Kuskokwim Kaiyuh Mountains Electromagnetics Geophysical Survey

The Kuskokwim Kaiyuh Mountains electromagnetic, magnetic, and radiometric airborne geophysical surveys cover parts of the northern Kaiyuh Mountains, Alaska. The surveys include parts of the Nulato and Ophir quadrangles south of Galena, Alaska. Time-domain electromagnetic data were collected with the helicopter-mounted SkyTEM 306HP system from July 22 to August 19, 2024, by SkyTEM Canada Incorporated. A total of 5,823.4 line kilometers were collected over a single survey block covering 2,037 square kilometers. Two special sub-survey blocks were defined to increase data coverage of specific holdings: the North Block--funded in collaboration with Doyon, Limited--and the South Block--funded in collaboration with Western Alaska Copper & Gold. The main survey block was flown with east-west line orientation and a nominal line spacing of 400 meters. The North Block was flown with an infilled effective line spacing of 200 meters, and the South Block was flown with an infilled effective line spacing of 200 meters, including north-south oriented lines in addition to east-west oriented lines The mean ground clearance was 45.8 +/- 10.2 meters with a nominal survey speed of 89.6 +/- 14.7 km/hr. The data were inverted to create two subsurface resistivity models, agf_sci and skytem_lci, presented herein. This work was supported by the State of Alaska capital improvement project funds. Doyon, Limited, and Western Alaska Copper & Gold funded additional survey lines over the North and South blocks, respectively, increasing data density in those area.

Publications

• GPR 2025-2. Kuskokwim airborne electromagnetic survey, northern Kaiyuh Mountains, Alaska.