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Basis for a flexible low-cost automated resistivity data acquisition and analysis system
264A
SITE INVESTIGATIONS:GEOPHYSICS
966184 Significance of discontinuity surveying in motorway alignment selection, southern Turkey I. Yilmazer, Engineering Geology, 40(1-2), 1995, pp 41-48. A case study from the Tarsus-Adana-Gaziantep motorway being constructed in southern Turkey displays well the role of a discontinuity survey in engineering geological and geotechnical work. The survey, which was carried out by visual inspection and practical field tests, indicated, on the basis of the consistency of the discontinuity systems in each rock exposure, that the suspected floating blocks were outcrops of in situ rock. Misinterpretation of the actual ground condition caused loss of both time and money. (from Author)
Geophysical techniques 966185 Ground geophysical study for development and exploration of E! Missikat radioactive minerals prospect, central Eastern Desert of Egypt E. M. Elkattan, H. S. Sadek, S. I. Rabie & H. I. Hassanein, Nuclear Geophysics, 9(4), 1995, pp 363-382. The importance of the area originates from previous studies, including airborne geophysics, surface geology and mining geology which indicate that the area has features of radioactive mineralization at the northeastern periphary of G. El Missikat. The present study deals with the use of ground geophysical methods (total-count radiometric and magnetic) in the exploration of radioactive mineralization and their relation to the geology and structural pattern of the area. (from Authors) 966186 Use of geophysical surveys during the planning, construction and remediation of landfills J. M. Reynolds & D. I. Taylor, in: Engineering geology of waste disposal, ed S.P. Bentley, (Geological Society of London; Engineering Geology Special Publication, 11), 1996, pp 93-98. Concurs that with current developments in data acquisition, processing, display and interpretation of geophysical data, the scope of environmental applications where multi-method geophysical surveys can be used is increasing rapidly. The range of geophysical methods currently available provides a powerful suite of investigative tools which complement direct observations. (from Authors) 966187 Formalized tracing of faults using geophysical data O. K. Tyapkin, Geophysical Journal, 14(1), 1994, pp 83-90. One of the most important methods for detailed studies is the study of fault structures whose indicators are 'fine' linear characteristics of physical fields. Using models, accuracy in determining the azimuths of the strike of linear features of spatially discretized physical fields was estimated. The possibility was studied of false tectonics of non-geological nature in the course of formalized processing of geophysical data, i.e. tectonics that can be characterized by methodology features of data acquisition and processing. (Author) 966188 Improvements in shallow high-resolution seismic reflection through PC-based systems R. D. Miller, R. D. Markiewicz, C. Mercy, Jianghai Xia & C. G. Maples, Computers & Geoseiences, 21(8), 1995, pp 957964. Increased dynamic range of recording equipment and decreased cost of processing hardware and software have made seismic reflection a cost-effective way of imaging geologic targets significant to environmental site classification. Some applications with demonstrated success include fault mapping with less than 4 m of vertical resolution at 300 m, detecting structure and stratigraphy associated with a hydrologic basin divide, and groundwater modeling of thick
sequences of alluvial, colluvial, and glacio-fluvial material. (from Authors) 966189 Anisotropic features of geometry and permeability in fractured rock masses Xing Zhang & D. J. Sanderson, Engineering Geology, 40(12), 1995, pp 65-75. A geometric anisotropy factor (,,If) of two-dimensional, natural fracture systems has been defined according to fracture spacing and orientation in a given direction. Geometric anisotropy of fracture systems has a major effect on the percolation threshold (the critical fracture density) of fracture systems below which the overall permeability is zero. A two-dimensional distinct element code (UDEC) has been used to calculate directional flow-rate of fracture systems. Simulated and natural fracture patterns, have been tested to examine the relation between geometric anisotropy and permeability anisotropy, which is demonstrated to have a power-law form. Also, the differential anisotropy factor (,4/) results in different universal exponents which govern the relation between fracture density and flow rates. (Authors) 966190 Oberflachenwellendaten zur Lokalisierung von Altlasten: ein Feldfall (Surface wave measurements for the location of waste deposits: a field study) C. Schneider & L. Dresen, Geophysical Transactions - Eotvos Lorand Geophysical Institute of Hungary, 39(4), 1994, pp 233-253. Describes the use of Rayleigh waves to detect near-surface inhomogenenus objects, like waste deposits etc. Rayleigh wave recordings have been integrated into conventional refraction seismic surveys at insignificant cost. It is shown that the Rayleigh wave technique is suitable for locating objects in layered media. A special dispersion analysis has been developed for delineating laterally heterogeneous nearsurface media. This method does not need any a-priori information about the underground. As a result, local dispersion curves are obtained, which represent the underground for any geophone position. The lateral variation of the surface wave signals is deduced from the variation of the local dispersion curves. In areas of smooth lateral variation dispersion curves can-be used within a rigorous inversion. This inversion leads to block-representations of the medium. Rayleigh wave signals can also be recompressed to improve resolution. (from English summary) 966191 Dolt reteges foldtani szerkezetek geoelektromos kututasi lehetosegenek vizsgalata anafitikus eloremodellezessel (Geological investigation of dipping beds with analytical forward modelling) A. Gyulai, Magyar Geofizika, 36(1), 1995, pp 40-67. The paper reviews potential field equations over a dipping bed. It presents apparent resistivity equations for different geoelectrical configurations. Apparent resistivity sections are computed perpendicularly to the strike of structures conraining at least two layers. Parameter sensitivities are defined for dipping beds and geoelectric configurations are investigated on the basis of parameter sensitivities to select the optimum geoelectrical array for exploration. (from English summary) 966192 Basis for a flexible low-cost automated resistivity data acquisition and analysis system M. A. Meju & M. Montague, Computers & Geosciences, 21(8), 1995, pp 993-999. An efficient and versatile automatic resistivity data acquisition and analysis system has been developed for use with any 4-eleetrode output resistivity meter. The acquisition hardware comprises a low-cost Digital Switching Unit which can be interfaced to a portable field microcomputer and a resistivity
SITE INVESTIGATIONS:DATA meter for automatic ground resistivity measurements. Data analysis can be effected in real-time using a simple effective direct inversion scheme that converts each apparent resistivity-electrode spacing data pair into a corresponding effective resistivity-depth information at a rate that is faster than that of acquisition leading to unhindered productivity. A practical evaluation of the infield data-analysis scheme is given and suggestions are offered for extending the basic system for tmnote-site monitoring applications. (from
Authors) 966193 Application of a geomembrane leak location survey at a UK waste disposal facility N. G. Mosley & F. Crozier, in: Engineering geology of waste disposal, ed S.P. Bentley, (Geological Society of London; Engineering Geology Special Publication, 11), 1996, pp 9-14. The technology exploits the electrical insulating properties of geomembranes. A voltage placed across the geomembrane is surveyed to identify anomalies where electrical current is flowing through leaks in the liner. In its first UK application both 'pin hole' leaks and larger cuts in the geomembrane were located and repaired prior to commissioning the waste disposal facility. (from Authors) 966194 Geomagnetism applications W. H. Campbell, US Geological Survey Circular, 1109, 1995, 31 pp. The societal uses of knowledge acquired from geomagnetism studies include research on space environment and satellite damage, pipeline management, electric power grid failure, communication interference, global position determination, mineral resource detection, Earth formation and structure, navigation, weather, and magnetoreception in organisms. (from Author) 966195 Temperature measuring technique using infra-red radiation (in Chinese) Cheng Wenkai & Liu Yongping, Journal - China Coal Society, 20(6), 1995, pp 578-582. Highlights of this research are as follows: principles of temperature measuring techniques using infra-red radiation for mine use, selection of infra-red probes, determination of working wave length, design of a optical system, processing of signals and scope of application in coal mines. (English summary)
Borehole and core logging 966196 Diagraphies, atome et geologie 0Veil logging, atom and geology) O. Serra, Memoires - Societe Geologique de France, 162, 1993(1994), pp 99-104. Well logging techniques exploit interactions of gamma photons and neutrons with atoms. They provide data which allow a much better geological study of the surface. The paper describes various techniques and their applications. (from English summary)
Processing and interpretation of data 966197 CLAIM: a new personal computer-assisted simulation model for teaching mineral exploration techniques C. Bauchau, M. Jaboyedoff & M. Vannier, Geological Association of Canada Special Paper, 40, 1993(1995), pp 685691. RMMS 336
J
265A
A new model, CLAIM, written in C language, works on a personal computer using MS-DOS. This new teaching method is fast, allows an instant comparison of students' results with the model, and has numerous graphic options. CLAIM simulates a sedimentary copper-bearing district covering an area of 400 km 2. The objective is for students to use geochemical and drilling data and topographic and geological maps to devise an optimum exploration strategy. (from Authors)
966198 A geochemical data management system for radioactive waste repository feasibility investigations C. P. Nathanail, in: Engineering geology of waste disposal, ed S.P. Bentley, (Geological Society of London; Engineering Geology Special Publication, 11), 1996, pp 245-248. The aim of this paper is to describe a data management system for the entry, validation and reporting of geochemical testing using dBase IV version 1.5 running under MS-DOS 5.0 on an IBM-compatible 486DX personal computer. Data entry is in four phases for sample register details, tracer sample analyses, hydrochemical sample inventory details and hydrochemicai sample analyses. Each record is committed on entry and then validated by a senior chemist. A six-stage validation scale was developed to track the progress of the analysis for individual determinands. Results are reported in full for each sample and as a series of summary sheets for rapid assessment. The summaries display the QA status of each analysis from 'not required' through 'pending' to 'fully documented procedures'. Output is to a laser printer and a series of Lotus 1-2-3 spreadsheet files for further analysis and interpretation. Reporting is both interim on a daily and fortnightly basis during testing and final upon completion of testing. (from Author) 966199 The use of text databases in the management of exploration data S. C. R. Mallender, in: Geological data management, ed J.R.A. Giles, (Geological Society, London; Special Publication, 97), 1995, pp 73-79. The management of exploration data concerns all the things that happen to a piece of exploration data during its life, and the management of the physical data is controlled by the information used to describe it. Descriptive information about each data item and each dataset is recorded and rerecorded on many transmittals as the physical data move from recording contractor, to processing contractor, to storage contractor. The main problem concerns the storage, retrieval and transmission of this descriptive information; the information is rarely 'processed' as such. Text databases are ideal in these circumstances: they can hold completely unstructured information, and allow users to find records using any data that appear anywhere in the content of the record. Accompanying software is used to provide a user interface to the text database, and this enables sophisticated systems which are very user-friendly to be developed easily. (from Author) 966200 Finite-difference modeling of faults and fractures R. T. Coates & M. Schoenberg, Geophysics, 60(5), 1995, pp 1514-1526. For the purposes of seismic propagation, a slip fault may be regarded as a surface across which the displacement caused by a seismic wave is discontinuous while the stress traction remains continuous. The simplest assumption is that this slip and the stress traction are linearly related. Such a linear slip interface condition is easily modeled when the fault is parallel to the finite-difference grid, but is more difficult to do for arbitrary nonplanar fault surfaces. To handle such situations equivalent medium theory is introduced to model material behavior in the cells of the finite-difference grid intersected by the fault. Virtually identical results were obtained from modeling the fault by: 1) an explicit slip interface condition (fault parallel to the grid) and 2) using the equivalent medium
SITE INVESTIGATIONS:GEOPHYSICS
966184 Significance of discontinuity surveying in motorway alignment selection, southern Turkey I. Yilmazer, Engineering Geology, 40(1-2), 1995, pp 41-48. A case study from the Tarsus-Adana-Gaziantep motorway being constructed in southern Turkey displays well the role of a discontinuity survey in engineering geological and geotechnical work. The survey, which was carried out by visual inspection and practical field tests, indicated, on the basis of the consistency of the discontinuity systems in each rock exposure, that the suspected floating blocks were outcrops of in situ rock. Misinterpretation of the actual ground condition caused loss of both time and money. (from Author)
Geophysical techniques 966185 Ground geophysical study for development and exploration of E! Missikat radioactive minerals prospect, central Eastern Desert of Egypt E. M. Elkattan, H. S. Sadek, S. I. Rabie & H. I. Hassanein, Nuclear Geophysics, 9(4), 1995, pp 363-382. The importance of the area originates from previous studies, including airborne geophysics, surface geology and mining geology which indicate that the area has features of radioactive mineralization at the northeastern periphary of G. El Missikat. The present study deals with the use of ground geophysical methods (total-count radiometric and magnetic) in the exploration of radioactive mineralization and their relation to the geology and structural pattern of the area. (from Authors) 966186 Use of geophysical surveys during the planning, construction and remediation of landfills J. M. Reynolds & D. I. Taylor, in: Engineering geology of waste disposal, ed S.P. Bentley, (Geological Society of London; Engineering Geology Special Publication, 11), 1996, pp 93-98. Concurs that with current developments in data acquisition, processing, display and interpretation of geophysical data, the scope of environmental applications where multi-method geophysical surveys can be used is increasing rapidly. The range of geophysical methods currently available provides a powerful suite of investigative tools which complement direct observations. (from Authors) 966187 Formalized tracing of faults using geophysical data O. K. Tyapkin, Geophysical Journal, 14(1), 1994, pp 83-90. One of the most important methods for detailed studies is the study of fault structures whose indicators are 'fine' linear characteristics of physical fields. Using models, accuracy in determining the azimuths of the strike of linear features of spatially discretized physical fields was estimated. The possibility was studied of false tectonics of non-geological nature in the course of formalized processing of geophysical data, i.e. tectonics that can be characterized by methodology features of data acquisition and processing. (Author) 966188 Improvements in shallow high-resolution seismic reflection through PC-based systems R. D. Miller, R. D. Markiewicz, C. Mercy, Jianghai Xia & C. G. Maples, Computers & Geoseiences, 21(8), 1995, pp 957964. Increased dynamic range of recording equipment and decreased cost of processing hardware and software have made seismic reflection a cost-effective way of imaging geologic targets significant to environmental site classification. Some applications with demonstrated success include fault mapping with less than 4 m of vertical resolution at 300 m, detecting structure and stratigraphy associated with a hydrologic basin divide, and groundwater modeling of thick
sequences of alluvial, colluvial, and glacio-fluvial material. (from Authors) 966189 Anisotropic features of geometry and permeability in fractured rock masses Xing Zhang & D. J. Sanderson, Engineering Geology, 40(12), 1995, pp 65-75. A geometric anisotropy factor (,,If) of two-dimensional, natural fracture systems has been defined according to fracture spacing and orientation in a given direction. Geometric anisotropy of fracture systems has a major effect on the percolation threshold (the critical fracture density) of fracture systems below which the overall permeability is zero. A two-dimensional distinct element code (UDEC) has been used to calculate directional flow-rate of fracture systems. Simulated and natural fracture patterns, have been tested to examine the relation between geometric anisotropy and permeability anisotropy, which is demonstrated to have a power-law form. Also, the differential anisotropy factor (,4/) results in different universal exponents which govern the relation between fracture density and flow rates. (Authors) 966190 Oberflachenwellendaten zur Lokalisierung von Altlasten: ein Feldfall (Surface wave measurements for the location of waste deposits: a field study) C. Schneider & L. Dresen, Geophysical Transactions - Eotvos Lorand Geophysical Institute of Hungary, 39(4), 1994, pp 233-253. Describes the use of Rayleigh waves to detect near-surface inhomogenenus objects, like waste deposits etc. Rayleigh wave recordings have been integrated into conventional refraction seismic surveys at insignificant cost. It is shown that the Rayleigh wave technique is suitable for locating objects in layered media. A special dispersion analysis has been developed for delineating laterally heterogeneous nearsurface media. This method does not need any a-priori information about the underground. As a result, local dispersion curves are obtained, which represent the underground for any geophone position. The lateral variation of the surface wave signals is deduced from the variation of the local dispersion curves. In areas of smooth lateral variation dispersion curves can-be used within a rigorous inversion. This inversion leads to block-representations of the medium. Rayleigh wave signals can also be recompressed to improve resolution. (from English summary) 966191 Dolt reteges foldtani szerkezetek geoelektromos kututasi lehetosegenek vizsgalata anafitikus eloremodellezessel (Geological investigation of dipping beds with analytical forward modelling) A. Gyulai, Magyar Geofizika, 36(1), 1995, pp 40-67. The paper reviews potential field equations over a dipping bed. It presents apparent resistivity equations for different geoelectrical configurations. Apparent resistivity sections are computed perpendicularly to the strike of structures conraining at least two layers. Parameter sensitivities are defined for dipping beds and geoelectric configurations are investigated on the basis of parameter sensitivities to select the optimum geoelectrical array for exploration. (from English summary) 966192 Basis for a flexible low-cost automated resistivity data acquisition and analysis system M. A. Meju & M. Montague, Computers & Geosciences, 21(8), 1995, pp 993-999. An efficient and versatile automatic resistivity data acquisition and analysis system has been developed for use with any 4-eleetrode output resistivity meter. The acquisition hardware comprises a low-cost Digital Switching Unit which can be interfaced to a portable field microcomputer and a resistivity
SITE INVESTIGATIONS:DATA meter for automatic ground resistivity measurements. Data analysis can be effected in real-time using a simple effective direct inversion scheme that converts each apparent resistivity-electrode spacing data pair into a corresponding effective resistivity-depth information at a rate that is faster than that of acquisition leading to unhindered productivity. A practical evaluation of the infield data-analysis scheme is given and suggestions are offered for extending the basic system for tmnote-site monitoring applications. (from
Authors) 966193 Application of a geomembrane leak location survey at a UK waste disposal facility N. G. Mosley & F. Crozier, in: Engineering geology of waste disposal, ed S.P. Bentley, (Geological Society of London; Engineering Geology Special Publication, 11), 1996, pp 9-14. The technology exploits the electrical insulating properties of geomembranes. A voltage placed across the geomembrane is surveyed to identify anomalies where electrical current is flowing through leaks in the liner. In its first UK application both 'pin hole' leaks and larger cuts in the geomembrane were located and repaired prior to commissioning the waste disposal facility. (from Authors) 966194 Geomagnetism applications W. H. Campbell, US Geological Survey Circular, 1109, 1995, 31 pp. The societal uses of knowledge acquired from geomagnetism studies include research on space environment and satellite damage, pipeline management, electric power grid failure, communication interference, global position determination, mineral resource detection, Earth formation and structure, navigation, weather, and magnetoreception in organisms. (from Author) 966195 Temperature measuring technique using infra-red radiation (in Chinese) Cheng Wenkai & Liu Yongping, Journal - China Coal Society, 20(6), 1995, pp 578-582. Highlights of this research are as follows: principles of temperature measuring techniques using infra-red radiation for mine use, selection of infra-red probes, determination of working wave length, design of a optical system, processing of signals and scope of application in coal mines. (English summary)
Borehole and core logging 966196 Diagraphies, atome et geologie 0Veil logging, atom and geology) O. Serra, Memoires - Societe Geologique de France, 162, 1993(1994), pp 99-104. Well logging techniques exploit interactions of gamma photons and neutrons with atoms. They provide data which allow a much better geological study of the surface. The paper describes various techniques and their applications. (from English summary)
Processing and interpretation of data 966197 CLAIM: a new personal computer-assisted simulation model for teaching mineral exploration techniques C. Bauchau, M. Jaboyedoff & M. Vannier, Geological Association of Canada Special Paper, 40, 1993(1995), pp 685691. RMMS 336
J
265A
A new model, CLAIM, written in C language, works on a personal computer using MS-DOS. This new teaching method is fast, allows an instant comparison of students' results with the model, and has numerous graphic options. CLAIM simulates a sedimentary copper-bearing district covering an area of 400 km 2. The objective is for students to use geochemical and drilling data and topographic and geological maps to devise an optimum exploration strategy. (from Authors)
966198 A geochemical data management system for radioactive waste repository feasibility investigations C. P. Nathanail, in: Engineering geology of waste disposal, ed S.P. Bentley, (Geological Society of London; Engineering Geology Special Publication, 11), 1996, pp 245-248. The aim of this paper is to describe a data management system for the entry, validation and reporting of geochemical testing using dBase IV version 1.5 running under MS-DOS 5.0 on an IBM-compatible 486DX personal computer. Data entry is in four phases for sample register details, tracer sample analyses, hydrochemical sample inventory details and hydrochemicai sample analyses. Each record is committed on entry and then validated by a senior chemist. A six-stage validation scale was developed to track the progress of the analysis for individual determinands. Results are reported in full for each sample and as a series of summary sheets for rapid assessment. The summaries display the QA status of each analysis from 'not required' through 'pending' to 'fully documented procedures'. Output is to a laser printer and a series of Lotus 1-2-3 spreadsheet files for further analysis and interpretation. Reporting is both interim on a daily and fortnightly basis during testing and final upon completion of testing. (from Author) 966199 The use of text databases in the management of exploration data S. C. R. Mallender, in: Geological data management, ed J.R.A. Giles, (Geological Society, London; Special Publication, 97), 1995, pp 73-79. The management of exploration data concerns all the things that happen to a piece of exploration data during its life, and the management of the physical data is controlled by the information used to describe it. Descriptive information about each data item and each dataset is recorded and rerecorded on many transmittals as the physical data move from recording contractor, to processing contractor, to storage contractor. The main problem concerns the storage, retrieval and transmission of this descriptive information; the information is rarely 'processed' as such. Text databases are ideal in these circumstances: they can hold completely unstructured information, and allow users to find records using any data that appear anywhere in the content of the record. Accompanying software is used to provide a user interface to the text database, and this enables sophisticated systems which are very user-friendly to be developed easily. (from Author) 966200 Finite-difference modeling of faults and fractures R. T. Coates & M. Schoenberg, Geophysics, 60(5), 1995, pp 1514-1526. For the purposes of seismic propagation, a slip fault may be regarded as a surface across which the displacement caused by a seismic wave is discontinuous while the stress traction remains continuous. The simplest assumption is that this slip and the stress traction are linearly related. Such a linear slip interface condition is easily modeled when the fault is parallel to the finite-difference grid, but is more difficult to do for arbitrary nonplanar fault surfaces. To handle such situations equivalent medium theory is introduced to model material behavior in the cells of the finite-difference grid intersected by the fault. Virtually identical results were obtained from modeling the fault by: 1) an explicit slip interface condition (fault parallel to the grid) and 2) using the equivalent medium