Induced polarization: Electrochemistry, fractal geometry, and geohydrologic applications.

Persistent Link:
http://hdl.handle.net/10150/184959
Title:
Induced polarization: Electrochemistry, fractal geometry, and geohydrologic applications.
Author:
Fink, James Brewster.
Issue Date:
1989
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The application of spectral induced polarization (SIP) to geohydrologic and geotechnical problems is considered. Some fundamental electrochemical characteristics of sulfides are reviewed. An alternate theory of the underlying cause of IP is presented. A modified field method is proposed. Two field sites are studied. Prevailing electrochemical thought is that most sulfides, especially pyrite and chalcopyrite, have passivating surface coatings. With this thought in mind, existing geophysically-oriented electrochemical measurements may be reinterpreted quite differently than has previously been done. Large impedances at low frequencies have traditionally been attributed by geophysicists to diffusional phenomena related to rapid reactions occurring at the sulfide surface. Large impedances at low frequencies with clays have traditionally been attributed to restrained ionic diffusion between zones of clay particles. Although they appear to be due to quite different mechanisms, both of these low frequency dispersions may be explained by a single rate limiting mechanism. Using fractal geometry, the large low frequency dispersions observed on sulfides may be explained by distributed high charge-transfer resistances on rough surfaces. With high surface resistances sulfides may behave like insulating clay particles and allow charge separation to occur in surface conduction current flow. Although displacement currents may flow in sulfides they are considered to be minimal in comparison to the surface conduction currents. The concept of a common polarization phenomenon allows the previous studies on rock samples containing clay particles and/or sulfides to be equated on the basis of particle size. With clay-coated sand grains it may be possible to estimate intrinsic hydraulic conductivity based on the interpreted polarizable grain size. Aquifers, and partially water saturated zones, may be IP targets if they have small amounts of polarizable clay minerals. Aquifer detection and grain size estimation are demonstrated. Theoretical work and field studies show the advantages of using a modified dipole-dipole array and data presentation methods. The large amounts of data gathered during broad-band SIP surveys are demonstrated to be very useful in layered-earth geohydrologic problems. The higher frequency data contain much earth-structure information, are easily gathered, and allow immediate qualitative structural interpretation. Lower frequency data contain information useful in aquifer characterization.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Induced polarization; Sulfides -- Electric properties; Geophysics
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Mining and Geological Engineering; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Sternberg, Ben K.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleInduced polarization: Electrochemistry, fractal geometry, and geohydrologic applications.en_US
dc.creatorFink, James Brewster.en_US
dc.contributor.authorFink, James Brewster.en_US
dc.date.issued1989en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe application of spectral induced polarization (SIP) to geohydrologic and geotechnical problems is considered. Some fundamental electrochemical characteristics of sulfides are reviewed. An alternate theory of the underlying cause of IP is presented. A modified field method is proposed. Two field sites are studied. Prevailing electrochemical thought is that most sulfides, especially pyrite and chalcopyrite, have passivating surface coatings. With this thought in mind, existing geophysically-oriented electrochemical measurements may be reinterpreted quite differently than has previously been done. Large impedances at low frequencies have traditionally been attributed by geophysicists to diffusional phenomena related to rapid reactions occurring at the sulfide surface. Large impedances at low frequencies with clays have traditionally been attributed to restrained ionic diffusion between zones of clay particles. Although they appear to be due to quite different mechanisms, both of these low frequency dispersions may be explained by a single rate limiting mechanism. Using fractal geometry, the large low frequency dispersions observed on sulfides may be explained by distributed high charge-transfer resistances on rough surfaces. With high surface resistances sulfides may behave like insulating clay particles and allow charge separation to occur in surface conduction current flow. Although displacement currents may flow in sulfides they are considered to be minimal in comparison to the surface conduction currents. The concept of a common polarization phenomenon allows the previous studies on rock samples containing clay particles and/or sulfides to be equated on the basis of particle size. With clay-coated sand grains it may be possible to estimate intrinsic hydraulic conductivity based on the interpreted polarizable grain size. Aquifers, and partially water saturated zones, may be IP targets if they have small amounts of polarizable clay minerals. Aquifer detection and grain size estimation are demonstrated. Theoretical work and field studies show the advantages of using a modified dipole-dipole array and data presentation methods. The large amounts of data gathered during broad-band SIP surveys are demonstrated to be very useful in layered-earth geohydrologic problems. The higher frequency data contain much earth-structure information, are easily gathered, and allow immediate qualitative structural interpretation. Lower frequency data contain information useful in aquifer characterization.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectInduced polarizationen_US
dc.subjectSulfides -- Electric propertiesen_US
dc.subjectGeophysicsen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineMining and Geological Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSternberg, Ben K.en_US
dc.contributor.committeememberGlass, Charles E.en_US
dc.contributor.committeememberFarmer, Ian W.en_US
dc.contributor.committeememberSumner, John S.en_US
dc.identifier.proquest9017194en_US
dc.identifier.oclc703632375en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.