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Application of spectral image analysis to soil micromorphology, 1. Methods of analysis
5A between total and surface-connected pore space is suggested. An improved technique to measure in situ roots is also described.
931034 Physical properties of ash flow tuff from Yucca Mountain, Nevada Nelson, P H; Anderson, L A
931030 Application of spectral image analysis to soil micromorphology, 1. Methods of analysis Protz, R; Sweeney, S J; Fox, C A
J Geophys Res V97, NB5, May 1992, P6823-6841
Geoderma V53, N3/4, June 1992, P275-287 Pit walls, polished soil surfaces, or thin sections, routinely examined to study micromorphoiogy, are surfaces which lend themselves to video imaging and automatic image analysis. Digitised images of polished sections were produced in the red, blue, and green wavelengths of visible light and in the UV wavelength. Spectral data sets were registered and the colour composite images analysed using the EASI/PACE spectral image analysis system. Features classified include skeletal grains and void space, organic materials, carbonates, depletion zones, manganese concretions and mottles. 931031 Applying X-ray CT to measure macropore diameters in undisturbed soil cores Peyton, g L; Haeffner, B A; Anderson, S H; Gantzer, C J Geoderma V53, N3/4, June 1992, P329-340
The use of X-ray CT data to quantify macropore hole perimeter, equivalent hole diameter, and hole porosities in undisturbed soil cores is described. Data analysis used an algorithm developed by the authors. Size distributions for two sets of soil samples are illustrated. 931032 Petrophysical analysis at the Cajon Pass scientific well: implications for fluid flow and seismic studies in the continental crust Vernik, L; Nur, A
J Geophys Res V97, NB4, April 1992, P5121-5134 The limited available core from the Cajon Pass borehole has been examined and physical, mineralogical, and microstructural properties evaluated. Petrophysical variations and their causes are discussed. The relatively low velocity and density and high permeability associated with altered fault zone rocks makes them detectable seismic reflectors and hydrologic conduits. Conversely, the crystalline intact matrix is essentially free of microcracks and interconnected channels. Factors affecting microcrack introduction into cores are discussed, and it is concluded that with the present state of knowledge, a unique interpretation of in situ stress from microcrack examination is not possible. 931033 Self-similar distribution and properties of macroscopic fractures at depth in crystalline rocks in the Cajon Pass scientific drill hole Barton, C A; Zoback, M D
J Geophys Res V97, NB4, April 1992, P5181-5200 The macroscopic natural fracture population revealed by the Cajon Pass borehole has been examined. Statistical distributions of fracture orientations, apertures, and spacings in the well, comparison of wellbore data with that available from cores and outcrops, and correlation of fracturing with lithology, physical properties, seismic wave velocities, porosity, resistivity, and thermal gradients are discussed. The relatively large hydraulically active fractures appear to be a subset of overall fracturation, rather than associated with the nearby San Andreas fault.
Ash flow tufts from 3 boreholes in the vicinity of the proposed Yucca Mountain Repository site have been examined in the laboratory. Density and porosity were measured on 198 samples, and electrical, seismic, and hydraulic properties were also measured on many of these. Mineralogical and physical data from other workers are used in analysis of dependence of the measured properties on lithology. 931035 Mean field calculation of effective permeability based on fractai pore space. Short communication Hansen, J P; Muller, J Trans Porous Media V8, NI, May 1992, P93-97
The attempts to predict rock permeability on the basis of the fractal characteristics of the porosity have not proved entirely successful, as pore space geometry cannot be uniquely determined by simple fractal models. A method is presented to estimate permeability using mean field (effective medium) theory. Assumptions are that pore space is characterised by a uniform fractal scaling and that internal conductances depend only on characteristic pore size. A simple probability density for the internal conductances is derived. This is used in calculating effective permeability and gives estimates consistent with experimental data. 931036 Joint geometry modelling in 3D and validations - a case study Kulatilake, P H S W; Wathugala, D N
Proc Conference on Fractured and Jointed Rock Masses, Lake Tahoe, 3-5 June 1992 P18-25. Publ California: Lawrence Berkeley Laboratory, 1992 The results of applying 8 joint geometry modelling schemes to a set of joint data from the Stripa mine granite are compared. Different estimates of both joint size and joint intensity parameters are returned. This demonstrates the need to apply a range of schemes and to verify against field data for each particular case. Further validation in other regions of the Stripa mine is recommended here. The scheme selected, developed for granite, is almost certainly invalid in sedimentary or metamorphic rocks. 931037 Development of network properties in natural fracture patterns Odling, N Proc Conference on Fractured and Jointed Rock Masses,
Lake Tahoe, 3-5 June 1992 P42-48. Publ California: Lawrence Berkeley Laboratory, 1992 Fracture connectivity is a function of fracture length and orientation distributions, density, and system geometry. A technique to identify network properties of fracture patterns using analysis of their cluster structures is presented and applied to 5 natural, 2 dimensional fracture patterns in Devonian sandstones. The development of cluster patterns as fracture density changes is described. The proportion of the largest cluster forming continuous pathways through the network provides a measure of connectivity. Although only a few long traces may be necessary to obtain connectivity, the probability that the fracture network is connected across any region increases with increasing fracture density.
© 1993 Pergamon Press Ltd. Reproduction not permitted
931034 Physical properties of ash flow tuff from Yucca Mountain, Nevada Nelson, P H; Anderson, L A
931030 Application of spectral image analysis to soil micromorphology, 1. Methods of analysis Protz, R; Sweeney, S J; Fox, C A
J Geophys Res V97, NB5, May 1992, P6823-6841
Geoderma V53, N3/4, June 1992, P275-287 Pit walls, polished soil surfaces, or thin sections, routinely examined to study micromorphoiogy, are surfaces which lend themselves to video imaging and automatic image analysis. Digitised images of polished sections were produced in the red, blue, and green wavelengths of visible light and in the UV wavelength. Spectral data sets were registered and the colour composite images analysed using the EASI/PACE spectral image analysis system. Features classified include skeletal grains and void space, organic materials, carbonates, depletion zones, manganese concretions and mottles. 931031 Applying X-ray CT to measure macropore diameters in undisturbed soil cores Peyton, g L; Haeffner, B A; Anderson, S H; Gantzer, C J Geoderma V53, N3/4, June 1992, P329-340
The use of X-ray CT data to quantify macropore hole perimeter, equivalent hole diameter, and hole porosities in undisturbed soil cores is described. Data analysis used an algorithm developed by the authors. Size distributions for two sets of soil samples are illustrated. 931032 Petrophysical analysis at the Cajon Pass scientific well: implications for fluid flow and seismic studies in the continental crust Vernik, L; Nur, A
J Geophys Res V97, NB4, April 1992, P5121-5134 The limited available core from the Cajon Pass borehole has been examined and physical, mineralogical, and microstructural properties evaluated. Petrophysical variations and their causes are discussed. The relatively low velocity and density and high permeability associated with altered fault zone rocks makes them detectable seismic reflectors and hydrologic conduits. Conversely, the crystalline intact matrix is essentially free of microcracks and interconnected channels. Factors affecting microcrack introduction into cores are discussed, and it is concluded that with the present state of knowledge, a unique interpretation of in situ stress from microcrack examination is not possible. 931033 Self-similar distribution and properties of macroscopic fractures at depth in crystalline rocks in the Cajon Pass scientific drill hole Barton, C A; Zoback, M D
J Geophys Res V97, NB4, April 1992, P5181-5200 The macroscopic natural fracture population revealed by the Cajon Pass borehole has been examined. Statistical distributions of fracture orientations, apertures, and spacings in the well, comparison of wellbore data with that available from cores and outcrops, and correlation of fracturing with lithology, physical properties, seismic wave velocities, porosity, resistivity, and thermal gradients are discussed. The relatively large hydraulically active fractures appear to be a subset of overall fracturation, rather than associated with the nearby San Andreas fault.
Ash flow tufts from 3 boreholes in the vicinity of the proposed Yucca Mountain Repository site have been examined in the laboratory. Density and porosity were measured on 198 samples, and electrical, seismic, and hydraulic properties were also measured on many of these. Mineralogical and physical data from other workers are used in analysis of dependence of the measured properties on lithology. 931035 Mean field calculation of effective permeability based on fractai pore space. Short communication Hansen, J P; Muller, J Trans Porous Media V8, NI, May 1992, P93-97
The attempts to predict rock permeability on the basis of the fractal characteristics of the porosity have not proved entirely successful, as pore space geometry cannot be uniquely determined by simple fractal models. A method is presented to estimate permeability using mean field (effective medium) theory. Assumptions are that pore space is characterised by a uniform fractal scaling and that internal conductances depend only on characteristic pore size. A simple probability density for the internal conductances is derived. This is used in calculating effective permeability and gives estimates consistent with experimental data. 931036 Joint geometry modelling in 3D and validations - a case study Kulatilake, P H S W; Wathugala, D N
Proc Conference on Fractured and Jointed Rock Masses, Lake Tahoe, 3-5 June 1992 P18-25. Publ California: Lawrence Berkeley Laboratory, 1992 The results of applying 8 joint geometry modelling schemes to a set of joint data from the Stripa mine granite are compared. Different estimates of both joint size and joint intensity parameters are returned. This demonstrates the need to apply a range of schemes and to verify against field data for each particular case. Further validation in other regions of the Stripa mine is recommended here. The scheme selected, developed for granite, is almost certainly invalid in sedimentary or metamorphic rocks. 931037 Development of network properties in natural fracture patterns Odling, N Proc Conference on Fractured and Jointed Rock Masses,
Lake Tahoe, 3-5 June 1992 P42-48. Publ California: Lawrence Berkeley Laboratory, 1992 Fracture connectivity is a function of fracture length and orientation distributions, density, and system geometry. A technique to identify network properties of fracture patterns using analysis of their cluster structures is presented and applied to 5 natural, 2 dimensional fracture patterns in Devonian sandstones. The development of cluster patterns as fracture density changes is described. The proportion of the largest cluster forming continuous pathways through the network provides a measure of connectivity. Although only a few long traces may be necessary to obtain connectivity, the probability that the fracture network is connected across any region increases with increasing fracture density.
© 1993 Pergamon Press Ltd. Reproduction not permitted