RADAR DETECTION OF SUBGLACIAL SULFIDES

Using an ice radar system, we detected anomalous reflection strengths over subglacial disseminated sulfide zones beneath the Mt. Henry Clay Glacier in southeast Alaska. The subglacial sulfide zones, which were verified by drill holes, were not detected by previous magnetic, helicopter EM, or ground-based time-domain EM surveys. The sulfide zones were mapped by measuring lateral variations in the strength of radar echoes from the ice-bedrock interface at the base of the glacier. The reflected power from these disseminated occurrences ranged from 20 percent to 60 percent of the theoretically predicted reflected power from a perfect conductor at the base of the ice. The empirical results of this experiment suggest that ice radar may be a useful tool for direct mineral exploration in ice-covered terrain.