256 research outputs found

    Kabbaldurga-type charnockitization: A local phenomenon in the granulite to amphibolite grade transition zone

    Get PDF
    In the deeply eroded Precambrian crust of South India and Sri Lanka, a series of spectacular exposures shows progressive development of coarse-grained charnockite through dehydration of amphibolite grade gneisses in different arrested stages. At Kabbaldurga, charnockitization of Archaean grey biotite-hornblende gneisses occurred about 2.5 Ga ago and evidently was induced by the influx of external carbonic fluids along a system of ductile shears and the foliation planes. The results of oxygen isotope thermometry and of geothermobarometry in adjacent areas indicate a P-T regime of 700 to 750 C and 5 to 7 kb. The decrease of water activity in the fluid infiltrated zones caused an almost complete breakdown of hornblende and biotite and the new growth of hypersthene. Detailed petrographic and geochemical studies revealed marked changes in mineralogy and chemistry from granodioritic to granitic which document the metasomatic nature of the process

    Gneiss-charnockite transformation at Kottavattam, Southern Kerala (India)

    Get PDF
    At Kottavattam, leucocratic granitic garnet-biotite gneisses (age less than 2 Ga) were partially transformed to coarse-grained charnockite along a system of conjugate fractures (N70E and N20W) and the foliation planes (N60 to 80W; dip 80 to 90 SW) about 550 m.y. ago. To examine and quantify changes in fabric, mineralogy, pore fluids and chemical composition associated with this process, large rock specimens showing gneiss-charnockite transition were studied in detail. The results of the present study corroborate the concept that charnockite formation at Kottavattam is an internally-generated phenomenon and was not triggered by the influx of carbonic fluids from a deep-seated source. It is suggested that charnockitization was caused by the following mechanism: (1) near-isothermal decompression during uplift of the gneiss complex led to an increase of the pore fluid pressure (P sub fluid greater than P sub lith) which - in a regime of anisotropic stress - triggered or at least promoted the development of conjugate fractures; (2) the simultaneous release of pore fluids from bursting fluid inclusions and their escape into the developing fracture system resulted in a drop of fluid pressure; and (3) the internal generation and buffering of the fluids and their, probably, limited migration in an entirely granitic rock system explains the absence of any significant metasomatic mass transfer

    Prognos (R) in the diagnosis of amalgam hypersensitivity - A diagnostic case-control study

    Get PDF
    Objective: We aimed to investigate whether the Prognos (R) device might be a useful tool in the diagnosis of disorders suspected to be due to dental amalgam fillings. Participants and Methods: A diagnostic case-control study was performed in 27 patients who complained about health problems attributed to amalgam ( cases), 27 healthy volunteers with amalgam fillings ( controls I), and 27 healthy amalgam-free volunteers ( controls II). All participants were tested before and after application of 300 mg DMPS (2.3-dimercapto-1-propanesulfonic acid) with Prognos, a diagnostic device for the energetic measurement of Traditional Chinese Medicine meridians. In addition, mercury was measured in blood, urine, and saliva, and a lymphocyte transformation test (LTT) was performed. Results: Diagnoses derived from the first and second Prognos testing did not agree above chance (Cohen's Kappa = -0.11, 95% confidence interval -0.33 to 0.10; p = 0.30). Agreement for secondary outcome measures was poor, too. Prognos measurements did not differ between cases and controls. Correlations with measurements in urine, blood and saliva were low. Conclusion: In this study Prognos could not be shown to be a useful tool in the diagnosis of disorders suspected to be due to dental amalgam fillings

    Complexity Theory for a New Managerial Paradigm: A Research Framework

    Get PDF
    In this work, we supply a theoretical framework of how organizations can embed complexity management and sustainable development into their policies and actions. The proposed framework may lead to a new management paradigm, attempting to link the main concepts of complexity theory, change management, knowledge management, sustainable development, and cybernetics. We highlight how the processes of organizational change have occurred as a result of the move to adapt to the changes in the various global and international business environments and how this transformation has led to the shift toward the present innovation economy. We also point how organizational change needs to deal with sustainability, so that the change may be consistent with present needs, without compromising the future

    Bolivian Marmosops

    Get PDF
    40 p. : ill., maps ; 26 cm.Electronic version available in portable document format (PDF).Includes bibliographical references (p. 34-37).In order to facilitate much-needed revisionary research on Marmosops, we summarize the currently accepted species-level taxonomy, provide full bibliographic citations for original descriptions of all 36 included nominal taxa, map their type localities, and list their type material (if known). We rediagnose the genus Marmosops, compare it with three other didelphid genera to which misidentified specimens of Marmosops have often been referred, and review the phylogenetic evidence that Marmosops is monophyletic. After describing a new species from the eastern-slope montane forests of Bolivia, we review the taxonomy of other Bolivian congeners based on morphological characters and published cytochrome-b gene sequences. Among our taxonomic results, we synonymize albiventris Tate (1931), dorothea Thomas (1911), and yungasensis Tate (1931) with M. noctivagus (Tschudi, 1845). By contrast, M. ocellatus (Tate, 1931), currently considered a synonym of dorothea, appears to be a valid species. Whereas published range maps of Bolivian species of Marmosops are demonstrably based on misidentified material and show little correspondence with known environmental factors, locality records based on specimens examined for this report make much more ecogeographic sense
    • …
    corecore