IP Chargeability and Resistivity:
Induced polarization (IP) anomalies are generally, but not always, a diagnostic indicator of economic mineralization. The IP anomalies correlate with both mineralization and alteration-related magnetic lows; however, IP anomalies often indicate the most abundant pyrite zones in altered rocks rather than areas of less-IP-reactive clay minerals, chalcopyrite, and bornite. Spectral IP has been used to classify different alteration zones and to distinguish noneconomic sulfides such as pyrite from chalcopyrite and bornite (Zonge and Wynn, 1975; Zonge and others, 2005). Resistivity and IP anomaly strengths correlate inversely with resistivity of the host rock and the thickness of any cover. Radiometric methods will show the potassic alteration if significant potassically altered parts of the system are exposed (Sinclair, 1995). (USGS – Open-File Report 2008–1321)
Figure 2 demonstrates the chargeability N1 (50m Stations). Mineralization on the Hat property has proven to be in direct relation to, but not limited to, higher Chargeability values.
Doubleview has used geophysical data as a strong vector to copper bearing parts of the Hat property. A thorough review of both geological and geophysical data has expanded the exploration search radius well beyond initial IP determined target areas. Careful plotting and analysis of a large number of data points has revealed additional exploration target areas. [Please visit the Exploration Targets page for details.]
Figure 3 and 4 respectively illustrate N3 (n=150 m) Chargeability, and N3 Chargeability with Interpretations as further confirmation of drilled sites and favoured exploration target areas.
Geophysics – Induced Polarization Survey – Resistivity:
The strength of Resistivity measurements are in general the inverse of Conductivity measurements. Although Resistivity is a simple concept, it is related to many factors, the most significant of which are porosity, presence of conductive minerals (such as sulphides), rock texture and many other less important factors. In simple terms, higher rock conductivity, due, for instance to the presence of sulphide minerals, is logically coupled to lower resistivity. Reviews of published studies show that occasionally low porous Andesite Porphyry demonstrates high resistivity values. Figures 5 and 6 illustrate Hat property resistivity surveys for electrode separations N1 (50 m) and N3 (n=150 m). Although the large areas of very low resistivity in northern parts of the property likely reflect a particular, relatively superficial, rock type, it is possible that the method is accessing deeper formations with strong sulphide mineralization. In the south, highly resistive Andesitic porphyry rocks are known to host many occurrences of sulphides, including chalcopyrite. The apparently expanding area of low resistivity with increasing depth is not explained by available information.
Low Resistivity foot print increases with depth in the IP Survey.