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Sample records for eugenia cerro atajo

  1. The formation placement and palaeoenvironment of the Middle Miocene Los Atajos Member, Trinidad

    NASA Astrophysics Data System (ADS)

    Wilson, Brent; Farfan, Philip; Hughes, Chantelle

    2017-07-01

    The age, palaeoenvironment and formation placement of the conglomeratic Los Atajos Member of central Trinidad have long been unclear. Seven samples (four from calcareous silts near the member's base exposed by building work at the Los Atajos Community Centre, and three from the underlying calcareous claystones of the Brasso Formation) were examined for calcareous microfossils. These indicate a conformable succession encompassing an overall regression. The oldest of the claystone samples, of uppermost early Middle Miocene Globorotalia fohsi fohsi Zone age (N11), contained an upper bathyal benthic foraminiferal assemblage, while the younger claystone samples yielded abundant, shallow neritic Hanzawaia carstensi. The recovery of the planktonic foraminifera Globorotalia mayeri but absence of Globigerinoides subquadratus suggest a Middle Miocene age (Globorotalia mayeri planktonic foraminiferal Zone; N14) for both the uppermost Brasso claystone sample and the Los Atajos Member. The benthic foraminiferal fauna in the Los Atajos is dominated by Rosalina subaraucana, with subdominant Cibicides ex gr. aknerianus and C. floridanus sensu Galloway and Heminway, and common Elphidium spp. This faunal succession has a close affinity with that of parts of the Lower to Middle Miocene Brasso Formation, especially the N10 Guaracara Limestone Member and the clays on which it sits. However, the Los Atajos Member assemblage differs markedly from that of the overlying Late Miocene San José Calcareous Silt Member of the Manzanilla Formation, from which the Los Atajos is separated by an unconformity of Globorotalia menardii (N15) Zone age. On these grounds, the Los Atajos Member is here placed within the Brasso Formation. The low diversity, high dominance benthic foraminiferal fauna and the associated ostracod assemblage in the Los Atajos are indicative of inner to shallower middle neritic palaeodepths in a carbonate-prone palaeoenvironment with marine vegetation and strong current action

  2. Maniac Talk - Dr. Eugenia Kalnay

    NASA Image and Video Library

    2015-03-31

    Eugenia Kalnay Maniac Lecture, March 31, 2015 Dr. Eugenia Kalnay, Distinguished University Professor and the first woman to get a doctorate in Meteorology from MIT, presented a Maniac Talk entitled, "Sheer luck: How I stumbled my way through a fantastic scientific career." Eugenia shared her life and times at the University of Buenos Aires, MIT, NASA, NOAA and University of Maryland, infused with dreams from her mother.

  3. Potentiation of antibiotic activity by Eugenia uniflora and Eugenia jambolanum.

    PubMed

    Coutinho, Henrique D M; Costa, José G M; Falcão-Silva, Vivyanne S; Siqueira-Júnior, José P; Lima, Edeltrudes O

    2010-08-01

    This is the first report about the modifying antibiotic activity of Eugenia uniflora L. and Eugenia jambolanum L. In this study the ethanol extract of E. uniflora and E. jambolanum was tested for their antimicrobial activity against strains of Escherichia coli. The growth of the two strains of E. coli bacteria tested was not inhibited in a clinically relevant form by the extract. The minimal inhibitory concentration was >or=1,024 microg/mL for both strains of E. coli assayed. Synergism between this extract and gentamicin was demonstrated. In the same extract synergism was observed between chlorpromazine and kanamycin and between amikacin and tobramycin, indicating the involvement of an efflux system in the resistance to these aminoglycosides. It is therefore suggested that extracts from E. uniflora L. and E. jambolanum L. could be used as a source of plant-derived natural products with modifying antibiotic activity to gentamicin.

  4. Overview of Cerro Prieto studies

    SciTech Connect

    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.

  5. Geothermal drilling in Cerro Prieto

    SciTech Connect

    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.

  6. Physiological development of cagaita (Eugenia dysenterica).

    PubMed

    da Silva, Monik Maryelle Moreira; da Silva, Edson Pablo; da Silva, Flávio Alves; Ogando, Felipe Iwagaki B; de Aguiar, Claudio Lima; Damiani, Clarissa

    2017-02-15

    It was evaluated the physiological aspects of the cagaita (Eugenia dysenterica) development, from anthesis to ripening. The fruits have been subjected to physical and chemical analysis during the fruit life cycle. The total fruit development comprised 37days. There was a steady increase in the total mass of the fruits and significant increase in transverse and longitudinal diameter, adjusting the double sigmoidal behavior in response to changes in the time. From the 23rd DAA, it was observed the beginning of loss of firmness, increase in total and soluble pectin content and a decrease in starch content. It occurred degradation of total chlorophyll and unmasking of carotenoids from 31st days after anthesis. A decrease in pH and, therefore, increase in acidity, low soluble solids content. The sucrose content was extremely low during the cycle. At the end of development, the respiratory and ethylene production peak was observed, suggesting climacteric behavior.

  7. Studies of Malagasy Eugenia – IV: Seventeen new endemic species, a new combination, and three lectotypifications; with comments on distribution, ecological and evolutionary patterns

    PubMed Central

    Snow, Neil; Callmander, Martin; Phillipson, Peter B.

    2015-01-01

    Abstract Seventeen new endemic species of the genus Eugenia L. (Myrtaceae) are proposed from Madagascar, including: Eugenia andapae N. Snow, Eugenia barriei N. Snow, Eugenia bemangidiensis N. Snow, Eugenia calciscopulorum N. Snow, Eugenia delicatissima N. Snow, Callm. & Phillipson, Eugenia echinulata N. Snow, Eugenia gandhii N. Snow, Eugenia hazonjia N. Snow, Eugenia iantarensis N. Snow, Eugenia malcomberi N. Snow, Eugenia manomboensis N. Snow, Eugenia obovatifolia N. Snow, Eugenia ranomafana N. Snow & D. Turk, Eugenia ravelonarivoi N. Snow & Callm., Eugenia razakamalalae N. Snow & Callm., Eugenia tiampoka N. Snow & Callm., and Eugenia wilsoniana N. Snow, and one new combination, Eugenia richardii (Blume) N. Snow, Callm. & Phillipson is provided. Detailed descriptions, information on distribution and ecology, distribution maps, vernacular names (where known), digital images of types, comparisons to morphologically similar species. Preliminary assessment of IUCN risk of extinction and conservation recommendations are provided, including Vulnerable (4 species), Endangered (2 species), and Critically Endangered (4 species). Lectotpyes are designated for Eugenia hovarum H. Perrier, Eugenia nompa H. Perrier, and Eugenia scottii H. Perrier respectively. PMID:25987885

  8. Modeling studies on Cerro Prieto

    SciTech Connect

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

    1982-10-01

    Numerical simulation techniques are employed in studies of the natural flow of heat and mass through the Cerro Prieto reservoir and of the effects of exploitation on the field's behavior. We consider a two-dimensional model that is based on the hydrogeologic model of Halfman et al. (this volume). The numerical code MULKOM is used in the simulation studies. In the simulations of the natural state of the Cerro Prieto system, we employ five models that differ in prescribed material properties, boundary conditions, or geologic features. For each of these models we compute the steady-state pressure and temperature distributions and compare them against known preproduction pressures and temperatures. A good match between observed and calculated temperature and pressure distributions was obtained, and a natural hot-water flow rate of about 10/sup -2/ kg/s m through the geothermal system was calculated. The models are then used to simulate the behavior of the field under exploitation during the years 1973 to 1978. An acceptable match of temperature and pressure changes in the producing reservoir was obtained. The resulting flow patterns illustrate the effects of cold water recharge, boiling zones and hot fluid flow from depth on the overall field performance. The fluid recharge patterns agree with some of those postulated in earlier studies.

  9. Antifungal activity of Eugenia umbelliflora against dermatophytes.

    PubMed

    Machado, Karina E; Cechinel Filho, Valdir; Cruz, Rosana C B; Meyre-Silva, Christiane; Cruz, Alexandre Bella

    2009-09-01

    Antifungal activities of Eugenia umbelliflora Berg. (Myrtaceae) were tested in vitro against a panel of standard and clinical isolates of human fungal pathogens (dermatophytes and opportunistic saprobes). Methanol extracts of leaves and fruits of E. umbelliflora were separately prepared and partitioned, to yield dichloromethane (DCM), ethyl acetate (EtOAc) and aqueous fractions (Aq). Three compounds (1-3) were obtained from the DCM extract using chromatographic procedures. Antifungal assays were performed using agar dilution techniques. Both extracts (fruits and leaves), their DCM and EtOAc fractions, and compound 2 (betulin and betulinic acid) presented selective antifungal activity against dermatophytes (Epidermophyton floccosum, Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Trichophyton mentagrophytes), with MIC values between 200 and 1000 microg/mL, and interestingly, inhibited 4/5 species with MIC values of < or = 500 microg/mL. The aqueous fractions of fruits and leaves, and compounds 1 (alpha, beta amyrin) and 3 (taraxerol) were inactive up to the maximum concentrations tested (1000 microg/mL).

  10. Asteroid 45 Eugenia - Lightcurves and the pole orientation

    NASA Technical Reports Server (NTRS)

    Taylor, R. C.; Birch, P. V.; Surdej, J.; Pospieszalska-Surdej, A.

    1988-01-01

    Three lightcurves obtained in 1969 and six from 1984 are presented for the 250-km U-type asteroid Eugenia. The asteroid's north pole is within + or - 10 deg of ecliptic longitude 106 deg and a latitude of +26 deg, in keeping with an amplitude-aspect pole analysis. While only one maximum and one minimum are present when observations are closest to both the north and south poles, there are two of each at other oppositions. It is suggested that this effect may be due to the surface albedo features of Eugenia.

  11. Geothermal Drilling in Cerro Prieto

    SciTech Connect

    Aguirre, B. D.; Garcia, G. S.

    1981-01-01

    To date, 71 geothermal wells have been drilled in Cerro Prieto. The activity has been divided into several stages, and, in each stage, attempts have been made to correct deficiencies that were gradually detected. Some of these problems have been solved; others, such as those pertaining to well casing, cement, and cementing jobs, have persisted. The procedures for well completion--the most important aspect for the success of a well--that were based on conventional oil well criteria have been improved to meet the conditions of the geothermal reservoir. Several technical aspects that have improved should be further optimized, even though the resolutions are considered to be reasonably satisfactory. Particular attention has been given to the development of a high-temperature drilling fluid capable of being used in drilling through lost circulation zones. Conventional oil well drilling techniques have been used except where hole-sloughing is a problem. Sulfonate lignitic mud systems have been used with good results. When temperatures exceed 300 C (572 F), it has been necessary to use an organic polymer to stabilize the mud properties.

  12. Resistivity monitoring at Cerro Prieto

    SciTech Connect

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

    1980-02-01

    In 1978 Lawrence Berkeley Laboratory, in cooperation with Comision Federal de Electricidad, began a program of dipole-dipole resistivity monitoring at the Cerro Prieto geothermal field. Dipole-dipole measurements were first made in 1978, then repeated in 1979: (a) to determine whether the field boundaries could be defined by surface resistivity measurements; and (b) to determine if changes in reservoir conditions due to production may be monitored by surface measurements. In 1979 data accuracy was improved to where estimated measurement errors were less than 3%. In addition, data coverage on a line over the field was expanded by 40% for greater depth of investigation and more information on the newer, eastern part of the field. Resistivity modeling of the expanded 1979 profile indicates that the resistive body associated with the zone of production (Wilt et al., 1978) dips steeply eastward, and may underlie the eastern part of the field. The model also shows a thin steeply dipping conductor adjacent to the resistive body that may be associated with faulting and fluid movement. Model perturbation studies have shown that small changes associated with cold-water influx, fault zone migrations, and formation of a steam zone would all be detectable with precision dipole-dipole measurements. Telluric profile measurements taken along line E-E' were found to yield a significant amount of reconnaissance information but are unsuitable for monitoring purposes.

  13. Geohydrology of the Cerro Prieto geothermal aquifer

    SciTech Connect

    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.

  14. Circumscription and synopsis of Eugenia section Speciosae Bünger & Mazine (Myrtaceae)

    PubMed Central

    de Oliveira Bünger, Mariana; Mazine, Fiorella Fernanda; Lucas, Eve J.; Stehmann, João Renato

    2016-01-01

    Abstract A new section of Eugenia (Myrtaceae) is described, segregate from Eugenia sect. Phyllocalyx. Phylogenetic studies suggest that Eugenia sect. Phyllocalyx as traditionally delimited is paraphyletic. To maintain the monophyly of each of the sections in Eugenia s.l., we herein opt to circumscribe a new section and recognize six taxa in sect. Speciosae, which has a distribution mostly in southeastern Brazil and northern South America. Nomenclatural notes are made and a taxonomic key is provided for the species of the section. PMID:27081351

  15. Quantitative model of the Cerro Prieto field

    SciTech Connect

    Halfman, S.E.; Lippmann, M.J.; Bodvarsson, G.S.

    1986-03-01

    A three-dimensional model of the Cerro Prieto geothermal field, Mexico, is under development. It is based on an updated version of LBL's hydrogeologic model of the field. It takes into account major faults and their effects on fluid and heat flow in the system. First, the field under natural state conditions is modeled. The results of this model match reasonably well observed pressure and temperature distributions. Then, a preliminary simulation of the early exploitation of the field is performed. The results show that the fluid in Cerro Prieto under natural state conditions moves primarily from east to west, rising along a major normal fault (Fault H). Horizontal fluid and heat flow occurs in a shallower region in the western part of the field due to the presence of permeable intergranular layers. Estimates of permeabilities in major aquifers are obtained, and the strength of the heat source feeding the hydrothermal system is determined.

  16. Quantitative Model of the Cerro Prieto Field

    SciTech Connect

    Halfman, S.E.; Lippmann, M.J.; Bodvarsson, G.S.

    1986-01-21

    A three-dimensional model of the Cerro Prieto geothermal field, Mexico, is under development. It is based on an updated version of LBL's hydrogeologic model of the field. It takes into account major faults and their effects on fluid and heat flow in the system. First, the field under natural state conditions is modeled. The results of this model match reasonably well observed pressure and temperature distributions. Then, a preliminary simulation of the early exploitation of the field is performed. The results show that the fluid in Cerro Prieto under natural state conditions moves primarily from east to west, rising along a major normal fault (Fault H). Horizontal fluid and heat flow occurs in a shallower region in the western part of the field due to the presence of permeable intergranular layers. Estimates of permeabilities in major aquifers are obtained, and the strength of the heat source feeding the hydrothermal system is determined.

  17. Exploration and development of Cerro Prieto

    SciTech Connect

    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.

  18. Sensitivity of fungi isolated from onychomycosis to Eugenia cariophyllata essential oil and eugenol.

    PubMed

    Gayoso, C W; Lima, E O; Oliveira, V T; Pereira, F O; Souza, E L; Lima, I O; Navarro, D F

    2005-03-01

    The antifungal activity of Eugenia cariophyllata essential oil and eugenol, its major constituent, on fungal strains isolated from onychomycosis was evaluated. The natural products presented prominent antifungal action with MIC of 1% and 4%, respectively.

  19. Chemistry of Silica in Cerro Prieto Brines

    SciTech Connect

    Weres, Oleh; Iglesias, Eduardo; Tsao, Leon

    1980-04-01

    The precipitation of amorphous silica from synthetic geothermal, brines which resemble the flashed brine at Cerro Prieto has been studied. It was found that part of the dissolved silica quickly polymerizes to form suspended colloidal silica. The colloidal silica flocculates and settles slowly at unmodified brine pH values near 7.35. Raising the pH of the brine to about 7.8 by adding base and stirring for a few minutes causes rapid and complete flocculation and settling. these results have been confirmed in the field using actual Cerro Prieto brine. Both in the laboratory and in the field quaternary amines were found to be effective with some brine compositions but not with others. Polyacrylamides do not work at all. These results suggest the following simple preinjection brine treatment process: age the brine for 10-20 minutes in a covered holding tank, add 20-30 ppm lime (CaO), stir for 5 minutes, and separate the flocculated silica from the brine using a conventional clarifier. The brine coming out of such a process will be almost completely free of suspended solids. The pilot plant tests needed to reduce this conceptual process to practice are discussed. The rate of deposition of silica scale from synthetic brines was separately studied. It was found that a modest decrease in pH could significantly reduce the scaling rate at a reasonable cost. The equilibrium chemistry of Cerro Prieto brine was studied theoretically. These calculations indicate that increasing the brine pH to remove silica might cause some precipitation of carbonate minerals, but also that this problem could easily be eliminated at a reasonable cost if it did arise.

  20. Cerro La Negra EAS Cherenkov array

    NASA Astrophysics Data System (ADS)

    Bello, P.; Garipov, G. K.; Khrenov, B. A.; Martínez, O.; Moreno, E.; Salazar, H.; Silaev, A. A.; Villaseñor, L.; Zepeda, A.

    2001-05-01

    The design of the air Cherenkov detector array for the Cerro La Negra site (elevation 4300 m asl) is presented. The most important features of the array are: autonomous operation of the detectors, low power electronics, laser communication lines and power supplied by solar panels and batteries. The joint operation of the array with water Cherenkov extensive air shower (EAS) particle detectors will allow to obtain information on EAS core positions, primary energies, arrival directions of the primary particles, and temporal profiles of the EAS pulses in air Cherenkov and particle detectors. The study of the EAS development above the shower maximum is among the main goals of this experiment. .

  1. HIV-1 Ribonuclease H Inhibitory Phenolic Glycosides from Eugenia hyemalis

    PubMed Central

    Bokesch, Heidi R.; Wamiru, Antony; Le Grice, Stuart F. J.; Beutler, John A.; McKee, Tawnya C.; McMahon, James B.

    2008-01-01

    Three new galloyl arbutins, hyemalosides A–C (1–3), along with nine known compounds were isolated from the evergreen tree Eugenia hyemalis. The structures of compounds 1–3 were determined by analysis of NMR and MS data. Compounds 1–3 inhibited HIV-1 RNase H in vitro with IC50 values of 1.46, >18, and 1.19 μM, respectively. However, in a XTT-based cell viability assay using the human T-cell line CEM-SS infected with HIV-1RT, none of the compounds inhibited the cytopathic effect of HIV-1 infection at the highest dose tested (20 μg/mL). PMID:18763827

  2. Impact of Parthenium weeds on earthworms (Eudrilus eugeniae) during vermicomposting.

    PubMed

    Rajiv, P; Rajeshwari, Sivaraj; Rajendran, Venckatesh

    2014-11-01

    The aim of this work is to evaluate the effect of Parthenium-mediated compost on Eudrilus eugeniae during the process of vermicomposting. Nine different concentrations of Parthenium hysterophorus and cow dung mixtures were used to assess toxicity. The earthworms' growth, fecundity and antioxidant enzyme levels were analysed every 15 days. The antioxidant activities of enzymes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)], considered as biomarkers, indicate the biochemical and oxidative stresses due to the toxin from Parthenium weeds. The earthworms' growth, biomass gain, cocoon production and antioxidant enzymes were in a low level in a high concentration of P. hysterophorus (without cow dung). The results clearly indicated that appropriate mixing of P. hysterophorus quantity is an essential factor for the survival of earthworms without causing any harm.

  3. Wound Healing Activity and Chemical Standardization of Eugenia pruniformis Cambess

    PubMed Central

    de Albuquerque, Ricardo Diego Duarte Galhardo; Perini, Jamila Alessandra; Machado, Daniel Escorsim; Angeli-Gamba, Thaís; Esteves, Ricardo dos Santos; Santos, Marcelo Guerra; Oliveira, Adriana Passos; Rocha, Leandro

    2016-01-01

    Background: Eugenia pruniformis is an endemic species from Brazil. Eugenia genus has flavonoids as one of the remarkable chemical classes which are related to the improvement of the healing process. Aims: To evaluate of wound healing activity of E. pruniformis leaves and to identify and quantify its main flavonoids compounds. Materials And Methods: Wound excision model in rats was used to verify the hydroethanolic and ethyl acetate extracts potential. The animals were divided in four groups of six and the samples were evaluated until the 15° day of treatment. Hydroxyproline dosage and histological staining with hematoxilin-eosin and Sirius Red were used to observe the tissue organization and quantify the collagen deposition, respectively. Chemical compounds of the ethyl acetate extract were identified by chromatographic techniques and mass spectrometry analysis and total flavonoids content was determined by spectrophotometric method. The antioxidant activity was determined by oxygen radical absorbing capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazylhydrate radical photometric (DPPH) assays. Results: The treated group with the ethyl acetate extract showed collagen deposition increase, higher levels of hidroxyproline, better tissue reorganization and complete remodeling of epidermis. Quercetin, kaempferol and hyperoside were identified as main compounds and flavonoids content value was 43% (w/w). The ORAC value of the ethyl acetate extract was 0.81± 0.05 mmol TE/g whereas the concentration to produce 50% reduction of the DPPH was 7.05± 0.09 μg/mL. Conclusion: The data indicate a wound healing and antioxidant activities of E. pruniformis. This study is the first report of flavonoids and wound healing activity of E. pruniformis. KEY MESSAGES Eugenia pruniformis extract accelerates wound healing in skin rat model, probably due to its involvement with the collagen deposition increase, higher levels of hidroxyproline, dermal remodelling and potent antioxidant activity

  4. Searching for Orbits Around the Asteroid 45 Eugenia

    NASA Astrophysics Data System (ADS)

    Prado, Antonio

    The present paper has the goal of searching and mapping orbits, with respect to the perturbations, for a spacecraft traveling around the asteroid 45 Eugenia. This asteroid is a triple system, which center of mass is in an elliptic orbit around the Sun. The perturbations considered in the present model are the ones due to the oblateness of the central body, the gravity field of the two satellite bodies, the Sun, the Moon and all the planets of the Solar System. This mapping is important, because it shows the relative importance of each force for a given orbit of the spacecraft, helping to make a decision about which forces needs to be included in the model for a given desired accuracy and nominal orbit. Another important application of this type of mapping is to find better orbits for a spacecraft travelling around this system, since it is expected that orbits that are less perturbed have good potential to require lower fuel consumption for station-keeping maneuvers. Simulations under different conditions are made in order to find those orbits. The main reason to study those trajectories is that, currently, there are several institutions in Brazil studying the possibility to make a mission to send a spacecraft to a triple asteroid (the so called ASTER mission), because there are many important scientific studies that can be performed in a system like that. This mission is still under study and the first choice for the target is the triple asteroid 2001SN263. A similar study that is performed here was made for this triple system recently (Prado, 2014), and the present paper has the goal of studying the system 45 Eugenia, in order to compare the orbits among those two systems with respect to the perturbations suffered by the orbits. The results will show this comparison and can be used if this second choice of target is considered. It is also useful to indicate the conditions of the orbits for a second future mission to a triple asteroid, which may be done in a more

  5. Geothermal development in Cerro Prieto Baja California, Mexico (1983)

    SciTech Connect

    Manon M.A.

    1983-09-01

    The actual stage of the expansion program and some of the main characteristics of the Cerro Prieto Geothermal Field are presented. This is similar to the one presented in this same conference back in 1981, but it has been updated.

  6. Chemical composition and antibacterial activity of essential oils of Eugenia species.

    PubMed

    Magina, Michele D A; Dalmarco, Eduardo M; Wisniewski, Alberto; Simionatto, Edesio L; Dalmarco, Juliana B; Pizzolatti, Moacir G; Brighente, Inês M C

    2009-07-01

    The essential oils of the leaves of Eugenia brasiliensis, Eugenia beaurepaireana, and Eugenia umbelliflora were analyzed by GC-MS. The major compounds found in the oil of E. brasiliensis were spathulenol (12.6%) and tau-cadinol (8.7%), of E. beaurepaireana were beta-caryophyllene (8.0%) and bicyclogermacrene (7.2%), and of E. umbelliflora were viridiflorol (17.7%) and beta-pinene (13.2%). These oils were assayed to determine their antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. All of the oils analyzed showed antibacterial activity, ranging from moderate to strong, which was most accentuated for the E. umbelliflora and E. brasiliensis oils, which strongly inhibited the growth of S. aureus giving values of MIC = 119.2 and 156.2 microg/mL, respectively.

  7. Evaluation of geologic characteristics at Cerro Prieto

    SciTech Connect

    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.

  8. Production characteristics of some Cerro Prieto wells

    SciTech Connect

    Goyal, K.P.; Halfman, S.E.; Truesdell, A.H.; Howard, J.H.

    1982-08-01

    An areal distribution of heat and mass production in the Cerro Prieto field has been presented for two different times to determine the initial state of the ..cap alpha.. and ..beta.. aquifers and the behavior of the field under production. It was found that, initially, the ..cap alpha.. and ..beta.. aquifers were hot and very hot respectively. Cold boundaries to the field were found to be located toward the west and northeast. Initially, fluid production from most wells was very high. M-53 and some wells southeast of Fault H produced very hot fluids at very high rates. Production from most wells declined over the years, possibly due to scaling in the wellbore, reduced recharge to the aquifer, high resistance to flow due to silica precipitation in the reservoir pores and/or relative permeability effects in the two-phase regions surrounding the wells. In most wells fluid enthalpies declined over the years, perhaps due to mixing with colder waters either drawn in from upper strata and/or from the cold lateral boundaries depending upon well location.

  9. Analysis of Cerro Prieto production data

    SciTech Connect

    Goyal, K.P.; Miller, C.W.; Lippmann, M.J.; Vonder Haar, S.P.

    1981-01-01

    Heat and mass production data from the Cerro Prieto field are analyzed in order to provide a basis for a detailed quantitative model of the system. It is found, in general, that the production from the individual wells decreased with time. This can be due to a reduction in permeability by silica deposition in the aquifer pores, relative permeability effects in a two-phase flow, and/or a reduced pressure gradient over years of production. Specific increases in the total mass production rate of the field are associated with the increased number of producing wells. Average enthalpy of the produced fluid varied over the years. It first increased, then decreased, and again increased. An increase in enthalpy was usually the result of adding higher enthalpy wells to those already in the field. The decrease in the enthalpy is thought to be mostly due to the mixing of relatively cold water with the geothermal aquifer fluid. Downhole pressures, temperatures and saturations in the flowing wells were calculated from the known wellhead data. Between 1973 and 1980, the pressures and temperatures have decreased by about 15 bars and 20/sup 0/C respectively, and the steam saturations have slightly increased in the near-well regions.

  10. Evaluation of Antioxidant, Immunomodulatory, and Cytotoxic Action of Fractions from Eugenia uniflora L. and Eugenia malaccensis L.: Correlation with Polyphenol and Flavanoid Content

    PubMed Central

    Figueirôa, Evellyne de Oliveira; de Melo, Cristiane Moutinho Lagos; Neves, Juliana Kelle de Andrade Lemoine; da Silva, Nicácio Henrique; Pereira, Valéria Rêgo Alves; Correia, Maria Tereza dos Santos

    2013-01-01

    An increasing number of biological activities presented by medicinal plants has been investigated over the years, and they are used in the search for new substances with lower side effects. Eugenia uniflora L. and Eugenia malaccensis L. (Myrtaceae) have many folk uses in various countries. This current study was designed to quantify the polyphenols and flavonoids contents and evaluate the immunomodulatory, antioxidant, and cytotoxic potentials of fractions from E. uniflora L. and E. malaccensis L. It was observed that the polyphenol content was higher in ethyl acetate fractions. These fractions have high antioxidant potential. E. malaccensis L. seeds showed the largest DPPH radical scavenger capacity (EC50 = 22.62). The fractions of E. malaccensis L. leaves showed lower antioxidant capacity. The samples did not alter the profile of proinflammatory cytokines and nitric oxide release. The results indicate that species of the family Myrtaceae are rich in compounds with antioxidant capacity, which can help reduce the inflammatory response. PMID:24089599

  11. Rediscovery of Eugenia fajardensis (Myrtaceae), a rare tree from the Puerto Rican Bank

    Treesearch

    Jorge C. Trejo-Torres; Marcos A. Caraballo-Ortiz; Miguel A. Vives-Heyliger; Christian W. Torres-Santana; William Cetzal-Ix; Joel A. Mercado-Diaz; Tomas A. Carlo

    2014-01-01

    Eugenia fragrans var.? fajardensis was described in 1895 and raised to species status in 1923 as E. fajardensis. In 1925, it was relegated to the synonymy of Anamomis fragrans (Myrcianthes fragrans). Since 2001, we have re-discovered wild plants and herbarium specimens, including a previously unidentified isotype of E. fajardensis, supporting the validity of this...

  12. Release from herbivory does not confer invasion success for Eugenia uniflora in Florida.

    PubMed

    Bohl Stricker, Kerry; Stiling, Peter

    2014-03-01

    One of the most commonly cited hypotheses explaining invasion success is the enemy release hypothesis (ERH), which maintains that populations are regulated by coevolved natural enemies where they are native but are relieved of this pressure in the new range. However, the role of resident enemies in plant invasion remains unresolved. We conducted a field experiment to test predictions of the ERH empirically using a system of native, introduced invasive, and introduced non-invasive Eugenia congeners in south Florida. Such experiments are rarely undertaken but are particularly informative in tests of the ERH, as they simultaneously identify factors allowing invasive species to replace natives and traits determining why most introduced species are unsuccessful invaders. We excluded insect herbivores from seedlings of Eugenia congeners where the native and invasive Eugenia co-occur, and compared how herbivore exclusion affected foliar damage, growth, and survival. We found no evidence to support the ERH in this system, instead finding that the invasive E. uniflora sustained significantly more damage than the native and introduced species. Interestingly, E. uniflora performed better than, or as well as, its congeners in terms of growth and survival, in spite of higher damage incidence. Further, although herbivore exclusion positively influenced Eugenia seedling survival, there were few differences among species and no patterns in regard to invasion status or origin. We conclude that the ability of E. uniflora to outperform its native and introduced non-invasive congeners, and not release from insect herbivores, contributes to its success as an invader in Florida.

  13. An Art Educator for All Seasons: The Many Roles of Eugenia Eckford Rhoads.

    ERIC Educational Resources Information Center

    Smith, Peter

    1990-01-01

    Investigates the role of women in U.S. art education by focusing on the art education contributions of Eugenia Eckford Rhoads. Presents a biographical sketch and describes her published works. Questions the role of sexism in how art educators judge the success or failure of a professional career. (KM)

  14. The hydrogeologic-geochemical model of Cerro Prieto revisited

    SciTech Connect

    Lippmann, M.J.; Halfman, S.E.; Truesdell, A.H.; Manon M., A.

    1989-01-01

    As the exploitation of the Cerro Prieto, Mexico, geothermal field continues, there is increasing evidence that the hydrogeologic model developed by Halfman et al. (1984, 1986) presents the basic features controlling the movement of geothermal fluids in the system. At the present time the total installed capacity at Cerro Prieto is 620 MWe requiring the production of more than 10,500 tonnes/hr of a brine-steam mixture. This significant rate of fluid production has resulted in changes in reservoir thermodynamic conditions and in the chemistry of the produced fluids. After reviewing the hydrogeologic-geochemical model of Cerro Prieto, some of the changes observed in the field due to its exploitation are discussed and interpreted on the basis of the model. 21 refs., 11 figs., 1 tab.

  15. Bioactivities of crude mucus proteins from Eudrilus eugeniae (African night crawler) and Perionyx excavatus (Blue worm).

    PubMed

    Prem-U-Domkit, K; Muangman, T; Klungsupya, P; Chantsavang, S; Kubera, A

    2017-01-01

    This study aimed to investigate the enzymatic anti-oxidative, hemolytic and cytotoxic activities of crude mucus proteins from the two earthworms including Eudrilus eugeniae (African night crawler) and Perionyx excavatus (Blue worm). The bioactivities were determined by hemolytic activity, cytotoxic activity using HepG2 human hepatocellular carcinoma cells, L-929 mouse fibroblast and TK6 human lymphoblast cell lines and antioxidant activity. The results indicated that the hemolytic activity of mucus proteins of P. excavatus was higher than that of E. eugeniae. The cytotoxic activity of the mucus proteins of E. eugeniae could inhibit the growth of HepG2 with the IC50 at 144.2 ± 0.18 µg/mL but showed no effect on L-929 and TK6. On the other hand, the crude proteins of P. excavatus decreased cell viability of both L-929 and HepG2 with their IC50 respectively were 6.87 ± 0.16 and 174.3 ± 0.19 µg/mL but they did not reduce the growth of TK6 cell line. The SOD-like activity of P. excavatus and E. eugeniae crude proteins were found with the IC50 at 149 µg/mL and 386.2 µg/mL, respectively. For GPx-like activity, crude proteins of P. excavatus exhibited significant (p ≤ 0.05) greater activity than those of E. eugeniae when tested at the concentration 100 µg/mL. This study revealed the bioactivities of crude mucus of earthworms which served as alternative natural proteins for the prophylaxis or treatment of free radical-related diseases as well as development of dietary supplements and cosmetics.

  16. Navajo minettes in the Cerros de las Mujeres, New Mexico

    NASA Astrophysics Data System (ADS)

    Vaniman, D.; Laughlin, A. W.; Gladney, E. S.

    1985-06-01

    The Cerros de las Mujeres in west-central New Mexico are three mafic minette plugs that should be considered part of the Navajo volcanic fields on the central Colorado Plateau. This newly recognized occurrence extends the Navajo volcanic fields to the southeastern margin of the Colorado Plateau, within 45 km of the extensional tectonic setting in which the Mogollon ash-flow tuff cauldrons occur. The Cerros de las Mujeres provide additional evidence for contemporaneous sodic and potassic volcanism within the Navajo volcanic fields.

  17. Preliminary simulation studies related to the Cerro Prieto Field

    SciTech Connect

    Lippmann, M.J.; Bodvarsson, G.S.; Witherspoon, P.A.; Rivera, J.R.

    1980-01-01

    Results of preliminary numerical simulations of the behavior of the Cerro Prieto field are discussed. The purpose of these studies is to examine: (1) the effect of using conventional isothermal methods of well test data analysis for geothermal systems, and (2) the influence of recharge from over under underlying aquifers on the temperature of a producing geothermal reservoir. 8 refs.

  18. Gas chemistry and thermometry of the Cerro Prieto geothermal field

    SciTech Connect

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

    1981-01-01

    Geothermal gases at Cerro Prieto are derived from high temperature reactions within the reservoir or are introduced with recharge water. Gases collected from geothermal wells should, therefore, reflect reservoir conditions. Interpretation of gas compositions of wells indicates reservoir temperatures, controls of oxygen and sulfur fugacities, and recharge source and direction.

  19. Diffuse CO2 degassing monitoring of Cerro Negro volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Hernández, Pedro A.; Alonso, Mar; Ibarra, Martha; Rodríguez, Wesly; Melián, Gladys V.; Saballos, Armando; Barrancos, José; Pérez, Nemesio M.; Álvarez, Julio; Martínez, William

    2017-04-01

    We report the results of fourteen soil CO2 efflux surveys by the closed accumulation chamber method at Cerro Negro volcano, Nicaragua. The surveys were undertaken from 1999 to 2016 to constrain the diffuse CO2 emission from this volcano and to evaluate the spatial and temporal variations of CO2 degassing rate in relation to the eruptive cycle. Cerro Negro is an active basaltic volcano belonging to the active Central American Volcanic Arc which includes a 1,100 Km long chain of 41 active volcanoes from Guatemala to Panama. Cerro Negro first erupted in 1850 and has experienced 21 eruptive eruptions with inter eruptive average periods between 7 and 9 years. Since the last eruption occurred on 5 August 1999, with erupted lava flows and ash clouds together with gas emissions, a collaborative research program between INETER and ITER/INVOLCAN has been established for monitoring diffuse CO2 emissions from this volcano. The first survey carried out at Cerro Negro was in December 1999, just 3 months after the 1999 eruption, with a total diffuse CO2 emission output estimated on 1,869 ± 197 td-1. The second survey carried out in March 2003, three years after the eruption, yielded a value of 432 ± 54 td-1. Both values that can be considered within the post-eruptive phase. The last survey performed at Cerro Negro was in November 2016, with an estimated diffuse CO2 emission of 63 ± 14 tṡd-1and soil CO2 efflux values ranging from non-detectable (˜0.5 g m-2 d-1) up to 7264 g m-2 d-1. The long-term record of diffuse CO2 emissions at Cerro Negro shows small temporal variations in CO2 emissions with a peak in 2004 (256 ± 26 td-1) followed by a peak in seismicity. Except this value, the rest of estimated values can be considered within the inter-eruptive phase, period during which a decreasing trend on the total diffuse CO2 output has been observed, with estimates between 10 and 83 tṡd-1. Regarding to the spatial distribution of diffuse CO2 values, most of relatively high CO2

  20. Antioxidant, Antihyperlipidaemic and Antidiabetic Activity of Eugenia Floccosa Bedd Leaves in Alloxan Induced Diabetic Rats

    PubMed Central

    Jelastin, Kala S Mary; Tresina, P.S.; Mohan, V.R.

    2011-01-01

    The ethanol extract of Eugenia floccosa Bedd (Family: Myrtaceae) leaf was investigated for its antioxidant, antihyperlipidaemic and antidiabetic effect in Wistar Albino rats. Diabetes was induced in Albino rats by administration of alloxan monohydrate (150mg/kg, i.p). The ethanol extracts of E. floccosa at a dose of 150 and 300mg/kg of body weight were administered at single dose per day to diabetes induced rats for a period of 14 days. The effect of ethanol extract of E. floccosa leaf extract on blood glucose, plasma insulin, creatinine, glycosylated haemoglobin, urea serum lipid profile [total cholesterol (TR), triglycerides (TG), low density lipoprotein – cholesterol (LDL-C), very low density lipoprotein – cholesterol (VLDL-C), high density lipoprotein – cholesterol (HDL-C) and phospholipid (PL)] serum protein, albumin, globulin, serum enzymes [serum glutamate pyruvate transaminases (SGPT) and serum glutamate oxaloacetate transaminases (SGOT), and alkaline phosphatase (ALP)], lipoprotein peroxidation (LPO) antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH) and glutathione peroxidase (GPx) were measured in the diabetic rats. The ethanol extract of Eugenia floccosa leaf elicited significant reductions of blood glucose (P<0.05), lipid parameters except HDL-C, serum enzymes and significantly increased HDL-C and antioxidant enzymes. The extracts also caused significant increase in plasma insulin (P<0.05) in the diabetic rats. From the above results, it is concluded that ethanol extract of Eugenia floccosa possesses significant antidiabetic, antihyperlipidaemic and antioxidant effects in alloxan induced diabetic rats. PMID:24826030

  1. Criteria for determining casing depth in Cerro Prieto

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    Hurtado, R.; Mercado, S.; Gamino, H. )

    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.

  4. Biodegradation of Garden Waste, Market Waste Using Eisenia fetida and Eudrilus eugenia and Assessment of Manure Quality on Tomato

    NASA Astrophysics Data System (ADS)

    Mohan, S. Mariraj

    2014-06-01

    Comparative study was performed to evaluate the vermicomposting efficiency of two earthworm species Eisenia fetida, Eudrilus eugenia from the garden wastes, vegetable market wastes. Three different experimental works were conducted. For each experiment three plastic vermibins were used. Experiment (1) mentioned for control without earthworms. Experiment (2) bedded with Eudrilus eugenia, Experiment (3) comprised of bedding with Eisenia fetida. Pre composting was allowed for 10 days after that Eudrilus eugenia, Eisenia fetida were added in respective vermibins. The multiplication of earthworms in terms of number was calculated at the end of vermicomposting. The N, P, K value of the manure in each vermibin was estimated before and after the completion of the experiment. High N, P, K value was obtained in Experiment (2) and Experiment (3) compared to control. Among the solid wastes, the vegetable wastes were degraded quickly by Eudrilus eugenia and also it has the best quality of manure. Eudrilus eugenia was found to be efficient for quick degradation of both garden wastes and vegetable wastes. After manure production, field trials were conducted using different fertilizers to assess the manure quality in the growth and yield of tomato plants. Six types of experimental trial pots were prepared where one was kept as control and five others were treated with different category of fertilizers. The treatment pots (P3) showed better growth parameters (leaf numbers, stem diameter, plant height) than the rest of the trial.

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

    SciTech Connect

    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.

  6. Polygenetic Nature of a Rhyolitic Dome: Cerro Pizarro, Eastern Mexico

    NASA Astrophysics Data System (ADS)

    Carrasco-Nuñez, G.; Riggs, N.

    2006-12-01

    Rhyolitic domes are commonly regarded as monogenetic volcanoes associated with single, brief eruptions, such as those forming basaltic scoria cones; this contrasts with domes of andesitic or dacitic composition that usually show a complex evolution. Rhyolitic domes are characterized by short-lived successions of pyroclastic and effusive activity associated with a series of discrete eruptive events that commonly last on the order of years to decades or perhaps centuries. Cerro Pizarro is an isolated rhyolitic dome with a volume of ~1.1 km3, located in the eastern Mexican Volcanic Belt, in the intermontane Serdán-Oriental basin. Cerro Pizarro has an eruptive history similar to a polygenetic volcano, including a complex evolution of alternating explosive and effusive eruptions, a cryptodome phase, and sector collapse, marked chemical variations with time, and long-term repose periods (~ 50-80 ky) between eruptions that reveals intermittent injection of magmas. Whereas major element chemistry does not show significant changes, trace and rare-earth elements show marked differences between the last eruptive episode and the initial and intermediate stages of activity. Other rhyolitic domes such as Glass Mountain, CA, Taylor Creek, NM, South Sister domes, OR, and the Mono Inyo complex, CA, show moderate to strong chemical variations. These domes, however, are related to larger volcanic fields or are dome complexes formed by numerous vents, in contrast with Cerro Pizarro, which is an isolated volcano with no apparent relation to nearby larger volcanic systems (e.g., Los Humeros caldera). This eruptive behavior provides new insights into how rhyolite domes may evolve. A protracted, complex evolution bears important implications for hazard assessment. Activity at Cerro Pizarro leads us to speculate that isolated rhyolitic systems may become reactivated, potentially after tens of thousands of years.

  7. The Cerro LOS Calvos and La Banderia chondrites

    NASA Astrophysics Data System (ADS)

    Whitlock, Randall; Lewis, Charles F.; Clark, James C.; Moore, Carleton B.

    1991-06-01

    The Cerro los Calvos meteorite is a single stone of 68.5 g found in the Nuevo Mercurio strewn field of Zacatecas, (Mexico). It is an unusual H4 chondrite. Its olivine (Fa12.5) and orthopyroxene (Fs 11.7, Wo 0.8) are reduced relative to typical H chondrites. The La Banderia meteorite of 54.3 g from the same vicinity is an LL5 chondrite of shock classification e.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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).

  10. Reservoir simulation and geochemical study of Cerro Prieto I wells

    SciTech Connect

    Lippmann, M.J. ); Truesdell, A.H. )

    1990-03-01

    Combined reservoir simulation and geochemical data analysis are used to investigate the effects of recharge and other reservoir processes occurring in the western part of the Cerro Prieto, Mexico, geothermal field (i.e., Cerro Prieto I area). Enthalpy-based temperatures and bottomhole temperatures are calculated based on simplified models of the system, considering different reservoir boundary conditions and zones of contrasting initial temperatures and reservoir properties. By matching the computed trends with geothermometer-based temperature and enthalpy histories of producing wells, the main processes active in the western area of Cerro Prieto are identified. This part of the geothermal system is strongly influenced by nearby groundwater aquifers; cooler waters readily recharge the reservoirs. In response to exploitation, the natural influx of cold water into the shallower alpha reservoir is mainly from the west and down Fault L, while the recharge to the deeper beta reservoir in this part of the field, seems to be only lateral, from the west and possibly south. 11 refs., 12 figs.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Chemical composition and evaluation of the antimicrobial activity of the essential oil from leaves of Eugenia platysema.

    PubMed

    Tenfen, Adrielli; Siebert, Diogo Alexandre; Yamanaka, Celina Noriko; Mendes de Córdova, Caio Maurício; Scharf, Dilamara Riva; Simionatto, Edésio Luiz; Alberton, Michele Debiasi

    2016-09-01

    This study describes the qualitative and quantitative chemical composition and evaluates the antibacterial activity of essential oil from Eugenia platysema leaves. Analysis by GC-FID and GC-MS allowed the identification of 22 compounds. Different from the other species of the Eugenia genus, the major compound found in the essential oil was the diterpene phytol (66.05%), being this the first report of the presence of this compound in the essential oils from Eugenia genus. The sesquiterpene elixene was the second most concentrated compound in the studied essential oil (9.16%). The essential oil from E. platysema was tested for its antibacterial activity against cell-walled bacteria and mollicute strains of clinical interest using the microdilution broth assay. The results showed that the essential oil of E. platysema was inactive until 1000 μg mL(-1) against tested bacteria.

  15. Magma-tectonic interactions in Nicaragua: the 1999 seismic swarm and eruption of Cerro Negro volcano

    NASA Astrophysics Data System (ADS)

    La Femina, Peter C.; Connor, Charles B.; Hill, Brittain E.; Strauch, Wilfried; Saballos, J. Armando

    2004-09-01

    A low-energy (Volcanic Explosivity Index [VEI] 1), small-volume (0.001 km 3 Dense Rock Equivalent [DRE]) eruption of highly crystalline basalt occurred at Cerro Negro volcano, Nicaragua, August 5-7, 1999. This eruption followed three earthquakes (each ˜ Mw 5.2) with strike-slip and oblique-slip focal mechanisms, the first of which occurred approximately 11 h before eruptive activity and within 1 km of Cerro Negro. Surface ruptures formed during these events extend up to 4 km from Cerro Negro, but concentrate ˜1 km south of Cerro Negro. Surface ruptures did not occur within 300 m of the cone, however, three new vents formed on the south flank and base of Cerro Negro and on trend with the Cerro La Mula-Cerro Negro volcanic alignment. Earthquake swarms were located northwest and southeast of Cerro Negro and seismicity was elevated for up to 11 days after the initial event. The temporal and spatial patterns of earthquake swarms, surface ruptures, and the eruption location can be explained using the Hill [J. Geophys. Res. 82 (1977) 1347] model for earthquake swarms in volcanic regions, where an eruption is triggered by tectonically induced changes in the regional stress field. In this model, tectonic strain, rather than magmatic overpressure causes dilation of the conduit for magma ascent. Numerical simulations for the 1999 eruption illustrate that the observed velocities (up to 75 m s -1) and fountain heights (50-300 m) can be achieved by eruption of magma with little excess magmatic pressure, in response to changes in Coulomb stress along the Cerro La Mula-Cerro Negro alignment. These observations and models show that 1999 Cerro Negro activity was a tectonically induced small-volume eruption in an arc setting, with the accommodation of extensional strain by dike injection.

  16. Methanogenic food web in the gut contents of methane-emitting earthworm Eudrilus eugeniae from Brazil

    PubMed Central

    Schulz, Kristin; Hunger, Sindy; Brown, George G; Tsai, Siu M; Cerri, Carlos C; Conrad, Ralf; Drake, Harold L

    2015-01-01

    The anoxic saccharide-rich conditions of the earthworm gut provide an ideal transient habitat for ingested microbes capable of anaerobiosis. It was recently discovered that the earthworm Eudrilus eugeniae from Brazil can emit methane (CH4) and that ingested methanogens might be associated with this emission. The objective of this study was to resolve trophic interactions of bacteria and methanogens in the methanogenic food web in the gut contents of E. eugeniae. RNA-based stable isotope probing of bacterial 16S rRNA as well as mcrA and mrtA (the alpha subunit of methyl-CoM reductase and its isoenzyme, respectively) of methanogens was performed with [13C]-glucose as a model saccharide in the gut contents. Concomitant fermentations were augmented by the rapid consumption of glucose, yielding numerous products, including molecular hydrogen (H2), carbon dioxide (CO2), formate, acetate, ethanol, lactate, succinate and propionate. Aeromonadaceae-affiliated facultative aerobes, and obligate anaerobes affiliated to Lachnospiraceae, Veillonellaceae and Ruminococcaceae were associated with the diverse fermentations. Methanogenesis was ongoing during incubations, and 13C-labeling of CH4 verified that supplemental [13C]-glucose derived carbon was dissimilated to CH4. Hydrogenotrophic methanogens affiliated with Methanobacteriaceae and Methanoregulaceae were linked to methanogenesis, and acetogens related to Peptostreptoccocaceae were likewise found to be participants in the methanogenic food web. H2 rather than acetate stimulated methanogenesis in the methanogenic gut content enrichments, and acetogens appeared to dissimilate supplemental H2 to acetate in methanogenic enrichments. These findings provide insight on the processes and associated taxa potentially linked to methanogenesis and the turnover of organic carbon in the alimentary canal of methane-emitting E. eugeniae. PMID:25615437

  17. Methanogenic food web in the gut contents of methane-emitting earthworm Eudrilus eugeniae from Brazil.

    PubMed

    Schulz, Kristin; Hunger, Sindy; Brown, George G; Tsai, Siu M; Cerri, Carlos C; Conrad, Ralf; Drake, Harold L

    2015-08-01

    The anoxic saccharide-rich conditions of the earthworm gut provide an ideal transient habitat for ingested microbes capable of anaerobiosis. It was recently discovered that the earthworm Eudrilus eugeniae from Brazil can emit methane (CH4) and that ingested methanogens might be associated with this emission. The objective of this study was to resolve trophic interactions of bacteria and methanogens in the methanogenic food web in the gut contents of E. eugeniae. RNA-based stable isotope probing of bacterial 16S rRNA as well as mcrA and mrtA (the alpha subunit of methyl-CoM reductase and its isoenzyme, respectively) of methanogens was performed with [(13)C]-glucose as a model saccharide in the gut contents. Concomitant fermentations were augmented by the rapid consumption of glucose, yielding numerous products, including molecular hydrogen (H2), carbon dioxide (CO2), formate, acetate, ethanol, lactate, succinate and propionate. Aeromonadaceae-affiliated facultative aerobes, and obligate anaerobes affiliated to Lachnospiraceae, Veillonellaceae and Ruminococcaceae were associated with the diverse fermentations. Methanogenesis was ongoing during incubations, and (13)C-labeling of CH4 verified that supplemental [(13)C]-glucose derived carbon was dissimilated to CH4. Hydrogenotrophic methanogens affiliated with Methanobacteriaceae and Methanoregulaceae were linked to methanogenesis, and acetogens related to Peptostreptoccocaceae were likewise found to be participants in the methanogenic food web. H2 rather than acetate stimulated methanogenesis in the methanogenic gut content enrichments, and acetogens appeared to dissimilate supplemental H2 to acetate in methanogenic enrichments. These findings provide insight on the processes and associated taxa potentially linked to methanogenesis and the turnover of organic carbon in the alimentary canal of methane-emitting E. eugeniae.

  18. Enhancement of the Antifungal Activity of Antimicrobial Drugs by Eugenia uniflora L.

    PubMed Central

    Santos, Karla K.A.; Matias, Edinardo F.F.; Tintino, Saulo R.; Souza, Celestina E.S.; Braga, Maria F.B.M.; Guedes, Gláucia M.M.; Costa, José G.M.; Menezes, Irwin R.A.

    2013-01-01

    Abstract Candidiasis is the most frequent infection by opportunistic fungi such as Candida albicans, Candida tropicalis, and Candida krusei. Ethanol extract from Eugenia uniflora was assayed, for its antifungal activity, either alone or combined with four selected chemotherapeutic antimicrobial agents, including anphotericin B, mebendazole, nistatin, and metronidazole against these strains. The obtained results indicated that the association of the extract of E. uniflora to metronidazole showed a potential antifungal activity against C. tropicalis. However, no synergistic activity against the other strains was observed, as observed when the extract was associated with the other, not enhancing their antifungal activity. PMID:23819641

  19. Chemical composition and larvicidal activity of Eugenia triquetra essential oil from Venezuelan Andes.

    PubMed

    Mora, Flor D; Avila, Jorge L; Rojas, Luis B; Ramírez, Rosslyn; Usubillaga, Alfredo; Segnini, Samuel; Carmona, Juan; Silva, Bladimiro

    2010-06-01

    The chemical constituents of the essential oil obtained by hydrodistillation of the leaves of Eugenia triquetra O. Berg, collected in Táchira State, Venezuela, were identified by GC-MS analysis. Twenty-six components, which made up 88.5% of the oil, were identified. The major constituents were linalool (17.5%), limonene (16.9%), alpha-pinene (11.6%), beta-pinene (8.7%), and p-cymene (3.7%). The essential oil was tested against third-instar larvae of Aedes aegypti, showing a LC50 value of 64.8 +/- 5.6 ppm.

  20. Essential oil of clove (Eugenia caryophyllata) augments the humoral immune response but decreases cell mediated immunity.

    PubMed

    Halder, Sumita; Mehta, Ashish K; Mediratta, Pramod K; Sharma, Krishna K

    2011-08-01

    The present study was undertaken to explore the effect of the essential oil isolated from the buds of Eugenia caryophyllata on some immunological parameters. Humoral immunity was assessed by measuring the hemagglutination titre to sheep red blood cells and delayed type hypersensitivity was assessed by measuring foot pad thickness. Clove oil administration produced a significant increase in the primary as well as secondary humoral immune response. In addition, it also produced a significant decrease in foot pad thickness compared with the control group. Thus, these results suggest that clove oil can modulate the immune response by augmenting humoral immunity and decreasing cell mediated immunity.

  1. Distribution of Thermophilic Acidophiles at Cerro Negro, Nicaragua, an Analog for Acid-Sulfate Weathering Environments on Early Mars

    NASA Astrophysics Data System (ADS)

    Rogers, K. L.; Stephenson, S.; McCollom, T. M.; Hynek, B. M.

    2010-04-01

    Cerro Negro, Nicaragua is an excellent terrestrial analog for putative acid-sulfate weathering systems on early Mars. Sulfur- and sulfate-reducing acidophiles are found throughout Cerro Negro and can further elucidate the habitability of early Mars.

  2. Geophysical Investigations of Magma Plumbing Systems at Cerro Negro Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    MacQueen, Patricia Grace

    Cerro Negro near Leon, Nicaragua is a very young (163 years), relatively small basaltic cinder cone volcano that has been unusually active during its short lifespan (recurrence interval 6--7 years), presenting a significant hazard to nearby communities. Previous studies have raised several questions as to the proper classification of Cerro Negro and its relation to neighboring Las Pilas-El Hoyo volcano. Analysis of Bouguer gravity data collected at Cerro Negro has revealed connected positive density anomalies beneath Cerro Negro and Las Pilas-El Hoyo. These findings suggest that eruptions at Cerro Negro may be tapping a large magma reservoir beneath Las Pilas-El Hoyo, implying that Cerro Negro should be considered the newest vent on the Las Pilas-El Hoyo volcanic complex. As such, it is possible that the intensity of volcanic hazards at Cerro Negro may eventually increase in the future to resemble those pertaining to a stratovolcano. Keywords: Cerro Negro; Las Pilas-El Hoyo; Bouguer gravity; magmatic plumbing systems; potential fields; volcano.

  3. Evolution of Salmonella Cerro on a dairy farm over an eight-year period

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serovar Cerro, frequently isolated from dairy cattle and an occasional pathogen of humans, was recurrently isolated over an eight-year period on a dairy farm in south-central Pennsylvania. The genomes of 18 S. Cerro isolates recovered directly from the feces of in...

  4. Complete Genome Sequence and Methylome of Salmonella enterica subsp. enterica Cerro, a Frequent Dairy Cow Serovar.

    PubMed

    Haley, Bradd J; Pirone, Cary; Muruvanda, Tim; Brown, Eric; Allard, Marc; Karns, Jeffrey S; Van Kessel, Jo Ann S

    2016-01-28

    Salmonella enterica subsp. enterica serovar Cerro is an infrequent pathogen of humans and other mammals but is frequently isolated from the hindgut of asymptomatic cattle in the United States. To further understand the genomic determinants of S. Cerro specificity for the bovine hindgut, the genome of isolate CFSAN001588 was fully sequenced and deposited in the GenBank database.

  5. Atmospheric conditions at Cerro Armazones derived from astronomical data

    NASA Astrophysics Data System (ADS)

    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

  6. Spectra of Artificial Light Sources Near Cerro Tololo Interamerican Observatory

    NASA Astrophysics Data System (ADS)

    Whiting, A. B.

    2003-12-01

    I present objective-prism spectra of the major sources of artificial light visible from Cerro Tololo, as part of a study on present and impending light pollution. Spectra were obtained photographically using an improvised (but quite effective) objective-prism technique. Illumination from nearby towns is dominated by high-pressure sodium vapor lights, though a few mercury vapor/halogen lights (belonging to sports venues) are disproportionately bright. A nearby mine has installed low-pressure sodium lights, and the advantage (for astronomers) is obvious.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Vermicomposting of paper mill solid waste using epigeic earthworm Eudrilus eugeniae.

    PubMed

    Ponmani, S; Udayasoorian, C; Jayabalakrishnan, R M; Kumar, K Vinoth

    2014-07-01

    A 90 day study was conducted to evaluate the efficiency of an exotic earthworm species (Eudrilus eugeniae) for decomposition of different types of organic substrates (mixed liquor suspended solids, cow dung and leaf litter) into valuable vermicompost. Mixed liquor suspended solids (MLSS) and leaf litter (LL) were mixed with cow dung (CD) in eight different ratios with three replicates for each treatment. All vermibeds expressed a significant decrease in pH, organic carbon, C:N ratio and an increase in total nitrogen, phosphorus and potash. Overall, earthworms could maximize decomposition and mineralization efficiency in bedding with lower proportions of MLSS. Maximum value for earth worm zoo mass and higher concentration of nutrient content was observed in CD + MLSS + LL in 1:1:2 ratios. Earthworm mortality tended to increase with increasing proportion of MLSS and maximum mortality in E. eugeniae was recorded for MLSS treatment alone. Results indicate that vermicomposting might be useful for managing the energy and nutrient of MLSS on a low-input basis. Products of this process can be used for sustainable land restoration practices.

  9. Vermicomposting of different forms of water hyacinth by the earthworm Eudrilus eugeniae, Kinberg.

    PubMed

    Gajalakshmi, S; Ramasamy, E V; Abbasi, S A

    2002-04-01

    Six-month long trials were conducted on different vermireactors fed with one of the following forms of water hyacinth: (a) fresh whole plants, (b) dried whole plants, (c) chopped pieces of fresh plants, (d) 'spent' weed taken from reactors after extracting volatile fatty acids (VFAs), (e) precomposted fresh weed and (f) precomposted spent weed. The first four forms were studied with and without cowdung. The experiments revealed three clear trends (i) of the various forms of the weed assessed, the precomposted forms were the most favoured as feed by Eudrilus eugeniae, Kinberg, while the fresh whole form was the least favoured, (ii) the different forms of spent weed were favoured over the corresponding forms of fresh weed, and (iii) blending of cowdung (approximately 14% of the feed mass) with different forms of water hyacinth had a significant positive impact on vermicast output, growth in worm zoomass, and production of offspring relative to the corresponding unblended feed. In all reactors, the 'parent' earthworms steadily grew in size over the six-month span, and produced offspring. There was no mortality. The experiments thus confirm that water hyacinth can be sustainably vermicomposted in any of the forms with E. eugeniae.

  10. Conserved lamin A protein expression in differentiated cells in the earthworm Eudrilus eugeniae.

    PubMed

    Kalidas, Ramamoorthy M; Raja, Subramanian Elaiya; Mydeen, Sheik Abdul Kader Nagoor Meeran; Samuel, Selvan Christyraj Johnson Retnaraj; Durairaj, Selvan Christyraj Jackson; Nino, Gopi D; Palanichelvam, Karuppaiah; Vaithi, Arumugaswami; Sudhakar, Sivasubramaniam

    2015-09-01

    Lamin A is an intermediate filament protein found in most of the differentiated vertebrate cells but absent in stem cells. It shapes the skeletal frame structure beneath the inner nuclear membrane of the cell nucleus. As there are few studies of the expression of lamin A in invertebrates, in the present work, we have analyzed the sequence, immunochemical conservation and expression pattern of lamin A protein in the earthworm Eudrilus eugeniae, a model organism for tissue regeneration. The expression of lamin A has been confirmed in E. eugeniae by immunoblot. Its localization in the nuclear membrane has been observed by immunohistochemistry using two different rabbit anti-sera raised against human lamin A peptides, which are located at the C-terminus of the lamin A protein. These two antibodies detected 70 kDa lamin A protein in mice and a single 65 kDa protein in the earthworm. The Oct-4 positive undifferentiated blastemal tissues of regenerating earthworm do not express lamin A, while the Oct-4 negative differentiated cells express lamin A. This pattern was also confirmed in the earthworm prostate gland. The present study is the first evidence for the immunochemical identification of lamin A and Oct-4 in the earthworm. Along with the partial sequence obtained from the earthworm genome, the present results suggest that lamin A protein and its expression pattern is conserved from the earthworm to humans.

  11. Multiple asteroid systems (45) Eugenia and (87) Sylvia: Sensitivity to external and internal perturbations

    NASA Astrophysics Data System (ADS)

    Beauvalet, L.; Marchis, F.

    2014-10-01

    Satellites of asteroids are a widely used way to determine the masses and other dynamical parameters of their systems. We make such a determination here, using data from the two triple-asteroid systems, (45) Eugenia and (87) Sylvia, that come from the Hubble Space Telescope and adaptive optics on three 8-10 m class telescopes (Keck, VLT, Gemini North). First, we determined what set of parameters can be precisely derived from a limited number of observations. Next, we deduced constraints on the inner structure of the main body of the systems. To do this, we fit our dynamical model ODIN to simulated observations to determine at what confidence level we can constrain the dynamical parameters. We deduced that the mass of the satellites is too small to be fitted with confidence, while the polar oblateness J2 of the primary can be constrained. Then, ODIN was fitted to observations of the systems to obtain the values of the polar oblateness J2. The difference between the theoretical value of J2, and our estimate deduced from the motion of the satellites, suggests that Eugenia is differentiated. We explore the properties needed by a dense and spherical core, surrounded by a less dense layer, to explain this difference. The lack of agreement between the different dynamical studies of Sylvia prevents us from making any definitive conclusion, but the large range of possible solutions points to an interesting inner structure.

  12. Pharmacological basis for the empirical use of Eugenia uniflora L. (Myrtaceae) as antihypertensive.

    PubMed

    Consolini, A E; Baldini, O A; Amat, A G

    1999-07-01

    The rational basis for the use of Eugenia uniflora L. (Myrtaceae) as antihypertensive in Northeastern Argentina was assessed in normotensive rats. Intraperitoneal administration of the aqueous crude extract (ACE) decreased blood pressure (BP) of normotensive rats dose-dependently until 47.1 +/- 8.2% of control. The effective-dose 50 was 3.1 +/- 0.4 mg dried leaves/kg (d.l./kg) (yielding of ACE: 17% w/w). To determine the origin of hypotensive activity. Alpha-adrenergic antagonistic and vasorelaxant ACE activities were tested. The dose-response curve for phenylephrine on BP was inhibited non-competitively until 80% of its maximal effect (at 8 mg d.l. ACE/kg). Perfusion pressure (PP) of rat hindquarters (previously vasoconstricted by high-K+) was decreased by ACE in a concentration-dependent manner until -32.3 +/- 11.5% of tonic contraction at 1.2 g d.l. ACE/100 ml. In addition, A.C.E demonstrated diuretic activity at a dose (120 mg d.l./kg) higher than the hypotensive one. It was almost as potent as amiloride, but while amiloride induced loss of Na+ and saving of K+, ACE induced decrease in Na+ excretion. The results suggest that the empirical use of Eugenia uniflora L. (Myrtaceae) is mostly due to a hypotensive effect mediated by a direct vasodilating activity, and to a weak diuretic effect that could be related to an increase in renal blood flow.

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

    SciTech Connect

    Grannell, R.B.; 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.

  14. Mantle Xenoliths of Cerro Mercedes, Costa Rica, Central America

    NASA Astrophysics Data System (ADS)

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

    2003-12-01

    Mantle peridotite occurs as xenoliths in lavas and bombs at Cerro Mercedes, a Plio-Quaternary potassic alkaline basalt volcano approximately 70 km behind the volcanic front of northern Costa Rica (Tournon and Alvarado, 1997). Mineral exploration led to the first discovery of abundant mantle xenoliths in Central America (Vargas and Alfaro, 1992). The compositions of 71 xenoliths recovered in January 2003 include dunite, harzburgite, lherzolite and olivine websterite. Twenty xenoliths have a diameter of at least 3 cm. The nodules are abundant in basalt outcrops and the rare bombs. In spite of substantial soil development in a rain forest environment, both xenoliths and host lava remain well preserved. Olivine, pyroxenes and spinel are common, plagioclase is present and garnet appears to be absent. There is no obvious shearing or deformation and several pyroxenes are as much as 1 cm in diameter. The mineralogy suggests a relatively shallow upper mantle source, within either the lithosphere or possibly the uppermost asthenosphere. Cerro Mercedes, at latitude 10° 58' N and longitude 82° 21' W, lies along the Rio San Juan, which is locally the border between Nicaragua and Costa Rica, Central America. This location approximately coincides with a boundary between dominantly depleted mantle to the northwest and OIB or Galapagos-like mantle to the southeast. We will use mineralogical data to better define the likely depths and oxidation states of representative nodules and isotopic data to define the type of mantle source.

  15. Exploration and development of the Cerro Prieto geothermal field

    SciTech Connect

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

    1983-10-01

    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 U.S. organizations sponsored by the U.S. Department of Energy, joined CFE in this endeavor. An evaluation of the different studies carried out at Cerro Prieto has shown that: surface electrical resistivity and seismic reflection surveys are useful in defining targets for exploratory drilling; 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; geochemical surveys help to define zones of recharge and paths of fluid migration; and reservoir engineering studies are necessary in establishing the characteristics of the reservoir and in predicting its response to fluid production.

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

    NASA Astrophysics Data System (ADS)

    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 (

  17. Techniques for rehabilitation of wells in Cerro Prieto

    SciTech Connect

    Puente, H.G.; Mendoza, M.A.

    1995-12-31

    In the Cerro Prieto Geothermal Field, 12 to 16 wells are repaired annually. This is mainly due to the silica scaling that occurs in the production casing and the zones adjacent to the formation. There are wells that have been worked over on four or five occasions and their productive life has been increased up to 15 years. Many times, when the production casing will no longer permit the cementation of liner of a lesser diameter inside, it is the practice to open a window, generally in the 9 5/8 inch {phi} casing above the production zone and sidetrack it a few meters from the original well. We expose, with this technique, a new section of the reservoir, free of scaling that in many cases, permits us to recover steam production equivalent to the one obtained when the well was originally drilled. This paper presents the methodology used in the Cerro Prieto Field to diagnose and define the type of repair advisable in each instance.

  18. Exploration and development of the Cerro Prieto geothermal field

    SciTech Connect

    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.

  19. Fluid evolution of Cerro Colorado Porphyry Copper Mine

    NASA Astrophysics Data System (ADS)

    Tsang, Debbie Pui Wai; Wallis, Simon

    2014-05-01

    The Cerro Colorado porphyry copper deposit is the northernmost currently active copper mine in Chile, producing 90.5kt copper per year. It belongs to one of the Paleocene to early Eocene porphyry copper deposits that are distributed along the western slope of the main Andean Cordillera in Northern Chile (Bouzari & Clark, 2002). Active commercial production began in 1994, and the estimated reserves within the supergene blanket can sustain further 12 years of copper mining. Field studies of the well-exposed geology around the mine site and the access to drilled cores that penetrate into the hypogene zone provide a good opportunity to study the temporal relationship between magmatism, hypogene and supergene ore formation of the region. The geological evolution of Cerro Colorado area can be generalized as follows. The Cretaceous Cerro Empexa Formation, consisting of a sequence of volcanic rocks, mainly andesitic lava and breccia, lahars, some ignimbrite intercalations and dacitic tuff (Charrier, Pinto & Rodrigues, 2007), was intruded by tonalitic to dioritic magma in Middle-Eocene. Magmatic activities generated brecciated rocks accompanying with different alteration zones radiate outward from the intrusion. The mineralized hypogene protore later interacted with ground water, creating the supergene blanket, which is now the principal mining target of Cerro Colorado. Several plutonic lithologies with slight but distinct compositional differences were exposed in the valleys around the mine site. The presence of these several phases of small-scale intrusions suggests the ore genesis may be related to multiple pulses of heating and associated fluid flow. Complementarily, on-site geologists have reported occurrences of early stage biotites vein cutting into phyllitic alteration zone, or across terminal stage quartz-pyrite veins in the drilled cores. These observations are direct evidences of at least two major distinct phases of fluid flow, and imply the ore mineralization

  20. Physiological and biochemical mechanisms of the ornamental Eugenia myrtifolia L. plants for coping with NaCl stress and recovery.

    PubMed

    Acosta-Motos, José-Ramón; Diaz-Vivancos, Pedro; Álvarez, Sara; Fernández-García, Nieves; Sanchez-Blanco, María Jesús; Hernández, José Antonio

    2015-10-01

    We studied the response of Eugenia myrtifolia L. plants, an ornamental shrub native to tropical and subtropical areas, to salt stress in order to facilitate the use of these plants in Mediterranean areas for landscaping. E. myrtifolia plants implement a series of adaptations to acclimate to salinity, including morphological, physiological and biochemical changes. Furthermore, the post-recovery period seems to be detected by Eugenia plants as a new stress situation. Different physiological and biochemical changes in Eugenia myrtifolia L. plants after being subjected to NaCl stress for up to 30 days (Phase I) and after recovery from salinity (Phase II) were studied. Eugenia plants proved to be tolerant to NaCl concentrations between 44 and 88 mM, displaying a series of adaptative mechanisms to cope with salt-stress, including the accumulation of toxic ions in roots. Plants increased their root/shoot ratio and decreased their leaf area, leaf water potential and stomatal conductance in order to limit water loss. In addition, they displayed different strategies to protect the photosynthetic machinery, including the limited accumulation of toxic ions in leaves, increase in chlorophyll content, changes in chlorophyll fluorescence parameters, leaf anatomy and antioxidant defence mechanisms. Anatomical modifications in leaves, including an increase in palisade parenchyma and intercellular spaces and decrease in spongy parenchyma, served to facilitate CO2 diffusion in a situation of reduced stomatal aperture. Salinity produced oxidative stress in Eugenia plants as evidenced by oxidative stress parameters values and a reduction in APX and ASC levels. Nevertheless, SOD and GSH contents increased. The post-recovery period is detected as a new stress situation, as observed through effects on plant growth and alterations in chlorophyll fluorescence and oxidative stress parameters.

  1. Reservoir engineering studies of the Cerro Prieto geothermal field

    NASA Astrophysics Data System (ADS)

    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.

  2. Progress on the biphase turbine at Cerro Prieto

    SciTech Connect

    Cerini, D.; Hays, L.; Studhalter, W.

    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.

  3. Properties of Cerro Prieto rock at simulated in situ conditions

    SciTech Connect

    Schatz, J.F.

    1981-01-01

    Rocks from the Cerro Prieto Geothermal Field were tested under simulated in situ conditions in the laboratory to determine their properties and response to pore pressure reduction as would be caused by reservoir production. The primary purpose of the project was to provide information on compaction and creep as they may contribute to surface subsidence. Results show typical compressibilities for reservoir rocks of about 1 x 10/sup -6/ psi/sup -1/ and creep compaction rates of about 1 x 10/sup -9/ sec/sup -1/ when triggered by 1000 psi pore pressure reduction. This creep rate would cause significant porosity reduction if it continued for several years. Therefore it becomes important to learn how to correctly extrapolate such data to long times.

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

    USGS Publications Warehouse

    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. Reservoir simulation studies on the Cerro Prieto geothermal field

    SciTech Connect

    Castaneda, M.; Abril, A.; Arellano, V.; Marquez, R.

    1982-01-01

    A reservoir engineering and simulation study is being carried out on the Cerro Prieto geothermal field. A preliminary material balance has been applied to the old part of this field. A single block with constant properties in the horizontal direction was used for this preliminary material balance. The vertical block column was subdivided in several levels in order to take into account the known lithologic column. From existing pressure and enthalpy field histories, a single phase (liquid) reservoir assumption was selected. Under this assumption, a lateral radial recharge was considered in obtaining the pressure and enthalpy history match. These preliminary results indicate that another type of recharge is probably taking place in this part of the field, rather than lateral radial.

  6. Scale incidence on production pipes of Cerro Prieto geothermal wells

    SciTech Connect

    Mercado, S.; Hurtado, R. ); Bermejo, F.; Terrazas, B.; Hernandez, L. . Coordinadora Ejecutiva de Cerro Prieto)

    1989-01-01

    Scaling of geothermal wells in the Cerro Prieto field is a problem that has been experienced since the plant start-up, but has been diminished by selection of the main productive strata (avoiding the mixing of water from different temperature layers) and using orifice restrictions at the wellhead discharge. This last technique works in some new wells with a wellhead pressure of 120 bars. One hundred fifty wells have been drilled with the deepest production well being 3650 m. The drilling for exploration and production wells continues at the present time. Around one hundred million tons of a water-steam mixture is extracted every year; 40% is separated steam which is used in three geothermoelectric power stations having a total of 620 MWe of installed capacity.

  7. Estudio de seeing en la zona del Cerro Champaqui (I)

    NASA Astrophysics Data System (ADS)

    Diaz, R. J.; Eikenberry, S.; Scott, J.; Levato, H.; Firpo, V.; Farina, C.; Piroddi, D.; Jamud, N.; Bosch, G.; Mudrik, A.; Guzzo, P.; Donoso, V.; Recabarren, P.; Seifer, E.

    We report the results of the most recent seeing feasibility study performed in the region of Cerro Champaqui (2800m) at the mountain range of Sierras Grandes at the Province of Cordoba. We also describe the high frequency DIMM device built for this and other seeing samplings obtained at the provinces of San Juan; San Luis and Cordoba. This work is part of a long term project started in 2006; in search of sites of very low turbulence and suited for near infrared telescopes with active and adaptive optics. Two of the sites have been monitored during a total of 46 nights distributed in six months of the period 2011-2012. The preliminary results suggest the existence of `sub-arcsecond' seeing conditions during extended periods of time in at least one location in the mountain range in the SW of Cordoba and NE of San Luis provinces. FULL TEXT IN SPANISH

  8. The origin of the Cerro Prieto geothermal brine

    USGS Publications Warehouse

    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.

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

    SciTech Connect

    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.

  10. A study on the effect of chemically synthesized magnetite nanoparticles on earthworm: Eudrilus eugeniae

    NASA Astrophysics Data System (ADS)

    Samrot, Antony V.; Justin, C.; Padmanaban, S.; Burman, Ujjala

    2017-02-01

    Most look into the benefits of the nanoparticles, but keeping aside the benefits; this study focuses on the impacts of nanoparticles on living systems. Improper disposal of nanoparticles into the environment is a subject of pollution or nano-pollution which in turn affects the flora and fauna in the ecosystem, particularly soil ecosystem. Thus, this study was done to understand the impacts of chemically synthesized magnetite nanoparticles on earthworm— Eudrilus eugeniae, a soil-dependent organism which acquires food and nutrition from decaying matters. The chemically synthesized magnetite nanoparticles were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Earthworms were allowed to interact with different concentrations of synthesized nanoparticles and the effect of the nanoparticles was analysed by studying the phenotypic changes followed by histology and inductively coupled plasma optical emission spectrometry analyses.

  11. Vermicomposting of distillation waste of citronella plant (Cymbopogon winterianus Jowitt.) employing Eudrilus eugeniae.

    PubMed

    Deka, H; Deka, S; Baruah, C K; Das, J; Hoque, S; Sarma, N S

    2011-07-01

    Laboratory experiment on vermicomposting of distillation waste of java citronella (Cymbopogon winterianus Jowitt.) was carried out employing Eudrilus eugeniae, in two seasonal trials, covering summer and winter periods. Two vermicomposting treatments were conducted in earthen pots, one with citronella plant waste only (CW) and the other, a mixture of citronella waste and cowdung in the proportion 5:1 (CW+CD). Vermicomposting of citronella waste resulted reduction in C/N ratio (83.5-87.7%), enhancement of ash content and a number of macro and micronutrients. The FT-IR spectroscopy of the vermicompost revealed the reduction in aliphatic and aromatic compound as well as increase in amide group after the 105 days stabilization process. The vermicompost output was significantly enhanced in CW+CD treatment than CW treatment. Even, nutrient content of the vermicompost was also higher in CW+CD treatment than CW alone indicating the positive role of cowdung in improvement of quantity and quality.

  12. A study on the effect of chemically synthesized magnetite nanoparticles on earthworm: Eudrilus eugeniae

    NASA Astrophysics Data System (ADS)

    Samrot, Antony V.; Justin, C.; Padmanaban, S.; Burman, Ujjala

    2016-12-01

    Most look into the benefits of the nanoparticles, but keeping aside the benefits; this study focuses on the impacts of nanoparticles on living systems. Improper disposal of nanoparticles into the environment is a subject of pollution or nano-pollution which in turn affects the flora and fauna in the ecosystem, particularly soil ecosystem. Thus, this study was done to understand the impacts of chemically synthesized magnetite nanoparticles on earthworm—Eudrilus eugeniae, a soil-dependent organism which acquires food and nutrition from decaying matters. The chemically synthesized magnetite nanoparticles were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Earthworms were allowed to interact with different concentrations of synthesized nanoparticles and the effect of the nanoparticles was analysed by studying the phenotypic changes followed by histology and inductively coupled plasma optical emission spectrometry analyses.

  13. Characterization of anthocyanins from the fruits of baguaçu (Eugenia umbelliflora Berg).

    PubMed

    Kuskoski, E Marta; Vega, José M; Rios, José J; Fett, Roseane; Troncoso, Ana M; Asuero, Agustin G

    2003-08-27

    Anthocyanin pigments in the berries of baguaçu (Eugenia umbelliflora Berg), a tropical fruit from Brazil, were extracted with 0.1% HCl in ethanol, and the crude anthocyanin extract was purified by Amberlite XAD-7 open-column chromatography. Six major anthocyanins were isolated by preparative HPLC, and their chemical structures were identified by spectroscopic methods (TLC, UV-vis, MS, and (1)H NMR). Delphinidin 3-O-beta-glucopyranoside, cyanidin 3-O-beta-glucopyranoside, petunidin 3-O-beta-glucopyranoside, pelargonidin 3-O-beta-glucopyranoside, peonidin 3-O-beta-glucopyranoside, and malvidin 3-O-beta-glucopyranoside were identified. On the basis of chromatographic data the total anthocyanin content was 342 mg/100 g of fresh baguaçu berries. Therefore, the concomitant presence of six anthocyanins in a single plant species makes this product promising as a new pigment source.

  14. Antimycoplasmic activity and seasonal variation of essential oil of Eugenia hiemalis Cambess. (Myrtaceae).

    PubMed

    Zatelli, Gabriele Andressa; Zimath, Priscila; Tenfen, Adrielli; Mendes de Cordova, Caio Maurício; Scharf, Dilamara Riva; Simionatto, Edésio Luiz; Alberton, Michele Debiasi; Falkenberg, Miriam

    2016-09-01

    The purpose of this work was to study the chemical composition and antimycoplasmic and anticholinesterase activities of the essential oil of Eugenia hiemalis leaves collected throughout the year. A total of 42 compounds were identified by CG, and are present in almost every seasons. Sesquiterpenes were dominant (86.01-91.48%), and non-functionalised sesquiterpenes comprised the major fraction, which increased in the summer; monoterpenes were not identified. The major components were spathulenol (5.36-16.06%), δ-cadinene (7.50-15.93%), bicyclogermacrene (5.70-14.24%) and β-caryophyllene (4.80-9.43%). The highest oil yield was obtained in summer and autumn. Essential oils presented activity against three evaluated Mycoplasma strains, but no activity was observed in the anticholinesterase assay.

  15. Anthocyanins from Eugenia brasiliensis edible fruits as potential therapeutics for COPD treatment.

    PubMed

    Flores, Gema; Dastmalchi, Keyvan; Paulino, Sturlainny; Whalen, Kathleen; Dabo, Abdoulaye J; Reynertson, Kurt A; Foronjy, Robert F; D'Armiento, Jeanine M; Kennelly, Edward J

    2012-10-01

    Nine anthocyanins (1-9) from the edible fruits of Eugenia brasiliensis were identified by HPLC-PDA and LC-MS, and seven of these are described for the first time in this Brazilian fruit. Two of the major anthocyanins, delphinidin (8) and cyanidin (9), were studied for their inhibitory activity against chemokine interleukin-8 (IL-8) production before and after cigarette smoke extract (CSE) treatment of cells. In non-treated cells the amount of IL-8 was unchanged following treatment with cyanidin and delphinidin in concentrations 0.1-10 μM. Both delphinidin (8) and cyanidin (9) decreased the production of IL-8 in treated cells, at 1 and 10 μM, respectively. Delphinidin (8) demonstrated IL-8 inhibition in the CSE treated cells in a dose-dependent manner.

  16. Anthocyanins from Eugenia brasiliensis edible fruits as potential therapeutics for COPD treatment

    PubMed Central

    Flores, Gema; Dastmalchi, Keyvan; Paulino, Sturlainny; Whalen, Kathleen; Dabo, Abdoulaye J.; Reynertson, Kurt A.; Foronjy, Robert F.; D Armiento, Jeanine M.; Kennelly, Edward J.

    2012-01-01

    Nine anthocyanins (1–9) from the edible fruits of Eugenia brasiliensis were identified by HPLC-PDA and LC-MS, and seven of these are described for the first time in this Brazilian fruit. Two of the major anthocyanins, delphinidin (8) and cyanidin (9), were studied for their inhibitory activity against chemokine interleukin-8 (IL-8) production before and after cigarette smoke extract (CSE) treatment of cells. In non-treated cells the amount of IL-8 was unchanged following treatment with cyanidin and delphinidin in concentrations 0.1–10 M. Both delphinidin (8) and cyanidin (9) decreased the production of IL-8 in treated cells, at 1 M and 10 M, respectively. Delphinidin (8) demonstrated IL-8 inhibition in the CSE treated cells in a dose-dependent manner. PMID:25005941

  17. Lead contamination in Eugenia dyeriana herbal preparations from different commercial sources in Malaysia.

    PubMed

    Ang, H H

    2008-06-01

    The Drug Control Authority (DCA) of Malaysia implemented the phase three registration of traditional medicines on 1 January, 1992. A total of 100 products in various pharmaceutical dosage forms of a herbal preparation, containing Eugenia dyeriana, either single or combined preparations (more than one medicinal plant), were analyzed for the presence of lead contamination, using atomic absorption spectrophotometry. These samples were bought from different commercial sources in the Malaysian market, after performing a simple random sampling. Results showed that 22% of the above products failed to comply with the quality requirement for traditional medicines in Malaysia. Although this study showed that 78% of the products fully complied with the quality requirement for traditional medicines in Malaysia pertaining to lead, however, they cannot be assumed safe from lead contamination because of batch-to-batch inconsistency.

  18. Essential oil of the leaves of Eugenia uniflora L.: antioxidant and antimicrobial properties.

    PubMed

    Victoria, Francine Novack; Lenardão, Eder João; Savegnago, Lucielli; Perin, Gelson; Jacob, Raquel Guimarães; Alves, Diego; da Silva, Wladimir Padilha; da Motta, Amanda de Souza; Nascente, Patricia da Silva

    2012-08-01

    Essential oil (EO) of the leaves of Eugenia uniflora L. (Brazilian cherry tree) was evaluated for its antioxidant, antibacterial and antifungal properties. The acute toxicity of the EO administered by oral route was also evaluated in mice. The EO exhibited antioxidant activity in the DPPH, ABTS and FRAP assays and reduced lipid peroxidation in the kidney of mice. The EO also showed antimicrobial activity against two important pathogenic bacteria, Staphylococcus aureus and Listeria monocytogenes, and against two fungi of the Candida species, C. lipolytica and C. guilliermondii. Acute administration of the EO by the oral route did not cause lethality or toxicological effects in mice. These findings suggest that the EO of the leaves of E. uniflora may have the potential for use in the pharmaceutical industry.

  19. Efficacy of an essential oil of Eugenia caryophyllata against Psoroptes cuniculi.

    PubMed

    Fichi, G; Flamini, G; Giovanelli, F; Otranto, D; Perrucci, S

    2007-02-01

    The acaricidal activity of Eugenia caryophyllata essential oil was evaluated in vitro and in vivo on Psoroptes cuniculi, a mange mite. In vitro, different concentrations of the oil were tested and the observed mites mortality was compared with that observed in untreated and treated (Acacerulen R) controls. In vivo, six P. cuniculi infected rabbits were topically treated with the oil diluted at 2.5% and compared with untreated and treated control groups of six rabbits each. In vitro, up to the concentration of 0.10% the oil gave highly significant (P<0.01) percentages of mite mortality respect to the untreated controls, but only up to 0.16% it showed the same efficacy of Acacerulen R. In vivo, the treatment with the essential oil cured all infested rabbits and no statistical differences were observed respect to the treated control group. The untreated rabbits remained infested.

  20. Mating system and pollen dispersal in Eugenia dysenterica (Myrtaceae) germplasm collection: tools for conservation and domestication.

    PubMed

    Rodrigues, Eduardo B; Collevatti, Rosane G; Chaves, Lázaro J; Moreira, Lucas R; Telles, Mariana P C

    2016-04-01

    Eugenia dysenterica DC. (Myrtaceae) is a perennial tree producing edible fruits and ornamental flowers of potential value widely distributed in Brazilian "Cerrados" (savannas), but available genetic resources and potential for future breeding programs must be evaluated. Here we evaluated the reproductive system and pollen-mediated gene flow in one generation of Eugenia dysenterica germplasm collection of Agronomy School, Federal University of Goiás (in Goiânia city, Central Brazil). We collected leaves from all adults from the germplasm collection (682 plants) and seeds (542) from 23 mother-trees. Genotypes were obtained for seven microsatellite loci. Genetic diversity was high and did not significantly differ between adults (H e = 0.777) and progeny arrays (H e = 0.617). Our results showed that E. dysenterica has an allogamous mating system in the germplasm collection (t m = 0.957), but with high and significant biparental inbreeding (t m - t s = 0.109). Because sibs are very close to each other, mating between closely related individuals is likely. Paternity correlation was also relatively high, indicating a 11.9 % probability that a randomly chosen pair of outcrossed progeny from the same array are full sibs. The maximum pollen dispersal distance (224 m), estimated using assignment test, corresponded to the boundaries of the orchard. We were able to assign the paternity to only 64 % of the 349 seeds analyzed, indicating potential pollen immigration to the germplasm collection. The variance effective population size estimated for one maternal family in the germplasm collection (N ev = 3.42) is very close to the theoretical maximum value for half-sibs (Nev = 4.0). Because E. dysenterica has a long life cycle and generation time, the maintenance of an effective population size of at least 100 in the germplasm collection is suggested, which can be achieved by maintaining a seed-trees number around 30 individuals.

  1. Cerro Negro, Nicaragua: A Key Mars Analog Environment for Acid-Sulfate Weathering

    NASA Astrophysics Data System (ADS)

    Hynek, B. M.; Rogers, K. L.; McCollom, T. M.

    2007-07-01

    Cerro Negro Volcano, Nicaragua, is being investigated as an analog for acid-sulfate weathering of Mars-like basalts. Our goal is to better understand the mineral alteration pathways and the astrobiological potential of early Mars.

  2. Acid-Sulfate Weathering of Basalts at Cerro Negro Volcano, Nicaragua: An Early Mars Analog

    NASA Astrophysics Data System (ADS)

    Marcucci, E. C.; Hynek, B. M.; McCollom, T. M.; Rogers, K. L.

    2010-03-01

    Cerro Negro, Nicaragua is a high temperature, low pH, S-rich environment, proposed to explain some acid-sulfate weathering on Mars. Simultaneously, we are analyzing field samples, laboratory experiments, theoretical modeling, and microbial studies.

  3. Comparison of the radiological dose from the Cerro Grande fire to a natural wildfire.

    PubMed

    Volkerding, John M

    2004-01-01

    Since the Cerro Grande fire burned portions of a Department of Energy facility where nuclear weapons research occurs, it is important to determine if the fire posed greater risk to the public than a natural fire. All wildfires release radioactive as well as other toxic pollutants into the atmosphere. Thus, it is important to determine if the radioactive air emissions from the Cerro Grande fire were statistically different than those from a natural wildfire, specifically the Viveash fire.

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

    USGS Publications Warehouse

    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.

  5. The chemical composition and biological activity of clove essential oil, Eugenia caryophyllata (Syzigium aromaticum L. Myrtaceae): a short review.

    PubMed

    Chaieb, Kamel; Hajlaoui, Hafedh; Zmantar, Tarek; Kahla-Nakbi, Amel Ben; Rouabhia, Mahmoud; Mahdouani, Kacem; Bakhrouf, Amina

    2007-06-01

    The essential oil extracted from the dried flower buds of clove, Eugenia caryophyllata L. Merr. & Perry (Myrtaceae), is used as a topical application to relieve pain and to promote healing and also finds use in the fragrance and flavouring industries. The main constituents of the essential oil are phenylpropanoids such as carvacrol, thymol, eugenol and cinnamaldehyde. The biological activity of Eugenia caryophyllata has been investigated on several microorganisms and parasites, including pathogenic bacteria, Herpes simplex and hepatitis C viruses. In addition to its antimicrobial, antioxidant, antifungal and antiviral activity, clove essential oil possesses antiinflammatory, cytotoxic, insect repellent and anaesthetic properties. This short review addresses the chemical composition and biological effects of clove essential oil, and includes new results from GC/MS analysis and a study of its antimicrobial activity against a large number of multi-resistant Staphylococcus epidermidis isolated from dialysis biomaterials.

  6. Chemical Composition of Four Essential Oils of Eugenia from the Brazilian Amazon and Their Cytotoxic and Antioxidant Activity.

    PubMed

    da Silva, Joyce Kelly R; Andrade, Eloisa Helena A; Barreto, Leilane H; da Silva, Nádia Carolina F; Ribeiro, Alcy F; Montenegro, Raquel C; Maia, José Guilherme S

    2017-07-08

    Background:Eugenia species are appreciated for their edible fruits and are known as having anticonvulsant, antimicrobial and insecticidal actions. Methods: The plant material was collected in the southeastern Pará state of Brazil and submitted to hydrodistillation. GC-MS analyzed the oils, and their antioxidant and cytotoxic activities were evaluated by the DPPH and MTT assays. Results: The main components identified in the Eugenia oils were 5-hydroxy-cis-calemene, (2E,6E)-farnesol, (2E,6Z)-farnesol, caryophylla-4(12),8(13)-dien-5α-ol-5β-ol, E-γ-bisabolene, β-bisabolene, germacrene D, and ishwarane. The oil of E. egensis showed the most significant antioxidant activity (216.5 ± 11.6 mg TE/mL), followed by the oils of E. flavescens (122.6 ± 6.8 mg TE/mL) and E. patrisii (111.2 ± 12.4 mg TE/mL). Eugenia oils were cytotoxic to HCT-116 (colon cancer) cells by the MTT assay, where the most active was the oil of E. polystachya (10.3 µg/mL), followed by the oils of E. flavescens (13.9 µg/mL) and E. patrisii (16.4 µg/mL). The oils of E. flavescens and E. patrisii showed the highest toxicity for MRC5 (human fibroblast) cells, with values of 14.0 µg/mL and 18.1 µg/mL, respectively. Conclusions: These results suggest that Eugenia oils could be tested in future studies for the treatment of colon cancer and oxidative stress management.

  7. Chemical Composition of Four Essential Oils of Eugenia from the Brazilian Amazon and Their Cytotoxic and Antioxidant Activity

    PubMed Central

    da Silva, Joyce Kelly R.; Andrade, Eloisa Helena A.; Barreto, Leilane H.; da Silva, Nádia Carolina F.; Ribeiro, Alcy F.; Montenegro, Raquel C.; Maia, José Guilherme S.

    2017-01-01

    Background: Eugenia species are appreciated for their edible fruits and are known as having anticonvulsant, antimicrobial and insecticidal actions. Methods: The plant material was collected in the southeastern Pará state of Brazil and submitted to hydrodistillation. GC-MS analyzed the oils, and their antioxidant and cytotoxic activities were evaluated by the DPPH and MTT assays. Results: The main components identified in the Eugenia oils were 5-hydroxy-cis-calemene, (2E,6E)-farnesol, (2E,6Z)-farnesol, caryophylla-4(12),8(13)-dien-5α-ol-5β-ol, E-γ-bisabolene, β-bisabolene, germacrene D, and ishwarane. The oil of E. egensis showed the most significant antioxidant activity (216.5 ± 11.6 mg TE/mL), followed by the oils of E. flavescens (122.6 ± 6.8 mg TE/mL) and E. patrisii (111.2 ± 12.4 mg TE/mL). Eugenia oils were cytotoxic to HCT-116 (colon cancer) cells by the MTT assay, where the most active was the oil of E. polystachya (10.3 µg/mL), followed by the oils of E. flavescens (13.9 µg/mL) and E. patrisii (16.4 µg/mL). The oils of E. flavescens and E. patrisii showed the highest toxicity for MRC5 (human fibroblast) cells, with values of 14.0 µg/mL and 18.1 µg/mL, respectively. Conclusions: These results suggest that Eugenia oils could be tested in future studies for the treatment of colon cancer and oxidative stress management. PMID:28930266

  8. Geology of the Cerro Summit quadrangle, Montrose County, Colorado

    USGS Publications Warehouse

    Dickinson, Robert G.

    1966-01-01

    The Cerro Summit quadrangle covers 58 square miles of dissected plateau on the south flank of the Gunnison uplift in southwestern Colorado. It lies east of the Uncompahgre River valley and south of the Black Canyon of the Gunnison River. Rocks dip gently in most of the quadrangle, but they are locally upturned and faulted on the margin of the Gunnison uplift and are intensely deformed in the core of the uplift. The rocks exposed are of Precambrian, late Mesozoic, and Cenozoic age. Precambrian rocks include metasedimentary schist and gneiss, granitic pegmatite, and olivine gabbro. The oldest Mesozoic rocks exposed are continental, fresh-water, and lagoonal deposits in the Late Jurassic Entrada Sandstone, Wanakah Formation, and Morrison Formation. Channel-fill deposits that unconformably overlie the Jurassic rocks are possibly the Burro Canyon Formation of Early Cretaceous age. Upper Cretaceous rocks include marine and nearshore deposits of the Dakota Sandstone, Mancos Shale, and Pictured Cliffs Sandstone, and the fresh- and brackish-water sandstone, shale, and coal of the Fruitland Formation. Rocks of Late Cretaceous age that crop out in the adjacent Cimarron Ridge area may also have been deposited in this quadrangle but are now eroded; these rocks include the nonmarine Kirtland Shale and an unnamed volcanic conglomerate and tuff breccia. Nine faunal zones in the Mancos Shale help to establish the correct correlation of units in the Upper Cretaceous. The Pictured Cliffs Sandstone, Fruitland Formation, and Kirtland Shale of the Cerro Summit area have been mapped by some geologists as the Mesaverde Formation. Fossils indicate that the rocks are younger than the type Mesaverde. The unnamed volcanic rocks represent major volcanism in nearby areas. A Late Cretaceous (Maestrichtian) age for the volcanism is indicated by palynological evidence and an isotopic age of approximately 66 million years. Middle Tertiary rocks are conglomerate and tuff breccia. Upper Tertiary or

  9. 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

    NASA Astrophysics Data System (ADS)

    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.

  10. The evolutionary history of Eugenia sect. Phyllocalyx (Myrtaceae) corroborates historically stable areas in the southern Atlantic forests.

    PubMed

    de Oliveira Bünger, Mariana; Fernanda Mazine, Fiorella; Forest, Félix; Leandro Bueno, Marcelo; Renato Stehmann, João; Lucas, Eve J

    2016-12-01

    Eugenia sect. Phyllocalyx Nied. includes 14 species endemic to the Neotropics, mostly distributed in the Atlantic coastal forests of Brazil. Here the first comprehensive phylogenetic study of this group is presented, and this phylogeny is used as the basis to evaluate the recent infrageneric classification in Eugenia sensu lato (s.l.) to test the history of the evolution of traits in the group and test hypotheses associated with the history of this clade. A total of 42 taxa were sampled, of which 14 were Eugenia sect. Phyllocalyx for one nuclear (ribosomal internal transcribed spacer) and four plastid markers (psbA-trnH, rpl16, trnL-rpl32 and trnQ-rps16). The relationships were reconstructed based on Bayesian analysis and maximum likelihood. Additionally, ancestral area analysis and modelling methods were used to estimate species dispersal, comparing historically climatic stable (refuges) and unstable areas. Maximum likelihood and Bayesian inferences indicate that Eugenia sect. Phyllocalyx is paraphyletic and the two clades recovered are characterized by combinations of morphological characters. Phylogenetic relationships support a link between Cerrado and south-eastern species and a difference in the composition of species from north-eastern and south-eastern Atlantic forest. Refugia and stable areas identified within unstable areas suggest that these areas were important to maintain diversity in the Atlantic forest biodiversity hotspot. This study provides a robust phylogenetic framework to address important historical questions for Eugenia s.l. within an evolutionary context, supporting the need for better taxonomic study of one of the largest genera in the Neotropics. Furthermore, valuable insight is offered into diversification and biome shifts of plant species in the highly environmentally impacted Atlantic forest of South America. Evidence is presented that climate stability in the south-eastern Atlantic forest during the Quaternary contributed to the

  11. A simulation of the Cerro Hudson SO2 cloud

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.; Doiron, Scott D.; Lait, Leslie R.; Newman, Paul A.; Krueger, Arlin J.

    1993-01-01

    An isentropic trajectory model is used to simulate the evolution of the southern hemisphere SO2 cloud associated with the eruption of Cerro Hudson. By matching the parcel trajectories with total ozone mapping spectrometer SO2 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 SO2 cloud which was still clearly observed 19 days after the eruption. The trajectory model simulation of the SO2 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 stratospheric polar and midlatitude regions are nearly isolated from each other during the late August period.

  12. Radon and ammonia transects across the Cerro Prieto geothermal field

    SciTech Connect

    Semprini, L.; Kruger, P.

    1981-01-01

    Radon and ammonia transects, conducted at the Cerro Prieto geothermal field, involve measurement of concentration gradients at wells along lines of structural significance in the reservoir. Analysis of four transects showed radon concentrations ranging from 0.20 to 3.60 nCi/kg and ammonia concentrations from 17.6 to 59.3 mg/l. The data showed the lower concentrations in wells of lowest enthalpy fluid and the higher concentrations in wells of highest enthalpy fluid. Linear correlation analysis of the radon-enthalpy data indicated a strong relationship, with a marked influence by the two-phase conditions of the produced fluid. It appears that after phase separation in the reservoir, radon achieves radioactive equilibrium between fluid and rock, suggesting that the phase separation occurs well within the reservoir. A two-phase mixing model based on radon-enthalpy relations allows estimation of the fluid phase temperatures in the reservoir. Correlations of ammonia concentration with fluid enthalpy suggests an equilibrium partitioning model in which enrichment of ammonia correlates with higher enthalpy vapor.

  13. Evolution of the Cerro Prieto reservoirs under exploitation

    SciTech Connect

    Truesdell, A.H.; Lippmann, M.J.; Puente, H.G.

    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.

  14. Performance of casings in Cerro Prieto production wells

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Effect of temperature on growth and reproduction of the epigeic earthworm, Eudrilus Eugeniae (Kinberg).

    PubMed

    Shagoti, U M; Amoji, S D; Biradar, V A; Biradar, P M

    2001-07-01

    Influence of temperature on growth and reproduction of Eudrilus eugeniae has been investigated by laboratory culturing at regulated 25.0 degrees C, 30.0 degrees C, 37.5 degrees C and 40.0 degrees C and in fluctuating (22.7-27.3 degrees C) room temperature of prevailing (winter) season over 16 weeks. All worms died during first and tenth week at 40.0 degrees C and 37.5 degrees C respectively. Weight (biomass) and growth of worms cultured at different temperature varied significantly (P<0.01). The mean growth (mg/g live weight/day) at 25.0 degrees C., 30.0 degrees C, 35.0 degrees C, 37.5 degrees C and in fluctuating temperatures was 1,074.04 +/- 6.07, 1,554.01 degrees 192.37, 148.1 +/- 15.28, 192.83 +/- 25.8 and 1450.4 +/- 162.1 respectively. Growth declined after maturity drastically with coccon production. At 25.0 degrees C though worms are sexually mature, they failed to produce cocoons within 16 weeks whereas, at 35.0 degrees C and 37.5 degrees C they did not sexually mature. Worms attained sexual maturity at a mean weight of about 1000 mg/worm. The mean per cent maturity was higher and earlier in fluctuating temperatures and at 30.0 degrees C than at 25.0 degrees C. Cocoon production was observed only at 30.0 degrees C and in fluctuating temperatures with a mean of 0.9 and 1.5 cocoons/ wom/week and the cumulative cocoon number of 10.8 and 14.7/worm over 16th week respectively. The fluctuating temperature of uncontrolled room environment and 30.0 degrees C were favorable for various life activities of the worms. Eudrilus eugeniae appears to have range of temperature optima more than 25.0 degrees C and less than 28 degrees C. The climatic conditions prevailing in whole of the peninsular India during winter season are favourable for employing this worm in intensive field scale vermiculturing practices.

  17. Spatial and Temporal Variations of Diffuse Carbon Dioxide Emission From Cerro Negro Volcano, Nicaragua, Central America

    NASA Astrophysics Data System (ADS)

    Galindo, I.; Melián, G.; Salazar, J.; Hernández, P.; Pérez, N.; Strauch, W.

    2002-12-01

    Cerro Negro is a basaltic cinder cone that has erupted 22 times since its birth in 1850. It is part of a group of four young cinder cones NW of Las Pilas volcano. Cerro Negro's most recent activity was on 5 August 1999 when erupted ash clouds at heights of about 7 km. In December 1999, three months after the eruption, a surface flux survey was carried out at Cerro Negro. Soil CO2 efflux values ranged from 0.5 to 35,000 gm-2d-1 and the total diffuse CO2 output was estimated about 2,800 td-1. Soil temperature reached values above 300°C on the NE flank of the volcano (Salazar et al., 2001). The goal of this study is to evaluate how diffuse CO2 degassing rate at Cerro Negro changes through its eruptive cycle and improve its volcano monitoring program. From Febraury 26 to March 11, 2002, a new diffuse CO2 degassing survey was carried out at Cerro Negro. Sampling distribution was similar to the 1999 survey covering an area of (0.6 Km2). Diffuse CO2 emission rates for the 2002 survey showed a wide range of values from 0.3 to 26,500 gm-2d-1. Most of the study area showed soil CO2 efflux values above 110 gm-2d-1, and the highest CO2 efflux rate was observed in the Northeastern sector of the crater. Soil temperature was also recorded during the survey, and the highest value was observed in the NE flank reaching temperatures up to 450°C. The total diffuse CO2 output for the 2002 survey was estimated about 280 td-1, which is one order of magnitude lower than the estimated for the 1999 survey. This significant temporal variation on diffuse CO2 emission rate seems to be clearly related to the eruptive cycle of Cerro Negro. If we consider that the statistically eruptive cycle for Cerro Negro is less than a decade, it is obvious that the December 1999 survey was performed within its post-eruptive period, while the recent 2002 survey was carried out two years and a half after the most recent eruption of Cerro Negro, within its inter-eruptive period. These results suggest that

  18. Alkaline magmatism in the Amambay area, NE Paraguay: The Cerro Sarambí complex

    NASA Astrophysics Data System (ADS)

    Gomes, C. B.; Velázquez, V. F.; Azzone, R. G.; Paula, G. S.

    2011-07-01

    The Early Cretaceous alkaline magmatism in the northeastern region of Paraguay (Amambay Province) is represented by stocks, plugs, dikes, and dike swarms emplaced into Carboniferous to Triassic-Jurassic sediments and Precambrian rocks. This magmatism is tectonically related to the Ponta Porã Arch, a NE-trending structural feature, and has the Cerro Sarambí and Cerro Chiriguelo carbonatite complexes as its most significant expressions. Other alkaline occurrences found in the area are the Cerro Guazú and the small bodies of Cerro Apuá, Arroyo Gasory, Cerro Jhú, Cerro Tayay, and Cerro Teyú. The alkaline rocks comprise ultramafic-mafic, syenitic, and carbonatitic petrographic associations in addition to lithologies of variable composition and texture occurring as dikes; fenites are described in both carbonatite complexes. Alkali feldspar and clinopyroxene, ranging from diopside to aegirine, are the most abundant minerals, with feldspathoids (nepheline, analcime), biotite, and subordinate Ti-rich garnet; minor constituents are Fe-Ti oxides and cancrinite as the main alteration product from nepheline. Chemically, the Amambay silicate rocks are potassic to highly potassic and have miaskitic affinity, with the non-cumulate intrusive types concentrated mainly in the saturated to undersaturated areas in silica syenitic fields. Fine-grained rocks are also of syenitic affiliation or represent more mafic varieties. The carbonatitic rocks consist dominantly of calciocarbonatites. Variation diagrams plotting major and trace elements vs. SiO 2 concentration for the Cerro Sarambí rocks show positive correlations for Al 2O 3, K 2O, and Rb, and negative ones for TiO 2, MgO, Fe 2O 3, CaO, P 2O 5, and Sr, indicating that fractional crystallization played an important role in the formation of the complex. Incompatible elements normalized to primitive mantle display positive spikes for Rb, La, Pb, Sr, and Sm, and negative for Nb-Ta, P, and Ti, as these negative anomalies are

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Purification of betulinic acid from Eugenia florida (Myrtaceae) by high-speed counter-current chromatography.

    PubMed

    Frighetto, Nelson; Welendorf, Rodolfo Max; Pereira da Silva, Ana Maria; Nakamura, Marcos Jun; Siani, Antonio Carlos

    2005-01-01

    A high yield of betulinic acid (up to 17% from the ethanolic extract) was found in the leaves of Eugenia florida collected in south-eastern Brazil, making this species a potential commercial source of the title compound. Extracts of E. florida were subjected to solvent partition, and rapid high-speed counter-current chromatography (HSCCC) was applied to the semi-crude extracts to afford betulinic acid in high purity. The mobile and stationary phases were derived from the two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (10:5:2.5:1). The developing solvent system (stationary and mobile phases) for optimum HSCCC separation was chosen by dissolving the fraction to be chromatographed in the proposed solvent mixture and determining the amount of betulinic acid in each phase by densitometric TLC. Purified betulinic acid was characterized by 13C-NMR, GC-MS and co-injection of its methyl ester with standards in GC-FID. The HSCCC technique is commonly employed to isolate triterpene glycosides, but is applied in this study to an aglycone.

  1. Bioconversion of herbal industry waste into vermicompost using an epigeic earthworm Eudrilus eugeniae.

    PubMed

    Kumari, Mamta; Kumar, Sudhir; Chauhan, Rajinder Singh; Ravikanth, K

    2011-11-01

    The aim of the present study was to investigate the potential of bioconversion of industrial herbal waste to vermicompost using Eudrilus eugeniae. Vermibeds were made using a mixture of herbal waste and cowdung (1 : 1) in comparison with the use of cowdung alone as substrate, resulting in vermicomposts 1 and 2, respectively. Different parameters were studied and it was observed that the nutrient profile of vermicompost 1 strongly influenced the growth of pea (Pisum sativum) and marigold plant (Tagetus erectus). The dry and fresh weight of shoots and roots, number of flowers, total yield in terms of fruit showed significant increase with vermicompost 1. Furthermore, vermicompost 1 (herbal waste and cow dung as substrate) resulted in a significant reduction in TOC by 58% in comparison with vermicompost 2 (cowdung as substrate). The C : N ratio was less than 20 in vermicompost 1 as well as in vermicompost 2, which indicated an advanced degree of stabilization and mineralization. The ability of earthworms to survive, grow and breed in the vermibed fed with the herbal waste indicates the sustainability and efficiency of a heterogeneous kind of organic waste. The results of the study suggested that bulk industrial herbal waste can be utilized as a substrate for vermicomposting and this can be proposed as an alternative for waste disposal in a clean green manner, promoting the concept of organic farming.

  2. Antimicrobial activities of Eugenia caryophyllata extract and its major chemical constituent eugenol against Streptococcus pneumoniae.

    PubMed

    Yadav, Mukesh Kumar; Park, Seok-Won; Chae, Sung-Won; Song, Jae-Jun; Kim, Ho Chul

    2013-12-01

    In this study, we investigate the antimicrobial activities of both Eugenia caryophyllata (Ec) extract and its major component eugenol (4-allyl-2-methoxyphenol) against Streptococcus pneumoniae. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by microdilution method. Pneumococcal biofilms were detected by crystal-violet microtiter plate assay, followed by colony-forming unit counts and visualized by scanning electron microscope (SEM). The synergistic effect of eugenol and penicillin was determined by checker-board method. Both the eugenol and the Ec extract inhibited pneumococcal growth in a concentration-dependent manner. The MIC and MBC of eugenol were 0.06% and 0.12%, respectively. Eugenol at a concentration of 0.12% completely killed S. pneumoniae within 60 min of exposure. The kill rate of planktonic cells was most rapid during the first 15 min of contact with eugenol. The addition of eugenol or Ec extract inhibited in vitro biofilm formation. In already established biofilms, the inhibitory effect of eugenol or Ec extract was more significant in terms of cell viability than in terms of disruption of the biofilm matrix. SEM analysis revealed non-viable and disruptive action of eugenol on the cell membrane of bacteria of biofilms. It was found that eugenol and penicillin produced a synergistic effect against S. pneumoniae. In conclusion, eugenol and Ec extract efficiently inhibited S. pneumoniae in planktonic growth and within biofilms.

  3. Anti-inflammatory activity of Eugenia punicifolia extract on muscular lesion of mdx dystrophic mice.

    PubMed

    Leite, Paulo Emílio Corrêa; de Almeida, Kessiane Belshoff; Lagrota-Candido, Jussara; Trindade, Pablo; da Silva, Rafael Ferreira; Ribeiro, Manuel Gustavo L; Lima-Araújo, Katia G; Santos, Wilson C; Quirico-Santos, Thereza

    2010-12-15

    Eugenia punicifolia known as "pedra-ume caá" is a shrub largely distributed in the Amazon region popularly used in decoctions or infusions as a natural therapeutic agent, which can interfere on cholinergic nicotinic neurotransmission. This work aimed to investigate a putative anti-inflammatory effect of dichloromethane fraction of E. punicifolia extract (Ep-CM) in the muscular lesion of mdx dystrophic mice, considering that activation of cholinergic mechanisms mitigates inflammation. A polymer containing the Ep-CM was implanted in mdx gastrocnemius muscle before onset of myonecrosis for local slow and gradual release of bioactive compounds and mice sacrificed 7 days or 9 weeks after surgery. Comparing to control muscle, treatment did not alter choline acetyltransferase and acetylcholinesterase enzymatic activities, but decreased metaloproteases-9 and -2 activities and levels of tumor necrosis factor α and NFκB transcription factor. In addition, treatment also reduced levels of bioactive IL-1β form and cleaved caspase-3, related to early events of cellular death and inflammatory activation and further increased myogenin expression without affecting collagen production which is associated with fibrosis. In vivo treatment of mdx dystrophic mice with Ep-CM caused significant reduction of muscular inflammation and improved skeletal muscle regeneration without inducing fibrosis. © 2010 Wiley-Liss, Inc.

  4. Bioactive Formylated Flavonoids from Eugenia rigida: Isolation, Synthesis, and X-ray Crystallography.

    PubMed

    Zaki, Mohamed A; Nanayakkara, N P Dhammika; Hetta, Mona H; Jacob, Melissa R; Khan, Shabana I; Mohammed, Rabab; Ibrahim, Mohamed A; Samoylenko, Volodymyr; Coleman, Christina; Fronczek, Frank R; Ferreira, Daneel; Muhammad, Ilias

    2016-09-23

    Two new flavonoids, rac-6-formyl-5,7-dihydroxyflavanone (1) and 2',6'-dihydroxy-4'-methoxy-3'-methylchalcone (2), together with five known derivatives, rac-8-formyl-5,7-dihydroxyflavanone (3), 4',6'-dihydroxy-2'-methoxy-3'-methyldihydrochalcone (4), rac-7-hydroxy-5-methoxy-6-methylflavanone (5), 3'-formyl-2',4',6'-trihydroxy-5'-methyldihydrochalcone (6), and 3'-formyl-2',4',6'-trihydroxydihydrochalcone (7), were isolated from the leaves of Eugenia rigida. The individual (S)- and (R)-enantiomers of 1 and 3, together with the corresponding formylated flavones 8 (6-formyl-5,7-dihydroxyflavone) and 9 (8-formyl-5,7-dihydroxyflavone), as well as 2',4',6'-trihydroxychalcone (10), 3'-formyl-2',4',6'-trihydroxychalcone (11), and the corresponding 3'-formyl-2',4',6'-trihydroxydihydrochalcone (7) and 2',4',6'-trihydroxydihydrochalcone (12), were synthesized. The structures of the isolated and synthetic compounds were established via NMR, HRESIMS, and electronic circular dichroism data. In addition, the structures of 3, 5, and 8 were confirmed by single-crystal X-ray diffraction crystallography. The isolated and synthetic flavonoids were evaluated for their antimicrobial and cytotoxic activities against a panel of microorganisms and solid tumor cell lines.

  5. Dipeptidyl peptidase-4 inhibition by Pterocarpus marsupium and Eugenia jambolana ameliorates streptozotocin induced Alzheimer's disease.

    PubMed

    Kosaraju, Jayasankar; Madhunapantula, Subbarao V; Chinni, Santhivardhan; Khatwal, Rizwan Basha; Dubala, Anil; Muthureddy Nataraj, Satish Kumar; Basavan, Duraiswamy

    2014-07-01

    Alzheimer's disease (AD), the most common form of dementia, is characterized by the loss of normal functions of brain cells and neuronal death, ultimately leading to memory loss. Recent accumulating evidences have demonstrated the therapeutic potential of anti-diabetic agents, such as dipeptidyl peptidase-4 (DPP-4) inhibitors, for the treatment of Alzheimer's disease (AD), providing opportunities to explore and test the DPP-4 inhibitors for treating this fatal disease. Prior studies determining the efficacy of Pterocarpus marsupium (PM, Fabaceae) and Eugenia jambolana (EJ, Myrtaceae) extracts for ameliorating type 2 diabetes have demonstrated the DPP-4 inhibitory properties indicating the possibility of using of these extracts even for the treating AD. Therefore, in the present study, the neuroprotective roles of PM and EJ for ameliorating the streptozotocin (STZ) induced AD have been tested in rat model. Experimentally, PM and EJ extracts, at a dose range of 200 and 400mg/kg, were administered orally to STZ induced AD Wistar rats and cognitive evaluation tests were performed using radial arm maze and hole-board apparatus. Following 30 days of treatment with the extracts, a dose- and time-dependent attenuation of AD pathology, as evidenced by decreasing amyloid beta 42, total tau, phosphorylated tau and neuro-inflammation with an increase in glucagon-like peptide-1 (GLP-1) levels was observed. Therefore, PM and EJ extracts contain cognitive enhancers as well as neuroprotective agents against STZ induced AD. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Hybrid nanomaterial for stabilizing the antibiofilm activity of Eugenia carryophyllata essential oil.

    PubMed

    Grumezescu, Alexandru Mihai; Chifiriuc, Mariana Carmen; Saviuc, Crina; Grumezescu, Valentina; Hristu, Radu; Mihaiescu, Dan Eduard; Stanciu, George A; Andronescu, Ecaterina

    2012-12-01

    The aim of the present study was to demonstrate that Fe(3)O(4)/oleic acid core/shell nanostructures could be used as systems for stabilizing the Eugenia carryophyllata essential oil (EO) on catheter surface pellicles, in order to improve their resistance to fungal colonization. EO microwave assisted extraction was performed in a Neo-Clevenger (related) device and its chemical composition was settled by GC-MS analysis. Fe(3)O(4)/oleic acid-core/shell nanoparticles (NP) were obtained by a precipitation method under microwave condition. High resolution transmission electron microscopy (HR-TEM) was used as a primary characterization method. The NPs were processed to achieve a core/shell/EO coated-shell nanosystem further used for coating the inner surface of central venous catheter samples. The tested fungal strains have been recently isolated from different clinical specimens. The biofilm architecture was assessed by confocal laser scanning microscopy (CLSM). Our results claim the usage of hybrid nanomaterial (core/shell/coated-shell) for the stabilization of E. carryophyllata EO, which prevented or inhibited the fungal biofilm development on the functionalized catheter, highlighting the opportunity of using these nanosystems to obtain improved, anti-biofilm coatings for biomedical applications.

  7. Pharmacological effects of Eugenia uniflora (Myrtaceae) aqueous crude extract on rat's heart.

    PubMed

    Consolini, Alicia E; Sarubbio, Marisol Gracía

    2002-06-01

    The effect of aqueous crude extract (ACE) of Eugenia uniflora L. (Myrtaceae) was studied on rat's perfused ventricles. This plant is used in South American traditional medicine as an antihypertensive and we already demonstrated previously its hypotensive properties. In this paper, maximal left intraventriclular pressure (P) of rat's hearts beating at 0.2 Hz firstly increased to 162.1+/-11.1% of basal value during 1-3 min of perfusing ACE 0.6%. Maximum rate of contraction (+P) also increased to duplicating +P/P ratio. Both types of effect were significantly decreased by either propranolol 0.35 microM, and pre-treatment with reserpine (5 mg/kg), suggesting that they were caused by a compound that releases cathecolamines with beta-adrenergic action. Nevertheless, after 20 min of perfusing ACE, ventricles decreased P to about 50% of their basal value, suggesting a negative-inotropic compound present in the extract. The perfusion of 1.2% ACE decreased P in a pressure-[Ca](o) curve (0.5-2 mM) in a non-competitive manner, suggesting that an irreversible Ca-blocking compound is also present in the extract. In summary, E. uniflora ACE has a dual effect on the heart related to its hypotensive action and is probably responsible for the therapeutic or adverse effects in patients under cardiac risk.

  8. Dr Eugenia Rose Aylmer Cooper (1898-1991): Manchester's renowned female anatomist and neurohistologist.

    PubMed

    Shreeve, David R

    2016-11-01

    Having excelled in histology, Dr Eugenia Cooper, following graduation in medicine in Manchester, embarked on a career spanning 44 years in anatomy and histology at Manchester University. Her inimitable character was readily remembered by those she had taught. She was the first female graduate to gain an MD with gold medal for her thesis on the histology of the endocrine organs. However, her main study was the development of the human brainstem from the early weeks of gestation, which remains the basis for anatomical understanding today. More controversial was her theory on circulation and absorption of the cerebrospinal fluid. On retiring as Reader in Histology, she expressed disappointment at not being appointed a professor, which she considered was due to her gender. Possibly to compensate for this, she had studied law as an additional interest. She continued in research for a further 10 years in reproductive pharmacology. After retirement she donated her medals to the University, three to be awarded in medicine and histology, which have now lapsed, but the medals in computer science and music continue to be important rewards. © The Author(s) 2014.

  9. Efficacy of combination herbal product (Curcuma longa and Eugenia jambolana) used for diabetes mellitus.

    PubMed

    Rao, Sadia Saleem; Najam, Rahila

    2016-01-01

    The purpose of this research was to evaluate the efficacy of a combination herbal product that is traditionally used for managing diabetes mellitus. Herbal drug contains Curcuma longa and Eugenia jambolanain the ratio of 1:1. It was orally administered at the dose of 1082 mg/70 kg twice a day for a period of 6 weeks to alloxan induced diabetic rats and compared with glibenclamide (standard). The effects of drug were observed at intervals, with respect to random and fasting glucose levels. HbA1C was also monitored after the drug treatment to monitor the overall diabetic effect. Results revealed that the combination of two herbs significantly reduced fasting and random glucose levels with HbA1C of less than 6% (p<0.001) in comparison to diabetic control. The control of fasting blood glucose levels by herbal combination is similar to the standard drug, glibenclamide (p<0.05). Random glucose levels by herbal combination is better than standard drug after one week and six weeks of treatment (p<0.01 and p<0.001 respectively) and similar after third week of treatment (p<0.05). Also, herbal drug combination showed HbA1C closer to the standard drug. It shows that this herbal combination can be of potential benefit in managing diabetes mellitus in future.

  10. The traditional ayurvedic medicine, Eugenia jambolana (Jamun fruit), decreases liver inflammation, injury and fibrosis during cholestasis.

    PubMed

    Donepudi, Ajay C; Aleksunes, Lauren M; Driscoll, Maureen V; Seeram, Navindra P; Slitt, Angela L

    2012-04-01

    Cholestasis is a common disease of the liver. Chronic cholestasis eventually leads to hepatic cirrhosis and fibrosis, and rodent chronic cholestasis models are used to study aspects of fibrosis and cirrhosis. Cholestasis-induced liver injury and fibrosis are associated with increased oxidative stress and inflammation. Few pharmacological therapies exist for treatment of cholestasis or cirrhosis, but it is known that humans with better nutritional intake are less likely to develop certain types of cirrhosis. Eugenia jambolana (Jamun) is a tropical berry fruit rich in antioxidant anthocyanin compounds. As anthocyanins decrease cellular lipid peroxidation and oxidative stress, it was hypothesized that Jamun fruit extract (JFE) administration could protect against cholestatic liver injury and inflammation in mice. Starting 24 h after sham or bile-duct ligation (BDL) surgery, male C57Bl/6 mice were administered vehicle or JFE (100 mg/kg, po) for 10 days. Mice that underwent BDL had elevated serum ALT levels, which were reduced to 60% by JFE treatment. Likewise, BDL caused hepatic inflammation, macrophage infiltration, fibrosis and necrosis, all of which were largely improved by JFE. Interestingly, hepatoprotection was observed in JFE-treated BDL mice, despite suppressed transporter expression and increased hepatic bile acid concentrations. Jamun fruit phytochemicals decreased hepatic inflammation and oxidative stress, and protected against hepatocellular injury in mice. Jamun warrants further investigation as a potential antioxidant/anti-inflammatory therapy not only to treat cholestasis but also other liver diseases with an inflammatory component. © 2011 John Wiley & Sons A/S.

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

    SciTech Connect

    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.

  12. The complete genome sequence and methylome of Salmonella enterica subsp. enterica serovar Cerro, a frequent dairy cow strain

    USDA-ARS?s Scientific Manuscript database

    Salmonella enterica subsp. enterica serovar Cerro is an infrequent pathogen of humans and other mammals, but is frequently isolated from the hindgut of asymptomatic cattle in the United States. To further understand the genomic determinants of S. Cerro specificity for the bovine hindgut, the genome ...

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

    SciTech Connect

    Truesdell, A.H. ); Lippmann, M.J. )

    1990-04-01

    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. 15 refs., 10 figs., 1 tab.

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

    USGS Publications Warehouse

    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.

  15. Geology and geochemistry of Pelagatos, Cerro del Agua, and Dos Cerros monogenetic volcanoes in the Sierra Chichinautzin Volcanic Field, south of México City

    NASA Astrophysics Data System (ADS)

    Agustín-Flores, Javier; Siebe, Claus; Guilbaud, Marie-Noëlle

    2011-04-01

    This study focuses on the geology and geochemistry of three closely-spaced monogenetic volcanoes that are located in the NE sector of the Sierra Chichinautzin Volcanic Field near México City. Pelagatos (3020 m.a.s.l.) is a small scoria cone (0.0017 km 3) with lava flows (0.036 km 3) that covered an area of 4.9 km 2. Cerro del Agua scoria cone (3480 m.a.s.l., 0.028 km 3) produced several lava flows (0.24 km 3) covering an area of 17.6 km 2. Dos Cerros is a lava shield which covers an area of 80.3 km 2 and is crowned by two scoria cones: Tezpomayo (3080 m.a.s.l., 0.022 km 3) and La Ninfa (3000 m.a.s.l., 0.032 km 3). The eruptions of Cerro del Agua and Pelagatos occurred between 2500 and 14,000 yr BP. The Dos Cerros eruption took place close to 14,000 yr BP as constrained by radiocarbon dating. Rocks from these three volcanoes are olivine-hypersthene normative basaltic andesites and andesites with porphyritic, aphanitic, and glomeroporphyritic textures. Their mineral assemblages include olivine, clinopyroxene, and orthopyroxene phenocrysts (≤ 10 vol.%) embedded in a trachytic groundmass which consists mainly of plagioclase microlites and glass. Pelagatos rocks also present quartz xenocrysts. Due to their high Cr and Ni contents, and high Mg#s, Pelagatos rocks are considered to be derived from primitive magmas, hence the importance of this volcano for understanding petrogenetic processes in this region. Major and trace element abundances and petrography of products from these volcanoes indicate a certain degree of crystal fractionation during ascent to the surface. However, the magmas that formed the volcanoes evolved independently from each other and are not cogenetically related. REE, HFSE, LILE, and isotopic (Sr, Nd, and Pb) compositions point towards a heterogeneous mantle source that has been metasomatized by aqueous/melt phases from the subducted Cocos slab. There is no clear evidence of important crustal contributions in the compositions of Pelagatos and

  16. Old cinder cone or young composite volcano?: The nature of Cerro Negro, Nicaragua

    NASA Astrophysics Data System (ADS)

    McKnight, Steven B.; Williams, Stanley N.

    1997-04-01

    Determining whether a volcano is a cinder cone or a composite volcano is important because its classification categorizes the magmatic system and associated volcanic hazards. The criteria of age and size of the volcano that are usually used for this assessment are inadequate for active, young volcanoes. Other criteria on which that determination can be based are magma production rates, cone morphology, and eruption style. Cerro Negro is an active, young, small basaltic volcano in northwestern Nicaragua that is similar to both cinder cones and composite volcanoes in many ways. It has had at least 22 historically documented eruptions since it first appeared in 1850; the most recent occurred in late 1995. The magma production rate for Cerro Negro (˜1.6 km3/k.y.) is of the same magnitude as those of a variety of composite volcanoes and an order of magnitude higher than the production rate for the Parícutin cinder cone region of the Trans-Mexican volcanic belt. Structurally, Cerro Negro's cone, is a composite of scoria and lavas cut by dikes around a dense volcanic core. Cerro Negro's shape has been more like a composite volcano than a cinder cone, except when infrequent sub-Plinian eruptions have altered the cone to make it look like a cinder cone. Comparisons of Cerro Negro to well-known, historically active cinder cones and young composite volcanoes show that it is best described as a young composite volcano. The future hazards posed by Cerro Negro are, therefore, not those associated with cinder cone eruptions, but the potentially more dangerous ones of composite volcanoes.

  17. Ultraviolet-B Protective Effect of Flavonoids from Eugenia caryophylata on Human Dermal Fibroblast Cells

    PubMed Central

    Patwardhan, Juilee; Bhatt, Purvi

    2015-01-01

    Background: The exposure of skin to ultraviolet-B (UV-B) radiations leads to deoxyribonucleic acid (DNA) damage and can induce production of free radicals which imbalance the redox status of the cell and lead to increased oxidative stress. Clove has been traditionally used for its analgesic, anti-inflammatory, anti-microbial, anti-viral, and antiseptic effects. Objective: To evaluate the UV-B protective activity of flavonoids from Eugenia caryophylata (clove) buds on human dermal fibroblast cells. Materials and Methods: Protective ability of flavonoid-enriched (FE) fraction of clove was studied against UV-B induced cytotoxicity, anti-oxidant regulation, oxidative DNA damage, intracellular reactive oxygen species (ROS) generation, apoptotic morphological changes, and regulation of heme oxygenase-1 (HO-1) gene through nuclear factor E2-related factor 2 antioxidant response element (Nrf2 ARE) pathway. Results: FE fraction showed a significant antioxidant potential. Pretreatment of cells with FE fraction (10–40 μg/ml) reversed the effects of UV-B induced cytotoxicity, depletion of endogenous enzymatic antioxidants, oxidative DNA damage, intracellular ROS production, apoptotic changes, and overexpression of Nrf2 and HO-1. Conclusion: The present study demonstrated for the first time that the FE fraction from clove could confer UV-B protection probably through the Nrf2-ARE pathway, which included the down-regulation of Nrf2 and HO-1. These findings suggested that the flavonoids from clove could potentially be considered as UV-B protectants and can be explored further for its topical application to the area of the skin requiring protection. SUMMARY Pretreatment of human dermal fibroblast with flavonoid-enriched fraction of Eugenia caryophylata attenuated effects of ultraviolet-B radiationsIt also conferred protection through nuclear factor E2-related factor 2-antioxidant response pathway and increased tolerance of cells against oxidative stress

  18. Quorum Quenching and Microbial Control through Phenolic Extract of Eugenia Uniflora Fruits.

    PubMed

    Rodrigues, Adeline Conceição; Zola, Flávia Guimarães; Ávila Oliveira, Brígida D'; Sacramento, Nayara Thais Barbosa; da Silva, Elis Regina; Bertoldi, Michele Corrêa; Taylor, Jason Guy; Pinto, Uelinton Manoel

    2016-10-01

    We describe the characterization of the centesimal composition, mineral and phenolic content of Eugenia uniflora fruit and the determination of the antioxidant, antimicrobial and quorum quenching activities of the pulp phenolic extract. Centesimal composition was determined according to standard methods; trace elements were measured by total reflection X-ray fluorescence spectroscopy. The phenolic compounds were extracted by solid-phase chromatography and quantified by spectrophotometry. Antioxidant activity was determined by using 3 different methods. Antimicrobial activity was evaluated against a panel of foodborne microorganisms and antiquorum sensing activity in Chromobacterium violaceum was performed by measuring inhibition of quorum sensing dependent violacein production. The centesimal composition (per 100 g of pulp) was as follows: protein 3.68 ± 0.21 g, lipids 0.02 ± 0.03 g, carbohydrates 10.31 g and fiber 2.06 g. Trace elements (mg/g of pulp) were determined as: K 0.90, Ca 3.36, Fe 0.60, Zn 0.17, Cl 0.56, Cr 0.06, Ni 0.04, and Cu 0.07. The pulp is a source of phenolic compounds and presents antioxidant activity similar to other berries. The fruit phenolic extract inhibited all tested bacteria. We also found that the fruit phenolic extract at low subinhibitory concentrations inhibited up to 96% of violacein production in C. violaceum, likely due to the fruit's phenolic content. This study shows the contribution of E. uniflora phenolic compounds to the antioxidant, antimicrobial and the newly discovered quorum quenching activity, all of which could be used by the food and pharmaceutical industries to develop new functional products.

  19. The gastroprotective effects of Eugenia dysenterica (Myrtaceae) leaf extract: the possible role of condensed tannins.

    PubMed

    Prado, Ligia Carolina da Silva; Silva, Denise Brentan; de Oliveira-Silva, Grasielle Lopes; Hiraki, Karen Renata Nakamura; Canabrava, Hudson Armando Nunes; Bispo-da-Silva, Luiz Borges

    2014-01-01

    We applied a taxonomic approach to select the Eugenia dysenterica (Myrtaceae) leaf extract, known in Brazil as "cagaita," and evaluated its gastroprotective effect. The ability of the extract or carbenoxolone to protect the gastric mucosa from ethanol/HCl-induced lesions was evaluated in mice. The contributions of nitric oxide (NO), endogenous sulfhydryl (SH) groups and alterations in HCl production to the extract's gastroprotective effect were investigated. We also determined the antioxidant activity of the extract and the possible contribution of tannins to the cytoprotective effect. The extract and carbenoxolone protected the gastric mucosa from ethanol/HCl-induced ulcers, and the former also decreased HCl production. The blockage of SH groups but not the inhibition of NO synthesis abolished the gastroprotective action of the extract. Tannins are present in the extract, which was analyzed by matrix assisted laser desorption/ionization (MALDI); the tannins identified by fragmentation pattern (MS/MS) were condensed type-B, coupled up to eleven flavan-3-ol units and were predominantly procyanidin and prodelphinidin units. Partial removal of tannins from the extract abolished the cytoprotective actions of the extract. The extract exhibits free-radical-scavenging activity in vitro, and the extract/FeCl3 sequence stained gastric surface epithelial cells dark-gray. Therefore, E. dysenterica leaf extract has gastroprotective effects that appear to be linked to the inhibition of HCl production, the antioxidant activity and the endogenous SH-containing compounds. These pleiotropic actions appear to be dependent on the condensed tannins contained in the extract, which bind to mucins in the gastric mucosa forming a protective coating against damaging agents. Our study highlights the biopharmaceutical potential of E. dysenterica.

  20. Eugenia uniflora Dentifrice for Treating Gingivitis in Children: Antibacterial Assay and Randomized Clinical Trial.

    PubMed

    Jovito, Vanessa de Carvalho; Freires, Irlan Almeida; Ferreira, Danilo Augusto de Holanda; Paulo, Marçal de Queiroz; Castro, Ricardo Dias de

    2016-01-01

    School-age children are frequently at high risk for the onset of biofilm-dependent conditions, including dental caries and periodontal diseases. The objective of this study was to evaluate the clinical efficacy of a dentifrice containing Eugenia uniflora Linn. (Surinam cherry) extract versus a triclosan-based comparator in treating gingivitis in children aged 10-12 years. The in vitro antibacterial potential of the dentifrice was tested against oral pathogens (Streptococcus mutans, Streptococcus oralis and Lactobacillus casei). Then a phase-II clinical trial was conducted with 50 subjects aged 10-12 years, with clinical signs of gingivitis. The subjects were randomly assigned to the experimental group (n=25) and control group (n=25), in which participants used the experimental dentifrice and a triclosan-based fluoridated dentifrice (Colgate Total 12(r)), respectively. Clinical examinations assessed the presence of gingivitis (primary outcome) and biofilm accumulation (secondary outcome) using the Gingival-Bleeding Index (GBI) and Simplified Oral Hygiene Index (OHI-S), respectively, at baseline and after seven days of tooth brushing 3x/day. The data were analyzed using paired and unpaired t-test (GBI) and Wilcoxon and Mann-Whitney (OHI-S), with p≤0.05. The experimental dentifrice showed efficient antibacterial activity in vitro. In the clinical trial, a significant reduction in gingival bleeding was observed in both experimental and control groups (p<0.0001), with no statistical difference between them (p=0.178), although a small size effect was observed. Biofilm accumulation was only reduced in the control group (p=0.0039). In conclusion, E. uniflora dentifrice showed anti-gingivitis properties in children aged 10-12 years. Thus, it may be a potentially efficient and safe product to be used alternatively in preventive dental practice.

  1. Municipal solid waste management through vermicomposting employing exotic species of earthworm Eudrilus eugeniae.

    PubMed

    Chaudhari, R D; Datar, M T; Babookani, M Rabiei

    2011-01-01

    Majority of municipal (urban) solid waste (MSW) is disposed of in landfills (anaerobic composting). However, this disposal system is reported to produce hazardous environmental impacts and new policies are initiated to protect the environment from such impacts by discouraging the practice of disposal of solid waste in landfills. Eco-friendly disposal alternatives to landfills need to be explored. One of the technological options for treatment and disposal of organic solid wastes is vermicomposting. Commercial vermicomposting is reported to be practicable for treatment and disposal of many organic solids and byproducts in agricultural production and processing industries. However, this alternative has not been tried for MSW on large scale. This paper highlights the application of vermicomposting for treatment of organic solid waste, generated at urban residential area at Pune [organic component of this urban solid waste (MSW)]. Vermicomposting was tried on this segregated solid waste using exotic species of earthworm--Eudrilus eugeniae--commonly called 'African Night Crawler'. Bench scale reactor studies were carried out on organic solid waste under controlled optimum environmental conditions (moisture content: 48-52 percent, pH: 7.0-7.2, temperature: ambient), with variable vermi-loading [40-80 g of worms/kg of urban solid waste (MSW)]. Characteristics of solid waste were monitored through conventional parameters and additional environmental parameters like BOD5 and COD. The results of investigative studies are encouraging and indicate that organic solid waste can be treated in a reasonable period of 32-34 days through vermicomposting with around 60 percent reduction in the volume.

  2. A preliminary study of the acaricidal activity of clove oil, Eugenia caryophyllus.

    PubMed

    Mahakittikun, Vanna; Soonthornchareonnon, Noppamas; Foongladda, Sooporn; Boitano, John Joseph; Wangapai, Teerapong; Ninsanit, Prapakorn

    2014-03-01

    The search for more eco-friendly acaricides has prompted testing of medicinal plants from botanical sources. To evaluate the eradication of house dust mites (HDM), Dermatophagoides pteronyssinus, by direct contact using the essential clove oil (Eugenia caryophyllus). A pilot study was initiated to determine the killing power of clove oil. Synthetic fibers were immersed in 2% clove oil for 30 min, dried in a hot air oven at 60°C for 2 hrs after which 0.5 gm of HDMs were exposed to these coated fibers placed in the Siriraj Chamber (SC). Two additional long-term methods were employed. Ten mites were placed in the SC and 10 μl of clove oil was pipetted or sprayed onto them. These latter two procedures were each carried out for 3 consecutive days at 0, 1, 3 and 6 months. The solutions antimicrobial and antifungal properties were evaluated by exposing common bacteria and fungi to sterile filter disks impregnated with the mixture, and after overnight incubation, the disc diffusion method on nutrient agar was used. Ethyl alcohol served as the placebo. 99% and 81%, respectively, while the placebo mortality was <5%. The zone of inhibition indicated significant clearance for all the bacteria and fungi indicating greater biocidal activity when compared to the controls. SEMs revealed dead mites on the fibers. The effectiveness of pipetting and spraying was 99% and 81%, respectively, while the placebo mortality was <5%. The zone of inhibition indicated significant clearance for all the bacteria and fungi indicating greater biocidal activity when compared to the controls. Clove oil is a promising agent for killing dust mites with a potential use in dust-mite laden mattresses. Spraying diminishes in efficiency after 3 months.

  3. Assessment of anti-cholinesterase activity and cytotoxicity of cagaita (Eugenia dysenterica) leaves.

    PubMed

    Gasca, Cristian A; Castillo, Willian O; Takahashi, Catarina Satie; Fagg, Christopher W; Magalhães, Pérola O; Fonseca-Bazzo, Yris M; Silveira, Dâmaris

    2017-02-24

    Eugenia dysenterica ex DC Mart. (Myrtaceae) is a Brazilian tree with pharmacological and biological properties. The aqueous leaf extract, rich in polyphenols, was tested in the human neuroblastoma cell line SH-SY5Y to evaluate its effect on cell viability. The extract and two isolated compounds were also assessed for the potential inhibitory activity on acetylcholinesterase, an enzyme related to Alzheimer's disease. A simple chromatographic method using Sephadex LH-20 was developed to separate catechin and quercetin from the aqueous leaf extract of E. dysenterica. Identification was carried out by spectroscopic techniques IR, UV, and (1)H and (13)C NMR. The IC50 values were obtained by constructing dose-response curves on a graph with percentage inhibition versus log of inhibitor concentration and compared with physostigmine, a well-known AChE inhibitor. The extract was toxic for SH-SY5Y cells at concentrations higher than 7.8 μg/ml given for 24 h. The decline in SH-SY5Y cell viability appears to be related to its antiproliferative activity. The extract also showed relatively moderate acetylcholinesterase inhibitory activity of 66.33% ± 0.52% at 1.0 mg/ml with an IC50 value of 155.20 ± 2.09 μg/ml. Physostigmine, quercetin, and catechin showed IC50 values of 18.69 ± 0.07, 46.59 ± 0.49, and 42.39 ± 0.67 μg/ml, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Metagenomic analysis of the bovine hindgut from Salmonella Kentucky and Cerro-shedding dairy cows

    USDA-ARS?s Scientific Manuscript database

    In the United States Salmonella enterica subsp. enterica serovars Kentucky and Cerro are frequently isolated from dairy cows that appear asymptomatic. Although they are not major contributors to the salmonellosis burden, these serovars have been implicated in human clinical cases in recent years. To...

  5. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Topical report

    SciTech Connect

    Thomson, J.S.; Grizzle, P.L.; Reynolds, J.W.

    1988-03-01

    Preparative charge-transfer chromatographic methods have been developed for grouping aromatic hydrocarbons by the number of condensed aromatic rings they contain. Cerro Negro neutral fractions were used as test probes in methods development. Monoaromatic, diaromatic, and polyaromatic-polar concentrates were separated from three Cerro Negro distillates and a residue. Concentrations of these ring number groups are compared for the 425 to 550/degree/C boiling range of Cerro Negro with those of two similar boiling conventional crudes and one aromatic crude. Mass spectrometric and fluorometric data on Cerro Negro fractions indicated that charge transfer separation techniques described in this report grouped aromatic hydrocarbons well by ring number for the 1-, 2-, and 3-ring fractions of material boiling below 550/degree/C. Aromatic ring number separations are less satisfactory for higher boiling material, and material containing 4 or more aromatic rings. Better separation methods are needed for high boiling (>550/degree/C) neutral fractions. Sulfur compounds are not separated by ring number in the same manner as hydrocarbons on the charge transfer material (2,4-dinitroanilinopropylsilica) used. The separations should be performed on sulfur-free material for optimum results. 22 refs., 12 figs., 4 tabs.

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

    SciTech Connect

    Rudell, T. M.; Gille, R. 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?

  7. The Cerro Grande Fire - From Wildfire Modeling Through the Fire Aftermath

    SciTech Connect

    Rudell, T. M.; Gille, R. 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?

  8. Metagenomic analysis of the bovine hindgut from Salmonella Kentucky and Cerro-shedding dairy cows

    USDA-ARS?s Scientific Manuscript database

    In the United States Salmonella enterica subsp. enterica serovars Kentucky and Cerro are frequently isolated from dairy cows that appear asymptomatic. Although they are not major contributors to the salmonellosis burden, these serovars have been implicated in human clinical cases in recent years. To...

  9. Summary of recent progress in understanding the Cerro Prieto Geothermal Field, Baja, California, Mexico

    SciTech Connect

    Lippmann, M.J.; Witherspoon, P.A.

    1980-07-01

    Geological and geophysical studies indicate that the Cerro Prieto reservoir is quite heterogeneous due to complex lithofacies fault structures, and hydrothermal alteration. Geochemical investigations have provided clues on the origin of the geothermal fluids, their recharge paths and on the reservoir processes accompanying the exploitation of the field. Well tests have yielded information on the permeability of the reservoir. (MHR)

  10. The kinetics of the smectite to illite transformation in Cretaceous bentonites, Cerro Negro, New Mexico

    SciTech Connect

    Elliot, W C.; Edenfield, N M.; Wampler, J M.; Matisoff, G; Long, Philip E. )

    1998-12-01

    The thermal effects, as well as the survivability and origins of microorganisms in Cretaceous rocks, are evaluated from the timing and extent of the smectite to illite transformation in Cretaceous bentonites collected from cores outside the thermal aureole of the Pliocene Cerro Negro volcanic neck. Overall, randomly ordered mixed-layered illite-smectite (I-S) is the predominant clay mineral in these bentonites, and the K-Ar ages of I-S range from 36 to 48 Ma (21 analyses, two additional analyses were outside this range). Increased temperature from burial is thought to be the primary factor forming I-S in these bentonites. Kinetic model calculations of the smectite to illite transformation are also consistent with T-S formed by burial without any appreciable thermal effects due to the emplacement of Cerro Negro. In a core angled toward Cerro Negro, the percentages of illite layers in I-S from the bentonite closest to Cerro Negro are slightly higher (32-37%) than in most other bentonites in this study. The K-Ar ages of the closest I-S are slightly younger as a group (38-43 Ma; Average= 41 Ma; N= 4) than those of I-S further from Cerro Negro in the same core (41-48 Ma; Average= 44 Ma; N= 6). A small amount of illite in this I-S may have formed by heat from the emplacement of Gene Negro, but most illite formed from burial. Vitrinite reflectance, however, appears to record the effects of heating from Cerro Negro better than I-S. Tentatively, the temperature of this heat pulse, based on vitrinite data alone, ranged from 100 to 125 degrees C and this is most evident in the CNAR core. The upper temperature, 125 degrees C, approximates the sterilization temperatures for most microorganisms, and these temperatures probably reduced a significant portion of the microbial population. Thermophiles may have survived the increased temperatures from the combined effects of burial and the intrusion of Cerro Negro.

  11. Eruptive Variations During the Emplacement of Cerro Pinto, an Ambitious Rhyolite Dome, Puebla, Mexico

    NASA Astrophysics Data System (ADS)

    Zimmer, B.; Riggs, N.; Carrasco-Nunez, G.

    2006-12-01

    Cerro Pinto is a rhyolite dome complex located in the eastern Trans-Mexican Volcanic Belt. The complex is composed of four tuff rings and four domes that were emplaced in three distinct eruptive stages marked by changes in vent location and eruptive character. Each of these stages contained eruptive sequences that follow simple rhyolite-dome models, in which a pyroclastic phase is followed immediately by effusive dome emplacement. However, some aspects of the eruptive history, such as the occurrence of explosive reactivation and dome destruction through a lateral blast are uncommon in small rhyolitic structures and are more commonly associated with polygenetic structures, such as stratovolcanoes or calderas. In these larger structures, new pulses of magma often initiate reactivation, but at Cerro Pinto the story is different. Major and trace element geochemistry suggest that Cerro Pinto was sourced by a small, isolated magma chamber, unassociated with any surrounding silicic centers and did not experience any change in chemical composition over the course of the eruption. Based on these data and field observations, it is inferred that Cerro Pinto's eruptive variations were not the result of the influx of a new magma batch, but were the result of both phreatomagmatic interactions and the presence of a small magma chamber that was zoned with respect to volatiles. Both of these factors are commonly encountered in volcanologic studies, but documentation of their influence on smaller structures is under represented. Rhyolite domes have long been considered relatively simple volcanic structures with only localized hazard implications. However, the eruptive variations displayed by Cerro Pinto suggest that isolated rhyolite dome evolutions can be much more complex with the potential for explosive reactivation and dome collapse; events that must be taken into consideration when making hazard assessments.

  12. The degassing character of a young volcanic center: Cerro Negro, Nicaragua

    NASA Astrophysics Data System (ADS)

    Lucic, Gregor; Stix, John; Sherwood Lollar, Barbara; Lacrampe-Couloume, Georges; Muñoz, Angélica; Carcache, Martha Ibarra

    2014-09-01

    Cerro Negro volcano is a young basaltic cinder cone which is part of the Nicaraguan volcanic arc. Eruptive activity at Cerro Negro is characterized by explosive strombolian to subplinian eruptions driven by volatile-rich basaltic magma ascending rapidly from various crustal depths (>15 to 6 km) resulting in the onset of precursory activity only ˜30 min before an eruption. In this paper, we present a comprehensive degassing characterization of the volcano over a 4-year period aimed at improving our understanding of the magmatic plumbing network and its relationship with regional tectonics. A total of 124 individual soil gas samples were collected between 2010 and 2013 and analyzed for stable carbon isotopes (δ13C) from CO2. High temperature fumaroles were sampled for δ18O, δD, and 3He/4He isotope analysis, and major degassing zones were mapped using soil CO2 flux measurements. Gases at Cerro Negro are characterized by a strong 3He/4He mantle signature (6.3 to 7.3 RA), magmatic δ13C ratios (-2.3 to -3.0 ‰), meteoric δ18O and δD ratios, and stable CO2 fluxes (31 t d-1). The lack of δ13C fractionation and an increase in the relative mantle component from 2002 to 2012 suggest that the volatile flux at Cerro Negro originates from the mantle and ascends to the surface via a series of crustal fractures that act as permeable conduits. Despite the lack of new eruptions, the hydrothermal system of Cerro Negro continues to evolve due to seasonal inputs of meteoric water, slope failures that expose and bury sites of active degassing, and bursts of regional seismicity that have the potential to open up new conduits for gas release as well as magma. Continuing geophysical and geochemical monitoring of the main edifice and the recently formed south zone is essential, as the volcano remains overdue to erupt.

  13. Acute effect of essential oil of Eugenia caryophyllata on cognition and pain in mice.

    PubMed

    Halder, Sumita; Mehta, Ashish K; Mediratta, Pramod K; Sharma, Krishna K

    2012-06-01

    The essential oil of Eugenia caryophyllata (clove oil; Family: Myrtaceae) is used in dental care as an antiseptic and analgesic. The study aims to evaluate the effect of clove oil on experimental models of pain and cognition in mice. To observe the acute effects of clove oil at different doses, the elevated plus maze was used for the assessment of cognition, and the tail flick and formalin tests were used for the study of pain. The formalin test showed that clove oil (0.1 ml/kg, i.p.) demonstrated significantly reduced pain response in both the phases. The lower doses (0.025 and 0.05 ml/kg, i.p.) reduced the formalin-induced pain response significantly in the second phase only. The tail-flick test showed variable response. The dose 0.1 ml/kg, clove oil, significantly decreased the tail-flick latency at 30 min and this effect was reversed by naloxone (1 mg/kg). On the contrary, the dose 0.025 ml/kg of clove oil, at 30 and 60 min increased the mean tail-flick latency compared to control group, but this effect was not statistically significant. Yet naloxone significantly (p < 0.05) reversed the effect of clove oil 0.025 ml/kg at 30 min. Clove oil (0.025 and 0.05 ml/kg, i.p.) significantly reversed the scopolamine-induced retention memory deficit induced by scopolamine, but clove oil (0.1 ml/kg, i.p.) significantly reversed both acquisition as well as retention deficits in elevated plus maze induced by the scopolamine. Clove oil exhibits reduced pain response by a predominantly peripheral action as evidenced by formalin test and the tail flick test showed the involvement of opioid receptors. Clove oil also significantly improved scopolamine-induced retention memory deficit at all doses.

  14. Genesis and evolution of the Cerro Prieto Volcanic Complex, Baja California, Mexico

    NASA Astrophysics Data System (ADS)

    García-Sánchez, L.; Macías, J. L.; Sosa-Ceballos, G.; Arce, J. L.; Garduño-Monroy, V. H.; Saucedo, R.; Avellán, D. R.; Rangel, E.; Layer, P. W.; López-Loera, H.; Rocha, V. S.; Cisneros, G.; Reyes-Agustín, G.; Jiménez, A.; Benowitz, J. A.

    2017-06-01

    The Cerro Prieto Volcanic Complex (CPVC), located in northwestern Mexico, is the only surface manifestation of the Cerro Prieto Geothermal Field, the third largest producer of geothermal energy in the world. This geothermal field and the Salton Sea in the USA sit in a pull-apart basin that belongs to the trans-tensional tectonic zone that includes the San Andreas Fault system and the Salton Trough basin to the NW and the East Pacific Rise to the SE. In spite of its strategic importance in the generation of geothermal energy, the origin of Cerro Prieto and its relationship with the geothermal reservoir were unknown. In this contribution, we discuss the origin, evolution, and mechanisms of formation of this small monogenetic volcano and the magmas that fed the system. The volcanic complex is located on top of the Cerro Prieto left lateral fault to the northwest of the Cerro Prieto Geothermal Field. The complex consists of a lava cone and a series of domes (˜0.15 km3) protruding from Tertiary sandstones and recent unconsolidated sediments of the alluvial plain of the Colorado River. The Cerro Prieto Volcanic Complex consists of seven stratigraphic units emplaced in a brief time span around 78-81 ka. Its activity began with the extrusion of a dacitic lava that came into contact with water-saturated sediments, causing brecciation of the lava. The activity continued with the emplacement of dacitic domes and a dyke that were destroyed by a phreatic explosion emplacing a lithic-rich breccia. This phreatic explosion formed a 300-m-wide and 40-m-deep circular crater. The activity then migrated ˜650 m to the SW where three dacitic lava domes were extruded and ended with the emplacement of a fissure-fed lava flow. Subsequent remobilization of the rocks in the complex has generated debris and hyperconcentrated flow deposits interbedded with fluviatile sediments in the surrounding terrain. All rocks of the CPVC are dacites with phenocrysts of plagioclase, orthopyroxene, and Fe

  15. Dynamics of diffuse CO2 emission and eruptive cycle at Cerro Negro volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Rodriguez, F.; Melian, G.; Barrancos, J.; Padilla, G.; Diaz, M.; Calvo, D.; Nolasco, D.; Perez, N.; Hernandez Perez, P. A.; Ibarra, M.; Strauch, W.; Muñoz, A.

    2009-12-01

    Cerro Negro volcano is the youngest of a group of cinder cones NW of Las Pilas at 25 km from León (Nicaragua) with 685 meters above sea level and one of the most active volcanoes of Nicaragua. It has erupted 21 times since its birth in 1850, with an eruptive cycle about 7-8 years. Since the last eruption, occurred on 5 August 1999, with erupted lava flows and ash clouds together with gas emissions, a research collaboration program between INETER and ITER was established for monitoring diffuse CO2 emissions from Cerro Negro. Since then, ten CO2 surface efflux surveys have been undertaken covering an area of 0,6 km2, in order to evaluate the spatial and temporal variations of CO2 degassing rate in relation with the eruptive cycle of Cerro Negro. Soil CO2 efflux measurements were performed always by means of a portable NDIR sensor according to the accumulation chamber method. A total diffuse CO2 emission output of 1869 t d-1 was estimated for the 1999 survey; just 3 months after the 1999 eruption which can be considered within the post-eruptive phase. For the 2002 and 2003 surveys, considered within the inter-eruptive phase, a clear decreasing tendency on the total diffuse CO2 output was observed, with estimates of 431 and 84 t d-1, respectively. However, during the 2004 a slightly increase on the total diffuse CO2 emission was observed, reaching up to 256 t d-1. The observed relatively increase was addressed to the occurrence of a seismic swarm at Cerro Negro during the survey. The yearly surveys performed at Cerro Negro from 2005 until present, have always shown background levels of CO2 emission, with 68, 38, 45, 10 and 12 t d-1, respectively. The temporal evolution of the diffuse CO2 emissions from Cerro Negro will allow us to determine the typical range of seasonal or other transient departures from its normal or “baseline” behaviour and its relation with the eruptive cycle.

  16. Bioactivity of crude ethanol extract and fractions of Eugenia uniflora (Myrtaceae) in the hepatopancreas of Oreochromis niloticus L.

    PubMed

    Fiuza, Tatiana S; Silva, Paulo C; De Paula, José R; Tresvenzol, Leonice M F; Sabóia-Morais, Simone M T

    2009-01-01

    This study evaluates the bioactivity of the crude ethanol extract and ethyl acetate, hexane and chloroform fractions obtained from Eugenia uniflora leaves using the hepatopancreas of Oreochromis niloticus L. as an experimental model. The ethanol extract and fractions were administered to the fish orally with their feed. Twenty-four hours later, the fish were sacrificed and their livers dissected, fixed in neutral formalin, embedded in paraffin and sectioned. Histological analyses were performed using Masson's trichrome and Haematoxylin-Eosin. Histochemical studies were performed using Feulgen, PAS (Periodic Acid Schiff) and PAS + salivary amylase and Sudan IV stain. The qualitative analysis of the material showed that the crude extract and the ethyl, chloroform and hexane fractions induced vasodilation, vascular congestion and toxicity due to the presence of eosinophilic granular cells, rodlet cells, some leukocytic infiltrate and rare focal necroses. The Nile tilapia proved to be a satisfactory model for screening plant products.

  17. Antinociceptive and hypothermic evaluation of the leaf essential oil and isolated terpenoids from Eugenia uniflora L. (Brazilian Pitanga).

    PubMed

    Amorim, Ana Carolina L; Lima, Cleverton Kleiton F; Hovell, Ana Maria C; Miranda, Ana Luisa P; Rezende, Claudia M

    2009-10-01

    Eugenia uniflora L. (Myrtaceae), known as Brazilian cherry tree, is a fruity tree spread all over Brazil used in popular medicine to treat inflammations, rheumatic pain and fever, as hypoglycemic, diuretic and has been widely used in the cosmetics industry. The present study discusses the chemical composition, the antinociceptive and hypothermic profile of the essential oil of pitangueira leaves. The chemical composition was evaluated by GC-MS and the main constituent of the oil was characterized, after isolation, as a mixture of atractylone (1) and 3-furanoeudesmene (2). The essential oil, its pentane fraction and the isolated mixture of sesquiterpenes (1 and 2), given orally, significantly inhibited the acetic acid-induced abdominal constrictions, increased the latency time in hot plate test and showed a hypothermic effect. The results suggest that the responsible for the antinociceptive and hypothermic effect were the isolated furanosesquiterpenes. These findings provided additional pharmacological information and may contribute for the use of Brazilian cherry tree as a phytomedicine.

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

    USGS Publications Warehouse

    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

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Comparative assessment of heavy metals content during the composting and vermicomposting of Municipal Solid Waste employing Eudrilus eugeniae.

    PubMed

    Soobhany, Nuhaa; Mohee, Romeela; Garg, Vinod Kumar

    2015-05-01

    This study was undertaken to have comparative assessment of heavy metals content during composting and vermicomposting processing of Municipal Solid Waste (MSW). Six scenarios were set up in which three experiments were for composting (controls) denoted as S1 for food waste, S2 for paper waste and S3 for yard waste and the corresponding replicates for vermicomposting processes were S4, S5 and S6. Vermicomposting caused significant reduction in Cd (43.3-73.5%), Cr (11.3-52.8%), Cu (18.9-62.5%), Co (21.4-47.6%), Zn (34.6%) and Ni (19.9-49.6%) compared to composting which showed a progressive increase. Addition of worms did not show any effect on Fe and Mn, most probably from the genesis of organic-bound complexes. The efficacy of utilizing Eudrilus eugeniae was indicated by the high values of bioconcentration factors (BCFs) which were in the order of Cd>Ni>Cu>Co>Cr>Zn and the increase amount of these metals in the earthworms' tissue after the vermicomposting processes. Different values of BCFs were obtained for different heavy metals and this accounted that earthworms exert different metabolic mechanisms. Regression analysis of the reduction percentages (R) in relation to BCF showed that RCdtot.S6, RCrtot.S5 and RCutot.S6 were significantly correlated with BCFCd.S6, BCFCr.S5 and BCFCu.S6 respectively. Thus, in comparison to simple composting processes, data analysis suggested the feasibility of inoculating E. eugeniae to MSW in order to mitigate the content of toxic heavy metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Chemical and microbiological changes during vermicomposting of coffee pulp using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis) species.

    PubMed

    Raphael, Kurian; Velmourougane, K

    2011-06-01

    Coffee pulp is the main solid residue from the wet processing of coffee berries. Due to presence of anti-physiological and anti-nutritional factors, coffee pulp is not considered as adequate substrate for bioconversion process by coffee farmers. Recent stringent measures by Pollution Control authorities, made it mandatory to treat all the solid and liquid waste emanating from the coffee farms. A study was conducted to evaluate the efficiency of an exotic (Eudrilus eugeniae) and a native earthworm (Perionyx ceylanesis) from coffee farm for decomposition of coffee pulp into valuable vermicompost. Exotic earthworms were found to degrade the coffee pulp faster (112 days) as compared to the native worms (165 days) and the vermicomposting efficiency (77.9%) and vermicompost yield (389 kg) were found to significantly higher with native worms. The multiplication rate of earthworms (280%) and worm yield (3.78 kg) recorded significantly higher with the exotic earthworms. The percentage of nitrogen, phosphorous, potassium, calcium and magnesium in vermicompost was found to increase while C:N ratio, pH and total organic carbon declined as a function of the vermicomposting. The plant nutrients, nitrogen (80.6%), phosphorus (292%) and potassium (550%) content found to increase significantly in the vermicompost produced using native earthworms as compared to the initial values, while the calcium (85.7%) and magnesium (210%) content found to increase significantly in compost produced utilizing exotic worms. Vermicompost and vermicasts from native earthworms recorded significantly higher functional microbial group's population as compared to the exotic worms. The study reveals that coffee pulp can be very well used as substrate for vermicomposting using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis).

  2. Fluid flow model of the Cerro Prieto Geothermal Field based on well log interpretation

    SciTech Connect

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

    1982-08-10

    The subsurface geology of the Cerro Prieto geothermal field was analyzed using geophysical and lithologic logs. The distribution of permeable and relatively impermeable units and the location of faults are shown in a geologic model of the system. By incorporating well completion data and downhole temperature profiles into the geologic model, it was possible to determine the direction of geothermal fluid flow and the role of subsurface geologic features that control this movement.

  3. Fluid flow model of the Cerro Prieto geothermal field based on well log interpretation

    SciTech Connect

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

    1982-10-01

    The subsurface geology of the Cerro Prieto geothermal field was analyzed using geophysical and lithologic logs. The distribution of permeable and relatively impermeable units and the location of faults are shown in a geologic model of the system. By incorporating well completion data and downhole temperature profiles into the geologic model, it was possible to determine he direction of geothermal fluid flow and the role of subsurface geologic features that control this movement.

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

    USGS Publications Warehouse

    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.

  5. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Topical report. [Metal content in Cerro Negro heavy petroleum

    SciTech Connect

    Pearson, C.D.; Green, J.A.; Green, J.B.

    1988-01-01

    Nickel, vanadium, and iron were determined in distilled and chromatographically separated fractions from Cerro Negro heavy petroleum. Corresponding data were also obtained on two samples of Wilmington, California, heavy crude and one Mayan, Mexico, heavy oil for comparison. For the Cerro Negro crude, the ratio of porphyrinic to nonporphyrinic forms of metals was also determined on selected fractions using visible spectroscopy. In all four heavy petroleums, significant levels of metals were found only in the highest boiling distillate available, ca. 550-700/sup 0/C (1000-1300/sup 0/F), and the residue. Typically, the distillation residue contained >95 percent of a given metal. All crudes contained metalloorganics of the following types: strongly acidic, weakly acidic, strongly basic, weakly basic, and neutral, but the relative distribution of metals among each class was crude dependent. Generally, nickel and vanadium distributions for a given crude followed one another very closely, while those for iron were often inconclusive because of poor mass balances for that element. Attempts to concentrate metalloorganics through liquid chromatographic separation methods largely unsuccessful. The wide variety of types of metal-containing compounds in the crudes examined precluded the use of a single approach for their isolation or preconcentration. 21 refs., 1 fig., 12 tabs.

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

    SciTech Connect

    Barker, C.E.; 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.

  7. Temporal Variations of Magnetic Field Associated with Seismic Activity at Cerro Machin Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Londono, J. M.; Serna, J. P.; Guzman, J.

    2011-12-01

    A study of magnetic variations was carried out at Cerro Machin Volcano, Colombia for the period 2009 -2010, with two permanent magnetometers located at South and North of the central dome, separated about 2.5 km each other. After corrections, we found that there is no clear correlation between volcanic seismicity and temporal changes of magnetic field for each magnetometer station, if they are analyzed individually. On the contrary, when we calculated the residual Magnetic field (RMF), for each magnetometer, and then we made the subtraction between them, and plot it vs time, we found a clear correlation of changes in local magnetic field with the occurrence of volcanic seismicity (ML >1.6). We found a change in the RMF between 1584 nT and 1608 nT, each time that a volcano-tectonic earthquake occurred. The máximum lapse time between the previous change in RMF and the further occurrence of the earthquake is 24 days, with an average of 11 days. This pattern occurred more than 9 times during the studied period. Based on the results, we believed that the simple methodology proposed here, is a good tool for monitoring changes in seismicity associated with activity at Cerro Machín volcano. We suggest that the temporal changes of RMF at Cerro Machín Volcano, are associated with piezo-magnetic effects, due to changes in strain-stress inside the volcano, produced by the interaction between local faulting and magma movement.

  8. The late Miocene elasmobranch assemblage from Cerro Colorado (Pisco Formation, Peru)

    NASA Astrophysics Data System (ADS)

    Landini, Walter; Altamirano-Sierra, Alì; Collareta, Alberto; Di Celma, Claudio; Urbina, Mario; Bianucci, Giovanni

    2017-01-01

    The new late Miocene elasmobranch assemblage from Cerro Colorado (Pisco Formation) described herein provides a first comprehensive view on the composition and structure of this community in the Pisco Basin (Peru), one of the most important Neogene Konservat-Lagerstätten of the world. The studied assemblage includes at least 21 species attributed to 10 families and 5 orders: 7 taxa are recorded for the first time in the Pisco Formation and 3 for the first time in the fossil record of Peru. Three shark-tooth bearing intervals have been recognized at Cerro Colorado. Changes in the taxonomic composition of these three fossiliferous deposits allowed us to reconstruct ecological, trophic and environmental dynamics over the stratigraphic succession of Cerro Colorado. In particular, the environmental scenario of the most diversified shark tooth-bearing interval (ST-low1) is consistent with a shallow marine coastal area, influenced by both brackish and open sea waters, dominated by a community of small mesopredator sharks that used this ecospace as reproductive ground (nursery) and recruitment area.

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

    SciTech Connect

    Valette-Silver, J.N.; 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.

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

    USGS Publications Warehouse

    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.

  11. 1. Fourteen Years Of Diffuse CO2 Monitoring At Cerro Negro Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Barrancos Martinez, Jose; Melián, Gladys; Ibarra, Martha; Álvarez, Julio; Rodríguez, Fátima; Nolasco, Dácil; Padilla, Germán; Calvo, David; Dionis, Samara; Padrón, Eleazar; Hernández, Iñigo; Hernández, Pedro A.; Pérez, Nemesio M.; Muñoz, Angélica

    2013-04-01

    7. Cerro Negro is an active basaltic volcano belonging to the active Central American Volcanic Belt, which includes a 1,100 Km long chain of 41 active volcanoes from Guatemala to Panama. Cerro Negro first erupted in 1850 and has experienced 21 eruptive eruptions with inter eruptive average periods between 7 and 9 years. Since the last eruption occurred on 5 August 1999, with erupted lava flows and ash clouds together with gas emissions, a collaborative research program between INETER and ITER was established for monitoring diffuse CO2 emissions from this volcano. Until 2012, twelve soil CO2 emission surveys covering an area of 0,6 km2 have been performed by means of the accumulation chamber method to evaluate the spatial and temporal variations of CO2 degassing rate in relation to the eruptive cycle of Cerro Negro. A total diffuse CO2 emission output of 1,869 t•d-1 was estimated for the 1999 survey; just 3 months after the 1999 eruption which can be considered within the post-eruptive phase. For the April, 2002 and March, 2008 surveys, considered within the inter-eruptive phase, a clear decreasing tendency on the total diffuse CO2 output was observed, with estimates of 431 and 10 t•d-1, respectively, except a small increment in 2004, to 256 t d-1, associated with an anomalous seismic activity. The higher anomalies are located around the crater of 1995 and 1999. An increasing on the total CO2 emission has been observed, from December 2008 to February 2011, with total diffuse CO2 output estimates from 12 t•d-1 to 43 t•d-1, respectively. These temporal variations show a close relationship between diffuse CO2 emission and the eruptive cycle at Cerro Negro. This relationship indicates that monitoring CO2 emission is an important geochemical tool for the volcanic surveillance at Cerro Negro. References: (1) Rodríguez et al. (2009) AGU Fall Meeting 2009. EOS, AGU,V21-2017 . (2) Padilla et al. (2008). IV Reunión de la Red Española de Volcanología, Almagro 2008

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

    USGS Publications Warehouse

    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

  13. Synergisms in Alpha-glucosidase Inhibition and Antioxidant Activity of Camellia sinensis L. Kuntze and Eugenia uniflora L. Ethanolic Extracts

    PubMed Central

    Vinholes, Juliana; Vizzotto, Márcia

    2017-01-01

    Background: Camellia sinensis, the most consumed and popular beverages worldwide, and Eugenia uniflora, a Brazilian native species, have been already confirmed to have beneficial effects in the treatment of diabetes mellitus. However, their potential acting together against an enzyme linked to this pathology has never been exploited. Objective: The aim of this study was to evaluate the inhibitory properties of individual and combined ethanolic extracts of the leaves of C. sinensis and E. uniflora over alpha-glucosidase, a key digestive enzyme used on the Type 2 diabetes mellitus (T2DM) control. In addition, their inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) and peroxyl radicals was also assayed. Materials and Methods: Enzyme inhibition and antioxidant potential were assessed based on in vitro assays. Total phenolic compounds, carotenoids, and chlorophylls A and B were achieved using spectrophotometric methods. Results: E. uniflora was almost 40 times more active on alpha-glucosidase than C. sinensis and combined extracts showed a significant synergistic effect with an obtained IC50 value almost 5 times lower than the theoretical value. C. sinensis extract was twice more active than E. uniflora concerning DPPH•, in contrast, E. uniflora was almost 10 times more effective than C. sinensis on inhibition of peroxyl radicals with a significant synergistic effect for combined extracts. The extracts activities may be related with their phytochemicals, mainly phenolic compounds, and chlorophylls. Conclusion: Combined C. sinensis and E. uniflora ethanolic extracts showed synergistic effect against alpha-glucosidase and lipid peroxidation. These herbal combinations can be used to control postprandial hyperglycemia and can also provide antioxidant defenses to patients with T2DM. SUMMARY Alfa-glucosidase and antioxidant Interaction between Camellia sinensis L. Kuntze and Eugenia uniflora L. ethanolic extracts was investigated.Extracts showed

  14. Synergisms in Alpha-glucosidase Inhibition and Antioxidant Activity of Camellia sinensis L. Kuntze and Eugenia uniflora L. Ethanolic Extracts.

    PubMed

    Vinholes, Juliana; Vizzotto, Márcia

    2017-01-01

    Camellia sinensis, the most consumed and popular beverages worldwide, and Eugenia uniflora, a Brazilian native species, have been already confirmed to have beneficial effects in the treatment of diabetes mellitus. However, their potential acting together against an enzyme linked to this pathology has never been exploited. The aim of this study was to evaluate the inhibitory properties of individual and combined ethanolic extracts of the leaves of C. sinensis and E. uniflora over alpha-glucosidase, a key digestive enzyme used on the Type 2 diabetes mellitus (T2DM) control. In addition, their inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(•)) and peroxyl radicals was also assayed. Enzyme inhibition and antioxidant potential were assessed based on in vitro assays. Total phenolic compounds, carotenoids, and chlorophylls A and B were achieved using spectrophotometric methods. E. uniflora was almost 40 times more active on alpha-glucosidase than C. sinensis and combined extracts showed a significant synergistic effect with an obtained IC50 value almost 5 times lower than the theoretical value. C. sinensis extract was twice more active than E. uniflora concerning DPPH(•), in contrast, E. uniflora was almost 10 times more effective than C. sinensis on inhibition of peroxyl radicals with a significant synergistic effect for combined extracts. The extracts activities may be related with their phytochemicals, mainly phenolic compounds, and chlorophylls. Combined C. sinensis and E. uniflora ethanolic extracts showed synergistic effect against alpha-glucosidase and lipid peroxidation. These herbal combinations can be used to control postprandial hyperglycemia and can also provide antioxidant defenses to patients with T2DM. Alfa-glucosidase and antioxidant Interaction between Camellia sinensis L. Kuntze and Eugenia uniflora L. ethanolic extracts was investigated.Extracts showed synergistic effect over alpha-glucosidase and peroxyl radicals

  15. Modeling discharge requirements for deep geothermal wells at the Cerro Prieto geothermal field, MX

    SciTech Connect

    Menzies, Anthony J.; Granados, Eduardo E.; Puente, Hector Gutierrez; Pierres, Luis Ortega

    1995-01-26

    During the mid-l980's, Comision Federal de Electricidad (CFE) drilled a number of deep wells (M-200 series) at the Cerro Prieto geothermal field, Baja California, Mexico to investigate the continuation of the geothermal reservoir to the east of the Cerro Prieto-II and III production areas. The wells encountered permeability at depths ranging from 2,800 to 4,400 m but due to the reservoir depth and the relatively cold temperatures encountered in the upper 1,000 to 2,000 m of the wells, it was not possible to discharge some of the wells. The wells at Cerro Prieto are generally discharged by injecting compressed air below the water level using 2-3/8-inch tubing installed with either a crane or workover rig. The objective of this technique is to lift sufficient water out of the well to stimulate flow from the reservoir into the wellbore. However, in the case of the M-200 series wells, the temperatures in the upper 1,000 to 2,000 m are generally below 50 C and the heat loss to the formation is therefore significant. The impact of heat loss on the stimulation process was evaluated using both a numerical model of the reservoir/wellbore system and steady-state wellbore modeling. The results from the study indicate that if a flow rate of at least 300 liters/minute can be sustained, the well can probably be successfully stimulated. This is consistent with the flow rates obtained during the successful stimulations of wells M-202 and M-203. If the flow rate is closer to 60 liters/minute, the heat loss is significant and it is unlikely that the well can be successfully discharged. These results are consistent with the unsuccessful discharge attempts in wells M-201 and M-205.

  16. Paleomagnetic evidence for an episodic eruptive history of the Cerros del Rio volcanic field, New Mexico

    NASA Astrophysics Data System (ADS)

    Hudson, M. R.; Thompson, R. A.

    2011-12-01

    The Pliocene to Quaternary (~2.6-1.14 Ma) Cerros del Rio volcanic field of northern New Mexico forms a dissected basaltic plateau sourced by multiple eruptive centers. Paleomagnetic data compliment geologic mapping, geochronologic and geochemical data to define the spatial and temporal eruptive history of Cerros del Rio volcanic deposits. The preserved stratigraphic sequence reflects three principal phases of volcanism; 1) 2.7-2.6 Ma, 2) 2.5-2.2 Ma, and 3) 1.5-1.1 Ma. Paleomagnetic data collected from 85 sites that span the area of the volcanic field largely sample phase-1 deposits that record the Guass normal-polarity chron or phase-2 deposits that record the Matuyama reversed-polarity chron. A grand mean of individual sites (excluding transitional directions) is D = 352.8°, I = 49.7°, k= 14, a95 = 3.9. However, normal- and reversed-polarity group means are not statistically antipodal, with the normal-polarity inclination being significantly shallower than an expected (55°) dipole inclination. This failed reversal test suggests that paleosecular variation has not be fully averaged within both polarity groups, despite a basis on abundant data from multiple eruptive centers. Compared to variation recorded by the full volcanic field, site directions from individual eruptive centers have restricted dispersion, indicating that the centers formed quickly relative to paleosecular variation. Grouping data within individual eruptive centers to calculate eruptive-group means (EGM), directions of the normal- and reversed-polarity EGM remain skewed from antipodal. Modal analysis demonstrates the presence of multiple directional clusters among the normal-polarity EGM whereas the frequency distribution of reversed polarity EGM are symmetrical about their maximum. These paleomagnetic directional characteristics indicate that voluminous phase-1 deposits of the Cerros del Rio volcanic field probably erupted episodically during short time intervals and that several individual

  17. The Cerro Negro accumulation of Venezuela's Orinoco Belt - the favorable convergence of several geological processes

    SciTech Connect

    Swanson, D.C. ); Tarache, C. )

    1993-02-01

    The Cerro Negro Area is a major part of eastern Venezuela's Orinoco Belt. Here upper Eocene fluvial-deltaic deposits of the Oficina Fm. reservoir billions of barrels of heavy oil, much of which is in valley-fill deposits. Maturation, migration and accumulation of these hydrocarbons in thick, porous and permeable sandstones were the logical conclusion to several major geological events in eastern Venezuela during the Tertiary. In the Cerro Negro Area, Cretaceous clastics were deposited on an igneous and metamorphic basement after which the sea withdrew northward toward the axial part of the Eastern Venezuelan Basin. The basement and Cretaceous deposits were weathered and eroded during the Eocene, Oligocene, and early Miocene, forming the unconformity on which the Oficina Fm. is deposited. Historic reconstruction begins with this unconformity, a paleotopographic surface strongly influencing the character and distribution of the overlying Oficina Fm. As relative sea level fell and gradients increased, streams incised into the shelf while transporting great amounts of coarse clastic load northward. At Cerro Negro, a mature topography of low ridges and hills were developed with differential elevations of several hundred feet. During the Miocene, a sea transgressed across the stream-etched unconformity. Streams carrying large amounts of clastic load encountered an elevating sea level. They consequently dropped their coarse load, forming long, linear, transgressive, valley-fill deposits. By Late Miocene, hydrocarbons generated in the deeper basin began to migrate southward through the long linear fluvial-deltaic clastic conduits that were separated laterally and vertically into complex [open quotes]plumbing systems.[close quotes] As the hydrocarbons moved shelfward, normal faults cut the conduits into numerous reservoir segments. The timing between migration and faulting is critical to present-day hydrocarbon distribution in these segments.

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

    USGS Publications Warehouse

    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)

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  1. Boiling and condensation processes in the Cerro Prieto beta reservoir under exploitation

    SciTech Connect

    Truesdell, A. , Menlo Park, CA ); Manon, A.; Quijano, L. ); Coplen, T. ); Lippmann, M. )

    1992-01-01

    The deep Cerro Prieto (Baja California, Mexico) beta reservoir is offset vertically by the southwest-northeast trending, normal H fault. Under exploitation pressures in the upthrown block have decreased strongly resulting in boiling and high-enthalpy production fluids. Significant differences in fluid chemical and isotopic compositions are observed in the two parts of the reservoir and particularly in an anomalous zone associated with the H fault. These differences result from intense boiling and adiabatic steam condensation, as well as from leakage of overlying cooler water along the fault.

  2. First results from optical turbulence measurements at Cerro Las Campanas in 2010

    NASA Astrophysics Data System (ADS)

    Berdja, A.; Prieto, G.; Thomas-Osip, J. E.

    2011-09-01

    We report preliminary results from optical turbulence measurements carried out in 2010 at Cerro Las Campanas, the future site for the Giant Magellan Telescope (GMT). The instruments involved are MooSci, a lunar scintillometer for the near-ground optical turbulence profile, Differential Image Motion Monitor (DIMM) for the whole atmosphere total seeing, and MASS Multiple Aperture Scintillation Sensor (MASS) for high-altitude optical turbulence estimation. The main purpose of these measurements is to anticipate the optical turbulence strength above the future GMT enclosure, and to provide a means to model the future adaptive optics performance. We also discuss the significance of such a combination of instruments and some hypothetical limitations.

  3. Impacts of the Cerro Grande fire on Homestead era and Manhattan Project properties at Los Alamos National Laboratory.

    SciTech Connect

    McGehee, E. D.; Isaacson, J.

    2001-01-01

    In May of 2000, the Cerro Grande Fire burned approximately 8,000 acres of Department of Energy (DOE) managed land at the Los Alamos National Laboratory (LANL). Although the fire was generally of low intensity, it impacted a significant number of LANL's cultural resources. Historic wooden properties were affected more heavily than prehistoric archaeological sites. This paper will provide an overview of the Homestead and Manhattan Project Periods at LANL and will discuss the effects of the Cerro Grande Fire on historic wooden properties. Post-fire cultural resource management issues will also be discussed.

  4. Antidiabetic Activity of Self Nanoemulsifying Drug Delivery System from Bay Leaves (Eugenia polyantha Wight) Ethyl Acetate Fraction

    NASA Astrophysics Data System (ADS)

    Prihapsara, F.; Harini, M.; Widiyani, T.; Artanti, A. N.; Ani, I. L.

    2017-02-01

    Insulin resistance is caused by inability of target tissues to insulin response. Bay leaves (Eugenia polyantha Wight) fraction or extract have been used for the treatment of antidibetic mellitus type-2 resistance insulin (ADMRI) but it has low solubility and bioavailability. To overcome these problems, ethyl acetate fraction of bay leaves was formulated into self nanoemulsifying drug delivery system (SNEDDS) using Virgin Coconut Oil (VCO) as a carrier oil. This study aims to produce nanoherbal medicine, determine effect of nanoherbal preparation derived from bay leaves as an anti-ADMRI. The results showed that the optimum SNEDDS formula was tween 80 : PEG 400 : Virgin Coconut Oil (30% : 60% : 10%) in 5 mL. It has emulsification time 13.00 seconds with the average of droplet size value 84.5 nanometer and zeta potential value ± 0.2 mV. Morphological observation showed the nanoemulsion particles has spherical shaped and stable in different pH media. Hypoglycaemic effect of single dose metformin, SNEDDS, combination a-half dose of SNEEDS with metformin value is 28.3%; 15.6%; 34.6% respectively.

  5. Clusia hilariana and Eugenia uniflora as bioindicators of atmospheric pollutants emitted by an iron pelletizing factory in Brazil.

    PubMed

    da Silva, Luzimar Campos; de Araújo, Talita Oliveira; Siqueira-Silva, Advanio Inácio; Pereira, Tiago Augusto Rodrigues; Castro, Letícia Nalon; Silva, Eduardo Chagas; Oliva, Marco Antonio; Azevedo, Aristéa Alves

    2017-10-09

    The objectives of this work were to evaluate if the pollution emitted by the pelletizing factory causes visual symptoms and/or anatomical changes in exposed Eugenia uniflora and Clusia hilariana, in active biomonitoring, at different distances from a pelletizing factory. We characterize the symptomatology, anatomical, and histochemistry alterations induced in the two species. There was no difference in the symptomatology in relation to the different distances of the emitting source. The foliar symptoms found in C. hilariana were chlorosis, necrosis, and foliar abscission and, in E. uniflora, were observed necrosis punctuais, purple spots in the leaves, and increase in the emission of new leaves completely purplish. The two species presented formation of a cicatrization tissue. E. uniflora presented reduction in the thickness of leaf. In C. hilariana, it was visualized hyperplasia of the cells and the adaxial epidermis did not appear collapsed due to thick cuticle and cuticular flanges. Leaves of C. hilariana showed positive staining for iron, protein, starch, and phenolic compounds. E. uniflora showed positive staining for total phenolic compounds and starch. Micromorphologically, there was accumulation of particulate matter on the leaf surface, obstruction of the stomata, and scaling of the epicuticular wax in both species. It was concluded that the visual and anatomical symptoms were efficient in the diagnosis of the stress factor. C. hilariana and E. uniflora showed to be good bioindicators of the atmospheric pollutants emitted by the pelletizing factory.

  6. De novo assembly of Eugenia uniflora L. transcriptome and identification of genes from the terpenoid biosynthesis pathway.

    PubMed

    Guzman, Frank; Kulcheski, Franceli Rodrigues; Turchetto-Zolet, Andreia Carina; Margis, Rogerio

    2014-12-01

    Pitanga (Eugenia uniflora L.) is a member of the Myrtaceae family and is of particular interest due to its medicinal properties that are attributed to specialized metabolites with known biological activities. Among these molecules, terpenoids are the most abundant in essential oils that are found in the leaves and represent compounds with potential pharmacological benefits. The terpene diversity observed in Myrtaceae is determined by the activity of different members of the terpene synthase and oxidosqualene cyclase families. Therefore, the aim of this study was to perform a de novo assembly of transcripts from E. uniflora leaves and to annotation to identify the genes potentially involved in the terpenoid biosynthesis pathway and terpene diversity. In total, 72,742 unigenes with a mean length of 1048bp were identified. Of these, 43,631 and 36,289 were annotated with the NCBI non-redundant protein and Swiss-Prot databases, respectively. The gene ontology categorized the sequences into 53 functional groups. A metabolic pathway analysis with KEGG revealed 8,625 unigenes assigned to 141 metabolic pathways and 40 unigenes predicted to be associated with the biosynthesis of terpenoids. Furthermore, we identified four putative full-length terpene synthase genes involved in sesquiterpenes and monoterpenes biosynthesis, and three putative full-length oxidosqualene cyclase genes involved in the triterpenes biosynthesis. The expression of these genes was validated in different E. uniflora tissues. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Eugenia punicifolia (Kunth) DC. as an adjuvant treatment for type-2 diabetes mellitus: a non-controlled, pilot study.

    PubMed

    Sales, Débora Simone; Carmona, Fabio; de Azevedo, Bruna Cestari; Taleb-Contini, Silvia Helena; Bartolomeu, Ana Carolina Duó; Honorato, Fernando B; Martinez, Edson Z; Pereira, Ana Maria Soares

    2014-12-01

    Type-2 diabetes mellitus (DM) is a highly prevalent disease with significant morbidity and mortality around the world. However, there is no universally effective treatment, because response to different treatment regimens can vary widely among patients. In this study, we aimed to investigate whether the use of the powdered dried leaves of Eugenia punicifolia (Kunth) DC. (Myrtaceae) is effective as an adjuvant to the treatment of patients with type-2 DM. Fifteen patients were enrolled in a pilot, non-controlled study, and received E. punicifolia for 3 months. After treatment, we observed a significant decrease in glycosylated hemoglobin, basal insulin, thyroid-stimulating hormone, C-reactive protein, and both systolic and diastolic blood pressure. There were no changes in fasting and postprandial glycemia. The compounds myricetin-3-O-rhamnoside, quercetin-3-O-galactoside, quercetin-3-O-xyloside, quercetin-3-O-rhamnoside, kaempferol-3-O-rhamnoside, phytol, gallic acid, and trans-caryophyllene present in the powdered dried leaves of E. punicifolia may be responsible for the therapeutic effect. In conclusion, the powdered leaves of E. punicifolia are promising as an adjuvant in the treatment of type-2 DM and deserve further investigation.

  8. Treatment with extracts of Momordica charantia and Eugenia jambolana prevents hyperglycemia and hyperinsulinemia in fructose fed rats.

    PubMed

    Vikrant, V; Grover, J K; Tandon, N; Rathi, S S; Gupta, N

    2001-07-01

    Insulin resistance has been implicated as a major contributor to the development of hyperglycemia in NIIDM patients. Herbal extracts of Momordica charantia (MC) and Eugenia jambolana (EJ) have been shown to reduce hyperglycemia in diabetic animal models and human patients. However, no work has been done so far to assess their effect on insulin resistance. This study was undertaken to study the effects of different doses (100,200 and 400 mg per day) of alcoholic and aqueous extracts of MC and EJ on the metabolic parameters (body weight and serum glucose, insulin and triglycerides levels) of fructose fed rats. Fructose feeding for 15 days increased serum glucose and insulin levels markedly and triglycerides levels marginally vs. control (75.46+/-2.41 vs. 55.59+/-2.89 mg/dl, 6.26+/-1.27 vs. 15.04+/-2.43 mg/dl and 50.93+/-3.30 vs.41.1+/-3.33 mg/dl, respectively). Treatment with 400 mg per day of aqueous extracts of MC and EJ for 15 days substantially prevented hyperglycemia and hyperinsulinemia induced by a diet high in fructose (63.52+/-2.9 and 66.46+/-2.2 vs. 75.46+/-2.4, respectively).

  9. Eugenia jambolana Pretreatment Prevents Isoproterenol-Induced Myocardial Damage in Rats: Evidence from Biochemical, Molecular, and Histopathological Studies

    PubMed Central

    Shukla, Santosh Kumar; Singh, Usha Rani; Ahmad, Sayeed; Maheshwari, Ankur; Misro, Manmohan; Dwivedi, Shridhar

    2014-01-01

    Abstract Preventive effects of hydroalcoholic extract of fruit pulp of Eugenia jambolana (HEEJ) on isoproterenol (ISP)-induced myocardial damage in rats were evaluated. Rats were pre-treated with HEEJ (100, 200, and 400 mg/kg) daily for 30 days. ISP (85 mg/kg bw) was administered on the 28th and 29th days at an interval of 24 h. Ischemic control group exhibited significant increases in oxidative stress parameters, markers of inflammation, cardiac damage markers, and apoptotic markers. Oral pre-treatment with HEEJ (100, 200, and 400 mg/kg bw) provided cardioprotective activity by decreasing levels of malondialdehyde, cardiac markers (serum glutamate oxaloacetate transaminase, creatine kinase-myocardial band, cardiac troponin I), and markers of inflammation (interleukin-6, C-reactive protein, and tumor necrosis factor alpha); and increased levels of superoxide dismutase and reduced glutathione. HEEJ (400 mg/kg bw) was found to exert significantly greater effects in comparison to HEEJ (100 and 200 mg/kg bw). Apoptotic marker Bcl-2 was increased, while Bax was decreased in pre-treated rats, which was further confirmed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. The present study provides evidence that pre-treatment with HEEJ attenuates oxidative stress, apoptosis and improves cardiac architecture in ISP-induced rats and, hence, is cardioprotective. PMID:24325453

  10. Evaluation of seasonal chemical composition, antibacterial, antioxidant and anticholinesterase activity of essential oil from Eugenia brasiliensis Lam.

    PubMed

    Siebert, Diogo Alexandre; Tenfen, Adrielli; Yamanaka, Celina Noriko; de Cordova, Caio Maurício Mendes; Scharf, Dilamara Riva; Simionatto, Edésio Luiz; Alberton, Michele Debiasi

    2015-02-01

    This study describes the seasonal composition and the antibacterial, antioxidant and anticholinesterase activity of the essential oil from Eugenia brasiliensis leaves. Analysis by using GC allowed the identification of 40 compounds. It was observed that the monoterpenes varied more (42%) than the sesquiterpenes (14%), and that the monoterpene hydrocarbons suffered the greatest variation throughout the year (64%). Major compounds were spathulenol in the spring (16.02 ± 0.44%) and summer (18.17 ± 0.41%), τ-cadinol in the autumn (12.83 ± 0.03%) and α-pinene (15.94 ± 0.58%) in the winter. Essential oils were tested for their antibacterial activity, and the best result was obtained from the autumn oil, with MIC = 500 μg mL(- 1) against Staphylococcus saprophyticus and Pseudomonas aeruginosa. Antioxidant activity was evaluated using DPPH, lipid peroxidation and iron-reducing power assays, as well as the anticholinesterase activity. Both tests showed a weak performance of the essential oils.

  11. Scavenger Activity Evaluation of the Clove Bud Essential Oil (Eugenia caryophyllus) and Eugenol Derivatives Employing ABTS+• Decolorization

    PubMed Central

    Merchán Arenas, Diego R.; Acevedo, Amner Muñoz; Vargas Méndez, Leonor Y.; Kouznetsov, Vladimir V.

    2011-01-01

    The essential oil (EO) of clove bud dried fruits from Eugenia caryophyllus was obtained by a conventional hydrodistillation process in an excellent yield (11.7 %). Its chemical composition was analyzed by GC-MS, identifying eugenol as a main constituent (60.5%). Four eugenol-like molecules, γ-diisoeugenol, hydroxymethyleugenol, dihydroeugenol and 1,3-dioxanylphenol, were synthesized using eugenol or isoeugenol as initial precursors under green chemistry protocols. To evaluate the possible antioxidant capacity of eugenol compounds including the clove bud EO, the Trolox® Equivalent Antioxidant Capacity value, obtained by the ABTS+• radical-cation discoloration method, was employed. The methodology was performed in a UV-Vis reader of 96-well microplates (dilution methodology), using well-known antioxidant agents (BHA, BHT and vitamin E) as reference compounds. It was found that the prepared eugenol derivatives had a more potent free radical scavenger activity than the reference compounds. In particular, the most active molecules, γ-diisoeugenol and 1,3-dioxanylphenol, were ca. 3-fold more potent than vitamin E. PMID:22145105

  12. Eugenia uniflora fruit (red type) standardized extract: a potential pharmacological tool to diet-induced metabolic syndrome damage management.

    PubMed

    Oliveira, Pathise Souto; Chaves, Vitor Clasen; Bona, Natália Pontes; Soares, Mayara Sandrielly Pereira; Cardoso, Juliane de Souza; Vasconcellos, Flávia Aleixo; Tavares, Rejane Giacomelli; Vizzotto, Marcia; Silva, Luísa Mariano Cerqueira da; Grecco, Fabiane Borelli; Gamaro, Giovana Duzzo; Spanevello, Roselia Maria; Lencina, Claiton Leoneti; Reginatto, Flávio Henrique; Stefanello, Francieli Moro

    2017-08-01

    The aim of this study was to investigate the effect of Eugenia uniflora fruit (red type) extract on metabolic status, as well as on neurochemical and behavioral parameters in an animal model of metabolic syndrome induced by a highly palatable diet (HPD). Rats were treated for 150days and divided into 4 experimental groups: standard chow (SC) and water orally, SC and E. uniflora extract (200mg/kg daily, p.o), HPD and water orally, HPD and extract. Our data showed that HPD caused glucose intolerance, increased visceral fat, weight gain, as well as serum glucose, triacylglycerol, total cholesterol and LDL cholesterol; however, E. uniflora prevented these alterations. The extract decreased lipid peroxidation and prevented the reduction of superoxide dismutase and catalase activities in the prefrontal cortex, hippocampus and striatum of animals submitted to HPD. We observed a HPD-induced reduction of thiol content in these cerebral structures. The extract prevented increased acetylcholinesterase activity in the prefrontal cortex caused by HPD and the increase in immobility time observed in the forced swim test. Regarding chemical composition, LC/MS analysis showed the presence of nine anthocyanins as the major compounds. In conclusion, E. uniflora extract showed benefits against metabolic alterations caused by HPD, as well as exhibited antioxidant and antidepressant-like effects. Copyright © 2017. Published by Elsevier Masson SAS.

  13. Anti-herpes simplex virus activities of Eugenia caryophyllus (Spreng.) Bullock & S. G. Harrison and essential oil, eugenol.

    PubMed

    Tragoolpua, Y; Jatisatienr, A

    2007-12-01

    In this study, an extract from the flower buds of Eugenia caryophyllus (Spreng.) Bullock & S. G. Harrison and the essential oil, eugenol, were evaluated for their anti-herpes simplex virus properties on standard HSV-1(F), standard HSV-2(G) and ten HSV isolates. The plaque reduction assay showed that HSV-1(F), HSV-2(G), two HSV-1 isolates (2, 30) and four HSV-2 isolates (1, 2, 3, 21) were inhibited by E. caryophyllus. Only HSV-1 isolates 1 and 30 were inhibited by eugenol. Thus, strains or isolates of viruses may affect the range of inhibition. Moreover, particles of HSV standard strains were directly inactivated by E. caryophyllus and eugenol. The total virus yield of HSV standard strains and isolates at 30 h also declined after treatment with E. caryophyllus and eugenol. The E. caryophyllus extract exerted higher antiviral replication on HSV-2(G) than on HSV-1(F). The inhibition of the viral yield of HSV-1 isolates was higher than standard HSV-1(F) and standard HSV-2(G) was also inhibited more than most of the HSV-2 isolates. The anti-HSV activity of eugenol against HSV-1(F) and HSV isolates was stronger than with the E. caryophyllus crude extract. However, the percentage inhibition was more pronounced on HSV-1(F) than on HSV-2(G). Moreover, HSV-1(1) and HSV-2(1, 32) could not replicate when eugenol was included in the assay.

  14. Liposomes incorporating essential oil of Brazilian cherry (Eugenia uniflora L.): characterization of aqueous dispersions and lyophilized formulations.

    PubMed

    Yoshida, P A; Yokota, D; Foglio, M A; Rodrigues, R A F; Pinho, S C

    2010-01-01

    Multilamellar liposomes incorporating essential oil of Brazilian cherry (Eugenia uniflora L.) leaves were produced by dry film hydration. Gas chromatography demonstrated the compounds found in the essential oil were effectively incorporated in the aqueous dispersions of liposomes. Differential scanning calorimetry analyses revealed the incorporation of the essential oil did not cause phase separation in the membrane structure; the gel-liquid crystalline transition temperature (main transition) remained the same despite the higher heterogeneity indicated by the transition peak broadening. Different cryoprotectors (sucrose and trehalose) were added to the liposomal formulations to be tested in their ability to protect the liposomal structure during the lyophilization. The morphological aspect of the lyophilized powders analysed by scanning electron microscopy showed significant differences among the samples with and without cryoprotectors. Fourier-transform infrared spectroscopy indicated the cryoprotectors interacted effectively with the polar heads of phospholipids in the bilayer. In terms of water absorption, trehalose was identified as a much more effective protector agent against it than sucrose. The cryoprotectors showed different degrees of effectiveness of preservation of the liposomal structure when the rehydration assays of lyophilized liposomes were carried out, as particle size measurements indicated a moderate process of fusion when the formulations with sucrose were rehydrated.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Dating thermal events at Cerro Prieto using fission-track annealing

    SciTech Connect

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

    1981-01-01

    The duration of heating in the Cerro Prieto reservoir was estimated by relating the fading of spontaneous fission tracks in detrital apatite to observed temperatures. The rate of fading is a function of both time and temperature. The apparent fission track age of the detrital apatites then, is a function of both their source age and their time-temperature history. 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. The temperature in well T-366, where complete annealing first occurs, was estimated to be between 160 and 180{sup 0}C. Complete annealing at these temperatures requires 10{sup 4} and 10{sup 3} years, respectively. Well M-94 has an apparently complex thermal history. Geothermometers in this well indicate temperatures some 50 to 100{sup 0}C higher than those measured directly in the borehole. Fission tracks are partially preserved in M-94 where paleotemperatures were as high as 200{sup 0}C and are erased where geothermometers indicate temperatures of 250{sup 0}C. This implies a thermal event less than 10{sup 1} years and greater than 10{sup 0} years in duration.

  17. 3D gravimetric investigation of the Cerro do Jarau structure, Rio Grande do Sul, Brazil

    NASA Astrophysics Data System (ADS)

    Giacomini, Bruno B.; Leite, Emilson P.; Crósta, Alvaro P.

    2017-04-01

    The Cerro do Jarau structure is possibly the third Brazilian basaltic crater formed in continental flood basalt of the Serra Geral Formation, Paraná Basin, a large igneous province (LIP) in southern Brazil. It is a nearly circular landform with a diameter of approximately 13 km that rises 200 m above the plains of the "pampas" in southern Brazil. In this work, Bouguer anomalies were calculated from gravity accelerations measured on the area of this structure. The residual Bouguer map shows a strong positive anomaly trending NE-SW, located in the northeastern part of the structure, a feature not commonly associated with impact structures. However, the negative anomaly present in its center and the circular positive anomaly surrounding the central portion are typical of impact structures. The residual Bouguer anomaly varies from -2 mGal to 8 mGal. The positive circular anomaly is not spatially coincident with the rim of the structure. Based on the interpretation of our gravimetric data, the estimated diameter of the structure is 12 km and the central portion has a diameter of approximately 5 km, both slightly smaller than previously suggested. The Bouguer anomaly map was inverted into a 3D density model using a constrained inversion method with a maximum density contrast of 0.5 g cm-3. This model was interpreted to associate densities with rock types, resulting in a geological model. This geological model is in accordance with the meteorite impact nature of Cerro do Jarau.

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

    SciTech Connect

    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{degrees} 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).

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

    SciTech Connect

    Not Available

    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{degrees} 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).

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

    SciTech Connect

    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. Small biphase wellhead plant for the Cerro Prieto Mexico geothermal field

    SciTech Connect

    Oropeza, A.; Hays, L.

    1996-12-31

    In a system of geothermal wells in a geothermal field, there are different production conditions of the flows, temperatures and pressures. At plants where the installed capacity requires the use of many wells, it is necessary to regulate the well`s pressure to ensure a stable condition for the turbines. Reducing the steam pressure on the wellhead is achieved by using an orifice plate (flash orifice). Use of an orifice plate results in a waste or loss of well pressure that could be utilized for production of electricity. The Cerro Prieto field, operated by the Comision Federal de Electricidad (CFE), has many wells operating at a very high pressure and producing a lot of water. Much of this pressure and water is not utilized in the production of electricity. With the purpose of taking advantage of this pressure CFE has evaluated a proposal by Biphase Energy Co. Biphase has designed and patented a turbine that works directly with the steam and water mixture coming from the wellhead, acting as a separator. Biphase has developed a model of its turbine and successfully operated it in Coso Hot Springs California. Knowing this CFE has signed an agreement with Biphase Energy Company to install and operate a biphasic turbine at the Cerro Prieto geothermal field located near Mexicali, Mexico.

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

    SciTech Connect

    Carbognani, L.; Hazos, M.; Sanchez, V. ); 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).

  3. Engaging communities in post-fire restoration: forest treatments and community-agency relations after the Cerro Grande fire

    Treesearch

    Robert L. Ryan; Elisabeth M. Hamin

    2006-01-01

    Our research provides advice to managers in their work in post-fire forest rehabilitation based on focus groups and interviews in the Los Alamos, New Mexico, community after the Cerro Grande fire of 2000. We address two key issues: how different restoration efforts compare to natural revegetation from the public?s perspective, and how to effectively communicate with...

  4. VTEM airborne EM, aeromagnetic and gamma-ray spectrometric data over the Cerro Quema high sulphidation epithermal gold deposits, Panama

    NASA Astrophysics Data System (ADS)

    Kwan, Karl; Prikhodko, Alexander; Legault, Jean M. Plastow, Geoffrey C.; Kapetas, John; Druecker, Michael

    2016-03-01

    In March 2012, a helicopter-borne versatile time-domain electromagnetic (VTEM), magnetic and radiometric survey was flown over the Cerro Quema high sulphidation (HS) epithermal gold deposits and the surrounding area. The Cerro Quema deposits are located in the Azuero Peninsula, Panama, approximately 8 km east of Güerita. The gold mineralisation is associated with clay-pyrite alterations topped by an acid-leached resistive cap, and the principal ores are pyrite-rich sulphides located within mineralised vuggy silica rocks. The geophysical data over the Cerro Quema deposits have been analysed. The electromagnetic (EM) responses over the deposits are characterised by resistivity highs and chargeability lows, surrounded by resistivity lows and chargeability highs. Radiometric Th/K ratio highs and magnetic susceptibility lows are observed over the deposits. These geophysical signatures over the Cerro Quema deposits are characteristic responses from HS epithermal gold deposits. The success of the VTEM survey points to the applicability of the regional helicopter electromagnetic, magnetic and gamma-ray spectrometry (EM-Mag-Spec) surveys for the exploration of similar HS epithermal gold deposits to depths < 500 m in weathered terrains.

  5. Examination of the home destruction in Los Alamos associated with the Cerro Grande Fire - July 10, 2000

    Treesearch

    Jack D. Cohen

    2000-01-01

    I arrived at Los Alamos on May 14, 2000 to conduct an examination of the home destruction associated with the Cerro Grande Fire. My examination occurred between the afternoon of 5/14 and late afternoon on 5/16. I had contact with the southern command post incident management team, the Los Alamos Fire Department, and the Santa Fe National Forest.The...

  6. The impact of the eruptions of Mount Pinatubo and Cerro Hudson on antarctic aerosol levels during the 1991 austral spring

    NASA Technical Reports Server (NTRS)

    Pitts, M. C.; Thomason, L. W.

    1993-01-01

    At the beginning of the 1991 Austral spring, volcanic aerosols from Mt. Pinatubo and Cerro Hudson were present in the polar stratosphere of the Southern Hemisphere. Satellite observations of aerosol extinction were used to identify and track the movement of these aerosols in the vicinity of the Antarctic vortex during August through November 1991. A layer of mature Mt. Pinatubo aerosols was identified near 21 km and a layer of fresh Cerro Hudson aerosols was identified near 12 km. This altitude separation of the Mt. Pinatubo and Cerro Hudson aerosols was observed throughout the period. Below 15 km, the polar stratosphere was subject to episodes of strong wave activity which transported the Cerro Hudson aerosols poleward and, after the middle of September, they became a persistent feature beneath the vortex. Above 15 km, signatures of Mt. Pinatubo aerosols were observed near the vortex boundary, but significant portions of the vortex interior remained free of any detectable intrusions of Mt. Pinatubo aerosols until the final warming in mid-November.

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

    SciTech Connect

    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.

  8. Record of Edessa scabriventris Stål (Hemiptera: Pentatomidae) associated to Eugenia uniflora (Brazilian-Cherry) and Psidium guajava (Guava) (Myrtaceae), in north-northeastern Brazil.

    PubMed

    Lima, Mauricio S; Fernandes, José A M; Lima, Iracilda M M

    2010-01-01

    This study reports for the first time Edessa scabriventris Stål on Eugenia uniflora (Brazilian-cherry) and on Psidium guajava (guava) (Myrtaceae), fruit trees with economic value. Its geographic distribution is extended with records for the states of Alagoas (Maceió Municipality 35°45'11.16''W; 9°40'18.52''S) and Pará (Belém Municipality 48°28'14.65''W; 1°26'14.83''S), north-northeastern Brazil.

  9. Evolution of tuff ring-dome complex: the case study of Cerro Pinto, eastern Trans-Mexican Volcanic Belt

    NASA Astrophysics Data System (ADS)

    Zimmer, Brian W.; Riggs, Nancy R.; Carrasco-Núñez, Gerardo

    2010-12-01

    Cerro Pinto is a Pleistocene rhyolite tuff ring-dome complex located in the eastern Trans-Mexican Volcanic Belt. The complex is composed of four tuff rings and four domes that were emplaced in three eruptive stages marked by changes in vent location and eruptive character. During Stage I, vent clearing produced a 1.5-km-diameter tuff ring that was then followed by emplacement of two domes of approximately 0.2 km3 each. With no apparent hiatus in activity, Stage II began with the explosive formation of a tuff ring ~2 km in diameter adjacent to and north of the earlier ring. Subsequent Stage II eruptions produced two smaller tuff rings within the northern tuff ring as well as a small dome that was mostly destroyed by explosions during its growth. Stage III involved the emplacement of a 0.04 km3 dome within the southern tuff ring. Cerro Pinto's eruptive history includes sequences that follow simple rhyolite-dome models, in which a pyroclastic phase is followed immediately by effusive dome emplacement. Some aspects of the eruption, however, such as the explosive reactivation of the system and explosive dome destruction, are more complex. These events are commonly associated with polygenetic structures, such as stratovolcanoes or calderas, in which multiple pulses of magma initiate reactivation. A comparison of major and trace element geochemistry with nearby Pleistocene silicic centers does not show indication of any co-genetic relationship, suggesting that Cerro Pinto was produced by a small, isolated magma chamber. The compositional variation of the erupted material at Cerro Pinto is minimal, suggesting that there were not multiple pulses of magma responsible for the complex behavior of the volcano and that the volcanic system was formed in a short time period. The variety of eruptive style observed at Cerro Pinto reflects the influence of quickly exhaustible water sources on a short-lived eruption. The rising magma encountered small amounts of groundwater that

  10. The Organic Chemistry of Volcanoes: Case Studies at Cerro Negro, Nicaragua and Oldoinyo Lengai, Tanzania

    NASA Astrophysics Data System (ADS)

    Teague, A. J.; Seward, T. M.; Gize, A. P.; Hall, T.

    2005-12-01

    Though it has long been known that volcanoes emit organic compounds within their fumarolic gases, it is only in recent years that a concerted attempt has been made to catalogue and quantify the species and fluxes. Two general lines of interest dominate this study. Firstly, volcanic gases represent some of the most likely environments in which the precursor molecules necessary for the origin of life were synthesised. The existence of an active, abiotic, organic chemistry in such settings today is fundamental to our understanding of the early Earth. Secondly, the presence of halogenated organic compounds is of interest to the atmospheric sciences, particularly with respect to their ozone depleting potential. It is clear that natural sources of halocarbons must exist, and though current natural fluxes are low with respect to the anthropogenic signature, volcanogenic halocarbons may have proved to be significant during the eruption of supervolcanoes and continental flood basalts. In this study, gases were collected from fumaroles in the craters of two, very different, active volcanoes. Cerro Negro, a young basaltic cinder cone belonging to the Central American Volcanic Belt, could be defined as a typical subduction zone volcano. Gases were collected from Cerro Negro during March 2003 and 2004 from a single fumarole discharging close to the crater floor. In contrast, Oldoinyo Lengai is the world's only active carbonatite volcano and represents the most extreme case of alkali volcanism in the East African Rift system. Fieldwork was conducted in the northern summit crater of Lengai over 8 days in October 2003. In this period, the volcano was in near continuous eruption and gases were sampled from two fumaroles situated within 20m of the eruptive centre, though measured gas temperatures were low at around 195°C. Organic compounds were collected using a variety of activated carbon, molecular sieve type adsorbents, packed into glass cartridges. The water and acid matrix of

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

    SciTech Connect

    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.

  12. Autophagy induced by purple pitanga (Eugenia uniflora L.) extract triggered a cooperative effect on inducing the hepatic stellate cell death.

    PubMed

    Denardin, Cristiane C; Martins, Leo A M; Parisi, Mariana M; Vieira, Moema Queiroz; Terra, Silvia R; Barbé-Tuana, Florencia M; Borojevic, Radovan; Vizzotto, Márcia; Emanuelli, Tatiana; Guma, Fátima Costa Rodrigues

    2017-04-01

    Activated hepatic stellate cells (HSC) are the major source of collagen I in liver fibrosis. Eugenia uniflora L. is a tree species that is widely distributed in South America. E. uniflora L. fruit-popularly known as pitanga-has been shown to exert beneficial properties. Autophagy contributes to the maintenance of cellular homeostasis and survival under stress situation, but it has also been suggested to be an alternative cell death pathway. Mitochondria play a pivotal role on signaling cell death. Mitophagy of damaged mitochondria is an important cell defense mechanism against organelle-mediated cell death signaling. We previously found that purple pitanga extract induced mitochondrial dysfunction, cell cycle arrest, and death by apoptosis and necrosis in GRX cells, a well-established activated HSC line. We evaluated the effects of 72-h treatment with crescent concentrations of purple pitanga extract (5 to 100 μg/mL) on triggering autophagy in GRX cells, as this is an important mechanism to cells under cytotoxic conditions. We found that all treated cells presented an increase in the mRNA expression of autophagy-related protein 7 (ATG7). Concomitantly, flow cytometry and ultrastructural analysis of treated cells revealed an increase of autophagosomes/autolysosomes that consequentially led to an increased mitophagy. As purple pitanga extract was previously found to be broadly cytotoxic to GRX cells, we postulated that autophagy contributes to this scenario, where cell death seems to be an inevitable fate. Altogether, the effectiveness on inducing activated HSC death can make purple pitanga extract a good candidate on treating liver fibrosis.

  13. Effect of the Ethyl Acetate Fraction of Eugenia uniflora on Proteins Global Expression during Morphogenesis in Candida albicans

    PubMed Central

    Silva-Rocha, Walicyranison P.; de Azevedo, Matheus F.; Ferreira, Magda R. A.; da Silva, Julhiany de Fátima; Svidzinski, Terezinha I. E.; Milan, Eveline P.; Soares, Luiz A. L.; Rocha, Keyla B. F.; Uchôa, Adriana F.; Mendes-Giannini, Maria J. S.; Fusco Almeida, Ana M.; Chaves, Guilherme M.

    2017-01-01

    Candida albicans is able to switch from yeast to hyphal growth and this is an essential step for tissue invasion and establishment of infection. Due to the limited drug arsenal used to treat fungal infections and the constant emergence of resistant strains, it is important to search for new therapeutic candidates. Therefore, this study aimed to investigate by proteomic analysis the role of a natural product (Eugenia uniflora) in impairing hypha formation in C. albicans. We also tested the potential action of E. uniflora to prevent and treat oral candidiasis induced in a murine model of oral infection and the ability of polymorphonuclear neutrophils to phagocytize C. albicans cells treated with the ethyl acetate fraction of the extract. We found that this fraction greatly reduced hypha formation after morphogenesis induction in the presence of serum. Besides, several proteins were differentially expressed in cells treated with the fraction. Surprisingly, the ethyl acetate fraction significantly reduced phagocytosis in C. albicans (Mean 120.36 ± 36.71 yeasts/100 PMNs vs. 44.68 ± 19.84 yeasts/100 PMNs). Oral candidiasis was attenuated when C. albicans cells were either pre-incubated in the presence of E. uniflora or when the fraction was applied to the surface of the oral cavity after infection. These results were consistent with the reduction in CFU counts (2.36 vs. 1.85 Log10 CFU/ml) and attenuation of tissue damage observed with histopathological analysis of animals belonging to treated group. We also observed shorter true hyphae by direct examination and histopathological analysis, when cells were treated with the referred natural product. The E. uniflora ethyl acetate fraction was non-toxic to human cells. E. uniflora may act on essential proteins mainly related to cellular structure, reducing the capacity of filamentation and attenuating infection in a murine model, without causing any toxic effect on human cells, suggesting that it may be a future therapeutic

  14. Effect of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora, a tree native to the Atlantic Forest.

    PubMed

    de Almeida, D J; Faria, M V; da Silva, P R

    2012-12-06

    Habitat fragmentation, caused by the expansion of agriculture in natural areas, may be one of the strongest impacts humans have on the ecosystem. These changes can decrease the number of individuals in a population, leading to endogamy. In allogamous species, endogamy can have a negative effect on reproductive capacity. In this study, we analyzed the effects of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora L., a tree species native to the Atlantic Forest. We analyzed 4 populations, 3 of which were connected by forest corridors and 1 of which was isolated by agricultural fields on all sides. For microsporogenesis analysis, 9000 meiocytes representing all stages of meiosis were evaluated. To perform the pollen viability test, we evaluated 152,000 pollen grains. Microsporogenesis was stable in plants from populations that were connected by forest corridors (abnormalities, less than 6%), while microsporogenesis in plants from the isolated population showed a higher level of abnormalities (13-29%). Average pollen viability was found to be more than 93% in the non-isolated populations and 82.62% in the isolated population. The χ(2) test showed that, in the isolated population, the meiotic index was significantly lower than that in the non-isolated populations (P = 0.03). The analysis of variance for the percentage of viable pollen grains confirmed the significant difference between the isolated and non-isolated populations. Our data show that forest fragmentation has a direct effect on microsporogenesis and pollen viability in E. uniflora and can directly influence the reproductive capacity of isolated populations of this species.

  15. Analyses of several seed viability markers in individual recalcitrant seeds of Eugenia stipitata McVaugh with totipotent germination.

    PubMed

    Calvi, G P; Aud, F F; Ferraz, I D K; Pritchard, H W; Kranner, I

    2017-01-01

    The use of biochemical seed viability markers is often compromised by the unknown partitioning of analytes in bulk seed lots consisting of inseparable populations of viable and nonviable seeds. We took advantage of an unusual morphological syndrome found in the recalcitrant, undifferentiated seeds of Eugenia stipitata: one seed can be cut into several parts, each of which can germinate and develop into seedlings. We used four seed parts from one individual seed to analyse seed moisture content (MC), seed viability and the antioxidant glutathione (γ-glutamyl-cysteinyl-glycine; GSH), glutathione disulphide (GSSG) and intermediates of glutathione synthesis and breakdown. Seeds were exposed to different environmental MC to induce various levels of desiccation stress. Upon storage at high seed MC, seed viability was maintained, while GSH concentration increased and the glutathione half-cell reduction potential (EGSSG/2GSH ) was less negative than -215 mV, indicating GSH production and highly reducing conditions. Storage at low seed MC led to loss of GSH, resulting in a shift in EGSSG/2GSH , and seed death. In contrast, the cyst(e)ine half-cell reduction potential (ECySS/2CYS ) could not distinguish between the viability categories. Previous studies on seed populations revealed that the probability for a seed being alive is 50% at EGSSG/2GSH values between -180 and -160 mV. The single seed approach revealed that the window in which seed viability was lost could be slightly shifted towards more negative values. We discuss the contribution of cellular pH to EGSSG/2GSH and recommend E. stipitata as a recalcitrant seed model to study stress response on a single seed basis. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Chemical Profiling of the Essential Oils of Syzygium aqueum, Syzygium samarangense and Eugenia uniflora and Their Discrimination Using Chemometric Analysis.

    PubMed

    Sobeh, Mansour; Braun, Markus Santhosh; Krstin, Sonja; Youssef, Fadia S; Ashour, Mohamed L; Wink, Michael

    2016-11-01

    The essential oil compositions of the leaves of three related Myrtaceae species, namely Syzygium aqueum, Syzygium samarangense and Eugenia uniflora, were investigated using GLC/MS and GLC/FID. Altogether, 125 compounds were identified: α-Selinene (13.85%), β-caryophyllene (12.72%) and β-selinene constitute the most abundant constituents in S. aqueum. Germacrene D (21.62%) represents the major compound in S. samarangense whereas in E. uniflora, spathulenol (15.80%) represents the predominant component. Multivariate chemometric analyses were used to discriminate the essential oils using hierarchical cluster analysis (HCA) and principal component analysis (PCA) based on the chromatographic results. The antimicrobial activity of the popularly used E. uniflora essential oil was assessed using broth microdilution method against six Gram-positive, three Gram-negative bacteria and two fungi. The oil showed moderate antimicrobial activity against Bacillus licheniformis exhibiting MIC and MMC of 0.63 mg/ml. The cytotoxic activity of E. uniflora essential oil was investigated against Trypanosoma brucei brucei (T. b. brucei) and MCF-7 cancer cell line using MTT assay. It showed moderate activity against MCF-7 cells with an IC50 value of 76.40 μg/ml. On the other hand, T. brucei was highly susceptible to E. uniflora essential oil with IC50 of 11.20 μg/ml, and a selectivity index of 6.82. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

  17. Eugenia dysenterica DC. (Myrtaceae) exerts chemopreventive effects against hexavalent chromium-induced damage in vitro and in vivo.

    PubMed

    Ávila, Renato Ivan de; Mattos Alvarenga, Cátia Belo; Ávila, Paulo Henrique Marcelino de; Moreira, Roger Cardoso; Arruda, Andréa Fernandes; Fernandes, Thaís de Oliveira; Rodrigues, Bruna Dos Santos; Andrade, Wanessa Machado; Batista, Aline Carvalho; Paula, José Realino de; Valadares, Marize Campos

    2016-11-01

    Eugenia dysenterica DC. (Myrtaceae) has been widely used in the folk medicine and it presents phytochemicals constituents associated to antioxidant properties. The objective of this study was to investigate the protective effects of E. dysenterica leaf hydroalcoholic extract (EDE) in vitro and in vivo using AMJ2-C11 cells and Swiss mice exposed to hexavalent chromium [Cr(VI)], respectively. AMJ2-C11 cells were pretreated with EDE and exposed to Cr(VI) to evaluate cytotoxicity and the pathways involved in the chemopreventive effects of the extract. Mice were daily pretreated with EDE and then exposed to Cr(VI). Survival analysis, histopathological examination and determination of Cr levels in biological tissues were carried out. In vitro studies showed that pretreatment of the AMJ2-C11 cells with EDE protected against the cytotoxicity and oxidative stress induced by Cr(VI). Consequently, the pretreatment with EDE reduced reactive oxygen species and apoptosis triggered by Cr(VI), probably by a marked antioxidant and chelating activities demonstrated by EDE. Regarding in vivo studies, pretreatment for 10 days with EDE increased survival of the mice exposed to Cr(VI). In addition, EDE prevented liver and kidney pathological damages, in parallel with reduction in chromium levels found in these organs and plasma. EDE also showed a marked antioxidant potential associated with the presence of polyphenols, especially flavonoids and tannins, as confirmed by HPLC-PDA. The study showed that EDE protects against Cr(VI)-induced damage in vitro and in vivo supporting further studies for the development of therapeutic products applied to prevent the damage induced by toxic metals, especially Cr(VI).

  18. Transcriptional profile of Paracoccidioides induced by oenothein B, a potential antifungal agent from the Brazilian Cerrado plant Eugenia uniflora

    PubMed Central

    2013-01-01

    Background The compound oenothein B (OenB), which is isolated from the leaves of Eugenia uniflora, a Brazilian Cerrado plant, interferes with Paracoccidioides yeast cell morphology and inhibits 1,3-β-D-glucan synthase (PbFKS1) transcript accumulation, which is involved in cell wall synthesis. In this work we examined the gene expression changes in Paracoccidioides yeast cells following OenB treatment in order to investigate the adaptive cellular responses to drug stress. Results We constructed differential gene expression libraries using Representational Difference Analysis (RDA) of Paracoccidioides yeast cells treated with OenB for 90 and 180 min. Treatment for 90 min resulted in the identification of 463 up-regulated expressed sequences tags (ESTs) and 104 down-regulated ESTs. For the 180 min treatment 301 up-regulated ESTs and 143 down-regulated were identified. Genes involved in the cell wall biosynthesis, such as GLN1, KRE6 and FKS1, were found to be regulated by OenB. Infection experiments in macrophages corroborated the in vitro results. Fluorescence microscopy showed increased levels of chitin in cells treated with OenB. The carbohydrate polymer content of the cell wall of the fungus was also evaluated, and the results corroborated with the transcriptional data. Several other genes, such as those involved in a variety of important cellular processes (i.e., membrane maintenance, stress and virulence) were found to be up-regulated in response to OenB treatment. Conclusions The exposure of Paracoccidioides to OenB resulted in a complex altered gene expression profile. Some of the changes may represent specific adaptive responses to this compound in this important pathogenic fungus. PMID:24119145

  19. Suppression of VEGF-induced angiogenesis and tumor growth by Eugenia jambolana, Musa paradisiaca, and Coccinia indica extracts.

    PubMed

    M, Harsha Raj; Ghosh, Debidas; Banerjee, Rita; Salimath, Bharathi P

    2017-12-01

    Abnormal angiogenesis and evasion of apoptosis are hallmarks of cancer. Accordingly, anti-angiogenic and pro-apoptotic therapies are effective strategies for cancer treatment. Medicinal plants, namely, Eugenia jambolana Lam. (Myrtaceae), Musa paradisiaca L. (Musaceae), and Coccinia indica Wight & Arn. (Cucurbitaceae), have not been greatly investigated for their anticancer potential. We investigated the anti-angiogenic and pro-apoptotic efficacy of ethyl acetate (EA) and n-butanol (NB) extracts of E. jambolana (seeds), EA extracts of M. paradisiaca (roots) and C. indica (leaves) with respect to mammary neoplasia. Effect of extracts (2-200 μg/mL) on cytotoxicity and MCF-7, MDA-MB-231 and endothelial cell (EC) proliferation and in vitro angiogenesis were evaluated by MTT, (3)[H]thymidine uptake and EC tube formation assays, respectively. In vivo tumour proliferation, VEGF secretion and angiogenesis were assessed using the Ehrlich ascites tumour (EAT) model followed by rat corneal micro-pocket and chicken chorioallantoic membrane (CAM) assays. Apoptosis induction was assessed by morphological and cell cycle analysis. EA extracts of E. jambolana and M. paradisiaca exhibited the highest cytotoxicity (IC50 25 and 60 μg/mL), inhibited cell proliferation (up to 81%), and tube formation (83% and 76%). In vivo treatment reduced body weight (50%); cell number (16.5- and 14.7-fold), secreted VEGF (∼90%), neoangiogenesis in rat cornea (2.5- and 1.5-fold) and CAM (3- and 1.6-fold) besides EAT cells accumulation in sub-G1 phase (20% and 18.38%), respectively. Considering the potent anti-angiogenic and pro-apoptotic properties, lead molecules from EA extracts of E. jambolana and M. paradisiaca can be developed into anticancer drugs.

  20. A molecular connection of Pterocarpus marsupium, Eugenia jambolana and Gymnema sylvestre with dipeptidyl peptidase-4 in the treatment of diabetes.

    PubMed

    Kosaraju, Jayasankar; Dubala, Anil; Chinni, Santhivardhan; Khatwal, Rizwan Basha; Satish Kumar, M N; Basavan, Duraiswamy

    2014-02-01

    Pterocarpus marsupium (PM) (Leguminosae), Eugenia jambolana (EJ) (Myrtaceae) and Gymnema sylvestre (GS) (Asclepiadaceae) are the most important medicinal plants in the Indian system of traditional medicine for the treatment of hyperglycemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors are the emerging class of anti-diabetic agents. However, only few compounds are commercially available. Therefore, in the present study we tried to explore the naturally occurring PM, EJ and GS semi-standardized extracts for their potential DPP-4 inhibition in vitro and in vivo. DPP-4 inhibition was evaluated by in vitro inhibitory assay, and enzyme kinetics were calculated using one-phase exponential decay equation. Glucose load (2 g/kg) was administered to control and diabetic rats 30 min following extract administration (100, 200 and 400 mg/kg) orally once, and blood samples were withdrawn at 0, 0.5, 1, 1.5, 2 and 3 h to measure plasma active glucagon-like peptide-1 (GLP-1) levels. PM and EJ inhibit DPP-4 potently with IC50 values of 273.73 ± 2.96 and 278.94 ± 6.73 µg/mL, respectively, compared to GS (773.22 ± 9.21 µg/mL). PM, EJ and GS exhibit long duration of action with enzyme inhibitory half-lives of 462.3, 317.2 and 153.8 min, respectively. Extracts significantly increase GLP-1 levels compared to negative control groups and peak GLP-1 level was observed at 2 h for PM and EJ, whereas for GS it was at 1.5 h Taken together, results suggest the extracts may have potent DPP-4 inhibitory action, and their hypoglycemic action attributed through an increase in plasma active GLP-1 levels.

  1. Effects of topical and systemic administration of Eugenia caryophyllata buds essential oil on corneal anesthesia and analgesia

    PubMed Central

    Khalilzadeh, Emad; Hazrati, Reza; Saiah, Gholamreza Vafaei

    2016-01-01

    Clinical studies suggest that essential oil of Eugenia caryophyllata (Clove) buds (EOEC) is efficacious in the treatment of dental pain. In the present study, we investigated the analgesic and local anesthetic effects of EOEC and its possible mechanisms of action in acute corneal pain in rats. EOEC was extracted by hydro-distillation in a Clevenger type apparatus from clove buds. The acute corneal pain was induced by applying a drop (40 µl) of 5 M NaCl solution on the corneal surface, and the numbers of eye wipes were counted during the first 30 s. The mechanical sensation of the cornea was evaluated by calibrated Von Frey filaments. Systemic administration of EOEC (100 and 200 mg/kg, SC) and morphine (2.5 and 5 mg/kg, IP) produced a significant antinociceptive effect in acute corneal pain. Pretreatment with naloxone or atropine prevented the EOEC-induced analgesia. However, L-arginine and methylene blue did not change the suppressive effect of EOEC on corneal pain response. Topical application of EOEC, eugenol and lidocaine significantly decreased corneal sensitivity. Combination treatments of eugenol (25 µg) with lidocaine (0.5%) and EOEC (50 µg) with lidocaine (0.5%) also significantly suppressed corneal sensitivity. Systemic administration of EOEC produced analgesia in the acute corneal pain through mechanisms that involved both opioidergic and cholinergic systems. In addition, topical instillation of EOEC, eugenol, and lidocaine produced local anesthesia in the rat cornea. Sub-anesthetic doses of EOEC or eugenol produced a significant local anesthetic effect when concurrently used with the sub-anesthetic dose of lidocaine. PMID:27651809

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Changing fluvial styles in volcaniclastic successions: A cretaceous example from the Cerro Barcino Formation, Patagonia

    NASA Astrophysics Data System (ADS)

    Umazano, A. Martín; Krause, J. Marcelo; Bellosi, Eduardo S.; Perez, Mariano; Visconti, Graciela; Melchor, Ricardo N.

    2017-08-01

    The Cretaceous Puesto La Paloma (PLPM) and Cerro Castaño (CCM) members (Cerro Barcino Formation, Chubut Group) are pyroclastic-rich, alluvial successions deposited in the Somuncurá-Cañadón Asfalto Basin during sag and endorheic conditions. The PLPM comprises sheet-like tuffaceous sandstone strata, whereas the overlying CCM includes sheet-to ribbon-channel sandstone bodies intercalated within tuffaceous and fine-grained sediments. In this context, the goals of this contribution were: i) to make a detailed documentation of the contrasting sedimentary palaeonvironments; and ii) to infer the allocyclic controls that governed the sedimentation of both units. The study area is located in the western sector of the basin, where six localities, which were studied. Six facies associations were defined including ash-falls, sheet-floods, shallow lakes, aeolian, fluvial channel-belts, and reworked debris-flows. We defined four stratigraphic intervals for the studied sections, denominated 1 to 4 in chronological order of deposition, which increase their thicknesses toward the Puesto Mesa-Cerro León site. The interval 1 (18-42 m thick) corresponds to the PLPM and includes numerous pedogenized sheet-flood deposits, carbonate-rich lacustrine, aeolian sandy facies, and ash-fall beds. The interval 1 is interpreted as an ephemeral and unconfined alluvial system that interacted with aeolian dunes and dry interdune zones. The interval 2 (20-47 m thick) represents the lower part of the CCM. It shows an alternation of fluvial channel-belt deposits and vegetated floodplain facies with sediments originated from sheet-floods, lakes, and few ash-falls and debris-flows. The mean palaeoflow was toward E-SE, except in the northernmost locality where the drainage was towards SW. Proportion of channel-belt bodies ranges from 10 to 36%, reaching higher values in the northern part of the study area, where they are also thicker. The interval 2 represents a permanent, meandering or locally low

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

    SciTech Connect

    Mazor, E.; 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.

  6. Preliminary studies of brine reinjection at the Cerro Prieto Geothermal Field

    SciTech Connect

    Rivera, J.R.; Mercado, S.G.; Tsang, C.F.

    1980-01-01

    At the present time, Units 1 and 2 of the Cerro Prieto power plant generate 75 MW of power. For this purpose, about 2200 t/h of fluids are produced. At present, a number of studies are being conducted to evaluate alternative methods of injection. The methods being considered are: cold or hot injection with open, closed or mixed systems. For each of these systems, laboratory tests will be carried out using columns packed with different grain-sized sands. The sands used are from alluvial fans of the Cucapa range. The purpose of these tests is to establish the scale-forming tendencies of the water when injected under different conditions. 5 refs.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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.

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

    USGS Publications Warehouse

    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.

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

    SciTech Connect

    Balice, Randy G.; Bennett, Kathryn D.; Wright, Marjorie A.

    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.

  11. A new MOS mask cutter facility at Gemini/Cerro Tololo observatories

    NASA Astrophysics Data System (ADS)

    Wyman, Robert T.; Trancho, Gelys; Tighe, Roberto

    2010-07-01

    The installation and commissioning of a new laser cutter facility in La Serena, Chile is a cooperative effort between Gemini Observatory and the Cerro Tololo Inter-American Observatory. This system enables the cutting of aluminum and carbon fiber slit masks for three multi-object spectrographs operating in Chile: GMOS-S, Flamingos-2, and Goodman spectrograph. Selection of the new laser cutter tool was based on slit mask specifications developed for two materials. Prior to the commissioning all slit mask production was performed at Gemini's Northern base facility with a similar laser cutter system. The new facility supports two observatories and enhances the capabilities for both. This paper will discuss the observatory arrangement with respect to mask data tracking and handling. The laser system and facility will be discussed along with mask cutting performance, process development and manufacturing methods.

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

    SciTech Connect

    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.

  13. Jardin botanico {open_quotes}Cerro Prieto, B.C.{close_quotes} Mexico

    SciTech Connect

    Gutierrez Gomez, C.

    1996-12-31

    The Cerro Prieto Geothermal Field is located at North of the Baja California State in Mexico, (32{degrees}22` - 32{degrees}26` N, 115{degrees}12` - 115{degrees}18` W) is part of the Colorado River Delta geological sub-province. This geothermal field is the more important in Mexico and in Latin America. The surface occupied by the installations (power plants, wells and evaporation lake) is of 12 km{sup 2} and in future it may reach 20 km{sup 2}. The construction of a Botanical Garden is projected in this field. Their main objectives are: to preserve the botanical patrimony of the regional flora, to promote the botanical research and the adoption of educational programs on this address.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Geological interpretation of self-potential data from the Cerro Prieto geothermal field

    SciTech Connect

    Corwin, R.F.; Fitterman, D.V.

    1980-02-01

    A source mechanism based on concepts of irreversible thermodynamics and consisting of heat or fluid flow along a north-south trending zone of faulting is proposed for the self-potential anomaly measured over the Cerro Prieto geothermal reservoir. The source region is represented by a vertical plane of that separates regions of differing streaming potential or thermoelectric coupling coefficients. The coupling coefficient contrast could be caused by vertical offset of rock units along faults. The depth to the top of the source plane is about 1.3 km, its vertical extent is about 11 km, and its length along strike is about 10 km. Geological, geophysical, and mineralogical evidence supports the existence of an important north-south geological trend roughly corresponding in location to the proposed self-potential source plane.

  16. Phytolaccaceae infructescence from Cerro del Pueblo Formation, Upper Cretaceous (late Campanian), Coahuila, Mexico.

    PubMed

    Cevallos-Ferriz, Sergio R S; Estrada-Ruiz, Emilio; Pérez-Hernández, Balam Rodrigo

    2008-01-01

    The Upper Cretaceous (late Campanian) Cerro del Pueblo Formation, Coahuila, Mexico, contains a diverse group of angiosperms represented mainly by their reproductive structures. Among these, a new permineralized infructescence is recognized based on its morphological and anatomical characters. It is a multiple infructescence composed of berry fruits with six locules, each containing a single seed with a curved embryo developed from a campylotropous ovule with pendulous placentation; integumentary anatomy is similar to that of Phytolacca spp. (Phytolaccaceae). Though this new plant from Coahuila shares reproductive characters with Phytolacca, the constant number (six) of carpels per fruit and pendulous placentation strongly support the recognition of a new taxon, Coahuilacarpon phytolaccoides Cevallos-Ferriz, Estrada-Ruiz, et Pérez-Hernández (Phytolaccaceae, Caryophyllales). This new record adds to the known plant diversity of low latitude North America (northern Mexico) and demonstrates the long geologic history of the group.

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

    NASA Astrophysics Data System (ADS)

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

    SciTech Connect

    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.

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

    SciTech Connect

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

    1981-10-01

    The purpose of this study is to examine the characteristics of geophysical well logs against the sand-shale series of the sedimentary column of the Cerro Prieto Geothermal Field, Mexico. The study shows 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. Porosity of coastal deltaic sandstones, Cerro Prieto geothermal field, Baja California, Mexico

    SciTech Connect

    Vonder Haar, S.P.

    1984-04-01

    Core porosity values for sandstones and density log-derived porosities for sandstone-siltstone-shale sequences indicate a range from less than 1% to 40% at the Cerro Prieto geothermal field, Baja California, Mexico. Mean porosity values indicate that a general trend of decreasing porosities with increasing depth from 35% at 600 m to 10% at 2300 m is complicated by the 15 to 30% porosities in the 350/sup 0/C hot water zone at about 2700 m depth. Scanning electron microscopy documents secondary dissolution porosity, mineral overgrowths, and abundant clay minerals. Core permeability ranges from 0.1 to 1000 millidarcies for the more than 50 cores studied. The porosity variability indicates that geothermal systems provide an ideal setting for testing concepts of dissolution porosity and increased secondary dissolution permeability that could be useful for nuclear waste storage as well as petroleum reservoir engineering.

  1. [Reptiles from Cerro Colorado and its surroundings, Cumana, Sucre State, Venezuela].

    PubMed

    Oliveros, O; Prieto, A; Comejo, P

    2000-01-01

    An inventory of the reptiles that inhabit in Cerro Colorado and its surroundings, was performed from March, 1994 to March, 1995. There were reported 8 species of snakes and 7 of lizards enclosed in 4 and 5 families repectively. Aspects observed were ecolology as habitat, activity, reproduction and relative abundance. The more abundant species of lizards were: Cnemidophorus femniscatus, Ameiva bifrontata, (Teiidae), Tropidurus hispidus (Tropiduridae), Gonatodes vittatus and Hemidactylus mabouia (Gekkonidae) and the ophidians: Leptodeira annulata and Mastigodryas amarali (Colubridae). It is believed that the changes occurred in the zone influenced the increase of the relative abundance of the species Leptotyphlops goudotii (Leptotyphlopidae) arid Gymnophthalmus speciosus(Gymnophthalmidae) and perhaps in the disappearance of others that have been reported at the xerophitic or semixerophitic zones of the Sucre State of Venezuela.

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

    PubMed

    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.

  3. Mercury in freshwater fish and clams from the Cerro Prieto geothermal field of Baja California, Mexico

    SciTech Connect

    Gutierrez-Galindo, E.A.; Munoz, G.F.; Flores, A.A.

    1988-08-01

    Several reports have expressed concern about the potential toxicity hazards and environmental contamination of mercury emissions from geothermal fields in Hawaii, New Zealand, Iceland, California and Mexico. Inorganic mercury discharged from the sources may accumulate in the sediments of rivers or lakes and, after microbiological methylation may become concentrated in the edible tissue of fish. This study involves assessment of geothermal mercury pollution arising from Cerro Prieto. For this purpose the fish Tilapia mossambica and the clam Corbicula fluminea were collected from the freshwater courses of the Mexicali Valley. Reports indicated that in 1982, 13 t of T. mossambica were destinated for human consumption. A further aim was to provide base line data and information relevant to the level of mercury contamination for the Mexicali Valley.

  4. Population structure and admixture in Cerro Largo, Uruguay, based on blood markers and mitochondrial DNA polymorphisms.

    PubMed

    Sans, Mónica; Merriwether, D Andrew; Hidalgo, Pedro C; Bentancor, Nilo; Weimer, Tania A; Franco, Maria Helena L P; Alvarez, Inés; Kemp, Brian M; Salzano, Francisco M

    2006-01-01

    Recent studies of the Uruguayan population revealed different amounts of Amerindian and African genetic contributions. Our previous analysis of Afro-Uruguayans from the capital city of the Department of Cerro Largo showed a high proportion of African genes, and the effects of directional mating involving Amerindian women. In this paper, we extended the analysis to a sample of more than 100 individuals representing a random sample of the population of the whole Department. Based on 18 autosomal markers and one X-linked marker, we estimated 82% European, 8% Amerindian, and 10% African contributions to their ancestry, while from seven mitochondrial DNA site-specific polymorphic markers and sequences of hypervariable segment I, we determined 49% European, 30% Amerindian, and 21% African maternal contributions. Directional matings between Amerindian women and European men were detected, but differences involving Africans were not significant. Data about the specific origins of maternal lineages were also provided, and placed in a historical context.

  5. Climate Reconstruction and Historical Fire Regime in Cerro El Mohinora, Chihuahua, Mexico

    NASA Astrophysics Data System (ADS)

    Cerano-Paredes, J.; Villanueva-Diaz, J.; Arreola-Avila, J. G.; Sanchez-Cohen, I.; Valdez-Cepeda, R. D.; Garcia, G.

    2007-05-01

    Tree rings constitute one of the most important sources of low and high frequency resolution for climate reconstruction for the last millennium. Chronologies of total ring width, earlywood, and latewood were developed from a Douglas-fir in a mixed conifer stand in Cerro El Mohinora, Chihuahua, Mexico. The tree-ring chronology extended back in time for 349 years (1657 - 2005) showing a high sensibility to climate variability. Therefore, total ring width indices were used as a proxy of the climate variability in the area. Intensive droughts were observed in the periods 1695-1715, 1753-1760, 1786-1792, 1798-1806, 1819-1830, 1841-1870, 1890-1899, 1906-1912, 1924-1941, 1971-1977, and 1994- 2005. The most prolonged droughts took place in the periods 1695-1715, 1841-1870, 1924-1941, and 1994-2005. Pluvials were less frequent in this reconstruction and were observed for the 1680s, 1900s, and 1970s. Pine species were sampled for fire frequency studies at the upper and lower watershed of Cerro El Mohinora. The fire frequency reconstruction extended from 1800 to 2005 for the upper watershed, and fire years were detected in 1999, 1988, 1971, 1967, 1964, 1950, 1945, 1923, 1904, 1889, 1882, 1873, 1862, 1853, and 1837. At the lower watershed fire frequency was reconstructed from 1900 to 2005. Fires were present for the years 1995, 1988, 1985, 1971, 1945, 1943, 1933, 1923, and 1900. Common fire years for upper and lower elevations were observed in 1988, 1971, 1945, and 1923. The fire year of 1971 affected the whole watershed and could be related to the severe drought prevailing in that decade. Preliminary results show a good correspondence between prolonged dry conditions and presence of fires, but further analysis remain to be done.

  6. Simultaneous observations of the phase-locked 2 day wave at Adelaide, Cerro Pachon, and Darwin

    NASA Astrophysics Data System (ADS)

    Walterscheid, R. L.; Hecht, J. H.; Gelinas, L. J.; MacKinnon, A.; Vincent, R. A.; Reid, I. M.; Franke, S. J.; Zhao, Y.; Taylor, M. J.; Pautet, P. D.

    2015-03-01

    The Southern Hemisphere summer 2 day wave (TDW) is the most dramatic large-scale event of the upper mesosphere. The winds accelerate over ~1 week, may attain > 70 m/s, and are often accompanied by a near disappearance of the diurnal tide and stabilization of the period close to 48 h. We denote this as the phase-locked 2 day wave (PL/TDW). We have examined airglow and meteor radar (MR) wind data from the Andes Lidar Observatory (Cerro Pachon, Chile:30°S, 289.3°E), MR data from Darwin (12.5°S, 131°E) and airglow and medium frequency radar data from the University of Adelaide (34.7°S, 138.6°E) for the behavior of the TDW during the austral summers of 2010, 2012, and 2013. The Cerro Pachon and Adelaide sites are located at similar latitudes separated in longitude by about 120°. We find a remarkable coincidence between the TDW oscillations at Chile and Adelaide for the period January-February 2010. The oscillations are nearly in phase in terms of local time and the minima and maxima repeat at nearly the same local time from cycle to cycle consistent with a phase-locked wave number 3 TDW. Data for this and other years (including Darwin) show that the amplitude of the diurnal tide decreases when the TDW is largest and that this occurs when the period is close to 48 h. These observations support the proposal that the PL/TDW is a subharmonic parametric instability wherein the diurnal tide transfers energy to a TDW that is resonant at nearly 48 h.

  7. Changes in fungal population of fly ash and vinasse mixture during vermicomposting by Eudrilus eugeniae and Eisenia fetida: documentation of cellulase isozymes in vermicompost.

    PubMed

    Pramanik, Prabhat; Chung, Young Ryun

    2011-06-01

    Fly ash (FA) and vinasse (VN), two industrial wastes, are generated in huge amounts and cause serious hazards to the environment. In this experiment, different proportions of these two wastes were used as food for two epigeic earthworms (Eisenia fetida and Eudrilus eugeniae) to standardize the recycling technique of these two wastes and to study their effect on fungal especially cellulolytic fungal population, cellulase activity and their isozyme pattern, chitin content and microbial biomass of waste mixture during vermicomposting. Increasing VN proportion from 25% to 50% or even higher, counts of both fungi and cellulolytic fungi in waste mixtures were significantly (P ≤ 0.05) increased during vermicomposting. Higher cellulase activity in treatments having 50% or more vinasse might be attributed to the significantly (P ≤ 0.05) higher concentration of group I isozyme while concentrations of other isozymes (group II and III) of cellulase were statistically at par. Higher chitin content in vinasse-enriched treatments suggested that fungal biomass and fungi-to-microbial biomass ratio in these treatments were also increased due to vermicomposting. Results revealed that Eudrilus eugeniae and Eisenia fetida had comparable effect on FA and VN mixture during vermicomposting. Periodical analysis of above-mentioned biochemical and microbial properties and nutrient content of final vermicompost samples indicated that equal proportion (1:1, w/w) of FA and VN is probably the optimum composition to obtain best quality vermicompost. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Metabolic variations, antioxidant potential, and antiviral activity of different extracts of Eugenia singampattiana (an endangered medicinal plant used by Kani tribals, Tamil Nadu, India) leaf.

    PubMed

    John, K M Maria; Ayyanar, Muniappan; Jeeva, Subbiah; Suresh, Murugesan; Enkhtaivan, Gansukh; Kim, Doo Hwan

    2014-01-01

    Eugenia singampattiana is an endangered medicinal plant used by the Kani tribals of South India. The plant had been studied for its antioxidant, antitumor, antihyperlipidemic, and antidiabetic activity. But its primary and secondary metabolites profile and its antiviral properties were unknown, and so this study sought to identify this aspect in Eugenia singampattiana plant through different extraction methods along with their activities against porcine reproductive and respiratory syndrome virus (PRRSV). The GC-MS analysis revealed that 11 primary metabolites showed significant variations among the extracts. Except for fructose all other metabolites were high with water extract. Among 12 secondary metabolites showing variations, the levels of 4-hydroxy benzoic acid, caffeic acid, rutin, ferulic acid, coumaric acid, epigallocatechin gallate, quercetin, myricetin, and kaempferol were high with methanol extract. Since the flavonoid content of methanol extracts was high, the antioxidant potential, such as ABTS, and phosphomolybdenum activity increased. The plants antiviral activity against PRRSV was for the first time confirmed and the results revealed that methanol 25 µg and 75 to 100 µg in case of water extracts revealed antiviral activity.

  9. Description of a New Galapagos Giant Tortoise Species (Chelonoidis; Testudines: Testudinidae) from Cerro Fatal on Santa Cruz Island

    PubMed Central

    Chiari, Ylenia; Garrick, Ryan C.; Russello, Michael A.; Benavides, Edgar; Watkins-Colwell, Gregory J.; Glaberman, Scott; Tapia, Washington; Gibbs, James P.; Cayot, Linda J.; Caccone, Adalgisa

    2015-01-01

    The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises. PMID:26488886

  10. Late-stage magmatic to deuteric/metasomatic accessory minerals from the Cerro Boggiani agpaitic complex (Alto Paraguay Alkaline Province)

    NASA Astrophysics Data System (ADS)

    Comin-Chiaramonti, Piero; Renzulli, Alberto; Ridolfi, Filippo; Enrich, Gaston E. R.; Gomes, Celso B.; De Min, Angelo; Azzone, Rogério G.; Ruberti, Excelso

    2016-11-01

    This work describes rare accessory minerals in volcanic and subvolcanic silica-undersaturated peralkaline and agpaitic rocks from the Permo-Triassic Cerro Boggiani complex (Eastern Paraguay) in the Alto Paraguay Alkaline Province. These accessory phases consist of various minerals including Th-U oxides/silicates, Nb-oxide, REE-Sr-Ba bearing carbonates-fluorcarbonates-phosphates-silicates and Zr-Na rich silicates. They form a late-stage magmatic to deuteric/metasomatic assemblage in agpaitic nepheline syenites and phonolite dykes/lava flows made of sodalite, analcime, albite, fluorite, calcite, ilmenite-pyrophanite, titanite and zircon. It is inferred that carbonatitic fluids rich in F, Na and REE percolated into the subvolcanic system and metasomatically interacted with the Cerro Boggiani peralkaline and agpaitic silicate melts at the thermal boundary layers of the magma chamber, during and shortly after their late-stage magmatic crystallization and hydrothermal deuteric alteration.

  11. Description of a New Galapagos Giant Tortoise Species (Chelonoidis; Testudines: Testudinidae) from Cerro Fatal on Santa Cruz Island.

    PubMed

    Poulakakis, Nikos; Edwards, Danielle L; Chiari, Ylenia; Garrick, Ryan C; Russello, Michael A; Benavides, Edgar; Watkins-Colwell, Gregory J; Glaberman, Scott; Tapia, Washington; Gibbs, James P; Cayot, Linda J; Caccone, Adalgisa

    2015-01-01

    The taxonomy of giant Galapagos tortoises (Chelonoidis spp.) is currently based primarily on morphological characters and island of origin. Over the last decade, compelling genetic evidence has accumulated for multiple independent evolutionary lineages, spurring the need for taxonomic revision. On the island of Santa Cruz there is currently a single named species, C. porteri. Recent genetic and morphological studies have shown that, within this taxon, there are two evolutionarily and spatially distinct lineages on the western and eastern sectors of the island, known as the Reserva and Cerro Fatal populations, respectively. Analyses of DNA from natural populations and museum specimens, including the type specimen for C. porteri, confirm the genetic distinctiveness of these two lineages and support elevation of the Cerro Fatal tortoises to the rank of species. In this paper, we identify DNA characters that define this new species, and infer evolutionary relationships relative to other species of Galapagos tortoises.

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

    SciTech Connect

    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.

  13. The Cerro Aguas Calientes caldera, NW Argentina: an example of a tectonically controlled, polygenetic, collapse caldera, and its regional significance

    NASA Astrophysics Data System (ADS)

    Petrinovic, Ivan A.; Martí, Joan; Aguirre-Diaz, Gerardo J.; Guzmán, Silvina R.; Geyer, Adelina; Grosse, Pablo; Salado Paz, Natalia

    2010-05-01

    Polygenetic, silicic collapse calderas such as Cerro Galán, Pastos Grandes, La Pacana, Vilama, Negra Muerta, Farallón Negro, Cerro Guacha, among others are common in the central Andes. Here we describe in detail the Cerro Aguas Calientes caldera in NW Argentina, which comprises two caldera-forming episodes occurred at 17.15 Ma and 10.3 Ma, respectively. We analyse the significance of its structural setting, composition, size and the subsidence style of both caldera episodes. Our results reveal that the caldera eruptions had a tectonic trigger. In both cases, an homogeneous dacitic crystal-rich (>60 vol. % of crystals) reservoir of batholitic size became unstable due to the effect of increasing regional transpression, favouring local dilation throughout minor strike slip faults from which ring faults nucleated and permitted caldera collapse. Both episodes are similar in shape, location and products of the resulting calderas. The 17.15 Ma caldera has an elliptical shape (17 × 14 km) and is elongated in a N30° trend; both intracaldera and extracaldera ignimbrites covered an area of around 620 km2 with a minimum volume estimate of 138 km3 (DRE). The 10.3 Ma episode generated another elliptical caldera (19 ×14 km), with the same orientation as the previous one, from which intracaldera and outflow ignimbrites covered a total area of about 1,700 km2, representing a minimum eruption volume of 341 km3 (DRE). In this work we discuss the significance of the Cerro Aguas Calientes caldera in comparison with other well known examples from the central Andes in terms of tectonic setting, eruption mechanisms, and volumes of related ignimbrites. We suggest that our kinematic model is a common volcano-tectonic scenario during the Cenozoic in the Puna and Altiplano, which may be applied to explain the origin of other large calderas in the same region.

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

    NASA Astrophysics Data System (ADS)

    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

  15. δ13C Degassing Dynamics of a Young Volcanic Center, Cerro Negro, Nicaragua

    NASA Astrophysics Data System (ADS)

    Lucic, G.; Stix, J.; Wing, B. A.; Muñoz, A.; Ibarra, M.; Sherwood Lollar, B.; Lacrampe-Couloume, G.

    2011-12-01

    Measurement of gas-phase δ13C values above active volcanic centers has the potential for monitoring magma dynamics associated with degassing and recharge events above subduction zones. The strong isotopic partitioning between C in the gas and melt, and C isotopic differences among magmas enables degassed CO2 to give insight into processes happening deep underground. Cerro Negro volcano in Nicaragua is an ideal center for detecting such magma interactions due to its rich history of volcanic activity and unusual eruption style. It is a subduction-driven, basaltic cinder cone that erupts on average once every 20 years with light to moderate intensity explosive eruptions (Volcanic Explosivity Index: 1-3) commonly accompanied by lava flows. Amid these eruptions are periods of extreme quiescence with very little seismic activity and gas emissions, suggesting rapid magmatic changes beneath the volcano. The brief lag time (on average 30 min). separating precursors and eruption supports this interpretation. In this study, we compare the isotopic composition of gas samples collected from fumaroles, fractures and other thermal areas on the volcano over a period of nearly 2 decades (1992-2011) in order to constrain the magmatic evolution beneath Cerro Negro. While the general systematics of the entire dataset are broadly consistent with degassing models for the natural evolution of CO2 and δ13C values, recent sampling campaigns suggest that new magma may be entering the system. Gases collected in January 2011 after 12 years of quiescence reveal CO2 concentrations ranging from 1-100%, with δ13C values varying from -1.5% to -10.4% with a mean of -3.3±0.28 % for 32 samples. Only limited spatial variability is present in this dataset: inner crater mean δ13C = -4.0±0.12 %, outer crater (-2.4±0.46 %), flanks (-4.4±0.26 %), and thermal areas to the N (-3.5±0.24 %) and SE (-2.5±0.25 %). Based on previous work, a lack of substantial spatial variation in δ values is

  16. Hydrothermal alteration of sediments associated with surface emissions from the Cerro Prieto geothermal field, Baja, California, Mexico

    SciTech Connect

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

    1981-01-01

    Surface emissions from the Cerro Prieto geothermal reservoir are restricted to a 100 km/sup 2/ area on the western side of the field, near the volcano Cerro Prieto and the lake Laguna Vulcano. Some 57 surface emissions, explored in 1979, were classified into hot springs, mud pots, pools, fumaroles and geysers (Valette and Esquer-Patino, 1979). 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/sup 0/C: increase of quartz, feldspar and illite, with subsequent disappearance of kaolinite, montmorillonite, calcite and dolomite. These mineral assemblages seem to be characteristics of the discharge from high intensity geothermal fields.

  17. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Detailed separation and analysis of sulfur compounds

    SciTech Connect

    Vogh, J.W.; Reynolds, J.W.

    1988-10-01

    Neutral fractions of Cerro Negro crude oil have been analyzed for sulfur compound composition by several separation and identification methods. Sulfides were isolated by such procedures as adsorption and ligand exchange liquid chromatography and by sulfone derivative formation. New techniques in adsorption and ligand exchange chromatography were developed for Cerro Negro sulfide isolation, and these samples were analyzed by mass spectroscopy. The Cerro Negro 200--425/degree/C sulfide fraction contained alkyl sulfides and alkyl- or alkylaromatic disulfides as the most prominent components. The 425--550/degree/C fraction was more complex with many aromatic sulfide and disulfide compounds. Thiophenes were found to be abundant and complex in the neutral fractions. Conventional liquid chromatographic methods do not resolve thiophenes from aromatic hydrocarbons, and only newly developed ligand exchange chromatography procedures were found to produce useful thiophene concentrates. The fractions obtained were analyzed by mass spectroscopy and sulfur-sensitive gas chromatography. Thiophenes were found to span a range of molecular weight and ring number somewhat similar to the aromatic hydrocarbons. 36 refs., 8 figs., 17 tabs.

  18. Interannual correlations between sea surface temperature and concentration of chlorophyll pigment off Punta Eugenia, Baja California during different remote forcing conditions

    NASA Astrophysics Data System (ADS)

    Herrera-Cervantes, H.; Lluch-Cota, S. E.; Lluch-Cota, D. B.; Gutiérrez-de-Velasco, G.

    2013-05-01

    Interannual correlation between satellite-derived sea surface temperature (SST) and surface chlorophyll a (Chl a) are examined in the coastal upwelling zone off Punta Eugenia on the west coast of the Baja California Peninsula, area identified as intense biological productivity and oceanographic transition between mid-latitude and tropical ocean conditions. We used empirical orthogonal functions (EOF) analysis separately and jointly on the two fields from 1997 through 2007, a time period dominated by different remote forcing; ENSO conditions (weak, moderate and strong) and the largest intrusion of subarctic water reported in the last 50 yr. Coastal Upwelling Index anomalies (CUI) and the Multivariate ENSO Index (MEI) were used to identify the influence of local (wind stress) and remote (ENSO) forcing over the interannual variability of both variables. The individual EOF1 analysis showed the greater variability of SST and Chla offshore, their corresponding amplitude time series presented the highest peaks during the intrusion of subartic water (2002-2004) and were significantly correlated with the MEI (RSST ≈ 0.68, RChl a ≈ -0.30, P < 0.001) and moderately correlated with the CUI (RSST ≈ -0.4, RChl a ≈ 0.25, P < 0.001), showing similar trends. The joint EOF1 and the SST-Chl a correlations pattern show the area where both variables covary tightly; a band near to the coast with the largest correlations (R > |0.4|) mainly regulated by ENSO cycles. This was revealed when we calculate the homogeneous correlations for the periods El Niño-La Niña and the intrusion of subartic water. Both, SST and Chl a showed higher coupling and two distinct physical-biological responses; on average ENSO influence were clearly along the coast mostly in SST while the subarctic water influence, were observed offshore mostly in Chl a. We found a coastal chlorophyll bloom correlated strongly with high wind stress anomalies that reach the coast off Punta Eugenia during spring and

  19. Interannual correlations between sea surface temperature and concentration of chlorophyll pigment off Punta Eugenia, Baja California, during different remote forcing conditions

    NASA Astrophysics Data System (ADS)

    Herrera-Cervantes, H.; Lluch-Cota, S. E.; Lluch-Cota, D. B.; Gutiérrez-de-Velasco, G.

    2014-05-01

    Interannual correlation between satellite-derived sea surface temperature (SST) and surface chlorophyll a (Chl a) are examined in the coastal upwelling zone off Punta Eugenia on the west coast of the Baja California Peninsula, an area than has been identified as having intense biological productivity and oceanographic transition between midlatitude and tropical ocean conditions. We used empirical orthogonal functions (EOF) analysis separately and jointly on the two fields from 1997 through 2007, a time period dominated by different remote forcing: ENSO (El Niño-Southern Oscillation) conditions (weak, moderate and strong) and the largest intrusion of subarctic water reported in the last 50 years. Coastal upwelling index anomalies (CUI) and the multivariate ENSO index (MEI) were used to identify the influence of local (wind stress) and remote (ENSO) forcing over the interannual variability of both variables. The spatial pattern of the individual EOF1 analysis showed the greater variability of SST and Chl a offshore, their corresponding amplitude time series presented the highest peaks during the strong 1997-2000 El Niño-La Niña cycles and during the 2002-2004 period associated to the intrusion of subarctic water. The MEI is well correlated with the individual SST principal component (R ≈ 0.67, P < 0.05) and poorly with the individual Chl a principal component (R = -0.13). The joint EOF1 and the SST-Chl a correlation patterns show the area where both variables covary tightly; a band near the coast where the largest correlations occurred (| R | > 0.4) mainly regulated by ENSO cycles. This was spatially revealed when we calculated the homogeneous correlations for the 1997-1999 El Niño-La Niña period and during the 2002-2004 period, the intrusion of subarctic water period. Both, SST and Chl a showed higher coupling and two distinct physical-biological responses: on average ENSO influence was observed clearly along the coast mostly in SST, while the subarctic water

  20. Cerro Negro, Nicaragua: A key Mars Analog Environment for Acid-Sulfate Weathering

    NASA Astrophysics Data System (ADS)

    Hynek, B. M.; Rogers, K. L.; McCollom, T. M.

    2008-12-01

    Sulfate-rich bedrock has been discovered in many locations on Mars and has been studied by both orbiting spacecraft and landers. It appears that in most cases these minerals are produced by acid-sulfate weathering of igneous rocks, which may have been a widespread process for the first billion years of Mars' history. The origin of life on Earth may have occurred in iron-sulfur hydrothermal settings and it is conceivable that early Mars had similar environmental conditions. An excellent terrestrial analog for acid- sulfate weathering of Mars-like basalts exists at Cerro Negro (CN), Nicaragua, where sulfur-bearing gases interact with recently erupted basaltic ash in numerous fumaroles. To date, we have made two expeditions to CN to assess the chemical, mineralogical, and biological conditions. At the fumaroles pH ranges from <1 to 5 and temperatures range from 40 to 400° C. Basalts with a chemical composition very similar to those on Mars are being chemically altered in the solfatara setting. In a few years, freshly erupted basalt can be converted into predominately Ca-, Mg-, and Fe-sulfates, Fe-hydroxides (including jarosite), clays, and free silica. Altered rocks have up to 30 wt% SO3 equivalent, which is similar to the Meridiani Planum bedrocks and inferred in other sulfate-bearing bedrock on Mars. Moreover, heavily weathered rocks have silica contents up to 80 wt%, similar to silica-rich soils at Gusev Crater that possibly formed in hydrothermal environments. Samples were collected for biological analysis including enrichment and isolation of novel thermophiles as well as molecular characterization of thermophile diversity. The low water and nutrient levels found in solfatara environments lead to less biomass when compared to hot springs with similar geochemical conditions. Nonetheless, microbes are thriving in these hot, acidic vent environments. At Cerro Negro solfatara, we are characterizing the metabolic and phylogenetic diversity of resident microbial

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

    NASA Astrophysics Data System (ADS)

    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

  2. The Cerro Tololo Inter-American Observatory Summer Student Programs in La Serena, Chile

    NASA Astrophysics Data System (ADS)

    Kaleida, Catherine C.; Smith, C.; Van Der Bliek, N. S.; James, D.

    2014-01-01

    The Cerro Tololo Inter-American Observatory (CTIO) offers positions for U.S. and Chilean student interns during the Chilean summer months of January-March (northern winter semester) at the CTIO offices in La Serena, Chile. CTIO is part of the National Optical Astronomy Observatory (NOAO) of the United States, focused on the development of astronomy in the southern hemisphere. Six undergraduate research assistantships are offered for U.S. physics and astronomy undergraduate students through the NSF-funded Research Experiences for Undergraduates (REU) program. The CTIO-funded Prácticas de Investigación en Astronomía (PIA) program is run concurrently with the REU program, and offers two research assistantships for Chilean undergraduate or 1st or 2nd year masters students, also at the CTIO offices in La Serena, Chile. The CTIO REU and PIA programs provide exceptional opportunities for students considering a career in astronomy to engage in substantive research activities with scientists working at the forefront of contemporary astrophysics. Student participants work on specific research projects in close collaboration with members of the CTIO scientific and technical staff, such as galaxy clusters, gravitational lensing, supernovae, planetary nebulae, stellar populations, star clusters, star formation, variable stars and interstellar medium. The CTIO REU and PIA programs emphasize observational techniques and provide opportunities for direct observational experience using CTIO's state-of-the-art telescopes and instrumentation. The programs run for 10 weeks, from mid-January to the end of March. A two-night observing run on Cerro Tololo and a field trip to another observatory in Chile are included for students of both programs. These positions are full time, and those selected will receive a modest stipend and subsidized housing on the grounds of the offices of CTIO in La Serena, as well as travel costs to and from La Serena. In addition, the students have the

  3. Photosynthesis within Mars' volcanic craters?: Insights from Cerro Negro Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    Rogers, K. L.; Hynek, B. M.; McCollom, T. M.

    2011-12-01

    Discrete locales of sulfate-rich bedrocks exist on Mars and in many cases represent the products of acid-sulfate alteration of martian basalt. In some places, the products have been attributed to hydrothermal processes from local volcanism. In order to evaluate the habitability of such an environment, we are investigating the geochemical and biological composition of active fumaroles at Cerro Negro Volcano, Nicaragua, where fresh basaltic cinders similar in composition to martian basalts are altered by acidic, sulfur-bearing gases. Temperatures at active fumaroles can reach as high as 400°C and the pH of the steam ranges from <0 to 5. Adjacent to some fumaroles, silica is being precipitated from condensing steam on the crater walls and endolithic photosynthetic mats are found at 1-2 cm depth within these silica deposits. We have analyzed one of these mats, Monkey Cheek (T=65°C, pH ~4.5), for both Archaeal and Bacterial diversity. Cloning of PCR-amplified 16S rRNA genes reveals a diverse community of Bacteria, with eight phyla represented. The most common bacterial sequences belonged to the Cyanobacteria and Ktedonobacteria, however Actinobacteria, alpha-Proteobacteria and Acidobacteria were also identified. Many of the cyanobacterial sequences were similar to those of the eukaryotic Cyanidiales, red algae that inhabit acidic, geothermal environments. Many of sequences related to Ktedonobacteria and Actinobacteria have also been found in acid mine drainage environments. The Archaeal community was far less diverse, with sequences matching those of unclassified Desulfurococcales and unclassified Thermoprotei. These sequences were more distant from isolated species than the bacterial sequences. Similar bacterial and archaeal communities have been found in hot spring environments in Yellowstone National Park, Greenland, Iceland, New Zealand and Costa Rica. Some of Mars' volcanoes were active for billions of years and by analogy to Cerro Negro, may have hosted

  4. The age and thermal history of Cerro Rico de Potosi, Bolivia

    USGS Publications Warehouse

    Cunningham, C.G.; Zartman, R.E.; McKee, E.H.; Rye, R.O.; Naeser, C.W.; Sanjines, V.O.; Ericksen, G.E.; Tavera, V.F.

    1996-01-01

    Cerro Rico de Potosi, Bolivia, is the world's largest silver deposit and has been mined since the sixteenth century for silver, and for tin and zinc during the twentieth century, together with by-product copper and lead. The deposit consists primarily of veins that cut an altered igneous body that we interpret to be a dacitic volcanic dome and its underlying tuff ring and explosion breccia. The deposit is compositionally and thermally zoned, having a core of cassiterite, wolframite, bismuthinite, and arsenopyrite surrounded by a peripheral, lower-temperature mineral assemblage consisting principally of sphalerite, galena, lead sulfosalt, and silver minerals. The low-temperature assemblage also was superim-posed on the high-temperature assemblage in response to cooling of the main hydrothermal system. Both the dacite dome and the ore fluids were derived from a larger magmatic hydrothermal source at depth. The dome was repeatedly fractured by recurrent movement on the fault system that guided its initial emplacement. The dome was extruded at 13.8 ?? 0.2 Ma (2??), based on U-Th-Pb dating of zircon. Mineralization and alteration occurred within about 0.3 my of dome emplacement, as indicated by a 40Ar/39Ar date of 13.76 ?? 0.10 Ma (1??) for sericite from the pervasive quartz-sericite-pyrite alteration associated with the main-stage, high-temperature, mineralization. The last thermal event able to reset zircon fission tracks occurred no later than 12.5 ?? 1.1 Ma (1??). as indicated by fission-tract dating. Minor sericite. and magmatic-steam alunite veins, were episodically formed around 11 Ma and between 8.3 and 5.7 Ma; the younger episodes occurring at the time of extensional fracturing at Cerro Rico and widespread volcanism in the adjacent Los Frailes volcanic field. None of these younger events appear to be signific-ant thermal/mineralizing events: the exceptionally flat thermal release pattern of 39Ar from sericite and the results of the fission-tract dating of

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

    PubMed Central

    Gonzales, Gustavo F; Salirrosas, Amelia

    2005-01-01

    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 < 0.01). At 1 minute of life, pulse oxygen saturation was 15% lower at high altitude than at sea level. Apgar score at 1 minute was significantly lower at high altitude (P < 0.05). Neurological score at 24 hours was also lower at high altitude than at sea level. Head circumference, and Apgar score at 5 minutes were similar at sea level and at high altitude (P:NS). Incidence of low birth-weight (<2500 g) at high altitude (5.4%) was similar to that observed at sea level (2.29%) (P:NS). Incidences of low pulse oxygen saturation (<30%), low Apgar score at first minute (<7) and low neurological score at 24 h (<19) were significantly higher at high altitude than at sea level (P < 0.0001; P

  6. Chemical and biological evaluation of essential oils from two species of Myrtaceae - Eugenia uniflora L. and Plinia trunciflora (O. Berg) Kausel.

    PubMed

    Lago, João Henrique G; Souza, Elisângela Dutra; Mariane, Bruna; Pascon, Renata; Vallim, Marcelo A; Martins, Roberto Carlos C; Baroli, Adriana A; Carvalho, Bianca A; Soares, Marisi G; dos Santos, Roberta T; Sartorelli, Patricia

    2011-11-25

    The chemical composition and antimicrobial activity of essential oils obtained from leaves of two Myrtaceae species-Eugenia uniflora L. and Plinia trunciflora (O. Berg) Kausel-were determined. Analysis by GC/MS as well as determination of Kovatz indexes indicated atractylone (26.78%) and curzerene (17.96%) as major constituents of E. uniflora oil and α-cadinol (19.15%), apiole (11.15%) and cubenol (5.43%) as main components in P. trunciflora oil. Both essential oils were tested for antimicrobial activity against yeasts and bacteria. E. uniflora and P. trunciflora essential oils were active towards two Gram-positive bacteria, Streptococcus equi and Staphylococcus epidermis. In addition, biological activity of both essential oils was detected for pathogenic yeasts of the genus Candida and Cryptococcus. E. uniflora was active towards all yeast tested and exhibited interesting minimal inhibitory concentrations (0.11 to 3.75 mg/mL) across a broad spectrum of activity.

  7. Eugenol isolated from the essential oil of Eugenia caryophyllata induces a reactive oxygen species-mediated apoptosis in HL-60 human promyelocytic leukemia cells.

    PubMed

    Yoo, Chae-Bin; Han, Ki-Tae; Cho, Kyu-Seok; Ha, Joohun; Park, Hee-Juhn; Nam, Jung-Hwan; Kil, Uk-Hyun; Lee, Kyung-Tae

    2005-07-08

    Eugenol is a major component of essential oil isolated from the Eugenia caryophyllata (Myrtaceae), which has been widely used as a herbal drug. In this study, we investigated the effects of eugenol on the cytotoxicity, induction of apoptosis, and the putative pathways of its actions in human promyelocytic leukemia cells (HL-60) under the standard laboratory illumination. Eugenol-treated HL-60 cells displayed features of apoptosis including DNA fragmentation and formation of DNA ladders in agarose gel electrophoresis. We observed that eugenol transduced the apoptotic signal via ROS generation, thereby inducing mitochondrial permeability transition (MPT), reducing anti-apoptotic protein bcl-2 level, inducing cytochrome c release to the cytosol, and subsequent apoptotic cell death. Taken together, the present study demonstrated that ROS plays a critical role in eugenol-induced apoptosis in HL-60, and this is the first report on the mechanism of the anticancer effect of eugenol.

  8. Studies of Malagasy Eugenia - IV: Seventeen new endemic species, a new combination, and three lectotypifications; with comments on distribution, ecological and evolutionary patterns.

    PubMed

    Snow, Neil; Callmander, Martin; Phillipson, Peter B

    2015-01-01

    Seventeen new endemic species of the genus Eugenia L. (Myrtaceae) are proposed from Madagascar, including: Eugeniaandapae N. Snow, Eugeniabarriei N. Snow, Eugeniabemangidiensis N. Snow, Eugeniacalciscopulorum N. Snow, Eugeniadelicatissima N. Snow, Callm. & Phillipson, Eugeniaechinulata N. Snow, Eugeniagandhii N. Snow, Eugeniahazonjia N. Snow, Eugeniaiantarensis N. Snow, Eugeniamalcomberi N. Snow, Eugeniamanomboensis N. Snow, Eugeniaobovatifolia N. Snow, Eugeniaranomafana N. Snow & D. Turk, Eugeniaravelonarivoi N. Snow & Callm., Eugeniarazakamalalae N. Snow & Callm., Eugeniatiampoka N. Snow & Callm., and Eugeniawilsoniana N. Snow, and one new combination, Eugeniarichardii (Blume) N. Snow, Callm. & Phillipson is provided. Detailed descriptions, information on distribution and ecology, distribution maps, vernacular names (where known), digital images of types, comparisons to morphologically similar species. Preliminary assessment of IUCN risk of extinction and conservation recommendations are provided, including Vulnerable (4 species), Endangered (2 species), and Critically Endangered (4 species). Lectotpyes are designated for Eugeniahovarum H. Perrier, Eugenianompa H. Perrier, and Eugeniascottii H. Perrier respectively.

  9. An atmospheric radiation model for the Very Large Telescope at Cerro Paranal in Chile

    NASA Astrophysics Data System (ADS)

    Noll, S.; Kausch, W.; Barden, M.; Jones, A. M.; Szyszka, C.; Kimeswenger, S.

    2012-04-01

    The quality of ground-based astronomical observations is strongly affected by scattering, absorption, and radiation processes in the Earth's atmosphere. For effective telescope time management, it is important to accurately estimate the wavelength-dependent contribution of the Earth's atmosphere to the observed flux. For this reason we developed an atmospheric radiation model for the Very Large Telescope of the European Southern Observatory at Cerro Paranal in the Atacama desert. It is comprised of all relevant components, i.e. scattered moonlight, scattered starlight, zodiacal light, molecular radiation and absorption in the lower atmosphere, and airglow line and continuum emission in the upper atmosphere. The model covers the entire wavelength range from the near-UV to the mid-IR. Thermal radiation and absorption in the lower atmosphere are computed applying the LBLRTM radiative transfer code and suitable time-averaged atmospheric profiles for the telescope site. Scattered light from extended sources, such as zodiacal light and airglow, is estimated by 3D single scattering calculations and a multiple scattering correction. The intensity and variability of airglow emission lines and continuum is derived by a semi-empirical model based on more than 1000 high signal-to-noise spectra of the FORS1 instrument taken over six years. A comparison of the resulting combined model with observed data yields an accuracy of about 20 per cent, which is a significant improvement over previous models.

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

    SciTech Connect

    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.

  11. TOMS and AVHRR observations of drifting volcanic clouds from the August 1991 eruptions of Cerro Hudson

    NASA Astrophysics Data System (ADS)

    Constantine, Emily K.; Bluth, Gregg J. S.; Rose, William I.

    Clouds of fine volcanic ash (1-15 μm) and sulfur dioxide gas from Cerro Hudson's three August 1991 eruptions were measured with the infrared advanced very high resolution radiometer (AVHRR) and the ultraviolet total ozone mapping spectrometer (TOMS). TOMS data show that the first eruption released 700 kT SO2 on August 8, a second eruption on August 12 produced about 600 kT, and the third on August 15 released about 2700 kT SO2. Following the third eruption, the SO2 and ash appear to have separated, with the ash residing at lower levels near the tropopause and losing 90% of its mass within a few days, while the SO2 was stratospheric, losing only two-thirds of its mass over the first week. A fragment of the volcanic cloud drifted across Australia on August 19-20 where it was characterized by both TOMS and AVHRR; because this cloud was a significant concern to aviation, it offers a successful test of long-term cloud detection by satellites.

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

    PubMed

    Tantaleán, Henry; Stanish, Charles; Rodríguez, Alexis; Pérez, Kelita

    2016-01-01

    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.

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

    PubMed Central

    2016-01-01

    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. PMID:27144824

  14. Durability of various cements in a well of the Cerro Prieto geothermal field

    SciTech Connect

    Krause, Ralph F., Jr.; Kukacka, Larry E.

    1982-10-08

    The durability of each of 16 different cements was evaluated by both room temperature compressive strength and water permeability measurements, following various periods of treatment of the cements in flowing geothermal fluid of the Cerro Prieto field of Mexico. Some of these cements were selected through a Department of Energy program to develop improved cements for geothermal well completion while the others were contributed by several other institutions interested in the tests. Two types of specimens of the cements were used in the tests: (a) 50 mm cubes which were precured 1 da in molds under water in an autoclave at 200 C and 20 MPa and (b) cement slurries which were prepared and cast in sandstone cups at the field. Federal de Electricidad a set of both types of specimens was installed in baskets which were placed 700 m downhole a well at 214 C, and an identical set of specimens was installed in special aboveground vessels near the wellhead. Following periods of 1 da. 3 mo, 6 mo. and 12 mo, specimens were withdrawn from the geothermal treatment and divided evenly between the Instituto de Investigaciones Electricas and the National Bureau of Standards for property measurements. This paper gives the downhole results by the latter laboratory. Final values will be published when the results of both laboratories are collated and reviewed.

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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.

  17. Far-IR Measurements at Cerro Toco, Chile: FIRST, REFIR, and AERI

    NASA Technical Reports Server (NTRS)

    Cageao, Richard P.; Alford, J. Ashley; Johnson, David G.; Kratz, David P.; Mlynczak, Martin G.

    2010-01-01

    In mid-2009, the Radiative Heating in the Underexplored Bands Campaign II (RHUBC-II) was conducted from Cerro Toco, Chile, a high, dry, remote mountain plateau, 23degS , 67.8degW at 5.4km, in the Atacama Desert of Northern Chile. From this site, dominant IR water vapor absorption bands and continuum, saturated when viewed from the surface at lower altitudes, or in less dry locales, were investigated in detail, elucidating IR absorption and emission in the atmosphere. Three FTIR instruments were at the site, the Far-Infrared Spectroscopy of the Troposphere (FIRST), the Radiation Explorer in the Far Infrared (REFIR), and the Atmospheric Emitted Radiance Interferometer (AERI). In a side-by-side comparison, these measured atmospheric downwelling radiation, with overlapping spectral coverage from 5 to100um (2000 to 100/cm), and instrument spectral resolutions from 0.5 to 0.64/cm, unapodized. In addition to the FTIR and other ground-based IR and microwave instrumentation, pressure/temperature/relative humidity measuring sondes, for atmospheric profiles to 18km, were launched from the site several times a day. The derived water vapor profiles, determined at times matching the FTIR measurement times, were used to model atmospheric radiative transfer. Comparison of instrument data, all at the same spectral resolution, and model calculations, are presented along with a technique for determining adjustments to line-by-line calculation continuum models. This was a major objective of the campaign.

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

    SciTech Connect

    Schoeberl, M.R.; Lait, L.R.; Newman, P.A.; Krueger, A.J. ); Doiron, S.D. )

    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.

  19. Cerro Negro bitumen degradation by a consortium of marine benthic microorganisms.

    PubMed

    Potter, T L; Duval, B

    2001-01-01

    Cerro Negro bitumen, separated from an Orimulsion sample, was incubated for up to 120 days with sediments collected at a petroleum-impacted site in Tampa Bay, Florida. Biodegradation conditions were optimized by increasing bitumen surface area, continuous agitation on a shaker apparatus, use of a complete growth medium, and maintenance at 37 degrees C. Aerobic degradation conditions were promoted by maintaining sediment contact with the laboratory atmosphere. Bitumen recovered in solvent extracts when compared to autoclaved controls decreased by up to 40% during the first 56 days. There was no detectable change after this. Molasses addition and use of a culture enriched from the sediments did not change the extent or rate of decrease in bitumen recovery. Chemical fractionation of bitumen control and degraded bitumen showed that aromatic and aliphatic fractions were depleted by approximately equals 50%. Accumulation of polars was observed; however, the apparent increase was relatively small when compared to the mass loss of the other fractions. Selected biomarker ratios were not affected by incubation indicating their utility for fingerprinting the source bitumen in environmental samples. PAH distribution in the aromatic fraction favored the higher alkyl-homologues with the relative degree of alkylation increasing as the mass of bitumen recovered decreased with degradation. The study showed that up to 40% of the bitumen was bioaccessible and that bioremediation may be a treatment option for sediments contaminated with bitumen by an Orimulsion spill.

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

    NASA Astrophysics Data System (ADS)

    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.

  1. Into the Cone: A Ground Penetrating Radar Investigation of Near Vent Processes at Cerro Negro Volcano

    NASA Astrophysics Data System (ADS)

    Courtland, L. M.; Kruse, S. E.; Connor, C.

    2009-12-01

    Cinder cones are often assumed to grow via Strombolian activity as described by McGetchin et al (1974). Data with which to evaluate this and other models has historically been collected via eyewitness accounts, photography of eruptions, and mapping of exposed deposits. However, the dangerous nature of eruptions often prohibits near vent observations and accessible deposits are rare. Therefore, in order to gain a better understanding of near vent processes which may be used in volcanic modeling and hazard assessment, new data collection techniques must be implemented. Ground penetrating radar (GPR) imaging of tephra can reveal details of deposits at depths of approximately 2-20+ meters. Data collected in the fall of 2007 is here used to investigate the near vent processes of Cerro Negro, an active basaltic cinder cone in Nicaragua. Each of three GPR profiles begins at the crater rim and continues down the cone to the tephra blanket. One transect follows the prevailing wind direction (SW) while the other two head off at angles to the first: one to the NW and one to the SSW. The data display evidence of cone steepening over time, patterns of ballistic and tephra dispersal, and faulting within the cone, among other features.

  2. A Climatology of Ripple Instabilities in the OH Airglow at Cerro Pachon, Chile

    NASA Astrophysics Data System (ADS)

    Gelinas, L. J.; Hecht, J. H.; Walterscheid, R. L.; Rudy, R. J.

    2015-12-01

    Airglow imaging provides a unique means by which to study many wave-related phenomena in the 80 to 100 km altitude regime. Observations reveal quasi-monochromatic disturbances associated with atmospheric gravity waves (AGWs) as well as small-scale instabilities often called ripples. Ripples are wavelike features that resemble AGWs in appearance, but have short horizontal wavelengths (<15 km) and short lifetimes (a few tens of minutes). The end product of the breakdown of ripples is turbulence, leading to increased eddy diffusion. Thus, ripple observations may help refine our understanding of the occurrence of turbulence in the upper Mesosphere and Lower Thermosphere. The Aerospace Corporation's Nightglow Imager (ANI) is located at the Andes Lidar Observatory near the crest of Cerro Pachon, Chile. ANI observes nighttime OH emission (near 1.6 microns) every 2 seconds over an approximate 73 degree field of view, which allows the study of AGW and ripple features over very short temporal and spatial scales. An automated wave detection algorithm is used to identify ripple and quasi monochromatic wave features in the ANI data. Ripples are characterized by their wavelength, orientation, drift speed and location in the image. Quasi-monochromatic waves are quantified by wavelength, wave period and propagation direction. We present a climatology of ripple instabilities at Chile, including comparisons to the background quasi-monochromatic wave field. Lidar and radar data are used to determine the background wind and temperatures, which allows comparisons between ripple observations and evanescent regions and potentially unstable regions identified by Richardson number.

  3. Simultaneous Observations of the Phase-Locked Two Day Wave at Adelaide and Cerro Pachon

    NASA Astrophysics Data System (ADS)

    Walterscheid, R. L.; Hecht, J. H.; Vincent, R. A.; Franke, S. J.; Taylor, M. J.; Pautet, P.; Zhao, Y.

    2013-12-01

    The phase locked two day wave (PL/TDW) during austral summer is the most dramatic large scale event of the upper mesosphere. The PL/TDW wave can achieve amplitudes exceeding 70 m/s and involve the entire southern hemisphere and much of the northern hemisphere. The winds accelerate over a period of about 1 week and are accompanied by a near disappearance of the diurnal tide and stabilization of the two-day wave period at close to 48 hours. We have examined meteor wind data from the Andes Lidar Observatory at Cerro Pachon, Chile (30S, 70.1W) and MF radar data from the University of Adelaide (34.7S, 138.6E) located at similar latitudes. We find a remarkable coincidence between the oscillations. When adjustments for the separation in longitude are made the oscillations are nearly in phase. The amplitude of the oscillation is significantly greater at Chili, where winds approach 100 m/s. The diurnal tide is greatly diminished at both locations. These observations support the explanation that the PL/TDW is a subharmonic parametric instability of the diurnal tide (Walterscheid and Vincent, JGR, 1996). We will also present analysis of airglow data for the two-day wave at both locations.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

    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.

  6. Curve Number and Peakflow Responses Following the Cerro Grande Fire on a Small Watershed.

    SciTech Connect

    Springer, E. P.; Hawkins, Richard H.

    2005-01-01

    The Curve Number (CN) method is routinely used to estimate runoff and peakflows following forest fires, but there has been essentially no literature on the estimated value and temporal variation of CNs following wildland fires. In May 2000, the Cerro Grande Fire burned the headwaters of the major watersheds that cross Los Alamos National Laboratory, and a stream gauging network presented an opportunity to assess CNs following the fire. Analysis of rainfall-runoff events indicated that the pre-fire watershed response was complacent or limited watershed area contributed to runoff. The post-fire response indicated that the complacent behavior continued so the watershed response was not dramatically changed. Peakflows did increase by 2 orders of magnitude following the fire, and this was hypothesized to be a function of increase in runoff volume and changes in watershed network allowing more efficient delivery of runoff. More observations and analyses following fires are needed to support definition of CNs for post-fire response and mitigation efforts.

  7. Predicting Channel Evolution and Sediment and Contaminant Transport Following the Cerro Grande Fire, New Mexico

    NASA Astrophysics Data System (ADS)

    Wilson, C. J.; Canfield, H. E.; Crowell, K. J.; Lane, L. J.

    2003-12-01

    The May 2000 Cerro Grande Fire severely burned the headwaters of many of the canyon streams draining through the Los Alamos National Laboratory (LANL), Los Alamos County and Pueblos in Northern New Mexico. The fire increased observed flood magnitudes and hillslope erosion rates by one to two orders of magnitude above pre-fire conditions. A set of modeling activities was undertaken to predict the potential impacts of post-fire floods on channel and floodplain evolution, and sediment and contaminant transport in the steep streams draining the burn area. A contaminant transport model, Reach6, was developed and coupled to the HEC6T sediment transport model to predict redistribution and offsite transport of contaminated channel and floodplain sediments. Model predictions were tested against observed flood data. In particular, the HEC6T predictions were tested against high-resolution Airborne Laser Swath Mapping (ALSM) topographic data, collected before and after a 1440 cfs flash flood in a canyon contaminated with low levels of legacy Pu. The ALSM data showed the spatial distribution of channel and floodplain scour and deposition throughout the canyon. These data formed the backbone of our model testing process, along with observed sediment and Pu concentration data. Good correlation was found between predicted and observed data for the 1440cfs event, and led to application of the HEC6T model in assessing the effectiveness of remediation and stabilization strategies for Pueblo Canyon. LANL LA-UR-03-6382.

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

    SciTech Connect

    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.

  9. Cerro Prieto Contents of the Technical Information Files Generated at the Field

    SciTech Connect

    Olmos, Miguel Angel Ayuso

    1987-01-20

    The creation of a computer data bank for the Cerro Prieto Geothermal Field, resulted from the need for fast and flexible management of the increasing and voluminous information generated from the large number of wells drilled in recent years. The data are needed for updating the thermodynamic evolution of the field in order to define field history and validate mathematical analyses applications. This data bank compiles 20 files with all technical information issued from the time of initial field exploration to the end of 1986. To use the data bank, a series of programs and subroutines were created simultaneously for data base management to allow access and add new data as well as data analysis and data graphics. Tables of global statistics of the informations contained in the 20 files are shown in the paper, as an example of one application of the general use of the data base. For particular and specific applications, depending on users’ needs for the data. 3 tabs., 1 fig.

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

    NASA Astrophysics Data System (ADS)

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

    1999-12-01

    Each year, Cerro Tololo Inter-American Observatory (CTIO) 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. 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 16 REU students (with 4 more coming in 2000). Thirteen (and counting) publications have resulted from CTIO REU projects; all 4 REU students in the 1999 program attended the 194th AAS meeting to present posters based on their projects. We present here an overview of the REU program at CTIO.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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. 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.

    NASA Astrophysics Data System (ADS)

    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.

  15. Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: potential use in environmental risk assessment.

    PubMed

    Neves, Natália Rust; Oliva, Marco Antonio; da Cruz Centeno, Danilo; Costa, Alan Carlos; Ribas, Rogério Ferreira; Pereira, Eduardo Gusmão

    2009-06-01

    The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM(Fe)) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM(Fe) application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

  16. Pitanga (Eugenia uniflora L.) fruit juice and two major constituents thereof exhibit anti-inflammatory properties in human gingival and oral gum epithelial cells.

    PubMed

    Josino Soares, Denise; Walker, Jessica; Pignitter, Marc; Walker, Joel Michael; Imboeck, Julia Maria; Ehrnhoefer-Ressler, Miriam Margit; Montenegro Brasil, Isabella; Somoza, Veronika

    2014-11-01

    Pitanga, Eugenia uniflora L., is a tropical fruit, which may be consumed as juice. While beneficial health effects of Eugenia uniflora L. leaf extracts have extensively been studied, limited data are available on an anti-inflammatory potential of pitanga juice. The aim of the presented study was to investigate anti-inflammatory properties of pitanga juice with regards to a prevention of inflammation-related periodontal diseases. For this purpose, six healthy volunteers swirled pitanga juice, containing 35% pitanga pulp, for 10 min. Thereafter, oral gum epithelial cells were harvested using a sterile brush and stimulated with lipopolysaccharides from Porphyromonas gingivalis (PG-LPS) for 6 h. Furthermore, human gingival fibroblasts (HGF-1) were used to elucidate the anti-inflammatory potential of pitanga juice constituents, cyanidin-3-glucoside and oxidoselina-1,3,7(11)-trien-8-one, in juice representative concentrations of 119 μg ml(-1) and 30 μg ml(-1), respectively. For the first time, an anti-inflammatory impact of pitanga juice on gingival epithelial cells was shown by means of an attenuation of IL-8 release by 55 ± 8.2% and 52 ± 11% in non-stimulated and PG-LPS-stimulated cells, respectively. In addition, both cyanidin-3-glucoside and oxidoselina-1,3,7(11)-trien-8-one reduced the LPS-stimulated CXCL8 mRNA expression by 50 ± 15% and 37 ± 18% and IL-8 release by 52 ± 9.9% and 45 ± 3.7% in HGF-1 cells, when concomitantly incubated with 10 μg ml(-1)PG-LPS for 6 h, revealing an anti-inflammatory potential of the volatile compound oxidoselina-1,3,7(11)-trien-8-one for the first time.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Public health surveillance after a volcanic eruption: lessons from Cerro Negro, Nicaragua, 1992.

    PubMed

    Malilay, J; Real, M G; Ramirez Vanegas, A; Noji, E; Sinks, T

    1996-09-01

    The eruption of the Cerro Negro volcano near León, Nicaragua, on 9 April 1992 distributed an estimated 1.7 million tons of ash over a 200 square kilometer area. An assessment was conducted to evaluate the health effects on approximately 300,000 residents, using routine data obtained by the national epidemiologic surveillance system. It was found that rates of visits to health care facilities for acute diarrheal and respiratory illnesses increased in two study communities, one within and one near the disaster zone. Specifically, visits for acute diarrhea were nearly 6 times more numerous than before the eruption in both communities, while visits for acute respiratory diseases were 3.6 times more frequent in Malpaisillo (the community near the disaster zone) and 6.0 times more frequent in Telica (the community within it). Most of the visits were for infants and children less than 5 years old. Increased diarrheal disease morbidity, which commonly occurs after volcanic eruptions, demands detailed investigation of the type and quality of water supplies following heavy ashfall. Ash-related respiratory problems should be further examined to determine the spectrum of such diseases and the timing of illness onsets among infants and other special population subgroups. Data collected on health conditions before and after an eruption by passive surveillance can be used to detect eruption-related morbidity. Systems already in place, such as Nicaragua's national epidemiologic surveillance system, can be modified or extended so as to increase their sensitivity to new cases and hence their ability to provide appropriate notification to medical relief agencies.

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

    NASA Astrophysics Data System (ADS)

    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, RMS<0.75 s, Gap < 180° 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 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.

  1. Downwelling Far-Infrared Radiance Spectra Measured by FIRST at Cerro Toco, Chile

    NASA Astrophysics Data System (ADS)

    Mast, J. C.; Mlynczak, M. G.; Cageao, R.; Kratz, D. P.; Latvakoski, H.; Johnson, D. G.; Mlawer, E. J.; Turner, D. D.

    2015-12-01

    The Far-Infrared Spectroscopy of the Troposphere (FIRST) instrument is a Fourier transform spectrometer developed by NASA Langley Research Center in collaboration with the Space Dynamics Laboratory and the Harvard-Smithsonian Center for Astrophysics. FIRST was initially developed for measuring the far-infrared portion of Earth's longwave spectrum as a balloon borne instrument and later was reconfigured to operate as a ground-based instrument. In its current ground-based configuration FIRST was deployed at 17500 ft on Cerro Toco, a mountain in the Atacama Desert of Chile, from August to October, 2009. There the integrated precipitable water (IPW) was as low as 0.02 cm. FIRST measurements from days with IPW between 0.024 and 0.035 cm during the campaign are presented here between 200 cm-1 and 800 cm-1. Significant spectral development in the far-IR is observed over the entire 200 cm-1 to 800 cm-1 band. Water vapor and temperature profiles from radiosonde and GVRP measurements are used as inputs to the AER Line-by-Line Radiative Transfer Model (LBLRTM) utilizing the AER v3.2 line parameter database. Uncertainties in both the measured and modeled radiances are accounted for in this study. The residual LBLRTM - FIRST is calculated to assess agreement between the measured and modeled spectra. Measured and model radiances generally agree to within the combined uncertainties for wavenumbers greater than 360 cm-1. At wavenumbers less than 360 cm-1 persistent troughs in the residual are present outside of the combined uncertainties. These features are present on different days and at different water vapor amounts. Possible solutions for these features are discussed.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    USGS Publications Warehouse

    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. Volcano-ice-sea interaction in the Cerro Santa Marta area, northwest James Ross Island, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Calabozo, Fernando M.; Strelin, Jorge A.; Orihashi, Yuji; Sumino, Hirochika; Keller, Randall A.

    2015-05-01

    We present here the results of detailed mapping, lithofacies analysis and stratigraphy of the Neogene James Ross Island Volcanic Group (Antarctic Peninsula) in the Cerro Santa Marta area (northwest of James Ross Island), in order to give constraints on the evolution of a glaciated volcanic island. Our field results included recognition and interpretation of seventeen volcanic and glacial lithofacies, together with their vertical and lateral arrangements, supported by four new unspiked K-Ar ages. This allowed us to conclude that the construction of the volcanic pile in this area took place during two main eruptive stages (Eruptive Stages 1 and 2), separated from the Cretaceous bedrock and from each other by two major glacial unconformities (U1 and U2). The U1 unconformity is related to Antarctic Peninsula Ice sheet expansion during the late Miocene (before 6.2 Ma) and deposition of glacial lithofacies in a glaciomarine setting. Following this glacial advance, Eruptive Stage 1 (6.2-4.6 Ma) volcanism started with subaerial extrusion of lava flows from an unrecognized vent north of the study area, with eruptions later fed from vent/s centered at Cerro Santa Marta volcano, where cinder cone deposits and a volcanic conduit/lava lake are preserved. These lava flows fed an extensive (> 7 km long) hyaloclastite delta system that was probably emplaced in a shallow marine environment. A second unconformity (U2) was related to expansion of a local ice cap, centered on James Ross Island, which truncated all the eruptive units of Eruptive Stage 1. Concomitant with glacier advance, renewed volcanic activity (Eruptive Stage 2) started after 4.6 Ma and volcanic products were fed again by Cerro Santa Marta vents. We infer that glaciovolcanic eruptions occurred under a moderately thin (~ 300 m) glacier, in good agreement with previous estimates of paleo-ice thickness for the James Ross Island area during the Pliocene.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Movement of geothermal fluid in the Cerro Prieto field as determined from well log and reservoir engineering data

    SciTech Connect

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

    1982-01-01

    A hydrogeologic model of the Cerro Prieto geothermal field in its undisturbed state, developed on the basis of well log and reservoir engineering data, is discussed. According to this model, geothermal fluid enters the field from the east through a deep (>10,000 ft) sandstone aquifer which is overlain by a thick shale unit which locally prevents the upward migration of the fluid. As it flows westward, the fluid gradually rises through faults and sandy gaps in the shale unit. Eventually, some of the fluid leaks to the surface in the western part of the field, while the rest mixes with surrounding colder waters.

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

    SciTech Connect

    Grant, M.A.; 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.

  9. Some aspects of the response of geothermal reservoirs to brine reinjection with application to the Cerro Prieto Field

    SciTech Connect

    Tsang, C.F.; Bodvarsson, G.S.; Lippmann, M.J.; Rivera, J.R.

    1980-01-01

    In this paper, preliminary results of two reinjection studies will be described: (1) Initial investigation of several possible reinjection patterns for the Cerro Prieto geothermal field have been made based on a method developed by Gringarten and Sauty (1975). The resulting data show what may be expected from different reinjection schemes and may provide useful guidelines for the eventual choice of an optimal well arrangement. A numerical model was used to study the injection pressure expected when colder water is injected into a hot reservoir. 3 refs.

  10. Diverse subaerial and sublacustrine hot spring settings of the Cerro Negro epithermal system (Jurassic, Deseado Massif), Patagonia, Argentina

    NASA Astrophysics Data System (ADS)

    Guido, Diego M.; Campbell, Kathleen A.

    2012-06-01

    The Late Jurassic (~ 150 Ma) Cerro Negro volcanic-epithermal-geothermal system (~ 15 km2 area), Deseado Massif, Patagonia, Argentina, includes two inferred volcanic emission centers characterized by rhyolitic domes linked along NW-SE regional faults that are associated with deeper level Au/Ag mineralization to the NW, and with shallow epithermal quartz veins and mainly travertine surface hot spring manifestations to the SE. Some travertines are silica-replaced, and siliceous and mixed silica-carbonate geothermal deposits also are found. Five hot spring-related facies associations were mapped in detail, which show morphological and textural similarities to Pleistocene-Recent geothermal deposits at Yellowstone National Park (U.S.A.), the Kenya Rift Valley, and elsewhere. They are interpreted to represent subaerial travertine fissure ridge/mound deposits (low-flow spring discharge) and apron terraces (high-flow spring discharge), as well as mixed silica-carbonate lake margin and shallow lake terrace vent-conduit tubes, stromatolitic mounds, and volcano-shaped cones. The nearly 200 mapped fossil vent-associated deposits at Cerro Negro are on a geographical and numerical scale comparable with subaerial and sublacustrine hydrothermal vents at Mammoth Hot Springs, and affiliated with Yellowstone Lake, respectively. Overall, the Cerro Negro geothermal system yields paleoenvironmentally significant textural details of variable quality, owing to both the differential preservation potential of particular subaerial versus subaqueous facies, as well as to the timing and extent of carbonate diagenesis and silica replacement of some deposits. For example, the western fault associated with the Eureka epithermal quartz vein facilitated early silicification of the travertine deposits in the SE volcanic emission center, thereby preserving high-quality, microbial macro- and micro-textures of this silica-replaced "pseudosinter." Cerro Negro provides an opportunity to reconstruct

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

    NASA Astrophysics Data System (ADS)

    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

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

    USGS Publications Warehouse

    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. 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

    NASA Astrophysics Data System (ADS)

    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.

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

    USGS Publications Warehouse

    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.

  15. Barrier-bar system in Cerro Negro, orinoco Petroliferous belt, Venezuela, and its implication in oil exploration and exploitation

    SciTech Connect

    Rodriguez, A.

    1985-02-01

    Barrier bars are important stratigraphic traps for oil and/or gas because of deposition in relatively shallow and often agitated waters, which allow barriers to develop excellent primary porosity and high permeability. Barrier bars can be developed as component facies of other depositional systems such as deltas or as independent interdeltaic systems associated with a major delta. In each case, different facies relationships such as distributary channel, mouth-bar, distal-bar, and prodelta facies would be present in a deltaic setting. Barrier bars, lagoons, washover-fans, and nonmarine facies could occur in an independent interdeltaic system. Different sand geometry patterns and reservoir characteristics are found in each system. In the Cerro Negro area, the sedimentary parameters are composite sand bodies, Ophiomorpha-type burrows, bioturbation structures, shell fragments, and an interfingering of brackish and shallow-marine fauna. Seven continuously cored wells and more than 100 geophysical well logs were used to determine lithofacies associations and to construct computer-drawn maps. These data were used to propose and support an independent interdeltaic barrier-bar system as the depositional model for the Cerro Negro area. Barriers were found to be mainly parallel to a paleoshoreline, and to have porosity values greater than 20% and permeability values greater than 500 md. It is interesting to note that different rates of heavy oil production can be related to the facies present.

  16. Spontaneous Potential Anomalies on Active Volcanoes: New Time and Spatial Series from Masaya, Telica, and Cerro Negro, Nicaragua

    NASA Astrophysics Data System (ADS)

    Lehto, H.; Pearson, S.; Connor, C.; Sanford, W.; Saballos, A.

    2006-12-01

    Considerable effort worldwide has gone into monitoring heat and mass transfer at active volcanoes because such information may provide clues about changes in volcanic activity and impending eruptions. Here we present new time and spatial series of spontaneous potential (SP) anomalies from Masaya and Telica volcanoes, and spatial series collected at Cerro Negro volcano. Our primary purpose is to investigate correlations between more easily and cheaply monitored SP and CO2 gas flux, measured by an infrared CO2 analysis system. SP data were collected using nonpolarizing Pb-PbCL2 electrodes that we constructed following the approach of Petiau. Mapping at both Masaya, and Cerro Negro reveals broad correlations between SP anomalies and CO2 flux through soils. In addition, we monitored temperature, barometric pressure, and rainfall at one minute intervals from May-August, 2006 at Masaya and Telica volcanoes. During this period it is clear that SP responds to changes in volcanic activity, with transient anomalies of 75 mV as well as atmospheric forcing due to rainfall, producing anomalies of 56 mV and related phenomena. Preliminary lab experiments provide further details of the electrokinetic origin of these SP anomalies. Our preliminary work supports the idea that large and inexpensive networks of electrodes might track changes in SP anomalies associated with changes in mass flow at active volcanoes.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Analysis and simulatin of rock avalanche sequence in the Cerro Caquilluco landslide (Tacna, Peru)

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni B.; Frattini, Paolo; Valbuzzi, Elena; Hermanns, Reginald L.

    2014-05-01

    The Cerro Caquilluco (Tacna, Peru) rock avalanche complex has a total volume of about 15 km3 and a length of 43 km, extending from 3900 m a.s.l to 530 m a.s.l.. Based on geomorphological interpretation and lithological evidences, we reconstructed a possible rock-avalanches sequence consisting of at least nine major events. For each event, we calculated the mobilized volumes through the comparison of pre- and post-failure morphology. We argue that the first rock avalanche event corresponds to the Cerrillos Negros rock avalanche, characterized by a distal tongue shaped lobe, 11 km long, 3 km wide and 25 to 60 m thick (rough volume estimate 1.15 km3), deposited along the piedmont surface (average slope: 2° ). The reconstruction of pristine pre-failure morphology was accomplished by mimicking the preserved morphology close to the source area, and by removing the deposited volumes from the rock avalanche path. For this, we made the hypothesis that the old paleosurface was already eroded by valleys progressively moving upstream during a wetter climate, as suggested by Hoke et al (2007) for similar conditions in northern Chile. The reconstruction of the pre-event morphology required several attempts to fit the eroded and the deposited volumes. Finally, a total mobilized volume of about 10.2 km2 was obtained for this event. For the successive scenarios of slide retrogression, we used the morphologies obtained by previous scenarios as pre-failure morphologies, and we calculated, by difference with current topography, the lobe volumes. The volumes of single rock avalanche episodes decrease from the first to the last event, roughly following a power-law decay. This behavior is comparable to that described by Utili and Crosta (2011) for retrogressive instabilities in rocky cliffs. The rock-avalanche events have been simulated, to verify the different scenarios in terms of spreading area and maximum runout, by using SPH (Smooth Particle Hydrodynamics) and Finite Element codes

  19. Geochemical study of products associated with spontaneous oxidation of coal in the Cerro Pelado Formation, Venezuela

    NASA Astrophysics Data System (ADS)

    Martínez, M.; Márquez, G.; Alejandre, F. J.; Del Río, J. J.; Hurtado, A.

    2009-02-01

    The aim of this research work is a geochemical, mineralogical, and textural characterization of spontaneously smouldered coal-derived products in northwestern Venezuela (Cerro Pelado Formation, some 10 km from Pedregal city). Several solid samples were collected from this formation, six of unweathering coal, an other six of resulting unmelted rocks forming on a surface coal bed, and the last four of mineralizations found accumulating around gas vents. The fresh coal and the unmelted material were analysed by scanning electron microscopy, X-ray diffraction, and proximate techniques. Products such as magnetite and chabazite-K were identified in the alteration rocks. Likewise, both materials were also studied in order to determine the mobilization of 17 elements into the environment; such elements were analysed through inductively coupled plasma atomic emission spectroscopy on extracts obtained by a sequential extraction method: each sample was firstly extracted with MilliQ water and then the resultant residue was washed. This and the subsequently resulting residues are extracted according to the mentioned procedure by using, respectively, ammonium acetate, chlorhydric acid, peroxide and chlorhydric acid, nitric acid and fluorhydric acid, and nitric acid. The studied elements are classified as highly mobile (Na, Ni, ...), nearly immobile (Ti, P) and partially mobile (Mg, Fe, K, ...). In regards to mineralizations around fumaroles associated with smoldering coal seams, Fourier-transform infrared spectroscopy and X-ray diffraction analyses have revealed the presence of salammoniac, mascagnite and other solid combustion compounds formed by reaction of gas emitted from coal oxidation, in addition to previously non-reported sulfur-rich by-products associated with gas fissures, particularly ammonium thiosulfate, a phase first obtained only synthetically in the laboratory. Another objective of the research was to collect and analyse gases escaping from surficial vents

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

    USGS Publications Warehouse

    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 <2 mm fraction than the materials collected from storms that produced comparable sediment-runoff concentrations but not 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

  1. Storm Water Quality in Los Alamos Canyon following the Cerro Grande Fire

    SciTech Connect

    M. Johansen; B. Enz; B. Gallaher; K. Mullen; D. Kraig

    2001-04-01

    In May 2000, the Cerro Grande Fire burned about 7400 acres of forest on the Los Alamos National Laboratory (LANL) and about 10,000 acres in watersheds above LANL on Santa Fe National Forest lands. The resulting burned landscapes raised concerns of increased storm water runoff and transport of contaminants by runoff in the canyons traversing LANL. On June 2 and 3, 2000, rain fell in the Los Alamos Canyon watershed generating storm water runoff in the canyon bottom. This event was important in that it was the first significant runoff on LANL following the fire and occurred in a canyon containing known legacy waste sites. Samples from this runoff were analyzed for radionuclide, metal, inorganic, and organic constituents. Results show radionuclide concentrations at or below previous (pre-fire) maximum levels at locations on LANL and downstream. However, greater concentrations of some fallout-associated radionuclides (cesium-137 and strontium-90) were seen arriving on LANL from upstream areas compared to pre-fire conditions. Tests indicate most of the radionuclides in the samples were bound to sediments, not dissolved in water. Most radionuclide concentrations in sediments were below LANL Screening Action Levels, with cesium-137 and strontium-90 as exceptions. Most radionuclide concentrations in samples taken at LANL's downstream boundary were greater than those taken upstream, indicating the presence of contributing sources on LANL. For comparison purposes, doses were calculated on a mrem per liter of unfiltered water basis for 11 radionuclides commonly associated with atmospheric fallout and with LANL operations. The maximum dose was 0.094 mrem per liter unfiltered water and was largely associated with plutonium-239/240. In contrast, all filtered samples had total doses less than 0.001 mrem per liter. Compared to past data, potential doses were not increased by the fire during this initial runoff event. Of the 25 metals tested for, seven were above pre-fire levels

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  4. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Distillation and determination of routine chemical/physical properties: Topical report

    SciTech Connect

    Green, J.B.; Grizzle, P.L.; Thomson, J.S.; Shay, J.Y.; Diehl, B.H.; Hornung, K.W.; Sanchez, V.

    1988-10-01

    Part A discusses distillation of Cerro Negro heavy oil and general chemical/physical properties determined on each distillate and the residue. Based on GC-simulated distillation results, compounds boiling up to 700/degree/C atmospheric equivalent boiling point (AEBP) were distilled; nevertheless, total distillate yield represented only 55 weight percent of the whole crude. As revealed by comparative data on other crudes contained in the report, overall, chemical/physical properties of Cerro Negro crudes resemble those of tar sand bitumens and other geochemically related organic matter. Part B examines methodology for determining average molecular weights of Cerro Negro fractions and like materials. The theory and practice of vapor pressure osmometry (VPO) as applied to fossil fuels was critically evaluated through its application to Cerro Negro fractions and pure compounds, and by comparison of VPO results to those from other methods. Both solute-solute and solute-solvent intermolecular associations cause VPO data to be erroneously high, especially in cases where either the solutes and/or solvents are relatively polar. 79 refs., 24 figs., 6 tabs.

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. Evaluation of the synergistic effect of Allium sativum, Eugenia jambolana, Momordica charantia, Ocimum sanctum, and Psidium guajava on hepatic and intestinal drug metabolizing enzymes in rats

    PubMed Central

    Kumar, Devendra; Trivedi, Neerja; Dixit, Rakesh K.

    2016-01-01

    Aims/Background: This study was to investigated the synergistic effect of polyherbal formulations (PHF) of Allium sativum L., Eugenia jambolana Lam., Momordica charantia L., Ocimum sanctum Linn., and Psidium guajava L. in the inhibition/induction of hepatic and intestinal cytochrome P450 (CYPs) and Phase-II conjugated drug metabolizing enzymes (DMEs). Consumption of these herbal remedy has been extensively documented for diabetes treatment in Ayurveda. Methodology: PHF of these five herbs was prepared, and different doses were orally administered to Sprague–Dawley rats of different groups except control group. Expression of mRNA and activity of DMEs were examined by real-time polymerase chain reaction and high performance liquid chromatography in isolated liver and intestine microsomes in PHF pretreated rats. Results: The activities of hepatic and intestinal Phase-II enzyme levels increased along with mRNA levels except CYP3A mRNA level. PHF administration increases the activity of hepatic and intestinal UDP-glucuronyltransferase and glutathione S-transferase in response to dose and time; however, the activity of hepatic sulfotransferase increased at higher doses. Conclusions: CYPs and Phase-II conjugated enzymes levels can be modulated in dose and time dependent manner. Observations suggest that polyherbal formulation might be a possible cause of herb-drug interaction, due to changes in pharmacokinetic of crucial CYPs and Phase-II substrate drug. PMID:27757267

  8. Synergistic effect of Eugenia jambolana Linn. and Solidago canadensis Linn. leaf extracts with deltamethrin against the dengue vector Aedes aegypti Linn. at Mysore.

    PubMed

    Raghavendra, B S; Prathibha, K P; Vijayan, V A

    2013-06-01

    With the goal in mind to minimize the application of environmentally hazardous chemical insecticides, the larvicidal activity of two plant extracts along with deltamethrin was studied at University of Mysore. The extracts of Solidago canadensis and Eugenia jambolana were employed for working out the synergistic efficacy against Aedes aegypti larvae, as the extracts of both the plants exhibited high efficacy when applied individually. The deltamethrin when analyzed separately, LC50 and LC90 values were 0.00045 and 0.00148 ppm, respectively. Synergistic studies with two plant extracts on deltamethrin revealed S. canadensis as more effective with synergistic factor(SF) of 4.090 for LC50 value and 4.781 for LC90 followed by E. jambolana with SF 1.80 for LC50 and 2.467 for LC90 at 1:1 ratio of the phytoextracts and deltamethrin. Thus, S. canadensis was found to be a better larvicidal and synergistic agent. Combination of phytochemical and insecticide were found to be more effective than insecticides or phytochemicals alone which could be a good ecofriendly and cost-effective approach to reduce the dose of chemicals with high residual effect to be applied in vector control programs.

  9. Complementary and comparative study on hypoglycemic and antihyperglycemic activity of various extracts of Eugenia jambolana seed, Momordica charantia fruits, Gymnema sylvestre, and Trigonella foenum graecum seeds in rats.

    PubMed

    Yadav, Mukesh; Lavania, Amita; Tomar, Radha; Prasad, G B K S; Jain, Shalini; Yadav, Hariom

    2010-04-01

    In present study, we investigated hypoglycemic and antihyperglycemic potential of five extracts (water, ethanol, methanol, hexane, and chloroform) of four plants (i.e., seeds of Eugenia jambolana, fruits of Momordica charantia, leaves of Gymnema sylvestre, and seeds of Trigonella foenum graecum) alone and/or in combination with glimepiride in rats. Ethanol extract of E. jambolana, water extract of M. charantia, ethanol extract of G. sylvestre, and water extract of T. graecum exhibited highest hypoglycemic and antihyperglycemic activity (most active) in rats among all the extracts, while hexane extracts exhibited least activities. Most active extracts were further studied to dose-dependent (200, 100, and 50 mg/kg body weight (bw)) hypoglycemic and antihyperglycemic effects alone and in combination with glimepiride (20, 10, and 5 mg/kg bw). The combination of most active extracts (200 mg/kg bw) and lower dose of glimepiride (5 mg/kg bw) showed safer and potent hypoglycemic as well as antihyperglycemic activities without creating severe hypoglycemia in normal rats, while higher doses (200 mg/kg bw of most active extracts, and 10 and 20 mg/kg bw of glimepiride) were generated lethal hypoglycemia in normal rats. From this study, it may be concluded that the ethanol extract of E. jambolana seeds, water extract of M. charantia fruits, ethanol extract of G. sylvestre leaves, and water extract of T. graecum seeds have higher hypoglycemic and antihyperglycemic potential and may use as complementary medicine to treat the diabetic population by significantly reducing dose of standard drugs.

  10. Kinetic assessment and effect on developmental physiology of a trypsin inhibitor from Eugenia jambolana (Jambul) seeds on Helicoverpa armigera (Hübner).

    PubMed

    Singh, Dushyant; Jamal, Farrukh; Pandey, Prabhash K

    2014-02-01

    A trypsin inhibitor was purified from the seeds of Eugenia jambolana (Jambul) with a fold purification of 14.28 and a yield recovery of 2.8%. Electrophoretic analysis of E. jambolana trypsin inhibitor (EjTI) revealed a molecular weight of approximately 17.4 kDa on 12% denaturing polyacrylamide gel electrophoresis with or without reduction. EjTI exhibited high stability over a wide range of temperatures (4-80 °C for 30 min) and pH (3.0-10.0) and inhibited trypsin-like activities of the midgut proteinases of fourth instar Helicoverpa armigera larvae by approximately 86%. Feeding assays containing 0.05, 0.15, and 0.45 (% w/w) EjTI on functionally important fourth-instar larvae indicated a dose-dependent downfall in the larval body weight as well as on extent of survival. The nutritional analysis suggests that EjTI exerts toxic effects on H. armigera. Dixon plot analysis revealed competitive inhibition of larval midgut proteinases by EjTI, with an inhibition constant (Ki ) of approximately 3.1 × 10(-9) M. However, inhibitor kinetics using double reciprocal plots for trypsin inhibition demonstrated a mixed inhibition pattern. These observations suggest the potential of E. jambolana trypsin inhibitor protein in insect pest management. © 2014 Wiley Periodicals, Inc.

  11. Antioxidant properties of the essential oil of Eugenia caryophyllata and its antifungal activity against a large number of clinical Candida species.

    PubMed

    Chaieb, Kamel; Zmantar, Tarek; Ksouri, Riadh; Hajlaoui, Hafedh; Mahdouani, Kacem; Abdelly, Chedly; Bakhrouf, Amina

    2007-09-01

    Many essential oils are known to possess an antioxidant activity and antifungal properties and therefore they potentially act as antimycotic agents. Essential oil of clove (Eugenia caryophyllata) was isolated by hydrodistillation. The chemical composition of the essential oil was analysed by gas chromatography and gas chromatography/mass spectroscopy. The antioxidant effect of the tested oil was evaluated by measuring its 2,2-diphenyl-l-1-picrylhydrazil radical scavenging ability and the antiradical dose required to cause a 50% inhibition (IC50) was recorded. The antifungal activity of essential oils was evaluated against 53 human pathogenic yeasts using a disc paper diffusion method. Our results show that the major components present in the clove bund oil were eugenol (88.6%), eugenyl acetate (5.6%), beta-caryophyllene (1.4%) and 2-heptanone (0.9%). The tested essential oil exhibited a very strong radical scavenging activity (IC50 = 0.2 microg ml-1) when compared with the synthetic antioxidant (tert-butylated hydroxytoluene, IC50 = 11.5 microg ml-1). On the other hand, this species displayed an important antifungal effect against the tested strains. It is clear that clove oil shows powerful antifungal activity; and it can be used as an easily accessible source of natural antioxidants and in pharmaceutical applications.

  12. Solvent-free microwave extraction coupled with headspace single-drop microextraction of essential oils from flower of Eugenia caryophyllata Thunb.

    PubMed

    Jiang, Chunzhu; Sun, Ying; Zhu, Xiaonan; Gao, Yan; Wang, Liying; Wang, Jian; Wu, Liwei; Song, Daqian

    2010-09-01

    Solvent-free microwave extraction coupled with headspace single-drop microextraction was developed for extracting the essential oils from Eugenia caryophyllata Thunb. Carbonyl iron powders were mixed with the sample to extract essential oils from the dried plant materials and single-drop solvent was used to simultaneously extract essential oils from the headspace. The single-drop of decane was suspended from the tip of a microsyringe and exposed to the headspace above the sample. After the extraction was finished, the single-drop was injected into gas chromatographic system and analyzed by GC-MS. The effects of the experimental parameters, including microwave power, microwave irradiation time, the ratio of carbonyl iron powder to sample, extraction solvent, single-drop volume and extraction time, were investigated. Sixteen compounds in the essential oils of E. caryophyllata T. were obtained and identified. The constituents of essential oils obtained by hydro-distillation and solvent-free microwave extraction-headspace single-drop microextraction were not obviously different. Compared with hydro-distillation, the proposed method required shorter extraction time and less amount of the sample.

  13. Magnetic Ligand Fishing as a Targeting Tool for HPLC-HRMS-SPE-NMR: α-Glucosidase Inhibitory Ligands and Alkylresorcinol Glycosides from Eugenia catharinae

    PubMed Central

    Wubshet, Sileshi G.; Brighente, Inês M. C.; Moaddel, Ruin; Staerk, Dan

    2016-01-01

    A bioanalytical platform combining magnetic ligand fishing for α-glucosidase inhibition profiling and HPLC-HRMS-SPE-NMR for structural identification of α-glucosidase inhibitory ligands, both directly from crude plant extracts, is presented. Magnetic beads with N-terminus-coupled α-glucosidase were synthesized and characterized for their inherent catalytic activity. Ligand fishing with the immobilized enzyme was optimized using an artificial test mixture consisting of caffeine, ferulic acid, and luteolin before proof-of-concept with the crude extract of Eugenia catharinae. The combination of ligand fishing and HPLC-HRMS-SPE-NMR identified myricetin 3-O-α-l-rhamnopyranoside, myricetin, quercetin, and kaempferol as α-glucosidase inhibitory ligands in E. catharinae. Furthermore, HPLC-HRMS-SPE-NMR analysis led to identification of six new alkylresorcinol glycosides, i.e., 5-(2-oxopentyl)resorcinol 4-O-β-d-glucopyranoside, 5-propylresorcinol 4-O-β-d-glucopyranoside, 5-pentylresorcinol 4-O-[α-d-apiofuranosyl-(1→6)]-β-d-glucopyranoside, 5-pentylresorcinol 4-O-β-d-glucopyranoside, 4-hydroxy-3-O-methyl-5-pentylresorcinol 1-O-β-d-glucopyranoside, and 3-O-methyl-5-pentylresorcinol 1-O-[β-d-glucopyranosyl-(1→6)]-β-d-glucopyranoside. PMID:26496505

  14. In vitro safety and efficacy evaluations of a complex botanical mixture of Eugenia dysenterica DC. (Myrtaceae): Prospects for developing a new dermocosmetic product.

    PubMed

    Moreira, Larissa Cleres; de Ávila, Renato Ivan; Veloso, Danillo Fabrini Maciel Costa; Pedrosa, Tatiana Nascimento; Lima, Emerson Silva; do Couto, Renê Oliveira; Lima, Eliana Martins; Batista, Aline Carvalho; de Paula, José Realino; Valadares, Marize Campos

    2017-04-04

    In the context of developing a new natural product-based cosmetic, the in vitro efficacy and safety evaluations of a complex botanical mixture based on Eugenia dysenterica leaf hydroalcoholic extract (EDE) (2.5-1000μg/mL) were carried out. Chromatographic analysis demonstrated the presence of the tannin (ellagic acid) and flavonoids (quercetin and gallic acid) which characterize the EDE as a polyphenol-rich mixture. Using HFF-1 fibroblasts, it was shown that EDE promoted cell regeneration after UVA exposure. It also led to the inhibition of the collagenase, elastase and tyrosinase enzymes, which are involved in skin-related disorders. In terms of toxicological evaluation, the EDE was classified as non-phototoxic through the 3T3 Neutral Red Uptake Phototoxicity Test (OECD N° 432, 2004) and non-eye irritant by Bovine Corneal Opacity and Permeability (OECD N° 437, 2013) assay, in conjunction with corneal histomorphometric analysis. Furthermore, the EDE has no skin sensitization potential as demonstrated by a two-out-of-three prediction model [protein-binding/haptenization (OECD N° 442C, 2015), keratinocyte and dendritic cell activations]. In addition, it was shown that the EDE seems to be non-genotoxic through the cytokinesis-block micronucleus assay (OECD N° 487, 2014) using HepG2 cells. When considered together, these findings support the use of EDE botanical mixture in cosmetic/pharmaceutical products.

  15. A re-appraisal of the stratigraphy and volcanology of the Cerro Galán volcanic system, NW Argentina

    USGS Publications Warehouse

    Folkes, Christopher B.; Wright, Heather M.; Cas, Ray A.F.; de Silva, Shanaka L.; Lesti, Chiara; Viramonte, Jose G.

    2011-01-01

    From detailed fieldwork and biotite 40Ar/39Ar dating correlated with paleomagnetic analyses of lithic clasts, we present a revision of the stratigraphy, areal extent and volume estimates of ignimbrites in the Cerro Galán volcanic complex. We find evidence for nine distinct outflow ignimbrites, including two newly identified ignimbrites in the Toconquis Group (the Pitas and Vega Ignimbrites). Toconquis Group Ignimbrites (~5.60–4.51 Ma biotite ages) have been discovered to the southwest and north of the caldera, increasing their spatial extents from previous estimates. Previously thought to be contemporaneous, we distinguish the Real Grande Ignimbrite (4.68 ± 0.07 Ma biotite age) from the Cueva Negra Ignimbrite (3.77 ± 0.08 Ma biotite age). The form and collapse processes of the Cerro Galán caldera are also reassessed. Based on re-interpretation of the margins of the caldera, we find evidence for a fault-bounded trapdoor collapse hinged along a regional N-S fault on the eastern side of the caldera and accommodated on a N-S fault on the western caldera margin. The collapsed area defines a roughly isosceles trapezoid shape elongated E-W and with maximum dimensions 27 × 16 km. The Cerro Galán Ignimbrite (CGI; 2.08 ± 0.02 Ma sanidine age) outflow sheet extends to 40 km in all directions from the inferred structural margins, with a maximum runout distance of ~80 km to the north of the caldera. New deposit volume estimates confirm an increase in eruptive volume through time, wherein the Toconquis Group Ignimbrites increase in volume from the ~10 km3 Lower Merihuaca Ignimbrite to a maximum of ~390 km3 (Dense Rock Equivalent; DRE) with the Real Grande Ignimbrite. The climactic CGI has a revised volume of ~630 km3 (DRE), approximately two thirds of the commonly quoted value.

  16. Sulphur-Rich Melt At Upper Crustal Levels At Cerro La Torta, Central Andes: Evidence From Melt Inclusions Assemblages.

    NASA Astrophysics Data System (ADS)

    Cannatelli, C.; Godoy, B.; Alvear, B.; Moncada, D.

    2016-12-01

    Central Andes present some of the biggest and most important porphyry copper ore deposits in the world. Porphyry copper ore formation is related to precipitation of ore minerals from sulphur and chlorine-rich fluids. Genesis of these deposits occurred 4 km below surface, while mineralized fluids are released by magmatic melts located between 5 and 15 km depth (Sillitoe, 2010). Cerro La Torta is part of a cluster of <105 ka rhyodacitic domes related to the waning stage of the Altiplano-Puna Volcanic Complex at Central Andes (Tierney et al., 2016). These domes reflect a crystal-rich mush layer at the upper crust - named Altiplano-Puna Magma Body (APMB) - which is proposed to be a voluminous partially molten body locate at shallow depth (4-25 km), with a thickness up to 11 km (Ward et al., 2014). Cerro La Torta is a crystal-rich ( 40% vol.) dacitic flow with plagioclase, amphibole, biotite, and quartz phenocrysts on a glassy (up to 50% vol.) groundmass. During detailed petrographic observation, two types of Melt Inclusions Assemblages (MIAs) were observed in the plagioclase. Group I is found in the core of crystals, and contains sulphide, pyrite ± bubbles. Group II of bubble-bearing MIAs is observed at the rim of the phenocrysts, with no associated sulphide mineral present. Melt Inclusions size ranges from 10-40 µm, suggesting an intermediate cooling rate (Roedder 1979). Out hypothesis is that during cooling, Group I MIA is trapped as result of a metal sulfur-rich event, leading to the suggestion that sulphide-bearing MIAs from Cerro La Torta are the evidence of mineralized magmas ponding at shallow crustal levels. Furthermore, the presence of MIAs in the mush-type magmas related to the APMB implies that such systems are suitable to porphyry copper ore generation. Roedder, 1979. The Evolution of the Igneous Rocks. 15-57 Sillitoe, 2010. Econ. Geol. 105:3-41 Tierney et al., 2016. Geology 44:683-686. doi:10.1130/G37968.1Ward et al., 2014. Earth Planet Sci Letters 404:43-54

  17. Chemical and petrological heterogenity of lithospheric mantle beneath N Patagonia (Argentina) - case study of Cerro Chenque xenoliths.

    NASA Astrophysics Data System (ADS)

    Kozdrowska, Dominika; Matusiak-Małek, Magdalena; Ntaflos, Theodoros; Puziewicz, Jacek; Bjerg, Ernesto

    2015-04-01

    Mantle-xenoliths-bearing, back-arc Pliocene - Quaternary alkali basalts occur in N Patagonia, Argentina (Bjerg et al., 2005, J. of S. Am. Sci.). The Cerro Chenque (Rio Negro province) trachybasaltic lavas carry small (up to 10 cm in diameter) xenoliths of anhydrous, spinel bearing harzburgites, dunites and less abundant clino- , orthopyroxenites, websterites. The xenolith suite comprises also gabbros and norites, which are not discussed in this study. All the phases forming xenoliths are rich in Mg (Fo=90.5-93.5%; mg#Opx=0.90-0.94; mg#Cpx=0.91-0.95). Composition of spinel is extremely variable (mg#=0.65-0.85; cr#=0.00-0.70). Three types (A, B, C) of REE patterns occur in clinopyroxene and orthopyroxene: (1) type A (harzburgites and orthopyroxenites) is U-shaped in both the pyroxenes, REE contents vary significantly (e.g. La=~0.5 primitive mantle values (PM), ~5 PM, and ~50PM); (2) type B (dunites and harzburgites) clinopyroxene has flat HREE and is continuously enriched in LREE up to 10x PM, orthopyroxene is U-shaped; (3) type C (harzburgites) clinopyroxene is convex upward, La=5-7PM), orthopyroxene is continuously depleted in LREE. Clinopyroxene of all the types is poor in Ti, while normalized content of other trace elements is strongly variable. Trace element compositions of Cerro Chenque xenolithc clinopyroxene cover whole compositional range of mantle-derived clinopyroxene from Rio Negro province presented by Bjerg et al., 2005 (op.cit.). In xenoliths where clino- and orthopyroxene are in equilibrium, the calculated temperatures are always around 1000°C (Brey and Köhler,1990, JoP). No spinel-clinopyroxene symplectites suggesting peridotite provenance from garnet stability field were observed. Strong variations in rock-type and chemical composition of minerals forming Cerro Chenque xenoliths suggest complicated structure of upper mantle beneath N Patagonia. At present stage of study we suggest that Earth's lithospheric mantle in this region: - suffered from

  18. GPR investigation of tephra fallout, Cerro Negro volcano, Nicaragua: a method for constraining parameters used in tephra sedimentation models

    NASA Astrophysics Data System (ADS)

    Courtland, L. M.; Kruse, S. E.; Connor, C. B.; Connor, L. J.; Savov, I. P.; Martin, K. T.

    2012-08-01

    Most tephra fallout models rely on the advection-diffusion equation to forecast sedimentation and hence volcanic hazards. Here, we test the application of the advection-diffusion equation to tephra sedimentation using data collected on the proximal (350 to ~1,200 m from the vent) to medial (greater than ~1,200 m from the vent) tephra blanket of a basaltic cinder cone, Cerro Negro volcano, located in Nicaragua. Our understanding of tephra depositional processes at this volcano is significantly improved by combination of sample pit data in the medial zone and high-resolution ground-penetrating radar (GPR) data collected in the near vent and proximal zones. If the advection-diffusion equation applies, then the thickness of individual tephra deposits should have Gaussian crosswind profiles and exponential decay with distance away from the vent. At Cerro Negro, steady trade winds coupled with brief eruptions of relatively low energy (VEI 2-3) create relatively simple deposits. GPR data were collected along three crosswind profiles at distances of 700-1,600 m from the vent; sample pits were used to estimate thickness of the 1992 tephra deposit up to 13 km from the vent. Horizons identified in proximal GPR profiles exhibit Gaussian distributions with a high degree of statistical confidence, with diffusion coefficients of ~500 m2 s-1 estimated for the deposits, confirming that the advection-diffusion equation is capable of modeling sedimentation in the proximal zone. The thinning trend downwind of the vent decreases exponentially from the cone base (350 m) to ~1,200 m from the vent. Beyond this distance, deposit overthickening occurs, identified in both GPR and sample pit datasets. The combined data reveal three depositional regimes: (1) a near-vent region on the cone itself, where fallout remobilizes in granular flows upon deposition; (2) a proximal zone in which particles fall from a height of less than ~2 km; and (3) a medial zone, in which particles fall from ~4 to 7

  19. Groundmass Crystallization of A'a and Pahoehoe flows of Cerro Azul, Galapagos and Mauna Loa, Hawaii

    NASA Astrophysics Data System (ADS)

    Teasdale, R.; Geist, D.; Wanless, D.; Cashman, K.

    2001-12-01

    Crystallinities of 1998 lavas from Cerro Azul, Galapagos are distinguished from 1843 Mauna Loa, Hawaii lavas by higher modal proportions of groundmass plagioclase crystals. In both cases, a'a lava was erupted first, followed by emplacement of pahoehoe flows. The 1843 Mauna Loa eruption lasted 90 days and produced both a'a and inflated pahoehoe flows (1). The 1998 Galapagos flows were emplaced over the course of 37 days, and the transition from a'a to pahoehoe flow morphology corresponds with decreased eruption rate during the last week of the eruption. Samples were collected along the length of flows from both volcanoes. Modal groundmass plagioclase increases down-flow for each flow type from each volcano. A'a and pahoehoe flows of Cerro Azul consistently have higher crystallinities (41% and 14%) than equivalent flow types at Mauna Loa (29% and 7%). Whereas Cerro Azul groundmass crystals are exclusively plagioclase, the groundmass of Mauna Loa lavas consists of plagioclase and pyroxene crystals, similar to Kilauea lavas. Proportions of plagioclase crystals and flow morphologies are consistent with predictions that groundmass crystal morphology plays a significant role in the development of crystal networks and yield strength, which instigates the development of a'a flow morphology (2, 3). Galapagos volcanoes tend to have more a'a than their Hawaiian counterparts Mauna Loa and Kilauea. Volcano slopes do not appear to control the proportion of each flow type (4); rather, abundance of groundmass plagioclase appears to be the distinguishing factor. An important distinction between the two systems is that Galapagos lavas have consistently higher Al2O3 content than Hawaiian volcanoes. High Al203 results in a comparatively high abundance of groundmass plagioclase, and may partly explain the prevalence of a'a. We note that while the relative abundance of a'a and pahoehoe flow morphologies on other volcanoes is rarely quantified, Mount Etna is also distinguished by abundant

  20. Variations in trace element partition coefficients in sanidine in the Cerro Toledo Rhyolite, Jemez Mountains, New Mexico: Effects of composition, temperature, and volatiles

    SciTech Connect

    Stix, J. ); Gorton, M.P. )

    1990-10-01

    Trace element partition coefficients have been measured for one plagioclase and five sanidine mineral separates from the Cerro Toledo Rhyolite, New Mexico. Sanidine partition coefficients vary substantially and systematically within the Cerro Toledo Rhyolite. Partition coefficients for Ca, Sr, Zn, La, and Eu are lowest in the most evolved rhyolites, whereas Sm and HREE partition coefficients are highest. Rubidium partition coefficients remain constant, while those for Ba, Ce, and Th are variable. Variations of the Sr, Zn, La, and Eu partition coefficients are correlated with the Ca contents and partition coefficients of the sanidines. Calcium may have controlled the distribution of these elements in the sanidine by modifying the feldspar structure. The low Ca partition coefficients in sanidines for the most evolved rhyolites may be the consequence of modification of the melt structure, possibly due to increased volatile contents at the top of the magma chamber(s) during evolution of the Cerro Toledo Rhyolite. The Zn and La partition coefficients between sanidine and melt also may have been controlled by this change in melt structure. Modelling using major elements and the constant Rb partition coefficient for sanidine indicates 70% crystallization of magma during Cerro Toledo Rhyolite time by removal of 68% sanidine and 32% quartz. Estimates of the volume (1) of initial parental magma and (2) of the magma that crystallized during this period are 11,670 km{sup 3} and 8,170 km{sup 3}, respectively. The average intrusion rate of silicic magma during Cerro Toledo Rhyolite activity was 35 {times} 10{sup {minus}3} km{sup 3}/a.

  1. Eruptive history of the youngest Mexican Shield and Mexico's most voluminous Holocene eruption: Cerro El Metate

    NASA Astrophysics Data System (ADS)

    Oryaëlle Chevrel, Magdalena; Guilbaud, Marie-Noelle; Siebe, Claus

    2016-04-01

    Small to medium-sized shield volcanoes are an important component of many volcanic fields on Earth. The Trans-Mexican Volcanic Belt, one of the most complex and active continental arcs worldwide, displays a large number of such medium-sized volcanoes. In particular the Michoacán-Guanajuato Volcanic Field (MGVF) situated in central Mexico, is the largest monogenetic volcanic field in the world and includes more than 1000 scoria cones and about four hundred medium-sized volcanoes, also known as Mexican shields. The Mexican shields nevertheless represent nearly 70% of the total volume erupted since 1 Ma and hence played a considerable role in the formation of the MGVF. However, the source, storage, and transport as well as the physical properties (density, viscosity, volatile content, etc.) of the magmas involved in these eruptions remain poorly constrained. Here, we focus on Cerro El Metate, the youngest monogenetic andesite shield volcano of the field. New C14 dates for the eruption yield a young age (~AD 1250), which briefly precedes the initial rise of the Tarascan Empire (AD 1350-1521) in this region. This volcano has a minimum volume of ~9.2 km3 DRE, and its viscous lava flows were emplaced during a single eruption over a period of ~35 years covering an area of 103 km2. By volume, this is certainly the largest eruption during the Holocene in Mexico, and it is the largest andesitic effusive eruption known worldwide for this period. Such a large volume of lava erupted in a relatively short time had a significant impact on the environment (modification of the hydrological network, forest fires, etc.), and hence, nearby human populations probably had to migrate. Its eruptive history was reconstructed through detailed mapping, and geochemical and rheological analyses of its thick hornblende-bearing andesitic flows. Early and late flows have distinct morphologies, chemical and mineralogical compositions, and isotopic signatures which show that these lavas were fed by

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

    PubMed Central

    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

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

    NASA Astrophysics Data System (ADS)

    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

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  6. Lack of immediate effects from the 1979-80 Imperial and Victoria earthquakes on the exploited Cerro Prieto geothermal reservoir

    SciTech Connect

    Truesdell, A.H.; Lippmann, M.J.

    1986-06-01

    In 1979-1980 two large earthquakes of local magnitude (M/sub L/) greater than 6.0 occurred near the Cerro Prieto geothermal field. It has been suggested that related to these seismic events there was an abrupt temperature increase in the wells completed in the shallow (alpha) reservoir. A careful study of the geochemistry of the produced fluids, as well as a cursory reservoir engineering analysis, cannot confirm either the data or the hypothesis of a massive influx of hot water into the system related to those events. Our study shows that the cold water recharge of the alpha reservoir in response to the production-induced drawdown continued, unaffected by the two earthquakes.

  7. Evidence for static stress changes triggering the 1999 eruption of Cerro Negro Volcano, Nicaragua and regional aftershock sequences

    NASA Astrophysics Data System (ADS)

    Díez, M.; La Femina, P. C.; Connor, C. B.; Strauch, W.; Tenorio, V.

    2005-02-01

    Remarkable evidence of coupling between tectonic and magmatic events emerges from investigation of three tectonic earthquakes, aftershock sequences and eruption of Cerro Negro volcano, Nicaragua in 1999. Here, we explain this coupling through static stress changes following three Mw 5.2 earthquakes. We use focal mechanism solutions to estimate fault system geometry and magnitude of slip from these events, which are then used to calculate the change in minimum horizontal principal stress (σ3) for the region and the change in Coulomb failure stress on optimally oriented fault planes. Results of these simulations indicate that σ3 was reduced by ~0.08 MPa and that Coulomb failure stress was raised by 0.001 to 0.2 MPa in the region. A Kolmogorov-Smirnov test demonstrates spatial correlation of Coulomb failure stress changes and triggered seismicity and volcanism, and suggests that these small changes in static stress can trigger subsequent geophysical events under appropriate circumstances.

  8. Coal occurrence and characteristics as related to environment of deposition in Cerro Negro area of Orinoco Tar Sands, Venezuela

    SciTech Connect

    Rodriguez, A.

    1983-03-01

    Sedimentological analysis of cores taken in the Cerro Negro area of the Orinoco Tar Sands have provided lithological, textural, mineralogical, and paleontological data which have enabled facies identification. These facies have been interpreted as belonging from an upper delta plain to a semi-restricted shallow marine environment of deposition. Coal beds occur in all the wells analyzed. These occurrences are closely associated with specific facies, such as the back-barrier lagoonal facies of the semirestricted environment of deposition and the backswamp facies of the delta plain. More importantly these coal beds present very distinguishable characteristics, such as variation in thickness from few inches in the back-barrier facies to 5 ft (1.5 m) in the delta plain facies. Their organic composition also ranges from micrite/atrinite to vitrinite and exinite in different proportions. Therefore, it is believed that variations in thickness and perhaps in organic composition are related to facies changes.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  11. The Cerro Aguas Calientes caldera, NW Argentina: An example of a tectonically controlled, polygenetic collapse caldera, and its regional significance

    NASA Astrophysics Data System (ADS)

    Petrinovic, I. A.; Martí, J.; Aguirre-Díaz, G. J.; Guzmán, S.; Geyer, A.; Paz, N. Salado

    2010-07-01

    Polygenetic, silicic collapse calderas are common in the central Andes. Here we describe in detail the Cerro Aguas Calientes caldera in NW Argentina, which comprises two caldera-forming episodes that occurred at 17.15 Ma and 10.3 Ma. We analyse the significance of its structural setting, composition, size and the subsidence style of both caldera episodes. We find that the caldera eruptions had a tectonic trigger. In both cases, an homogeneous dacitic crystal-rich (>60 vol.% of crystals) reservoir of batholithic size became unstable due to the effect of increasing regional transpression, which favoured local dilation through minor strike-slip faults from which ring faults nucleated and permitted caldera collapse. Both calderas are similar in shape, location and products. The 17.15 Ma caldera has an elliptical shape (17 × 14 km) elongated in a N30° trend; both intracaldera and extracaldera ignimbrites covered an area of around 620 km 2 with a minimum volume estimate of 140 km 3 (DRE). The 10.3 Ma episode generated another elliptical caldera (19 × 14 km), with the same orientation as the previous one, from which intracaldera and outflow ignimbrites covered a total area of about 1700 km 2, representing a minimum eruption volume of 350 km 3(DRE). In this paper we discuss the significance of the Cerro Aguas Calientes caldera in comparison with other well known examples from the central Andes in terms of tectonic setting, eruption mechanisms, and volumes of related ignimbrites. We suggest that our kinematic model is a common volcano-tectonic scenario during the Cenozoic in the Puna and Altiplano, which may be applied to explain the origin of other large calderas in the same region.

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

    NASA Astrophysics Data System (ADS)

    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

  13. 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

    SciTech Connect

    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.

  14. Evaluation of the potential effect of Allium sativum, Momordica charantia, Eugenia jambolana, Ocimum sanctum, and Psidium guajava on intestinal p-glycoprotein in rats

    PubMed Central

    Kumar, Devendra; Trivedi, Neerja; Dixit, Rakesh K.

    2017-01-01

    Aims/Background: This study was evaluated synergistic effect of a polyherbal formulation (PHF) of Allium sativum L., Eugenia jambolana Lam., Momordica charantia L., Ocimum sanctum Linn., and Psidium guajava L. on p-glycoprotein (Pgp) of intestine. These five herbs were traditionally used for diabetes. These herbs are commonly present in Ayurvedic product as antidiabetics in India. Materials and Methods: PHF was prepared by five indigenous herbs. Different doses (50, 100 and 200 mg/kg/day) of were orally administered to Sprague-Dawley rats of different groups for multiple weeks except control groups. Alteration in Pgp expression was evaluated by real-time-polymerase chain reaction and western blotting while modulation in activity of Pgp was evaluated using rhodamine 123 (Rh123) as transport substrate by in-situ absorption and everted gut sac method. Results: In PHF, pretreated group received 50, 100 and 200 mg/kg/day for 7 days, mRNA level decreased by 1.75, 2.45 and 2.37-fold, respectively, as compared to control. Similarly, when PHF at dose of 100 mg/kg/day was given consequently for 4 weeks, maximum decrease in Pgp expression level was observed only after 1 week and further increase in the treatment duration did not produce significant decrease compared to the 1st week treatment. Pgp mediated transport of Rh123 was significantly decreased with everted gut sac prepared from PHF pretreated rats (1 week) compared to those prepared from vehicle treated rats. Conclusions: We report that PHF pretreatment downregulated the expression of intestinal Pgp and this downregulated intestinal Pgp would result in decreased functional activity. In addition, this downregulated Pgp expression might affect the bioavailability of antidiabetic Pgp substrate drugs. PMID:28163963

  15. Determination of carotenoids, total phenolic content, and antioxidant activity of Arazá (Eugenia stipitata McVaugh), an Amazonian fruit.

    PubMed

    Garzón, G Astrid; Narváez-Cuenca, Carlos-Eduardo; Kopec, Rachel E; Barry, Andrew M; Riedl, Kenneth M; Schwartz, Steven J

    2012-05-09

    The fruit of Arazá (Eugenia stipitata McVaugh) native to the Colombian Amazon is considered a potentially economically valuable fruit for the Andean economy due to its novel and unique taste. The fruit has an intense yellow color, but its chemical composition and properties have not been well studied. Here we report the identification and quantitation of carotenoids in the ripe fruit using high performance liquid chromatography (HPLC) with photodiode array detector (PDA) and atmospheric pressure chemical ionization (APcI) mass spectrometry (MS/MS). The qualitative carotenoid profile of the fruit according to maturity stage was also observed. Furthermore, antioxidant activity of the peel and pulp were assessed using the ferric reducing ability of plasma (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods, in addition to chemical indexes and total phenolic content. Multiple carotenoids were identified in the peel and pulp including four xanthophylls (free and esterified as their mono and diesters) and two carotenes. One of the xanthophylls was tentatively identified as zeinoxanthin, while the others were identified as lutein, zeaxanthin, and β-cryptoxanthin. Carotenes included α-carotene and β-carotene. The total carotenoid content was significantly higher in the peel (2484 ± 421 μg/100 g FW) than in the pulp (806 ± 348 μg/100 g FW) with lutein, β-cryptoxanthin, and zeinoxanthin as the major carotenoid components. The unique carotenoid composition of this fruit can differentiate it from other carotenoid-rich fruits and perhaps be useful in authentication procedures. Overall, results from this study suggest that Colombian Arazá may be a good edible source of carotenoids important in retinal health as well as carotenoids with provitamin A activity. Therefore, Arazá fruit can be used as a nutraceutical ingredient and in production of functional foods in the Colombian diet.

  16. Nutrient and enzymatic changes of hydrolysed tannery solid waste treated with epigeic earthworm Eudrilus eugeniae and phytotoxicity assessment on selected commercial crops.

    PubMed

    Ravindran, B; Contreras-Ramos, S M; Wong, J W C; Selvam, A; Sekaran, G

    2014-01-01

    Animal fleshing (ANFL) is the predominant proteinaceous solid waste generated during processing of leather and it is confronting disposal problems. The aim of this study was to assess the potential of epigeic earthworm Eudrilus eugeniae to utilize and transform the fermented ANFL in the solid state (SSF) and submerged state (SmF) into a value added product along a low residence period (25 days). A total of six treatment units containing different waste mixture compositions were established. Fifty healthy and non-clitellated earthworms were introduced in three different treatment containers: control, SSF, and SmF (+worm). Another set of treatment mixtures (control, SSF, SmF) was established without earthworms (-worm) to compare the results. The products were characterized for physico-chemical, enzymatic analysis and seedling growth parameters to compare the differences in the process with and without earthworms. The changes observed in the analytical parameters were in the following order: SSF > SmF > control mixtures (p < 0.05). The vermicompost showed a significant reduction in heavy metals, total organic carbon and an increase in total Kjeldhal nitrogen as compared to the product untreated by earthworms. The maximum enzymatic activities were observed after 21 days of vermicomposting. The relative seed germination of vermicompost extracts were in the order of tomato (Lycopersicon esculentum) > green gram (Vigna radiata) > cucumber (Cucumis sativus) > bottle gourd (Lagenaria siceraria (Mol.) Standl.) and showed no phytotoxicity effects. The results indicated that the combination of both ANFL hydrolysis through fermentation and vermicomposting is a good alternative to the management of this kind of waste.

  17. The long-term resistance mechanisms, critical irrigation threshold and relief capacity shown by Eugenia myrtifolia plants in response to saline reclaimed water.

    PubMed

    Acosta-Motos, José Ramón; Hernández, José Antonio; Álvarez, Sara; Barba-Espín, Gregorio; Sánchez-Blanco, María Jesús

    2017-02-01

    Salts present in irrigation water are serious problems for commercial horticulture, particularly in semi-arid regions. Reclaimed water (RW) typically contains, among others elements, high levels of salts, boron and heavy metal. Phytotoxic ion accumulation in the substrate has been linked to different electric conductivities of the treatments. Based on these premises, we studied the long-term effect of three reclaimed water treatments with different saline concentrations on Eugenia myrtifolia plants. We also looked at the ability of these plants to recover when no drainage was applied. The RW with the highest electric conductivity (RW3, EC = 6.96 dS m(-1)) provoked a number of responses to salinity in these plants, including: 1) accumulation and extrusion of phytotoxic ions in roots; 2) a decrease in the shoot/root ratio, leaf area, number of leaves; 3) a decrease in root hydraulic conductivity, leaf water potential, the relative water content of leaves, leaf stomatal conductance, the leaf photosynthetic rate, water-use efficiency and accumulated evapotranspiration in order to limit water loss; and 4) changes in the antioxidant defence mechanisms. These different responses induced oxidative stress, which can explain the damage caused in the membranes, leading to the death of RW3 plants during the relief period. The behaviour observed in RW2 plants was slightly better compared with RW3 plants, although at the end of the experiment about 55% of the RW2 plants also died, however RW containing low salinity level (RW1, EC = 2.97 dS m(-1)) can be effective for plant irrigation.

  18. In vitro evaluation of the antibacterial potential and modification of antibiotic activity of the Eugenia uniflora L. essential oil in association with led lights.

    PubMed

    Pereira, Nara L F; Aquino, Pedro E A; Júnior, José G A S; Cristo, Janyketchuly S; Vieira Filho, Marcos A; Moura, Flávio F; Ferreira, Najla M N; Silva, Maria K N; Nascimento, Eloiza M; Correia, Fabrina M A; Cunha, Francisco A B; Boligon, Aline A; Coutinho, Henrique D M; Matias, Edinardo F F; Guedes, Maria I F

    2017-09-01

    Due to the great biodiversity of its flora, Brazil provides combat tools against bacterial resistance with the utilization of natural products with vegetable origin. Therefore, the present study had as its objective to evaluate the antibacterial potential of the Eugenia uniflora essential oil (EuEO) in vitro, as well as to analyze the modulatory effect of the oil against antibiotics by gaseous contact and to compare them when associated with a LED apparatus. The chemical components were characterised by gas chromatography which revealed the presence of the isoflurane-germacrene, considered the major component (61.69%). The MIC obtained from the EuEO was ≥256 μg/mL for S. aureus and ≥1024 μg/mL for E. coli. When combined with antibiotics, the EuEO presented synergism reducing the MIC when associated, with the exception of gentamicin against E. coli, where an antagonistic effect was observed. The was an interference of the EuEO over the activity of ciprofloxacin when associated with red and blue LED lights, increasing the inhibition halos against S. aureus and E. coli. Norfloxacin presented similar results to ciprofloxacin against S. aureus bacteria. When combined, norfloxacin and the EuEO presented synergism against S. aureus, which did not occur in the combination with ciprofloxacin. Interference occurred only with blue light for E. coli. Thus, it was observed that the EuEO causes changes in the activity of antibiotics, the same occurring with the use of LED lights, without significant differences in the association of the oil and the lights with the antibiotics tested. Further research is needed to elucidate the modulatory effects of the EuEO, as well as its association with LED lights. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Diabetic therapeutic effects of ethyl acetate fraction from the roots of Musa paradisiaca and seeds of Eugenia jambolana in streptozotocin-induced male diabetic rats.

    PubMed

    Panda, D K; Ghosh, Debidas; Bhat, B; Talwar, S K; Jaggi, M; Mukherjee, R

    2009-11-01

    The folklore medicine of primitive people has been greatly appreciated for centuries. Many researchers study the curative efficiency and mode of action of various medicinal plants. Serum glucose level, lipid profile, glucose tolerance, hepatic and muscle glycogen contents as well as the activities of hepatic hexokinase and glucose-6-phosphatase recovered significantly after oral administration of ethyl acetate fractions of Eugenia jambolana (E. jambolana) or Musa paradisiaca (M. paradisiaca) in separate (E. jambolana L.: 200 mg/kg of body weight and M. paradisiaca: 100 mg/kg of body weight) or combined form for 90 days (twice a day through gavage) to streptozotocin-induced diabetic rats. The loss in body weight of diabetic animals was reversed and serum levels of insulin as well as C-peptide, which were found to be reduced in diabetic rats, increased significantly after oral administration of the fractions. A histological study of the rats' pancreas revealed that after 90 days of oral treatment with the plant fractions in separate or combined form, the size and volume of pancreatic islets in diabetic treated rats increased significantly compared with the diabetic control group. Treatment of diabetic rats with the combined dose (300 mg/kg of body weight) of plant fractions (200 mg E. jambolana and 100 mg M. paradisiaca) was found to be more effective than treatment with the individual fraction. The doses of E. jambolana and M. paradisiaca selected for this study are the optimum antihyperglycemic doses of the plant fractions, which were determined after conducting a dose-dependent study at various dose levels (50-500 mg/kg) in our pilot experiments. The plant fractions were found to be free from metabolic toxicity. Through HPTLC finger printing, three different compounds were noted in the ethyl acetate fraction of E. jambolana L. and eight different compounds in the ethyl acetate fraction of M. paradisiaca L.

  20. Eugenia jambolana (Java Plum) Fruit Extract Exhibits Anti-Cancer Activity against Early Stage Human HCT-116 Colon Cancer Cells and Colon Cancer Stem Cells

    PubMed Central

    Charepalli, Venkata; Reddivari, Lavanya; Vadde, Ramakrishna; Walia, Suresh; Radhakrishnan, Sridhar; Vanamala, Jairam K. P

    2016-01-01

    The World Health Organization predicts over a 70% increase in cancer incidents in developing nations over the next decade. Although these nations have limited access to novel therapeutics, they do have access to foods that contain chemopreventive bioactive compounds such as anthocyanins, and as such, consumption of these foods can be encouraged to combat cancer. We and others have previously characterized the anti-colon cancer properties of dietary anthocyanins from different sources. Eugenia jambolana (Java plum) is a tropical medicinal fruit rich in anthocyanins, however, its anti-colon cancer properties are not well characterized. Furthermore, recent evidence suggests that colon cancer stem cells (colon CSCs) promote resistance to chemotherapy, relapse of tumors and contribute to poor prognosis. The objectives of this study were to 1) characterize the anthocyanin profile of Java plum using HPLC-MS; and 2) determine the anti-proliferative (cell counting and MTT) and pro-apoptotic (TUNEL and caspase 3/7 glo assay) properties of Java plum fruit extract (JPE) using HCT-116 colon cancer cell line and colon CSCs (positive for CD 44, CD 133 and ALDH1b1 markers). HPLC-MS analysis showed that JPE contains a variety of anthocyanins including glucosides of delphinidin, cyanidin, petunidin, peonidin and malvidin. JPE anthocyanins suppressed (p < 0.05) proliferation in HCT-116 cells and elevated (p < 0.05) apoptosis in both HCT-116 cells and colon CSCs. JPE also suppressed the stemness in colon CSCs as evaluated using colony formation assay. These results warrant further assessment of the anti-cancer activity of JPE, and its molecular mechanisms using pre-clinical models of colon cancer. PMID:26927179

  1. Effects of the Cerro Grande Fire (Smoke and Fallout Ash) on Soil Chemical Properties Within and Around Los Alamos National Laboratory

    SciTech Connect

    Fresquez, P.R.; Velasquez, W.R.; Naranjo, L. Jr.

    2000-11-01

    Soil surface (0- to 2-in. depth) samples were collected from areas within and around Los Alamos National Laboratory (LANL) just after the Cerro Grande fire, analyzed for radionuclides, radioactivity, and trace elements (heavy metals), and compared to soil samples collected in 1999 from the same sites. In addition, many types of organic substances (volatile and semivolatile organic compounds, organochlorine pesticides, polychlorinated biphenyls, high explosives, and dioxin and dioxin-like compounds) were assessed in soils from LANL, perimeter, and regional sites after the fire. Results show that impacts to regional, perimeter, and on-site (mesa top) areas from smoke and fallout ash as a result of the Cerro Grande fire were minimal.

  2. Multiple approaches to understanding the taxonomic status of an enigmatic new scorpion species of the genus Tityus (Buthidae) from the biogeographic island of Paraje Tres Cerros (Argentina).

    PubMed

    Ojanguren-Affilastro, Andrés A; Adilardi, Renzo S; Cajade, Rodrigo; Ramírez, Martín J; Ceccarelli, F Sara; Mola, Liliana M

    2017-01-01

    Tityus curupi n. sp., belonging to the bolivianus complex, is described from the biogeographically distinct area of Paraje Tres Cerros in north-eastern Argentina. We also present a molecular species delimitation analysis between Tityus curupi n. sp. and its sister species Tityus uruguayensis Borelli 1901 to confirm species integrity. Furthermore, a cytogenetic analysis is presented for these two species which contain different multivalent associations in meiosis, as a consequence of chromosome rearrangements, and the highest chromosome numbers in the genus.

  3. Multiple approaches to understanding the taxonomic status of an enigmatic new scorpion species of the genus Tityus (Buthidae) from the biogeographic island of Paraje Tres Cerros (Argentina)

    PubMed Central

    Adilardi, Renzo S.; Cajade, Rodrigo; Ramírez, Martín J.; Ceccarelli, F. Sara; Mola, Liliana M.

    2017-01-01

    Tityus curupi n. sp., belonging to the bolivianus complex, is described from the biogeographically distinct area of Paraje Tres Cerros in north-eastern Argentina. We also present a molecular species delimitation analysis between Tityus curupi n. sp. and its sister species Tityus uruguayensis Borelli 1901 to confirm species integrity. Furthermore, a cytogenetic analysis is presented for these two species which contain different multivalent associations in meiosis, as a consequence of chromosome rearrangements, and the highest chromosome numbers in the genus. PMID:28746406

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

    SciTech Connect

    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.

  5. Impact of Santiago de Chile urban atmospheric pollution on anthropogenic trace elements enrichment in snow precipitation at Cerro Colorado, Central Andes

    NASA Astrophysics Data System (ADS)

    Cereceda-Balic, F.; Palomo-Marín, M. R.; Bernalte, E.; Vidal, V.; Christie, J.; Fadic, X.; Guevara, J. L.; Miro, C.; Pinilla Gil, E.

    2012-02-01

    Seasonal snow precipitation in the Andes mountain range is evaluated as an environmental indicator of the composition of atmospheric emissions in Santiago de Chile metropolitan area, by measuring a set of representative trace elements in snow samples by ICP-MS. Three late winter sampling campaigns (2003, 2008 and 2009) were conducted in three sampling areas around Cerro Colorado, a Central Andes mountain range sector NE of Santiago (36 km). Nevados de Chillán, a sector in The Andes located about 500 km south from the metropolitan area, was selected as a reference area. The experimental results at Cerro Colorado and Nevados de Chillán were compared with previously published data of fresh snow from remote and urban background sites. High snow concentrations of a range of anthropogenic marker elements were found at Cerro Colorado, probably derived from Santiago urban aerosol transport and deposition combined with the effect of mining and smelting activities in the area, whereas Nevados de Chillán levels roughly correspond to urban background areas. Enhanced concentrations in surface snow respect to deeper samples are discussed. Significant differences found between the 2003, 2008 and 2009 anthropogenic source markers profiles at Cerro Colorado sampling points were correlated with changes in emission sources at the city. The preliminary results obtained in this study, the first of this kind in the southern hemisphere, show promising use of snow precipitation in the Central Andes as a suitable matrix for receptor model studies aimed at identifying and quantifying pollution sources in Santiago de Chile.

  6. U-Th-Pb zircon dating of the 13.8-Ma dacite volcanic dome at Cerro Rico de Potosi, Bolivia

    USGS Publications Warehouse

    Zartman, R.E.; Cunningham, C.G.

    1995-01-01

    The temporal relationship between the extrusion of the Miocene dacite volcanic dome at Cerro Rico de Potasi, Bolivia, and the associated Ag-Sn mineralization has an important bearing on the heat and metal sources for this world class mineral deposit. The present study uses U-Th-Pb dating of sparse zircon contained in the dacite to demonstrate that, at most, only several hundred thousand years separate dome emplacement from main stage mineralization. -from Authors

  7. The August 1991 Cerro Hudson Volcanic Eruption: A Re-analysis of SO2 Release Twenty-Five Years Later from a New TOMS Perspective

    NASA Astrophysics Data System (ADS)

    Fisher, B. L.; Krotkov, N. A.; Bhartia, P. K.; Miles, G.; Haffner, D. P.; Carn, S. A.; Leonard, P.

    2016-12-01

    The Cerro Hudson volcano in the Andes Mountains of Chile erupted explosively twice in August 1991. Although greatly overshadowed by the eruption of Mount Pinatubo two months earlier, the Cerro Hudson eruptions that occurred between August 12-15 were one of the largest of the twentieth century, injecting over 1.5 Tg of SO2 into the atmosphere and produced an ash columnthat reached an altitude of 18 km. The SO2 cloud resulting from the eruptions encircled the earth twice over the next two weeks. As it propagated Eastward, the plume was observed by several polar orbiting satellites, most notably the Total Ozone Mapping Spectrometer (TOMS) on board Nimbus 7. This presentation will revisit the 1991 Cerro Hudson eruption and examine the propagation of the SO2 plume following the August 12-15 eruption sequence as observed by TOMS. The TOMS instrument observes top of the atmosphere solar backscattered radiances at six discrete ultraviolet (UV) wavelengths. We will show results from our SO2 retrieval algorithm and calibrations applied to the TOMS BUV radiances. Although TOMS was originally designed to measure total column ozone, the SO2 cross section is strongly absorbing in two of the six TOMS UV channels. Our retrieval uses four of the six TOMS channels to retrieve four geophysical parameters: SO2, ozone, the effective reflectivity and its spectral dependence.

  8. Variations in depositional systems of the Micocene Oficina Formation in the Cerro Negro area using a sequence stratigraphic analysis: Application to siliciclastic exploration

    SciTech Connect

    Rodriguez, A. )

    1991-03-01

    The Cerro Negro oil-sands area is located in eastern Venezuela. Although the Oficina Formation is the major oil-producing formation in this region, until now no attempt has been made to analyze and produce a sedimentological model for these sediments using modern sedimentological sequence stratigraphic techniques in which variations in depositional styles could be documented. Seven continuously cored wells penetrating the Oficina Formation provide the 1955.9 m (6417 ft) of cored section employed in this study. The sedimentological information gathered during analysis of the cored sedimentary sections comes from the study of lithology, trace fossils and bioturbation structures, abundant shell fragments, clay mineralogical assemblages, and microfaunal data. This information provides a basis for recognizing 13 facies as representative of the cored sedimentary intervals and leads one to divide the sedimentary section into four genetically related facies assemblages or stratigraphic units. This interpretation is supported by computer-drawn isopach maps of selected sands within each stratigraphic unit, sand percentage, and sand isolith maps of individual stratigraphic units. This deltaic to shallow-marine facies model proposed for Cerro Negro predicts that sand bodies should have different trends, thicknesses, and distribution, depending upon the stratigraphic unit in which they were formed. Therefore, the model can be used as a guide in exploration studies of this and other areas having similar geological characteristics to those of Cerro Negro.

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

    SciTech Connect

    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

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

    NASA Astrophysics Data System (ADS)

    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 (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

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

    NASA Astrophysics Data System (ADS)

    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

  12. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Detailed separation and analysis of basic compounds

    SciTech Connect

    Green, J. B.; Green, J. A.; Yu, Shirley K.-T.; Grizzle, P. L.

    1989-06-01

    Methodology for separation and analysis of basic compounds in petroleum and syncrudes is described. Petroleum bases primarily consist of two general types or compound groups: alkylaromatic species with at least one nitrogen and potentially other heteroatoms incorporated into the aromatic nucleus, and predominantly aliphatic structures containing weakly basic functionalities such as sulfoxide, amide, and other carbonyl-based moieties. Nonaqueous ion exchange liquid chromatography effectively separates these two compound groups. Each compound group is further fractionated into subtypes using an HPLC method employing a silica column and a programmed ternary mobile phase containing propanoic acid. Within each group, compounds elute from the HPLC column in order of increasing basicity. The above also holds for syncrudes, except that aromatic nitrogen types greatly predominate over all weakly basic types and that amino-substituted aromatics are present in addition to azaarene-type structures. The bulk of the report discusses separation strategy, methodology, and results supporting separation selectivity as described above. In addition, nonaqueous titration, infrared, mass spectrometric (MS) and GC/MS techniques for analysis of subfractions are described along with representative results from their application. Limited compositional data from analysis of bases from Wilmington and Cerro Negro petroleums and SRC-II coal liquid are also presented. Prior work in analysis of basic compounds is reviewed and future research direction is addressed. 84 refs., 16 figs., 23 tabs.

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

    PubMed

    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.

  14. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Detailed separation and analysis of basic compounds

    SciTech Connect

    Green, J.B.; Green, J.A.; Yu, Shirley K.-T.; Grizzle, P.L.

    1989-06-01

    Methodology for separation and analysis of basic compounds in petroleum and syncrudes is described. Petroleum bases primarily consist of two general types or compound groups: alkylaromatic species with at least one nitrogen and potentially other heteroatoms incorporated into the aromatic nucleus, and predominantly aliphatic structures containing weakly basic functionalities such as sulfoxide, amide, and other carbonyl-based moieties. Nonaqueous ion exchange liquid chromatography effectively separates these two compound groups. Each compound group is further fractionated into subtypes using an HPLC method employing a silica column and a programmed ternary mobile phase containing propanoic acid. Within each group, compounds elute from the HPLC column in order of increasing basicity. The above also holds for syncrudes, except that aromatic nitrogen types greatly predominate over all weakly basic types and that amino-substituted aromatics are present in addition to azaarene-type structures. The bulk of the report discusses separation strategy, methodology, and results supporting separation selectivity as described above. In addition, nonaqueous titration, infrared, mass spectrometric (MS) and GC/MS techniques for analysis of subfractions are described along with representative results from their application. Limited compositional data from analysis of bases from Wilmington and Cerro Negro petroleums and SRC-II coal liquid are also presented. Prior work in analysis of basic compounds is reviewed and future research direction is addressed. 84 refs., 16 figs., 23 tabs.

  15. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum detailed separation and analysis of acidic compounds

    SciTech Connect

    Green, J.B.; Yu, S.K.T.; Green, J.A.; Doughty, D.A.; Vogh, J.W.; Grigsby, R.D.

    1989-10-01

    An HPLC method for fractionation of whole acid concentrates into nominal compound class subfractions is described. The method utilizes silica columns and gradient elution with eluents containing a strong base, tetramethyl-ammonium hydroxide. The performance of the method is evaluated through analysis of subfractions obtained from a coal liquid, Wilmington, CA, petroleum and Cerro Negro heavy oil. Methods developed specifically for analysis of whole acid concentrates and subfractions are described in detail. These include: (1) an infrared method for determination of total hydroxyl and carboxyl groups after their conversion to trifluoroacetate and 2,2,2-trifluoresters, respectively. (2) an NMR method for functional group analysis based on methylation of acidic groups with {sup 13}C-enriched methyl iodide, (3) a nonaqueous titration procedure employing the potassium salt of dimethyl sulfoxide as a titrant for acidic compounds, (4) GC/MS analysis of hydroxyaromatic compounds after their conversion to trifluoroacetate esters, and (5) probe microdistillation high resolution mass spectrometric analysis of acid fractions exhibiting low volatility. 146 refs., 38 figs., 27 tabs.

  16. Structural interplay between plutons during the construction of a batholith (Cerro Aspero batholith, Sierras de Córdoba, Argentina)

    NASA Astrophysics Data System (ADS)

    Pinotti, Lucio; Tubía, José M.; D'Eramo, Fernando; Vegas, Néstor; Sato, Ana M.; Coniglio, Jorge; Aranguren, Aitor

    2006-05-01

    Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural modifications as a result of the coalescence of two plutons, Alpa Corral and Talita, during the construction of a large granitic batholith, Cerro Aspero, in the Sierras Pampeanas of Córdoba (Argentina). The Alpa Corral granite is a small and nearly circular pluton, while the larger Talita pluton displays a marked N-S elongation. The NW quadrangle of the Alpa Corral pluton underwent a deformation resulting in foliation trajectories that outline a crescent moon pattern whose inner arc is concordant with the Alpa Corral/Talita contact. The highest values for the magnetic susceptibility and its anisotropy are concentrated in the coalescence zone between both plutons. The magmatic and sub-magmatic nature of the microstructures demonstrates that such a deformation was caused by the southward overriding of the largest Talita pluton while the Alpa Corral pluton was not yet fully crystallized. Rb-Sr geochronology indicates that this process took place 369±9 Ma ago, long after the Famatinian (Ordovician to Early Devonian) deformation of the country rocks, which confirms a synmagmatic, rather than a regional, deformational event.

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

    SciTech Connect

    Truesdell, A.H.; Lippmann, M.J.

    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.

  18. Velafrons coahuilensis, a new labeosaurine haddrosaurid (Dinosauria: Ornithopoda) from the Late Campanian Cerro del Pueblo formation, Coahuila, Mexico

    USGS Publications Warehouse

    Gates, Terry A.; Sampson, Scott D.; de Jesus, Carlos R. Delgado; Zanno, Lindsay E.; Eberth, David; Hernandez-Rivera, Rene; Aguillon-Martinez, Martha C.; Kirkland, James I.

    2007-01-01

    A new lambeosaurine hadrosaurid, Velafrons coahuilensis, is described as the first lambeosaurine from the Cerro del Pueblo Formation of Coahuila, Mexico, and the first lambeosaurine genus to be named from North America in more than 70 years. Although the holotype specimen is a juvenile individual—as evidenced by its incomplete crest development and relative size compared to other North American lambeosaurines—ontogeny independent autapomor-phies have been identified including quadrate with narrow quadratojugal notch and a postorbital with well developed, dorsally positioned squamosal process. Additionally, this taxon is unique in that the prefrontal is not dorsally deflected and anteroposteriorly expanded as in other lambeosaurine taxa of its size, but rather retains the frontal-prefrontal “clamp” present in smaller individuals of other taxa. Phylogenetic analysis places Velafrons in a polytomy with numerous other fan-crested lambeosaurines. The crest structure of Velafrons more closely resembles that of Corythosaurus and Hypacrosaurus because it possesses an anteriorly projecting nasal process over the dorsal premaxilla process. Biogeo-graphically, Velafrons is one of three distinct hadrosaurids known from approximately 73.5 Ma—two lambeosaurines and one hadrosaurine—all restricted to the southern region of the Western Interior Basin of North America.

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

    NASA Astrophysics Data System (ADS)

    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 (<10 %) microphenocrysts of either olivine or orthopyroxene. The small compositional range and low phenocryst content indicate evolution controlled by low percentages (<10 %) of fractional crystallization of olivine and clinopyroxene of magmas similar to the least evolved rocks from the field, accompanied by assimilation during rapid ascent through the crust. Evolved 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.

  20. Relationship of radon concentration to spacial and temporal variations of reservoir thermodynamic conditions in the Cerro Prieto Geothermal Field

    SciTech Connect

    Semprini, L.; Kruger, P.

    1982-08-10

    Measurements of radon concentration in produced fluids in Cerro Prieto are evaluated with respect to spacial and temporal variations in reservoir thermodynamic conditions and the rock mass to fluid mass ratio emanation. Observed higher concentration of radon at wells with higher fluid enthalpy can be attributed to the higher steam fraction in the wellhead fluid. Correlations of radon concentration to specific volume of pore fluid leads to improved correlations coefficients. The improvement results from the dependence of specific volume on both enthalpy and reservoir temperature. Temporal variations in radon concentration reflect changing phase conditions in the reservoir. Observations over a 2-year interval show significant changes in the producing zones. For example, the constant, low concentration along the western edge of the field indicates a fluid of low steam saturation. In the eastern area, radon concentrations have increased significantly suggesting an increase in the steam saturation in this part of the reservoir due to exploitation. Other areas, e.g., the southeast area, show decreased radon concentration, indicating a decrease in the vapor content of the field. Concurrent measurements of ammonia, a soluble component of the noncondensable gases, support the observation of partitioning of gas components, with wellhead concentration dependent on spacial variations in steam saturation over the field.

  1. Material control and accountability (MC&A) recovery from the Cerro Grande fire at Los Alamos National Laboratory

    SciTech Connect

    Haag, William Earl

    2001-01-01

    During the week of May 10-14, 2000, the Cerro Grande Fire scorched over 40,000 acres of prime forestland and destroyed over 400 homes in the Los Alamos community and several structures at the Los Alamos National Laboratory (LANL). Of the land affected by the fire, nearly one quarter of it was Laboratory property. All of LANL's 64 material balance areas (MBAs) were affected to some degree, but one Category I technical area and several Category I11 and IV areas sustained heavy damage. When the MC&A personnel were allowed to return to work on May 23, they addressed the following problems: How do we assure both ourselves and the Department of Energy (DOE) that no nuclear materials had been compromised? How do we assist the nuclear material (NM) custodians and their operating groups so that they can resume normal MC&A operations? Immediately after the return to work, the Laboratory issued emergency MC&A assurance actions for Category I through Category IV facilities. We conducted special inventories, area walkthroughs, and other forms of evaluation so that within a month after the fire, we were able to release the last MBA to resume work and assure that all nuclear material had been accounted for. This paper discusses the measures LANL adopted to ensure that none of its nuclear material had been compromised.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Composite Chemostratigraphy of Lavas From the Casitas Shield, Descabezado Grande-Cerro Azul Volcanic Complex, Chilean Andes

    NASA Astrophysics Data System (ADS)

    Wulff, A. H.

    2003-12-01

    The Descabezado Grande-Cerro Azul (DGCA) volcanic complex is located at approximately 35.5 degrees S in the transitional Southern Volcanic Zone (SVZ) of the Chilean Andes. The complex is characterized by two large latest Pliocene to early Holocene volcanic edifices and many smaller vents rising above a plateau comprising lavas of an earlier shield-building stage, the Casitas Shield. This plateau has been deeply encised, revealing stacks of lava flows exposed along the valley walls. More than 100 lava flows from eight vertical stratigraphic sections have been analyzed for complete major and trace element abundances. These have been compiled in a composite chemical stratigraphy representing much of the history of this stage of volcanism. At least twelve eruptive episodes were identified based on field observations (soil development, erosional features, mingled top and bottom rubble zones, etc.). Lavas flowed south and west from the proposed vent location(s) primarily filling paleovalleys, constrained to the west by topographic highs composed of tilted metasediments and a granodioritic stock. A number of long flows served as the basis in the field for physical correlations between sections, and were used to evaluate within-flow compositional variation. The top flows on the shield have a single date of .34 My. The composite chemical stratigraphy shows changes in lava compositions reflecting both differences in parental magmas and the secular dominance of certain petrogenetic processes over others. In general, lavas become more evolved through episodes 1-5, and are relatively constant in composition during episodes 6-8. More mafic lavas erupted during episode 9, including lavas that are among the most primitive in the SVZ. These lavas are characterized by high Cr (254-267 ppm) and MgO (8-8.3%), and low LILE, P2O5, Al2O3, Na2O, and K2O, and probably represent a different parental magma. Lavas erupted during episodes 10 and 11 are progressively more evolved, becoming

  4. The Los Alamos Reservoir: A Gauge for Increased Erosion after the Cerro Grande Fire, Los Alamos, New Mexico

    NASA Astrophysics Data System (ADS)

    Lavine, A.; Katzman, D.; Reneau, S. L.; Kuyumjian, G. A.; Gardner, J. N.; Malmon, D. V.

    2001-12-01

    The Cerro Grande fire of May 2000 burned approximately 17,400 ha in the eastern Jemez Mountains in the vicinity of Los Alamos, New Mexico. Changes in surface characteristics caused by the fire, including the development of hydrophobic soils and the loss of vegetation and litter layers, resulted in major increases in runoff and erosion relative to pre-fire conditions. This study documents sedimentation in the Los Alamos reservoir, located in upper Los Alamos Canyon, providing a unique datum for estimating pre- and post-fire erosion rates in a montane watershed. The reservoir was built in 1943 for water storage, and had a maximum holding capacity of ~42,000 m3. The drainage basin upstream from the reservoir has an area of 16.5 km2, ranges in elevation from 2320 to 3180 m, and largely supported a mixed conifer forest prior to the fire. Thirty percent of the basin experienced moderate to high severity burn during the Cerro Grande fire, including some of the steepest parts of the basin; 33% experienced low severity burn and 37% was unburned. Draining of the reservoir to mitigate the potential for flooding down-canyon allowed for detailed surveying of the top of pre- and post-fire sediments. A total station survey in June 2000, following a single post-fire flood, showed a holding capacity of ~34,500 m3. The post-fire deposits in the reservoir were less than 0.3 m thick, and comprised ~1200 m3 of sediment deposited during 1 event. This yields an estimate of ~6200 m3 of sediment accumulation in 57 years, or an average of ~110 m3/yr prior to the fire, equivalent to an average basin-wide denudation rate of ~ 0.007 mm/yr. This low rate is consistent with the well-vegetated nature of the basin prior to the fire, and the absence of evidence for extensive surface runoff and erosion. When the total station survey was repeated in June 2001, a large delta front consisting of gravels and sands had formed a subaerial platform at the head of the reservoir. The post-fire deposits also

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

    SciTech Connect

    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.

  6. Columnar jointing in vapor-phase-altered, non-welded Cerro Galán Ignimbrite, Paycuqui, Argentina

    USGS Publications Warehouse

    Wright, Heather M.; Lesti, Chiara; Cas, Ray A.F.; Porreca, Massimiliano; Viramonte, Jose G.; Folkes, Christopher B.; Giordano, Guido

    2011-01-01

    Columnar jointing is thought to occur primarily in lavas and welded pyroclastic flow deposits. However, the non-welded Cerro Galán Ignimbrite at Paycuqui, Argentina, contains well-developed columnar joints that are instead due to high-temperature vapor-phase alteration of the deposit, where devitrification and vapor-phase crystallization have increased the density and cohesion of the upper half of the section. Thermal remanent magnetization analyses of entrained lithic clasts indicate high emplacement temperatures, above 630°C, but the lack of welding textures indicates temperatures below the glass transition temperature. In order to remain below the glass transition at 630°C, the minimum cooling rate prior to deposition was 3.0 × 10−3–8.5 × 10−2°C/min (depending on the experimental data used for comparison). Alternatively, if the deposit was emplaced above the glass transition temperature, conductive cooling alone was insufficient to prevent welding. Crack patterns (average, 4.5 sides to each polygon) and column diameters (average, 75 cm) are consistent with relatively rapid cooling, where advective heat loss due to vapor fluxing increases cooling over simple conductive heat transfer. The presence of regularly spaced, complex radiating joint patterns is consistent with fumarolic gas rise, where volatiles originated in the valley-confined drainage system below. Joint spacing is a proxy for cooling rates and is controlled by depositional thickness/valley width. We suggest that the formation of joints in high-temperature, non-welded deposits is aided by the presence of underlying external water, where vapor transfer causes crystallization in pore spaces, densifies the deposit, and helps prevent welding.

  7. Soft-bottom crustacean assemblages in Mediterranean marine caves: the cave of Cerro Gordo (Granada, Spain) as case study

    NASA Astrophysics Data System (ADS)

    Navarro-Barranco, C.; Guerra-García, J. M.; Sánchez-Tocino, L.; García-Gómez, J. C.

    2012-12-01

    Although marine caves are priority conservation areas according to the Directive 92/43/CEE of the European Community, there is a lack of studies dealing with their soft-bottom communities. For a case study, we selected the Cerro Gordo cave at 15 m depth. Three different zones were defined: a semi-dark 25-m long entrance area, a dark intermediate area of 35 m, and the final zone at 90 m from the entrance. Sediment samples were taken from these zones as well as from outside the cave (control) by SCUBA diving. Six rectangular cores of 10 × 250 cm2 were collected in each site for macrofaunal study, and three more replicates were taken to analyze physico-chemical parameters. The granulometry showed a clear gradient from medium sands outside the cave to silt and clay in the inner zone. Measurements of the crustacean assemblages showed that the number of species and abundance were significantly higher outside the cave (30-40 species, >4,000 ind m-2) than inside (5-10 species, <1,000 ind m-2). Multivariate analyses showed a clear difference in species composition between outside and inside the cave. Caprellids, tanaids, cumaceans, and decapods were only found outside the cave, while gammarids and isopods were present both outside and inside the cave. The gammarid Siphonoecetes sabatieri and the tanaid Apseudes latreilli were the dominant species outside the cave, while the gammarids Harpinia pectinata, Harpinia crenulata, and Harpinia ala were dominant inside. The present study represents an increase in depth range and geographic distribution for Kupellonura mediterranea and Monoculodes packardi. This is the first description of soft-bottom crustacean communities from submarine caves of southern Spain.

  8. Observations of a Breakdown of a Mountain Wave Near 84 km Altitude Over Cerro Pachon Chile from the Andes Lidar Observatory

    NASA Astrophysics Data System (ADS)

    Hecht, J. H.; Gelinas, L. J.; Rudy, R. J.; Walterscheid, R. L.; Taylor, M. J.; Pautet, P. D.; Fritts, D. C.; Smith, S. M.; Franke, S. J.; Mlynczak, M. G.

    2015-12-01

    Mountain waves are produced by flow over orography. They propagate almost vertically, and are characterized by nearly zero velocity phase speed. The altitude to which they typically propagate is not well documented. They are thought to mainly dissipate by absorption in a critical layer although large-amplitude wave breakdown is also thought to occur. There have been almost no direct observations of the breakdown of mountain waves in the upper mesosphere and lower thermosphere. The region over Cerro Pachon Chile (a 2715 meter mountain in the Andes where large astronomical telescopes are located) is especially favorable to the production of mountain waves. In 2009 Smith and colleagues reported on the first observations of such waves propagating into the mesopause region (85 to 95 km) from El Leoncito Argentina, where waves over Cerro Pachon could be seen using airglow observations. The Aerospace Corporation's Nightglow Imager (ANI) is located at the Andes Lidar Observatory near the crest of Cerro Pachon. ANI observes nighttime OH emission (near 1.6 microns) every 2 seconds over an approximate 73 degree field of view. ANI had previously been used to the breakdown of Kelvin-Helmholtz instability features not associated with a specific gravity wave. Here we present OH airglow observations, originating near 84 km, from 22 UT to 3 UT on 8/9 July 2012 that show the breakdown of a mountain wave into instability features that subsequently dissipate into turbulence. These multi-hour observations provide the most detailed images to date of the breakdown of a mountain wave. The causes for, and the results of, the breakdown of this mountain wave are discussed.

  9. Cerro Toledo Rhyolite, Jemez Volcanic Field, New Mexico: {sup 40}Ar/{sup 39}Ar geochronology of eruptions between two caldera-forming events

    SciTech Connect

    Spell, T.L. |; McDougall, I.; Doulgeris, A.P.

    1996-12-01

    The Cerro Toledo Rhyolite comprises a group of domes and tephra which were erupted during the interval between two caldera-forming ignimbrites, the Tshirege Member and Otowi Member of the Bandelier Tuff, in the Jemez Volcanic Field, New Mexico. To provide a chronologic framework for geochemical and isotopic studies on these rhyolites, which record the evolution of the Bandelier magma system during this interval, a {sup 40}Ar/{sup 39}Ar geochronology study was undertaken. Pumice from major pyroclastic fall deposits within the rhyolite tephra and samples from the rhyolite domes were dated as well as the stratigraphically bracketing Bandelier Tuff. The {sup 40}Ar/{sup 39}Ar ages for the two members of the Bandelier Tuff Yield and interval of 380{+-}20 k.y. between these caldera forming eruptions. During this interval nine major pyroclastic pumice units were deposited in the sections studies, for which six yield isochron ages, one a weighted mean age, one a maximum age, and one no reliable age due to lack of sanidine. {sup 40}Ar/{sup 39}Ar dates on pumice fall units within the Cerro Toledo Rhyolite tephra indicate that eruptive activity occurred at > 1.59, 1.54, 1.48, 1.37 and 1.22 Ma. {sup 40}Ar/{sup 39}Ar dating of Cerro Toledo Rhyolite domes indicates these were erupted within the caldera at 1.54, 1.45, 1.38-1.34, and 1.27 Ma. The dates obtained indicate that eruptive activity occurred throughout the 380 k.y. interval between the two members of the Bandelier Tuff, but suggest that eruptions producing both tephra and domes occurred during discrete intervals at ca. 1.54, 1.48 and 1.38-1.34 Ma. 43 refs., 5 figs., 3 tabs.

  10. Contrasting compositional trends of rocks and olivine-hosted melt inclusions from Cerro Negro volcano (Central America): implications for decompression-driven fractionation of hydrous magmas

    NASA Astrophysics Data System (ADS)

    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 (<1 wt %) from primitive basaltic melt (average SiO2 = 49 wt %, MgO = 7.6 wt %, H2O = 6 wt %) as it ascended to the surface from the depth of about 14 km. The crystallization occurred at increasing liquidus temperature from 1,050 to 1,090 °C in the pressure range from 400 to 50 MPa and was induced by release of mixed H2O-CO2 fluid from the melt at decreasing pressure. Matrix glass compositions fall at the high-Si end of the melt inclusion trend and represent the final stage of melt crystallization during and after eruption. The bulk compositions of erupted Cerro Negro magmas (tephras and lavas) range from high- to low-MgO (3-10 wt %) basalts, which form a compositional array crossing the trend of melt inclusions so that virtually no rock from Cerro Negro has composition akin to true melt represented by the inclusions. The variations of the bulk magma (rocks) and melt (melt inclusions) compositions can be generated in a dyke connecting a deep primitive magma reservoir with the Cerro Negro edifice. While the melt inclusions represent the compositional trend of instantaneous melts along the magma pathway at decreasing pressure and H2O content, occurrence of low-Mg to 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.

  11. Characterization of Cerro Negro crude. Part I. Physical and chemical separations. [Project shared by Bartlesville Energy Technology Center, US DOE, and Institute de Tecnologico del Venezolana Petroleo

    SciTech Connect

    Grizzle, P.L.; Green, J.B.; Sanchez, V.; Murgia, E.; Lubkowitz, J.

    1981-09-01

    The scheme couples distillation and ion exchange and solid liquid chromatography in an attempt to prepare narrow-boiling, chemically unique fractions, which can be analyzed further or can supply data for process development. For evaluation of the separation approach, a Cerro Negro crude from the Venezuelan Orinoco basin has been studied in a cooperative program between the United States Department of Energy and the Institute de Tecnologico del Venezolana Petroleo. These fractions may be analyzed by ir, uv, fluorescence, and nuclear magnetic resonance spectroscopy, as well as various mass spectroscopy methods. The approach appears to be promising. 5 figures, 6 tables.

  12. Geochemistry of the Neoproterozoic (800-767 Ma) Cerro Bori orthogneisses, Dom Feliciano Belt in Uruguay: tectonic evolution of an ancient continental arc

    NASA Astrophysics Data System (ADS)

    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.

  13. Analysis of heavy oils: Method development and application to Cerro Negro heavy petroleum: Preliminary separation and analysis of acid, base, saturate, and neutral-aromatic fractions

    SciTech Connect

    Green, J.B.; Sturm, G.P. Jr.; Reynolds, J.W.; Thomson, J.S.; Yu, S.K-T.; Grigsby, R.D.; Tang, S.Y.; Shay, J.Y.; Hirsch, D.E.; Sanchez, V.

    1988-10-01

    Cerro Negro 200-425/degree/, 425-550/degree/, and 550-700/degree/C distillates and >700/degree/C residue were separated into acid, base, and neutral concentrates using an improved nonaqueous ion exchange liquid chromatographic procedure. Neutral concentrates were further separated into neutral aromatic and saturated hydrocarbon fractions. A dual column, normal phase high performance liquid chromatographic method was developed for the saturate-aromatic separation. Mass and elemental balances are given for separations of all distillates and the residue. In addition, fractions from the 200-425/degree/C and 425-550/degree/C distillates were analyzed by high resolution mass spectrometry. The applicability of published separation approaches and methods to heavy oil analysis is critically reviewed; the bulk of the available methodology developed for conventional petroleum and synfuels was found to be unproven or unsuitable for heavy oil analysis. Cerro Negro was found to contain 18.2 weight percent acids, 17.6 weight percent bases, 46.9 weight percent neutral aromatics, and 14.7 weight percent saturated hydrocarbons. Saturate fractions contained predominantly cycloparaffins, neutral-aromatics were largely comprised of aromatic hydrocarbons and sulfur compounds, bases were largely nitrogen-containing compounds, and acids were mostly oxygen-containing compounds and nitrogen compounds of pyrrolic type. 145 refs., 24 figs., 21 tabs.

  14. Proposed Future Disposition of Certain Cerro Grande Fire Flood and Sediment Retention Structures at Los Alamos National Laboratory, Los Alamos, New Mexico

    SciTech Connect

    N /A

    2002-08-07

    This environmental assessment (EA) has been prepared to analyze the environmental consequences resulting from the future disposition of certain flood retention structures built in the wake of the Cerro Grande Fire within the boundaries of Los Alamos National Laboratory (LANL). In May 2000, a prescription burn, started on Federally-administered land to the northwest of LANL, blew out of control and was designated as a wildfire. This wildfire, which became known as the Cerro Grande Fire, burned approximately 7,650 acres (3,061 hectares) within the boundaries of LANL before it was extinguished. During the fire a number of emergency actions were undertaken by the Department of Energy (DOE), National Nuclear Security Administration (NNSA) to suppress and extinguish the fire within LANL; immediately thereafter, NNSA undertook additional emergency actions to address the post-fire conditions. Due to hydrophobic soils (non-permeable soil areas created as a result of very high temperatures often associated with wild fires) and the loss of vegetation from steep canyon sides caused by the fire, surface runoff and soil erosion on hillsides above LANL were greatly increased over prefire levels. The danger to LANL facilities and structures and homes located down-canyon from the burned area was magnified.

  15. Recycling of water, carbon, and sulfur during subduction of serpentinites: A stable isotope study of Cerro del Almirez, Spain

    USGS Publications Warehouse

    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.

  16. The ~ 2500 yr B.P. Chicoral non-cohesive debris flow from Cerro Machín Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    Murcia, H. F.; Hurtado, B. O.; Cortés, G. P.; Macías, J. L.; Cepeda, H.

    2008-04-01

    Cerro Machín Volcano (CMV) is located in the central part of the Colombian Andes (2750 m asl), 150 km southwest of Bogotá. It is considered the most dangerous active volcano of Colombia. CMV has experienced at least six major explosive eruptions during the last 5000 years. These eruptions have emplaced many types of pyroclastic deposits with associated lahars that have traveled more than 100 km. One of these lahars is called Chicoral Debris Flow Deposit (DFD2). This deposit is exposed as discontinuous terraces (3-20 m thick) along the Coello and Magdalena rivers up to 109 km from the source. The DFD2 covers a minimum area of 62 km 2 and has a minimum volume of 0.57 km 3. It comprises two dacite-rich volcaniclastic units. Grain-size analysis reveals that the matrix content and sorting increase with distance while the average grain size decreases. The clay content of the DFD2 matrix is approximately 1%, thus categorizing it as a non-cohesive debris flow. Radiocarbon dates obtained from underlying and overlying paleosols yielded ages of 2505 + 65 and 1640 + 45 yr B.P., respectively. These dates suggest that DFD2 is related to the ~ 2600 yr B.P. El Guaico eruption of CMV. This eruption produced a block-and-ash flow that filled and blocked the Toche River up to 5 km from the volcano. Subsequent remobilization of this loose material by runoff water generated a massive debris flow that traveled 91 km along the Toche and Coello rivers and continued across the Espinal Alluvial Fan debouching into the Magdalena River where it continued another 18 km prior to its transformation into a sediment-laden flow. Because the last eruption of the volcano occurred ca. 900 years ago, no historic activity of CMV is known among inhabitants of the region. Hence the region has developed without awareness of volcanic hazards. Therefore an assessment of volcanic hazards is essential for understanding and evaluating the vulnerability and risk to which people are exposed in case of a future

  17. The Temporal and Spatial Association of Faulting and Volcanism in the Cerros del Rio Volcanic Field - Rio Grande Rift, USA

    NASA Astrophysics Data System (ADS)

    Thompson, R. A.; Hudson, M. R.; Minor, S. A.; McIntosh, W. C.; Miggins, D. P.; Grauch, V.

    2008-12-01

    The Plio-Pleistocene Cerros del Rio volcanic field (CdRVF) in northern New Mexico is one of the largest ( greater than 700 square kilometers) predominantly basaltic and andesitic volcanic centers of the Rio Grande rift; it records the late-stage, volcano-tectonic evolution of the SW part of the Espanola Basin. The CdRVF reflects both regional proclivity toward Pliocene basaltic volcanism following protracted Neogene extensional tectonism and localized eruptive response to migration of basin- bounding faults. Approximately 180 cubic kilometers of flat lying to gently dipping basalt, andesite, and minor dacite lava flows and pyroclastic deposits of the CdRVF were erupted from more than 50 exposed vents between 2.8 Ma and 1.14 Ma. Subsurface interpretations of drill hole data and incised canyon exposures of the Rio Grande show that volcanic deposits are interbedded with Santa Fe Group sediments deposited in actively subsiding sub-basins of the southernmost Espanola Basin. Major basin-bounding faults in this area strike north to northwest, dip basinward, and have mostly dip-slip and subordinate strike-slip displacement. Although major basin-bounding faults were active prior to the onset of volcanism in the CdRVF, protracted extension resulted in a westward migration of graben-bounding faults. Phases of coeval volcanism at 2.8-2.6 Ma, 2.5-2.2 Ma, and 1.5-1.1 Ma, decreased in eruptive volume through time and are delineated on the basis of mapped stratigraphy, argon geochronology, paleomagnetic and aeromagnetic properties, and record a syntectonic westward migration of eruptive centers. The alignment of vent areas with mapped faults strongly suggests deep magmatic sources utilized local structures as conduits (i.e. faults and fractures developed in response to regional stress). However, some near-surface feeder dikes associated with eroded cinder cones record orientations that are not typically correlative with regional fault patterns suggesting near-surface conduits are

  18. Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de la Muerte, Costa Rica.

    PubMed

    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

  19. NMR and GC/MS investigation of the saturate and distillate fractions from the Cerro Negro heavy petroleum crude

    SciTech Connect

    Netzel, D. A.; Guffey, F. D.

    1987-08-01

    Six fractions of the Cerro Negro heavy petroleum crude have been evaluated using nuclear magnetic resonance spectroscopy (NMR) and gas chromatography/mass spectrometry (GC/MS). The fractions include four saturated hydrocarbon distillate fractions distilling above 200/sup 0/C (200 to 425/sup 0/C (392 to 797/sup 0/F), 425 to 550/sup 0/C (797 to 1022/sup 0/F), 550 to 700/sup 0/C (1022 to 1292/sup 0/F), and >700/sup 0/C (>1292/sup 0/F)) and two distillate subfractions designated as <200/sup 0/C and >200/sup 0/C. The >700/sup 0/C and 550 to 700/sup 0/C saturated hydrocarbon fractions are not suited for analyses by combined GC/MS because their distillation ranges are higher than the upper limit of material that will elute from the gas chromatographic column. The /sup 1/H and /sup 13/C NMR spectral data for the 550 to 700/sup 0/C and >700/sup 0/C fractions indicate that normal and branched alkanes with an average carbon chainlength of C/sub 10/ are present but must be bonded to a larger molecular moiety based upon mass spectral evidence and boiling point considerations. Normal and branched alkanes were not detected in either 200 to 425/sup 0/C or 425 to 550/sup 0/C samples at concentrations of 0.01% by weight. NMR data for the 200 to 425/sup 0/C fraction give no indication of normal alkanes with C chainlengths >9. Branched alkanes possibly of the isoprenoid-like structure are present. The average molecular structural representation is an alkyl-substituted dicyclic alkane. Average molecular structural representation for the 425 to 550/sup 0/C fraction is also an alkyl-substituted dicyclic alkane. However, at least one of the alkyl substituents has a chainlength >10. Both normal and branched alkanes of C/sub 7-12/ were detected in the <200/sup 0/C subfraction. Alkanes of C/sub 12-31/ were in the >200/sup 0/C sample. /sup 1/H and /sup 13/C spectra for both subfractions indicate similar chemical composition. 12 refs., 6 figs., 8 tabs.

  20. Metamorphic evolution of the Río de la Plata Craton in the Cinco Cerros area, Buenos Aires Province, Argentina

    NASA Astrophysics Data System (ADS)

    Massonne, Hans-Joachim; Dristas, Jorge A.; Martínez, Juan Cruz

    2012-10-01

    A metapelite and an interlayered granite were studied from the Cinco Cerros area ca. 65 km WNW of the city of Mar del Plata. Garnet in these samples is slightly zoned with core and rim compositions of pyr17(gro + andr)6spes1.5alm75.5 and pyr13.5(gro + andr)5.5spes2alm80, respectively, in the metapelite. Corresponding compositions in the granite are pyr15(gro + andr)3.5spes3.5alm78 and pyr11(gro + andr)3.5spes4.5alm81. We used the PERPLE_X computer software package to calculate P-T pseudosections. From the pseudosection of the metapelite P-T conditions of 6.7 kbar and 670 °C were derived for an early metamorphic stage. Subsequently, a pressure release occurred at decreasing temperatures. The final metamorphic P-T conditions recorded by the studied rock are 4.5 kbar and 600 °C compatible with the absence of cordierite, staurolite, and an Al2SiO5-phase. Garnet in the granitoid crystallized between 715 and 690 °C at a pressure around 7.7 kbar. U-Th-Pb age dating with the electron microprobe was performed. 16 analyses of monazite in the metapelite formed three clusters resulting in ages of I: 2073 ± 11.4 (1σ) Ma, II: 1913 ± 11.0 (1σ) Ma, and III: 1805 ± 20.8 (1σ) Ma. Thus, the Paleoproterozoic metamorphic event can be related to the Trans-Amazonian cycle and was followed by slow cooling. As our study area is close to the margin of the Río de la Plata Craton, where abundant magmatic arc-derived plutonic rocks are outcropping, we interpret the derived P-T data as follows: A heating event (not recorded by the studied rocks) resulted from magmas that intruded during the Trans-Amazonian cycle. This event was followed by slow exhumation, probably caused by erosion, accompanied by thermal relaxation.

  1. Rock-magnetism and ore microscopy of the magnetite-apatite ore deposit from Cerro de Mercado, Mexico

    NASA Astrophysics Data System (ADS)

    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

  2. Geochemical homogeneity of a long-lived, large silicic system; evidence from the Cerro Galán caldera, NW Argentina

    NASA Astrophysics Data System (ADS)

    Folkes, Chris B.; de Silva, Shanaka L.; Wright, Heather M.; Cas, Raymond A. F.

    2011-12-01

    By applying a number of analytical techniques across a spectrum of spatial scales (centimeter to micrometer) in juvenile components, we show that the Cerro Galán volcanic system has repeatedly erupted magmas with nearly identical geochemistries over >3.5 Myr. The Cerro Galán system produced nine ignimbrites (˜5.6 to 2 Ma) with a cumulative volume of >1,200 km3 (DRE; dense rock equivalent) of calc-alkaline, high-K rhyodacitic magmas (68-71 wt.% SiO2). The mineralogy is broadly constant throughout the eruptive sequence, comprising plagioclase, quartz, biotite, Fe-Ti oxides, apatite, and titanite. Early ignimbrite magmas also contained amphibole, while the final eruption, the most voluminous Cerro Galán ignimbrite (CGI; 2.08 ± 0.02 Ma) erupted a magma containing rare amphibole, but significant sanidine. Each ignimbrite contains two main juvenile clast types; dominant "white" pumice and ubiquitous but subordinate "grey" pumice. Fe-Ti oxide and amphibole-plagioclase thermometry coupled with amphibole barometry suggest that the grey pumice originated from potentially hotter and deeper magmas (800-840°C, 3-5 kbar) than the more voluminous white pumice (770-810°C, 1.5-2.5 kbar). The grey pumice is interpreted to represent the parental magmas to the Galán system emplaced into the upper crust from a deeper storage zone. Most inter-ignimbrite variations can be accounted for by differences in modal mineralogy and crystal contents that vary from 40 to 55 vol.% on a vesicle-free basis. Geochemical modeling shows that subtle bulk-rock variations in Ta, Y, Nb, Dy, and Yb between the Galán ignimbrites can be reconciled with differences in amounts of crystal fractionation from the "grey" parent magma. The amount of fractionation is inversely correlated with volume; the CGI (˜630 km3) and Real Grande Ignimbrite (˜390 km3) return higher F values (proportion of liquid remaining) than the older Toconquis Group ignimbrites (<50 km3), implying less crystal fractionation took

  3. Mapping the edge of the Cerros del Rio volcanic field, New Mexico: a piece of the puzzle to understanding a potential geothermal resource

    NASA Astrophysics Data System (ADS)

    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

  4. Facies Variations Along an Ancient Deep-Water Axial Channel Belt: Insights from the Upper Cretaceous Cerro Toro Formation, Magallanes-Austral Basin, Patagonia

    NASA Astrophysics Data System (ADS)

    Malkowski, M. A.; Jobe, Z. R.; Sharman, G.; Graham, S. A.

    2015-12-01

    The Upper Cretaceous Cerro Toro Formation preserves a >150 kilometer long deep-water axial channel belt in the Magallanes-Austral Basin in southern Patagonia. Considerable work over the past decade in the Chilean basin sector reveals a 3.5-8 km wide channel-levee system that transported coarse-grained sediment from north to south via a range of low- to high-density turbidity currents, debris flows, and transitional/hybrid flows. In contrast, the more proximal deposits preserved in the Argentine basin sector to the north received little focus. This study documents new sedimentology, stratigraphy, and U-Pb geochronology from the Cerro Toro Formation in Argentina, allowing for a basin-scale comparison of the timing of deposition, sediment sources, and facies and grain size variability. Two ash beds from the base of the section yield U-Pb zircon ages of 90.4 ± 2 Ma and 88.0 ± 3 Ma, suggesting similar, if not slightly older, ages for the lower Cerro Toro Formation when compared to equivalent units to the south. U-Pb detrital zircon age spectra reveal similar provenance trends along the entire outcrop belt, with peak age populations at 310-260, 160-135, and 110-82 Ma. Preliminary statistical analyses of more than 5700 meters of new and previously published detailed stratigraphic sections suggest that, in general, characteristics such as mean bed thickness and net to gross remain fairly consistent along the outcrop belt. However, the bed thickness distributions are log-normal, and the northern sector has higher maximum bed thickness than the southern sector. There are also gradual variations in the down-system (north to south) proportion of lithofacies. For instance, in the northern (Argentine) sector, lithofacies representing mass wasting processes (e.g., debris flow conglomerates and mass-transport deposits) account for as much as ~80 percent of the stratigraphic thickness, whereas near the southern end of the channel belt, coarse-grained facies are almost entirely

  5. Paleogeography And Diachronous Infill Of An Ancient Deep-Marine Foreland Basin, Upper Cretaceous Cerro Toro Axial Channel, Magallanes Basin, Chile

    NASA Astrophysics Data System (ADS)

    Bernhardt, A.; Jobe, Z. R.; Grove, M.; Lowe, D. R.

    2011-12-01

    The details of how narrow, orogen-parallel ocean basins are filled with sediment by large axial submarine channels is important to understand because these depositional systems commonly form in through-like basins in various tectonic settings. The Magallanes foreland basin is an excellent location to study an orogen-parallel deep-marine system. Conglomerate lenses of the Upper Cretaceous Cerro Toro Formation have been previously interpreted to represent the fill of a single submarine channel (4-8 km wide, > 100 km long) that funneled coarse detritus southward along the basin axis. This interpretation was based on lithologic correlations. New U/Pb dating of zircons from volcanic ashes and sandstones, coupled with strontium isotope stratigraphy, refine the controls on depositional ages and provenance. Results demonstrate that north-south oriented conglomerate lenses are contemporaneous within error limits (~ 84-82 Ma) supporting that they represent parts of an axial channel belt. Channel deposits 20 km west of the axial location are 87-82 Ma in age. These channels are partly contemporaneous with the ones within the axial channel belt, making it likely that they represent feeders to the axial channel system. The northern Cerro Toro Formation spans an Turonian to Campanian interval (~ 90-82 Ma) whereas the formation top, 70 km to the south, is as young as ~ 76 Ma. Kolmogorov-Smirnoff statistical analysis on detrital zircon age distributions shows that the northern uppermost Cerro Toro Formation yields a statistically different age distribution than other samples from the same formation but shows no difference relative to the overlying, much finer-grained Tres Pasos Formation. These results suggest the partly coeval deposition of both formations representing the gradual transition from an out-of-grade to a graded margin system. Integration of previously acquired geochronologic and stratigraphic data with new data show a pronounced southward younging pattern in all four

  6. Operation and Performance of a Biphase Turbine Power Plant at the Cerro Prieto Geothermal Field (Final Report)

    SciTech Connect

    Hays, Lance G.

    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

  7. Quaternary eruptive history and hazard-zone model at Nevado del Tolima and Cerro Machin volcanoes, Colombia

    NASA Astrophysics Data System (ADS)

    Thouret, J. C.; Cantagrel, J.-M.; Robin, C.; Murcia, A.; Salinas, R.; Cepeda, H.

    1995-07-01

    areas potentially affected by future eruptions both at Nevado del Tolima and at active Cerro Machin 12 km southward. The extent of areas likely to be affected by tephra-falls, debris flows, pyroclastic flows or surges, debris avalanches and lava flows is shown. Subplinian and plinian eruptions of Nevado del Tolima were used to represent the moderate and large events to be expected. 300,000 people live within a 35-km distance from those volcanoes, which have exhibited a behaviour more explosive than Nevado del Ruiz. Despite the small-sized ice cap, debris flows are the most probable hazard for even a minor eruption, because of the very steep slope gradient, and because of probable interactions of hot eruptive products with ice and snow. Additionally, scoria flows and debris avalanches can be directed toward the southeast and could be transformed into debris flows that would devastate the Combeima valley and suburbs of Ibaguécity, where about 50,000 people live

  8. Diverse mantle and crustal components in lavas of the NW Cerros del Rio volcanic field, Rio Grande Rift, New Mexico

    NASA Astrophysics Data System (ADS)

    Duncker, K. E.; Wolff, J. A.; Harmon, R. S.; Leat, P. T.; Dickin, A. P.; Thompson, R. N.

    1991-09-01

    Products of Pliocene (2 4 Ma) mafic to intermediate volcanism in the northwestern Cerros del Rio, a dominantly mafic volcanic field in the Española Basin of the Rio Grande Rift (RGR), range from 49% to 63% SiO2 and exhibit diversity in silica saturation, trace-element patterns, and isotopic compositions. Tholeiites, which are largely confined to west of the Rio Grande, have trace-element abundances that resemble those of oceanic basalts, but with mild depletions in Nb and Ta, and high 87Sr/86Sr, low 143Nd/144Nd, and high δ18O compared to typical OIB. They are regarded as asthenospherically-derived magmas contaminated with continental crust. Alkali basalts and hawaiites erupted from vents east of the Rio Grande are geochemically distinct, having generally higher overall incompatible-element abundances, but with pronounced depletions in K, Rb, Nb and Ta with respect to Th and LREE. Spatially-associated benmoreites, mugearites and latites (collectively termed “evolved” lavas) have similar trace-element characteristics to the mafic mildly-alkaline compositions, but are typically not as depleted in K. Hawaiites and evolved lavas exhibit a good negative correlation of 143Nd/144Nd with SiO2, due to interaction with lower continental crust. The most silicic “evolved” lavas carry the highest proportions of crustal material, and consequently have higher K/Th than the related hawaiites. Several (mostly mafic) lavas contain abundant crustally-derived resorbed quartz xenocrysts in O-isotope disequilibrium with the host magma. The δ18O values of xenocrystic quartz range over 4‰, indicating a variety of quartz-bearing crustal contaminants beneath the Española Basin. The hawaiites, with their unusual combination of trace-element enrichments and depletions, cannot be generated by any process of fractionation or crustal contamination superposed on a common mantle source type (oceanic or arc-source). It is a regional mantle source type, inasmuch as it was also present

  9. Experimental constraints on the origin of K-rich melts erupted at Cerro La Pilita, Central Mexico

    NASA Astrophysics Data System (ADS)

    Weaver, S.; Wallace, P. J.; Johnston, A.

    2011-12-01

    The variability of SiO2, K2O, and H2O in primitive arc lavas indicates a heterogeneous distribution of slab-derived components and variability in source mineralogy in the subarc mantle. These heterogeneities are most prominent beneath continental arcs, as seen in the wide geochemical range of primitive lavas that produce the cinder cones of Central Mexico. For example, despite their close proximity (within 3 km) Cerro La Pilita and Volcán Jorullo produced geochemically distinct primitive melts (shoshonite at La Pilita: SiO2=49.2, K2O=2.8, MgO=8.3; med-K basaltic andesite at Jorullo: SiO2=52.1, K2O=0.7, MgO=9.3). These compositional differences suggest geochemical heterogeneity in the mantle source. Previous work has constrained the source composition for Jorullo melts to be harzburgite (depleted mantle). Here we present the results of piston-cylinder experiments aimed at determining the potential source mineralogy that produced the K-rich melts of La Pilita. We performed high-P, high-T experiments to determine the H2O-undersaturated phase relations of La Pilita melt JOR-46. Barclay and Carmichael (2004) reproduced the erupted phenocryst assemblage of JOR-46 at H2O-saturated conditions and indicate that La Pilita lavas contained at least 2.5-4.5 wt% H2O during phenocryst equilibration. We used these H2O estimates to justify near-liquidus experiments from 1.0-2.0 GPa with 5 wt% H2O. By constraining the H2O-undersaturated liquidus we can describe the permissible mantle residuum JOR-46 last equilibrated with prior to segregation. Preliminary results for JOR-46 suggest that from 1.1-1.4 GPa, olivine(ol)+spinel(sp)±clinopyroxene(cpx) crystallize on the liquidus. At higher pressures, ol becomes unstable and cpx is the primary crystalline phase. The liquidus temperature ranges from ~1150°C to 1200°C from 1.1-1.7 GPa. The melt is multiply saturated with an ol+cpx assemblage to 1.4 kbar at 1150°C. We do not observe orthopyroxene(opx) in any high-pressure experiments

  10. The 2011 Cerro Hudson volcano eruption (Southern Andes, Chile): Pre-eruptive inflation and hot spots observed with InSAR and thermal imagery

    NASA Astrophysics Data System (ADS)

    Delgado, F.; Pritchard, M. E.; Lohman, R. B.

    2013-12-01

    Cerro Hudson is one of most active volcanoes of the Southern Andes with at least 12 documented Holocene eruptions including two large caldera forming eruptions (VEI>6) at 6700 and 3600 years BP and one of the largest eruptions of the 20th century in 1991 -- VEI of 5 and ~2.7 km3 of dense rock equivalent erupted material. The volcano had smaller eruptions in 1971 (VEI 3) and 2011 (VEI of 1-2), but despite its persistent activity, there is little monitoring because of its remote location. In this work we focus on remote sensing observations to better characterize the activity of Cerro Hudson between the 1991 and 2011 eruptions and during the 2011 eruption. Our primary technique is satellite-based interferometric synthetic aperture radar (InSAR). Although InSAR studies at Cerro Hudson are challenging given the poor data coverage as well as the presence of ice, snow and vegetation, the data show that the volcano inflated between 2004 and 2010 with a maximum range change rate between 2 and 3 cm/yr, about half of the deformation rate observed during a previously detected deformation episode from 1993-1999. Inversion for an inflating point source suggests magma accumulation beneath the SW part of the caldera at an average depth of 10 km -- deeper than the depths estimated for the magma chamber of the 1991 eruption (3 km) and a deformation event between 1993 and 1999 (5-6 km), and in a slightly different location with smaller volume changes. The center of deformation is located a few km away from the eruption location near the caldera ring fault, but the predicted static Coloumb stress changes due to the inferred inflation source would enhance motion on the caldera ring fault, suggesting that the deformation and eruptive vents may be linked. We also analize nighttime satellite thermal images from MODIS and ASTER for pixel-integrated temperatures above the background temperatures in the ice filled caldera. While MODIS did not show any unambiguous evidence for the eruption

  11. Distribution of metals in acid-base-neutral fractions of Cerro Negro 550-700 degree C distillate and 700 degree C+ residue

    SciTech Connect

    Pearson, C.D.; Green, J.A.; Green, J.B.; Anderson, R.P. )

    1989-04-01

    Heavy crude oils generally have high metals content and are difficult to upgrade. Vanadium and nickel are among the most common metals and can cause catalyst poisoning and corrosion during processing. The continuing decrease in reserves of conventional crude oil has made it increasingly important that new techniques be developed for demetallization to permit upgrading and use of these difficult resources. Knowledge of the chemical composition of nickel and vanadium complexes in petroleum will assist the process designer to devise better demetallization processes. This paper describes a new approach to the speciation of metals in crude oils and residues. The Cerro Negro 550-700{degree}C distillate and 700{degree}C+ residue are broken down into acid, base, and neutral fractions and the nickel, vanadium, and iron determined in each fraction. An attempt is made to answer the questions: (1) is distribution governed by the chemical structure of the metalloorganic molecules; (2) within a given chemical fraction, are subfractions present which contain a major portion of the total metal content; (3) does the particular metal (i.e., Ni vs V) affect the separation behavior This paper is the sixth and final chapter in a book describing the development of analytical methodology for the analytical characterization of Cerro Negro Orinoco belt crude oil. Chapters already published address the distillation and determination of routine physical and chemical properties, the separation of acid, base, and neutral fractions and saturate/aromatic split of the neutral fractions, and the detailed separation and analysis of sulfur compounds and aromatic hydrocarbons. The chapters on detailed separation and analysis of acidic and basic compounds are currently being written. They are based on previously reported analytical procedures.

  12. The structure and evolution of magmatic complexes in fold-and-thrust belts - a case study of Cerro Negro, Neuquén Province, Argentina

    NASA Astrophysics Data System (ADS)

    Gürer, D.; Galland, O.; Leanza, H. A.; Sassier, C.; Cobbold, P. R.; Rossello, E. A.

    2012-04-01

    In contrast to the classical concept of magma ascent in extensional settings, recent studies show that volcanism also occurs in compressional settings. The nature of the interplay between magmatism and tectonics in fold-and-thrust belts however, remains a major question, notably in active margins. The mechanisms of magma transport in such settings and whether magmatism affects tectonic deformation need to be addressed. Therefore, we carried out detailed structural mapping and sampling of an intrusive complex: the Cerro Negro of Tricao Malal, Neuquén Province, Argentina. This intrusive system belongs to a magmatic province that intruded into the intensely deformed Agrio fold-and-thrust belt, located between 37°S and 38°S in the Argentinean foothills of the Andes. The fold-and-thrust belt has resulted from intense E-W shortening, and contains tight folds and thrusts, trending N-S. The intrusive complex crops out as a network of sills and dykes around a main intrusion, all of which are of andesitic composition. The plumbing system of Cerro Negro is well exposed so that the structural relations between the intrusions and the tectonic structures can be studied. We have identified at least two generations of intrusions: two thick sills that predate or are coeval with deformation, and numerous sub-vertical dykes that strike N-S, i.e. perpendicular to the shortening. We observed that the main intrusive body and the dykes have formed in a central anticline, the dykes being close to the hinge. Furthermore, the dykes crosscut folded sills, postdating all visible deformation. From the structural and temporal relationships between the anticline and the dykes, we infer that local stresses controlled the formation of the dykes during outer-arc stretching. This illustrates how tectonic deformation may control magma emplacement. Conversely, the traces of the main tectonic structures curve around the intrusive complex, suggesting that the latter influenced the tectonic

  13. Geology, geochronology, and geochemistry of basaltic flows of the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra, central New Mexico

    USGS Publications Warehouse

    Maldonado, F.; Budahn, J.R.; Peters, L.; Unruh, D.M.

    2006-01-01

    The geochronology, geochemistry, and isotopic compositions of basaltic flows erupted from the Cat Hills, Cat Mesa, Wind Mesa, Cerro Verde, and Mesita Negra volcanic centres in central New Mexico indicate that each of these lavas had unique origins and that the predominant mantle involved in their production was an ocean-island basalt type. The basalts from Cat Hills (0.11 Ma) and Cat Mesa (3.0 Ma) are similar in major and trace element composition, but differences in MgO contents and Pb isotopic values are attributed to a small involvement of a lower crustal component in the genesis of the Cat Mesa rocks. The Cerro Verde rock is comparable in age (0.32 Ma) to the Cat Hills lavas, but it is more radiogenic in Sr and Nd, has higher MgO contents, and has a lower La/Yb ratio. This composition is explained by the melting of an enriched mantle source, but the involvement of another crustal component cannot be disregarded. The Wind Mesa rock is characterized by similar age (4.01 Ma) and MgO contents, but it has enriched rare-earth element contents compared with the Cat Mesa samples. These are attributed to a difference in the degree of partial melting of the Cat Mesa source. The Mesita Negra rock (8.11 Ma) has distinctive geochemical and isotopic compositions that suggest a different enriched mantle and that large amounts of a crustal component were involved in generating this magma. These data imply a temporal shift in magma source regions and crustal involvement, and have been previously proposed for Rio Grande rift lavas. ?? 2006 NRC Canada.

  14. Identification and Antioxidant Activity of the Extracts of Eugenia uniflora Leaves. Characterization of the Anti-Inflammatory Properties of Aqueous Extract on Diabetes Expression in an Experimental Model of Spontaneous Type 1 Diabetes (NOD Mice)

    PubMed Central

    Simon Gonzalez Schumacher, Nayara; Colomeu, Talita Cristina; de Figueiredo, Daniella; Carvalho, Virginia de Campos; Baú Betim Cazarin, Cinthia; Prado, Marcelo Alexandre; Molina Meletti, Laura Maria; de Lima Zollner, Ricardo

    2015-01-01

    Medical and folklore reports suggest that Eugenia uniflora (E. uniflora) is a functional food that contains numerous compounds in its composition, with anti-inflammatory, antioxidant and anti-diabetic effects. In the present study, we investigated the best solvents (water, ethanol and methanol/acetone) for extracting bioactive compounds of E. uniflora leaves, assessing total phenols and the antioxidant activity of the extracts by 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), 2,2′-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Oxygen Radical Absorbance Capacity (ORAC) assays, identifying hydrolysable tannins and three phenolic compounds (ellagic acid, gallic acid and rutin) present in the leaves. In addition, we evaluated the incidence of diabetes, degree of insulitis, serum insulin, hepatic glutathione and tolerance test glucose in non-obese diabetic (NOD) mice. Our results suggest that the aqueous extract presents antioxidant activity and high total phenols, which were used as a type 1 diabetes mellitus (DM-1) treatment in NOD mice. We verified that the chronic consumption of aqueous extract reduces the inflammatory infiltrate index in pancreatic islets, maintaining serum insulin levels and hepatic glutathione, and reducing serum lipid peroxidation as well as the risk for diabetes. PMID:26783951

  15. Identification and Antioxidant Activity of the Extracts of Eugenia uniflora Leaves. Characterization of the Anti-Inflammatory Properties of Aqueous Extract on Diabetes Expression in an Experimental Model of Spontaneous Type 1 Diabetes (NOD Mice).

    PubMed

    Schumacher, Nayara Simon Gonzalez; Colomeu, Talita Cristina; de Figueiredo, Daniella; Carvalho, Virginia de Campos; Cazarin, Cinthia Baú Betim; Prado, Marcelo Alexandre; Meletti, Laura Maria Molina; Zollner, Ricardo de Lima

    2015-10-09

    Medical and folklore reports suggest that Eugenia uniflora (E. uniflora) is a functional food that contains numerous compounds in its composition, with anti-inflammatory, antioxidant and anti-diabetic effects. In the present study, we investigated the best solvents (water, ethanol and methanol/acetone) for extracting bioactive compounds of E. uniflora leaves, assessing total phenols and the antioxidant activity of the extracts by 2,2-Diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), 2,2'-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Oxygen Radical Absorbance Capacity (ORAC) assays, identifying hydrolysable tannins and three phenolic compounds (ellagic acid, gallic acid and rutin) present in the leaves. In addition, we evaluated the incidence of diabetes, degree of insulitis, serum insulin, hepatic glutathione and tolerance test glucose in non-obese diabetic (NOD) mice. Our results suggest that the aqueous extract presents antioxidant activity and high total phenols, which were used as a type 1 diabetes mellitus (DM-1) treatment in NOD mice. We verified that the chronic consumption of aqueous extract reduces the inflammatory infiltrate index in pancreatic islets, maintaining serum insulin levels and hepatic glutathione, and reducing serum lipid peroxidation as well as the risk for diabetes.

  16. Development and validation of a selective and effective pressurized liquid extraction followed by liquid chromatography-mass spectrometry method for the determination of fructosazine analogues in the ammonia treated extract of Eugenia jambolana Lamarck seeds.

    PubMed

    Zhao, Minjie; Arau Jo, Michel Mozeika; Dal, Stéphanie; Sigrist, Séverine; Bergaentzlé, Martine; Ramanitrahasimbola, David; Andrianjara, Charles; Marchioni, Eric

    2016-11-18

    This study describes a selective and effective pressurized liquid extraction (PLE) coupled with HPLC-DAD-ESI/MS method for the identification and quantification of three fructosazine analogues (FZAs), fructosazine, 2,6- and 2,5-deoxyfructosazine in Madeglucyl(®) (MG) which is an ammonia treated extract of Eugenia jambolana Lamarck seeds, and is the world's first anti-diabetic phytodrug. FZAs were extracted from MG by PLE using methanol as extraction solvent. The PLE extract was then analyzed directly by HPLC-DAD-ESI/MS without cleanup step. Chromatographic separation of these highly related structures was achieved on a porous graphic carbon (PGC) column. The identification of the target FZAs was confirmed by the similar retention time, similar UV and MS spectra to the corresponding pure standards. The quantification was performed by using an electrospray positive ionization mass spectrometry in the selected ion monitoring (SIM) mode. The PLE procedure was optimized and overall method was validated in terms of sensitivity, linearity, selectivity and matrix effect, precision, accuracy and recovery, and stability of the target FZAs in the aqueous solution and in the PLE extracts solution of MG. The developed method was proved to be selective, sensitive, precise, accurate for the quantification of FZAs in MG.

  17. 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

    USGS Publications Warehouse

    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

  18. 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

    NASA Astrophysics Data System (ADS)

    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

  19. Late Quaternary Activity on the Cerro Goden Fault, Puerto Rico and Limitations of High-resolution Seismic Reflection/refraction Data for Trench-scale Investigations

    NASA Astrophysics Data System (ADS)

    Zachariasen, J.; Prentice, C. S.; Schweig, E.; Abreu, R.; Rymer, M. J.; Catchings, R. D.

    2005-12-01

    The Cerro Goden Fault runs along the base of the La Cadena de San Francisco range north of Añasco in western Puerto Rico, and joins with the Great Southern Puerto Rico Fault zone. This fault zone disrupts Eocene and older rocks but its Quaternary history is unclear. It bounds the northern Añasco Valley, which is seismically active. Offshore investigations suggest the fault cuts the sea floor (Grindlay et al., 2005) and an onshore reconnaissance study by Mann et al. (2005) found geomorphic evidence of Quaternary displacement. We gathered high-resolution seismic reflection/refraction data along two lines that crossed the projection of the fault in the Añasco Valley to help identify possible fault strands in the near subsurface. The seismic data were gathered using a shoot-through acquisition method with a BETSY-Seisgun shooting source consisting of 8-gauge, 400 grain shotgun blanks set in holes drilled about 30 cm below the ground surface. Both lines had shot and geophone spacings of 5 m. Common Depth Point (CDP) spacings for both lines were 2.5 m in the shallow section of the profiles. We used the results from the seismic lines to site six trenches where the data revealed discontinuities, possibly attributable to faulting, within the upper 2-3 meters. Our trenches ranged in depth from 2 - 5 meters, but in none of the trenches did we find evidence of surface faulting. A mountain-front-facing subsurface scarp, which may have been produced by older Quaternary faulting, appeared in several trenches. Holocene fluvial sediments have been deposited against this scarp and have buried it, but are unfaulted. Our results suggest either that the Cerro Goden Fault has not been active since the deposition of the Holocene fluvial sediments or that the high-resolution seismic data were not adequate to define the location of fault traces to the precision necessary for trench investigations. Both the seismic data and the buried scarps suggest there may be faults at depth, but

  20. Petrological constraints on magma storage and transfer beneath Volcán Cerro Machín (Colombia): A volcano showing signs of unrest

    NASA Astrophysics Data System (ADS)

    Muir, D.; Caricchi, L.; Mendez, R.; Londoño, J. M.

    2012-04-01

    Cerro Machín Volcano, located in the Central Cordillera (Colombia) is a dacitic volcano positioned along a large-scale fracture system. Past activity is characterised by explosions of varying intensities and by the effusion of lava domes, with 6 main eruptive cycles occurring over the last 10 kyrs. Currently, the volcano presents two central domes with a total diameter of about 3 km, where two fumarolic fields are located. The rest of the edifice is composed of a 600 m thick ring of pyroclastic flows. Recent seismic swarms, located at depths between 18 and 2 km, have prompted further investigation of this volcanic system. Erupted products are dacitic with similar bulk chemistries to Pinatubo (65.1 wt% SiO2, 2.1 wt% MgO, 2.1 wt% K2O, 4.3 wt% CaO and 4.4 wt% Na2O) apart from FeOT, which at 3.3 wt%, is lower by around 1 wt%. The mineralogical assemblage is composed of plagioclase, quartz, hornblende (two populations: high- and low-Mg) and biotite phenocrysts along with ilmenite, magnetite, and accessory apatite and zircon. All phases, both in products of explosive eruption and dome samples, appear to be at equilibrium with an absence of sieve textures in plagioclase and no dehydration reaction rims in the hydrous phases. Because of the similarities in bulk composition, phase equilibria experiments for Pinatubo (Scaillet et al., 2001) can be used to provide information on the storage conditions of Machín magmas prior to eruption. The presence of biotite suggests temperatures lower than 750°C with melt water contents of at least 5.7 wt % corresponding to water saturation pressures between 225 and 240 MPa. Analyses to determine the amount of sulphur present in the magma are currently being performed to assess its possible influence on the stability of biotite (Scaillet et al., 2001). The lack of evidence of mineral resorption in the eruptive products may imply relatively low magmatic temperatures or fast rates of magma transfer beneath Cerro Machín volcano. We are

  1. Petrological evolution of subducted rodingite from seafloor metamorphism to dehydration of enclosing antigorite-serpentinite (Cerro del Almirez massif, southern Spain)

    NASA Astrophysics Data System (ADS)

    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

  2. Characterization of post-fire surface cover, soils, and burn severity at the Cerro Grande Fire, New Mexico, using hyperspectral and multispectral remote sensing

    USGS Publications Warehouse

    Kokaly, R.F.; Rockwell, B.W.; Haire, S.L.; King, T.V.V.

    2007-01-01

    Forest fires leave behind a changed ecosystem with a patchwork of surface cover that includes ash, charred organic matter, soils and soil minerals, and dead, damaged, and living vegetation. The distributions of these materials affect post-fire processes of erosion, nutrient cycling, and vegetation regrowth. We analyzed high spatial resolution (2.4??m pixel size) Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) data collected over the Cerro Grande fire, to map post-fire surface cover into 10 classes, including ash, soil minerals, scorched conifer trees, and green vegetation. The Cerro Grande fire occurred near Los Alamos, New Mexico, in May 2000. The AVIRIS data were collected September 3, 2000. The surface cover map revealed complex patterns of ash, iron oxide minerals, and clay minerals in areas of complete combustion. Scorched conifer trees, which retained dry needles heated by the fire but not fully combusted by the flames, were found to cover much of the post-fire landscape. These scorched trees were found in narrow zones at the edges of completely burned areas. A surface cover map was also made using Landsat Enhanced Thematic Mapper plus (ETM+) data, collected September 5, 2000, and a maximum likelihood, supervised classification. When compared to AVIRIS, the Landsat classification grossly overestimated cover by dry conifer and ash classes and severely underestimated soil and green vegetation cover. In a comparison of AVIRIS surface cover to the Burned Area Emergency Rehabilitation (BAER) map of burn severity, the BAER high burn severity areas did not capture the variable patterns of post-fire surface cover by ash, soil, and scorched conifer trees seen in the AVIRIS map. The BAER map, derived from air photos, also did not capture the distribution of scorched trees that were observed in the AVIRIS map. Similarly, the moderate severity class of Landsat-derived burn severity maps generated from the differenced Normalized Burn Ratio (dNBR) calculation

  3. Integrated model for the natural flow regime in the Cerro Prieto hydrothermal system, B. C. , Mexico, based upon petrological and isotope geochemical criteria

    SciTech Connect

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

    1981-01-01

    Studies of cuttings and core 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. A map showing the first occurrence of hydrothermal epidote shows a dome-shaped top to the steam-producing zone. The hottest of the mapped mineral zones - the biotite vermiculite zone - shows a dome displaced to the northeast relative to the epidote zone. Patterns of mineral zones observed in wells are consistent with patterns of oxygen isotopic ratios in calcite and quartz. Using both criteria all of the boreholes so far studied were classified as belonging to one of four different regimes. These are: (a) the thermal plume of upward flowing water close to boiling, marked by a regular sequence of prograde mineral zones and large isotopic shifts; (b) the discharge system where fluid leaks to the surface, as indicated by the occurrence of only a few low temperature mineral zones, which extend over large depth intervals with little isotope exchange; (c) the horizontal flow zone, in which boreholes penetrate reversals of both mineral zones and isotope shifts with increasing depth; and (d) the recharge zone where cold water is descending. Plotting these four types of boreholes on a map reveals a simple, consistent, pattern. This is interpreted to have been produced by a thermal plume dipping at 45/sup 0/ to the northeast.

  4. 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

    USGS Publications Warehouse

    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

  5. Chemical and mineralogical trends during acid-sulfate alteration of pyroclastic basalt at Cerro Negro volcano and implications for early Mars

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.; Hynek, Brian M.; Rogers, Karyn; Moskowitz, Bruce; Berquó, Thelma S.

    2013-09-01

    alteration of pyroclastic basalts in active fumaroles at Cerro Negro volcano, Nicaragua, was studied as a means to infer the mineralogical and chemical consequences of basalt alteration in analogous environments on early Mars. At this site, recently erupted basaltic cinders are undergoing alteration by SO2-bearing steam. During alteration, silicate phenocrysts, including plagioclase, olivine, and augite, react much more rapidly than basaltic glass. Secondary mineralogy is dominated by a very limited number of phases that include amorphous silica, gypsum, Fe-bearing natroalunite, and Fe-oxides/oxyhydroxides, including hematite and magnetite. The major element chemistry of the deposits is controlled by two processes: gradual depletion of the major cations other than Si as the basalt components decompose and elements are mobilized out of the deposits, and enrichment in Ca and S from precipitation of gypsum, with Ca apparently supplied from sources below the surface. Reaction path models constrained by these observations but extrapolated to Martian conditions predict that alteration of pyroclastic deposits in similar environments on Mars should produce a secondary mineral assemblage that includes amorphous silica, Fe-bearing natroalunite, anhydrite, kieserite, and hematite. Iron-bearing natroalunite was found to produce a Mössbauer signal similar to that of jarosite, suggesting that this phase should be considered as an alternative to the jarosite component identified at Meridiani Planum. Spheroidal hematite formed in close association with natroalunite suggests a pathway for formation of hematite deposits on Mars.

  6. Observation and modeling of gravity wave propagation through reflection and critical layers above Andes Lidar Observatory at Cerro Pachón, Chile

    NASA Astrophysics Data System (ADS)

    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.

  7. Paleoparasitological finding of eggs of nematodes in rodent coprolites dated at the early Holocene from the archaeological site Cerro Casa de Piedra 7, Santa Cruz, Argentina.

    PubMed

    Sardella, N H; Fugassa, M H

    2011-12-01

    The aim of the present study was to examine the parasite remains present in rodent coprolites collected from the archaeological site Cerro Casa de Piedra 7 (CCP7), located in the Perito Moreno National Park (47°57'S, 72°05'W), Santa Cruz Province, Argentina. Eight coprolites obtained from the layer 17, dated at 10,620 ± 40 to 9,390 ± 40 yr B.P., were examined for parasites. Feces were processed whole, rehydrated, homogenized, subjected to spontaneous sedimentation, and examined via light microscopy. Eggs of parasites were measured and photographed. Seven of 8 coprolites possessed 199 eggs of 2, probably new, species of nematodes, including 43 eggs of Heteroxynema sp. Hall, 1916 (Cavioxyura sp. Quentin, 1975) (Oxyurida, Heteroxynematidae), and 156 eggs of Trichuris sp. Roederer, 1761 (Trichinellida, Trichuridae). Heteroxynema sp. is cited for the first time from ancient material worldwide. The finding of Trichuris spp. in both rodents and other host samples from the area under study is indicative of the stability of the biological and environmental conditions for this nematode genus to establish in the Patagonian Early Holocene. The rodent host was assigned to an unknown species of Caviomorpha (Hystricognathi) that lived during the Pleistocenic transition in Patagonia.

  8. Comparative efficacy of Zataria multiflora Boiss., Origanum compactum and Eugenia caryophyllus essential oils against E. coli O157:H7, feline calicivirus and endogenous microbiota in commercial baby-leaf salads.

    PubMed

    Azizkhani, Maryam; Elizaquível, Patricia; Sánchez, Gloria; Selma, María Victoria; Aznar, Rosa

    2013-09-02

    Ready-to-eat salads using baby-leaf and multi-leaf mixes are one of the most promising developments in the fresh-cut food industry. There is great interest in developing novel decontamination treatments, which are both safe for consumers and more efficient against foodborne pathogens. In this study, emulsions of essential oils (EOs) from Origanum compactum (oregano), Eugenia caryophyllus (clove), and Zataria multiflora Boiss (zataria) were applied by spray (0.8 ml) after the sanitizing washing step. The aim was to investigate their ability to control the growth of potentially cross-contaminating pathogens and endogenous microbiota in commercial baby leaves, processed in a fresh-cut produce company. Zataria EO emulsions of 3%, 5% and 10% reduced Escherichia coli O157:H7 by 1.7, 2.2 and 3.5 log cfu/g in baby-leaf salads after 5 days of storage at 7°C. By contrast, reductions in E. coli O157:H7 counts remained the same when clove was applied at concentrations of 5% and 10% (2.5 log cfu/g reduction). Oregano (10%) reduced inoculated E. coli O157:H7 counts in baby-leaf salads by a maximum of 0.5 log cfu/g after 5 days of storage. Zataria showed strong antimicrobial efficacy against E. coli O157:H7 and also against the endogenous microbiota of baby-leaf salads stored for 9 days. Feline calicivirus (FCV), a norovirus surrogate, survived on inoculated baby-leaf salads during refrigerated storage (9 days at 7°C) regardless of treatment. Refrigeration temperatures completely annulled the effectiveness of the EOs against FCV inoculated in baby-leaf salads as occurred in FCV cultures. This study shows that EOs, and zataria in particular, have great potential use as an additional barrier to reduce contamination-related risks in baby-leaf salads. However, further research should be done into foodborne viruses in order to improve food safety.

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

    SciTech Connect

    Rupp, Susan P.

    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

  10. The dynamics of serpentinite dehydration reactions in subduction zones: Constrains from the Cerro del Almirez ultramafic massif (Betic Cordillera, SE Spain)

    NASA Astrophysics Data System (ADS)

    Dilissen, Nicole; Garrido, Carlos J.; López Sánchez-Vizcaíno, Vicente; Padrón-Navarta, José Alberto

    2015-04-01

    Arc volcanism, earthquakes and subduction dynamics are controlled by fluids from downgoing slabs and their effect on the melting and rheology of the overlying mantle wedge. High pressure dehydration of serpentinite in the slab and the subduction channel is considered as one of the main sources of fluids in subduction zones. Even though this metamorphic reaction is essential in subduction activities, the behavior of the fluids, the kinetics and thermodynamics during the breakdown reaction are still poorly understood. The Cerro del Almirez (Nevado-Filábride Complex, Betic Cordillera, SE Spain) uniquely preserves the dehydration front from antigorite serpentinite to chlorite-harzburgite and constitutes a unique natural laboratory to investigate high-pressure dehydration of serpentinite. This reaction occurred in a subduction setting releasing up to 13 wt% of water, contributing significantly to the supply of fluids to the overlying mantle wedge. A key to the understanding of the metamorphic conditions prevailing during serpentinite dehydration is to study the two prominent textures -granofels and spinifex-like chlorite harzburgite- occurring in this reaction product. The detailed texture differences in the Chl-harzburgite can provide insights into diverse kinetic and thermodynamic conditions of this dehydration reaction due to variations in effective pressure and drainage conditions. It has been proposed that difference in overpressure (P') and deviation from growth equilibrium, i.e. overstepping, is responsible for these two types of textures [Padrón-Navarta et al., 2011]. The magnitude and duration of P' is highly dependent on dehydration kinetics [Connolly, 1997]. The fast pressure drop, with spinifex-texture as a product, can be linked to draining events expected after hydrofracturing, which are recorded in grain size reduction zones in this massif. According to this hypothesis, mapping of textural variation in Chl-harzburgite might be used as a proxy to

  11. Heterogeneous pumice populations in the 2.08-Ma Cerro Galán Ignimbrite: Implications for magma recharge and ascent preceding a large-volume silicic eruption

    USGS Publications Warehouse

    Wright, Heather M.; Folkes, Christopher B.; Cas, Ray A.F.; Cashman, Katharine V.

    2011-01-01

    Triggering mechanisms of large silicic eruptions remain a critical unsolved problem. We address this question for the ~2.08-Ma caldera-forming eruption of Cerro Galán volcano, Argentina, which produced distinct pumice populations of two colors: grey (5%) and white (95%) that we believe may hold clues to the onset of eruptive activity. We demonstrate that the color variations correspond to both textural and compositional variations between the clast types. Both pumice types have bulk compositions of high-K, high-silica dacite to low-silica rhyolite, but there are sufficient compositional differences (e.g., ~150 ppm lower Ba at equivalent SiO2 content and 0.03 wt.% higher TiO2 in white pumice than grey) to suggest that the two pumice populations are not related by simple fractionation. Trace element concentrations in crystals mimic bulk variations between clast types, with grey pumice containing elevated Ba, Cu, Pb, and Zn concentrations in both bulk samples (average Cu, Pb, and Zn concentrations are 27, 35, and 82 in grey pumice vs. 11, 19, and 60 in white pumice) and biotite phenocrysts and white pumice showing elevated Li concentrations in biotite and plagioclase phenocrysts. White and grey clasts are also texturally distinct: White pumice clasts contain abundant phenocrysts (44–57%), lack microlites, and have highly evolved groundmass glass compositions (76.4–79.6 wt.% SiO2), whereas grey pumice clasts contain a lower percentage of phenocrysts/microphenocrysts (35–49%), have abundant microlites, and have less evolved groundmass glass compositions (69.4–73.8 wt.% SiO2). There is also evidence for crystal transfer between magma producing white and grey pumice. Thin highly evolved melt rims surround some fragmental crystals in grey pumice clasts and appear to have come from magma that produced white pumice. Furthermore, based on crystal compositions, white bands within banded pumice contain crystals originating in grey magma. Finally, only grey

  12. Rock magnetic evidence of non-random raw material selection criteria in Cerro Toledo Obsidian Artifacts from Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Gregovich, A.; Feinberg, J. M.; Steffen, A.; Sternberg, R. S.

    2014-12-01

    Stone tools are one of the most enduring forms of ancient human behavior available to anthropologists. The geologic materials that comprise stone tools are a reflection of the rocks that were available locally or through trade, as are the intended use of the tools and the knapping technology needed to produce them. Investigation of the rock magnetic and geochemical characteristics of the artifacts and the geological source materials provides a baseline to explore these past behaviors. This study uses rock magnetic properties to explore the raw material selection criteria involved in the production of obsidian tools in the region around Valles Caldera in northern New Mexico. Obsidian is locally abundant and was traded by tribes across the central United States. Here we compare the rock magnetic properties of a sample of obsidian projectile points (N =25) that have been geochemically sourced to the Cerro Toledo obsidian flow with geological samples collected from four sites within the same flow (N =135). This collection of archaeological artifacts, albeit small, contains representatives of at least 8 different point styles that were used over 6000 years from the Archaic into the Late Prehistoric. Bulk rock hysteresis parameters (Mr, Ms, Bc, and Bcr) and low-field susceptibility (Χ) measurements show that the projectile points generally contain a lower concentration of magnetic minerals than the geologic samples. For example, the artifacts' median Ms value is 2.9 x 10-3 Am2kg-1, while that of the geological samples is 6.5 x 10-3 Am2kg-1. The concentration of magnetic minerals in obsidian is a proxy for the concentration of microlites in general, and this relationship suggests that although obsidian was locally abundant, toolmakers employed non-random selection criteria resulting in generally lower concentrations of microlites in their obsidian tools.

  13. Models of Metabolic Community Structure in Martian Habitable Environments: Constraints from a Terrestrial Analog Acid-Sulfate Fumarole Environment, Cerro Negro Volcano, Nicaragua

    NASA Astrophysics Data System (ADS)

    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

  14. Measurements of downwelling far-infrared radiance during the RHUBC-II campaign at Cerro Toco, Chile and comparisons with line-by-line radiative transfer calculations

    NASA Astrophysics Data System (ADS)

    Mast, Jeffrey C.; Mlynczak, Martin G.; Cageao, Richard P.; Kratz, David P.; Latvakoski, Harri; Johnson, David G.; Turner, David D.; Mlawer, Eli J.

    2017-09-01

    Downwelling radiances at the Earth's surface measured by the Far-Infrared Spectroscopy of the Troposphere (FIRST) instrument in an environment with integrated precipitable water (IPW) as low as 0.03 cm are compared with calculated spectra in the far-infrared and mid-infrared. FIRST (a Fourier transform spectrometer) was deployed from August through October 2009 at 5.38 km MSL on Cerro Toco, a mountain in the Atacama Desert of Chile. There FIRST took part in the Radiative Heating in Unexplored Bands Campaign Part 2 (RHUBC-II), the goal of which is the assessment of water vapor spectroscopy. Radiosonde water vapor and temperature vertical profiles are input into the Atmospheric and Environmental Research (AER) Line-by-Line Radiative Transfer Model (LBLRTM) to compute modeled radiances. The LBLRTM minus FIRST residual spectrum is calculated to assess agreement. Uncertainties (1-σ) in both the measured and modeled radiances are also determined. Measured and modeled radiances nearly all agree to within combined (total) uncertainties. Features exceeding uncertainties can be corrected into the combined uncertainty by increasing water vapor and model continuum absorption, however this may not be necessary due to 1-σ uncertainties (68% confidence). Furthermore, the uncertainty in the measurement-model residual is very large and no additional information on the adequacy of current water vapor spectral line or continuum absorption parameters may be derived. Similar future experiments in similarly cold and dry environments will require absolute accuracy of 0.1% of a 273 K blackbody in radiance and water vapor accuracy of ∼3% in the profile layers contributing to downwelling radiance at the surface.

  15. Large rock avalanches in southern Perù: the Cerro Caquilluco - Cerrillos Negros rock slide - avalanche (Tacna, Tomasiri, Perù)

    NASA Astrophysics Data System (ADS)

    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

  16. The anatomy of a cinder cone: preliminary paleomagnetic, rock magnetic, structural, and petrologic data from the La Cienega volcano, Cerros del Rio volcanic field, northern New Mexico

    NASA Astrophysics Data System (ADS)

    Petronis, M. S.; Foucher, M.; Lineline, J.; Van Wyk de Vries, B.

    2011-12-01

    The Cerros del Rio volcanic field is one of several middle Pliocene to Pleistocene basaltic volcanic fields of the axial Rio Grande Rift in central and northern New Mexico. It is a monogenetic volcanic field that comprises about 60 cinder-spatter cones, occupies ~ 700 km2, and ranges in age from 2.7 Ma to 1.1 Ma. Eruptive centers are typically central vent volcanoes, ranging from low-relief shields to steep-sided, breached cinder and spatter cone remnants. They represent short eruptive events that likely were derived from rapidly evolving reservoir-conduit systems. Mining activity has exposed the volcanic plumbing system of the Cienega Mine cinder cone, just west of Santa Fe, NM. Here, geologists from France and USA have been investigating the exposed roots of this eviscerated Pliocene volcano to investigate magma conduit geometry, magma flow structures, and eruption patterns. We are testing models for magma transport and volcano construction using a variety of field and laboratory tools. Common models of volcanic construction envision the magma feeder as a dike or pipe-like conduit transporting molten rock from a deep reservoir to the eruptive vent. We posit that small volcanic pluming systems are inherently more complex and actually involve numerous feeder geometries throughout the volcano lifespan. Our preliminary work suggests that the simple exteriors of some cinder cones hide a long life and complex history, both of which would change the appreciation of the related volcanic hazards in active systems. The Cienega Mine cinder cone consists of several meter- to decimeter-wide intrusions that connect to eruptive centers. These intrusions show a continuity of brittle to ductile structures from their margins to interiors. We have collected samples across each intrusion as well as along strike for anisotropy of magnetic susceptibility (AMS) and petrographic analysis in order to establish magma flow patterns. AMS results yield a remarkably consistent dataset that

  17. Predicting Change in Sediment Transport Rates in the Wake of the Cerro Grande Fire: Limitations and Potential of a Physically-based Approach

    NASA Astrophysics Data System (ADS)

    Canfield, H. E.; Wilson, C. J.; Lane, L. J.; McLin, S. G.; Earles, A.

    2001-12-01

    One of the benefits of physically based hydrologic models is that since they are based on physics, they can potentially be used to describe hydrologic response to change. On the Pajarito Plateau in New Mexico the introduction of cattle in the late 1800s, and then establishment of the Los Alamos National Laboratory in the 1940s has had a profound effect on the cover on the watersheds surrounding Los Alamos, with a proliferation of a more dense under story, on the hillsides, and more impermeable areas at the town site. Since the establishment of the Laboratory, there have been several large forest fires, most recently, the Cerro Grande Fire in May 2000. Hydrologic models suggest an eight-fold increase in the 100yr-6hr-flood peak in Los Alamos Canyon, and a corresponding three to four fold increase in sediment transport in the Canyon under post-burn conditions. However, the magnitude of the predicted scour depends strongly on what processes are allowed to occur in the model. The predicted scour is much greater if the model incorporates an observed inset channel, where modeled velocities are much greater than in the full wetted area. Furthermore, the model suggests that armoring has the potential to cut off the supply of sediment in the bed, so that scour and sediment transport are limited by the capability of the flow to transport larger particles that might otherwise armor the bed. Therefore, the magnitude of the predicted increase in sediment transport depends strongly on the ability of channels to armor as well as an a-priori understanding of how scour and deposition will occur in the canyon in response to flows much greater than the historical record. As such, reliance on model estimates of sediment transport based on the physics of flow is inadequate for assessing the effects of change and, at-best, provides only a range in the possible response to an extreme event. In this poster we examine available data on post-fire armoring rates, and observations about

  18. Crystallization conditions and petrogenesis of the lava dome from the ˜900 years BP eruption of Cerro Machín Volcano, Colombia

    NASA Astrophysics Data System (ADS)

    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 <800 °C) during early stages of ascent or storage at shallower levels. Based on amphibole mineral chemistry, the felsic resident melt had a rhyolitic composition (71 ± 2 wt.% SiO2), whereas the hybrid magma, from which the amphibole rims crystallized, was dacitic (64 ± 3 wt.% SiO2). The bulk 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

  19. Carbon Concentration Excursions in Apatite Phenocrysts from the Cerro Galan Ignimbrite: A SIMS View into the Transient pre-Eruptive Volatile History of a Supervolcano

    NASA Astrophysics Data System (ADS)

    Boyce, J. W.; Hervig, R. L.

    2006-12-01

    In nearly all igneous rock compositions, apatite is the most abundant mineral that regularly incorporates significant quantities of volatile elements into its structure, making it a potentially useful tool for exploring magmatic processing of volatiles (as well as REEs, Sr, Nd, and Pb isotopes, all of which are typically abundant in apatite). We have developed an analytical protocol that permits measurement of C, H, F, S, and Cl in ~8μm diameter regions of apatite using the Cameca 6f SIMS. A primary Cs+ beam (4-10 nA) is used in conjunction with electron gun charge-compensation to sputter negative ions from polished sections and unpolished crystal faces mounted in volatile-free indium mounts. We operated at mass resolving powers sufficient to separate all potential interferences (such as ^{31}PH and 16O2 from ^{32}S, and 17O from 16OH). Quantifying the SIMS data requires a set of standards that are 1) homogeneous at the few-micron scale; and 2) well-calibrated with multiple, reliable, independent volatile content measurements. Using values combed from the literature and other unpublished sources, we have assembled a set of apatite standards, none of which are proven to meet either criteria. Nevertheless, these materials allow us to create calibration curves for all of the volatile elements listed above. Traverses across polished basal sections of apatite phenocrysts from the ~1000 km3 Cerro Galan ignimbrite, Argentina (courtesy of C. Schirnick) yield the following results: Apatites are fluorine-rich, and contain significant and reproducible intracrystalline variations in C, H, S, and Cl. Positive carbon concentration excursions (up to 360 ppm) are factors of 2-7 greater than apatite baseline concentrations (40-60 ppm), the largest of which correlate with position in different grains. In the majority of the traverses, these carbon excursions also correlate spatially with 25-30% increases in sulfur concentration. We suggest that these dramatic increases in carbon

  20. A reconnaissance of U-Pb zircon ages in the Cerro Galán system, NW Argentina: Prolonged magma residence, crystal recycling, and crustal assimilation

    NASA Astrophysics Data System (ADS)

    Folkes, Chris B.; de Silva, Shanaka L.; Schmitt, Axel K.; Cas, Raymond A. F.

    2011-09-01

    206Pb/ 238U ages obtained from Secondary Ionization Mass Spectrometry (SIMS) analyses of zircon crystals in eight ignimbrites from Cerro Galán (Central Andes) reveal insights into magma dynamics and crystallization histories of a sustained (> 3.5 Ma), large-volume, crystal-rich magmatic system. This makes the Galán volcanic system an excellent example of repeated large-volume ignimbrite eruptions from a single magmatic system with eruptive recurrence intervals between ~ 50 ka and possibly > 1 Ma. 40Ar/ 39Ar sanidine and biotite ages indicate eruption ages between ~ 2.0 and 5.6 Ma, although biotite results are likely affected by extraneous 40Ar. In each ignimbrite, interiors of zircon autocrysts frequently crystallized up to several 100's ka prior to eruption, consistent with long upper-crustal residence times of the pre-eruptive Galán magmas. Many ignimbrites also contain zircon antecrysts that crystallized in the preceding cycle in the Galán eruptive sequence. Finally, rare (~ 540 to 500 Ma) zircon xenocrysts are also present, derived from basement rocks that comprise the regional upper crust into which the Galán magmas intruded. In some cases, near eruption-age zircon has overgrown xenocrysts and antecryst cores. We infer that silicic magmas were repeatedly intruded into the shallow crust, whereby antecrysts became recycled from non-erupted progenitors to the earlier ignimbrite eruptions. Complex crystal populations observed in the Galán Ignimbrites are consistent with those detected in other large 'monotonous' ignimbrites, but Galán differs from many other silicic systems in that it represents a well-preserved system that frequently tapped silicic magma from the same long-lived spatially-focused system. The magma dynamics revealed by our reconnaissance zircon geochronology are consistent throughout the magmatic cycles at Galán and are independent of eruptive volume: pre-eruptive zircon crystallization within < 500 ka prior to eruption, with episodic

  1. Cerros del Norte Conservation Act

    THOMAS, 113th Congress

    Sen. Udall, Tom [D-NM

    2013-02-07

    Senate - 06/27/2013 Placed on Senate Legislative Calendar under General Orders. Calendar No. 108. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  2. Astronomical Use of Cerro Sacromonte

    NASA Astrophysics Data System (ADS)

    López Camacho, María de Lourdes

    2016-11-01

    This work takes up research data from several years ago, from the end of the century to be more precise; it deals with the sunrise registration during dates as solstices and equinoxes, among others, that match pre-Hispanic festivities in turn. Registration was carried out from the entrance of the Church of The Sacromonte, located at the top of a hill, in the town of Amecameca, State of Mexico. This observation showed the existence of a calendar's horizon, where the Sun marks the seasons along the geographic landmarks, and where places of worship of pre-Hispanic times have been found in the high mountains as well as some modern remains.

  3. 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

    NASA Astrophysics Data System (ADS)

    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

  4. Paleomagnetic, Anisotropy of Magnetic Susceptibility, and 40AR/39AR Data from the Cienega Volcano, Cerros del Rio Volcanic Field, New Mexico

    NASA Astrophysics Data System (ADS)

    Foucher, M. S.; Petronis, M. S.; Lindline, J.; Van Wyk de Vries, B.

    2012-12-01

    Cinder cone eruptions are typically interpreted to have formed by the ascension of magma through a simple conduit. Recent field work and laboratory studies on different excavated volcanoes around the world suggest that magma transport within cinder cones can involve a complex system of feeder geometries. We studied the Cienega volcano, a cinder cone in the Cerros del Rio volcanic field, northern New Mexico, in order to better understand the complexity and the evolution of volcanic plumbing systems in the development of cinder cone volcanoes. We hypothesized that cinder cone plumbing systems are inherently complex and involve numerous feeder geometries (e.g. dikes, sills) and flow patterns both towards and away from the central vent complex. The Cienega volcano comprises tephra fall deposits as well as several vents, multiple intrusions, and numerous lava flow sequences. We inspected the magmatic plumbing system using different laboratory methods including paleomagnetic, anisotropy of magnetic susceptibility (AMS), rock magnetic and thin section studies. We collected samples across each outcrop of the feeder system. The dikes are olivine porphyritic basalts with major clinopyroxene, calcic plagioclase feldspar, magnetite, and xenocrystic quartz. Most samples display a trachytic texture with plagioclase crystals showing a preferred orientation parallel to the dike margins. The magnetic information is held predominantly by a cubic phase magnetite with a low- to moderate-Ti composition of Single or Pseudo-Single Domain grains. The AMS results show various flow directions. Three of six dikes yielded magma flow directions away from the vent. The other dikes showed both a subvertical flow, which corresponds to the typical movement of magma in a dike originating from a deeper crustal level, and a downward flow direction. We concluded that magma initially flowed upward from the magma chamber until it encountered flow resistance. At this structural level (the current

  5. Comparison of 36Cl and 3He measurements in glacial surfaces on the tropical Altiplano (Cerro Tunupa volcano, 20°S)

    NASA Astrophysics Data System (ADS)

    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

  6. Cerro de Vidrio rhyolitic dome: evidence for Late Pliocene volcanism in the central Andean flat-slab region, Lama-Veladero district, 29°20'S, San Juan Province, Argentina

    NASA Astrophysics Data System (ADS)

    Bissig, Thomas; Clark, Alan H.; Lee, James K. W.

    2002-10-01

    Magmatic activity in the El Indio-Pascua Au-Ag-Cu belt, situated in the Cordillera Principal at latitudes 29-30°S at the center of the southern Central Andean flat subduction regime, did not, as previously assumed, cease at 5-6 Ma but continued locally until the Late Pliocene. New and essentially identical 40Ar- 39Ar laser step-heating ages of 2.1±0.5 Ma (biotite) and 2.0±0.2 Ma (glass) are recorded for a rhyolitic dome, the Cerro de Vidrio, in the northern Valle del Cura region near the Veladero Au (-Ag) property. The rhyolite is geochemically distinct from local Upper Miocene volcanic rocks; it is slightly but unequivocally peraluminous and does not exhibit significant REE fractionation apart from a pronounced negative Eu anomaly, a feature also shown by the Upper Paleozoic-Lower Mesozoic basement units of the area. This suggests that magma generation occurred in a garnet-free environment, which implies anatexis at shallower levels than for the rhyolites of the Upper Miocene Vallecito Formation.

  7. 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

    USGS Publications Warehouse

    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 (<10% generally) and lithic-poor (<5% generally) rhyodacitic ignimbrite, lacking a preceding plinian fallout deposit. The CGI is preserved up to 80 km from the structural margins of the caldera, but almost certainly was deposited up to 100 km from the caldera in some places. Only one emplacement unit is preserved in proximal to medial settings and in most distal settings, suggesting constant flow conditions, but where the pyroclastic flow moved into a palaeotopography of substantial valleys and ridges, it interacted with valley walls, resulting in flow instabilities that generated 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 (<20 cm) and were not transported far from source points. All data suggest that the pyroclastic flow system producing the CGI was characterised throughout by high sedimentation rates, resulting from high particle concentration and suppressed turbulence at the depositional boundary layer, despite being a low aspect ratio ignimbrite. Based on these features, we question whether high velocity and momentum are necessary to account for extensive flow mobility. It is proposed that the CGI was deposited by a pyroclastic flow system that developed a substantial, high particle concentration granular under-flow, which flowed with suppressed turbulence. High particle

  8. Geomorphology, internal structure, and successive development of a glacier foreland in the semiarid Chilean Andes (Cerro Tapado, upper Elqui Valley, 30°08‧ S., 69°55‧ W.)

    NASA Astrophysics Data System (ADS)

    Monnier, Sébastien; Kinnard, Christophe; Surazakov, Arzhan; Bossy, William

    2014-02-01

    We use geomorphological analysis, sedimentological survey, remote sensing, and ground penetrating radar (GPR) in order to understand the complex landform assemblage found in front of the Cerro Tapado glacier in the upper Elqui River catchment, semiarid Andes of Chile. The geomorphological analysis highlights prominent boundaries dividing the landform assemblage into (from the upper part to the lower part) an upper latero-frontal moraine complex, an upper debris-covered glacier, a lower debris-covered glacier, two rock glaciers, and a lower morainic complex. The sedimentological survey highlights the rather small size of the surface debris (in general < 20 cm) and the predominance of porphyritic rhyolite. Remote sensing data show that, between 1956 and 2010, considerable (> 400 m) receding of the glacier occurred, along with downslope displacements (dm-m·y- 1) of most of the landform units and a significant evolution of the thermokarst features on the debris-covered glaciers. Considerable surface lowering occurred in the upper part of the assemblage, while localized bulging is seen along the morphological boundaries in the lower units. The GPR profiles highlight spectacular internal structure in the upper debris-covered glacier with up to 80 m of buried ice. In the other landform units, the internal structure is less visible and more heterogeneous. The analysis of the radar wave velocity along the GPR profiles reveals the occurrence of air-filled and moist zones in the internal structure. The geomorphological assemblage is fundamentally characterized by its morphological, structural, and dynamical boundaries and defined as a young (probably < 2000 years) polygenetic construction with landform units having added to/overlapped one another. The rock glaciers do not derive from the present debris-covered glacier but preexist to it.

  9. Detailed chronology of a giant Pleistocene rock-avalanche sequence in the hyperarid southern Peru revealed by jointly applied 10Be and 3He cosmic ray exposure dating : The Study case of the Cerro Caquilluco landslide complex.

    NASA Astrophysics Data System (ADS)

    Swann, Zerathe; Laurence, Audin; Carlos, Benavente; Régis, Braucher; Pierre-Henri, Blard; Didier, Bourlès; Julien, Carcaillet; Fabrizio, Delgado; Pascal, Lacroix; Valderrama Patricio, Murillo; Aster Team

    2015-04-01

    Giant landslides are recognized to be remarkably abundant on the Western Andean front of southern Peru and northern Chile, especially in the Arica Bend region (e.g. Crosta et al., 2014a). This area is characterized by strong topographic gradients and subsequent incision of deep canyons, due to the evolution of the Andean range that provide suitable conditions for the development of such instabilities. The climate is hyper-arid (Atacama Desert), although rare but highly impulsive wet events have been evidenced since the Pleistocene. In parallel, this region is submitted to strong (Mw 8-9) and recurrent (~100 yrs) subduction earthquakes. Previous studies suggest that large landslides represent the main agent of erosion of the Western Cordillera, providing soft material for subsequent fluvial remobilization. However the lack of time constrains on the numerous fossil landslides identified away from major canyons still hamper to assess a real mass balance of sliding material versus the known fluvial erosion and tectonic uplift rates. Finally the role of landslides in the long-term erosion rates of the Andean range on its arid flank remains quantitatively unknown. Recently, two studies gave divergent opinions about the main factor supposed to control the slope failures in that region. Based on cosmogenic nuclides derived erosion rates, McPhillips et al. (2014) argue that the last Holocene climate variation did not have had any effect on the rate of landsliding, suggesting that here landslides are mainly triggered by earthquake. On the other hand, Margirier et al. (2014) have showed a temporal correlation between a failure episode of the giant Chuquibamba landslide and the Ouki wet climatic event identified on the Altiplano ~100 ka ago. In this study we focus on dating the Cerro Caquilluco rock avalanche complex described by Crosta et al. (2014). With a total volume of about 15 km3, a length of 43 km and an internal structure characterized by various depositional lobes

  10. Geothermal well completions in Cerro Prieto

    SciTech Connect

    Dominguez, B.; Cobo Rivera, J.M.

    1981-01-01

    Geothermal well completion criteria have evolved from 1964 to this date. The evolution started with the common techniques used in oil-well completion and gradually changed to accommodate the parameters directly related to the mineralogic characteristics of the geothermal fluids. While acceptable completions can now be achieved, research techniques and data collection should be improved to optimize the procedures.

  11. Cerro Tololo Inter-American Observatory (CTIO)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    CTIO is operated by the ASSOCIATION OF UNIVERSITIES FOR RESEARCH IN ASTRONOMY Inc. (AURA), under a cooperative agreement with the National Science Foundation as part of the National Optical Astronomy Observatories....

  12. Cerro Prieto geothermal field: exploration during exploitation

    SciTech Connect

    Not Available

    1982-07-01

    Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. The description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field are presented. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development.

  13. Geothermal well drilling manual at Cerro Prieto

    SciTech Connect

    Fernandez P., A.; Flores S., M.

    1982-08-10

    The objective of the drilling manual is to solve all problems directly related to drilling during the construction of a well. In this case, the topics dealt which are drilling fluids and hydraulics to be applied in the field to improve drilling progress, eliminate risks and achieve good well-completion. There are other topics that are applicable such as drill bits and the drilling string, which are closely linked to drilling progress. On this occasion drilling fluid and hydraulics programs are presented, in addition to a computing program for a Casio FX-502P calculator to be applied in the field to optimize hydraulics and in the analysis of hydraulics for development and exploration wells at their different intervals.

  14. Spatio-temporal evolution of anthropogenic deformation around Cerro Prieto geothermal field in the Mexicali Valley, B.C., Mexico, between 1993 and 2009 from DInSAR and leveling.

    NASA Astrophysics Data System (ADS)

    Sarychikhina, Olga; Glowacka, Ewa; Robles, Braulio; Mojarro, Jose

    2014-05-01

    Land subsidence is an environmental hazard which could be caused by withdrawal of large amounts of fluid from beneath the earth's surface. Land subsidence is an issue in several geothermal fields worldwide (e.g., Geysers, USA (Mossop and Segall, 1997), Wairakei-Tauhara, New Zealand (Allis et al., 2009)). Cerro Prieto geothermal field (CPGF), located in the Mexicali Valley, northwest Mexico, 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 (e.g. Glowacka et al., 1996, 1999; Carnec and Fabriol, 1999; Sarychikhina et al., 2011). 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. Detection of land subsidence and monitoring of the spatial and temporal changes of its pattern and magnitude can provide important information about the dynamics of this process and controlling geological structures. The technique of Differential Synthetic Aperture Radar Interferometry (DInSAR) has been demonstrated to be a very effective technique for measuring ground deformation. This study presents an application of DInSAR interferogram stacking technique to investigate the land subsidence in the Mexicali Valley near CPGF. C-band ENVISAR ASAR images acquired between 2003 and 2009 from the ascending (track 306, frame 639) and descending track (track 84, frame 2961), obtained from the European Space Agency (ESA), as part of ESA CAT-1 project (ID - C1P3508), were used. Gamma ISP and DIFF/GEO software packages were used to calculate differential interferograms from SLC data and for differential interferograms stacking (Wegmüller and Werner, 1997). Eight average annual deformation rate maps were generated for 2005 (descending

  15. Microbicide activity of clove essential oil (Eugenia caryophyllata).

    PubMed

    Nuñez, L; Aquino, M D'

    2012-10-01

    Clove essential oil, used as an antiseptic in oral infections, inhibits Gram-negative and Gram-positive bacteria as well as yeast. The influence of clove essential oil concentration, temperature and organic matter, in the antimicrobial activity of clove essential oil, was studied in this paper, through the determination of bacterial death kinetics. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were the microorganisms selected for a biological test. To determine the temperature effect, they were assayed at 21° and 37° C. The concentration coefficient was determined with 0.4%, and 0.2% of essential oil. The influence of the presence of organic matter was determined with 0.4% of essential oil. The results obtained demonstrated that Escherichia coli were more sensitive even though the essential oil exerted a satisfactory action in three cases. In the three microbial species, 0.4% of essential oil at 21° C have reduced the bacterial population in 5 logarithmic orders. Organic matter reduces the antibacterial activity even though the bactericide efficacy was not lost. Clove essential oil can be considered as a potential antimicrobial agent for external use.

  16. Discussion of 'Geomorphology, internal structure, and successive development of a glacier foreland in the semiarid Chilean Andes (Cerro Tapado, upper Elqui Valley, 30°08‧ S, 69°55‧ W.)', by S. Monnier, C. Kinnard, A. Surazakov and W. Bossy, Geomorphology 207 (2014), 126-140

    NASA Astrophysics Data System (ADS)

    Nobes, David C.

    2015-12-01

    Recently, Monnier et al. (2014, Geomorphology 207, 126-140) suggested that diffraction events with air-wave velocities along profile CD were caused by an air-filled void at depth within one of the glaciers of the Cerro Tapado, Chile. This is not physically possible. The velocity at which radar travels to and from the scattering feature that causes a diffraction is at the velocity that surrounds and overlies the scatterer. Thus, their air-wave velocity features are on the surface of the glacier, not at depth. Their three-layer model for profile CD, therefore, is more appropriately a two-layer model, with a lower density layer, with more air and debris, overlying a denser layer, likely corresponding to the firn-ice transition. In addition, they carried out common mid-point (CMP) velocity profiles. While it is encouraging that they have made such an attempt, the results will be affected significantly by the surface and subsurface topography, truncated beds, unconformities, etc., because CMP profiles inherently assume flat-lying surface and subsurface boundaries. The CMP results, while useful, must therefore be treated with caution and assumed to be highly inaccurate and only be used as general guides to vertical velocity variations.

  17. Magnetotelluric studies at the Cerro Prieto geothermal field

    SciTech Connect

    Goubau, W.M.; Goldstein, N.E.; Clarke, J.

    1981-01-01

    During three years of magnetotelluric surveying, data were acquired at 26 sites distributed over 190 km/sup 2/ around the production area. A relatively well-defined strike of N27W +- 1.5/sup 0/ (magnetic) was established. The simple model shown suggests a lateral discontinuity in the vicinity of Nueva Leon.

  18. Geothermal Well Maintenance and Repair in Cerro Prieto

    SciTech Connect

    Aguirre, B. D.; Blanco, F. V.

    1981-01-01

    When the first well is drilled at a geothermal field, procedures for the cleaning, repair, and control of wells should be established. This aspect will be increasingly important as more wells are drilled. Equipment, tools and techniques need to be improved to achieve economic and safe results. Different systems have been developed and applied in maintenance of wells, in problems of casing incrustations, repairs, plugging, and well control. These systems should be improved, even though they have been reasonably satisfactory to date.

  19. Pressure transient testing at Cerro Prieto Geothermal Field

    SciTech Connect

    Rivera, J.R.; Samaniego, F.V.; Schroeder, R.C.

    1980-01-01

    Because of the inherent problems in applying pressure build-up tests to wells producing two-phase fluids, it was decided to use variable flow tests of short duration known as two-rates tests. In these tests of variation in the well flow rates can be used to intepret the transient pressure response in order to determine reservoir parameters such as permeability, well-bore damage and mean reservoir pressure in the well drainage area. Some examples will illustrate the application of this technique. 11 refs.

  20. Drilling rate for the Cerro Prieto stratigraphic sequence

    SciTech Connect

    Prian C, R.

    1981-01-01

    Drilling practice at the field has been modified in several ways as better information is being obtained. The stratigraphic sequence of the area is made up of three sedimentary rock units of deltaic origin having different densities. These units have been named non-consolidated, semi-consolidated, and consolidated rocks; the thermal reservoirs are located in the latter. To investigate how the drilling rates are affected by the three rock units, plots of drilling advance versus time were made for a large number of wells. A typical plot is shown and drilling rates are practically constant in three different zones; that is, the drilling rate has only two breaks or changes in slope.

  1. Cerro Prieto reinjection tests: studies of a multilayer system

    SciTech Connect

    Tsang, C.F.; Mangold, D.C.; Doughty, C.; Lippmann, M.J.

    1981-01-01

    The response of the two-reservoir system to reinjection was modeled assuming a semi-realistic vertical distribution of materials. Different depths of production and reinjection, and the possible influence of an intervening layer of lower permeability between these two depths were incorporated into the model. Reinjection at different depths and at different flowrates was studied in order to analyze the thermohydrological responses of this two-layered reservoir system to a number of possible reinjection schemes.

  2. Petrological imaging of an active pluton beneath Cerro Uturuncu, Bolivia

    NASA Astrophysics Data System (ADS)

    Muir, Duncan D.; Blundy, Jon D.; Hutchinson, Michael C.; Rust, Alison C.

    2014-03-01

    Uturuncu is a dormant volcano in the Altiplano of SW Bolivia. A present day ~70 km diameter interferometric synthetic aperture radar (InSAR) anomaly roughly centred on Uturuncu's edifice is believed to be a result of magma intrusion into an active crustal pluton. Past activity at the volcano, spanning 0.89 to 0.27 Ma, is exclusively effusive and almost all lavas and domes are dacitic with phenocrysts of plagioclase, orthopyroxene, biotite, ilmenite and Ti-magnetite plus or minus quartz, and microlites of plagioclase and orthopyroxene set in rhyolitic groundmass glass. Plagioclase-hosted melt inclusions (MI) are rhyolitic with major element compositions that are similar to groundmass glasses. H2O concentrations plotted versus incompatible elements for individual samples describe a trend typical of near-isobaric, volatile-saturated crystallisation. At 870 °C, the average magma temperature calculated from Fe-Ti oxides, the average H2O of 3.2 ± 0.7 wt% and CO2 typically <160 ppm equate to MI trapping pressures of 50-120 MPa, approximately 2-4.5 km below surface. Such shallow storage precludes the role of dacite magma emplacement into pre-eruptive storage regions as being the cause of the observed InSAR anomaly. Storage pressures, whole-rock (WR) chemistry and phase assemblage are remarkably consistent across the eruptive history of the volcano, although magmatic temperatures calculated from Fe-Ti oxide geothermometry, zircon saturation thermometry using MI and orthopyroxene-melt thermometry range from 760 to 925 °C at NNO ± 1 log. This large temperature range is similar to that of saturation temperatures of observed phases in experimental data on Uturuncu dacites. The variation in calculated temperatures is attributed to piecemeal construction of the active pluton by successive inputs of new magma into a growing volume of plutonic mush. Fluctuating temperatures within the mush can account for sieve-textured cores and complex zoning in plagioclase phenocrysts, resorption of quartz and biotite phenocrysts and apatite microlites. That Fe-Ti oxide temperatures vary by ~50-100 °C in a single thin section indicates that magmas were not homogenised effectively prior to eruption. Phenocryst contents do not correlate with calculated magmatic temperatures, consistent with crystal entrainment from the mush during magma ascent and eruption. Microlites grew during ascent from the magma storage region. Variability in the proportion of microlites is attributed to differing ascent and effusion rates with faster rates in general for lavas >0.5 Ma compared to those <0.5 Ma. High microlite contents of domes indicate that effusion rates were probably slowest in dome-forming eruptions. Linear trends in WR major and trace element chemistries, highly variable, bimodal mineral compositions, and the presence of mafic enclaves in lavas demonstrate that intrusion of more mafic magmas into the evolving, shallow plutonic mush also occurred further amplifying local temperature fluctuations. Crystallisation and resorption of accessory phases, particularly ilmenite and apatite, can be detected in MI and groundmass glass trace element covariation trends, which are oblique to WRs. Marked variability of Ba, Sr and La in MI can be attributed to temperature-controlled, localised crystallisation of plagioclase, orthopyroxene and biotite within the evolving mush.

  3. Chilean Astronomers and the Birth of Cerro Tololo

    NASA Astrophysics Data System (ADS)

    Moreno, H.

    1990-11-01

    P# JMEN. Hace treinta afios que se tnict6 en Chile la de n luga adecuado pata establecer observatoro astron6ini- Co, que a en wi ieflector de 1 in de diam'etrr . importante destacar el papel que le corres-pondi6 al Obseiwatorio Nacional de Ia Universidad de `Chile -- re'.-. tarde Departamento de de la inisma Univer- sidad .- en 1 de este proycoto. Los resultados han ido mucho mct5 impoftaftes lo esperado . de tal nodo q. el prc -ama destinado a instalar ui telescopio de tama- f ha I levado al establ ecimiento de iri centro de acti- cientfica de relieve inten-acional. ALb(TRA . Thifty years ago the search for a site adequate for the est 1ishment of an astronomical was fn (Thile. Initially it was planned that the main telescope would be a 1 in i-cf lector. It is importaft to the role played by th O Astm-'n6mioo Nacional de la Unfversidad de Cbf Ic - later 0: Depaftamento de of the same University - in the development of this project. The results have been much more important than was e:-:pected initially: in thiS way the prr gram for a telescope of moderate size was transfo -med in a major project wh i ch 1 cad to the estab 1 ). shinent of an i nt i ona 1 center of scieftific research. AQ/ W : OBSERVATORIES

  4. Geothermal well maintenance and repair in Cerro Prieto

    SciTech Connect

    Dominguez, B.; Vital Blaneo, F.

    1981-01-01

    When the first well is drilled at a geothermal field, procedures for the cleaning, repair, and control of wells should be established. This aspect will be increasingly important as more wells are drilled. Equipment, tools and techniques need to be improved to achieve economic and safe results. Different systems have been developed and applied in maintenance of wells, in problems of casing incrustations, repairs, plugging, and well control. These systems should be improved, even though they have been reasonably satisfactory to date.

  5. Temperature distribution in the Cerro Prieto geothermal field

    SciTech Connect

    Castillo B, F.; Bermejo M, F.J.; Domiguez A, B.; Esquer P, C.A.; Navarro O, F.J.

    1981-01-01

    A series of temperature and pressure logs and flow rate measurements was compiled for each of the geothermal wells drilled to different reservoir depths between October 1979 and December 1980. Based on the valuable information obtained, a series of graphs showing the thermal characteristics of the reservoir were prepared. These graphs clearly show the temperature distribution resulting from the movement of fluids from the deep regions toward the higher zones of the reservoir, thus establishing more reliable parameters for locating new wells with better production zones. Updated information based on data from new deep wells drilled in the geothermal field is presented here. This new information does not differ much from earlier estimates and theories. However, the influence of faulting and fracturing on the hydrothermal recharge of the geothermal reservoir is seen more clearly.

  6. Sensory profile and acceptability for pitanga (Eugenia uniflora L.) nectar with different sweeteners.

    PubMed

    Freitas, Mírian Luisa Faria; Dutra, Mariana Borges de Lima; Bolini, Helena Maria André

    2016-12-01

    The objective of this study was to evaluate the sensory properties and acceptability of pitanga nectar samples prepared with sucrose and different sweeteners (sucralose, aspartame, stevia with 40% rebaudioside A, stevia with 95% rebaudioside A, neotame, and a 2:1 cyclamate/saccharin blend). A total of 13 assessors participated in a quantitative descriptive analysis and evaluated the samples in relation to the descriptor terms. The acceptability test was carried out by 120 fruit juice consumers. The results of the quantitative descriptive analysis of pitanga nectar showed that samples prepared with sucralose, aspartame, and the 2:1 cyclamate/saccharin blend had sensory profiles similar to that of the sample prepared with sucrose. Consumers' most accepted samples were prepared with sucrose, sucralose, aspartame, and neotame. The sweeteners that have the greatest potential to replace sucrose in pitanga nectar are sucralose and aspartame. © The Author(s) 2016.

  7. Time-intensity profile of pitanga nectar (Eugenia uniflora L.) with different sweeteners: Sweetness and bitterness.

    PubMed

    Freitas, Mírian Luisa Faria; de Lima Dutra, Mariana Borges; Bolini, Helena Maria André

    2016-01-01

    Pitanga has been used by the Brazilian food industry mainly for juice production. This fruit shows good economic potential due to its high concentration of vitamins and minerals. The aim of the present work was to characterize the time-intensity profile of pitanga nectar sweetened with different sweeteners to verify differences on the perception of sweet and bitter tastes. The sweeteners used to replace sucrose were sucralose, aspartame, stevia 40% rebaudioside A, stevia 95% rebaudioside A, neotame, and 2:1 cyclamate/saccharin blend. Fifteen assessors were selected according to their discriminating capability and trained to participate in the time-intensity analysis for sweetness and bitterness. The samples prepared with sucralose and 2:1 cyclamate/saccharin blend presented a similar sweetness profile to the sample prepared with sucrose, and the samples prepared with sucralose and aspartame presented a similar bitterness profile to the sample prepared with sucrose. Thus, sucralose would be the most suitable sweetener to replace sucrose in pitanga nectar. © The Author(s) 2015.

  8. Assessment of sustainable vermiconversion of water hyacinth at different reactor efficiencies employing Eudrilus eugeniae kinberg.

    PubMed

    Gajalakshmi, S; Ramasamy, E V; Abbasi, S A

    2001-11-01

    The viability of vermireactors fed with different proportions of water hyacinth (WH) and cowdung (CD) was assessed over six-month trials. All reactors performed sustainably with a steadily rising vermicast output, worm zoomass, and number of offspring. There was no mortality in any of the reactors. A change in the WH:CD ratios from 4:1 to 6:1 had no discernable impact on the reactor performances. Attempts were also made to improve the efficiency of the reactors in terms of vermicast production per unit time and per unit digester volume. These attempts led to the 'high-rate' vermireactor in which 5.6 times greater vermicast was produced per litre of digester volume per day than in the 'low-rate' reactors. The high-rate vermireactors also performed sustainably, with steady vermicast output, animal growth, and reproduction.

  9. Neonatal diet composition modulates ileum mitochondrial function in a neonatal pig model Eugenia Carvalho1

    USDA-ARS?s Scientific Manuscript database

    The composition of postnatal diet (i.e., breastmilk vs. formula) has a strong influence on a variety of physiological outcomes in infants, but the impact on bioenergetics and mitochondrial function remains an open question. In a published study (1), early ingestion of dairy-based infant formula vs....

  10. Antiviral activity of crude extracts of Eugenia jambolana Lam. against highly pathogenic avian influenza (H5N1) virus.

    PubMed

    Sood, Richa; Swarup, D; Bhatia, S; Kulkarni, D D; Dey, S; Saini, M; Dubey, S C

    2012-03-01

    Crude extracts of leaves and bark of E. jambolana were tested for antiviral activity against highly pathogenic avian influenza virus (H5N1) by CPE reduction assay in three different layouts to elucidate virucidal, post-exposure and preexposure antiviral activity of the extracts. The cold and hot aqueous extracts of bark and hot aqueous extract of leaves of E. jambolana showed significant virucidal activity (100% inhibition) which was further confirmed in virus yield reduction assay (-98 to 99% reduction) and by egg based in ovo assay. The selective index (CC50/EC50) of hot aqueous extract (248) and cold aqueous extract (43.5) of bark of E. jambolana showed their antiviral potential against H5N1 virus. The significant virucidal activity of leaves and bark of E. jambolana merits further investigation as it may provide alternative antiviral agent for managing avian influenza infections in poultry farms and potential avian-human transmission.

  11. Cerro Xalapaxco: an unusual tuff cone with multiple explosion craters, in central Mexico (Puebla)

    NASA Astrophysics Data System (ADS)

    Abrams, Michael J.; Siebe, Claus

    1994-11-01

    The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits. The morphology of the cone and the characteristics of its deposits point to the involvement of significant quantities of groundwater during its eruption. The phreatomagmatic eruptions which led to the cone's formation pierced an alluvial fan, whose source is a glacially carved canyon near the summit of La Malinche volcano. The large canyon was cut during repeated glacial episodes, the last of which ended ca. 8500 years ago. The present alluvial fan mostly consists of reworked glacio-fluviatile andesite/dacite material from La Malinche. Rising magma encountered substantial amounts of groundwater within the limestone basement and in overlying intercalated pyroclastic and glacio-fluviatile deposits of the alluvial fan. Short-lived phreatomagmatic eruptions produced surge and airfall deposits. Xenoliths found in the cone beds are composed of dacite and andesite clasts, limestone, chert, and rare ignimbrite fragments. No juvenile material could be unequivocally identified, but is represented most probably by porphyritic dacite similar in texture and composition to La Malinche lavas. The multiple craters were formed as a response to changes in water and magma supply during the short-lived eruption. Hence, the locations where ideal magma/water ratios existed to fuel phreatomagmatic explosions shifted in time and space. Analysis of diameter/depth ratios of the craters indicates that the activity shifted from the center of the cone to its periphery in the west. Due to the configuration of the hydrographic environment, more groundwater flowing from La Malinche was available from the fan on the uphill side than below the cone at later stages of the eruption. The apparently anomalous position of the tuff cone on the slopes of a stratovolcano in a presently dry environment can be explained by more humid climatic conditions prevailing at the time of eruption.

  12. Proceedings: third symposium on the Cerro Prieto geothermal field, Baja California, Mexico

    SciTech Connect

    Not Available

    1981-01-01

    These proceedings include both English and Spanish versions of each paper presented at the symposium. Illustrations and tables, which have been placed between the two versions, include captions in both languages. Forty-one papers are included. Five papers were indexed for EDB previously. Separate abstracts were prepared for thirty-three papers and three were listed by title.

  13. Thermal Expansion Behavior of Cerro Prieto Sandstones and Other Sedimentary Rocks Under Stress

    SciTech Connect

    Contreras, E.; Bermejo, F.

    1983-12-15

    This paper describes the experimental work and presents the results of a research program carried out to investigate the thermal expansion behavior of sedimentary rocks under high stress conditions. The aspects that were investigated include the effects of temperature, temperature cycling, and confining pressure. Furthermore, the validity of the usual assumption on thermal expansion isotropy was investigated. On the other hand, the matrix thermal expansion concept is analyzed and its physical meaning and aplications are discussed. The effect of temperature on porosity is also a subject investigated regarding experimental methods for its estimation and comparison of earlier results. The experiments carried out consisted basically of thermal strain versus temperature measurements on jacketed and unjacketed samples subjected to different confining pressures and covering the temperature range from 25 C to 280 C and the pressure range from 3.0 MPa to 34.4 MPa. A review of earlier work is included as a reference frame to discuss and compare the results of this work, as well as to emphasize the limited extent of the research on thermal expansion behavior of sedimentary rocks that had been accomplished. Results are presented by means of thermal strain versus temperature curves and tabular data of thermal expansion coefficients. Several important conclusions for laborarory and field applications are reached from each of the aspects investigated. The wide research scope of considerable amount of data reported may represent an important contribution to the knowledge of thermal expansion behavior of sedimentary rocks.

  14. Geomorphic Mapping and Ground Penetration Radar Studies Along the Cerro Goden Fault Zone, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Velez, L.; Asencio, E.

    2016-12-01

    Geomorphic mapping was completed on aspect and hillshade maps created from LiDAR data. Late Quaternary deposits and geomorphic features (deflected drainages and scarps) were mapped and identified on the LiDAR data, to the east of the hills forming the eastern edge of the Añasco Valley. Four geomorphic features were mapped: (1) a linear, apparently incised portion of the Añasco river channel, (2) a deflected drainage reaching the main Añasco river channel, and (3) a sharp, almost 90o deflection, of the main Añasco river channel and, (4) the deflection of a small drainage and an apparent scarp. No reliable geomorphic features were observed to the west of the hills forming the eastern edge of the Añasco Valley. A Ground Penetrating Radar (GPR) profile was acquired at site 4 (the deflection of a small drainage and an apparent scarp). The GPR profile images two almost vertical apparent fault stands buried under an undeformed gravel-fill layer.

  15. Cerro Xalapaxco: An Unusual Tuff Cone with Multiple Explosion Craters, in Central Mexico (Puebla)

    NASA Technical Reports Server (NTRS)

    Abrams, M. J.; Siebe, C.

    1994-01-01

    The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits.

  16. Shrinking forests under warming: evidence of Podocarpus parlatorei (pino del cerro) from the subtropical Andes.

    PubMed

    Quiroga, María Paula; Pacheco, Silvia; Malizia, Lucio R; Premoli, Andrea C

    2012-01-01

    Phylogeography in combination with ecological niche modeling (ENM) is a robust tool to analyze hypotheses on range shifts under changing climates particularly of taxa and areas with scant fossil records. We combined phylogeographic analysis and ENM techniques to study the effects of alternate cold and warm (i.e., glacial and interglacial) periods on the subtropical montane cold-tolerant conifer Podocarpus parlatorei from Yungas forests of the central Andes. Twenty-one populations, comprising 208 individuals, were analyzed by sequences of the trnL -trnF cpDNA region, and 78 sites were included in the ENM. Eight haplotypes were detected, most of which were widespread while 3 of them were exclusive of latitudinally marginal areas. Haplotype diversity was mostly even throughout the latitudinal range. Two distribution models based on 8 bioclimatic variables indicate a rather continuous distribution during cooling, while under warming remained within stable, yet increasingly fragmented, areas. Although no major range shifts are expected with warming, long-lasting persistence of cold-hardy taxa inhabiting subtropical mountains may include in situ and ex situ conservation actions particularly toward southern (colder) areas.

  17. Acid-Sulfate Weathering of Cerro Negro Basalt: An Early Mars Analog

    NASA Astrophysics Data System (ADS)

    Marcucci, E. C.; Hynek, B. M.; McCollom, T. M.

    2012-05-01

    Understanding the weathering in an acidic volcanic environment gives insights into paleoconditions that formed the sulfates we see on Mars today. A series of experiments and models show the main secondary minerals and controls on their formation.

  18. Characterization by XRD and electron paramagnetic resonance (EPR) of waste materials from 'Cerro Matoso' Mine (Colombia)

    SciTech Connect

    Hernandez, Y.; Carriazo, J.G.; Almanza, O. . E-mail: oaalmanzam@unal.edu.co

    2006-07-15

    Materials from a mining process, in which ferronickel metal extraction is the principal aim, were studied. The residual solid (scum) obtained in this process leads to large-scale accumulation of a vitreous material (pollutant) which creates an environmental problem. These materials were characterized by EPR, X-ray diffraction and X-ray fluorescence. The results indicate that the analyzed solids are rich in Fe{sub 2}O{sub 3} and NiO among other oxides. The scum material shows diffraction signals corresponding to the minerals enstatite (pyroxene) and {alpha}-alumina. Moreover, the scum EPR analysis showed a broad line around g = 2.1 corresponding to Fe{sup 3+} clusters in a complex glassy matrix. An analysis of EPR at different temperatures was also performed. The objective of this work, as a first exploratory stage, is to develop a better understanding of the residual solids in order to identify potential applications.

  19. Carbon isotope geochemistry of hydrocarbons in the Cerro Prieto geothermal field, Baja California Norte, Mexico

    NASA Technical Reports Server (NTRS)

    Des Marais, D. J.; Stallard, M. L.; Nehring, N. L.; Truesdell, A. H.

    1988-01-01

    Hydrocarbon abundances and stable-isotopic compositions were measured in wells M5, M26, M35 and M102, which represent a range of depths (1270-2000 m) and temperatures (275-330 degrees C) in the field. In order to simulate the production of the geothermal hydrocarbons, gases were collected from the pyrolysis of lignite in the laboratory. This lignite was obtained from a well which sampled rock strata which are identical to those occurring in the field, but which have experienced much lower subsurface temperatures. In both the well and the laboratory observations, high-temperature environments favored higher relative concentrations of methane, ethane and benzene and generally higher delta 13C-values in the individual hydrocarbons. The best correlation between the laboratory and well data is obtained when laboratory-produced gases from experiments conducted at lower (400 degrees C) and higher (600 degrees C) temperatures are mixed. This improved correlation suggests that the wells are sampling hydrocarbons produced from a spectrum of depths and temperatures in the sediments.

  20. Late glacial and late Holocene moraines in the Cerros Cuchpanga, central Peru*1

    NASA Astrophysics Data System (ADS)

    Wright, H. E.

    1984-05-01

    Small ice fields on the western cordillera northeast of Lima were expanded to three times their present size in the recent past, and the regional snow line was probably about 100 m lower than it is today. Outwash from the expanded glaciers formed deltas of silt in valley-bottom lakes. When the ice lobes retreated, the reduced outwash was trapped behind recessional moraines, and the clear meltwater infiltrated into the limestone bedrock and emerged at the heads of the deltas in spring pools. The delta surfaces then became covered with peat, and radiocarbon dates for the base of the peat (1100 ± 70 and 430 ± 70 yr B.P. for two different deltas) indicate that the maximum ice advance was older than those dates and, thus, older than the Little Ice Age of many north-temperate regions. Much older moraines date from expansion of the same local summit glaciers to even lower levels in the main valleys, which had previously been inundated by the cordilleran ice field. The cordilleran deglaciation and this expansion of local glaciers probably occurred between 12,000 and 10,000 yr ago, on the basis of slightly contradictory radiocarbon dates.

  1. Carbon isotope geochemistry of hydrocarbons in the Cerro Prieto geothermal field, Baja California Norte, Mexico

    USGS Publications Warehouse

    Des Marais, D.J.; Stallard, M.L.; Nehring, N.L.; Truesdell, A.H.

    1988-01-01

    Hydrocarbon abundances and stable-isotopic compositions were measured in wells M5, M26, M35 and M102, which represent a range of depths (1270-2000 m) and temperatures (275-330??C) in the field. In order to simulate the production of the geothermal hydrocarbons, gases were collected from the pyrolysis of lignite in the laboratory. This lignite was obtained from a well which sampled rock strata which are identical to those occurring in the field, but which have experienced much lower subsurface temperatures. In both the well and the laboratory observations, high-temperature environments favored higher relative concentrations of methane, ethane and benzene and generally higher ??13C-values in the individual hydrocarbons. The best correlation between the laboratory and well data is obtained when laboratory-produced gases from experiments conducted at lower (400??C) and higher (600??C) temperatures are mixed. This improved correlation suggests that the wells are sampling hydrocarbons produced from a spectrum of depths and temperatures in the sediments. ?? 1988.

  2. Carbon isotope geochemistry of hydrocarbons in the Cerro Prieto geothermal field, Baja California Norte, Mexico

    NASA Technical Reports Server (NTRS)

    Des Marais, D. J.; Stallard, M. L.; Nehring, N. L.; Truesdell, A. H.

    1988-01-01

    Hydrocarbon abundances and stable-isotopic compositions were measured in wells M5, M26, M35 and M102, which represent a range of depths (1270-2000 m) and temperatures (275-330 degrees C) in the field. In order to simulate the production of the geothermal hydrocarbons, gases were collected from the pyrolysis of lignite in the laboratory. This lignite was obtained from a well which sampled rock strata which are identical to those occurring in the field, but which have experienced much lower subsurface temperatures. In both the well and the laboratory observations, high-temperature environments favored higher relative concentrations of methane, ethane and benzene and generally higher delta 13C-values in the individual hydrocarbons. The best correlation between the laboratory and well data is obtained when laboratory-produced gases from experiments conducted at lower (400 degrees C) and higher (600 degrees C) temperatures are mixed. This improved correlation suggests that the wells are sampling hydrocarbons produced from a spectrum of depths and temperatures in the sediments.

  3. WITHDRAWN: The Palaeocene Cerro Munro tonalite intrusion (Chubut Province, Argentina): A plutonic remnant of explosive volcanism?

    NASA Astrophysics Data System (ADS)

    Rodríguez, C.; Aragón, E.; Castro, A.; Pedreira, R.; Sánchez-Navas, A.; Díaz-Alvarado, J.; D´Eramo, F.; Pinotti, L.; Aguilera, Y.; Cavarozzi, C.; Demartis, M.; Hernando, I. R.; Fuentes, T.

    2017-10-01

    The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error in Journal of South American Earth Sciences, 78C (2017) 30 - 60, 10.1016/j.jsames.2017.06.002. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

  4. Geologic map of the Cerro Gordo Peak 7.5' Quadrangle, Inyo County, California

    USGS Publications Warehouse

    Stone, Paul; Dunne, George C.; Conrad, James E.; Swanson, Brian J.; Stevens, Calvin H.; Valin, Zenon C.

    2004-01-01

    This digital map database, compiled from new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying pamphlet, it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24,000 or smaller.

  5. Cerro Xalapaxco: An Unusual Tuff Cone with Multiple Explosion Craters, in Central Mexico (Puebla)

    NASA Technical Reports Server (NTRS)

    Abrams, M. J.; Siebe, C.

    1994-01-01

    The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits.

  6. The dancing sky: 6 years of night-sky observations at Cerro Paranal

    NASA Astrophysics Data System (ADS)

    Patat, F.

    2008-04-01

    Aims: This work provides the results of the first six years of operation by the systematic night-sky monitoring at ESO-Paranal (Chile). Methods: The UBVRI night-sky brightness was estimated on about 10 000 VLT-FORS1 archival images, obtained on more than 650 separate nights, distributed over 6 years, and covering the descent from maximum to minimum of sunspot cycle n. 23. Additionally, a set of about 1000 low-resolution, optical, night-sky spectra were extracted and analysed. Results: The unprecedented database discussed in this paper has led to detecting a clear seasonal variation of the broad-band night-sky brightness in the VRI passbands, similar to the well-known semi-annual oscillation of the Na I D doublet. The spectroscopic data demonstrate that this seasonality is common to all spectral features, with the remarkable exception of the OH rotational-vibrational bands. A clear dependency on the solar activity is detected in all passbands and is particularly pronounced in the U band, where the sky brightness decreased by ~0.6 mag arcsec-2 from maximum to minimum of solar cycle n. 23. No correlation is found between solar activity and the intensity of the Na I D doublet and the OH bands. A strong correlation between the intensity of N I 5200 Å and [OI]6300, 6364