Recent Advances and Applications in Complex Resistivity Measurements

Abstract

Several years of accumulat,ing complex resistivity spectral measurements have indicated that. there are &ill many unexplored areas in induced polarization surveying that need to be investigated for a more complete understanding of t,he polarization process. In a,ddition to providing mineral discrimination capabilities, complex resistivity spectra can be used to differentiate between various barren host, rock responses, to facilitat,e the complete removal of elect,romagnetic coupling, and to identify pipeline, fence, and various other cultural coupling effects.Results of field measurements are presented in an effort t,o demonstrate the utility of and necessity for making complete spectral measurements for serious geophysical interpretation. Correlation of field measurements with laboratory measurements on rare samples from the same area. demonstrates that, strong electromagnetic coupling can be acciu-ately removed from complete spectra without removing t,he important rock response.Recent field and laboratory measurement' s indicat,c that most, if not all, intluced polarization responses att,ribut,rd to magnetite arc not really due to this mineral but can he traced to a host rock alteration response. Also, characteristic host, rock signatures for sulfide environments appear to vary according to loc*alit,y and t.ype of deposits making it impossible to provide a universal set, of signatures for sulfide deposits.

Seawater capacitance – a promising proxy for mapping and characterizing drifting hydrocarbon plumes in the deep ocean

“…This is similar to using spectral IP to detect and characterize disseminated sulfide minerals on land (Sumner, 1976;Zonge and Wynn, 1975;Sheriff, 2002), in that both processes induce a temporary distributed charge accumulation. A measurement cell was filled with seawater ( Fig.…”

“…Results are normalized geometrically to provide two volume-independent parameters (usually resistivity and phase shift) for a polarizing material. The polarization effect is a surface-sensitive phenomenon due to any of several different electro-chemical/electro-physical mechanisms, each of which behaves like a frequency-dependent distributed capacitance (Sumner, 1976;Zonge and Wynn, 1975;Slater and Lesmes, 2002). Thus, finely disseminated target materials, in very small percentages in a host matrix or in seawater, are more easily detected (make better targets) than the same materials in a concentrated form.…”

Lithium resources and requirements by the year 2000

“…Fortunately the state-of-the art for elec trical methods has made rapid advances in recent years. For example, using alternating electrical currents and measuring the resistivity as a function of the frequency has been advocated as a means to distinguish copper sulfides from noncopper sulfides (Zonge and Wynn, 1975). We are currently starting a research program which will employ such a method to try to deduce more about the nature of the basin sediments.…”

Electromagnetic coupling with a collinear array on a two-layer anisotropic earth

“…Several examples of complex-plane rock spectra and a discussion of the application of coupling removal from field data can be found in Zonge and Wynn (1975) and Wynn and Zonge (1975). In this section the contribution of the rock Apparent resistivity = 1027.3 ohm-meters Phase at 0.1 Hz = 8.0 milliradians PFE for 0.1 to 1.0 Hz * 1.5 show an example of the electrical spectral response of an altered and mineralized rock; this is a type "A" response as named by Zonge, Wynn, and Young (1976).…”

“…Figures Hand 15 show an example of the electrical spectral response of a barren igneous rock. This spectrum is called a type "C" response in Zonge and Wynn (1975). The measurement was made in the laboratory in such a manner as to avoid coupling and other These two laboratory data sets can be combined with three theoretical isotropic coupling data sets from table 6 to generate a group of synthetic field results.…”