Düsseldorf, Universiẗat, Diss., 2001. / Enth.: Bd. 1. Bd. 2. Anhang.

The Altiplano-Puna Volcanic Complex in the Central Andes is one of the youngest large silicic volcanic fields (LSVFs) in the world, erupting over 13,000 km³ of material during multiple supereruptions from 11 to 1 Ma. Understanding the timescales over which magma is stored in the crust prior to eruption is crucial to understanding the development of LSVFs such as the APVC. The residence time of a magma is defined as the time between magma formation and its eruption. While the eruption age of a volcanic system is generally well constrained through ⁴⁰Ar/³⁹Ar dating of sanidine and biotite crystals, determining the time of magma formation offers a bigger challenge. U-Pb dating of zircon—an early crystallizing, ubiquitous phase in silicic systems—is a commonly used method for determining the timing of magma formation. U-Pb zircon ages were collected for 16 ignimbrites representing the temporal and spatial distribution of the APVC. Zircon crystallization histories show significant overlap between eruptive centers of similar age separated by as much as 200 km. Ignimbrites erupted from the same multicyclic caldera show little relationship. This suggests that ignimbrites may share a deeper, regional source. Timescales of zircon crystallization for individual ignimbrites range from ~400 ka to more than 1 Ma, with little correlation with age or erupted volume. Ignimbrites with longer crystallization timescales frequently exhibit a stepped age distribution and highly variable U contents, suggesting that these ignimbrites likely formed in a very crystalline, low melt fraction environment while ignimbrites with short crystallization times and constrained U concentrations crystallized in high melt fraction systems. Zircon crystallization histories record periods of continuous zircon crystallization in the APVC that extend over 1.5-2 Ma pulses and correlate well with eruptive pulses recognized by previous studies. Overall, zircon crystallization histories of the magmas feeding ignimbrite eruptions in the APVC record long timescales of magmatic activity from a shared regional source, likely the Altiplano-Puna Magma Body currently detectable underlying the APVC. / Graduation date: 2012

Zugl.: Halle (Saale), Univ., Diss., 2005

Berlin, Freie Universiẗat, Diss., 2003. / Dateiformat: zip, Dateien im Pdf-Format.

Berlin, Freie Universiẗat, Diss., 2004. / Dateiformat: zip, Dateien im PDF-Format.

El Servicio Nacional de Sanidad Agropecuaria e Inocuidad Alimentaría y el Programa Nacional de Erradicación de la Fiebre Aftosa (SENASAG-PRONEFA Distrital La Paz),en Junio del 2003 pone en marcha el proyecto “Estrategia Regional para la Declaratoria de Zona Libre de Fiebre Aftosa al Altiplano del Departamento de La Paz” a través de la Oficina Internacional de Epizootias (OIE), que es la institución que certifica dicho estatus sanitario a nivel internacional, habilitando de esta manera a; zonas, regiones y países que obtengan tal certificación a ser participes del mercado externo. Uno de los requisitos que solicita la OIE para este tipo de proyectos, es el de estructurar un sistema de vigilancia epidemiológica actualizado en la zona, región o país que se proponga como libre de fiebre aftosa, el cual es objetivo principal del presente trabajo, en la zona norte del Altiplano Paceño. La actual zona propuesta como libre de fiebre aftosa presenta un índice de pobreza del 90-95% según (La Unidad de Políticas Económicas, 2001), y las tierras de esta área son inaptas para la agricultura, debido a su clima y ecología, pero se identifico un gran potencial para la ganadería Camélida y Ovina. Por las características sanitarias de la zona, en la misma no se presento la fiebre aftosa pero la misma es susceptible a la enfermedad por la presencia de animales que son susceptibles a la misma, siendo de esta manera otras las enfermedades prevalentes de esta zona.

Memoria para optar al título de Químico Farmacéutico / El altiplano o puna por sus características ambientales, es una región natural única en América del Sur, abarca el centro y sur del Perú, el norte de Chile, parte de Bolivia, y el noreste de Argentina. En el altiplano existen muchas especies vegetales, pero hay algunas que despiertan mayor interés en los pobladores locales, ya que son utilizados como combustible o forman parte de su dieta diaria y usos medicinales. En este trabajo se investigaron siete plantas de cuatro géneros diferentes: Caiophora, Senecio, Parastrephia y Myrica, con el objetivo de dar un respaldo científico a las propiedades que la medicina folclórica les atribuye, así como dar a conocer estas especies desde un punto de vista fitoquímico y farmacológico, para lo cual se realizó un screening fitoquímico, antimicrobiano y antioxidante de estas plantas pre-andinas y del altiplano chileno. Para ello se debió obtener los diferentes extractos, infusos y aceite esencial de las distintas plantas a estudiar, para su análisis fitoquímico y evaluación farmacológica, y determinar la actividad antimicrobiana por medio del bioensayo de bioautografía, siembra en superficie de agar y concentración mínima inhibitoria La evaluación de la actividad antioxidante de los extractos se realizó frente a la enzima xantina oxidasa (XO). La investigación del material vegetal de las siete especies, está constituido por la parte aérea de cada especie en estudio; comenzó con la remoción del exudado resinoso (ERES) usando como disolvente diclorometano, para continuar con el secado y la molienda de la planta sin resina. Posteriormente el material se sometió a extracción usando disolventes de polaridad creciente, comenzando con hexano (EHEX), seguido de diclorometano (EDCM), acetato de etilo (EACET) y metanol (EMEOH), para posterior evaluación microbiológica de cada uno de ellos. Las dos especies del género Caiophora (C. sepiaria y C. rahmeri) presentaron actividad contra bacterias Gram (+). Con la bacteria Gram (-) E. coli, mostraron actividad los aceites esenciales de ambas especies. Además C. rahmeri presentó también efecto con los extractos apolares y polares frente a E. coli. El género Senecio representado por Senecio nutans, Senecio adenophyllus y Senecio trifurcifolius mostró actividad antimicrobiana de amplio espectro, tanto para microorganismos Gram (+) como Gram (-). Al comparar los extractos obtenidos de estas especies, Senecio nutans y Senecio adenophyllus tienen mayor actividad antimicrobiana que el Senecio trifurcifolius. La actividad antimicrobiana en S. nutans la podemos atribuir tanto al exudado resinoso, a los extractos y especialmente al aceite esencial de esta especie. El Senecio nutans fue el único en presentar actividad contra la levadura Saccharomyces cerevisiae, con una concentración mínima inhibitoria (CMI) de 180 μg/mL. Los extractos apolares como el exudado resinoso y el aceite esencial de Parastrephia. lúcida presentaron actividad antimicrobiana, siendo superior la del exudado resinoso mostrando un efecto de amplio espectro, tanto con microorganismos Gram (+): M. flavus, B. subtilis y con Gram (-): E. coli y K. pneumoniae teniendo una CMI para el exudado resinoso de 160, 70, 100, 170 μg/mL respectivamente; y para el aceite esencial 160, 160, 160 μg/mL con los mismos microorganismos. Myrica pavonis, presentó actividad antimicrobiana en el exudado resinoso y aceite esencial, mostrando una actividad de amplio espectro, tanto con microorganismos Gram (+): B. subtilis; como Gram (-): E. coli. El exudado resinoso presenta una CMI de 170 y 90 μg/mL para B. subtilis y E. coli respectivamente. Referente a la actividad antioxidante se puede concluir que de las plantas que fueron estudiadas sólo el S. trifurcifolius presentó capacidad antioxidante teniendo un efecto inhibitorio 15,7%, determinada por el método de xantina oxidasa (XO). En las siete plantas en estudio se observó que el aceite esencial obtenido de cada una de ellas fue el que presentó mejor actividad antimicrobiana, confirmando su uso popular y contribuyendo al conocimiento científico de estas especies pre-andinas y de la zona del altiplano, desde el punto de vista químico y farmacológico / The high plateau or “puna” is a unique environmental region of South America due to its particular features. This area includes central and southern of Peru, northern of Chile, part of Bolivia, and northeast of Argentina. There are many indigenous plant species in this high plateau, some of these are of great interest because the inhabitants of the region used as fuels, meal or medicine. The flora of this region is composed of plants of tiny leaves which keeps the from loosing humidity. In this thesis seven plants were researched, belonging to four different groups: Caiophora, Senecio, Parastrephia and Myrica, with the aim of giving a scientific endorsement to the properties that the medicine folkloric attributes to them, as well as presenting these species from a fitoquímico and pharmacological point of view, for which a fitoquímico screening was realised, antimicrobial and antioxidant these pre- Andean plants and the Chilean plateau. For it one was due to obtain the different extracts, infused and essential oil of the different plants to study, for its fitoquímico analysis and pharmacological evaluation, and to determine the antimicrobial activity by means of the bioautography bio-test, seeds in surface of agar and inhibiting harassing concentration The evaluation of the activity antioxidant of the extracts was realised in front of the enzyme xanthin oxidasa (XO). The plant material of the seven species investigated is the aerial part. Te first step was the removal of the resinous exudates (ERES) using solvent dichloromethane, followed by milling and drying. Subsequently, the material was submitted to extraction using solvent of increasing polarities, beginning with hexane (EHEX), followed by dichloromethane (EDCM), ethyl acetate (EACET) and methanol (EMET). Extracts of the two species of the genus Caiophora (C. sepiaria and C. rahmeri were active against Gram (+) bacteria. Both essential oils were also active against E. coli, a Gram (-) bacteria. In addition, polar and non polar extracts of Caiophora rahmeri were active against E. coli. Genus Senecio represented by Senecio nutans, Senecio adenophyllus and Senecio trifurcifolius showed a wide spectrum of antimicrobial activity, for both Gram (+) and Gram (-) bacteria. When comparing the extracts obtained from these species, S. nutans and S. adenophyllus had the highest antibacterial activity. The antimicrobial activity of S. nutans can be attribute so to both the resinous exudates to the extracts and especially to the essential oil of this species. The Senecio nutans was the only plant species which showed activity against a the yeast Saccharomyces cerevisiae with a Minimal Inhibitory Concentration (MIC) of 180 μg/mL. The non polar extracts such as the resinous exudates and essential oils of Parastrephia lucida showed antibacterial activity, the resinous exudate being more active, and which also showed a wide spectrum effect against both Gram (+) and Gram (-) bacteria. MICs for the resinous exudates against M. flavus, B. subtilis, E. coli and K. pneumoniae were 160, 70, 100, 170 μg/mL respectively, and for the essential oil 160, 160, 160 μg/mL respectively. The resinous exudates and essential oil of Myrica pavonis showed antimicrobial activity, with a wide spectrum of activity for against both the Gram (+) B. subtilis and Gram (-) E. coli. MICs were 170 and 90 μg/mL for B. subtilis and E. coli respectively. Referring to the activity antioxidant it is possible to be concluded that of the plants that were studied only the S. trifurcifolius presented/displayed capacity antioxidant having an inhibiting effect 15.7%, determined by the xanthin method oxidasa (XO). In the seven plants studied, the highest antimicrobial activity was observed in the essential oils. This is in agreement with their popular use. This thesis contributes to the scientific knowledge of these pre-andean species from the chemical and pharmacological point of view

A study was undertaken to evaluate the general sheep marketing process in Bolivia, to determine the present economic structure of farm units belonging to Altiplano sheep producers, to analyze the economics of marketing Altiplano sheep at an earlier age, and to analyze the economics of using various local products as a supplemental sheep feed in Bolivia. In general the Bolivian sheep marketing process is inadequate and inefficient because of lack of marketing information, poor producer-buyer contact, lack of commercial sheep transportation, slaughterhouses lacking in facilities and hygienic conditions, and apparently unattractive retail methods. By selling their relatively unproductive male sheep before they are one year old and replacing them with ewes and yearling ewes, the results of the study indicate that the "criollo" and semi-improved sheep producers could increase the return to their sheep enterprise by 43 percent and 10 percent, respectively, and that they could increase the value of sheep available for sale or trade by 67 per cent and 13 percent, respectively. To help determine the economics of feeding sheep a supplemental ration in Bolivia, a sheep feeding experiment was des1gned to test three breed-types of sheep, and two roughage-to-concentrate ratios. Two hundred and thirty-five lambs were fed for 63 days. The results of the study indicate that fattening lambs commercially in Bolivia is potentially profitable.

Four multicyclic complex calderas and smaller ignimbrite shields located within the Altiplano Puna Volcanic Complex of the Central Andes (APVC) erupted 13000 km�� of magma within the last 11 Ma. One of the largest and most complex of these is the Cerro Guacha Caldera. Ar-Ar age determinations and paleomagnetic directions suggest that the Cerro Guacha Caldera was formed by two major eruptions, caldera collapse, resurgence cycles and several smaller eruptions. Two major ignimbrites (> 600 km��) are found with ������Ar-�����Ar from biotites and sanidines of 5.65 �� 0.01Ma for the 1300 km�� (magma volume) Guacha ignimbrite and 3.49 �� 0.01Ma for the 800 km�� Tara Ignimbrite. The last major eruption occurred on the western flank producing the 1.72 �� 0.02 Ma Puripica Chico Ignimbrite with a volume of approximately 10 km��. Characteristic remanent magnetization data (ChRM) for these ignimbrites show that the Guacha has reverse polarity, while the Tara is normally polarized and the magnetic fingerprints have allowed their current full extents to be identified. A conspicuous lineament of volcanic structures in the eastern part of the caldera, bordering a caldera moat, filled out welded ignimbrites and sedimentary lacustrine sequences suggest an earlier 60x40 km outer collapse associated with the Guacha explosive episode. A central graben formed on the Guacha welded ignimbrite is related to a first episode of resurgence. Evidence of a second 30 x15 km inner collapse includes offset of welded Guacha ignimbrites and alignment of lava domes associated with the Tara ignimbrite. A second resurgence episode is suggested by the presence of an uplifted central block consisting primarily of welded Tara ignimbrite. As a whole the three ignimbrites (Guacha, Tara and Puripica Chico) share the same petrological and geochemical characteristics: high-K series, compositional ranges from dacite to rhyolite, with andesitic members present as lavas (for the Guacha and Puripica Chico Ignimbrites) and as pumices (for the Tara Ignimbrite). Highest silica content is found in the Chajnantor dome. Rayleigh modeling for Ba, Rb and Sr suggests at least 60% of crystal fractionation to account for the compositional variation between the Guacha andesite and the Chajnantor dome. Dy/Hb ratio increases with time from the Guacha andesite to the Negreal andesite suggesting stabilization of garnet owing to crustal thickening. Fe-Ti exchange geothermometry for the Tara Ignimbrite yielded log fO��� values ranging from -13.06 to -13.38 and temperatures of 714�� to 801��C. Amphibole geobarometry yielded pressures ranging from 150 to 180 MPa equivalent to 5.3 and 6.4 km depth respectively for the Tara Ignimbrite; the pressures range between 133 to 242 MPa, equivalent to 5.0 to 9.2 km depth for the Guacha Ignimbrite. The zircon saturation method yielded saturation temperatures of 716�� and 705��C for the Guacha and Chajnantor dome respectively and 784��C for the Tara Ignimbrite. The zircon crystallization range for the magmas of the Cerro Guacha Caldera is 1.25 Ma for the Guacha Ignimbrite; 1.09 Ma for the Puripica Chico Ignimbrite and 0.95 Ma for the Tara Ignimbrite. Recycling of antecrystic zircons within the caldera magmas is continuos through time. / Graduation date: 2012

This research is focused on the application of both new and established seismic interferometry techniques to a single area: the Altiplano in the Andes region. This area has already been widely studied in terms of its geological evolution. Nevertheless, a single accepted theory has not yet been developed to explain why the topography of the Andes incorporates such a large area of low relief at this altitude. The Altiplano is therefore an interesting zone to study. This research introduces and analyses new concepts and methodologies, such as retrieving surface and body waves between earthquakes by using interferometry. Nevertheless, several factors, such as the quality of recordings, the separation between sources, and the velocity gradient of the medium, had to be taken into account for body and surface wave retrieval. This research also analysed the retrieval of body waves by means of seismic interferometry applied to coda wave arrivals. Results show that due to the attenuation of S waves produced by the zone of partial molten material, when using S coda waves, seismic interferometry does not achieve the objective of wave retrieval. On the other hand, P coda waves gave good results. Also, the combined methodology of interferometry by cross-correlation and convolution was shown to account for the behaviour of the retrieved waves and provided an indication of how the distribution of sources affects the Green’s functions estimates for body waves in this area. Another point covered by this research was the analysis of passive recordings in order to retrieve surface and body waves. Results indicate that surface and body waves could be retrieved. However, in order to retrieve body waves, special circumstances are required, such as lateral continuity of the Moho, a relative strong Moho impedance contrast, and simplicity of the geologic structure because these factors will contribute to a strong signal like that obtained in critical reflections making interferometry results more successful.