Geology and geochemistry of Zn-Pb-Ag vein-breccias at Whoopee Creek, Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1998

Zn-Pb-Ag mineralization at the Whoopee Creek occurrence extends over an area of at least 150 × 300 m with a very subtle surface expression. Sphalerite- and galena-bearing vein-breccias cut fine-grained sandstones, siltstones, and lesser shales of the Upper Devonian to Lower Mississippian Endicott Group, and possibly the Isikut Member of the Kayak Shale. Most samples of sulfide-bearing rock contain 2–38 percent combined Pb+Zn, with high Ag concentrations (as much as 380 ppm) and a few enriched Au values (as much as 1 ppm). Soils with 100– >2000 ppm Zn, 100–10,000 ppm Pb, and elevated Ag and Cd concentrations define a broad belt overlying much, but not all, of the mineralized float.

The Whoopee Creek occurrence is a high-grade example of a series of vein-breccia prospects occurring in Endicott Group rocks across the central and western Brooks Range. Although they have few analogs worldwide, they appear to be the products of large-scale fluid transport, possibly related to dewatering of one or a series of sedimentary basins during a period of Mississippian extension and related high heat flow.