sino, ]emás, también por el enorme peso de su magisterio, ejercido durante años, tanto en E tados Unidos, como en España, especialmente en la Universidad Autónoma de Madrid, que se ha dirigido siempre a hacer que los estudiantes entiendan el estudio de la literatur como una investigación y un trabajo en el que deben usar no solamente la expresión clara y precisa de sus conclusiones, sino una mirada interdisciplinar a los fenómenos qub son objeto de su estudio. Y finalmente por la larga y frnctífera colaboración directa -e indirecta- con nuestra revista y con nuestro Departamento de Lengua española y literaturas ~spánicas, en Ljubljana. En nuestra memoria quedará siempre su estancia e intervención en el Simposio internacional dedicado al cuarto centenario de la publicación de la primera parte de Don Quijote. Como en la memoria de todos permanecerá el impacto que supuso aquella legendaria Historia social de la literatura española (en colaboración con Iris ¡M. Zavala y Carlos Blanco Aguinaga o el estudio de la literatura fascista española, o esa forma nueva de ver y leer los textos medievales, al Arcipreste de Hita, el Romancero adicional castellano o La, Celestina, en el siglo quince; al propio Cervantes, en la edad conrictiva; o a los autores realistas del diecinueve, Clarín y, sobre todo, Galdós.

  8. The geochemistry and isotope hydrology of the Southern Mexicali Valley in the area of the Cerro Prieto, Baja California (Mexico) geothermal field

    Science.gov (United States)

    Portugal, Enrique; Izquierdo, Georgina; Truesdell, Alfred; Álvarez, Julio

    2005-11-01

    Groundwaters from the phreatic aquifer within and surrounding of the Cerro Prieto geothermal field were analyzed geochemically and isotopically in order to establish a hydrodynamic model of the study zone, which is located in the Mexicali Valley between 655,000-685,000 m E-W and 3,605,000-3,576,000 m N-S relative to UTM coordinates. Based on their chemical composition three types of water were recognized: chloride, sulfate and bicarbonate. However four groups of water were identified on a statistical multi-variable method of cluster analysis (A-D). The average temperature is 25 °C; with a few exceptions in the south where temperature can be as high as 47 °C. Stable isotope ratios for some waters plot close to the world meteoric line, corresponding to the original unaltered waters of the zone. The hydrogeochemistry varies in relation to three principal processes: evaporation, infiltration of water used in agriculture and rock interaction by reaction with evaporitic deposits. Major quartz, calcite and plagioclase and minor smectite, kaolinite, halite, sylvite and gypsum were identified by X-ray diffraction in lacustrine sediments of the central part of the zone. Chemical modeling indicates saturation with respect to calcite and undersaturation with respect to gypsum. By incorporating chemical and isotope data into geological and isopotential well information, a hydrodynamic model has been postulated. In this hydrodynamic model the water (A) enters the study zone from the east and it is originally of the old Colorado River water. The water samples on which the model is based were draw from agricultural wells that intersected two aquifers, a shallow and a deep one, representing the recharge to the zone. The salinity of the deep aquifer water (B) is lower than that of the shallow aquifer water (C) and so is the stable isotope ratio. The difference is though to be due to dissolution of evaporates, evaporation and possible infiltration of spent agriculture water. Both

  9. Crystallization conditions and petrogenesis of the lava dome from the ˜900 years BP eruption of Cerro Machín Volcano, Colombia

    Science.gov (United States)

    Laeger, Kathrin; Halama, Ralf; Hansteen, Thor; Savov, Ivan P.; Murcia, Hugo F.; Cortés, Gloria P.; Garbe-Schönberg, Dieter

    2013-12-01

    The last known eruption at Cerro Machín Volcano (CMV) in the Central Cordillera of Colombia occurred ˜900 years BP and ended with the formation of a dacitic lava dome. The dome rocks contain both normally and reversely zoned plagioclase (An24-54), unzoned and reversely zoned amphiboles of dominantly tschermakite and pargasite/magnesio-hastingsite composition and olivine xenocrysts (Fo = 85-88) with amphibole/clinopyroxene overgrowth, all suggesting interaction with mafic magma at depth. Plagioclase additionally exhibits complex oscillatory zoning patterns reflecting repeated replenishment, fractionation and changes in intrinsic conditions in the magma reservoir. Unzoned amphiboles and cores of the reversely zoned amphiboles give identical crystallization conditions of 910 ± 30 °C and 360 ± 70 MPa, corresponding to a depth of about 13 ± 2 km, at moderately oxidized conditions (f = +0.5 ± 0.2 ΔNNO). The water content in the melt, calculated based on amphibole chemistry, is 7.1 ± 0.4 wt.%. Rims of the reversely zoned amphiboles are relatively enriched in MgO and yield higher crystallization temperatures (T = 970 ± 25 °C), slightly lower melt H2O contents (6.1 ± 0.7 wt.%) and overlapping pressures (410 ± 100 MPa). We suggest that these rims crystallized following an influx of mafic melt into a resident magma reservoir at mid-crustal depths, further supported by the occurrence of xenocrystic olivine. Crystallization of biotite, albite-rich plagioclase and quartz occurred at comparatively low temperatures (probably rock chemistry of the CMV lava dome dacites is homogenous. They have elevated (La/Nb)N ratios of 3.8-4.5, typical for convergent margin magmas, and display several geochemical characteristics of adakites. Both Sr and Nd isotope compositions (87Sr/86Sr ˜0.70497, 143Nd/144Nd ˜0.51267) are among the most radiogenic observed for the Northern Volcanic Zone of the Andes. They are distinct from oceanic crust that has been subducted in the region

  10. Los indios y los empedrados sotaquireños

    Directory of Open Access Journals (Sweden)

    Edwin Giovanni Quesada-Cárdenas

    2016-09-01

    Full Text Available Este artículo de investigación describe la preparación de los platos culinarios tradicionales del municipio de Sotaquirá (Boyacá, que hacen parte de los saberes ancestrales que han prevalecido generacionalmente en los habitantes del municipio; ya que caracterizan la identidad sotaquireña. También se exponen algunos elementos sobre la gestión de la administración municipal (2012-2015 para promover la permanencia y reconocimiento de estos saberes como patrimonio cultural. El contenido del artículo es el resultado de la investigación “Identidad campesina en torno a los oficios tradicionales en el municipio de Sotaquirá (2013-2015”; que tuvo como fin describir las costumbres culturales en torno a los oficios tradicionales, que configuran la identidad campesina de los habitantes del municipio de Sotaquirá. El enfoque metodológico fue cualitativo desde la corriente socio-critica; se usaron la entrevista y la observación participante para reconocer la importancia de los platos que se configuran como aspectos fundamentales de la identidad de los sotaquireños. Se destaca que este trabajo logró generar espacios de reflexión con los entrevistados respecto de los oficios tradicionales culinarios del municipio en torno al reconocimiento del valor de los platos como patrimonio cultural y las particularidades del plato de acuerdo con los contextos familiares.

  11. Los celtas en Celtiberia

    Directory of Open Access Journals (Sweden)

    Majolie LENERZ-DE WILDE

    2009-12-01

    Full Text Available RESUMEN: Se discute la forma en que se produjo la formación de la cultura celtibérica, bien como proceso de aculturación inducido por contactos con mercenarios celtas, o bien por inmigración de una población céltica. Sobre ese fondo se sitúan y analizan los objetos relacionables con la cultura de La Teñe, Los resultados hablan en favor de una migración, si bien numéricamente pequeña.ABSTRACT: The paper discusses the question how the Celtiberian culture may have evolved: by a process of acculturation, caused by contacts with Celtic mercenaries, or by the immigration of a Celtic population. Against this background, finds which show relations to the La Tène culture, are put together and analysed. The results point to an immigration, even if only a small one.

  12. Hasta los últimos confines

    Directory of Open Access Journals (Sweden)

    Córdoba, Joaquín Mª

    2005-04-01

    Full Text Available El 19 de mayo de 1798, la flota encargada de trasladar el ejército que iba a conquistar Egipto levó anclas del puerto de Toulon. Aunque tres años después la aventura se saldara en fracaso, el siglo XIX comenzó así con este temprano intento francés, que consiguió dominar durante algún tiempo el Valle del Nilo, soñó abrir el Canal de Suez y decidió el desarrollo moderno de los estudios sobre la cultura islámica y el antiguo Egipto. Desde entonces y hasta la I Guerra Mundial, el mundo iba a vivir la incesante expansión europea, particularmente la de sus grandes estados como Inglaterra, Francia, Alemania y Rusia, cuyos viajeros, exploradores, colonos y ejércitos llegarían a todos los rincones del mundo…

  13. Los Alamos Programming Models

    Energy Technology Data Exchange (ETDEWEB)

    Bergen, Benjamin Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-07

    This is the PDF of a powerpoint presentation from a teleconference on Los Alamos programming models. It starts by listing their assumptions for the programming models and then details a hierarchical programming model at the System Level and Node Level. Then it details how to map this to their internal nomenclature. Finally, a list is given of what they are currently doing in this regard.

  14. Cuento: Los mellizos

    Directory of Open Access Journals (Sweden)

    Policarpo Varón

    1967-05-01

    Full Text Available Menecmo había adquirido el hábito de caminar un rato por las calles, - después de concluír su trabajo- en las tardes, antes de regresar a su cuarto. Con las manos en los bolsillos, aspirando el humo de un cigarrillo dejaba vagar sus pies al azar. Esto le proporcionaba no pocas sorpresas, y un conocimiento de la ciudad y de sus gentes, si no envidiable, sí respetable ...

  15. Pautas para los autores

    OpenAIRE

    2013-01-01

    Memorias es una revista de ciencias sociales y humanas que publica artículos de investigación sobre el desarrollo regional, territorial y local, considerando la articulación de los factores determinantes culturales, sociales, políticos, económicos y CTI. Su público objetivo son investigadores, grupos de investigación, profesores, y estudiantes de Colombia y otros países.

  16. en los pivotes centrales

    Directory of Open Access Journals (Sweden)

    Reynaldo Roque Rodés

    2005-01-01

    Full Text Available Se hace una revisión y comentarios sobre las ventajas y limitantes del empleo del LEPA (Low Enery Precision Aplication en los sistemas de riego de pivotes centrales. Estos sistemas o filosofía de manejo del agua para condiciones de escasez o mala calidad del líquido es una alternativa viable para la producción de alimentos. Introducida en la década del 80 en las planicies del sur de Texas, donde la alta evaporación del agua y la necesidad de regar grandes áreas con pivotes centrales obligaba a la búsqueda de una alternativa para incrementar al máximo la eficiencia de aplicación del riego. Aún en fase de estudio e introducción en Cuba para áreas específicas, puede ser una solución de incremento de los rendimientos de los cultivos, empleando menos agua y aguas con calidad limitada

  17. general de los suelos

    Directory of Open Access Journals (Sweden)

    Greco Cid L.

    2006-01-01

    Full Text Available En este trabajo se analiza y discute la introducción y el perfeccionamiento de un conjunto de ideas y criterios para la caracterización hidrofísica de suelos en áreas pequeñas como pueden ser fincas, granjas u otras, así como a escala de parcelas experimentales. El analisis está enfocado fundamentalmente desde el punto de vista metodológico, como herramienta en la caracterización de pequeñas áreas o parcelas que requieren de estudios detallados de determinadas propiedades y fenómenos que no están disponibles en mapas o informaciones obtenidas de trabajos a gran escala. Las principales propiedades físicas que se analizan se obtienen de las relaciones de masa y volumen de los constituyentes del suelo, así como de las relaciones de los constituyentes del suelo referidos tanto al volumen externo de la muestra como al volumen de solidos y los parámetros edafológicos fundamentales utilizados en el calculo de las relaciones hídricas (agua-aire en el suelo.

  18. Entre cerros, lagos y ciénega. Sociedad y condiciones de salud en el México prehispánico

    Directory of Open Access Journals (Sweden)

    Héctor Favila Cisneros

    2013-01-01

    Full Text Available Se comparan las condiciones de vida y salud de tres poblaciones prehispánicas mesoamericanas con ecosistemas similares, que se ubican en el Altiplano Central mexicano, a través de la observación macroscópica de osamentas y del registro de los indicadores de salud: cribra orbitalia, hiperostosis, hipoplasia del esmalte dental, así como la periostitis en estas tres series esqueléticas. Los resultados indican un porcentaje importante de problemas nutricionales en sinergia con infecciones no específicas de los sitios del Altiplano Central, así como también un porcentaje considerable de periostitis en los tres grupos analizados.

  19. Miranda en los estados unidos

    OpenAIRE

    Castro, Hermann

    2014-01-01

    El estudio del contexto histórico de los EstadosUnidos durante los viajes de personajes clavespara la independencia de Colombia, en estecaso Francisco de Miranda, ayuda a entender laspolíticas y percepciones de los independentistasy luego estadistas que participaron en lasprimeras relaciones internacionales entre losdos países. Se propone en este trabajo darleuna dimensión histórica a las experiencias deMiranda en los Estados Unidos.

  20. en los medios de prensa

    Directory of Open Access Journals (Sweden)

    Luis Alejandro Nitrihual Valdebenito

    2007-01-01

    Full Text Available Este trabajo presenta los resultados de un análisis de contenido realizado a la Revista de Libros de El Mercurio entre los años 2002-2004, y muestra la importancia de la publicidad en esta revista cultural y, en general, en los medios de comunicación. Con esto queremos mostrar la relevancia que tiene la empresa publicitaria en los modernos medios de comunicación.

  1. Los mercados virtuales como contraste de los mercados financieros

    OpenAIRE

    Ellafi, Saif; Vilker, Ana Silvia

    2014-01-01

    ¿Se comportan los mercados de las economías virtuales de forma similar a los mercados financieros reales? Dado que los primeros son pequeños con bienes y servicios finitos, surge la posibilidad de estudiarlos como si se trataran de abstracciones de la realidad o modelos de textos de economía y finanzas que cumplen supuestos imposibles en la realidad. Entonces, se procurará extrapolar y comparar el comportamiento de los agentes en ellas, con el de los mercados financieros para observar caracte...

  2. Los abrigos pintados de Helechal : un nuevo conjunto de arte rupestre esquemático en Badajoz

    Directory of Open Access Journals (Sweden)

    María Isabel Martínez Perelló

    1995-01-01

    Full Text Available La historia del descubrimiento de los abrigos que aquí damos a conocer se remonta a septiembre de 1982, cuando Don José Merino Martín, «Polín», vecino del pueblo pacense de Helechal, acompañado de algunos amigos redescubre de manera fortuita el Abrigo del Zarzal y el Abrigo Superior del Cerro de Las Moriscas, en la Sierra de Tiros (Helechal,T.M. Benquerencia de la Serena, Badajoz. Estos abrigos habían sido estudiados ya por el abate Breuil en 1933, olvidándose después su ubicación exacta, por lo que su localización supuso para el señor Merino un estímulo para buscar nuevas estaciones rupestres en la sierra, que se vio incrementado al comenzarse la transformación de esa sierra para ser utilizada como coto de caza privado. Desde entonces y hasta nuestros días una veintena de nuevos abrigos con pinturas rupestres han sido descubiertos. En mayo de 1990 los vecinos de Helechal pusieron tales hallazgos en conocimiento de la Junta de Extremadura, información que ésta nos remitió para que procediéramos a su estudio.

  3. Próxima NIIF 15: 'Los ingresos de los contratos con los clientes'

    OpenAIRE

    Rodríguez García, Ferran

    2014-01-01

    Los dos principales emisores de normas internacionales de información financiera, el International Accounting Standards Board (IASB) y el Financial Accounting Standards Board (FASB) de los EUA han emitido, a finales del pasado mes de mayo y coordinadamente, sendas y respectivas normas de contenido común en las que se regula el reconocimiento contable de los ingresos ordinarios de las empresas procedentes de los contratos establecidos con clientes. Ambas normas resultaran de aplicación efectiv...

  4. Coccidiosis en los animales

    OpenAIRE

    Sánchez Herrera, Manuel

    2011-01-01

    Los trabajos llevados a cabo por mí sobre coccidiosis en el Departamento de Anatomía Comparada de la Escuela de Medicina de Harvard, me dan tema para llenar el requisito reglamentario en el concurso extraordinario para Profesores Agregados en el presente año.' Las experiencias fueron hechas en 1931 bajo la direccién del Profesor de Anatomía Comparada, Dr. Ernest Edward Tyzzer, y se emplearon más o menos 150 pollos de 6 a 73 días de edad. La historia clínica de cada pollo comprendía su edad, s...

  5. Los cinco sentidos

    OpenAIRE

    Tamir, Abraham; Ruiz Beviá, Francisco

    2014-01-01

    Percibimos el mundo que nos rodea por medio de nuestros cinco sentidos principales, la vista, el oído, el tacto, el gusto y el olfato. Los sentidos alimentan nuestro cerebro con bits de información que nos ayudan a construir una imagen del complicado mundo que nos rodea. Científicamente un sentido se define como un medio de recibir información del mundo exterior o de nuestro cuerpo y convertirla en un código electroquímico que es procesado por el cerebro.

  6. Los Delitos especiales

    OpenAIRE

    2003-01-01

    La presente investigación se divide en tres Partes. La Primera Parte se ocupa del concepto de delito especial. En ella se defiende un concepto de delito especial simple y dependiente de la autoría y la tentativa. Lo primero obedece a la pluralidad de fundamentos de los delitos especiales. Lo segundo, por una parte, a que no cualquier concepto de autor, sino sólo un concepto restrictivo es compatible con el concepto de delito especial; y, por otra, a que, aunque ello no es lógicamente necesari...

  7. Delitos especiales, Los

    OpenAIRE

    2003-01-01

    La presente investigación se divide en tres Partes. La Primera Parte se ocupa del concepto de delito especial. En ella se defiende un concepto de delito especial simple y dependiente de la autoría y la tentativa. Lo primero obedece a la pluralidad de fundamentos de los delitos especiales. Lo segundo, por una parte, a que no cualquier concepto de autor, sino sólo un concepto restrictivo es compatible con el concepto de delito especial; y, por otra, a que, aunque ello no es lógicamente necesari...

  8. Los hermanos Graco

    OpenAIRE

    Antolínez Escudero, Adrián

    2016-01-01

    Las figuras delos hermanos Graco son unas de las más debatidas y cuestionadas de la historia, no solo de la historia de Roma, sino de la misma historia de Europa. Vivieron en tiempos convulsos, pues la República de Roma empezaba a mostrar signos evidentes de agotamiento, dando sus últimos coletazos, que supusieron la puerta de entrada para el surgimiento del que posteriormente se conocería como Imperio Romano. Los factores que ayudaron a acabar con el régimen republicano romano son variados, ...

  9. null Cerro Negro, Nicaragua Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This cinder cone in western Nicaragua has a name that means "black hill." It has erupted more than 20 times since its birth in 1850. Explosive eruptions from the...

  10. FLOODPLAIN, CERRO GORDO COUNTY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

  11. Cooperación y conflicto entre empresas, comunidades, nuevos movimientos sociales y el papel del gobierno. El caso de Cerro de San Pedro

    Directory of Open Access Journals (Sweden)

    José G. Vargas-Hernández

    2009-01-01

    Full Text Available El objetivo de este trabajo es analizar las relaciones de cooperación y conflicto entre la Compañía Minera (MSX y las comunidades de San Pedro, Soledad y San Luis Potosí, los Nuevos Movimientos Sociales y los tres niveles de gobierno involucrados. La compañía Minera inició operaciones en una mina a cielo abierto de oro y plata con el apoyo de oficiales de los gobiernos locales, estatales y federal. Los habitantes de estas comunidades apoyados por grupos ambientalistas y Organizaciones No Gubernamentales argumentan que el proyecto contamina las fuentes de agua fresca, además de perturbar el medio ambiente y la ecología de la región. En tal sentido el artículo analiza el impacto, la interacción social y de conflicto entre los distintos actores desde una perspectiva local y socio-ambiental, previa contextualización histórica de subregión y el desarrollo de la industria minera.

  12. Los Anhelos Del Agro

    Directory of Open Access Journals (Sweden)

    Chaparro G. A.

    1942-08-01

    Full Text Available Hablemos hoy del campesino y de su desventura, y hagámoslo, perfectamente libres de toda insana y falaz intención demagógica. Démosle el frente con resolución a esa obscura costumbre de halagar las pasiones de las gentes y explotar con fines proclives las profundas esperanzas y los honrados anhelos de los campesinos, y digamos que en Colombia, y en muchos países de América, se ha abusado impunemente de esa masa resignada que sustenta las economías de estos países, y se ha desconocido el meollo verdadero de sus problemas fundamentales, sin que las fórmulas prácticas de resolvemos íntegramente hayan aparecido, limitándose la acción a meras iniciativas aisladas e inconexas a veces contradictorias, cuyos resultados quedan perdidos en medio de la magnitud total de las situaciones.

  13. Los Cuadernos INTEMAC

    Directory of Open Access Journals (Sweden)

    Calavera Vayá, Ana

    2008-06-01

    Full Text Available Since it’s foundation in June 1967 the Technical Institute for Materials and Construction (INTEMAC established the incentivation of technical training and the researching vocation of it’s staff as it’s goals. For the past eighteen years INTEMAC’s quarterlies have represented the shaping of this spirit, for what the Institute has become well known in the building business. Covering more and more topics every year, the sixty-six titles which have been published until now have all been dedicated to a big variety of issues such as the pre-standardization, the creation of guides of practical application on specific subjects, pathology or the building works of a certain importance inside the national panorama. Trying to maintain, altogether, a certain balance between edification issues, civil construction and rehabilitation of already existing buildings.The publication of INTEMAC’s quarterly has never stopped, with a three-month periodicity, programmed with a lot of anticipation, and a bilingual edition in Spanish and English, which is around 2500 copies nowadays. The following text tries to be a mirror of the evolution of this publication throughout time, with a few comments which will help the reader guess what we expect from the future days.Desde su fundación, en Junio de 1967, el Instituto Técnico de Materiales y Construcciones (INTEMAC estableció como uno de sus objetivos la incentivación de la formación técnica y de la vocación investigadora de su plantilla. Durante los últimos dieciocho años los Cuadernos INTEMAC han representado la plasmación de este espíritu, por el que el Instituto ha llegado a ser bien conocido en el mundo de la Construcción. Cubriendo campos cada vez más amplios, los 66 números publicados hasta ahora se han dedicado a asuntos tan variados como la pre-normativa, la creación de guías de aplicación práctica sobre temas concretos, la patología o las obras de una especial importancia

  14. Exploración sobre las migraciones internas en las provincias y los municipios de Cuba (1995-1997 y 1998-2000

    Directory of Open Access Journals (Sweden)

    Norma Montes Rodríguez

    2003-01-01

    Full Text Available El artículo analiza las migraciones internas en Cuba atendiendo a dos escalas territoriales: provincial y municipal. El análisis se basa en la comparación de la dinámica migratoria de los períodos 1995-1997 y 1998-2000. La definición de estos períodos la pone el año 1997, año en que el Decreto-Ley 217 va a regular el ingreso temporal o permanente en la Ciudad de La Habana, y especialmente en los municipios de Habana Vieja, Centro Habana, Cerro y 10 de Octubre. Algunos de los resultados de la investigación evidencian como un proceso restrictivo en la llegada de emigrantes a La Capital puede cambiar el sentido de la emigración hacia otros territorios antes no considerados, o considerados menos, como lugar de destino. Las fuentes estadísticas utilizadas ha sido las Estadísticas Continuas desde 1995 al 2000 (Oficina Nacional de Estadísticas y Anuario Demográfico de la Oficina Nacional de Estadística.

  15. Estado de conservación de Melanomys zunigae (Sanborn 1949 y de los mamíferos pequeños en las Lomas de Lima

    Directory of Open Access Journals (Sweden)

    José Luis Mena

    2013-04-01

    Full Text Available En la costa y vertiente occidental ocurren los principales endemismos de mamíferos peruanos. Así mismo, a lo largo de la costa central, sobresale el único mamífero endémico del departamento de Lima, el ratón arrozalero de Zúñiga, Melanomys zunigae (Sanborn, 1949, registrado en las lomas de Atocongo y el cerro San Jerónimo por Enrique Zúñiga en 1942. Desde entonces se han realizado esporádicas evaluaciones, no necesariamente dirigidas a su búsqueda, aunque sin ningún registro. Nuestro estudio tuvo como objetivo la búsqueda de evidencias de la presencia de M. zunigae en las lomas de Lima, basados en un trampeo no exhaustivo y posteriormente en un análisis de regurgitos de la lechuza de los arenales (Athene cunicularia. Desafortunadamente no registramos ningún individuo de M. zunigae; sin embargo, encontramos evidencias que el impacto de la expansión urbana estaría afectando los ensamblajes de mamíferos pequeños en las lomas de Lima. Varios factores pudieron haber determinado la desaparición de M. zunigae. Entre estas se incluyen la destrucción del hábitat, invasión de especies exóticas y el aislamiento de las lomas.

  16. The Marianas-San Marcos vein system: characteristics of a shallow low sulfidation epithermal Au-Ag deposit in the Cerro Negro district, Deseado Massif, Patagonia, Argentina

    Science.gov (United States)

    Vidal, Conrado Permuy; Guido, Diego M.; Jovic, Sebastián M.; Bodnar, Robert J.; Moncada, Daniel; Melgarejo, Joan Carles; Hames, Willis

    2016-08-01

    The Cerro Negro district, within the Argentinian Deseado Massif province, has become one of the most significant recent epithermal discoveries, with estimated reserves plus resources of ˜6.7 Moz Au equivalent. The Marianas-San Marcos vein system contains about 70 % of the Au-Ag resources in the district. Mineralization consists of Upper Jurassic (155 Ma) epithermal Au- and Ag-rich veins of low to intermediate sulfidation style, hosted in and genetically related to Jurassic intermediate composition volcanic rocks (159-156 Ma). Veins have a complex infill history, represented by ten stages with clear crosscutting relationships that can be summarized in four main episodes: a low volume, metal-rich initial episode (E1), an extended banded quartz episode with minor mineralization (E2), a barren waning stage episode (E3), and a silver-rich late tectonic-hydrothermal episode (E4). The first three episodes are interpreted to have formed at the same time and probably from fluids of similar composition: a 290-230 °C fluid dominated by meteoric and volcanic waters (-3‰ to -0‰ δ18Owater), with <3 % NaCl equivalent salinity and with a magmatic source of sulfur (-1 to -2 ‰ δ34Swater). Metal was mainly precipitated at the beginning of vein formation (episode 1) due to a combination of boiling at ˜600 to 800 m below the paleowater table, and associated mixing/cooling processes, as evidenced by sulfide-rich bands showing crustiform-colloform quartz, adularia, and chlorite-smectite banding. During episodes 2 and 3, metal contents progressively decrease during continuing boiling conditions, and veins were filled by quartz and calcite during waning stages of the hydrothermal system, and the influx of bicarbonate waters (-6 to -8.5 ‰ δ18Owater). Hydrothermal alteration is characterized by proximal illite, adularia, and silica zone with chlorite and minor epidote, intermediate interlayered illite-smectite and a distal chlorite halo. This assemblage is in agreement with

  17. Comparison of 36Cl and 3He measurements in glacial surfaces on the tropical Altiplano (Cerro Tunupa volcano, 20°S)

    Science.gov (United States)

    Schimmelpfennig, Irene; Blard, Pierre-Henri; Lavé, Jérôme; Benedetti, Lucilla; Aster Team

    2016-04-01

    The combination of two or more cosmogenic nuclides measured in the same rock samples allow complex landscape exposure histories to be quantified, due to the nuclide-specific production and decay rates. In supposedly simple exposure scenarios, such as moraine chronologies, the use of more than one nuclide can also help identify outliers caused by geomorphological bias (e.g. "inheritance") or analytical problems (e.g. nuclide loss or contamination during chemical extraction). The two cosmogenic in situ nuclides 3He and 36Cl are potentially very useful to be simultaneously measured in quartz-lacking lithologies, but their application is more challenging than that of combined 10Be and 26Al measurements, which are routinely employed in quartz-bearing rocks. This is, amongst other things, because the production of 3He and 36Cl depend on various compositional factors. Therefore, 3He and 36Cl have rarely been measured in the same samples so far. Here, we present 36Cl measurements in plagioclases extracted from four moraine boulders and one roche moutonnée on the southern flank of Cerro Tunupa volcano, located in the tropical Bolivian Andes (3800-4500 m, 20°S). In pyroxenes of these samples, 3He has previously been measured to gain insights into the local deglaciation history and climate conditions about 15 kyr ago during the Lake Tauca highstand (Blard et al., 2009, 2013). The ages calculated from the measured 3He and 36Cl concentrations of the 5 samples range from 12 kyr to 180 kyr and are generally in good agreement. The good age agreement of a boulder surface (TU-1C) that is significantly older than the other boulder ages from this moraine confirm the suspicion, that it was exposed to cosmic radiation previous to its last deposition (Blard et al., 2009, 2013). In contrast, the 36Cl age of the roche moutonnée surface (TU2) is significantly younger than the corresponding 3He age, but fits well with the adjacent moraine mean age. It thus arises the question if the 3He

  18. Análisis paleoambiental y procedencia de los depósitos en el extremo suroeste de la sierra de Aconquija, provincia de Catamarca

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2012-12-01

    Full Text Available Se realizó el estudio de facies y petrografía de los depósitos sedimentarios y volcaniclásticos-sedimentarios expuestos en la zona de cerro Atajo, cerro Blanco y alrededores del río Capillita, provincia de Catamarca, con el fin de analizar los paleoambientes sedimentarios y la proveniencia de los mismos. Estos comprenden bancos rojos depositados por sistemas fluviales correspondientes a la Formación Hualfin (Eoceno-Mioceno inferior? y acumulaciones clásticas, volcaniclásticas y depósitos volcánicos primarios intercalados, del Complejo Volcánico Farallón Negro (Mioceno superior- Plioceno. La asociación de facies de la Formación Hualfin está caracterizada por el desarrollo de una sucesión de formas de lecho predominantemente arenosas, en menor medida, barras gravosas conformando un sistema fluvial entrelazado arenoso poco profundo perenne. Las muestras analizadas de la Formación Hualfin corresponden a arenitas cuarzosas, derivadas principalmente del resultado de la erosión de rocas graníticas y gnéisicas con elevados porcentajes de cuarzo, que muestran proveniencias de interior cratónico y orógeno reciclado cuarzoso. El paleoambiente de los depósitos del Complejo Volcánico Farallón Negro evoluciona desde un sistema fluvial de río entrelazado distal areno dominado a uno de sistema fluvial entrelazado gravoso asociado a flujos de gravedad, para culminar en un sistema fluvial entrelazado gravoso somero. En estos depósitos se han podido diferenciar de base a techo: wackes cuarzosas, con proveniencias de orógeno reciclado que habría derivado del basamento; wackes líticas, con alto porcentaje de fragmentos líticos volcánicos de basaltos y con proveniencia de arco no disectado. Wackes feldespáticas, con altos porcentajes de plagioclasa y en menor medida clastos de andesitas, producto del cambio composicional del aporte volcánico.

  19. Los pros y los contras del uso de la mariguana

    OpenAIRE

    Cleva Villanueva

    2010-01-01

    La mariguana es la droga más usada en todo el mundo. El presente estudio analiza los efectos de los fitocanabinoides (contenidos en la mariguana) y de los canabinoides endógenos (producidos en el organismo). Se evalúan las posibilidades terapéuticas destacando el efecto antiemético (único uso aceptado). Al final se emite una opinión sobre la legalización basada en los efectos permanentes que produce y que están asociados al uso en edad temprana.

  20. Los santos patronos de los migrantes Mexicanos a Estados Unidos

    OpenAIRE

    Rafael Alarcón; Macrina Cardenas Montaño

    2013-01-01

    La mayor parte los migrantes mexicanos indocumentados que buscan encontrar un empleo en Estados Unidos son católicos, por esta razón, han incorporado a la devoción de los santos patronos sus tribulaciones que incluyen el trayecto desde sus comunidades de origen a la frontera norte, los peligros del cruce indocumentado, la búsqueda de trabajo y la posible deportación. El objetivo central de este artículo es analizar las características más importantes de tres devociones de los migrantes indocu...

  1. Los imaginarios de los futuros periodistas en Francia

    Directory of Open Access Journals (Sweden)

    M Santos-Sainz

    2013-02-01

    Full Text Available El artículo se centra en investigar las diferencias de percepción de las realidades profesionales y sociales según la pertenencia socio-profesional del ámbito familiar de los futuros periodistas y según la pertenencia de género. La metodología se basa en dos niveles de estudio. El primero responde al análisis de los datos empíricos sobre las características sociales de los estudiantes de periodismo antes de integrar los estudios dispensados por los centros de formación profesionalizada en periodismo de las universidades públicas de Estrasburgo, Burdeos, Tours y Marsella. El segundo nivel de análisis se construye a partir de toda una serie de entrevistas en profundidad que trazan el pasado familiar y permiten conocer los valores y representaciones de la profesión de los estudiantes del Instituto de Periodismo de Burdeos. Los resultados demuestran que los estudiantes de periodismo no son una categoría homogénea. Las diferencias respecto a su origen social resultan notables e influyen sobremanera en el imaginario de la profesión.

  2. An empirical calibration for {sup 4}He quantification in minerals and rocks by laser fusion and noble gas mass spectrometry using Cerro de Mercado (Durango, Mexico) fluorapatite as a standard

    Energy Technology Data Exchange (ETDEWEB)

    Sole, Jesus [Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, 04510 Mexico, D.F. (Mexico)]. E-mail: jsole@geologia.unam.mx; Pi, Teresa [Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Cd. Universitaria, 04510 Mexico, D.F. (Mexico)

    2005-04-11

    An empirical calibration with a natural mineral standard (fluorapatite from Cerro de Mercado, Mexico) is proposed as a method to determine the {sup 4}He concentration of mineral and rock samples. The procedure is based on the fusion of several aliquots of the fluorapatite standard with a well-spaced weight distribution in order to obtain a good correlation in coordinates of {sup 4}He peak height versus fluorapatite weight. The weight is then converted to moles using the accepted mineral age (31.4 Ma) and appropriate formula. Experimental peak height of {sup 4}He for the unknown samples are converted to moles with the regression determined for fluorapatite. The procedure is fast and inexpensive, and both precision and accuracy are always below 10% and usually about 3-5%.

  3. Determinación de las estructuras tubulares presentes en el Pit6 en el depósito laterítico de níquel de Cerro Matoso

    OpenAIRE

    Castrillón Peña, Andrés

    2012-01-01

    Una sucesión de rocas con fósiles de organismos bentónicos en el depósito laterítico de níquel de Cerro Matoso S.A. (CMSA), localizadas en el extremo nororiental del cuerpo ultramáfico Denominado en proceso minero Pit6 a la altura del Banco 42, fueron estudiadas y analizadas Con petrografía, XRD, XRF y SEM. Estas rocas permiten precisar la génesis del yacimiento más importante de níquel en el país actualmente. La sucesión de rocas calcáreas autigénicas fosilíferas y depósitos ...

  4. Aprovechamiento sostenible de los pastizales

    Directory of Open Access Journals (Sweden)

    Salvador Rebollo

    2003-01-01

    Full Text Available Debido a la gran extensión ocupada por los ecosistemas de pastizal y a su relativamente elevado grado de naturalidad, la gestión de los pastizales tendrá importantes implicaciones en la conservación de numerosas especies silvestres de los distintos niveles tróficos. En este artículo sugerimos ideas básicas para que el aprovechamiento de los pastizales no comprometa su viabilidad futura. Para ello, repasamos el concepto de ecosistema de pastizal, describimos sus distintas configuraciones dependiendo de la intensidad del aprovechamiento, señalamos importantes componentes del pastizal que favorecen su estabilidad y que permitirán un manejo sostenible de los mismos y, finalmente, exponemos las características básicas que debe tener un plan de seguimiento y control de la explotación de los pastizales

  5. Los piratas en Cartagena

    Directory of Open Access Journals (Sweden)

    Soledad Acosta de Samper

    1964-06-01

    Full Text Available Cartagena ha sido siempre para mi espíritu una de las ciudades más interesantes de Colombia, no tan solo por su poética belleza, por la amable hospitalidad que siempre he recibido en ella las veces que la he visitado, y por su heroica historia -desde el descubrimiento, al empezar el siglo XVI, hasta los acontecimientos ocurridos allí en el año último--, sino también porque en sus playas vaga par a mi el recuerdo de mi padre, a cuyo lado visité en la infancia aquellas magníficas murallas; aquellas ruinas asombrosas de una grandeza que aún no ha muerto.

  6. Los otros signos

    Directory of Open Access Journals (Sweden)

    Sáez, Carlos

    2004-12-01

    Full Text Available The aim of this article is to study the signs and symbols that appear in the hispanic medieval documents and manuscripts whose form does not derive from the word subscripsi or from the cross. These signs and symbols have usually been considered simply as mere elements to validate the charters. However, these elements were useful as a mean of visual communication between the high classes, able to generate charters, and the rest of medieval society, the majority illiterate.

    Este trabajo se enmarca en el proyecto de investigación Usos, prácticas y modelos de conservación de lo escrito en la península ibérica entre los siglos XI a XVII, n° de referencia BHA 2002-02541, financiado por el Ministerio de Ciencia y Tecnología, dirigido por Carlos Sáez (Universidad de Alcalá.

  7. Los palacios de Themis

    OpenAIRE

    Hugo Arciniega

    2000-01-01

    Hugo Arciniega reseña el estado en que se encontraba el sistema penitenciario mexicano al mediar el siglo xix. Por medio de un seguimiento filológico del proceso que llevó a la construcción de la cárcel de la Acordada durante el régimen colonial, y del análisis arquitectónico y urbanístico de esta cárcel, el autor expone las condiciones en que vivían los presos mexicanos hacia 1840, cuando Ignacio Cumplido, el editor de El Mosaico Mexicano, ingresó como recluso. De las críticas que hiciera es...

  8. Los impactos del turismo

    Directory of Open Access Journals (Sweden)

    Tomás Franco Aliaga

    1999-01-01

    Full Text Available El turismo aparece, dentro de la economía española, como una actividad determinante desde los años sesenta. Sus efectos beneficiosos se han dejado sentir no sólo en la Balanza de Pagos o en el Producto Interior Bruto, sino que también han impactado favorablemente en el empleo y en la cultura. Sin embargo, esas repercusiones no han sido tan positivas en el medio ambiente, pues nuestras costas sufren numerosos problemas urbanísticos, infraestucturales y de contaminación diversa.Tourism appears, within the Spanish economy, as a determinant activity since the sixties. Its beneficial effects have showed not only on the Balance of Payments or the Gross Domestic Product, but also on employment and the culture. However, those effects have not been as positive for the environment since our coasts are suffering a lot from urbanism, infrastructure and pollution problems.

  9. Hasta los últimos confines

    OpenAIRE

    Córdoba, Joaquín Mª

    2005-01-01

    El 19 de mayo de 1798, la flota encargada de trasladar el ejército que iba a conquistar Egipto levó anclas del puerto de Toulon. Aunque tres años después la aventura se saldara en fracaso, el siglo XIX comenzó así con este temprano intento francés, que consiguió dominar durante algún tiempo el Valle del Nilo, soñó abrir el Canal de Suez y decidió el desarrollo moderno de los estudios sobre la cultura islámica y el antiguo Egipto. Desde entonces y hasta la I Guerra Mundial, el mundo iba a vivi...

  10. Los muertos del Floreanismo

    Directory of Open Access Journals (Sweden)

    Enrique Ayala Mora

    2008-06-01

    Full Text Available El artículo analiza el crimen político durante las primeras décadas de vida de la República del Ecuador. Específicamente centra su estudio en el período dominado por la figura de Juan José Flores, primer presidente del Ecuador. La inestabilidad política, la precariedad de las alianzas entre las élites regionales, la crisis económica generada por las guerras de Independencia, las conspiraciones y la violencia que caracterizaron al período de surgimiento de las repúblicas andinas hicieron del crimen político un “vicio de nacimiento”. El asesinato del general Antonio José de Sucre, la muerte de los miembros de la sociedad El Quiteño Libre, el homicidio de Juan Otamendi, entre otros, hicieron patente esta característica.

  11. The flow dynamics of an extremely large volume pyroclastic flow, the 2.08-Ma Cerro Galán Ignimbrite, NW Argentina, and comparison with other flow types

    Science.gov (United States)

    Cas, Ray A.F.; Wright, Heather M.; Folkes, Christopher B.; Lesti, Chiara; Porreca, Massimiliano; Giordano, Guido; Viramonte, Jose G.

    2011-01-01

    The 2.08-Ma Cerro Galán Ignimbrite (CGI) represents a >630-km3 dense rock equivalent (VEI 8) eruption from the long-lived Cerro Galán magma system (∼6 Ma). It is a crystal-rich (35–60%), pumice (multiple depositional units, often separated by pyroclastic surge deposits. The CGI preserves a widespread sub-horizontal fabric, defined by aligned elongate pumice and lithic clasts, and minerals (e.g. biotite). A sub-horizontal anisotropy of magnetic susceptibility fabric is defined by minute magnetic minerals in all localities where it has been analysed. The CGI is poor in both vent-derived (‘accessory’) lithics and locally derived lithics from the ground surface (‘accidental’) lithics. Locally derived lithics are small (order to explain the contemporaneous maintenance of high particle concentration, high sedimentation rate at the depositional boundary layer and a high level of mobility, it is also proposed that the flow(s) was continuously supplied at a high mass feeding rate. It is also proposed that internal gas pressure within the flow, directed downwards onto the substrate over which the flow was passing, reduced the friction between the flow and the substrate and also enhanced its mobility. The pervasive sub-horizontal fabric of aligned pumice, lithic and even biotite crystals indicates a consistent horizontal shear force existed during transport and deposition in the basal granular flow, consistent with the existence of a laminar, shearing, granular flow regime during the final stages of transport and deposition.

  12. Los 'Colorados': Etnohistoria y Toponimia

    NARCIS (Netherlands)

    Gómez-Rendón, J.

    2015-01-01

    Los "colorados" comprendían varios grupos étnicos emparentados etnolingüísticamente que ocupaban el piedemonte andino occidental desde El Carchi hasta Bolívar así como las tierras bajas del Pacífico en los sistemas hidrográficos de los ríos Esmeraldas y Guayas. Aunque la ocupación "colorada" de esta

  13. Los objetivos del desarrollo

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    Currie Lauchlin

    1993-12-01

    Full Text Available To broach the goals of development implies broaching the problem of economic growth in a critical manner. Not only the concept of growth but also the means of achieving it in practice should be questioned. Growth is not an end, it is a means of gaining access to development And development should not be understood as a goal, but as a permanent process of learning tending towards more control over the environment and greater levels of well-being. It is not a matter of increasing GNP linearly; development must occur, sustained growth that, without being a threat to mm or to our natural resources, can lead to the eradication of absolute and relati.ve poverty. The low rates of growth of the developing countries constitute structural problem that can /lot be reso1.ved by resorting to the neo-classical mechanisms of mobility, nor to the Keynesian formulas. These have served as a source of inspiration to the Harrod-lX:m3r·type models of growth which limit themselves to stimulating savings and ending unemployment by concentrating exclusively on the monetary demand. Getting OUt of the vicious circle of low growth implies eradicating poverty with respect into the immediateness of a direct attack on the problem. with respect to the developed counties, growth is starting to became harmful, and, given the prevalence of ostensible consumption and of pecuniary emulation, it is imperative to foment non-economic motivation that will permit the eradication of relative poverty.

    Abordar los objetivos del desarrollo implica abordar de manera crítica el problema del crecimiento econ

  14. PERSPECTIVA SEXUAL DE LOS ADOLESCENTES

    OpenAIRE

    Chaves Araya, Mariana

    2011-01-01

    El presente estudio tiene como objetivo identificar los conocimientos, actitudes y prácticas sexuales de adolescentes, con el fin de establecer el abordaje apropiado de las necesidades relacionadas con la sexualidad en este grupo de jóvenes. Para tal efecto, se realizó una encuesta al 85% de los estudiantes de décimo y undécimo años de los siete colegios del cantón central de Puntarenas, Chacarita y Barranca. Se logró determinar que los jóvenes tienen conocimientos sobre anatomía y fis...

  15. Los jaklexa y el saber

    Directory of Open Access Journals (Sweden)

    Simón Esmeral Ariza

    2014-02-01

    Full Text Available "En aquella época, cuando el calendario n o había nacido y el tiempo no había aprendido a contar, Aluna Jaba, iniciaba su obra creadora". Ella, Aluna Jaba, la madre pensamiento,la madre Universal, la magna mater, la creadora de estemundo fantástico Yreal de los que se autodenominan "los hermanos mayores" los que en su cosmovisión han hecho de la Sierra Nevada de Santa Marta, "el corazón del mundo", de aquellos que se han autodenominado Yen verdad son los guardianes del saber, los sabios de este mundo lleno de misterios y conocimientos "LosJaklexa" , aquellos que por designio de la madre han echado sobre sus hombros el cuidado y los destinos del "Universo" son los mismos querelata el mito Kággaba en el cual los hijos de Mama Ywisa llevan sobre sus hombros el universo entero.

  16. Del ENIAC, hasta los andares

    OpenAIRE

    2014-01-01

    Si bien los computadores actuales, en todas sus variantes —portátiles, tabletas, teléfonos inteligentes—, resultan más pequeños, baratos y rápidos que los precedentes, no es menos cierto que el estudio minucioso de las viejas glorias de la historia de la informática nos puede facilitar la comprensión, no solo de algunos de los aspectos de la tecnología informática de aquel momento e incluso de la actual, sino también de los rasgos socioculturales propios del entorno científico y huma...

  17. Los 5 entierros de Pessoa

    Directory of Open Access Journals (Sweden)

    Juan Manuel Roca

    1998-05-01

    Full Text Available Nació en Medellín (Antioquia en 1946. Ha publicado, entre otros, los siguientes libros: Memoria del agua (1973, Luna de ciegos (1974, Los ladrones nocturnos (1977, Señal de cuentos (1979, Fabulario real (1980, País secreto (1988, Ciudadano de la noche (1989, Pavana con el diablo (1990, Monólogos (1994, Cuaderno de mapas (1994, La farmacia del ángel (1995, Vengo a golpear a tu puerta (1997, Tertulia de ausentes (1998. Los poemas son inéditos y su autor los ha cedido al Boletín.

  18. Terapia intensiva: El problema de los medios y los fines

    Directory of Open Access Journals (Sweden)

    Carlos Gherardi

    2011-12-01

    Full Text Available La tecnología médica aplicada a la medicina del paciente agudo y grave permitió la creación de un área asistencial diferenciada y el desarrollo del cuidado intensivo como una nueva especialidad. Los nuevos medios disponibles para reemplazar o asistir funciones de órganos vitales fueron los determinantes de este avance tan importante en el desarrollo de toda la alta complejidad médica en los últimos cuarenta años. Sin embargo la aplicabilidad de estos medios, que en este caso son los soportes vitales, no se han podido sustraer de la filosofía del imperativo tecnológico que ha impregnado a toda la cultura de la sociedad contemporánea. Se observa en este tiempo una influencia perniciosa que perturba el recuerdo permanente de los fines de la medicina, que no son los de evitar la muerte o a la consideración del valor vida como un absoluto ajeno a las preferencias del paciente. Las decisiones finales en circunstancias irreversibles, en que sólo es posible mantener una vida biológica, deben ser tomadas por los médicos y los familiares.

  19. Geología y geoquímica de los cuerpos básicos alcalinos al sur de los lagos Musters y Colhué Huapí, cuenca del golfo San Sorge, Chubut

    Directory of Open Access Journals (Sweden)

    Nilda D Menegatti

    2014-12-01

    Full Text Available En la región de los lagos Colhué Huapí y Musters, situada en la sierra de San Bernardo en el centro sur de la provincia del Chubut, afloran cuerpos ígneos básicos de carácter alcalino con estructuras de stocks, sills, lopolitos y diques, con edades comprendidas entre el Eoceno y Pleistoceno. En este trabajo, se presentan los resultados obtenidos del estudio efectuado en los cerros Negro, Cresta-Puricelli, Guacho, Solo, San Bernardo, Cresta-Trompete y Los Leones-Tumba del Indio, todos ellos localizados al sur de la localidad de Sarmiento. La litología identificada corresponde a gabro, monzogabro nefelínico, sienita nefelínica, basalto y basanita, siendo el gabro la variedad predominante. De acuerdo a la forma, el tamaño, los gradientes texturales y la presencia de zeolitas que presentan los cuerpos intrusivos, se considera que éstos se emplazaron en niveles corticales altos (<1 km. La mayoría de las rocas analizadas son básicas con un porcentaje de SiO2 entre 44 y 48 %, y se caracterizan por el alto contenido en Fe2O3 (10,66-14,67 %, TiO2 (1,23-3,37 % y álcalis (3,35-5,91 %. Los diagramas normalizados tienen el diseño típico de basaltos alcalinos de intraplaca, compatibles con una fuente de tipo OIB enriquecida en elementos incompatibles, con residuo granatífero en la fuente y ausencia de contaminación con la placa subducida o cortical. La pendiente pronunciada de la curva normalizada de REE (La/Yb = 10,2-22,4 señala relativamente bajos grados de fusión parcial. A partir del análisis estructural se plantea un ambiente extensional para el emplazamiento de estos cuerpos que es coherente con lo que indican las características geoquímicas.

  20. Los santos patronos de los migrantes Mexicanos a Estados Unidos

    Directory of Open Access Journals (Sweden)

    Rafael Alarcón

    Full Text Available La mayor parte los migrantes mexicanos indocumentados que buscan encontrar un empleo en Estados Unidos son católicos, por esta razón, han incorporado a la devoción de los santos patronos sus tribulaciones que incluyen el trayecto desde sus comunidades de origen a la frontera norte, los peligros del cruce indocumentado, la búsqueda de trabajo y la posible deportación. El objetivo central de este artículo es analizar las características más importantes de tres devociones de los migrantes indocumentados en Tijuana, Baja California, México: Santo Toribio Romo, el "Santo Pollero" que fue canonizado en 2000, el Beato Juan Bautista Scalabrini, fundador de los Misioneros Scalabrinianos y Juan Soldado quien surgió de la religiosidad popular.

  1. Los Palaeotheriidae (Perissodactyla, Mammalia del Eoceno de la Cuenca del Duero (Castilla y Leon, Espana

    Directory of Open Access Journals (Sweden)

    Cuesta Ruiz-Colmenares, M. A.

    1993-04-01

    Full Text Available The systematic study of the Palaeotheriidae (Perissodactyla, Mammalia of the Eocene of the Duero Bassin (Castilla y León, Spain has permited to identify 3 new species: Palaeotherium giganteum nov. sp., Cantabrotherium casanovasae nov. sp. and Franzenium durense nov. sp., all of the Mazaterón bed (middle Eocene-upper Eocene, MP16-17, Almazán subbassin, Soria. Franzenium durense nov. sp. is present also in Caenes (middle Eocene, MP16, southoccidental area, Salamanca. The described forrns display a special combination of primitive characters, mainly in the premolars, with almost void molarization, and derived characters, detaching a strong hipsodonty; such combination is not known in the other species of the Family. In a biogeographical order this fauna shows a strong endemic character, with a almost complete independence of the occidental Europe and subpyrenean area, and only sorne peninsular beds, Llamaquique (Oviedo and Huérmeces del Cerro (Guadalajara have similar forms. In 3 other beds, situates in the southoccidental area, Casaseca de Campeán (middle Eocene, MP13-14, Zamora, Molino del Pico (upper Eocene-Oligocene, Zamora and San Morales (Middle Eocene, MP16, Salamanca the Palaeotheriidae are very rares and the limited material doesn't have to perrnit the identification at the generic level.El estudio sistemático de los Palaeotheriidae (Perissodactyla, Marnmalia del Eoceno de la Cuenca del Duero (Castilla y León, España ha permitido identificar tres nuevas especies: Palaeotherium giganteum nov. sp., Cantabrotherium casanovasae nov. sp. y Franzenium durense nov. sp., todas ellas del yacimiento de Mazaterón (Eoceno medio-Eoceno superior, MP16-17, subcuenca de Almazán, Soria. Franzenium durense nov. sp. está también presente en Caenes (Eoceno medio, MP16, área suroccidental, Salamanca. Las formas descritas presentan una especial combinación de caracteres primitivos, principalmente en los premolares, con molarización pr

  2. Importancia relativa dada por los consumidores a los atributos de calidad de los alimentos

    OpenAIRE

    Lupín, Beatriz

    2009-01-01

    Los atributos de calidad son valoraciones que realizan las personas. Varios autores como Grunert et al. (2000) y Caswell et al. (2002) analizan los mismos considerando diversas perspectivas. Así, los atributos se pueden clasificar en intrínsecos -sensoriales y organolépticos y los relacionados con la seguridad alimentaria, el origen del producto, la trazabilidad y el impacto ambiental- y extrínsecos -certificación, precio, marca, confianza en el productor o negocio, denominación de origen y e...

  3. Los abuelos de nuestro rock

    Directory of Open Access Journals (Sweden)

    Jacobo Celnik

    2016-12-01

    Full Text Available Los Yetis. Una bomba atómica a go go. La historia de los abuelos de nuestro rock. Diego Londoño; Pulso & Letra Editores, Instituto para el Desarrollo de Antioquia, Instituto de Cultura y Patrimonio de Antioquia, 2014, 98 págs., fotografías.

  4. Los medios ante la crisis

    OpenAIRE

    Restrepo, Javier Dario

    1995-01-01

    La ponencia analiza el papel que los medios de comunicación deben cumplir en la actual crisis política que atraviesa Colombia. La actual crisis permite poner en duda la capacidad de los medios para encontrar y difundir solola verdad.

  5. Los Angeles og San Francisco

    DEFF Research Database (Denmark)

    Ørstrup, Finn Rude

    1998-01-01

    Kompendium udarbejdet til en studierejse til Los Angeles og San Francisco april-maj 1998 Kunstakademiets Arkitektskole, Institut 3H......Kompendium udarbejdet til en studierejse til Los Angeles og San Francisco april-maj 1998 Kunstakademiets Arkitektskole, Institut 3H...

  6. El reclutamiento de los mejores

    OpenAIRE

    DeWinter, Urbain Ben

    2014-01-01

    Las universidades anglosajonas obtienen los mejores resultados en las clasificaciones internacionales. Un repaso por el amplio panorama de las instituciones académicas de Estados Unidos, como el que aquí se propone, servirá para detectar las claves de su sistema universitario y las estrategias empleadas para atraer a los mejores profesionales en su apuesta por la calidad.

  7. Geochemical Processes Controlling Chromium Transport in the Vadose Zone and Regional Aquifer, Los Alamos, New Mexico

    Science.gov (United States)

    Longmire, P.; Ding, M.; Rearick, M.; Vaniman, D.; Katzman, D.

    2008-12-01

    The environmental aqueous geochemistry of Cr is of considerable interest to physical scientists and toxicologists in quantifying the fate and transport of this metal in surface and subsurface environments. Chromium(VI) solutions were released from cooling towers to a stream channel within Sandia Canyon at Los Alamos National Laboratory, NM from 1956 to 1971. These solutions have migrated 293 m depth through the vadose zone, containing several saturated zones, to the regional water table. Concentrations of total dissolved Cr, mainly as Cr(VI), in the regional aquifer range between 0.17 to 8.46 mM. The regional aquifer is characterized by calcium-sodium-bicarbonate solution, contains dissolved oxygen (0.09 to 0.22 mM), and has a circumneutral pH (6.8 to 8.3). Geochemical processes controlling the fate and transport of Cr in groundwater at Los Alamos include a combination of adsorption and precipitation reactions within aquifer systems. Vadose zone material containing hydrous ferric oxide, smectite, silica glass, and calcite widely range in their ability to adsorb Cr(VI) under basic pH conditions. Overall, the vadose zone at Los Alamos is relatively oxidizing, however, basalt flows are locally reducing with respect to Fe. Ferrous iron concentrated within the Cerros del Rio basalt has been shown through batch experiments to reduce Cr(VI) to Cr(III) resulting in precipitation of chromium(III) hydroxide. Regional aquifer material, consisting of silicates, oxides, and calcite, vary in the amount of Fe(II) available in reactive minerals to effectively reduce Cr(VI) to Cr(III). The results of our studies (1) directly assess the relationship between mineralogical characterization and transport behavior of Cr using site-specific hydrogeologic material and (2) provide site-specific adsorption and precipitation parameters obtained through the experiments to refine the fate and transport modeling of Cr within the vadose zone and regional aquifer. Natural attenuation of Cr at Los

  8. El Retorno de los Heraclidas

    Directory of Open Access Journals (Sweden)

    Antonio LÓPEZ EIRE

    2009-10-01

    Full Text Available Un detenido examen de las leyendas que hacen referencia al «retorno de los Heraclidas», nos lleva a considerar que una de las estirpes griegas —los dorios— no se mantuvo alejada desde un principio de los restantes linajes helénicos. No parece pueda deducirse de la llamada «invasión doria» el consiguiente derrumbamiento del mundo micénico. El pertinente estudio de las distintas manifestaciones de la cultura permite afirmar que incluso el dialecto dorio-nordoccidental no se desarrolló independientemente de los demás dialectos griegos. En fin, se termina diciendo que junto a eteocretenses y cidones, cohabitan en Creta los dorios y aqueos.

  9. TODOS LOS TIEMPOS

    Directory of Open Access Journals (Sweden)

    Juan José López de la Cruz

    2011-05-01

    Full Text Available RESUMEN La intervención sobre la arquitectura pasada no es más que un asunto concreto de una concepción universal de los procesos de transformación que incumben a todo el proyecto de arquitectura. Podríamos pensar que la acción arquitectónica es siempre una alteración de nuestro mundo ya existente, por lo que proyectar no es sino repensar una y otra vez sobre él, un fabuloso intento de transformar continuamente la realidad, construida o figurada, para acomodarla a lo variable de nuestro pensamiento en constante cambio. Este modo de aproximarnos al proyecto de arquitectura como alteración de una realidad continua, permanente antes y después del proyecto, observa el tiempo como materia de investigación y reflexión, el proyecto se convierte entonces en el Aleph capaz de reunir todos los instantes reales o imaginados que atañen a un lugar, entendiendo la arquitectura como una superposición de momentos entretejidos donde, a través de estrategias de alteración, podemos rescatar tiempos pasados y proyectar instantes futuros como quien recorre senderos que se bifurcan y se reencuentran, pudiendo reemprender caminos descartados en su día o descubriendo convergencias que han de producirse en un mañana a través del proyecto. La reunión de ayeres, presentes y futuros que propicia el proyecto de arquitectura permite incorporar a nuestro ámbito cultural realidades consideradas aparentemente agotadas, al tiempo que nos incita a imaginar nuestras intervenciones como un estadio más de una realidad permanente que volverá a ser ineludiblemente alterada en tiempos venideros. Este viaje pendular a través del tiempo del proyecto de arquitectura, induce a entender la degradación y la obsolescencia como parte del ciclo vital pero no siendo necesariamente el fin de éste, sino un momento intermedio a partir del cual explorar nuevas posibilidades formalizadas a través de la metamorfosis de la materia y los espacios degradados. Simult

  10. Las Armas de los Conquistadores. Las Armas de los Aztecas

    Directory of Open Access Journals (Sweden)

    Bruhn de Hoffmeyer, Ada

    1986-12-01

    Full Text Available ¿Qué clase de armas utilizaron los españoles en la conquista del Nuevo Mundo? No eran las mismas o idénticos tipos de armas en todas partes. Tampoco eran los mismos tipos y categorías que se utilizaban en aquella época en la Penínula Ibérica o en Europa occidental. Aunque los españoles llegaron al Nuevo Mundo con sus propias armas, fabricadas en España, en Italia, en Flandes, en Alemania —mejor dicho, en todo el mundo europeo del emperador Carlos V—, éstas no todas eran idóneas para los conquistadores de Méjico en el reino de los aztecas, o en Perú en el reino de los incas. Por varias razones. Las armas con que los conquistadores llegaron al Mundo Nuevo americano no eran completamente uniformes por razones económicas.

  11. Importancia de los alcanos en el estudio de los carbones

    Directory of Open Access Journals (Sweden)

    José E. Sánchez

    2010-07-01

    Full Text Available Los carbones la Vega, La Vega Oxidado y Tres Bancos, fueron extraídos secuencialmente con los siguientes solventes: H^O, HCl 10%, NaOH 10%, n-Heptano, Éter, Tolueno, Cloroformo, Tetrahidrofurano (THF y Piridina. Se encontraron diferencias significativas en la extractabilidad con THF y Piridina debidas a cambios producidos por la oxidación. Se detectaron n-alcanos de C^ a C^^, en los primeros cuatro extractos con solventes orgánicos. Los perfiles cromatográficos de estos compuestos muestran una distribución dependiente del rango que se mantiene aiin después de la oxidación. Lxis pirocromatogramas de los carbones y de los residuos de extracción se caracterizan por una serie de dobletes de n-1-alqueno/n-alcano cuya distribución también depende del rango de los carbones. Esta característica, atribuible sólo a diferencias en las condiciones geológicas locales, podría utilizarse como indicador del grado de metamorfismo.

  12. Los conductores re-examinados: El transcurso del tiempo deteriora significativamente los conocimientos de los conductores

    Directory of Open Access Journals (Sweden)

    Francisco J. Martos

    2012-01-01

    Full Text Available Dos mil cinco conductores, 1204 hombres y 801 mujeres, una muestra representativa de la población española de conductores, fueron nuevamente examinados utilizando un cuestionario que reproducía fielmente un examen de conducir realizado por la Dirección General de Tráfico (DGT. Las preguntas fueron clasificadas en"“muy importantes", "importantes" y "poco importantes". El 96.5 % de los conductores, suspendió el examen. Los resultados eran tanto peores cuanto más tiempo había transcurridodesde la obtención del permiso de conducir. Esto era independiente de la importancia de las preguntas, de la mayor o menor frecuencia de conducción y afectaba por igual a hombres y mujeres. Las mujeres obtienen mejores puntuaciones en señalización mientras que los hombres son mejores en las preguntas de seguridad vial. Los resultados también demostraban que los conductores profesionales y los de mayor nivel educativo sufren un menor deterioro. Tales resultados nos llevan a considerar la relación que estos datos puedan tener en los niveles de accidentalidad y la conveniencia de establecer pautas para la actualización del conocimiento de los conductores. Finalmente, se discute la relevancia que el examen que se utiliza para obtener el permiso de conducir tiene como indicador o predictor de una futura conducción segura.

  13. El reconocimiento y los medios

    Directory of Open Access Journals (Sweden)

    Sandra Meléndez Labrador

    2016-05-01

    Full Text Available Recognition and the media recopila los aportes al campo de la comunicación y al estudio de los medios que viene desarrollando Rousiley Maia sobre la base de la teoría crítica de Axel Honneth, desde 1998 tras su formación posgradual en Política en la Universidad de Nottingham (UK y como directora del grupo de investigación Pesquisa em Mídia e Esfera Pública (EME, de la Universidade Federal de Minas Gerais (UFMG en Brasil. El objetivo general del libro es ofrecer luces respecto a lo que la autora denomina ‘interfaces’ –las posibles conexiones– entre la teoría del reconocimiento de Honneth, la teoría política de la comunicación y la investigación empírica de los medios de comunicación, es decir, entre los estudios de los medios y los estudios de las luchas por el reconocimiento, en dinámicas que involucran la democracia, la esfera pública, la identidad, las minorías y grupos menos favorecidos, el compromiso cívico y los movimientos sociales.

  14. Los delitos de lesa humanidad

    Directory of Open Access Journals (Sweden)

    José Luis González González

    2014-02-01

    Full Text Available Concepto de delitos de lesa humanidad. ¿Porqué surgieron los delitos de lesa humanidad?. ¿Cuándo surgieron los delitos de lesa humanidad?. Condiciones o características de los delitos de lesa humanidad. Modalidades o figuras de los crímenes de lesa humanidad. Aspectos generales a todos los delitos. ConclusionesLa respuesta debe elaborarse necesariamente en el marco del derecho penal internacional y derecho humanitario, que a través del tiempo fueron creando normas, que prohibían ciertas conductas, y de esa manera pretendieron proteger los bienes jurídicos de mayor trascendencia e importancia para el Hombre.El concepto fue evolucionando a través de la historia y ampliándose la nómina de actos prohibidos, llegando a la definición más elaborada en el Estatuto de Roma de la Corte Penal Internacional (ERCPI, que reclama también, la concreción de elementos objetivos y subjetivos para conformar un tipo penal especial, que se hallan comprendidos, como dice el preámbulo del Estatuto de Roma (cuarto párrafo entre “los crímenes más graves de trascendencia para la comunidad internacional en su conjunto”.

  15. Los centenarios y sus corazones

    OpenAIRE

    Ramos Cortés, Miriam Rosa

    2016-01-01

    Los centenarios constituyen un paradigma excepcional de envejecimiento. La población centenaria se ha incrementado rápidamente en los últimos años y las enfermedades cardiovasculares son su principal causa de muerte. Hay pocos datos sobre la anatomía cardiaca, la fisiología y fisiopatología de los centenarios, no sólo debido a la relativa escasez de este tipo de individuos, sino también porque a menudo son poco estudiados. Hipótesis de trabajo: Un buen conocimiento acerca de cómo es y cómo se...

  16. Osteomas de los senos paranasales

    OpenAIRE

    Gay Escoda, Cosme; Bescos Atín, M.

    1990-01-01

    Se revisaron 21 pacientes con osteomas de los senos paranasales de un total de 86 pacientes estudiados, afectos de osteomas de la región craneofacial, con una media de edad de cincuenta años y predominio masculino (211). La localización más frecuente de los osteomas paranasales fue el seno frontal (57 por 100), seguido de los senos maxilar, etmoidal y esfenoidal. Se destaca la gran proporción de casos que fueron diagnosticados fortuitamente (45 por 100). La cefalea fue el síntoma más precoz y...

  17. Los Alamos Climatology 2016 Update

    Energy Technology Data Exchange (ETDEWEB)

    Bruggeman, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-10

    The Los Alamos National Laboratory (LANL or the Laboratory) operates a meteorology monitoring network to support LANL emergency response, engineering designs, environmental compliance, environmental assessments, safety evaluations, weather forecasting, environmental monitoring, research programs, and environmental restoration. Weather data has been collected in Los Alamos since 1910. Bowen (1990) provided climate statistics (temperature and precipitation) for the 1961– 1990 averaging period, and included other analyses (e.g., wind and relative humidity) based on the available station locations and time periods. This report provides an update to the 1990 publication Los Alamos Climatology (Bowen 1990).

  18. El Museo de los desplazados

    OpenAIRE

    Left Hand Rotation

    2013-01-01

    Museo de los Desplazados es una plataforma de colaboración que surge como conclusión del proyecto “Gentrificación no es un nombre de señora”, en el que se analiza el papel de la cultura en los procesos de gentrificación. Museo de los Desplazados is a collaboration platform that comes as a conclusion of the project "Gentrificación no es un nombre de señora", in which we examines the role of culture in the process of gentrification.

  19. El mimo entre los griegos

    Directory of Open Access Journals (Sweden)

    Manuel Briceño Jauregui

    1969-05-01

    Full Text Available El instinto de imitación ha encontrado siempre su expresión en todos los pueblos. De todas las formas de entretenimiento, el mimo es a la vez la más primitiva y estable. En el mundo antiguo existen juglares, acróbatas, diversiones públicas de todas clases realizadas por hombres y mujeres, que prueban sus múltiples habilidades en las plazas de mercado, en las calles, con motivo de festividades públicas, o en los banquetes privados -como cuenta Jenofonte en el Simposio para entretención de los huéspedes a la mesa.

  20. LOS ESTUDIOS DE POBREZA URBANA

    Directory of Open Access Journals (Sweden)

    Rina De León Herrera

    2007-08-01

    Full Text Available En este artículo se intenta mostrar en forma sucinta la evolución de los estudios de pobreza urbana; se retoma para ello la producción escritural de investigadores que han hecho aportes valiosos sobre la temática en diferentes épocas y espacios geográficos. La información se ha organizado en dos unidades de análisis: la producción escritural en los países desarrollados y en los países en desarrollo.