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Pore pressure and fluid flow during the deformational history of geologic structures are directly influenced by tectonic deformation events. In this contribution, 2D plane strain finite element analysis is used to study the influence of different permeability distributions on the pore pressure field and associated flow regimes during the evolution of visco‐elastic single‐layer buckle folds. The buckling‐induced fluid flow regimes indicate that flow directions and, to a lesser degree, their magnitudes vary significantly throughout the deformation and as a function of the stratigraphic permeability distribution. The modelling results suggest that the volumetric strain and the permeability distribution significantly affect the resulting flow regime at different stages of fold development. For homogeneous permeability models (k > 10?21 m2), low strain results in a mostly pervasive fluid flow regime and is in agreement with previous studies. For larger strain conditions, fluid focusing occurs in the buckling layer towards the top of the fold hinge. For low permeabilities (<10?21 m2), local focused flow regimes inside the buckling layer emerge throughout the deformation history. For models featuring a low‐permeability layer embedded in a high‐permeability matrix or sandwiched between high‐permeability layers, focused flow regimes inside the folded layer result throughout the deformation history, but with significant differences in the flow vectors of the surrounding layers. Fluid flow vectors induced by the fold can result in different, even reversed, directions depending on the amount of strain. In summary, fluid flow regimes during single‐layer buckling can change from pervasive to focused and fluid flow vectors can be opposite at different strain levels, that is the flow vectors change significantly through time. Thus, a complete understanding of fluid flow regimes associated with single‐layer buckle folds requires consideration of the complete deformation history of the fold. 相似文献
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Merve Çalışkan 《Conservation and Management of Archaeological Sites》2017,19(4):288-318
Ancient places of performance are often considered for reuse as a means of promoting archaeological sites. Therefore, local authorities and decision makers have a difficult task of balancing the conservation and management of the sites with the carrying capacity. In this paper, the bouleuterion, a ‘rediscovered’ structure, at the Teos archaeological site, in Turkey is evaluated and presented as a preliminary case study with the hopes that these issues will be taken into consideration by the managing body in the creation of a management plan for the site. The evaluation is made by assessing socio-economic and intangible heritage significance, policies guiding changes at the site, a qualitative survey at the site and by defining the structure’s carrying capacity. The site’s strengths, weaknesses, opportunities, and threats are used to create criteria and make proposals for its reuse. The study concludes that the bouleuterion cannot be reused as a venue in its present condition and makes recommendations for future use. 相似文献
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Marko Rukavina Mladen Obad Šćitaroci Tatjana Lolić 《Conservation and Management of Archaeological Sites》2013,15(5-6):340-363
ABSTRACTThis article explores factors concerning the urban integration of archaeological heritage in towns and settlements. Archaeological heritage refers to visible, immovable archaeological remains (such as the remains of buildings or structures), sites, and areas (larger complexes). As part of the multidisciplinary process of archaeological heritage management, based on understanding the significance of a site and the goal of enhancing and preserving archaeological heritage in situ, urban integration and its determining factors have not been the subject of systematic research. The present study is derived from the application of deductive research based on theoretical assumptions validated by a qualitative survey. Research has identified 17 factors as the basis for the urban integration of archaeological heritage in towns and settlements. These factors represent a theoretical and practical contribution not only to urban planning but also to archaeological heritage management. 相似文献
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Thermal–hydrological–mechanical coupling processes suggest that fault permeability should undergo dynamic change as a result of seismic slip. In igneous rocks, a fault's slip surface may have much higher permeability than the surrounding rock matrix and therefore operate as a conduit for fluids. We conducted laboratory experiments to investigate changes in fracture permeability (or transmissivity) of a fault in granite due to shear slip and cyclic heating and cooling. Our experiments showed that high initial fracture transmissivity (>10?18 m3) was associated with a high friction coefficient and that transmissivity decreased during slip. We propose that this reduction in transmissivity reflects the presence of gouge in fracture voids, increasing the area of contact in the fault plane and reducing the hydraulic aperture. In contrast, when initial fracture transmissivity was low (<10?18 m3), we observed that friction was lower and transmissivity increased during slip. The high transmissivity and high friction may be explained by large areas of bare rock being in contact on the slip surface. Slip velocity had little influence on the evolution of permeability, probably because gouge produced at different slip velocities had similar grain size distributions, or because gouge leaked from the slip surface. Transmissivity decreased with increasing temperature in heating tests, probably due to thermal expansion increasing normal stress on the fracture. Frictional heating did not influence transmissivity during the shearing tests. 相似文献
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高光谱仪作为一种无损检测方法,其\"图谱合一\"的特性使很多在正射影像上无法区分的类别变得可分。因此,本研究以清代张士保《论道图》为例,利用高光谱相机采集影像,经过最小噪声分离变换、主成分变换、掩膜等处理对画作的墨线进行了提取,实现了图像增强效果,并且发现了两处人眼无法识别的隐含信息。图像增强及隐含信息的发现对书画鉴定、修复提供重要依据,并开拓了新视野。 相似文献
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Thermal springs commonly occur along faults because of the enhanced vertical permeability afforded by fracture zones. Field and laboratory studies of fault zone materials document substantial heterogeneities in fracture permeabilities. Modeling and field studies of springs suggest that spatial variations in permeability strongly influence spring locations, discharge rates and temperatures. The impact of heterogeneous permeability on spring geochemistry, however, is poorly documented. We present stable isotope and water chemistry data from a series of closely spaced thermal springs associated with the Hayward Fault, California. We suggest that substantial spatial variations observed in δ18O and chloride values reflect subsurface fluid transport through a poorly connected fracture network in which mixing of subsurface waters remains limited. Our measurements provide insight into the effect of fracture zone heterogeneities on spring geochemistry, offer an additional tool to intuit the nature of tectonically induced changes in fault zone plumbing, and highlight the need to consider local variations when characterizing fracture zone fluid geochemistry from spring systems with multiple discharge sites. 相似文献
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BRUCE MITCHELL 《The Canadian geographer》2008,52(2):131-145
The rewards and challenges related to a research program that involves interactions between basic and applied research are shared. Specific experience is examined regarding integrated water resource management, capacity enhancement in developing countries and writing textbooks. Key lessons include the manner in which applied research and practice inform and enhance basic research, the role of theoretical and conceptual frameworks in guiding applied research, the need to understand the distinction between multidisciplinary and interdisciplinary models and the importance of facilitating evolution from visions, strategies and plans to action. 相似文献
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The Lost City hydrothermal field (LCHF) is hosted in serpentinite at the crest of the Atlantis Massif, an oceanic core complex close to the mid‐Atlantic Ridge. It is remarkable for its longevity and for venting low‐temperature (40–91°C) alkaline fluids rich in hydrogen and methane. IODP Hole U1309D, 5 km north of the LCHF, penetrated 1415 m of gabbroic rocks and contains a near‐conductive thermal gradient close to 100°C km?1. This is remarkable so close to an active hydrothermal field. We present hydrothermal modelling using a topographic profile through the vent field and IODP site U1309. Long‐lived circulation with vent temperatures similar to the LCHF can be sustained at moderate permeabilities of 10?14 to 10?15 m2 with a basal heatflow of 0.22 W m?2. Seafloor topography is an important control, with vents tending to form and remain in higher topography. Models with a uniform permeability throughout the Massif cannot simultaneously maintain circulation at the LCHF and the near‐conductive gradient in the borehole, where permeabilities <10?16 m2 are required. A steeply dipping permeability discontinuity between the LCHF and the drill hole is required to stabilize venting at the summit of the massif by creating a lateral conductive boundary layer. The discontinuity needs to be close to the vent site, supporting previous inferences that high permeability is most likely produced by faulting related to the transform fault. Rapid increases in modelled fluid temperatures with depth beneath the vent agree with previous estimates of reaction temperature based on geochemical modelling. 相似文献
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Established techniques that have been successfully used to characterize pore systems in conventional reservoir rocks lack the resolution and scalability required to adequately characterize the nano‐ to micrometer scale pore systems found in shale and cannot be applied on stressed samples. We have therefore investigated the utility of Klinkenberg gas slippage measurements for shale pore structure characterization. In contrast to other approaches, slippage measurements characterize the effective porosity of core samples and can be applied at stress conditions experienced in the reservoir during production. Slippage measurements on horizontally and vertically oriented samples from the Eagle Ford Shale Formation, Texas, USA, at a range of stress states revealed two orders of magnitude in slippage variation over five orders of magnitude permeability range. Slippage measurements are negatively correlated with permeability and follow similar trends to those found in other studies on higher permeability rocks. The samples had varying degrees of slippage anisotropy, which allowed interpretation of the relative contribution of tortuosity and pore size to permeability anisotropy. Slippage and therefore average effective pore size was found to vary up to one order of magnitude at a given permeability, warranting investigation of the significance this might have on flow properties and ultimately hydrocarbon production from shale. 相似文献