COMPARING RESOLVE AND DC RESISTIVITY OVER ALLUVIAL OVERBURDEN IN THE YUKON TERRITORY.

摘要

The intent of this study is to compare FEM Resolve airborne surveys to ground DC resistivity surveys for alluvial gold exploration in the Klondike Gold Field of the Yukon Territory, Canada. Placer gold exploration in the Yukon has been going on since the late 1890s, , Since the late 1990s many new techniques have been tried including seismic, GPR and DC resistivity. Resistivity surveys produce the best results; but it is slow, especially at 3 m electrode spacing. After careful evaluation, the Resolve method was considered to be able to map the subsurface within the large permafrost filled valleys that can be 50 to 80 feet deep, with up to 25 feet of frozen muck at the surface with the remainder being frozen gravel. The idea is to determine if we can distinguish thickness of muck, the thickness of gravel for volume calculation, and bedrock dips since most of the placer gold is found in dipping bedrock. Producing a map of bedrock topography that takes a couple of hours survey time instead of 6 weeks for ground resistivity surveys will speed up exploration. Numerous test sites have been surveyed using the Resolve and ground DC Resistivity systems over complex overburden settings and variable bedrock depths on placer gold bearing drainages in the Yukon Territory, Canada. Tests sites for this study were selected in areas with extensive drill hole data to validate both surveys. The goal of the study is to see if we can fast track the RESOLVE survey to map the frozen muck (organic) layer, the gravel thickness and the bedrock topography. The study will be used to provide a practical guide for evaluating DC Resistivity surveys for different overburden mapping applications in the Yukon.