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Sample records for argentera massif south-western

  1. Carboniferous high-pressure metamorphism of Ordovician protoliths in the Argentera Massif (Italy), Southern European Variscan belt

    Rubatto, Daniela; Ferrando, Simona; Compagnoni, Roberto; Lombardo, Bruno

    2010-04-01

    The age of high-pressure metamorphism is crucial to identify a suitable tectonic model for the vast Variscan orogeny. Banded H P granulites from the Gesso-Stura Terrain in the Argentera Massif, Italy, have been recently described (Ferrando et al., 2008) relicts of high-pressure metamorphism in the western part of the Variscan orogen. Bulk rock chemistry of representative lithologies reveals intermediate silica contents and calc-alkaline affinity of the various cumulate layers. Enrichment in incompatible elements denotes a significant crustal component in line with intrusion during Ordovician rifting. Magmatic zircon cores from a Pl-rich layer yield scattered ages indicating a minimum protolith age of 486 ± 7 Ma. Carboniferous zircons (340.7 ± 4.2 and 336.3 ± 4.1 Ma) are found in a Pl-rich and a Pl-poor layer, respectively. Their zoning, chemical composition (low Th/U, flat HREE pattern and Ti-in-zircon temperature) and deformation indicate that they formed during the high-pressure event before decompression and mylonitisation. The proposed age for high-pressure metamorphism in the Argentera Massif proves that subduction preceded anatexis by less than 20 Ma. The new data allow a first-order comparison with the Bohemian Massif, which is located at the eastern termination of the Variscan orogen. Similarities in evolution at either end of the orogen support a Himalayan-type tectonic model for the entire European Variscides.

  2. Cancer distribution pattern in south-western Nigeria | Awodele ...

    The burden of cancer in Nigeria is appreciable with about 100,000 new cancer cases been reported in the country each year. This study aimed to determine the level of occurrence and pattern of distribution of different cancer types in two major functional cancer registries in south-western Nigeria. A desk review of the level ...

  3. Explaining ecological clusters of maternal depression in South Western Sydney.

    Eastwood ED, John; Kemp, Lynn; Jalaludin, Bin

    2014-01-24

    The aim of the qualitative study reported here was to: 1) explain the observed clustering of postnatal depressive symptoms in South Western Sydney; and 2) identify group-level mechanisms that would add to our understanding of the social determinants of maternal depression. Critical realism provided the methodological underpinning for the study. The setting was four local government areas in South Western Sydney, Australia. Child and Family practitioners and mothers in naturally occurring mothers groups were interviewed. Using an open coding approach to maximise emergence of patterns and relationships we have identified seven theoretical concepts that might explain the observed spatial clustering of maternal depression. The theoretical concepts identified were: Community-level social networks; Social Capital and Social Cohesion; "Depressed community"; Access to services at the group level; Ethnic segregation and diversity; Supportive social policy; and Big business. We postulate that these regional structural, economic, social and cultural mechanisms partially explain the pattern of maternal depression observed in families and communities within South Western Sydney. We further observe that powerful global economic and political forces are having an impact on the local situation. The challenge for policy and practice is to support mothers and their families within this adverse regional and global-economic context.

  4. Explaining ecological clusters of maternal depression in South Western Sydney

    2014-01-01

    Background The aim of the qualitative study reported here was to: 1) explain the observed clustering of postnatal depressive symptoms in South Western Sydney; and 2) identify group-level mechanisms that would add to our understanding of the social determinants of maternal depression. Methods Critical realism provided the methodological underpinning for the study. The setting was four local government areas in South Western Sydney, Australia. Child and Family practitioners and mothers in naturally occurring mothers groups were interviewed. Results Using an open coding approach to maximise emergence of patterns and relationships we have identified seven theoretical concepts that might explain the observed spatial clustering of maternal depression. The theoretical concepts identified were: Community-level social networks; Social Capital and Social Cohesion; "Depressed community"; Access to services at the group level; Ethnic segregation and diversity; Supportive social policy; and Big business. Conclusions We postulate that these regional structural, economic, social and cultural mechanisms partially explain the pattern of maternal depression observed in families and communities within South Western Sydney. We further observe that powerful global economic and political forces are having an impact on the local situation. The challenge for policy and practice is to support mothers and their families within this adverse regional and global-economic context. PMID:24460690

  5. A habitat overlap analysis derived from Maxent for Tamarisk and the South-western Willow Flycatcher

    Patricia York; Paul Evangelista; Sunil Kumar; James Graham; Curtis Flather; Thomas Stohlgren

    2011-01-01

    Biologic control of the introduced and invasive, woody plant tamarisk (Tamarix spp, saltcedar) in south-western states is controversial because it affects habitat of the federally endangered South-western Willow Flycatcher (Empidonax traillii extimus). These songbirds sometimes nest in tamarisk where floodplain-level invasion replaces native habitats. Biologic control...

  6. Climate change and runoff in south-western Australia

    Silberstein, R. P.; Aryal, S. K.; Durrant, J.; Pearcey, M.; Braccia, M.; Charles, S. P.; Boniecka, L.; Hodgson, G. A.; Bari, M. A.; Viney, N. R.; McFarlane, D. J.

    2012-12-01

    SummaryThis paper presents the results of computer simulations of runoff from 13 major fresh and brackish river basins in south-western Australia (SWA) under climate projections obtained from 15 GCMs with three future global warming scenarios equivalent to global temperature rises of 0.7 °C, 1.0 °C and 1.3 °C by 2030. The objective was to apply an efficient methodology, consistent across a large region, to examine the implications of the best available projections in climate trends for future surface water resources. An ensemble of rainfall-runoff models was calibrated on stream flow data from 1975 to 2007 from 106 gauged catchments distributed throughout the basins of the study area. The sensitivity of runoff to projected changes in mean annual rainfall is examined using the climate 'elasticity' concept. Averaged across the study area, all 15 GCMs project declines in rainfall under all global warming scenarios with a median decline of 8% resulting in a median decline in runoff of 25%. Such uniformity in projections from GCMs is unusual. Over SWA the average annual runoff under the 5th wettest and 5th driest of the 45 projections of the 2030 climate declines by 10 and 42%, respectively. Under the 5th driest projection the runoff decline ranges from 53% in the northern region to 40% in the southern region. Strong regional variations in climate sensitivity are found with the proportional decline in runoff greatest in the northern region and the greatest volumetric declines in the wetter basins in the south. Since the mid 1970s stream flows into the major water supply reservoirs in SWA have declined by more than 50% following a 16% rainfall reduction. This has already had major implications for water resources planning and for the preservation of aquatic and riparian ecosystems in the region. Our results indicate that this reduction in runoff is likely to continue if future climate projections eventuate.

  7. Radiotherapy in the Barwon South Western Region: a rural perspective

    Henry, Margaret J.; Jones, Phil; Coory Michael; Chapman, Adam; Morrissy, Kate; Matheson, Leigh M.; Pitson, Graham; Lynch, Rod; Healy, Pat; Ashley, David

    2014-01-01

    Cancer-related mortality rates are higher in rural areas compared with urban regions. Whether there are corresponding geographical variations in radiotherapy utilisation rates (RURs) is the subject of this study. RURs for the regional centre of Geelong and rural areas of the Barwon South Western Region were calculated using a population-based database (2009). Lower RURs were observed for rural patients compared with the Geelong region for prostate cancer (15.7% vs 25.8%, P=0.02), rectal cancer (32.8% vs 44.7%, P=0.11), lymphoma (9.4% vs 26.2%, P=0.05), and all cancers overall (25.6% vs 28.9%, P=0.06). This lower rate was significant in men (rural, 19.9%; Geelong, 28.3%; P=0.00) but not in women (rural, 33.6%; Geelong, 29.7%; P=0.88). Time from diagnosis to radiotherapy was not significantly different for patients from the two regions. Tumour staging within the rural and Geelong regions was not significantly different for the major tumour streams of rectal, prostate and lung cancer (P=0.61, P=0.79, P=0.43, respectively). A higher proportion of tumours were unstaged or unstageable in the rural region for lung (44% vs 18%, P<0.01) and prostate (73% vs 57%, P<0.01) cancer. Lower RURs were observed in our rural region. Differences found within tumour streams and in men suggest a complexity of relationships that will require further study.

  8. Contrasting evidence of Holocene ice margin retreat, south-western Greenland

    Levy, L. B.; Larsen, N. K.; Davidson, T. A.

    2017-01-01

    Constraining the Greenland Ice Sheet's (GrIS) response to Holocene climate change provides calibrations for ice sheet models that hindcast past ice margin fluctuations. Ice sheet models predict enhanced ice retreat in south-western Greenland during the middle Holocene; however, few geological...... observations corroborating the extensive retreat are available. We present new data from lake sediment cores from the Isua region, south-western Greenland, which provide constraints on Holocene fluctuations of the GrIS margins. Our data indicate that the main GrIS margin was 30 km west of its present...

  9. Predictors of Mortality in a Critical Care Unit in South Western Kenya

    Abstract. Background: Critical care in developing countries has been ... which may impact the quality of care. Hospitals also ... and referral facility located in South Western Kenya in Bomet .... p=0.01). As regards end of life care; 40.4% of those.

  10. Description of a new moss frog from the south-western Cape (Anura ...

    A new species of moss frog, genus Arthroleptella, is described from the Kleinrivier mountains of the south-western Cape. It is morphologically indistinguishable from the other three species in the area. The four Cape species are allopatric, each has a unique male advertisement call, and preliminary molecular data shows ...

  11. How do we know how much groundwater is stored in south-western Cape mountains?

    Midgley, JJ

    2001-07-01

    Full Text Available Isotopes of water (D, O-18) in rain and streams were used to obtain an estimate of the amount of ground water in the south-western Cape Mountains. It was assumed that the groundwater reservoir is well-mixed and that the water isotope signals...

  12. HIV/AIDS: Knowledge and attitudes of dentists in South-Western ...

    Objective: The purpose of this study was to assess the knowledge and attitudes of dentists in South-Western Nigeria in relation to HIV/AIDS. Materials and methods: A questionnaire survey of 164 dentists in Lagos, Ibadan and Benin The data was analyzed using Epi-info statistical software. Results: The modes of ...

  13. The birds of the alien Acacia thickets of the South-western Cape

    About 1876, the Cape Superintendent of Plantations began using the Australian Acacia cyanophylla and A. ... Strandveld; but 38 % of all nests recorded in the South-western Cape are in Acacia. S. senegalensis is .... of mixed exotic trees, often including some Acacia but also Eucalyptus, Pinus, Quercus,. Populus and other ...

  14. Principals' Leadership Skills and School Effectiveness: The Case of South Western Nigeria

    Bolanle, Akinola Oluwatoyin

    2013-01-01

    The study sought to find out the leadership skills possessed by Principals of public secondary schools in south western Nigeria and the relationship between these leadership skills and school effectiveness in terms of student academic achievement. The descriptive survey research design was employed for the study. 154 Principals and 770 teachers,…

  15. Philorhizus occitanus sp. n. from the South-Western Alps (Piedmont, Italy (Coleoptera: Carabidae, Dromiini

    Gianni Allegro

    2015-12-01

    Full Text Available Philorhizus occitanus sp. n. from the South-Western Alps (Ellero Valley and Maira Valley is described. This new species is similar to P. crucifer and P. notatus as far as the external morphology is concerned, but it is distinguished by the color pattern and the shape of elytra, as well as by the features of the median lobe of aedeagus. P. liguricus, which is easily distinguished from P. occitanus sp. n. by the external morphology, was already recorded from the South-Western Alps and from the Ligurian Apennines. P. occitanus sp. n. is a likely close relative of P. notatus, although the affinities of this relict flightless new species remain uncertain.

  16. Prevalence of Legionella spp. in water systems of hospitals and hotels in South Western Greece.

    Fragou, K; Kokkinos, P; Gogos, C; Alamanos, Y; Vantarakis, A

    2012-01-01

    The aim of the present study was to determine the prevalence of Legionella spp. in water systems of hospitals and hotels located in South Western Greece, to study the molecular epidemiology of the isolated strains and their possible association with bacterial contamination (total count and Pseudomonas aeruginosa), the water pH, and temperature. A prevalence survey for Legionella spp. by culturing techniques in water distribution systems of eight hospitals and nine hotels occurred in South Western Greece. Water sampling and microbiological analysis were carried out following the ISO methods. Legionella pneumophila was detected in 33% and 36% of the distribution systems of hospitals and hotels, respectively. Our survey results suggest a frequent prevalence of elevated concentrations of Legionella spp. in water systems of hospitals and hotels. Our investigation has confirmed the need to regularly monitor the microbiological condition of water systems in hospitals and hotels.

  17. Cutaneous adornment in the Yoruba of south-western Nigeria - past and present.

    George, Adekunle O; Ogunbiyi, Adebola O; Daramola, Olaniyi O M

    2006-01-01

    The traditional practice of cutaneous adornment is rich and vast amongst the Yoruba in the south-western part of Nigeria. There are varieties of traditionally made products, such as oils, soaps, fragrances, and beads, that have been employed over the years to enhance body beauty. This rich cultural heritage, however, has more or less given way to the values of Western culture, together with the disadvantages of the latter, manifesting as sequelae on the skin.

  18. Changes in the forest ecosystems in areas impacted by aridization in south-western Romania

    Pravalie, Remus; Sîrodoev, Igor; Peptenatu, Daniel

    2014-01-01

    Background In the past few decades, global climate change has accentuated the intensification of aridization in South-Western Romania, with direct and indirect consequences on the quality of forest ecosystems. In addition to qualitative deterioration, the quantitative changes brought about by intensive anthropic deforestation have created the conditions for a decline in the size of forest areas on vast tracts of land. The paper aims to analyze the qualitative and quantitative changes in the f...

  19. A new GPS velocity field in the south-western Balkans: insights for continental dynamics

    D'Agostino, N.; Avallone, A.; Duni, L.; Ganas, A.; Georgiev, I.; Jouanne, F.; Koci, R.; Kuka, N.; Metois, M.

    2017-12-01

    The Balkans peninsula is an area of active distributed deformation located at the southern boundary of the Eurasian plate. Relatively low strain rates and logistical reasons have so far limited the characterization and definition of the active tectonics and crustal kinematics. The increasing number of GNSS stations belonging to national networks deployed for scientific and cadastral purposes, now provides the opportunity to improve the knowledge of the crustal kinematics in this area and to define a cross-national velocity field that illuminates the active tectonic deformation. In this work we homogeneously processed the data from the south western Balkans and neighbouring regions using available rinex files from scientific and cadastral networks (ALBPOS, EUREF, HemusNET, ITALPOS, KOPOS, MAKPOS, METRICA, NETGEO, RING, TGREF). In order to analyze and interpret station velocities relative to the Eurasia plate and to reduce the common mode signal, we updated the Eurasian terrestrial reference frame described in Métois et al. 2015. Starting from this dataset we present a new GPS velocity field covering the south western part of the Balkan Peninsula. Using this new velocity field, we derive the strain rate tensor to analyze the regional style of the deformation. Our results (1) improve the picture of the general southward flow of the crust characterizing the south western Balkans behind the contractional belt at the boundary with Adriatic and (2) provide new key elements for the understanding of continental dynamics in this part of the Eurasian plate boundary.

  20. A Q fever cluster among workers at an abattoir in south-western Sydney, Australia, 2015

    Heidi Lord

    2016-11-01

    Full Text Available Background: In September 2015, the Public Health Unit of the South Western Sydney Local Health District was notified of two possible Q fever cases. Case investigation identified that both cases were employed at an abattoir, and both cases advised that co-workers had experienced similar symptoms. Public Health Unit staff also recalled interviewing in late 2014 at least one other Q fever case who worked at the same abattoir. This prompted an outbreak investigation. Methods: The investigation incorporated active case finding, microbiological analysis, field investigation and a risk factor survey. Included cases were laboratory definitive or suspected cases occurring from October 2014 to October 2015, residing or working in south-western Sydney. A suspected case had clinically compatible illness, high-risk exposure and was epidemiologically linked to another confirmed case. A confirmed case included laboratory detection of C. burnetii. Results: Eight cases met the case definition with seven confirmed (including a deceased case and one suspected. The eight cases were all males who had been employed at an abattoir in south-western Sydney during their incubation period; symptom onset dates ranged from November 2014 to September 2015. Field investigation identified multiple potential risk factors at the abattoir, and the majority (75% of employees were not vaccinated against Q fever despite this high-risk setting. Conclusion: This cluster of Q fever in a single abattoir confirms the significance of this zoonotic disease as an occupational hazard among persons working in high-risk environments. Implementation of Q fever vaccination programmes should eliminate Q fever in high-risk occupational settings.

  1. Microfossils in the Ordovician erratic boulders from South-western Finland

    Nõlvak, J.

    1995-12-01

    Full Text Available Chitinozoans, ostracods and acritarchs found in four glacially transported limestone boulders from the south-western coast of Finland have been studied in order to test the usefulness of these microfossil groups in age determinations. Also rare specimens of conodonts, inarticulated brachiopods and foraminifers were found. Baltic limestone (or Östersjö limestone was the most problematic, because only fossils with calcitic or phosphatic shells are preserved. It is concluded that the boulders identified correlate with the Uhaku and Rakvere stages of the Middle Ordovician.

  2. Features of change of permanent snow patches in the Mongun-Taiga Massif, 1966–2011

    D. A. Ganyushkin

    2013-01-01

    Full Text Available The article is dedicated to perennial snow patches of Mongun-Taiga mountain massif (south-western Tuva, their morphology, present state and dynamics over the last 45 years. We created a scheme of snow patch classification with regard to genesis of relief and position on the slopes. Dynamics of snow patches is analyzed for periods between several time points – 1966 (on basis of aerial photos, 2000, 2007–2008 and 2011 (on basis of field measurements and observations. From 1966 to 2008 the number of snow patches decreased by 4 times, the total area – by 15 times, the altitudinal zone of snow patches moved 250–300 m up. In 2008–2011 the altitudinal zone of snow patches partly recovered, its lower limit moved 250 m down, periglacial snow patches recovered, a new type – snow patches of buried ice and debris-covered glaciers appeared. It could be the first face of the process of small glaciers recovery in the massif. Using the changes of the altitudinal position of snow patches in comparison with data of the closest meteorological station we estimated the amount of annual precipitation, critical for the existence of local snow patches.

  3. Morphological and cytological diversity of goldenrods (Solidago L. and Euthamia Nutt. from south-western Poland

    Szymura Magdalena

    2015-06-01

    Full Text Available Correlations between the morphology and cytology of invasive species and the effectiveness of invasion are among the most interesting questions in invasion ecology. Amongst exceptionally successful worldwide plant invaders, species of goldenrod (Solidago and Euthamia are considered. The main aim of the study was to compare the morphology (concerning life traits and cytology of the selected goldenrods occurring in south-western Poland with the effectiveness of their invasion. The results of the study, conducted in south-western Poland, showed that life traits of invasive Solidago and Euthamia taxa were clearly not connected with the effectiveness of invasion. The most widespread species, S. gigantea and S. altissima, had the highest ramets and uncommon species such as Euthamia graminifolia and S. virgaurea had short ramets. However, S. canadensis, which is tall, is also uncommon. The most frequent species (S. gigantea produced smaller inflorescence than less frequent species (S. altissima, S. canadensis and Euthamia graminifolia. The spread of particular taxa was also not connected with the ploidy level and DNA content.

  4. Survey of blindness and low vision in Egbedore, South-Western Nigeria.

    Kolawole, O U; Ashaye, A O; Adeoti, C O; Mahmoud, A O

    2010-01-01

    Developing efficient and cost-effective eye care programmes for communities in Nigeria has been hampered by inadequate and inaccurate data on blindness and low vision. To determine the prevalence and causes of blindness and low vision among adults 50 years and older in South-Western Nigeria in order to develop viable eye care programme for the community. Twenty clusters of 60 subjects of age 50 years and older were selected by systematic random cluster sampling. Information was collected and ocular examinations were conducted on each consenting subject. Data were recorded in specially designed questionnaire and analysed using descriptive statistical methods. Out of the 1200 subjects enrolled for the study, 1183(98.6%) were interviewed and examined. Seventy five (6.3%)) of the 1183 subjects were bilaterally blind and 223(18.9%) had bilateral low vision according to WHO definition of blindness and low vision. Blindness was about 1.6 times commoner in men than women. Cataract, glaucoma and posterior segment disorders were major causes of bilateral blindness. Bilateral low vision was mainly due to cataract, refractive errors and posterior segment disorders. The prevalence of blindness and low vision in this study population was high. The main causes are avoidable. Elimination of avoidable blindness and low vision calls for attention and commitment from government and eye care workers in South Western Nigeria.

  5. Reproductive and population parameters of spiny dogfish Squalus acanthias in the south-western Atlantic Ocean.

    Colonello, J H; Cortés, F; Belleggia, M; Massa, A M

    2016-05-01

    The objective of this study was to estimate reproductive and population parameters of the spiny dogfish Squalus acanthias for the south-western Atlantic Ocean. In total, 2714 specimens (1616 males and 1098 females) were collected from surveys carried out using research vessels. Males ranged from 225 to 861 mm total length (LT ) and females from 235 to 925 mm LT . The size at maturity of females (651 mm) was significantly greater than that of males (565 mm). The maximum proportion of mature individuals (Pmax ) of the gestation ogive was 156 mm). The temporal and spatial co-occurrence of non-gravid adult females at different stages of ovarian development, as well as gravid females at all embryonic development stages would indicate that the female reproductive cycle in the south-western Atlantic Ocean is asynchronous. The results indicate that S. acanthias is susceptible to fishing pressure on account of its length at maturity, extended reproductive cycles and low fecundity. © 2016 The Fisheries Society of the British Isles.

  6. Psychopathology among senior secondary school students in Ilesa, south western Nigeria.

    Fatoye, F O; Morakinyo, O

    2003-09-01

    The prevalence rate of psychopathology and the relationship between psychopathology and some socio-demographic variables and consolidated current drug use were studied in 600 randomly selected senior secondary school students in Ilesa, south-western Nigeria. The 30-item version of the General Health Questionnaire and the WHO student drug use questionnaire were administered for the study. The findings revealed that the prevalence of psychopathology among the study population was 39.5%. There were significant positive associations between psychopathology and belonging to low socio-economic status, coming from a polygamous family and self-rated poor academic performance. The results also showed that although psychopathology was commoner amongst respondents who were engaged in current use of psychoactive substances than those who were not, the difference was not significant. The implications of these findings within the context of the limitations of the study and the importance of effective preventive and therapeutic student mental health services are discussed.

  7. Parkia biglobosa as an economic resource for rural women in south-western Burkina Faso

    Andersen, Mette-Helene Kronborg; Lykke, Anne Mette; Ilboudo, Jean-Baptiste

    2013-01-01

    An approach for commercialising a product from Parkia biglobosa in order to improve the economic situation of rural women in south-western Burkina Faso was explored. Income is generated from sales of a derivative from the fermented seeds called soumbala. About one fifth of the women (18%) were...... involved in the sale of soumbala, and 34% of those not participating in soumbala sales were interested in getting involved, suggesting that there is a basis for expanding the soumbala trade. Possible factors that could motivate more women to participate in soumbala sales were sustainability, sowing...... of seeds and amount of seeds harvested per year. In addition, 90% of the informants managed Parkia sustainably, suggesting that enhanced exploitation of Parkia for commercial purposes can be ecologically sustainable if present management techniques are maintained. The results suggest that Parkia have...

  8. Invasive vascular plant species of oxbow lakes in south-western Poland

    Spałek Krzysztof

    2015-06-01

    Full Text Available Natural water reservoirs are very valuable floristic sites in south-western Poland. Among them, the most important for the preservation of biodiversity of flora are oxbow lakes. The long-term process of human pressure on habitats of this type caused disturbances of their biological balance. Changes in the water regime, industrial development and chemisation of agriculture, especially in the period of the last two hundred years, led to systematic disappearances of localities of many plant species connected with rare habitats and also to the appearance of numerous invasive plant species. They are: Azolla filiculoides, Echinocystis lobata, Erechtites hieraciifolia, Impatiens glandulifera, I. parviflora, Reynoutria japonica, Solidago canadensis, S. gigantea and S. graminifolia. Field works were conducted in years 2005-2012.

  9. Selected Determinants of Coopetition of Industrial Enterprises in South-Western Poland in 2009–2011

    Tomaszewski Marek

    2014-06-01

    Full Text Available When studying literature on the issue coopetition it may be found that this issue has become more and more popular in recent years. However, this finding was not confirmed in economic practice. Reluctance or concerns about coopetition result from caution and distrust of Polish entrepreneurs in relation to other players on the market. In the previous socio-political conditions this approach was successful. However, the current situation forces small and medium-sized enterprises to draw attention to the strategy of “sleeping with the enemy.” In this context, the objective of the study was to answer the question of what factors influence establishing coopetition in south-western Poland in a simulative or detrimental way.

  10. Acid ran and below-cloud scavenging in south-western China

    Tanner, P.A.; Lei, H.C.; Huang, M.Y.; Shen, Z.L.

    1997-01-01

    Major urban areas in south-western China exhibit unique air pollution problems due to increasing use of high sulphur-content fuels in an environment of unfavourable topography and climate. Ambient levels of sulphur dioxide exceed the air quality objectives, and this gas is the major precursor of acid rain. Cloudwater chemistry studies are reported for urban, suburban and countryside locations, during the period 1985-89. Although cloudwater acidity was found to increase towards the cloud base, the acidity was much greater for rainwater samples collected simultaneously, and was more pronounced in urban rather than neighbouring suburban or countryside regions. The main contribution to the acidity arises from below-cloud scavenging of gas and aerosol and model calculations are able to simulate this behaviour

  11. Norm Levels in Mine Pit Lakes in South-Western Spain

    Manjón, G.; Galván, J.; Mantero, J.; Díaz, I.; García-Tenorio, R.

    2015-01-01

    Former mining activities in a pyritic area in south-western Spain have generated mine pits in which underground water and rainwater has accumulated. The accumulated waters have produced oxidation of the pyrite and, consequently, the pit water has become acidic, causing the dissolution of metals and radionuclides of natural origin. The paper discusses the activity concentration levels of uranium isotopes and other radionuclides in water samples and sediments collected from these mine pit lakes. Tributaries of the nearby Odiel River, when crossing the mining area, show low pH values and high concentrations of uranium isotopes due to acid mine drainage. Through the analysis of several isotope activity ratios, the presence of radionuclides in the pit lakes and the influence of these radionuclides on the surrounding area and the Odiel River are evaluated. (author)

  12. Being alone and expectations lost: a critical realist study of maternal depression in South Western Sydney.

    Eastwood, John G; Kemp, Lynn A; Jalaludin, Bin B

    2015-01-01

    The study reported here is part of a critical realist multilevel study. It seeks to identify and explain complex perinatal contextual social and psychosocial mechanisms that may influence the developmental origins of health and disease, with a focus on the role of postnatal depression. The aims of the greater study are to: (1) describe the phenomenon of postnatal depression in South Western Sydney; and (2) identify mechanisms that would add to our understanding of the psycho-social causes of maternal depression. This paper will move beyond our previous quantitative descriptions of individual-level predictors of depressive symptoms by seeking the views of local mothers and practitioners, to explain the mechanisms that might be involved. The study was set in South Western Sydney, New South Wales, Australia. An Explanatory Theory Building Method was used. The previously reported quantitative study was a non-linear principal component analysis and logistic regression study of 15,389 months delivering in 2002 and 2003. This intensive qualitative study used open coding of interviews, of seven practitioners and three naturally occurring mothers groups, to enable maximum emergence. The theoretical concepts identified were: attachment and nurturing, infant temperament, unplanned pregnancy and sole parenthood, support for mothers, access to services, stress, financial hardship, isolation and marginalisation, mothers' "loss of control" and "power", and expectations and dreams. Being alone and expectations lost emerged as possible triggers of stress and depression for mothers. These findings might also apply to others who have their dreams shattered during life's transitions. In these situations social and cultural context can either nurture and support or marginalise and isolate. The challenge for policy and practice is to support mothers and their partners during the transition to parenthood within a challenging social and material context.

  13. A habitat overlap analysis derived from maxent for tamarisk and the south-western willow flycatcher

    York, Patricia; Evangelista, Paul; Kumar, Sunil; Graham, James; Flather, Curtis; Stohlgren, Thomas

    2011-06-01

    Biologic control of the introduced and invasive, woody plant tamarisk ( Tamarix spp, saltcedar) in south-western states is controversial because it affects habitat of the federally endangered South-western Willow Flycatcher ( Empidonax traillii extimus). These songbirds sometimes nest in tamarisk where floodplain-level invasion replaces native habitats. Biologic control, with the saltcedar leaf beetle ( Diorhabda elongate), began along the Virgin River, Utah, in 2006, enhancing the need for comprehensive understanding of the tamarisk-flycatcher relationship. We used maximum entropy (Maxent) modeling to separately quantify the current extent of dense tamarisk habitat (>50% cover) and the potential extent of habitat available for E. traillii extimus within the studied watersheds. We used transformations of 2008 Landsat Thematic Mapper images and a digital elevation model as environmental input variables. Maxent models performed well for the flycatcher and tamarisk with Area Under the ROC Curve (AUC) values of 0.960 and 0.982, respectively. Classification of thresholds and comparison of the two Maxent outputs indicated moderate spatial overlap between predicted suitable habitat for E. traillii extimus and predicted locations with dense tamarisk stands, where flycatcher habitat will potentially change flycatcher habitats. Dense tamarisk habitat comprised 500 km2 within the study area, of which 11.4% was also modeled as potential habitat for E. traillii extimus. Potential habitat modeled for the flycatcher constituted 190 km2, of which 30.7% also contained dense tamarisk habitat. Results showed that both native vegetation and dense tamarisk habitats exist in the study area and that most tamarisk infestations do not contain characteristics that satisfy the habitat requirements of E. traillii extimus. Based on this study, effective biologic control of Tamarix spp. may, in the short term, reduce suitable habitat available to E. traillii extimus, but also has the potential

  14. Causes of blindness and career choice among pupils in a blind school; South Western Nigeria.

    Fadamiro, Christianah Olufunmilayo

    2014-01-01

    The causes of Blindness vary from place to place with about 80% of it been avoidable. Furthermore Blind people face a lot of challenges in career choice thus limiting their economic potential and full integration into the society. This study aims at identifying the causes of blindness and career choice among pupils in a school for the blind in South -Western Nigeria. This is a descriptive study of causes of blindness and career choice among 38 pupils residing in a school for the blind at Ikere -Ekiti, South Western Nigeria. Thirty eight pupils comprising of 25 males (65.8%) and 13 females (34.2%) with age range from 6-39 years were seen for the study, The commonest cause of blindness was cataract with 14 cases (36.84%) while congenital glaucoma and infection had an equal proportion of 5 cases each (13.16%). Avoidable causes constituted the greatest proportion of the causes 27 (71.05%) while unavoidable causes accounted for 11 (28.9%). The law career was the most desired profession by the pupils 11 (33.3%) followed by Teaching 9 (27.3%), other desired profession includes engineering, journalism and farming. The greatest proportion of causes of blindness identified in this study is avoidable. There is the need to create public awareness on some of the notable causes particularly cataract and motivate the community to utilize available eye care services Furthermore there is need for career talk in schools for the blind to enable them choose career where their potential can be fully maximized.

  15. Childhood injuries in Ilesa, South-Western Nigeria: causes, pattern, and outcome.

    Adegoke, S A; Ademola, A S; Dedeke, I O F; Oyelami, O A

    2010-01-01

    In Sub-Saharan Africa, infections and undernutrition are the leading causes of childhood death; however injuries are now contributing significantly to childhood morbidity and mortality. To determine the aetiology, morbidity and mortality associated with injuries in children in South-Western Nigeria. This was an observational cross-sectional study of consecutive childhood injury attendances and admissions into the hospital's Children Emergency Room (CHER) over a one-year period. Socio-demographic data as well as the data on the cause, site, and possible risks of injury; parts of the body affected and eventual outcome of the patients were documented. Injury accounted for 382 (10.6%) of the 3,604 attendances, 142 (11.9%) of 1193 admissions and 11 (20.4%) of 54 deaths in CHER. Their ages ranged from six weeks to 15 years, with a mean (SD) of 6.7 (3.9) years, and a male:female ratio of 1.6:1. Road traffic accidents, 130 (34.0%), were the most common cause, followed by falls 119 (31.2%), cuts 44 (11.5%), bits 26 (6.8%), and burns 24 (6.3%). Injuries occurred mostly at home 154 (40.1%), on the road 142 (37.4%), and at school 59 (15.2%). Lack of supervision and/or poor anticipation of potential dangers were the leading risks associated with childhood injuries. Injuries contribute significantly to childhood deaths in South-Western Nigeria. A well-orchestrated public enlightenment programme to improve home, school, and road supervision of children as well as concerted efforts to make these places safer could help ameliorate the situation.

  16. Changes in the forest ecosystems in areas impacted by aridization in south-western Romania.

    Pravalie, Remus; Sîrodoev, Igor; Peptenatu, Daniel

    2014-01-06

    In the past few decades, global climate change has accentuated the intensification of aridization in South-Western Romania, with direct and indirect consequences on the quality of forest ecosystems. In addition to qualitative deterioration, the quantitative changes brought about by intensive anthropic deforestation have created the conditions for a decline in the size of forest areas on vast tracts of land. The paper aims to analyze the qualitative and quantitative changes in the forest ecosystems in South-Western Romania, changes due to the synergic context of the global climate changes and the anthropic pressures of the past three decades. In order to capture the evolution of aridization in the study area, specific aridization indexes have been calculated, such as the De Martonne index and the UNEP aridity index. 1990 and 2011 satellite images have been used in order to quantify the qualitative changes. The results obtained indicated that, in the past two decades, the quality of the biomass declined as a result of the increase in the climatic aridity conditions (De Martonne si UNEP aridity index, indicating in the last decades, annual values under 15 mm/°C, and under 0.5 mm/mm, that means that the values situated under these thresholds, describe arid and semi-arid climate conditions). Also, the uncontrolled logging across vast surfaces caused the loss of forest ecosystems by 7% in the overall study area, during the last three decades. The severe effects of aridization meant, first of all, a significant decline in the quality of the ecosystem services supplied by forests. In the absence of viable actions to correct the present situation, the extremely undesirable consequences of an ecological and social nature will arise in the near future.

  17. REE, Sm-Nd and U-Pb zircon study of eclogites from the Alpine External Massifs (Western Alps): Evidence for crustal contamination

    Paquette, J.L.; Eidgenoessische Technische Hochschule, Zurich; Menot, R.P.; Peucat, J.J.

    1989-01-01

    A geochemical and geochronological study of the Alpine External Crystalline Massifs (AECM) of Aiguilles Rouges, Belledonne and Argentera was undertaken in order to constrain the geodynamic evolution of this segment of the Variscan foldbelt. Another aim of the study is to characterize the behaviour of isotopic markers, in particular the U-Pb zircon system, under high-grade metamorphic conditions. The whole-rock geochemistry of eclogites and amphibolites was investigated using major and trace element (including the REE) analytical techniques; isotopic studies were performed by application of the Sm-Nd whole-rock and U-Pb zircon methods. In terms of regional geological history, the early development of metamorphic and magmatic activity in the AECM is typical of the extensional tectonic regime observed throughout the Variscan foldbelt during the Cambro-Ordovician (i.e. basic magmatism dated at 475-450 Ma). The composition of the metabasic rocks is closely similar to tholeiites emplaced into thinned continental crust which are generally associated with the initial stages of oceanic rifting. The source regions for these metabasics are characterized by initial ε Nd values between +6 and +8, suggesting depleted mantle sources influenced by a weak crustal component and/or the existence of a metasomatised lithosphere. The multi-stage eclogite-facies metamorphism is dated at 425-395 Ma (i.e. Silurian). An application of the U-Pb method, associated with the artificial abrasion of zircon grains, has led to the recognition of a weak crustal contamination in the metabasic protoliths. This is implied by the Archaean and Lower Proterozoic upper intercepts on Concordia - devoid of geological significance - which reflect the presence of a pre-existing basement to the AECM. (orig./WL)

  18. Massification of Higher Education and Students' Accommodation ...

    Massification of Higher Education and Students' Accommodation: The ... of students' accommodation at the University of Dar es salaam (UDSM) over the past 50 years. ... and the quality of learning, as well as the quality of students' life.

  19. Stability assessment of the stopes and crown pillar of the S’Argentera abandoned mines (Ibiza, Spain) using geomechanical classifications, an empirical approach and numerical analysis focused on a possible tourist exploitation

    Jordá-Bordehore, L.; Jordá-Bordehore, R.; Durán Valsero, J.J.; Romero-Crespo, P.L.

    2017-01-01

    The argentiferous lead mines of S’Argentera in Ibiza (Balearic Islands, Spain) are some abandoned underground workings from the first decade of the 20th century. The stability of the main stopes and the crown pillar of the mines has been evaluated - part of which is located below the road between Santa Eulalia and San Carles de Peralta. The possibility of allowing public access to the surface of the mining area and setting up a project of a “show mine” on the underground stopes and galleries is analysed. The stability is assessed with an empirical approach using the O index, the scaled span method and a stability graph together with a numerical approach. Results show that the stopes of the mines are globally stable but some lack an adequate safety factor. Therefore some local reinforcements and monitoring are needed. The finite element modelling in two dimensions yields realistic results on the current stope stability and possible rock falls which have already occurred. [es

  20. Water yield issues in the jarrah forest of south-western Australia

    Ruprecht, J. K.; Stoneman, G. L.

    1993-10-01

    The jarrah forest of south-western Australia produces little streamflow from moderate rainfall. Water yield from water supply catchments for Perth, Western Australia, are low, averaging 71 mm (7% of annual rainfall). The low water yields are attributed to the large soil water storage available for continuous use by the forest vegetation. A number of water yield studies in south-western Australia have examined the impact on water yield of land use practices including clearing for agricultural development, forest harvesting and regeneration, forest thinning and bauxite mining. A permanent reduction in forest cover by clearing for agriculture led to permanent increases of water yield of approximately 28% of annual rainfall in a high rainfall catchment. Thinning of a high rainfall catchment led to an increase in water yield of 20% of annual rainfall. However, it is not clear for how long the increased water yield will persist. Forest harvesting and regeneration have led to water yield increases of 16% of annual rainfall. The subsequent recovery of vegetation cover has led to water yields returning to pre-disturbance levels after an estimated 12-15 years. Bauxite mining of a high rainfall catchment led to a water yield increase of 8% of annual rainfall, followed by a return to pre-disturbance water yield after 12 years. The magnitude of specific streamflow generation mechanisms in small catchments subject to forest disturbance vary considerably, typically in a number of distinct stages. The presence of a permanent groundwater discharge area was shown to be instrumental in determining the magnitude of the streamflow response after forest disturbance. The long-term prognosis for water yield from areas subject to forest thinning, harvesting and regeneration, and bauxite mining are uncertain, owing to the complex interrelationship between vegetation cover, tree height and age, and catchment evapotranspiration. Management of the forest for water yield needs to acknowledge

  1. Soils in an agricultural landscape of Jokioinen, south-western Finland

    M. YLI-HALLA

    2008-12-01

    Full Text Available Eleven pedons in an agricultural landscape at elevations 80-130 m above sea level in Jokioinen, south-western Finland were investigated and classified according to Soil Taxonomy, the FAO-Unesco system (FAO, and the World Reference Base for Soil Resources system (WRB. The soils were related to geomorphology of the landscape which is characterized by clayey fields and forested bedrock high areas covered with glacial till. A Spodosol/Podzol was found in a coarse-sandy soil in an esker while the sandy loam in a bedrock high area soils did not have an E horizon. A man-made mollic epipedon was found in a cultivated soil which had a sandy plow layer while clayey plow layers were ochric epipedons. Cambic horizons, identified by structure and redox concentrations, were common in cultivated soils. In a heavy clay soil, small slickensides and wedge-shaped aggregates, i.e., vertic characteristics, were found. Histosols occurred in local topographic depressions irrespective of the absolute elevation. According to the three classification systems, the following catenas are recognized: Haplocryods - Dystro/Eutrocryepts -Haplocryolls - Cryaquepts - Cryosaprists (Soil Taxonomy, Podzols - Regosols - Cambisols - Histosols (FAO-Unesco, and Podzols - Cambisols - Phaeozems - Gleysols - Histosols (WRB.;

  2. Unmet social needs and teenage pregnancy in Ogbomosho, South-western Nigeria.

    Salami, Kabiru K; Ayegboyin, Matthew; Adedeji, Isaac A

    2014-12-01

    Consistent high teenage pregnancy rates in South-western Nigeria are characteristically underpinned by the unmet social needs of the teenagers. To elicit intergenerational views on the influence of unmet social needs on teenage pregnancy. Through a descriptive and cross-sectional design, a total of 174 respondents who were either pregnant teenagers, teenage mothers during the survey or had been pregnant as teenagers, were interviewed, using questionnaire supplemented with 12 key informant interviews. With the mean age of 16.5 years, and educational status range of between primary and below (25.8%) and tertiary (9.8%) levels, only 39.7% respondents were married, about half (47.7%) remained single while others were separated (12.6%). Less than half (44.9%) of the respondents were engaged in occupational activities. The unmet material and financial supports expected from parents (43.1%), the lack of free education from government up till secondary school level (51.2%), the lack of sex education and knowledge needs for signs of maturity (53.4%) and discouragement from friends not to have boyfriend (66.1%) prone teenagers to unplanned pregnancy. Promotion of sexual education and parental care is encouraged as strategy against unplanned pregnancy among teenagers.

  3. Fauna and Geographical Distribution of Scorpions in Ilam Province, South Western Iran.

    Sharifinia, Narges; Gowhari, Iman; Hoseiny-Rad, Manijeh; Aivazi, Ali Ashraf

    2017-06-01

    Scorpions' stings and their own mortalities place them among the most important health and medical problems. The dreadful features and especially their poisonous stings are considered a major cause of human stress and abhorrence/phobia. The current study aimed to study the scorpion fauna of Ilam Province, south western Iran in order to manage scorpionism related problems. In this field-laboratory investigation during March 2014 to February 2015, different parts of Ilam Province were surveyed. Nine sampling parts were selected based on geographical situation, scorpionism reports, weather, flora, and local data. Capturing scorpion was done employing a black light, and a long forceps from dusk to midnight. The collected scorpions were placed to 70% ethyl alcohol. All specimens were determined based on the valid taxonomic keys, furthermore their sexes were studied. Out of the 391 collected scorpions, 11 species were identified as follows: Hottentotta saulcyi , Mesobuthus eupeus , Compsobuthus matthiesseni , Razianus zarudnyi , Hemiscorpius lepturus , Androctonus crassicauda , Orthochirus iranus , Odontobuthus bidentatus , Buthacus macrocentrus , Scorpio maurus , and Polisius persicus . Eleven species of Buthidae, Scorpionidae and Hemiscorpiidae families from high risk areas were identified. Despite the low surface of the province, such different species reveals a diverse scorpion fauna that, in turn, shows good and suitable habits of scorpions, as considered by health staff.

  4. An examination of knowledge, attitudes and practices related to lead exposure in South Western Nigeria

    Sridhar Mynepalli KC

    2006-03-01

    Full Text Available Abstract Background Lead is a highly toxic and pervasive metal. Chronic exposure to low levels is responsible for significant health effects, particularly in children. Prevention remains the best option for reducing childhood lead exposure, however the knowledge, attitudes and practices to lead exposure in many developing countries is not known. Methods: We conducted four focus group discussions (FGD to evaluate knowledge attitudes and practices to lead exposure in Nigeria. An FGD guide was developed from the literature and preliminary discussion with members of the public. Participants in the FGD were randomly selected from adults living in Ibadan, South Western Nigeria in 2004. Results We found that there was limited awareness of the sources of lead exposure in the domestic environment and participants had little knowledge of the health effects of chronic low-dose lead exposure. Conclusion We conclude that the findings of this study should be used, in conjunction with others, to develop appropriate health education intervention for lead exposure in the domestic environment.

  5. Ageing, sexuality and enhancement among Yoruba people in south western Nigeria.

    Agunbiade, Ojo Melvin; Ayotunde, Titilayo

    2012-01-01

    Sexual health across the life course is influenced by biological and psychosocial factors. The paper explores sexuality and associated practices among older Yoruba people with a view to identifying the implications of cultural beliefs and practices for sexual health in later life. A total of 64 vignette-based in-depth interviews and 12 focus-group discussions were held with older adults (50-75 years) in two Yoruba communities in south western Nigeria. Findings portray sexuality as an important aspect of old age, with sexual intercourse being construed as having physical and spiritual consequences. This same perspective also emerged as participants' attributed factors affecting sexual desire in old age to religious beliefs, poverty, ill health and the non-availability of a partner. Gender differences were dominant on sexual desire and pleasure in old age. Participants' views on causes of sexual dysfunction identified biological, psychosocial and spiritual factors. Sexual decline in old age was considered redeemable with the support of biomedical and traditional medicines. However, only traditional medicine was considered beneficial in addressing sexual dysfunctions that had spiritual dimensions.

  6. Gender and health analysis of sexual behaviour in south-western Nigeria.

    Jegede, A S; Odumosu, O

    2003-04-01

    This paper reports the main results of a series of interviews conducted among the Yoruba of south-western Nigeria. Fifty men and fifty women differing in socio-demographic backgrounds were studied. The study revealed that during their first sexual experience, Yoruba girls are at risk of contacting sexually transmitted diseases and of having unplanned pregnancies because of the traditional control measures and lack of adequate sex education even among those from non-traditional backgrounds. Choice of marriage partner is influenced by the kin, which encourages early marriage and multiple sexual relationships through polygyny. Yoruba men do not like contraceptives and the women suffer more of the consequences of sexual relationships than men. Sexual decision-making in Yoruba culture is characterised by certain specific problems of structural and cultural origins such as separate lifestyle of men and women, seeing the discussion of sexuality as a taboo, male dominance, and the perceived side effects of contraceptives. There is need for expanded sexual and reproductive health education strategies targeted at both males and females in this community especially among the adolescent group.

  7. Exploitation of Aquatic Resources in Ahanve, Badagry, south-western Nigeria

    Orijemie, Emuobosa Akpo

    2014-11-01

    Full Text Available The Badagry Cultural Area (BCA is one of the significant socio-cultural places in coastal south-western Nigeria. Palynological and archaeological studies at Ahanve, a settlement in the BCA were undertaken recently to improve the understanding of past human exploitation of aquatic resources. Collected data revealed contrasts in the availability and utilisation of aquatic resources between a first occupation phase (9th-17th centuries AD and a second occupation phase (17th century AD to present. The environment during the first phase was characterised by secondary forest and freshwater swamp. During this period, the inhabitants consumed cat-fish (Clariidae and bivalves (Anodonta sp., and engaged in salt production. The salt was produced from brine obtained from the Atlantic Ocean. Aquatic food resources were supplemented with terrestrial animal and plant foods. During the second occupation phase, aquatic resources (cat-fish and bivalves declined and subsequently disappeared; salt production was discontinued while terrestrial foods, particularly plant-based types, increased significantly. These events coincided with the arrival of European travellers. Oral sources suggest that the decline in the exploitation of aquatic resources was in part due to the fear of being taken captive while on fishing expeditions, restrictions by Europeans who controlled the water-ways, and the massive importation of salt which replaced local production.

  8. Analyzing farming systems diversity: a case study in south-western France

    Choisis, J. P.; Thevenet, C.; Girbon, A.

    2012-11-01

    The huge changes in agricultural activities, which may be amplified by the forthcoming Common Agriculture Policy reform, call the future of crop-livestock systems into question and hence the impact of these changes on landscapes and biodiversity. We analyzed relationships between agriculture, landscape and biodiversity in south-western France. The study area covered about 4,000 ha and included four villages. We conducted a survey of 56 farms. Multivariate analysis (multiple factor analysis and cluster analysis) were used to analyze relationships between 25 variables and to build a typology. The type of farming (beef and/or dairy cattle, cash crops), size (area and workforce) and cultivation practices, among others, were revealed as differentiating factors of farms. Six farming types were identified (1) hillside mixed crop-livestock farms, (2) large corporate farms, (3) extensive cattle farms, (4) large intensive farms on the valley sides, (5) small multiple-job holdings, and (6) hobby farms. The diversity of farming systems revealed the variable impact of the main drivers of change affecting agricultural development, particularly the enlargement and modernization of farms along with the demography of agricultural holdings. (Author) 41 refs.

  9. Drinking water insecurity: water quality and access in coastal south-western Bangladesh.

    Benneyworth, Laura; Gilligan, Jonathan; Ayers, John C; Goodbred, Steven; George, Gregory; Carrico, Amanda; Karim, Md Rezaul; Akter, Farjana; Fry, David; Donato, Katherine; Piya, Bhumika

    2016-01-01

    National drinking water assessments for Bangladesh do not reflect local variability, or temporal differences. This paper reports on the findings of an interdisciplinary investigation of drinking water insecurity in a rural coastal south-western Bangladesh. Drinking water quality is assessed by comparison of locally measured concentrations to national levels and water quality criteria; resident's access to potable water and their perceptions are based on local social surveys. Residents in the study area use groundwater far less than the national average; salinity and local rainwater scarcity necessitates the use of multiple water sources throughout the year. Groundwater concentrations of arsenic and specific conductivity (SpC) were greater than surface water (pond) concentrations; there was no statistically significant seasonal difference in mean concentrations in groundwater, but there was for ponds, with arsenic higher in the dry season. Average arsenic concentrations in local water drinking were 2-4 times times the national average. All of the local groundwater samples exceeded the Bangladesh guidance for SpC, although the majority of residents surveyed did not perceive their water as having a 'bad' or 'salty' taste.

  10. TRANSFORMATION OF THE INITIAL ISOTOPIC COMPOSITION OF PRECIPITATION IN CAVES OF THE SOUTH-WESTERN CAUCASUS

    Vladimir Mikhalenko

    2015-01-01

    Full Text Available The paper presents preliminary results and interpretation from an ongoing research project in the Novy Afon and Abrskil caves of Abkhazia. The research have demonstrated that δ18O and δD analyses of drip and ground waters in two caves in the South-Western Caucasian region allows to better understand interaction between isotopic composition of precipitation, soil, and vadose zone. Drip and ground water samples from the caves were compared with the present-day Global (GMWL and the Local Meteoric Water Lines (LMWL. They fall along the GMWL and LMWL and are tied by equation δD = 5.74δ18O - 6.98 (r2 = 0.94. Drip water isotopic composition is similar to that from lakes and pools. The incline of δ18O - δD line differs from GMWL and LMWL. It reflects a possible result from secondary condensation and evaporation and water-rock interaction, and depends on the climate aridity level.

  11. [Coexistence of maternal overweight or obesity and stunted children in south-western Benin households].

    Dembélé, Bernard; Sossa Jérôme, Charles; Saizonou, Jacques; Makoutodé, Patrick Charles; Mongbo Adé, Virginie; Guedègbé Capo-Chichi, Justine; Dona Ouendo, Marius-Edgard

    To determine the prevalence and determinants of coexistence of maternal overweight or obesity and stunted children (DBM / SCOM) in south-western Benin households. This cross-sectional study was carried out in June 2015 on 357 mother-child pairs randomly selected by a two-stage sampling technique in the city of Comè and its surroundings. Data on socio-economic factors, family, health care, dietary quality were collected by questionnaires, observation and documentary review. Anthropometric measurements were performed in mothers and children. A logistic regression analysis model was used to search for determinants of the coexistence of the two aspects of malnutrition. 19.3% of mothers were overweight and 5.7% were obese. 46% of children were stunted. The prevalence of DBM / SCOM was 11.5%. The main factors associated with DBM/SCOM were the child's age, the mother's occupation, ethnicity, social status and educational level, and the size, economic level, transportation means and food insecurity of the household. A high frequency of the coexistence of maternal overweight or obesity and stunting was observed in Comè households. Interventions based on the identified determinants are needed to act simultaneously on the double burden of malnutrition in Comè.

  12. A Salmonella Typhimurium outbreak linked to Vietnamese bread rolls in South Western Sydney, Australia, 2015

    Meena Chandra

    2017-06-01

    Full Text Available Introduction: In September 2015, the South Western Sydney (SWS Public Health Unit was notified of a cluster of Salmonella Typhimurium (STm cases with a common multiple-locus variable-number tandem repeats analysis (MLVA pattern. An investigation was conducted to identify a source and contain the outbreak. Methods: The cluster was initially identified through routine geographic information system cluster scanning applied to the New South Wales Notifiable Conditions Management System. Additional cases were identified through a complaint to local council about a bakery. The bakery was inspected and 48 environmental and food swabs were collected for analysis. Results: A total of 26 suspected cases were identified, of which 14 were interviewed. STm MLVA type 3-16-9-11-523 was identified in 19 of 26 case stool specimens. Most cases (12/14 consumed bread rolls containing pork or chicken with chicken liver pâté and raw egg mayonnaise filling. Five cases identified a common bakery exposure. Environmental and food samples from the bakery isolated STm with an identical MLVA pattern. Discussion: An STm cluster in SWS was investigated and found to be linked to Vietnamese bread rolls containing pork or chicken with chicken liver pâté and raw egg mayonnaise filling. Confirmation of a distinct MLVA pattern among STm isolates from clinical, food and environmental samples provided evidence to establish an epidemiological link between the cases and the implicated premises and informed public health action to contain the outbreak.

  13. An investigation into users' information security awareness on social networks in south western Nigeria

    Julius O. Okesola

    2016-11-01

    Full Text Available Background: Social networks (SNs offer new and exciting opportunities for interaction among people, cutting across different stratum of the society and providing a ubiquitous mechanism that supports a wide variety of activities. They are at the same time being exploited by criminals to fraudulently obtain information from unsuspecting users. Unfortunately, the seamless communication and semblance of safety assumed by most users make them oblivious to the potential online dangers. Objective: Using quantitative methods on selected social sites, this study empirically examined the information security awareness of SN users in south western Nigeria. Method: A self-designed research instrument was administered for data collection while descriptive and inferential statistics were employed using chi-square, cross-tabulation and t-test for data analysis and result interpretation. Result: Findings from the analysed data suggest that the risk perception vary among male and female SN users and that the general perception of risks regarding SN usage is also very low. Conclusion: Adequate security awareness coupled with detailed legal measures are required to keep SNs secured. However, an individual is duly responsible for the habit of ignoring potential risks posed by the networks.

  14. 222Rn activity concentration differences in groundwaters of three Variscan granitoid massifs in the Sudetes (NE Bohemian Massif, SW Poland)

    Przylibski, Tadeusz A.; Gorecka, Joanna

    2014-01-01

    Based on research conducted in three Variscan granitoid massifs located within the crystalline Bohemian Massif, the authors confirmed that the higher the degree of their erosional dissection, the smaller the concentration of 222 Rn in groundwaters circulating in these massifs. This notion implies that radon waters and high-radon waters, from which at least some of the dissolved radon should be removed before feeding them as drinking water to the water-supply system, could be expected in granitoid massifs which have been poorly exposed by erosion. At the same time, such massifs must be taken into account as the areas of possible occurrence of radon medicinal waters, which in some countries can be used for balneotherapy in health resorts. Slightly eroded granitoid massifs should be also regarded as very probable radon prone areas or areas of high radon potential. - Highlights: • The concentration of 222 Rn in groundwater depends on the zone of the granitoid massif which is exposed on the ground surface. • The highest 222 Rn concentrations occur in the least eroded granitoid massifs, the lowest in massifs with exposed root parts. • The stronger the erosional dissection of a granitoid massif, the lower 222 Rn concentration in groundwaters in this massif. • Not all granitoid massifs are areas with groundwaters containing high concentrations of 222 Rn. • The least eroded granitoid massifs are radon prone areas with the occurrence of high-radon and radon groundwaters

  15. Information-seeking behaviour and adoption of organic farming practices among vegetable farmers in South Western Nigeria / Sijuwade Adebukola Adebayo

    Adebayo, Sijuwade Adebukola

    2013-01-01

    This study analyzed information-seeking behaviour and adoption of organic .farming practices among vegetable farmers in South-Western Nigeria. This is based on the fact that conventional intensive agricultural systems have side-effects which compromise food production in terms of quality and safety. As a result many are now stating that conventional agriculture represents an unsuitable long-term option. Specifically, the study identified the personal characteristics of the farmers, profile or...

  16. Mercury Pollution Studies of Some Rivers Draining the Bibiani-Anwiaso-Bekwai Mining Community of South Western Ghana

    V.K. Nartey; L.K. Doamekpor; S. Sarpong-Kumankuma; T. Akabzaa; F.K. Nyame; J.K. Kutor; D. Adotey

    2011-01-01

    The project assessed the extent of mercury pollution of some rivers that drain the Bibiani-Anwiaso- Bekwai district which is a typical mining community in the south western part of Ghana. In the study, surfacewater and sediment samples were collected from seven streams that drain this mining community and analyzed for total mercury, organic mercury and elemental mercury. Mercury concentrations of non-filtered water was determined using the ICP-OES after reduction with stannous chloride (SnCl2...

  17. Contribution To The Geology Of Basement Rocks In The South Western Desert Of Egypt

    Sadek, M.F.; Khyamy, A.A.

    2003-01-01

    Three major Precambrian basement inliers are exposed in the South Western Desert of Egypt between Long. 29 degree E and the River Nile within the Uweinat-Bir Safsaf-Aswan E-W uplift system. These are Bir Safsaf, Gabal EI-Asr and Gabal Umm Shaghir areas. Smaller outcrops include Gabal EI-Gara El-Hamra and Gabal El-Gara EI-Soda, Gabal Siri, GabaI EI-Fantas and Aswan-Kalabsha area as well as the scattered outcrops around Darb El-Arbain road. Band ratios 5/7, 5/1, 4 of Landsat TM images were applied to delineate the borders, the lithologic units and structural features of low relief basement outcrops within the surrounding flat lying sedimentary rocks and sand plains. These basement rocks comprise ortho gneisses (assumed by many authors as related to old continent pre Pan-African rocks), G 1 tonalite-granodiorite, and G2 monzogranite-alkali feldspar granite intruded by variable dykes. The boundaries between the basement exposures and the sedimentary rocks are marked by nonconformity surfaces or sets of faults. Both basement and sedimentary rocks are intruded by Mesozoic syenite-G3 granites, rhyolite, trachytic plugs and Upper Cretaceous to Tertiary basalts. The basement exposures are structurally controlled by major E- W fault systems. Their vertical uplifting is overprinted by folding the overlying sedimentary rocks. This study revealed that, the different basement exposures in the SE of the Western Desert of Egypt are similar in appearance and field relations to the Pan-African basement rocks extending towards the east of the River Nile and exposed everywhere in the Eastern Desert of Egypt

  18. Soil preferences and morphological diversity of goldenrods (Solidago L. from south-western Poland

    Magdalena Szymura

    2013-04-01

    Full Text Available Invasive plants in their new range can differ from their ancestors, including traits ultimately influencing habitat preferences, competitiveness and dispersal ability. In Europe Solidago species are considered as one of the worst invaders of American origin. In this study the frequency of occurrence of Solidago species, their soil preferences and morphological diversity, in Silesia (south-western Poland, Central Europe were surveyed. On the basis of phytosociological relevés, made using the Braun-Blanquet method, in 75 plots, we determined the composition of species co-occurring with particular Solidago species. The height of ramets, as well as length and width of inflorescences of Solidago species were measured. We also determined the basic soil properties and noted the presence of trees overshading the ground vegetation. The compositional variation of vegetation and its relation to environmental traits: soil properties (texture, pH, percentage of organic matter, total nitrogen, nitrate, phosphorus, potassium and calcium content and presence of canopy were analyzed by multivariate ordination methods (CA and CCA. Goldenrod species, in most cases (74.3% occurred singly, two on one plot – rather rarely (mostly S. canadensis with S. altissima, whereas three Solidago species co-occurred only in three plots. Particular species differed in the height of the plant and inflorescence size, the exception was lack of difference between S. altissima and S. canadensis. S. virgaurea often occurred under trees canopy and the populations were separated from other goldenrod species. The species co-occurring with S. altissima and S. canadensis were the ruderal species, whereas plants from wet meadows occurred in plots with S. gigantea. The distribution of S. graminifolia was very limited, but inside its range it was able to occupy different habitats. The plots, where particular Solidago species occurred, did not differ significantly with respect to soil

  19. Geographic disparities of asthma prevalence in south-western United States of America

    Lung-Chang Chien

    2014-11-01

    Full Text Available Asthma is one of the most prevalent chronic diseases in the United States of America (USA, and many of its risk factors have so far been investigated and identified; however, evidence is limited on how spatial disparities impact the disease. The purpose of this study was to provide scientific evidence on the location influence on asthma in the four states of south- western USA (California, Arizona, New Mexico and Texas which, together, include 360 counties. The Behavioral Risk Factor Surveillance System database for these four states covering the period of 2000 to 2011 was used in this analysis, and a Bayesian structured additive regression model was applied to analyse by a geographical information system. After adjusting for individual characteristics, socioeconomic status and health behaviour, this study found higher odds associated with asth- ma and a likely cluster around the Bay Area in California, while lower odds appeared in several counties around the larger cities of Texas, such as Dallas, Houston and San Antonio. The significance map shows 43 of 360 counties (11.9% to be high-risk areas for asthma. The level of geographical disparities demonstrates that the county risk of asthma prevalence varies significantly and can be about 19.9% (95% confidence interval: 15.3-25.8 higher or lower than the overall asthma prevalence. We provide an efficient method to utilise and interpret the existing surveillance data on asthma. Visualisation by maps may help deliver future interventions on targeted areas and vulnerable populations to reduce geographical disparities in the burden of asthma.

  20. An algorithm for detecting Trichodesmium surface blooms in the South Western Tropical Pacific

    Y. Dandonneau

    2011-12-01

    Full Text Available Trichodesmium, a major colonial cyanobacterial nitrogen fixer, forms large blooms in NO3-depleted tropical oceans and enhances CO2 sequestration by the ocean due to its ability to fix dissolved dinitrogen. Thus, its importance in C and N cycles requires better estimates of its distribution at basin to global scales. However, existing algorithms to detect them from satellite have not yet been successful in the South Western Tropical Pacific (SP. Here, a novel algorithm (TRICHOdesmium SATellite based on radiance anomaly spectra (RAS observed in SeaWiFS imagery, is used to detect Trichodesmium during the austral summertime in the SP (5° S–25° S 160° E–170° W. Selected pixels are characterized by a restricted range of parameters quantifying RAS spectra (e.g. slope, intercept, curvature. The fraction of valid (non-cloudy pixels identified as Trichodesmium surface blooms in the region is low (between 0.01 and 0.2 %, but is about 100 times higher than deduced from previous algorithms. At daily scales in the SP, this fraction represents a total ocean surface area varying from 16 to 48 km2 in Winter and from 200 to 1000 km2 in Summer (and at monthly scale, from 500 to 1000 km2 in Winter and from 3100 to 10 890 km2 in Summer with a maximum of 26 432 km2 in January 1999. The daily distribution of Trichodesmium surface accumulations in the SP detected by TRICHOSAT is presented for the period 1998–2010 which demonstrates that the number of selected pixels peaks in November–February each year, consistent with field observations. This approach was validated with in situ observations of Trichodesmium surface accumulations in the Melanesian archipelago around New Caledonia, Vanuatu and Fiji Islands for the same period.

  1. Climate change induced occupational stress and reported morbidity among cocoa farmers in South-Western Nigeria

    Abayomi Samuel Oyekale

    2015-05-01

    Full Text Available Introduction and objective. Climate change is one of the major development hurdles in many developing countries. The health outcome of farm households are related to climate change, which is related to several external and internal health-related issues, such as management of occupational stressors. This study seeks, inter alia, to determine the climate related occupational stress and factors influencing reported sick times among cocoa farmers. Material and Method. Data were collected from selected cocoa farmers in South-Western Nigeria. Descriptive statistics and Negative Binomial regression were used for data analyses. Results. The results showed that cocoa farmers were ageing, and that the majority had cultivating cocoa for most of their years of farming. Cocoa was the primary crop for the majority of the farmers, while 92.00% of the farmers in Osun state owned the cultivated cocoa farms. The forms of reported climate change induced occupational stresses were increase in pest infestation (74.5% in Ekiti state, difficulties in weed control (82.1% in Ekiti state, missing regular times scheduled for spraying cocoa pods (45.7% in Ondo state, inability to spray cocoa effectively (58.5% in Ondo state, and reduction in cocoa yield (71.7% in Ekiti state. The Negative Binomial regression results showed that the age of farmers (0.0103, their education (-0.0226, years of cocoa farming (-0.0112, malaria infection (0.4901, missed spraying (0.5061, re-spraying of cocoa (0.2630, reduction in cocoa yield (0.20154, contact with extension (0.2411 and residence in Ondo state (-0.2311 were statistically significant (p<0.05. Conclusion. Climate change influences the farm operations of cocoa farmers with resultant occupational stresses. Efforts to assist cocoa farmers should include, among others, provision of weather forecasts and some form of insurance.

  2. The Neo-Tectonic Structure of the South western Tip of the Okinawa Trough

    Chia-Yen Ku

    2009-01-01

    Full Text Available The Ilan Plain is located at the south western tip of the Okinawa Trough backarc basin, which prop a gates west ward into the Taiwan orogen. From three moderate earthquakes which occurred near the coast line of the Ilan Plain, one of magnitude 6.2 on 15 May 2002 and the other two of magnitudes 5.51 and 5.49 on 5 March 2005, we at tempted to understand the relation ship between the earthquake mechanisms and the geological context. Seven seismic reflection pro files collected roughly parallel to the coast line of the Ilan Plain were used in this work. A structural fault, with a significant normal faulting component trending approximately ENE-WSW, is identified to the east of the doublet earth quakes of 5 March 2005. Be cause this fault follows the ENE-WSW trend of the after shock seismicity, we named it the Ilan Shelf Fault, which might ex tend to the east be yond the Ilan continental shelf spur. How ever, the centroid seismic moment ten sorsolutions for the doublet earth quakes of 5 March 2005 are of a left-lateral strike-slip faulting type which are consistent with onland GPS observations. Hence, the Ilan Shelf Fault may have a left-lateral strike-slip component. Based on GPS data, we suggest that the northern Central Range block, bounded in the west by the Lishan Fault and in the north by the Ilan Shelf Fault, rotates clock wise. This rotation is ascribed to the northwestward collision of the Luzon Arc against Tai wan. Thus, there is a left-lateral strike-slip and an extensional motion along the Ilan Shelf Fault. The northern Central Range block is tilting north ward which may also in duce the normal faulting component of the Ilan Shelf Fault. In short, the Ilan Shelf Fault could be a major tectonic and structural feature bounding the southern end of the Okinawa Trough backarc basin.

  3. Sedimentary lipid biomarkers in the magnesium rich and highly alkaline Lake Salda (south-western Anatolia

    Jérôme Kaiser

    2016-06-01

    Full Text Available Lake Salda located in south-western Anatolia is characterized by the presence of living stromatolites and by a low diversity of both phytoplankton and zooplankton due to high pH and magnesium concentration. The most abundant, free sedimentary lipids of the uppermost centimetres of the lake sediments were studied as potential environmental biomarkers, and proxies based on glycerol dialkyl glycerol tetraethers (GDGT were tested in this extreme environment. Dinosterol and tetrahymanol are potentially relevant biomarkers for the dinoflagellate Peridinium cinctum and ciliates, respectively. C20:1 and C25:2 highly branched isoprenoid (HBI alkenes, and n-C17 alkane and n-C17:1 alkene are considered as representing, respectively, diatoms and Cyanobacteria involved in the formation of the stromatolites. Isoprenoid GDGT-0 is assumed to be derived mainly from Euryarchaeota (methanogens, and crenarchaeol from Thaumarchaeota. Allochthonous organic material is represented by long-chain n-alkanes and n-alkanols derived from land plant leaf waxes, as well as branched GDGTs produced by soil bacteria. While pH and temperature proxies based on branched GDGTs are likely not applicable in Lake Salda, TEX86 (tetraether index of tetraethers consisting of 86 carbons, a proxy based on isoprenoid GDGTs, potentially allows estimating mean annual lake surface temperature. Interestingly, C23 and C25 1,2 diols, which have a yet unknown origin, were found for the first time in lake sediments. This study represents the first investigation of sedimentary lipid distribution in an alkaline and magnesium-rich lake in Anatolia, and provides a basis for future biomarker-based paleoenvironmental reconstruction of Lake Salda.

  4. Voices from the Gila: health care issues for rural elders in south-western New Mexico.

    Averill, Jennifer B

    2002-12-01

    A goal of the Healthy People 2010 initiative is to reduce or eliminate health disparities in vulnerable populations, including populations from rural and minority ethnic backgrounds. Rural communities, including elderly populations, experience lower rates of personal income, educational attainment, health-insurance coverage, access to emergency and specialty care services, and reported health status than do urban communities. A need exists to address identified research priorities, such as the perceptions of rural elders, their family members, and health care providers. The purposes of this study were to explore the health care perceptions, needs, and definitions of health for multicultural rural elders in one county of south-western New Mexico, and to consider practice implications. Informed consent procedures followed the University of New Mexico Health Sciences Center Human Research Review Committee guidelines. Research methods. This critical ethnography incorporated ethnographic interviews, ethnographic participant observation, photography, review of pertinent documents, and analysis of contextual factors. The sample consisted of 22 participants. Definitions of health varied with socioeconomic status, encompassing avoidance of contact with the health care system, obtaining needed medications, remaining independent, a sense of spiritual belonging, eating wisely, and exercising moderately. Three major concerns emerged from the analysis: the escalating cost of prescription drugs, access-to-care issues, and social isolation. The primary limitation was the small sample size. Although the researcher's position as an outsider to local communities may also have affected the outcome, it provided fresh insight to regional problems. The study addressed national research priorities for a vulnerable group of rural elders. Nursing implications include the need for expanded knowledge and educational preparation regarding elder issues and community-level services, inclusion of

  5. Resources Management for Income Optimization on Smallholder Food Crop Farms in South-Western Nigeria

    Adeniyi, OR.

    2013-01-01

    Full Text Available Agricultural mobilization based purely on resources availability factor alone may falter due to inadequate attention that is hitherto paid to other complementary factors. Empirical evidence from the current study conducted on typical small-holder farms in South-western Nigeria has shown that while the availability of the required input resources were essential in raising income on small-holder farms, resources management choice factor was the most relatively crucial. With better choice of management and careful selection of enterprises, the current level of available resources at the disposal of small-holder farmers in the study area was adequate to make them economically viable and improve their potential savings. Income realizable with 'better' management plan option was N 359,761.79 per hectare while ₦ 164,213.88 per hectare was earned with the current level of resources use and enterprise combination. The better management plan recommended the cultivation of cassava/yam (0.59 ha., maize/cassava (0.34 ha., Banana-plantain (0.26 ha and maize/cocoyam (0.22 ha on 1.42 hectares of land instead of the current 2.37 hectares (67% increase cultivated mostly to sole cropping. However, the additional human and financial requirements of the proposed better management plan called for dedicated and active government action programmes in form of provision of most input needs of farmers at subsidized rates, provision of extension and training in modern farm management and organization techniques and establishment of advisory service centers to monitor and supervise the use of resource inputs on farms.

  6. GRAVITY VARIATIONS AND RECENT GEODYNAMICS OF THE SOUTH-WESTERN PART OF THE BAIKAL REGION

    V. Yu. Timofeev

    2013-01-01

    Full Text Available Modern methods for determination of gravity values make it possible to obtain measurements with the accuracy up to 10–9 from g0 of the normal value (up to 1 microgal = 10 m/sec2. While all the systematic and periodic effects are excluded, a question is raised about stability of the gravity field of the Earth over time. Changes of the altitude (the Earth’s radius with time can be estimated with an accuracy of 0.1 mm by modern space geodetic techniques, such as VLBI method. Our experiments for evaluation of stability of the gravity values over the past decades are based on the data obtained by Russian and foreign observatories using absolute ballistic laser gravimeters. The results put a limit of 10–10 per year to changes of the Earth’s radius. These estimations can be useful for testing hypotheses in tectonics.Measurements of non-tidal variations of gravity (Δg, which were obtained from 1992 to 2012 at the Talaya seismic station (located in the south-western part of the Baikal region, are interpreted together with GPS observation data. At the Talaya seismic station, the linear component of gravity variations corresponds to changes in the elevation of this site. The correlation coefficient is close to the normal value of the vertical gradient of gravity. At this site, coseismic gravity variations at the time of the Kultuk earthquake (27 August 2008, Mw=6.3 were caused by a combined effect of the change of the site’s elevation and deformation of the crust. Our estimations of the coseismic effects are consistent with results obtained by modeling based on the available seismic data.

  7. The negotiation of sexual relationships among school pupils in south-western Uganda.

    Nyanzi, S; Pool, R; Kinsman, J

    2001-02-01

    The objective of the study was to explore how school-going adolescents in south-western Uganda negotiate sexual relationships. Qualitative data were obtained from 15 boys and 15 girls (14-18 years old), during a series of role plays, focus group discussions and one-to-one interviews. A questionnaire was administered to 80 pupils (12-20 years old) from the same school. Most of the pupils were sexually active. Sexual relationships between boys and girls were mediated by peers. Boys initiated relationships. Exchange played an important role in the negotiation of sexual relationships. Money or gifts were given and received in exchange for sexual favours and to strengthen the relationship. To maximize gains, some adolescents had sexual relationships with adults. Sexual relationships were characterized by ambiguity. Love is intertwined with sexual desire, money and prestige. Girls have to be explicit enough to get a good deal; if they are too explicit they will be stigmatized as 'loose' but if they are not interested in money they may be suspected of wanting to spread HIV. Boys try to persuade girls that they have money, but do not want to emphasize this too much. In sexual negotiations a boy must persuade a girl that although he is modern and sophisticated (i.e. experienced) he does not chase after every girl; the girl does not want to come over as an unsophisticated virgin, but does not want to give the impression that she is loose either. There is a tension between the traditional ideal of female chastity and submissiveness and the modern image of sexual freedom. Multiple partnerships were highly valued as a sign of sophistication. Condoms were not considered important. Interventions aimed at reducing the spread of HIV do not seem to be having an effect on the behaviour of this group of adolescents. On the contrary, risky attitudes and behaviour are part of an adolescent ideal of modernity and sophistication. New approaches are needed to persuade this group of the

  8. The Ecology of the Ural Owl at South-Western Border of Its Distribution (Slovenia

    Al Vrezec

    2016-04-01

    Full Text Available In Slovenia the Ural Owl (Strix uralensis is on its south-western limit of distribution and belongs to the southern subspecies Strix uralensis macroura. Dark coloured owls are characteristic for this subspecies and represent between 5 to 15% of the population. Slovenian breeding population size is estimated at 400 to 700 pairs. The densities of territories ranges between 0.9 to 13.4 territories per 10 km2, and the highest are reached in mountain forests of southern Dinaric region. In the forests with dominant deciduous trees, e.g. Beech (Fagus sylvatica and Pedinculate Oak (Quercus robur, the breeding densities are significantly higher than in the forests with higher proportion of coniferous trees, e.g. Norway Spruce (Picea abies. The species does not select specific altitude and throughout Slovenia it occurs between 150 and 1600 m a.s.l.  The most of the nest found at natural nest-sites were in tree holes or semi-holes (56% and at the tree stumps (20%. Nest boxes were occupied less frequently in Slovenia with occupancy rate of 29%. At least in mountain regions breeding begins quite late, between 15 March to 21 June. Average clutch size is 3.3 ± 1.0 eggs per nest. About 80% of all nests are successful raising at least one young. The diet shifts significantly between breeding and non-breeding period due to the seasonality in prey availability. According to the biomass the most important prey in breeding period are mice (Muridae, voles (Arvicollidae and mole (Talpa europaea, but in the non-breeding period voles and dormice (Gliridae predominate. Large Fat Dormouse (Glis glis seems to have very important role in the post-breeding period, but not in the breeding period due to its dormancy. As a large forest-dwelling predator the Ural Owl shapes the raptor community in the forest by excluding mezopredator species, as Tawny Owl (Strix aluco, what allows smaller raptors, e.g. Boreal Owl (Aegolius funereus to expend their ranges to lower elevations

  9. Insecticide resistance in Anopheles gambiae from south-western Chad, Central Africa

    Etang Josiane

    2008-09-01

    Full Text Available Abstract Background Indoor residual spraying and insecticide-treated nets (ITN are essential components of malaria vector control in Africa. Pyrethroids are the only recommended compounds for nets treatment because they are fast-acting insecticides with low mammalian toxicity. However, there is growing concern that pyrethroid resistance may threaten the sustainability of ITN scaling-up programmes. Here, insecticide susceptibility was investigated in Anopheles gambiae sensu lato from an area of large scale ITN distribution programme in south-western Chad. Methods Susceptibility to 4% DDT, 0.05% deltamethrin, 0.75% permethrin, 0.1% bendiocarb and 5% malathion was assessed using the WHO standard procedures for adult mosquitoes. Tests were carried out with two to four days-old, non-engorged female mosquitoes. The An. gambiae Kisumu strain was used as a reference. Knockdown effect was recorded every 5 min and mortality scored 24 h after exposure. Mosquitoes were identified to species and molecular form by PCR-RFLP and genotypes at the kdr locus were determined in surviving specimens by Hot Oligonucleotide Ligation Assay (HOLA. Results During this survey, full susceptibility to malathion was recorded in all samples. Reduced susceptibility to bendiocarb (mortality rate of 96.1% was found in one sample out of nine assayed. Increased tolerance to pyrethroids was detected in most samples (8/9 with mortality rates ranging from 70.2 to 96.6% for deltamethrin and from 26.7 to 96.3% for permethrin. Pyrethroid tolerance was not associated with a significant increase of knock-down times. Anopheles arabiensis was the predominant species of the An. gambiae complex in the study area, representing 75 to 100% of the samples. Screening for kdr mutations detected the L1014F mutation in 88.6% (N = 35 of surviving An. gambiae sensu stricto S form mosquitoes. All surviving An. arabiensis (N = 49 and M form An. gambiae s.s. (N = 1 carried the susceptible allele

  10. Aberrant use and poor quality of trypanocides: a risk for drug resistance in south western Ethiopia.

    Tekle, T; Terefe, G; Cherenet, T; Ashenafi, H; Akoda, K G; Teko-Agbo, A; Van Den Abbeele, J; Gari, G; Clausen, P-H; Hoppenheit, A; Mattioli, R C; Peter, R; Marcotty, T; Cecchi, G; Delespaux, V

    2018-01-05

    Trypanocidal drugs have been used to control African animal trypanosomosis for several decades. In Ethiopia, these drugs are available from both authorized (legal) and unauthorized (illegal) sources but documentation on utilization practices and quality of circulating products is scanty. This study looked at the practices of trypanocidal drug utilization by farmers and the integrity of active ingredient in trypanocides sold in Gurage zone, south western Ethiopia. The surveys were based on a structured questionnaire and drug quality determination of commonly used brands originating from European and Asian companies and sold at both authorized and unauthorized markets. One hundred farmers were interviewed and 50 drug samples were collected in 2013 (Diminazene aceturate = 33 and Isometamidium chloride = 17; 25 from authorized and 25 from unauthorized sources). Samples were tested at the OIE-certified Veterinary Drug Control Laboratory (LACOMEV) in Dakar, Senegal, by using galenic standards and high performance liquid chromatography. Trypanosomosis was found to be a major threat according to all interviewed livestock keepers in the study area. Diminazene aceturate and isometamidium chloride were preferred by 79% and 21% of the respondents respectively, and 85% of them indicated that an animal receives more than six treatments per year. About 60% of these treatments were reported to be administered by untrained farmers. Trypanocidal drug sources included both unauthorized outlets (56%) and authorized government and private sources (44%). A wide availability and usage of substandard quality drugs was revealed. Twenty eight percent of trypanocidal drugs tested failed to comply with quality requirements. There was no significant difference in the frequency of non-compliance between diminazene-based and isometamidium chloride products (P = 0.87) irrespective of the marketing channel (official and unofficial). However, higher rates of non-compliant trypanocides

  11. Qualitative Interpretation Of Aerogravity And Aeromagnetic Survey Data Over The South Western Part Of The Volta River Basin Of Ghana

    George Hinson; Aboagye Menyeh; David Dotse Wemegah

    2015-01-01

    Abstract The study area South western part of Volta River Basin of Ghana covering an area of 8570 km2 which is one-eleventh the area of the Volta River basin of Ghana has been subjected to numerous academic research works but geophysical survey works because of virtual perceptive reasons. It is now believed to overly mineral-rich geological structures hence the use of magnetic and gravity survey methods to bring out these mineral-rich geological structures.Geographically it study area is loca...

  12. Oxygen isotope records of Globigerina bulloides across a north-south transect in the south-western Indian Ocean

    Khare, N.; Chaturvedi, S.K.; Saraswat, R

    , Washington, D.C). Lutjeharms, J.R.E., N.M. Walters and B.R. Allanson. 1985. Oceanic frontal systems and biologicalenhancement. p.11-21. In: Antarctic Nutrient Cycles and Food Webs. ed. by W.R. Siegfried et al., Springer-Verlag, NewYork. Matsumoto, K., J...: Ocean Sci. J.: 44(2); 2009; 117-123 OXYGEN ISOTOPE RECORDS OF GLOBIGERINA BULLOIDES ACROSS A NORTH-SOUTH TRANSECT IN THE SOUTH-WESTERN INDIAN OCEAN N. Khare 1* , S. K. Chaturvedi 2 and R. Saraswat 3 1. Ministry of Earth Sciences, Block...

  13. Heat flow map of the Bohemian massif

    Cermak, V [Geophys. Inst., CS Acad. of Sci.

    1977-01-01

    Forty seven heat flow values for the Bohemian massif were used to determine the heat flow pattern of the area. By including data from neighboring countries it was possible to draw an isothermal map outlining the geothermal activity. As a result, it is possible to closely correlate the heat flow and the tectonic structure. It is obvious that the areas of high geothermal activity correspond to zones of crustal weakness associated with two major faults bordering the rigid central section of the massif. The highest heat flow values coincide with the axis of the sedimentary basin. The development of these heat flow patterns should assist in the recognition of probable areas of geothermal resources and several promising sites are readily discernible.

  14. Climate Change Impact on Various Land Cover Types Water Balance in South Western Hungary

    Csáki, Péter; Béla Brolly, Gábor; Czimber, Kornél; Kalicz, Péter; Kisfaludy, Balázs; Gribovszki, Zoltán

    2014-05-01

    Water balance of Zala county (South Western Hungary) was analyzed using remote-sensing based evapotranspiration (ET) 1-km spatial resolution maps for Hungary by Szilagyi and Kovacs over the 1999-2008 period [Szilagyi J., Kovacs A., 2011: A calibration-free evapotranspiration mapping technique for spatially-distributed regional-scale hydrologic modeling. J. Hydrol. Hydromech., 59, 2011, 2, 118-130.]. Mean (1999-2008 period) annual evapotranspiration and runoff (as the difference of precipitation and evapotranspiration: R = P - ET) were analyzed in the context of land cover types (artificial surfaces, agricultural areas, forest and semi natural areas, wetlands, water bodies). The average ET of Zala county was 581 mm/year, it was more than 89 percent of the mean annual precipitation (650 mm/year). The highest mean annual ET values (1999-2008) determined for water bodies and wetlands. Forest and semi natural areas had higher mean annual value than agricultural areas, the lowest rate belonged to artificial surfaces. The maximum ET value was very high in case of water bodies (845 mm) as well as forest and semi natural areas (828 mm). Runoff was the largest on artificial surfaces (89 mm/year), and it was especially low for wetlands. Spatially-distributed calibration parameter of Budyko-model (alfa) was calculated by using temperature, precipitation and ET values. Another parameter, beta (which gives the relationship between pan-evapotranspiration and actual evapotranspiration) was calculated for those pixels, where the ET value was higher than the precipitation value, because the Budyko-type model for such type of pixels is not valid. The two parameter maps (alfa and beta) aggregate all of the factors affecting ET, dominantly the surface cover. They can be used for evaluating future ET and runoff in spatially-distributed mode. ET and runoff predictions have been done for three periods (2011-2040, 2041-2070, 2071-2100) using the parameter maps (alfa and beta) and future

  15. Detection of rock strength at Branisko massif

    Lazarová Edita

    2000-09-01

    Full Text Available When monitoring and optimizing the driving proces of the exploratory gallery by a computer system, conditions for verification of the interaction between desintegrating head of driving machine and rock massif were created. One of the output values of this mathematical model is the model strength at a simple pressure ótlH, which is defined as a pressure at the discus and the massif contact during the desintigration (a near limit of massif strength. By geological and geological engineering exploration, the section of length 2340 m was divided into fourty-two geological sections and five quasi-homogeneous massif enviroments. In the article, results of scleroscopic strength óCI , the strength in a simple pressure determined from the point load test and the strength at simple pressure ótlH are confronted . The main advance of the electronic geomechanical monitoring is the density of gained information. The two-seconds sample period of input and output data during the driving process makes it possible to describe driving circumstances in an almost continual way for each millimeter of the built tunnel. Then the information about changes of disintegrated rock properties, have the same density (frequency. By comparing a quantity of data gained by examining the index of point strength, scleroscopic strength and the model strength in a simple pressure from the monitoring process of driving process it is obvious that during the driving of exploratory gallery of motorway tunnel Branisko, a proportion of data number from the three “type examinations” of strength was reached and it was approximately 1:7:5000. Approximately in the same proportion, there were determined values for the 42 geologic sections (I. – XLII., which were defined in detail by the geologic, engineering geologic, hydrogeologic and geotechnic research.. The presented quantity values of presented rock mass strength for each geologic section are presented by their arithmetic average

  16. Les Gammaridae (Crustaces, Amphipodes) du Massif Central

    Goedmakers, Annemarie

    1974-01-01

    Une prospection systématique des eaux courantes du Massif Central a permis de reconnaître le nombre d’espèces des Gammaridés présentes dans cette région. On a trouvé les espèces suivantes: Gammarus pulex (Linnaeus, 1758), G. fossarum Koch, 1835, et G. ibericus Margalef, 1951. G. ibericus, espèce

  17. Stable carbon isotopic assessment of prehistoric diets in the south-western Cape, Cape Town, South Africa

    Sealy, J C

    1984-01-01

    This thesis consists of a stable carbon isotopic assessment of the diets of the Holocene human inhabitants of the south-western Cape, South-Africa. Samples of the foods these people ate were collected from each of the four major physiographic zones in the area, and their /sup 13/C//sup 12/C ratios measured. A total of more than 200 such analyses enabled the estimation of the average delta /sup 13/C values of prehistoric human diets in each zone. This information is used to interpret delta /sup 13/C measurements on a series of archaeological human skeletons. The results are consistent with a model of prehistoric subsistence behaviour in which people living at the coast made intensive use of marine food resources throughout the Holocene, consuming such a large proportion of these foods that they must have spent much, if not all of their time at the coast. Inland skeletons reflect an almost entirely terrestrial diet. These results contradict hypotheses about seasonal population movements between the coast and the interior generated from excavated archaeological material. Considerable changes in many of our current views of the Late Stone Age of the south-western Cape will have to be made in order to accommodate these data.

  18. Monarchical Activities of the Yoruba Kings of South Western Nigeria: A Cultural Heritage in Printmaking Visual Documentary.

    Emmanuel Bankole Oladumiye

    2014-10-01

    Full Text Available Printmaking is a visual documentary media of art which was used as a medium of expression in analyzing myth and mythology monarchical activities of the Yorubas in South Western Nigeria in this study. The  monarchical activities of the Yoruba Kings, is  the cultural heritage and legacy that people do guide jealously and considered to be of high cultural value. The Yoruba Kings of South Western Nigeria are traditional entity which passed through the rites of installing kings for the throne fore fathers as a leader with symbol of authority between the people and the spirit world. The kings in Yoruba kingdom is so much respected that they are seen as divine and representative of God on earth and they are exalted into the position of deity because of his monarchical duties to his subjects at large. The funfairs that accompany the monarch roles  are worth documenting using printmaking as vehicle of visual and historical expression of myths and mythologies demonstrating African culture which stands out as sacred. The discourse also relies on oral testimonies written and archival documents. The materials used for the execution of the prints are rubber, wood, plate, offset printing inks and glass which records the events as an alternative to the use of photographic documentation. The research examine the philosophy behind the monarchical roles of the Yoruba Kings in print visuals based on the cultural heritage of the Yoruba people it employs an exploratory qualitative methods rely on literature review.

  19. Meteorological and oceanographic aspects of a winter storm over the south-western Cape Province, South Africa

    Jury, M.R.; Shillington, F.A.; Prestidge, G.; Maxwell, C.D.

    1986-01-01

    In May the southern hemisphere circumpolar jet stream accelerates in response to a growing temperature gradient between the pole and equator. Initially, the jet stream may 'spin up' in pulses, causing the upper air current to become unstable and to meander equatorwards out of the higher latitudes (40-50 degrees S). Winter storms induced by the jet stream and which move, from west to east, to the south of the African continent are then guided by the upper air currents further north. Between 15 and 17 May 1984, such a sequence of synoptic weather events developed and the south-western Cape came under the influence of the 'roaring 40's'. In this article a chronology of the storm and its meteorological effects are described using data collected at the Koeberg nuclear power station, the Cape Town Airport Weather Office and across the south-western Cape. The destructive effects of the storm, particularly felt along the coast as a result of large swells and a significant storm surge, are discussed

  20. The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient

    Espinoza, Jhan Carlo; Marengo, José Antonio; Ronchail, Josyane; Carpio, Jorge Molina; Flores, Luís Noriega; Guyot, Jean Loup

    2014-01-01

    Unprecedented wet conditions are reported in the 2014 summer (December–March) in South-western Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m 3 s −1 ) at Porto Velho and 380% (25 000 m 3 s −1 ) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Niña and/or warmer than normal tropical South Atlantic, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South Atlantic. Our results suggest that the tropical and subtropical South Atlantic SST gradient is a main driver for moisture transport from the Atlantic toward south-western Amazon, and this became exceptionally intense during summer of 2014. (letter)

  1. Hydraulic properties and scale effects investigation in regional rock aquifers, south-western Quebec, Canada

    Nastev, M.; Savard, M. M.; Lapcevic, P.; Lefebvre, R.; Martel, R.

    This paper reports on the characterization of hydraulic properties of regional rock aquifers carried out within a groundwater resources assessment project in the St. Lawrence Lowlands of south-western Quebec. To understand the aquifer behavior at both the fracture level and at field scale, hydraulic investigations were carried out using various aquifer tests. The groundwater flow at the local scale is controlled mostly by the fracture system. Results of the constant-head injection tests show a weak decreasing trend of hydraulic conductivity with depth indicating that a major part of the groundwater flow occurs in the first meters of the rock sequence. At the regional scale, the equivalent porous media approach is applicable. The hydraulic conductivity measurements were correlated to the scale of the aquifer tests expressed with the investigated aquifer volume. A simple interpolation procedure for the hydraulic conductivity field was developed based on the distance between field measurements and the tested aquifer volumes. The regional distribution of the hydraulic conductivity for the major fractured aquifer units indicates that dolostone is the most permeable whereas sandstone and crystalline rocks are the least permeable units. Este artículo trata de la caracterización de las propiedades hidráulicas en acuíferos regionales rocosos, la cual se llevó a cabo dentro del proyecto de evaluación de los recursos de agua subterránea en St. Lawrence Lowlands al suroeste de Quebec. Para entender el comportamiento del acuífero tanto a nivel de fractura como a escala del campo, se ejecutaron investigaciones hidráulicas usando varias pruebas de acuífero. El flujo del agua subterránea a escala local está controlado principalmente por el sistema de fracturas. Los resultados de las pruebas de inyección con cabeza constante muestran una tendencia decreciente débil de la conductividad hidráulica con la profundidad, indicando que la mayor parte del flujo de agua

  2. Individual and health facility factors and the risk for obstructed labour and its adverse outcomes in south-western Uganda

    Turyakira Eleanor

    2011-10-01

    Full Text Available Abstract Background Obstructed labour is still a major cause of maternal morbidity and mortality and of adverse outcome for newborns in low-income countries. The aim of this study was to investigate the role of individual and health facility factors and the risk for obstructed labour and its adverse outcomes in south-western Uganda. Methods A review was performed on 12,463 obstetric records for the year 2006 from six hospitals located in south-western Uganda and 11,180 women records were analysed. Multivariate logistic regression analyses were applied to control for probable confounders. Results Prevalence of obstructed labour for the six hospitals was 10.5% and the main causes were cephalopelvic disproportion (63.3%, malpresentation or malposition (36.4% and hydrocephalus (0.3%. The risk of obstructed labour was statistically significantly associated with being resident of a particular district [Isingiro] (AOR 1.39, 95% CI: 1.04-1.86, with nulliparous status (AOR 1.47, 95% CI: 1.22-1.78, having delivered once before (AOR 1.57, 95% CI: 1.30-1.91 and age group 15-19 years (AOR 1.21, 95% CI: 1.02-1.45. The risk for perinatal death as an adverse outcome was statistically significantly associated with districts other than five comprising the study area (AOR 2.85, 95% CI: 1.60-5.08 and grand multiparous status (AOR 1.89, 95% CI: 1.11-3.22. Women who lacked paid employment were at increased risk of obstructed labour. Perinatal mortality rate was 142/1000 total births in women with obstructed labour compared to 65/1000 total births in women without the condition. The odds of having maternal complications in women with obstructed labour were 8 times those without the condition. The case fatality rate for obstructed labour was 1.2%. Conclusions Individual socio-demographic and health system factors are strongly associated with obstructed labour and its adverse outcome in south-western Uganda. Our study provides baseline information which may be used by

  3. Re–Os geochemistry and geochronology of the Ransko gabbro–peridotite massif, Bohemian Massif

    Ackerman, Lukáš; Pašava, J.; Erban, V.

    2013-01-01

    Roč. 48, č. 7 (2013), s. 799-804 ISSN 0026-4598 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : Re–Os * geochronology * gabbro * Bohemian Massif * Ni–Cu mineralization Subject RIV: DD - Geochemistry Impact factor: 2.667, year: 2013

  4. Desertification and its effect on the erosion of vegetation in the south-western region of Saudi Arabia.

    Abd El-Salam, Magda Magdy; Elhakem, Abeer Hamdy

    2016-03-01

    This study was conducted in Jazan region of south-western Saudi Arabia. Vegetation cover, frequency, abundance and soil characteristics were analysed at three locations with different quantitative and descriptive vegetation characteristics. Plant species were classified into three primary communities dominated by Salvadora persic, Acacia tortilis and Ziziphus spini-Christi. The results indicated that the distribution of plant species is controlled by soil characteristics. Very limited water resources are also limiting factor in vegetation growth. Among the three studied sites, desert and coastal environments are affected by desertification. Rehabilitation of the degraded lands requires collaborative efforts and support from the different related governmental sectors. Ecological conservation and sustainable development must be adopted as tools of rehabilitation.

  5. Older persons' views and experience of elder abuse in South Western Nigeria: a community-based qualitative survey.

    Cadmus, Eniola Olubukola; Owoaje, Eme Theodora; Akinyemi, Oluwaseun Oladapo

    2015-06-01

    Conventionally, existing information on elder abuse has been institution based, professionally driven, and in high-income countries. This study addresses the prevailing gap in knowledge through direct consultation of older persons in the community about their perceptions of elder abuse. Eight focus group discussions were carried out among males and females aged 60 years and above in a rural and an urban community in south western Nigeria. Data were transcribed and analyzed based on emergent themes. Findings from the study show that the perception of abuse by the respondents included the standard typologies except sexual abuse as well as societal issues such as disrespect and lack of recognition. Our study revealed a high level of awareness and experience of elder abuse among the participants in both communities. Effective social welfare and health services aided by targeted government policies are needed to improve the quality of life of the elderly. © The Author(s) 2014.

  6. Prevalence of dyslipidaemia and associated risk factors in a rural population in South-Western Uganda: a community based survey.

    Gershim Asiki

    Full Text Available The burden of dyslipidaemia is rising in many low income countries. However, there are few data on the prevalence of, or risk factors for, dyslipidaemia in Africa.In 2011, we used the WHO Stepwise approach to collect cardiovascular risk data within a general population cohort in rural south-western Uganda. Dyslipidaemia was defined by high total cholesterol (TC ≥ 5.2 mmol/L or low high density lipoprotein cholesterol (HDL-C 6% (men aOR=3.00, 95%CI=1.37-6.59; women aOR=2.74, 95%CI=1.77-4.27. The odds of high TC was also higher among married men, and women with higher education or high BMI.Low HDL-C prevalence in this relatively young rural population is high whereas high TC prevalence is low. The consequences of dyslipidaemia in African populations remain unclear and prospective follow-up is required.

  7. Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

    Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

    2013-05-01

    Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Potential impacts of climate change on flow regime and fish habitat in mountain rivers of the south-western Balkans.

    Papadaki, Christina; Soulis, Konstantinos; Muñoz-Mas, Rafael; Martinez-Capel, Francisco; Zogaris, Stamatis; Ntoanidis, Lazaros; Dimitriou, Elias

    2016-01-01

    The climate change in the Mediterranean area is expected to have significant impacts on the aquatic ecosystems and particular in the mountain rivers and streams that often host important species such as the Salmo farioides, Karaman 1938. These impacts will most possibly affect the habitat availability for various aquatic species resulting to an essential alteration of the water requirements, either for dams or other water abstractions, in order to maintain the essential levels of ecological flow for the rivers. The main scope of this study was to assess potential climate change impacts on the hydrological patterns and typical biota for a south-western Balkan mountain river, the Acheloos. The altered flow regimes under different emission scenarios of the Intergovernmental Panel on Climate Change (IPCC) were estimated using a hydrological model and based on regional climate simulations over the study area. The Indicators of Hydrologic Alteration (IHA) methodology was then used to assess the potential streamflow alterations in the studied river due to predicted climate change conditions. A fish habitat simulation method integrating univariate habitat suitability curves and hydraulic modeling techniques were used to assess the impacts on the relationships between the aquatic biota and hydrological status utilizing a sentinel species, the West Balkan trout. The most prominent effects of the climate change scenarios depict severe flow reductions that are likely to occur especially during the summer flows, changing the duration and depressing the magnitude of the natural low flow conditions. Weighted Usable Area-flow curves indicated the limitation of suitable habitat for the native trout. Finally, this preliminary application highlighted the potential of science-based hydrological and habitat simulation approaches that are relevant to both biological quality elements (fish) and current EU Water policy to serve as efficient tools for the estimation of possible climate

  9. Regional distribution patterns of chemical parameters in surface sediments of the south-western Baltic Sea and their possible causes

    Leipe, T.; Naumann, M.; Tauber, F.; Radtke, H.; Friedland, R.; Hiller, A.; Arz, H. W.

    2017-12-01

    This study presents selected results of a sediment geochemical mapping program of German territorial waters in the south-western Baltic Sea. The field work was conducted mainly during the early 2000s. Due to the strong variability of sediment types in the study area, it was decided to separate and analyse the fine fraction (<63 μm, mud) from more than 600 surficial samples, combined with recalculations for the bulk sediment. For the contents of total organic carbon (TOC) and selected elements (P, Hg), the regional distribution maps show strong differences between the analysed fine fraction and the recalculated total sediment. Seeing that mud contents vary strongly between 0 and 100%, this can be explained by the well-known grain-size effect. To avoid (or at least minimise) this effect, further interpretations were based on the data for the fine fraction alone. Lateral transport from the large Oder River estuary combined with high abundances and activities of benthic fauna on the shallow-water Oder Bank (well sorted fine sand) could be some main causes for hotspots identified in the fine-fraction element distribution. The regional pattern of primary production as the main driver of nutrient element fixation (C, N, P, Si) was found to be only weakly correlated with, for example, the TOC distribution in the fine fraction. This implies that, besides surface sediment dynamics, local conditions (e.g. benthic secondary production) also have strong impacts. To the best of the authors' knowledge, there is no comparable study with geochemical analyses of the fine fraction of marine sediments to this extent (13,600 km2) and coverage (between 600 and 800 data points) in the Baltic Sea. This aspect proved pivotal in confidently pinpointing geochemical "anomalies" in surface sediments of the south-western Baltic Sea.

  10. Use and perception of the psychostimulant, khat (catha edulis) among three occupational groups in south western Uganda.

    Ihunwo, A O; Kayanja, F I B; Amadi-Ihunwo, U B

    2004-09-01

    To examine the use of and perception of the psychostimulant, khat (catha edulis) in three towns in south-western Uganda. Cross-sectional survey. Mbarara, Kabale and Fort Portal. Three categories of respondents prone to khat chewing habit were selected; One hundred and thirty students, thirty five law enforcement officials and sixteen transporters. Khat chewers existed within the sampled population. The relationship between tobacco smoking, drinking alcoholic beverages and the khat chewing habit was established. Out of 181 respondents, 164(90.6%) had heard of khat, 126(69.6%) had seen it and 57(31.5%) had chewed khat before. As at the time of this study, 37(20.4%) still chewed khat. Within the three categories of subjects, the use of khat was highest among law enforcement officials (97.1%), followed by transporters (68.8%) and students (9.2%). The majority of khat chewers were in the age range of 16-25 years. There was a clear correlation between khat chewing and the use of stimulants such as alcoholic beverages and tobacco smoking. Those who smoked cigarettes were twenty-eight times more likely to chew khat (OR=28.95% CI=9.6,83.7). Euphoria, suppressed sleep and increased sexual desire were the most predominant effects experienced by khat chewers. The knowledge of khat is widespread and its consumption is on the increase among students, law enforcement officials and transporters in south-western Uganda. This calls for attention considering the public health implications.

  11. Seaweed beds support more juvenile reef fish than seagrass beds in a south-western Atlantic tropical seascape

    Eggertsen, L.; Ferreira, C. E. L.; Fontoura, L.; Kautsky, N.; Gullström, M.; Berkström, C.

    2017-09-01

    Seascape connectivity is regarded essential for healthy reef fish communities in tropical shallow systems. A number of reef fish species use separate adult and nursery habitats, and hence contribute to nutrient and energy transfer between habitats. Seagrass beds and mangroves often constitute important nursery habitats, with high structural complexity and protection from predation. Here, we investigated if reef fish assemblages in the tropical south-western Atlantic demonstrate ontogenetic habitat connectivity and identify possible nurseries on three reef systems along the eastern Brazilian coast. Fish were surveyed in fore reef, back reef, Halodule wrightii seagrass beds and seaweed beds. Seagrass beds contained lower abundances and species richness of fish than expected, while Sargassum-dominated seaweed beds contained significantly more juveniles than all other habitats (average juvenile fish densities: 32.6 per 40 m2 in Sargassum beds, 11.2 per 40 m2 in back reef, 10.1 per 40 m2 in fore reef, and 5.04 per 40 m2 in seagrass beds), including several species that are found in the reef habitats as adults. Species that in other regions worldwide (e.g. the Caribbean) utilise seagrass beds as nursery habitats were here instead observed in Sargassum beds or back reef habitats. Coral cover was not correlated to adult fish distribution patterns; instead, type of turf was an important variable. Connectivity, and thus pathways of nutrient transfer, seems to function differently in east Brazil compared to many tropical regions. Sargassum-dominated beds might be more important as nurseries for a larger number of fish species than seagrass beds. Due to the low abundance of structurally complex seagrass beds we suggest that seaweed beds might influence adult reef fish abundances, being essential for several keystone species of reef fish in the tropical south-western Atlantic.

  12. Stability assessment of the stopes and crown pillar of the S’Argentera abandoned mines (Ibiza, Spain) using geomechanical classifications, an empirical approach and numerical analysis focused on a possible tourist exploitation; Evaluación de la estabilidad de las labores y pilar corona en las minas abandonadas de S’Argentera (Ibiza, España) combinando clasificaciones geomecánicas, métodos empíricos y análisis numérico - enfocado a su posible aprovechamiento turístico.

    Jordá-Bordehore, L.; Jordá-Bordehore, R.; Durán Valsero, J.J.; Romero-Crespo, P.L.

    2017-09-01

    The argentiferous lead mines of S’Argentera in Ibiza (Balearic Islands, Spain) are some abandoned underground workings from the first decade of the 20th century. The stability of the main stopes and the crown pillar of the mines has been evaluated - part of which is located below the road between Santa Eulalia and San Carles de Peralta. The possibility of allowing public access to the surface of the mining area and setting up a project of a “show mine” on the underground stopes and galleries is analysed. The stability is assessed with an empirical approach using the O index, the scaled span method and a stability graph together with a numerical approach. Results show that the stopes of the mines are globally stable but some lack an adequate safety factor. Therefore some local reinforcements and monitoring are needed. The finite element modelling in two dimensions yields realistic results on the current stope stability and possible rock falls which have already occurred. [Spanish] Las minas de S’Argentera en Ibiza (Islas Baleares, España) son unas labores subterráneas de plomo argentífero abandonadas desde la primera década del siglo XX. Se ha analizado la estabilidad geotécnica de las cámaras y del pilar corona de las minas (sobre parte del cual pasa la carretera entre Santa Eulalia y San Carles de Peralta), dado que se está contemplando en un futuro permitir el acceso a la parte superior del conjunto de minas e iniciar un proyecto de rehabilitación turística de las labores subterráneas. Se ha evaluado la estabilidad combinando un enfoque empírico mediante el índice Q, método gráfico de estabilidad y ancho escalado, y métodos numéricos de elementos finitos para análisis tensodeformacional. El resultado del análisis muestra que las cámaras de las minas son estables pero algunas no poseen un adecuado factor de seguridad. Por lo tanto son necesarios algunos refuerzos y monitoreo puntuales. La modelización tensodeformacional en dos

  13. Boys Go Fishing, Girls Work at Home: Gender Roles, Poverty and Unequal School Access among Semi-Nomadic Fishing Communities in South Western Madagascar

    Nascimento Moreira, Catarina; Rabenevanana, Man Wai; Picard, David

    2017-01-01

    Drawing from data gathered in South Western Madagascar in 2011, the work explores the combination of poverty and traditional gender roles as a critical factor in determining unequal school access among young people from semi-nomadic fishing communities. It demonstrates that from the age of early puberty, most boys go fishing with their fathers and…

  14. Machinery penile injuries associated with traditional trousers of the Yoruba of South-western Nigeria: A consideration for proper work clothes

    A.A. Popoola

    2012-03-01

    Full Text Available Appropriateness of garments for different vocations to avoid unintended injury to the worker has always been recognized. This report of two cases of machinery penile injuries in patients wearing the traditional trousers of the Yoruba tribe of south-western Nigeria emphasizes the need for wearing appropriate clothes when operating machines.

  15. From disaster to sustainability: floods, changing property relations and water management in the south-western Netherlands, c. 1500-1800

    Cruijningen, van P.J.

    2014-01-01

    When large parts of the south-western Netherlands flooded in the fifteenth and sixteenth centuries the main cause was insufficient maintenance of the sea defences. The subsequent re-embankment of the polders resulted in changes to both soil conditions and property relations in the region. The Church

  16. Qualitative Interpretation Of Aerogravity And Aeromagnetic Survey Data Over The South Western Part Of The Volta River Basin Of Ghana

    George Hinson

    2015-04-01

    Full Text Available Abstract The study area South western part of Volta River Basin of Ghana covering an area of 8570 km2 which is one-eleventh the area of the Volta River basin of Ghana has been subjected to numerous academic research works but geophysical survey works because of virtual perceptive reasons. It is now believed to overly mineral-rich geological structures hence the use of magnetic and gravity survey methods to bring out these mineral-rich geological structures.Geographically it study area is located at the south western part of the Voltaian basin at latitudes 07o 00 N and 08o 00 N and longitudes 02o 00 W and 01o 00 W respectively. Airborne gravity and magnetic survey methods were employed in the data collection. The field data correction and error reduction were applied to the two raw data on the field after which Geosoft Oasis Montaj 7.01 Encom Profile Analysis P.A 11 and 13 Model Vision 12 and ArcGIS 10.0 were used to process enhance e.g. reduce to pole at low latitude first vertical derivative etc. model the reduced and corrected airborne magnetic data and also to produce maps from them data. Low-to-moderate-to-high gravity and magnetic anomalies were obtained in the complete Bouguer anomaly CBA and total magnetic intensity TMI reduced to pole at low latitude with many of these anomalies trending NE-SW by which the Birimian Metasediments and Metavolcanics can be said to be part of the causative structures of these anomalies with cross-cut NW-SE faults. From the quantitative point of view the intrusive granitic bodies of the study area have a mean depth location of 1.7 km while the isolated anomaly is located at a depth of 1.4 km computed from Euler deconvolution. The NE-SW trending anomalies show the trend direction of their causative structures which are the basement rocks and the basinal intrusive bodies.

  17. Environmental patterns and biomass distribution of gelatinous macrozooplankton. Three study cases in the South-western Atlantic Ocean

    H. W. Mianzan

    2000-12-01

    Full Text Available Periodic swarms or blooms of gelatinous macrozooplankton have a negative effect on many human activities such as tourism, fisheries, and industry, but for several reasons (sampling procedures, underestimation of their real abundance, etc., they have often been neglected in the local literature. The high spatial resolution exercise of the South-western Atlantic anchovy Engraulis anchoita Recruitment Project (SARP was therefore also suitable for estimating standing stocks of jelly macrozooplankton, attempting to establish particular environmental patterns exerting control on the spatial distribution of these facultative carnivorous predators in coastal frontal environments. These studies were carried out through a sampling programme on board the German R/V Meteor in three different systems, convergence and divergent, in the South-western Atlantic Ocean: Region A (42°S on the Argentine shelf, characterised by tidal mixing fronts; Region B (36°S, the freshwater outflow from Río de la Plata; and Region C (28°S, under upwelling events in subtropical waters on the Brazilian shelf. In general, a dominance of gelatinous macrozooplankton, compared with the other fraction of macrozooplankton and micronekton was observed. Mean standing stock of the gelatinous zooplankton was always greater than 50% of organic carbon (org. C in every section analysed. The lobate ctenophore Mnemiopsis leidyi dominated the zooplankton biomass in Region A, Argentina. It represented 60% of total org. C and was more abundant at the stratified zone of the front. Ctenophores were also dominant in Region B, Río de la Plata, where the related species Mnemiopsis mccradyi and the cydippid ctenophore Pleurobrachia pileus comprised 81% of total org. C. Mnemiopsis was most common in areas of vertical thermal and saline stratification, while Pleurobrachia was dominant in the less stratified areas. Gelatinous zooplankton was also the principal component of the macrozooplankton biomass

  18. An overview on geochemistry of Proterozoic massif-type ...

    A critical study of 311 published WR chemical analyses, isotopic and mineral chemistry of ... Keywords. Massif anorthosite complexes; overview; geochemistry; high-Al gabbro. J. Earth ...... (123–2920 ppm) unlike the experimental results of.

  19. Stress distribution and seismicity patterns of the 2011 seismic swarm in the Messinia basin, (South-Western Peloponnesus, Greece

    G. Chouliaras

    2013-01-01

    Full Text Available In this investigation we examine the local stress field and the seismicity patterns associated with the 2011–2012 seismicity swarm in the Messinia basin, south-western Peloponnesus, Greece, using the seismological data of the National Observatory of Athens (NOA. During this swarm more than 2000 events were recorded in a 12 month period by the Hellenic Unified Seismological Network (HUSN and also by the additional local installation of four portable broadband seismographic stations by NOA.

    The results indicate a Gaussian distribution of swarm activity and the development of a seismicity cluster in a pre-existing seismic gap within the Messinia basin. Centroid Moment Tensor solutions demonstrate a normal fault trending northwest–southeast and dipping to the southwest primarily due to an extensional stress field. During this seismicity swarm an epicentre migration of the three largest shocks is observed, from one end of the rupture zone in the north-western part of the cluster, towards the other edge of the rupture in the south-eastern part of the cluster. This migration is found to follow the Coulomb failure criterion that predicts the advancement and retardation of the stress field and the patterns of increases and decreases of the seismicity rate (b-value of the frequency–magnitude relation.

  20. Immigrant maternal depression and social networks. A multilevel Bayesian spatial logistic regression in South Western Sydney, Australia.

    Eastwood, John G; Jalaludin, Bin B; Kemp, Lynn A; Phung, Hai N; Barnett, Bryanne E W

    2013-09-01

    The purpose is to explore the multilevel spatial distribution of depressive symptoms among migrant mothers in South Western Sydney and to identify any group level associations that could inform subsequent theory building and local public health interventions. Migrant mothers (n=7256) delivering in 2002 and 2003 were assessed at 2-3 weeks after delivery for risk factors for depressive symptoms. The binary outcome variables were Edinburgh Postnatal Depression Scale scores (EPDS) of >9 and >12. Individual level variables included were: financial income, self-reported maternal health, social support network, emotional support, practical support, baby trouble sleeping, baby demanding and baby not content. The group level variable reported here is aggregated social support networks. We used Bayesian hierarchical multilevel spatial modelling with conditional autoregression. Migrant mothers were at higher risk of having depressive symptoms if they lived in a community with predominantly Australian-born mothers and strong social capital as measured by aggregated social networks. These findings suggest that migrant mothers are socially isolated and current home visiting services should be strengthened for migrant mothers living in communities where they may have poor social networks. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Lesion Distribution and Epidemiology of Mycobacterium bovis in Elk and White-Tailed Deer in South-Western Manitoba, Canada

    Todd K. Shury

    2011-01-01

    Full Text Available Surveillance for Mycobacterium bovis in free-ranging elk (Cervus elaphus and white-tailed deer (Odocoileus virginianus from south-western Manitoba was carried out from 1997 to 2010 to describe the lesions, epidemiology, and geographic distribution of disease. Tissues were cultured from animals killed by hunters, culled for management, blood-tested, or found opportunistically. Period prevalence in elk was approximately six times higher than deer, suggesting a significant reservoir role for elk, but that infected deer may also be involved. Prevalence was consistently higher in elk compared to deer in a small core area and prevalence declines since 2003 are likely due to a combination of management factors instituted during that time. Older age classes and animals sampled from the core area were at significantly higher risk of being culture positive. Positive elk and deer were more likely to be found through blood testing, opportunistic surveillance, and culling compared to hunting. No non-lesioned, culture-positive elk were detected in this study compared to previous studies in red deer.

  2. Detection of Urinary Tract Infection (UTI Among Pregnant Women in Oluyoro Catholic Hospital, Ibadan, South-Western Nigeria

    Okonko, I. O.

    2010-01-01

    Full Text Available This study reports the detection of urinary tract infections among 80 pregnant women in Oluyoro Catholic Hospital Ibadan, South-Western, Nigeria for a period of 6 months. It was carried out to detect the presence of urinary tract infection in pregnant women, and to isolate and to identify the pathogens responsible for the infection. A total of 80 clean voided mid-stream urine samples were collected from pregnant women between the ages of 21-40 years. The results showed 38 bacterial isolates with an incidence of 47.5% in this population. The isolates were identified based on colonial morphology, microscopic characteristics, and biochemical tests using Bergey’s Manual of Determinative Bacteriology. Escherichia coli 16(42.1% was the most predominant organism. This was followed by Staphylococcus aureus 11(28.9%, Klebsiella aerogenes 7(18.4%, Pseudomonas aeruginosa 2(5.3%, and a mixed culture of Klebisella aerogenes and Staphylococcus aureus 2(5.3%. Urine microscopy revealed the presence of Pus cells in the urine samples collected. Two samples, representing 2.5% of the samples contained yeast cells, suggesting that Candidiasis was also predominant. The high incidence rate of 47.5% reported in this study should be of great concern, as not only do UTIs pose a threat to health, but they also impose an economic and social burden due to the stigma associated with these infections.

  3. Trophic ecology of yellownose skate Zearaja chilensis, a top predator in the south-western Atlantic Ocean.

    Belleggia, M; Andrada, N; Paglieri, S; Cortés, F; Massa, A M; Figueroa, D E; Bremec, C

    2016-03-01

    The diet and trophic level (TL ) of the yellownose skate Zearaja chilensis in the south-western Atlantic Ocean (35°-54° S), and how these varied in relation to body size, sex, maturity stage, depth and region were determined by analysis of stomach contents. From 776 specimens analysed, 671 (86·5%) ranging from 180 to 1190 mm total length (LT ) had prey in their stomachs. The diet was dominated by fishes, mainly the notothenioid Patagonotothen ramsayi and the Argentine hake Merluccius hubbsi. The consumption of fishes and crabs increased with increasing predator size, and these preys were more important in the north than in the south. Isopods and other crustaceans were consumed more in the south and their consumption decreased as the size of Z. chilensis increased. The TL of Z. chilensis increased with LT from 4·29 to 4·59 (mean 4·53), confirming their ecological role as a top predator. The small and large size classes exhibited a low diet overlap and the highest spatial segregation, whereas medium and large specimens had higher co-occurrence and dietary overlap indices. A clear distinction in tooth shape was noted between sexes in adult specimens, with males having longer cusps. This sexual heterodonty may be related to reproductive behaviour, increasing the grasping ability of males during courtship, because there were no differences in diet between the sexes. © 2016 The Fisheries Society of the British Isles.

  4. Site properties for Crimean juniper (Juniperus excelsa) in semi-natural forests of south western Anatolia, Turkey.

    Ozkan, Kürsad; Gulsoy, Serkan; Aerts, Raf; Muys, Bart

    2010-01-01

    We explored the semi-natural forests in south western Anatolia along a gradient between Mediterranean and continental climates to determine the site requirements of Juniperus excelsa in Turkey. We hypothesized that environmental variables and indicator species can be used to predict differences in occurrence and cover of J. excelsa and can therefore support decision making in reforestation management planning. Plant species composition and environmental variables were assessed in 153 plots. Association between J. excelsa and other plant species and environmental variables were analyzed using Fisher exact probability tests and stepwise discriminant analysis. High altitude (> 1000 m) as a proxy for an Oromediterranean climate, and high surface stoniness as a proxy for low competition by other tree species, are positive site properties for J. excelsa. The tree species avoids Eumediterranean and Supramediterranean plant communities. Twelve plant species, including the herbs Dianthus zonatus, Ajuga chamaepitys and Paronchia carica and the shrub Cotoneaster nummularia may be used as site indicators for J. excelsa restoration. Platanus orientalis, with similar site requirements but at present negatively associated to J. excelsa due to competitive effects, may be considered an additional indicator if stand conversion (harvesting and replacing P. orientalis) is part of the management plan.

  5. Genetic connectivity and phenotypic plasticity in the cyprinodont Aphanius farsicus from the Maharlu Basin, south-western Iran.

    Gholami, Z; Esmaeili, H R; Erpenbeck, D; Reichenbacher, B

    2015-03-01

    Meristic and morphometric characteristics, including otolith data, of the Farsi tooth-carp Aphanius farsicus, which is endemic to the endorheic Maharlu Basin in south-western Iran, were analysed for a sample of 92 individuals from four spring-streams; DNA sequence data (cytochrome b gene) are presented for 29 specimens. Some phenotypic variation was detected but the genetic data clearly indicate connectivity between the populations. Possible links between phenotypic variation and environmental variables such as water temperature, habitat size and absence or presence of predators and competitors are discussed. Based on a literature survey and the new data, it is concluded that population connectivity is maintained during times of droughts via large aquifers that formed during the late Pliocene to early Pleistocene, when the extant endorheic Maharlu Basin was created. Based on new data presented here and previous work, it is apparent that plastic and constant characteristics are present in Aphanius species, and that, if a population becomes isolated, a given trend of evolution may give rise to a taxonomically useful characteristic. © 2015 The Fisheries Society of the British Isles.

  6. Geographical traceability of virgin olive oils from south-western Spain by their multi-elemental composition.

    Beltrán, María; Sánchez-Astudillo, María; Aparicio, Ramón; García-González, Diego L

    2015-02-15

    The geographical traceability of virgin olive oil can be controlled by chemical species that are linked to the production area. Trace elements are among these species. The hypothesis is that the transfer of elements from the soil to the oil is subjected to minor variations and therefore this chemical information can be used for geographical traceability. In order to confirm this hypothesis, the trace elements of virgin olive oils from south-western Spain were analysed, and the same elements were determined in the corresponding olive-pomaces and soils. The differences in the concentration were studied according to cultivars and locations. Results show some coincidences in the selection of elements in soils (W, Fe, Na), olive-pomace (W, Fe, Na, Mg, Mn, Ca, Ba, Li) and olive oils (W, Fe, Mg, Mn, Ca, Ba, Li, Bi), which supports their utility in traceability. In the case of olive oils, 93% of the samples were correctly classified in their geographical origins (96% for Beas, 77% for Gibraleón, 91% for Niebla, and 100% for Sanlúcar de Guadiana). Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Calculation of paleohydraulic parameters of a fluvial system under spatially variable subsidence, of the Ericson sandstone, South western Wyoming

    Snyder, H.; Leva-Lopez, J.

    2017-12-01

    During the late Campanian age in North America fluvial systems drained the highlands of the Sevier orogenic belt and travelled east towards the Western Interior Seaway. One of such systems deposited the Canyon Creek Member (CCM) of the Ericson Formation in south-western Wyoming. At this time the fluvial system was being partially controlled by laterally variable subsidence caused by incipient Laramide uplifts. These uplifts rather than real topographic features were only areas of reduced subsidence at the time of deposition of the CCM. Surface expression at that time must have been minimum, only minute changes in slope and accommodation. Outcrops around these Laramide structures, in particular both flanks of the Rock Springs Uplift, the western side of the Rawlins uplift and the north flank of the Uinta Mountains, have been sampled to study the petrography, grain size, roundness and sorting of the CCM, which along with the cross-bed thickness and bar thickness allowed calculation of the hydraulic parameters of the rivers that deposited the CCM. This study reveals how the fluvial system evolved and responded to the very small changes in subsidence and slope. Furthermore, the petrography will shed light on the provenance of these sandstones and on the relative importance of Sevier sources versus Laramide sources. This work is framed in a larger study that shows how incipient Laramide structural highs modified the behavior, style and architecture of the fluvial system, affecting its thickness, facies characteristics and net-to-gross both down-dip and along strike across the basin.

  8. Mammal occurrence and roadkill in two adjacent ecoregions (Atlantic Forest and Cerrado in south-western Brazil

    Nilton C. Cáceres

    2010-10-01

    Full Text Available This paper examines the frequencies of mammal roadkill in two adjacent biogeographic ecoregions (Atlantic Forest and Cerrado of Brazil. Mammals were recorded during a seven-year period and over 3,900 km of roads, in order to obtain data for frequencies of species in habitats (sites and frequencies of species killed by cars on roads. Sites (n = 80 within ecoregions (Cerrado, n = 57; Atlantic Forest, n = 23 were searched for records of mammals. Species surveyed in the entire region totaled 33, belonging to nine orders and 16 families. In the Cerrado, 31 species were recorded in habitats; of these, 25 were found dead on roads. In the Atlantic Forest ecoregions, however, we found 21 species in habitats, 16 of which were also found dead on roads. There was no overall significant difference between ecoregions for frequencies of occurrence in habitats or for roadkills, but there were differences between individual species. Hence, anteaters were mostly recorded in the Cerrado ecoregion, whereas caviomorph rodents tended to be more frequent in the Atlantic Forest ecoregion (seen mainly by roadkills. The greater number of species (overall and threatened and the greater abundance of species records in the Cerrado suggest that this ecoregion has a greater biodiversity and is better conserved than the Atlantic Forest ecoregion, in the state of Mato Grosso do Sul, south-western Brazil.

  9. Variations of the Geomagnetic Field During the Holocene-Pleistocene: Relative Paleointensity Records From South-Western Argentina

    Gogorza, C. S.

    2008-05-01

    I present a review of the research carried out by the Group of Geomagnetism at Universidad Nacional del Centro (Argentina) on paleointensity records from bottom sediments from three lakes: Escondido (Gogorza et al., 2004), Moreno (Gogorza et al., 2006) and El Trébol (Gogorza et al., 2007; Irurzun et al., 2008) (South-Western Argentina, 41° S, 71° 30'W). Based on these studies, we construct a first relative (RPI) stack for South-Western Argentina covering the last 21,000 14C years BP. The degree of down-core homogeneity of magnetic mineral content as well as magnetic mineral concentration and grain sizes vary between all lakes and are quantified by high-resolution rock magnetic measurements. Rock magnetic studies suggest that the main carriers of magnetization are ferrimagnetic minerals, predominantly pseudo-single domain magnetite The remanent magnetization at 20 mT (NRM20mT) was normalized using the anhysteric remanent magnetization at 20mT (ARM20mT), the saturation of the isothermal remanent at 20 mT (SIRM20mT) and the low field magnetic susceptibility {k}. Coherence function analysis indicates that the normalised records are free of environmental influences. Our paleointensity (NRM20mT/ ARM20mT) versus age curve shows a good agreement with published records from other parts of the world suggesting that, in suitable sediments, paleointensity of the geomagnetic field can give a globally coherent, dominantly dipolar signal. References Gogorza, C.S.G., Irurzun, M.A., Chaparro, M.A.E., Lirio, J.M., Nuñez, H., Bercoff, P.G., Sinito, A.M. Relative Paleointensity of the Geomagnetic Field over the last 21,000 years bp from Sediment Cores, Lake El Trébol, (Patagonia, Argentina). Earth, Planets and Space. V58(10), 1323-1332. 2006. Gogorza, C.S.G., Sinito, A.M., Lirio, J.M., Nuñez, H., Chaparro, M.A.E., Bertorello, H.R. Paleointensity Studies on Holocene-Pleistocene Sediments from Lake Escondido, Argentina. Physical of the Earth and Planetary Interiors, Elsevier, ISSN

  10. Tourist Traffic In The Aconcagua Massif Area

    Marek Aneta

    2015-09-01

    Full Text Available The aim of the article is an analysis of tourist traffic in the Aconcagua massif, one of the most popular peaks of the Seven Summits. On the basis of statistical data, the tourist traffic was analysed in a temporal and spatial perspective. The applied data made it possible to capture the dynamics of visits in the period 2000/2001 – 2012/2013 and with a breakdown into months, which helped analyse the tourist traffic in this area. In each of the analysed periods, January dominates. Data concerning the origin of tourists according to countries and continents, their age, gender and type of mountaineering activity were also taken into account. Most tourists came from Argentina, the USA and Germany. These are people of age groups 21–30 (33% and 31–40 (31%. Men account for over 75% of visitors. The favourite mountaineering activity is climbing (about 60%. Aconcagua has invariably been a very popular peak among tourists and climbers. It is a place for training and acclimatisation for alpinists, participating in Himalayan expeditions and climbers collecting peaks of the Seven Summits.

  11. Serological investigation of bovine brucellosis in three cattle production systems in Yewa Division, south-western Nigeria

    Simeon I.B. Cadmus

    2013-04-01

    Full Text Available Limited data are available on the risk factors responsible for the occurrence of brucellosis amongst different cattle production systems in Nigeria despite its significant impact on livestock production. Consequently, a cross-sectional study was conducted to determine the prevalence of bovine brucellosis in three cattle production systems in Yewa Division of Ogun State, south-western Nigeria. A total of 279 blood samples (sedentary = 88; transhumance = 64; trade = 127 were examined for antibodies to Brucella sp. using the Rose Bengal test (RBT and competitive enzyme-linked immunosorbent assay (cELISA. Overall, 24 (8.6% and 16 (5.7% of the animals tested seropositive for Brucella using RBT and cELISA, respectively. The herd seroprevalences based on RBT and cELISA were 31.6% and 15.8%, respectively. The results using cELISA reveal higher seroprevalence in the trade cattle (7.9%; confidence intervals [CI] = 3.2% – 12.6% and those in a sedentary system (5.7%; CI = 0.9% – 10.5% than in cattle kept under a transhumant management system (1.6%; CI = 1.5% – 4.7%. Age (> 3 years; p = 0.043 and breed (Djali; p = 0.038 were statistically significant for seropositivity to brucellosis based on cELISA, but sex (female, p = 0.234, production system (trade and sedentary; p = 0.208 or herd size (> 120; p = 0.359 was not. Since breeding stock is mostly sourced from trade and sedentary cattle, it is important that routine serological screening should be conducted before introducing any animal into an existing herd.

  12. Analysis of Farmer’s Choices for Climate Change Adaptation Practices in South-Western Uganda, 1980–2009

    Alex Zizinga

    2017-12-01

    Full Text Available Climate change is a serious threat to the livelihoods of rural communities, particularly in mountainous areas because they are very sensitive to such changes. In this study, we assessed the household determinants to climate change adaptation drawing from a case study of agricultural adaptation in the Mount Rwenzori area of South Western Uganda. The study identified the major adaptation practices that are adopted by farmers to cope with the impacts of climate change and using available on-farm technologies. A total of 143 smallholder farmers were sampled and interviewed using field based questionnaires, field observations, and key informant interviews. Data was cleaned, entered and analysed using SPSS and Stata software for descriptive statistics. Thereafter, a Multinomial logistic regression model was used to assess the drivers of farmers’ choice for adaptation practices, factors influencing the choice of adaptation, and barriers. The major adaptation practices that were identified included; use of different crop varieties, tree planting, soil and water conservation, early and late planting, and furrow irrigation. Discrete choice model results indicated the age of the household head, experience in farming, household size, climate change shocks, land size, use of agricultural inputs, landscape position (location, and crop yield varied significantly (p > 0.05, which influenced farmers’ choice of climate change adaptation practices. The main barriers to adaptation included inadequate information on adaptation methods and financial constraints, leading us to conclude that contextual adaptation practices are more desirable for adoption to farmers. Adapting to climate change needs support from government and other stakeholders, however the implementation is more successful when appropriate and suitable choices are employed.

  13. Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland.

    Jussi Lampinen

    Full Text Available Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas.

  14. Increasing Aridity is Enhancing Silver Fir (Abies Alba Mill). Water Stress in its South-Western Distribution Limit

    Macias, M. [Department of Geology, University of Helsinki, Gustaf Haellstroeminkatu 2, P.O. Box 64, FI-00014 Helsinki (Finland); Andreu, L.; Bosch, O.; Gutierrez, E. [Departament d' Ecologia, Universitat de Barcelona, Avgda. Diagonal, 645, Barcelona, 08028, Catalonia (Spain); Camarero, J.J. [Unidad de Recursos Forestales, Centro de Investigacion Agroalimentaria, Gobierno de Aragon, Apdo. 727, Zaragoza, 50080, Aragon (Spain)

    2006-12-15

    Tree populations located at the geographical distribution limit of the species may provide valuable information about the response of tree growth to climate warming across climatic gradients. Dendroclimatic information was extracted from a network of 10 silver-fir (Abies alba) populations in the south-western distribution limit of the species (Pyrenees, NE Iberian Peninsula). Ring-width chronologies were built for five stands sampled in mesic sites from the Main Range in the Pyrenees, and for five forests located in the southern Peripheral Ranges where summer drought is more pronounced. The radial growth of silver-fir in this region is constrained by water stress during the summer previous to growth, as suggested by the negative relationship with previous September temperature and, to a lesser degree, by a positive relationship with previous end of summer precipitation. Climatic data showed a warming trend since the 1970s across the Pyrenees, with more severe summer droughts. The recent warming changed the climate-growth relationships, causing higher growth synchrony among sites, and a higher year-to-year growth variation, especially in the southernmost forests. Moving-interval response functions suggested an increasing water-stress effect on radial growth during the last half of the 20th century. The growth period under water stress has extended from summer up to early autumn. Forests located in the southern Peripheral Ranges experienced a more intense water stress, as seen in a shift of their response to precipitation and temperature. The Main-Range sites mainly showed a response to warming. The intensification of water-stress during the late 20th century might affect the future growth performance of the highly-fragmented A. alba populations in the southwestern distribution limit of the species.

  15. Process-based modelling to evaluate simulated groundwater levels and frequencies in a Chalk catchment in south-western England

    Brenner, Simon; Coxon, Gemma; Howden, Nicholas J. K.; Freer, Jim; Hartmann, Andreas

    2018-02-01

    Chalk aquifers are an important source of drinking water in the UK. Due to their properties, they are particularly vulnerable to groundwater-related hazards like floods and droughts. Understanding and predicting groundwater levels is therefore important for effective and safe water management. Chalk is known for its high porosity and, due to its dissolvability, exposed to karstification and strong subsurface heterogeneity. To cope with the karstic heterogeneity and limited data availability, specialised modelling approaches are required that balance model complexity and data availability. In this study, we present a novel approach to evaluate simulated groundwater level frequencies derived from a semi-distributed karst model that represents subsurface heterogeneity by distribution functions. Simulated groundwater storages are transferred into groundwater levels using evidence from different observations wells. Using a percentile approach we can assess the number of days exceeding or falling below selected groundwater level percentiles. Firstly, we evaluate the performance of the model when simulating groundwater level time series using a spilt sample test and parameter identifiability analysis. Secondly, we apply a split sample test to the simulated groundwater level percentiles to explore the performance in predicting groundwater level exceedances. We show that the model provides robust simulations of discharge and groundwater levels at three observation wells at a test site in a chalk-dominated catchment in south-western England. The second split sample test also indicates that the percentile approach is able to reliably predict groundwater level exceedances across all considered timescales up to their 75th percentile. However, when looking at the 90th percentile, it only provides acceptable predictions for long time periods and it fails when the 95th percentile of groundwater exceedance levels is considered. By modifying the historic forcings of our model

  16. Asymptomatic bacteriuria among elderly and middle-aged rural community-dwellers in South-Western Nigeria

    Olowe OA

    2013-07-01

    Full Text Available OA Olowe,1 OB Makanjuola,1 KO Olabiyi,1 PO Akinwusi,2 CO Alebiosu,2 MA Isawumi,3 MB Hassan,3 EO Asekun-Olarinmoye,4 WO Adebimpe,4 TA Adewole5 1Department of Medical Microbiology and Parasitology, 2Department of Medicine, 3Department of Ophthalmology, 4Department of Community Medicine, 5Department of Biochemistry, College of Health Sciences, Osun State University, Osogbo, Osun State, Nigeria Abstract: Asymptomatic bacteriuria in elderly individuals has been well described in institutionalized settings, but to a lesser extent in the community. The purpose of this study was to determine the pathogens responsible for asymptomatic bacteriuria in elderly and middle-aged individuals in Alajue-Ede, South-Western Nigeria, and to identify any associated factors. Mid-stream urine samples were collected from apparently healthy elderly and middle-aged volunteers who were participating in community health screening. Samples were processed and bacterial isolates were identified following standard procedures. In total, 128 volunteers (48 men, 76 women participated in the study. Twenty-eight (22.6% urinary pathogens were isolated, comprising Klebsiella species in five (17.9%, Pseudomonas aeruginosa in one (3.6%, Escherichia coli in 19 (67.9%, and Proteus species in three (10.7% cases. Women were identified as being at higher risk of asymptomatic bacteriuria, and the prevalence also increased with increasing age in men. The elderly in this community have a high prevalence of asymptomatic bacteriuria, and screening for comorbid medical conditions may be of benefit. Keywords: asymptomatic bacteriuria, urinary pathogens, elderly, urinary tract infection

  17. Indoor inhalation dose estimates due to radon and thoron in some areas of South-Western Punjab (India))

    Kumar, S.; Singh, S.; Bajwa, B. S.; Singh, B.; Sabharwal, A. D.; Eappen, K. P.

    2008-01-01

    LR-115 (type II)-based radon-thoron discriminating twin-chamber dosemeters have been used for estimating radon 222 Rn) and thoron 220 Rn) concentrations in dwellings of south-western Punjab (India)). The present study region has shown pronounced cases of cancer incidents in the public [Thakur, Rao, Rajwanshi, Parwana and Kumar (Epidemiological study of high cancer among rural agricultural community of Punjab in Northern India. Int J Environ Res Public Health 2008; 5(5):399-407) and Kumar et al. (Risk assessment for natural uranium in subsurface water of Punjab state (India)). Hum Ecol Risk Assess 2011;17:381-93)]. Radon being a carcinogen has been monitored in some dwellings selected randomly in the study area. Results show that the values of radon 222 Rn) varied from 21 to 79 Bq m -3 , with a geometric mean of 45 Bq m -3 [geometric standard deviation (GSD 1.39)], and those of thoron 220 Rn) from minimum detection level to 58 Bq m -3 with a geometric mean of 19 Bq m -3 (GSD 1.88). Bare card data are used for computing the progeny concentration by deriving the equilibrium factor (F) using a root finding method [Mayya, Eappen and Nambi (Methodology for mixed field inhalation dosimetry in monazite areas using a twin-cup dosemeter with three track detectors. Radiat Prot Dosim 1998; 77(3): 177-84)]. Inhalation doses have been calculated and compared using UNSCEAR equilibrium factors and by using the calculated F-values. The results show satisfactory comparison between the values. (authors)

  18. Meteorological and hydrological extremes derived from taxation records: case study for south-western Moravia (Czech Republic)

    Chromá, Kateřina; Brázdil, Rudolf; Valášek, Hubert; Zahradníček, Pavel

    2013-04-01

    Meteorological and hydrological extremes (MHEs) cause great material damage or even loss of human lives in the present time, similarly as it was in the past. In the Czech Lands (recently the Czech Republic), systematic meteorological and hydrological observations started generally in the latter half of the 19th century. Therefore, in order to create long-term series of such extremes, it is necessary to search for other sources of information. Different types of documentary evidence are used in historical climatology and hydrology to find such information. Some of them are related to records connected with taxation system. The taxation system in Moravia allowed farmers to request tax relief if their crops have been damaged by MHEs. The corresponding documents contain information about the type of extreme event and the date of its occurrence; often also impacts on crops or land may be derived. The nature of events leading to damage include particularly hailstorms, torrential rain, flash floods, floods (in regions along larger rivers), less frequently windstorms, late frosts and in some cases also information about droughts or extreme snow depths. However, the results obtained are influenced by uncertainties related to taxation records - their temporal and spatial incompleteness, limitation of the MHEs occurrence in the period of main agricultural work (May-August) and the purpose for which they were originally collected (primarily tax alleviation, i.e. information about MHEs was of secondary importance). All these aspects related to the study of MHEs from taxation records are demonstrated for five estates (Bítov, Budkov, Jemnice with Staré Hobzí, Nové Syrovice and Uherčice) in the south-western part of Moravia for the 18th-19th centuries. The analysis shows importance of taxation records for the study of past MHEs as well as great potential for their use.

  19. Pattern of antimicrobial usage in livestock animals in south-western Nigeria: The need for alternative plans

    Hezekiah K. Adesokan

    2015-04-01

    Full Text Available Resistance to antibiotics has continued to increase, placing future animal and human disease management in real danger. The developing countries characterised by widespread indiscriminate antibiotic use and in which ‘third-generation’ antibiotics are not readily available or affordable are the worst affected. A 3-year (2010–2012 retrospective survey of antibiotic usage in livestock production in three selected states of south-western Nigeria was conducted. Data obtained from eight purposively selected licensed veterinary pharmaceutical sales establishments in the area, based on keeping detailed sales records for the study period, were analysed using Stata Version 12. Results showed that tetracyclines (33.6%, fluoroquinolones (26.5% and beta-lactams/aminoglycosides (20.4% constituted the majority of the antibiotics used over the 3 years. The differences in the quantities of antibiotic types used within each antimicrobial class were statistically significant for tetracyclines (F = 59.87; p < 0.0001 and fluoroquinolones (F = 43.97; p < 0.0001 but not for beta-lactams/aminoglycosides (F = 3.21; p = 0.148. Furthermore, antibiotic consumption increased by 40.4% between 2010 and 2012. Although statistically insignificant (F = 0.277; p = 0.762, the increasing trend across the years was at rates of 23.5% between 2010 and 2011 and 13.8% between 2011 and 2012. In addition, the findings show a significantly higher consumption rate (t = 15.21; df = 5; p < 0.0001 during the rainy (52.5% than the dry (47.5% seasons. The current increasing trend in antibiotic usage holds a serious danger for the future and therefore calls for alternative plans to safeguard future livestock production, food security and human health. This becomes more imperative considering emerging resistance against tetracyclines and fluoroquinolones, the foremost remedies for livestock diseases in most developing countries.

  20. 14 C dating and isotopic composition of lacustrine sediment in the Vale do Ribeira, south-western Sao Paulo State

    Saia, Soraya E.M.G.; Pessenda, Luiz C.R.; Gouveia, Susy E.M.; Vidotto, Elaine; Ledru, Marie-Pierre; Karmann, Ivo; Amaral, Paula G.; Bendassoli, Jose A.

    2005-01-01

    This work is part of a multi and interdisciplinary study involving paleoenvironmental records based on systematic and joint actions of pollen, isotopic composition ( 12 C, 13 C and 14 N, 15 N) and 14 C dating of lacustrine sediment. Samplings have been made in the Lagoa Grande located at Parque Estadual de Turismo do Alto Ribeira - PETAR, in the Vale do Ribeira, south-western Sao Paulo state. This integration must improve significantly the studies of vegetation and climate changes that occurred during the Late Pleistocene in the southeastern region of Brazil. The δ 13 C results of lacustrine sediment presented values from -23 to -30 per mille with isotopic tendencies of enrichment-depletion in the whole profile. The highest values of total organic carbon (TOC) and C/N associated with depleted δ 13 C values, were linked to organic matter from C 3 land plant and interpreted as the presence of denser arboreal vegetation around the lake. The smallest values of TOC and C/N associated with enriched δ 13 C values were linked to phytoplanktonic influence and/or the presence of less dense arboreal vegetation around the lake. These fluctuations reflect changes in quality and quantity of sedimentary organic matter linked to vegetation changes and the production of organic matter within the sedimentation basin connected with lake level variations. The combination of C/N and δ 13 C data on a cross-plot diagram shows a general distribution of points lying close to the planktonic (algal) organic matter. However, the scattering of certain points indicates a slight contribution from C 3 land plants. The variations in arboreal pollen (%AP) along the core are characterized by AP values between 40 and 80%. The 14C dating indicated Modern age at the shallow horizons to 1,030 years BP for the deeper horizon. (author)

  1. Knowledge, attitudes and practices of traceability among livestock traders in south-western Nigeria: implications for sustainable livestock industry.

    Adesokan, Hezekiah K; Ocheja, Samuel E

    2014-01-01

    Livestock diseases and other animal health events are a threat to achieving sustainable livestock industry. The knowledge of trace-back and the practice of providing feedback on diseases encountered in slaughtered animals from the abattoir to the farm can help limit the spread as well as manage potential future incidents of such diseases. We assessed the knowledge, attitudes and practices of 200 willing livestock traders on traceability in Bodija Municipal Abattoir, south-western Nigeria. The results reveal that the majority of these traders had poor knowledge (79.5 %) and practices (74.0 %) of traceability, though 89.5 % demonstrated good attitudes. While 22.9 % knew that traceability could be an effective means to control diseases, only a lower proportion (9.0 %) knew the health status of the animals being purchased. Though 29.0 % reported the diseases encountered in their animals during slaughter to the farm, only 9.5 % followed up to ensure the farmers take steps at preventing further occurrence of the reported diseases. While age (p = 0.000; 0.014) and education (p = 0.000; 0.000) were both significant for good knowledge and attitudes, frequency of condemned cases (p = 0.000) and length of years in the trade (p = 0.004) were, respectively, significant for good knowledge and attitudes with none associated with practice. These poor levels of knowledge and practices of traceability are a threat to sustainable livestock industry, food security and human health; hence, there is an urgent need to institute national feedback mechanism on slaughtered animals in order to strengthen interventions against diseases at farm levels.

  2. Sero-epidemiological survey and risk factors associated with brucellosis in dogs in south-western Nigeria.

    Ayoola, Modupe Comfort; Ogugua, Akwoba Joseph; Akinseye, Victor Oluwatoyin; Joshua, Tunde Olu; Banuso, Morenikeji Folusho; Adedoyin, Folashade Julianah; Adesokan, Hezekiah Kehinde; Omobowale, Temidayo Olutayo; Abiola, John Olusoji; Otuh, Patricia Ihuaku; Nottidge, Helen Oyebukola; Dale, Emma-Jane; Perrett, Lorraine; Taylor, Andrew; Stack, Judy; Cadmus, Simeon Idowu Babalola

    2016-01-01

    In Nigeria, there is limited information on brucellosis particularly in dogs, despite its public health implications. We undertook a sero-epidemiological survey of brucellosis in dogs to determine the prevalence of the disease and associated risk factors for its occurrence in Nigeria. A cross-sectional study was conducted to screen dogs in south-western Nigeria for antibodies to Brucella sp using the rapid slide agglutination test (RSA) and Rose Bengal test (RBT), with positive samples confirmed respectively by serum agglutination test (SAT) and competitive enzyme linked immunosorbent assay (cELISA). Data were analyzed with STATA-12. From the 739 dog sera tested, 81 (10.96%) were positive by RSA and 94 (12.72%) by RBT; these were corroborated with SAT (4/81; 4.94%) and cELISA (1/94; 1.06%), respectively. Logistic regression identified location (OR=0.04; 95% CI: 0.02-0.09), breed (OR=1.71; 95% CI: 1.34-2.19), age (OR=0.10; 95% CI: 0.04-0.30) and management system (OR=8.51; 95% CI: 1.07-68.05) as risk factors for Brucella infection by RSA. However, location (OR=10.83; 95% CI: 5.48-21.39) and history of infertility (OR=2.62; 95% CI: 1.41-4.84) were identified as risk factors using RBT. Given the 10.96% to 12.72% seroprevalence of brucellosis recorded in this study, we advocate control of the disease in dogs, and public health education for those at risk of infection. Again, further studies are required to elucidate the role of dogs in the epidemiology of brucellosis in Nigeria considering the conducive human-animal interface and ecological factors responsible for the transmission of the disease.

  3. Massification to Marketization of Higher Education: Private University Education in Bangladesh

    Ahmed, Jashim Uddin

    2016-01-01

    Massification of higher education is a contemporary phenomenon, and Bangladesh is an excellent example of massification in the sector. With increased alertness worldwide among nations, policy-makers and development bodies, massification of higher education is a requirement of time. Increasing number of youth also contribute to the phenomenon…

  4. Exploring infant feeding practices: cross-sectional surveys of South Western Sydney, Singapore, and Ho Chi Minh City.

    Leow, Timothy Yong Qun; Ung, Andrew; Qian, Shelley; Nguyen, Jessie Thanh; An, Yvonne; Mudgil, Poonam; Whitehall, John

    2017-06-13

    Infant feeding practices are known to influence the child's long-term health. Studies have associated obesity and other diseases with reduced breastfeeding and early introduction of high calorie beverages (HCBs). The rising prevalence of obesity is already a problem in most developed countries, especially Australia, but cultural differences are influential. Our aim is to examine and compare infant feeding practices and educational levels of respondents through questionnaires in three culturally different sites: Campbelltown (South Western Sydney), Australia, Singapore and Ho Chi Minh City, Vietnam (HCMC). Consenting parents and carers (aged ≥18 years old) of at least one child (≤6 years old) were recruited from paediatric clinics in Campbelltown, Singapore and HCMC. Participants completed an infant feeding practices questionnaire regarding breastfeeding, beverage and solid initiation in addition to the parent's ethnicity, age, and educational level. Data was analysed quantitatively using SPSS. Two hundred eighty-three participants were recruited across the three sites, HCMC (n = 84), Campbelltown (n = 108), and Singapore (n = 91). 237 (82.6%) children were breastfed but in all only 100 (60.2%) were exclusively breastfed for five months or more. There was a statistical difference in rates of breast feeding between each region. HCMC (n = 18, 21.4%) had the lowest, followed by Campbelltown (n = 35, 32.4%), and then Singapore (n = 47, 51.7%). There was also a difference in rates of introduction of HCBs by 3 years of age, with those in HCMC (n = 71, 84.5%) were higher than Campbelltown (n = 71, 65.8%) and Singapore (n = 48, 52.8%). The educational level of respondents was lower in Vietnam where only 46.4% (n = 39) had completed post-secondary education, compared to 75.0% (n = 81) in Campbelltown and 75.8% (n = 69) in Singapore. Rates of breast feeding were inversely correlated with rates of introduction of HCB and positively related to

  5. Tropical Peat and Peatland Development in the Floodplains of the Greater Pamba Basin, South-Western India during the Holocene.

    Kumaran, Navnith K P; Padmalal, Damodaran; Limaye, Ruta B; S, Vishnu Mohan; Jennerjahn, Tim; Gamre, Pradeep G

    2016-01-01

    Holocene sequences in the humid tropical region of Kerala, South-western (SW) India have preserved abundance of organic-rich sediments in the form of peat and its rapid development in a narrow time frame towards Middle Holocene has been found to be significant. The sub-coastal areas and flood plains of the Greater Pamba Basin have provided palaeorecords of peat indicating that the deposits are essentially formed within freshwater. The combination of factors like stabilized sea level and its subsequent fall since the Middle Holocene, topographic relief and climatic conditions led to rapid peat accumulation across the coastal lowlands. The high rainfall and massive floods coupled with a rising sea level must have inundated > 75% of the coastal plain land converting it into a veritable lagoon-lake system that eventually led to abrupt termination of the forest ecosystem and also converted the floodplains into peatland where accumulation of peat almost to 2.0-3.0 m thickness in coastal lowlands and river basins during the shorter interval in the Middle Holocene. Vast areas of the coastal plains of Kerala have been converted into carbon rich peatland during the Middle Holocene and transforming the entire coastal stretch and associated landforms as one of the relatively youngest peatlands in the extreme southern tip of India. Unlike the uninterrupted formation of peatlands of considerable extent during the Holocene in Southeast Asia, the south Peninsular Indian region has restricted and short intervals of peatlands in the floodplains and coastal lowlands. Such a scenario is attributed to the topographic relief of the terrain and the prevailing hydrological regimes and environmental conditions as a consequence of monsoon variability since Middle Holocene in SW India. Considering the tropical coastal lowlands and associated peatlands are excellent repositories of carbon, they are very important for regional carbon cycling and habitat diversity. The alarming rate of land

  6. Evaluation of blood reservation and use for caesarean sections in a tertiary maternity unit in south western Nigeria

    Oshodi Yussuf A

    2010-09-01

    Full Text Available Abstract Background Haemorrhage from obstetric causes is the most common cause of maternal mortality in the developing world. Prevention of mortality from haemorrhage will necessarily involve prompt blood transfusions among other life saving measures. There are however limited stocks of fresh or stored blood in many health care facilities in Sub Saharan Africa. Caesarean section has been identified as a common indication for blood transfusion in obstetrics practice and its performance is often delayed by non availability of blood in our centre. An evaluation of blood reservation and use at caesarean sections in a tertiary maternity unit in Lagos, south western Nigeria should therefore assist in formulating the most rational blood transfusion policies. Methods Case records of 327 patients who had elective and emergency caesarian sections at the Lagos State University Teaching Hospital between 1st October and 31st December 2007 were reviewed. Data pertaining to age, parity, booking status, type and indication for Caesarean section, pre- and post-operative packed cell volume, blood loss at surgery, units of blood reserved in the blood bank, unit(s of blood transfused and duration of hospital stay was extracted and the data analysed. Results There were 1056 deliveries out of which 327 (31% were by Caesarean section. During the study period, a total of 654 units of blood were reserved in the blood bank and subsequently made available in theatre. Out of this number, only 89 (13.6% were transfused to 41 patients. Amongst those transfused, twenty-six (54% were booked and 31 (75.6% had primary caesarian section. About 81% of those transfused had emergency caesarean section. The most common indication for surgery among those transfused were placenta praevia (9 patients with 21 units of blood and cephalo-pelvic disproportion (8 patients with 13 units. Conclusion Even though a large number of units of blood was reserved and made available in the theatre at

  7. Urban-rural disparities in the nutritional status of school adolescent girls in the Mizan district, south-western Ethiopia.

    Berheto, Tezera M; Mikitie, Wondafrash K; Argaw, Alemayehu

    2015-01-01

    Malnutrition that occurs during adolescence has important consequences for the future growth and development of the individual, particularly in girls in developing countries. Besides limiting growth, adolescent malnutrition has important consequences for society. Despite this, there is a lack of information on the nutritional status of adolescent girls in Ethiopia. This study was therefore performed to help redress this lack of data and to provide information for future improvements by health planners and policy makers. A comparative cross-sectional study design was employed to determine the urban-rural disparity in nutritional status of adolescent school girls in the Mizan district in south-western Ethiopia. A two-stage sampling procedure was used to randomly select 622 adolescent girls, 311 each from urban and rural locations. Trained field workers used structured questionnaires to obtain the desired information from the respondents. Anthropometric measurements of height and weight were collected using standard procedures and appropriate quality control measures. Height-for-age Z-scores and body mass index (BMI)-for-age Z-scores were generated using AnthroPlus software. The independent sample t-test and χ2 test were used to determine statistical significance. There were no significant differences in the ages or physical activities of the two populations of girls studied. Consumption of cereal, vegetables, sweets, sugars, fats, meat, and eggs was similar between the two groups, although slight differences were found with regard to legumes, milk, and fruit consumption. No significant differences were found in the prevalence of mild underweight girls and overweight girls in the urban and rural groups (26.5% vs 22.3% and 7.5% vs 5.2%, respectively). Significant stunting was, however, present in the rural population (40.9% vs. 17.8% in the urban group). Although overall lower than the reference data provided by WHO, the mean BMI-for-age Z-scores and height-for-age Z

  8. Contrasted accumulation patterns of persistent organic pollutants and mercury in sympatric tropical dolphins from the south-western Indian Ocean

    Dirtu, Alin C.; Malarvannan, Govindan; Das, Krishna; Dulau-Drouot, Violaine; Kiszka, Jeremy J.; Lepoint, Gilles; Mongin, Philippe; Covaci, Adrian

    2016-01-01

    Due to their high trophic position and long life span, small cetaceans are considered as suitable bioindicators to monitor the presence of contaminants in marine ecosystems. Here, we document the contamination with persistent organic pollutants (POPs) and total mercury (T-Hg) of spinner (Stenella longirostris, n =21) and Indo-Pacific bottlenose dolphins (Tursiops aduncus, n=32) sampled from the coastal waters of La Réunion (south-western Indian Ocean). In addition, seven co-occurring teleost fish species were sampled and analyzed as well. Blubber samples from living dolphins and muscle from teleosts were analyzed for polychlorinated biphenyls (PCBs), DDT and metabolites (DDTs), chlordanes (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). Methoxylated PBDEs (MeO-PBDEs), reported as having a natural origin, were also analyzed. T-Hg levels were measured in blubber and skin biopsies of the two dolphin species. Stable isotopes δ 13 C and δ 15 N values were determined in skin of the dolphins and in the muscle of teleosts. For PCBs, HCHs and T-Hg, concentrations were significantly higher in T. aduncus than in S. longirostris. For other POP levels, intra-species variability was high. MeO-PBDEs were the dominant compounds (55% of the total POPs) in S. longirostris, while PCBs dominated (50% contribution) in T. aduncus. Other contaminants showed similar profiles between the two species. Given the different patterns of POPs and T-Hg contamination and the δ 15 N values observed among analyzed teleosts, dietary and foraging habitat preferences most likely explain the contrasted contaminant profiles observed in the two dolphin species. Levels of each class of contaminants were significantly higher in males than females. Despite their spatial and temporal overlap in the waters of La Réunion, S. longirostris and T. aduncus are differently exposed to contaminant accumulation. - Highlights: • POPs and total Hg were

  9. Contrasted accumulation patterns of persistent organic pollutants and mercury in sympatric tropical dolphins from the south-western Indian Ocean

    Dirtu, Alin C. [Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Department of Chemistry, “Al. I. Cuza” University of Iasi, 700506 Iasi (Romania); Malarvannan, Govindan [Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Das, Krishna [University of Liege, MARE Center, Laboratory for Oceanology, 4000 Liege (Belgium); Dulau-Drouot, Violaine [Groupe Local d’Observation et d’Identification des Cétacés (GLOBICE), 30 Chemin Parc Cabris, Grand Bois, 97410 Saint Pierre, La Réunion (France); Kiszka, Jeremy J. [Marine Sciences Program, Department of Biological Sciences, Florida International University, 3000 NE 151st, North Miami, FL 33181 (United States); Lepoint, Gilles [University of Liege, MARE Center, Laboratory for Oceanology, 4000 Liege (Belgium); Mongin, Philippe [Brigade Nature Océan Indien (BNOI)/ONCFS, 12 Allée de la Foret – Parc de la Providence, 97400 Saint Denis, La Réunion (France); Covaci, Adrian, E-mail: adrian.covaci@uantwerpen.be [Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2016-04-15

    Due to their high trophic position and long life span, small cetaceans are considered as suitable bioindicators to monitor the presence of contaminants in marine ecosystems. Here, we document the contamination with persistent organic pollutants (POPs) and total mercury (T-Hg) of spinner (Stenella longirostris, n =21) and Indo-Pacific bottlenose dolphins (Tursiops aduncus, n=32) sampled from the coastal waters of La Réunion (south-western Indian Ocean). In addition, seven co-occurring teleost fish species were sampled and analyzed as well. Blubber samples from living dolphins and muscle from teleosts were analyzed for polychlorinated biphenyls (PCBs), DDT and metabolites (DDTs), chlordanes (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). Methoxylated PBDEs (MeO-PBDEs), reported as having a natural origin, were also analyzed. T-Hg levels were measured in blubber and skin biopsies of the two dolphin species. Stable isotopes δ{sup 13}C and δ{sup 15}N values were determined in skin of the dolphins and in the muscle of teleosts. For PCBs, HCHs and T-Hg, concentrations were significantly higher in T. aduncus than in S. longirostris. For other POP levels, intra-species variability was high. MeO-PBDEs were the dominant compounds (55% of the total POPs) in S. longirostris, while PCBs dominated (50% contribution) in T. aduncus. Other contaminants showed similar profiles between the two species. Given the different patterns of POPs and T-Hg contamination and the δ{sup 15}N values observed among analyzed teleosts, dietary and foraging habitat preferences most likely explain the contrasted contaminant profiles observed in the two dolphin species. Levels of each class of contaminants were significantly higher in males than females. Despite their spatial and temporal overlap in the waters of La Réunion, S. longirostris and T. aduncus are differently exposed to contaminant accumulation. - Highlights: • POPs and total

  10. Women as whole blood donors: offers, donations and deferrals in the province of Huelva, south-western Spain.

    Prados Madrona, Dalmiro; Fernández Herrera, María Dolores; Prados Jiménez, Dalmiro; Gómez Giraldo, Sonsoles; Robles Campos, Rita

    2014-01-01

    Women seem more willing to donate blood than men despite the limitations that affect their donation rate. The aim of our study was to determine the role of women in altruistic donation of blood in Huelva, a province in south-western Spain. We registered 87,601 offers to donate whole blood between January 1st, 2005 and December 31st, 2009. We statistically analysed variables such as sex, age, offers, deferrals and donations, problems in venous access, vasovagal reactions, weight and blood pressure to establish their significance according to donor gender. With regards to gender, 52.3% of donors were women and 47.7% men. Of the 87,601 offers to donate blood, 46.5% were from females and 53.5% from males. More females than males made their first donation during the study period. However, 43.9 % of donations were from women, whereas 56.1% were from men. Overall 8.7% of offers were deferred, 62.7% of which due to a low haemoglobin concentration, which was the most frequent cause of deferral in women. Difficulties in venous access and vasovagal reactions were also more frequent in female donors than in male donors. By the end of the study period, donor fidelity was 58.6% for men and 48.6% for women. In the province of Huelva, women are more altruistically inclined than men to give blood, with the percentages of donors and first-time donors being higher among females. However, there are restrictions to women giving blood, especially low haemoglobin concentration, which reduce the number of female blood donations. Women also have more difficulty when blood is withdrawn and are more susceptible to vasovagal reactions, which negatively affect their experience as donors. Measures should be taken to reduce these barriers to encourage women to continue to offer to donate blood, thereby ensuring that they become regular donors, which is a key factor in guaranteeing an adequate supply of blood within the region of Andalusia.

  11. Tropical Peat and Peatland Development in the Floodplains of the Greater Pamba Basin, South-Western India during the Holocene.

    Navnith K P Kumaran

    Full Text Available Holocene sequences in the humid tropical region of Kerala, South-western (SW India have preserved abundance of organic-rich sediments in the form of peat and its rapid development in a narrow time frame towards Middle Holocene has been found to be significant. The sub-coastal areas and flood plains of the Greater Pamba Basin have provided palaeorecords of peat indicating that the deposits are essentially formed within freshwater. The combination of factors like stabilized sea level and its subsequent fall since the Middle Holocene, topographic relief and climatic conditions led to rapid peat accumulation across the coastal lowlands. The high rainfall and massive floods coupled with a rising sea level must have inundated > 75% of the coastal plain land converting it into a veritable lagoon-lake system that eventually led to abrupt termination of the forest ecosystem and also converted the floodplains into peatland where accumulation of peat almost to 2.0-3.0 m thickness in coastal lowlands and river basins during the shorter interval in the Middle Holocene. Vast areas of the coastal plains of Kerala have been converted into carbon rich peatland during the Middle Holocene and transforming the entire coastal stretch and associated landforms as one of the relatively youngest peatlands in the extreme southern tip of India. Unlike the uninterrupted formation of peatlands of considerable extent during the Holocene in Southeast Asia, the south Peninsular Indian region has restricted and short intervals of peatlands in the floodplains and coastal lowlands. Such a scenario is attributed to the topographic relief of the terrain and the prevailing hydrological regimes and environmental conditions as a consequence of monsoon variability since Middle Holocene in SW India. Considering the tropical coastal lowlands and associated peatlands are excellent repositories of carbon, they are very important for regional carbon cycling and habitat diversity. The

  12. Characterization of the non-polio enterovirus infections associated with acute flaccid paralysis in South-Western India.

    Rongala Laxmivandana

    Full Text Available Non-polio enteroviruses (NPEVs have been reported frequently in association with acute flaccid paralysis (AFP cases during Polio Surveillance Programs (PSPs worldwide. However, there is limited understanding on the attributes of their infections. This study reports characteristics of NPEVs isolated from AFP cases, investigated during PSPs held in 2009-2010, in Karnataka and Kerala states of south-western India having varied climatic conditions. NPEV cell culture isolates derived from stool specimens that were collected from 422 of 2186 AFP cases (<1-14 years age and 17 of 41 asymptomatic contacts; and details of all AFP cases/contacts were obtained from National Polio Laboratory, Bangalore. The distribution of NPEV infections among AFP cases and circulation pattern of NPEV strains were determined by statistical analysis of the data. Genotyping of all NPEV isolates was carried out by partial VP1 gene sequencing and phylogenetic analysis. NPEV positive AFP cases were significantly higher in children aged <2 years; with residual paralysis; in summer months; and in regions with relatively hot climate. Genotyping of NPEVs identified predominance of human enteroviruses (HEV-B species [81.9%-Echoviruses (E: 57.3%; coxsackieviruses (CV B: 15%; numbered EVs: 8.9%; CVA9: 0.7%] and low levels of HEV-A [14.5%-CVA: 6%; numbered EVs: 8.5%] and HEV-C [3.6%-CVA: 2.6%; numbered EVs: 1%] species, encompassing 63 genotypes. EV76 (6.3% and each of E3, CVB3 and E9 (4.97% were found frequently during 2009 while E11 (6.7%, CVB1 (6.1%, E7 (5.1% and E20 (5.1% were detected commonly in 2010. A marked proportion of AFP cases from children aged <2 years; presenting with fever; and from north and south interior parts of Karnataka state was detected with E/numbered EVs than that found with CVA/CVB. This study highlights the extensive genetic diversity and diverse circulation patterns of NPEV strains in AFP cases from different populations and climatic conditions.

  13. New DDT inputs after 30 years of prohibition in Spain. A case study in agricultural soils from south-western Spain

    Munoz-Arnanz, Juan; Jimenez, Begona

    2011-01-01

    This study provides information on the current status of contamination by DDT in agricultural soils in south-western Spain. A recent use of technical DDT in at least 17% of the soils was found based on the values ( p,p ' /p,p ' =[p,p ' -DDE+p,p ' -DDD]/[p,p ' -DDT]. According to the ratio R o,p ' /p,p ' =[o,p ' -DDT]/[p,p ' -DDT], a dicofol type contamination was detected in about 27% of the soils. A wide range of concentrations was observed (0.08-11.1 ng/g d.w.) regardless of the type of crop soil. Enantiomeric fractions (EFs), based on the chiral analysis of o,p'-DDT residues differed from the racemic value (0.500) in most soils but they were not correlated with the study variables [DDTs], SOM, R p,p ' /p,p ' and R o,p ' /p,p ' . Given the health risks posed by DDT, our findings support how the environmental control of legacy pollutants such as DDT cannot be neglected. - Highlights: → Fresh technical DDT inputs detected in agricultural soils. → A Dicofol type contamination was found in agricultural soils from south-western Spain. → EFs of o,p'-DDT do not provide a good measure for overall DDT degradation. - Based on the isomeric ratio R p,p ' /p,p ' , a plausible recent input of technical DDT was found in agricultural soils from south-western Spain after more than 30 years of DDT ban.

  14. Four new species of the genus Mannerheimia Mäklin, 1880 (Coleoptera: Staphylinidae: Omaliinae) from south-western China and Taiwan.

    Shavrin, Alexey V

    2018-04-12

    Four new species of the genus Mannerheimia Mäklin, 1880 from south-western China and Taiwan are described and illustrated: M. grandilobata Shavrin, sp.n. (China: Yunnan), M. emeishanensis Shavrin, sp.n. (China: Sichuan), M. maculata Shavrin, sp.n. (China: Yunnan) and M. taiwanica Shavrin, sp.n. (Taiwan: Taichung Hsien, Nantou Hsien), the first records of the genus from China and Taiwan. A key to species known from China and Taiwan and distributional maps for each species are provided.

  15. Multielement instrumental neutron activation analysis of macroalgae Cystoseira used as biomonitor of the Black Sea coastal waters pollution (South-Western Crimea, Sevastopol)

    Kravtsova, A.V.; Mil'chakova, N.A.; Frontas'eva, M.V.

    2013-01-01

    For the first time for Sevastopol region the peculiarities of 26 (Na, Mg, Al, Cl, K, Ca, Sc, V, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Sb, I, Cs, Ba, Sm, Nd, Ag, Au and U) macro- and microelements accumulation in the thalli of brown algae Cystoseira from the coastal waters of south-western Crimea (the Black Sea) were studied using instrumental neutron activation analysis (INAA). The possibility of using brown algae Cystoseira as a biomonitor of coastal waters pollution was shown

  16. Massification and Quality Assurance in Tertiary Education: The ...

    The study sets out to examine massification and its impact on quality assurance in tertiary education and the extent to which lecturer–student ratio, adequacy of infrastructure and pedagogical resources affect quality in tertiary institutions. Two research questions and one hypothesis were posed to guide the investigation.

  17. An Andean type Palaeozoic convergence in the Bohemian Massif

    Schulmann, K.; Konopásek, J.; Janoušek, V.; Lexa, O.; Lardeaux, J.-M.; Edel, J.-B.; Štípská, P.; Ulrich, Stanislav

    2009-01-01

    Roč. 341, č. 2-3 (2009), s. 266-286 ISSN 1631-0713 Institutional research plan: CEZ:AV0Z30120515 Keywords : Bohemian Massif * Saxothuringian oceanic subduction * building of Variscan orogenic root system * channel flow Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.931, year: 2009

  18. Grass survey of the Itremo Massif records endemic central highland ...

    Twenty species are endemic to the central highlands, and a further 1 4 species are restricted to Madagascar. Five ecological groups of grasses were identified in the Itremo Massif: shade species in gallery forests, open wet area species, fire grasses, anthropogenic disturbance associated grasses and rock-dwelling grasses.

  19. Anti-malarial drug safety information obtained through routine monitoring in a rural district of South-Western Senegal

    Brasseur Philippe

    2012-12-01

    Full Text Available Abstract Background Knowing the safety profile of anti-malarial treatments in routine use is essential; millions of patients receive now artemisinin combination therapy (ACT annually, but the return on information through current systems is as yet inadequate. Cohort event monitoring (CEM is a WHO (World Health Organization-recommended practice; testing its performance and feasibility in routine practice in malaria-endemic is important. Methods A nine-year CEM-based study of the safety of artesunate-amodiaquine (ASAQ at five peripheral health facilities in a rural district of South-western Senegal. Staff (nurses, health workers were trained to collect actively and systematically information on the patient, treatment and events on a purposely designed questionnaire. The occurrence and severity of events was collected before, during and after treatment up to 28 days in order to generate information on all adverse events (AEs as well as treatment-emerging signs/symptoms (TESS. Laboratory tests (haematology, liver and renal was planned for at least 10% of cases. Results During 2001–2009, 3,708 parasitologically-confirmed malaria cases (mean age = 16.0 ± 12.7 years were enrolled (26% and 52% of all and parasitologically-confirmed ASAQ treatments, respectively. Treatment was supervised in 96% of cases. Products changed over time: 49% were a loose combination of individually-packaged products (available 2001–03, 42% co-blistered products (2004–09 and 9% a fixed-dose co-formulation (2006–09; dosing was age-based for 42%, weight-based for 58%. AS and AQ were correctly dosed in 97% and 82% of cases with the loose and 93% and 86% with the fixed combination, but only 50% and 42% with the co-blistered product. Thirty-three per cent (33% of patients had at least one sign/symptom pre-treatment, 12% had at least one AE and 9% a TESS (total events 3,914, 1,144 and 693, respectively. AEs overestimated TESS by 1.2-2 fold (average 1.7. Changes in

  20. Predicting the risk of an endemic focus of Leishmania tropica becoming established in South-Western Europe through the presence of its main vector, Phlebotomus sergenti Parrot, 1917.

    Barón, S D; Morillas-Márquez, F; Morales-Yuste, M; Díaz-Sáez, V; Gállego, M; Molina, R; Martín-Sánchez, J

    2013-09-01

    The aim of the study was the construction of risk maps for exposure to Phlebotomus sergenti, the main vector of Leishmania tropica, with a view to identifying hot spots for the potential establishment of this parasite in the southwest of Europe. Data were collected on the presence/absence of this vector and the ecological and climatic characteristics of 662 sampling sites located in the southeast, centre and northeast of the Iberian Peninsula (south-western Europe). The environmental factors associated with the distribution of P. sergenti were determined. The best predictors for the presence of this dipteran were ‘altitude’, ‘land use’, ‘land surface temperature’, ‘aspect’, ‘adjacent land cover’, ‘absence of vegetation in wall’ and the ‘absence of PVC pipes in the drainage holes of retaining walls’. Risk maps for exposure to the vector were drawn up based on these variables. The validation of the predictive risk model confirmed its usefulness in the detection of areas with a high risk of P. sergenti being present. These locations represent potential hot spots for an autochthonous focus of L. tropica becoming established. The risk maps produced for P. sergenti presence revealed several areas in the centre and south of the Iberian Peninsula to be the most prone to this process, which would make it possible for the disease to enter south-western Europe.

  1. The geology of uranium in the Saint-Sylvestre granite district (Limousin, Massif Central, France); La geologie de l'uranium dans le massif granitique de Saint-Sylvestre (Limousin - Massif Central Francais)

    Marquaire, C.; Moreau, M.; Barbier, J.; Ranchin, G.; Carrat, H.G.; Coppens, R.; Senecal, J.; Koszotolanyi, C.; Dottin, H

    1969-07-01

    This report concerns the geology of uranium in Limousin, more particularly in the St-Sylvestre massif, and the related phenomena: regional geology, petrographic and geochemical zonal distribution observed in various granite massifs, uranium movement in connection with surface alteration, geochronology of uranium ore. The work is made up of six articles covering the various scientific aspects listed above. Each article is headed with an abstract. The paper comprises the following chapters: Foreword by Marcel ROUBAULT. 1. Ch. MARQUAIRE, M. MOREAU Outline of geological conditions in Northern Limousin and distribution of uraniferous occurrences. 2. J. BARBIER, G. RANCHIN, H. G. CARRAT and R. COPPENS Geology of the St-Sylvestre Massif and uranium geochemistry - Introduction to laboratory studies - Problems of methodology. 3. J. BARBIER and G. RANCHIN Petrographical and geochemical zones in the St-Sylvestre granite massif (Limousin - French 'Massif Central'). 4. J. BARBIER and G. RANCHIN Uranium geochemistry in the St-Sylvestre Massif (Limousin - French 'Massif Central') - Occurrences of primary geochemical uranium and replacement processes. 5. J. SENEGAL Monograph of the Brugeaud orebody. 6. R. COPPENS, Ch. KOSZTOLANYI and H. DOTTIN Geochronological study of the Brugeaud mine. 1969. (authors) [French] Ce memoire est consacre a la geologie de l'uranium dans le Limousin, plus specialement dans le massif de St-Sylvestre, et aux phenomenes qui s'y rattachent: geologie regionale, phenomenes de zonalite petrographique et geochimique dans certains massifs granitiques, mouvements de l'uranium lies a l'alteration superficielle, geochronologie du minerai d'uranium. L'ouvrage comprend six articles qui recouvrent les differents aspects scientifiques enumeres. Chacun de ces six articles est precede d'un resume. La composition du memoire st la suivante: Marcel ROUBAULT, Preface. 1. Ch. MARQUAIRE, M. MOREAU Esquisse geologique du

  2. The geology of uranium in the Saint-Sylvestre granite district (Limousin, Massif Central, France); La geologie de l'uranium dans le massif granitique de Saint-Sylvestre (Limousin - Massif Central Francais)

    Marquaire, C; Moreau, M; Barbier, J; Ranchin, G; Carrat, H G; Coppens, R; Senecal, J; Koszotolanyi, C; Dottin, H

    1969-07-01

    This report concerns the geology of uranium in Limousin, more particularly in the St-Sylvestre massif, and the related phenomena: regional geology, petrographic and geochemical zonal distribution observed in various granite massifs, uranium movement in connection with surface alteration, geochronology of uranium ore. The work is made up of six articles covering the various scientific aspects listed above. Each article is headed with an abstract. The paper comprises the following chapters: Foreword by Marcel ROUBAULT. 1. Ch. MARQUAIRE, M. MOREAU Outline of geological conditions in Northern Limousin and distribution of uraniferous occurrences. 2. J. BARBIER, G. RANCHIN, H. G. CARRAT and R. COPPENS Geology of the St-Sylvestre Massif and uranium geochemistry - Introduction to laboratory studies - Problems of methodology. 3. J. BARBIER and G. RANCHIN Petrographical and geochemical zones in the St-Sylvestre granite massif (Limousin - French 'Massif Central'). 4. J. BARBIER and G. RANCHIN Uranium geochemistry in the St-Sylvestre Massif (Limousin - French 'Massif Central') - Occurrences of primary geochemical uranium and replacement processes. 5. J. SENEGAL Monograph of the Brugeaud orebody. 6. R. COPPENS, Ch. KOSZTOLANYI and H. DOTTIN Geochronological study of the Brugeaud mine. 1969. (authors) [French] Ce memoire est consacre a la geologie de l'uranium dans le Limousin, plus specialement dans le massif de St-Sylvestre, et aux phenomenes qui s'y rattachent: geologie regionale, phenomenes de zonalite petrographique et geochimique dans certains massifs granitiques, mouvements de l'uranium lies a l'alteration superficielle, geochronologie du minerai d'uranium. L'ouvrage comprend six articles qui recouvrent les differents aspects scientifiques enumeres. Chacun de ces six articles est precede d'un resume. La composition du memoire st la suivante: Marcel ROUBAULT, Preface. 1. Ch. MARQUAIRE, M. MOREAU Esquisse geologique du Nord Limousin et repartition des mineralisations

  3. Uranium mineralization in the Bohemian Massif and its exploration

    Matolin, M.; Pluskal, O.; Rene, M.

    1981-01-01

    Long-term systematic and planned uranium survey including airborne, carborne, ground, logging and laboratory radiometric measurements as well as geological and geochemical investigations have shown a difference in radioactivity of two regional geological units in Czechoslovakia. The higher regional radioactivity of the Variscan granitoid rocks of the Bohemian Massif differs from that of the West Carpathians and is associated with more frequent uranium mineralization. Endogenous vein-type uranium mineralization has a spatial association with high-radioactivity granitoids in the Bohemian Massif. Airborne prospection defined rock radioactivity features on a regional scale while surface and subsurface radiometric and geological investigations using various techniques localized important uranium deposits. Complex statistical evaluation of numerous geophysical and geological data was studied in order to delineate uranium-favourable areas. (author)

  4. Hydrogeology of the Olševa massif (Slovenia

    Jure Krivic

    2002-12-01

    Full Text Available Olševa consists of highly pervious carbonates, forming a relatively big fractured and karstified aquifer. Due to its high-altitude mountainous nature, the aquifer is unpolluted and therefore has to be regarded as a potential source of drinking water for the future.The Olševa aquifer is tectonically divided into three parts. Groundwater from the two smaller aquifers, covering areas of 1,9 and 0,8 km2, located in eastern part of Ol{eva massif, flows toward Northeast into Meža river basin. In spite of several transversal faults, the rest of Olševa massif forms a relatively uniform aquifer that is conveying groundwater in westerly direction towards Rjavica valley. Rjavica valley in Austria represents the discharge area of a majority of groundwater from the main Ol{eva aquifer.

  5. Expedition 357 Preliminary Report: Atlantis Massif Serpentinization and Life

    Früh-Green, GL; Orcutt, BN; Green, S; Cotterill, C; McCaig, AM; Expedition 357 Scientists,

    2016-01-01

    International Ocean Discovery Program (IODP) Expedition 357 successfully cored an east–west transect across the southern wall of Atlantis Massif on the western flank of the Mid-Atlantic Ridge to study the links between serpentinization processes and microbial activity in the shallow subsurface of highly altered ultramafic and mafic sequences that have been uplifted to the seafloor along a major detachment fault zone. The primary goals of this expedition were to (1) examine the role of serpent...

  6. Quelques phases granitiques intrusives dans le Massif des Trois Seigneurs

    Nieuwenhuys, W.H.

    1956-01-01

    Pendant les étés de 1953, 1954 et 1955 j’ai effectué des travaux de terrain dans le Massif des Trois Seigneurs, Pyrénées orientales, sous la direction du Professeur L.U. de Sitter. Ces travaux de terrain comprennent entre autres le levé d’une carte géologique de la partie centrale et Sud-Ouest de ce

  7. Leaching Characteristics of Uranium And Copper from Their Mineralization in the Carbonate Rich latosol of Abu-Thor Locality, South Western Sinai, Egypt

    El-Sheikh, E.M.; Ghazala, R.A.; Abdelwarith, A.; Salem, F.; Ali, S.

    2015-01-01

    The chemical processing of the poly-mineralized carbonate rich latosol ore occurring at Abu-Thor locality of south western Sinai area has been studied for the recovery of uranium and copper metal values. A technological sample assaying 700 ppm U and 9.7% Cu was collected. In the present study, two successive percolation leaching procedures were performed after determination of optimum leaching factors by agitation leaching process. The first was carried out for uranium recovery by using urea as organic leaching agent which was possible to achieve leaching efficiency exceeding 90.3%. This procedure was followed by a second one for copper recovery using ammonium hydroxide solution and ammonium carbonate. The obtained dissolution efficiency was about 93%. The leached metal values namely U and Cu from the studied ore were then extracted as marketable products in the form of ammonium diuranate and copper sulphate, respectively.

  8. Seroepidemiological investigation of foot-and-mouth disease virus serotypes in cattle around Lake Mburo National Park in South-Western Uganda

    Mwiine, Frank Norbert; Ayebazibwe, Chrisostom; Alexandersen, Søren

    2010-01-01

    Foot-and-mouth disease (FMD) outbreaks in cattle occur annually in Uganda. In this study the authors investigated antibodies against FMD virus (FMDV) in cattle in surrounding areas of Lake Mburo National Park in South-western Uganda. Two hundred and eleven serum samples from 23 cattle herds were...... examined for the presence of antibodies against FMDV non-structural proteins and structural proteins using Ceditest® FMDV-NS and Ceditest® FMDV type O (Cedi Diagnostics BV, Lelystad, The Netherlands). Furthermore, serotype-specific antibodies against the seven serotypes of FMDV were determined using in......-house serotype-specific Solid Phase Blocking ELISAs (SPBE). Of the sera tested, 42.7% (90/211) were positive in the ELISA for antibodies against non-structural proteins, while 75.4% (159/211) had antibodies against the structural proteins of FMDV serotype O. Titres of ≥ 1:160 of serotype-specific antibodies...

  9. An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

    Brown, R.W.; Gleadow, A.J.W.; Rust, D.J.; Summerfield, M.A.; De Wit, M.C.J.

    1990-01-01

    Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of ∼ 14 μm with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 μm). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author)

  10. An early cretaceous phase of accelerated erosion on the south-western margin of Africa: evidence from apatite fission track analysis and the offshore sedimentary record

    Brown, R.W.; Gleadow, A.J.W. (La Trobe Univ., Bundoora (Australia)); Rust, D.J.; Summerfield, M.A. (Edinburgh Univ. (UK)); De Wit, M.C.J. (De Beers Consolidated Mines Ltd., Kimberley (South Africa))

    1990-01-01

    Apatite fission track ages and confined track length distributions have been determined for rock samples from the south-western continental margin of Africa. The apatite ages fall into two groups, one having early Cretaceous ages and mean confined track lengths of {approx} 14 {mu}m with very few short tracks, and the other having older ages with confined track length distributions containing a significant proportion of strongly annealed tracks (<10 {mu}m). In any particular area the older apatite ages only occur above a critical threshold elevation, forming a regional pattern in the data and indicating cooling of the upper few kilometres of the crust during the early cretaceous. This episode of cooling is shown to have been the consequence of an accelerated phase of erosion associated with the early stages of rifting and break-up of Gondwana, and correlates with sedimentation patterns derived from borehole data for the adjacent offshore basin. (author).

  11. Plasticity of trophic interactions among sharks from the oceanic south-western Indian Ocean revealed by stable isotope and mercury analyses

    Kiszka, Jeremy J.; Aubail, Aurore; Hussey, Nigel E.; Heithaus, Michael R.; Caurant, Florence; Bustamante, Paco

    2015-02-01

    Sharks are a major component of the top predator guild in oceanic ecosystems, but the trophic relationships of many populations remain poorly understood. We examined chemical tracers of diet and habitat (δ15N and δ13C, respectively) and total mercury (Hg) concentrations in muscle tissue of seven pelagic sharks: blue shark (Prionace glauca), short-fin mako shark (Isurus oxyrinchus), oceanic whitetip shark (Carcharhinus longimanus), scalloped hammerhead shark (Sphyrna lewini), pelagic thresher shark (Alopias pelagicus), crocodile shark (Pseudocarcharias kamoharai) and silky shark (Carcharhinus falciformis), from the data poor south-western tropical Indian Ocean. Minimal interspecific variation in mean δ15N values and a large degree of isotopic niche overlap - driven by high intraspecific variation in δ15N values - was observed among pelagic sharks. Similarly, δ13C values of sharks overlapped considerably for all species with the exception of P. glauca, which had more 13C-depleted values indicating possibly longer residence times in purely pelagic waters. Geographic variation in δ13C, δ15N and Hg were observed for P. glauca and I. oxyrinchus. Mean Hg levels were similar among species with the exception of P. kamoharai which had significantly higher Hg concentrations likely related to mesopelagic feeding. Hg concentrations increased with body size in I. oxyrinchus, P. glauca and C. longimanus. Values of δ15N and δ13C varied with size only in P. glauca, suggesting ontogenetic shifts in diets or habitats. Together, isotopic data indicate that - with few exceptions - variance within species in trophic interactions or foraging habitats is greater than differentiation among pelagic sharks in the south-western Indian Ocean. Therefore, it is possible that this group exhibits some level of trophic redundancy, but further studies of diets and fine-scale habitat use are needed to fully test this hypothesis.

  12. Sedimentary environments in the south-western Barents Sea during the last deglaciation and the Holocene: a case study outside the Ingøydjupet trough

    Mauro Pau

    2016-05-01

    Full Text Available A lithological and foraminiferal study of newly acquired sediment cores outside the Ingøydjupet (Ingøy Deep trough has been carried out to improve constraints on the last deglacial history in the south-western Barents Sea. Three lithofacies and three foraminiferal facies were identified. The lowermost lithological unit is a diamicton interpreted as glacial till. It contains a low-abundance, ecologically mixed foraminiferal assemblage, presumably resulting from glacial reworking. Above the diamicton, a layer of ice-rafted debris (IRD, likely associated with intensive iceberg production, marks the initial destabilization of the marine-based ice sheet. At this time, ca. 15.6–15.0 Ky B.P., opportunistic foraminiferal species Nonionellina labradorica and Stainforthia spp. reached peak abundance. During the south-western Barents Sea ice-margin retreat, presumably corresponding to the Bølling interstadial, a sequence of glaciomarine laminations was deposited conformably on the layer of IRD. Sedimentation rates were apparently high (estimated about 0.4 cm per year and the foraminiferal fauna was dominated by Elphidium spp. and Cassidulina reniforme, species common for glacier-proximal environments. A hiatus at the top of the deglacial unit is likely linked to the high bottom-current activity associated with a strengthened inflow of Atlantic water masses into the Barents Sea. The uppermost lithological unit is represented by the Holocene marine sandy mud. It contains a high-abundance, high-diversity foraminiferal fauna with common cassidulinids, Cibicides spp., Epistominella pusilla and planktic species.

  13. Effect of nine years of animal waste deposition on profile distribution of heavy metals in Abeokuta, south-western Nigeria and its implication for environmental quality.

    Azeez, J O; Adekunle, I O; Atiku, O O; Akande, K B; Jamiu-Azeez, S O

    2009-09-01

    Uncontrolled deposition of waste from animal farms is a common practice in south-western Nigeria, and the presence of heavy metals in soil constitutes environmental and health hazards by polluting the soil, ground water, adjoining streams and rivers. The study investigated the profile distribution of Mn, Pb, Cd, Zn, Fe, Cu, Ni and Cr in some tropical Alfisols in south-western Nigeria after nine years disposal of animal wastes. The amount of these metals in the soil horizons was high enough to cause health and phytotoxic risks. All the metals except Zn and Cr increased down the profile, while Mn, Pb, Cd, Fe, Cu and Ni accumulated at 80-120 cm depth. The increment of these metals at this depth over the top soil were 26%, 143%, 72%, 47%, 328% for Mn, Pb, Cd, Cu and Ni, respectively. It thus, shows their mobility and the possibility of polluting ground water. The Mn content at the poultry and cattle waste sites increased by 127% and 25%, respectively over the control, while that of cattle and swine dump site for Cd content were 9.82 and 15.63 mg kg(-1), respectively. Lead content also increased by 8.52 and 5.25 mg kg(-1), respectively. There was the accumulation of Zn and Cu at the swine dump site while the cattle dump site had the highest amounts of nickel and chromium. The least amount of Fe was recorded at the swine waste dump site. The reduction in organic matter with depths together with the reduced pH might have favored the mobility of the metals. The ranking of pollution among the sites was poultry>swine>cattle>sheep and could be due to the type of ration fed, the vaccination programmes, sanitation programmes and other management practices.

  14. The early childhood oral health program: a qualitative study of the perceptions of child and family health nurses in South Western Sydney, Australia.

    Veale, Maxine; Ajwani, Shilpi; Johnson, Maree; Nash, Linda; Patterson, Tiffany; George, Ajesh

    2016-05-16

    Early childhood caries affects nearly half the population of Australian children aged 5 years and has the potential to negatively impact their growth and development. To address this issue, an Early Childhood Oral Health (ECOH) program, facilitated by Child and Family Health Nurses (CFHNs), commenced in 2007 in New South Wales, Australia. This study builds on the previous evaluation of the program. It aims to explore the perceptions of CFHNs regarding the implementation of the ECOH program in South Western Sydney and the challenges and barriers related to its sustainability. A descriptive qualitative design was used in this study. Two focus groups were conducted with 22 CFHNs who were sampled from two Community Health Centres in South Western Sydney, Australia. Data were transcribed verbatim and thematic analysis was undertaken. Most CFHNs acknowledged the importance of early childhood oral health promotion and were providing education, oral assessments and referrals during child health checks. Many stressed the need for collaboration with other health professionals to help broaden the scope of the program. Some barriers to implementing the program included confusion regarding the correct referral process, limited feedback from dental services and the lack of oral health awareness among parents. The study findings suggest that the ECOH program is being sustained and effectively implemented into practice by CFHNs. Improvement in the referral and feedback process as well as enhancing parental knowledge of the importance of infant and child oral health could further strengthen the effectiveness of the program. Expanding oral health education opportunities into general practice is advocated, while regular on-line training for CFHNs is preferred. Future research should include strategies to reduce non-attendances, and an assessment of the impact on the prevalence of childhood caries of the ECOH program.

  15. Tracking populations of Phytophthora ramorum within trees and across the South-western Oregon tanoak (Notholithocarpus densiflorus) forest with DNA fingerprinting and the relative fitness of dominant and rare individuals

    Jennifer Britt; Everett Hansen

    2011-01-01

    Since the discovery of Phytophthora ramorum Werres, De Cock & Man In't Veld in south-western Oregon forests in 2001, newly infected areas are detected each year. Yet, there are still gaps in our knowledge about how the pathogen spreads or where new infections come from. Our study aims to track the spread of P. ramorum...

  16. Productivity and residual benefits of grain legumes to sorghum under semi-arid conditions in south-western Zimbabwe: Unravelling the effects of water and nitrogen using a simulation model

    Ncube, B.; Dimes, J.P.; Wijk, van M.T.; Twomlow, S.J.; Giller, K.E.

    2009-01-01

    The APSIM model was used to assess the impact of legumes on sorghum grown in rotation in a nutrient-limited system under dry conditions in south-western Zimbabwe. An experiment was conducted at Lucydale, Matopos Research Station, between 2002 and 2005. The model was used to simulate soil and plant

  17. Mohorovicic discontinuity depth analysis beneath North Patagonian Massif

    Gómez Dacal, M. L.; Tocho, C.; Aragón, E.

    2013-05-01

    The North Patagonian Massif is a 100000 km2, sub-rectangular plateau that stands out 500 to 700 m higher in altitude than the surrounding topography. The creation of this plateau took place during the Oligocene through a sudden uplift without noticeable internal deformation. This quite different mechanical response between the massif and the surrounding back arc, the short time in which this process took place and a regional negative Bouguer anomaly in the massif area, raise the question about the isostatic compensation state of the previously mentioned massif. In the present work, a comparison between different results about the depth of the Mohorovicic discontinuity beneath the North Patagonian Massif and a later analysis is made. It has the objective to analyze the crustal thickness in the area to contribute in the determination of the isostatic balance and the better understanding of the Cenozoic evolution of the mentioned area. The comparison is made between four models; two of these were created with seismic information (Feng et al., 2006 and Bassin et al., 2000), another model with gravity information (Barzaghi et al., 2011) and the last one with a combination of both techniques (Tassara y Etchaurren, 2011). The latter was the result of the adaptation to the work area of a three-dimensional density model made with some additional information, mainly seismic, that constrain the surfaces. The work of restriction and adaptation of this model, the later analysis and comparison with the other three models and the combination of both seismic models to cover the lack of resolution in some areas, is presented here. According the different models, the crustal thickness of the study zone would be between 36 and 45 Km. and thicker than the surrounding areas. These results talk us about a crust thicker than normal and that could behave as a rigid and independent block. Moreover, it can be observed that there are noticeable differences between gravimetric and seismic

  18. Social Class Barriers of the Massification of Higher Education in Taiwan

    Ru-Jer, Wang

    2012-01-01

    In recent years, the rapid growth of higher education in Taiwan has led to an essential shift from education for the elite to the massification of higher education. Although this massification is making higher education more accessible, one of the main concerns is whether opportunities for higher education are the same among all social classes in…

  19. Dynamics of multiple insecticide resistance in the malaria vector Anopheles gambiae in a rice growing area in South-Western Burkina Faso

    Ouédraogo Jean-Bosco

    2008-09-01

    Full Text Available Abstract Background Insecticide resistance of the main malaria vector, Anopheles gambiae, has been reported in south-western Burkina Faso, West Africa. Cross-resistance to DDT and pyrethroids was conferred by alterations at site of action in the sodium channel, the Leu-Phe kdr mutation; resistance to organophosphates and carbamates resulted from a single point mutation in the oxyanion hole of the acetylcholinesterase enzyme designed as ace-1R. Methods An entomological survey was carried out during the rainy season of 2005 at Vallée du Kou, a rice growing area in south-western Burkina Faso. At the Vallée du Kou, both insecticide resistance mechanisms have been previously described in the M and S molecular forms of An. gambiae. This survey aimed i to update the temporal dynamics and the circumsporozoite infection rate of the two molecular forms M and S of An. gambiae ii to update the frequency of the Leu-Phe kdr mutation within these forms and finally iii to investigate the occurrence of the ace-1R mutation. Mosquitoes collected by indoor residual collection and by human landing catches were counted and morphologically identified. Species and molecular forms of An. gambiae, ace-1R and Leu-Phe kdr mutations were determined using PCR techniques. The presence of the circumsporozoite protein of Plasmodium falciparum was determined using ELISA. Results Anopheles gambiae populations were dominated by the M form. However the S form occurred in relative important proportion towards the end of the rainy season with a maximum peak in October at 51%. Sporozoite rates were similar in both forms. The frequency of the Leu-Phe kdr mutation in the S form reached a fixation level while it is still spreading in the M form. Furthermore, the ace-1R mutation prevailed predominately in the S form and has just started spreading in the M form. The two mutations occurred concomitantly both in M and S populations. Conclusion These results showed that the Vallée du Kou

  20. Early fracturing in argillaceous massifs and related carbonate transfer

    Beaudoin, B.; Dennebouy, S.; Parize, O.; Brulhet, J.; Trouiller, A.

    2004-01-01

    To be sure of the stability in the future of underground storage in argillaceous massifs needs to understand the present-day properties of the sediment in the light of its history. It is why early fracturing and associated carbonate transfer in shaly-marly massifs is one of the major themes of the MINANDRA Partnership (Ecole des Mines de Paris + ANDRA + some collaborators). That joint program involves tens of geo-scientists, and we would like to present here the main objects we study and the methods we apply. The base of the project is made of selected large reference-outcrops where an early fracturing is undoubtedly visible in the field. Two sets of such outcrops are presently worked in south-eastern France: - Aptian-albian marls (Marnes Bleues), at Bevons (near 04-Sisteron) and Saint-Andre de Rosans (W. of 05-Serres). - Domerian marls, at Clue du Vancon (E. of 04-Sisteron). Both are made of thick marls and intercalated limestone beds and nodules. (authors)

  1. Geophysical monitoring as an information source of rock massif behaviour

    Pavel Bláha

    2008-06-01

    Full Text Available Geophysical measurements are an integral part of engineering-geological investigation where theypresent a wide range of useful information about the tested geological medium and about its geotechnicalqualities. Lately, repeated geophysical measurements in different time intervals have been used to judgethe changes occurring in the rock massif. These measurements bear the characteristics of total monitoring.This total monitoring contains series of repeated measurements and further an integrated spectrum of linkedactivities including evaluation, comparison with the warning state and making a decision about takingprecautions. From the range of geophysical methods and methodologies used for monitoring in full sensewe may mention, for example, continuous seismoacoustic measurements in mining constructions; (whichmay result even in recalling of the personnel, and further, also seismic measurements in the surroundingsof atomic power stations and measurements considering the protection against radioactive elements and their decay components.As a full monitoring we may also classify measurements in dumping sites with the aid of repeated geoelectrical measurements in the system of fixed electrodes under impermeable foils.These measurements are mostly carried out from time to time followed by taking immediate action when the foil is found damaged. In practice the term monitoring is used, although not very correctly, for all periodically repeated measurements, which do not result in taking action or interference, but supply a wide range of information about the rock massif behavior in time.

  2. Geological and geophysical investigations at Sierra del Medio massif - Argentine

    Perucca, J.C.; Llambias, E.; Puigdomenech, H.H.; Cebrelli, E.; Castro, C.E.; Grassi, I.; Salinas, L.I.

    1987-01-01

    Geological investigations were performed at Sierra del Medio (Chubut Province), a mountainous massif of about 25 km by 8 km of migmatic origin, which emerges from a depressed tectonic trench or graben called Pampa de Gastre. The most ancient rocks belong to biotitic and anphibolic schist that passed almost entirely to tonalitoid migmatites with a second process producing granitic rocks. Boreholes were drilled on the basis of conclusions from Landsat satellites imagery and aerial photographic sets, folowed by field work on geological, petrographic, geophysical and hydrogeological features at surface, structural interpretation supported by geostatistical computations. Two sets of boreholes were drilled to investigate subsurface rock behaviour al 300 m depth and 800 m depth respectively, beginning at peripheral places and ending at the central part or selected site. Basic purposes of boreholes were to define structural and petrographic features of the rock massif by a good comprehension of master joints and faulting distribution with its belts of alteration mylonitization or brecciation, mechanical properties of samples, chemical composition and varitions, petrographic facies and mineralogy. Boreholes provided data to investigate joints, faults and dikes as general discontinuities for hydraulic research like permeability or effective hydraulic conductivity, and their geostatistical modelling. Boreholes are also being prepared for geophysical logging from which logthermal ones have already been completed. (Author) [es

  3. Gold in Accessory Zircon (the Kozhim Massif, Subpolar Urals)

    Denisova, Yuliya; Pystin, Aleksandr

    2017-12-01

    The crystals of zircon due to their resistance to external impact of various processes can reveal information about the environment of their formation and the inclusions observed of them. Zircon contains different mineral inclusions: biotite, plagioclase, quartz, apatite, etc. However, there is no information about gold inclusions in the zircons from granites of the Sudpolar Urals. The study results of the inclusions of gold in accessory zircon of the Kozhim granitic massif are presented in this paper. The studied mineral is a dark-brown translucent short-prismatic crystal containing the inclusion of gold and the allocations of quartz. According to studies, the inclusion of gold formed during the growth of zircon and it is the gold covered with a thin film of oxide gold. It was confirmed that the crystallization of the studied zircon occurred at a temperature of 800°C and above on the stage of formation of granites of Kozhim massif. The assumption is made about the additional temperature in the course of which was caused by decreasing of temperature up to 700° C and below during postmagmatic stage.

  4. Area monitoring of ambient dose rates in parts of South-Western Nigeria using a GPS-integrated radiation survey meter

    Okeyode, I.C.; Rabiu, J.A.; Alatise, O.O.; Makinde, V.; Akinboro, F.G.; Mustapha, A.O.; Al-Azmi, D.

    2017-01-01

    A radiation monitoring system comprising a Geiger-Muller counter connected to a smart phone via Bluetooth was used for a dose rate survey in some parts of south-western Nigeria. The smart phone has the Geographical Positioning System, which provides the navigation information and saves it along with the dose rate data. A large number of data points was obtained that shows the dose rate distribution within the region. The results show that the ambient dose rates in the region range from 60 to 520 nSv -1 and showed a bias that is attributable to the influence of geology on the ambient radiation dose in the region. The geology influence was demonstrated by superimposing the dose rate plot and the geological map of the area. The potential applications of the device in determining baseline information and in area monitoring, e.g. for lost or abandoned sources, radioactive materials stockpiles, etc., were discussed in the article, particularly against the background of Nigeria's plan to develop its nuclear power program. (authors)

  5. A joint analysis of wave and surge conditions for past and present extrem events in the south-western Baltic Sea

    Groll, Nikolaus; Gaslikova, Lidia

    2017-04-01

    Extreme marine events in the south-western Baltic Sea like the historic storm in 1872 are rare, but have large impacts on human safety and coastal infrastructure. The aforementioned extreme storm event of 1872 and has cost over 250 human lives, left severely damaged infrastructure and caused land loss due to coastal erosion. Recent extreme events also result in drastic impacts to coastal regions. Using results from numerical wave and hydrodynamic model simulations we will present a joint analysis of wave and water level conditions for selected extreme events. For the historic event the numerical models have been forced by reconstructed wind and pressure fields from pressure readings. Simulated atmospheric conditions from reanalysis have been used for the more recent events. The height of the water level due to the possible previous inflow of water masses in the Baltic Sea basin, as well as possible seiches and swell effects have been incorporated in the simulations. We will discuss similarities and differences between the historic and the more recent marine hazard events.

  6. Looking for long-term changes in hydroid assemblages (Cnidaria, Hydrozoa) in Alboran Sea (South-Western Mediterranean): a proposal of a monitoring point for the global warming

    González-Duarte, Manuel María; Megina, Cesar; Piraino, Stefano

    2014-12-01

    In the last 20-30 years, the temperature of the Mediterranean Sea has increased and global warming is allowing the establishment of tropical-affinity species into more temperate zones. Sessile communities are particularly useful as a baseline for ecological monitoring; however, a lack of historical data series exists for sessile marine organisms without commercial interest. Hydroids are ubiquitous components of the benthic sessile fauna on rocky shores and have been used as bio-indicators of environmental conditions. In this study on the benthic hydroid assemblages of the Chafarinas Islands (Alboran Sea, South-Western Mediterranean), we characterized the hydroid assemblages, identified the bathymetric gradients, and compared them with a previous study carried out in 1991. Hydroid assemblages showed a significant difference both between year and among depths. Furthermore, eight species not present in 1991 were found, including two possible new species and the tropical and subtropical species Sertularia marginata. Due to its strategic position at the entrance of the Mediterranean and the existence of previous data on hydroid assemblages, the Chafarinas Islands are proposed as a possible monitoring point for entrance of Atlantic tropical species into the Mediterranean Sea.

  7. Spatial data fusion and analysis for soil characterization: a case study in a coastal basin of south-western Sicily (southern Italy

    Donato Sollitto

    2012-03-01

    Full Text Available Salinization is one of the most serious problems confronting sustainable agriculture in semi-arid and arid regions. Accurate mapping of soil salinization and the associated risk represent a fundamental step in planning agricultural and remediation activities. Geostatistical analysis is very useful for soil quality assessment because it makes it possible to determine the spatial relationships between selected variables and to produce synthetic maps of spatial variation. The main objective of this paper was to map the soil salinization risk in the Delia-Nivolelli alluvial basin (south-western Sicily, southern Italy, using multivariate geostatistical techniques and a set of topographical, physical and soil hydraulic properties. Elevation data were collected from existing topographic maps and analysed preliminarily to improve the estimate precision of sparsely sampled primary variables. For interpolation multi-collocated cokriging was applied to the dataset, including textural and hydraulic properties and electrical conductivity measurements carried out on 128 collected soil samples, using elevation data as auxiliary variable. Spatial dependence among elevation and physical soil properties was explored with factorial kriging analysis (FKA that could isolate and display the sources of variation acting at different spatial scales. FKA isolated significant regionalised factors which give a concise description of the complex soil physical variability at the different selected spatial scales. These factors mapped, allowed the delineation of zones at different salinisation risk to be managed separately to control and prevent salinization risk. The proposed methodology could be a valid support for land use and soil remediation planning at regional scale.

  8. Diagnosis and treatment of malaria in peripheral health facilities in Uganda: findings from an area of low transmission in south-western Uganda

    Clarke Siân

    2007-04-01

    Full Text Available Abstract Background Early recognition of symptoms and signs perceived as malaria are important for effective case management, as few laboratories are available at peripheral health facilities. The validity and reliability of clinical signs and symptoms used by health workers to diagnose malaria were assessed in an area of low transmission in south-western Uganda. Methods The study had two components: 1 passive case detection where all patients attending the out patient clininc with a febrile illness were included and 2 a longitudinal active malaria case detection survey was conducted in selected villages. A malaria case was defined as any slide-confirmed parasitaemia in a person with an axillary temperature ≥ 37.5°C or a history of fever within the last 24 hrs and no signs suggestive of other diseases. Results Cases of malaria were significantly more likely to report joint pains, headache, vomiting and abdominal pains. However, due to the low prevalence of malaria, the predictive values of these individual signs alone, or in combination, were poor. Only 24.8% of 1627 patients had malaria according to case definition and > 75% of patients were unnecessarily treated for malaria and few slide negative cases received alternative treatment. Conclusion In low-transmission areas, more attention needs to be paid to differential diagnosis of febrile illnesses In view of suggested changes in anti-malarial drug policy, introducing costly artemisinin combination therapy accurate, rapid diagnostic tools are necessary to target treatment to people in need.

  9. An appraisal of the geologic structure beneath the Ikogosi warm spring in south-western Nigeria using integrated surface geophysical methods

    J.S Ojo

    2011-06-01

    Full Text Available An integrated surface geophysical investigation involving resistivity and magnetic methods was carried out in the immediate vicinity of the Ikogosi warm spring situated in south-western Nigeria with a view to delineating its subsurface geological sequence and evaluating the structural setting beneath the warmspring. Total field magnetic measurements and vertical electrical sounding (VES data were acquired along five N-S traverses. Magnetic and VES data interpretation
    involved inverse modelling. The inverse magnetic models delineated fractured quartzite/faulted areas within fresh massive quartzite at varying depths and beneath all traverses. The geoelectrical sections developed from VESinterpretation results also delineated a subsurface sequence consisting of a topsoil/weathered layer, fresh quartzite, fractured/faulted quartzite and fresh quartzite bedrock. It was deduced that the fractured/faulted quartzite may have acted as conduit for the
    movement of warm groundwater from profound depths to the surface while the spring outlet was located on a geological interface  (lineament.

  10. The effect of caesarean section on self-esteem amongst primiparous women in South-Western Nigeria: a case-control study.

    Loto, Olabisi M; Adewuya, Abiodun O; Ajenifuja, Olusegun K; Orji, Ernest O; Owolabi, Alexander T; Ogunniyi, Solomon O

    2009-09-01

    This study aims to assess the level of self-esteem of newly delivered mothers who had caesarean section (CS) and evaluate the sociodemographic and obstetrics correlates of low self-esteem in them. Newly delivered mothers who had CS (n = 109) and who had spontaneous vaginal delivery (SVD) (n = 97) completed questionnaires on sociodemographic and obstetrics variables within 1 week of delivery. They also completed the Rosenberg self-esteem scale. RESULTS. Women with CS had statistically significant lower scores on the self-esteem scale than women with SVD (p = 0.006). Thirty (27.5%) of the CS group were classified as having low self-esteem compared with 11 (11.3%) of the SVD group (p = 004). The correlates of low self-esteem in the CS group included polygamy (odd ratio (OR) 4.99, 95% confidence interval (95% CI) 1.62-15.33) and emergency CS (OR 4.66, 95% CI 1.55-16.75). CS in South-Western Nigerian women is associated with lowered self-esteem in the mothers.

  11. Work-related stress perception and hypertension amongst health workers of a mission hospital in Oyo State, south-western Nigeria

    Akinwumi O. Owolabi

    2012-04-01

    Objective: This study was a work site cross-sectional descriptive study carried out amongst the health workers at the Baptist Medical Centre Ogbomoso, Oyo State, south-western Nigeria. The aim of the study was to discern the prevalence of perceived work stress and to explore the relationship between perceived work stress and the presence of hypertension. Methods: A total of 324 consenting health workers of the institution were administered the job demand-control questionnaire to assess work stress. A standardised questionnaire was used to collect socio-demographic data and other personal data. Measurements of blood pressure, weight and height were carried out and body mass indices were calculated. Results: More than a quarter (26.2% of the subjects perceived themself as stressed at work. The single largest group of hypertensive subjects was seen amongst subjects with work stress. Conclusion: A significant number of health workers in this study is afflicted by work-related stress and perceived work stress was found to be significantly associated with higher hypertension prevalence.

  12. A case study on the diagnosis and consequences of flash floods in south-western Romania: The upper basin of Desnatui River

    Morosanu Gabriela Adina

    2014-01-01

    Full Text Available The paper examines the flash floods that may appear in a representative river basin occupying the south-western Romania and also feature an example of the most recent flash flood from 2005-2006, more specifically, its causes and consequences. In order to accomplish the objectives, hydrological data were used to identify the characteristics of the floods. Finally, the case study of the flash flood was delivered through the field research, observational method, discussion with the authorities and investigation of the meteorological and hydrological available data. The research offers an insight on the dimension of damages triggered by a flash flood event, based on the statistical data provided by the village hall and the few remaining places preserving the traces of the floods (houses, bridges. Because we could not provide all the necessary data in order to determine the frequency and scale of such risk phenomena, the analysis is assessed on general hydrological statistics of flood events between 1964 to 2011. By leading the research, it resulted that the specific feature of the upper basin of Desnatui River is its temporary drainage and that in the periods of high flow, the capacity of the river channels is diminshed and the floods may occur. The paper succeeds to revive the insufficient scientific concerns on this kind of hydrological risks issued in the space occupied by the upper basin of Desnatui River and eventually, to supply the need for such study in the context of modern hydrological research preoccupations.

  13. Use of Traditional Weather/Climate Knowledge by Farmers in the South-Western Free State of South Africa: Agrometeorological Learning by Scientists

    Gugulethu Zuma-Netshiukhwi

    2013-11-01

    Full Text Available The variety of natural indicators, associated with weather forecasting and climate prediction, as used by farmers in the South-Western Free State province of South Africa, is described. Most farmers in this area were not familiar with the application of weather forecasts/climate predictions for agricultural production, or with other science-based agrometeorological products. They relied almost fully on their experience and traditional knowledge for farming decision making. The indicators for traditional knowledge are demonstrated here in broad terms, relying on the stories and indications from observations and years of experience of their use by the farmers. These means of engagement with the natural environment, are skills not well understood by most scientists, but useful to the farmers. They range from the constellation of stars, animal behavior, cloud cover and type, blossoming of certain indigenous trees, appearance and disappearance of reptiles, to migration of bird species and many others. It is suggested that some short-term traditional forecasts/predictions may be successfully merged with science-based climate predictions. The traditional knowledge and its use, reported on in this paper, is what scientists learned from farmers. Berkes was right that scholars have wasted too much time and effort on a science versus traditional knowledge debate; we should reframe it instead as a science and traditional knowledge dialogue and partnership. The complications of a changing climate make this even more necessary.

  14. First report of autochthonous non-vectorial canine leishmaniasis in New Caledonia, south-western Pacific: implications for new control measures and recommendations on importation of dogs.

    Daval, Nathalie; Marchal, Céline; Guillaumot, Laurent; Hüe, Thomas; Ravel, Christophe; Keck, Nicolas; Kasbari, Mohamed

    2016-02-25

    Canine leishmaniasis (CanL), a parasitic zoonotic disease caused by Leishmania infantum and usually transmitted by phlebotomine sandflies, has rarely been reported in Pacific islands, which have been regarded until now as leishmaniasis-free territory. Here, we report the first autochthonous CanL case in New Caledonia (south-western Pacific) and the investigations carried out 1) to determine how infection was introduced into and transmitted among these dogs and 2) to assess the risks to animal and public health. Extensive epidemiological and entomological investigations in and around the focus were carried out. Leishmaniasis infection was confirmed by histopathology, indirect fluorescent antibody test, real-time PCR, and culture. Parasite strain was typed by the isoenzymatic technique. The survey revealed close contacts between the autochthonous dog and two infected bitches imported from Spain, but failed to find any possible vector or disease spreading to other animals or humans. L. infantum zymodeme MON-1, the most frequent type in the Mediterranean basin, was identified. Although transplacental and venereal transmissions could not be excluded, the evidence was in favour of non-vectorial, direct dog-to-dog transmission. This study corroborates the possibility of non-vectorial routes (transplacental, venereal, and direct dog-to-dog) of canine leishmaniasis transmission in New Caledonia and raises the debate of relevant test requirements and diagnostic sensitivity prior to importation of dogs in Leishmania-free regions. New leishmaniasis control measures and recommendations to avoid future CanL introduction on the island are discussed.

  15. The Livelihood Patterns of Iran's South-western Cities in Texts of Islamic Period (10th- 15th A.D

    mohammad ebrahim zarei

    2016-06-01

    Full Text Available The Urbanization of Islamic period, which affected by Islamic beliefs, differed from that in Sassanid period. This research endeavors to reveal the perspective of economic atmosphere of Islamic cities in region of study subject. Such perspective has been provided by employing the documents and written historical information in Muslim geographers' books based on historical approach. Furthermore, such research  investigates not only the effect of geographical elements on the inhabitant's livelihood from 10th to 15th century with geographical dispersion of  Iran's south- western zones but also the influence of governments on economical and livelihood perspective of such cities in Islamic period. The natural, political- cultural reasons, secure commercial roads and governmental policies had a significant impact on the means of livelihood. The available geographical and historical texts have offered credible evidence of the explanation of the elements such as urbanization, agricultural, gardening, industry, trade and urban services in such period with a social perspective of such cities.

  16. The geology of uranium in the Saint-Sylvestre granite district (Limousin, Massif Central, France)

    Marquaire, C.; Moreau, M.; Barbier, J.; Ranchin, G.; Carrat, H.G.; Coppens, R.; Senecal, J.; Koszotolanyi, C.; Dottin, H.

    1969-01-01

    This report concerns the geology of uranium in Limousin, more particularly in the St-Sylvestre massif, and the related phenomena: regional geology, petrographic and geochemical zonal distribution observed in various granite massifs, uranium movement in connection with surface alteration, geochronology of uranium ore. The work is made up of six articles covering the various scientific aspects listed above. Each article is headed with an abstract. The paper comprises the following chapters: Foreword by Marcel ROUBAULT. 1. Ch. MARQUAIRE, M. MOREAU Outline of geological conditions in Northern Limousin and distribution of uraniferous occurrences. 2. J. BARBIER, G. RANCHIN, H. G. CARRAT and R. COPPENS Geology of the St-Sylvestre Massif and uranium geochemistry - Introduction to laboratory studies - Problems of methodology. 3. J. BARBIER and G. RANCHIN Petrographical and geochemical zones in the St-Sylvestre granite massif (Limousin - French 'Massif Central'). 4. J. BARBIER and G. RANCHIN Uranium geochemistry in the St-Sylvestre Massif (Limousin - French 'Massif Central') - Occurrences of primary geochemical uranium and replacement processes. 5. J. SENEGAL Monograph of the Brugeaud orebody. 6. R. COPPENS, Ch. KOSZTOLANYI and H. DOTTIN Geochronological study of the Brugeaud mine. 1969. (authors) [fr

  17. Chromitites of the Akkarginskiy massif (the Southern Urals

    D. E. Saveliev

    2018-03-01

    Full Text Available We consider the geological features of ultramafic rock and chrome ore deposits. It is shown that all studied deposits are podiform in morphology that is typical for the ophiolite ultramafic rocks. Morphological and chemical features of the accessory and oreforming spinels are described. Accessory chrome spinels from ultramafic rocks are middle-Cr and high-Cr in chemistry (>42% Cr2O3. All studied ore-forming chrome spinels from deposits in the Main Ore Zone are high-Cr (54–63% Cr2O3. Some middle-Cr oreforming spinels were found in deposit of the East Ore Zone (48% Cr2O3. We adduce a proof of the tectonic origin of present-day structure of the Akkarginskiy massif and its chrome ore deposits.

  18. HT-LP thermometamorphism modelling : Agly massif, French Pyrenees.

    Tournaire Guille, Baptiste; Pascal, Marie-Lola; Lejeune, Anne-Marie; Annen, Catherine

    2017-04-01

    Owing to the strongly anomalous thermal gradients implied, HT-LP metamorphism is a worldwide type of processes in which magma emplacement and solidification at relatively high levels in the crust must be considered as a potentially major heat source. Thermal modelling (e.g. Annen et al. 2005) is an appropriate tool for constraining the part played by such processes in practical cases of thermometamorphism. We study the Agly massif, an exhumed part of middle crust from the Variscan belt in the French Pyrenees. This massif is a classical example of HT-LP metamorphism (Vielzeuf 1996), composed of a metasedimentary cover, mainly micaschists aged from upper Cambrian to Devonian, unconformably overlying an older basement of para- and orthogneisses. The Variscan metamorphic facies extend from greenschists, in the upper part of the cover, to granulites in the basement (Fonteilles 1976). The apparent geotherm of about 110°/km in the metasedimentary cover (amphibolite and greenschist facies) has given way to contrasting interpretations. Magmatic activity partly synchronous with and probably related to the Variscan thermometamorphism is observed at the outcropping level as at least 4 magmatic bodies of mantle origin (Touil 1994), of Stephanian age, including granodiorites and subordinate diorites and gabbros. Recent U/Pb datations on zircons (Tournaire-Guille et al., in prep) also reveal the presence of lower Cambrian magmatism in the gneisses, therefore confirming their interpretation as a pre-Variscan basement. The location (depth), volume (thickness), temperature (composition) and timing of magma emplacement are the parameters controlling the thermal effect to be modelled with a Matlab® code (Annen et al. 2005). In order to constrain these parameters, we have updated the lithostratigraphy and the PT conditions of the Variscan metamorphism in the Agly area. Mineralogic and petrologic data exploited in thermobarometric analyses compared with thermodynamic PerpleX modelling

  19. Ozone exposure, defoliation of beech (Fagus sylvatica L.) and visible foliar symptoms on native plants in selected plots of South-Western Europe

    Ferretti, Marco; Calderisi, Marco; Bussotti, Filippo

    2007-01-01

    The relationships between crown defoliation of beech, visible foliar symptoms on native vegetation and ozone exposure were investigated on permanent monitoring sites in South-Western Europe in the years 2000-2002. Relationships between defoliation of beech and O 3 (seasonal mean, 2-week maximum, AOT40) were investigated by means of multiple regression models (11 plots, 1-3 years of data each) and a model based on temporal autocorrelation of defoliation data (14 plots, 1-3 years of data each). Different multiple regression techniques were used. The four models generated (R 2 = 0.71-0.85, explained variance in cross-validation 61-78%) identified several significant predictors of defoliation, with AOT40 (p = 0.008) and foliar content of phosphorous (p = 0.0002-0.0004) being common to all models. The autocorrelation model (R 2 = 0.55; p 35,000 ppbh). O 3 -like visible foliar symptoms were recorded on 65 species at 47% of the common monitoring sites in 2001 and 38% in 2002. No relationship was found between O 3 exposure, frequency of symptomatic sites and frequency of species with symptoms (R 2 = 0.11; p > 0.05). A number of questions related to the ecological and methodological basis of the survey were identified. Inherent sampling and non-sampling errors and multicollinearity of the data suggest great caution when examining results obtained from mensurational, correlative studies. - Ozone AOT40 was identified as a significant predictor of defoliation of beech, but a limited relationship was found between ozone exposure and visible symptoms on native vegetation

  20. The socio-economic burden of human African trypanosomiasis and the coping strategies of households in the South Western Kenya foci.

    Salome A Bukachi

    2017-10-01

    Full Text Available Human African Trypanosomiasis (HAT, a disease caused by protozoan parasites transmitted by tsetse flies, is an important neglected tropical disease endemic in remote regions of sub-Saharan Africa. Although the determination of the burden of HAT has been based on incidence, mortality and morbidity rates, the true burden of HAT goes beyond these metrics. This study sought to establish the socio-economic burden that households with HAT faced and the coping strategies they employed to deal with the increased burden.A mixed methods approach was used and data were obtained through: review of hospital records; structured interviews (152; key informant interviews (11; case narratives (12 and focus group discussions (15 with participants drawn from sleeping sickness patients in the south western HAT foci in Kenya. Quantitative data were analysed using descriptive statistics while qualitative data was analysed based on emerging themes.Socio-economic impacts included, disruption of daily activities, food insecurity, neglect of homestead, poor academic performance/school drop-outs and death. Delayed diagnosis of HAT caused 93% of the affected households to experience an increase in financial expenditure (ranging from US$ 60-170 in seeking treatment. Out of these, 81.5% experienced difficulties in raising money for treatment resorting to various ways of raising it. The coping strategies employed to deal with the increased financial expenditure included: sale of agricultural produce (64%; seeking assistance from family and friends (54%; sale/lease of family assets (22%; seeking credit (22% and use of personal savings (17%.Coping strategies outlined in this study impacted negatively on the affected households leading to further food insecurity and impoverishment. Calculation of the true burden of disease needs to go beyond incidence, mortality and morbidity rates to capture socio-economic variables entailed in seeking treatment and coping strategies of HAT

  1. Climate changes in south western Iberia and Mediterranean Outflow variations during two contrasting cycles of the last 1 Myrs: MIS 31-MIS 30 and MIS 12-MIS 11

    Sánchez Goñi, M. F.; Llave, E.; Oliveira, D.; Naughton, F.; Desprat, S.; Ducassou, E.; Hodell, D. A.; Hernández-Molina, F. J.

    2016-01-01

    Grain size analysis and physical properties of Sites U1388, U1389 and U1390 collected in the Contourite Depositional System of the Gulf of Cádiz during the Integrated Ocean Drilling Program (IODP) Expedition 339 "Mediterranean Outflow" reveal relative changes in bottom current strength, a tracer of the dynamics of the Mediterranean Outflow Water (MOW), before and after the Middle Pleistocene Transition (MPT). The comparison of MOW behavior with climate changes identified by the pollen analysis and δ18O benthic foraminifera measurements of Site U1385, the Shackleton Site, collected in the south western Iberian margin shows that the interval MIS 31-MIS 30, ~ 1.1-1.05 million years ago (Ma), before the MPT, was marked by wetter climate and weaker bottom current than the interval MIS 12-MIS 11 (0.47-0.39 Ma), after the MPT. Similarly, the increase in fine particles from these glacials to interglacials and in coarse fraction from interglacials to glacials was coeval with forest and semi-desert expansions, respectively, indicating the lowering/enhancement of MOW strength during periods of regional increase/decrease of moisture. While these findings may not necessarily apply to all glacial/interglacial cycles, they nonetheless serve as excellent supporting examples of the hypothesis that aridification can serve as a good tracer for MOW intensity. The strongest regional aridity during MIS 12 coincides with a remarkable increase of coarse grain size deposition and distribution that we interpret as a maximum in MOW strength. This MOW intensification may have pre-conditioned the North Atlantic by increasing salinity, thereby triggering the strong resumption of the Meridional Overturning Circulation that could contribute to the great warmth that characterizes the MIS 11c super-interglacial.

  2. Long-range atmospheric transport of persistent organochlorinated compounds from south and mainland south-eastern Asia to a remote mountain site in south-western China.

    Xu, Yue; Zhang, Gan; Li, Jun; Chakraborty, Paromita; Li, Hua; Liu, Xiang

    2011-11-01

    A range of organochlorinated compounds have been consumed in China, India and the countries of mainland southeast Asia (MSA). Considering their persistence in the environment and ability in long-range atmospheric transport (LRAT), the potential outflow of these compounds from this region is therefore of great concern in the context of the global distribution of toxic chemicals. As part of a monitoring campaign aimed at investigating the LRAT of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) from southern China, MSA and northern India, atmospheric levels of OCPs and PCBs were measured once a week from October 2005 through December 2006 at Tengchong Mountain (TM), a remote site located in south-western China. The average concentrations of OCPs were found to be higher than those in other remote stations in the Arctic and the Tibetan plateau, except for α-hexachlorocyclohexane (α-HCH). A high level of β-HCH and low α-HCH/β-HCH ratio was attributed to an accidental release of β-HCH from unknown sources, besides obvious evidence of lindane (γ-HCH) and technical HCH usage. Temporal variations of chlordanes and endosulfan were related to the usage pattern of these compounds, as well as LRAT. In contrast, dichlorodiphenyltrichloroethane (DDT) exhibited a relatively minor seasonal variation. The OCP levels at the monitoring site were found to be related to the air parcel back trajectories on the basis of four distinct clusters. Elevated levels of HCHs and DDTs were observed when air parcels originated from northern India where considerable OCP usage was reported recently, while high levels of γ-HCH and TC (trans-chlordane) were mainly associated with air masses from southern China and northern MSA. The study highlighted the high background level of OCPs as well as their temporal patterns of trans-boundary LRAT in the MSA region.

  3. An abattoir-based study on the prevalence and economic losses due to cystic echinococcosis in slaughtered herbivores in Ahwaz, south-western Iran.

    Ahmadi, N A; Meshkehkar, M

    2011-03-01

    A 10-year (1998-2008) retrospective study was carried out to investigate the prevalence and long-term trend of hydatid disease in slaughtered herbivores in the large complex abattoir of Ahwaz (the capital of Khuzestan province, south-western Iran). A total of 3,583,417 animals including 2,815,982 sheep, 427,790 goats and 339,645 cattle were inspected macroscopically for hydatid cysts in the 10-year period, and overall 155,555 (4.24%) livers and 228,172 (6.37%) lungs were condemned. Cystic echinococcosis (CE) was responsible for 36.08% and 48.04% of total liver and lung condemnations, respectively. The prevalence of pulmonary hydatid disease in sheep, goats and cattle was 2.22, 5.43 and 6.99%, respectively; on the other hand, the prevalence of hepatic hydatid disease for those animals was 1.26, 2.57 and 2.80%, respectively. Data showed an overall downward long-term trend for CE in all livestock slaughtered during the study period (P trend was still observed. The total annual economic loss incurred due to hydatidosis in all ruminants slaughtered at Ahwaz municipal abattoir was estimated to be US$459,659.6, based on the market prices in the year 2008. This number corresponds to a loss of US$300,620.4 for cattle, US$123,490.0 for sheep and US$35,549.2 for goats. The current results provide baseline data for the future monitoring of this potentially important disease in the region, and also suggest that a thorough investigation leading to a disease control strategy is required to reduce the economic and public health consequences of CE.

  4. Floristic patterns and disturbance history in karri ( Eucalyptus diversicolor: Myrtaceae) forest, south-western Australia: 2. Origin, growth form and fire response

    Wardell-Johnson, Grant W.; Williams, M. R.; Mellican, A. E.; Annells, A.

    2007-03-01

    We examined the influence of disturbance history on the floristic composition of a single community type in karri forest, south-western Australia. Cover-abundance of 224 plant species and six disturbance and site-based environmental variables were recorded in 91, 20 m × 20 m quadrats. Numerical taxonomic and correlation approaches were used to relate these and 10 plant species-group variables based on origin, growth form and fire response. Ordination revealed no discernable pattern of sites based on floristic composition. However, all 10 species-group variables were significantly correlated with the ordination axes. Species richness within these groups varied with category and with respect to many of the disturbance and site variables. We encountered low diversity of vascular plants at the community level and limited diversity of growth forms. Thus most species were herbs (62.1%) or shrubs (30.3%), and there were no epiphytes and few species of trees or climbers. Although many introduced species were recorded (18.3% of all taxa), virtually all (83%) were herbs that demonstrated little persistence in the community, and there was limited evidence of transformer species. Time-since-fire (and other disturbance) influenced species richness more than the number of recent past fires because of a high proportion of ephemerals associated with the immediate post-fire period. Long-lived shrubs with soil stored seed dominate numerically, and in understorey biomass in comparison with neighboring vegetation types because of their greater flexibility of response following irregular, but intense disturbance events. However, interactions between nutrient status, regeneration mechanisms and community composition may be worthy of further investigation.

  5. A community survey of the pattern and determinants of household sources of energy for cooking in rural and urban south western, Nigeria.

    Desalu, Olufemi Olumuyiwa; Ojo, Ololade Olusola; Ariyibi, Ebenezer Kayode; Kolawole, Tolutope Fasanmi; Ogunleye, Ayodele Idowu

    2012-01-01

    The use of solid fuels for cooking is associated with indoor pollution and lung diseases. The objective of the study was to determine the pattern and determinants of household sources of energy for cooking in rural and urban South Western, Nigeria. We conducted a cross sectional study of households in urban (Ado-Ekiti) and rural (Ido-Ekiti) local council areas from April to July 2010. Female respondents in the households were interviewed by trained interviewers using a semi-structured questionnaire. A total of 670 households participated in the study. Majority of rural dwellers used single source of energy for cooking (55.6%) and urban dwellers used multiple source of energy (57.8%). Solid fuel use (SFU) was higher in rural (29.6%) than in urban areas (21.7%). Kerosene was the most common primary source of energy for cooking in both urban and rural areas (59.0% vs.66.6%) followed by gas (17.8%) and charcoal (6.6%) in the urban areas, and firewood (21.6%) and charcoal (7.1%) in the rural areas. The use of solid fuel was strongly associated with lack of ownership of dwellings and larger household size in urban areas, and lower level of education and lower level of wealth in the rural areas. Kerosene was associated with higher level of husband education and modern housing in urban areas and younger age and indoor cooking in rural areas. Gas was associated with high income and modern housing in the urban areas and high level of wealth in rural areas. Electricity was associated with high level of education, availability of electricity and old age in urban and rural areas respectively. The use of solid fuel is high in rural areas, there is a need to reduce poverty and improve the use of cleaner source of cooking energy particularly in rural areas and improve lung health.

  6. Primary discussion on the characteristics and metallogenesis of Lingshan composite massif in northeastern Jiangxi province

    Zhang Ping; Tian Bangsheng

    2005-01-01

    A large amount of measured data has been applied to elaborate magmatic metallogenesis of Lingshan composite massif in northeastern Jiangxi Province, and to set up a metallogenetic model for polymetallic deposits, the detailed description on the characteristics of Nb-Ta, W-Sn and Pb-Zn deposits have been given. It is suggested that the Lingshan composite massif is of a ring-like multiphase batholith. Both differences and regular changes exist in following aspects such as spatial distribution, petrology, petrochemistry, microelements, REE and so on. The genetic type of the massif is regarded as A-type granite. Important mineral resources associated with the massif are Nb-Ta, W-Sn and Pb-Zn deposits. (authors)

  7. ECOLOGY-ECONOMICAL ASSESSMENT OF NEW RECLAMATION METHOD FOR CURRENTLY WORKING TECHNOGENIC MASSIFS

    Alexey Strizhenok

    2017-01-01

    Full Text Available One of the most relevant problems of the mining industry is the need to reduce the negative impact of technogenic massifs formed by wastes of extraction and processing of mineral raw materials. This problem has a significant meaning for currently used massifs, because traditional ways of reclamation are not suitable for them. The article describes the results of a scientific study on the development of the most efficient reclamation method for currently used technogenic massifs. Described in detail the main results of the field observations, methods and equipment of laboratory experiments conducted to determine agro-chemical properties of the soil and optimal composition of binder agent. The article also provides ecological and economic assessment of the proposed method of reclamation. The study was conducted on the example of the real technogenic massif, formed by wastes of phosphorus ore processing.

  8. Three steps of serpentinization in an eclogitized oceanic serpentinization front (Lanzo Massif - Western Alps)

    DEBRET, Baptiste; NICOLLET, christian; ANDREANI, Muriel; SCHWARTZ, Stéphane; GODARD, Marguerite

    2013-01-01

    The Lanzo peridotite massif is a fragment of oceanic lithosphere generated in an ocean-continent transition context and eclogitized during alpine collision. Despite the subduction history, the massif has preserved its sedimentary oceanic cover, suggesting that it may have preserved its oceanic structure. It is an exceptional case for studying the evolution of a fragment of the lithosphere from its oceanization to its subduction and then exhumation. We present a field and petrological study re...

  9. Geophysical research results of buried relief and distribution groundwater runoff of the Aragats massif

    V.P. Vardanyan; A.H. Hovhannisyan

    2017-01-01

    Based on the synthesis and reinterpretation of long-term data of geophysical studies together with the hydrology - hydrological materials it has been received new data about the buried topography and spatial distribution of groundwater runoff of the Aragats massif. First of all, it requires to determine the structure of its buried relief, which is basically a regional relief aquitard. The underground water sources are considered to be precipitation on the massif (approximately 83% of the tota...

  10. Lytostratigraphy of the eocene sediments in the Serbian-Macedonian Massif, Republic of Macedonia

    Stojanova, Violeta; Petrov, Gose; Sijakova-Ivanova, Tena

    2017-01-01

    This paper presents the lithostratography of the eocene sedimentary series in the Serbian Macedonian massif on the territory of the Republic of Macedonia. Sediments of Eocene age in the Serbian Macedonian massif are represented in the Delchevo, Deve Bair and Strumi ca basin, with the orientation of NW-SE to S-J. With lithostratigraphic studies of eocene sediments in the basins in SMM, 3 superposition lithostratigraphic units (lithozones) were isolated:...

  11. Structural and kinematic evolution of a Miocene to Recent sinistral restraining bend: the Montejunto massif, Portugal

    Curtis, Michael L.

    1999-01-01

    The Montejunto massif lies in the apex of a large-scale restraining bend at the southern termination of a sinistral transpressive fault system, in the Lusitanian basin of Portugal. Cenozoic deformation within the Montejunto massif initiated with southerly directed thrusting along the southern boundary of the massif, in association with the development of the E-W oriented Montejunto anticline, probably during the Langhian. Deformation switched to the northern boundary of the massif, in association with a change to NW-directed thrusting and continued development of the Montejunto anticline. The youngest set of structures within the massif is related to the sinistral reactivation of the Arieiro fault system, and steeply inclined bedding. This late phase of deformation represents the accommodation of a component of sinistral displacement across the restraining bend along mechanical anisotropies formed during this progressive Cenozoic deformation event. Variation in the kinematic style of the Main Arieiro fault is related to the angle ( α) between the fault plane and the displacement vector. Where α≈20°, abrupt pene-contemporaneous switches in displacement direction are recorded along the fault, whereas strike-slip kinematics predominate where α<20°. The timing of deformation events in the Montejunto massif is uncertain. However, correlation with the established Cenozoic Africa/Europe plate convergence directions may provide potential temporal constraints.

  12. Ozone exposure, defoliation of beech (Fagus sylvatica L.) and visible foliar symptoms on native plants in selected plots of South-Western Europe

    Ferretti, Marco [Dipartimento di Biologia Vegetale, Universita di Firenze, Piazzale Cascine 28, I-50144 Florence (Italy)]. E-mail: m.ferretti@linnaea.it; Calderisi, Marco [Dipartimento di Biologia Vegetale, Universita di Firenze, Piazzale Cascine 28, I-50144 Florence (Italy)]. E-mail: calderisi@chemiometria.it; Bussotti, Filippo [Dipartimento di Biologia Vegetale, Universita di Firenze, Piazzale Cascine 28, I-50144 Florence (Italy)]. E-mail: filippo.bussotti@unifi.it

    2007-02-15

    The relationships between crown defoliation of beech, visible foliar symptoms on native vegetation and ozone exposure were investigated on permanent monitoring sites in South-Western Europe in the years 2000-2002. Relationships between defoliation of beech and O{sub 3} (seasonal mean, 2-week maximum, AOT40) were investigated by means of multiple regression models (11 plots, 1-3 years of data each) and a model based on temporal autocorrelation of defoliation data (14 plots, 1-3 years of data each). Different multiple regression techniques were used. The four models generated (R {sup 2} = 0.71-0.85, explained variance in cross-validation 61-78%) identified several significant predictors of defoliation, with AOT40 (p = 0.008) and foliar content of phosphorous (p = 0.0002-0.0004) being common to all models. The autocorrelation model (R {sup 2} = 0.55; p < 0.0001) was used to calculate expected defoliation on the basis of the previous year's defoliation, and model predictions were used as an estimate of expected defoliation under constant site and environmental condition. Residuals (predicted-measured) plotted against current AOT40 shows that a possible effect of ozone occurs only at very high AOT40 (>35,000 ppbh). O{sub 3}-like visible foliar symptoms were recorded on 65 species at 47% of the common monitoring sites in 2001 and 38% in 2002. No relationship was found between O{sub 3} exposure, frequency of symptomatic sites and frequency of species with symptoms (R {sup 2} = 0.11; p > 0.05). A number of questions related to the ecological and methodological basis of the survey were identified. Inherent sampling and non-sampling errors and multicollinearity of the data suggest great caution when examining results obtained from mensurational, correlative studies. - Ozone AOT40 was identified as a significant predictor of defoliation of beech, but a limited relationship was found between ozone exposure and visible symptoms on native vegetation.

  13. High Resolution Mapping of Soil Properties Using Remote Sensing Variables in South-Western Burkina Faso: A Comparison of Machine Learning and Multiple Linear Regression Models.

    Forkuor, Gerald; Hounkpatin, Ozias K L; Welp, Gerhard; Thiel, Michael

    2017-01-01

    Accurate and detailed spatial soil information is essential for environmental modelling, risk assessment and decision making. The use of Remote Sensing data as secondary sources of information in digital soil mapping has been found to be cost effective and less time consuming compared to traditional soil mapping approaches. But the potentials of Remote Sensing data in improving knowledge of local scale soil information in West Africa have not been fully explored. This study investigated the use of high spatial resolution satellite data (RapidEye and Landsat), terrain/climatic data and laboratory analysed soil samples to map the spatial distribution of six soil properties-sand, silt, clay, cation exchange capacity (CEC), soil organic carbon (SOC) and nitrogen-in a 580 km2 agricultural watershed in south-western Burkina Faso. Four statistical prediction models-multiple linear regression (MLR), random forest regression (RFR), support vector machine (SVM), stochastic gradient boosting (SGB)-were tested and compared. Internal validation was conducted by cross validation while the predictions were validated against an independent set of soil samples considering the modelling area and an extrapolation area. Model performance statistics revealed that the machine learning techniques performed marginally better than the MLR, with the RFR providing in most cases the highest accuracy. The inability of MLR to handle non-linear relationships between dependent and independent variables was found to be a limitation in accurately predicting soil properties at unsampled locations. Satellite data acquired during ploughing or early crop development stages (e.g. May, June) were found to be the most important spectral predictors while elevation, temperature and precipitation came up as prominent terrain/climatic variables in predicting soil properties. The results further showed that shortwave infrared and near infrared channels of Landsat8 as well as soil specific indices of redness

  14. Oxytetracycline and penicillin-G residues in cattle slaughtered in south-western Nigeria: implications for livestock disease management and public health.

    Adesokan, Hezekiah K; Agada, Charity A; Adetunji, Victoria O; Akanbi, Ibikunle M

    2013-01-01

    After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA). The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg) and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg) in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38) were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline) and 0.017% (penicillin-G) of the acceptable daily intake (ADI). Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.

  15. Oxytetracycline and penicillin-G residues in cattle slaughtered in south-western Nigeria: Implications for livestock disease management and public health

    Hezekiah K. Adesokan

    2013-07-01

    Full Text Available After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA. The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38 were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline and 0.017% (penicillin-G of the acceptable daily intake (ADI. Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.

  16. HIV status and hearing loss among children between 6 and 12 years of age at a large urban health facility in south western Uganda.

    Nakku, Doreen; Nyaiteera, Victoria; Llowet, Evelyn; Nanseera, Dennis; Nakalema, Gladys; Westerberg, Brian; Bajunirwe, Francis

    2017-10-01

    Pediatric HIV infection and treatment may increase the risk for hearing loss (HL), both sensorineural (SNHL) and conductive hearing loss (CHL). There is limited data on this subject, especially from sub Saharan Africa. The aim of this study was therefore to compare the prevalence of hearing loss among HIV positive and negative children, to determine the types of hearing loss and whether Nevirapine (NVP) based antiretroviral therapy (ART) is associated with HL. We conducted a cross sectional study at two tertiary health facilities in south western Uganda. We consecutively enrolled 79 HIV negative and 148 HIV positive children aged between 6 and 12 years. Inclusion criteria were completion of written consent, ability to follow instructions to perform an audiogram and absence of congenital HL. We conducted hearing screening using the iPad Shoebox ® audiometer, and confirmatory assessments were conducted using pure tone audiometry. Hearing was classified as either normal hearing, CHL, SNHL or mixed. Of the 227 children enrolled, 115 (50.7%) were female. The mean age was 9.2 years (median = 9). Based on self-report, frequency of HL among HIV positive children was 6.8% and 20.3% among HIV negative children (p=children was 8.8% compared to 10.1% among the HIV negative children (p = 0.74). CHL was generally more frequent than SNHL but SNHL occurred more frequently among HIV positive (7.4%) compared to HIV negative children (3.8%). No association was found between NVP based ART and HL (p = 0.41). Logistic regression showed that older age of the child (p = 0.01), previous ear infection (p=children. Older age of the child, previous ear infection, use of TB drugs and long duration on ART among the HIV positive children increase the odds of having hearing loss among children. However, use of NVP was not associated with HL. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A climate change context for the decline of a foundation tree species in south-western Australia: insights from phylogeography and species distribution modelling.

    Dalmaris, Eleftheria; Ramalho, Cristina E; Poot, Pieter; Veneklaas, Erik J; Byrne, Margaret

    2015-11-01

    A worldwide increase in tree decline and mortality has been linked to climate change and, where these represent foundation species, this can have important implications for ecosystem functions. This study tests a combined approach of phylogeographic analysis and species distribution modelling to provide a climate change context for an observed decline in crown health and an increase in mortality in Eucalyptus wandoo, an endemic tree of south-western Australia. Phylogeographic analyses were undertaken using restriction fragment length polymorphism analysis of chloroplast DNA in 26 populations across the species distribution. Parsimony analysis of haplotype relationships was conducted, a haplotype network was prepared, and haplotype and nucleotide diversity were calculated. Species distribution modelling was undertaken using Maxent models based on extant species occurrences and projected to climate models of the last glacial maximum (LGM). A structured pattern of diversity was identified, with the presence of two groups that followed a climatic gradient from mesic to semi-arid regions. Most populations were represented by a single haplotype, but many haplotypes were shared among populations, with some having widespread distributions. A putative refugial area with high haplotype diversity was identified at the centre of the species distribution. Species distribution modelling showed high climatic suitability at the LGM and high climatic stability in the central region where higher genetic diversity was found, and low suitability elsewhere, consistent with a pattern of range contraction. Combination of phylogeography and paleo-distribution modelling can provide an evolutionary context for climate-driven tree decline, as both can be used to cross-validate evidence for refugia and contraction under harsh climatic conditions. This approach identified a central refugial area in the test species E. wandoo, with more recent expansion into peripheral areas from where it had

  18. The planktonic food web of the Bizerte lagoon (south-western Mediterranean) during summer: I. Spatial distribution under different anthropogenic pressures

    Sakka Hlaili, Asma; Grami, Boutheina; Niquil, Nathalie; Gosselin, Michel; Hamel, Dominique; Troussellier, Marc; Hadj Mabrouk, Hassine

    2008-06-01

    The structure and the trophic interactions of the planktonic food web were investigated during summer 2004 in a coastal lagoon of south-western Mediterranean Sea. Biomasses of planktonic components as well as bacterial and phytoplankton production and grazing by microzooplankton were quantified at four stations (MA, MB, MJ and R) inside the lagoon. Station MA was impacted by urban discharge, station MB was influenced by industrial activity, station MJ was located in a shellfish farming sector, while station R represented the lagoon central area. Biomasses and production rates of bacteria (7-33 mg C m -3; 17.5-35 mg C m -3 d -1) and phytoplankton (80-299 mg C m -3; 34-210 mg C m -3 d -1) showed high values at station MJ, where substantial concentrations of nutrients (NO 3- and Si(OH) 4) were found. Microphytoplankton, which dominated the total algal biomass and production (>82%), were characterized by the proliferation of several chain-forming diatoms. Microzooplankton was mainly composed of dinoflagellates ( Torodinium, Protoperidinium and Dinophysis) and aloricate ( Lohmaniellea and Strombidium) and tintinnid ( Tintinnopsis, Tintinnus, Favella and Eutintinnus) ciliates. Higher biomass of these protozoa (359 mg C m -3) was observed at station MB, where large tintinnids were encountered. Mesozooplankton mainly represented by Calanoida ( Acartia, Temora, Calanus, Eucalanus, Paracalanus and Centropages) and Cyclopoida ( Oithona) copepods, exhibited higher and lower biomasses at stations MA/MJ and MB, respectively. Bacterivory represented only 35% of bacterial production at stations MB and R, but higher fractions (65-70%) were observed at stations MA and MJ. Small heterotrophic flagellates and aloricate ciliates seemed to be the main controllers of bacteria. Pico- and nanophytoplankton represented a significant alternative carbon pool for micrograzers, which grazing represented 67-90% of pico- and nano-algal production in all stations. Microzooplankton has, however, a

  19. High Resolution Mapping of Soil Properties Using Remote Sensing Variables in South-Western Burkina Faso: A Comparison of Machine Learning and Multiple Linear Regression Models.

    Gerald Forkuor

    Full Text Available Accurate and detailed spatial soil information is essential for environmental modelling, risk assessment and decision making. The use of Remote Sensing data as secondary sources of information in digital soil mapping has been found to be cost effective and less time consuming compared to traditional soil mapping approaches. But the potentials of Remote Sensing data in improving knowledge of local scale soil information in West Africa have not been fully explored. This study investigated the use of high spatial resolution satellite data (RapidEye and Landsat, terrain/climatic data and laboratory analysed soil samples to map the spatial distribution of six soil properties-sand, silt, clay, cation exchange capacity (CEC, soil organic carbon (SOC and nitrogen-in a 580 km2 agricultural watershed in south-western Burkina Faso. Four statistical prediction models-multiple linear regression (MLR, random forest regression (RFR, support vector machine (SVM, stochastic gradient boosting (SGB-were tested and compared. Internal validation was conducted by cross validation while the predictions were validated against an independent set of soil samples considering the modelling area and an extrapolation area. Model performance statistics revealed that the machine learning techniques performed marginally better than the MLR, with the RFR providing in most cases the highest accuracy. The inability of MLR to handle non-linear relationships between dependent and independent variables was found to be a limitation in accurately predicting soil properties at unsampled locations. Satellite data acquired during ploughing or early crop development stages (e.g. May, June were found to be the most important spectral predictors while elevation, temperature and precipitation came up as prominent terrain/climatic variables in predicting soil properties. The results further showed that shortwave infrared and near infrared channels of Landsat8 as well as soil specific indices

  20. Preandean geological configuration of the eastern North Patagonian Massif, Argentina

    Daniel A. Gregori

    2013-11-01

    Full Text Available The Preandean geological configuration of the eastern North Patagonian Massif is established through the use of geological and geophysical analysis. The positive gravity anomalies located near the Atlantic coast are due to 535 and 540 Ma old rocks belonging to the Pampean Orogeny (Precambrian–middle Cambrian, which are widely recognized in central and northern Argentina. The Famatinian Cycle (Ordovician–Devonian is represented by a Silurian–Devonian marine basin equivalent to those of eastern-central Argentina and South Africa, and which was deformed at the end of the Devonian by an ∼E–W to WNW–ESE compressional event, part of the Famatinian Orogeny. Containing strong gravity gradients, the NW–SE belt is coincident with fault zones which were originated during the Gondwanide Orogeny. This event also produced NW–SE overthrusting of the Silurian–Devonian sequences and strike-slip faults that displaced blocks in the same direction. This deformation event belongs to the Gondwanide Orogeny that includes movements related to a counterclockwise rotation of blocks in northern Patagonia. The strong negative anomalies located in the western part of the area stem from the presence of rocks of the Jurassic Cañadón Asfalto basin interbedded in the Marifil Complex. These volcaniclastic sequences show mild deformation of accommodation zones in a pre-Jurassic paleorelief.

  1. Deforestation Along the Maya Mountain Massif Belize-Guatemala Border

    Chicas, S. D.; Omine, K.; Arevalo, B.; Ford, J. B.; Sugimura, K.

    2016-06-01

    In recent years trans-boundary incursions from Petén, Guatemala into Belize's Maya Mountain Massif (MMM) have increased. The incursions are rapidly degrading cultural and natural resources in Belize's protected areas. Given the local, regional and global importance of the MMM and the scarcity of deforestation data, our research team conducted a time series analysis 81 km by 12 km along the Belize-Guatemalan border adjacent to the protected areas of the MMM. Analysis drew on Landsat imagery from 1991 to 2014 to determine historic deforestation rates. The results indicate that the highest deforestation rates in the study area were -1.04% and -6.78% loss of forested area per year in 2012-2014 and 1995-1999 respectively. From 1991 to 2014, forested area decreased from 96.9 % to 85.72 % in Belize and 83.15 % to 31.52 % in Guatemala. During the study period, it was clear that deforestation rates fluctuated in Belize's MMM from one time-period to the next. This seems linked to either a decline in deforestation rates in Guatemala, the vertical expansion of deforestation in Guatemalan forested areas and monitoring. The results of this study urge action to reduce incursions and secure protected areas and remaining forest along the Belize-Guatemalan border.

  2. DEFORESTATION ALONG THE MAYA MOUNTAIN MASSIF BELIZE-GUATEMALA BORDER

    S. D. Chicas

    2016-06-01

    Full Text Available In recent years trans-boundary incursions from Petén, Guatemala into Belize’s Maya Mountain Massif (MMM have increased. The incursions are rapidly degrading cultural and natural resources in Belize’s protected areas. Given the local, regional and global importance of the MMM and the scarcity of deforestation data, our research team conducted a time series analysis 81 km by 12 km along the Belize-Guatemalan border adjacent to the protected areas of the MMM. Analysis drew on Landsat imagery from 1991 to 2014 to determine historic deforestation rates. The results indicate that the highest deforestation rates in the study area were −1.04% and −6.78% loss of forested area per year in 2012-2014 and 1995-1999 respectively. From 1991 to 2014, forested area decreased from 96.9 % to 85.72 % in Belize and 83.15 % to 31.52 % in Guatemala. During the study period, it was clear that deforestation rates fluctuated in Belize's MMM from one time-period to the next. This seems linked to either a decline in deforestation rates in Guatemala, the vertical expansion of deforestation in Guatemalan forested areas and monitoring. The results of this study urge action to reduce incursions and secure protected areas and remaining forest along the Belize-Guatemalan border.

  3. Local Seismicity of the Rainbow Massif on the Mid-Atlantic Ridge

    Horning, G.; Sohn, R. A.; Canales, J. P.; Dunn, R. A.

    2018-02-01

    The Rainbow massif, an oceanic core complex located in a nontransform discontinuity on the Mid-Atlantic Ridge (36°N), is notable for hosting high-temperature hydrothermal discharge through ultramafic rocks. Here we report results from a 9 month microearthquake survey conducted with a network of 13 ocean bottom seismometers deployed on and around the Rainbow massif as part of the MARINER experiment in 2013-2014. High rates ( 300 per day) of low-magnitude (average ML 0.5) microearthquakes were detected beneath the massif. The hypocenters do not cluster along deeply penetrating fault surfaces and do not exhibit mainshock/aftershock sequences, supporting the hypothesis that the faulting associated with the exhumation of the massif is currently inactive. Instead, the hypocenters demarcate a diffuse zone of continuous, low-magnitude deformation at relatively shallow (serpentinized ultramafic host rock, and although the seismic network we deployed was not capable of constraining the focal mechanism of most events, our analysis suggests that serpentinization may play an important role in microearthquake generation at the Rainbow massif.

  4. The Alto Moxoto Terrain in Eastern Paraiba ('Caldas Brandao Massif')

    Neves, Benjamim Bley de Brito; Campos Neto, Mario da Costa; Souza, Solange Lucena de; Schmus, William Randall Van; Fernandes, Tania Maria Gomes

    2001-01-01

    The Alto Moxoto Terrane (TAM), at the east of Paraiba State is mostly composed of sheared ortho gneisses, porphyritic granodioritic gneisses and it bears an imbricated sheet of Al-rich (garnet-biotite-sillimanite) gneisses, deeply affected by migmatization phenomena. This litho-structural assemblage is drawing a regional asymmetric anti formal structure, with its axial zone running parallel to the B R-230 highway (E-W trending). It is limited in both, north (Alto Pajeu terrane) and south (Rio Capibaribe terrane) sides by important shear zones, which are feather faults connected with the development of the Pernambuco lineament, to the southwest. The adopted designation of 'terrane' is based upon its singular geological features, in terms of lithological and structural characteristics, Paleoproterozoic in age and sharp limits with the different confining terranes. TAM is here considered as a mega-fragment of the Atlantica Super continent, that was built up by the Paleoproterozoic Collage ('Transamazonian') and that was preserved in the framework of West Gondwana (Brasiliano/Pan African Collage) as a 'terrane'. This terrane shows conspicuous continuity to the far interior of the province, to the southwestern part of Pernambuco State, and so doing, it demonstrates that the former designation of 'Caldas Brandao Massif must be ruled out, as obsolete for many reasons. Geochronological determinations using Rb-Sr, Sm-Nd and U-Pb methods confirm the Paleoproterozoic age of this terrane, with the presence of some Archean protoliths as well as the various degrees of structural reworking and isotopic reseting promoted by the Brasiliano Cycle. This cycle was responsible for some intrusive granites, for most of the general geological features, like usual informal limits and even the present shape of the TAM, a typical reworked 'basement inlier'. (author)

  5. Geochemical aspects of alkaline massif of Banhadao, PR, Brazil

    Ruberti, E.; Gomes, C.B.; Dutra, C.V.

    1987-01-01

    The alkaline massif of Banhadao, located near Cerro Azul, State of Parana, southern Brazil, occupies an area of about 8 Km 2 and is constituted by three magnetic associations: a group of mesocratic to leucocratic coarse nepheline syenites (NeS) (melanite NeS, NeS I, and light reddish and grey varieties of NeS II); a second group of medium to fine-grained ultrabasic to basic rocks (phlogopite melteigites and petrologically related malignites and feldspar-melanite ijolites); and a group of fine-grained to aphanitic phonolotic dikes, cutting NeS. The rocks of the complex are miaskitic, showing low concentrations of trace elements (V, Th and mainly REE), lack of rare metal silicates, and relative abundance of apatite and sphene. NeS are distinguished by a differentiation trend in which highly differentiated end members are enriched in alkalis and Al 2 O 3 , with decrease in MgO, FeO (total), CaO and TiO 2 . The less differentiated melanite-rich rocks show higher concentrations in Zr, Nb, Y and V. Phlogopite melteigites and associated rocks show the highest contents of MgO, FeO (total), CaO and TiO 2 , and the lowest concentration of alkalis and Al 2 O 3 ; they are significantly enriched in Ba and are the only rocks with detectable amounts of Ni, Cu and Cr. The phonolites are chemically similar to NeS. The Banhadao rocks were probably formed during successive intrusions of two different magmas types. The source of NeS and phonolites was probably a nephelinitic magma, while phlogopite melteigites and related rocks were probably derived from an alkali-enriched ferromagnesian magna. Both parent magmas probably derived by melting of rocks of the lower crust or upper mantle. (author) [pt

  6. The rockfall observatory in the Reintal, Wetterstein Massif, German Alps

    Schöpa, Anne; Turowski, Jens M.; Hovius, Niels

    2017-04-01

    The Reintal is an Alpine valley in the Wetterstein Massif close to the Zugspitze, Germany's highest mountain. Due to the variety of active geomorphic processes, including rockfalls off the steep limestone cliffs, debris flows, and snow avalanches, and the river Partnach, the Reintal has been the field area of many geomorphological and hydrological research campaigns over the last few decades. In 2014, the Geomorphology Section of the GFZ Potsdam started to install a monitoring network to detect and classify rockfalls in the Reintal. The network includes six seismic stations, optical and infrared cameras, and two weather stations measuring air and rock temperature, air pressure and relative humidity, precipitation, wind speed and direction, and solar radiation. The continuous observations of the network are supplemented by repeated field campaigns including terrestrial laser scans of a prominent rockfall niche at the Hochwanner mountain. The about 1,500 m high north face of the Hochwanner experienced the detachment of a 2.8 Mio m3 rockfall about 500 years ago that created the so-called Steingerümpel (German for rock debris deposit) and dammed the river Partnach. The cliff still shows high rockfall activity, and an 80,000 m3 block can be expected to fall in the near future. In this contribution, the layout of the observatory and details of the seismic network centered around the Hochwanner north face are described. Furthermore, the network data of a severe thunderstorm event in June 2016, that triggered many rockfalls and debris flows in the Reintal, is presented.

  7. The tardi-Pan-African granitoids of South-Westerner Anti-Atlas (Morocco: Evolution from magnesian to ferroan type. Example of the Ifni inlier

    El Aouli, E. H.

    2007-06-01

    Full Text Available The study of the neoproterozoic granitoids in the Ifni Inlier and those of the other inliers in south-westerner Anti-Atlas shows that this magmatism evolves from magnesian to ferroan type. In the Ifni inlier, these granitoids outcrop within the sedimentary and volcanogenic formations of the Ouarzazate Super- Group SGO (615 to 540 My. They belong to two distinct magmatic episodes (i an early one composed of magnesian granitoids with alkali-calcic and metaluminous to slightly aluminous character (quartz bearing diorite, granodiorite and monzogranite intrusive in the lower formations of the SGO, and (ii a late episode associated to the summit of the SGO volcanites, which includes granites and sub-volcanic syenogranites of iron-bearing type and alkali-calcic to alkaline affinity. These magmatisms resulting from the partial melting of mixed material mark the end of the last Panafrican episode and would be set up in a transition from orogenic to anorogenic settings which announce the Paleozoic cycle. They would be contemporary to posterior with the exhumation of the extensive metamorphic domes of the Western Anti-Atlas.El estudio de los granitoides neoproterozoicos de la “boutonnière” (complejo plutono-metamórfico profundo con geometría subcircular de Ifni y de los de otras “boutonnières” del dominio suroccidental del Anti-Atlas, demuestra que este magmatismo evoluciona desde un tipo magnésico hacia un tipo férrico. En la “boutonnière” de Ifni, estos granitoides afloran en el interior de formaciones sedimentarias y volcano-sedimentarias del Supergrupo de Ouarzazate SGO (615 a 540 Ma. Pertenecen a dos episodios magmáticos diferentes (i un episodio precoz compuesto de granitoides magnésicos, calcoalcalinos y metaluminosos a poco aluminosos (dioritas con cuarzo, granodioritas y monzogranitos que intruyen en las formaciones inferiores del SGO, (ii un episodio tardío asociado con un vulcanismo terminal a techo del

  8. Contribution of atmospheric processes affecting the dynamics of air pollution in South-Western Europe during a typical summertime photochemical episode

    M. Gonçalves

    2009-02-01

    3 surface concentrations. The O3 chemical formation involves the oxidation of less NMVOCs in the NEIP than in the CIP domains, due to differences in chemical sensitivity between these areas. The dry deposition is an important sink in the lowest layer of the model, together with vertical diffusion flows. Finally, the contributions from cloud processes, wet deposition and heterogeneous chemistry are negligible during the whole episode, characterized by a high solar radiation and neither precipitation nor cloudiness. This process analysis provides new quantitative information about the origin of the peaks of O3 and its precursors, aiding the design of abatement strategies in South-Western Europe.

  9. Palynostratigraphical correlation of the excavated Miocene lignite seams of the Yataǧan basin (Muǧla Province, south-western Turkey)

    Bouchal, Johannes Martin; Grímsson, Friðgeir; Denk, Thomas

    2016-04-01

    The excavated main lignite seams and overlying lacustrine sediments of the opencast mines Eskihisar, Salihpaşalar, and Tı naz, Muǧla Province, south-western Turkey were investigated using a high taxonomic resolution palynological approach. The Eskihisar section comprises 47m and 56 samples of which 30 were usable for palynological analysis. The Tı naz section comprises 75 m and 29 samples of which 15 were usable for palynological analysis. Finally, the Salihpaşalar section comprises 25 m and 26 samples of which 16 were usable for palynological analysis. The age of the palynological sections is middle to late Miocene based on radiometric dating and vertebrate fossils. In order to investigate dispersed pollen and spores and their botanical affinities a combined light microscopy and scanning electron microscopy approach was used. The rich palynoflora comprises: seven types of algal cysts (Botryococcus, Zygnemataceae), seventeen spore types belonging to Lycopsida (club mosses), Marsileaceae (water-clover), Osmundaceae, Pteridaceae (brake), and Polypodiaceae; 14 types of gymnosperm pollen belonging to Ephedraceae (Mormon tea), Cupressaceae, Pinaceae (Cathaya, cedar, hemlock, pine, spruce); five types of monocotyledone pollen belonging to Poaceae (grasses, common reed), and Typhaceae (bulrush, bur-reed); ca 90 dicotyledone pollen types belonging to Altingiaceae (sweet gum), Amaranthaceae (goosefoot), Anacardiaceae (sumac family), Apiaceae (parsley family), Aquifoliaceae (holly), Asteraceae (sunflower family), Betulaceae (alder, birch, hazel, hophornbeam, hornbeam), Campanulaceae (bellflower family), Cannabaceae (hackberries), Caprifoliaceae (honeysuckle, teasel family), Caryophyllaceae (pink family), Ericaceae (heather family), Eucommiaceae, Euphorbiaceae (spurge family), Fabaceae (bean family), Fagaceae (beech, oak), Geraniaceae (storkbills), Juglandaceae (hickory, walnut, wingnut), Lamiaceae (bagflower), Linaceae (flax), Lythraceae (waterwillow), Malvaceae

  10. Sedimentary connection between rock glaciers and torrential channels: definition, inventory and quantification from a test area in the south-western Swiss Alps

    Kummert, Mario; Barboux, Chloé; Delaloye, Reynald

    2017-04-01

    order to validate these estimations, the resulting sediment transfer rates are compared to transfer rates calculated from repeated terrestrial LiDAR surveys on selected study cases. This contribution presents results from the application of this methodology in a test study area in the south-western Swiss Alps. The methodology reveals itself suitable to identify rock glaciers connected to the torrential network. For each of the detected rock glaciers, an estimation of the sediment yield is proposed. The transfer rates range from tens of cubic meters per year for some slow moving and/or partially connected landforms, to several thousands of cubic meters per year. References: Delaloye R. (2004). Contribution à l'étude du pergélisol de montagne en zone marginale. GeoFocus vol. 10, Thèse, Département de Géosciences/Géographie, Université de Fribourg. Delaloye, R., Lambiel, C., Gärtner-Roer, I. (2010). Overview of rock glacier kinematics research in the Swiss Alps. Seasonal rhythm, interannual variations and trends over several decades. Geogr. Helv., 65: 2, 135-145. Delaloye, R., Morard, S., Barboux, C., Abbet, D., Gruber, V., Riedo, M. & Gachet, S. (2013). Rapidly moving rock glaciers in Mattertal. In: Graf, C. (Eds). Mattertal - ein Tal in Bewegung. Publikation zur Jahrestagung der Schweizerischen Geomorphologischen Gesellschaft 29. Juni - 1. Juli 2011, St. Niklaus, Birmensdorf, Eidg. Forschungsanstalt WSL, 113 - 124. Gärtner-Roer, I. (2012). Sediment transfer rates of two active rockglaciers in the Swiss Alps. Geomorphology, 167-168, 45-50. Lugon, R. & Stoffel, M. (2010). Rock glacier dynamics and magnitude-frequency relations of debris flows in a high-elevation watershed : Ritigraben, Swiss Alps. Global and Planetary Change, 73, 202-210.

  11. Anaplasma marginale infection in cattle from south-western Amazonia Infecção por Anaplasma marginale em bovinos na Amazônia Sul Ocidental, Brasil

    Luciana Gatto Brito

    2010-03-01

    Full Text Available The present study provides the first epidemiological data regarding infection by Anaplasma marginale in cattle reared in south-western Brazilian Amazonia. One simple procedure was adapted for the extraction of DNA from blood clots collected in seven microregions of Rondônia State and two mesoregions of Acre State. PCR method was used to asses the frequency of A. marginale infections in 4 to12-month-old cattle. The cattle infection was investigated by polymerase chain reaction (PCR using the specific primer "msp5" for A. marginale. The DNA amplifications revealed that the mean frequency of A. marginale infection was 98.6% (1,627/1,650 in samples from Rondonia, and 92.87% (208/225 in samples from Acre. The high frequency of A. marginale infections in 4 to 12-month-old cattle indicate a situation of enzootic stability in the studied areas and are comparable to those detected by immunodiagnosis in different endemic regions in Brazil. The DNA extraction of clotted blood method described here can be used for epidemiological studies on anaplasmosis and other bovine hemoparasites.O presente estudo fornece os primeiros dados epidemiológicos relativos a infecção por Anaplasma marginale em bovinos criados na Amazônia Sul Ocidental brasileira. Foi adaptado um procedimento simples para a extração de DNA a partir de coágulos sanguíneos coletados em sete microrregiões do estado de Rondônia e duas mesoregiões do estado do Acre. A técnica da reação em cadeia da polimerase (PCR foi aplicada para avaliar a freqüência da infecção por A. marginale em bovinos com idade entre 4 e 12 meses. Após a extração do DNA de cada amostra, a infecção nos bovinos foi investigada pela amplificação do gene "msp5" de A. marginale. As técnicas de amplificação do DNA revelaram que a freqüência de infecção por A. marginale foi de 98,6% (1.627/1.650 nas amostras provenientes de Rondônia e de 92,87% (208/225 nas amostras do Acre. A alta freqüência da

  12. Petrology, geochemistry and source characteristics of the Burpala alkaline massif, North Baikal

    N.V. Vladykin

    2017-07-01

    Full Text Available The Burpala alkaline massif contains rocks with more than 50 minerals rich in Zr, Nb, Ti, Th, Be and rare earth elements (REE. The rocks vary in composition from shonkinite, melanocratic syenite, nepheline and alkali syenites to alaskite and alkali granite and contain up to 10% LILE and HSFE, 3.6% of REE and varying amounts of other trace elements (4% Zr, 0.5% Y, 0.5% Nb, 0.5% Th and 0.1% U. Geological and geochemical data suggest that all the rocks in the Burpala massif were derived from alkaline magma enriched in rare earth elements. The extreme products of magma fractionation are REE rich pegmatites, apatite–fluorite bearing rocks and carbonatites. The Sr and Nd isotope data suggest that the source of primary melt is enriched mantle (EM-II. We correlate the massif to mantle plume impact on the active margin of the Siberian continent.

  13. Immunohistochemical localization of CYP1A, vitellogenin and Zona radiata proteins in the liver of swordfish (Xiphias gladius L.) taken from the Mediterranean Sea, South Atlantic, South Western Indian and Central North Pacific Oceans

    Desantis, S.; Corriero, A.; Cirillo, F.; Deflorio, M.; Brill, R.; Griffiths, M.; Lopata, A.L.; Serna, J.M. de la; Bridges, C.R.; Kime, D.E.; De Metrio, G.

    2005-01-01

    Cytochrome P4501A (CYP1A) monoxygenase, vitellogenin (Vtg) and Zona radiata proteins (Zrp) are frequently used as biomarkers of fish exposure to organic contaminants. In this work, swordfish liver sections obtained from the Mediterranean Sea, the South African coasts (South Atlantic and South Western Indian Oceans) and the Central North Pacific Ocean were immunostained with antisera against CYP1A, Zrp, and Vtg. CYP1A induction was found in hepatocytes, epithelium of the biliary ductus and the endothelium of large blood vessels of fish from the Mediterranean Sea and South African waters, but not from the Pacific Ocean. Zrp and Vtg were immunolocalized in hepatocytes of male swordfish from the Mediterranean Sea and from South African waters. Plasma Dot-Blot analysis, performed in Mediterranean and Pacific specimens, revealed the presence of Zrp and Vtg in males from Mediterranean but not from Pacific. These results confirm previous findings about the potential exposure of Mediterranean swordfish to endocrine, disrupting chemicals and raise questions concerning the possible presence of xenobiotic contaminants off the Southern coasts of South Africa in both the South Atlantic and South Western Indian Oceans

  14. First data on Sm-Nd systematization of Khanka Massif metamorphic rocks, Primor'e

    Mishkin, M.A.; Khanchuk, A.I.; Zhuravlev, D.Z.; Lavrik, S.N.

    2000-01-01

    The age of the metamorphic rocks of the Khanka massif, Primor'e, is determined through the method of the Sm-Nd isotopic dating. The results of the isotopic studies on the amphibolites of the Nakhimov suite of the Khanka massif indicated that the rocks of this suite are not older than 1.7 billion years. The obtained age corresponds to the time of the amphibolite protolith formation, the source whereof is the moderately depleted mantle. The isotopic age of the amphibole and plagioclase mineral fractions constitutes 733 ± 25 mln years, which reflects the time of the Nakhimov suite rocks metamorphism [ru

  15. Uranium and thorium in rocks and minerals of Zaangarsk alkaline massif

    Zhmodin, S.M.; Gofman, A.M.; Ksenzova, V.I.; Malmova, Z.V.; Nemirovskaya, N.A.

    1981-01-01

    U and Th distribution in rocks of the massif of alkaline-granitoid formation is studied using the methods of γ-spectrometry and neutron- fragment radiography. Predominant accumulation of U and Th in final products of magmatic differentiation - foyaites - is established. U and Th concentrations increased sharply during postmagmatic stage of alkaline massif formation - in permatites and metasomatically alterated rocks (Th/U and U/K ratios can serve as criteria for identification of such formations). The increase of U part, connected with accessory minerals in pegmatites and metasomatically alterated rocks, is pointed out. For U in postmagmatically alterated rocks high concentrations due to microcracks are characteristic [ru

  16. Sm-Nd dating of the Verkhneundytkansky massif of autonomous anorthosites (Aldanian Shield)

    Sukhanov, M.K.; Lennikov, A.M.; Zhuravlev, D.Z.

    1991-01-01

    Geochronological investigation of four typical rocks of the Verkhneundyransky anorthosite massif as well as rock-forming minerals of one of the samples is carried out by the method of Sm-Nd dating. Model ayes of the investigated rocks which were calculated with respect to the depleted mantle, constitute 2.22-2.35 bullion ylars which well agrees with the isochronous age. The experimental points fall well on the regression line which attests that the crystallization of the investigated massif proceeded rather fast and the latter could not assimilate the crustal matter to a considerable extent

  17. The influence of tectonical structures on the stability rock massif in the area of the magnesite deposit Jelšava of the Dúbrava massif

    Sasvári Tibor

    2002-12-01

    Full Text Available Magnesite deposits Dúbrava and Miková are located in Carboniferous formations between Brádno and Ochtiná (Dúbrava massif. Carboniferous magnesites are, according to the lithostratigraphic division of Early Paleozoic complexes of Gemericum by Bajaník et al. (1983, situated in the Dobšiná Group, more precisely in the upper part of the Ochtiná Formation, in the environment of black schists with intercalation of metabasalts and their pyroclastics. In the lower parts of the formation are small-pebble conglomerates and polymict sandstones. Carbonatic bodies of the Dúbrava massif has the directional length, 4 500 m, course NE-SW, inclination 55-60o to SE and maximal thickness 600 m. A calculation in 1967 indicated above 500 millions kt of reserves whish after a modification of conditional parameters was reduced to its three fifths. Reserves excluded during the second calculation had a higher content of Fe2O3 causing the lowering of fireproof products quality.In the text the structural and stability conditions in the area of the Dúbrava deposit and the Miková deposit of the Dúbrava massif are analysed.

  18. Environmental characterization of lake ecosystems located in Serbo Macedonian massif (FYRM)

    Dolenec, Tadej; Serafimovski, Todor; Lojen, Sonja; Dolenec, Matej; Tasev, Goran; Kramar, Sabina; Rogan Šmuc, Nastja; Vrhovnik, Petra

    2015-01-01

    This mineralogical, geochemical and isotopic characteristics of recent lacustrine sediments, of Anodonta cygnea shells and of fish species Rutilus rutilus dojranensis from the Lake Dojran (FY Republic of Macedonia, southern part of the Serbo-Macedonian Massif (SMM)), which provide indirect evidence regarding biomineralization and calcification processes as well as various geological problems. Environmental pollution can seriously impair physiological functions such as the secre...

  19. The Massification of Higher Education in the UK: Aspects of Service Quality

    Giannakis, Mihalis; Bullivant, Nicola

    2016-01-01

    This article explores several aspects of service quality for the provision of higher education. Alongside the trend of the massification of higher education over the past two decades, higher education institutions are required to review quality across a range of outputs, besides teaching and learning. The study was undertaken within the…

  20. N-S crustal shear system in the Bundelkhand massif: a unique ...

    56

    In the light of our detailed geological studies of the massif (Singh and Bhattacharya,. 2010 .... relations with, and displace, the earlier shear systems, i.e. BS1, BS2 and BS3 (Fig. 3D), (3) ..... and shear zone patterns: The South Indian case. Jour.

  1. Massification and Diversity of Higher Education Systems: Interplay of Complex Dimensions

    Guri-Rosenblit, Sarah; Sebkova, Helena; Teichler, Ulrich

    2007-01-01

    This paper provides a synthetic overview of the complex dimensions that shape the interrelations between the massification of higher education systems and their structure and composition. Many higher education systems worldwide expanded extensively in the last decades, and have undergone wide and deep structural changes. Most notably, the…

  2. Massification and Diversification as Complementary Strategies for Economic Growth in Developed and Developing Countries

    Tyndorf, Darryl; Glass, Chris R.

    2016-01-01

    Numerous microeconomic studies demonstrate the significant individual returns to tertiary education; however, little empirical evidence exists regarding the effects of higher education massification and diversification agendas on long-term macroeconomic growth. The researchers used the Uzawa-Lucas endogenous growth model to tertiary education…

  3. Late Paleozoic volcanic rocks of the Intra-Sudetic Basin, Bohemian Massif: Petrological and geochemical characteristics

    Ulrych, Jaromír; Fediuk, F.; Lang, Miloš; Martinec, Petr

    2004-01-01

    Roč. 64, č. 2 (2004), s. 127-153 ISSN 0009-2819 R&D Projects: GA AV ČR(CZ) IAA3013903 Keywords : Late Paleozoic * volcanic rocks * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.643, year: 2004

  4. Geophysical research results of buried relief and distribution groundwater runoff of the Aragats massif

    V.P. Vardanyan

    2017-03-01

    Overall, the new data concerning the structure of the buried relief of Aragats massif and the distribution of its underground runoff allow to develop effective measures for the selection of underground waters and their rational usage for the purpose of water supply and irrigation.

  5. Significance of geological units of the Bohemian Massif, Czech Republic, as seen by ambient noise interferometry

    Růžek, Bohuslav; Valentová, L.; Gallovič, F.

    2016-01-01

    Roč. 173, č. 5 (2016), s. 1663-1682 ISSN 0033-4553 R&D Projects: GA ČR GAP210/12/2336; GA MŠk LM2010008 Institutional support: RVO:67985530 Keywords : ambient noise * geological units * Bohemian Massif * velocity model Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.591, year: 2016

  6. Permian fauna of the Krkonoše Piedmont Basin (Bohemian Massif, Central Europe)

    Zajíc, Jaroslav

    2014-01-01

    Roč. 70, 3/4 (2014), s. 131-142 ISSN 0036-5343 Institutional support: RVO:67985831 Keywords : faunal lists * palaeogeography * palaeoenvironment * stratigraphy * Early Permian * Krkonoše Piedmont Basin * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy

  7. Upper Cretaceous to Pleistocene melilitic volcanic rocks of the Bohemian Massif: Petrology and mineral chemistry

    Skála, Roman; Ulrych, Jaromír; Krmíček, Lukáš; Fediuk, F.; Balogh, K.; Hegner, E.

    2015-01-01

    Roč. 66, č. 3 (2015), s. 197-216 ISSN 1335-0552 Institutional support: RVO:67985831 Keywords : Bohemian Massif * Cenozoic volcanism * isotope geochemistry * melilitic rock * mineralogy * petrology Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.523, year: 2015

  8. Cenozoic alkaline volcanic rocks with carbonatite affinity in the Bohemian Massif: Their sources and magma generation

    Ulrych, Jaromír; Štěpánková-Svobodová, Jana

    2014-01-01

    Roč. 46, 1/2 (2014), s. 45-58 ISSN 0369-2086 R&D Projects: GA AV ČR(CZ) IAA300130902 Institutional support: RVO:67985831 Keywords : alkaline volcanic rocks * melilitic rocks * carbonatites * magma generation * metasomatism * Cenozoic * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy

  9. Assessment of flora condition and transformation extent at the Degelen mountain massif

    Tuleubaev, B.A.; Sejsebaev, A.T.; Sultanova, B.M.; Dzhanin, B.T.

    2000-01-01

    The article describes current condition of vegetation at the Degelen mountain massif and assessment of vegetation disturbance in areas of underground nuclear testing. It also presents results of studying flora transformation, species and cinotic composition, structural and spatial distribution within the Degelen technical site. (author)

  10. TOURISTIC POTENTIAL, MANAGEMENT AND DEVELOPMENT IN THE RARĂU MASSIF

    Dinu OPREA-GANCEVICI

    2011-06-01

    Full Text Available As a socio-economic activity, tourism is strongly influenced by numerous factors that determine the size and direction of tourist flows. Mountain tourism is no exception; the mountainous land relief, which generates this type of tourism, possesses a large array of factors which, by definition, represent true attractions for tourists (morphometric elements, types and landforms, oxygen-rich air, specific flora and fauna, but also several factors that may inhibit tourist activity proper (development capacity, climate, natural phenomena hazards.In particular, with reference to the Rarău Massif, we shall emphasize its tourist potential, especially the geomorphologic one, but we shall also highlight the evolution and the present state of infrastructure (accommodation facilities, tourist paths. The cartographic analysis and representation were obtained using dedicated software, generically called Geographic Informatics Systems (GIS, and a social research method as well – the questionnaire. As such, our research features several maps that highlight the differentiated land relief potential as well as the potential resulted from the application of questionnaires, thus bringing into the foreground the areas with maximal morphologic attractiveness and implicitly potential for tourist activity. In order to make the most of the entire massif and to diversify tourist routes we propose new itineraries with a view to covering the entire area more effectively and offering new exploration variants for the massif. The applied questionnaire proves the connection between the tourist potential of land relief and tourists’ perceptions of the tourist sights in the Rarău Massif.

  11. Modeling the uplift in the Ardennes-Rhenish Massif: Mechanical weakening under the Eifel?

    Garcia-Castellanos, D.; Cloetingh, S.A.P.L.; van Balen, R.T.

    2000-01-01

    Middle Pleistocene uplift in the Eifel has been interpreted as the isostatic response of the lithosphere to a deep buoyant hot body. The spatial and temporal distribution of the uplift in the Ardennes-Rhenish Massif Region has recently been constrained by new data of river incision that have been

  12. Geology of the Menderes Massif and the Lycian Nappes South of Denizli, Western Taurides

    Aral İ. OKAY

    1989-06-01

    Full Text Available Mount Honaz region in the Western Taurides is made up of superimposed several tectonic units. In the west, monotonous green metashales called the Honaz shale occur at the base of the tectonic stack. Honaz shale is tectonically overlain by weakly metamorphosed, massif white limestone, thinly bedded cherty limestone and shale which covers the Mendercs massif. Menderes massif is in turn tectonically overlain by the Sandak complex of the Lycian nappes made up of Mesozoic dolomites and limestones and ophiolite mainly of harzburgite lies oven the Sandak complex. All these tectonic units form an eastward overturned major anticline called the Honaz anticline; a pelagic sedimentary sequence of Late Cretaceous—Middle/Late Eocene age, called the Göbecik Tepe complex, occurs tectonically beneath the overturned limb of the Honaz anticline. The Göbecik Tepe complex constitutes the relative autochthonous in the region of the Mount Honaz. Different tectonic units in the Mount Honaz region show effects of Late Cretaceous, Middle Eocene and Late Eocene/Oligocene tectonics. Obduction of the ophiolite over the Sandak complex probably occurred during the Late Cretaceous, while the age of thrusting of the Sandak complex over the Menderes massif is probably Middle Eocene. Emplacement of these tectonic units over the Göbecik Tepe complex and the formation of the Honaz anticline is of Late Eocene/Oligocene age.

  13. New Paleomagnetic Data From Upper Gabbros Supports Limited Rotation of Central Semail Massif in Oman Ophiolite

    Horst, A. J.; Sarah, T.; Hartley, E.; Martin, J.

    2017-12-01

    Paleomagnetic data from northern massifs of the Oman ophiolite demonstrate substantial clockwise rotations prior to or during obduction, yet data from southern massifs are recently suggested to be remagnetized during obduction and show subsequent smaller counterclockwise rotations. To better understand paleomagnetic data from the southern massifs, we conducted a detailed paleomagnetic and rock magnetic study of 21 sites in upper gabbros and 5 sites in lower crustal gabbros within the central Semail massif. Samples treated with progressive thermal demagnetization yield interpretable magnetizations with dominant unblocking between 500-580°C that implies characteristic remanent magnetization (ChRM) components carried by low-titanium magnetite and nearly pure magnetite. Rock magnetic and scanning electron microscopy data provide additional support of the carriers of magnetization. ChRMs from sites with samples containing partially-serpentinized olivine are similar to sites with samples lacking olivine, where the carriers appear to be fine magnetite intergrowths in pyroxene. The overall in situ and tilt-corrected mean directions from upper gabbros are distinct from the lower gabbros, from previous data within the massif, and also directions from similar crustal units in adjacent Rustaq and Wadi Tayin massifs. After tilt correction for 10-15° SE dip of the crust-mantle boundary, the mean direction from upper gabbros is nearly coincident with in situ lower gabbros. The tilt-corrected direction from upper gabbros is also consistent with an expected direction from the Late Cretaceous apparent polar wander path for Arabia at the age of crustal accretion ( 95Ma). These results suggest the upper crustal section in Semail has likely only experienced minor tilting since formation and acquisition of magnetization. Due to slow cooling of middle to lower gabbros in fast-spread crust, the lower gabbro sites likely cooled later or after obduction, and thus yield a distinct

  14. Defining conditions of garnet growth across the central and southern Menderes Massif, western Turkey

    Etzel, T. M.; Catlos, E. J.; Kelly, E. D.; Cemen, I.; Ozerdem, C.; Atakturk, K. R.

    2017-12-01

    Here we apply thermodynamic modeling using Theriak-Domino to garnet-bearing rocks from the central and southern portions of the Menderes Massif to gain insight into the dynamics of western Turkey as the region experienced a transition from collisional to extensional tectonics. To this end, we report new pressure-temperature (P-T) paths from garnet-bearing rocks collected along the Alasehir detachment fault, a prominent exhumation structure in the central portion of the Menderes Massif in western Turkey, constituting the southern margin of the Alasehir Graben. These paths are compared to those from the Selimiye shear zone in the Southern (Cine) Massif. Two Alasehir garnets collected from the same outcrop record two P-T paths: 1) a prograde path beginning at 565oC and 6.4 kbar increasing to 592 oC and 7.5 kbar; and 2) near isobaric growth initiating at 531oC and 7.1 kbar and terminating at 571oC and 7.3 kbar. High-resolution P-T paths could not be modeled for the majority of Alasehir samples due to diffusional modification of garnet. However, conditions were estimated by garnet isopleth thermobarometry at the point of highest spessartine content for each crystal. Calculated P-T values for this subset of samples range between 566-651oC and 6.2-6.8 kbar. Despite this broad range, these P-T conditions are consistent with what is observed in the modeled paths. Th-Pb ages of matrix monazite range from 35.8±3.0 to 20.6±2.4 Ma, suggesting metamorphism in the central Menderes Massif occurred over a 15 m.y. period. Selimiye shear zone rocks show distinct N-shaped P-T paths, suggesting garnets in the central and southern portion of the Menderes Massif record distinctly different tectonic histories.

  15. Occurrence of springs in massifs of crystalline rocks, northern Portugal

    Pacheco, Fernando António Leal; Alencoão, Ana Maria Pires

    2002-02-01

    An inventory of artesian springs emerging from fractures (fracture springs) was conducted in the Pinhão River Basin and Morais Massif, northern Portugal, comprising an area of approximately 650 km2. Over 1,500 springs were identified and associated with geological domains and fracture sets. Using cross-tabulation analysis, spring distributions by fracture sets were compared among geological environments, and the deviations related to differences in rock structure and, presumably, to differences in deformational histories. The relation between spring frequencies and rock structures was further investigated by spectral determination, the model introduced in this study. Input data are the spring frequencies and fracture lengths in each geological domain, in addition to the angles between fracture strikes and present-day stress-field orientation (θ). The model's output includes the so-called intrinsic densities, a parameter indexing spring occurrence to factors such as fracture type and associated deformational regime and age. The highest densities (12.2 springs/km of lineament) were associated with young shear fractures produced by brittle deformation, and the lowest (0.1) with old tensional and ductile fractures. Spectral determination also relates each orientation class to a dominant structural parameter: where spring occurrence is controlled by θ, the class is parallel to the present-day stress-field orientation; where the control is attributed to the length of fractures, the spring occurrence follows the strike of large-scale normal faults crossing the region. Résumé. Un inventaire des sources artésiennes émergeant de fractures (sources de fractures) a été réalisé dans le bassin de la rivière Pinhão et dans le massif de Morais, dans le nord du Portugal, dans une région couvrant environ 650 km2. Plus de 1,500 sources ont été identifiées et associées à des domaines géologiques et à des ensembles de fractures. Grâce à une analyse de tableaux

  16. Research of dynamical Characteristics of slow deformation Waves as Massif Responses on Explosions

    Hachay, Olga; Khachay, Oleg; Shipeev, Oleg

    2013-04-01

    The research of massif state with use of approaches of open system theory [1-3] was developed for investigation the criterions of dissipation regimes for real rock massifs, which are under heavy man-caused influence. For realization of that research we used the data of seismic catalogue of Tashtagol mine. As a result of the analyze of that data we defined character morphology of phase trajectories of massif response, which was locally in time in a stable state: on the phase plane with coordinates released by the massif during the dynamic event energy E and lg(dE/dt) there is a local area as a ball of twisted trajectories and some not great bursts from that ball, which are not greater than 105 joules. In some time intervals that burst can be larger, than 105 joules, achieving 106 joules and yet 109 joules. [3]. Evidently there are two reciprocal depend processes: the energy accumulation in the attracted phase trajectories area and resonance fault of the accumulated energy. But after the fault the system returns again to the same attracted phase trajectories area. For analyzing of the thin structure of the chaotic area we decided to add the method of processing of the seismic monitoring data by new parameters. We shall consider each point of explosion as a source of seismic or deformation waves. Using the kinematic approach of seismic information processing we shall each point of the massif response use as a time point of the first arrival of the deformation wave for calculation of the wave velocity, because additionally we know the coordinates of the fixed response and the coordinates of explosion. The use of additional parameter-velocity of slow deformation wave propagation allowed us with use method of phase diagrams identify their hierarchic structure, which allow us to use that information for modeling and interpretation the propagation seismic and deformation waves in hierarchic structures. It is researched with use of that suggested processing method the thin

  17. U-Pb geochronology by La-CIP-MS and petrography of Sao Carlos massif - stanniferous province of Rondonia

    Debowski, Beatriz P.; Geraldes, Mauro Cesar; Nogueira, Camila; Almeida, Bruna Saar de

    2015-01-01

    U-Pb dating by ICP-MS-LA were performed in four samples of the Massif Sao Carlos massif, representative of the younger Granites of Rondonia belonging to the stanniferous province of the same State. Dated samples are granites of pink in colour and coarse-grained to porphyry with main mineralogy consisting of feldspar pertitic to mesopertitic, quartz, plagioclase in lower proportion, biotite and amphibole in some cases. Ages obtained were 986 ± 14 Ma, 974 ± 10 Ma, ± 8 Ma 992.7 and 996 ± 8 Ma and represent the age of crystallization of the Massif. Such ages are concordant with others reported on the bibliography ratifying the inclusion of the massif in the younger Granites of Rondonia, which are directly associated with the most significant mineralization of cassiterite in the State

  18. Problems of geologic survey of high level radioactive waste repositories illustrated on the testing site in the Melechov Massif

    Mlcoch, B.

    1997-01-01

    Major attention is paid to problems associated with the geologic maps of the prospective repository site, which lies within the Bohemian Massif. Structural geology, survey through boreholes, and primary database are also discussed briefly. (P.A.)

  19. Influence of geotechnical properties of the rocks of massif Vajarska on the technology of used blasting operations

    Oreská ¼udmila

    1997-12-01

    Full Text Available Geotechnical properties of a rock massif have a decisive influence on the technology of blasting operations and on the resulting fragmentation of the blast. Parameters of the blasting operations were given for the limestone deposit Vajarska on the base of knowledge about fractures of the massif Vajarska. The computer programm is used to choice new para-meters for the blasting operations in HIROCEM, a.s., Rohožník.

  20. The ophiolite massif of Kahnuj (western Makran, Southern Iran): new geological and geochronological data; Le massif ophiolitique de Kahnuj (Makran occidental, Iran meridional): nouvelles donnees geologiques et geochronologiques

    Kananian, A. [University of Tarbiat Modarress, Geological Dept., Faculty of Science, Teheran (Iran, Islamic Republic of); Juteau, Th.; Bellon, H. [Universite de Bretagne Occidentale, IUEM, 29 - Brest (France); Darvishzadeh, A. [University of Teheran, Geological Dept., Faculty of Science, Teheran (Iran, Islamic Republic of); Sabzehi, M. [Geological Survey of Iran, Teheran (Iran, Islamic Republic of); Whitechurch, H. [Universite Louis Pasteur, EOST, Institut de Physique du Globe, 67 - Strasbourg (France); Ricou, L.E. [Institut de Physique du Globe, 75 - Paris (France)

    2001-05-01

    The ophiolite massif of Kahnuj (600 km{sup 2}) consists, from bottom to top, of layered gabbros, isotropic gabbros and ouralite gabbros, agmatites of dioritic to plagio-granitic composition, a sheeted dyke complex and lastly a basaltic pillow lava unit. Amphiboles from gabbros were dated ({sup 40}K-{sup 40}Ar ages) between 156 and 139 Ma and the agmatites are nearly contemporaneous. Potassic granitic veins dated at 93-88 Ma are related to the development of the Ganj arc complex. (authors)

  1. Hydrogeologic characterization of the Cachoeira Deposit Massif, Caetite, state of Bahia, Brazil

    Bottura, J.A.; Albuquerque Filho, J.L.; Ojima, L.M.

    1984-01-01

    The hydrogeologic applications for the characterization of rock massifs in future mining activity areas are presented. The study was performed in the Cachoeira uranium deposit (Anomaly no.13 - Lagoa Real Project) located in the south-central portion of the state of Bahia, Caetite municipality, belonging to the Brazilian Nuclear Enterprise - NUCLEBRAS. The massif occuring in the area is composed of a group or series of rocks classified generically as gneisses, displaying different geotechnical classes. In order to consubstantiate the hydrogeologic/ hydrogeotechnical characterization, pumping and infiltration tests were performed, as well as periodic water level measurements in piezometers and drill-holes. In this manner, a hydrogeotechnical classification was made possible and a quantitative evaluation of the volume of water that will be drained was elaborated, orviding necessary contributions for research diggings and exploration. (D.J.M.) [pt

  2. Metagenomic identification of active methanogens and methanotrophs in serpentinite springs of the Voltri Massif, Italy

    William J. Brazelton

    2017-01-01

    Full Text Available The production of hydrogen and methane by geochemical reactions associated with the serpentinization of ultramafic rocks can potentially support subsurface microbial ecosystems independent of the photosynthetic biosphere. Methanogenic and methanotrophic microorganisms are abundant in marine hydrothermal systems heavily influenced by serpentinization, but evidence for methane-cycling archaea and bacteria in continental serpentinite springs has been limited. This report provides metagenomic and experimental evidence for active methanogenesis and methanotrophy by microbial communities in serpentinite springs of the Voltri Massif, Italy. Methanogens belonging to family Methanobacteriaceae and methanotrophic bacteria belonging to family Methylococcaceae were heavily enriched in three ultrabasic springs (pH 12. Metagenomic data also suggest the potential for hydrogen oxidation, hydrogen production, carbon fixation, fermentation, and organic acid metabolism in the ultrabasic springs. The predicted metabolic capabilities are consistent with an active subsurface ecosystem supported by energy and carbon liberated by geochemical reactions within the serpentinite rocks of the Voltri Massif.

  3. Musa massif: mapping, petrology and petrochemical, Rio Maria, SE from Para State

    Gastal, M.C.P.

    1987-01-01

    The petrological, geochemical and geochronological studies allow some insight on the genesis and evolution of the Musa Massif. The different facies of the granitic body are cogenetic, although each of these facies presents some peculiarities in its genesis and evolution. These data suggests that the granite magma evolution was complex or, alternatively, that the facies were generated by liquids derived from different sources. A model of magmatic emplacement, genesis and differentiation is proposed and discussed. The granitic facies show a calc-alkaline compositions, exhibiting strong analogies with cordilleran granites or magnetite granites. An age of 1692 +- 11 Ma (Rb/Sr) with IR of 0,70777 +- 0,00023 was obtained for different facies of Massif. A preliminary attempt to individualize geochronology the principal facies was done and showed that there is a coincidence between the ages and the emplacement sequence of these facies of the pluton. (author)

  4. Behaviour of uranium during late-Hercynian and alpine metamorphisms in the Aiguilles rouges and Belledonne (Valorcine, Lauziere) massifs. Western Alps

    Negga, H.S.

    1984-01-01

    The purpose of this research thesis is to define the origin of numerous uranium anomalies in the external crystalline Alpine massifs, more precisely the massif of the Aiguilles Rouges and the massif of Belledonne. The primary cause of uranium mineralization in the first massif appears to have been the retrograde metamorphism events of the late-Hercynian age. In the second massif, the same conditions of uranium mineralization appear to have been realised, but with a much higher calcium activity in the fluids. After having explained the choice of the selected areas, the sampling and the chemical analysis performed, the author describes the geological and structural framework of Western Alps: geological history of the paleozoic platform, regional geology of the studied massifs. The next part reports the petrographic and geochemical study, the analysis of the mineral chemistry, of the alteration and the metamorphism. Then the author describes the geochemistry of uranium and thorium within the studied structures

  5. The ophiolite massif of Kahnuj (western Makran, Southern Iran): new geological and geochronological data

    Kananian, A.; Juteau, Th.; Bellon, H.; Darvishzadeh, A.; Sabzehi, M.; Whitechurch, H.; Ricou, L.E.

    2001-01-01

    The ophiolite massif of Kahnuj (600 km 2 ) consists, from bottom to top, of layered gabbros, isotropic gabbros and ouralite gabbros, agmatites of dioritic to plagio-granitic composition, a sheeted dyke complex and lastly a basaltic pillow lava unit. Amphiboles from gabbros were dated ( 40 K- 40 Ar ages) between 156 and 139 Ma and the agmatites are nearly contemporaneous. Potassic granitic veins dated at 93-88 Ma are related to the development of the Ganj arc complex. (authors)

  6. The Oldest Granites of Russia: Paleoarchean (3343 Ma) Subalkali Granites of the Okhotsk Massif

    Kuzmin, V. K.; Bogomolov, E. S.; Glebovitskii, V. A.; Rodionov, N. V.

    2018-02-01

    The Paleoarchean age (3.34 Ga) of subalkali granite magmatism first established for the Kukhtui uplift of the Okhotsk Massif suggests a formation time of the mature continental K-rich crust in this region as early as the Paleoarchean. According to the geological structural, mineralogical-geochemical, geochronological, and isotopic-geochemical data, the Kukhtui uplift can be considered as the most ancient Paleoarchean province in Russia: the ancient consolidation core of the sialic protocrust of the Okhotsk-Omolon Craton.

  7. Automated data collection based on RoboDiff at the ESRF beamline MASSIF-1

    Nurizzo, Didier, E-mail: Didier.nurizzo@esrf.fr; Guichard, Nicolas; McSweeney, Sean; Theveneau, Pascal; Guijarro, Matias; Svensson, Olof; Mueller-Dieckmann, Christoph; Leonard, Gordon [ESRF, The European Synchrotron, 71, Avenue des Martyrs,CS 40220, 38043 Grenoble (France); Bowler, Matthew W. [EMBL Grenoble Outstation, 71 Avenue des Martyrs, CS90181, 38042 Grenoble Cedex 9 (France)

    2016-07-27

    The European Synchrotron Radiation Facility has a long standing history in the automation of experiments in Macromolecular Crystallography. MASSIF-1 (Massively Automated Sample Screening and evaluation Integrated Facility), a beamline constructed as part of the ESRF Upgrade Phase I program, has been open to the external user community since July 2014 and offers a unique completely automated data collection service to both academic and industrial structural biologists.

  8. Quaternary glaciation of the Lato Massif, Zanskar Range of the NW Himalaya

    Orr, Elizabeth N.; Owen, Lewis A.; Saha, Sourav; Caffee, Marc W.; Murari, Madhav K.

    2018-03-01

    The glacial chronostratigraphy and history of the Lato Massif of Zanskar northern India is defined for the first time using geomorphic mapping and 10Be surface exposure dating. Three local glacial stages, the Lato, Shiyul and Kyambu, are dated to 244-49, 25-15 and 3.4-0.2 ka, respectively. The Lato glacial stage was the most extensive period of glaciation, characterized by expanded ice caps with glaciers advancing to ∼16 km from their present position. Large till deposits are associated with this glacial stage, which represent a time of heightened glacial erosion and localized incision, and increased rates of sediment transfer and deposition. The glacial style transitioned to entrenched valley glaciation during the Shiyul glacial stage. Hummocky moraine complexes reflecting fluctuating glacier margins characterize this glaciation. Glaciers have been confined to the cirques and headwalls of the massif during and since the Kyambu glacial stage. Equilibrium-line altitude (ELA) reconstructions help define the shifts in glaciation over time, with ELA depressions changing from 470 ± 140, 270 ± 80 to 100 ± 30 m for the Lato, Shiyul and Kyambu glacial stages, respectively. The change of glacial style during the latter part of the Quaternary is similar to other regions of the Transhimalaya and Tibet suggesting that this pattern of glaciation may reflect regional climatic forcing. The evolution of the Lato Massif from an isolated alpine plateau to a steeply incised massif over the last several glacial-interglacial cycles may have also influenced the shifts from ice cap to valley glaciation.

  9. Man-induced transformation of mountain meadow soils of Aragats mountain massif (Armenia)

    Avetisyan, M. H.

    2018-01-01

    The article considers issues of degradation of mountain meadow soils of the Aragats mountain massif of the Republic of Armenia and provides the averaged research results obtained for 2013 and 2014. The present research was initiated in the frames of long-term complex investigations of agroecosystems of Armenia’s mountain massifs and covered sod soils of high mountain meadow pasturelands and meadow steppe grasslands lying on southern slope of Mt. Aragats. With a purpose of studying the peculiarities of migration and transformation of flows of major nutrients namely carbon, nitrogen, phosphorus in study mountain meadow and meadow steppe belts of the Aragats massif we investigated water migration of chemical elements and regularities of their leaching depending on different belts. Field measurement data have indicated that organic carbon and humus in a heavily grazed plot are almost twice as low as on a control site. Lysimetric data analysis has demonstrated that heavy grazing and illegal deforestation have brought to an increase in intrasoil water acidity. The results generated from this research support a conclusion that a man’s intervention has brought to disturbance of structure and nutrient and water regimes of soils and loss of significant amounts of soil nutrients throughout the studied region.

  10. Geodynamic movements and deformations of the Sudetic structural unit of the Bohemian Massif

    Schenk, V.; Jechumtálová, Z.; Schenková, Z.; Kottnauer, P.

    2003-04-01

    The African plate pushes to European orogenic Alpine structures that transfer the compression further to Variscan structural units, including the Bohemian Massif. Central parts of the Bohemian Massif are relatively deep-seated and, therefore, some of marginal parts of the Massif and its border geological structures should be affected intensively and moved distinctly with respect to the central parts. The geodynamical GPS network EAST SUDETEN is located just over the area mentioned above, i.e. it covers both kinetically quasi-effected and quasi-non-effected structural blocks. GPS data observed already for six annual campaigns (1997-2002) were processed and movement vectors of individual network sites were assessed. Applied data processing did not allow errors in the horizontal direction 2 mm and in the vertical direction 5-6 mm to be exceeded. Since time series of coordinate changes for several network sites gave rather pronounce movement trends, preliminary deformations among individual structural blocks were evaluated and compared to other geological, geophysical and geodetic materials. The investigation has been supported by the Grant Agency of the Czech Republic, projects 205/97/0679 and 205/01/0480, and by the research programme of the Ministry of Education, Youth and Sport of the Czech Republic, project LN00A005 "Dynamics of the Earth".

  11. Crystal structure of modular sodium-rich and low-iron eudialyte from Lovozero alkaline massif

    Rozenberg, K. A.; Rastsvetaeva, R. K., E-mail: rast@ns.crys.ras.ru; Aksenov, S. M. [Federal Scientific Research Center “Crystallography and Photonics”, Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2016-09-15

    The structure of the sodium-rich representative of the eudialyte group found by A.P. Khomyakov at the Lovozero massif (Kola Peninsula) is studied by X-ray diffraction. The trigonal cell parameters are: a = 14.2032(1) and c = 60.612(1) Å, V = 10589.13 Å3, space group R3m. The structure is refined to the final R = 5.0% in the anisotropic approximation of atomic displacement parameters using 3742|F| > 3σ(F). The idealized formula (Z = 3) is Na{sub 37}Ca{sub 10}Mn{sub 2}FeZr{sub 6}Si{sub 50}(Ti, Nb){sub 2}O{sub 144}(OH){sub 5}Cl{sub 3} · H{sub 2}O. Like other 24-layer minerals of the eudialyte group, this mineral has a modular structure. Its structure contains two modules, namely, “alluaivite” (with an admixture of “eudialyte”) and “kentbrooksite,” called according to the main structural fragments of alluaivite, eudialyte, and kentbrooksite. The mineral found at the Lovozero alkaline massif shows some chemical and symmetry-structural distinctions from the close-in-composition labyrinthite modular mineral from the Khibiny massif. The difference between the minerals stems from different geochemical conditions of mineral formation in the two regions.

  12. Rainwater chemistry at the summit and southern flank of the Itatiaia massif, Southeastern Brazil

    Mello, William Z. de; Almeida, Marcelo D. de

    2004-01-01

    Wet deposition and related rainwater chemistry were studied at the Itatiaia massif, on which is settled the Itatiaia National Park (INP). Samples were simultaneously collected on a weekly basis over 12 months, using automated wet and dry samplers, at the INP-Headquarters (INP-Hq; altitude=820 m) and the Itatiaia Plateau (It-Pt; altitude=2460 m). Conductivity, pH, Na + , K + , Mg 2+ , Ca 2+ , NH 4 + , Cl - , NO 3 - and SO 4 2- were determined in 36 rainwater samples. Volume-weighted mean (VWM) pH was lower at the INP-Hq (4.9) than at the It-Pt (5.3). Very strong correlation between Cl - and Na + was found for the INP-Hq (r=0.99). At the Itatiaia massif, SO 4 2- , NO 3 - , and NH 4 + comprised together about 60% of the total inorganic ions and appear to exert the major control on rainwater pH. - Rainwater chemistry at the Itatiaia massif in SE Brazil is strongly dominated by S and N inorganic species, and influenced by human activities

  13. The peculiarities of structurizing enclosing rock massif while developing a coal seam

    Kozyreva, E. N.; Shinkevich, M. V.

    2017-09-01

    Different concepts of the development of geo-mechanical processes during longwall mining of a seam which are fundamentally different from the conventional ones are introduced in the article. Fundamental principles of the model for structurizing enclosing rock mass while longwall mining along the strike are described. The model was developed on the bases of non-linear geomechanical laws. According to the model, rock mass in the area of mining operation is organized as rock geomechanical layers with shifting arches. And the formation period of shifting arches in disintegrated rock mass is divisible by the length of the stope. Undulate characteristic of a massif as a peculiarity of man-made structurization of a massif is defined. It is shown that structuring the broken massif causes the formation of block-structured system and it can be detected while monitoring the ground pressure in powered support props. The results of the research allow decreasing the negative influence of a ground pressure and can be applied to specify parameters for controlling the roof, defining geometrical dimensions of a mining section and positioning of holing chute (face entry).

  14. Tourist Activities-Disturbance Factors of Natural Environment in Ciucaș Massif

    Luminița Costina SĂFTOIU

    2014-10-01

    Full Text Available The study outlines how tourism activities can disturb the natural environment in Ciucaș Massif. Methods used are based on bibliographic research and GIS analysis of morphometric features. Results show that the Ciucaș Massif, as one of the most important mountain in central Romania, is made of conglomerates, which lend specific features to topography. Having several natural sights (The Old Ladies Council, The Sphinx of Bratocea, Zăganului Ridge this massif is declared a protected natural area. The geomorphologic processes: compactions, mudflows, the deepening of tourist paths, rills and gully erosion have a negative impact on the landscape and even on the entire environment, causing erosion and loss of soil and vegetation. Also, the increased number of tourist accommodation facilities and 21 marked tourist trails have resulted in shrinking of forest areas, hayfields and pastures.These numerous changes which occur in this mountain area, lead, in time, to radical, irreversible changes and can affect the local economic development.

  15. Geology and uranium occurrences in the Forez tertiary plain (in the French 'Massif Central'); Geologie et mineralisations uraniferes de la plaine tertiaire du Forez (Massif Central francais)

    Duclos, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses - 92 (France). Centre d' Etudes Nucleaires

    1967-01-01

    In the first part, the observations made during the geological survey of the Forez Tertiary plain (in the French 'Massif Central') are recalled. Then, using various methods, the author lists the formations according to chronology. Finally, a reconstitution of the geological history of this subsidence basin is attempted. In the second part, the occurrence of 17 uranium bearing geochemical anomalies is commented upon. Each of these various anomalies is given a place on the stratigraphic scale. This enables the author to put the successive phases of uranium deposition into their proper perspective in the history of the plain. In conclusion, the author points out the usefulness of these uraniferous geochemical anomalies. (author) [French] Dans la premiere partie, l'auteur rappelle les observations faites au cours de l'etude geologique de la plaine tertiaire du Forez (Massif Central francais). Puis se servant de differentes methodes, il etablit une chronologie des formations. Enfin, il termine par un essai de reconstitution de l'histoire geologique de ce bassin de subsidence. Dans la deuxieme partie, il commente la decouverte de 17 anomalies geochimiques uraniferes. Il situe ces differentes anomalies dans la serie stratigraphique. Ceci lui permet de replacer les depots successifs de l'uranium dans l'histoire de la plaine. Enfin, il indique l'interet de ces anomalies geochimiques uraniferes. (auteur)

  16. A cross-sectional study examining the prevalence and risk factors for anti-microbial-resistant generic Escherichia coli in domestic dogs that frequent dog parks in three cities in south-western Ontario, Canada.

    Procter, T D; Pearl, D L; Finley, R L; Leonard, E K; Janecko, N; Reid-Smith, R J; Weese, J S; Peregrine, A S; Sargeant, J M

    2014-06-01

    Anti-microbial resistance can threaten health by limiting treatment options and increasing the risk of hospitalization and severity of infection. Companion animals can shed anti-microbial-resistant bacteria that may result in the exposure of other dogs and humans to anti-microbial-resistant genes. The prevalence of anti-microbial-resistant generic Escherichia coli in the faeces of dogs that visited dog parks in south-western Ontario was examined and risk factors for shedding anti-microbial-resistant generic E. coli identified. From May to August 2009, canine faecal samples were collected at ten dog parks in three cities in south-western Ontario, Canada. Owners completed a questionnaire related to pet characteristics and management factors including recent treatment with antibiotics. Faecal samples were collected from 251 dogs, and 189 surveys were completed. Generic E. coli was isolated from 237 of the faecal samples, and up to three isolates per sample were tested for anti-microbial susceptibility. Eighty-nine percent of isolates were pan-susceptible; 82.3% of dogs shed isolates that were pan-susceptible. Multiclass resistance was detected in 7.2% of the isolates from 10.1% of the dogs. Based on multilevel multivariable logistic regression, a risk factor for the shedding of generic E. coli resistant to ampicillin was attending dog day care. Risk factors for the shedding of E. coli resistant to at least one anti-microbial included attending dog day care and being a large mixed breed dog, whereas consumption of commercial dry and home cooked diets was protective factor. In a multilevel multivariable model for the shedding of multiclass-resistant E. coli, exposure to compost and being a large mixed breed dog were risk factors, while consumption of a commercial dry diet was a sparing factor. Pet dogs are a potential reservoir of anti-microbial-resistant generic E. coli; some dog characteristics and management factors are associated with the prevalence of anti

  17. Neogene Uplift and Exhumation of Plutonic Bodies in the Beni Bou Ifrour Massif (Nador, northeastern Morocco)

    Lebret, Noëmie; Jolivet, Laurent; Branquet, Yannick; Bourdier, Jean-Louis; Jolivet, Marc; Marcoux, Eric

    2013-04-01

    In Neogene times, the whole Mediterranean Sea was the center of an intense magmatic activity. This post-collisional magmatism produced a large amount of volcanic edifices through the Alpine belts, together with some intrusives. These plutonic bodies can be associated with skarn-type mineralization, well-known in Elba Island or Serifos Island (Cyclades), where they are generally exhumed by detachment faults. In Morocco, the plutons hosted by the Beni Bou Ifrour massif are connected to the biggest skarn-type iron concentrations of the country (production > 60 Mt, reserves ≈ 25 Mt). The purpose of this work is to explain the late uplift of this massif and subsequent exhumation of the intrusives. As a final product of the Africa-Eurasia plate convergence since ca. 70 Ma, the Rif Mountains constitute the westernmost segment of the Mediterranean Alpine belts. In the oriental part of this range, volcanic summits and Paleozoic to Mesozoic massifs outcrop in the surrounding Mio-Pliocene plains. The Beni Bou Ifrour massif, in the Nador province, consists in a dome-shaped folded Mesozoic series (Domerian to Barremian) affected by a slight epizonal regional metamorphism (ca. 14-12 Ma), dislocated by Neogene NE-SW faults and eventually sealed by upper Miocene transgressive sediments. The hosted intrusives (7.58 ± 0.03 Ma; Duggen et al., 2005) are the plutonic equivalents to the potassic calc-alkaline lavas (andesites mainly) from the surrounding "satellite" volcanic massifs. They turn out to stand in higher topographic position than the younger shoshonitic lavas of the neighboring Gourougou stratovolcano (6.12 ± 0.01 Ma; Duggen et al., 2005). Previous studies have attributed this uplift to the action of normal faults (pull-apart basins; Guillemin & Houzay, 1982), thrusting (Kerchaoui, 1985; 1995) or even of a caldeira resurgence (El Bakkali, 1995). To discriminate against those exhumation mechanisms, field work has been performed, coming along with new cross-sections to

  18. Biodiversity impact of the aeolian periglacial geomorphologic evolution of the Fontainebleau Massif (France)

    Thiry, M.; Liron, M. N.

    2009-04-01

    Landscape features The geomorphology of the Fontainebleau Massif is noteworthy for its spectacular narrow ridges, up to 10 km long and 0.5 km wide, armored by tightly cemented sandstone lenses and which overhang sandy depressions of about 50m. Denudation of the sandstone pans lead to a highly contrasted landscape, with sandstone ridges ("platières") towering sandy depressions ("vallées") and limestone plateaus ("monts"). This forms the geological frame of the spectacular sceneries of the Fontainebleau Massif (Thiry & Liron, 2007). Nevertheless, there is little know about the erosive processes that have built-up these landscapes. Periglacial processes, and among them aeolian ones, appear significant in the development of the Fontainebleau Massif physiography. The periglacial aeolian geomorphology Dunes and dune fields are known since long and cover about 15% to 25% of the Fontainebleau Massif. The aeolian dunes developed as well on the higher parts of the landscape, as well as in the lower parts of the landscape. The dunes are especially well developed in the whole eastern part of the massif, whereas the western part of the massif is almost devoid of dunes. Nevertheless, detailed mapping shows that dunes can locally be found in the western district, they are of limited extension, restricted to the east facing backslope of outliers. Loamy-sand covers the limestone plateaus of the "monts". The loam cover is of variable thickness: schematically thicker in the central part of the plateaus, where it my reach 3 m; elsewhere it may thin down to 0,20-0,30 m, especially at the plateau edges. Blowout hollows are "negative" morphologies from where the sand has been withdrawed. Often these blowouts are decametric sized and well-delimited structures. Others, more complex structures, are made up of several elongated hectometric hollows relaying each other from and which outline deflation corridor more than 1 km long. A characteristic feature of these blowout hollows is the

  19. Improving access to interventions among mothers screened positive for post-partum depression (PPD) at National Programme on Immunization (NPI) clinics in south-western and south-eastern Nigeria - A service development report.

    Bakare, Muideen O; Bello-Mojeed, Mashudat A; Munir, Kerim M; Duduyemi, Olaniyi O; Orovwigho, Andrew O; Odetunde, Odutola I; Taiwo, Olufemi G; Olofinlade, Jushua A; Omotoso, Olakunle N; Famurewa, Olayinka H; Omolabi, Oladipupo O; Jejeloye, Adebayo O

    2017-01-01

    We investigate the possibility of improving access to interventions among mothers screened positive for post-partum depression (PPD) at National Programme on Immunization (NPI) clinics randomly selected from Lagos and Enugu States in south-western and south-eastern Nigeria respectively. The principle of human centred design was employed by engaging the mothers screened positive for PPD to be part of the decision making regarding their further assessment and intervention services. The study brought intervention services to primary healthcare centre at the NPI clinics. Improvement in willingness to seek interventions was observed among the mothers screened positive for PPD in this study when compared to our observation in a previous report, where mothers diagnosed with PPD were referred and requested to visit a mental health facility closer to their NPI clinics for further assessment and interventions (95.2% versus 33.7%). Interventional services for the mothers diagnosed with PPD also impact positively on the growth parameters of their infants on follow-up. Principle of human centred design improved access to intervention services among the mothers and infants studied. NPI clinics at primary healthcare level would provide appropriate forum for early screening of mothers for PPD and interventions in low-resource setting like Nigeria. There would be improvement in maternal and child health coverage if the Nigerian Government can adapt human centred design principles employed in this study nationwide.

  20. Evaluation of shrub and tree species used for revegetating copper mine wastes in the south-western United States. [Dodonea viscosa (L. ) Jacq. , Baccharis sarothroides Gray, Cerdicium microphyllum Torr. , and Nicotiana glauca Grah

    Norem, M A; Day, A D; Ludeke, K L

    1982-12-01

    The revegetation work begun in 1970 at Cyprus Pima Mine, an open pit copper mine south-west of Tucson, Arizona, was evaluated to determine the effects of slope aspect and mining waste material on plant survival and growth. Only one shrub, Dodonea viscosa (L.) Jacq. (hopbush), survived on the east slope. Baccharis sarothroides Gray (desert broom) was prolific on the north aspect. Cerdicium microphyllum Torr. (palo verde) survived best on the east slope and Nicotiana glauca Grah. (desert tobacco) survived only on the north slope. The survival of the other tree species was not affected by slope aspect. Slope exposure did not affect tree size, except for Eucalyptus microtheca Muell. (tiny capsule eucalyptus) which grew larger on the north slope. E. rostrata Schlechtend (red gum eucalyptus) grew taller in overburden than in tailing on the east slope. Differences in soil material within each slope exposure did not significantly affect growth of the other tree species. In semi-arid regions, such as south-western Arizona, even slight differences in available moisture may determine the survival of a plant species in the area. (Refs. 11).

  1. Exploring the Care Relationship between Grandparents/Older Carers and Children Infected with HIV in South-Western Uganda: Implications for Care for Both the Children and Their Older Carers

    Rwamahe Rutakumwa

    2015-02-01

    Full Text Available The care of children orphaned by HIV/AIDS in sub-Saharan Africa is often undertaken by grandparents, yet little is known about the care relationship between grandparent and grandchild. Our aim was to examine this relationship to understand the needs and responsibilities of both the HIV positive child and older carer and the nature of the relationship, and to assess the implications for care for the children and the older carers. A qualitative study was conducted with 40 purposively sampled children (13–17 years and their older carers (50 years and above. Participants were recruited from two clinics in south-western Uganda. Up to three semi-structured interviews were held with each participant. Data were analysed using a thematic framework approach. We found that the care relationship was mostly reciprocal: HIV positive children depended on carers for basic and health needs and carers counted on the children for performing tedious household tasks. The relationship was also characterised by challenges, sometimes causing tension between child and carer. We conclude that: (1 interventions targeting HIV positive children need to also address the needs of older carers, and (2 carers and children would benefit from psychosocial support and social protection.

  2. Yield, SDG lignan, cadmium, lead, oil and protein contents of linseed (Linum usitatissimum L. cultivated in trials and at different farm conditions in the south-western part of Finland

    Marketta Saastamoinen

    2013-06-01

    Full Text Available Linseed varieties were studied in variety trials and under farm conditions in south-western Finland in the years 2007−2010. The variation in yield, oil, protein, SDG lignan, cadmium and lead contents were studied in 8 oil and 2 fibre linseed varieties. Genotypic, environmental and genotype x environment interaction variance estimates were calculated. Fibre varieties ‘Belinka’ and ‘Martta’ had higher protein and lower oil contents than oil linseed varieties.The SDG lignan contents of linseed varieties varied between 3635−9560 mg kg-1. Rather high genotypic variance was found in yield, oil, protein and SDG lignan contents. Variety ‘Laser’ had lower SDG lignan content. ‘Abacus’, ‘Helmi’ and ‘Martta’ had the highest SDG lignan contents. Variation in cadmium and lead contents were caused by environmental effects. The highest cadmium contents, 0.82−1.69 mg kg-1, were found in soils fertilized by wastewater sludge about 20 years ago and at fields with low bottom soil pH (4.1−4.5.

  3. N-S crustal shear system in the Bundelkhand massif: A unique crustal evolution signature in the northern Indian peninsula

    Singh, S. P.; Bhattacharya, A. R.

    2017-12-01

    The Bundelkhand massif, located in the northern part of the Indian shield, is a poly-deformed and poly-metamorphic terrain. This paper reports a new shear system developed throughout the massif in the form of N-S trending quartz veins that are sometimes quartzo-feldspathic and rarely granitic in composition. The veins are vertical and commonly occur in conjugate sets. This tectono-magmatic event appears to represent the youngest shear system of the massif as it cross-cuts all the earlier shear systems (E-W, NE-SE and NW-SE). Emplacement of this N-S vein system may have taken place due to extensional processes that developed some cracks along which siliceous magma was vertically emplaced. The complete absence of signature of the N-S event from the surrounding sedimentary cover of Vindhyan Supergroup, Bijawar and Gwalior Groups suggests that this shear system is pre-tectonic to the nearly E-W trending passive basins developed at the margins of the Bundelkhand craton. Further, several workers have considered the Bundelkhand massif as a part of the Aravalli craton. However, due to the absence of N-S, as well as the other (i.e., E-W, NW-SE and NW-SE), tectonic fabrics of the Bundelkhand massif in other cratons of the Peninsular India, and vice versa, makes the Bundelkhand block a separate and unique craton of its own and is not part of the Aravalli craton.

  4. Timing and duration of Variscan high-pressure metamorphism in the French Massif Central: A multimethod geochronological study from the Najac Massif

    Lotout, Caroline; Pitra, Pavel; Poujol, Marc; Anczkiewicz, Robert; Van Den Driessche, Jean

    2018-05-01

    Accurate dating of eclogite-facies metamorphism is of paramount importance in order to understand the tectonic evolution of an orogen. An eclogite sample from the Najac Massif (French Massif Central, Variscan belt) displays a zircon-bearing garnet-omphacite-amphibole-rutile-quartz peak assemblage. Pseudosection modeling suggests peak pressure conditions of 15-20 kbar, 560-630 °C. Eclogite-facies garnet displays Lu-enriched cores and Sm-rich rims and yields a Lu-Hf age of 382.8 ± 1.0 Ma and a Sm-Nd age of 376.7 ± 3.3 Ma. The ages are interpreted as marking the beginning of the prograde garnet growth during the initial stages of the eclogite-facies metamorphism, and the high-pressure (and temperature) peak reached by the rock, respectively. Zircon grains display chondrite-normalized REE spectra with variably negative, positive or no Eu anomalies and are characterized by either enriched or flat HREE patterns. However, they yield a well constrained in situ LA-ICP-MS U-Pb age of 385.5 ± 2.3 Ma, despite this REE pattern variability. Zr zonation in garnet, Y content in zircon and the diversity of zircon HREE spectra may suggest that zircon crystallized prior to and during incipient garnet growth on the prograde P-T path, recording the initial stages of the eclogite-facies conditions. Consequently, the zircon age of 385.5 ± 2.3 Ma, comparable within error with the Lu-Hf age obtained on garnet, is interpreted as dating the beginning of the eclogite-facies metamorphism. Accordingly, the duration of the prograde part of the eclogite-facies event is estimated at 6.1 ± 4.3 Myr. Subsequent exhumation is constrained by an apatite U-Pb age at 369 ± 13 Ma.

  5. How are the emplacement of rare-element pegmatites, regional metamorphism and magmatism interrelated in the Moldanubian domain of the Variscan Bohemian Massif, Czech Republic?

    Melleton, J.; Gloaguen, E.; Frei, D.; Novák, M.; Breiter, Karel

    2012-01-01

    Roč. 50, č. 6 (2012), s. 1751-1773 ISSN 0008-4476 Institutional support: RVO:67985831 Keywords : LCT pegmatite * rare-element-enriched magma * columbite-tantalite * LA-SF-ICP-MS dating * Variscan orogeny * Bohemian Massif * Moldanubian domain * Bohemian Massif (Czech Republic) Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.180, year: 2012

  6. Extensional ductile tectonics of the Sioule metamorphic series (Variscan French Massif Central)

    Faure, M.; Grolier, J.; Pons, J.

    1993-09-01

    In the Northern part of the Variscan French Massif Central, the Sioule series, from top to bottom, consists of a pre-Viséan granite, migmatite, gneiss and mica schist. Two ductile deformations have been recognized. The earlier phase is characterized by a north-east-south-west trending stretching lineation; the second phase, characterized by a north-west-south-east trending mineral, stretching and crenulation lineation, is better marked in the lower mica schist part than in the upper granito-gneissic part. This second phase occurred during retrogression of the metamorphic rocks; related shear criteria indicate a top to the south-west shear. The Namurian-Westphalian magmatic bodies such as the Echassières leucogranite, Pouzol-Servant microgranite and numerous north-east -south-west trending microgranite dykes are emplaced in extensional fractures related to the same north-west-south-east maximum stretching direction. The asymmetrical shapes of the two granitic massifs indicate that they intruded towards the south-east. The synkinematic retrogression of the metamorphic rocks, the shape of the magmatic bodies and a re-examination of the numerous available data support the interpretation that the deformation is due to the extensional tectonic regime related to the Variscan crustal re-quilibration. This interpretation is in agreement with the correlation of the Sioule series with the Chavanon series. The two series belong to a unique tectono-metamorphic unit left-laterally offset by the Stephanian motion of the Sillon Houiller fault. This study also shows that the Sillon Houiller did not play a significant part during the Namurian-Westphalian extensional tectonics of the Massif Central.

  7. Distribution of uranium, thorium and potassium in the alkaline rocks of Pocos de Caldas massif

    Rocha, E.B.

    1985-01-01

    The Pocos de Caldas massif, with area about 800 Km 2 , represents the greatest complex of alkaline rocks existent in the American continent. Although values of U and Th are well Known in the mineralized areas, few has been registered with respect to the distribution of those elements outside the ore deposits. The rocks of the massif, in general, present high contents of U and Th when confronted with the surrouding country rocks. The distribution of the U and Th appoint a relevant additional data in the discussion on the hypothesis of nepheline syenites bodies formation in Pocos de Caldas by crystal fractionation processes. In this work are provided results of the U, Th and K distribution in the main petrographic facies occurring in the several studies places of the massif, yielded by gamma-ray spectrometric analysis of the samples. Those analysis disclose that khibinites present average values about 38 ppm U and 120 ppm Th; lujavrites, about 14 ppm U and more than 70 ppm Th; U-Th depleted nepheline synites, about 12 ppm U and 38 ppm Th, Th/U ratios are close to 3,0 in the nepheline syenites, about 3,7 in the phonolites, reaching values close to 4,0 in the khibinites. These values are comparable with others Th/U ratios of selected series of alkaline rocks reported in the international literature. Uranium and Th comparative data, attained by delayed neutron counting activation analysis also are given. The results obtained for the fluorimetric analysis show loss of U leaching is greater in the fine-grained rocks (phonolites) than coarse-grained ones (lujavrites, Khibinites). The autoradiographic studies reveal that radioactive elements are found concentrated in mineral phases. A new assessment of the radiogenic heat production it is also available. (Author) [pt

  8. Constraining the deformation and exhumation history of the Ronda Massif, Southern Spain

    Myall, Jack; Donaldson, Colin

    2016-04-01

    The Ronda peridotite, southern Spain is comprised of four peridotite units hosted within metasedimentary units of the Betic Cordillera, Western Alps. These four areas of differing mineral facies are termed: the Garnet Mylonite , the Foliated Spinel Peridotite, the Granular Spinel Peridotite and the Foliated Plagioclase Peridotite. Whilst two of these units show a strong NE-SW foliation, the granular unit has no foliation and the Plagioclase facies shows a NW-SE foliation. The massif is separated from the metasedimentary host through a mylonite shear zone to the NW and thrust faults to the SE. The Garnets contain rims of Kelyphite which when combined with the rims of Spinel on the Plagioclase crystals illustrate the complicated exhumation of this massif. The Kelyphite shows the breakdown of garnet back to spinel and pyroxene showing the deeper high pressure high temperature mineral is under shallowing conditions whereas in contrast to this the low pressure low temperature plagioclase crystals have spinel rims showing that they have been moved into deeper conditions. The P-T-t pathway of the massif suggests slow exhumation to allow for partial recrystallisation of not only the garnets and plagioclases but of a 100m band of peridotite between the Foliated Spinel Peridotite and the Granular Spinel Peridotite facies. The tectonic model for the Ronda Peridotite that best describes the field data and subsequent lab work of this study is Mantle Core complex and slab roll back models. These models support mantle uprising during an extensional event that whereby slab roll back of the subducting lithosphere provides uplift into a void and emplacement into the crust. Further extension and final exhumation causes rotation of a mantle wedge into its present day position.

  9. VARIATION OF MACROMYCETES SPECIES COMPOSITION IN TWO FOREST HABITATS FROM GIUMALĂU MASSIF (EASTERN CARPATHIANS, ROMANIA

    BÎRSAN Ciprian

    2013-12-01

    Full Text Available Norway spruce (Picea abies is the most common species with a large spreading in forests from Giumalău Massif. In this study the authors investigated the macromycetes species composition in two forest communities from Giumalău Massif: Hieracio transsilvanico-Piceetum and Leucanthemo waldsteinii-Fagetum. A total of 243 macromycetes species in 30 sampling areas have been identified. Changes in macromycetes species composition have been related to environmental factors (altitude and vegetation (canopy cover, plant species diversity. The results suggest that variation in macromycetes species composition in the two forests types from Giumalău Massif is directly related to abiotic factors (altitude, woody species composition and plants communities’ structure.

  10. Hydration of the Atlantis Massif: Halogen, Noble Gas and In-Situ δ18O Constraints

    Williams, M. J.; Kendrick, M. A.; Rubatto, D.

    2017-12-01

    A combination of halogen (Cl, Br, I), noble gases (He, Ne, Ar, Kr and Xe) and in situ oxygen isotope analysis have been utilized to investigate the fluid-mobile element record of hydration and alteration processes at the Atlantis Massif (30°N on the Mid-Atlantic Ridge). The sample suite investigated includes serpentinite, talc-amphibole ± chlorite schist and hydrated gabbro recovered by seafloor drilling undertaken at sites on a transect across the Atlantis Massif during IODP Expedition 357. Serpentine mesh and veins analysed in-situ by SHRIMP SI exhibit δ18O from 6‰ down to ≈0‰, suggesting serpentinization temperatures of 150 to >280°C and water/rock ratios >5. Differences of 1.5-2.5‰ are observed between adjacent generations of serpentine, but the δ18O range is similar at each investigated drilling site. Halogen and noble gas abundances in serpentinites, talc-amphibole schist and hydrated gabbro have been measured by noble gas mass spectrometry of both irradiated and non-irradiated samples. Serpentinites contain low abundances of halogens and noble gases (e.g. 70-430 ppm Cl, 4.7-12.2 x 10-14 mol/g 36Ar) relative to other seafloor serpentinites. The samples have systematically different Br/Cl and I/Cl ratios related to their mineralogy. Serpentinites retain mantle-like Br/Cl with a wide variation in I/Cl that stretches toward seawater values. Talc-amphibole schists exhibit depletion of Br and I relative to Cl with increasing Cl abundances, suggesting tremolite exerts strong control on halogen abundance ratios. Serpentinites show no evidence of interaction with halogen-rich sedimentary pore fluids. Iodine abundances are variable across serpentinites, and are decoupled from Br and Cl; iodine enrichment (up to 530 ppb) is observed within relatively oxidised and clay-bearing samples. Serpentinized harzburgites exhibit distinct depletion of Kr and Xe relative to atmospheric 36Ar in seawater. Oxygen isotope compositions and low abundances of both halogens

  11. Miocene metamorphism of pan-African granites in the Edough Massif (NE Algeria)

    Hammor, D.; Lancelot, J.

    1998-01-01

    The Edough Massif is the eastern most crystalline core of the Maghrebides that represents the African segment of the west Mediterranean Alpine belt. U-Pb zircon dating provides upper intercept ages of 595± My and 606±55 My and orthogneiss of the lower unit and a deformed leucogranite of the upper pelitic unit, respectively. These ages suggest emplacement of the two granitoids during the Pan-African orogeny. Monazites from a paragneiss sample gave a 18± My U-Pb age that points to a Miocene age of the high-temperature metamorphism. (authors)

  12. Evidence for partial melting of eclogite from the Moldanubian Zone of the Bohemian Massif, Czech Republic

    Miyazaki, T.; Nakamura, D.; Tamura, A.; Svojtka, Martin; Arai, S.; Hirajima, T.

    2016-01-01

    Roč. 111, č. 6 (2016), s. 405-419 ISSN 1345-6296 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100131203 Program:Program interní podpory projektů mezinárodní spolupráce AV ČR Institutional support: RVO:67985831 Keywords : partial melting * eclogite * leucocratic pockets * Bohemian Massif * Moldanubian Zone Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.409, year: 2016

  13. Lateral displacement of crustal units relative to underlying mantle lithosphere: Example from the Bohemian Massif

    Babuška, Vladislav; Plomerová, Jaroslava

    2017-01-01

    Roč. 48, December (2017), s. 125-138 ISSN 1342-937X R&D Projects: GA ČR GAP210/12/2381; GA MŠk(CZ) LD15029; GA MŠk LM2010008; GA MŠk(CZ) LM2015079 Institutional support: RVO:67985530 Keywords : Bohemian Massif * Teplá-Barrandian mantle lithosphere * Zone Erbendorf-Vohenstrauss * Jáchymov Fault Zone Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: Volcanology Impact factor: 6.959, year: 2016

  14. Geology and uranium occurrences in the Forez tertiary plain (in the French 'Massif Central')

    Duclos, P.

    1967-01-01

    In the first part, the observations made during the geological survey of the Forez Tertiary plain (in the French 'Massif Central') are recalled. Then, using various methods, the author lists the formations according to chronology. Finally, a reconstitution of the geological history of this subsidence basin is attempted. In the second part, the occurrence of 17 uranium bearing geochemical anomalies is commented upon. Each of these various anomalies is given a place on the stratigraphic scale. This enables the author to put the successive phases of uranium deposition into their proper perspective in the history of the plain. In conclusion, the author points out the usefulness of these uraniferous geochemical anomalies. (author) [fr

  15. A new species of Pristimantis (Anura, Craugastoridae) from the Cajas Massif, southern Ecuador

    Sánchez-Nivicela, Juan C.; Celi-Piedra, Elvis; Posse-Sarmiento, Valentina; Urgiles, Verónica L.; Yánez-Muñoz, Mario; Cisneros-Heredia, Diego F.

    2018-01-01

    Abstract A new species of Pristimantis is described from the highland paramos on the eastern slopes of the Cajas Massif, southern Andes of Ecuador, at 3400 m. This new species is characterized by having a distinctive reddish color, cutaneous macroglands in suprascapular region and surfaces of arm and legs, and by lacking dentigerous processes of vomers. The cutaneous macroglands are similar to those exhibited by several species of the Pristimantis orcesi group, and may suggest a close phylogenetic relationship. The new species could be a latitudinal substitution of Pristimantis orcesi in the southern Andes of Ecuador. PMID:29713233

  16. Forecast of promising areas for uranium prospection at the metamorphic Massif of Isla de la Juventud

    Gongora, L.E.; Macola, E.; Sanchez, J.; Torres, J.C.; Alaminos, C.; LLanes, A.; Morales, M.

    1995-01-01

    A mineralization conceptual model for uranium of the metamorphic Massif of Isla de la Juventud was established taking into account the study of the geological and metallogenic characteristic of the territory. The determined indications of mineralization were plotted on the geological map in order to conform a forecasting map and the selection of 22 hypothetical promising areas was carried out. As result of the field words three really promising areas were selected. A group of exploration techniques needed to evaluate the targets areas is presented

  17. Uranium mineralization possibilities in metamorphic Massif of Isla de Juventud, Cuba

    Gongora Dominguez, L.E.; Llanes Castro, A.I.; Pena Fortes, B.; Capote Rodriguez, G.

    1996-01-01

    The geologic and metallogenic characteristic of the metamorphic Massif shows the presence of possible uranium vein type mineralization as a result of a hidrotermal genetic process. Metalliferous fluids rising along the fault system were responsible for the deposition of the uranium in the reduction zones, i.e. presence of pyrite, organic matter and others. This type of uranium minerization is proposed for the Bibijagua area and for the Revolucion and Lela area the same type is expected. The gamma spectrometric analysis was used to evaluate the geological samples

  18. A-type granites from the Guéra Massif, Central Chad: Petrology, geochemistry, geochronology, and petrogenesis.

    Pham, Ngoc Ha T.; Shellnutt, J. Gregory; Yeh, Meng-Wan; Lee, Tung-Yi

    2017-04-01

    The poorly studied Saharan Metacraton of North-Central Africa is located between the Arabian-Nubian Shield in the east, the Tuareg Shield in the west and the Central African Orogenic Belt in the south. The Saharan Metacraton is composed of Neoproterozoic juvenile crust and the relics of pre-Neoproterozoic components reactivated during the Pan-African Orogeny. The Republic of Chad, constrained within the Saharan Metacraton, comprises a Phanerozoic cover overlying Precambrian basement outcroppings in four distinct massifs: the Mayo Kebbi, Tibesti, Ouaddaï, and the Guéra. The Guéra massif is the least studied of the four massifs but it likely preserves structures that were formed during the collision between Congo Craton and Saharan Metacraton. The Guéra Massif is composed of mostly granitic rocks. The granitoids have petrologic features that are consistent with A-type granite, such as micrographic intergrowth of sodic and potassic feldspar, the presence of sodic- and iron-rich amphibole, and iron-rich biotite. Compositionally, the granitic rocks of the Guéra Massif have high silica (SiO2 ≥ 68.9 wt.%) content and are metaluminous to marginally peraluminous. The rocks are classified as ferroan calc-alkalic to alkali-calcic with moderately high to very high Fe* ratios. The first zircon U/Pb geochronology of the silicic rocks from the Guéra Massif yielded three main age groups: 590 Ma, 570 Ma, 560 Ma, while a single gabbro yielded an intermediate age ( 580 Ma). A weakly foliated biotite granite yielded two populations, in which the emplacement age is interpreted to be 590 ± 10 Ma, whereas the younger age (550 ± 11 Ma) is considered to be a deformation age. Furthermore, inherited Meso- to Paleoproterozoic zircons are found in this sample. The geochemical and geochronology data indicate that there is a temporal evolution in the composition of rocks with the old, high Mg# granitoids shifting to young, low Mg# granitoids. This reveals that the A-type granites in

  19. Geomorphology and anthropogenic impact including military constraints in a microtidal wave-dominated embayment in south western Sardinia (Porto Pino beach, SCI ITB040025, Mediterranean Sea). Implications for beach management.

    De Muro, Sandro; Buosi, Carla; Pusceddu, Nicola; Frongia, Paolo; Passarella, Marinella; Ibba, Angelo

    2016-04-01

    The coastal zones of the Mediterranean have undergone increasing pressure over the last century. The intensifying coastal development and the increasing tourist impact have led to an intense transformation of the coastlines and adjacent marine areas. The beach and the coastal dune play an important role in protecting the coastline. Thus, the study of its geomorphological evolution and of its anthropic modification is fundamental in order to adopt the best management practices. In this regard, the LIFE Project (LIFE13NAT/IT/001013) SOSS DUNES (Safeguard and management Of South-western Sardinian Dunes) aims to safeguard the dune habitats and the beach system in a site belonging to the Natura 2000 network, an EUwide network of nature protection areas established under the 1992 Habitats Directive. This project is focused on a microtidal wave-dominated embayment located in south western Sardinia (Italy, Mediterranean Sea) called Porto Pino beach comprised in the SCI (Site of Community Importance) "Promontory, dunes and wetland of Porto Pino (ITB040025)". This research aims to investigate the geomorphological processes, the evolution and the main human impacts on Porto Pino beach as an useful tool for both conservation and coastal management. The coastal area of Porto Pino is represented by sandy shorelines extending for a total length of 5 km characterized by a wide primary and secondary dune systems, a backshore wetland lagoon and marsh area arranged parallel to the coastline. This littoral area can be ideally divided into three parts: the first, about 600 m long, in the north-west part characterized by the highest human pressure due to touristic activity on the foredunes and deposition of beach wrack; the second part in the south-east, about 1100 m long, characterized by a complex dune system (primary and secondary foredunes); and the third southernmost part included in a military area, about 3300 m long, characterized by transgressive dune system with low human

  20. Conservation systematics of the shield-backed trapdoor spiders of the nigrum-group (Mygalomorphae, Idiopidae, Idiosoma): integrative taxonomy reveals a diverse and threatened fauna from south-western Australia.

    Rix, Michael G; Huey, Joel A; Cooper, Steven J B; Austin, Andrew D; Harvey, Mark S

    2018-01-01

    The aganippine shield-backed trapdoor spiders of the monophyletic nigrum -group of Idiosoma Ausserer s. l. are revised, and 15 new species are described from Western Australia and the Eyre Peninsula of South Australia: I. arenaceum Rix & Harvey, sp. n. , I. corrugatum Rix & Harvey, sp. n. , I. clypeatum Rix & Harvey, sp. n. , I. dandaragan Rix & Harvey, sp. n. , I. formosum Rix & Harvey, sp. n. , I. gardneri Rix & Harvey, sp. n. , I. gutharuka Rix & Harvey, sp. n. , I. incomptum Rix & Harvey, sp. n. , I. intermedium Rix & Harvey, sp. n. , I. jarrah Rix & Harvey, sp. n. , I. kopejtkaorum Rix & Harvey, sp. n. , I. kwongan Rix & Harvey, sp. n. , I. mcclementsorum Rix & Harvey, sp. n. , I. mcnamarai Rix & Harvey, sp. n. , and I. schoknechtorum Rix & Harvey, sp. n. Two previously described species from south-western Western Australia, I. nigrum Main, 1952 and I. sigillatum (O. P.-Cambridge, 1870), are re-illustrated and re-diagnosed, and complementary molecular data for 14 species and seven genes are analysed with Bayesian methods. Members of the nigrum -group are of long-standing conservation significance, and I. nigrum is the only spider in Australia to be afforded threatened species status under both State and Commonwealth legislation. Two other species, I. formosum Rix & Harvey, sp. n. and I. kopejtkaorum Rix & Harvey, sp. n. , are also formally listed as Endangered under Western Australian State legislation. Here we significantly relimit I. nigrum to include only those populations from the central and central-western Wheatbelt bioregion, and further document the known diversity and conservation status of all known species.

  1. Conservation systematics of the shield-backed trapdoor spiders of the nigrum-group (Mygalomorphae, Idiopidae, Idiosoma: integrative taxonomy reveals a diverse and threatened fauna from south-western Australia

    Michael G. Rix

    2018-05-01

    Full Text Available The aganippine shield-backed trapdoor spiders of the monophyletic nigrum-group of Idiosoma Ausserer s. l. are revised, and 15 new species are described from Western Australia and the Eyre Peninsula of South Australia: I. arenaceum Rix & Harvey, sp. n., I. corrugatum Rix & Harvey, sp. n., I. clypeatum Rix & Harvey, sp. n., I. dandaragan Rix & Harvey, sp. n., I. formosum Rix & Harvey, sp. n., I. gardneri Rix & Harvey, sp. n., I. gutharuka Rix & Harvey, sp. n., I. incomptum Rix & Harvey, sp. n., I. intermedium Rix & Harvey, sp. n., I. jarrah Rix & Harvey, sp. n., I. kopejtkaorum Rix & Harvey, sp. n., I. kwongan Rix & Harvey, sp. n., I. mcclementsorum Rix & Harvey, sp. n., I. mcnamarai Rix & Harvey, sp. n., and I. schoknechtorum Rix & Harvey, sp. n. Two previously described species from south-western Western Australia, I. nigrum Main, 1952 and I. sigillatum (O. P.-Cambridge, 1870, are re-illustrated and re-diagnosed, and complementary molecular data for 14 species and seven genes are analysed with Bayesian methods. Members of the nigrum-group are of long-standing conservation significance, and I. nigrum is the only spider in Australia to be afforded threatened species status under both State and Commonwealth legislation. Two other species, I. formosum Rix & Harvey, sp. n. and I. kopejtkaorum Rix & Harvey, sp. n., are also formally listed as Endangered under Western Australian State legislation. Here we significantly relimit I. nigrum to include only those populations from the central and central-western Wheatbelt bioregion, and further document the known diversity and conservation status of all known species.

  2. Conservation systematics of the shield-backed trapdoor spiders of the nigrum-group (Mygalomorphae, Idiopidae, Idiosoma): integrative taxonomy reveals a diverse and threatened fauna from south-western Australia

    Rix, Michael G.; Huey, Joel A.; Cooper, Steven J.B.; Austin, Andrew D.; Harvey, Mark S.

    2018-01-01

    Abstract The aganippine shield-backed trapdoor spiders of the monophyletic nigrum-group of Idiosoma Ausserer s. l. are revised, and 15 new species are described from Western Australia and the Eyre Peninsula of South Australia: I. arenaceum Rix & Harvey, sp. n., I. corrugatum Rix & Harvey, sp. n., I. clypeatum Rix & Harvey, sp. n., I. dandaragan Rix & Harvey, sp. n., I. formosum Rix & Harvey, sp. n., I. gardneri Rix & Harvey, sp. n., I. gutharuka Rix & Harvey, sp. n., I. incomptum Rix & Harvey, sp. n., I. intermedium Rix & Harvey, sp. n., I. jarrah Rix & Harvey, sp. n., I. kopejtkaorum Rix & Harvey, sp. n., I. kwongan Rix & Harvey, sp. n., I. mcclementsorum Rix & Harvey, sp. n., I. mcnamarai Rix & Harvey, sp. n., and I. schoknechtorum Rix & Harvey, sp. n. Two previously described species from south-western Western Australia, I. nigrum Main, 1952 and I. sigillatum (O. P.-Cambridge, 1870), are re-illustrated and re-diagnosed, and complementary molecular data for 14 species and seven genes are analysed with Bayesian methods. Members of the nigrum-group are of long-standing conservation significance, and I. nigrum is the only spider in Australia to be afforded threatened species status under both State and Commonwealth legislation. Two other species, I. formosum Rix & Harvey, sp. n. and I. kopejtkaorum Rix & Harvey, sp. n., are also formally listed as Endangered under Western Australian State legislation. Here we significantly relimit I. nigrum to include only those populations from the central and central-western Wheatbelt bioregion, and further document the known diversity and conservation status of all known species. PMID:29773959

  3. Petrology of Ortsog-Uul peridotite-gabbro massif in Western Mongolia

    Shapovalova, M.; Tolstykh, N.; Shelepaev, R.; Cherdantseva, M.

    2017-12-01

    The Ortsog-Uul mafic-ultramafic massif of Western Mongolia is located in a tectonic block with overturned bedding. The massif hosts two intrusions: a rhythmically-layered peridotite-gabbro association (Intrusion 1) and massive Bt-bearing amphibole-olivine gabbro (Intrusion 2). Intrusions 1 and 2 have different petrology features. Early Intrusion 1 (278±2.5Ma) is characterized by lower concentrations of alkalis, titanium and phosphorus than late Intrusion 2 (272±2Ma). The chondrite-normalized REE and primitive mantle-normalized rare elements patterns of Ortsog-Uul intrusions have similar curves of elements distribution. However, Intrusion 2 is characterized higher contents of REE and rare elements. High concentrations of incompatible elements are indicative of strong fractionation process. It has been suggested that Intrusions 1 and 2 derived from compositionally different parental melts. Model calculations (COMAGMAT-3.57) show that parental melts of two intrusions were close to high-Mg picrobasaltic magmas. The concentration of MgO in melt is 16.21 (Intrusion 1) and 16.17 (Intrusion 2). Isotopic data of Ortsog-Uul magmatic rocks exhibit different values of εNd (positive and negative) for Intrusion 1 and 2, respectively.

  4. Rapakivi texture in porphyritic dikes within the Karavanke Granitic Massif (Slovenia

    Giuliano Bellieni

    2002-01-01

    Full Text Available The northern Karavanke Granitic Massif straddles the Slovenian–Austrian border. The investigated area lies in northern Slovenia, and extends from the western Slovenian–Austrian border to the east for about 30 km, with a maximum width of 2 km. The massif exhibits a bimodal magmatic association comprising mainly syenogranite and syenite with contemporaneous gabbroic rocks. Rocks of intermediate composition are less abundant and show field, textural and chemical features suggesting that they have formed as a result of the interaction (mixing and mingling between felsic and mafic magmas. Plagioclasemantled alkali feldspars occur in dikes of porphyritic syenite, which cut larger bodies of gabbroic rocks. Field, mineralogical, petrographic and geochemical evidences suggest that the porphyritic syenite is a hybrid rock, formed by the interaction of mafic and felsic magmas. The formation of plagioclase-mantled alkali feldspar can be explained by the introduction of alkali feldspar from felsic, syenogranitic magma into more mafic magma, causing local undercooling in the portion of mafic magma surrounding the crystals. This resulted in the growth of cellular plagioclase, with quartz infilling, in a thermally and compositionally equilibrating system.

  5. The topographic signature of Quaternary tectonic uplift in the Ardennes massif (Western Europe)

    Sougnez, N.; Vanacker, V.

    2011-04-01

    Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 y. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This study aims to analyze the link between tectonic uplift rates and landscape morphology based on slope and channel morphometric indexes. To achieve this objective, we selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif (a Palaeozoic massif of NW Europe, principally located in Belgium) that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm yr-1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our analysis indicates that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronic, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.

  6. The hydrothermal alteration in the context of geologic evolution from Pocos de Caldas Alkaline Massif, MG-SP

    Garda, G.M.

    1990-01-01

    The Pocos de Caldas Alkaline Massif covers 800 km 2 , a quarter of which is hydrothermally altered. Such proportion is uncommon, when compared to the know alkaline massifs of the world. The hydrothermal alteration is associated with Zr, U and Mo mineralizations which are predominantly located in the central-southern portion of the massif, in the central-eastern circular structure. The colour of the altered rock (and its soil) in that area is typically whitish beige to yellowish white and is regionally called potassic rock. The Osamu Utsumi Mine, also referred to as the uranium ore of Campo do Cercado, is located 25 Km to the south of Pocos de Caldas City and was explored, from 1977 to 1989, through the open pit method. A sequence of alteration minerals adapted to lowering temperatures should be expected; however, only illite and alkaline feldspar are observed in the hydrothermally altered portions of the massif, and their formation must have been controlled mainly by kinetic, other than thermal factors. The irrestrict circulation of relatively hotter hydrothermal fluids must have happened at the beginning of the process, diminishing immediately after the cooling of the brecciated areas (and the subjacent magmatic body), leading the system to kinetics levels that made subsequent hydrothermal alteration impossible. (author)

  7. Uraninite, coffinite and brannerite from shear-zone hosted uranium deposits of the Bohemian Massif (Central European Variscan belt)

    René, Miloš; Dolníček, Z.

    2017-01-01

    Roč. 7, č. 4 (2017), č. článku 50. ISSN 2075-163X Institutional support: RVO:67985891 Keywords : uranium deposits * mineralogy * uraninite * coffinite * brannerite * Moldanubian Zone * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 2.088, year: 2016 http://www.mdpi.com/2075-163X/7/4/50

  8. Temporal evolution of mineralization events in the Bohemian Massif inferred from the Re-Os geochronology of molybdenite

    Ackerman, Lukáš; Haluzová, Eva; Creaser, R. A.; Pašava, J.; Veselovský, F.; Breiter, Karel; Erban, V.; Drábek, M.

    2017-01-01

    Roč. 52, č. 5 (2017), s. 651-662 ISSN 0026-4598 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : Re-Os * geochronology * molybdenite * Bohemian Massif * granite Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 3.396, year: 2016

  9. Permo-Carboniferous volcanism in late Variscan continental basins of the Bohemian Massif (Czech Republic): geochemical characteristic

    Ulrych, Jaromír; Pešek, J.; Štěpánková-Svobodová, Jana; Bosák, Pavel; Lloyd, F. E.; Seckendorff, von, V.; Lang, Miloš; Novák, Jiří Karel

    2006-01-01

    Roč. 66, č. 1 (2006), s. 37-56 ISSN 0009-2819 R&D Projects: GA AV ČR(CZ) IAA3013903 Institutional research plan: CEZ:AV0Z30130516 Keywords : Permo-Carboniferous * volcanics * continental basin * Bohemian Massif * underplating * crustal anatexis * Sr-Nd isotopes Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.824, year: 2006

  10. Comprenhensive Program of Engineering and Geologic Surveys for Designing and Constructing Radioactive Waste Storage Facilities in Hard Rock Massifs

    Gupalo, T.; Milovidov, V.; Prokopoca, O.; Jardine, L.

    2002-01-01

    Geological, geophysical, and engineering-geological research conducted at the 'Yeniseisky' site obtained data on climatic, geomorphologic, geological conditions, structure and properties of composing rock, and conditions of underground water recharge and discharge. These results provide suficient information to make an estimate of the suitability of locating a radioactive waste (RW) underground isolation facility at the Nizhnekansky granitoid massif.

  11. Monazite and zircon as major carriers of Th, U, and Y in peraluminous granites: examples from the Bohemian Massif

    Breiter, Karel

    2016-01-01

    Roč. 110, č. 6 (2016), s. 767-785 ISSN 0930-0708 R&D Projects: GA ČR GA14-13600S Institutional support: RVO:67985831 Keywords : zircon * monazite * granites * trace elements * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.236, year: 2016

  12. Granitic magma emplacement and deformation during early-orogenic syn-convergent transtension: The Stare Sedlo complex, Bohemian Massif

    Tomek, Filip; Žák, J.; Chadima, Martin

    2015-01-01

    Roč. 87, JUL (2015), s. 50-66 ISSN 0264-3707 Institutional support: RVO:67985831 Keywords : anisotropy of magnetic susceptibility (AMS) * Bohemian Massif * pluton emplacement * granite * transtension * Variscan orogeny Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.926, year: 2015

  13. Modelling the Middle Pleistocene uplift in the Ardennes-Rhenish Massif: Thermo-mechanical weakening under the Eifel?

    Garcia-Castellanos, D.; Cloetingh, S.A.P.L.; van Balen, R.T.

    2000-01-01

    Middle Pleistocene uplift in the Eifel has been interpreted as the isostatic response of the lithosphere to a deep buoyant hot body. The spatial and temporal distribution of the uplift in the Ardennes-Rhenish Massif Region has recently been constrained by new data of river incision that have been

  14. The Dilemma and Solutions for the Conflicts between Equality and Excellence in the Massification of Higher Education in Taiwan

    Hsiou-Huai, Wang

    2012-01-01

    Equality and excellence are two core values underlying many educational endeavors; however, they are often in conflict and controversy. This article intends to examine the dilemma created by such controversies in the context of massification of higher education in Taiwan and attempt to provide solutions from both the theoretical and policy…

  15. Late Cretaceous and Cenozoic dynamics of the Bohemian Massif inferred from the paleostress history of the Lusatian Fault Belt

    Coubal, Miroslav; Málek, Jiří; Adamovič, Jiří; Štěpančíková, Petra

    2015-01-01

    Roč. 87, July 1 (2015), s. 26-49 ISSN 0264-3707 R&D Projects: GA ČR GAP210/12/0573 Institutional support: RVO:67985831 ; RVO:67985891 Keywords : paleostress * fault kinematics * Lusatian Fault Belt * Elbe fault system * Bohemian Massif * Alpine foreland Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.926, year: 2015

  16. among health workers in south western Nigeria

    Objective: To appraise the level of awareness about prenatal diagnosis among health workers in southwestern Nigeria and its utilization. Methodology: ... awareness about it, and upon which the right attitude of referral is developed. In our ... information on religion, location of practice, field of practice and years in practice.

  17. ABNORMALITD3S IN SOUTH WESTERN NIGERIA

    Fusarium moniliforme andAspergillusflavus were isolated from all the categories of seed tested. ... acremonium and Nigrospora oryzae were also associated with purple/pink discolouration ... the basis of presence and characteristics of typical.

  18. The Vascular Flora of Rarău Massif (Eastern Carpathians, Romania. Note I

    Adrian Oprea

    2012-10-01

    Full Text Available The present study is concerned with the flora of the Rarău Massif, an area lying in the northeastern part of Romania, nearby the town of Câmpulung Moldovenesc. This study attempt to list all the vascular plants (i.e. ferns, conifers, and flowering plants from the whole area of Rarău Massif. Till now, there are published several papers on this area, but no paper deals with the whole surface of Rarău Massif. The research was carried out between 2000 to 2011. During the study period, 1377 taxa (1089 species and 288 subspecies, belonging to 95 families and 411 genera; 43 of the species belong to Pteridophytes, 8 belongs to Gymnosperms, and 1038 belongs to Angiosperms (835 Dicotyledons, 203 Monocotyledons subdivisions. The largest families (in terms of the number of species and subspecies included are: Asteraceae (167, Poaceae (78, Brassicaceae (53, Rosaceae and Lamiaceae (50, Scrophulariaceae and Cyperaceae (47, Caryophyllaceae and Ranunculaceae (42. The highest number of species, of a certain genus, is like the next: Carex L. (39, Centaurea L. (25, Hieracium L. (21, Festuca L. (19, Senecio L. (12, Cirsium, Pilosella, and Poa (11, etc. Since the flora of the area is analysed according to Raunkiaer’s life forms, the results are as follows: Hemicryptophytes 605 species (H=55.6%, Cryptophytes (also called Geophytes 137 species (G=12.6%, Therophytes 120 species (11.0%, Phanerophytes 84 species (Ph=7.7%, Chamaephytes 57 species (Ch=5.2%, Hemitherophytes 77 species (Ht=7.1%, Helo-hydatophytes 8 species (HH=0.7%, and Epiphytes 1 species (Ep=0.1%. The phytogeographic elements are the next ones: European=375 species (36.6%, Eurasian=349 species (34.0%, Circumboreal=148 species (14.8%, Cosmopolite=37 species (3.6%, Carpathians=31 species (3.0%, Pontics=19 species (1.9%, Mediterranean-submediterrannean=11 species (1.1%, and Adventitious=2 species (0.2%. The number of endemic and near-endemic taxa (species and subspecies within the study area is 53 (5.2%.

  19. Origin of natural waters and gases within the Upper Carboniferous coal-bearing and autochthonous Miocene strata in South-Western part of the Upper Silesian Coal Basin, Poland

    Kotarba, Maciej J.; Pluta, Irena

    2009-01-01

    The molecular and stable isotope compositions of coalbed gases from the Upper Carboniferous strata and natural gases accumulated within the autochthonous Upper Miocene Skawina Formation of the Debowiec-Simoradz gas deposit were determined, as well as the chemical and stable isotope compositions of waters from the Skawina Formation and waters at the top of the Upper Carboniferous strata of the Kaczyce Ridge (the abandoned 'Morcinek' coal mine) in the South-Western part of the Upper Silesian Coal Basin. Two genetic types of natural gases within the Upper Carboniferous coal-bearing strata were identified: thermogenic (CH 4 , small amounts of higher gaseous hydrocarbons, and CO 2 ) and microbial (CH 4 , very small amounts of ethane, and CO 2 ). Thermogenic gases were generated during the bituminous stage of coalification and completed at the end of the Variscan orogeny. Degassing (desorption) of thermogenic gases began at the end of late Carboniferous until the late Miocene time-period and extended to the present-day. This process took place in the Upper Carboniferous strata up to a depth of about 550 m under the sealing Upper Miocene cover. A primary accumulation zone of indigenous, thermogenic gases is present below the degassing zone. Up to 200 m depth from the top of the Upper Carboniferous strata, within the weathered complex, an accumulation zone of secondary, microbial gas occurs. Waters within these strata are mainly of meteoric origin of the infiltration period just before the last sea transgression in the late Miocene and partly of marine origin having migrated from the Upper Miocene strata. Then, both methanogenic archaebacteria and their nutrients were transported by meteoric water into the near-surface Carboniferous strata where the generated microbial CH 4 saturated coal seams. Waters within the Miocene strata of the Debowiec-Simoradz and Zablocie are of marine origin, and natural gases accumulated within autochthonous Miocene strata of the Debowiec

  20. U/Pb dating: brioverian age of the Erquy series (Armorican massif, France)

    Cocherie, A.; Chantraine, J.; Egal, E.; Fanning, C.M.; Dabard, M.P.; Paris, F.; Le Herisse, A.

    2001-01-01

    New U/Pb analyses obtained with a high-resolution ion microprobe (SHRIMP) fix an age of 608 ± 7 Ma for spilites of the Erquy series, in Cadomian rocks of the Armorican massif, France. This Neo-proterozoic age re-integrates this unit into the Brioverian, the age it was initially assigned to. A Rb/sr whole-rock dating in the 1970's had undermined the regional Cadomian model, by suggesting an Ordovician age for these rocks; this was apparently further supported by the discovery of organic remains, interpreted as Paleozoic micro-fossils. The reassessment of this paleontologic attribution and the new isotope dating are a final confirmation of the age of this series. (authors)

  1. Application of GIS technologies to monitor secondary radioactive contamination in the Delegen mountain massif

    Alipbeki, O.; Kabzhanova, G.; Kurmanova, G.; Alipbekova, Ch.

    2016-06-01

    The territory of the Degelen mountain massif is located within territory of the former Semipalatinsk nuclear test site and it is an area of ecological disaster. Currently there is a process of secondary radioactive contamination that is caused by geodynamic processes activated at the Degelen array, violation of underground hydrological cycles and as a consequence, water seepage into the tunnels. One of the methods of monitoring of geodynamic processes is the modern technology of geographic information systems (GIS), methods of satellite radar interferometry and high accuracy satellite navigation system in conjunction with radioecological methods. This paper discusses on the creation of a GIS-project for the Degelen array, facilitated by quality geospatial analysis of the situation and simulation of the phenomena, in order to maximize an objective assessment of the radiation situation in this protected area.

  2. Characterization of potassic materials of Pocos de Caldas alkaline massif, Southeastern Brazil

    Goncalves, P.; Navarro, F.C.; Roveri, C.D.; Bergerman, M.G.

    2016-01-01

    Potassium, which has featured in Brazil's agricultural sector and in the world's in the application of fertilizers, is present in magmatic rocks, such as nepheline syenite and phonolite, found in the Alkaline Massif of Pocos de Caldas (AMPC). The rare earth elements (REE), in turn, also occur in this region and have important uses in various industrial fields. The aim of this study was to investigate the potential of potassic rocks of AMPC in the fertilizer and rare earths industry. Five samples were collected and characterized. It was observed that there was no preferential concentration by granulometric range of potassium oxide, alumina, silica and iron oxide. Feldspathic mass, potash feldspar, and muscovite were found in all samples. The samples show REE with amounts greater than those found in the earth's crust, except for lutetium and scandium and possessed average content of potassium oxide from 8.70 to 14.40%. (author)

  3. Mineral compositions of plutonic rocks from the Lewis Hills massif, Bay of Islands ophiolite

    Smith, Susan E.; Elthon, Don

    1988-01-01

    Mineral compositions of residual and cumulate rocks from the Lewis Hills massif of the Bay of Islands ophiolite complex are reported and interpreted in the context of magnetic processes involved in the geochemical evolution of spatially associated diabase dikes. The mineral compositions reflect greater degrees of partial melting than most abyssal peridotites do and appear to represent the most depleted end of abyssal peridotite compositions. Subsolidus equilibration between Cr-Al spinal and olivine generally has occurred at temperatures of 700 to 900 C. The spinel variations agree with the overall fractionation of basaltic magmas producing spinels with progressively lower Cr numbers. The compositions of clinopyroxenes suggest that the fractionation of two different magma series produced the various cumulate rocks.

  4. The cooling history and the depth of detachment faulting at the Atlantis Massif oceanic core complex

    Schoolmeesters, Nicole; Cheadle, Michael J.; John, Barbara E.; Reiners, Peter W.; Gee, Jeffrey; Grimes, Craig B.

    2012-10-01

    Oceanic core complexes (OCCs) are domal exposures of oceanic crust and mantle interpreted to be denuded to the seafloor by large slip oceanic detachment faults. We combine previously reported U-Pb zircon crystallization ages with (U-Th)/He zircon thermochronometry and multicomponent magnetic remanence data to determine the cooling history of the footwall to the Atlantis Massif OCC (30°N, MAR) and help establish cooling rates, as well as depths of detachment faulting and gabbro emplacement. We present nine new (U-Th)/He zircon ages for samples from IODP Hole U1309D ranging from 40 to 1415 m below seafloor. These data paired with U-Pb zircon ages and magnetic remanence data constrain cooling rates of gabbroic rocks from the upper 800 m of the central dome at Atlantis Massif as 2895 (+1276/-1162) °C Myr-1 (from ˜780°C to ˜250°C); the lower 600 m of the borehole cooled more slowly at mean rates of ˜500 (+125/-102) °C Myr-1(from ˜780°C to present-day temperatures). Rocks from the uppermost part of the hole also reveal a brief period of slow cooling at rates of ˜300°C Myr-1, possibly due to hydrothermal circulation to ˜4 km depth through the detachment fault zone. Assuming a fault slip rate of 20 mm/yr (from U-Pb zircon ages of surface samples) and a rolling hinge model for the sub-surface fault geometry, we predict that the 780°C isotherm lies at ˜7 km below the axial valley floor, likely corresponding both to the depth at which the semi-brittle detachment fault roots and the probable upper limit of significant gabbro emplacement.

  5. The topographic signature of Quaternary tectonic uplift in the Ardennes massif (Western Europe

    N. Sougnez

    2011-04-01

    Full Text Available Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 y. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This study aims to analyze the link between tectonic uplift rates and landscape morphology based on slope and channel morphometric indexes. To achieve this objective, we selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif (a Palaeozoic massif of NW Europe, principally located in Belgium that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm yr−1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our analysis indicates that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronic, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.

  6. The Gondwana Orogeny in northern North Patagonian Massif: Evidences from the Caita Có granite, La Seña and Pangaré mylonites, Argentina

    Daniel A. Gregori

    2016-07-01

    Full Text Available Structural analyses in the northern part of the North Patagonia Massif, in the foliated Caita Có granite and in La Seña and Pangaré mylonites, indicate that the pluton was intruded as a sheet-like body into an opening pull-apart structure during the Gondwana Orogeny. Geochronological studies in the massif indicate a first, lower to middle Permian stage of regional deformation, related to movements during indentation tectonics, with emplacement of foliated granites in the western and central areas of the North Patagonian Massif. Between the upper Permian and lower Triassic, evidence indicates emplacement of undeformed granitic bodies in the central part of the North Patagonian Massif. A second pulse of deformation between the middle and upper Triassic is related to the emplacement of the Caita Có granite, the development of mylonitic belts, and the opening of the Los Menucos Basin. During this pulse of deformation, compression direction was from the eastern quadrant.

  7. Geologic-geochemical characteristics of Guidong granitic massif and recognition of geo-tectonic environment at the time of its emplacement

    Jianhong, Li; Shanyuan, Wei; Mingyue, Feng [Beijing Research Inst. of Uranium Geology, Beijing (China); Liang, Liang [East China Inst. of Technology, Fuzhou (China)

    2004-11-01

    Based on the study of geologic characteristics, such as mineralogic assemblage, structural and textural features of granite of Guidong granitic massif, and by using petrochemical, trace-element and isotopic data, and some petrochemical, trace-element and isotopic diagrams widely applied to the identification of geo-tectonic environments, authors recognize that Guidong granitic massif was emplaced in post-orogenic collision environment. (authors)

  8. Instrument-Aided Assessment of the Effect of Natural and Technogenic Factors on the Geomechanical State of a Massif Enclosing an HPP Turbine Room

    Abramov, N. N., E-mail: Abramov@goi.kolasc.net.ru; Epimakhov, Yu. A. [Russian Academy of Sciences, Mining Institute, Kola Scientific Center (Russian Federation)

    2016-05-15

    A package of geophysical criteria has been developed using seismic spatiotemporal tomography (SST) of a rock massif to perform an instrument-aided assessment of the effect of natural and technogenic factors on the geomechanical state of a rock massif enclosing an underground turbine room at an HPP. Results are presented for a detailed assessment for the underground turbine room at the Verkhnyaya Tuloma HPP on the Kola peninsula.

  9. Foraminiferal and radiolarian biostratigraphy of the youngest (Late Albian through Late Cenomanian) sediments of the Tatra massif, Central Western Carpathians

    Bąk, Krzysztof; Bąk, Marta

    2013-06-01

    Bąk, K. and Bąk M. 2013. Foraminiferal and radiolarian biostratigraphy of the youngest (Late Albian through Late Cenomanian) sediments of the Tatra massif, Central Western Carpathians. Acta Geologica Polonica, 63 (2), 223-237. Warszawa. The foraminiferal and radiolarian biostratigraphy of selected sections of the Zabijak Formation, the youngest sediments of the Tatra massif (Central Western Carpathians), have been studied. Benthic foraminifers, mainly agglutinated species, occur abundantly and continuously throughout the studied succession, while planktic foraminifers are generally sparse. Five planktic and two benthic foraminiferal zones have been recognized. The marly part of the Zabijak Formation comprises the Pseudothalmanninella ticinensis (Upper Albian) through the Rotalipora cushmani (Upper Cenomanian) planktic foraminiferal zones, and the Haplophragmoides nonioninoides and Bulbobaculites problematicus benthic foraminiferal zones. The radiolarians were recognized exclusively in the Lower Cenomanian part of the formation.

  10. Sm-Nd age of ultrabasite-basite massifs of east part of Baikal-Mujya ophiolite belt

    Izokh, A.Eh.; Gibsher, A.S.; Zhuravlev, D.Z.; Balykin, P.A.

    1998-01-01

    Two stratified ultrabasite-basite massifs of the Urals mountains were selected for isotope-geochemical studies. The intrusives, related to plutonic members of the island-arc associations, were used for dating. The Sm-Nd method indicated that one more belt, namely the Vend belt, is taking shape in the Baikal-Mujya tectonic collage alongside with the later Riphean (pre-Baikal) episubconduction belt of stratified intrusives [ru

  11. Boundaries of mantle–lithosphere domains in the Bohemian Massif as extinct exhumation channels for high-pressure rocks

    Babuška, Vladislav; Plomerová, Jaroslava

    2013-01-01

    Roč. 23, č. 3 (2013), s. 973-987 ISSN 1342-937X R&D Projects: GA ČR GA205/07/1088; GA ČR GAP210/12/2381; GA AV ČR IAA300120709 Institutional research plan: CEZ:AV0Z30120515 Keywords : Bohemian Massif * mantle lithosphere domains * fossil olivine fabric * high pressure Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 8.122, year: 2013

  12. Volcanic and geochemical evolution of the Teno massif, Tenerife, Canary Islands: some repercussions of giant landslides on ocean island magmatism

    Longpré, Marc-Antoine; Troll, Valentin R.; Walter, Thomas R.; Hansteen, Thor H.

    2009-01-01

    Large-scale, catastrophic mass wasting is a major process contributing to the dismantling of oceanic intraplate volcanoes. Recent studies, however, have highlighted a possible feedback relationship between flank collapse, or incipient instability, and subsequent episodes of structural rearrangement and/or renewed volcano growth. The Teno massif, located in northwestern Tenerife (Canary Islands), is a deeply eroded Miocene shield volcano that was built in four major eruptive phases punctuated ...

  13. Peculiarity of rock massif deformation under explosion impact (by the example of Zarechie area of the Semipalatinsk Test Site)

    Gorbunova, Eh.M.

    2003-01-01

    The paper systematize the results of study of man-caused situation formed outside the central zone of underground nuclear explosion (CZ UNE), at a testing area of the Semipalatinsk Test Site (STS) - Zarechie. The consequence effects of nuclear testing appeared in the rock massif and on the ground surface in the radius of 0.3-5 km from event epicenter are described. (author)

  14. Constraints on the origin of gabbroic rocks from the Moldanubian-Moravian units boundary (Bohemian Massif, Czech Republic and Austria)

    Ulrych, Jaromír; Ackerman, Lukáš; Kachlík, V.; Hegner, E.; Balogh, K.; Langrová, Anna; Luna, J.; Fediuk, F.; Lang, M.; Filip, Jiří

    2010-01-01

    Roč. 61, č. 3 (2010), s. 175-191 ISSN 1335-0552 R&D Projects: GA AV ČR IAA3013403; GA AV ČR IAA300130902 Institutional research plan: CEZ:AV0Z30130516 Keywords : gabbroic rocks * geochemistry * Sr-Nd isotopes * K-Ar ages * Moravian Unit * Moldanubian Unit * Bohemian Massif Subject RIV: DD - Geochemistry Impact factor: 0.909, year: 2010

  15. Joint inversion of teleseismic P waveforms and surface-wave group velocities from ambient seismic noise in the Bohemian Massif

    Růžek, Bohuslav; Plomerová, Jaroslava; Babuška, Vladislav

    2012-01-01

    Roč. 56, č. 1 (2012), s. 107-140 ISSN 0039-3169 R&D Projects: GA ČR GA205/07/1088; GA AV ČR IAA300120709; GA MŠk LM2010008 Institutional research plan: CEZ:AV0Z30120515 Keywords : receiver function * seismic noise * joint inversion * Bohemian Massif * velocity structure Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.975, year: 2012

  16. Developing the lithotectonic framework and model for sulphide mineralization in the Jebilet Massif, Morocco: implications for regional exploration

    Lusty, Paul A.J.; Goodenough, Kathryn M.; Essaifi, Abderrahim; Maacha, Lhou

    2015-01-01

    The central Jebilet massif, part of the North African Variscan Belt, hosts significant polymetallic sulphide mineralization. It is generally considered syngenetic and has many features of volcanogenic massive sulphide (VMS) mineralization. However, some characteristics are not compatible with a classic VMS model and two alternative scenarios for formation have been proposed. Our preliminary research favours a complex, multi-stage development of the sulphide deposits...

  17. Tectonic strain changes affecting the development of deep seated gravitational slope deformations in the Bohemian Massif and Outer Western Carpathians

    Stemberk, Josef; Hartvich, Filip; Blahůt, Jan; Rybář, Jan; Krejčí, O.

    2017-01-01

    Roč. 289, SI (2017), s. 3-17 ISSN 0169-555X R&D Projects: GA MŠk(CZ) LG15007; GA MŠk(CZ) LM2015079 Institutional support: RVO:67985891 Keywords : Deep seated gravitational slope deformations * Displacement monitoring * Tectonic strain changes * Bohemian Massif * Outer Western Carpathians Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 2.958, year: 2016

  18. Structure, emplacement, and tectonic setting of Late Devonian granitoid plutons in the Teplá–Barrandian unit, Bohemian Massif

    Žák, J.; Kratinová, Zuzana; Trubač, J.; Janoušek, V.; Sláma, Jiří; Mrlina, Jan

    2011-01-01

    Roč. 100, č. 7 (2011), s. 1477-1495 ISSN 1437-3254 R&D Projects: GA AV ČR KJB300120702 Institutional research plan: CEZ:AV0Z30120515; CEZ:AV0Z30130516 Keywords : Bohemian Massif * Teplá-Barrandian unit * Variscan orogeny * granite * pluton * subduction Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.342, year: 2011

  19. Seismic refraction technique aplications in the geotechnical characterization of the Cachoeira deposit massif, Caetite, State of Bahia, Brazil

    Malagutti Filho, W.; Oliveira Braga, T. de.

    1984-01-01

    Geophysical surveys throught the Cachoeira Uranium deposit massif were carried out with the purpose of assisting in the geotechnical characterization for the implantation of the Mining-Industrial Complex projects on the Lagoa Real uranium deposits, Caetite municipality, state of Bahia, Brazil. This study discusses the methodology utilized in the geophysical surveys and their results as well as their applications to the geotechnical characterization as a whole. (D.J.M.) [pt

  20. Fate of leaf-litter N in forest and grassland along a pedo-climatic gradient in south-western Siberia: an in situ 15N-labelling experiment

    Brédoire, Félix; Zeller, Bernd; Nikitich, Polina; Barsukov, Pavel A.; Rusalimova, Olga; Bakker, Mark R.; Legout, Arnaud; Bashuk, Alexander; Kayler, Zachary E.; Derrien, Delphine

    2017-04-01

    The suitability of Siberia for agriculture is expected to increase in the next decades due to strong and rapid climatic changes, but little is known on the environmental drivers of soil fertility there, especially nitrogen (N). Plant-available N is mainly derived from litter decomposition. South-western (SW) Siberia is located on the transition between several bioclimatic zones that are predicted to shift and extend along with climate change (steppe, forest-steppe, sub-taiga). The soils of this region are formed on a common loess deposit but they are submitted to different climatic conditions and vegetation cover. In the south of the region, typically in steppe/forest-steppe, soil freezes over winter because of a relatively shallow snow-pack, and water shortages are frequent in summer. In the north, typically in sub-taiga, the soil is barely frozen in winter due to a thick snow-pack and sufficient soil moisture in summer. In this study, we characterized the dynamics of leaf litter decomposition and the transfer of N from leaf litter to the soil and back to plants. Four sites were chosen along a climate gradient (temperature, precipitation and snow depth). At each site, we applied 15N-labelled leaf litter on the soil surface in experimental plots in an aspen (Populus tremula L.) forest and in a grassland. Twice a year during three years, we tracked the 15N derived from the decomposing labelled-litter in the organic layers, in the first 15 cm of the soil, and in above-ground vegetation. Soil temperature and moisture were monitored at a daily timestep over three years and soil water budgets were simulated (BILJOU model, Granier et al. 1999). We observed contrasting patterns in the fate of litter-derived 15N between bioclimatic zones. Over three years, along with faster decay rates, the release of leaf litter-N was faster in sub-taiga than in forest-steppe. As such, higher quantities of 15N were transferred into the soil in sub-taiga. The transfer was also deeper there

  1. Cl-rich hydrous mafic mineral assemblages in the Highiș massif, Apuseni Mountains, Romania

    Bonin, Bernard; Tatu, Mihai

    2016-08-01

    The Guadalupian (Mid-Permian) Highiș massif (Apuseni Mountains, Romania) displays a bimodal igneous suite of mafic (gabbro, diorite) and A-type felsic (alkali feldspar granite, albite granite, and hybrid granodiorite) rocks. Amphibole is widespread throughout the suite, and yields markedly high chlorine contents. Three groups are identified: Cl-rich potassic hastingsite (2.60-3.40 wt% Cl) within A-type felsic rocks and diorite, mildly Cl-rich pargasite to hornblende (0.80-1.90 wt% Cl) within gabbro, and low F-Cl hornblende within gabbro and hybrid granodiorite. Coexisting biotite is either Cl-rich within diorite, or F-Cl-poor to F-rich within A-type felsic rocks. Chlorine and fluorine are distributed in both mafic phases, according to the F-Fe and Cl-Mg avoidance rules. The low-Ti contents suggest subsolidus compositions. Cl-rich amphibole within diorite and A-type felsic rocks yields a restricted temperature range - from 575 °C down to 400 °C, whereas mildly Cl-rich amphibole within gabbro displays the highest range - from 675 to 360 °C. Temperatures recorded by Cl-rich biotite within diorite range from 590 to 410 °C. Biotite within A-type felsic rocks yields higher temperatures than amphibole: the highest values- from 640 to 540 °C - are recorded in low-F-Cl varieties, whereas the lowest values- from 535 to 500 °C - are displayed by F-rich varieties. All data point to halogen-rich hydrothermal fluids at upper greenschist facies conditions percolating through fractures and shear zones and pervasively permeating the whole Highiș massif, with F precipitating as interstitial fluorite and Cl incorporating into amphibole, during one, or possibly several, hydrothermal episodes that would have occurred during a ~ 150 My-long period of time extending from the Guadalupian (Mid-Permian) to the Albian (Mid-Cretaceous).

  2. Seismotectonic significance of the 2008–2010 Walloon Brabant seismic swarm in the Brabant Massif, Belgium

    Van Noten, Koen; Lecocq, Thomas; Shah, Anjana K.; Camelbeeck, Thierry

    2015-01-01

    Between 12 July 2008 and 18 January 2010 a seismic swarm occurred close to the town of Court-Saint-Etienne, 20 km SE of Brussels (Belgium). The Belgian network and a temporary seismic network covering the epicentral area established a seismic catalogue in which magnitude varies between ML -0.7 and ML 3.2. Based on waveform cross-correlation of co-located earthquakes, the spatial distribution of the hypocentre locations was improved considerably and shows a dense cluster displaying a 200 m-wide, 1.5-km long, NW-SE oriented fault structure at a depth range between 5 and 7 km, located in the Cambrian basement rocks of the Lower Palaeozoic Anglo-Brabant Massif. Waveform comparison of the largest events of the 2008–2010 swarm with an ML 4.0 event that occurred during swarm activity between 1953 and 1957 in the same region shows similar P- and S-wave arrivals at the Belgian Uccle seismic station. The geometry depicted by the hypocentral distribution is consistent with a nearly vertical, left-lateral strike-slip fault taking place in a current local WNW–ESE oriented local maximum horizontal stress field. To determine a relevant tectonic structure, a systematic matched filtering approach of aeromagnetic data, which can approximately locate isolated anomalies associated with hypocentral depths, has been applied. Matched filtering shows that the 2008–2010 seismic swarm occurred along a limited-sized fault which is situated in slaty, low-magnetic rocks of the Mousty Formation. The fault is bordered at both ends with obliquely oriented magnetic gradients. Whereas the NW end of the fault is structurally controlled, its SE end is controlled by a magnetic gradient representing an early-orogenic detachment fault separating the low-magnetic slaty Mousty Formation from the high-magnetic Tubize Formation. The seismic swarm is therefore interpreted as a sinistral reactivation of an inherited NW–SE oriented isolated fault in a weakened crust within the Cambrian core of

  3. Large plates and small blocks: The Variscan orogeny in the Bohemian Massif

    Kroner, Uwe; Romer, Rolf L.

    2017-04-01

    The Bohemian Massif of the Central European Variscides consists of several late Proterozoic / early Paleozoic low-strain crustal units, namely the Bruno-Vistulian continental block of the Laurussian plate that is juxtaposed with the Tepla-Barrandian Unit and the Lausitz block of the Gondwana plate. These pre-Variscan low-strain units are separated by high-strain zones that contain the mid- and lower crustal record of the Variscan orogeny (400-300 Ma), with nappes reflecting successive subduction exhumation events, voluminous migmatites and a wide range of geochemically contrasting granites. Although the principal constraints are undisputed, there is no consensus regarding the general tectonics of this area. Here we present a plate tectonic model explaining the Bohemian Massif as an orogenic wedge with a Gondwana pro-wedge and a Laurussia retro-wedge area. The principal formation steps are as follows. Subduction of the oceanic crust of the Gondwana plate, i.e. the southern part of the Rheic Ocean eventually followed by continental subduction of the distal Peri-Gondwana shelf produced the early Devonian (U)HP complexes now exposed in the uppermost allochthonous units. The arrival of the Tepla-Barrandian Cadomian block initiates a flip of subduction polarity, leading to the complete closure of the Rheic Ocean in the late Devonian coeval with the exhumation of the early Variscan (U)HP units. Caused by the Lausitz block entering the plate boundary zone in the early Carboniferous, this early subduction accretion stage was followed by continent continent collision. The resulting orogenic wedge is characterized by an intra-continental subduction zone in the pro-wedge area superimposed by the crustal stack of early and mid-Variscan accreted units. Due to heating of the subducted slab in the mantle, the isothermal exhumation of this deeply buried continental crust caused HT-LP metamorphism during the final transpressional stage. Lateral extrusion tectonics coeval with the

  4. Late Carboniferous remagnetisation of Palaeozoic rocks in the NE Rhenish Massif, Germany

    Zwing, A.; Bachtadse, V.; Soffel, H. C.

    During stepwise thermal and alternating field demagnetisation experiments on Devonian and Lower Carboniferous carbonate and clastic rocks from the north-eastern part of the Rhenish Massif, Germany, three components of magnetisation (A, B, C) are identified. Component A is a recent viscous overprint that parallels the local present day geomagnetic field. Component B is mainly observed from 260 up to 550 °C during thermal demagnetisation and is carried by magnetite. In two localities, where red siltstones and red carbonate rocks were sampled, component B is stable up to 670 °C, indicating the presence of hematite. Three clusters of in situ B directions can be identified, which are controlled by the tectonic position of the sampling areas. These are from NW to SE: the Remscheid anticline (RA), the Lüdenscheid syncline (LS) and the Attendorn and Wittgenstein synclines (AS/WS). Standard and inclination-only fold tests, using parametric resampling, yield optimal statistical parameters at increasing amounts of untilting ranging from 0% in the South up to 57% in the North of the NE Rhenish Massif. Despite the variations in optimal untilting, the resulting site mean directions of component B do not differ significantly in inclination. These results are interpreted to reflect the acquisition of magnetisation during progressive northward migration of the deformation front in Late Carboniferous times. The resulting palaeolatitudes (RA: 1°S +2°-3°; LS: 2°S +3°-2°; AS/WS: 1°S +3°-4°) are in good agreement with the predicted position of the sampling area in the Late Carboniferous, as derived from a published Apparent Polar Wander Path for Baltica and Laurentia. The unblocking temperature spectra and the synfolding nature of B yield strong evidence that chemical processes, possibly driven by fluid migration during orogenesis, caused this remagnetisation. A third component C was observed in zones of tight folding with steeply dipping to overturned bedding planes and is

  5. The Atlantis Bank Gabbro Massif, SW Indian Ridge: the Largest Know Exposure of the Lower Crust in the Oceans

    Dick, H. J.; Kvassnes, A. J.; Kinoshita, H.; MacLeod, C. J.; Robinson, P. T.

    2017-12-01

    Until the discovery of oceanic core complexes little was known and much inferred about the lower ocean crust at slow-spreading ridges. Their study shows the ocean crust isn't simply a uniform layer-cake of pillow lavas, sheeted dikes and gabbros, but is highly variable in thickness, composition and architecture, and even absent over large regions. The 660 km2 Atlantis Bank Gabbro Massif in the rift-mountains of the SW Indian Ridge flanking the Atlantis II Transform is the magmatic end member for ocean core complexes, and best approximates `average' slow-spread crust. Thus it has been a focus for drilling since its discovery in 1986, leading to the current attempt to drill to Moho there (Project SloMo). There are 3 ODP and IODP drill holes on its crest: 1508-m deep Hole 735B, 158-m deep Hole 1105A, and 809.4-m deep Hole U1473. These provide a 200 Kyr view of lower crustal accretion at a slow-spread ocean ridge. Here we extend this view to 2.7 Myr. Mapping and sampling shows the gabbro massif extends nearly the length of a single 2nd order magmatic ridge segment. With numerous inliers of the dike-gabbro transition at numerous locations, and a crust-mantle boundary, traced for 30-km along the transform wall, it would appear to represent a full section of the lower crust. As Moho is at 5.5 ± 1 km mbsf near Hole 735B, and 4.5 km beneath the transform, it is likely a serpentinization front. The crust-mantle boundary was crossed by dives at 4 locations. In each case gabbros at the base of the crust crystallized from melt that had previously fractionated 50% or more from a likely parent. Thus the gabbro massif must be laterally zoned, and the parental mantle melts had to have been emplaced at the center of the paleo-ridge segment, before intruding laterally to the distal end of the complex. Gabbros on a lithospheric flow line down the center of the massif closely resemble those from the drill holes. This shows that while lateral variations in crustal composition and

  6. Petrographic, geochemical and isotopic evidence of crustal assimilation processes in the Ponte Nova alkaline mafic-ultramafic massif, SE Brazil

    Azzone, Rogério Guitarrari; Montecinos Munoz, Patricio; Enrich, Gaston Eduardo Rojas; Alves, Adriana; Ruberti, Excelso; Gomes, Celsode Barros

    2016-09-01

    Crustal assimilation plus crystal fractionation processes of different basanite magma batches control the evolution of the Ponte Nova cretaceous alkaline mafic-ultramafic massif in SE Brazil. This massif is composed of several intrusions, the main ones with a cumulate character. Disequilibrium features in the early-crystallized phases (e.g., corrosion and sieve textures in cores of clinopyroxene crystals, spongy-cellular-textured plagioclase crystals, gulf corrosion texture in olivine crystals) and classical hybridization textures (e.g., blade biotite and acicular apatite crystals) provide strong evidence of open-system behavior. All samples are olivine- and nepheline-normative rocks with basic-ultrabasic and potassic characters and variable incompatible element enrichments. The wide ranges of whole-rock 87Sr/86Sri and 143Nd/144Ndi ratios (0.70432-0.70641 and 0.512216-0.512555, respectively) are indicative of crustal contribution from the Precambrian basement host rocks. Plagioclase and apatite 87Sr/86Sr ratios (0.70422-0.70927) obtained for the most primitive samples of each intrusion indicate disequilibrium conditions from early- to principal-crystallization stages. Isotope mixing-model curves between the least contaminated alkaline basic magma and heterogeneous local crustal components indicate that each intrusion of the massif is differentiated from the others by varied degrees of crustal contribution. The primary mechanisms of crustal contribution to the Ponte Nova massif involve the assimilation of host rock xenoliths during the development of the chamber environment and the assimilation of partial melts from the surrounding host rocks. Thermodynamic models using the melts algorithm indicate that parental alkaline basic magmas can be strongly affected by contamination processes subsequently to their initial stages of crystallization when there is sufficient energy to assimilate partial melts of crustal host rocks. The assimilation processes are considered to

  7. STRUCTURAL FEATURES OF THE NİĞDE MASSIF IN THE ÇAMARDI (NİĞDE DISTRICT

    Ramazan DEMİRCİOĞLU

    2017-04-01

    Full Text Available In the Çamardı (Niğde district, the Niğde Massif is composed of marbles, gneisses, quartzites and amphibolites. These rocks of the Massif have been cut by Cretaceous aged granodiorites. The Paleocene-Eocene aged low-grade metamorphic rocks constitute the autochthonous cover of the Massif. These units are tectonically overlain by the Upper Cretaceous-Paleocene aged flyschoid and island arc type rocks. The Oligocene-Quaternary aged terrestrial and volcanic rocks constitute the youngest units in the district. The metamorphics of the Niğde Massif have been subjected to at least four phase ductile deformation (D1, D2, D3, and D4 and folding. Through the D1 phase deformation, the rocks of the Massif have been folded as recumbent-isoclinal folds (F1-F2 phase folding and have gained a structure with a foliation (S1 which is parallel to the axial planes. Owing to the isoclinal and intense folding of the bedding planes (S0 of the rocks, bedding transposition have developed and transposed folding structures have formed. Through the D2 phase deformation, northeast-southwest trending and both northeast and southwest dipping map scale folds (F3 phase folding have developed. As a result of the interference of F1-F2 and F3 phase folds, in the district, folds, generated by Type-2 folding, have formed (mushroom folds. Second phase mesoscopic folds are of tight-isoclinal geometry and display asymmetrical and inclined fold feature. In the study area, as a result of   D3 phase folding a large dome structure has developed in the district. And D4 phase folds have formed map scale synformal and antiformal structures that are trending approximately perpendicular to D2 phase, plunging south-east and trending northwest-southeast. Through D4 phase deformation, the cover rocks have been deformed together with the basement rocks (F5 phase that they overlie. The microscopic observations show that Cretaceous-Eocene aged rocks have been subjected to low

  8. Internal structure of the Aar Massif: What can we learn in terms of exploration for deep geothermal energy?

    Herwegh, Marco; Baumberger, Roland; Wehrens, Philip; Schubert, Raphael; Berger, Alfons; Maeder, Urs; Spillmann, Thomas

    2014-05-01

    The successful use of deep geothermal energy requires 3D flow paths, which allow an efficient heat exchange between the surrounding host rocks and the circulating fluids. Recent attempts to exploit this energy resource clearly demonstrate that the new technology is facing sever problems. Some major problems are related to the prediction of permeability, the 3D structure of the flow paths and the mechanical responses during elevated fluid pressures at depths of several kilometers. Although seemingly new in a technical perspective, nature is facing and solving similar problems since the beginning of the Alpine orogeny. Based on detailed studies in the Hasli Valley (Aar Massif) we can demonstrate that deformation and fluid flow are strongly localized along mechanical anisotropies (e.g. lithological variations, brittle and ductile faults). Some of them already evolved during Variscan and post-Variscan times. Interestingly, these inherited structures are reactivated over and over again during the Alpine orogeny. Their reactivation occurred at depths of ~13-15 km with elevated temperatures (400-475°C) and involved both ductile and brittle deformation processes. Brittle deformation in form of hydrofracking was always present due to the circulating fluids. It is this process, which was and still is responsible for seismic activity. With progressive uplift and exhumation of the Aar Massif, ductile deformation structures became replaced by brittle cataclasites and fault gouges during fault activity at shallower crustal levels. Existing hydrotest data from the Grimsel Test Site (Nagra's underground research laboratory) indicate that these brittle successors of the ductile shear zones are domains of enhanced recent fluid percolation. Note that although being exposed today, the continuation of these fault structures are still active at depth in both brittle and ductile deformation modes, a fact that can be inferred from recent uplift rates and the active seismicity. On the

  9. The Taavinunnanen gabbro massif. A compilation of results from geological, geophysical and hydrogeological investigations

    Gentzschein, B.; Tullborg, E.L.

    1985-01-01

    The gabbro massif at Taavinunnanen, northern Sweden, is one of the study sites which has been investigated by the Swedish Nuclear Fuel and Waste Management Co (SKB) in order to study different geological environments within the scope of the long-range program for final disposal of spent nuclear fuel. A 700 metres long borehole was drilled within the gabbro. Regional geophysics, geological mapping, petrographical studies, mineralogical studies of rock-forming materials and of fracture fillings as well as hydrogeological tests were carried out. The gabbro shows primary differentiation. Thus, the composition varies from gabbroic to ultrabasic. The gabbro body is intersected by severeal granite dikes. These dikes exhibit a higher hydraulic conductivity and a higher fracture frequency than the gabbro. Comparison of hydraulic conductivity and fracture frequency in the gabbro itself indicates a high degree of sealing of the fractures mainly caused by smectites. Calcite is almost lacking down to a depth of 75 metres, indicating a relatively rapid transport of surface waters down to this depth. With 27 refs. (author)

  10. Ultramafites in the Gogolow-Jordanow massif and their predicted raw material evaluation

    Ciemniewska, M.; Czemier-Kowalska, M.; Lindner, M.; Salacinski, R.

    1981-01-01

    Based on mineralogical-petrographic analysis, it was established that the primary rocks of ultramafites were dunites and verlites which were exposed to intensive serpentinization, talcing, amphibolization, chloritization and carbonization. The constant components of rocks are ore minerals of paragenesis: chromite-ferrospinel-magnetite. Geochemical studies indicated the content (g/T): Cr 100-4800, Ni 100-3500, Co 30-160, Cu 1-100, while the computed values of the correlation coefficient revealed the existence of a link between Cr Ni, Co and Cr, Co and Ni. The mineralogical-petrographic composition, as well as the geological position of the studied massif indicate its affiliation to the ultramafites of the Alpine type and formation at the early stage of development of the geosyncline in the boundary zone between the consolidated gneiss block of the Archean and the mobile zone in relation to the deep faults. Although industrial concentrations of the expected were not found, the conducted observations make it possible to approach development of new prospecting concepts. Manifestation of the chromite mineralization and the ore accumulation in the region should be considered hydrothermal-metasomatic.

  11. Elastic and electrical properties and permeability of serpentinites from Atlantis Massif, Mid-Atlantic Ridge

    Falcon-Suarez, Ismael; Bayrakci, Gaye; Minshull, Tim A.; North, Laurence J.; Best, Angus I.; Rouméjon, Stéphane

    2017-11-01

    Serpentinized peridotites co-exist with mafic rocks in a variety of marine environments including subduction zones, continental rifts and mid-ocean ridges. Remote geophysical methods are crucial to distinguish between them and improve the understanding of the tectonic, magmatic and metamorphic history of the oceanic crust. But, serpentinite peridotites exhibit a wide range of physical properties that complicate such a distinction. We analysed the ultrasonic P- and S-wave velocities (Vp, Vs) and their respective attenuation (Qp-1, Qs-1), electrical resistivity and permeability of four serpentinized peridotite samples from the southern wall of the Atlantis Massif, Mid-Atlantic Ridge, collected during International Ocean Discovery Program Expedition 357. The measurements were taken over a range of loading-unloading stress paths (5-45 MPa), using ∼1.7 cm length, 5 cm diameter samples horizontally extracted from the original cores drilled on the seafloor. The measured parameters showed variable degrees of stress dependence, but followed similar trends. Vp, Vs, resistivity and permeability show good inter-correlations, while relationships that included Qp-1 and Qs-1 are less clear. Resistivity showed high contrast between highly serpentinized ultramafic matrix (>50 Ω m) and mechanically/geochemically altered (magmatic/hydrothermal-driven alteration) domains (serpentinization and the alteration state of the rock, contrasted by petrographic analysis. This study shows the potential of combining seismic techniques and controlled source electromagnetic surveys for understanding tectonomagmatic processes and fluid pathways in hydrothermal systems.

  12. Hydrochemical characteristics and spatial analysis of groundwater quality in parts of Bundelkhand Massif, India

    Ali, Syed Ahmad; Ali, Umair

    2018-03-01

    The tribulations of water quality have become more serious than the quantity, as the environmental evils are getting more severe day by day in different parts of the world. Large number of components like soil, geology, sewage disposal, effluents and other environmental conditions in which the water tends to reside or move and interact with ground and biological characteristics, greatly persuade the groundwater quality. Therefore, hydrochemical study has been carried out graphically and spatially in GIS environment in part of Bundelkhand Massif. The hydrochemical study exposes the water quality by measuring the concentration of parameters and comparing them with the drinking water and irrigation standards. Groundwater samples have been collected and analysed for physiochemical characteristics in order to understand the hydrochemistry of the water. The results revealed that ground water is alkaline in nature and total hardness observed in all samples falls under moderately hard to very hard category. At some places higher concentration of Cl- could be dangerous from health point of view. Major hydrochemical facies were identified using Piper Trilinear diagram and Durov diagrams, etc. Analysis of different determinations such as sodium adsorption ratio, residual sodium carbonate and per cent sodium revealed that most of the samples are unsuitable for irrigation. It was also observed that the quality of groundwater was not suitable for drinking purpose in industrial and irrigation area. In the area, few sampling sites showed unsuitability because of influences of urban and industrial waste discharge, aquifer material mineralogy, other anthropogenic activities and increased human interventions.

  13. First insights on the molybdenum-copper Bled M'Dena complex (Eglab massif, Algeria)

    Lagraa, Karima; Salvi, Stefano; Béziat, Didier; Debat, Pierre; Kolli, Omar

    2017-03-01

    Molybdenum-Copper showings in the Eglab massif (eastern part of the Reguibat rise of Algeria), are found in quartz-monzodiorite and granodiorite of the Bled M'Dena complex, a Paleoproterozoic circular structure of ∼5 km in diameter, comprising volcanic and intrusive suites. The latter consist of quartz-diorite, quartz-monzodiorite and granodiorite with a metaluminous normative composition. They display an "adakitic character" with moderate light rare-earth element (LREE) enrichment, minor Eu anomalies, high Sr/Y ratio and low Yb concentration, suggestive of a hydrous, arc magma of volcanic-arc affinity. The mineralization occurs mostly in quartz + molybdenite + chalcopyrite stockwork veins marked by widespread propylitic alteration along the selvages. Molybdenite and chalcopyrite are commonly associated with calcite, which precipitated at relatively late stages of the hydrothermal alteration. Fluid inclusions related to the mineralization stage, range from aqueous to aqueous-carbonic to solid bearing. The latter inclusions have the highest homogenization temperature (up to ∼400 °C), are salt saturated, and commonly contain molybdenite and/or chalcopyrite crystals. The petrology and geochemistry of the host rocks, the style of the hydrothermal alteration, the ore mineral associations, and the characteristics of the fluid inclusions, are all coherent in indicating that the Bled M'Dena represents a Paleoproterozoic porphyry style Mo mineralization, which is far unreported in the African continent.

  14. Stimulation Of The Methane Production With The Use Of Changing Of The Rock Massif Physical Conditions

    Baev Mikhail

    2017-01-01

    Full Text Available The commercial coalbed methane production success is majorly defined by the effectiveness of the use of special gas inflow stimulation methods. The necessity of using of such methods issubject to the aspects of searching and displacement of methane within the coal compound. Theanalysis of the ways of methane production stimulation from virgin coal formations is given. The description of the process of hydraulic fracturing (fracturing as the most common stimulation method during the commercial coalbed methane production as well as its major advantages are presented. The present work provides data about the initiated laboratory research of sands collected from Kemerovo region deposits for the purpose of finding of the most prospective samples by means of anchoring of fractures. The prospectivity and ability to implement the hydraulic fracturing with the use of locally available sands acting as proppants are shown. The influence of the strain-stress state of the rock massif on the alteration of permeability and the necessity of its extension study with respect to different technological features of hydraulic fracturing is shown

  15. IODP Expedition 340T: Borehole Logging at Atlantis Massif Oceanic Core Complex

    Donna Blackman

    2013-03-01

    Full Text Available Integrated Ocean Drilling Program (IODP Expedition 340T returned to the 1.4-km-deep Hole U1309D at Atlantis Massif to carry out borehole logging including vertical seismic profiling (VSP. Seismic, resistivity, and temperature logs were obtained throughout the geologic section in the footwall of this oceanic core complex. Reliable downhole temperature measurements throughout and the first seismic coverage of the 800–1400 meters below seafloor (mbsf portionof the section were obtained. Distinct changes in velocity, resistivity, and magnetic susceptibility characterize the boundaries of altered, olivine-rich troctolite intervals within the otherwise dominantly gabbroic se-quence. Some narrow fault zones also are associated with downhole resistivity or velocity excursions. Small deviations in temperature were measured in borehole fluid adjacent to known faults at 750 mbsf and 1100 mbsf. This suggests that flow of seawater remains active along these zones of faulting and rock alteration. Vertical seismic profile station coverage at zero offsetnow extends the full length of the hole, including the uppermost 150 mbsf, where detachment processes are expected to have left their strongest imprint. Analysis of wallrock properties, together with alteration and structural characteristics of the cores from Site U1309, highlights the likely interplay between lithology, structure, lithospheric hydration, and core complex evolution.

  16. Lichen flora particular features of Degelen mountain massif in location of underground nuclear explosion carrying out

    Ajdarkhanova, G.S.; Andreeva, E.I.; Tuleubaev, B.A.

    1998-01-01

    The 25 kinds of dominant lichens of the Degelen mountain massif of the former Semipalatinsk test site are studied. It is defined, that complex of ecological factors have influence on spreading of lichen flora ceno-population. Lichens heterogeneousness in ability to radionuclides accumulation is determining of variety its anatomic-morphologic structure and physiological activity as well as physico-chemical properties of soils in places of its inhabited place. It is determined, that lichens are able to exist within limits of exposure dose capacity 18-3000 μR/h and under radioactivity by α-radiation 233-426 Bq/kg, by β-radiation 7000-15000 Bq/kg and Cs 137 150-620 Bq/kg. The largest accumulating ability have Parmelia scortea (570 Bq/kg), Parmelia fraudans (620 Bq/kg), Parmelia cetrata (470 Bq/kg), Parmelia conspersa (340 Bq/kg). Cesium-137 in lichens in 2-8 times higher than maximum permissible dose. Complete relation is showed between lichens and inhabitated substrates created conditions for determination of radiation situation by precise characteristics of lichen flora

  17. Micro-FTIR and EPMA Characterisation of Charoite from Murun Massif (Russia

    Maria Lacalamita

    2018-01-01

    Full Text Available Combined micro-Fourier transform infrared (micro-FTIR and electron probe microanalyses (EPMA were performed on a single crystal of charoite from Murun Massif (Russia in order to get a deeper insight into the vibrational features of crystals with complex structure and chemistry. The micro-FTIR study of a single crystal of charoite was collected in the 6000–400 cm−1 at room temperature and after heating at 100°C. The structural complexity of this mineral is reflected by its infrared spectrum. The analysis revealed a prominent absorption in the OH stretching region as a consequence of band overlapping due to a combination of H2O and OH stretching vibrations. Several overtones of the O-H and Si-O stretching vibration bands were observed at about 4440 and 4080 cm−1 such as absorption possibly due to the organic matter at about 3000–2800 cm−1. No significant change due to the loss of adsorbed water was observed in the spectrum obtained after heating. The occurrence of well-resolved water bending vibration bands at about 1595 and 1667 cm−1 accounts for more than one structural water molecule as expected by charoite-90 polytype structure model from literature. The chemical composition of the studied crystal is close to the literature one.

  18. Spatial variability in channel and slope morphology within the Ardennes Massif, and its link with tectonics

    Sougnez, N.; Vanacker, V.

    2010-09-01

    Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 years. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This work focuses on a wide range of slope and river channel morphometric indices to study their behavior and strength in regions affected by low to moderate tectonic activity. We selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm year-1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our data indicate that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronous, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.

  19. Geochemistry of Spodosols formed in holocene till, Norra Storfjaellet Massif, northern Sweden

    Earl-goulet, J.R.; Mahaney, W.C.; Milner, M.W.; Hancock, R.G.V.

    1997-01-01

    Silt and clay size fractions of soils, from a transect of six Spodosols formed in the Norra Storfjaellet Massif, were analyzed by neutron activation to determine the degree to which pedogenic processes have influenced the distribution of macro, micro and trace elements. The distributions of Mg, Ca and Fe, together with Co, Cr and other trace elements in the profiles, suggest the presence of different parent materials, with A and E horizons arising from an influx of aeolian sediment. Translocation processes, both physical and chemical, occurred in the soil concentrating Fe and Br in the spodic(Bs) horizons of the profiles. The rare earth elements (REEs) are predominantly associated with the heavy mineral fraction of the soil material. The distributions of chondrite normalized REEs patterns of the profiles indicate that light rare earth element (LREE) concentrations increase with horizon depth. The depletion of LREEs in the upper soil horizons confirms the presence of material that is chemically different from that in the lower horizons, thus indicating a distinct chemical difference from the local glacial deposits. (author)

  20. Les dykes basiques du massif ancien de l'Ourika (Atlas de Marrakech, Maroc): géochimie et significationThe basic dykes of the Ourika old massif (High Atlas of Marrakech): Geochemistry and significance

    Barakat, Ahmed; Marignac, Christian; Bouabdelli, Mohamed

    The Precambrian massif of Ourika is crosscut by two systems of basic dykes, striking N40°E and N90-120°E. Using incompatible trace elements, the two systems form two distinct chemical groups, displaying a continental tholeiitic affinity. The composition variations between the two defined groups can be due to heterogeneities of mantle sources and to contamination, during the magma ascent, by the continental crust. The emplacement of these basic dykes, before the late-PIII formations, can be related to the Neoproterozoic distension generalised to the Anti-Atlas chain. To cite this article: A. Barakat et al., C. R. Geoscience 334 (2002) 827-833.

  1. Petrological and geochemical studies of alkaline rocks from continental Brazil. The tunas massif, state of Parana

    Gomes, C.B.; Barbieri, M.

    1987-01-01

    The Tunas massif, outcropping 80 km from the city of Curitiba, Parana State, southern Brazil, covers about 22 km 2 . It intruded into Precambrian metaigneous and metasedimentary units about 80 Ma ago (K/Ar and Rb/Sr data); five subcircular volcanic structures are recognized. Syenites and alkali syenites (plus some pulaskites) are the main rock-types, with subordinate alkali gabbros, syenogabbros, essexites and syenodiorites; small late syenitic dikes are also found. Magmatic breccias containing clasts of all rock-types are widespread. Main minerals are feldspars (both alkali feldspars and plagioclases, varying from bytownite to more sodic members), Ca-pyroxenes (Ti-salites grading towards ferrosalites and aegirine-augites), amphiboles (mainly pargasites, although kaersutites and katophorites are also present), Fe-biotites (sometimes enriched in Ti), olivines (hortonolites to ferrohortonolites), quartz and feldspathoids (both fresh and altered nephelines and sodalites); main accessories are Ti-magnetites (with exsolved ilmenite) and apatite. In the AFM diagram, whole rock chemistry depicts a typical alkaline trend. Binary variation diagrams (D.I. vs. several elements) show positive correlation for Si, Na and K, and negative slopes for Mg and Ca. The variation in the amounts of Ni, Cr and V with differentiation can be explained by withdrawal of olivine, Ca-pyroxenes and magnetite, and that of Sr and Ba by the fractionation of feldspars. The rocks are also relatively enriched in REE, a trend which is more pronounced for the light REE. Mass balance calculations show that the overall differentiation trend of the Tunas rocks can be explained by crystal fractionation, although several complexities arise and point to more complex genetic patterns. Isotopic Rb/Sr ratios are consistent with a mantle origin for the parental magma; dike rocks, however, with 87 Sr 86 Sr i = 0.70777 - 0.70806, were probably contaminated by crustal material. (author) [pt

  2. Isotopic characteristic of meteoric water and groundwater in Ahaggar massif (central Sahara)

    Saighi, O.; Michelot, J.L.; Filly, A.

    2001-01-01

    The mean contents of both oxygen-18 and deuterium in precipitation from the Ahaggar massif (central Sahara) are: δ 18 O = -3 per mille and 2 H = -15 per mille. The heterogeneity in meteoric events and the great scattering of these isotopic contents can be ascribed to the origins and the histories of air masses. The main contribution comes from the inflow of the Guinean monsoon during summer months. During winter, the N/W winds, arriving in the area from the Moroccan coast, provide some rains. The deuterium excess of these precipitation are up to +10 per mille, indicating that the air masses generating these rains are supplied by the recycling of the continental air moisture. Groundwater resources are produced in some little phreatic aquifers, which are recharged by sporadic wadi floods. Aquifer zones that are the most favourable are located in the valleys and occur as three overlying levels of unequal importance: the alluvial aquifer, the weathered zone of the underlying substratum and the deep aquifer of fissured basement. The alluvial aquifer contain weakly mineralised water (0.3 g/l). Their stable isotopes contents (δ 18 O∼ -2.7 per mille) and 14 C activity of them (> 100 pmc) are comparable to present meteoric water, allowing modern meteoric waters to be identified. The weathered zone groundwater's are more mineralised (0.8 g/l) and its isotopic contents (δ 18 O∼ -4.2 per mille) and intermediate radiocarbon activity, prove their old water component. The basement's groundwater are more mineralised (> 1 g/l) and their very depleted isotopic contents (δ 18 O∼ -9 per mille) diverge clearly from the present precipitation. Furthermore, the absence of 3 H and 14 C activity of them, prove an old heritage, resulting from recharge during the last humid episode of the Holocene. (author)

  3. Pb and O isotope systematics in granulite facies xenoliths, French Massif Central: Implications for crustal processes

    Downes, H.; Kempton, P.D.; Harmon, R.S.; Briot, D.; Leyreloup, A.F.

    1991-01-01

    Pb and O isotope data are represented for a suite of granulite facies xenoliths found within Tertiary alkaline volcanic rocks of the Massif Central, France. The suite consists of ultramafic and mafic cumulates, metagabbros which are considered to represent basic liquids, felsic meta-igneous lithologies (charnockites) and metasediments. Ranges of δ 18 O values are +6.9 to +9.8per mille for mafic xenoliths, +9.3 to +10.2per mille for felsic meta-igneous samples and +6.1 to +11.8per mille for the metasediments. By comparison, δ 18 O values for mantle peridotites from the same region range from +5.1 to +6.9per mille, whilst local Hercynian granitoids vary from +8.6 to +12.0per mille. The 206 Pb/ 204 Pb ratios of the granulite xenoliths are between 17.77 and 19.19, 207 Pb/ 204 Pb ratios vary from 15.51 to 15.69, and 208 Pb/ 204 Pb ratios range from 38.07 to 40.07. In general, metasedimentary granulites have the more radiogenic Pb isotope compositions, whereas mafic meta-igneous samples are less radiogenic. These isotopic characteristics can be explained as the result of the interaction of mafic magmas with the metasedimentary crust into which they intruded. The release of heat also provoked melting of the more fusible parts of the lower crust and led to the formation of late-orogenic Hercynian granitoids. However, an additional component which provides less radiogenic Pb is also needed in the source of the granitoids; this may be the felsic meta-igneous xenoliths or middle/upper crustal gneisses. (orig.)

  4. Sr and Nd isotope geochemistry of coexisting alkaline magma series, Cantal, Massif Central, France

    Downes, H.

    1984-01-01

    Sr and Nd isotope analyses are presented for Tertiary continental alkaline volcanics from Cantal, Massif Central, France. The volcanics belong to two main magma series, silica-saturated and silica-undersaturated (with rare nephelinites). Trace element and isotopic data indicate a common source for the basic parental magmas of both major series; the nephelinites in contrast must have been derived from a mantle source which is isotopically and chemically distinct from that which gave rise to the basalts and basanites. 87 Sr/ 86 Sr initial ratios range from 0.7034 to 0.7056 in the main magma series (excluding rhyolites) and 143 Nd/ 144 Nd ratios vary between 0.512927 and 0.512669; both are correlated with increasing SiO 2 in the lavas. The data can be explained by a model of crustal contamination linked with fractional crystallisation. This indicates that crustal magma chambers are the sites of differentiation since only rarely do evolved magmas not show a crustal isotopic signature and conversely basic magmas have primitive isotopic ratios unless they contain obviuos crustal-derived xenocrysts. Potential contaminants include lower crustal granulites or partial melts of upper crustal units. Equal amounts of contamination are required for both magma series, refuting hypotheses of selective contamination of the silica-saturated series. The isotopic characteristics of the apparently primary nephelinite lavas demonstrates widespread heterogeneity in the mantle beneath Cantal. Some rhyolites, previously thought to be extremely contaminated or to be crustally derived, are shown to have undergone post-emplacement hydrothermal alteration. (orig.)

  5. Conventional U-Pb dating versus SHRIMP of the Santa Barbara Granite Massif, Rondonia, Brazil

    Sparrenberger, I.; Bettencourt, Jorge S.; Tosdal, R.M.; Wooden, J.L.

    2002-01-01

    The Santa Ba??rbara Granite Massif is part of the Younger Granites of Rondo??nia (998 - 974 Ma) and is included in the Rondo??nia Tin Province (SW Amazonian Craton). It comprises three highly fractionated metaluminous to peraluminous within-plate A-type granite units emplaced in older medium-grade metamorphic rocks. Sn-mineralization is closely associated with the late-stage unit. U-Pb monazite conventional dating of the early-stage Serra do Cicero facies and late-stage Serra Azul facies yielded ages of 993 ?? 5 Ma and 989 ?? 13 Ma, respectively. Conventional multigrain U-Pb isotope analyses of zircon demonstrate isotopic disturbance (discordance) and the preservation of inherited older zircons of several different ages and thus yield little about the ages of Sn-granite magmatism. SHRIMP U-Pb ages for the Santa Ba??rbara facies association yielded a 207Pb/206Pb weighted-mean age of 978 ?? 13 Ma. The textural complexity of the zircon crystals of the Santa Ba??rbara facies association, the variable concentrations of U, Th and Pb, as well as the mixed inheritance of zircon populations are major obstacles to using conventional multigrain U-Pb isotopic analyses. Sm-Nd model ages and ??Nd (T) values reveal anomalous isotopic data, attesting to the complex isotopic behaviour within these highly fractionated granites. Thus, SHRIMP U-Pb zircon and conventional U-Pb monazite dating methods are the most appropriate to constrain the crystallization age of the Sn-bearing granite systems in the Rondo??nia Tin Province.

  6. Nature of radioactive contamination of components of ecosystems of streamflows from tunnels of Degelen massif

    Panitskiy, A.V.; Lukashenko, S.N.

    2015-01-01

    The paper provides data on environmental contamination due to radionuclides' migration with water. As a result of investigations there was obtained data on character of contamination of soil cover, surface water and underflow from tunnels of Degelen massif. Character of radionuclides' spatial distribution in environment was also shown. Mobility ranges of radionuclides' vertical and horizontal movements have been established in soils both across and along the stream flow. There was also shown a possibility to forecast radionuclides' concentration in soil by specific activity of these radionuclides in water. Different concentrations of radionuclides in associated components of the ecosystem (surface waters – ground waters – soils) have shown disequilibrium of their condition in this system. Generalization of investigation results for tunnel water streams' with water inflows, chosen as investigation objects in this work, allows to forecast radionuclides' behavior in meadow soils and other ecosystems of water streams from tunnels of Degelen test site. Based on analysis of curves, describing radionuclides' behavior in horizontal direction, we can forecast, that at this stage 137 Cs and 239+240 Pu would not be distributed more than 1.5 km from the access to the daylight surface, 90 Sr – not more than 2 km. - Highlights: • Contamination of soil cover, surface water and groundwater from tunnels of Degelen nuclear test area. • Radionuclides in associated components of the ecosystem showed disequilibrium. • Forecast that 137 Cs and 239+240 Pu will not be distributed more than 1.5 km from tunnel exits. • Forecast that 90 Sr will not be distributed more than 2 km

  7. THE GLACIER COMPLEXES OF THE MOUNTAIN MASSIFS OF THE NORTH-WEST OF INNER ASIA AND THEIR DYNAMICS

    Kirill Chistyakov

    2011-01-01

    Full Text Available The subject of this paper is the glaciation of the mountain massifs Mongun-Taiga, Tavan-Boghd-Ola, Turgeni-Nuru, and Harhira-Nuru. The glaciation is represented mostly by small forms that sometimes form a single complex of dome-shaped peaks. According to the authors, the modern glaciated area of the mountain massifs is 21.2 km2(Tavan-Boghd-Ola, 20.3 km2 (Mongun-Taiga, 42 km2 (Turgeni-Nuru, and 33.1 km2 (Harhira-Nuru. The area of the glaciers has been shrinking since the mid 1960’s. In 1995–2008, the rate of reduction of the glaciers’ area has grown considerably: valley glaciers were rapidly degrading and splitting; accumulation of morainic material in the lower parts of the glaciers accelerated. Small glaciers transformed into snowfields and rock glaciers. There has been also a degradation of the highest parts of the glaciers and the collapse of the glacial complexes with a single zone of accumulation into isolated from each other glaciers. Reduced snow cover area has led to a rise in the firn line and the disintegration of a common accumulation area of the glacial complex. In the of the Mongun-Taiga massif, in 1995–2008, the firn line rose by 200–300 m. The reduction of the glaciers significantly lagged behind the change in the position of the accumulation area boundary. In the past two years, there has been a significant recovery of the glaciers that could eventually lead to their slower degradation or stabilization of the glaciers in the study area.

  8. Using remote sensing imagery and GIS to identify land cover and land use within Ceahlau Massif (Romania

    GEORGE CRACU

    2014-11-01

    Full Text Available Using remote sensing imagery and GIS to identify land cover and land use within Ceahlău Massif (Romania. In this study we considerer land cover and land use asessment within Ceahlău Massif (Romania using satellite imagery and GIS . To achieve this goal, we used a Landsat 7 ETM + satellite image, which was processed using specialized software in analyzing satellite images and GIS software in several stages:  Downloading, importing and layer stack of all spectral bands composing satellite image;  Establishment of areas of interest for each category of land cover and land use, which were digitized on - screen and for which spectral signatures characteristics were established;  Supervised image classification using Maximum Likelihood Method;  Importing the resulting m ap (raster in GIS environment and creating the final land cover/land use map for Ceahlău Massif. In the study area we identified nine land cover/land use classes: deciduous forests, mixed forests, coniferous forests, secondary grasslands, subalpine vegeta tion, alpine meadows, agricultural land, lakes and built area. By analizing the spatial distribution of these classes, it was found that forests are the best represented class, occupying an area of 188.4 km² (56.4% of total, followed by secondary grassl and, which occupies an area of 68.2 km² (20.4% of total, lakes (26.6 km² or 7.98% of total and agricultural land (16.1 km² or 4.86%

  9. Perceptions of social and environmental changes in a Mediterranean forest during the last 100 years: the Gavarres Massif.

    Rodríguez-Carreras, Roser; Ubeda, Xavier; Outeiro, Luís; Asperó, Francesc

    2014-06-01

    During the last century the landscape of the mid-Mediterranean mountains has undergone major transformations. The precipitous decline in the economic viability of forest products has engendered ever-thickening forests and agricultural lands have reverted to forest land cover. The related exodus of existing inhabitants since 1960 has led to new styles of occupancy: residential and touristic land uses have emerged while the primary and secondary sectors have largely disappeared. The object of the present study is to review how these transformations have developed in a specific area of north-eastern of Catalonia, known as the Gavarres Massif. The study applies a qualitative approach, based on interviews with stakeholders including active members of the local community and others who utilize or visit the area, all of whom are representatives of different social groups with a wide range of interests and points of view with regard to the massif. The information collected from the perspectives and opinions of the participants is coupled with objective data about the area. The result of this investigation is a rich variety of perceptions on landscape and social transformation and its current functional dynamics. Analyzing the information obtained allows us to understand the fact that the disappearance of the rural world is directly related to the collapse of an entire economic system that relied on the environment. In this study, two divergent points of view arise, one which supports recovering past landscapes and another which favours managing changes, conserving the existing landscape. Proposals for the current and future territorial management of Les Gavarres are presented. The diversity of opinions which emerges with regard to managing necessary changes in the massif emphasizes the importance of increased social dialogue. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Palaeomagnetism in the Sines massif (SW Iberia) revisited: evidences for Late Cretaceous hydrothermal alteration and associated partial remagnetization

    Ribeiro, P.; Silva, P. F.; Moita, P.; Kratinová, Z.; Marques, F. O.; Henry, B.

    2013-10-01

    This study revisits the palaeomagnetism of the Sines massif (˜76 Ma) in the southwestern Iberian Margin (Portugal). The palaeomagnetic analysis was complemented by a comprehensive study of the magnetic mineralogy by means of rock magnetic measurements and petrographic observations. The overall dispersion of palaeomagnetic directions (declination ranging between ˜N0° and ˜N50°) and their migration observed during stepwise demagnetizations have revealed the superposition of remanence components. We interpret this complex palaeomagnetic behaviour as related to the regional hydrothermalism associated with the last stages of Late Cretaceous magmatic activity. This environment favoured mineralogical alteration and a partial chemical remagnetization, giving in most samples a composite magnetization, which has been erroneously interpreted as the primary one in a previous study, then leading to a questionable model for Cretaceous Iberia rotation. Nonetheless, for some samples a single component has been isolated. Interesting rock magnetic properties and microscopic observations point to a well-preserved magnetic mineralogy for these samples, with magnetite clearly of primary origin. The associated ChRM mean direction (D/I = 3.9°/46.5°, α95 = 1.7°, N = 31 samples) then represents the true primary magnetization of the Sines massif. This new palaeomagnetic direction and the corresponding palaeomagnetic pole (long = 332.0°, lat = -79.5°, A95 = 1.7°) agrees with those from the other palaeomagnetic works for the same period and region (e.g. the Sintra and Monchique massifs), yielding a lack of significant rotation of Iberia relative to stable Europe since the uppermost Late Cretaceous (Campanian-Maastrichtian).

  11. Tectonic evolution of part of the Southern Metamorphic Belt of the Armorican Massif including the Ile de Groix

    Richards, Lawrence Edward

    The Southern Metamorphic Belt (SMB) of the Armorican Massifextends 400km along the south coast of Brittany and into Vendee. It is separated from the Central Armorican Domain by a major, late-Hercynian shear belt, known as the South Armorican Shear Zone. In the area studied, belts of metasedimentary and metavolcanic schist of uncertain age are separated by belts of granitic gneiss; areas of migmatite and Hercynian granite plutons cross-cut these belts. Three distinctive lithologic assemblages have been identified in the schist belts, characteristic of different depositional environments: the Le Pouldu Group, Kerleven and Gouesnach formations probably originated as abyssal black shales deposited on oceanic crust; the St. Laurent Formation and Melgven Schists probably formed as distal greywacke deposits on a deep continental shelf; the Nerly and Beg-Meil formations probably formed in a proximal marine or fluviatile environment. These disparate assemblages were tectonically juxtaposed by overthrusting (obduction) before an amphibolite facies metamorphism and deformation during the Cadomian Orogeny. The Moelan Gneiss, a Lower Ordovician alkali-granite intrusion, postdates M1/D1 and probably formed in a rifting environment at the onset of ocean-floor spreading along an axis south of the present Armorican Massif. The famous blueschists of the Ile de Groix probably formed in a subduction zone on the south side of the ocean and were obducted onto the passive southern margin of the Armorican Massif following closure of the ocean and continental collision. A second phase of regional deformation, producing a cataclastic foliation in the Moelan Gneiss, probably resulted from the collision. Large-scale overthrusting of the southern continent onto the Armorican Massif took place, causing metamorphism with partial melting at depth generating migmatites. A third phase of pervasive deformation may correlate with oroclinal bending of the Ibero-Armorican Arc during the Hercynian

  12. Fission track and petrostructural analysis of carbonatic massif of Tamazert ( high central Atlas, Morocco) and neogene reactivation of the north-atlasic fault

    Ziad, N.; Khazrouni, S.; Tayebi, M.; Bouabdli, A.; Poupeau, G.

    2001-01-01

    The uranium fission-track dating method is used in geochronological survey of basic apatites extracted from the Tamazert complex. The result of this survey coupled with those of petrostructural analysis of this massif enabled as to distinguish three age groups: 32.4 Myr, 23.3 Myr and 12.6 Myr. The first age corresponds to the setting up of the massif, whereas the two other ages indicate later emissions. The setting up of the sill whose age is 12.6 Myr induced a partial rejuvenation of the emission age og the massif. This late volcanic emission is probably related to the north-atlasic fault activity. 4 figs., 1 tab., 30 refs. (au)

  13. K-Ar cooling age profile from Joinville massif (PR and SC, Brazil) and Dom Feliciano belt (SC, Brazil) - Tectonics entanglement

    Siga Junior, O.; Basei, M.A.S.; Kawashita, K.

    1990-01-01

    A K-Ar cooling age profile using different minerals from metamorphic rocks of the Joinville Massif and Dom Feliciano Belt is presented. Three main geochronological domains are distinguishable, from NW to SE: 1) Northern part of the Joinville Massif (NJM); 2) Southern part of the Joinville Massif (SJM) and 3) Dom Feliciano Belt (DBF). Geochronological domains 1 and 3 yielded K-Ar values in the range 800-500 Ma and 700-500 Ma, respectively, which show a clear influence of the Brasiliano Cycle. The granulite terrain comprising the SMJ exhibits ages older than 1700 Ma, indicating that this area was cool during the Late Proterozoic Brasiliano Cycle. The SJM and NJM limit is marked by a rapid Transition from Early Proterozoic ages in the SJM to Late Proterozoic ages in the NJM. On the other hand the contact between the SJM and DFB is interpreted as a thrust at a high, relatively cool crustal level. (author)

  14. Interpretation of the chemical compositions of the cumulates of the gabro-anorthositic massif of Piau River - Bahia State

    Cruz, M.J.M.; Demange, M.; Fonteilles, M.

    1989-01-01

    The Rio Piau gabbroic and anorthositic complex is an Archean layered body; intrusive in the charnokitic and enderbitic terrains of the Jequie nucleous (Sao Francisco Craton, Bahia State, Brazil). The geochemical data of the Rio Piau massif consists of two magmatic series, better identified by REE, titanium, phosphorous, niobium and gallium contents. These two magmatic series show an evolution following the typical tholeiitic and several types of cumulatic rocks. The evolution of each magmatic series is made up by differentiation and accumulation, from basic terms (MgO = 10%) up to intermediate terms (MgO = 2%) and shows an evolution similar to the Skaergaard trends. (author) [pt

  15. K-Ar and Rb-Sr dating results of the Malyshevsky leucogranite massif (eastern slope of the Middle Urals)

    Smirnov, V.N.; Ivanov, K.S.; Ronkin, Yu.L.; Levin, V.Ya.; Bushlyakov, I.N.; Lepikhina, O.P.; Popova, O.Yu.

    2005-01-01

    The age of leucogranites and minerals forming the Malyshevsky massif was identified by the methods of K-Ar- and Rb-Sr dating for refining the sequence of magmatic complexes formation on the eastern slope of the Middle Urals. The obtained isotope age values, i.e. 229-277 mln. years (K-Ar) and 277.1±1.1 mln. years (Rb-Sr), permit considering the age of 277 mln. years as the period of the leucogranites formation and of the associated molybdenum mineralization [ru

  16. Subduction metamorphism in the Himalayan ultrahigh-pressure Tso Morari massif: An integrated geodynamic and petrological modelling approach

    Palin, Richard M.; Reuber, Georg S.; White, Richard W.; Kaus, Boris J. P.; Weller, Owen M.

    2017-06-01

    The Tso Morari massif is one of only two regions where ultrahigh-pressure (UHP) metamorphism of subducted crust has been documented in the Himalayan Range. The tectonic evolution of the massif is enigmatic, as reported pressure estimates for peak metamorphism vary from ∼2.4 GPa to ∼4.8 GPa. This uncertainty is problematic for constructing large-scale numerical models of the early stages of India-Asia collision. To address this, we provide new constraints on the tectonothermal evolution of the massif via a combined geodynamic and petrological forward-modelling approach. A prograde-to-peak pressure-temperature-time (P-T-t) path has been derived from thermomechanical simulations tailored for Eocene subduction in the northwestern Himalaya. Phase equilibrium modelling performed along this P-T path has described the petrological evolution of felsic and mafic components of the massif crust, and shows that differences in their fluid contents would have controlled the degree of metamorphic phase transformation in each during subduction. Our model predicts that peak P-T conditions of ∼2.6-2.8 GPa and ∼600-620 ∘C, representative of 90-100 km depth (assuming lithostatic pressure), could have been reached just ∼3 Myr after the onset of subduction of continental crust. This P-T path and subduction duration correlate well with constraints reported for similar UHP eclogite in the Kaghan Valley, Pakistan Himalaya, suggesting that the northwest Himalaya contains dismembered remnants of what may have been a ∼400-km-long UHP terrane comparable in size to the Western Gneiss Region, Norway, and the Dabie-Sulu belt, China. A maximum overpressure of ∼0.5 GPa was calculated in our simulations for a homogeneous crust, although small-scale mechanical heterogeneities may produce overpressures that are larger in magnitude. Nonetheless, the extremely high pressures for peak metamorphism reported by some workers (up to 4.8 GPa) are unreliable owing to conventional thermobarometry

  17. Les roches basiques et ultrabasiques des Lacs Robert et le Trias de Chamrousse (Massif de Belledonne) Etude petrologique et geologique

    Tex, den E.

    1950-01-01

    La région que j’ai étudiée et relevée est située dans les Alpes françaises, à environ 4° longitude est et 50°15’ latitude nord, et à environ 2000 mètres d’altitude. Elle fait partie de la chaîne dite „chaîne de Belledonne” qui s’étend des massifs de Beaufort et du Grand Mont dans le N N E jusqu’à

  18. Ecology, reproductive biology and conservation of Picris willkommii (Schultz Bip.) Nyman (Asteraceae): an endemic, protected species from therophytic grasslands of South-Western Iberian Peninsula; Ecologia, biologia reproductiva y conservacion de Picris willkommii (Schultz Bip.) Nyman (Asteraceae): endemismo protegido integrado en pastos terofiticos del suroeste de la Peninsula Iberica

    Monteagudo Sanchez-Movellan, F. J.; Butler Sierra, I.; Bastida Milian, F.

    2009-07-01

    Current knowledge of the biology of Picris willkommii and his grade of threat, seem not to be sufficient to ensure long term persistence of this plant species endemic to the South-Western Iberian Peninsula. In Spain, main populations of the species are narrowly restricted to therophytic grasslands around the town of Ayamonte, by the Guadiana river drainage. Results of the present study indicate that P. willkommii behaves as a very versatile, colonizing species in most of the habitats of their natural range, where it appears to be well suited to the cyclic disturbance dynamics imposed by local, traditional land uses, i.e. extensive rain-fed agriculture. Moreover, it is easy to grow under controlled conditions. Results could be helpful for conservation and population recovery purposes, as recent changes in land use, shifting from agricultural traditional systems to urban expansion or alternative agricultural systems, pose at risk P. willkommii populations due to habitat loss. (Author) 35 refs.

  19. Geochronology and geochemistry of early Paleozoic intrusive rocks from the Khanka Massif in the Russian Far East: Petrogenesis and tectonic implications

    Xu, Ting; Xu, Wen-Liang; Wang, Feng; Ge, Wen-Chun; Sorokin, A. A.

    2018-02-01

    This paper presents new geochronological and geochemical data for early Paleozoic intrusive rocks from the Khanka Massif in the Russian Far East, with the aim of elucidating the Paleozoic evolution and tectonic attributes of the Khanka Massif. New U-Pb zircon data indicate that early Paleozoic magmatism within the Khanka Massif can be subdivided into at least four stages: 502, 492, 462-445, and 430 Ma. The 502 Ma pyroxene diorites contain 58.28-59.64 wt% SiO2, 2.84-3.69 wt% MgO, and relatively high Cr and Ni contents. Negative εHf(t) values (- 1.8 to - 0.4), along with other geochemical data, indicate that the primary magma was derived from partial melting of mafic lower crust with the addition of mantle material. The 492 Ma syenogranites have high SiO2 and K2O contents, and show positive Eu anomalies, indicating the primary magma was generated by partial melting of lower crust at relatively low pressure. The 445 Ma Na-rich trondhjemites display high Sr/Y ratios and positive εHf(t) values (+ 1.8 to + 3.9), indicating the primary magma was generated by partial melting of thickened hydrous mafic crust. The 430 Ma granitoids have high SiO2 and K2O contents, zircon εHf(t) values of - 5.4 to + 5.8, and two-stage model ages of 1757-1045 Ma, suggesting the primary magma was produced by partial melting of heterogeneous Proterozoic lower crustal material. The geochemistry of these early Paleozoic intrusive assemblages indicates their formation in an active continental margin setting associated with the subduction of a paleo-oceanic plate beneath the Khanka Massif. The εHf(t) values show an increasingly negative trend with increasing latitude, revealing a lateral heterogeneity of the lower crust beneath the Khanka Massif. Regional comparisons of the magmatic events indicate that the Khanka Massif in the Russian Far East has a tectonic affinity to the Songnen-Zhangguangcai Range Massif rather than the adjacent Jiamusi Massif.

  20. Geology and uranium occurrences in the Forez tertiary plain (in the French 'Massif Central'); Geologie et mineralisations uraniferes de la plaine tertiaire du Forez (Massif Central francais)

    Duclos, P. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses - 92 (France). Centre d' Etudes Nucleaires

    1967-01-01

    In the first part, the observations made during the geological survey of the Forez Tertiary plain (in the French 'Massif Central') are recalled. Then, using various methods, the author lists the formations according to chronology. Finally, a reconstitution of the geological history of this subsidence basin is attempted. In the second part, the occurrence of 17 uranium bearing geochemical anomalies is commented upon. Each of these various anomalies is given a place on the stratigraphic scale. This enables the author to put the successive phases of uranium deposition into their proper perspective in the history of the plain. In conclusion, the author points out the usefulness of these uraniferous geochemical anomalies. (author) [French] Dans la premiere partie, l'auteur rappelle les observations faites au cours de l'etude geologique de la plaine tertiaire du Forez (Massif Central francais). Puis se servant de differentes methodes, il etablit une chronologie des formations. Enfin, il termine par un essai de reconstitution de l'histoire geologique de ce bassin de subsidence. Dans la deuxieme partie, il commente la decouverte de 17 anomalies geochimiques uraniferes. Il situe ces differentes anomalies dans la serie stratigraphique. Ceci lui permet de replacer les depots successifs de l'uranium dans l'histoire de la plaine. Enfin, il indique l'interet de ces anomalies geochimiques uraniferes. (auteur)

  1. Occurrence of an unknown Atlantic eruption in the Chaîne des Puys volcanic field (Massif Central, France)

    Jouannic, G.; Walter-Simonnet, A. V.; Bossuet, G.; Cubizolle, H.; Boivin, P.; Devidal, J. L.; Oberlin, C.

    2014-08-01

    A volcanic ash layer, called MF1, was recently identified in Holocene sediments from the Gourgon and Molhiac peat bogs (Monts du Forez, French Massif Central). This ash layer consists of colorless shards with a heterogeneous trachytic to rhyolitic composition. The trace elements analyzed by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) attest to a local origin. Radiocarbon dating of peat samples taken within and below the ash layer indicates the best age at 6339 ± 61 cal yr BP, i.e. an age contemporaneous with the volcanic activity of Montchal, Montcineyre and Pavin volcanoes from the Chaîne des Puys volcanic field. These volcanoes are characterized by basaltic and trachytic products, thus the rhyolitic composition of MF1 tephra suggests that it is likely originated from an unknown eruption. These results again confirm the interest of studying the distal volcanic ash fallouts in order to establish or specify records of past eruptions of volcanic fields. Identification of this new tephra layer also provides an additional tephrochronological marker for Eastern French Massif Central.

  2. A distinctive new frog species (Anura, Mantellidae supports the biogeographic linkage of two montane rainforest massifs in northern Madagascar

    Mark D. Scherz

    2018-03-01

    Full Text Available We describe a new species of the genus Gephyromantis, subgenus GephyromantisVatomantis (Mantellidae, Mantellinae, from moderately high elevation (1164–1394 m a.s.l. on the Marojejy, Sorata, and Andravory Massifs in northern Madagascar. The new species, Gephyromantis (Vatomantis lomorina sp. n. is highly distinct from all other species, and was immediately recognisable as an undescribed taxon upon its discovery. It is characterised by a granular, mottled black and green skin, reddish eyes, paired subgular vocal sacs of partly white colour, bulbous femoral glands present only in males and consisting of three large granules, white ventral spotting, and a unique, amplitude-modulated advertisement call consisting of a series of 24–29 rapid, quiet notes at a dominant frequency of 5124–5512 Hz. Genetically the species is also strongly distinct from its congeners, with uncorrected pairwise distances ≥10 % in a fragment of the mitochondrial 16S rRNA gene to all other nominal Gephyromantis species. A molecular phylogeny based on 16S sequences places it in a clade with species of the subgenera Laurentomantis and Vatomantis, and we assign it to the latter subgenus based on its morphological resemblance to members of Vatomantis. We discuss the biogeography of reptiles and amphibians across the massifs of northern Madagascar, the evidence for a strong link between Marojejy and Sorata, and the role of elevation in determining community sharing across this landscape.

  3. Geochemical study of water-rock interaction processes on geothermal systems of alkaline water in granitic massif

    Buil gutierrez, B.; Garcia Sanz, S.; Lago San Jose, M.; Arranz Yague, E.; Auque Sanz, L.

    2002-01-01

    The study of geothermal systems developed within granitic massifs (with alkaline waters and reducing ORP values) is a topic of increasing scientific interest. These systems are a perfect natural laboratory for studying the water-rock interaction processes as they are defined by three main features: 1) long residence time of water within the system, 2) temperature in the reservoir high enough to favour reaction kinetics and finally, 3) the comparison of the chemistry of the incoming and outgoing waters of the system allows for the evaluation of the processes that have modified the water chemistry and its signature, The four geothermal systems considered in this paper are developed within granitic massifs of the Spanish Central Pyrenes; these systems were studied from a geochemical point of view, defining the major, trace and REE chemistry of both waters and host rocks and then characterizing the composition and geochemical evolution of the different waters. Bicarbonate-chloride-sodic and bicarbonate-sodic compositions are the most representative of the water chemistry in the deep geothermal system, as they are not affected by secondary processes (mixing, conductive cooling, etc). (Author)

  4. Remelting of nanogranitoids in UHP felsic granulites from Erzgebirge (Bohemian Massif, Germany)

    Acosta-vigil, A.; Stöckhert, B.; Hermann, J.; Yaxley, G.; Cesare, B.; Bartoli, O.

    2017-12-01

    Crustal melting commonly takes place at pressures ≤ 1.5 GPa. Anatexis at UHP conditions, however, can occur during subduction of continental crust down to mantle depths. Understanding the timing, mechanisms and nature of this process is important as it has major mechanical and geochemical implications. One way to address this problem is through the novel studies of nanogranitoids in migmatites and granulites (Cesare et al. 2015). We have remelted crystallized former melt inclusions (nanogranitoids) trapped in garnets of diamond-bearing UHP felsic granulites from Erzgebirge, Bohemian Massif. These rocks are made of Qtz+Phe+Pl+Grt+Ky+Bt+Dia, and their peak conditions have been estimated at P≥4.5 GPa and T≥1000 ºC. Nanogranitoids appear homogeneously distributed throughout the entire garnet crystals, are 5-50 µm across and often isometric, with partially developed negative crystal shape, and were trapped during garnet growth in the presence of melt. The mineral assemblage within nanogranites consists of Qtz+Pl+Phe+Pg+Phl±Ky±Dia±Gr±Ap±Rt (Stöckhert et al. 2009). Fragments of nanogranitoids-bearing garnets were loaded inside gold capsules, enclosed in SiO2 or C powders that acted as cushion, either dry or with H2O in excess, and subjected to conditions between 975-1100 ºC and 2.5-4.5 GPa for 2-24 hrs. Re-homogenization has not been completely achieved. Nanogranitoids partially melt, melt often coexists with Als, diamond or Gr, and Grt grows into the melt to form a higher #Mg and Ti, ≈5 µm fringe. Preliminary EMP analyses indicate that melts are granitic sensu stricto, with low FeOt+MgO (≈2 wt%), moderate to high in ASI, and high in TiO2 (≈0.4-0.8 wt%), P2O5 (up to 1 wt%) and volatiles (100-EMP totals ≈ 10-15 wt%). These preliminary results suggest that (i) anatexis started in the presence of a H2O-rich fluid phase, (ii) melt was present and equilibrated at quite high T (>850-950 ºC, Hayden & Watson 2007) at or close to peak conditions, (iii) Als

  5. Dating an actively exhuming metamorphic core complex, the Suckling Dayman Massif in SE Papua New Guinea

    Oesterle, J.; Seward, D.; Little, T.; Stockli, D. F.; Mizera, M.

    2016-12-01

    Low-temperature thermochronology is a powerful tool for revealing the thermal and kinematic evolution of metamorphic core complexes (MCCs). Most globally studied MCCs are ancient, partially eroded, and have been modified by deformation events that postdate their origin. The Mai'iu Fault is a rapidly slipping active low-angle normal fault (LANF) in the Woodlark Rift in Papua New Guinea that has exhumed a >25 km-wide (in the slip direction), and over 3 km-high domal fault surface in its footwall called the Suckling-Dayman massif. Some knowledge of the present-day thermal structure in the adjacent Woodlark Rift, and the pristine nature of this active MCC make it an ideal candidate for thermochronological study of a high finite-slip LANF. To constrain the thermal and kinematic evolution of this MCC we apply the U/Pb, fission-track (FT) and (U-Th)/He methods. Zircon U/Pb analyses from the syn-extensional Suckling Granite that intrudes the footwall of the MCC yield an intrusion age of 3.3 Ma. Preliminary zircon FT ages from the same body indicate cooling below 300 °C at 2.7 Ma. Ages decrease to 2.0 Ma with increasing proximity to the Mai'iu Fault and imply cooling controlled by tectonic exhumation. Almost coincident zircon U/Pb and FT ages from the nearby syn-extensional Mai'iu Monzonite, on the other hand, record extremely rapid cooling from magmatic temperatures to 300 °C at 2 Ma. As apparent from the preliminary He extraction stage, these syn-extensional plutons have young zircon and apatite (U-Th)/He ages. These initial results suggest that the Mai'iu Fault was initiated as an extensional structure by 3.3 Ma. We infer that it reactivated an older ophiolitic suture that had emplaced the Papuan Ultramafic body in the Paleogene. Rapid cooling of the Mai'iu Monzonite indicates that it was intruded into a part of the MCC's footwall that was already shallow in the crust by 2 Ma. This inference is further supported by the mineral andalusite occurring in the contact

  6. Volcanic avalanche fault zone with pseudotachylite and gouge in French Massif Central

    Bernard, Karine; van Wyk de Vries, Benjamin

    2017-11-01

    Structures and textures with sedimentological variations at different scales of the lithofacies assemblage help us to constrain the basal kinematic transition from non-depositional to depositional conditions during volcanic avalanche emplacement. In the well-exposed impact-sheared contact along volcanic avalanche fault zone in the French Massif Central, we observe how the granular textures of the pseudotachylite and fault gouge have recorded the propagation of shock wave with granular oscillatory stress. Sequential events of basal aggradation along avalanche fault zone have been established related to fractal D-values, temperature pressure regime and oscillatory stress during slow wave velocity. A typical lithofacies assemblage with a reverse grading shows the pseudotachylite and fault gouge. A cataclastic gradient is characterised by the fractal D-values from 2.7 in jigsaw breccias with pseudotachylite partial melt, to 2.6 in the polymodal gouge. Shock, brecciation and comminution produce cataclastic shear bands in the pseudotachylite and quartz microstructures along the basal contact of the volcanic debris-avalanche deposit. Gouge microstructures show granular segregation, cataclasis with antithetic rotational Riedel shear, and an arching effect between the Riedel shear bands. X-ray microtomography provided 3D microfabrics along the clastic vein in the sandy-gouge. From the available statistical dataset, a few equations have been developed implicating the same cataclastic origin with a co-genetic evolution of lithofacies. An impact wave during primary shear propagation may contribute to produce hydroclastic matrix, pseudotachylite partial melt and proximal gouge thixotropy with v 50m/s and a T < 654 °C. The interseismic period with oscillatory stress is related to crushed clasts and basaltic melt around 800 °C, Riedel shear bands with granular segregation along the fault gouge. The secondary shock by matrix-rich avalanche (ΔP = 10GPa, T ≥ 1000-1500

  7. Overview of Hole GT2A: Drilling middle gabbro in Wadi Tayin massif, Oman ophiolite

    Takazawa, E.; Kelemen, P. B.; Teagle, D. A. H.; Coggon, J. A.; Harris, M.; Matter, J. M.; Michibayashi, K.

    2017-12-01

    Hole GT2A (UTM: 40Q 655960.7E / 2529193.5N) was drilled by the Oman Drilling Project (OmDP) into Wadi Gideah of Wadi Tayin massif in the Samail ophiolite, Oman. OmDP is an international collaboration supported by the International Continental Scientific Drilling Program, the Deep Carbon Observatory, NSF, IODP, JAMSTEC, and the European, Japanese, German and Swiss Science Foundations, with in-kind support in Oman from the Ministry of Regional Municipalities and Water Resources, Public Authority of Mining, Sultan Qaboos University, and the German University of Technology. Hole GT2A was diamond cored in 25 Dec 2016 to 18 Jan 2017 to a total depth of 406.77 m. The outer surfaces of the cores were imaged and described on site before being curated, boxed and shipped to the IODP drill ship Chikyu, where they underwent comprehensive visual and instrumental analysis. 33 shipboard scientists were divided into six teams (Igneous, Alteration, Structural, Geochem, Physical Properties, Paleomag) to describe and analyze the cores. Hole GT2A drilled through the transition between foliated and layered gabbro. The transition zone occurs between 50 and 150 m curation corrected depth (CCD). The top 50 m of Hole GT2A is foliated gabbro whereas the bottom 250 m consists of layered gabbro. Brittle fracture is observed throughout the core. Intensity of alteration vein decreases from the top to the bottom of the hole. On the basis of changes in grain size and/or modal abundance and/or appearance/disappearance of igneous primary mineral(s) five lithological units are defined in Hole GT2A (Unit I to V). The uppermost part of Hole GT2A (Unit I) is dominated by fine-grained granular olivine gabbro intercalated with less dominant medium-grained granular olivine gabbro and rare coarse-grained varitextured gabbro. The lower part of the Hole (Units II, III and V) is dominated by medium-grained olivine gabbro, olivine melagabbro and olivine-bearing gabbro. Modally-graded rhythmic layering with

  8. TRANSITION FROM CARBONATE PLATFORM TO PELAGIC DEPOSITION (MID JURASSIC- LATE CRETACEOUS, VOURINOS MASSIF, NORTHERN GREECE

    NICOLAOS CARRAS

    2004-03-01

    Full Text Available A Jurassic- Cretaceous carbonate succession crops out along the Zyghosti Rema, Kozani (Northern Greece. The substratum consists of the ophiolitic succession of the Vourinos Massif (Pelagonian Domain: serpentinites tectonically overlain by basalts, with thin lenses of radiolarian cherts of middle Bathonian age. The contact with the overlying Jurassic limestones is tectonic. Eight informal units have been distinguished within the Mesozoic limestones, from the base upwards. (A bioclastic, intraclastic and oolitic packstone (Callovian- Oxfordian. (B bioclastic packstone and coral boundstone (Oxfordian . (C bioclastic and oncoidal wackestone with Clypeina jurassica (Oxfordian- Upper Kimmeridgian. (D (Upper Kimmeridgian- Portlandian: oncoidal packstone and rudstone (facies D1; intraclastic and bioclastic grainstone and packstone (facies D2; neptunian dykes with intraclastic and bioclastic wackestone and packstone filling (facies D3; neptunian dykes with Fe-Mn rich laterite filling and with pink silty filling of early Late Cretaceous age. An unconformity surface, due to emersion and erosion of the platform during the latest Jurassic- Early Cretaceous, is overlain by (E intraclastic, bioclastic packstone and grainstone (Cenomanian. (F massive body of debrites with coral, echinoderm, algae and rudist large clasts (facies F1 (Cenomanian; turbiditic beds of bioclastic, intraclastic and lithoclastic rudstone and grainstone (facies F2. (G thin bedded bioclastic mudstone and wackestone with planktonic foraminifers and radiolarians, alternating with turbiditic beds of bioclastic, intraclastic packstone and rudstone and with conglomeratic levels and slumped beds of the previous turbidites (upper Santonian- lower Campanian. (H: bioclastic packstone with planktonic foraminifers (facies H1 (lower Campanian - ?Maastrichtian; amalgamated turbiditic beds of bioclastic wackestone and packstone with planktonic foraminifers (facies H2; turbiditic beds of bioclastic

  9. Effect of Aspect on Climate Variation in Mountain Ranges of Shen-nongjia Massif, Central China

    ZHANG Yi

    2018-01-01

    The aim of this study was to better understand the mechanisms of regional climate variation in mountain ranges with con-trasting aspects as mediated by changes in global climate. It may help predict trends of vegetation variations in native ecosystems in natural reserves. As measures of climate response, temperature and precipitation data from the north, east, and south-facing mountain ranges of Shennongjia Massif in the coldest and hottest months (January and July), different seasons (spring, summer, autumn, and win-ter) and each year were analyzed from a long-term dataset (1960 to 2003) to tested variations characteristics, temporal and spatial quan-titative relationships of climates. The results showed that the average seasonal temperatures and precipitation in the north, east, and south aspects of the mountain ranges changed at different rates. The average seasonal temperatures change rate ranges in the north, east, and south-facing mountain ranges were from –0.0210℃ /yr to 0.0143℃ /yr,–0.0166℃ /yr to 0.0311℃ /yr, and –0.0290℃ /yr to 0.0084℃ /yr, respectively,and seasonal precipitation variation magnitude were from –1.4940 mm/yr to 0.6217 mm/yr, –1.6833 mm/yr to 2.6182 mm/yr, and –0.8567 mm/yr to 1.4077 mm/yr, respectively. The climates variation trend among the three mountain ranges were different in magnitude and direction, showing a complicated change of the climates in mountain ranges and some inconsistency with general trends in global climate change. The climate variations were significantly different and positively correlated cross mountain ranges, revealing that aspects significantly affected on climate variations and these variations resulted from a larger air circulation sys-tem, which were sensitive to global climate change. We conclude that location and terrain of aspect are the main factors affecting dif-ferences in climate variation among the mountain ranges with contrasting aspects.

  10. Palaeomagnetic constraints on the evolution of the Atlantis Massif oceanic core complex (Mid-Atlantic Ridge, 30°N)

    Morris, A.; Pressling, N.; Gee, J. S.

    2012-04-01

    Oceanic core complexes expose lower crustal and upper mantle rocks on the seafloor by tectonic unroofing in the footwalls of large-slip detachment faults. They represent a fundamental component of the seafloor spreading system at slow and ultraslow axes. One of the most extensively studied oceanic core complexes is Atlantis Massif, located at 30°N at the intersection of the Atlantis Transform Fault and the Mid Atlantic Ridge (MAR). The central dome of the massif exposes the corrugated detachment fault surface and was drilled during IODP Expedition 304/305 (Hole U1309D). This sampled a 1.4 km faulted and complexly layered footwall section dominated by gabbroic lithologies with minor ultramafic rocks. Palaeomagnetic analyses demonstrate that the gabbroic sequences at Atlantis Massif carry highly stable remanent magnetizations that provide valuable information on the evolution of the section. Thermal demagnetization experiments recover high unblocking temperature components of reversed polarity (R1) throughout the gabbroic sequences. Correlation of structures observed on oriented borehole (FMS) images and those recorded on unoriented core pieces allows reorientation of R1 remanences. The mean remanence direction in true geographic coordinates constrains the tectonic rotation experienced by the Atlantis Massif footwall, indicating a 46°±6° counterclockwise around a MAR-parallel horizontal axis trending 011°±6°. The detachment fault therefore initiated at a steep dip of >50° and then rotated flexurally to its present day low angle geometry (consistent with a 'rolling-hinge' model for detachment evolution). In a number of intervals, the gabbros exhibit a complex remanence structure with the presence of additional intermediate temperature normal (N1) and lower temperature reversed (R2) polarity components, suggesting an extended period of remanence acquisition during different polarity intervals. Sharp break-points between different polarity components suggest

  11. Rhenium-osmium isotopes in pervasively metasomatized mantle xenoliths from the Bohemian Massif and implications for the reliability of Os model ages

    Kochergina, Y. V.; Ackerman, Lukáš; Erban, V.; Matusiak-Malek, M.; Puziewicz, J.; Halodová, P.; Špaček, P.; Trubač, J.; Magna, T.

    2016-01-01

    Roč. 430, July 15 (2016), s. 90-107 ISSN 0009-2541 Institutional support: RVO:67985831 Keywords : Bohemian Massif * depletion age * Ohře/Eger rift * Os isotopes * peridotite xenolith * Re-Os * sub-continental lithospheric mantle Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.347, year: 2016

  12. Behavior of trace elements in quartz from plutons of different geochemical signature: A case study from the Bohemian Massif, Czech Republic

    Breiter, Karel; Ackerman, Lukáš; Svojtka, Martin; Müller, A.

    175/176, 15 August (2013), s. 54-67 ISSN 0024-4937 R&D Projects: GA ČR GAP210/10/1105 Institutional support: RVO:67985831 Keywords : Quartz * trace elements * granites * fractionation * Bohemian Massif Subject RIV: DD - Geochemistry Impact factor: 3.654, year: 2013

  13. Plio-Pleistocene basanitic and melilititic series of the Bohemian Massif: K-Ar ages, major/trace element and Sr–Nd isotopic data

    Ulrych, Jaromír; Ackerman, Lukáš; Balogh, K.; Hegner, E.; Jelínek, E.; Pécskay, Z.; Přichystal, A.; Upton, B. G. J.; Zimák, J.; Foltýnová, R.

    2013-01-01

    Roč. 73, č. 4 (2013), s. 429-450 ISSN 0009-2819 Institutional support: RVO:67985831 Keywords : Bohemian Massif * Plio-Pleistocene * Basanite * Melilitite * K-Ar age * Magmatism * Sr–Nd isotopes Subject RIV: DD - Geochemistry Impact factor: 1.397, year: 2013

  14. Multiple fluid sources/pathways and severe thermal gradients during formation of the Jílové orogenic gold deposit, Bohemian Massif, Czech Republic

    Zachariáš, J.; Žák, Karel; Pudilová, M.; Snee, L. W.

    2013-01-01

    Roč. 54, October (2013), s. 81-109 ISSN 0169-1368 Institutional research plan: CEZ:AV0Z30130516 Institutional support: RVO:67985831 Keywords : Orogenic gold deposits * Carbon isotopes * Oxygen isotopes * Bismuth * Age * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.383, year: 2013

  15. Deciphering the Variscan tectonothermal overprint and deformation partitioning in the Cadomian basement of the Teplá-Barrandian unit, Bohemian Massif

    Hajná, J.; Žák, J.; Kachlík, V.; Chadima, Martin

    2012-01-01

    Roč. 101, č. 7 (2012), s. 1855-1873 ISSN 1437-3254 Institutional support: RVO:67985831 Keywords : Avalonian-Cadomian belt * Bohemian Massif * Shear zone * Teplá-Barrandian unit * transpression * Variscan orogeny Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.261, year: 2012

  16. Origin of eclogite and garnet pyroxenite from the Moldanubian Zone of the Bohemian Massif, Czech Republic and its implication to other mafic layers embedded in orogenic peridotites

    Obata, M.; Hirajima, T.; Svojtka, Martin

    2006-01-01

    Roč. 88, 1-2 (2006), s. 321-340 ISSN 0930-0708 R&D Projects: GA AV ČR IAA3013006 Institutional research plan: CEZ:AV0Z30130516 Keywords : eclogite * pyroxenite * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.038, year: 2006

  17. Pleistocene speleothem fracturing in the foreland of the Western Carpathians: a case study from the seismically active eastern margin of the Bohemian Massif

    Bábek, O.; Briestenský, Miloš; Přecechtělová, G.; Štěpančíková, Petra; Hellstrom, J.C.; Drysdale, R.N.

    2015-01-01

    Roč. 59, č. 3 (2015), s. 491-506 ISSN 1641-7291 R&D Projects: GA ČR GAP210/12/0573 Institutional support: RVO:67985891 Keywords : speleothems * U/Th series dating * palaeoseismicity * Pleistocene * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.858, year: 2015

  18. Multiphase formation of the Obří důl polymetallic skarn deposit, West Sudetes, Bohemian Massif: geochemistry and Re–Os dating of sulfide mineralization

    Veselovský, F.; Ackerman, Lukáš; Pašava, J.; Žák, Karel; Haluzová, Eva; Creaser, R. A.; Dobeš, P.; Erban, V.; Tásler, R.

    2018-01-01

    Roč. 53, č. 5 (2018), s. 665-682 ISSN 0026-4598 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : Bohemian Massif * polymetallic skarn deposit * West Sudetes * arsenopyrite * Re–Os geochronology Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 3.396, year: 2016

  19. Origin of the Okrouhlá Radouň episyenite-hosted uranium deposit, Bohemian Massif, Czech Republic: fluid inclusion and stable isotope constraints

    Dolníček, Z.; René, Miloš; Hermannová, S.; Prochaska, W.

    2014-01-01

    Roč. 49, č. 4 (2014), s. 409-425 ISSN 0026-4598 R&D Projects: GA MŠk ME10083 Institutional support: RVO:67985891 Keywords : Bohemian Massif * Uranium mineralization * Episyenite * Fluid inclusions Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.561, year: 2014

  20. Gammarus orinos n. sp. from the Massif Central (France): its genetic and morphological distinction from Gammarus ibericus Margalef, 1951 (Crustacea, Amphipoda)

    Pinkster, Sjouk; Scholl, Adolf

    1984-01-01

    Until 1974 Gammarus ibericus was known only from the type-locality in Spain. In that year, Goedmakers recorded the species from many localities in the Massif Central, France. Indeed, these populations show a great morphological resemblance to the Spanish ones. These French populations were used in

  1. Graptolite assemblages and stratigraphy of the lower Silurian Mrákotín Formation, Hlinsko Zone, NE interior of the Bohemian Massif (Czech Republic)

    Štorch, Petr; Kraft, P.

    2009-01-01

    Roč. 84, č. 1 (2009), s. 51-74 ISSN 1214-1119 R&D Projects: GA AV ČR IAA3013405 Institutional research plan: CEZ:AV0Z30130516 Keywords : graptolites * stratigraphy * Llandovery * Hlinsko Zone * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.983, year: 2009

  2. Late Hercynian volcanic and hypovolcanic phenomena in South of the French Massif Central. Associated mineralization: U, F, Ba, Pb, Zn, Sn, W

    Badia; Fuchs

    1983-01-01

    Volcanism of the Stephanian period produced lava rich in potassium and fluorine with mineralization of U, F, Sn, W without Mo in the French Massif Central. Permian volcanism and associated magmatism are reviewed. Studied elements allow the characterization of their thermalism. These mineralizations are important for prospection [fr

  3. The Blaník Gneiss in the southern Bohemian Massif (Czech Republic): a rare rock composition among the early palaeozoic granite of Variscan Central Europe

    René, Miloš; Finger, F.

    2016-01-01

    Roč. 110, č. 4 (2016), 503-514 ISSN 0930-0708 R&D Projects: GA MŠk ME 555 Institutional support: RVO:67985891 Keywords : leucogranite * turmaline * petrology * geochemistry * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.236, year: 2016

  4. Types of soft-sediment deformation structures in a lacustrine Ploužnice member (Stephanian, Gzhelian, Pennsylvanian, Bohemian Massif), their timing, and possible trigger mechanism

    Stárková, M.; Martínek, K.; Mikuláš, Radek; Rosenau, N.

    2015-01-01

    Roč. 104, č. 5 (2015), s. 1277-1298 ISSN 1437-3254 Institutional support: RVO:67985831 Keywords : soft-sediment deformation structures * bioturbation * early diagenetic carbonate * lacustrine facies * Bohemian Massif * Stephanian C * Krkonoše Piedmont Basin Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.133, year: 2015

  5. The Nysa-Morava Zone: an active tectonic domain with Late Cenozoic sedimentary grabens in the Western Carpathians' foreland (NE Bohemian Massif)

    Špaček, P.; Bábek, O.; Štěpančíková, Petra; Švancara, J.; Pazdírková, J.; Sedláček, J.

    2015-01-01

    Roč. 104, č. 4 (2015), s. 963-990 ISSN 1437-3254 R&D Projects: GA ČR GAP210/12/0573; GA MŠk LM2010008 Institutional support: RVO:67985891 Keywords : Bohemian Massif * Upper Morava Basin * tectonic evolution * seismicity * sedimentary grabens Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.133, year: 2015

  6. New data for paleoprotherozoic PGE-bearing anorthosite of Kandalaksha massif (Baltic shield): U-Pb and Sm-Nd ages

    Steshenko, Ekaterina; Bayanova, Tamara; Serov, Pavel

    2015-04-01

    The aims of this researches were to study the isotope U-Pb age of zircon and rutile and Sm-Nd (rock forming and sulphide minerals) on Kandalaksha anorthosite massif due to study of polimetamorphic history. In marginal zone firstly have been obtained the presence of sulphide mineralization with PGE (Chashchin, Petrov , 2013). Kandalaksha massif is located in the N-E part of Baltic shield and consists of three parts. Marginal zone (mesocratic metanorite) lies at the base of the massif. Main zone is composed of leucocratic metagabbro. The upper zone is alteration of mataanorthosite and leucocratic metagabbro. All rocks were subjected to granulate polymetamorphism. Two fractions of single grains from anorthosite of the massif gave precise U-Pb age, which is equal to 2450± 3 Ma. Leucocratic gabbro-norite were dated by U-Pb method, with age up to 2230 ± 10 Ma. This age reflects the time of granulite metamorphism according to data of (Mitrofanov, Nirovich, 2003). Two fractions of rutile have been analyzed by U-Pb method and reflect age of 1700 ± 10 Ma. It is known that the closure temperature of U-Pb system rutile is 400-450 ° C (Mezger et.al., 1989), thus cooling processes of massif rocks to these temperatures was about 1.7 Ga. These data reflect one of the stages of metamorphic alteration of the massif. Three stages of metamorphism are distinguished by Sm-Nd method. Isotope Sm-Nd dating on Cpx-WR line gives the age of 2311 Ma which suggested of high pressure granulite metamorphism. Moreover Cpx-Pl line reflect the age 1908 Ma of low pressure granulite metamorphism. Also two-points (Grt-Rt) Sm-Nd isochrone yield the age 1687 Ma of the last metamorphic alterations in Kandalaksha anorthosite massif. Model Sm-Nd age of the leucocratic gabbro-norite is 2796 Ma with positive ɛNd (+0.32). It means that the source of gabbro-norite was mantle reservoir. All investigations are devoted to memory of academician PAS F. MItrofanov which was a leader of scientific school for

  7. Use of Digital Elevation Models to understand map landforms and history of the magmatism Khibiny Massif (Kola Peninsula, Russia)

    Chesalova, Elena; Asavin, Alex

    2016-04-01

    This work presents an improved geomorphological methodology that uses 3D model of relief, remotely-sensed data, geological, geophysical maps and tools of Geographical Information Systems. On the basis of maps of 1: 50,000 and 1: 200,000 the Digital Elevation model (DEM) of Khibiny massif was developed. We used software ARC / INFO v10.2 ESRI. A DEM was used for analyzing landform by extracting the slope gradient, curvature, valley pro?les, slope, aspect and so on. The results were gradually re?ned from the interpretation of satellite imagery and geological map Geomorphological analysis will allow us to determine spatial regularities in inner massive construction. We try to found areas where gas emissions (CH4/H2) enrich, according to morphometry, geology, tectonic and other environments. The main regional blocks were de?ned by different morphological evidences: impression zone, similar to subsidence caldera; uplift zone, domed area (located in the highest part of massif and zone of intersection of main faults) and others. It says that there are the few stages in the development of the Khibiny massif. There is no common concept of the consequence of intrudes magmatic phases now. And we hope that our geomorphical analysis take a new evidences about this problems. Locations of the blocks' borders (tectonic zones) were recognized by lineament analysis of valleys and tectonic faults presented in relief. Erosion system is represented by valleys of 4 ranks. It inherits the zone of tectonic disturbances 3 groups of faults were recognized: 1) Global lineament system cross whole peninsula - existing before Khibiny massif intrusion; 2) Faults associated with the formation of the intrusive phases sequence and magma differentiation and with later collision history during magma cooling; 3) Crack system related to neotectonic process. We believed that if different magmatic phases intrude in similar tectonic environment, the common spatial system of faults will be formed. Really we

  8. Clockwise rotation of the Santa Marta massif and simultaneous Paleogene to Neogene deformation of the Plato-San Jorge and Cesar-Ranchería basins

    Montes, Camilo; Guzman, Georgina; Bayona, German; Cardona, Agustin; Valencia, Victor; Jaramillo, Carlos

    2010-10-01

    A moderate amount of vertical-axis clockwise rotation of the Santa Marta massif (30°) explains as much as 115 km of extension (stretching of 1.75) along its trailing edge (Plato-San Jorge basin) and up to 56 km of simultaneous shortening with an angular shear of 0.57 along its leading edge (Perijá range). Extensional deformation is recorded in the 260 km-wide, fan-shaped Plato-San Jorge basin by a 2-8 km thick, shallowing-upward and almost entirely fine-grained, upper Eocene and younger sedimentary sequence. The simultaneous initiation of shortening in the Cesar-Ranchería basin is documented by Mesozoic strata placed on to lower Eocene syntectonic strata (Tabaco Formation and equivalents) along the northwest-verging, shallow dipping (9-12° to the southeast) and discrete Cerrejón thrust. First-order subsidence analysis in the Plato-San Jorge basin is consistent with crustal stretching values between 1.5 and 2, also predicted by the rigid-body rotation of the Santa Marta massif. The model predicts about 100 km of right-lateral displacement along the Oca fault and 45 km of left-lateral displacement along the Santa Marta-Bucaramanga fault. Clockwise rotation of a rigid Santa Marta massif, and simultaneous Paleogene opening of the Plato-San Jorge basin and emplacement of the Cerrejón thrust sheet would have resulted in the fragmentation of the Cordillera Central-Santa Marta massif province. New U/Pb ages (241 ± 3 Ma) on granitoid rocks from industry boreholes in the Plato-San Jorge basin confirm the presence of fragments of a now segmented, Late Permian to Early Triassic age, two-mica, granitic province that once spanned the Santa Marta massif to the northernmost Cordillera Central.

  9. Felsic granulite with layers of eclogite facies rocks in the Bohemian Massif; did they share a common metamorphic history?

    Jedlicka, Radim; Faryad, Shah Wali

    2017-08-01

    High pressure granulite and granulite gneiss from the Rychleby Mountains in the East Sudetes form an approximately 7 km long and 0.8 km wide body, which is enclosed by amphibolite facies orthogneiss with a steep foliation. Well preserved felsic granulite is located in the central part of the body, where several small bodies of mafic granulite are also present. In comparison to other high pressure granulites in the Bohemian Massif, which show strong mineral and textural re-equilibration under granulite facies conditions, the mafic granulite samples preserve eclogite facies minerals (garnet, omphacite, kyanite, rutile and phengite) and their field and textural relations indicate that both mafic and felsic granulites shared common metamorphic history during prograde eclogite facies and subsequent granulite facies events. Garnet from both granulite varieties shows prograde compositional zoning and contains inclusions of phengite. Yttrium and REEs in garnet show typical bell-shaped distributions with no annular peaks near the grain rims. Investigation of major and trace elements zoning, including REEs distribution in garnet, was combined with thermodynamic modelling to constrain the early eclogite facies metamorphism and to estimate pressure-temperature conditions of the subsequent granulite facies overprint. The first (U)HP metamorphism occurred along a low geothermal gradient in a subduction-related environment from its initial stage at 0.8 GPa/460 °C and reached pressures up to 2.5 GPa at 550 °C. The subsequent granulite facies overprint (1.6-1.8 GPa/800-880 °C) affected the rocks only partially; by replacement of omphacite into diopside + plagioclase symplectite and by compositional modification of garnet rims. The mineral textures and the preservation of the eclogite facies prograde compositional zoning in garnet cores confirm that the granulite facies overprint was either too short or too faint to cause recrystallisation and homogenisation of the eclogite

  10. Phase equilibria modelling and zircon dating for Precambrian metapelites from Xinghuadukou Group in Lvlin Forest of Erguna Massif, NE China

    Xu, Jiulei; Zheng, Changqing; Tajcmanova, Lucie; Zhong, Xin; Xu, Xuechun; Han, Xiaomeng; Wang, Zhaoyuan

    2017-04-01

    Xinghuadukou Group, the basement metamorphic complex of Erguna Massif in NE China, is considered to be Mesoproterozoic with Sm-Nd age of 1157±32 Ma. However, the new zircon data from these metamorphic supracrustal rocks in Lvlin Forest show that they formed in Neoproterozoic with the age of 800 Ma. Old zircon age with 2.5 Ga, 2.0 Ga and 1.8 Ga, indicate that the Erguna Massif had an affinity to both Columbia and Rodinia continents. Furthermore, we also present 500 Ma metamorphic age in micashists and 500 Ma age of adjacent granitoids that might have thermally influenced its surrounding. No detailed studies have been undertaken on the metamorphic evolution of the Xinghuadukou Complex. The typical paragneissic mineral assemblage of garnet sillimanite mica schist is Grt+Sil+Bt+Mus+Qtz±Kfs. (Zhou et al., 2011) proposed that the Xinghuadukou Complex appears to have undergone similar granulite facies metamorphic conditions based on the similarity of mineral assemblages to the Mashan Complex in the Jiamusi Massif, NE China. However, the new phase equilibria modelling result shows that these rocks are high amphibolite facies product with 650℃. We can easily find K-feldspar formed by partial melting due to the consuming of muscovite. Also the remaining muscovite is directly connected with a fluid channel in thin sections which indicate that the remaining muscovite formed from retrograde with the existence of fluid. The zoned garnet has low MgO and high CaO content in rims and high MgO and low CaO content in core. It seems that this garnet has high pressure and low temperature (HP-LT) in rims and low pressure and high temperature (LP-HT) in core which would point to an anti-clockwise metamorphic evolution. Zhou, J.B., Wilde, S.A., Zhang, X.Z., Zhao, G.C., Liu, F.L., Qiao, D.W., Ren, S.M. and Liu, J.H., 2011b. A> 1300km late Pan-African metamorphic belt in NE China: new evidence from the Xing'an block and its tectonic implications. Tectonophysics, 509(3): 280-292.

  11. The Finero phlogopite-peridotite massif: an example of subduction-related metasomatism

    Zanetti, Alberto; Mazzucchelli, Maurizio; Rivalenti, Giorgio; Vannucci, Riccardo

    The Finero peridotite massif is a harzburgite that suffered a dramatic metasomatic enrichment resulting in the pervasive presence of amphibole and phlogopite and in the sporadic occurrence of apatite and carbonate (dolomite)-bearing domains. Pyroxenite (websterite) dykes also contain phlogopite and amphibole, but are rare. Peridotite bulk-rock composition retained highly depleted major element characteristics, but was enriched in K, Rb, Ba, Sr, LREE (light rare earth elements) (LaN/YbN=8-17) and depleted in Nb. It has high radiogenic Sr (87Sr/86Sr(270)=0.7055-0.7093), low radiogenic Nd (ɛNd(270)=-1 to -3) and EMII-like Pb isotopes. Two pyroxenite - peridotite sections examined in detail show the virtual absence of major and trace element gradients in the mineral phases. In both rock types, pyroxenes and olivines have the most unfertile major element composition observed in Ivrea peridotites, spinels are the richest in Cr, and amphibole is pargasite. Clinopyroxenes exhibit LREE-enriched patterns (LaN/YbN 16), negative Ti and Zr and generally positive Sr anomaly. Amphibole has similar characteristics, except a weak negative Sr anomaly, but incompatible element concentration 1.9 (Sr) to 7.9 (Ti) times higher than that of coexisting clinopyroxene. Marked geochemical gradients occur toward apatite and carbonate-bearing domains which are randomly distributed in both the sections examined. In these regions, pyroxenes and amphibole (edenite) arelower in mg## and higher in Na2O, and spinels and phlogopite are richer in Cr2O3. Both the mineral assemblage and the incompatible trace element characteristics of the mineral phases recall the typical signatures of ``carbonatite'' metasomatism (HFSE depletion, Sr, LILE and LREE enrichment). Clinopyroxene has higher REE and Sr concentrations than amphibole (amph/cpxDREE,Sr=0.7-0.9) and lower Ti and Zr concentrations. It is proposed that the petrographic and geochemical features observed at Finero are consistent with a subduction

  12. A critique of massification of higher education in Poland and the United States: Mass-media discourse analysis

    Łukasz Stankiewicz

    2017-01-01

    Full Text Available The nearly universal access to higher education (HE in developed countries was once praised as a great democratic achievement, and a basis for both economic development and social mobility. After the onset of the 2008 recession, the narratives changed considerably. The most radical critics of HE propose a partial “deschooling” of society by reversing the process of massification. This paper aims to present a critical discourse analysis (CAD of the “don’t go to college” discourse that became popular in Poland and the United States. I trace the differences in the way the decision to go to college is conceptualized in Poland and the U.S to the differences in dominant political ideologies – democratic and egalitarian in the U.S., paternalistic and conservative in Poland. I also show how recent changes in the actual HE systems put those ideologies at odds with the educational realities of both countries.

  13. Short Term vs Long Term Environmental Reconstruction from Carbonated Deposits of the Limagne Area (Massif Central, France)

    Barbecot, F.; Gibert, E.; Amokrane, Y.; Massault, M.; Noret, A. [Centre National de la Recherche Scientifique Interaction et Dynamique des Environnements de Surface, Universite Paris (France); Ghaleb, B. [Geotop, Universite du Quebec a Montreal, Montreal (Canada)

    2013-07-15

    A 80 cm sequence has been cored from carbonated travertine in the limagne area (French Massif Central, France) in order to document recent environmental fluctuations (0-100 a) of gaseous springs, in relation to the environmental and geochemical parameters that control the isotopic signatures of modern carbonate deposits. The chronology of these finely laminated deposits that are ideal for reconstructing hydrological conditions at very narrow time steps is determined through AMS-{sup 14}C and {sup 210}Pb/{sup 226}Ra radiometric methods. Preliminary results highlight a high enrichment in stable isotopes (eg up to +8 per mille vs VPDB for {delta}{sup 13}C), likely linked to both recharge temperature and degassing processes. Moreover, two general trends are superimposed: the first one, cyclic, may be correlated to the hydrologic annual/biannual budget while the second one, linear, implies a long term environmental trend. (author)

  14. New petrographic, geochemical and geochronological data for the Reguengos de Monsaraz pluton (Ossa Morena Zone, SW Iberian Massif, Portugal)

    Antunes, A.; Santos, J. F.; Azevedo, M. R.; Mendez, M. H.; Ribeiro, S.

    2010-07-01

    The Reguengos de Monsaraz pluton is a late to post-tectonic Variscan intrusion occurring in the Ossa Morena Zone (Iberian Variscan Chain). The dominant lithological types are tonalites and granodiorites, but the internal area of the massif is composed of gabbro-dioritic rocks. Field evidence shows that the intrusion is heterogeneous at mesoscopic scale suggesting that the emplacement of mafic and felsic magmas was contemporaneous. Petrographic and geochemical studies reveal that the different lithologic types define a continuous sequence with compositions varying from metaluminous to slightly peraluminous and a typical calc-alkaline signature. In Harker variation diagrams, it is possible to observe systematic rectilinear correlations pointing to the involvement of magma mingling/mixing processes in the petrogenesis of this sequence. Rb-Sr isotopic data, using a mineral-mineral pair from a granodiorite sample, yielded an age of 298 Ma, interpreted as a cooling age after igneous crystallization. (Author) 13 refs.

  15. Migration of 137Cs artificial radionuclide in the valley of the Takhtakushuk river of the Degelen massif

    Panitskij, A.V.

    2005-01-01

    Study of horizontal and vertical radionuclide distribution in the valley of the Takhtakushuk River of the 'Degelen' Massif is carried out in the framework of ecological and biological investigations of soil and plant cover within radioactive contaminated areas, and radionuclide migration in biological chain 'soil - plant - animal'. For the first time, the pool-type method was used in the studies of soil of the valley that allows tracing solid and liquid substances migrating by means of surface and soil drainage from its head to final part. This paper presents some physical and chemical properties of the study landscape's soils, radionuclide content in soil genetic horizons of the valley. The study results showed that major mass of 137 Cs radionuclide is sorbed by soil humus and fine-dispersed clay particles of grass soils within the valley. (author)

  16. K-Ar ages of the low-grade metamorphic rocks in the Altar massif, Northwest Sonora, Mexico

    Hayama, Yoshikazu; Shibata, Ken; Takeda, Hideo.

    1984-01-01

    The K-Ar ages of low-grade regional metamorphism, granodiorite intrusion and its contact metamorphism were studied in the Altar massif of Northwest Sonora, Mexico. The results gave the ages of 55 Ma for metamorphic hornblende and 15 to 17 Ma for mica of metamorphic rocks and granodiorite. About the meaning of these discordant ages and the too young ages of 15 to 17 Ma against the previously presented data, we pointed out the following two possibilities; 1) the contact effect of the Miocene granodiorite on the regional metamorphic rocks of the Laramide phase, 2) both regional metamorphism and granodiorite intrusion took place during the Laramide phase, whereas the young ages, 15 to 17 Ma, show the time of temperature release after the low-angle thrust movement, which is well known in the hinterland of the Sevier orogenic belt in Nevada and Utah. (author)

  17. A preliminary spatial-temporal study of some soil characteristics in the calcareous massif of Sicó, Portugal.

    Torres, Maria Odete; Neves, Maria Manuela

    2016-04-18

    The mountainous massif of Sicó, in the centre of Portugal, is an extensive area composed of calcareous Jurassic formations. Hillside calcareous soils, with high pH, present chemical restrictions to support plant growth and are subjected to important erosion processes leading to their degradation if not protected by vegetation. In a first year of study some soil physicochemical characteristics have been measured in some geo-referenced locations of a larger design experiment and an exploratory spatial analysis has been performed. The objective of this study was to present some suggestions in order to give sustainable phosphorus fertiliser recommendations aiming to establish pastures in these soils and thus support traditional livestock activity. Ten years apart, those soil characteristics have been measured again in the same locations and comparisions have been made. The objective was to understand the variability of the soil properties under study in order to better adequate the fertiliser soil management regarding the area restoration.

  18. Use of isotopes to study groundwater recharge in arid zones: Application to the crystalline Ahaggar massif (central Sahara)

    Saighi, O.

    1999-01-01

    In the crystalline and igneous Ahaggar massif, the water resources are found in some small-scale phreatic aquifers which are recharged by sporadic wadi floods. The most favourable aquifer zones are localized in the valleys, consisting of three overlying levels of varying importance: the alluvial aquifer, the weathered zone of the underlying substratum, and the deep aquifer of fissured basement, the extent of which is not limited only to wadis. In order to evaluate the recharge to the different aquifers, chemical and isotopic analyses have been carried out on a hundred samples taken at different depths. Measurements of oxygen-18, deuterium, carbon-13, carbon-14 and tritium have been carried out on these samples

  19. Endolithic microbial communities in carbonate precipitates from serpentinite-hosted hyperalkaline springs of the Voltri Massif (Ligurian Alps, Northern Italy).

    Quéméneur, Marianne; Palvadeau, Alexandra; Postec, Anne; Monnin, Christophe; Chavagnac, Valérie; Ollivier, Bernard; Erauso, Gaël

    2015-09-01

    The Voltri Massif is an ophiolitic complex located in the Ligurian Alps close to the city of Genova (Northern Italy) where several springs discharge high pH (up to 11.7), low salinity waters produced by the active serpentinization of the ultramafic basement. Mixing of these hyperalkaline waters with the river waters along with the uptake of atmospheric carbon dioxide forms brownish carbonate precipitates covering the bedrock at the springs. Diverse archaeal and bacterial communities were detected in these carbonate precipitates using 454 pyrosequencing analyses of 16S ribosomal RNA (rRNA) genes. Archaeal communities were dominated by members of potential methane-producing and/or methane-oxidizing Methanobacteriales and Methanosarcinales (Euryarchaeota) together with ammonia-oxidizing Nitrososphaerales (Thaumarchaeota) similar to those found in other serpentinization-driven submarine and terrestrial ecosystems. Bacterial communities consisted of members of the Proteobacteria, Actinobacteria, Planctomycetes, Bacteroidetes, Chloroflexi, and Verrucomicrobia phyla, altogether accounting for 92.2% of total retrieved bacterial 16S rRNA gene sequences. Amongst Bacteria, potential chemolithotrophy was mainly associated with Alpha- and Betaproteobacteria classes, including nitrogen-fixing, methane-oxidizing or hydrogen-oxidizing representatives of the genera Azospirillum, Methylosinus, and Hydrogenophaga/'Serpentinomonas', respectively. Besides, potential chemoorganotrophy was attributed mainly to representatives of Actinobacteria and Planctomycetales phyla. The reported 16S rRNA gene data strongly suggested that hydrogen, methane, and nitrogen-based chemolithotrophy can sustain growth of the microbial communities inhabiting the carbonate precipitates in the hyperalkaline springs of the Voltri Massif, similarly to what was previously observed in other serpentinite-hosted ecosystems.

  20. Tectono-metamorphic evolution of the Jomolhari massif: Variations in timing of syn-collisional metamorphism across western Bhutan

    Regis, Daniele; Warren, Clare J.; Young, David; Roberts, Nick M. W.

    2014-03-01

    Our current understanding of the rates and timescales of mountain-building processes is largely based on information recorded in U-bearing accessory minerals such as monazite, which is found in low abundance but which hosts the majority of the trace element budget. Monazite petrochronology was used to investigate the timing of crustal melting in migmatitic metasedimentary rocks from the Jomolhari massif (NW Bhutan). The samples were metamorphosed at upper amphibolite to granulite facies conditions (~ 0.85 GPa, ~ 800 °C), after an earlier High-Pressure stage (P > 1.4 GPa), and underwent partial melting through dehydration melting reactions involving muscovite and biotite. In order to link the timing of monazite growth/dissolution to the pressure-temperature (P-T) evolution of the samples, we identified 'chemical fingerprints' in major and accessory phases that were used to back-trace specific metamorphic reactions. Variations in Eu anomaly and Ti in garnet were linked to the growth and dissolution of major phases (e.g. growth of K-feldspar and dehydration melting of muscovite/biotite). Differences in M/HREE and Y from garnet core to rim were instead related to apatite breakdown and monazite-forming reactions. Chemically zoned monazite crystals reacted multiple times during the metamorphic evolution suggesting that the Jomolhari massif experienced a prolonged high-temperature metamorphic evolution from 36 Ma to 18 Ma, significantly different from the P-T-time path recorded in other portions of the Greater Himalayan Sequence (GHS) in Bhutan. Our data demonstrate unequivocally that the GHS in Bhutan consists of units that experienced independent high-grade histories and that were juxtaposed across different tectonic structures during exhumation. The GHS may have been exhumed in response to (pulsed) mid-crustal flow but cannot be considered a coherent block.

  1. Magmatism and crustal extension: Constraining activation of the ductile shearing along the Gediz detachment, Menderes Massif (western Turkey)

    Rossetti, Federico; Asti, Riccardo; Faccenna, Claudio; Gerdes, Axel; Lucci, Federico; Theye, Thomas

    2017-06-01

    The Menderes Massif of western Turkey is a key area to study feedback relationships between magma generation/emplacement and activation of extensional detachment tectonics. Here, we present new textural analysis and in situ U-(Th)-Pb titanite dating from selected samples collected in the transition from the undeformed to the mylonitized zones of the Salihli granodiorite at the footwall of the Neogene, ductile-to-brittle, top-to-the-NNE Gediz-Alaşheir (GDF) detachment fault. Ductile shearing was accompanied by the fluid-mediated sub-solidus transformation of the granodiorite to orthogneiss, which occurred at shallower crustal levels and temperatures compatible with the upper greenschist-to-amphibolite facies metamorphic conditions (530-580 °C and P system ages during fluid-assisted syn-tectonic re-crystallisation in the transition from magma crystallization and emplacement (at 16-17 Ma) to the syn-tectonic, solid-state shearing (at 14-15 Ma). A minimum time lapse of ca. 1-2 Ma is then inferred between the crustal emplacement of the Salihli granodiorite and nucleation of the ductile extensional shearing along the Gediz detachment. The reconstruction of the cooling history of the Salihli granodiorite documents a punctuated evolution dominated by two episodes of rapid cooling, between 14 Ma and 12 Ma ( 100 °C/Ma) and between 3 and 2 Ma ( 105 °C/Ma). We relate the first episode to nucleation and development of post-emplacement of ductile shearing along the GDF and the second to brittle high-angle faulting, respectively. Our dataset suggests that in the Menderes Massif the activation of ductile extension was a consequence, rather than the cause, of magma emplacement in the extending crust.

  2. Temporal evolution of mineralization events in the Bohemian Massif inferred from the Re-Os geochronology of molybdenite

    Ackerman, Lukáš; Haluzová, Eva; Creaser, Robert A.; Pašava, Jan; Veselovský, František; Breiter, Karel; Erban, Vojtěch; Drábek, Milan

    2017-06-01

    Molybdenite is a common mineral accompanying Sn-W, Au, and base metal mineralizations located in different geotectonic units of the Bohemian Massif, but it is also widespread in granitoids and/or related quartz veins/pegmatites forming disseminated Mo mineralization. Thirty Re-Os ages were obtained for molybdenite samples from the Bohemian Massif to provide constraints on the timing and duration of mineralization event(s) within the framework of previously published geochronological data for the host and/or associated rocks. The obtained data for Sn-W-(Li) deposits in the Erzgebirge metallogenetic province indicate the predominance of one and/or multiple short-time mineralization events taking place between ˜319 and 323 Ma, with the exception of the Krupka deposit associated with the Altenberg-Teplice caldera where the data may suggest prolonged activity until ˜315 Ma. The ages of the Pb-Zn-(Au-Mo) Hůrky u Rakovníka and Fe-Cu-As Obří důl mineralizations from the exocontacts of the Čistá pluton and Krkonoše-Jizera Plutonic Complex, respectively, provide evidence for synchronous emplacement of the ore and the associated granitic rocks. In contrast, the Padrť Fe-As-Mo mineralization postdates the age of the associated Padrť granite. Disseminated Mo mineralization in Cadomian and Variscan granitoids and/or related to quartz veins/pegmatites provides Re-Os ages that overlap with the previously published geochronological data for the host rocks, suggesting coeval evolution. Molybdenite samples from the Sázava suite granites of the Central Bohemian Plutonic Complex (CBPC) have resolvable younger ages than their host granites, but similar to the age of spatially related Au mineralization which is associated with the latest evolution of the CBPC.

  3. K-Ar ages of some metamorphic rocks of Oban massif and their implications for the tectonothermal evolution of Southeastern Nigeria

    Ekwueme, B.N.; Itaya, Tetsumaru; Yabe, Hisatomo

    2000-01-01

    The following K-Ar ages have been obtained on mineral separates from some metamorphic rocks in the Oban massif: amphibolites (592-930 Ma), banded gneisses (492-538 Ma), granodioritic gneiss (502 Ma), schists (514-519 Ma) and charnockite (481 Ma). Comparison of these ages with previous dates obtained by the Rb-Sr whole rock method and the Pb-Pb evaporation technique on single zircon throws light on the cooling history and orogenic events in the Oban massif. The banded gneiss in the Oban massif yields a zircon age of 1932±5 Ma, indicating that it was emplaced during the early Proterozoic (Eburnean orogeny). The K-Ar age of 492-538 Ma suggests that these rocks were metamorphosed during the Pan-African orogeny. This age is similar to the Rb-Sr isochron age of 510±10 Ma earlier suggested to be the age of migmatization in the Oban massif. The amphibolite yielded Rb-Sr isochron ages of 784±31 Ma and 1313±37 Ma. The age of 1313±37 Ma fits into the Kibaran event. The K-Ar hornblende age of 930±37 Ma on the same amphibolite strongly suggests that this amphibolite belongs to an event older than Pan-African (600±150 Ma) and has not been reset perfectly by the Pan-African event. The migmatitic schists in the Oban massif yielded a Rb-Sr isochron age of 527±16 Ma which has been interpreted as the age of its migmatization. One sample of this schist, however, gave a model age of 676±24 Ma. The K-Ar ages for the Oban massif schists (514-519 Ma) are close to the Rb-Sr isochron age of ca. 527 Ma and confirm that a metamorphic event occurred in the area at this time. This was followed by final cooling at 515±10 Ma. Charnockite in the Oban area has yielded a zircon age of 584±20 Ma, which is Pan-African. The age possibly dates the time of formation of the charnockites. The K-Ar age (481 Ma) obtained in this study is approximately 100 Ma younger than the zircon age and possibly dates the subsequent cooling of the charnockite through hornblende blocking temperature. (author)

  4. Post-Hercynian subvolcanic magmatism in the Serre Massif (Central-Southern Calabria, Italy)

    Romano, V.; Cirrincione, R.; Fiannacca, P.; Mazzoleni, P.; Tranchina, A.

    2009-04-01

    In the Serre Massif (Central-Southern Calabria, Italy) dykes and subvolcanic bodies intrude diffusively both Hercynian metamorphic rocks and late-Hercynian granitoids. They range in composition from basaltic andesites to dacite-rhyodacites and can be ascribed to the extensive magmatic activity that affects the entire Hercynian orogenic belt in late Paleozoic - early Mesozoic time. The geodinamic framework of the magmatic activity is still matter of debate, nevertheless most authors agree in correlating magmatism both to the late-orogenic collapse of the Hercynian belt and to the lithosphere thinning responsible for the subsequent continental rifting. In this work, we propose a petrogenetic model for acidic to basic hypabissal bodies from southern Calabria in order to define the nature of sources, discriminate magmatic processes and supply a contribution in the geodynamic reconstruction of the Late Palaeozoic in the Calabria-Peloritani Orogen. In relation to their geochemical affinity, studied dykes have been divided in two groups: a medium- to high-K calc-alkaline and a tholeiitic one. Dykes belonging to the former group, andesitic and dacitic-rhyodacitic in composition, show typical features of subduction-related magmatism, such as LILE and LREE enrichments, depletions in HFSE, peaks in Rb, Th and Ce, accentuated troughs in Ba, Nb-Ta, P and Ti (White and Dupré, 1986; McCulloch and Gamble, 1991), contrasting with the late Hercynian collisional context. On the other side, features typical of intra-plate magmatic activity, such as a moderate enrichment in Ta, Nb, Ce, P, Zr, Hf and Sm relative to MORB composition are also present in studied rocks (Shimizu & Arculus, 1975; Pearce, 1982). REE-patterns are strongly to weakly fractionated for the andesitic rocks (Lan/Ybn = 10.03-13.98) and the dacitic-rhyodacitic ones (Lan/Ybn = 6.00 to 2.82), respectively. The latter rocks exhibit a very slight negative Eu anomaly, whereas no Eu anomaly is recognizable in the andesite

  5. Fault slip versus slope deformations: Experience from paleoseismic trenches in the region with low slip-rate faults and strong Pleistocene periglacial mass wasting (Bohemian Massif)

    Špaček, P.; Valenta, Jan; Tábořík, Petr; Ambrož, V.; Urban, M.; Štěpančíková, Petra

    2017-01-01

    Roč. 451, 7 SEP (2017), s. 56-73 ISSN 1040-6182 R&D Projects: GA ČR GAP210/12/0573; GA MŠk(CZ) LM2015079; GA MŠk 7AMB13AT023 Institutional support: RVO:67985891 Keywords : Active faulting * Paleoseismology * Slope deformation * Solifluction * Colluvium * Quaternary * Bohemian massif Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 2.199, year: 2016

  6. Three-dimensional velocity model of the crust of the Bohemian Massif and its effects on seismic tomography of the upper mantle

    Karousová, Hana; Plomerová, Jaroslava; Babuška, Vladislav

    2012-01-01

    Roč. 56, č. 1 (2012), s. 249-267 ISSN 0039-3169 R&D Projects: GA ČR GA205/07/1088; GA AV ČR IAA300120709 Institutional research plan: CEZ:AV0Z30120515 Keywords : crustal structure * seismic methods * Bohemian Massif * teleseismic tomography Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.975, year: 2012

  7. A contribution of airborne magnetic, gamma ray spectrometric data in understanding the structure of the Central Jebilet Hercynian massif and implications for mining

    Maacha, Lhou; Jaffal, Mohammed; Jarni, Abdelmajid; Kchikach, Azzouz; Mouguina, El Mostafa; Zouhair, Mohamed; Ennaciri, Aomar; Saddiqi, Omar

    2017-10-01

    The Central Jebilet massif, well-known for its mining potential, has been explored for several years by the Managem Group, in collaboration with the National Office of Hydrocarbons and Mines (ONHYM), Morocco. This massif was surveyed by high-resolution magnetic and gamma-ray spectrometric methods in 1997 as part of a broader exploration program. In order to better exploit the results of this survey in understanding the structure of the Central Jebilet massif, we performed a series of processing of the collected data. The qualitative interpretation of this data highlighted the various magnetic domains, structures (e.g., lineaments and faults), and mafic intrusions. Euler deconvolution calculations provided estimates of the spatial location and depth of the magnetic sources, and spectral analysis of the magnetic data allowed further refinement of these depth estimates. Quantitative interpretation of some anomalies associated with exposed gossans allowed the characterization of their causative bodies, inferred to be sulfide deposits. The magnetic character of both the potential massive-sulfide bodies and the basic magmatic rocks (gabbro) were determined by the aeromagnetic data. Gamma ray spectrometric data has helped facilitate lithological discrimination and alteration zones, based on the radio-elemental distribution in the area. For example, the Thorium to Potassium ratio (Th/K) was used to highlight potassic alteration zones associated with massive-sulfide deposits in the Central Jebilet. The combined magnetic and radiometric study reveals the magnetic character of the Central Jebilet gossans, due to the content of pyrrhotite, which along with potassic alterations, has been recognized in all the known deposits of the Marrakech region. The results of this geophysical campaign supplement the existing geological and structural maps of Central Jebilet massif.

  8. U-Pb zircon geochronology and Sm-Nd-Pb isotopic constraint for precambrian plutonic rocks in the northeastern part of Ryeongnam massif, Korea

    Chang, Ho-Wan

    2003-01-01

    The Ryeongnam massif is composed of Precambrian gneisses, Paleozoic and Mesozoic sedimentary rocks and extensive Triassic-Jurassic plutonic rocks of felsic to mafic composition. In the northeast Ryeongnam massif, the oldest rocks belong to the Sobaegsan gneiss complex, which is composed of orthogneisses, paragneisses and mafic plutonic rocks. U-Pb zircon ages for the felsic and mafic intrusive bodies within the Sobaegsan gneiss complex are: the Icheon granite gneiss, 2357±43 and 2342±47 Ma; the Buncheon granite gneiss, 1963±5 Ma; the Pyeonghae granite gneiss, 1936±21 Ma; the Ogbang amphibolite, 1918±10 Ma; the Imwon leucogranite gneiss, 1826±20 Ma. The Hyeondong biotite schist, which is intruded by the Buncheon granite gneiss and the Ogbang amphibolite, yielded an age of 2271±44 Ma. The Nd-Sm-Pb isotopic data indicate that the felsic plutonic rocks are derived from an older Archean crust. The Nd T DM ages are Archean, and the εNd values are negative for the felsic rocks and positive for the amphibolite. Common Pb isotope compositions also indicate a crustal source for the felsic intrusives. The U-Pb ages of Precambrian rocks of the Ryeongnam massifs are similar to those in the Gyeonggi massif, and may have a similar crustal evolutionary history. The Precambrian rocks of South Korea could be related either to the North China block or to the South China block, as the isotope ages and patterns are not unique to either block. Similarly, a geologic correlation with Japan, although possible, is tenuous at present. (author)

  9. Influence of the Istranca-Rhodope Massifs and strands of the North Anatolian Fault on oil potential of Thrace Basin, NW Turkey

    Coskun, B.

    2000-01-01

    The Thrace Basin (NW Turkey) is an intermontane trough bounded to the north and west by the granitic and metamorphic rocks of the Istranca and Rhodope Massifs. Recent subsurface studies of the NW portion of the Thrace Basin have led to the identification of two trends in geothermal gradient, both of which are oriented approximately NW-SE (i.e. parallel to the depositional axis of the basin). Geological and geophysical data indicate that, due to the thrust of the Istranca Massif upon the Rhodope Massif, the subsurface temperature may have increased in the northern part of the basin. Other controls were wrench-fault activity of the Splays of the North Anatolian Fault (SNAF) and continuing basinal subsidences. The thermal history of the southern part of the basin was affected by Miocene ophiolitic emplacement to the west in Greece. The presence of a belt of intrabasinal palaeotopography (mainly Palaeozoic rocks) also contributed to increased geothermal gradients in the southern part of the study area. The basin is divisible into northern and southern zones of subsidence, which are separated by the Kuleli-Babaeski High. During the Oligocene, subsidence rates were highest in the northern zone and in the western sector of the southern zone. Later, during the Miocene, basin subsidence was associated with intense tectonic activity of the SNAF and with the emplacement of ophiolites to the west. A map of the top of the oil generation zone, based on TTI values calculated by the Lopatin method, indicates the presence of two maturation zones in the basin ; these were separated by the Late Oligocene Kuleli-Babaeski High. Oil generation in these zones was influenced by rapid subsidence, by a NW-SE oriented wrench fault system associated with the NAF and also by tectonic activity of the Istranca and Rhodope Massifs in the study area

  10. Two-phase southward subduction of the Mongol-Okhotsk oceanic plate constrained by Permian-Jurassic granitoids in the Erguna and Xing'an massifs (NE China)

    Liu, Huichuan; Li, Yinglei; He, Hongyun; Huangfu, Pengpeng; Liu, Yongzheng

    2018-04-01

    Geodynamics of the Mongol-Okhotsk oceanic plate southward subduction are still pending problems. This paper presents new zircon LA-ICP-MS U-Pb age and whole-rock geochemical data for the middle Permian to Middle Jurassic granitoids in the western Erguna and central Xing'an massifs. 267-264 Ma, 241 Ma and 173 Ma I-type granites, and 216 Ma A-type granites were identified in the Erguna and Xing'an massifs (NE China). The I-type granites were produced by partial melting of the lower mafic crust. The 216 Ma A-type granites were derived from partial melting of crustal materials with tonalitic to granodioritic compositions. The 267-264 Ma and 241 Ma I-type granites were generated in an Andean-type arc setting, wheras the 216 Ma A-type and 173 Ma granites were formed in supra subduction extensional setting. We summarized previous age data of the middle Permian to Middle Jurassic magmtaic rocks in the Erguna and Xing'an Massifs and identified two isolated phases of magmatic activity including the ca. 267-225 Ma and ca. 215-165 Ma periods, with a significant magmatic gap at ca. 225-215 Ma. These middle Permian to Middle Jurassic magmatic rocks are closely related to the southward subduction of the Mongol-Okhotsk ocean. A two-stage tectonic evolutionary model was proposed to account for these geological observations in the Erguna and Xing'an massifs, involving Permian to Middle Triassic continuous southward subduction of the Mongol-Okhotsk oceanic plate and Late Triassic to Jurassic slab-rollback and supra subduction extension.

  11. Seismic anisotropy of the French Massif Central and predisposition of Cenozoic rifting and volcanism by Variscan suture hidden in the mantle lithosphere

    Babuška, Vladislav; Plomerová, Jaroslava; Vecsey, Luděk; Granet, M.; Achauer, U.

    2002-01-01

    Roč. 21, č. 4 (2002), s. U407-U429 ISSN 0278-7407 R&D Projects: GA ČR GV205/98/K004; GA ČR GA205/01/1154; GA AV ČR IAA3012908 Institutional research plan: CEZ:AV0Z3012916 Keywords : seismic anisotropy * Massif Central * mantle lithosphere Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.697, year: 2002

  12. Estimation of surface runoff for calculating recharge in the karstic massif of Ports of Beseit (Tarragona, Spain) combining water balance in the soil and analysis of flow hydrographs

    Espinosa Martinez, S.; Custodio, E.

    2016-07-01

    For the right estimation of aquifer recharge by precipitation surface taking into account runoff is particularly relevant. Non considering it in the estimation of the groundwater resources can overestimate them. In the Baix Ebre aquifer system, in southern Catalonia, the surface and vadose zone runoff produced in the karstified carbonate formations in the Ports de Beseit massif has to be evaluated in order to achieve a better estimation of the resources transferred from this massif to the Plana de La Galera plain. Starting from the conceptual hydrogeological model, the average annual runoff is estimated. It includes the discharge from temporal perched aquifers in the Ports de Beseit massif, in the Matarraña river basin, and in the SE watershed to the Plana de La Galera plain. This is performed by analyzing the river and tributaries hydrographs, the filling and emptying hydrographs of the Ulldecona reservoir, and the soil water balance using the Visual Balan code applied to obtain the runoff in the Ulldecona reservoir watershed. The runoff has been estimated about 105±20 mm·yr−1, which represents 20–30% of average annual recharge in the Ports, estimated with soil water balance and atmospheric chloride deposition balance, about 350–500 mm·yr−1, which is mostly transferred laterally to the Plana de La Galera plain. (Author)

  13. Estimation of surface runoff for calculating recharge in the karstic massif of Ports of Beseit (Tarragona, Spain) combining water balance in the soil and analysis of flow hydrographs

    Espinosa Martinez, S.; Custodio, E.

    2016-01-01

    For the right estimation of aquifer recharge by precipitation surface taking into account runoff is particularly relevant. Non considering it in the estimation of the groundwater resources can overestimate them. In the Baix Ebre aquifer system, in southern Catalonia, the surface and vadose zone runoff produced in the karstified carbonate formations in the Ports de Beseit massif has to be evaluated in order to achieve a better estimation of the resources transferred from this massif to the Plana de La Galera plain. Starting from the conceptual hydrogeological model, the average annual runoff is estimated. It includes the discharge from temporal perched aquifers in the Ports de Beseit massif, in the Matarraña river basin, and in the SE watershed to the Plana de La Galera plain. This is performed by analyzing the river and tributaries hydrographs, the filling and emptying hydrographs of the Ulldecona reservoir, and the soil water balance using the Visual Balan code applied to obtain the runoff in the Ulldecona reservoir watershed. The runoff has been estimated about 105±20 mm·yr−1, which represents 20–30% of average annual recharge in the Ports, estimated with soil water balance and atmospheric chloride deposition balance, about 350–500 mm·yr−1, which is mostly transferred laterally to the Plana de La Galera plain. (Author)

  14. Formation of pyroxenite layers in the Totalp ultramafic massif (Swiss Alps) - Insights from highly siderophile elements and Os isotopes

    van Acken, David; Becker, Harry; Walker, Richard J.; McDonough, William F.; Wombacher, Frank; Ash, Richard D.; Piccoli, Phil M.

    2010-01-01

    Pyroxenitic layers are a minor constituent of ultramafic mantle massifs, but are considered important for basalt generation and mantle refertilization. Mafic spinel websterite and garnet-spinel clinopyroxenite layers within Jurassic ocean floor peridotites from the Totalp ultramafic massif (eastern Swiss Alps) were analyzed for their highly siderophile element (HSE) and Os isotope composition. Aluminum-poor pyroxenites (websterites) display chondritic to suprachondritic initial γOs (160 Ma) of -2 to +27. Osmium, Ir and Ru abundances are depleted in websterites relative to the associated peridotites and to mantle lherzolites worldwide, but relative abundances (Os/Ir, Ru/Ir) are similar. Conversely, Pt/Ir, Pd/Ir and Re/Ir are elevated. Aluminum-rich pyroxenites (clinopyroxenites) are characterized by highly radiogenic 187Os/ 188Os with initial γOs (160 Ma) between +20 and +1700. Their HSE composition is similar to that of basalts, as they are more depleted in Os, Ir and Ru compared to Totalp websterites, along with even higher Pt/Ir, Pd/Ir and Re/Ir. The data are most consistent with multiple episodes of reaction of mafic pyroxenite precursor melts with surrounding peridotites, with the highest degree of interaction recorded in the websterites, which typically occur in direct contact to peridotites. Clinopyroxenites, in contrast, represent melt-dominated systems, which retained the precursor melt characteristics to a large extent. The melts may have been derived from a sublithospheric mantle source with high Pd/Ir, Pt/Ir and Re/Os, coupled with highly radiogenic 187Os/ 188Os compositions. Modeling indicates that partial melting of subducted, old oceanic crust in the asthenosphere could be a possible source for such melts. Pentlandite and godlevskite are identified in both types of pyroxenites as the predominant sulfide minerals and HSE carriers. Heterogeneous HSE abundances within these sulfide grains likely reflect subsolidus processes. In contrast, large grain

  15. Age and geochemistry of Neoproterozoic granitoids in the Songnen-Zhangguangcai Range Massif, NE China: Petrogenesis and tectonic implications

    Luan, Jin-Peng; Xu, Wen-Liang; Wang, Feng; Wang, Zhi-Wei; Guo, Peng

    2017-10-01

    This study presents new zircon U-Pb ages and geochemical data for Neoproterozoic granitoids in the Songnen-Zhangguangcai Range Massif (SZRM) of NE China. This dataset provides insights into the Neoproterozoic tectonic setting of the SZRM and the links between this magmatism and the evolution of the Rodinia supercontinent. The zircon U-Pb dating indicates that the Neoproterozoic magmatism within the SZRM can be subdivided into two stages: (1) a ∼917-911 Ma suite of syenogranites and monzogranites, and (2) an ∼841 Ma suite of granodiorites. The 917-911 Ma granitoids contain high concentrations of SiO2 (67.89-71.18 wt.%), K2O (4.24-6.91 wt.%), and Al2O3 (14.89-16.14 wt.%), and low concentrations of TFe2O3 (1.63-3.70 wt.%) and MgO (0.53-0.88 wt.%). They are enriched in the light rare earth elements (LREE) and the large ion lithophile elements (LILE), are depleted in the heavy REE (HREE) and the high field strength elements (HFSE; e.g., Nb, Ta, and Ti), and have slightly positive Eu anomalies, indicating that they are geochemically similar to high-K adakitic rocks. They have zircon εHf (t) values and TDM2 ages from -4.4 to +1.5 and 1915 Ma to 1592 Ma, respectively, suggesting that they were derived from a primary magma generated by the partial melting of ancient thickened lower crustal material. In comparison, the 841 Ma granodiorites contain relatively low concentrations of Al2O3 (14.50-14.58 wt.%) and K2O (3.27-3.29 wt.%), relatively high concentrations of TFe2O3 (3.78-3.81 wt.%) and the HREE, have negative Eu anomalies, and have zircon εHf (t) values and TDM2 ages from -4.7 to +1.0 and 1875 to 1559 Ma, respectively. These granodiorites formed from a primary magma generated by the partial melting of ancient crustal material. The ∼917-911 Ma magmatism within the SZRM is inferred to have formed in an orogenic setting, whereas the ∼841 Ma magmatism formed in an anorogenic setting related to either a post-orogenic tectonic event or the onset of Neoproterozoic

  16. Sylvicultural procedures in catchment areas of the mountain streams as exemplified by the Skrzyczne massif in Poland

    Małek Stanisław

    2014-03-01

    Full Text Available Extensive disintegration of spruce forests in the Beskidy Mts. in South Poland generates a need to regenerate sizeable areas as well as to rebuild forest stands which have defended themselves against breakdown. In practice, the magnitude of relevant management tasks does not allow for keeping up with the progressive destruction of forest, especially at higher altitudes, where natural regeneration does not occur as much as necessary. In addition, the species composition is limited to spruce, sometimes accompanied by beech and fir, whereas other species have a negligible share. What may be helpful in solving this problem is the method of regeneration of such areas and of establishment of under-canopy cultures, consisting of patchwork, multi-stage regeneration task performance, starting from the areas with the best chance of reforestation success and using the existing self-sown trees. Such areas undoubtedly include habitats with better water balance, i.e. humid habitats (in the case of larger areas, distinguished in the forest management plan as humid forest site types. The aim of the present study was to propose management of watercourses and headwater areas in the region of the Skrzyczne massif where the selected catchments are situated on the southern (the Malinowski Stream and the northern (the Roztoka Czyrna stream slopes of this massif. The research was carried out in August 2012 and included juxtaposition of available hydrological maps with actual field conditions along with identification of springs and streams and the course of their beds in order to update the existing data. The updating of the forest numerical maps in the existing databases of the State Forests IT System (SILP included verification of the course of streams and determination of their nature (permanent or periodic with a division into the existing ones and the added ones. The data was recorded against the background of the division of the forest surface, contour lines

  17. The Alleret Maar lacustrine sequence (French Massif Central): a 150 ka long early-middle Pleistocene continental paleoenvironmental record.

    Nomade, S.; Pastre, J.; Guillou, H.; Gauthier, A.; Scaillet, S.

    2008-12-01

    Lacustrine maar sequences of the French Massif Central are of great interest for paleoclimatic and paleoenvironmental reconstructions of mid-latitudes Quaternary continental environments. In particular, the western Velay region yields exceptional sequences spanning the last 450 ka (Reille et al., J. Quat. Sci. 2000). However, older sequences remain largely unknown despite the presence of interbedded alkaline tephras allowing precise absolute radiochronological control of many lacustrine squences. The Alleret maar is a 1500 m wide phreatomagmatic crater that provides a long lacustrine sequence (41 m). The upper part of this sequence (AL2 core, 14.6 m) was studied between 2005 and 2006 (Pastre et al., C. R. Acad Sci, 2007). A 39Ar/40Ar date (557 ± 5ka) obtained from an interbedded tephra layer located at 7m as well as the associated pollen data attribute the beginning of this sequence to the MIS 15. Thanks to the AL3 core recovered in 2005 (40.6 m, CNRS Meudon) several new tephra layers were discovered in the bottom part of this lacustrine sequence. Three new 39Ar/40Ar ages (single crystal analyses) from trachytic tephra layers were obtained at the LSCE Argon Laboratory (France). These layers are located at -30.2, -36.2 and -39.2m. Ages obtained relative to the ACR-2 flux standard (1,201Ma, Kuiper et al., Science, 2008) range from 692 ± 6 ka (MSWD: 2.3, n=18) for the youngest (-30.2m) to 726 ± 9Ka Ka (MSWD: 2.2, n=12) for the lowest tephra located at -39.2m. These new dates indicate a relatively homogeneous deposition rate of 3.5cm/ka and that the last 10 meters cover the MIS 17-MIS18 period. According to these current radiochronological data the complete lacustrine sequence last more than 150ka. Ongoing sedimentary and pollen studies will allow to extend the paleoenvironmental and paleoclimatic records of the French Massif Central towards the beginning of the early middle Pleistocene.

  18. Structural, metamorphic and geochronological insights on the Variscan evolution of the Alpine basement in the Belledonne Massif (France)

    Fréville, Kévin; Trap, Pierre; Faure, Michel; Melleton, Jérémie; Li, Xian-Hua; Lin, Wei; Blein, Olivier; Bruguier, Olivier; Poujol, Marc

    2018-02-01

    A structural and petrochronological study was carried out in the southern part of the Belledonne crystalline massif. A first tectonometamorphic event, Dx, corresponds to the eastward thrusting of the Chamrousse ophiolitic complex characterized by a low-temperature-moderate-pressure metamorphism reaching 0.535 ± 0.045 GPa and 427.5 ± 17.5 °C. A subsequent D1 deformation is defined by a penetrative S1 foliation that mostly dips toward the west and displays an E-W- to NE-SW-trending mineral and stretching lineation L1. D1 is associated with a top-to-the east shearing and is responsible for the crustal thickening accommodated by the eastward nappe stacking and the emplacement of the Chamrousse ophiolitic complex upon the Rioupéroux-Livet unit. This event is characterized by an amphibolite facies metamorphism (0.58 GPa ± 0.06; 608 ± 14 °C) that attains partial melting at the base of the nappe pile (0.78 ± 0.07 GPa; 680.5 ± 11.5 °C). LA-ICP-MS U-Pb dating of monazite grains from the mica schists of the Rioupéroux-Livet unit constrain the age of D1 to 337 ± 7 Ma. The D2 tectono-metamorphic event is characterized by NE-SW trending, upright to NE-verging synfolial folding. Folding associated with D2 is pervasively developed in all lithotectonic units with the development of a steeply-dipping S2 foliation. In particular, D2 involves the uppermost weakly metamorphosed Taillefer unit. LA-ICP-MS U-Pb dating performed on detrital zircon grains shows that the Taillefer conglomerates was deposited during the Visean. A zircon SIMS U-Pb age of 352 ± 1 Ma from a plagioglase-rich leucocratic sill of the Rioupéroux-Livet unit is interpreted as the age of magmatic emplacement. Our results suggest that the D2 event took place between 330 Ma and 310 Ma. We propose a new interpretation of the tectonometamorphic evolution of the southern part of the Belledonne massif, focusing on the Middle Carboniferous stages of the Variscan orogeny.

  19. High frequency measurement of P- and S-wave velocities on crystalline rock massif surface - methodology of measurement

    Vilhelm, Jan; Slavík, Lubomír

    2014-05-01

    For the purpose of non-destructive monitoring of rock properties in the underground excavation it is possible to perform repeated high-accuracy P- and S-wave velocity measurements. This contribution deals with preliminary results gained during the preparation of micro-seismic long-term monitoring system. The field velocity measurements were made by pulse-transmission technique directly on the rock outcrop (granite) in Bedrichov gallery (northern Bohemia). The gallery at the experimental site was excavated using TBM (Tunnel Boring Machine) and it is used for drinking water supply, which is conveyed in a pipe. The stable measuring system and its automatic operation lead to the use of piezoceramic transducers both as a seismic source and as a receiver. The length of measuring base at gallery wall was from 0.5 to 3 meters. Different transducer coupling possibilities were tested namely with regard of repeatability of velocity determination. The arrangement of measuring system on the surface of the rock massif causes better sensitivity of S-transducers for P-wave measurement compared with the P-transducers. Similarly P-transducers were found more suitable for S-wave velocity determination then P-transducers. The frequency dependent attenuation of fresh rock massif results in limited frequency content of registered seismic signals. It was found that at the distance between the seismic source and receiver from 0.5 m the frequency components above 40 kHz are significantly attenuated. Therefore for the excitation of seismic wave 100 kHz transducers are most suitable. The limited frequency range should be also taken into account for the shape of electric impulse used for exciting of piezoceramic transducer. The spike pulse generates broad-band seismic signal, short in the time domain. However its energy after low-pass filtration in the rock is significantly lower than the energy of seismic signal generated by square wave pulse. Acknowledgments: This work was partially

  20. Development of a Comprehensive Plan for Scientific Research, Exploration, and Design: Creation of an Underground Radioactive Waste Isolation Facility at the Nizhnekansky Rock Massif

    Jardine, L J

    2005-01-01

    ISTC Partner Project No.2377, ''Development of a General Research and Survey Plan to Create an Underground RW Isolation Facility in Nizhnekansky Massif'', funded a group of key Russian experts in geologic disposal, primarily at Federal State Unitary Enterprise All-Russian Design and Research Institute of Engineering Production (VNIPIPT) and Mining Chemical Combine Krasnoyarsk-26 (MCC K-26) (Reference 1). The activities under the ISTC Partner Project were targeted to the creation of an underground research laboratory which was to justify the acceptability of the geologic conditions for ultimate isolation of high-level waste in Russia. In parallel to this project work was also under way with Minatom's financial support to characterize alternative sections of the Nizhnekansky granitoid rock massif near the MCC K-26 site to justify the possibility of creating an underground facility for long-term or ultimate isolation of radioactive waste (RW) and spent nuclear fuel (SNF). (Reference 2) The result was a synergistic, integrated set of activities several years that advanced the geologic repository site characterization and development of a proposed underground research laboratory better than could have been expected with only the limited funds from ISTC Partner Project No.2377 funded by the U.S. DOE-RW. There were four objectives of this ISTC Partner Project 2377 geologic disposal work: (1) Generalize and analyze all research work done previously at the Nizhnekansky granitoid massif by various organizations; (2) Prepare and issue a declaration of intent (DOI) for proceeding with an underground research laboratory in a granite massif near the MCC K-26 site. (The DOI is similar to a Record of Decision in U.S. terminology). (3) Proceeding from the data obtained as a result of scientific research and exploration and design activities, prepare a justification of investment (JOI) for an underground research laboratory in as much detail as the available site characterization

  1. Derivation of P-T paths from high-pressure metagranites - Examples from the Gran Paradiso Massif, western Alps

    Massonne, Hans-Joachim

    2015-06-01

    Metamorphosed granites (SiO2 ≥ 70 wt.%) are, in fact, a common rock type in high pressure (HP) and ultrahigh pressure (UHP) terrains, but these rocks were rarely used to derive metamorphic P-T paths. To test the suitability of HP metagranites for such derivations, two metagranites from the Gran Paradiso Massif were studied applying elemental mapping of phengite and garnet and calculated P-T pseudosections contoured by various chemical and modal parameters. Both rocks contain phengite with maximum Si contents of about 3.42 Si per formula unit (pfu) and 3.55 Si pfu in cores, and accessory garnet which is compositionally zoned. Garnet core compositions are rich in grossular component (XCa up to 0.72). Only a rough P-T path could be derived with peak pressures below 2 GPa because, for instance, Si contents in phengite become geobarometrically insensitive at HP conditions, when biotite is not anymore stable. A test of the pseudosection approach to a metagranite from the North Qaidam UHP metamorphic belt resulted in an ambiguous finding. In fact, compositions of garnet and phengite in this rock are indicative of both UHP and specific HP conditions ( 1.3 GPa, 530 °C), but the latter conditions fit the entire mineralogical observations better.

  2. Sulfur isotope composition of orogenic spinel lherzolite massifs from Ariege (north-eastern pyrenees, France): An ion microprobe study

    Chaussidon, M. (Centre de Recherches Petrographiques et Geochimiques, Vandoeuvre-les-Nancy (France)); Lorand, J. (Unite associee au CNRS, Paris (France))

    1990-10-01

    The orogenic spinel lherzolite massifs from Ariege, which represent tectonically emplaced fragments of the sub-continental upper mantle, are composed mainly of variously depleted peridotites. These rocks are crosscut by two generations of pyroxenites. The first is made up of layered pyroxenites, which are interpreted either as crystal segregates from Triassic continental tholeiites or as subducted parts of the oceanic crust re-injected within the upper mantle. The second consists of amphibole-rich dikes separated from Cretaceous alkali basalts. Forty sulfide grains, occurring either as inclusions within silicates or as interstitial grains, were investigated by ion microprobe for their sulfur isotopic compositions. Comparison between sulfide inclusions in silicates and interstitial sulfide grains strongly suggests that serpentinization and pyrenean metamorphism had no significant effect don the {delta}{sup 34}S values. Likewise, these values are broadly independent of the degree of partial melting. The negative {delta}{sup 34}S values of the massive peridotites could represent an ancient depletion event in the upper mantle. By contrast, the positive {delta}{sup 34}S values observed in the layered pryoxenites and the amphibole-rich dikes indicate that the two parent magmas had in common a mantle source variously enriched in {sup 34}S. Therefore, the present study reveals two extreme reservoirs characterized by different {delta}{sup 34}S values in the upper mantle. This range of variations can explain most {delta}{sup 34}S values found in MORB, continental tholeiites, and alkali basalts.

  3. Evolution of hut access facing glacier shrinkage in the Mer de Glace basin (Mont Blanc massif, France)

    Mourey, Jacques; Ravanel, Ludovic

    2016-04-01

    Given the evolution of high mountain environment due to global warming, mountaineering routes and huts accesses are more and more strongly affected by glacial shrinkage and concomitant gravity processes, but almost no studies have been conducted on this relationship. The aim of this research is to describe and explain the evolution over the last century of the access to the five alpine huts around the Mer de Glace glacier (Mont Blanc massif), the larger French glacier (length = 11.5 km, area = 30 km²), a major place for Alpine tourism since 1741 and the birthplace of mountaineering, by using several methods (comparing photographs, surveying, collecting historical documents). While most of the 20th century shows no marked changes, loss of ice thickness and associated erosion of lateral moraines generate numerous and significant changes since the 1990s. Boulder falls, rockfalls and landslides are the main geomorphological processes that affect the access, while the glacier surface lowering makes access much longer and more unstable. The danger is then greatly increased and the access must be relocated and/or equipped more and more frequently (e.g. a total of 520 m of ladders has been added). This questions the future accessibility to the huts, jeopardizing an important part of mountaineering and its linked economy in the Mer de Glace area.

  4. Methane- and Hydrogen-Influenced Microbial Communities in Hydrothermal Plumes above the Atlantis Massif, Mid Atlantic Ridge

    Stewart, C. L.; Schrenk, M.

    2017-12-01

    Ultramafic-hosted hydrothermal systems associated with slow-spreading mid ocean ridges emit copious amounts of hydrogen and methane into the deep-sea, generated through a process known as serpentinization. Hydrothermal plumes carrying the reduced products of water-rock interaction dissipate and mix with deep seawater, and potentially harbor microbial communities adapted to these conditions. Methane and hydrogen enriched hydrothermal plumes were sampled from 3 sites near the Atlantis Massif (30°N, Mid Atlantic Ridge) during IODP Expedition 357 and used to initiate cultivation experiments targeting methanotrophic and hydrogenotrophic microorganisms. One set of experiments incubated the cultures at in situ hydrostatic pressures and gas concentrations resulting in the enrichment of gammaproteobacterial assemblages, including Marinobacter spp. That may be involved in hydrocarbon degradation. A second set of experiments pursued the anaerobic enrichment of microbial communities on solid media, resulting in the enrichment of alphaproteobacteria related to Ruegeria. The most prodigious growth in both case occurred in methane-enriched media, which may play a role as both an energy and carbon source. Ongoing work is evaluating the physiological characteristics of these isolates, including their metabolic outputs under different physical-chemical conditions. In addition to providing novel isolates from hydrothermal habitats near the Lost City Hydrothermal Field, these experiments will provide insight into the ecology of microbial communities from serpentinization influenced hydrothermal systems that may aid in future exploration of these sites.

  5. U-Th-Pb dating of the Brossasco ultrahigh-pressure metagranite, Dora-Maira massif, western Alps

    Paquette, J.L.; Montel, J.M. [Centre National de la Recherche Scientifique, 63 - Clermont-Ferrand (France); Chopin, C. [Ecole Normale Superieure, 75 - Paris (France). Lab. de Geologie

    1999-01-01

    The Brossasco metagranite is part of the coherent ultrahigh-pressure metamorphic terrane in the Dora-Maira massif and, although it has reached Alpine peak metamorphic conditions of about 725 C/30 kbar, still locally preserves an undeformed magmatic texture. In order to obtain new chronological constraints on this key area of the western Alps, we studied the behaviour of the U-Th-Pb system in zircons and monazites from such an undeformed facies. Only zircon fractions containing very small needle-shaped inclusions are concordant at 304{+-}3 Ma. This result is interpreted as the emplacement age of the granite. All other zircons show an old inherited memory and the more U-rich of these crystals were affected by an episodic Pb loss with a poorly defined lower intercept at 60{+-}45 Ma. Both TIMS (thermo-ionisation mass spectrometry) and electron-microprobe analysis of monazites show that this last event has also disturbed their U-Pb and Th-Pb isotopic systems, without resetting them completely. Comparison with cofacial rock-types which have been completely reworked under these extreme P-T conditions shows that deformation and mass transfer as well as the nature of the protoliths and the characteristics of their zircons have a much more pronounced influence on the behaviour of isotopic systems than the temperature and/or pressure parameters. This evidence is an obvious limitation to the use of the blocking-temperature concept. (orig.)

  6. Rock Magnetic Properties of Remagnetised Devonian and Carboniferous Carbonate and Clastic Rocks From The NE Rhenish Massif, Germany

    Zwing, A.; Matzka, J.; Bachtadse, V.; Soffel, H. C.

    Previous studies on remagnetised carbonate rocks from the North American and Eu- ropean Variscides reported characteristic rock magnetic properties which are thought to be diagnostic for a chemical remagnetisation event. Their hysteresis properties with high ratios of Mrs/Ms and Hcr/Hc indicate the presence of a mixture of single-domain and superparamagnetic magnetite (Jackson, et al. 1990). In order to test if this fin- gerprint can be identified in remagnetised carbonate and clastic rocks from the NE Rhenish Massif, Germany, a series of rock magnetic experiments has been carried out. The hysteresis properties of the remagnetised clastic rocks indicate the domi- nance of large MD particles, as can be expected for detrital sediments. The carbon- ates yield significantly higher ratios of Mrs/Ms and Hcr/Hc than the clastic rocks, but only partly correspond to the characteristic properties of remagnetised carbon- ates described above. The latter might be attributed to detrital input into the carbonate platforms. Additional low-temperature remanence measurements show a wide vari- ety of phenomena, including Verwey transitions and indications for the presence of superparamagnetic grains. However, the low-temperature experiments do not allow a straightforward discrimination between the clastic and carbonate rocks and suggest more complex magnetomineralogies than expected from the hysteresis measurements alone.

  7. U-Th-Pb dating of the Brossasco ultrahigh-pressure metagranite, Dora-Maira massif, western Alps

    Paquette, J.L.; Montel, J.M.; Chopin, C.

    1999-01-01

    The Brossasco metagranite is part of the coherent ultrahigh-pressure metamorphic terrane in the Dora-Maira massif and, although it has reached Alpine peak metamorphic conditions of about 725 C/30 kbar, still locally preserves an undeformed magmatic texture. In order to obtain new chronological constraints on this key area of the western Alps, we studied the behaviour of the U-Th-Pb system in zircons and monazites from such an undeformed facies. Only zircon fractions containing very small needle-shaped inclusions are concordant at 304±3 Ma. This result is interpreted as the emplacement age of the granite. All other zircons show an old inherited memory and the more U-rich of these crystals were affected by an episodic Pb loss with a poorly defined lower intercept at 60±45 Ma. Both TIMS (thermo-ionisation mass spectrometry) and electron-microprobe analysis of monazites show that this last event has also disturbed their U-Pb and Th-Pb isotopic systems, without resetting them completely. Comparison with cofacial rock-types which have been completely reworked under these extreme P-T conditions shows that deformation and mass transfer as well as the nature of the protoliths and the characteristics of their zircons have a much more pronounced influence on the behaviour of isotopic systems than the temperature and/or pressure parameters. This evidence is an obvious limitation to the use of the blocking-temperature concept. (orig.)

  8. Rare-earth, yttrium and zirconium mobility associated with the uranium mineralisation at Okrouhla Radoun, Bohemian Massif, Czech Republic

    Milos, Rene [Academy of Sciences of the Czech Republic, Prague (Czech Republic). Inst. of Rock Structure and Mechanics

    2015-01-15

    The mobility of rare-earth elements (REE), Y and Zr during the Late-Variscan and post-Variscan mineralisation event in the Okrouhla Radoun. uranium deposit has been investigated to elucidate their behaviour during the hydrothermal alteration of leucogranites and high-grade metamorphic rocks in the Moldanubian Zone (Bohemian Massif). The alteration of leucogranites has caused enrichment in Na, Ca, Fe{sup 3+}, Zr and the bulk of REE while depleting K, Fe{sup 2+}, Si, Th, Rb and Ba. The alteration of high-grade metasediments has also led to an enrichment in Na and Ca while depleting K, Si, Rb and Ba. However, this change is connected to the depletion of REE, as well as the enrichment of P and Th in the bulk. The high mobility of Y and Zr during formation of the uranium mineralisation is supported by the occurrence of Y- and Zr-rich coffinite (up to 3.4 wt.% Y{sub 2}O{sub 3} and 13.8 wt.% ZrO{sub 2}). The massive hydrothermal alteration of host rocks, as well as the high mobility of REE, Y and Zr indicate an influx of oxidised basinal fluids in the Permian to the crystalline rocks of the Moldanubian Zone.

  9. Grand Sarcoui volcano (Chaîne des Puys, Massif Central, France), a case study for monogenetic trachytic lava domes

    Miallier, D.; Pilleyre, T.; Boivin, P.; Labazuy, P.; Gailler, L.-S.; Rico, J.

    2017-10-01

    The Grand Sarcoui is a prominent trachytic volcano of the intraplate Quaternary volcanic field of Chaîne des Puys (Massif Central, France), which fulfills basic requirements for being qualified as monogenetic. Grand Sarcoui looks like a simple axisymmetric lava dome, but close observation reveals a complex and dissymmetric structure and composition. The construction of the dome, about 12.5 ka ago, combined both endogenous and exogenous growth which resulted in variable modes of emplacement and textures of the lava. One of its most interesting features is a large ( 0.29 106 m2) fan of deposits bearing hummocks and secondary hydro-eruption craters. Cross sections of these deposits demonstrate that they originated from a sector collapse accompanied by a blast-like event. The dome is covered by a thin layer of lapilli and ash, attributed to a delayed summit eruption which occurred about 10.6 ka ago, surprisingly late after its construction. So, this volcano has, at a reduced scale, features that are more usually observed in large composite volcanoes. However, some of these features differ slightly from those that have been documented to date, and they remain partly unexplained. This shows that monogenetic, well preserved, trachytic lava domes, are uncommon and poorly known, unlike rhyolitic, andesitic and dacitic domes.

  10. Tephras in lacustrine sediments of the Sarliève marsh (French Massif Central): age and preservation

    Fourmont, Agathe; Macaire, Jean-Jacques; Bréhéret, Jean-Gabriel; Argant, Jacqueline; Prat, Béatrice; Vernet, Gérard

    2006-12-01

    The Sarliève marsh sediments (Massif Central, France) contain two tephras. The first tephra [ 13.7±0.4ka(2δ), ca. 12 000 BP], regionally well known, enables to date the beginning of lacustrine infill to the Lateglacial. The second tephra, the 'tephra de Sarliève', the emitting volcano of which is unknown, would be dated to around the Early Subboreal from pollen data. This occurrence, after the discovery of the 'tephra de Beaunit', emphasizes that volcanic eruption(s) occurred in the 'Chaîne des Puys' or in the volcanic Cézallier more than 1000 years after the last known eruption (Pavin) in the 'Chaîne des Puys' at around 6.6/6.7 ka (5800/5900 BP). In the Sarliève piles, these tephras, well preserved in thick and more silicated deposits of deltas, were not observed in carbonated basin sediments where they were altered. The abundance of authigenic zeolites formed during the Lateglacial in restricted depocentre lacustrine waters allows us to detect initial CF1 tephra occurrence. To cite this article: A. Fourmont et al., C. R. Geoscience 338 (2006).

  11. Multidisciplinary characterisation of sedimentary processes in a recent maar lake (Lake Pavin, French Massif Central and implication for natural hazards

    E. Chapron

    2010-09-01

    Full Text Available Sedimentation processes occurring in the most recent maar lake of the French Massif Central (Lake Pavin are documented for the first time based on high resolution seismic reflection and multibeam bathymetric surveys and by piston coring and radiocarbon dating on a sediment depocentre developed on a narrow sub aquatic plateau. This new data set confirms the mid Holocene age of maar lake Pavin formation at 6970±60 yrs cal BP and highlights a wide range of gravity reworking phenomena affecting the basin. In particular, a slump deposit dated between AD 580–640 remoulded both mid-Holocene lacustrine sediments, terrestrial plant debris and some volcanic material from the northern crater inner walls. Between AD 1200 and AD 1300, a large slide scar mapped at 50 m depth also affected the southern edge of the sub aquatic plateau, suggesting that these gas-rich biogenic sediments (laminated diatomite are poorly stable. Although several triggering mechanisms can be proposed for these prehistoric sub-aquatic mass wasting deposits in Lake Pavin, we argue that such large remobilisation of gas-rich sediments may affect the gas stability in deep waters of meromictic maar lakes. This study highlights the need to further document mass wasting processes in maar lakes and their impacts on the generation of waves, favouring the development of dangerous (and potentially deadly limnic eruptions.

  12. Motor Park Discourse in South-Western Nigeria: Relations among ...

    Algeria (5); Benin (2); Botswana (3); Burkina Faso (3); Cameroon (8); Congo, Republic (1); Côte d'Ivoire (4); Egypt, Arab Rep. (14); Eritrea (1); Ethiopia (30); Ghana (27); Kenya (29); Lesotho (1); Libya (2); Madagascar (1); Malawi (4); Mauritius (3); Mozambique (1); Nigeria (221); Rwanda (3); Senegal (6); Sierra Leone (1) ...

  13. Characteristics of abortion care seekers in South-Western Nigeria ...

    Les renseignements ont été recueillis à l\\'aide d\\'un questionnaire de la part de 1876 femmes, à la recherche de l\\'avortement auprès des hôpitaux, les résultats montrent que la majorité (60%) avaient entre 15 et 24 ans dont les adolescentes ayant entre 1519 constituaient 32,7%. La majorité (63,2%) constituaient une ...

  14. Mercury content of shark from south-western Australian waters

    Caputi, N.; Edmonds, J.S.; Heald, D.I.

    1979-11-01

    Muscle samples from four species of commercially sought sharks off the Western Australia coast were analyzed for total mercury. While substantial amounts of mercury were accumulated by sharks, as by other marine fish, the lack of polluting industry on the coast indicates that such mercury levels probably are natural. Mercury concentrations generally increased with fish size. (4 graphs, 1 map, 8 references, 2 tables)

  15. Distribution of iodate in the south western Bay of Bengal

    Raju, G.R.K.; Rajendran, A.; Reddy, C.V.G.

    role in surface waters in the iodine system. A mole ratio of NO :PO :IO was found to be 94:10:1. Depletion of iodate, calculated in 2 ways, showed a linear model with the depletion of other nutrients in surface waters (above oxycline) suggesting a...

  16. Evaluation of some farm structures in South Western Nigeria ...

    The factors, which tend to reduce the service life and efficiency of these facilities, include roof leaks, abrasion of mud walls, decay and breakage of wooden members, corrosion of metal components, and pitting and cracking of concrete floors. Remedial measures taken include replastering of mud walls and cracked floors, ...

  17. Adolescent prostitution in south-western Nigeria: demographic ...

    Context: Adolescent prostitution, an interesting area of reproductive health focus, is of great socioeconomic and medical burden in Nigeria. Objective: This study aims to determine the demographic characteristics and risk factors for adolescent prostitution in Nigeria Method: This was a cross- sectional study using ...

  18. Traditional bonesetters in South Western Nigeria - Friends or Foes ...

    ... dislocations et déformités du membre qui avaient été traités auparavant par TERO et qui s'étaient par la suite presentés au collège hospitalier universitaire, Ibadan (en raison de complications à la suite du traitement chez TERO) entre le premier octobre 1999 et 31 mars 2000 ont été évalués. Résultats: Quatorze malades ...

  19. Farmers' Perception of Sustainable Agriculture in South- Western ...

    KENNY

    Pearson Product Moment Correlation (PPMC) was used to test the existence of relationships between the ... Key words Sustainable practices, industrial agriculture, agricultural technology, rural economy. Introduction .... consumers. 4.19. 1.11.

  20. Characterisation of the local pigeon in South Western Nigeria ...

    Nigerian Journal of Animal Science. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 2, No 2 (1999) >. Log in or Register to get access to full text downloads.

  1. Splenic Operations In A Teaching Hospital, South-Western Nigeria ...

    %. Conclusion: As trauma is the most common indication for operations on the spleen, spleen conservation should be practiced more often where open procedures are indicated. Keywords: Splenic operations, Spleen conservation surgery, ...

  2. The Palmiet River estuary in the south-western Cape

    the concentration and turnover of organiC matter. Four of the 19 species of .... and September 1980, giving a total of 28 days field work. On ...... supported no life. Despite the ..... 0,3 x 106 m3 year - 1, should balance evaporative water losses.

  3. Ethnobotanical Survey Of Anti-Asthmatic Plants In South Western ...

    The paper presents the results of an ethnobotanical survey of plants used in the treatment of asthma in Ogun, Osun and Oyo states. Twenty markets were visited and forty-six plants belonging to thirty-three different families were collected. The plants\\' families represented in the colle ction include,Amaryllidaceae, ...

  4. GIS Technique Applied To Surface Water Survey In South Western ...

    Spatially overlaying objects of hydrographic network features on the digital elevation model (DEM) and the geologic map, revealed that the Eleyele valley from the topographical point of view has all the topographic and physical structures conducive for the location of an effective dam. The geological conditions are adequate ...

  5. Malignant Gastrointestinal Tumours in South Western Nigeria: A ...

    OBJECTIVE: To document the pattern, age and sex distribution as well as histopathology characteristics of malignant tumours of the gastro-intestinal system in Lagos ... Colorectal cancers peaked in the 60–69 year age group, liver and stomach cancer occurred mostly between the 50–59 years age group. Over half of the ...

  6. Late Cenozoic cooling history of the central Menderes Massif and the contribution of erosion to rock exhumation during active continental extension

    Nilius, Nils-Peter; Wölfler, Andreas; Heineke, Caroline; Glotzbach, Christoph; Hetzel, Ralf; Hampel, Andrea; Akal, Cüneyt; Dunkl, István

    2017-04-01

    The Menderes Massif constitutes the western part of the Anatolide belt in western Turkey and experienced a prolonged history of post-orogenic extension. A large amount of the extension was accommodated by the two oppositely dipping Gediz and Büyük Menderes detachment faults, which led to the exhumation of the central Menderes Massif (Gessner et al., 2013). Previous studies proposed a synchronous, bivergent exhumation of the central Menderes Massif since the Miocene (Gessner et al., 2001), although only the evolution of the north-dipping Gediz detachment is well constrained (Buscher et al., 2013). Detailed structural and thermochronological investigations from the south-dipping Büyük Menderes detachment have still been missing. Here we present results from different thermochronometers, which constrain the cooling and exhumation history of footwall and hanging wall rocks of the Büyük Menderes detachment. Our new zircon and apatite (U-Th)/He and fission track ages of footwall rocks from the Büyük Menderes detachment document two phases of increased cooling and exhumation (Wölfler et al., in revision). The first episode of increased footwall exhumation ( 0.9 km/Myr) occurred during the middle Miocene, followed by a second phase during latest Miocene and Pliocene ( 1.0 km/Myr). Apatite fission track ages yield a slip rate for the Pliocene movement along the Büyük Menderes detachment of 3.0 (+1.1/-0.6) km/Myr. Thermochronological data of hanging wall units reflect a slow phase of exhumation ( 0.2 km/Myr) in the late Oligocene and an increased exhumation rate of 1.0 km/Myr during the early to middle Miocene, when hanging wall units cooled below 80 °C. In comparison with the Gediz detachment, our thermochronological data from the Büyük Menderes detachment confirms the concurrent activity of both detachments during the late Miocene and Pliocene. With respect to the relative importance of normal faulting and erosion to rock exhumation, a comparison with 10Be

  7. Coeval interaction between magmas of contrasting composition (Late Carboniferous-Early Permian Santa Eulália-Monforte massif, Ossa-Morena Zone): field relations and geochronological constraints

    Pereira, M.F.; Gama, C.; Rodríguez, C.

    2017-07-01

    The Santa Eulália-Monforte massif is a post-kinematic Late Carboniferous-Early Permian calc-alkaline composite massif (LC-EP) located in the Ossa-Morena Zone (OMZ, Portugal). This paper examines the field relationships between pinkish granites and mafic-intermediate rocks from the external ring of this massif and presents new U-Pb zircon age determinations. The estimated 206Pb/238U ages, 297±4Ma for the pinkish granite and 303±3Ma for a gabbro-diorite point to a short time interval between the crystallization of both magmas. At outcrop scale, contacts of the mafic-intermediate rocks with the host pinkish granite are sharp and corroborate this age relationship, but do not justify why the host-enclave contacts often has curved and irregular shapes, indicating liquid-liquid interaction. A full analysis of the distribution of U-Pb zircon ages and respective Th/U ratios suggests that the compositionally distinct magmas were roughly contemporaneous. The obtained ages also fit the LC-EP Iberian calc-alkaline suite that was formed contemporaneously to the development of the Iberian-Armorican Arc and when the Paleotethyan oceanic Plate subducted under the Eurasian active margin. Taking this geodynamic setting as a reference, the LC-EP Iberian calc-alkaline magmatism can be interpreted as most probably related to the Cimmerian cycle instead of the traditionally accepted model that ascribe a closer connection of this magmatism with the Variscan cycle. The Santa Eulália-Monforte massif is a post-kinematic Late Carboniferous-Early Permian calc-alkaline composite massif (LC-EP) located in the Ossa-Morena Zone (OMZ, Portugal). This paper examines the field relationships between pinkish granites and mafic-intermediate rocks from the external ring of this massif and presents new U-Pb zircon age determinations. The estimated 206Pb/238U ages, 297±4Ma for the pinkish granite and 303±3Ma for a gabbro-diorite point to a short time interval between the crystallization of both

  8. Coeval interaction between magmas of contrasting composition (Late Carboniferous-Early Permian Santa Eulália-Monforte massif, Ossa-Morena Zone): field relations and geochronological constraints

    Pereira, M.F.; Gama, C.; Rodríguez, C.

    2017-01-01

    The Santa Eulália-Monforte massif is a post-kinematic Late Carboniferous-Early Permian calc-alkaline composite massif (LC-EP) located in the Ossa-Morena Zone (OMZ, Portugal). This paper examines the field relationships between pinkish granites and mafic-intermediate rocks from the external ring of this massif and presents new U-Pb zircon age determinations. The estimated 206Pb/238U ages, 297±4Ma for the pinkish granite and 303±3Ma for a gabbro-diorite point to a short time interval between the crystallization of both magmas. At outcrop scale, contacts of the mafic-intermediate rocks with the host pinkish granite are sharp and corroborate this age relationship, but do not justify why the host-enclave contacts often has curved and irregular shapes, indicating liquid-liquid interaction. A full analysis of the distribution of U-Pb zircon ages and respective Th/U ratios suggests that the compositionally distinct magmas were roughly contemporaneous. The obtained ages also fit the LC-EP Iberian calc-alkaline suite that was formed contemporaneously to the development of the Iberian-Armorican Arc and when the Paleotethyan oceanic Plate subducted under the Eurasian active margin. Taking this geodynamic setting as a reference, the LC-EP Iberian calc-alkaline magmatism can be interpreted as most probably related to the Cimmerian cycle instead of the traditionally accepted model that ascribe a closer connection of this magmatism with the Variscan cycle. The Santa Eulália-Monforte massif is a post-kinematic Late Carboniferous-Early Permian calc-alkaline composite massif (LC-EP) located in the Ossa-Morena Zone (OMZ, Portugal). This paper examines the field relationships between pinkish granites and mafic-intermediate rocks from the external ring of this massif and presents new U-Pb zircon age determinations. The estimated 206Pb/238U ages, 297±4Ma for the pinkish granite and 303±3Ma for a gabbro-diorite point to a short time interval between the crystallization of both

  9. 10Be exposure dating of the timing of Neoglacial glacier advances in the Ecrins-Pelvoux massif, southern French Alps

    Le Roy, Melaine; Deline, Philip; Carcaillet, Julien; Schimmelpfennig, Irene; Ermini, Magali; Aster Team

    2017-12-01

    Alpine glacier variations are known to be reliable proxies of Holocene climate. Here, we present a terrestrial cosmogenic nuclide (TCN)-based glacier chronology relying on 24 new 10Be exposure ages, which constrain maximum Neoglacial positions of four small to mid-sized glaciers (Rateau, Lautaret, Bonnepierre and Etages) in the Ecrins-Pelvoux massif, southern French Alps. Glacier advances, marked by (mainly lateral) moraine ridges that are located slightly outboard of the Little Ice Age (LIA, c. 1250-1860 AD) maximum positions, were dated to 4.25 ± 0.44 ka, 3.66 ± 0.09 ka, 2.09 ± 0.10 ka, c. 1.31 ± 0.17 ka and to 0.92 ± 0.02 ka. The '4.2 ka advance', albeit constrained by rather scattered dates, is to our knowledge exposure-dated here for the first time in the Alps. It is considered as one of the first major Neoglacial advance in the western Alps, in agreement with other regional paleoclimatological proxies. We further review Alpine and Northern Hemisphere mid-to-high latitude evidence for climate change and glacier activity concomitant with the '4.2 ka event'. The '2.1 ka advance' was not extensively dated in the Alps and is thought to represent a prominent advance in early Roman times. Other Neoglacial advances dated here match the timing of previously described Alpine Neoglacial events. Our results also suggest that a Neoglacial maximum occurred at Etages Glacier 0.9 ka ago, i.e. during the Medieval Climate Anomaly (MCA, c. 850-1250 AD). At Rateau Glacier, discordant results are thought to reflect exhumation and snow cover of the shortest moraine boulders. Overall, this study highlights the need to combine several sites to develop robust Neoglacial glacier chronologies in order to take into account the variability in moraine deposition pattern and landform obliteration and conservation.

  10. A Search for Amino Acids and Nucleobases in the Martian Meteorite Roberts Massif 04262 Using Liquid Chromatography-Mass Spectrometry

    Callahan, Michael P.; Burton, Aaron S.; Elsila, Jamie E.; Baker, Eleni M.; Smith, Karen E.; Glavin, Daniel P.; Dworkin, Jason P.

    2013-01-01

    The investigation into whether Mars contains signatures of past or present life is of great interest to science and society. Amino acids and nucleobases are compounds that are essential for all known life on Earth and are excellent target molecules in the search for potential Martian biomarkers or prebiotic chemistry. Martian meteorites represent the only samples from Mars that can be studied directly in the laboratory on Earth. Here, we analyzed the amino acid and nucleobase content of the shergottite Roberts Massif (RBT) 04262 using liquid chromatography-mass spectrometry. We did not detect any nucleobases above our detection limit in formic acid extracts; however, we did measure a suite of protein and nonprotein amino acids in hot-water extracts with high relative abundances of beta-alanine and gamma-amino-eta-butyric acid. The presence of only low (to absent) levels of several proteinogenic amino acids and a lack of nucleobases suggest that this meteorite fragment is fairly uncontaminated with respect to these common biological compounds. The distribution of straight-chained amine-terminal eta-omega-amino acids in RBT 04262 resembled those previously measured in thermally altered carbonaceous meteorites. A carbon isotope ratio of -24(0/00) +/- 6(0/00) for beta-alanine in RBT 04262 is in the range of reduced organic carbon previously measured in Martian meteorites (Steele et al. 2012). The presence of eta-omega-amino acids may be due to a high temperature Fischer-Tropschtype synthesis during igneous processing on Mars or impact ejection of the meteorites from Mars, but more experimental data are needed to support these hypotheses.

  11. Uraninite, Coffinite and Brannerite from Shear-Zone Hosted Uranium Deposits of the Bohemian Massif (Central European Variscan Belt

    Miloš René

    2017-03-01

    Full Text Available New mineralogical data are presented for shear-zone hosted uranium mineralisation from selected uranium deposits that occur in the Bohemian Massif. The uranium mineralisation is in high-grade metamorphic rocks of the Moldanubian Zone and/or in granitic rocks of the Moldanubian batholith and Bor pluton as complex uraninite–coffinite and uraninite–coffinite–brannerite assemblages. For analysed coffinites and brannerites, anomalous enrichment of Y (up to 3.4 wt % Y2O3 and Zr (up to 13.8 wt % ZrO2 is significant. The microprobe data indicate that coffinites from the Rožná and Okrouhlá Radouň uranium deposits contain variable PbO (0–4.3 wt %, FeO (0–2.5 wt %, Al2O3 (0–3.5 wt %, P2O5 (0–1.8 wt %, and CaO (0.7–3.5 wt %. Brannerite is present in unaltered and altered grains with variable concentrations of U4+ (0–0.5 apfu, U6+ (0.06–0.49 apfu, Ti (0.90–2.63 apfu, Ca (0.09–0.41 apfu, and low concentrations of Al (0–0.19 apfu, Th (0–0.04 apfu, Y (0–0.08 apfu, Zr (0–0.13 apfu and REE (0–0.14 apfu.

  12. A NEW INTERPRETATION FOR THE GARNET ZONING IN METAPELITIC ROCKS OF THE SILGARÁ FORMATION, SOUTHWESTERN SANTANDER MASSIF, COLOMBIA

    Ríos Reyes Carlos Alberto

    2008-06-01

    Full Text Available A Barrovian sequence of the Silgará Formation at the southwestern Santander Massif, Colombian Andes, contains zoned garnets in which major and trace element zoning correlates with distribution of mineral inclusions, which may indicate that garnet growth rate varied through time and affected both composition and texture ofgarnets, although different garnet producing reactions have also played an important role in the chemical zoning of garent. However, a local metasomatism process associated to the action of late magmatic fluids associated to the emplacement of the Pescadero Pluton (external forcing mechanism would be also considered. In particular, Ca, Mn and Y zoning patterns in some garnets correspond with inclusion-rich vs. inclusion-free zones, althoughthe distribution of inclusions does not correlate with chemical zoning (i.e., the same inclusions are found in Ca-rich and Ca-poor zones of the garnet. There is a similar lack of correlation with accessory phases (apatite, monazite, xenotime, ilmenite or rutile. In a garnet from the garnet-staurolite zone, a high Mn core containsabundant and randomly oriented apatite, monazite and ilmenite inclusions, while a euhedral low Ca mantle zone is inclusion-free and the high Ca / low Mn rim zone contains apatite, monazite and ilmenite aligned parallel to the margins of the garnet. Inclusions in garnet can also represent mineral phases were not completely consumed during garnet growth. Association of garnet zoning trends and patterns with inclusion distribution may help differentiatebetween processes that identically affect major-element zoning but that produced variable textures in the garnet.

  13. Characterization of the paleo-hydrothermal fluids flow in the geothermal province of Limagne. (French Massif Central).

    Fréville, K.; Sizaret, S.

    2017-12-01

    Exploitation of the geothermal energy is a prime target to future energy supply. Understanding the nature and the flow of geothermal fluids is a key objective for describe the functioning of current hydrothermal systems. Located in the French Massif Central, the Limagne basin is a tertiary hemi-graben characterized by a high thermal gradient with numerous occurrences of CO2-rich thermo-mineral waters. This basin has potential for high-temperature geothermal energy, expressed by numerous natural high temperature water sources, as well as at Royat and Vichy were the surface temperature of the water can reach 33°C and 27°C, respectively. In order to better localize this potential, the geological evolution has to be deciphered. In this aim we study the flow processes of the paleo-fluids and estimate the direction and the velocity of the hydrothermal flow from the studies of the growth bands of comb quartz grain localized in vein. In a second time, the studies fluids inclusions within the quartz grain are used to characterize the nature of the fluids involved. Preliminary results show that the flow is discontinuous over the time with changes in velocities and directions during the growth of a single quartz grain. Two main flows were identified, i) a relatively fast upward flow at 10-6,-5 m.s-1; ii) a downward flow at about 10-5,-4 m.s-1. The results allow: (i) to discuss the processes controlling the fluids flow in the Limagne basin; and (ii) to suggest to delimitate the areas with high geothermal potential which integrate the flow variation in time.

  14. Quaternary river incision in the uplifted Rhenish massif (Ardennes, Belgium) - Insights from 10Be/26Al dating of river terraces

    Rixhon, Gilles; Bourlès, Didier; Braucher, Régis; Siame, Lionel; Bovy, Benoît.; Demoulin, Alain

    2010-05-01

    Although it constitutes the main tool to unravel the regional recent tectonics, the chronology of the Pleistocene river incision is still poorly constrained within the uplifted Rhenish-Ardennes massif (Belgium, western Europe). Here, we measure cosmogenic nuclides concentrations (10Be and 26Al) in terrace quartz or quartzite sediments of several Ardennian rivers (Meuse, Ourthe and Amblève) in order to date the so-called Younger Main Terrace (YMT), a key-level in the network evolution. Though these dating methods are successfully used to determine ages of superficial (e.g., glacial) deposits, dating of fluvial terraces remains difficult. Possible predepositional exposures of the sampled material (inherited 10Be and 26Al) may indeed bias the measurements towards higher nuclide concentrations while several postdepositional processes (burial, erosion) may cause a lowering of the 10Be and 26Al concentrations. In an attempt to overcome these difficulties, the selected fluvial deposits (five locations) were sampled using a profiling technique on as thick as possible sections (more than 3 m). We present the first absolute dating of the YMT in the lower Meuse valley (nearby the Dutch boundary), where we obtained an age of 630 ka for a terrace deposit buried beneath 3 m of Weichselian loess. This age is consistent with some previously published estimates based on paleomagnetic data and MIS correlations. However, our ages for the same terrace level within the Ardennes are significantly younger: >400 ka in the lower Ourthe, and only ~220 ka still farther upstream, in the lower Amblève. We thus demonstrate that the post-YMT incision occurred diachronically in NE Ardennes. The ~0.5 Ma timespan needed by the erosion wave to propagate from the lower Meuse towards the Ardennian headwaters contradicts the long-held statement of a climatically driven incision that would have been synchronous throughout the catchment.

  15. From ocean depths to mountain tops: uplift of the Troodos Massif (Cyprus) constrained by (U-Th)/He thermochronology and geomorphic analysis

    Morag, N.; Haviv, I.; Katzir, Y.

    2013-12-01

    The Troodos Massif of Cyprus, rising to nearly 2000 meters above sea level, encompasses one of the world's classic ophiolites. Following its formation at a seafloor spreading center in Late Cretaceous times, this slice of the NeoTethyan oceanic lithosphere was uplifted and eventually exposed on mountain tops during the Neogene. The final uplift and exhumation of the Troodos was previously assigned to Pleistocene age by observations in the circum-Troodos sedimentary strata. However, quantitative thermochronological and geomorphological data from the Massif itself were not available. Here we use apatite (U-Th)/He low-temperature thermochronology complemented by zircon (U-Th)/He and apatite fission track data, and combined with geomorphic analysis to constrain the exhumation and uplift history of the Troodos ophiolite. Apatite (U-Th)/He ages vary with depth from ~ 22 Ma at the top of the Gabbro sequence to ~ 6 Ma at the bottom of the sequence. The deepest sample from a Gabbro pegmatitic dyke intruding the ultramafic sequence yielded an age of ~ 3 Ma. Thermal modeling of apatite (U-Th)/He and fission track data delineates Plio - Pleistocene initiation of rapid uplift and exhumation of the Troodos ophiolite. The estimated cumulative exhumation since its initiation is 2-3 km. No evidence was found for significant uplift of the central Troodos area prior to that time. The geomorphic analysis delineates a bull's-eye zone at the center of the Troodos Massif, where local relief and channel steepness index are highest. The boundaries of this zone roughly correspond with the Mt. Olympus mantle outcrop and suggest recent, differential uplift of this zone relative to its surroundings. The most likely mechanism, which could drive such a focused bull's-eye uplift pattern is hydration of ultramafic rocks (serpentinization) leading to a decrease in rock density and subsequent diapiric uplift of the serpentinized lithospheric mantle.

  16. Using Telepresence to Connect and Engage Classes and the Public in the Exploration of Tamu Massif, the World's Largest Single Volcano

    Nanez-James, S. E.; Sager, W.

    2016-02-01

    Research published in 2013 showed that TAMU Massif, the largest mountain in the Shatsky Rise oceanic plateau, located approximately 1500 kilometers east of Japan, is the "World's Largest Single Volcano." This claim garnered widespread public interest and wonder concerning how something so big could remain so mysterious in the 21st century. This disconnect highlights the fact that oceans are still widely unexplored, especially the middle of the deep ocean. Because there is so much interest in TAMU Massif, a diverse outreach team lead by chief scientist Dr. William Sager from the University of Houston in partnership with the Texas State Aquarium and the Schmidt Ocean Institute (SOI) conducted a multifaceted ship-to-shore outreach project that included secondary school students, formal and informal educators, university students and professors, the aquarium and museum audience, and the general public. The objective was to work in conjunction with SOI and various other partners, including the Texas Regional Collaborative, the Aquarium of the Pacific, and the Houston Museum of Natural Science, to promote science and ocean literacy while inspiring future scientists - especially those from underserved and underrepresented groups - through ocean connections. Participants were connected through live ship-to-shore distance learning broadcasts of ongoing marine research and discovery of TAMU Massif aboard the R/V Falkor, allowing audiences to participate in real-time research and apply real world science to curriculum in the classrooms. These ship-to-shore presentations connected to existing curriculums and standards, lessons, and career interests of the students and educators with special teacher events and professional development workshops conducted from aboard the R/V Falkor.

  17. Trace element behavior during serpentinization/de-serpentinization of an eclogitized oceanic lithosphere: A LA-ICPMS study of the Lanzo ultramafic massif (Western Alps)

    DEBRET, Baptiste; ANDREANI, Muriel; GODARD, Marguerite; NICOLLET, Christian; SCHWARTZ, Stéphane; LAFAY, Romain

    2013-01-01

    Serpentinites are one of the major components of the oceanic lithosphere and are stable in the slab and the mantle wedge up to 100-150 km depth in subduction zones. During oceanic mantle hydration and alteration, they trap trace and fluid mobile (FME: B, Li, As, Sb, Rb, Ba, Cs, Sr, U and Pb) elements that participate to elemental transfer occurring between the dehydrating slab and the mantle wedge in subduction context. The Lanzo massif is an eclogitized oceanic lithosphere that preserved its...

  18. Late Mesoproterozoic to Early Paleozoic history of metamorphic basement from the southeastern Chiapas Massif Complex, Mexico, and implications for the evolution of NW Gondwana

    Weber, Bodo; González-Guzmán, Reneé; Manjarrez-Juárez, Román; Cisneros de León, Alejandro; Martens, Uwe; Solari, Luigi; Hecht, Lutz; Valencia, Victor

    2018-02-01

    In this paper, U-Pb zircon geochronology, Lu-Hf and Sm-Nd isotope systematics, geochemistry and geothermobarometry of metaigneous basement rocks exposed in the southeastern Chiapas Massif Complex are presented. Geologic mapping of the newly defined "El Triunfo Complex" located at the southeastern edge of the Chiapas Massif reveals (1) partial melting of a metamorphic basement mainly constituted by mafic metaigneous rocks (Candelaria unit), (2) an Ediacaran metasedimentary sequence (Jocote unit), and (3) occurrence of massif-type anorthosite. All these units are intruded by undeformed Ordovician plutonic rocks of the Motozintla suite. Pressure and temperature estimates using Ca-amphiboles, plagioclase and phengite revealed prograde metamorphism that reached peak conditions at 650 °C and 6 kbar, sufficient for partial melting under water saturated conditions. Relict rutile in titanite and clinopyroxene in amphibolite further indicate a previous metamorphic event at higher P-T conditions. U-Pb zircon ages from felsic orthogneiss boudins hosted in deformed amphibolite and migmatite yield crystallization ages of 1.0 Ga, indicating that dry granitic protoliths represent remnants of Rodinia-type basement. Additionally, a mid-Tonian ( 920 Ma) metamorphic overprint is suggested by recrystallized zircon from a banded gneiss. Zircon from folded amphibolite samples yield mainly Ordovician ages ranging from 457 to 444 Ma that are indistinguishable from the age of the undeformed Motozintla plutonic suite. Similar ages between igneous- and metamorphic- zircon suggest a coeval formation during a high-grade metamorphic event, in which textural discrepancies are explained in terms of differing zircon formation mechanisms such as sub-solidus recrystallization and precipitation from anatectic melts. In addition, some amphibolite samples contain inherited zircon yielding Stenian-Tonian ages around 1.0 Ga. Lu-Hf and Sm-Nd isotopes and geochemical data indicate that the protoliths of

  19. Petrological, Geochemical and Sr–Nd–O Isotopic Constraints on the Origin of Garnet and Spinel Pyroxenites from the Moldanubian Zone of the Bohemian Massif

    Svojtka, Martin; Ackerman, Lukáš; Medaris Jr., G.; Hegner, E.; Valley, J. W.; Hirajima, T.; Jelínek, E.; Hrstka, Tomáš

    2016-01-01

    Roč. 57, č. 5 (2016), s. 897-920 ISSN 0022-3530 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100131203 Program:Program interní podpory projektů mezinárodní spolupráce AV ČR Institutional support: RVO:67985831 Keywords : garnet and spinel pyroxenites * Bohemian Massif * Sr, Nd, and oxygen isotopes * trace elements * subduction Subject RIV: DD - Geochemistry Impact factor: 3.280, year: 2016

  20. X-ray color maps of the zoned garnets from Silgará Formation metamorphic rocks,SantanderMassif, Eastern Cordillera (Colombia

    Takasu Akira

    2010-12-01

    Full Text Available

    The metamorphic rocks of the Lower Paleozoic Silgará Formation of the Santander Massif, Eastern Cordillera (Colombia, were affected by a Barrovian-type metamorphism under low to high temperature and medium pressure conditions. These rocks contain garnet porphyroblasts, which show several kinds of chemical zoning patterns. The garnet grains behave as closed systems with respect to the rock matrix. Most of the observed zoning patterns are due to gradual changes in physicochemical conditions during growth. However, some garnet grains show complex zoning patterns during multiple deformation and metamorphic events.

  1. Sr isotope stratigraphy of some Rupelian carbonated laminites from the Limagne Basin: influence of seawater in the rift of the French Massif central?

    Briot, D.; Poidevin, J.L.

    1998-01-01

    87 Sr/ 86 Sr ratios of biogenic and abiotic calcites Upper Rupelian sediments in the Limagne rift (French Massif Central) define a smooth and regular negative correlation with time interrupted by repetitive sharp peaks; the progressive drop in isotopic ratio can be explained by the geological evolution of the river basin through time. Negative peaks are explained by synsedimentary volcanism, repeated marine incursions, or leaching of ancient evaporites. Comparison with available paleontologic data does not favour the volcanic explanation, but rather the influence of Rupelian marine waters. (authors)

  2. Re-Os and Lu-Hf isotopic constraints on the formation and age of mantle pyroxenites from the Bohemian Massif

    Ackerman, Lukáš; Bizimis, M.; Haluzová, Eva; Sláma, Jiří; Svojtka, Martin; Hirajima, T.; Erban, V.

    256/257, July (2016), s. 197-210 ISSN 0024-4937 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100131203 Program:Program interní podpory projektů mezinárodní spolupráce AV ČR Institutional support: RVO:67985831 Keywords : Bohemian Massif * Lu-Hf * mantle * pyroxenite * Re-Os Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.677, year: 2016

  3. Effects of interaction between ultramafic tectonite and mafic magma on Nd-Pb-Sr isotopic systems in the Neoproterozoic Chaya Massif, Baikal-Muya ophiolite belt

    Amelin, Yuri V.; Ritsk, Eugeni Yu.; Neymark, Leonid A.

    1997-04-01

    Sm-Nd, Rb-Sr and U-Pb isotopic systems have been studied in minerals and whole rocks of harzburgites and mafic cumulates from the Chaya Massif, Baikal-Muya ophiolite belt, eastern Siberia, in order to determine the relationship between mantle ultramafic and crustal mafic sections. Geological relations in the Chaya Massif indicate that the mafic magmas were emplaced into, and interacted with older solid peridotite. Hand picked, acid-leached, primary rock-forming and accessory minerals (olivine, orthopyroxene, clinopyroxene and plagioclase) from the two harzburgite samples show coherent behavior and yield 147Sm/ 144Nd- 143Nd/ 144Nd and 238U/ 204Pb- 206Pb/ 204Pb mineral isochrons, corresponding to ages of 640 ± 58 Ma (95% confidence level) and 620 ± 71 Ma, respectively. These values are indistinguishable from the crystallization age of the Chaya mafic units of 627 ± 25 Ma (a weighted average of internal isochron Sm-Nd ages of four mafic cumulates). The Rb-Sr and Sm-Nd isotopic systems in the harzburgite whole-rock samples were disturbed by hydrothermal alteration. These alteration-related isotopic shifts mimic the trend of variations in primary isotopic compositions in the mafic sequence, thus emphasizing that isotopic data for ultramafic rocks should be interpreted with great caution. On the basis of initial Sr and Nd values, ultramafic and mafic rocks of the Chaya Massif can be divided into two groups: (1) harzburgites and the lower mafic unit gabbronorites withɛ Nd = +6.6 to +7.1 andɛ Sr = -11 to -16; and (2) websterite of the lower unit and gabbronorites of the upper mafic unit:ɛ Nd = +4.6 to +6.1 andɛ Sr = -8 to -9. Initial Pb isotopic ratios are identical in all rocks studied, with mean values of 206Pb/ 204Pb= 16.994 ± 0.023 and 207Pb/ 204Pb= 15.363 ± 0.015. The similarity of ages and initial isotopic ratios within the first group indicates that the isotopic systems in the pre-existing depleted peridotite were reset by extensive interaction with

  4. L'érosion dans les environnements glaciaires : exemple du Glacier des Bossons (Massif du Mont-Blanc, Haute-Savoie, France)

    Godon , Cécile

    2013-01-01

    The study presented in this PhD memory aim at better define and quantify the present timeerosion processes in glacial and proglacial domain. The Glacier des Bossons, situated in theMont-Blanc massif (Haute-Savoie, France), is a good example of a natural and nonanthropizedsystem which allows us to study this topic. This glacier lies on two mainlithologies (the Mont-Blanc granite and the metamorphic bedrock) and this peculiarity is usedto determine the origin of the glacial sediments. The sedim...

  5. Geochronology and geochemistry of Mesozoic intrusive rocks in the Xing'an Massif of NE China: Implications for the evolution and spatial extent of the Mongol-Okhotsk tectonic regime

    Li, Yu; Xu, Wen-Liang; Tang, Jie; Pei, Fu-Ping; Wang, Feng; Sun, Chen-Yang

    2018-04-01

    This study presents new zircon U-Pb-Hf and whole-rock geochemical data for intrusive rocks in the Xing'an Massif of NE China, with the aim of furthering our understanding of the evolution and spatial influence of the Mongol-Okhotsk tectonic regime. Zircon U-Pb dating indicates that five stages of Mesozoic magmatism are recorded in the Xing'an Massif, namely during the Middle Triassic ( 237 Ma), the Late Triassic ( 225 Ma), the Early Jurassic ( 178 Ma), the Middle Jurassic ( 168 Ma), and the late Early Cretaceous ( 130 Ma). The Middle Triassic-Early Jurassic intrusive rocks in the Xing'an Massif are dominantly granodiorites, monzogranites, and syenogranites that formed from magma generated by partial melting of newly accreted continental crust. Geochemistry of the Middle Triassic-Early Jurassic granitoid suites of the Xing'an Massif indicates their formation at an active continental margin setting, related to the southwards subduction of the Mongol-Okhotsk oceanic plate. The Middle Jurassic monzogranites in the Xing'an Massif are geochemically similar to adakites and have εHf(t) values (+3.8 to +5.8) and Hf two-stage model ages (TDM2; 979-850 Ma) that are indicative of derivation from magma generated by partial melting of thickened juvenile lower crust. The Middle Jurassic monzogranites formed in a compressional setting related to the closure of the Mongol-Okhotsk Ocean. The late Early Cretaceous intrusive rocks in the Xing'an Massif are dominated by A-type granitoids that are associated with bimodal volcanic rocks, suggesting their formation in an extensional environment related to either (i) delamination of a previously thickened region of the crust, associated with the Mongol-Okhotsk tectonic regime; (ii) the subduction of the Paleo-Pacific Plate; or (iii) the combined influence of these two tectonic regimes.

  6. Gravimetric structure for the abyssal mantle massif of Saint Peter and Saint Paul peridotite ridge, Equatorial Atlantic Ocean, and its relation to active uplift

    KENJI F. MOTOKI

    2014-06-01

    Full Text Available This paper presents gravimetric and morphologic analyses based on the satellite-derived data set of EGM2008 and TOPEX for the area of the oceanic mantle massif of the Saint Peter and Saint Paul peridotite ridge, Equatorial Atlantic Ocean. The free-air anomaly indicates that the present plate boundary is not situated along the longitudinal graben which cuts peridotite ridge, but about 20 km to the north of it. The high Bouguer anomaly of the peridotite ridge suggests that it is constituted mainly by unserpentinised ultramafic rocks. The absence of isostatic compensation and low-degree serpentinisation of the ultramafic rocks indicate that the peridotite ridge is sustained mainly by active tectonic uplift. The unparallel relation between the transform fault and the relative plate motion generates near north-south compression and the consequent tectonic uplift. In this sense, the peridotite massif is a pressure ridge due to the strike-slip displacement of the Saint Paul Transform Fault.

  7. Les variations récentes (1975-2000 de l’englacement dans le Massif de l’Aconcagua (Mendoza, Argentine

    Julie Le Gall

    2008-03-01

    Full Text Available La région de Mendoza est particulièrement vulnérable au réchauffement climatique. Les glaciers du massif de l’Aconcagua ont amorcé un important retrait depuis la fin du Petit Âge de Glace. Or la disparition de ces glaciers risque d’entraîner une modification des régimes hydrologiques qui, jusqu’à présent, se caractérisaient par de hautes eaux estivales. Ce pic estival pourrait à l’avenir être atténué et remettre en cause les stratégies de gestion de la ressource en eau. Nous faisons ici le point sur les variations récentes de l’englacement et tentons de dessiner un scénario prospectif.Mendoza area is highly vulnerable to the global warming. The glaciers of the Aconcagua massif are currently shrinking, this trend of retreat began at the end of the Little Ice Age. The disappearance of glaciers may modify hydrological regimes. The discharge is currently at maximum during summer (related to glacier melt, but the peak discharge may occur during spring (related to snow melt in the next future. In this paper we synthesize the recent variations of the glaciers and propose a pattern of future variations.

  8. Thermo chronology by fission tracks of the conjugated rift margins of the Liguro-Provencal basin: Corsica and the Maures-Tanneron Massif

    Jakni, B.

    2000-01-01

    We have employed apatite fission-track (AFT) thermo-chronology on granitic and metamorphic samples taken from Corsican and Maures-Tanneron basement rocks as well as alpine 'schistes lustres' units in Corsica, in order to constrain the cooling histories and the tectonic evolution of the Liguro-Provencal basin margins. The AFT data indicate that: -) the Tanneron massif (AFT ages 145- 150 My) appears to record the earliest cooling history, reflecting thermal relaxation related to opening of the Tethys; -) the Maures basement (AFT ages 20-25 My) clearly records a thermo- tectonic evolution associated with Liguro-Provencal rifting; -) the island of Corsica, which was the main focus of this work and which shows a complex geomorphology and a poly-phased tectonic evolution. shows a remarkable zoning in the distribution of AFT ages, reflecting the signature of at least two post-Oligocene thermal events. Those events are related to the opening of Liguro-Provencal basin (20-25 My) in the west, and exhumation of the Hercynian basement related to Tyrrhenian extension (12- 16 My) in the east. In the east-Tenda shear zone, which forms the contact between the alpine units and Hercynian basement in northern Corsica, our results indicate that the Tenda Massif was being exhumed from about 21 Ma onwards. (author)

  9. GIS-based model of groundwater occurrence using geological and hydrogeological data in Precambrian Oban Massif southeastern Nigeria

    Sikakwe, Gregory Udie

    2018-06-01

    This research modeled geological and hydrogeological controls on groundwater occurrence in Oban Massif and environs southeastern Nigeria. Topographical, hydrogeological, and structural maps, including lithology samples from drilled bores, well completion, and pumping test data in the study area were procured. Collection of coordinates of rock sample locations and structural data on strike and dip of rock exposures was collected. Geological and structural information collected was overlaid on the topographical, hydrogeological and structural map and digitized to produce the geological map of the study area. Thematic map on geological groundwater prospect map of the study was prepared using multicriteria evaluation. Relative weights were assigned to various rock types based on their relative contribution to groundwater occurrence and the map was reclassified using geographic information system (ArcGIS10.1) analysis. Depth ranges of the various lithologic units from drilled boreholes were used to construct lithologic correlation section of the boreholes across the study area using RockWorks16 Program software. Hydrogeological parameters such as storativity, specific capacity, transmissivity, drawdown, pumping rate, static water level, total depth, and well yield were computed from well completion reports and aquifer test. Results shows that the geologic groundwater prospect map was categorized into very good (28.73 m2), good (9.66 m2), moderate (35.08 m2), fair (49.38 m2), and poor (77.63 m2) zones. Aquifer parameters showed ranges such as (specific capacity (1.81-31.16 m2/day/m), transmissivity (0.0033-12 m2/day), storativity (9.4 × 10-3-2.3), drawdown (2.2-17.65 m), pumping rate (0.75-3.57 l/s), static water level (0-20.5 m), and total depth (3.3-61 m). Borehole depths obtained in the basement are shallower than those in the sedimentary area. Aquifer test parameters obtained from boreholes across the study indicate better correspondence with zones identified as

  10. New petrographic, geochemical and geochronological data for the Reguengos de Monsaraz pluton (Ossa Morena Zone, SW Iberian Massif, Portugal

    Antunes, A.

    2010-06-01

    Full Text Available The Reguengos de Monsaraz pluton is a late to post-tectonic Variscan intrusion occurring in the Ossa Morena Zone (Iberian Variscan Chain. The dominant lithological types are tonalites and granodiorites, but the internal area of the massif is composed of gabbro-dioritic rocks. Field evidence shows that the intrusion is heterogeneous at mesoscopic scale suggesting that the emplacement of mafic and felsic magmas was contemporaneous. Petrographic and geochemical studies reveal that the different lithologic types define a continuous sequence with compositions varying from metaluminous to slightly peraluminous and a typical calc-alkaline signature. In Harker variation diagrams, it is possible to observe systematic rectilinear correlations pointing to the involvement of magma mingling/mixing processes in the petrogenesis of this sequence. Rb-Sr isotopic data, using a mineral-mineral pair from a granodiorite sample, yielded an age of 298 Ma, interpreted as a cooling age after igneous crystallization.

    El plutón de Reguengos de Monsaraz es una intrusión varisca tardi- a post- tectónica localizada en la Zona de Ossa Morena (Cadena Varisca Ibérica. Los tipos litológicos dominantes son las tonalitas y las granodioritas aunque la zona mas interna del macizo está formada por rocas gabro-dioríticas. Las evidencias de campo muestran que todos los tipos litológicos son heterogéneos a escala mesoscópica y sugieren que el emplazamiento de los magmas máficos y félsicos fue contemporáneo. Los estudios petrográficos y geoquímicos muestran que los diferentes litotipos definen una secuencia continua con una afinidad calcoalcalina típica y composiciones variando desde metaluminosas a peraluminosas. En los diagramas de Harker se observan correlaciones rectilíneas sistemáticas, lo que sugiere que la mezcla de magmas tuvo un papel decisivo en su petrogénesis. Los datos isotópicos de Rb-Sr, usando un par mineral-mineral de una granodiorita

  11. Creation and Plan of an Underground Geologic Radioactive Waste Isolation Facility at the Nizhnekansky Rock Massif in Russia

    Gupalo, T A; Kudinov, K G; Jardine, L J; Williams, J

    2004-01-01

    This joint geologic repository project in Russia was initiated in May 2002 between the United States (U.S.) International Science and Technology Center (ISTC) and the Federal State Unitary Enterprise ''All-Russian Research and Design Institute of Production Engineering'' (VNIPIPT). The project (ISTC Partner Project 2377) is funded by the U.S. Department of Energy Office of Civilian Radioactive Waste Management (DOE-RW) for a period of 2-1/2 years. ISTC project activities were integrated into other ongoing geologic repository site characterization activities near the Mining and Chemical Combine (MCC K-26) site. This allowed the more rapid development of a plan for an underground research laboratory, including underground design and layouts. It will not be possible to make a final choice between the extensively studied Verkhne-Itatski site or the Yeniseiski site for construction of the underground laboratory during the project time frame because additional data are needed. Several new sources of data will become available in the next few years to help select a final site. Studies will be conducted at the 1-km deep borehole at the Yeniseisky site where drilling started in 2004. And in 2007, after the scheduled shutdown of the last operating reactor at the MCC K-26 site, data will be collected from the rock massif as the gneiss rock cools, and the cool-down responses modeled. After the underground laboratory is constructed, the data collected and analyzed, this will provide the definitive evidence regarding the safety of the proposed geologic isolation facilities for radioactive wastes (RW). This data will be especially valuable because they will be collected at the same site where the wastes will be subsequently placed, rather than on hypothetical input data only. Including the operating costs for 10 to 15 years after construction, the cost estimate for the laboratory is $50M. With additional funding from non-ISTC sources, it will be possible to complete this

  12. The destabilization of the Pilatte hut (2577 m a.s.l. - Ecrins massif, France), a paraglacial process?

    Ravanel, Ludovic; Dubois, Laurent; Fabre, Sébastien; Duvillard, Pierre-Allain; Deline, Philip

    2015-04-01

    The Pilatte hut is located at 2572 m a.s.l. at Saint-Christophe-en-Oisans (south of the Ecrins Massif, France), at a 3-hours-walk from La Bérarde hamlet. Its capacity is 120 beds for hikers and climbers who are engaged in the ascent of Les Bans (3669 m a.s.l.). Built on a rocky ledge on the right side of the Pilatte Glacier (A = 2.64 km2; L = 2.6 km), it currently dominates the glacier by about 150 m. This relief results from the retreat of the glacier since the end of the Little Ice Age, as the till around the hut was deposited during this stage. The glacier has lost about 1.8 km in length during the same period. A first wooden hut was built in 1925 and presently serves as a winter refuge. In 1954, the growth of mountain activities led to the construction of a larger hut made of cemented stones. An extension to the west made of reinforced concrete was built in 1994. But in the late 1980s, severe damages to the 1954 part of the building were already recognized: vertical cracks lining the north and south facades, ,subsidence (c. 10 cm downstream) of the ground floor, cracked interior walls. Currently, the evolution of the instability is monitored by several methods: - since 2003, cracks in the building are surveyed by 25 Saugnac gauges, while an outside fracture in the rock is surveyed by a simple extensometer; - since 2009, 8 strain gauges allow to annually measure displacements along the main fractures that delimit the unstable rock mass; - a high-resolution topographic data set acquired by terrestrial laser scanning from the surface of the glacier in July 2014 has completed the monitoring. The acting process is a translational slide of a rock mass with a volume of about 300 000 m3, initiated by the glacier shrinkage. Therefore, it has to be considered as a paraglacial process. Even if the slide velocity is presently decreasing, a demolition project of the hut is under consideration in favor of a new building on the right side of the valley, 800 m downstream the

  13. Petrologic significance of Fe-rich staurolite in pelitic schists of the Silgará Formation, Santander Massif

    Carlos Alberto Ríos

    2016-01-01

    Full Text Available Medium grade metapelites of the Silgará Formation at the Santander Massif (Colombian Andes have been affected by a medium-pressure/high-temperature Barrovian type of metamorphism, developing a sequence of metamorphic zones (biotite, garnet, staurolite and sillimanite. These rocks record a complex tectonometamorphic evolution and reaction history. Metapelitic rocks from the staurolite zone are typically foliated, medium- to coarse-grained, pelitic to semipelitic schists that contain the mineral assemblage biotite + garnet + staurolite ± kyanite; all contain muscovite + quartz + plagioclase with minor K-feldspar, tourmaline, apatite, zircon, epidote, calcite, and Fe–Ti oxides. Field and microscopic evidences reveal that Fe-rich staurolite in pelitic schists is involved in several chemical reactions, which explains its formation and transformation to other minerals, which are very important to elucidate the reaction history of the Silgará Formation metapelites.   Significado Petrológico de Estaurolita Rica en Fe en Esquistos Pelíticos de la Formación Silgará, Macizo de Santander   Resumen Medium grade metapelites of the Silgará Formation en el Macizo de Santander (Andes Colombianos han sido afectadas por un metamorfismo de tipo Barroviense, el cual se ha producido en condiciones de media presión y alta temperatura, desarrollando una secuencia de zonas metamórficas (biotita, granate, estaurolita y silimanita. Estas rocas registran una evolución tectono-metamórfico e historia reacción compleja. Las metapelitas de la zona de la estaurolita están representadas por esquistos pelíticos a semipelíticos de grano medio a grueso típicamente foliados que contienen la paragénesis mineral biotita + granate + estaurolita ± cianita; todos contienen moscovita + cuarzo + plagioclasa con menor feldespato potásico, turmalina, apatito, zircón, epidota, calcita, y óxidos de Fe-Ti. Evidencias de campo y microscópicas revelan que la estaurolita

  14. A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites

    Woodruff, Laurel G.; Nicholson, Suzanne W.; Fey, David L.

    2013-01-01

    This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province, stretching from southwestern United States through eastern Canada; its extension into Norway is termed the Rogaland Anorthosite Province. This type of Fe-Ti-oxide deposit dominated by ilmenite rarely contains more than 300 million tons of ore, with between 10- to 45-percent titanium dioxide (TiO2), 32- to 45-percent iron oxide (FeO), and less than 0.2-percent vanadium (V). The origin of these typically discordant ore deposits remains as enigmatic as the magmatic evolution of their host rocks. The deposits clearly have a magmatic origin, hosted by an age-constrained unique suite of rocks that likely are the consequence of a particular combination of tectonic circumstances, rather than any a priori temporal control. Principal ore minerals are ilmenite and hemo-ilmenite (ilmenite with extensive hematite exsolution lamellae); occurrences of titanomagnetite, magnetite, and apatite that are related to this deposit type are currently of less economic importance. Ore-mineral paragenesis is somewhat obscured by complicated solid solution and oxidation behavior within the Fe-Ti-oxide system. Anorthosite suites hosting these deposits require an extensive history of voluminous plagioclase crystallization to develop plagioclase-melt diapirs with entrained Fe-Ti-rich melt rising from the base of the lithosphere to mid- and upper-crustal levels. Timing and style of oxide mineralization are related to magmatic and dynamic evolution of these diapiric systems and to development and movement of oxide cumulates and related melts. Active mines have developed large open pits with extensive waste-rock piles, but

  15. The timberline as result of the interactions among forest, abiotic environment and human activity in the Babia Gora massif, Western Carpathians

    Lajczak, Adam

    2016-04-01

    The timberline is one of the clearest and most easily discernible boundaries in nature (Troll 1973). Among the existing conceptual models clarifying the complex nature of the relationship between the timberline and the environment and human impact, the fullest seems to be the one presented by K. Holtmeier (2009). The quoted author comprehensively characterizes the timberline, taking into account its course, appearance and ecological characteristics. The aim of the work is to quantitatively assess the factors influencing the course of timberline and its changes over the last ca. 400 years in the Babia Góra massif (1725 m a.s.l.), the highest flysch ridge in the Western Carpathians, which is formed as an asymmetric ridge of kuesta type. Forests mainly in the upper montane zone have preserved their natural character in many areas. Old spruce tree growths are a particular advantage of the Babia Góra Mt., being there on the predominant section of the altitude zone of the timberline. In the rest of this zone, spruce forests have been under a direct or indirect influence of changes resulting from grazing with its 400-year history and forestry taking place about 100 years ago. The 60 m difference between the average altitude of the timberline on the northern (1335 m a.s.l.) and the southern slope (1395 m a.s.l.) on the Babia Góra Mt. can be explained with climatic conditions of these areas. The average gradient of the slope within the timberline ecotone on the southern slope of the massif is by 100 smaller, and the amount of solar energy delivered during the growing season is 40% higher (960 kWh/m2) than on the northern slope. The higher position of the timberline on the windward southern slope is favored by the dominant winds from S-W sector, thinner snow cover and earlier melting due to the lower precipitation on the slope and also due to the winnowing of snow onto the steep northern slope of the ridge. On the southern slope of the ridge there are no larger snow

  16. Migmatization and low-pressure overprinting metamorphism as record of two pre-Cretaceous tectonic episodes in the Santander Massif of the Andean basement in northern Colombia (NW South America)

    Zuluaga, C. A.; Amaya, S.; Urueña, C.; Bernet, M.

    2017-03-01

    The core of the Santander Massif in the northern Andes of Colombia is dominated by migmatitic gneisses with a 7.5 kbar. Lithologies are overprinted by low-pressure metamorphism, related to extensive Jurassic intrusions and linked with growth of cordierite and equilibration of low-pressure mineral assemblages, recorded metamorphic conditions are Pangaea.

  17. Metamorphic history of garnet-rich gneiss at Ktiš in the Lhenice shear zone, Moldanubian Zone of the southern Bohemian Massif, inferred from inclusions and compositional zoning of garnet

    Kobayashi, T.; Hirajima, T.; Kawakami, T.; Svojtka, Martin

    2011-01-01

    Roč. 124, 1/2 (2011), s. 46-65 ISSN 0024-4937 Institutional research plan: CEZ:AV0Z30130516 Keywords : Bohemian Massif * Lhenice shear zone * garnet * P-T path * partial melting Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.246, year: 2011

  18. Geochemical characteristics and petrogenesis of phonolites and trachytic rocks from the České Středohoří Volcanic Complex, the Ohře Rift, Bohemian Massif

    Ackerman, Lukáš; Ulrych, Jaromír; Řanda, Zdeněk; Erban, V.; Hegner, E.; Magna, T.; Balogh, K.; Frána, Jaroslav; Lang, Miloš; Novák, Jiří Karel

    224/225, May (2015), s. 256-271 ISSN 0024-4937 R&D Projects: GA AV ČR IAA3048201 Institutional support: RVO:67985831 ; RVO:61389005 Keywords : phonolite * trachyte * Sr–Nd–Li isotopes * Cenozoic alkaline volcanism * Ohře (Eger) Rift * Bohemian Massif Subject RIV: DD - Geochemistry Impact factor: 3.723, year: 2015

  19. Molybdenite-tungstenite association in the tungsten-bearing topaz greisen at Vítkov (Krkonoše-Jizera Crystalline Complex, Bohemian Massif): indication of changes in physico-chemical conditions in mineralizing system

    Pašava, J.; Veselovský, F.; Drábek, M.; Svojtka, Martin; Pour, O.; Klomínský, J.; Škoda, R.; Ďurišová, Jana; Ackerman, Lukáš; Halodová, P.; Haluzová, Eva

    2015-01-01

    Roč. 60, č. 3 (2015), s. 149-161 ISSN 1802-6222 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : LA-ICP-MS * EMPA * molybdenite * tungstenite * transitional Mo–W and W–Mo disulfides * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.326, year: 2015

  20. Transition from island-arc to passive setting on the continental margin of Gondwana: U-Pb zircon dating of Neoproterozoic metaconglomerates from the SE margin of the Teplá-Barrandian Unit, Bohemian Massif

    Sláma, Jiří; Dunkley, D. J.; Kachlík, V.; Kusiak, M. A.

    2008-01-01

    Roč. 461, 1-4 (2008), s. 44-59 ISSN 0040-1951 Institutional research plan: CEZ:AV0Z30130516 Keywords : Bohemian Massif * Teplá–Barrandian Unit * Neoproterozoic * Armorican Terrane Assemblage * Gondwana * zircon dating Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.677, year: 2008

  1. Petrogenesis of the Cenozoic alkaline volcanic rock series of the České Středohoří Complex (Bohemian Massif), Czech Republic: A case for two lineages

    Dostal, J.; Schellnutt, J. G.; Ulrych, Jaromír

    2017-01-01

    Roč. 317, June (2017), s. 677-706 ISSN 0002-9599 Institutional support: RVO:67985831 Keywords : Bohemian Massif * Central European volcanic province * continental alcaline volcanism * fractional crystallization * magmatic fluids Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 4.099, year: 2016

  2. Long-lasting Cadomian magmatic activity along an active northern Gondwana margin: U-Pb zircon and Sr-Nd isotopic evidence from the Brunovistulian Domain, eastern Bohemian Massif

    Soejono, I.; Janoušek, V.; Žáčková, E.; Sláma, Jiří; Konopásek, J.; Machek, Matěj; Hanžl, P.

    2017-01-01

    Roč. 106, č. 6 (2017), s. 2109-2129 ISSN 1437-3254 Institutional support: RVO:67985530 ; RVO:67985831 Keywords : Cadomian magmatic arc * Brunovistulian Domain * Bohemian Massif * Gondwana margin * U–Pb geochronology * geochemistry Subject RIV: DB - Geology ; Mineralogy; DC - Siesmology, Volcanology, Earth Structure (GFU-E) OBOR OECD: Geology; Volcanology (GFU-E) Impact factor: 2.283, year: 2016

  3. Geochemical and petrological constraints on mantle composition of the Ohře(Eger) rift, Bohemian Massif: peridotite xenoliths from the České Středohoří Volcanic complex and northern Bohemia

    Ackerman, Lukáš; Medaris Jr., G.; Špaček, P.; Ulrych, Jaromír

    2015-01-01

    Roč. 104, č. 8 (2015), s. 1957-1979 ISSN 1437-3254 R&D Projects: GA ČR GA205/09/1170 Institutional support: RVO:67985831 Keywords : Bohemian Massif * mantle * metasomatism * Ohře(Eger) rift * xenolith Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.133, year: 2015

  4. Lu-Hf geochronology on cm-sized garnets using microsampling: New constraints on garnet growth rates and duration of metamorphism during continental collision (Menderes Massif, Turkey)

    Schmidt, Alexander; Pourteau, Amaury; Candan, Osman; Oberhänsli, Roland

    2015-12-01

    This study shows Lu-Hf geochronology of zoned garnet crystals contained in mica schists from the southern Menderes Massif, Turkey. Selected samples are four 3-5 cm large garnet megacrysts of which several consecutive garnet shells have been sampled with a micro-saw and analyzed for dating. The results are used to extract growth rates of garnet, and also to improve the time constraint for Alpine-aged overprint of the Pan-African basement in the Menderes Massif. Lu-Hf ages of the sampled garnet shells are determined by two-point garnet-only isochrons using the garnets' Lu-depleted rim compositions. This yields a consistent decrease of age information from core to rim segments of individual garnet crystals and the calculated isochron ages propose a time frame of growth between 42.6 ± 1.9 and 34.8 ± 3.1 Ma. Major element profiles in the investigated garnets characterize zoning patterns indicative of prograde conditions: Rayleigh fractionated bell-shaped Mn and decreasing Fe/(Fe + Mg) are recorded by the garnets' core to rim compositions. Therefore the obtained Lu-Hf ages record timing of early prograde growth for the cores of the garnets. Two of the large garnet crystals also yield isochron ages of 58.83 ± 0.69 and 50.16 ± 0.84 Ma in their innermost cores, which appear to record an early nucleation event. This view, however, is not in concordance with the observed major element profiles of these garnets, and therefore is interpreted with caution. Termination of the garnet growth period is determined through the calculation of radial growth rates based on the size of the garnets and the Lu-Hf ages obtained for consecutive shells. Extrapolation of these rates potentially constrains the total duration for garnet growth terminating at 31 ± 6 Ma. Comparison of the growth rates calculated for individual crystals shows a variety of slow and fast growing garnets, and similar results have been previously obtained with the Rb-Sr and Sm-Nd isotope systems. The new data

  5. Petrology and geochemistry of primary magmas trapped in melt inclusions in scoria of Beaunit Maar (Chaîne des Puys, Massif Central, France)

    Jannot, S.; Schiano, P.; Boivin, P.; Clocchiatti, R.; Chazot, G.

    2003-04-01

    The Massif Central area, characterized by a typical intraplate alkaline serie, is the largest magmatic province of the West-European Rift system. Although it has been the subject of several studies, the nature of Massif Central sources is still a matter of debate and many hypotheses are proposed, including deep-rooted continental hotspot, metasomatised spinel lherzolites and an asthenospheric flow linked to the lithospheric root of the Alpine chain. The Chaîne des Puys is the last magmatic province of the French Massif Central and is composed of hundred young well-preserved volcanoes. The present work aims to supply information on the nature and the origin of the source chemistry of alkaline serie from the Chaîne des Puys, by characterizing the trace and major element composition of minute melts preserved as quenched glass inclusions inside olivines phenocrysts in scoria from the Beaunit Maar. Heating stage experiments performed at ambient pressure on partially crystallised primary melt inclusions suggest CO_2 oversaturation of the trapped melt, and an entrapment temperature around 1200^oC±10^oC. Daughter minerals analyses point to a Ti-and Ca-rich basaltic paragenesis, in good agreement with that of erupted basalts from the Chaîne des Puys. Major element compositions show that melts trapped in inclusions evolve by limited fractional crystallization. Inclusions trapped in the more primitive olivine phenocrysts (Fo85) have alkali-basalt compositions that fall on the primitive end of the compositional trend define by the lavas of the Chaîne des Puys. Their major element chemistry rules out the hypothesis of a mantle source in the spinel stability field and requires a garnet-bearing mantle source. Analyzed for trace-element composition by LA-ICP-MS, they display homogeneous, enriched patterns, similar to those characterizing oceanic island and continental basalts. They have high concentration of LILE and LREE/HREE ratios. Such trace-element feature are typical of

  6. Weathering profiles in granitoid rocks of the Sila Massif uplands, Calabria, southern Italy: New insights into their formation processes and rates

    Scarciglia, Fabio; Critelli, Salvatore; Borrelli, Luigi; Coniglio, Sabrina; Muto, Francesco; Perri, Francesco

    2016-05-01

    In this paper we characterized several weathering profiles developed on granitoid rocks in the Sila Massif upland (Calabria, southern Italy), integrating detailed macro- and micromorphological observations with physico-mechanical field tests and petrographic, mineralogical and geochemical analyses. We focused our attention on the main weathering and pedogenetic processes, trying to understand apparent discrepancies between weathering grade classes based on field description and geomechanical properties, and two common weathering indices, such as the micropetrographic index (Ip) and the chemical index of alteration (CIA). Our results showed that sericite on plagioclase and biotite chloritization, that represent inherited features formed during late-stage hydrothermal alteration of granitoid rocks, may cause an overestimation of the real degree of weathering of primary mineral grains under meteoric conditions, especially in lower weathering grade classes. Moreover, the frequent identification of Fe-Mn oxides and clay coatings of illuvial origin (rather than or in addition to those formed in situ), both at the macro- and microscale, may also explain an overestimation of the weathering degree with respect to field-based classifications. Finally, some apparent inconsistencies between field geomechanical responses and chemical weathering were interpreted as related to physical weathering processes (cryoclastism and thermoclastism), that lead to rock breakdown even when chemical weathering is not well developed. Hence, our study showed that particular caution is needed for evaluating weathering grades, because traditional field and geochemical-petrographic tools may be biased by inherited hydrothermal alteration, physical weathering and illuvial processes. On the basis of chronological constraints to soil formation obtained from a 42 ka-old volcanic input (mixed to granite parent materials) detected in the soil cover of the Sila Massif upland, a first attempt to estimate

  7. Domain structure and texture in fine grained symplectite from garnet breakdown in peridotite xenoliths (Zinst, Bavaria, Bohemian Massif)

    Habler, G.; Špaček, P.; Abart, R.

    2012-04-01

    Lherzolite xenoliths entrained in Oligocene basanite at the locality of Zinst (Bavaria, western Bohemian Massif) contain rare fine-grained symplectites forming about 5 millimeter sized patches comprising several microstructurally and chemically distinct concentric zones. The symplectites reflect a complex reaction history of lherzolite during decompression and interaction with melt. Here we focus on ultra-fine grained symplectite with an integrated bulk composition expressed in terms of garnet end-member component percentages as Prp(69-71)Alm(11-13)Grs(2.5-5)And(7.5-10)Uvr(4). According to the composition and the microstructural occurrence in lherzolite the ultra-fine grained symplectite is interpreted as a product of isochemical garnet breakdown, although the precursor phase is not preserved. Under cross polarized light patches with similar extinction show a domain microstructure in symplectite. BSE images reveal an intimate intergrowth of orthopyroxene, spinel and plagioclase. All phases have a shape preferred orientation within distinct domains, whereas discontinuous SPO changes occur at microstructural domain boundaries. Three types of symplectite were microstructurally discerned: The most pristine type A occurs in a 10-30 micrometers wide zone along the symplectite margin. Spinel forms several tens of nanometers wide rods or lamellae within Opx, whereas Pl and Opx represent the symplectite matrix. All phases show a strong SPO with the maximum elongation perpendicular to the symplectite boundary. At edges of this interface, the SPO of the symplectite phases changes accordingly. Discontinuities in SPO may coincide with changes in crystallographic orientation. EBSD data showed that symplectite phases have strict crystallographic orientation relations with Opx(100)//Spl(111) and Opx(010)//Spl(110). Whereas the initial lattice orientation is controlled by adjacent phases at the symplectite boundary, the crystallographic orientation within symplectite domains

  8. Chromium-rich lawsonite in high-Cr eclogites from the Făgăras Massif (South Carpathians)

    Negulescu, E.; Săbău, G.

    2012-12-01

    Lawsonite is a relatively rare phase in natural rocks, because of its thermal decomposition during exhumation, and Cr-bearing lawsonite being restricted to only a few occurrences worldwide. Here we report Cr-lawsonite in eclogites hosted in a medium-grade metamorphic complex. Several high-Cr eclogite lenses occur in the Topolog Complex (Făgăras Massif) of dominantly gneissic-amphibolitic composition. High Cr contents are the result of emerald-green mm-sized nodules containing Cr-rich minerals, embedded in a gray-green matrix of kyanite, clinopyroxene, garnet, amphibole, zoisite, and rutile. Garnets occur as porphyroblasts or in coronas around clinopyroxene aggregates probably replacing former magmatic pyroxene. Relict gabbroic textures (sometimes pegmatoid) and whole rock geochemistry indicate a gabbroic cumulate origin. The REE pattern, displaying a slight positive Eu anomaly and a tea spoon-shaped LREE depletion is also indicative of a cumulate origin, as also noted by Pe Piper & Piper (2002) for the Othrys gabbro (as well as others in the Vourinos and Pindos ophiolitic suites) with the same unusual REE-pattern. The emerald-green Cr-rich nodules are unevenly distributed in the rock, and always enclosed in Cr-rich clinopyroxenes (up to 5.46% Cr2O3) which may exhibit Cr-diffusion haloes towards normal Cr-free matrix pyroxene. The nodules consist of diablastic chromite, rutile and Cr-rich kyanite of up to 15.67 wt% Cr2O3, Cr-bearing epidote, to which Cr-rich staurolite (up to 10.45% Cr2O3; XMg up to 0.68) and Cr-rich lawsonite (up to 9.17% Cr2O3) may exceptionally associate. Cr concentrations in kyanite and lawsonite are, to our knowledge, the highest reported so far. Cr-lawsonite was identified in a single sample, as small single phase inclusions armoured in Cr-kyanite. Equilibrium PT-conditions of 2.6 GPa and 610o C were derived from the garnet-mantled clinopyroxene aggregates using multi-equilibria calculation with the PTGIBBS routine of Brandelik & Massonne

  9. Instability of a highly vulnerable high alpine rock ridge: the lower Arête des Cosmiques (Mont Blanc massif, France)

    Ravanel, L.; Deline, P.; Lambiel, C.; Vincent, C.

    2012-04-01

    Glacier retreat and permafrost degradation are actually more and more thought to explain the increasing instability of rock slopes and rock ridges in high mountain environments. Hot summers with numerous rockfalls we experienced over the last two decades in the Alps have indeed contributed to test/strengthen the hypothesis of a strong correlation between rockfalls and global warming through these two cryospheric factors. Rockfalls from recently deglaciated and/or thawing areas may have very important economic and social implications for high mountain infrastructures and be a fatal hazard for mountaineers. At high mountain sites characterized by infrastructures that can be affected by rockfalls, the monitoring of rock slopes, permafrost and glaciers is thus an essential element for the sustainability of the infrastructure and for the knowledge/management of risks. Our study focuses on a particularly active area of the Mont Blanc massif (France), the lower Arête des Cosmiques, on which is located the very popular Refuge des Cosmiques (3613 m a.s.l.). Since 1998, when a rockfall threatened a part of the refuge and forced to major stabilizing works, observations allowed to identify 10 detachments (20 m3 to > 1000 m3), especially on the SE face of the ridge. Since 2009, this face is yearly surveyed by terrestrial laser scanning to obtain high-resolution 3D models. Their diachronic comparison gives precise measurements of the evolution of the rock slope. Eight rock detachments have thus been documented (0.7 m3 to 256.2 m3). Rock temperature measurements at the ridge and the close Aiguille du Midi (3842 m a.s.l.), and observations of the evolution of the underlying Glacier du Géant have enable to better understand the origin of the strong dynamics of this highly vulnerable area: (i) rock temperature data suggest the presence of warm permafrost (i.e. close to 0°C) from the first meters to depth in the SE face, and cold permafrost in the NW face; (ii) as suggested by the

  10. La couverture tertiaire du flanc nord du massif du Troodos et de la partie méridionale de la Mésaoria : étude stratigraphique et micropaléontologique The Terciary Sediments of the Northern Flank of the Stroodos Massif and the Southern Part of Mesaoria : Stratigraphic and Micropaleonlogical Study

    Baroz F.

    2006-11-01

    Full Text Available Le massif pluto-volcanique du Troodos est ceinturé par une importante série sédimentaire le plus souvent à dominante crayeuse dont l'âge va du Maestrichtien au Messinien, époque à laquelle le Troodos émerge. La mer revient en transgression au Pliocène. Après une recherche bibliographique réinterprétant les principaux résultats des travaux antérieurs, une étude pétrographique, micropaléontologique et stratigraphique est réalisée à partir des échantillons recueillis suivant treize profils, sur le flanc N du Troodos et dans la partie méridionale de la Mésaoria. Cette étude montre que les craies résultent de la lithification de boues à Globigérinidés redéposées dans lesquelles les figures de courant et les slumps sont nombreux. Ces dépôts, qui s'organisent en un système progradantà partir du haut fond sous-marin du Troodos, forment sur son flanc N une série condensée présentant de nombreux et souvent spectaculaires hiatus stratigraphiques. Elle caractérise un environnement qui, bathyal inférieur au Maestrichtien-Paléocène, évolue en un milieu de dépôt néritique au Messinien. The plutonic-volcanic Troodos Massif is surrounded by thick sedimentory series, often developed in a predominantly chalky facies ; their age ranges from Maastrichtian to Messinian during which period the Troodos Massif emerged. The sea transgressively returned in Pliocene times. Hoving studied the references which lead to a reinterpretation of the main findings of previous investigations, a petrogrophic, micropaleontological and stratigrophic study of rock somples hos been made, gathered along thirteen profiles on the northern flank of the Troodos Massif and in the southern part of Mesaoria. The study reveals that the chalky resulted from a lithification of redeposited glogigerina oozes, showing numerous current marks and slump structures. These progroding deposits laid down on a Troodos seamount at the time, form a condensed series

  11. Pb-Pb Dating mono zircon from Gloria Norte Massif, Sergipano belt; Datacao de Pb-Pb em monozircao do Macico Gloria Norte, faixa Sergipana

    Lisboa, V.A.C.; Rosa, M.L.S.; Conceicao, H., E-mail: viniciuslisboa1@hotmail.com [Pós-Graduacão em Geociências e Análise de Bacias/Universidade Federal de Sergipe, São Cristóvão, SE (Brazil); Macambira, M.J.B.; Galarza, M.A. [Pós-Graduacão em Geociências/Universidade Federal do Pará, Belem, PA (Brazil); Rios, D.C. [Departamento de Geologia/Universidade Federal da Bahia, Salvador, BA (Brazil)

    2014-11-01

    The Gloria Norte Massif (MGN) has about 50 km{sup 2} in area, lies between the cities of Nossa Senhora da Gloria and Monte Alegre, northeastern Sergipe state, is composed of monzonitic rocks, being intrusive in metasediments Domain Macurure, in the Sergipano Belt. In this study Pb-Pb geochronological determinations were performed using the evaporation technique single crystals of zircon in MGN. Two samples were analyzed (03A and 12A) and the results were ages of 646 ± 2.5 Ma and 650 ± 4.5 Ma, place this magmatism in the Cryogenian period. These data may imply that around 645-655 Ma, there was an active magmatic arc in this region of the Sergipano Belt. (author)

  12. Geochemical Signature of Magmatic-Hydrothermal Fluids Exsolved from the Beauvoir Rare-Metal Granite (Massif Central, France: Insights from LA-ICPMS Analysis of Primary Fluid Inclusions

    Matthieu Harlaux

    2017-01-01

    Full Text Available The Beauvoir granite (Massif Central, France represents an exceptional case in the European Variscan belt of a peraluminous rare-metal granite crosscutting an early W stockwork. The latter was strongly overprinted by rare-metal magmatic-hydrothermal fluids derived from the Beauvoir granite, resulting in a massive topazification of the quartz-ferberite vein system. This work presents a complete study of primary fluid inclusions hosted in quartz and topaz from the Beauvoir granite and the metasomatized stockwork, in order to characterize the geochemical composition of the magmatic fluids exsolved during the crystallization of this evolved rare-metal peraluminous granite. Microthermometric and Raman spectrometry data show that the earliest fluid (L1 is of high temperature (500 to >600°C, high salinity (17–28 wt.% NaCl eq, and Li-rich (Te100 m and interaction with external fluids.

  13. Characterization of potassic materials of Pocos de Caldas alkaline massif, Southeastern Brazil; Caracterizacao de materiais potassicos do macico alcalino de Pocos de Caldas (MG)

    Goncalves, P.; Navarro, F.C.; Roveri, C.D. [Universidade Federal de Alfenas (UNIFAL), MG (Brazil); Bergerman, M.G., E-mail: pattypgpatty@gmail.com [Universidade de Sao Paulo (USP), SP (Brazil)

    2016-07-01

    Potassium, which has featured in Brazil's agricultural sector and in the world's in the application of fertilizers, is present in magmatic rocks, such as nepheline syenite and phonolite, found in the Alkaline Massif of Pocos de Caldas (AMPC). The rare earth elements (REE), in turn, also occur in this region and have important uses in various industrial fields. The aim of this study was to investigate the potential of potassic rocks of AMPC in the fertilizer and rare earths industry. Five samples were collected and characterized. It was observed that there was no preferential concentration by granulometric range of potassium oxide, alumina, silica and iron oxide. Feldspathic mass, potash feldspar, and muscovite were found in all samples. The samples show REE with amounts greater than those found in the earth's crust, except for lutetium and scandium and possessed average content of potassium oxide from 8.70 to 14.40%. (author)

  14. U-Pb La-ICP-ms geochronology and regional correlation of middle Jurassic intrusive rocks from the Garzon Massif, Upper Magdalena Valley and central cordillera, southern Colombia

    Bustamante, Camilo; Cardona, Agustin; Bayona, German; Mora, Andres; Valencia, Victor; Gehrels, George; Vervoort, Jeff

    2010-01-01

    New U-Pb zircon geochronology from four granitic units sampled along a southeast-northwest transect between the Garzon massif and the Serrania de las Minas (central cordillera), records a middle Jurassic magmatic activity with two different spatio-temporal domains at ca. 189 ma and 180-173 ma. Reconnaissance data suggest that the four granitoids are characterized by mineralogical and geochemical characteristics akin to a continental magmatic arc setting. The new results suggest that the southern Colombian continental margin includes remnants of tectonomagmatic elements formed by the subduction of the Farallon plate under the South American continental margin. This middle Jurassic arc magmatism is part of the broader Andean scale arc province, and is significant for understanding the tectonic and paleogeographic scenario that characterized the Mesozoic tectonic evolution of the northern Andes.

  15. NOTES ON THE DUVALIUS SPECIES OF THE TAYGETOS MASSIF (PELOPONNESE, SOUTHERN GREECE, WITH DESCRIPTION OF THE MALE FEATURES OF DUVALIUS (DUVALIUS MIREI DEUVE, 2001 (COLEOPTERA, CARABIDAE

    Achille Casale

    2010-12-01

    Full Text Available Four species of genus Duvalius (sensu stricto are known so far from caves and upper hypogean zone (M.S.S. in the Taygetos massif (Peloponnese, Southern Greece: Duvalius (Duvalius taygetanus Casale, 1979, D. (D. genesti Casale & Vigna Taglianti, 1984, D. (D. diaphanus (Rottenberg, 1874, and D. (D. mirei Deuve, 2001. Two of them, D. diaphanus and D. mirei, are large sized, sibling species with reduced but still evident and pigmented eyes, syntopic at high altitude above 2000 m a.s.l.. The male features and characters of the male genitalia of D. mirei are here described for the first time, and compared with those of D. diaphanus. Furthermore, a key for identification of the four sympatric Duvalius species known so far from Taygetos Mt. is provided.

  16. Unraveling the Quaternary river incision in the Moselle valley (Rhenish Massif, Germany): new insights from cosmogenic nuclide dating (10Be/26Al) of the Main Terrace complex

    Rixhon, Gilles; Cordier, Stéphane; Harmand, Dominique; May, Simon Matthias; Kelterbaum, Daniel; Dunai, Tibor; Binnie, Steven; Brückner, Helmut

    2014-05-01

    Throughout the whole river network of the Rhenish Massif, the terrace complex of the so-called Main Terrace forms the morphological transition between a wide upper palaeovalley (plateau valley) and a deeply incised lower valley. The youngest level of this Main Terrace complex (YMT), directly located at the edge of the incised valley, represents a dominant geomorphic feature in the terrace flight; it is often used as a reference level to identify the start of the main middle Pleistocene incision episode (Demoulin & Hallot, 2009). The latter probably reflects the major tectonic pulse that affected the whole Massif and was related to an acceleration of the uplift rates (Demoulin & Hallot, 2009). The Main terraces are particularly well preserved in the lower Moselle valley and are characterized by a constant absolute elevation of their base along a 150 km-long reach. Despite that various hypotheses have been proposed to explain this horizontality (updoming, faulting...), all studies assumed an age of ca. 800 ka for the YMT, mainly based on the questionable extrapolation of palaeomagnetic data obtained in the Rhine valley. Therefore, a reliable chronological framework is still required to unravel the spatio-temporal characteristics of the Pleistocene evolution of the Moselle valley. In this study, we apply cosmogenic nuclide dating (10Be/26Al) to fluvial sediments pertaining to the Main Terrace complex or to the upper Middle Terraces. Several sites along the lower Moselle were sampled following two distinct sampling strategies: (i) depth profiles where the original terrace (palaeo-)surface is well preserved and did not experience much postdepositional burial (e.g., loess cover); and (ii) the isochron technique where the sediment thickness exceeds 3 m. Cosmogenic nuclide ages recently obtained for three rivers in the Meuse catchment in the western Rhenish Massif demonstrated that the Main Terraces were younger than expected and their abandonment was diachronic along the

  17. A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites: Chapter K in Mineral Deposit Models for Resource Assessment

    Woodruff, Laurel G.; Nicholson, Suzanne W.; Fey, David L.

    2013-01-01

    This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province, stretching from southwestern United States through eastern Canada; its extension into Norway is termed the Rogaland Anorthosite Province. This type of Fe-Ti-oxide deposit dominated by ilmenite rarely contains more than 300 million tons of ore, with between 10- to 45-percent titanium dioxide (TiO2), 32- to 45-percent iron oxide (FeO), and less than 0.2-percent vanadium (V).

  18. Lower Brioverian formations (Upper Proterozoic) of the Armorican Massif (France): geodynamic evolution of source areas revealed by sandstone petrography and geochemistry

    Dabard, Marie Pierre

    1990-11-01

    Formations with interbedded cherts constitute an important part of the Lower Brioverian succession (Upper Proterozoic age) in the Armorican Massif (northwest France). These formations are composed of shale-sandstone alternations with interbedded siliceous carbonaceous members. Petrographic and geochemical study of the detrital facies shows that these rocks are compositionally immature. The wackes are rich in lithic fragments (volcanic fragments: 3-20% modal; sedimentary and metamorphic fragments: 0-7% modal) and in feldspar (5-16%). From the geochemical point of view, they are relatively enriched in Fe 2+MgO (about 5.5%) and in alkalis with {Na 2O }/{K 2O } ratios greater than 1. The CaO contents are low (about 0.3%). Slightly negative Eu anomalies are observed ( {Eu}/{Eu ∗} = 0.8 ). Their chemical compositions are in agreement with a dominantly acidic source area with deposition in a continental active margin setting. Compared with other Upper Proterozoic deposits of the Armorican Massif, the interbedded-chert formations appear rather similar to other deposits in North Brittany which accumulated in an intra-arc or back-arc basin environment. The formations with interbedded cherts are interpreted as having been deposited during an early stage of magmatic arc activity (around 640-630 Ma ago) in an immature marginal basin. The clastic supply to these formations is derived in part from early volcanic products (acidic to intermediate) which are linked to subduction beneath the North Armorican Domain. Another component is inherited from the reworking of 2000 Ma old basement relics. The opening of the back-arc domain, with associated basaltic volcanism, would bring about a progressive displacement of the interbedded-chert depositional basin towards the continental margin.

  19. Hydrothermal alterations and O, H, C isotopic characterization of fluids and minerals in uraniferous massif of Saint Sylvestre (France). Extension to other French intragranitic uranium deposits

    Turpin, L.

    1984-05-01

    Petrographical, mineralogical, geochemical and stable isotope ( 18 O/ 16 O, D/H, 13 C/ 12 C) studies have been performed on the leucogranitic massif of St Sylvestre (Limousin, Massif Central francais), particularly on the different hydrothermal alterations. The oxygen isotope geochemistry of granites confirms the unicity of the different facies and their sialic origin (delta 18 O whole rocks = +11.0 +- 0.5 per mill), with a major contribution of detritic sediments rich in organic matter and poor in carbonate (delta 13 C magm. CO 2 = -10.6 per mill). Late lamprophyres have a deep-seated origin (delta 18 O = + 6 per mill). The pervasive chloritization of granitic biotites occurs during the convective circulation of a fluid of meteoric origin, at temperatures around 350-450 0 C. The chemical composition of chlorite which is buffered by that of biotite and the large 18 O-shift of fluid towards high delta values indicate that water-rock ratio was not very high. Chloritization takes place in high permeability zones. In regions where porosity is generally low, fluids are ''canalised'' in localised micro-fissured zones. Very high water/rock ratios lead to the dissolution of quartz, and the formation of the ''feldspathic episyenite'' alteration facies. The isotopic features of this fluid (delta 18 O approximately - 8 per mill, deltaD approximately - 50 per mill) indicate an elevated altitude. An isotopically similar fluid is responsible for the later ''micaceous episyenite'' alteration facies, found in fractured zones. Mixing of this fluid with a sedimentary fluid (delta 18 O approximately + 10 per mill, deltaD approximately - 30 per mill, delta 13 C approximately - 18 per mill) yielded the conditions necessary for the deposit of primary economic ore. Such fluids, sedimentary or metamorphic in origin, have been recognized in most hercynian intragranitic U and Sn-W deposits [fr

  20. Debris flows of the mountain massif of Hjorthfjellet and Adventtoppen, Svalbard: Implications for gullies on mountains in the Argyre basin, Mars

    Reiss, D.; Hiesinger, H.; Zanetti, M.; Hauber, E.; Johnsson, A.; Carlsson, E.; Raack, J.; Olvmo, M.; Johansson, H. A. B.; Johansson, L.; Fredriksson, S.; Schmidt, H. T.; McDaniel, S.; Heldmann, J. L.; McKay, C. P.

    2008-09-01

    will focus on the regional distribution of gullies on the Hjorthfjellet and Adventtoppen mountain massif (Fig. 1, inset and Fig. 2), and detailed local studies of individual gullies on the same mountain massif are carried out as described by [8] and [9]. The Hjorthfjellet and Adventtoppen mountain massif consists of four stratigraphic units of sandstone and shales from the Tertiary and Mesozoic [10]. Several studies concerning talus slopes and debris flows on Svalbard have been performed in the last decades [e.g., 11, 12, 13, 14]. Regional studies of [14] using airborne imagery revealed that there are differences in the frequency and activity of debris flows on Svalbard between east- and west-facing slopes. Åkerman [14] suggested that differences in the solar radiation, the depth of the active layer and the amount of precipitation cause variances in the morphology and morphometry of the debris slopes as well as variances in the frequency and age of debris flows between east- and west-facing slopes. Studies and direct observations imply that debris flows on Svalbard are triggered by high intensity rainfall [e.g., 14, 15]. Gullies on mountains in Argyre basin, Mars For a comparative study on Mars we chose the Argyre region. Several isolated mountain massifs occur in the Nereidum and Charitum Montes (Fig. 3) with similar morphologies as the studied massif in Svalbard. A first data analysis with High Resolution Stereo Camera (HRSC) data revealed that gullies occur on the mountain slopes only at specific orientations. Fig. 4 shows an example of an isolated mountain, on which gullies only occur on west-facing slopes. Project Description The formation of gullies on Earth depends on several parameters, including rainfall and/or melting of snow, the presence of steep slopes, and sufficient amounts of fines/debris [e.g., 16]. As on Earth, the differences of slope angles and variabilities in bedrock and grain sizes influence the regional occurrence of gullies [17]. The main