Rock mass characterization around Saskatchewan potash mine openings using geophysical techniques: a review

1992 ◽  
Vol 29 (4) ◽  
pp. 666-674 ◽  
Author(s):  
D. J. Gendzwill ◽  
D. Stead

Saskatchewan potash deposits are found in relatively uniform, flat-bedded strata with few irregularities. Potash mines are highly automated and efficient, taking advantage of the uniform strata. However, anomalous geological conditions can lead to severe problems, especially with water inflows. One mine has been lost to flooding, and other mines now have or previously had large inflows of water. Geophysical techniques, especially the method of vertical seismic reflection from the surface, are used to predict anomalous geological conditions. Seismic, electric, and other geophysical methods are also used underground, sometimes in boreholes, to detect conditions around the mine openings such as the thickness of the salt cover over the mine, fractures around the opening, shale beds, the presence of water, and other rock properties. The mines generate seismic activity ranging from magnitude 3.7 earthquakes to tiny micro-earthquakes, and various field monitoring and laboratory testing programs have analyzed these. To avoid hazards discovered by geophysical methods, mine managers have often changed their plan of operation or even deleted large ore reserves. Key words : geophysics, potash mining, seismic, earthquakes.

2020 ◽  
Vol 12 (1) ◽  
pp. 1094-1104
Author(s):  
Nima Dastanboo ◽  
Xiao-Qing Li ◽  
Hamed Gharibdoost

AbstractIn deep tunnels with hydro-geological conditions, it is paramount to investigate the geological structure of the region before excavating a tunnel; otherwise, unanticipated accidents may cause serious damage and delay the project. The purpose of this study is to investigate the geological properties ahead of a tunnel face using electrical resistivity tomography (ERT) and tunnel seismic prediction (TSP) methods. During construction of the Nosoud Tunnel located in western Iran, ERT and TSP 303 methods were employed to predict geological conditions ahead of the tunnel face. In this article, the results of applying these methods are discussed. In this case, we have compared the results of the ERT method with those of the TSP 303 method. This work utilizes seismic methods and electrical tomography as two geophysical techniques are able to detect rock properties ahead of a tunnel face. This study shows that although the results of these two methods are in good agreement with each other, the results of TSP 303 are more accurate and higher quality. Also, we believe that using another geophysical method, in addition to TSP 303, could be helpful in making decisions in support of excavation, especially in complicated geological conditions.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1310
Author(s):  
Hajer Azaiez ◽  
Hakim Gabtni ◽  
Mourad Bédir

Electric resistivity sounding and tomography, as well as electromagnetic sounding, are the classical methods frequently used for hydrogeological studies. In this work, we propose the development and implementation of an original integrated approach using the unconventional hydro–geophysical methods of gravity and seismic reflection for the fast, large–scale characterization of hydrogeological potential using the Ain El Beidha plain (central Tunisia) as an analogue. Extending the values of vintage petroleum seismic reflection profiles and gravity data, in conjunction with available geological and hydrogeological information, we performed an advanced analysis to characterize the geometry of deep tertiary (Oligocene and Eocene) aquifers in this arid area. Residual and tilt angle gravity maps revealed that most gravity anomalies have a short wavelength. The study area was mainly composed of three major areas: the Oued Ben Zitoun and Ain El Beidha basins, which are both related to negative gravity trends corresponding to low–density subsiding depocenters. These basins are separated by an important NE–SW trend called “El Gonna–J. El Mguataa–Kroumet Zemla” gravity high. Evaluation of the superposition of detected lineaments and Euler deconvolution solutions’ maps showed several NE–SW and N–S relay system faults. The 3D density inversion model using a lateral and vertical cutting plane suggested the presence of two different tectonic styles (thin VS thick). Results from the gravity analysis were in concordance with the seismic analysis. The deep Oligocene and Eocene seismic horizons were calibrated to the hydraulic wells and surrounding outcrops. Oligocene and Eocene geological reservoirs appear very fractured and compartmented. The faulting network also plays an important role in enhancing groundwater recharge process of the Oligocene and Eocene aquifers. Finally, generated isochron maps provided an excellent opportunity to develop future comprehensive exploration surveys over smaller and more favorable areas’ sub–basins.


2005 ◽  
Vol 42 (4) ◽  
pp. 1105-1115 ◽  
Author(s):  
O Meric ◽  
S Garambois ◽  
D Jongmans ◽  
M Wathelet ◽  
J L Chatelain ◽  
...  

Several geophysical techniques (electromagnetic profiling, electrical tomography, seismic refraction tomography, and spontaneous potential and seismic noise measurement) were applied in the investigation of the large gravitational mass movement of Séchilienne. France. The aim of this study was to test the ability of these methods to characterize and delineate the rock mass affected by this complex movement in mica schists, whose lateral and vertical limits are still uncertain. A major observation of this study is that all the zones strongly deformed (previously and at present) by the movement are characterized by high electrical resistivity values (>3 kΩ·m), in contrast to the undisturbed mass, which exhibits resistivity values between a few hundred and 1 kΩ·m. As shown by the surface observations and the seismic results, this resistivity increase is due to a high degree of fracturing associated with the creation of air-filled voids inside the mass. Other geophysical techniques were tested along a horizontal transect through the movement, and an outstanding coherency appeared between the geophysical anomalies and the displacement rate curve. These preliminary results illustrate the benefits of combined geophysical techniques for characterizing the rock mass involved in the movement. Results also suggest that monitoring the evolution of the rock mass movement with time-lapse geophysical surveys could be beneficial.Key words: gravitational movement, geophysical methods, Séchilienne.


Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Donat Demanet ◽  
François Renardy ◽  
Kris Vanneste ◽  
Denis Jongmans ◽  
Thierry Camelbeeck ◽  
...  

As part of a paleoseismological investigation along the Bree fault scarp (western border of the Roer Graben), various geophysical methods [electrical profiling, electromagnetic (EM) profiling, refraction seismic tests, electrical tomography, ground‐penetrating radar (GPR), and high‐resolution reflection seismic profiles] were used to locate and image an active fault zone in a depth range between a few decimeters to a few tens of meters. These geophysical investigations, in parallel with geomorphological and geological analyses, helped in the decision to locate trench excavations exposing the fault surfaces. The results could then be checked with the observations in four trenches excavated across the scarp. Geophysical methods pointed out anomalies at all sites of the fault position. The contrast of physical properties (electrical resistivity and permittivity, seismic velocity) observed between the two fault blocks is a result of a differences in the lithology of the juxtaposed soil layers and of a change in the water table depth across the fault. Extremely fast techniques like electrical and EM profiling or seismic refraction profiles localized the fault position within an accuracy of a few meters. In a second step, more detailed methods (electrical tomography and GPR) more precisely imaged the fault zone and revealed some structures that were observed in the trenches. Finally, one high‐resolution reflection seismic profile imaged the displacement of the fault at depths as large as 120 m and filled the gap between classical seismic reflection profiles and the shallow geophysical techniques. Like all geophysical surveys, the quality of the data is strongly dependent on the geologic environment and on the contrast of the physical properties between the juxtaposed formations. The combined use of various geophysical techniques is thus recommended for fault mapping, particularly for a preliminary investigation when the geological context is poorly defined.


2018 ◽  
Vol 22 (3) ◽  
pp. 195-204 ◽  
Author(s):  
Sadegh Rezaei ◽  
Issa Shooshpasha ◽  
Hamed Rezaei

Today, geotechnical and geophysical techniques are used for landslide evaluation. Geotechnical methods provide accurate data, but are time consuming and costly. Geophysical techniques, however, are fast and inexpensive, yet their accuracy is lower than that of the geotechnical methods. Therefore, simultaneous use of geotechnical and geophysical methods provides a suitable solution for landslide evaluation. Availability of geotechnical and geophysical data makes it possible to investigate correlation between different parameters. Correlating geotechnical and geophysical parameters ends up lowering field investigation costs and enhancing subsurface survey speed in a landslide zone. In the present study, in order to evaluate Nargeschal landslide in Iran, ambient noise measurement, ERT survey, and geotechnical investigations were used. Once finished with data processing, the data obtained from geotechnical and geophysical investigations were correlated. These included SPT-N – electrical resistivity, soil moisture content – electrical resistivity, and SPT-N – shear wave velocity correlations. The correlations were examined using two methods, namely Spearman’s coefficient test and least square regression analysis. The results obtained from the two methods were in good agreement with one another. The correlations obtained in this study were of moderate to very strong strength and fell in the range of the results of previous studies. Investigation of the results indicated significant influences of ground water on electrical resistivity and soil stiffness on shear wave velocity. Results of this study can be used for soil classification and determination of mechanical and seismic characteristics of soil across various areas.


Author(s):  
Norman Herz ◽  
Ervan G. Garrison

Geophysical techniques are a commonplace tool in today's archaeology as a result of an extensive collaboration between scientists and archaeologists on both sides of the Atlantic. This "cross-fertilization" has produced growing subdisciplines, of which archaeological geophysics is one example. As may be recalled from our introductory chapter, K. Butzer defined geoarchaeology as archaeology done using a geological methodology. G. Rapp and J. A. Gifford describe archaeological geology as the use of geological techniques to solve archaeological problems. Fagan has called geoarchaeology a "far wider enterprise than geology," involving (1) geochemical and geophysical techniques to locate sites and features; (2) studies of site formation and spatial context; (3) geomorphology, palynology, paleobotany; (4) absolute and relative dating procedures; and (5) taphonomic studies. Archaeological geophysics is a major aspect of archaeological geology. The application of geophysical exploration techniques in archaeology is also known as archaeogeophysics. Geophysical methods of potential usefulness to archaeological geology fall within the following classes: 1. seismic: reflection/refraction 2. electrical & electromagnetic: resistivity and conductivity 3. magnetic 4. radar 5. microgravity 6. thermography All have been used on a variety of archaeological problems. The application of geophysical techniques has grown as (1) the access to the instruments and (2) the methodological understanding of the users have increased. Access to geophysical instrumentation has been made easier by the steady development in solid-state design and computerization, which has reduced size and costs as it has in almost every technical field. The beneficiaries are the geologists and archaeologists. The first to recognize the applicability of geophysical methods to archaeology were the geologists—more specifically, the geophysicists. Working in association with their archaeological colleagues, the earth scientists translated the objectives of the archaeologists into practice. Such cooperation was very productive but suffered from the same kinds of problems that dogged the early usage and acceptance of radiocarbon dating. The archaeologists' untutored enthusiasm, coupled with their lack of a true understanding of the physics and atmospheric chemistry inherent in that technique, led to a backlash of skepticism when dates reported by the first radiocarbon researchers were found to be in error.


Geophysics ◽  
1977 ◽  
Vol 42 (5) ◽  
pp. 1070-1084 ◽  
Author(s):  
H. R. Espey

This report provides statistics on worldwide use of geophysical methods in 1976. Data were obtained primarily through a survey questionnaire which was mailed out to more than 500 companies, government agencies, and universities that use geophysical techniques for petroleum exploration, oceanography, engineering, mining, geothermal exploration, and groundwater exploration. Response to the survey was excellent, providing detailed information on all types of airborne, land, and marine surveys. Computer processing was utilized in tabulating the statistics to provide detailed information on methods used, line‐miles covered, and average costs. Data not supplied on the questionnaire for costs or line‐mileage were estimated on the basis of worldwide averages to produce a more comprehensive report.


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