Principles of Induced Polarization for Geophysical Exploration, Volume 5

Preface

Acknowledgments

1. Introduction

A Historical Summary of IP Research

The IP Effect

IP Response

The Decay Curve

IP Measurement

The Basic IP Measurement △ V/V

Phase-Angle IP Measurement

Errors

Units Used in IP Surveying

The Glossary

2. Resistivity Principles

Resistivity Theory

Ohm's Law

Three-Dimensional Resistivity

Resistivity and Conductivity

Potential Field of a Current Electrode Pair

Refraction of Current Flow Lines

Equipotential Surfaces

Resistivity Anisotropy

Paradox of Anisotropy

Superposition and Reciprocity

Resistivity Type Curves by the Method of Images

Resistivity of Earth Materials

Resistivity Properties of Minerals

Electrical Conduction in Rocks

Resistivity of Mineralized Rocks

Resistivity Exploration Methods

Resistivity Equipment

Self-Potential

Resistivity Sounding

Resistivity Profiling

Pseudosection Plotting

3. Theory of Induced Polarization

Electrochemical Theory

The Electrode

Overvoltage

The Double Layer

Faradaic and Nonfaradaic Paths

Warburg Impedance

Membrane Polarization

Applications of Electrochemical Theory

Dielectric Constant

Electrical Models of Induced Polarization

Equivalent Circuit

The Decay Curve

Field of a Dipole

Electrical Polarization

Polarization

Induced Polarization

Magnetic Induced Polarization

The Equivalence of Frequency and Pulse Measurements

The Place of IP Theory in the Exploration Method

4. Laboratory Work in Induced Polarization

Electrical Measurements of Rocks

Types of Experiments

Sampling and Preparation

Electrical Measuring Equipment

Environmental Chamber

Sample Holders

Frequency-Domain Studies

Resistivity Spectrum

Interpretation of the Resistivity Spectrum

Effects of Current Density

Effect of Rock Saturation

Anisotropism

Time-Domain Measurements

Charge and Decay Cycles

Phase Measurement

Early Part of Decay Curve and the Comparison with Frequency Effects

Considerations of Laboratory and Field Results

5. IP Field Equipment

Historical Development

Design Considerations

Parameters to be Measured

Electrode Resistance

Voltage and Polarization Signals

Noise Characteristics of the Ground

The Signal-Gene Rating System

Motors and Generators

The IP Transmitter

The IP Receiver

Self-Potential Buckout

The Time-Domain Receiver

The Frequency IP Receiver

Digitized IP Field Equipment

Design Considerations from Frequency Analysis of a Square Wave

Filtering

6. Telluric Noise and Electromagnetic Coupling

Telluric (Earth) Currents

The Magnetosphere

Micropulsations

Man-Made Electrical Noise

Sferics

Methods of Avoiding Magnetotelluric Noise

Coupling of Electrical Circuits

Resistive Coupling

Capacitive Coupling

Cultural Coupling Effects

Electromagnetic Coupling

The EM-Coupling Problem

EM Coupling and Phase

EM Coupling Relationships — Correction Curve

EM Coupling for Small Inductive Effects Using the Dipole—Dipole Array

Methods of Avoiding EM Coupling

Detection and Identification of EM Coupling

7. IP Field Surveying

Field Procedures

Equipment List

Transportation

Survey Layout

Permission to Survey

The Current-Sending System in the Field

The Generator Station

Electrode Preparation

Review of Theory of Current Electrode Layout

Electrode Resistance

The Sender in Operation

The Voltmeter-Receiver System

Field Calibration Procedures

The Porous-Pot Potential Electrode

Reading The Receiver

IP Survey Conditions

Signal-to-Noise Ratio

Comparison of Electrode Arrays in IP Surveying

Safety

8. Drill-Hole and Underground Surveying and the Negative IP Effect

Differences Between Surface and Subsurface Methods

Theory

Survey Method

Interpretation

Techniques For Subsurface IP and Resistivity Surveys

Hole Logging For Rock Properties

Exploration Drill-Hole Surveying

Underground IP Surveying

Negative IP Effects 195

9 Interpretation of Induced-Polarization Data

Methods of Interpretation

Case-History Studies

Physical Model Studies

The Computation of Theoretical IP and Resistivity Curves

Master Curves

Direct Interpretation

Numerical Modeling

Grade Estimation of Mineralization Using the IP Method

Quality of the Interpreted Data

Review of Pseudosection Data

The Interpretation Report

10. The Complex-Resistivity Method

History of the Method

The Complex-Resistivity Survey

Host-Rock Response and CR Spectra

Separation of the Electromagnetic Coupling Component in Complex Resistivity Data

Identification of Type of Metal Ion

Signal Detection Capabilities of The Complex-Resistivity Method

Disadvantages of the Complex-Resistivity Method

Glossary of Terms Used in Induced-Polarization and Resistivity Exploration

References

Index

Developments in Economic Geology, 5: Principles of Induced Polarization for Geophysical Exploration focuses on the principles, methodologies, and approaches involved in induced polarization (IP), including anisotropism, electromagnetic coupling, and electrical circuits.

The book first takes a look at resistivity principles, theory of IP, and laboratory work in IP. Concerns cover electrical measurements of rocks, anisotropism, early part of decay curve and the comparison with frequency effects, electrical models of induced polarization, electrical polarization, resistivities of earth materials, and resistivity exploration methods. The manuscript then elaborates on IP field equipment, telluric noise and electromagnetic coupling, IP field surveying, and drill-hole and underground surveying and the negative IP effect. Discussions focus on differences between surface and subsurface methods, current-sending system in the field, telluric (earth) currents, electromagnetic coupling, design considerations, coupling of electrical circuits, design considerations, and signal-generating system.

The manuscript ponders on the complex-resistivity method and interpretation of induced-polarization data, including grade estimation of mineralization using the IP method, complex-resistivity survey, signal detection capabilities of the complex-resistivity method, and disadvantages of the complex-resistivity method.

The text is a valuable source of information for researchers wanting to study induced polarization.