Thesis (M.S. - Geology)--University of Arizona. / Fold. map and transparent overlay in pocket. Includes bibliographical references (leaves 85-87).

Thesis (M.S. - Geology)--University of Arizona. / Includes bibliographical references.

Thesis (M.S.)--California State University, Los Angeles, 1981. / Title from PDF of title page. Includes bibliographical references (p. 141-148).

Radioactive waste repositories, designed in accordance with the current UK concept, would be required to provide containment for thousands of years beneath hundreds of metres of rock. The physical processes, both geological and other processes, that might lead to migration of radionuclides are slow in comparison to human timescales — it is impractical to make an experiment of the whole system and so these systems are typically investigated through the use of numerical models. Predictive models are based on combinations of: assumptions, mathematical formulations and parameter values derived from experimental observations. The Ventilation Experiment in the Opalinus Clay at Mont Terri, Switzerland, was designed to involve geological and other physical processes that would be active during the excavation and construction phases of a repository, and with consequences for the repository performance during the operational phase. The experiment consisted of a 10m long tunnel of 1:3m diameter through which air of known relative humidity was circulated in order to force drying and re-saturation through the tunnel wall. Two such cycles over four years have been observed via installed instrumentation. Several numerical models have been constructed of the ventilation experiment by different international teams under the decovalex project using different approaches for cross-validation. Through participation in this project, a 1D model using Richards’ Equation was developed that effectively reproduces the hydrodynamic, mechanical and conservative mass transport results. During the course of developing that model, many other domains, meshes, formulations and software versions were investigated. Now that the field scale Ventilation Experiment can be reproduced with numerical models, the findings (assumptions, formulations, parameter values, computational methods and software) would be transferable to other argillaceous formations to enable predictive modelling of similar scenarios and contribute to the safe disposal of nuclear waste and other problems involving similar geological processes. Work of this type fills the gap between laboratory scale experiments and regional scale modelling of geological systems. The gap is especially wide for low-permeability formations because the size and time-scale limitations effect the ability to make direct observations and measurements. Two particular problems were also addressed in this work: that of the use relative permeability functions and also the computational treatment of the physical interface between the tunnel domain and the rock domain. A sensitive component in many models of unsaturated flow through porous media and covering a wide variety of applications, including reservoir engineering, is the representation of permeability at an unsaturated point (kx) as a scaling of the saturated permeability (ksat) by introducing some function of the pressure head, or saturation as the relative permeability (krel) in the relation kx = ksatkrel. The choice of the particular function and its parameter values adds little to our understanding of the physical parameters. A solution is proposed to the second problem, of how to computationally represent, implement and manage the interface between two physical (i.e. spatial) domains. The scheme maps every part of the boundary of one domain onto the corresponding part of the boundary of the other domain, storing the state variables in shared memory and converting between physical components.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A pesquisa foi desenvolvida a sul do MunicÃpio de IrauÃuba, englobando o distrito de JuÃ, em uma Ãrea de 130kmÂ. A RegiÃo Nordeste do Brasil, especificamente no do Estado do CearÃ, à marcada, geralmente, pelo clima seco e distribuiÃÃo irregular da quadra chuvosa. A captaÃÃo de Ãgua subterrÃnea, muitas vezes, à a Ãnica alternativa para suprir a falta deste recurso quando a estiagem prolongada compromete o abastecimento. Tendo em vista minimizar os erros inerentes da locaÃÃo de um poÃo realizou-se a anÃlise em detalhe das estruturas rÃpteis que afetam os terrenos prÃcambrianos. Litologicamente à constituÃda por rochas Ãgneas e metamÃrficas pertencentes as unidades Pelito-CarbonÃtica e MigmatÃtica. As rochas destas unidades foram submetidas a retrabalhamentos durante o Evento Brasiliano, registrando estruturas dÃcteis e rÃpteis. Nestes terrenos configura-se o âdomÃnio hidrogeolÃgico do cristalinoâ, com a ocorrÃncia de Ãgua subterrÃnea condicionada por estruturas rÃpteis que podem estar interconectadas, e adquirir porosidade secundÃria capaz de facilitar a percolaÃÃo e o armazenamento de fluidos. A caracterizaÃÃo estrutural das feiÃÃes rÃpteis, em escala de detalhe, foi realizada por meio da tÃcnica do âmetro linearâ. O estudo de imagens de sensoriamento remoto consistiu na aplicaÃÃo de tÃcnicas de processamento digital. De forma complementar, utilizou-se a geofÃsica terrestre atravÃs do caminhamento eletromagnÃtico. As direÃÃes de alinhamentos estruturais obtidas pela interpretaÃÃo das imagens de satÃlite sÃo compatÃveis com os resultados da interpretaÃÃo dos dados de fraturas, estudadas nas rochas. As principais famÃlias de fraturas identificadas sÃo a N-S e E-W, secundariamente, NE-SW e NW-SE. O uso da geofÃsica terrestre revelou zonas condutivas relacionada à presenÃa de fraturas em subsuperfÃcie. Com a integraÃÃo dos dados gerados foram selecionadas duas Ãreas potencialmente importantes para exploraÃÃo hidrogeolÃgica, correspondentes as concentraÃÃes C-01, norte de Juà e C-04 nas imediaÃÃes de JuÃ. / This research was carried out in a 130 km2 area, in the Juà village, south of the IrauÃuba town. The Northeast of Brazil, specially the countryside, is marked by arid climate and irregular distribution of rain. The captation of groundwater is normally the only solution to provide water during dry weather. To minimize the natural errors that occur during the location of a well we made detailed analysis of the reptile structures that affect the Precambrian terrains. Lithologically it is constituted by igneous and metamorphic rocks belonging to the Migmatitic and Pelitic-Carbonatic Units. These rocks were reworked during the Brasilian Event, which registered both ductile and ruptile structures. In these terrains the âhydrological domain of the crystallineâ is represented, in which the groundwater is controlled by ruptile structures that may be interconnected to the point of acquiring enough secondary porosity to facilitate the percolation and the storing of fluids. The structural characterization of these ruptile features was made in a detailed scale by means of the âlinear-meterâ technique. The remote sensing images study consisted on the application of digital processing techniques, as well as terrestrial geophysics by means of electromagnetic profiles. The structural trends obtained by satellite images are compatible with the results taken from fracturing data. The main fracture sets are N-S and E-W and secondarily, NE-SW and NW-SE. Geophysical studies revealed conductive zones related to the presence of subsurface fractures. Data integration led to two potentially important areas for hydrogeological exploration, which correspond to the C-01 (north of JuÃ) and C-04 (JuÃ) concentrations.

Geothermal reservoirs have become very popular in the last decades due to their renewable energy contents. Turkey has a high geothermal energy potential / especially Western Anatolia is a promising region in terms of its highest energy. B&uuml / y&uuml / k Menderes Graben system is a tectonically active extensional region and is undergoing a N&ndash / S extension leading to form geothermal fields in the graben. In the last decade, geothermal exploration, investigations and investments have been increased rapidly through the law related to geothermal energy assigned. The aim of this study is to analyze the geothermal fields located in the graben system in order to investigate their geological, hydrogeological and geochemical features and reservoir characteristics. A data set is compiled from the accessible archives, published papers and documents and several variables have been searched at every field in the graben. The variables include the fluid temperature, the distance to sea, the depth to the reservoir, the reservoir lithology, the chemical constituents, etc. In view of these variables the fields are compared and constrasted and their common characterisrics have been noted. Interpretation of the data set reveals that the fields have some common features and characters however some fields have got notable differences.