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Seismic reflection profiles across the ‘Mine Series’ in the Noranda camp of the Abitibi Belt, eastern Canad
SITE INVESTIGATIONS:GEOPHYSICS components of the IGM applied in different stages of the investigation. (from Author) 962232 GPS versus template - simple field and office experiments concerning GPS-determined positions and template-scaled map locations D. A. Brew & 6 others, US Geological Survey Bulletin, 2107, 1994, lap 199-205. Four simple experiments were done to test the reproducibility, or precision, of latitude and longitude positions determined with low-cost Global Positioning System (GPS) instruments and of such locations scaled from a topographic map using a transparent template. It is concluded that, although there may be discrepancies when a single GPS position is compared with a single plotted map location for a given site, the use of GPS-determined positions may be less of a problem than the combined problems involved in scaling locations from maps. It is recommended that geologists continue to plot locations of field stations in the conventional way, record the GPS positions of the stations for latitude and longitude data purposes, periodically compare the scaled locations of the GPS positions with the plotted map positions, and then make appropriate adjustments as needed to deal with any discrepancies. (from Authors) 962233 An empirical assessment of refraction error in leveling as a function of survey order and environment R. O. Castle, R. K. Mark & R. H. Shaw, US Geological Survey Bulletin, 2114, 1994, 50 pp. Analyses of the results obtained from three field tests intended to measure the accumulation of the unequalrefraction error (URE) in leveling demonstrate that this error can be quantified as a function of survey order and, less certainly, factors controlled by the local environment. The three experiments are: 1) the Gaitbersburg-Tueson refraction tests of the National Geodetic Survey, 2) the Saugus-Palmdale field test conducted jointly by the US Geological Survey the National Geodetic Survey, and 3) the Canadian or Eastern Townships experiment of the Geodetic Survey of Canada. (from Authors) 962234 Effect of faulting on fluid flow in porous sandstones: geometry and spatial distribution M. Antonellini & A. Aydin, American Association of Petroleum Geologists Bulletin, 79(5), 1995, pp 642-671. The paper presents a methodology to'describe fault geometry at different scales and to characterize the distribution of these scales on the flanks of a salt intrusion in the Colorado Plateau (Arches National Parks, US). This methodology is based on the recognition of the physical processes of faulting and on the quantitative characterization of the structural and petrophysical properties of faults in porous sandstones. The methods used include a variety of mapping techniques as well as techniques for determining fluid flow properties, The resulting study is a prototype for understanding seismic and subseismic scales of heterogeneity related to faulting and fracturing in subsurface reservoirs. (from Author)
Geophysical techniques 962235 Applications of shallow, high-resolution seismic reflection to various mining operations R. D. Miller & D. W. Steeples, Mining Engineering, 47(4), 1995, pp 355-361. Application of shallow, seismic reflection to problems associated with mineral exploration, mine planning, abandoned-mine detection and environmental evaluation has been successful in many geologic settings. The increased dynamic range of recording equipment and the decreased cost of processing hardware and software have made shallow, seismic
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reflection a cost-effective means of imaging geologic targets significant to mining operations. Seismic data possess sufficient resolution in many areas to detect faulting with displacement of less than 3 m in coal seams as thin as 2 m at depths of 200 m. Subsurface voids associated with abandoned mines at depths of less than 20 m can be detected and mapped. Complex geologic features associated with deposition of various hydrothermal minerals have been mapped at depths of more than 300 m. Faults in sulfurbearing cap rock over salt domes have been accurately located, allowing improved efficiency of the dissolution mining process. (Authors) 962236 Seismic reflection profiles across the 'Mine Series' in the Noranda camp of the Abitibi Belt, eastern Canada P. Verpaelst & 8 others, Canadian Journal of Earth Sciences, 32(2), 1995, pp 167-176. The Abitibi - Greenville Lith0probe project completed a regional (line 21) and a high-resolution (line 21-1) seismic survey in the Noranda Central Volcanic Complex of the Blake River Group, Abitibi, Quebec. Line 21 provides a regional framework in which the Archean crust is divided into three layers, two of which are discussed here. Within the regional data, the Mine Series of the Central Volcanic Complex is imaged as a semitransparent series of reflectors overlying a highly reflective east-facing structure interpretated as the suhvolcanic Flavrian pluton. The project was designed to test the applicability of seismic reflection profiling in providing structural and stratigraphie information for use in mineral exploration. (from Authors) 962237 Electrical resistivity mapping of the buried stream channel of the Canopic Branch in the western Nile Delta, Egypt M. M. EI-Gamili, F. F. Shaaban & O. A. EI-Morsi, Journal of African Earth Sciences, 19(1-2), 1994, pp 135-148. Buried stream channels, which can often be mapped accurately by resistivity, are favoured targets for exploration. Horizontal profiling, electrical soundings, or both, are generally used. In the Delta, the electrical sounding method was applied using a Sehlumberger electrode array with the maximum AB distance being 200 m. The field survey was conducted along profiles extending NE-SW, perpendicular to the expected historical Canopic buried stream channel. About 107 vertical electrical soundings (VES) were measured along eleven profiles. The results indicate three major lithofacies. From the thickness of the topmost facies and the paleotopography, the buried stream channels can be delineated. It is evident that two streams existed for the defunct Canopic branch. (from Authors) 962238 Application of the natural electric field for detecting karst conduits on Guam A. L. Lange & W. L. Barner, in: Karst geohazards:
engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 425-441. The purpose of the survey was the identification of zones of increased hydraulic conductivity in the coralline limestone to optimize monitoring locations for dye-tracer studies. Ten natural-potential anomalies were selected as drill sites and drilled to depths ranging between 9 and 28 meters. Results of the drilling demonstrate that well-defined positive naturalpotential anomalies are associated with sohitionally enhanced permeable zones with the coralline limestone groundwater system. (from Authors) 962239 Subsurface investigation of possible karst conditions at the Jewfish Creek bridge replacement, Key Largo, Florida R. C. Benson, L. Yuhr & B. C. Berkovitz, in: Karst
geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Baikema), 1995, pp 409-414.
Geophysical techniques 962235 Applications of shallow, high-resolution seismic reflection to various mining operations R. D. Miller & D. W. Steeples, Mining Engineering, 47(4), 1995, pp 355-361. Application of shallow, seismic reflection to problems associated with mineral exploration, mine planning, abandoned-mine detection and environmental evaluation has been successful in many geologic settings. The increased dynamic range of recording equipment and the decreased cost of processing hardware and software have made shallow, seismic
77A
reflection a cost-effective means of imaging geologic targets significant to mining operations. Seismic data possess sufficient resolution in many areas to detect faulting with displacement of less than 3 m in coal seams as thin as 2 m at depths of 200 m. Subsurface voids associated with abandoned mines at depths of less than 20 m can be detected and mapped. Complex geologic features associated with deposition of various hydrothermal minerals have been mapped at depths of more than 300 m. Faults in sulfurbearing cap rock over salt domes have been accurately located, allowing improved efficiency of the dissolution mining process. (Authors) 962236 Seismic reflection profiles across the 'Mine Series' in the Noranda camp of the Abitibi Belt, eastern Canada P. Verpaelst & 8 others, Canadian Journal of Earth Sciences, 32(2), 1995, pp 167-176. The Abitibi - Greenville Lith0probe project completed a regional (line 21) and a high-resolution (line 21-1) seismic survey in the Noranda Central Volcanic Complex of the Blake River Group, Abitibi, Quebec. Line 21 provides a regional framework in which the Archean crust is divided into three layers, two of which are discussed here. Within the regional data, the Mine Series of the Central Volcanic Complex is imaged as a semitransparent series of reflectors overlying a highly reflective east-facing structure interpretated as the suhvolcanic Flavrian pluton. The project was designed to test the applicability of seismic reflection profiling in providing structural and stratigraphie information for use in mineral exploration. (from Authors) 962237 Electrical resistivity mapping of the buried stream channel of the Canopic Branch in the western Nile Delta, Egypt M. M. EI-Gamili, F. F. Shaaban & O. A. EI-Morsi, Journal of African Earth Sciences, 19(1-2), 1994, pp 135-148. Buried stream channels, which can often be mapped accurately by resistivity, are favoured targets for exploration. Horizontal profiling, electrical soundings, or both, are generally used. In the Delta, the electrical sounding method was applied using a Sehlumberger electrode array with the maximum AB distance being 200 m. The field survey was conducted along profiles extending NE-SW, perpendicular to the expected historical Canopic buried stream channel. About 107 vertical electrical soundings (VES) were measured along eleven profiles. The results indicate three major lithofacies. From the thickness of the topmost facies and the paleotopography, the buried stream channels can be delineated. It is evident that two streams existed for the defunct Canopic branch. (from Authors) 962238 Application of the natural electric field for detecting karst conduits on Guam A. L. Lange & W. L. Barner, in: Karst geohazards:
engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Balkema), 1995, pp 425-441. The purpose of the survey was the identification of zones of increased hydraulic conductivity in the coralline limestone to optimize monitoring locations for dye-tracer studies. Ten natural-potential anomalies were selected as drill sites and drilled to depths ranging between 9 and 28 meters. Results of the drilling demonstrate that well-defined positive naturalpotential anomalies are associated with sohitionally enhanced permeable zones with the coralline limestone groundwater system. (from Authors) 962239 Subsurface investigation of possible karst conditions at the Jewfish Creek bridge replacement, Key Largo, Florida R. C. Benson, L. Yuhr & B. C. Berkovitz, in: Karst
geohazards: engineering and environmental problems in karst terrane. Proc. 5th conference, Gatlinburg 1995, ed B.F. Beck, (Baikema), 1995, pp 409-414.