This occurrence is in a 42.9-meter-thick fissile, carbonaceous black shale member of the Kayak Shale between a lower argillaceous member and an upper red limestone member. The black shale member contains red-brown, cherty ironstone nodules or concretions that vary from rounded forms about 4 centimeters in diameter to elongate forms about 8 by 38 centimeters in size. The concretions consist of quartz, calcite, siderite, pyrite (or marcasite?), minor sphalerite, and rare galena (Kurtak and others, 1995). There are also 2.5- to 5-centimeter sulfide-bearing beds in the black shale. Several samples of the concretions from a 6-meter-thick section of the black shale contained up to 13,152 parts per million (ppm) zinc, more than 2,000 ppm barium, and 52 ppm lead. Samples from a 10-centimeter-thick, cherty ironstone bed at the base of the black shale member contained up to 1,357 ppm zinc.Although this record describes a specific site, Kurtak and others (1995) note that it is representative of similar sulfide occurrences in a member of the Early Mississippian Kayak Shale that outcrops for several hundred kilometers along the north side of the Brooks Range.