Location: Harrys Creek is a small headwater tributary to Cunningham Creek, a north tributary to Hannum Creek. Hannum Creek is a north tributary to Inmachuk River. This prospect extends across Harrys Creek approximately 1,500 feet upstream of its mouth. It is locality 7 of Cobb (1972; MF 417; 1975; 75-429).
Geology: A poorly exposed, interlayered metasedimentary schist and dolomitic marble sequence strikes northwest across Harrys Creek and dips moderately (15 to 65 degrees) to the north in the general area. The presence of lode galena deposits was noted by 1905 (Moffit, 1905). On both sides of Harrys Creek, over a distance of 1,400 feet, local deeply weathered and gossanous exposures of bedrock and surficial debris in dozer trenches show evidence of alteration and mineralization in marble and siliceous schist (Hudson and others, 1977). The mineralization is near a contact between dolomitic marble and siliceous schist (Hudson and others, 1977). Herreid (1966) describes the silica-rich rock as quartzite and interprets it to be silicified marble. The silica-rich zones are coarse-grained, porous, and contain some quartz crystal-lined cavities (Herreid, 1966). Mineralization includes pods, veinlets, and disseminations of galena in silica-rich rock, in places with disseminated pyrite and sphalerite. Pebbles and cobbles of massive galena are abundant in the stream bed of Harrys Creek at and below the dolomitized marble. Boulangerite is disseminated with galena in gossan float from a dozer trench on the south side of the creek (Herreid, 1966). Light brown surficial material containing fragments of silica-rich rock and massive limonite gossan contained 0.05 % Cu, 4.0 % Pb, 0.62 % Zn, 0.04 ounces/ton Au, and 1 ounces/ton Ag. An 18 inch-wide gossan with a 2 to 3 inch core of galena assayed 0.05 % Cu, 10.0 % Pb, 2.2 % Zn, 1.76 ounces/ton Ag, and nil Au. Other elements were not determined in these two samples (Herreid, 1966, Table 1). Samples of surficial materials from slopes and dozer trenches have highly anomalous lead contents (greater than 1,000 ppm) over a length of 1,250 feet. These samples also contain some significant zinc anomalies (to greater than 1,000 ppm) but not copper; other elements were not analyzed for in these samples (Herreid, 1966, Table 2). Sampling by Mulligan (1965) also indicated traces of gold in the mineralized zones. The 1,400 foot length of this mineralized zone is indicated by natural exposures near the creek and six dozer trenches (totaling 1,250 feet of length) on the south side of the creek (Herried, 1966, Figure 2). The dozer trenches primarily expose deeply weathered material and not bedrock. Burand (1957) collected a series of 5-foot channel samples in two of the dozer trenches; (1) five samples of yellow, sandy soil with visible quartz and galena contained 2.3 to 5.8 % Pb, 0.37 to 10.11 ounces/ton Ag, and nil to 0.06 opunces/ton Au, (2) eight samples over poorly exposed carbonate-bearing bedrock contained 1.7 to 6.2 % Pb, 0.23 to 7.52 ounces/ton Ag, and nil to 0.03 ounces/ton Au, and (3) five fivesamples over a yellow clay-rich zone contained 2.3 to 9.6 % Pb, 6.42 to 10.09 ounces/ton Ag, and 0.01 to 0.06 ounces/ton Au. The mineralized zone is open to both the northwest and southeast. Similar mineralization is present on Hannum Creek (BN056), 4,000 feet southeast and on strike with the eastern exposures of this locality.
Workings: Six dozer trenches (totaling 1,250 feet of length) are present on the south side of the creek (Herried, 1966, Figure 2). The dozer trenches primarily expose deeply weathered material and not bedrock. The mineralized zone is open to both the northwest and southeast. Similar mineralization is present on Hannum Creek (BN056), 4,000 feet southeast and on strike with the eastern exposures of this locality.
Age: The deposit may be epigenetic and younger than the host metasedimentary rocks. Epigenetic deposits on Seward Peninsula are primarily Cretaceous in age, a significant period of regional metamorphism and granitic plutonism. The Inmachuk River and many of its tributaries, including Cunningham and Hannum Creeks, contain signficant placer gold deposits. Some lode gold deposits on southern Seward Peninsula are mid-Cretaceous in age (see Midnight Mountain, BN047). If the deposit is stratiform, it may be similar in age to its host sedimentary rocks. The protoliths for the metasedimentary rocks in this area are lower Paleozoic in age (Till and others, 1986).
Alteration: Development of silica-rich rock is characteristic; variably developed but extensive. The deposit is deeply weathered and oxidized. Dolomitic marble is also present.

Commodities (Major) - Ag, Au, Pb, Zn
Development Status: None
Deposit Model: Sulfide-bearing pods, veinlets, and disseminations in silica-rich metasedimenta

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5 valid minerals.