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A comparison of electrical and electromagnetic methods for the detection of hydraulic pathways in a fractured rock aquifer, Clare Valley, South Australia

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Abstract

Within fractured rock, the irregular and often unpredictable distribution and geometry of hydraulically conductive fractures produces large spatial variations in bore yield and groundwater quality. As fractures act as conduits for flow of both groundwater and electrical charge, methods which can efficiently detect the distribution of electrical pathways can be used to infer characteristics of significant hydrological parameters. This study compares the capabilities and limitations of electrical data obtained from direct current (DC) and electromagnetic (EM) surface azimuthal measurements, and from DC borehole-to-surface and cross-borehole measurements, for the interpretation of major hydrological structures in Clare Valley, South Australia. Electrical and EM surface methods are limited by poor depth sensitivity and the presence of conductive overburden, but provide useful tools for determining directional variations in resistivity at sites lacking bedrock exposure and boreholes. Application of borehole-to-surface methods yielded a better-resolved interpretation of sub-vertical fracture strike and was useful in identifying lateral variations in bedrock heterogeneity. Improved flexibility and sensitivity to measurements at depth permitted cross-borehole electrical tomography data to be used in reconstructing the spatial distribution of sub-horizontal, laterally extensive, electrically conductive zones. While the technique is restricted to small-scale sites with multiple boreholes, inferences can be made on fluid connections over a much larger regional scale. It is important to note, however, that while electrical methods provide valuable information about in-situ hydraulic pathways, they do not provide a complete hydraulic characterisation. Such a task requires integration of surface and borehole geophysics, geologic mapping, sampling and pumping tests of wells with packed-off intervals.

Résumé

Au sein des roches fracturées, l’irrégularité et l’imprédictible distribution et géométrie des fractures par lesquelles s’écoulent l’eau souterraine produit de larges variations spatiales entre les débits des forages et les paramètres de la qualité de l’eau. Comme les fractures conduisent et l’eau et les charges électriques, les méthodes qui peuvent de manière efficiente détecter la distribution des courants électriques peuvent être utilisées pour analyser les caractéristiques des principaux paramètres hydrologiques. Cette étude compare les capacités et les limites des données produites par Courant Direct (DC en Anglais) et par mesure Electromagnétique azimutale de surface (EM en Anglais), et par DC entre surface et forage et entre plusieurs forages, pour l’interprétation de la structure hydrologique de la Vallée de Clare, Australie du Sud. Les méthodes électriques et électromagnétiques sont limitées par la faible sensitivité à la profondeur et la présence d’une couverture conductrice, mais procure des outils utiles pour déterminer les variations directionnelles en terme de résistivité là où la roche n’est pas affleurante et dans les puits. L’application de la méthode d’investigation «forage à surface» apporte une meilleure interprétation des fractures sub-verticales et des hétérogénéités latérales. Les tomographies électriques entre forage bénéficient de la flexibilité et de la sensibilité des mesures en profondeur, et permettent de délimiter l’extension latérale des hétérogénéités sub-horizontales de zones conductrices. Alors que la technique est restreinte à de petits sites comprenant de nombreux forages, il est possible de reconstituer les connections hydrauliques à des échelles régionales. Il est important de noter que les méthodes fournissent des informations intéressantes mais pas des caractérisations hydrauliques complètes. Pour cela les données pourraient être complétées par des études plus poussées intégrant les différentes prospections géophysique, les données des cartes géologiques, des échantillonnages et des essais de pompage à différents intervalles de profondeur.

Resumen

La geometría, y con frecuencia impredecible, distribución irregular de fracturas hidráulicamente conductivas dentro de roca fracturada genera variaciones espaciales grandes en producción de pozos y calidad de agua subterránea. Debido a que las fracturas actúan como conductos de flujo de agua y carga eléctrica, los métodos que detectan eficientemente la distribución de trayectorias eléctricas pueden utilizarse para inferir las características de parámetros hidrológicos significativos. Este estudio compara las capacidades y limitaciones de datos eléctricos obtenidos de mediciones azimutales superficiales electromagnéticas (EM) y de corriente directa (DC), y de mediciones de DC realizadas en la superficie y pozos así como mediciones realizadas entre pozos para la interpretación de estructuras hidrológicas principales en el Valle Clare, sur de Australia. Los métodos superficiales eléctricos y EM están limitados por sensitividad de profundidad pobre y la presencia de cubierta conductiva, pero aportan herramientas útiles para determinar variaciones direccionales de resistividad en sitios que carecen de pozos y afloramientos rocosos. La aplicación de métodos superficiales y de pozos aportan una mejor interpretación del rumbo de fracturas sub-verticales y fue útil en identificar variaciones laterales en la heterogeneidad del macizo rocoso. El mejoramiento de flexibilidad y sensitividad en las mediciones profundas permitió que los datos de tomografía eléctrica de los pozos fuera utilizado en la reconstrucción de la distribución espacial de zonas eléctricas conductivas, sub-horizontales y lateralmente extensas. Aunque la técnica está restringida a sitios de pequeña escala con múltiples pozos, puede realizarse inferencias sobre relaciones entre fluidos en una escala regional mucho más grande. Sin embargo, es importante notar que aunque los métodos eléctricos aportan información valiosa acerca de las trayectorias hidráulicas in-situ, aún no proporcionan una caracterización hidráulica completa. Esta tarea requiere integrar geofísica superficial y de pozos, mapeo geológico, muestreo y pruebas de bombeo en pozos con intervalos sin empaque.

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References

  • Bear J (1979) Hydraulics of groundwater. McGraw-Hill, Keterpress, Jerusalem

  • Bebbington M, Vere-Jones D, Zheng X (1990) Percolation theory: a model for rock fracture? Geophys J Int 100:215–220

    Google Scholar 

  • Brown S (1989) Transport of fluid and electric current in a single fracture. J Geophys Res 94:9429–9438

    Google Scholar 

  • Brown D, Slater LD (1999) Focused packer testing using geophysical tomography and CCTV in a fissured aquifer. Q J Eng Geol 32(2):173–183

    Google Scholar 

  • Carlson DA, Taylor RW, Cherkaur DS (1996) Azimuthal electrical resistivity as a tool for determination of the orientation of preferred hydraulic transmissivity for a dolomite aquifer in southeastern Wisconsin. In: Proc Symp The Application of Geophysics to Engineering and Environmental Problems, 28 April–2 May 1996, Keystone, Colorado. Environmental and Engineering Geophysical Society, Englewood, Colorado, pp 51–60

  • Cook PG, Simmons CT (2000) Using environmental tracers to constrain flow parameters in fractured rock aquifers; Clare Valley, South Australia. In: Faybishenko B, Witherspoon PA, Benson SM (eds) Dynamics of fluids in fractured rock. Am Geophys Union Geophys Monogr 122:337–347

    Google Scholar 

  • Cook PG, Love AJ, Dighton JC (1999) Inferring ground water flow in fractured rock from dissolved radon. Ground Water 37(4):606–610

    CAS  Google Scholar 

  • Dailey JW, LaBrecque D, Nitao J (1992) Electrical resistivity tomography of vadose water movement. Water Resources Res 28(5):1429–1442

    Article  Google Scholar 

  • Daily W, Owen E (1991) Cross-borehole resistivity tomography. Geophysics 56(8):1228–1235

    Article  Google Scholar 

  • Ellis RG, Oldenburg DW (1994) The pole-pole 3-D DC-resistivity inverse problem: a conjugate gradient approach. Geophys J Int 119:187–194

    Google Scholar 

  • Fagerlund F, Heinson GS (2003) Detecting sub-surface groundwater flow in fractured rock using self-potential (SP) methods. Environ Geol 43:782–794

    Google Scholar 

  • Ferguson IJ, Taylor WJ, Schmigel K (1996) Electromagnetic mapping of saline contamination at an active brine pit. Can Geotech J 33:309–323

    Google Scholar 

  • Fetter CW (1994) Applied hydrogeology, 3rd edn. Prentice-Hall, New Jersey

  • Gernand JD, Heidtman JP (1997) Detailed pumping test to characterize a fractured bedrock aquifer. Ground Water 35(4):632–637

    CAS  Google Scholar 

  • Habberjam GM (1975) Apparent resistivity, anisotropy, and strike measurements. Geophys Prospect 23:211–247

    Google Scholar 

  • Hagrey SA (1994) Electric study of fracture anisotropy at Falkenberg, Germany. Geophysics 59(6):881–888

    Article  Google Scholar 

  • Hancock PL (1985) Brittle microtectonics: principles and practice. J Struct Geol 7(3/4):437–457

    Google Scholar 

  • Jämtlid A, Magnusson KA, Olsson O, Stenberg L (1984) Electrical borehole measurements for mapping the fracture zones in crystalline rock. Geoexploration 22:203–216

    Article  Google Scholar 

  • Jansen J, Taylor RW (1996) Determining fracture geometry from azimuthal resistivity data. In: Proc Symp The Application of Geophysics to Engineering and Environmental Problems, 28 April–2 May 1996, Keystone, Colorado. Environmental and Engineering Geophysical Society, Englewood, Colorado, pp 41–50

  • Kaelin B, Johnson LR (1999) Using seismic crosswell surveys to determine the aperture of partially water-saturated fractures. Geophysics 64(1):13–23

    Article  Google Scholar 

  • Karasaki K, Freifeld B, Cohen A, Grossenbacher K, Cook P, Vasco D (2000) A multidisciplinary fractured rock characterization study at Raymond field site, Raymond, CA. J Hydrol 236(1/2):17–34

    Google Scholar 

  • Keller GV, Frischknecht FC (1966) Electrical methods in geophysical prospecting. Pergamon Press, New York

  • Kirsch A (1996) An introduction to the mathematical theory of inverse problems. Springer, Berlin Heidelberg New York

  • Lane JW Jr, Haeni FP, Watson WM (1995) Use of a square-array direct-current resistivity method to detect fractures in crystalline bedrock in New Hampshire. Ground Water 33(3):476–485

    CAS  Google Scholar 

  • Lieblich DA, Haeni FP, Cromwell RE (1992) Integrated use of surface geophysical methods to indicate subsurface fractures at Tibbetts Road, Barrington, New Hampshire. US Geol Surv Water-Resources Inv Rep 92-4012

  • Love A, Cook P (1999) The importance of fractured rock aquifers. Dept Primary Industries Resources South Australia Rep Book 99/23

  • Löw S, Kelly V, Vomvoris S (1994) Hydraulic borehole characterisation through the application of moment methods to fluid conductivity logs. J Appl Geophys 31:117–131

    Article  Google Scholar 

  • Majer EL, Peterson JE, Daley T, Kaelin B, Myer LR, Queen J, D-Onfro P, Rizer W (1997) Fracture detection using crosswell and single well surveys. Geophysics 62(2):495–504

    Article  Google Scholar 

  • McNeil JD (1980) Electrical conductivity of soils and rock. Geonics Ltd, Ontario, Canada, Tech Note TN-5

  • Michalski A, Britton R (1997) The role of bedding fractures in the hydrology of sedimentary bedrock—evidence from the Newark Basin, New Jersey. Ground Water 35(2):318–327

    CAS  Google Scholar 

  • Morin RH, Carleton GB, Poirier S (1997) Fractured-aquifer hydrogeology from geophysical logs: the Passaic Formation, New Jersey. Ground Water 35(2):328–337

    CAS  Google Scholar 

  • Morton D, Love AJ (1998) Clare Valley groundwater resources. Dept Primary Industries Resources South Australia Progr Rep 2

  • Morton D, Love AJ, Clarke D, Martin R, Cook PG, McEwan K (1998) Clare Valley groundwater resources. Dept Primary Industries Resources South Australia Progr Rep 1

  • Paillet F (1993) Integrating geophysical well logs, surface geophysics, and hydraulic tests and geologic data in groundwater studies-theories and case histories. In: Proc Symp The Application of Geophysics to Engineering and Environmental Problems, 18–22 April 1993, San Diego, California. Environmental and Engineering Geophysical Society, Englewood, Colorado, pp 479–495

  • Renshaw CE (1995) On the relationship between mechanical and hydraulic apertures in rough walled fractures. J Geophys Res 100:24629–24636

    Article  Google Scholar 

  • Renshaw CE (1996) Influence of subcritical fracture growth on the connectivity of fracture networks. Water Resources Res 32:1519–1530

    Article  Google Scholar 

  • Renshaw CE (1997) Mechanical controls on the spatial density of opening-mode fracture networks. Geology 25(10):923–926

    Article  Google Scholar 

  • Renshaw CE (1999) Connectivity of joint networks with power law length distributions. Water Resources Res 35(9):2661–2670

    Article  Google Scholar 

  • Ritzi RW, Adolsek RH (1992) Relationship between anisotropic transmissivity and azimuthal resistivity surveys in shallow, fractured, carbonate flow systems. Ground Water 30:774–780

    Google Scholar 

  • Rust KA, Sandberg SK, Auken E (1997) Physical-scale modelling of the azimuthal electromagnetic response in the macroanisotropic case. In: Proc Symp The Application of Geophysics to Engineering and Environmental Problems, 23–26 March 1997, Reno, Nevada. Environmental and Engineering Geophysical Society, Englewood, Colorado, pp 715–723

  • Sandberg SK, Jagel DL (1996) The electromagnetic azimuthal resistivity method. In: Proc Symp The Application of Geophysics to Engineering and Environmental Problems, 28 April–2 May 1996, Keystone, Colorado. Environmental and Engineering Geophysical Society, Englewood, Colorado, pp 31–40

  • Sandberg EV, Olsson OL, Falk LR (1991) Combined interpretation of fracture zones in crystalline rock using single-hole and crosshole tomography and directional borehole-radar data. Log Analyst 32(2):108–119

    Google Scholar 

  • Sauck WA, Zabik SM (1992) Azimuthal resistivity techniques and the directional variation of hydraulic conductivity in glacial sediments. In: Proc Symp The Application of Geophysics to Engineering and Environmental Problems, 26–29 April 1992, Oakbrook, Illinois. Environmental and Engineering Geophysical Society, Englewood, Colorado, pp 197–222

  • Shapiro AM, Oki DS (2000) Estimating formation properties from early-time oscillatory water levels in a pumped well. J Hydrol 236(1/2):91–108

    Google Scholar 

  • Slater LD, Brown D, Binley A (1996) Determination of hydraulically conductive pathways in fractured limestone using cross-borehole electrical resistivity tomography. Eur J Environ Eng Geophys 1(1):35–52

    CAS  Google Scholar 

  • Slater LD, Binley A, Brown D (1997) Electrical imaging of fractures using groundwater salinity change. Ground Water 35(3):436–442

    CAS  Google Scholar 

  • Slater LD, Sandberg SK, Jankowski M (1998) Survey design procedures and data processing techniques applied to the EM azimuthal resistivity method. J Environ Eng Geophys 3(4):167–177

    Google Scholar 

  • Snow DT (1968) Fracture deformation and changes of permeability and storage upon changes of fluid pressure. Q J Colorado School Mines 63:201–244

    Google Scholar 

  • Stevens KM, Lodha GS, Holloway AL, Soonawala NM (1995) The application of ground penetrating radar for mapping fractures in plutonic rocks within the Whiteshell Research Area, Pinawa, Manitoba, Canada. J Appl Geophys 33(1/3):125–141

    Google Scholar 

  • Taylor RW, Flemming AH (1988) Characterising jointed systems by azimuthal resistivity surveys. Ground Water 26:464–473

    Google Scholar 

  • Wang T, Stodt JA, Stierman DJ, Murdoch LC (1991) Mapping hydraulic fractures using a borehole-to-borehole surface electrical resistivity method. Geoexploration 28:349–369

    Article  Google Scholar 

  • Warren BM (2001) Determining ratios of anisotropy using hydrogeological and geophysical methods in the Clare Valley, South Australia. Honours Thesis, Flinders University, South Australia

  • Watson KA, Barker RD (1999) Differentiating anisotropy and lateral effects using azimuthal resistivity offset Wenner soundings. Geophysics 64:739–745

    Article  Google Scholar 

  • Wilson T, Heinson G, Endres A, Halihan T (2000) Fractured rock geophysical studies in the Clare Valley, South Australia. Explor Geophys 31(1/2):255–259

    Google Scholar 

  • Zhang X, Sanderson DJ (1998) Numerical study of critical behaviour of deformation and permeability of fractured rock masses. Mar Petrol Geol 15:535–548

    Article  Google Scholar 

  • Zhou B, Greenhalgh SA (1999) Explicit expressions and numerical calculations for the Fréchet and second derivatives in 2.5D Helmloltz equation inversion. Geophys Prospect 47:443–468

    Article  Google Scholar 

Download references

Acknowledgments

The authors would like to thank Toby Wellman for his enthusiastic assistance with fieldwork, Thomas Wilson, Dr. Craig Simmons, Dr. Bing Zhou, Brooke Warren, Fritjof Fagerlund and Hashim Carey for their valuable discussions and contributions, and Dr. Andrew Love (Dept. for Water Resources) and Peter Cook (CSIRO) for access to boreholes and instrumentation. The Adelaide University Small Grant titled Geophysical Investigations of Fractured Rock Groundwater Resources financially supported this work. Thorough and constructive reviews by Dr. Andrew Binley and Dr. John Lane substantially improved this paper.

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  1. Damien Skinner

    Present address: URS Australia Pty Ltd, Level 3, The Hyatt Centre, 20 Terrace Road, 6004, East Perth, WA, Australia

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  1. School of Earth and Environmental Sciences, Geology and Geophysics, University of Adelaide, 5005, Adelaide, SA, Australia

    Damien Skinner & Graham Heinson

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Correspondence to Damien Skinner.

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Skinner, D., Heinson, G. A comparison of electrical and electromagnetic methods for the detection of hydraulic pathways in a fractured rock aquifer, Clare Valley, South Australia. Hydrogeology Journal 12, 576–590 (2004). https://doi.org/10.1007/s10040-004-0356-y

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