At WKP, the geologists are using a tool called CSAMT to plot the underground resistors. It has proved to be very accurate for WKP, that's partly why every drill has hit mineralisation.
CSAMT is a commonly-used, surface-based geophysical method which provides resistivity information of the subsurface. A suite of frequencies is transmitted into the ground and the received electric and magnetic fields are read along survey lines at receiver sites. The ratio of orthogonal, horizontal electric and magnetic field magnitudes (e.g. Ex and Hy) are used to calculate the resistivity structure of the earth. Calculated resistivity values relate to geology.
CSAMT results at WKP have shown strong resistive features (to >10,000 ohm-m). The resistivity results plotted as a depth-slice in Figure 20 show an array of three resistive trends (Western, Central and Eastern). The CSAMT results provide critical exploration data for drill planning. Resistive trends have been targeted by historical and Joint Venture drill programmes. The resistive zones correlate well with areas of silicification and mineralised quartz veining intercepted in drilling. Drillholes targeting all three resisitive trends have successfully identified three Au-Ag mineralised zonesThe Eastern Resistor (WKP Gorge), Central Resistor (T-Stream) and Western Resistor is described in section Item 7.
CSAMT has proved to be a primary exploration targeting tool on the WKP project. Strong resistors have highlight strong silicification of the rhyolite host, and invariably broad gold-silver mineralisation. Margins of resistors have proved useful in targeting vein/fault interpreted controlling structures, frequently with higher gold intercepts.
CSAMT resistivity has been shown to be a useful technique for identifying and defining zones of silicification and quartz veining. This technique is proving to be useful in exploring under the extensive mantling in the south and west of the project area where geological mapping and soil geochemistry may not be effective.
Here's the other interesting thing: in 2012 GEL did some more CSAMT lines over the WKP area, they'll be doing more soon. The already added lines were up to 1km south of the three areas they are looking at intensively, and 500mtrs north. Just how big is this area?