This occurrence is at the eastern margin of the Safari Creek Window where Upper Devonian Noatak Sandstone is thrust over Early Mississippian Kayak Shale (Kurtak and others, 1995). The Noatak Sandstone here consists of thick bedded, light gray to white sandstone with numerous quartz veinlets.
A 3-meter-wide zone with massive pods and lenses of galena, sphalerite, and minor chalcopyrite can be traced for 350 meters in float and rubble of silicified Noatak Sandstone. A 1.1-meter-thick chip sample across this zone assayed 25.2 percent lead, 8.5 percent zinc, 178 grams of silver per ton, and 925 parts per million copper. Several faults are present and there is evidence of post-mineralization movement. There is also stringer and disseminated mineralization adjacent to the massive mineralization. A 7.80-meter-wide chip sample averaged 11 percent lead, 7 percent zinc, and 274 grams of silver per ton. A VLF geophysical survey line across the mineralization showed no response.Lead-isotope values on galena are: Pb 206/204 = 18.281; Pb 207/204 = 15.608; and Pb 208/204 = 38.152. Kurtak and others (1995) suggest that these values could be explained mixing upper crustal lead with lead such as found in Devonian volcanogenic-massive-sulfide deposits in the Ambler District on the south side of the Brooks Range. They also suggest that the mineralization is the result of hydrothermal fluids which flowed along the thrust fault during the Cretaceous, Brooks Range orogeny.